cytochrome-c-t and Reperfusion-Injury

Cytochrome c (Cytc) and cytochrome c oxidase (COX) catalyze the terminal reaction of the mitochondrial electron transport chain (ETC), the reduction of oxygen to water. This irreversible step is highly regulated, as indicated by the presence of tissue-specific and developmentally expressed isoforms, allosteric regulation, and reversible phosphorylations, which are found in both Cytc and COX. The crucial role of the ETC in health and disease is obvious since it, together with ATP synthase, provides the vast majority of cellular energy, which drives all cellular processes. However, under conditions of stress, the ETC generates reactive oxygen species (ROS), which cause cell damage and trigger death processes. We here discuss current knowledge of the regulation of Cytc and COX with a focus on cell signaling pathways, including cAMP/protein kinase A and tyrosine kinase signaling. Based on the crystal structures we highlight all identified phosphorylation sites on Cytc and COX, and we present a new phosphorylation site, Ser126 on COX subunit II. We conclude with a model that links cell signaling with the phosphorylation state of Cytc and COX. This in turn regulates their enzymatic activities, the mitochondrial membrane potential, and the production of ATP and ROS. Our model is discussed through two distinct human pathologies, acute inflammation as seen in sepsis, where phosphorylation leads to strong COX inhibition followed by energy depletion, and ischemia/reperfusion injury, where hyperactive ETC complexes generate pathologically high mitochondrial membrane potentials, leading to excessive ROS production. Although operating at opposite poles of the ETC activity spectrum, both conditions can lead to cell death through energy deprivation or ROS-triggered apoptosis.

Topics: Adenosine Triphosphate; Animals; Apoptosis; Cell Respiration; Cytochromes c; Electron Transport Complex IV; Humans; Inflammation; Mitochondria; Models, Biological; Phosphorylation; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction

Ischemia/reperfusion (IR) injury is a central component in the pathogenesis of several diseases and is a leading cause of morbidity and mortality in the western world. Subcellularly, mitochondrial dysfunction, characterized by depletion of ATP, calcium-induced opening of the mitochondrial permeability transition pore, and exacerbated reactive oxygen species (ROS) formation, plays an integral role in the progression of IR injury. Nitric oxide (NO) and more recently nitrite (NO(2)(-)) are known to modulate mitochondrial function, mediate cytoprotection after IR and have been implicated in the signaling of the highly protective ischemic preconditioning (IPC) program. Here, we review what is known about the role of NO and nitrite in cytoprotection after IR and consider the putative role of nitrite in IPC. Focus is placed on the potential cytoprotective mechanisms involving NO and nitrite-dependent modulation of mitochondrial function.

Topics: Animals; Cytochromes c; Cytoprotection; Glutathione; Humans; Ischemic Preconditioning; Mice; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Mitochondrial Proton-Translocating ATPases; Nitric Oxide; Nitric Oxide Synthase; Nitrites; Protein Processing, Post-Translational; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Ubiquinone

Death of hepatocytes and other hepatic cell types is a characteristic feature of liver diseases as diverse as cholestasis, viral hepatitis, ischemia/reperfusion, liver preservation for transplantation and drug/toxicant-induced injury. Cell death typically follows one of two patterns: oncotic necrosis and apoptosis. Necrosis is typically the consequence of acute metabolic perturbation with ATP depletion as occurs in ischemia/reperfusion and acute drug-induced hepatotoxicity. Apoptosis, in contrast, represents the execution of an ATP-dependent death program often initiated by death ligand/death receptor interactions, such as Fas ligand with Fas, which leads to a caspase activation cascade. A common event leading to both apoptosis and necrosis is mitochondrial permeabilization and dysfunction, although the mechanistic basis of mitochondrial injury may vary in different settings. Prevention of these modes of cell death is an important target of therapy, but controversies still exist regarding which mode of cell death predominates in various forms of liver disease and injury. Resolution of these controversies may come with the recognition that apoptosis and necrosis frequently represent alternate outcomes of the same cellular pathways to cell death, especially for cell death mediated by mitochondrial permeabilization. An understanding of processes leading to liver cell death will be important for development of effective interventions to prevent hepatocellular death leading to liver failure and to promote cancer and stellate cell death in malignancy and fibrotic disease.

Topics: Acetaminophen; Animals; Apoptosis; Apoptosis Regulatory Proteins; Caspases; Cholestasis, Intrahepatic; Cytochromes c; fas Receptor; Humans; Hydrogen-Ion Concentration; Immunity, Innate; Liver; Membrane Glycoproteins; Mitochondria, Liver; Necrosis; NF-kappa B; Receptors, Tumor Necrosis Factor; Reperfusion Injury; Signal Transduction; TNF-Related Apoptosis-Inducing Ligand; Tumor Necrosis Factor-alpha

Ischemic stroke is divided into acute, subacute and convalescent phases according to the time of onset. Clinically, Mailuoning oral liquid (MLN O) is a traditional Chinese patent medicine for treating ischemic stroke. Previous studies have shown that MLN O could prevent acute cerebral ischemia-reperfusion. However, its underlying mechanism remains unclear.. To investigate the relationship between neuroprotection and apoptosis for clarifying MLN O mechanism in the recovery phase of ischemic stroke.. We imitated stroke using middle cerebral artery occlusion/reperfusion (MCAO/R) in vivo and oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro models. The infarct volume, neurological deficit scores, HE staining, Nissl staining, TUNEL staining, immunohistochemistry, and Western blot were correspondingly performed to find pathological changes and detect neuronal apoptosis in rat cerebral cortex. The contents of LDH, Cyt-c, c-AMP and BDNF in rat plasma and cerebral cortex were detected by ELISA. Cell viability was measured by CCK8 assay. Cell morphology, Hoechst 33342 staining and Annexin-V-Alexa Fluor 647/PI staining were performed to assess neuronal apoptosis. The expression levels of proteins were evaluated by western blotting.. MLN O obviously reduced brain infarct volume and neurological deficit scores in MCAO rats. MLN O inhibited inflammatory cell infiltration and neuronal apoptosis, but promoted gliosis, neuronal survival, and neuroprotection in the cortical region of MCAO rats. Additionally, MLN O decreased the amount of LDH and cytochrome c, while increasing the expression of c-AMP in the plasma and ischemic cerebral cortex of MCAO rats, and promoting the expression of BDNF in the cortical tissue of MCAO rats. Besides, MLN O improved cell viability, restored cell morphology, while attenuating cell damage, inhibiting neuronal apoptosis following OGD/R in PC-12 cells. Moreover, MLN O inhibited apoptosis by suppressing the expression of pro-apoptotic-associated proteins, including Bax, cytochrome c, Cleaved caspase 3 and HIF-1α, whereas accelerating the expression of Bcl-2 in vivo and in vitro. Furthermore, MLN O inhibited the activity of AMP-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR), but activated the signaling pathway of cAMP-response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) in MCAO rats and OGD/R-stimulated PC-12 cells.. These results demonstrated that MLN O inhibited AMPK/mTOR to affect apoptosis associated with mitochondria, leading to improve CREB/BDNF-mediated neuroprotection in the recovery period of ischemic stroke in vivo and in vitro.

Topics: AMP-Activated Protein Kinases; Animals; Apoptosis; Apoptosis Regulatory Proteins; Brain Ischemia; Brain-Derived Neurotrophic Factor; Cytochromes c; Infarction, Middle Cerebral Artery; Ischemic Stroke; Neuroprotection; Rats; Reperfusion Injury; TOR Serine-Threonine Kinases

Skeletal muscle is more resilient to ischemia-reperfusion injury than other organs. Tissue specific post-translational modifications of cytochrome c (Cytc) are involved in ischemia-reperfusion injury by regulating mitochondrial respiration and apoptosis. Here, we describe an acetylation site of Cytc, lysine 39 (K39), which was mapped in ischemic porcine skeletal muscle and removed by sirtuin5 in vitro. Using purified protein and cellular double knockout models, we show that K39 acetylation and acetylmimetic K39Q replacement increases cytochrome c oxidase (COX) activity and ROS scavenging while inhibiting apoptosis via decreased binding to Apaf-1, caspase cleavage and activity, and cardiolipin peroxidase activity. These results are discussed with X-ray crystallography structures of K39 acetylated (1.50 Å) and acetylmimetic K39Q Cytc (1.36 Å) and NMR dynamics. We propose that K39 acetylation is an adaptive response that controls electron transport chain flux, allowing skeletal muscle to meet heightened energy demand while simultaneously providing the tissue with robust resilience to ischemia-reperfusion injury.

Topics: Acetylation; Animals; Apoptosis; Cell Respiration; Cytochromes c; Lysine; Muscle, Skeletal; Phosphorylation; Protein Processing, Post-Translational; Reperfusion Injury; Swine

Selenomethionine (SeMet) is known to alleviate ischemia-reperfusion (I/R) injury. However, its details of action have not been thoroughly elucidated in mice with intestinal I/R injury. In this study, intestinal I/R injury mice models were established, and ELISAs were performed to determine the levels of redox factors, including glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA), in mice intestinal tissues. Furthermore, several apoptosis-related markers, such as cytochrome c (Cyt-c), Bcl-2, and Bax, were detected using qPCR and Western blotting, while caspase-3 was detected using Western blotting alone. The results showed that SeMet alleviated I/R damage by increasing GSH-Px, CAT, and SOD levels and reducing MDA levels. Our data demonstrated that SeMet reduced I/R injury and inhibited the expression of Cyt-c, Bax, and caspase-3. SeMet also increased the expression of Bcl-2 in the intestinal tissues of mice. In addition, the TUNEL assay results showed that SeMet mitigated apoptosis in the villi cells of the intestinal mucosa. The findings also revealed that I/R could lead to increased apoptosis levels and that SeMet alleviated I/R-induced apoptosis by mediating the Bax/cytochrome C/caspase-3 apoptotic signaling pathways in the intestinal I/R injury mice models. Thus, SeMet inhibited apoptosis and resulted in an increase of Bcl-2 levels; downregulated the expression of Bax, Cyt-c, and caspase-3; and alleviated the intestinal ischemia injury in mice. The I/R injury increased the cytosolic Bax, Cyt-c, and caspase-3 levels and significantly decreased Bcl-2 expression levels in the I/R group, compared to the Sham group. However, the levels of all markers were reversed post-SeMet pre-treatment.

Topics: Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspases; Cytochromes c; Glutathione Peroxidase; Ischemia; Mice; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; Selenomethionine; Superoxide Dismutase

Endoplasmic reticulum (ER) stress plays a central role in myocardial ischemia/reperfusion (I/R) injury. Irisin has been reported to have protective properties in ischemia disease. In this study, we aimed at investigating whether irisin could alleviate myocardial I/R injury by ER stress attenuation. The in vitro model of hypoxia/reoxygenation (H/R) was established, which resembles I/R in vivo. Cell viability and apoptosis were estimated. Expressions of cleaved caspase-3, cytochrome c, GRP78, pAMPK, CHOP, and eIF2α were assessed by western blot. Our results revealed that pre-treatment with irisin significantly decreased cytochrome c release from mitochondria and caspase-3 activation caused by H/R. Irsin also reduced apoptosis and increased cell viability. These effects were abolished by AMPK inhibitor compound C pre-treatment. Also, GRP78 and CHOP expressions were up-regulated in the H/R group compared to the control group; however, irisin attenuated their expression. The pAMPK level was significantly decreased compared to the control, and this effect could be partly reversed by metformin pre-treatment. These results suggest that ER stress is associated with cell viability decreasing and cardiomyocytes apoptosis induced by H/R. Irisin could efficiently protect cardiomyocytes from H/R-injury via attenuating ER stress and ER stress-induced apoptosis.

Topics: AMP-Activated Protein Kinases; Apoptosis; Caspase 3; Cytochromes c; Endoplasmic Reticulum Stress; Fibronectins; Humans; Hypoxia; Myocardial Reperfusion Injury; Myocytes, Cardiac; Reperfusion Injury

Calenduloside E (CE) isolated from Aralia elata (Miq.) Seem. is a natural triterpenoid saponin that can reportedly ameliorate myocardial ischemia/reperfusion injury. However, its potential roles and mechanism in cerebral ischemia/reperfusion injury are barely understood. In this study, we established an oxygen-glucose deprivation/reoxygenation (OGD/R) model in HT22 cells. We found that CE significantly attenuated the OGD/R-induced inhibition of cell viability and apoptotic cell death in HT22 cells. Moreover, CE treatment significantly ameliorated OGD/R-induced mitochondrial fission by inhibiting mitochondrial dynamin-related protein 1 (Drp1) recruitment and increasing Drp1 phosphorylation at Ser637. CE treatment significantly ameliorated OGD/R-induced mitochondrial dysfunction by increasing the mitochondrial membrane potential and reducing the mitochondrial ROS and cellular calcium accumulation. Moreover, CE treatment significantly inhibited the OGD/R-induced release of mitochondrial Cytochrome C and increase in Bax, Cleaved-caspase3 and Cleaved-caspase9 protein levels, whereas CE treatment significantly reversed the OGD/R-induced decrease in Bcl-2 and full length of caspase3 and caspase9 protein levels. In vivo, we found that CE treatment significantly ameliorated ischemic/hypoxic-induced brain infarct volume, neurological deficits, and neuronal apoptosis in mice after middle cerebral artery occlusion and reperfusion. CE treatment also significantly ameliorated the mitochondrial transmembrane potential, decreased Cytochrome C release, and reversed the increase in Bax, Cleaved-caspase3 and Cleaved-caspase9 protein levels and the decrease in Bcl-2 and full length of caspase3 and caspase9 protein levels induced by cerebral ischemia/reperfusion (I/R). All these results indicated that CE treatment exerted a neuroprotective effect by ameliorating mitochondrial dysfunction during cerebral I/R injury.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain Ischemia; Cytochromes c; Glucose; Mice; Mitochondria; Oleanolic Acid; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; Saponins

This study observed the effects of ethanol extract of Gastrodiae Rhizoma(GE) on multiple aspects of mitochondrial dysfunction by investigating the mitochondria isolated from rat brains subjected to focal middle cerebral artery occlusion/reperfusion(MCAO/R). SD rats were randomly divided into a sham operation group(Sham), a model group(MCAO/R), low-and high-dose ethanol extract of GE groups(262.3 and 524.6 mg·kg~(-1)), and a nimodipine group(Nim, 15 mg·kg~(-1)). After continuous intragastric administration for 7 days, the MCAO/R model was induced in rats by the suture method. The neurological function and percentage of cerebral infarction volume were measured 24 h after reperfusion, and mitochondrial ultrastructure was observed under an electron microscope. Mitochondria were separated by gradient centrifugation and detected for reactive oxygen species(ROS), malondialdehyde(MDA), respiratory chain enzyme complex Ⅰ-Ⅳ activity, mitochondrial permeability transition pore(mPTP), mitochondrial membrane potential(MMP), and mitochondrial adenosine triphosphate(ATP) content. Enzyme-linked immunosorbent assay(ELISA) was used to detect the expression of cytochrome C(Cyt C) in different sites. TUNEL staining was used to observe the apoptosis of brain tissues in each group, and Western blot was used to detect the expression of B-cell lymphoma 2(Bcl-2) and Bcl-2-associated X protein(Bax) in brain tissues. The experimental results revealed that compared with the Sham group, the MCAO/R group showed evident neurological dysfunction and cerebral infarction(P<0.01) accompanied by mitochondrial swelling and crest disappearance, increased ROS level and MDA content, inhibited activity of respiratory chain enzyme complex Ⅰ-Ⅳ, abnormal opening of mPTP, and reduced MMP and mitochondrial ATP(P<0.01). Besides, many Cyt C was released from mitochondria into the cytoplasm to induce apoptosis(P<0.01). The ethanol extract of GE positively affected the behavior deficit and mitochondrial health of MCAO/R rats, with the manifestations of decreased production of ROS and MDA(P<0.01), potentiated activity of mitochondrial respiratory chain enzyme complex Ⅰ-Ⅳ, and restored the level of mPTP(P<0.05). In addition, the ethanol extract of GE reduced the loss of MMP and the escape of Cyt C to the cytoplasm(P<0.05), reduced the number of TUNEL positive cells(P<0.01) accompanied by the decrease in Bax and the up-regulation of Bcl-2(P<0.01), and increased the level of ATP(P<

Topics: Adenosine Triphosphate; Animals; Apoptosis; bcl-2-Associated X Protein; Cytochromes c; Ethanol; Infarction, Middle Cerebral Artery; Mitochondria; Mitochondrial Permeability Transition Pore; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

Mitochondrial dynamics and function are important for cell survival regulation under stress. In this study, we report that cerebral ischemia/reperfusion (I/R) injury significantly reduced mitochondrial function through reduced PTEN-induced kinase 1 (PINK1) expression, ATP (Adenosine triphosphate) levels, and increased oxidative stress compared to sham rats. PINK1 overexpression mice significantly improved mitochondrial function by increased mitochondrial complex I, II, and III activities and ATP levels with concomitant decline in reactive oxygen species levels. PINK1 overexpression mice after I/R injury significantly reduced apoptosis through downregulation of cytochrome c, p53 expressions compared to cerebral I/R injury rats. Furthermore, we showed from parkin siRNA studies that PINK1 regulated phosphorylation parkin is critical to the protection against cerebral I/R injury. Altogether, we show that PINK1 mediated parkin regulation is key to the protection against cerebral I/R injury through regulation of mitochondrial function and apoptosis.

Topics: Adenosine Triphosphate; Animals; Apoptosis; Brain Ischemia; Cell Survival; Cytochromes c; Gene Expression Regulation; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Mitochondria; Oxidative Stress; Protein Kinases; Rats; Reactive Oxygen Species; Reperfusion Injury

It has been reported that brusatol (BRU) reduces cellular reactive oxygen species (ROS) level under hypoxia; here the protective effect of BRU against oxygen-glucose deprivation/reoxygenation (OGD-R)-induced injury in HepG2 cells and against anoxia/reoxygenation (A/R)-induced injury in rat liver mitochondria was investigated.. OGD-R-induced HepG2 cell viability loss was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and trypan blue staining. Mitochondrial ROS level in HepG2 cells was measured by MitoSOX staining. The cellular malondialdehyde and adenosine triphosphate level was measured by commercial kits. The mitochondrial membrane potential in HepG2 cells was measured by JC-1 staining. The protein level was detected by Western blotting. Rat liver mitochondria were separated by differential centrifugation. A/R-induced injury in isolated rat liver mitochondria was established by using a Clark oxygen electrode. The ROS generation in isolated mitochondria was evaluated using Amplex red/horseradish peroxidase.. BRU reduced mitochondrial ROS level and alleviated oxidative injury in HepG2 cells, thereby significantly inhibited OGD-R-induced cell death. During OGD-R, BRU improved mitochondrial function and inhibited the release of cytochrome c. Furthermore, BRU showed a clear protective effect against A/R-induced injury in isolated rat liver mitochondria. When isolated rat liver mitochondria were pretreated with BRU, A/R-induced ROS generation was significantly decreased, and mitochondrial respiratory dysfunction was ameliorated.. BRU pretreatment attenuated OGD-R-induced injury in HepG2 cells and A/R-induced injury in isolated rat liver mitochondria by inhibiting mitochondrial ROS-induced oxidative stress.

Topics: Adenosine Triphosphate; Animals; Cytochromes c; Glucose; Hep G2 Cells; Humans; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Mitochondria; Oxidative Stress; Oxygen; Protective Agents; Quassins; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

The warm ischemia-reperfusion injury confines the prevalence of allografts. To improve the success rate of allotransplantation, we designed experiments to study the mechanism of calcium-calmodulin-dependent protein kinase type 2 (CaMK II) in ischemia-reperfusion (I/R) injury.. We established the I/R model in SD rats and performed the liver transplantation (LT). As a result, the expression of CaMK II in tissues was detected. CaMK II was interfered with and overexpressed by the transference of the lentivirus vector, and the hepatocyte apoptosis and viability were inspected. At the same time, the content of cytochrome c and apoptosis-inducing factor (AIF) were determined. The measurement of mitochondrial membrane potential and detection of intercellular calcium levels were performed.. The expression of CaMK II significantly increased and is highly corresponded with the duration of warm ischemia. In BRL-3A cells and liver tissues, increased cellular apoptosis and less viability had been observed in the CaMK II overexpression group. Cytochrome c and AIF were also largely increased compared to the interfered group. Moreover, apparent mitochondrial membrane potential loss has also been detected in the CaMK II overexpression group.. It suggested that CaMK II induces cell apoptosis. Our findings may give a novel indication that inhibition of CaMK II could be a new way for the therapy of warm ischemia-reperfusion injury after LT in future clinical practice.

Topics: Animals; Apoptosis; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Cell Line; Cytochromes c; Disease Models, Animal; Hepatocytes; Liver; Liver Transplantation; Membrane Potential, Mitochondrial; Rats; Rats, Sprague-Dawley; Reperfusion Injury

The adaptation of mitochondrial homeostasis to ischemic injury is not fully understood. Here, we studied the role of dynamin-related protein 1 (Drp1) in this process. We found that mitochondrial morphology was altered in the early stage of ischemic injury while mitochondrial dysfunction occurred in the late stage of ischemia. Drp1 appeared to inhibit mitophagy by upregulating mito-Clec16a, which suppressed mito-Parkin recruitment and subsequently impaired the formation of autophagosomes in vascular tissues after ischemic injury. Moreover, ischemia-induced Drp1 activation enhanced apoptosis through inducing mitochondrial translocation of BAX and thereby increasing release of Cytochrome C to activate caspase-3/-9 signalling. Furthermore, Drp1 mediated metabolic disorders and inhibited the levels of mitochondrial glutathione to impair free radical scavenging, leading to further increases in ROS and the exacerbation of mitochondrial dysfunction after ischemic injury. Together, our data suggest a critical role for Drp1 in ischemic injury.

Topics: Animals; Apoptosis; Autophagosomes; Cell Line, Tumor; Cytochromes c; Dynamins; Glutathione; Ischemia; Mitochondria; Mitochondrial Dynamics; Mitophagy; Rats, Sprague-Dawley; Reperfusion Injury

The prefrontal cortex is the largest lobe of the brain and is consequently involved in stroke. There is no comprehensive practical pharmacological strategy for ameliorating prefrontal cortex injury induced by cerebral ischemia. Therefore, we studied the neuroprotective properties of verapamil (Ver) on mitochondrial dysfunction and morphological features of apoptosis in transient global ischemia/reperfusion (I/R). Ninety-six Wistar rats were allocated into four groups: control, I/R, I/R+Ver (10 mg/kg twice 1 hour prior to ischemia and 1 hour after reperfusion phase), and I/R+NaCl (vehicle). Animals were sacrificed, and mitochondrial dysfunction parameters (i.e., mitochondrial swelling, mitochondrial membrane potential, ATP concentration, ROS production, and cytochrome c release), antioxidant defense (i.e., superoxide dismutase, malondialdehyde, glutathione peroxidase, catalase, and caspase-3 activation), and morphological features of apoptosis were determined. The results showed that mitochondrial damage, impairment of antioxidant defense system, and apoptosis were significantly more prevalent in the I/R group in comparison with the other groups. Ver decreased mitochondrial damage by reducing oxidative stress, augmented the activity of antioxidant enzymes in the brain, and decreased apoptosis in the I/R neurons. The current study confirmed the role of oxidative stress and mitochondrial dysfunction in I/R progression and indicated the possible antioxidative mechanism of the neuroprotective activities of Ver.

Topics: Adenosine Triphosphate; Animals; Antioxidants; Apoptosis; Brain; Caspase 3; Cell Survival; Cytochromes c; Ischemic Attack, Transient; Male; Malondialdehyde; Mitochondria; Mitochondrial Swelling; Nerve Degeneration; Neurons; Prefrontal Cortex; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; RNA, Messenger; Verapamil

Cytochrome

Topics: Animals; Apoptosis; Brain; Caspase 3; Cell Respiration; Crystallography, X-Ray; Cytochromes c; Electron Transport Complex IV; Membrane Potential, Mitochondrial; Mitochondria; Molecular Dynamics Simulation; Mutagenesis, Site-Directed; Mutation; Oxidation-Reduction; Phosphorylation; Protein Conformation; Reactive Oxygen Species; Reperfusion Injury; Serine; Swine

Hydrogen is received as an inert gas that thought to be non-functional in vivo previously. Recently, emerging evidences showed that in ischemia/reperfusion (IR) condition, hydrogen reduced cellular reactive oxygen species (ROS) production and ameliorated cell apoptosis. However, the underlying mechanism of hydrogen on IR-induced apoptosis remains elusive. Here we tried to unravel the mode of action of hydrogen with rat adrenal medulla cell line PC-12 in vitro.. The mitochondrial functions before and after oxygen glucose deprivation and reperfusion (OGD/RP) were determined with corresponding dyes. The expression of Bcl-2, Bax, VDAC1, cytochrome c and caspase 9 was detected using qRT-PCR and Western Blotting method. Then Bcl-2 inhibitor, AB-199, was applied to investigate the role of Bcl-2 in OGD/RP-induced cell apoptosis. Finally, we manipulated the expression of VDAC1 with plasmids transfection to understand the effects of VDAC1 on Bcl-2-mediated anti-apoptosis in OGD/RP.. In this study, we demonstrated that hydrogen-rich saline (HRS) reduced OGD/RP-mediated neuronal loss by stimulating the expression of Bcl-2, which suppressed the activity of VDAC1. Consequently, HRS maintained the mitochondrial functions, restrained the release of cytochrome c and caspase 9 activation, resulting in ameliorated cell viability.. HRS ameliorated OGD/RP-induced PC-12 cell apoptosis and provided a novel treatment option for ischemia.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 9; Cell Death; Cell Hypoxia; Cell Survival; Cytochromes c; Glucose; Hydrogen; Hypoxia; Membrane Potential, Mitochondrial; Neurons; Neuroprotective Agents; Oxygen; PC12 Cells; Proto-Oncogene Proteins c-bcl-2; Rats; Reactive Oxygen Species; Reperfusion Injury; Saline Solution; Voltage-Dependent Anion Channel 1

Hepatic ischemia reperfusion (HIR) has been found to induce brain injury and cognitive dysfunction. Dynamin-related protein 1 (Drp1) mediated mitochondrial fission involves oxidative stress, apoptosis and several neurological diseases. In this study, we investigated whether Drp1 translocation to mitochondria was implicated in HIR induced hippocampus injury in young mice, and further detected the role of calcineurin in the regulation of mitochondrial dynamics. 2-week C57BL/6 mice were chosen to make HIR model. Western blot was used to detect mitochondrial dynamics regulating proteins in whole hippocampal tissues and extracted mitochondria. Transmission electron microscopy was used to observe mitochondrial morphology. TUNEL staining and ELISA (serum S100β/NSE concentrations) were used to evaluate neurons apoptosis and brain injury respectively. Drp1 inhibitor Mdivi-1 and calcineurin inhibitor FK506 were utilized to further confirm the role of Drp1 and calcineurin. Results showed that HIR affected mitochondrial dynamics in a fission-dominant manner with translocation of Drp1 to mitochondria in hippocampus of young mice. HIR induced increased expression of calcineurin and dephosphorylation of Drp1 at Ser637 in hippocampus. Treatment with Mdivi-1 and FK506 upregulated the phosphorylation of Drp1, inhibited Drp1 translocation to mitochondria, and alleviated mitochondrial fragmentation after HIR. What's more, Mdivi-1 and FK506 restrained cytochrome c release and cleaved caspase-3 expression, ameliorated hippocampal neurons apoptosis, and decreased serum S100β/NSE concentrations as well. These data suggest that calcineurin mediated Drp1 dephosphorylation and translocation to mitochondria play a crucial role in HIR induced mitochondrial fragmentation and neurons apoptosis in hippocampus.

Topics: Animals; Apoptosis; Calcineurin; Cytochromes c; Dynamins; Hippocampus; Liver; Mice; Mice, Inbred C57BL; Mitochondria, Liver; Mitochondrial Dynamics; Oxidative Stress; Phosphorylation; Quinazolinones; Reperfusion; Reperfusion Injury; Tacrolimus

Cerebrovascular disease (CVD) is one of the leading causes of mortality worldwide. The role of cytochrome c oxidase subunit 6B1 (COX6B1) in the central nervous system remains unclear. The present study aimed to analyze the role of COX6B1 in rat hippocampal neurons extracted from fetal rats. The subcellular localization of the neuron‑specific marker microtubule‑associated protein 2 was detected by immunofluorescence assay. Cell viability was assessed using a cell counting kit, and the levels of apoptosis and cytosolic Ca2+ were analyzed by flow cytometry. The expression levels of the molecular factors downstream to COX6B1 were determined using reverse transcription‑quantitative polymerase chain reaction and western blotting. Reoxygenation following oxygen‑glucose deprivation (OGD) decreased cell viability and the expression levels of COX6B1 in a time‑dependent manner, and 60 min of reoxygenation was identified as the optimal time period for establishing an ischemia/reperfusion (I/R) model. Overexpression of COX6B1 was demonstrated to reverse the viability of hippocampal neurons following I/R treatment. Specifically, COX6B1 overexpression decreased the cytosolic concentration of Ca2+ and suppressed neuronal apoptosis, which were increased following I/R treatment. Furthermore, overexpression of COX6B1 increased the protein expression levels of apoptosis regulator BCL‑2 and mitochondrial cytochrome c (cyt c), and decreased the protein expression levels of apoptosis regulator BCL2‑associated X and cytosolic cyt c in I/R model cells. Collectively, the present study results suggested that COX6B1 overexpression may reverse I/R‑induced neuronal damage by increasing the viability of neurons, by decreasing the cytosolic levels of Ca2+ and by suppressing apoptosis. These results may facilitate the development of novel strategies for the prevention and treatment of CVD.

Topics: Animals; Apoptosis; bcl-X Protein; Cell Survival; Cerebrovascular Disorders; Cytochromes c; Electron Transport Complex IV; Female; Glucose; Mitochondria; Neurons; Oxygen; Protective Agents; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Temporal Lobe

  To explore whether ischemic postconditioning will lighten hepatic apoptosis caused by hepatic ischemia/reperfusion injury by inhibiting the mitochondria pathway.. Pathomorphology of hepatic tissues in rats was observed under an optical microscope after hematoxylin-eosin (HE) staining. Hepatic apoptosis was detected using agarose gel electrophoresis (AGE) with DNA fragments and flow cytometry. Changes in morphology structure of mitochondria in hepatocytes of rats were observed under an electron microscope. Changes in mitochondria transmembrane potential of hepatocytes of rats were detected using a laser scanning confocal microscope (LSCM). Western blotting was adopted to detect changes in the expression of caspase-3 and cytochrome C protein in hepatocytes of rats.. Compared with that in I/R group, swelling degree of mitochondria in most hepatocytes of rats in ischemic postconditioning (IPOST) group and IPC group was lighter. Changes in expression of caspase-3 and cytochrome C protein in hepatic cells of rats: caspase-3 was lowly expressed and cytochrome C was highly expressed in S group. The expression of caspase-3 was evidently higher in I/R group than that in S group and expression of cytochrome C protein was evidently lower than that in S group (p<0.05). The expression of caspase-3 protein was evidently decreased in IPOST group and IPC group and the expression of cytochrome C protein was evidently increased (p<0.05).. IPOST can reduce hepatic apoptosis caused by hepatic ischemia/reperfusion injury in rats, which may be achieved by inhibiting the mitochondria pathway.

Topics: Animals; Apoptosis; Caspase 3; Cytochromes c; Gene Expression Regulation; Ischemic Postconditioning; Liver; Male; Mitochondria, Liver; Rats; Reperfusion Injury

Mitochondrial NADP

Topics: Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Catalase; Cytochromes c; Glutathione; Glutathione Peroxidase; Glutathione Reductase; Hydrogen Peroxide; Isocitrate Dehydrogenase; Liver; Male; Mice; Mice, Knockout; Mitochondria; NADP; Oxidative Stress; Reperfusion Injury; Survival Rate

Impaired mitochondrial function is a key factor attributing to the lung ischemia reperfusion injury (LIRI). Methylene blue (MB) has been reported to attenuate brain and renal ischemia-reperfusion injury. We hypothesized that MB also could have a protective effect against LIRI by preventing mitochondrial oxidative damage.. Isolated rat lungs were assigned to the following four groups (n = 6): a sham group: perfusion for 105 min without ischemia; I/R group: shutoff of perfusion and ventilation for 45 min followed by reperfusion for 60 min; and I/R + MB group and I/R + glutathione (GSH) group: 2 mg/kg MB or 4 μM glutathione were intraperitoneally administered for 2 h, and followed by 45 min of ischemia and 60 min of reperfusion.. MB lessened pulmonary dysfunction and severe histological injury induced by ischemia-reperfusion injury. MB reduced the production of reactive oxygen species and malondialdehyde and enhanced the activity of superoxide dismutase. MB also suppressed the opening of the mitochondrial permeability transition pore and partly preserved mitochondrial membrane potential. Moreover, MB inhibited the release of cytochrome c from the mitochondria into the cytosol and decreased apoptosis. Additionally, MB downregulated the mRNA expression levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-18).. MB protects the isolated rat lungs against ischemia-reperfusion injury by attenuating mitochondrial damage.

Topics: Animals; Apoptosis; Biological Transport; Cytochromes c; Cytokines; Enzyme Inhibitors; Lung; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Methylene Blue; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase; Transcription, Genetic

Hind limb ischemia-reperfusion injury is an important pathology in vascular surgery. Reactive oxygen species are thought to be involved in the pathogenesis of hind limb ischemia-reperfusion injury. SS-31, which belongs to a family of mitochondrion-targeted peptide antioxidants, was shown to reduce mitochondrial reactive oxygen species production. In this study, we investigated whether the treatment of SS-31 could protect hind limb from ischemia-reperfusion injury in a mouse model. The results showed that SS-31 treatment either before or after ischemia exhibited similar protective effects. Histopathologically, SS-31 treatment prevented the IR-induced histological deterioration compared with the corresponding vehicle control. SS-31 treatment diminished oxidative stress revealed by the reduced malondialdehyde level and increased activities and protein levels of Sod and catalase. Cellular ATP contents and mitochondrial membrane potential increased and the level of cytosolic cytC was decreased after SS-31 treatment in this IR model, demonstrating that mitochondria were protected. The IR-induced increase of levels of inflammatory factors, such as Tnf-α and Il-1β, was prevented by SS-31 treatment. In agreement with the reduced cytosolic cytC, cleaved-caspase 3 was kept at a very low level after SS-31 treatment. Overall, the effect of SS-31 treatment before ischemia is mildly more effective than that after ischemia. In conclusion, our results demonstrate that SS-31 confers a protective effect in the mouse model of hind limb ischemia-reperfusion injury preventatively and therapeutically.

Topics: Adenosine Triphosphate; Animals; Apoptosis; Caspase 3; Catalase; Cytochromes c; Disease Models, Animal; Hindlimb; Inflammation; Inflammation Mediators; Interleukin-1beta; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Mice, Inbred C57BL; Mitochondria, Muscle; Muscle, Skeletal; Oligopeptides; Oxidative Stress; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase; Tumor Necrosis Factor-alpha

Zucker fatty rats were subjected to warm ischaemia and 12 hours of reperfusion. Ind or NAD. Pretreatment decreased markers of liver injury while preserving mitochondrial cytochrome c content, which is related to the prevention of calcium-induced mitochondrial permeability transition (mPT), the decline in mitochondrial respiratory state 3 and ATP content. The generation of reactive oxygen species (ROS) was also diminished. Inhibition of GSK-3ß by Ind resulted in the prevention of cyclophilin-D (CypD) phosphorylation, unabling it to bind to the adenine nucleotide translocator (ANT), thus, preventing mPT induction. Furthermore, deacetylation of CypD at Lys residue by sirtuin 3 (SIRT3) caused its dissociation from ANT, contributing to an increase in mPT threshold in NAD

Topics: Adenosine Triphosphate; Animals; Antibiotics, Antineoplastic; Calcium; Cyclophilins; Cytochromes c; Fatty Liver; Glycogen Synthase Kinase 3 beta; Hepatic Artery; Indoles; Liver; Mitochondria, Liver; Mitochondrial ADP, ATP Translocases; NAD; Oximes; Peptidyl-Prolyl Isomerase F; Rats; Rats, Zucker; Reactive Oxygen Species; Reperfusion Injury; Sirtuins; Warm Ischemia

 To explore the potential effect of miR-125b on p53-mediated regulation of Bax/Cytochrome C/Caspase-3 apoptotic signaling pathway in rats with cerebral ischemia-reperfusion (CIR) injury..  Sprague-Dawley (SD) rats were used to conduct CIR injury and injected with miR-125b mimic/inhibitor or p53 inhibitor (Pifithrin-α, PFT-α). Dual-luciferase reporter gene assay was used to analyze the targeting relationship between miR-125b and p53. Longa scoring and Triphenyl tetrazolinm chloride (TTC) staining were used to test the neurologic function and determine infarct size, respectively. Hematoxylin-eosin (HE) and Nissl's stainings were conducted to observe the morphology of cortical neurons. Neuronal nuclei (NeuN) expression was detected by immunohistochemical staining. QRT-PCR was performed to detect the expressions of miR-125b and p53. TUNEL staining and Western blotting was used to determine neuronal apoptosis and expressions of Bax/Cytochrome C/Caspase-3 signaling pathway-related proteins, respectively..  Our results showed that miR-125b could directly target p53. As observed, overexpression of miR-125b could obviously reduce the neurological score, infarct size, and brain water content after CIR in rats, which also improved the morphology of cortical neurons, increased the number of neurons, reduced neuronal apoptosis, and inhibited the expressions of Bax/Cytochrome C/Caspase-3 pathway. Moreover,the similar results were observed in rats with CIR after injected with PFT-α. But no significant differences in each index were found in CIR group and CIR + anti-miR-125b + PFT-α group.. MiR-125b exerts protective effects on CIR injury through inhibition of Bax/Cytochrome C/Caspase-3signaling pathway via targeting p53, which is likely to be a promising treatment for CIR.. 3'-UTR: 3-untranslated region; CIR: cerebral ischemia-reperfusion; CIS: cerebral ischemic stroke; PFT-α: Pifithrin-α; PVDF: polyvinylidene fluoride; SD: Sprague-Dawley; TBST: tris buffered saline with tween. TTC staining: Triphenyl tetrazolinm chloride staining; TUNEL: Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Benzothiazoles; Brain Infarction; Brain Ischemia; Caspase 3; Caspases; Cytochromes c; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation; Male; MicroRNAs; Phosphopyruvate Hydratase; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Toluene; Tumor Suppressor Protein p53

Mitochondrial oxidative damage contributes to a wide range of pathologies including ischemia/reperfusion injury. Accordingly, protecting mitochondria from oxidative damage should possess therapeutic relevance. In the present study, we have designed and synthesized a series of novel indole-TEMPO conjugates that manifested good anti-inflammatory properties in a murine model of xylene-induced ear edema. We have demonstrated that these compounds can protect cells from simulated ischemia/reperfusion (s-I/R)-induced reactive oxygen species (ROS) overproduction and mitochondrial dysfunction. Furthermore, we have demonstrated that indole-TEMPO conjugates can attenuate organ damage induced in rodents via intestinal I/R injury. We therefore propose that the pharmacological profile and mechanism of action of these indole-TEMPO conjugates involve convergent roles, including the ability to decrease free radical production via lipid peroxidation which couples to an associated decrease in ROS-mediated activation of the inflammatory process. We further hypothesize that the protective effects of indole-TEMPO conjugates partially reside in maintaining optimal mitochondrial function.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Aspirin; Cyclic N-Oxides; Cytochromes c; Human Umbilical Vein Endothelial Cells; Humans; Indoles; Intestine, Small; Lipid Peroxidation; Male; Mice, Inbred ICR; Mitochondria; Molecular Dynamics Simulation; Neutrophil Infiltration; Oxidative Stress; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Tumor Necrosis Factor-alpha

Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has a positive effect on mitochondrial bioenergetics. In conclusion, these results demonstrate that P4 treatment is beneficial in preserving the mitochondrial functions that are altered in cerebral ischemic injury and thus can help in defining better therapies.

Topics: Animals; Behavior, Animal; Biomarkers; Brain Ischemia; Cytochromes c; Dopamine; Energy Metabolism; Infarction, Middle Cerebral Artery; Male; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Swelling; Neuroprotection; Oxidation-Reduction; Oxidative Stress; Progesterone; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Serotonin

Salidroside (Sal) is a natural antioxidant that elicits cardioprotective and neuroprotective effects in vivo and in vitro; however, its impact on hepatic ischemia/reperfusion (I/R) injury remains unclear. The purpose of this study was to investigate the hepatoprotective effects of salidroside against segmental (70%) warm hepatic I/R injury in rats. Animals were randomized into Sham, Sham+salidroside pretreatment (Sal), Sham+Sal+carboxyatractyloside (CATR), Sham+CATR, I/R, I/R+Sal, I/R+Sal+CATR and I/R+CATR groups. The hepatic artery, left portal vein and median liver lobes were occluded for 60min and then unclamped to allow reperfusion. Pretreatment with salidroside (20mg/kg/day for 7 days, intraperitoneally) significantly decreased serum alanine aminotransferase (sALT) and serum aspartate aminotransferase (sAST) levels after 6h and 24h of reperfusion and protected the liver against I/R-induced injury. However, this protective effect could be reversed by CATR, a mitochondrial permeability transition pore (MPTP) opener (5mg/kg 30min before I/R insult, intraperitoneally). Mechanistic studies have revealed that salidroside inhibits glycogen synthase kinase-3 beta (GSK-3β) activity and enhances the NF-E2-related factor (Nrf2)-dependent antioxidant response by activating the Akt signaling pathway, thereby reducing mitochondrial reactive oxygen species generation, increasing MPTP resistance and preventing apoptosis by suppressing cytochrome c release and caspase activation during reperfusion. Therefore, salidroside ameliorates hepatocyte death and apoptosis through activation of the GSK-3β/Nrf2-dependent antioxidant response and subsequent MPTP inhibition. These results provide experimental evidence supporting the clinical use of salidroside for hepatoprotection in surgical settings.

Topics: Animals; Antioxidants; Caspases; Cytochromes c; Cytoprotection; Enzyme Activation; Glucosides; Glycogen Synthase Kinase 3 beta; Liver; Male; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; NF-E2-Related Factor 2; Phenols; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Enriched environment (EE) has been reported to exert neuroprotective effect in animal models of ischemic stroke. However, the underlying mechanism remains unclear. The purpose of this study was to investigate the effect of EE treatment on neuronal apoptosis in the periinfarct cortex after cerebral ischemia/reperfusion (I/R) injury.. The cerebral I/R injury was established by middle cerebral artery occlusion (MCAO). A set of behavioral tests including the modified neurological severity score (mNSS), limb-placing test and foot-fault test were conducted. The infarct volume and the neuronal survival rate were evaluated by Nissl staining. The morphology and ultrastructure of ischemic neurons was examined by transmission electron microscopy. Neuronal apoptosis was assessed by double labeling of TdT-mediated dUTP-biotin nick end labeling (TUNEL) with NeuN. The expressions of apoptosis-related proteins were tested by western blotting and immunohistochemical labeling.. EE treatment improved neurological function, reduced infarct volume, increased neuronal survival rate and alleviated the morphological and ultrastructural damage of neurons (especially mitochondria) after I/R injury. EE treatment reduced the neuronal apoptosis, increased B cell lymphoma/leukemia-2 (Bcl-2) protein levels while decreased Bcl-2-associated X protein (Bax), cytochrome c, caspase-3 expressions and Bax/Bcl-2 ratio in the periinfarct cortex after cerebral I/R injury.. Our findings suggest that EE treatment inhibits neuronal apoptosis in the periinfarct cortex after focal cerebral I/R injury, which may be one of the possible mechanisms underlying the neuroprotective effects of EE.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain Diseases; Caspase 3; Cerebral Cortex; Cytochromes c; Gene Expression Regulation; Male; Neurons; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Oxidative stress has been implicated in the pathogenesis of neurodegenerative disorders, such as vascular cognitive impairment (VCI). The present study was performed to investigate the potential neuroprotective effect of the antioxidant astaxanthin (ATX) in a mouse model of VCI. VCI was induced in male ICR mice by repeated occlusion of the bilateral common carotid artery, leading to repeated cerebral ischemia/reperfusion (IR) injury. After surgery, the mice received ATX or an equal volume of vehicle by daily intragastric administration for 28days. The results showed that ATX treatment ameliorated learning and memory deficits after repeated cerebral IR. ATX administration rescued the number of surviving pyramidal neurons in the CA1 and CA3 regions. The concentration of malondialdehyde was decreased, and the levels of reduced glutathione and superoxide dismutase in the hippocampus were increased. Electron microphotography revealed that damage to the ultrastructure of neurons was also reduced by ATX administration. In addition, the expression levels of Cytochrome C (Cyt C), cleaved Caspase-3 and Bax were lower and the expression of Bcl-2 was higher compared to control IR mice. Our findings demonstrate that ATX is able to suppresse learning and memory impairment caused by repeated cerebral IR and that this effect is associated with attenuation of oxidative stress.

Topics: Animals; Antioxidants; Apoptosis; Brain Ischemia; Cytochromes c; Dementia, Vascular; Disease Models, Animal; Glutathione; Hippocampus; Learning; Male; Malondialdehyde; Maze Learning; Memory Disorders; Mice; Mice, Inbred ICR; Neurons; Neuroprotective Agents; Oxidative Stress; Reperfusion; Reperfusion Injury; Superoxide Dismutase; Xanthophylls

This study is aimed at validating the hypothesis that administration of cyclosporine-A (CsA) would be protective in lung ischemia-reperfusion (I/R) injury and in exploring the underlying mechanism.. Rabbits were divided into 4 groups: the control, sham operation, I/R, and I/R with CsA treatment. Flow cytometry was used to measure the mitochondrial membrane potential. Laser scanning confocal microscope was used to analyze mitochondrion permeability transition pore (MPTP). The apoptotic cell was detected by the TUNEL staining. Western blot was performed to analyze the protein expression levels.. CsA not only attenuated the histopathologic alterations in lung and mitochondria after I/R injury, but also attenuated I/R injury through increasing MPP and inhibiting MPTP opening. Besides, CsA attenuated I/R injury through suppressing the release of cytochrome-c (CytC), inhibiting cell apoptosis and decreasing the expression levels of cyclophilin-D (Cyp-D), adenine nucleotide translocase 1 (ANT1) and voltage-dependent anion channel 1 (VDAC1). Finally, we found that Cyp-D knockdown inhibits I/R injury-induced MPTP opening and cell apoptosis.. Our study found that the protective role of CsA on lung I/R injury depends on the inhibition of MPTP and CytC release, suppression of the activation of mitochondrial apoptosis pathway and the expressions of apoptotic-related proteins, as well as the decreased expression levels of ANT1 and VDAC1.

Topics: Adenine Nucleotide Translocator 1; Animals; Apoptosis; Cyclophilins; Cyclosporine; Cytochromes c; Flow Cytometry; Gene Knockdown Techniques; In Situ Nick-End Labeling; Lung Injury; Membrane Potential, Mitochondrial; Microscopy, Confocal; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Peptidyl-Prolyl Isomerase F; Rabbits; Reperfusion Injury; Voltage-Dependent Anion Channel 1

Neuronal apoptosis mediated by the mitochondrial apoptosis pathway is an important pathological process in cerebral ischemia-reperfusion injury. 14,15-EET, an intermediate metabolite of arachidonic acid, can promote cell survival during ischemia/reperfusion. However, whether the mitochondrial apoptotic pathway is involved this survival mechanism is not fully understood. In this study, we observed that infarct size in ischemia-reperfusion injury was reduced in sEH gene knockout mice. In addition, Caspase 3 activation, cytochrome C release and AIF nuclear translocation were also inhibited. In this study, 14,15-EET pretreatment reduced neuronal apoptosis in the oxygen-glucose deprivation and re-oxygenation group in vitro. The mitochondrial apoptosis pathway was also inhibited, as evidenced by AIF translocation from the mitochondria to nucleus and the reduction in the expressions of cleaved-caspase 3 and cytochrome C in the cytoplasm. 14,15-EET could reduce neuronal apoptosis through upregulation of the ratio of Bcl-2 (anti-apoptotic protein) to Bax (apoptosis protein) and inhibition of Bax aggregation onto mitochondria. PI3K/AKT pathway is also probably involved in the reduction of neuronal apoptosis by EET. Our study suggests that 14,15-EET could suppress neuronal apoptosis and reduce infarct volume through the mitochondrial apoptotic pathway. Furthermore, the PI3K/AKT pathway also appears to be involved in the neuroprotection against ischemia-reperfusion by 14,15-EET.

Topics: 8,11,14-Eicosatrienoic Acid; Animals; Apoptosis; Cytochromes c; Male; Mice, Inbred C57BL; Mitochondria; Phosphatidylinositol 3-Kinases; Reperfusion Injury; Signal Transduction

Ginkgolide K (GK) belongs to the ginkgolide family of natural compounds found in Ginkgo biloba leaves, which have been used for centuries to treat cerebrovascular and cardiovascular diseases. We evaluated the protective effects of GK against neuronal apoptosis by assessing its ability to sustain mitochondrial integrity and function. Co-immunoprecipitation showed that Drp1 binding to GSK-3β was increased after an oxygen-glucose deprivation/reperfusion (OGD/R) insult in cultured neuroblastoma cells. This induced Drp1 and GSK-3β translocation to mitochondria and mitochondrial dysfunction, which was attenuated by GK. GK also reduced mitochondrial fission by increasing Drp1 phosphorylation at Ser637 and inhibiting mitochondrial Drp1 recruitment. In addition, GK exposure induced GSK-3β phosphorylation at Ser9 and enhanced the interaction between adenine nucleotide translocator (ANT) and p-GSK-3β. This interaction suppressed the interaction between ANT and cyclophilin D (CypD), which inhibited mitochondrial permeability transition pore (mPTP) opening. Similarly, suppression of mitochondrial fission by Mdivi-1 also inhibited GSK-3β-induced mPTP opening. Treating mice with GK prevented GSK-3β and Drp1 translocation to mitochondria and attenuated mitochondrial dysfunction after middle cerebral artery occlusion. We therefore propose that by inhibiting mitochondrial fission and attenuating mPTP opening, GK exerts neuroprotective effects that mitigate or prevent neuronal damage secondary to ischemic stroke.

Topics: Animals; Apoptosis; Brain Ischemia; Cell Line; Cytochromes c; Dynamins; Ginkgolides; Glucose; Glycogen Synthase Kinase 3 beta; Ion Channel Gating; Lactones; Male; Mice; Mitochondrial Dynamics; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Neurons; Neuroprotective Agents; Oxygen; Protein Transport; Reactive Oxygen Species; Reperfusion Injury; Stroke

Glaucoma is one of the leading causes of preventable blindness diseases, affecting more than 2 million people in the United States. Recently, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors were found to exert preventive effects against glaucoma. Therefore, we investigated whether carbenoxolone (CBX), an 11β-HSD1 inhibitor, prevents chemical ischemia-reperfusion-induced cell death in human trabecular meshwork (HTM) cells. The present study demonstrated that CBX inhibited cell death caused by iodoacetic acid (IAA)-induced ischemia-reperfusion, and its effect was associated with the inhibition of 11β-HSD1 expression and activity. Furthermore, CBX reversed the IAA-induced structural damage on filamentous actin in HTM cells. In IAA-treated cells, the levels of 11β-HSD1 and the apoptosis-related factors Bax and FASL were increased throughout the reperfusion period, and CBX was able to attenuate the expression of 11β-HSD1 and the apoptosis-related factors. CBX also effectively suppressed IAA-induced intracellular ROS formation and cytochrome c release, which are involved in the mitochondrial apoptosis pathway. In addition, IAA-induced chemical ischemia-reperfusion stimulated TNF-α expression and NF-κB p65 phosphorylation, and these effects were attenuated by CBX. 11β-HSD1 RNAi also suppressed IAA-induced cell apoptosis via reduction of oxidative stress and inhibition of the pro-inflammatory pathway. Taken together, the present study demonstrated that the inhibition of 11β-HSD1 protected the TM against chemical ischemia-reperfusion injury, suggesting that the use of 11β-HSD1 inhibitors could be a useful strategy for glaucoma therapy.

Topics: 11-beta-Hydroxysteroid Dehydrogenase Type 1; Carbenoxolone; Cell Death; Cell Survival; Cells, Cultured; Cytochromes c; Eye Injuries; Humans; Iodoacetic Acid; Protective Agents; Reactive Oxygen Species; Reperfusion Injury; Trabecular Meshwork; Tumor Necrosis Factor-alpha

Hypoxia preconditioning has been proven to be an effective method to enhance the therapeutic action of mesenchymal stem cells (MSCs). However, the beneficial effects of hypoxic MSCs in ischemia/reperfusion (I/R) lung injury have yet to be investigated. In this study, we hypothesized that the administration of hypoxic MSCs would have a positive therapeutic impact on I/R lung injury at molecular, cellular, and functional levels.. I/R lung injury was induced in isolated and perfused rat lungs. Hypoxic MSCs were administered in perfusate at a low (2.5×105 cells) and high (1×106 cells) dose. Rats ventilated with a low tidal volume of 6 ml/kg served as controls. Hemodynamics, lung injury indices, inflammatory responses and activation of apoptotic pathways were determined.. I/R induced permeability pulmonary edema with capillary leakage and increased levels of reactive oxygen species (ROS), pro-inflammatory cytokines, adhesion molecules, cytosolic cytochrome C, and activated MAPK, NF-κB, and apoptotic pathways. The administration of a low dose of hypoxic MSCs effectively attenuated I/R pathologic lung injury score by inhibiting inflammatory responses associated with the generation of ROS and anti-apoptosis effect, however this effect was not observed with a high dose of hypoxic MSCs. Mechanistically, a low dose of hypoxic MSCs down-regulated P38 MAPK and NF-κB signaling but upregulated glutathione, prostaglandin E2, IL-10, mitochondrial cytochrome C and Bcl-2. MSCs infused at a low dose migrated into interstitial and alveolar spaces and bronchial trees, while MSCs infused at a high dose aggregated in the microcirculation and induced pulmonary embolism.. Hypoxic MSCs can quickly migrate into extravascular lung tissue and adhere to other inflammatory or structure cells and attenuate I/R lung injury through anti-oxidant, anti-inflammatory and anti-apoptotic mechanisms. However, the dose of MSCs needs to be optimized to prevent pulmonary embolism and thrombosis.

Topics: Animals; Antioxidants; Apoptosis; Biomarkers; Bronchoalveolar Lavage Fluid; Capillaries; Caspase 3; Cell Hypoxia; Cytochromes c; Cytosol; Glutathione; Hemodynamics; Hydrogen Peroxide; Intercellular Adhesion Molecule-1; Leukocyte Count; Lung Injury; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Mitogen-Activated Protein Kinases; NF-kappa B; Organ Size; Peroxidase; Protein Carbonylation; Proto-Oncogene Proteins c-bcl-2; Pulmonary Embolism; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Thiobarbituric Acid Reactive Substances; Thrombosis; Vascular Cell Adhesion Molecule-1

To explore the effects and molecular mechanisms of the combination between total Astragalus extract (TAE) and total Panax notoginseng saponins (TPNS) against cerebral ischemia-reperfusion injury.. C57BL/6 mice were randomly divided into sham-operated group, model group, TAE (110 mg/kg) group, TPNS (115 mg/kg) group, TAE-TPNS combination group and Edaravone (4 mg/kg) group, treated for 4 days, then, cerebral ischemia-reperfusion injury was established by bilateral common carotid artery (CCA) ligation for 20 min followed by reperfusion for 1 and 24 h.. The combination of TAE 110 mg/kg and TPNS 115 mg/kg could strengthen protective effects on cerebral ischemia injury, the mechanism underlying might be related to improving jointly the early energy metabolism, and relieving the delayed apoptosis via inhibiting the mitochondrial apoptosis pathway of JNK signal transduction.

Topics: Adenosine Diphosphate; Adenosine Triphosphate; Animals; Apoptosis; Astragalus Plant; Brain; Brain Ischemia; CA1 Region, Hippocampal; Caspase 3; Caspase 9; Cell Survival; Cytochromes c; Energy Metabolism; JNK Mitogen-Activated Protein Kinases; Mice, Inbred C57BL; Neurons; Neuroprotective Agents; Panax notoginseng; Plant Extracts; Reperfusion Injury; Saponins; Sodium-Potassium-Exchanging ATPase

Hemorrhagic shock and reperfusion (HSR) injury leads to a cascade of reactive oxygen species (ROS) production and mitochondrial dysfunction, which results in energy failure, cell death, and multiple organ dysfunction. Cytochrome c (cyt c) is the final electron carrier in the mitochondrial electron transport chain providing the electrochemical force for ATP production. We sought to determine whether exogenous cyt c administration would improve parameters of organ dysfunction and/or mitochondrial stability in a rat model of HSR.. Male rats were hemorrhaged to a mean arterial pressure (MAP) of 33 ± 2.0 mm Hg for 1 hour before resuscitation. Saline or cyt c (0.8 mg [HSR-LoCC] or 3.75 mg [HSR-HiCC]) was administered (i.v.) 30 minutes before resuscitation. Rats were euthanized by cardiac puncture 2 hours post-surgery and tissue collected and analyzed for lipid peroxidation, endogenous antioxidant activity (glutathione peroxidase (GPx) and catalase), TNF-α expression, mitochondrial function (complex-I activity), and circulating mitochondrial DNA (mtDNA).. Cyt c administration improved lactate clearance, decreased hepatic lipid peroxidation, increased hepatic GPx activity, restored pulmonary TNF-α to sham activity levels, and increased hepatic complex-I activity. Furthermore, addition of exogenous cyt c decreased circulating levels of mtDNA.. These studies demonstrate that cyt c reduces markers of physiologic stress, decreases oxidative stress, and lowers levels of circulating mtDNA. The impact of cytochrome c is organ specific. Further studies remain to determine the sum of the effects of cytochrome c on overall outcome.

Topics: Animals; Antioxidants; Catalase; Cytochromes c; Disease Models, Animal; DNA, Mitochondrial; Lipid Peroxidation; Male; Mitochondria; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Resuscitation; Shock, Hemorrhagic; Tumor Necrosis Factor-alpha

Dietary restriction or reduced food intake was supported to protect against renal and hepatic ischemic injury. In this vein, short fasting was recently shown to protect in situ rat liver against ischemia-reperfusion. Here, perfused ex vivo instead of in situ livers were exposed to ischemia-reperfusion to study the impact of disconnecting liver from extrahepatic supply in energetic substrates on the protection given by short-term fasting.. Perfused ex vivo livers using short (18 h) fasted compared with fed rats were submitted to ischemia-reperfusion and studied for release of cytolysis markers in the perfusate. Energetic stores are differently available in time and cell energetic charges (ratio of adenosine triphosphate plus half of the adenosine diphosphate concentrations to the sum of adenosine triphosphate + adenosine diphosphate + adenosine monophosphate concentrations), adenosine phosphates, and glycogen, which were further measured at different time points in livers.. Short fasting versus feeding failed to protect perfused ex vivo rat livers against ischemia/reperfusion, increasing the release of cytolysis markers (potassium, cytochrome c, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase) in the perfusate during reoxygenation phase. Toxicity of short fasting versus feeding was associated with lower glycogen and energetic charges in livers and lower lactate levels in the perfusate.. High energetic charge, intracellular content in glycogen, and glycolytic activity may protect liver against ischemia/reperfusion injury. This work does not question how much the protective role previously demonstrated in the literature for dietary restriction and short fasting. In fact, it suggests that exceeding the energy charge threshold value of 0.3 might trigger the effectiveness of this protective role.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Caloric Restriction; Cytochromes c; Fasting; Female; Glycogen; L-Lactate Dehydrogenase; Liver; Potassium; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Therapeutic hypothermia is effective to attenuate brain ischemia/reperfusion (I/R) injury after cardiac arrest, and multiple mechanisms have been proposed. Dynamin-related protein 1 (Drp1), a large GTPases of dynamin superfamily, predominantly controls mitochondrial fission and is related to IR-induced Cyt C release and apoptosis. However, the effect of therapeutic hypothermia on Drp1 and mitochondrial fission after cardiac arrest remains still unclear. In this study, non-cardiac arrest and post-cardiac arrest rats received 6-h normothermia (37-38°C) or therapeutic hypothermia (32-34°C), and the hippocampus was harvested at 6h and 72h after cardiac arrest. Results showed the expression of Drp1 and Cyt C increased after cardiac arrest, but therapeutic hypothermia partially reversed this increase at 6h after cardiac arrest. Transmission electron microscopy (TEM) also showed a change in morphology following therapeutic hypothermia after cardiac arrest. Moreover, therapeutic hypothermia could decrease the histopathological damage, inhibit the apoptosis of CA1 neurons and improve the survival and neurological outcomes at 72h after cardiac arrest. Taken together, our study demonstrates that therapeutic hypothermia is neuroprotective against global cerebral I/R injury, which is, at least partially, ascribed to the inhibition Drp1 and Cyt C expression and the protection of mitochondrial structure.

Topics: Animals; Apoptosis; Brain Ischemia; Cytochromes c; Dynamins; Heart Arrest; Hippocampus; Hypothermia, Induced; Male; Mitochondria; Neurons; Rats, Sprague-Dawley; Reperfusion Injury

Methanogenesis can indicate the fermentation activity of the gastrointestinal anaerobic flora. Methane also has a demonstrated anti-inflammatory potential. We hypothesized that enriched methane inhalation can influence the respiratory activity of the liver mitochondria after an ischemia-reperfusion (IR) challenge.. The activity of oxidative phosphorylation system complexes was determined after in vitro methane treatment of intact liver mitochondria. Anesthetized Sprague-Dawley rats subjected to standardized 60-min warm hepatic ischemia inhaled normoxic air (n = 6) or normoxic air containing 2.2% methane, from 50 min of ischemia and throughout the 60-min reperfusion period (n = 6). Measurement data were compared with those on sham-operated animals (n = 6 each). Liver biopsy samples were subjected to high-resolution respirometry; whole-blood superoxide and hydrogen peroxide production was measured; hepatocyte apoptosis was detected with TUNEL staining and in vivo fluorescence laser scanning microscopy.. Significantly decreased complex II-linked basal respiration was found in the normoxic IR group at 55 min of ischemia and a lower respiratory capacity (~60%) and after 5 min of reperfusion. Methane inhalation preserved the maximal respiratory capacity at 55 min of ischemia and significantly improved the basal respiration during the first 30 min of reperfusion. The IR-induced cytochrome c activity, reactive oxygen species (ROS) production and hepatocyte apoptosis were also significantly reduced.. The normoxic IR injury was accompanied by significant functional damage of the inner mitochondrial membrane, increased cytochrome c activity, enhanced ROS production and apoptosis. An elevated methane intake confers significant protection against mitochondrial dysfunction and reduces the oxidative damage of the hepatocytes.

Topics: Administration, Inhalation; Animals; Apoptosis; Cytochromes c; Electron Transport; Hepatocytes; Hydrogen Peroxide; Liver; Male; Methane; Mitochondria, Liver; Mitochondrial Membranes; Oxidative Phosphorylation; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxides

Myocardin-related transcription factor-A (MRTF-A) can transduce both biomechanical and humoral signals, which can positively modulate cardiac damage induced by acute myocardial infarction. However, the molecular mechanism that underlies the contribution that MRTF-A provides to the myocardium is not completely understood. The objective of this study was to investigate the effects of MRTF-A on myocardium apoptosis and its mechanisms. Our experiment results showed that MRTF-A expression increased and Bcl-2 expression reduced during myocardial ischemia-reperfusion in rat. Meanwhile, primary cardiomyocytes were pretreated with wild-type MRTF-A or siRNA of MRTF-A before exposure to hypoxia. We found that overexpression of MRTF-A in myocardial cells inhibited apoptosis and the release of cytochrome c. MRTF-A enhanced Bcl-2, which contributes to MRTF-A interaction with Bcl-2 in the nuclei of cardiomyocytes. MRTF-A upregulation expression of Bcl-2 in cardiomyocytes induced by hypoxia was inhibited by PD98059, an ERK1/2 inhibitor. In conclusions, MRTF-A improved myocardial cell survival in a cardiomyocyte model of hypoxia-induced injury; this effect was correlated with the upregulation of anti-apoptotic gene Bcl-2 through the activation of ERK1/2.

Topics: Animals; Apoptosis; Cell Survival; Cytochromes c; Hypoxia; Male; MAP Kinase Signaling System; Myocardial Infarction; Myocardial Ischemia; Myocardium; Myocytes, Cardiac; Nuclear Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Trans-Activators; Transcription Factors; Transcriptional Activation; Up-Regulation

Excessive mitochondrial fission activation has been implicated in cerebral ischemia-reperfusion (IR) injury. Hypothermia is effective in preventing cerebral ischemic damage. However, effects of hypothermia on ischemia-induced mitochondrial fission activation is not well known. Therefore, the aim of this study was to investigate whether hypothermia protect the brain by inhibiting mitochondrial fission-related proteins activation following cerebral IR injury. Adult male C57BL/6 mice were subjected to transient forebrain ischemia induced by 15min of bilateral common carotid artery occlusion (BCCAO). Mice were divided into three groups (n=48 each): Hypothermia (HT) group, with mild hypothermia (32-34°C) for 4h; Normothermia (NT) group, similarly as HT group except for cooling; Sham group, with vessels exposed but without occlusion or cooling. Hematoxylin and eosin (HE), Nissl staining, Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining and behavioral testing (n=6 each) demonstrated that hypothermia significantly decreased ischemia-induced neuronal injury. The expressions of Dynamin related protein 1 (Drp1) and Cytochrome C (Cyto C) (n=6 each) in mice hippocampus were measured at 3, 6, 24, and 72h of reperfusion. IR injury significantly increased expressions of total Drp1, phosphorylated Drp1 (P-Drp1 S616) and Cyto C under normothermia. However, mild hypothermia inhibited Drp1 activation and Cyto C cytosolic release, preserved neural cells integrity and reduced neuronal necrosis and apoptosis. These findings indicated that mild hypothermia-induced neuroprotective effects against ischemia-reperfusion injury is associated with suppressing mitochondrial fission-related proteins activation and apoptosis execution.

Topics: Animals; Apoptosis; Brain Ischemia; Cytochromes c; Dynamins; Hippocampus; Hypothermia, Induced; Male; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Dynamics; Pyramidal Cells; Recognition, Psychology; Reperfusion Injury

The purpose of this study was to determine whether c-jun NH2 amino-terminal kinases (JNK) and p38 mitogen-activated protein kinases (MAPK) were involved in morphine postconditioning (MpostC).. The isolated rat hearts were randomly assigned into one of the following groups. Hearts in the time control (TC) group were constantly perfused for 105min. Hearts in the ischemia-reperfusion (I/R) group were subjected to 45 min of ischemia followed by 1 h of reperfusion. MpostC was induced by 10 min of morphine administration at the onset of reperfusion. Anisomycin (an activator of JNK/p38 kinases) was administered with or without morphine during the first 10 min of reperfusion following the 45 min of ischemia. Mitochondria and cytosolic proteins were prepared to detect mitochondrial permeability transition (MPT) and cytochrome C (Cyt-c) respectively.. MpostC markedly reduced infarct size (IS/AAR), CK-MB release, and improved cardiac function recovery. However, these protective effects were partly abolished in the presence of anisomycin. I/R significantly increased the phosphorylation of JNK and p38 kinases, mitochondrial permeability transition (MPT) opening and Cyt-c release, while these effects were partly abolished by MpostC. The inhibitory effects of MpostC on the phosphorylation of JNK/p38 kinases, MPT opening and Cyt-c release were totally reversed by Anisocycin, which, used individually, did not show any influence on perfusion injury.. These findings suggest that MpostC protects isolated rat hearts against reperfusion injury via inhibiting JNK/p38 MAPKs and mitochondrial permeability transition pores signaling pathways.

Topics: Analgesics, Opioid; Animals; Blotting, Western; Cardiotonic Agents; Cytochromes c; Heart; In Vitro Techniques; JNK Mitogen-Activated Protein Kinases; Male; Mitochondria, Heart; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Morphine; Myocardium; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Random Allocation; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

We describe several novel curcumin analogues that possess both anti-inflammatory antioxidant properties and thrombolytic activities. The therapeutic efficacy of these curcumin analogues was verified in a mouse ear edema model, a rat arterial thrombosis assay, a free radical scavenging assay performed in PC12 cells, and in both in vitro and in vivo ischemia/reperfusion models. Our findings suggest that their protective effects partially reside in maintenance of optimal mitochondrial function.

Topics: Animals; Anti-Inflammatory Agents; Curcumin; Cytochromes c; Disease Models, Animal; Edema; Enzyme-Linked Immunosorbent Assay; Free Radical Scavengers; Human Umbilical Vein Endothelial Cells; Interleukin-6; Mice; Microscopy, Fluorescence; Mitochondria; Muscle, Skeletal; Oxidative Stress; PC12 Cells; Quantum Theory; Rats; Reactive Oxygen Species; Reperfusion Injury; Tumor Necrosis Factor-alpha

When given prior to brain ischemia, mitochondrial division inhibitor-1 (mdivi-1) attenuates the brain damage caused by ischemia. Here, we investigated the potential effects of post-ischemia mdivi-1 treatment (1mg/kg, i.p., administered immediately after 2h of ischemia and prior to reperfusion) using a MCAO rat model. Mdivi-1 treatment decreased infarct volume and improved neurological function. In addition, cytochrome C release was attenuated, and neuronal apoptosis was decreased. The mitochondrial fission protein dynamin-related protein 1 (Drp1) was decreased in the mitochondrial fraction but increased in the cytosolic fraction. Mdivi-1 treatment augmented the increases in the mRNA expression of peroxisome proliferator-activated receptor coactivator-1α, nuclear respiratory factor-1, and mitochondrial transcriptional factor A. In conclusion, when given after ischemia and prior to reperfusion, mdivi-1 can protect against brain damage by inhibiting the mitochondria-mediated apoptosis induced by mitochondrial fission. Post-ischemia mdivi-1 treatment might promote I/R-induced mitochondrial biogenesis.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Cytochromes c; Disease Models, Animal; Dynamins; Male; Mitochondria; Mitochondrial Dynamics; Neurons; Neuroprotective Agents; Organelle Biogenesis; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Quinazolinones; Rats; Rats, Wistar; Reperfusion Injury

Objective To investigate the protective effects of epigallocatechin-3-gallate (EGCG), a major polyphenol source in green tea, against hepatic ischaemia-reperfusion injury in mice. Methods The partial hepatic ischaemia-reperfusion injury model was created by employing the hanging-weight method in C57BL/6 male mice. EGCG (50 mg/kg) was administered via an intraperitoneal injection 45 min before performing the reperfusion. A number of markers of inflammation, oxidative stress, apoptosis and liver injury were measured after the ischaemia-reperfusion injury had been induced. Results The treatment groups were: sham-operated (Sham, n = 10), hepatic ischaemia-reperfusion injury (IR, n = 10), and EGCG with ischaemia-reperfusion injury (EGCG-treated IR, n = 10). Hepatic ischaemia-reperfusion injury increased the levels of biochemical and histological markers of liver injury, increased the levels of malondialdehyde, reduced the glutathione/oxidized glutathione ratio, increased the levels of oxidative stress and lipid peroxidation markers, decreased B-cell lymphoma 2 levels, and increased the levels of Bax, cytochrome c, cleaved caspase-3, and cleaved caspase-9. Pretreatment with EGCG ameliorated all of these changes. Conclusion The antioxidant and antiapoptotic effects of EGCG protected against hepatic ischaemia-reperfusion injury in mice.

Topics: Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Catechin; Cytochromes c; Disease Models, Animal; Glutathione; Glutathione Disulfide; Inflammation; Injections, Intraperitoneal; Lipid Peroxidation; Liver; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury

The neuroprotective effect of polydatin (PD) against hemorrhagic shock-induced mitochondrial injury has been described previously, and mitochondrial dysfunction and apoptosis were reportedly involved in ischemic stroke. In the present study the neuroprotective effect of PD in preventing apoptosis was evaluated following induction of focal cerebral ischemia by middle cerebral artery occlusion (MCAO) in rats. PD (30 mg/kg) was administered by caudal vein injection 10 min prior to ischemia/reperfusion (I/R) injury. 24 h following I/R injury, ameliorated modified neurological severity scores (mNSS) and reduced infarct volume were observed in the PD treated group. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Annexin V/propidium iodide assays demonstrated the anti-apoptotic effect of PD in the ischemic cortex. In addition, PD improved I/R injury‑induced mitochondrial dysfunction, reflected by morphological observations and measurements of mitochondrial membrane potential and intracellular ATP measurement. Western blot analysis revealed an increase in B‑cell lymphoma 2 apoptosis regulator (Bcl-2) expression, and a decrease in Bcl‑2‑associated protein X apoptosis regulator expression in the PD group in comparison with the vehicle treated group. PD treatment also prevented the release of cytochrome c from mitochondria into the cytoplasm, and blunted the activities of caspase‑9 and caspase‑3. Furthermore, PD treatment decreased the levels of reactive oxygen species in neurons isolated from the ischemic cortex. The findings of this study, therefore, suggest that PD has a dual effect, ameliorating both oxidative stress and mitochondria‑dependent apoptosis, making it a promising new therapy for the treatment of ischemic stroke.

Topics: Adenosine Triphosphate; Animals; Apoptosis; bcl-2-Associated X Protein; Biomarkers; Brain Ischemia; Cerebral Cortex; Cytochromes c; Disease Models, Animal; Glucosides; Male; Membrane Potential, Mitochondrial; Mitochondria; Neurons; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Stilbenes

Postconditioning mitigates ischemia-induced cellular damage via a modified reperfusion procedure. Mitochondrial permeability transition (MPT) is an important pathophysiological change in reperfusion injury. This study explores the role of MPT modulation underlying hypoxic postconditioning (HPoC) in PC12 cells and studies the neuroprotective effects of ischemic postconditioning (IPoC) on rats. Oxygen-glucose deprivation (OGD) was performed for 10 hr on PC12 cells. HPoC was induced by three cycles of 10-min reoxygenation/10-min rehypoxia after OGD. The MPT inhibitor N-methyl-4-isoleucine cyclosporine (NIM811) and the MPT inducer carboxyatractyloside (CATR) were administered to selective groups before OGD. Cellular death was evaluated by flow cytometry and Western blot analysis. JC-1 fluorescence signal was used to estimate the mitochondrial membrane potential (△Ψm ). Transient global cerebral ischemia (tGCI) was induced via the two-vessel occlusion and hypotension method in male Sprague Dawley rats. IPoC was induced by three cycles of 10-sec reperfusion/10-sec reocclusion after index ischemia. HPoC and NIM811 administration attenuated cell death, cytochrome c release, and caspase-3 activity and maintained △Ψm of PC12 cells after OGD. The addition of CATR negated the protection conferred by HPoC. IPoC reduced neuronal degeneration and cytochrome c release and cleaved caspase-9 expression of hippocampal CA1 neurons in rats after tGCI. HPoC protected PC12 cells against OGD by modulating the MPT. IPoC attenuated degeneration of hippocampal neurons after cerebral ischemia.

Topics: Animals; Caspase 3; Cell Death; Cytochromes c; Disease Models, Animal; Flow Cytometry; Fluoresceins; Formazans; Glucose; Hippocampus; Ischemic Postconditioning; Male; Membrane Potential, Mitochondrial; Oxygen; PC12 Cells; Rats; Reperfusion Injury; Tetrazolium Salts

PUMA (p53-upregulated modulator of apoptosis), a BH3-only member of the Bcl-2 protein family, is required for p53-dependent and p53-independent forms of apoptosis. PUMA has been invovled in the onset and progress of several diseases, including cancer, acquired immunodeficiency syndrome, and ischemic brain disease. Although many studies have shown that ischemia and reperfusion (I/R) can induce the apoptosis of astrocytes, the role of PUMA in I/R-mediated apoptosis of cerebral astrocyte apoptosis remains unclear. To mimic in vivo I/R conditions, primary mouse cerebral astrocytes were incubated in a combinational cultural condition of oxygen, glucose, and serum deprivation (OSGD) for 1 h followed by reperfusion (OSGD/R). Cell death determination assays and cell viability assays indicated that OSGD and OSGD/R induce the apoptosis of primary cerebral astrocytes. The expression of PUMA was significantly elevated in primary cerebral astrocytes during OSGD/R. Moreover, targeted down-regulation of PUMA by siRNA transfection significantly decreased the OSGD/R-induced apoptosis of primary cerebral astrocytes. We also found that OSGD and OSGD/R triggered the release of cytochrome c in astrocytes, indicating the dependence on a mitochondrial apoptotic pathway. Reactive oxygen species (ROS) was extremely generated during OSGD and OSGD/R, and the elimination of ROS by treated with N-acetyl-L-cysteine (NAC) remarkably inhibited the expression of PUMA and the apoptosis of primary cerebral astrocytes. The activation of Caspase 3 and Caspase 9 was extremely elevated in primary cerebral astrocytes during OSGD. In addition, we found that knockdown of PUMA led to the depressed expression of Bax, cleaved caspase-9 and caspase-3 during OSGD/R. These results indicate that PUMA is invovled in the apoptosis of cerebral astrocytes upon I/R injury.

Topics: Acetylcysteine; Animals; Animals, Newborn; Apoptosis; Apoptosis Regulatory Proteins; Astrocytes; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cell Hypoxia; Cell Survival; Cells, Cultured; Cytochromes c; Free Radical Scavengers; Gene Knockdown Techniques; Glucose; Mice, Inbred C57BL; Reactive Oxygen Species; Reperfusion Injury; RNA, Small Interfering; Transfection; Tumor Suppressor Proteins

Ischemic stroke is a major macrovascular complication of diabetes mellitus. Sitagliptin, a dipeptidyl peptidase-IV inhibitor, was recently shown to improve cognitive functions in diabetic rats; hence the present study was conducted to evaluate its protective effect against transient ischemia-reperfusion (I/R) in diabetic animals.. Diabetes was induced by streptozotocin (40 mg/kg). Six weeks later, cerebral I/R was induced by bicommon carotid occlusion for 15 min followed by 1h reperfusion. Sitagliptin (250 mg/kg; p.o.) was administered daily during the last 2 weeks before I/R.. The drug alleviated hippocampal injury inflicted by diabetes and/or I/R injury where it suppressed nuclear factor kappa (NF-κ)B, and consequently the downstream inflammatory cytokines tumor necrosis factor-α and interleukin-6. In parallel, the anti-inflammatory cytokine interleukin-10 was elevated. Antioxidant potential of sitagliptin was depicted, where it reduced neutrophil infiltration, lipid peroxides and nitric oxide associated with replenished reduced glutathione. Decline of excitatory amino acid glutamate content is a main finding which is probably mediated by the NF-κB signaling pathway as well as improved oxidant status. Sitagliptin exerted an anti-apoptotic effect as reflected by the reduction of the mitochondrial matrix component cytochrome -C and the key downstream executioner caspase-3. Histopathological examination corroborated the biochemical data.. These findings suggest that sitagliptin is endowed with neuroprotective properties which are probably mediated by its antioxidant, anti-inflammatory, and anti-apoptotic mechanisms and hence may provide a novel agent for the management of ischemic stroke in diabetics.

Topics: Animals; Brain Ischemia; Caspase 3; Cytochromes c; Diabetes Complications; Diabetes Mellitus, Experimental; Hippocampus; Hypoglycemic Agents; Interleukin-10; Male; Neuroprotective Agents; Neutrophil Infiltration; Pyrazines; Rats; Rats, Wistar; Reperfusion Injury; Sitagliptin Phosphate; Triazoles

Nitroalkene derivatives of oleic acid (OA-NO2) serve as high-affinity ligand for PPAR-γ, which regulates apoptosis, oxidation and inflammation and plays a central role in ischemia-reperfusion injury. In the present study, we elucidated the protective mechanisms of OA-NO2 against renal ischemia-reperfusion injury.. HK-2 cells were subjected to oxygen and glucose deprivation followed by re-oxygenation (OGD/R) to mimic renal ischemia-reperfusion injury. Cell apoptosis was analyzed by flow cytometry. Bax mitochondrial translocation, cytochrome c and apoptosis-inducing factor (AIF) cytosolic leakage and Akt/Gsk 3β phosphorylation were evaluated by Western blotting. Bax activation was visualized by immunocytochemistry. GW9662 and siRNA transfection were employed to examine the involvement of PPAR-γ.. OGD/R injury promoted mitochondrial translocation and activation of Bax, leakage of cytochrome c and AIF, subsequent caspase-3 activation, and eventually cell apoptosis. Pre-incubation with OA-NO2 (1.25 µM, 45min) inhibited Bax activation and blocked apoptotic cascade, while the protective effects were negated by GW9662 or PPAR-γ siRNA. Moreover, OA-NO2 restored Akt and Gsk 3β phosphorylation in a PPAR-γ-dependent way.. These findings suggest that OA-NO2 attenuates OGD/R-induced apoptosis by inhibiting Bax translocation and activation and the subsequent mitochondria-dependent apoptotic cascade in a PPAR-γ dependent manner.

Topics: Anilides; Apoptosis; Apoptosis Inducing Factor; bcl-2-Associated X Protein; Caspase 3; Cell Hypoxia; Cytochromes c; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Humans; Kidney; Mitochondria; Oleic Acid; PPAR gamma; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; Signal Transduction

Postconditioning can reduce ischemia-reperfusion (I/R)-induced cardiomyocyte apoptosis by targeting mitochondria. p53 upregulated modulator of apoptosis (PUMA) is involved in lethal I/R injury. Here, we hypothesized that postconditioning might inhibit mitochondrial pathway-mediated cardiomyocyte apoptosis by controlling PUMA expression. The cultured neonatal rat cardiomyocytes underwent 3 h of hypoxia and 3 h of reoxygenation. Postconditioning consisted of three cycles of 5 min reoxygenation and 5 min hypoxia after prolonged hypoxia. Hypoxic postconditioning reduced the levels of PUMA mRNA and protein. Concomitantly, the loss of mitochondrial membrane potential, cytochrome c release and caspase-3 activation were decreased significantly by postconditioning. Overexpression of PUMA increased greatly not only the number of apoptotic cardiomyocytes, but also the collapse of mitochondrial membrane potential, cytochrome c release and caspase-3 activation under postconditioning condition. The data suggest that reduction of PUMA expression mediates the endogenous cardioprotective mechanisms of postconditioning by disrupting mitochondrial apoptotic pathway.

Topics: Animals; Animals, Newborn; Apoptosis; Apoptosis Regulatory Proteins; Caspase 3; Cell Hypoxia; Cells, Cultured; Cytochromes c; Male; Membrane Potential, Mitochondrial; Mitochondria; Myocytes, Cardiac; Rats, Sprague-Dawley; Reperfusion Injury

Global or local ischemia contributes to the pathogenesis of acute kidney injury (AKI). Currently there are no specific therapies to prevent AKI. Potentiation of glycolytic metabolism and attenuation of mitochondrial respiration may decrease cell injury and reduce reactive oxygen species generation from the mitochondria. Meclizine, an over-the-counter anti-nausea and -dizziness drug, was identified in a 'nutrient-sensitized' chemical screen. Pretreatment with 100 mg/kg of meclizine, 17 h prior to ischemia protected mice from IRI. Serum creatinine levels at 24 h after IRI were 0.13 ± 0.06 mg/dl (sham, n = 3), 1.59 ± 0.10 mg/dl (vehicle, n = 8) and 0.89 ± 0.11 mg/dl (meclizine, n = 8). Kidney injury was significantly decreased in meclizine treated mice compared with vehicle group (p < 0.001). Protection was also seen when meclizine was administered 24 h prior to ischemia. Meclizine reduced inflammation, mitochondrial oxygen consumption, oxidative stress, mitochondrial fragmentation, and tubular injury. Meclizine preconditioned kidney tubular epithelial cells, exposed to blockade of glycolytic and oxidative metabolism with 2-deoxyglucose and NaCN, had reduced LDH and cytochrome c release. Meclizine upregulated glycolysis in glucose-containing media and reduced cellular ATP levels in galactose-containing media. Meclizine inhibited the Kennedy pathway and caused rapid accumulation of phosphoethanolamine. Phosphoethanolamine recapitulated meclizine-induced protection both in vitro and in vivo.

Topics: Acute Kidney Injury; Adenosine Triphosphate; Animals; Cell Respiration; Cytochromes c; Deoxyglucose; Disease Models, Animal; Epithelial Cells; Ethanolamines; Galactose; Glycolysis; Humans; Inflammation; Ischemic Preconditioning; Kidney; Kidney Tubules; L-Lactate Dehydrogenase; LLC-PK1 Cells; Male; Meclizine; Mice, Inbred C57BL; Mitochondria; Protective Agents; Reperfusion Injury; Sodium Cyanide; Swine; Up-Regulation

Carbon monoxide (CO) is an endogenous gaseous transmitter that exerts multi-protection in ischemia/reperfusion (I/R) injury, but few experimental studies regarding CO on myocardial I/R-induced apoptosis, as well as its underlying mechanism have been conducted. The present study was designed to investigate whether CO released from CO-releasing molecule-2 (CORM-2) is capable of ameliorating myocardial I/R-induced apoptosis via a mitochondrial apoptotic pathway. Primary cultures of neonatal rat cardiomyocytes were randomly distributed into four groups: Control, I/R (cultured cardiomyocytes were subjected to 2 h simulated ischemia followed by 4 h reperfusion), CORM-2 and inactive CORM-2 (iCORM-2) groups (20 µM CORM-2 and 20 µM iCORM-2 were administered at the beginning of reperfusion following ischemia, respectively). Flow cytometric analysis showed that CORM-2 treatment significantly decreased apoptosis of cardiomyocytes triggered by simulated I/R. CORM-2 partially recovered mitochondrial respiration and ultrastructure alteration, and lowered caspase-3 expression and the release of cytochrome c. Furthermore, CORM-2 partly reduced BAK/BAX expression in mitochondria, as well as the BAX level in the cytoplasm. Cardioprotection is lost when CORM-2 is replaced by iCORM-2. CORM-2 treatment, at the time of reperfusion, was concluded to attenuate myocardial I/R-induced apoptosis. The protection mechanisms may be targeted to the mitochondria and involved in the inhibition of the BAK/BAX‑mediated intrinsic pathway.

Topics: Animals; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Carbon Monoxide; Caspase 3; Cytochromes c; Gene Expression Regulation; Humans; Metabolic Networks and Pathways; Mitochondria; Myocytes, Cardiac; Organometallic Compounds; Rats; Reperfusion Injury

We have documented that tissue kallikrein (TK) prevents neurons from hypoxia/reoxygenation injury through the B2R-ERK1/2 pathway and the antihypoxic function of TK through Homer1b/c-ERK1/2 signaling pathways. The present study investigates the molecular mechanisms of exogenous TK activation of the B2R-ERK1/2 pathway through the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module in vivo. The cresyl violet staining results indicated that exogenous TK protected the rat hippocampal CA1 neurons against cerebral ischemia/reperfusion (I/R) injury. The immunoprecipitation (IP) and immunoblotting (IB) results revealed that exogenous TK upregulated the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module and upregulated the phosphorylation of Raf (p-Raf), MEK1/2 (p-MEK1/2), and ERK1/2 (p-ERK1/2). Meanwhile, exogenous TK upregulated the expression of nuclear factor-κB (NF-κB), depressed the release of cytochrome c (Cyt c) and bax from mitochondria to the cytosol, and depressed the activation of caspase-3. Take together, our results suggest that exogenous TK attenuated the cerebral I/R induced rat hippocampal CA1 neurons injury through activating the β-arrestin-2 assembled B2R-Raf-MEK1/2 signaling module and that the activated B2R-Raf-MEK1/2 signaling module could upregulate the expression of NF-κB, decrease the release of cytochrome c and bax from mitochondria to the cytosol, and depress the activation of caspase-3.

Topics: Animals; Arrestins; bcl-2-Associated X Protein; beta-Arrestin 2; beta-Arrestins; Brain Ischemia; CA1 Region, Hippocampal; Caspase 3; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Male; MAP Kinase Signaling System; Nerve Degeneration; Neurons; Oligodeoxyribonucleotides, Antisense; raf Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tissue Kallikreins; Up-Regulation

It is known that mitochondrial ATP-sensitive potassium channels (mitoKATP) play a significant role in protecting cerebral function from ischemia-reperfusion injury, which is related with a decrease in the mitochondrial matrix calcium. However, the effect of mitochondrial calcium uniporter (MCU) on diazoxide-induced cerebral protection is still indistinct. The purpose of the present paper is to further observe the relationship between mitoKATP and MCU, and to probe the mechanism. Adult male Wistar rats were randomly divided into five groups: the Sham group, the I-R group, the Dzx+I-R group, the Dzx+Sper+I-R group, and the Sper+I-R group. Rats not in the Sham group were exposed to 2-hour ischemia followed by 24-hour reperfusion. Diazoxide and spermine were administrated 30 minutes before ischemia or 10 minutes before reperfusion, respectively. After 24-hour reperfusion, animals were given neurological performance tests, overdosed with general anesthesia, and then their brains were excised for infarct volume, pathological changes, and apoptosis analysis. The beneficial effects of diazoxide (improved neurological deficits, decreased infarct volume, and apoptosis, evidenced by the decreased expression of cytochrome c and Bax) were significantly neutralized by spermine. The results of the present work suggest that diazoxide-induced cerebral protection against ischemia-reperfusion injury is mediated by spermine through apoptotic pathway.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain; Calcium Channels; Cytochromes c; Diazoxide; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Potassium Channels; Random Allocation; Rats, Wistar; Reperfusion Injury; Severity of Illness Index; Spermine

Apoptosis is one of the major mechanisms of neuronal injury during ischemic-reperfusion (I/R). Mitochondrial division inhibitor (mdivi-1) is a selective inhibitor of mitochondrial fission protein Drp1. The previous experiments support that mdivi-1 reduce I/R injury in the heart model of rat, but the neuroprotective effect of the mdivi-1 is not yet clearly defined at the cellular levels in brain. In our present study, we estimated a brain model of I/R injury in vitro by subjecting oxygen and glucose deprivation (OGD) followed by reoxygenation to the cultured rat primary hippocampal cells, which aimed to find the neuroprotective mechanism of mdivi-1. The cell was pretreated with mdivi-1 for 40 minutes and then ischemia for 6 hours followed by reperfusion for 20 hours. The redox state, cell apoptosis, and expression of Drp1, Bcl-2, Bax, and cytochrome C proteins were measured. The data showed that administration of mdivi-1 at the doses of 50 μM significantly reduced oxidative stress, attenuated cell apoptosis, upregulated Bcl-2 expression, and downregulated Drp1, Bax, and cytochrome C expression. The results suggested that mdivi-1 protected brain from OGD reperfusion injury, which through suppressing the ROS initiated mitochondrial pathway.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cells, Cultured; Cytochromes c; Dynamins; Hippocampus; Mitochondria; Neurons; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Quinazolinones; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

Intestinal ischemia-reperfusion (I/R) is a serious clinical dilemma with high morbidity and mortality. Remote organ damage, especially acute lung injury and liver injury are common complications that contribute to the high mortality rate. We previously demonstrated that activation of PKCβII is specifically involved in the primary injury of intestinal I/R. Considering the tissue-specific features of PKC activation, we hypothesized that some kind of PKC isoform may play important roles in the progression of secondary injury in the remote organ. Mice were studied in in vivo model of intestinal I/R. The activation of PKC isoforms were screened in the lung and liver. Interestingly, we found that PKCβII was also activated exclusively in the lung and liver after intestinal I/R. PKCβII suppression by a specific inhibitor, LY333531, significantly attenuated I/R-induced histologic damage, inflammatory cell infiltration, oxidative stress, and apoptosis in these organs, and also alleviated systemic inflammation. In addition, LY333531 markedly restrained p66shc activation, mitochondrial translocation, and binding to cytochrome-c. These resulted in the decrease of cytochrome-c release and caspase-3 cleavage, and an increase in glutathione and glutathione peroxidase. These data indicated that activated PKC isoform in the remote organ, specifically PKCβII, is the same as that in the intestine after intestinal I/R. PKCβII suppression protects against remote organ injury, which may be partially attributed to the p66shc-cytochrome-c axis. Combined with our previous study, the development of a specific inhibitor for prophylaxis against intestinal I/R is promising, to prevent multiple organ injury.

Topics: Animals; Apoptosis; Caspase 3; Cytochromes c; Glutathione; Indoles; Intestines; Liver; Lung; Male; Maleimides; Mice, Inbred ICR; Mitochondria; Protective Agents; Protein Kinase C beta; Protein Kinase Inhibitors; Reperfusion Injury; Shc Signaling Adaptor Proteins; Signal Transduction; Src Homology 2 Domain-Containing, Transforming Protein 1

Hydrogen, a popular antioxidant gas, can selectively reduce cytotoxic oxygen radicals and has been found to protect against ischemia-reperfusion (I/R) injury of multiple organs. Acute neuronal death during I/R has been attributed to loss of mitochondrial permeability transition coupled with mitochondrial dysfunction. This study was designed to investigate the potential therapeutic effect of hydrogen-rich saline on neuronal mitochondrial injury from global cerebral I/R in rats.. We used a four-vessel occlusion model of global cerebral ischemia and reperfusion, with Sprague-Dawley rats. The rats were divided randomly into six groups (n = 90): sham (group S), I/R (group I/R), normal saline (group NS), atractyloside (group A), hydrogen-rich saline (group H), and hydrogen-rich saline + atractyloside (group HA). In groups H and HA, intraperitoneal hydrogen-rich saline (5 mL/kg) was injected immediately after reperfusion, whereas the equal volume of NS was injected in the other four groups. In groups A and HA, atractyloside (15 μL) was intracerebroventricularly injected 10 min before reperfusion, whereas groups NS and H received equal NS. The mitochondrial permeability transition pore opening and mitochondrial membrane potential were measured by spectrophotometry. Cytochrome c protein expression in the mitochondria and cytoplasm was detected by western blot. The hippocampus mitochondria ultrastructure was examined with transmission electron microscope. The histologic damage in hippocampus was assessed by hematoxylin and eosin staining.. Hydrogen-rich saline treatment significantly improved the amount of surviving cells (P < 0.05). Furthermore, hydrogen-rich saline not only reduced tissue damage, the degree of mitochondrial swelling, and the loss of mitochondrial membrane potential but also preserved the mitochondrial cytochrome c content (P < 0.05).. Our study showed that hydrogen-rich saline was able to attenuate neuronal I/R injury, probably by protecting mitochondrial function in rats.

Topics: Animals; Antioxidants; Apoptosis; Brain Ischemia; Calcium; Cell Survival; Cytochromes c; Hydrogen; Infusions, Intraventricular; Male; Membrane Potential, Mitochondrial; Microscopy, Electron, Transmission; Mitochondria; Neurons; Neuroprotective Agents; Random Allocation; Rats, Sprague-Dawley; Reperfusion Injury; Sodium Chloride

To investigate the changes of platelet mitochondria in rats with tourniquet-induced limb ischemia-reperfusion (IR) injury.. Thirty SD rats were randomized equally into 5 groups including a control group and 4 limb IR injury groups for blood sampling at 2, 6, 12, or 24 h following IR injury induced by tourniquet on the thighs for 4 h. Platelet was separated from the blood samples for measurement of ATP content, mitochondrial membrane potentials, plasma cytochrome C level, and hydroperoxides.. Compared with the control group, the rats with tourniquet-induced limb IR injury showed significantly decreased ATP content, lowered mitochondrial membrane potential, and increased plasma cytochrome C and hydroperoxide levels in the platelets at 2 and 6 h following the injury (P<0.05 or 0.01). These alterations recovered partially but remained significantly different from the control levels at 12 h (P<0.05 or 0.01) until full recovery at 24 h. Limb IR injury did not cause significant variations of the platelet counts.. Tourniquet-induced limb IR injury can cause mitochondrial damage in the platelets, which occurs mainly in the early stage (6 h) and recovers gradually afterwards without significant impact on platelet counts.

Topics: Adenosine Triphosphate; Animals; Blood Platelets; Cytochromes c; Hydrogen Peroxide; Membrane Potential, Mitochondrial; Mitochondria; Platelet Count; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tourniquets

Opening of the mitochondrial permeability transition pore (mPTP) is a critical event during ischemia/reperfusion (I/R) injury. Recently, we showed that Panax quinquefolium saponin (PQS) alleviates apoptosis of cardiomyocytes by suppressing excessive endoplasmic reticulum stress (ERS) during I/R injury. Here, we hypothesized that this anti-apoptotic effect might be mediated through inhibition of mPTP and the mitochondrial apoptotic pathway.. Ninety-six healthy male Sprague-Dawley rats were randomly divided into sham, I/R, I/R+PQS (200 mg/kg/d), Cyclosporine A (CsA, 10 mg/kg), I/R+CsA (10 mg/kg), and I/R+PQS+CsA. I/R was modeled in rats by ligating the left anterior descending artery (LAD) for 30 min followed by 120 min of reperfusion. To evaluate the cardioprotective function of PQS, we measured hemodynamics, serum content of creatine kinase-MB (CK-MB), myocardial infarct size, and myocardial apoptotic index (AI). We investigated the underlying mechanism by examining changes in the mitochondrial ultrastructure and membrane potential (ΔΨm), dynamics of mPTP opening, expression of cleaved caspase-3, cleaved caspase-9 in the myocardium, Bcl-2 and Bax in the mitochondria versus cytosol, and translocation of cytochrome c.. Administration of PQS to I/R rats significantly reduced serum CK-MB level, infarct size and AI. In addition, PQS protected the mitochondrial structure, markedly inhibited mPTP opening and ΔΨm depolarization, led to upregulation of Bcl-2 and downregulation of Bax in the mitochondria compared to the cytosol, and suppressed the expression of cleaved caspase-9 and cleaved caspase-3, as well as I/R induced translocation of cytochrome c to the cytoplasm.. Our results show that PQS can alleviate apoptosis of cardiomyocytes during I/R injury, possibly due to repressed mitochondrial apoptotic pathway associated with the opening of mPTP induced by myocardial I/R injury.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspase 9; Cyclosporine; Cytochromes c; Cytosol; Endoplasmic Reticulum Stress; Male; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardial Reperfusion Injury; Myocytes, Cardiac; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Saponins

The aim of this study was to investigate the influence of atorvastatin on the opening of the mitochondrial permeability transition pore (MPTP) and the expression of cytochrome C (Cyt C) in Sprague-Dawley rats with cerebral ischemia-reperfusion (I/R). The rat model of cerebral artery ischemia was established by the suture-occluded method with ischemia for 2 h and reperfusion for 72 h. Thirty-four male rats were randomly divided into four groups: the normal group and the sham-operation group without any treatment, the I/R group with only intragastric administration of normal saline, and the intervention group, which received intragastric administration of 10 mg/kg atorvastatin at different times. All rats were sacrificed at 72 h. Compared with the I/R group, the morphology of nerve cells in the intervention group was reduced, the number of TUNEL-positive cells decreased, the expression of cortical cytoplasm Cyt C decreased, and the mitochondrial absorbance value increased. All of these differences were statistically significant. Atorvastatin could inhibit neuronal apoptosis and alleviate the cerebral I/R injury. The mechanism may be related to the blocking of the MPTP opening and the subsequent reduction of Cyt C release.

Topics: Animals; Anticholesteremic Agents; Apoptosis; Atorvastatin; Brain Ischemia; Cytochromes c; Disease Models, Animal; Heptanoic Acids; Infarction, Middle Cerebral Artery; Male; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Pyrroles; Rats, Sprague-Dawley; Reperfusion Injury

Ischemia reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI) in both native and transplanted kidneys. The objective of the present study was to evaluate whether low-molecular-weight fucoidan (LMWF) could attenuate renal IRI in an animal model and in vitro cell models and study the mechanisms in which LMWF protected from IRI.. Male mice were subjected to right renal ischemia for 30 min and reperfusion for 24 h, or to a sham operation with left kidney removed. Kidneys undergone IR showed characteristic morphological changes, such as tubular dilatation, and brush border loss. However, LMWF significantly corrected the renal dysfunction and the abnormal levels of MPO, MDA and SOD induced by IR. LMWF also inhibited the activation of MAPK pathways, which consequently resulted in a significant decrease in the release of cytochrome c from mitochondria, ratios of Bax/Bcl-2 and cleaved caspase-3/caspase-3, and phosphorylation of p53. LMWF alleviated hypoxia-reoxygenation or CoCl(2) induced cell viability loss and ΔΨm dissipation in HK2 renal tubular epithelial cells, which indicates LMWF may result in an inhibition of the apoptosis pathway through reducing activity of MAPK pathways in a dose-dependent manner.. Our in vivo and in vitro studies show that LMWF ameliorates acute renal IRI via inhibiting MAPK signaling pathways. The data provide evidence that LMWF may serve as a potential therapeutic agent for acute renal IRI.

Topics: Acute Kidney Injury; Animals; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Caspase 3; Cell Line; Cell Survival; Cobalt; Cytochromes c; Humans; Male; Malondialdehyde; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Mice; Mice, Inbred C57BL; Molecular Weight; Peroxidase; Phosphorylation; Polysaccharides; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; Superoxide Dismutase; Tumor Suppressor Protein p53

Hepatocellular apoptosis commonly occurs in ischemia/reperfusion (I/R) injury. The binding of tumor necrosis factor (TNF) to TNF receptor 1 (TNFR1) leads to the formation of a death-inducing signaling complex (DISC), which subsequently initiates a caspase cascade resulting in apoptosis. Heme oxygenase 1 (HO-1) confers cytoprotection against cell death in I/R injury and inhibits stress-induced apoptotic pathways in vitro. This study investigated the role of HO-1 in modulating TNF/TNFR1-mediated cell death pathways in hepatic I/R injury. Rats were pretreated with hemin, an HO-1 inducer, and zinc protoporphyrin (ZnPP), an HO-1 inhibitor, before undergoing hepatic I/R. Heme oxygenase 1 activity increased after reperfusion. Ischemia/reperfusion-induced hepatocellular apoptosis was attenuated by hemin, as determined by the caspase-3 and -8 activity assays and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling). Zinc protoporphyrin eliminated the cytoprotective effect of hemin. Hepatic TNFR1 protein expression was unchanged among the experimental groups, whereas mitochondrial TNFR1 protein increased after I/R. Ischemia/reperfusion increased the quantity of DISC components, including TRADD (TNFR1-associated death domain), FADD (Fas-associated death domain), and caspase-8, as well as the assembly of DISCs within the liver. In the mitochondrial fraction, TNFR1-associated caspase-8 was increased after I/R. These increases were attenuated by hemin; zinc protoporphyrin eliminated this effect. Our findings suggest that the cytoprotective effects of HO-1 are mediated by suppression of TNF/TNFR1-mediated apoptotic signaling, specifically by modulating apoptotic DISC formation and mitochondrial TNFR1 translocation during hepatic I/R.

Topics: Alanine Transaminase; Animals; Apoptosis; Bilirubin; Caspase 1; Caspase 8; Cytochromes c; Enzyme Inhibitors; Heme Oxygenase-1; Liver; Male; Mitochondria, Liver; Mitochondrial Swelling; Protoporphyrins; Rats; Rats, Sprague-Dawley; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Reperfusion Injury; Tumor Necrosis Factor-alpha

Ischemic postconditioning (IPoC) modulates the reperfusion maneuver to mitigate ischemia-reperfusion (I/R) injury. This study aims to investigate the effects and protective mechanism of IPoC on intestinal I/R injury.. Intestinal I/R was induced by occluding the superior mesenteric artery for 30 min followed by reperfusion for 60 min on male Wistar rats. IPoC was elicited by three cycles of 30-sec reperfusion and reocclusion of superior mesenteric artery at the initiation of reperfusion. Carboxyatractyloside (CATR), a mitochondrial permeability transition pore (mPTP) opener, and N-methyl-4-isoleucine cyclosporine (NIM811), an mPTP inhibitor, were administered separately in selected groups. The serum and intestinal sections were collected for analysis.. IPoC and the administration of NIM811 significantly diminished the expression of intestinal-type fatty acid-binding protein and lactate dehydrogenase (3427±236.8 U/L for I/R, 1190.5±36.7 U/L for IPoC, 1399.3±295.6 U/L for I/R+NIM811, and 2002±370.9 IU/L for IPoC+CATR) in portal blood, the release of cytosolic cytochrome c, and the cleaved caspase 9 expression in intestinal mucosa after intestinal I/R injury (P<0.05). Histopathologically, IPoC and NIM811 mitigated mucosal damage after I/R as well (Chiu's score, 3.8±0.4 for I/R, 0.2±0.2 for IPoC, 0.4±0.2 for I/R+NIM811, and 4.2±0.2 for IPoC+CATR; apoptotic index, 59.5%±4.6% for I/R, 15.7%±15.7% for I/R+IPoC, 3.5%±3.5% for I/R+NIM811, and 67.1%±9.3% in IPoC+CATR). CATR negated the protection conferred by IPoC.. IPoC and NIM811 attenuate intestinal I/R injury. The addition of CATR negated the effects of IPoC, indicating that the protective mechanism of IPoC was associated with the modulation of mPTP opening.

Topics: Animals; Apoptosis; Atractyloside; Caspase 3; Cyclosporine; Cytochromes c; Disease Models, Animal; Enzyme Activation; Fatty Acid-Binding Proteins; Intestinal Mucosa; Intestine, Small; Ischemic Postconditioning; L-Lactate Dehydrogenase; Ligation; Male; Malondialdehyde; Mesenteric Artery, Superior; Mesenteric Vascular Occlusion; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Bax and Bak, two pro-apoptotic Bcl-2 family proteins, have been implicated in acute kidney injury following renal ischemia/reperfusion; however, definitive evidence for a role of these genes in the disease process is lacking. Here we first examined two Bax-deficient mouse models and found that only conditional Bax deletion specifically from proximal tubules could ameliorate ischemic acute kidney injury. Global (whole mouse) knockout of Bax enhanced neutrophil infiltration without significant effect on kidney injury. In contrast, global knockout of Bak protected mice from ischemic acute kidney injury with improved renal function. Interestingly, in these models, Bax or Bak knockout attenuated renal tubular cell apoptosis without significantly affecting necrotic tubular damage. Cytochrome c release in ischemic acute kidney injury was also suppressed in conditional Bax- or global Bak-knockout mice. In addition, Bak deficiency prevented mitochondrial fragmentation in ischemic acute kidney injury. Thus, our gene-knockout studies support a critical role of Bax and Bak in tubular cell apoptosis in ischemic acute kidney. Furthermore, necrosis and apoptosis have distinguishable regulatory functions.

Topics: Acute Kidney Injury; Animals; Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Cytochromes c; Disease Models, Animal; Kidney Tubules, Proximal; Male; Mice; Mice, 129 Strain; Mice, Inbred BALB C; Mice, Inbred C57BL; Mice, Knockout; Mitochondria; Necrosis; Neutrophil Infiltration; Reperfusion Injury

Nelfinavir (NLF), an antiretroviral agent, preserves mitochondrial membranes integrity and protects mature brain against ischemic injury in rodents. Our study demonstrates that in neonatal mice NLF significantly limits mitochondrial calcium influx, the event associated with protection of the brain against hypoxic-ischemic insult (HI). Compared to the vehicle-treated mice, cerebral mitochondria from NLF-treated mice exhibited a significantly greater tolerance to the Ca(2+)-induced membrane permeabilization, greater ADP-phosphorylating activity and reduced cytochrome C release during reperfusion. Pre-treatment with NLF or Ruthenium red (RuR) significantly improved viability of murine hippocampal HT-22 cells, reduced Ca(2+) content and preserved membrane potential (Ψm) in mitochondria following oxygen-glucose deprivation (OGD). Following histamine-stimulated Ca(2+) release from endoplasmic reticulum, in contrast to the vehicle-treated cells, the cells treated with NLF or RuR also demonstrated reduced Ca(2+) content in their mitochondria, the event associated with preserved Ψm. Because RuR inhibits mitochondrial Ca(2+) uniporter, we tested whether the NLF acts via the mechanism similar to the RuR. However, in contrast to the RuR, in the experiment with direct interaction of these agents with mitochondria isolated from naïve mice, the NLF did not alter mitochondrial Ca(2+) influx, and did not prevent Ca(2+) induced collapse of the Ψm. These data strongly argues against interaction of NLF and mitochondrial Ca(2+) uniporter. Although the exact mechanism remains unclear, our study is the first to show that NLF inhibits intramitochondrial Ca(2+) flux and protects developing brain against HI-reperfusion injury. This novel action of NLF has important clinical implication, because it targets a fundamental mechanism of post-ischemic cell death: intramitochondrial Ca(2+) overload → mitochondrial membrane permeabilization → secondary energy failure.

Topics: Animals; Animals, Newborn; Brain; Calcium; Calcium Channels; Cytochromes c; Hypoxia-Ischemia, Brain; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Nelfinavir; Phosphorylation; Reperfusion Injury; Ruthenium Red

Cerebral ischemia-reperfusion (I-R) is a complex pathological process. Although autophagy can be evoked by ischemia, its involvement in the reperfusion phase after ischemia and its contribution to the fate of neurons remains largely unknown. In the present investigation, we found that autophagy was activated in the reperfusion phase, as revealed in both mice with middle cerebral artery occlusion and oxygen-glucose deprived cortical neurons in culture. Interestingly, in contrast to that in permanent ischemia, inhibition of autophagy (by 3-methyladenine, bafilomycin A 1, Atg7 knockdown or in atg5(-/-) MEF cells) in the reperfusion phase reinforced, rather than reduced, the brain and cell injury induced by I-R. Inhibition of autophagy either with 3-methyladenine or Atg7 knockdown enhanced the I-R-induced release of cytochrome c and the downstream activation of apoptosis. Moreover, MitoTracker Red-labeled neuronal mitochondria increasingly overlapped with GFP-LC3-labeled autophagosomes during reperfusion, suggesting the presence of mitophagy. The mitochondrial clearance in I-R was reversed by 3-methyladenine and Atg7 silencing, further suggesting that mitophagy underlies the neuroprotection by autophagy. In support, administration of the mitophagy inhibitor mdivi-1 in the reperfusion phase aggravated the ischemia-induced neuronal injury both in vivo and in vitro. PARK2 translocated to mitochondria during reperfusion and Park2 knockdown aggravated ischemia-induced neuronal cell death. In conclusion, the results indicated that autophagy plays different roles in cerebral ischemia and subsequent reperfusion. The protective role of autophagy during reperfusion may be attributable to mitophagy-related mitochondrial clearance and inhibition of downstream apoptosis. PARK2 may be involved in the mitophagy process.

Topics: Adenine; Animals; Apoptosis; Autophagy; Autophagy-Related Protein 5; Autophagy-Related Protein 7; Brain Ischemia; Cytochromes c; Cytoprotection; Glucose; Hypoxia; Male; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Mitochondria; Mitophagy; Neurons; Quinazolinones; Rats; Reperfusion Injury; Ubiquitin-Protein Ligases

It is well known that cardiomyocyte apoptosis contributes to ischemic heart damage. There is also increasing evidence that the polyphenolic compounds of natural origin, such as anthocyanins, may attenuate ischemia/reperfusion injury though the mechanisms of such protection are not clear. Following our previous studies showing the effect of certain anthocyanins on cytochrome c redox state, mitochondrial functions, and ischemia-induced caspase activation in the heart, here we investigated whether these anthocyanins can rescue cardiac cells from death by the mechanism involving the reduction of cytosolic cytochrome c.. Before global ischemia and reperfusion, isolated rat hearts were preloaded with cyanidin-3-O-glucoside (Cy3G) that has high cytochrome c-reducing capacity or pelargonidin-3-O-glucoside (Pg3G) that possesses low reducing activity. Cell death was evaluated assessing apoptosis by the TUNEL method or necrosis measuring the release of lactate dehydrogenase into perfusate.. The perfusion of hearts with 20-μM Cy3G prevented ischemia/reperfusion-induced apoptosis of cardiomyocytes: the number of TUNEL-positive myocytes was decreased by 73% if compared with the untreated ischemic group. The same effect was observed measuring the activity of lactate dehydrogenase as the measure of necrosis: perfusion with 20-μM Cy3G reduced the level of LDH release into the perfusate to the control level. The perfusion of hearts with 20-μM Pg3G did not prevent ischemia/reperfusion-induced apoptosis as well as necrosis.. Cy3G protected the rat heart from ischemia/reperfusion-induced apoptosis and necrosis; meanwhile, Pg3G did not exert any protective effect. The protective effect of Cy3G may be related due to its high capacity to reduce cytosolic cytochrome c.

Topics: Animals; Anthocyanins; Apoptosis; Cytochromes c; Cytoprotection; Glucosides; Male; Myocardial Ischemia; Myocytes, Cardiac; Necrosis; Rats; Rats, Wistar; Reperfusion Injury

Hydrogen sulfide (H2S) is the third most common endogenously produced gaseous signaling molecule, but its impact on hepatic ischemia/reperfusion (I/R) injury, especially on mitochondrial function, remains unclear. In this study, rats were randomized into Sham, I/R, ischemia preconditioning (IPC) or sodium hydrosulfide (NaHS, an H2S donor) preconditioning groups. To establish a model of segmental (70%) warm hepatic ischemia, the hepatic artery, left portal vein and median liver lobes were occluded for 60 min and then unclamped to allow reperfusion. Preconditioning with 12.5, 25 or 50 μmol/kg NaHS prior to the I/R insult significantly increased serum H2S levels, and, similar to IPC, NaHS preconditioning decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in the plasma and prevented hepatocytes from undergoing I/R-induced necrosis. Moreover, a sub-toxic dose of NaHS (25 μmol/kg) did not disrupt the systemic hemodynamics but dramatically inhibited mitochondrial permeability transition pore (MPTP) opening and thus prevented mitochondrial-related cell death and apoptosis. Mechanistic studies revealed that NaHS preconditioning markedly increased the expression of phosphorylated protein kinase B (p-Akt), phosphorylated glycogen synthase kinase-3 beta (p-GSK-3β) and B-cell lymphoma-2 (Bcl-2) and decreased the release of mitochondrial cytochrome c and cleaved caspase-3/9 levels. Therefore, NaHS administration prior to hepatic I/R ameliorates mitochondrial and hepatocellular damage through the inhibition of MPTP opening and the activation of Akt-GSK-3β signaling. Furthermore, this study provides experimental evidence for the clinical use of H2S to reduce liver damage after perioperative I/R injury.

Topics: Animals; Apoptosis; Aspartate Aminotransferases; Calcium; Caspase 3; Caspase 9; Cytochromes c; Enzyme Activation; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hemodynamics; Hydrogen Sulfide; Ischemic Preconditioning; Liver; Male; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Protective Agents; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

Previous studies have indicated that bone morphogenetic protein-7 (BMP-7) is neuroprotective against cerebral ischemia/reperfusion (IR) injury. The present study was undertaken to determine the molecular mechanisms involved in this effect. Adult male Wistar rats were subjected to 2 h of transient middle cerebral artery occlusion (MCAO), followed by 24 h of reperfusion. BMP-7 (10-4 g/kg) or vehicle was infused into rats at the onset of reperfusion via the tail vein. Neurological deficits, infarct volume, histopathological changes, oxidative stress-related biochemical parameters, neuronal apoptosis, and apoptosis-related proteins were assessed. BMP-7 significantly improved neurological and histological deficits, reduced the infarct volume, and decreased apoptotic cells after cerebral ischemia. BMP-7 also markedly enhanced the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and reduced the level of malondialdehyde (MDA) in IR rats. In addition, Western blot analysis indicated that BMP-7 prevented cytochrome c release, inhibited activation of caspase-3, caspase-9 and caspase-8. Our data suggested that BMP-7 has protective effects against cerebral IR injury in rats, and the neuroprotective effects may be attributed to attenuating oxidative stress and inhibiting neuronal apoptosis.

Topics: Animals; Apoptosis; Bone Morphogenetic Protein 7; Brain Ischemia; Caspase 3; Caspase 8; Caspase 9; Cytochromes c; Glutathione Peroxidase; Male; Malondialdehyde; Neurons; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury; Superoxide Dismutase

Mitochondrial division inhibitor (mdivi-1) is a derivative of quinazolinone that acts as a selective inhibitor of a mitochondrial fission protein Drp1. A previous study demonstrated that as a selective inhibitor of Drp1, mdivi-1 has a protective effect in an experimental model of heart ischemia/reperfusion injury. In this study, we investigated the protective effects of mdivi-1 on cerebral ischemia/reperfusion injury in a middle cerebral artery occlusion mouse model. We found that mdivi-1 (1.2mg/kg) significantly reduced cerebral damage induced by ischemia/reperfusion. This neuroprotective effect was dose-dependent. Mdivi-1 treatment blocked apoptotic cell death in cerebral ischemia/reperfusion injury, and significantly decreased the expression of Drp1 and Cytochrome C. These results suggest that mdivi-1 exerts neuroprotective effects against nerve injury after cerebral ischemia/reperfusion, and the underlying mechanism may be through the prevention of Cytochrome C release and suppression of the mitochondrial apoptosis pathway.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Cytochromes c; Dynamins; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Quinazolinones; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger

Chronic nicotine (Ch-NIC) exposure exacerbates ischemia/reperfusion (I/R)-induced oxidative stress and acute kidney injury (AKI), and mitochondrial production of reactive oxygen species (ROS) in cultured renal proximal tubule cells (RPTCs). Because Ser36-phosphorylated p66shc modulates mitochondrial ROS production and injury of RPTCs, we hypothesized that Ch-NIC exacerbates AKI by increasing stress-induced phosphorylation of p66shc.. We first tested whether Ch-NIC augments I/R-AKI-induced expression and phosphorylation of p66shc in vivo. We then examined whether knocking down p66shc, or impairing its Ser36 phosphorylation or binding to cytochrome c, alters the effects of Ch-NIC on oxidative stress (H₂O₂)-induced production of ROS, mitochondrial depolarization and injury in RPTCs in vitro.. We found that Ch-NIC increased the expression of p66shc in the control and ischemic kidneys, but only increased its Ser36 phosphorylation after renal I/R. Knocking down p66shc or impairing phosphorylation of its Ser36 residue, via the S36A mutation (but not the phosphomimetic S36D mutation), blunted Ch-NIC + H2O2-dependent ROS production, mitochondrial depolarization and injury in RPTCs. Additionally, Ch-NIC + H2O2-dependent binding of p66shc to mitochondrial cytochrome c was attenuated by S36A mutation of p66shc, and impairing cytochrome c binding (via W134F mutation) abolished ROS production, mitochondrial depolarization and injury, while ectopic overexpression of p66shc (which mimics Ch-NIC treatment) augmented oxidant injury. We determined that Ch-NIC stimulates the p66shc promoter through p53- and epigenetic modification (promoter hypomethylation).. Ch-NIC worsens oxidative stress-dependent acute renal injury by increasing expression and consequent oxidative stress-dependent Ser36 phosphorylation of p66shc. Thus, targeting this pathway may have therapeutic relevance in preventing/ameliorating tobacco-related kidney injury.

Topics: Acute Kidney Injury; Animals; Blotting, Western; Cells, Cultured; Cytochromes c; Hydrogen Peroxide; Immunoprecipitation; Kidney Tubules, Proximal; Luciferases; Male; Mice; Mice, Inbred C57BL; Mitochondria; Nicotine; Nicotinic Agonists; Oxidative Phosphorylation; Oxidative Stress; Phosphorylation; Promoter Regions, Genetic; Reactive Oxygen Species; Reperfusion Injury; Serine; Shc Signaling Adaptor Proteins; Src Homology 2 Domain-Containing, Transforming Protein 1; Transcriptional Activation

A recent study showed that the injection of mitochondria isolated from a nonischemic region mitigated myocardial injury. We tested the protective effects of infusing isolated mitochondria on the reperfusion injury in the liver of rats. A partial liver ischemia-reperfusion (I/R) model in male Wistar rats was used. At the 45th minute of liver ischemia, the recipient's spleen was infused with vehicle (I/R-vehicle group) or vehicle containing isolated mitochondria (7.7 × 10 ± 1.5 × 10/mL, I/R-mito group). After a 240-min reperfusion, the serum and livers were collected to assess tissue injury. Our results show that the elevation of serum alanine aminotransferase (414.3 ± 67.1 vs. 208.8 ± 30.2 U/L), the necrosis of hepatocytes on hematoxylin-eosin staining, increase in positive counts in TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining (59.5% ± 4.4% vs. 24.6% ± 9.1%), the expression of cytosolic cytochrome c, cleaved caspase 9, and 4-hydroxynonenal were all reduced in the I/R-mito group, compared with the I/R-vehicle group. The membrane potential of the isolated mitochondria measured by JC-1 fluorescence remained high, and the infused mitochondria were distributed in the liver parenchyma at 240 min after reperfusion. These results demonstrate that an intrasplenic infusion of viable mitochondria isolated from the donor before reperfusion significantly reduced I/R injury in the liver.

Topics: Alanine Transaminase; Animals; Apoptosis; Caspase 9; Cytochromes c; Hepatocytes; Liver; Male; Mitochondria, Liver; Necrosis; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury; Spleen

Reduced glutathione (GSH) has been shown to improve pulmonary graft preservation. Mitochondrial dysfunction is regarded to be the motor of ischemia-reperfusion injury (IR) in solid organs. We have shown previously that IR induces pulmonary mitochondrial damage. This study elucidates the impact of GSH preconditioning on the integrity and function of pulmonary mitochondria in the setting of warm pulmonary IR.. Wistar rats were subjected to control, sham, and to two-study-group conditions (IR30/60 and GSH-IR30/60) receiving IR with or without GSH preconditioning. Rats were anesthetized and received mechanical ventilation. Pulmonary in situ clamping followed by reperfusion generated IR. Mitochondria were isolated from pulmonary tissue. Respiratory chain complexes activities (I-IV) were analyzed by polarography. Mitochondrial viability (Ca2+-induced swelling) and membrane integrity (citrate synthase assay) were determined. Subcellular-fractional cytochrome C-content (Cyt C) was quantified by enzyme-linked immunosorbent assay (ELISA). Mitochondrial membrane potential (ΔΨm) was analyzed by fluorescence-activated cell sorting (FACS) after energizing and uncoupling. Inflammatory activation was determined by myeloperoxidase activity (MPO), matrix-metalloproteinase 9 (MMP-9) activity by gel zymography.. Pulmonary IR significantly reduced mitochondrial viability in combination with ΔΨm hyper-polarization. GSH preconditioning improved mitochondrial viability and normalized ΔΨm. Cyt C was reduced after IR; GSH protected from Cyt C liberation. Respiratory chain complex activities (I, II, III) declined during IR; GSH protected complex II function. GSH also protected from MMP-9 and neutrophil sequestration (P>.05).. GSH preconditioning is effective to prevent mitochondrial death and improves complex II function during IR, but not mitochondrial membrane stability. GSH-mediated amelioration of ΔΨm hyper-polarization appears to be the key factor of mitochondrial protection.

Topics: Animals; Apoptosis; Calcium; Cytochromes c; Disease Models, Animal; Drug Evaluation, Preclinical; Electron Transport; Glutathione; Granulocytes; Ischemic Preconditioning; Lung; Matrix Metalloproteinase 9; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Diseases; Oxygen Consumption; Pulmonary Edema; Rats; Rats, Wistar; Reperfusion Injury

The objectives of this study were to determine whether neutrophil depletion with anti-neutrophil serum (ANS) or preconditioning with the hydrogen sulfide (H(2)S) donor NaHS (NaHS-PC) 24 h prior to ischemia-reperfusion (I/R) would prevent postischemic mitochondrial dysfunction in rat intestinal mucosa and, if so, whether calcium-activated, large conductance potassium (BK(Ca)) channels were involved in this protective effect. I/R was induced by 45-min occlusion of the superior mesenteric artery followed by 60-min reperfusion in rats preconditioned with NaHS (NaHS-PC) or a BK(Ca) channel activator (NS-1619-PC) 24 h earlier or treated with ANS. Mitochondrial function was assessed by measuring mitochondrial membrane potential, mitochondrial dehydrogenase function, and cytochrome c release. Mucosal myeloperoxidase (MPO) and TNF-α levels were also determined, as measures of postischemic inflammation. BK(Ca) expression in intestinal mucosa was detected by immunohistochemistry and Western blotting. I/R induced mitochondrial dysfunction and increased tissue MPO and TNF-α levels. Although mitochondrial dysfunction was attenuated by NaHS-PC or NS-1619-PC, the postischemic increases in mucosal MPO and TNF-α levels were not. The protective effect of NaHS-PC or NS-1619-PC on postischemic mitochondrial function was abolished by coincident treatment with BK(Ca) channel inhibitors. ANS prevented the I/R-induced increase in tissue MPO levels and reversed mitochondrial dysfunction. These data indicate that neutrophils play an essential role in I/R-induced mucosal mitochondrial dysfunction. In addition, NaHS-PC prevents postischemic mitochondrial dysfunction (but not inflammation) by a BK(Ca) channel-dependent mechanism.

Topics: Animals; Benzimidazoles; Cytochromes c; Hydrogen Sulfide; Intestinal Diseases; Intestine, Small; Ischemic Preconditioning; Leukocyte Reduction Procedures; Male; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Diseases; Neutrophils; Peroxidase; Potassium Channels, Calcium-Activated; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfides; Tumor Necrosis Factor-alpha

The aim of this study was to investigate the effect of 17β-estradiol (E2) on hepatocyte apoptosis after reduced-size hepatic ischemia/reperfusion (I/R) injury and its mechanism. A rat model of reduced-size hepatic I/R injury was established. Sprague-Dawley rats were randomly allocated into sham, I/R, and E2 + I/R group. 17β-Estradiol (4 mg/kg) or the vehicle was administered i.p. 1 h before ischemia and immediately after operation. For each group, 10 rats were used to investigate the survival during a week after reperfusion. Blood samples and liver tissues were obtained in the remaining animals after 3, 6, 12, and 24 h of reperfusion to assess serum aspartate aminotransferase and alanine aminotransferase levels, liver tissue malondialdehyde concentration, superoxide dismutase activity, and histopathologic changes. Apoptosis ratio; expression of cytochrome c, Bcl-2, and Bax proteins; and enzymatic activities of caspase 9 and caspase 3 were performed in the samples at 12 h after reperfusion. The serum aspartate aminotransferase and alanine aminotransferase levels and tissue malondialdehyde concentration were increased in the I/R group, whereas the increase was significantly reduced by E2. The superoxide dismutase activity, depressed by I/R injury, was elevated back to normal levels by treatment with E2. Severe hepatic damage was observed by light microscopy in the I/R group, whereas administration of E2 resulted in tissue and cellular preservation. Furthermore, E2 inhibited hepatocellular apoptosis by upregulating the ratio of Bcl-2 and Bax expression, reduced cytosolic cytochrome c level, and decreased caspase 9 and caspase 3 activities. The 7-day survival rate was significantly higher in the E2 + I/R group than in the I/R group. These results indicated that E2 protects liver tissues from reduced-size hepatic I/R injury by suppressing mitochondrial apoptotic pathways.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Cytochromes c; Cytosol; Estradiol; Ischemia; Liver; Male; Malondialdehyde; Mitochondria; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors; Transaminases

Retinal ischemia plays a central role in several retinal diseases. The pathogenesis of retinal ischemia involves changes in gene expression. Valproic acid (VPA), a broad-spectrum histone deacetylase inhibitor, is an anticonvulsant and mood-stabilizing drug with neuroprotective effects. Here, we investigated whether VPA protects the retina and optic nerve axon from ischemic damage in a rat model and determined a possible protective mechanism. Adult male Wistar rats were randomized into sham, ischemia/reperfusion (I/R)-plus-vehicle, and I/R-plus-VPA groups. Rats received subcutaneous injections of 300 mg/kg VPA or phosphate-buffered saline twice a day after retinal ischemia induced by acute high intraocular pressure. Twenty-four hours after I/R, retinal neuron apoptosis was evaluated using the TUNEL assay. The expression of heat-shock protein 70 (Hsp70), activated-caspase-3, and apoptotic-protease-activating factor-1 (apaf-1), acetylation levels of histone H3, release of cytochrome c, and interaction between Hsp70 and apaf-1 were analyzed by immunoblotting analysis in all groups; the transcriptional activation of the Hsp70 gene and interaction between the Hsp70 promoter with p300 or HDAC1 were analyzed using chromatin immunoprecipitation assay. Seven days after I/R, the histological changes in the retina were evaluated using hematoxylin and eosin staining, and optic nerve axon damage was evaluated using toluidine blue staining and transmission electron microscopy. The density of retinal ganglion cells (RGCs) was analyzed using Fluoro-Gold retrograde labeling at 7, 14, 21 days after I/R. VPA markedly attenuated I/R-induced retinal neuron apoptosis, damage to RGCs, and morphological injury to the retina and optic nerve axons. VPA resulted in the upregulation of Hsp70 and hyperacetylation of histone H3, accompanied by Hsp70 promoter hyperacetylation, which may result from increased p300 recruitment to the Hsp70 promoter. Furthermore, VPA increased the binding between Hsp70 and apaf-1 to block apoptosome formation and reduced the release of cytochrome c and activation of caspase-3 in the retina after I/R. Therefore, VPA-mediated neuroprotection against I/R injury in the retina may involve cytoprotective Hsp70 induction via transcriptional activation and inhibition of the mitochondria-mediated apoptosis pathway.

Topics: Acetylation; Animals; Apoptosis; Apoptotic Protease-Activating Factor 1; Axons; Caspase 3; Cytochromes c; Histone Deacetylase Inhibitors; Histone Deacetylases; Histones; HSP70 Heat-Shock Proteins; In Situ Nick-End Labeling; Injections, Subcutaneous; Male; Neuroprotective Agents; Rats; Rats, Wistar; Reperfusion Injury; Retinal Diseases; Retinal Ganglion Cells; Transcriptional Activation; Valproic Acid

Activation of the NADPH oxidase subunit, NOX2, and increased oxidative stress are associated with neuronal death after cerebral ischemia and reperfusion. Inhibition of NOX2 by casein kinase 2 (CK2) leads to neuronal survival, but the mechanism is unknown. In this study, we show that in copper/zinc-superoxide dismutase transgenic (SOD1 Tg) mice, degradation of CK2α and CK2α' and dephosphorylation of CK2β against oxidative stress were markedly reduced compared with wild-type (WT) mice that underwent middle cerebral artery occlusion. Inhibition of CK2 pharmacologically or by ischemic reperfusion facilitated accumulation of poly(ADP-ribose) polymers, the translocation of apoptosis-inducing factor (AIF), and cytochrome c release from mitochondria after ischemic injury. The eventual enhancement of CK2 inhibition under ischemic injury strongly increased 8-hydroxy-2'-deoxyguanosine and phosphorylation of H2A.X. Furthermore, CK2 inhibition by tetrabromocinnamic acid (TBCA) in SOD1 Tg and gp91 knockout (KO) mice after ischemia reperfusion induced less release of AIF and cytochrome c than in TBCA-treated WT mice. Inhibition of CK2 in gp91 KO mice subjected to ischemia reperfusion did not increase brain infarction compared with TBCA-treated WT mice. These results strongly suggest that NOX2 activation releases reactive oxygen species after CK2 inhibition, triggering release of apoptogenic factors from mitochondria and inducing DNA damage after ischemic brain injury.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis Inducing Factor; Brain Infarction; Casein Kinase II; Cell Death; Cells, Cultured; Cinnamates; Cytochromes c; Deoxyguanine Nucleotides; DNA Damage; Enzyme Activation; Female; Histones; Male; Membrane Glycoproteins; Mice; Mice, Knockout; Mitochondria; NADPH Oxidase 2; NADPH Oxidases; Nerve Tissue Proteins; Phosphorylation; Reperfusion Injury; Superoxide Dismutase; Superoxide Dismutase-1

We tested the effectiveness of ischemic postconditioning (iPoC) in mitigating ischemia-reperfusion (I/R) injury of liver and the mechanism involves inhibiting the opening of the mitochondrial permeability transition pore (mPTP).. iPoC, performed by three cycles of 1 min I/R of the liver, was tested on a partial liver I/R model on rats. The serum alanine transaminase levels, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, cytochrome c release, the formation of 4-hydroxy-2-nonnenal-modified proteins, and mitochondrial membrane potential (Δψm) were measured. Atractyloside (ATR) and NIM811, which modify the opening of mPTP, were administered in selected groups.. iPoC, and NIM811, diminished the elevation of serum alanine transaminase level after I/R injury (174.0±28.3 U/L for iPoC; 94.3±25.4 U/L for control+NIM811) when compared with others (416.3±16.7 U/L for control, 557.0±86.7 U/L for iPoC+ATR, P<0.05). The expressions of cytosolic cytochrome c after I/R injury were decreased in iPoC and control+NIM811 groups when compared with others. After I/R, the apoptosis and the 4-hydroxy-2-nonnenal-modified proteins were attenuated in iPoC group when compared (apoptotic counts/50 HPF: 723.3±98.7 for iPoC, 1274±201.2 for control, 1057.6±39 for iPoC+ATR, P<0.05). The Δψm measured by flow cytometry was better preserved in iPoC and NIM811 groups.. iPoC attenuated cell deaths after I/R injury of liver. The protective effects were negated by the addition of ATR--a mPTP opener--and mimicked by injection of NIM811--a mPTP opening inhibitor. The study indicated iPoC conferred protection by modulating mPTP.

Topics: Alanine Transaminase; Animals; Cyclosporine; Cytochromes c; Heme Oxygenase (Decyclizing); Ischemic Postconditioning; Liver; Male; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Oxidative Stress; Rats; Rats, Wistar; Reperfusion Injury

High levels of homocysteine (Hcy) known as hyperhomocysteinemia (HHcy), contribute to autophagy and ischemia/reperfusion injury (I/R). Previous studies have shown that I/R injury and HHcy cause increased cerebrovascular permeability; however, the associated mechanism remains obscure. Interestingly, during HHcy, cytochome-c becomes homocysteinylated (Hcy-cyto-c). Cytochrome-c (cyto-c) transports electrons and facilitates bioenergetics in the system. However, its role in autophagy during ischemia/reperfusion injury is unclear. Tetrahydrocurcumin (THC) is a major herbal antioxidant and anti-inflammatory agent. Therefore, the objective of this study was to determine whether THC ameliorates autophagy during ischemia/reperfusion injury by reducing homocysteinylation of cyto-c in hyperhomocysteinemia pathological condition. To test this hypothesis, we employed 8-10-week-old male cystathionine-beta-synthase heterozygote knockout (CBS⁺/⁻) mice (genetically hyperhomocystemic mice). Experimental group was: CBS⁺/⁻, CBS⁺/⁻ + THC (25 mg/kg in 0.1% DMSO dose); CBS ⁺/⁻/I/R, and CBS⁺/⁻/I/R + THC (25 mg/kg in 0.1% DMSO dose). Ischemia was performed for 30 min and reperfusion for 72 h. THC was injected intra-peritoneally (I.P.) once daily for a period of 3 days after 30 min of ischemia. The infarct area was measured using 2,3,5-triphenyltetrazolium chloride staining. Permeability was determined by brain edema and Evans Blue extravasation. The brain tissues were analyzed for oxidative stress, matrix metalloproteinase-9 (MMP-9), damage-regulated autophagy modulator (DRAM), and microtubule-associated protein 1 light chain 3 (LC3) by Western blot. The mRNA levels of S-adenosyl-L-homocysteine hydrolases (SAHH) and methylenetetrahydrofolate reductase (MTHFR) genes were measured by quantitative real-time polymerase chain reaction. Co-immunoprecipitation was used to determine the homocysteinylation of cyto-c. We found that brain edema and Evans Blue leakage were reduced in I/R + THC-treated groups as compared to sham-operated groups along with reduced brain infarct size. THC also decreased oxidative damage and ameliorated the homocysteinylation of cyto-c in-part by MMP-9 activation which leads to autophagy in I/R groups as compared to sham-operated groups. This study suggests a potential therapeutic role of dietary THC in cerebral ischemia.

Topics: Animals; Antioxidants; Autophagy; Brain Ischemia; Curcumin; Cytochromes c; Hyperhomocysteinemia; Male; Mice; Mice, Knockout; Reperfusion Injury

Ferulic acid (FA), a phenolic compound found in various medicinal plants, has hepatoprotective effects against oxidative stress and inflammation. Here, we investigated the protective effects and the specific mechanisms of FA against hepatocyte apoptosis caused by ischemia/reperfusion (I/R). Mice were treated intraperitoneally with vehicle or FA 30 min prior to 60 min of ischemia. After 5h of reperfusion, serum aminotransferase activities and hepatic lipid peroxidation were elevated and hepatic glutathione content was depleted. These alterations were attenuated by FA. I/R increased caspase-3 activity and release of cytochrome c, and these were suppressed by FA. FA also attenuated the increases in the serum tumor necrosis factor (TNF)-α levels and TNF receptor type 1-associated DEATH domain protein and TNF receptor-associated factor 2 protein expressions. The cytosolic levels of Bcl-2-associated X protein (Bax), truncated BH3 interacting domain death agonist (tBid), and Bcl-2-like protein 11 were upregulated after reperfusion. The increases in Bax and tBid protein expression were attenuated by FA. Moreover, I/R induced c-Jun N-terminal kinase 1 (JNK1) and JNK2 phosphorylation, and FA attenuated the JNK activation. FA protects against I/R-induced hepatocyte apoptosis by attenuating oxidative stress and JNK activation.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Bcl-2-Like Protein 11; BH3 Interacting Domain Death Agonist Protein; Caspase 3; Caspase 8; Coumaric Acids; Cytochromes c; Cytosol; Glutathione; Hepatocytes; Lipid Peroxidation; Liver; Male; MAP Kinase Kinase 4; Membrane Proteins; Mice; Mice, Inbred ICR; Oxidative Stress; Proto-Oncogene Proteins; Reperfusion Injury; Signal Transduction; TNF Receptor-Associated Death Domain Protein; TNF Receptor-Associated Factor 2; Transaminases; Tumor Necrosis Factor-alpha; Up-Regulation

This study examines the impact of glycine (Gly) preconditioning on ischemia reperfusion (IR)-induced pulmonary mitochondrial injury to research the previously, in pig lungs, demonstrated Gly-dependent amelioration of pulmonary IR injury. IR injury was induced in rat lungs by 30 min pulmonary hilum clamping followed by 60 min reperfusion time. Rats were subjected to controls, shams and two study groups (IR30/60, Gly-IR30/60) receiving 37.5 mg Gly i.v. or not before IR induction. The wet/dry-weight ratio, mitochondria viability (MV), membrane integrity (MI), respiratory chain complex (RCC) activities, mitochondrial membrane potential (ΔΨm) and cytochrome C (Cyt C) content were analysed. In IR30/60, RCC and MV were impaired; Cyt C loss and MI combined with matrix metalloproteinase-9 (MMP-9) activation and ΔΨm alteration were observed when compared with controls. In Gly-IR30/60, complex II function and mitochondrial viability were protected during IR, and MMP-9 activation combined with tissue-water content accumulation and ΔΨm alteration were ameliorated. Cyt C loss, mitochondrial membranes damage, tissue GSH oxidation or neutrophil sequestration was not extenuated in Gly-IR30/60. Gly ameliorates IR-associated mitochondrial dysfunction and decay of viability and normalizes ΔΨm but does not protect from Cyt C liberation and mitochondrial membrane damage. Our data suggest that the previously described effect of Gly preconditioning results at least partially from mitochondrial protection. A dose-finding study is necessary to improve results of Gly preconditioning.

Topics: Animals; Apoptosis; Cytochromes c; Cytoprotection; Disease Models, Animal; Electron Transport Chain Complex Proteins; Enzyme Activation; Glutathione; Glycine; Lung; Male; Matrix Metalloproteinase 9; Membrane Potential, Mitochondrial; Mitochondria; Neutrophil Infiltration; Oxidation-Reduction; Protective Agents; Pulmonary Edema; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Activation of protein kinase C (PKC) has been implicated in the protection of ischemic preconditioning (IPC), but the exact role of PKC in early and late hepatic IPC is still unclear. The present study was conducted in order to investigate the differential role of PKC during early and late hepatic IPC. Rats were subjected to 90 min of partial hepatic ischemia followed by 3 (early IPC) and 24 h (late IPC) of reperfusion. IPC was induced by 10 min of ischemia following 10 min of reperfusion prior to sustained ischemia, and chelerythrine, a PKC inhibitor, was injected 10 min before IPC (5 mg/kg, i.v.). Chelerythrine abrogated the protection of early IPC, as indicated by increased serum aminotransferase activities and decreased hepatic glutathione content. While the IPC-treated group showed a few apoptotic cell deaths during both phases, chelerythrine attenuated these changes only at late IPC and limited IPC-induced inducible nitric oxide synthase (iNOS) and heme oxygenase-1 (HO-1) overexpression. Membrane translocation of PKC-δ and -ε during IPC was blocked by chelerythrine. Our results suggest that PKC might play a differential role in early and late IPC; activation of PKC-δ and -ε prevents necrosis in early IPC through preservation of redox state and prevents apoptosis in late IPC with iNOS and HO-1 induction. Therefore, PKC represents a promising target for hepatocyte tolerance to ischemic injury, and understanding the differential role of PKC in early and late IPC is important for clinical application of IPC.

Topics: Acetophenones; Animals; Apoptosis; Benzophenanthridines; Benzopyrans; Cytochromes c; Heme Oxygenase-1; Ischemic Preconditioning; Liver Diseases; Male; Nitric Oxide Synthase Type II; p38 Mitogen-Activated Protein Kinases; Protein Kinase C; Protein Kinase C-delta; Protein Kinase C-epsilon; Rats; Reperfusion Injury

This aim of this study was to explore the effects and molecular mechanisms of Astragalus extract against cerebral ischemia injury through the energy metabolism and apoptosis pathways of c‑Jun N-terminal kinase (JNK) signal transduction. After the bilateral common carotid artery of C57BL/6 mice was occluded for 20 min followed by 1-h reperfusion, the ATP content, total adenine nucleotides (TAN), energy charge (EC), and sodium potassium ATPase (Na(+)-K(+)‑ATPase) activity were decreased markedly in brain tissues. Astragalus extract markedly increased the ATP and ADP levels, EC value, and Na(+)-K(+)-ATPase activity. Twenty-four and 48 h after reperfusion, the neurocyte survival rate decreased and apoptosis rate increased, while the expression of phosphorylated JNK1/2, cytochrome c (Cyt C), and cysteine aspartic acid-specific protease (caspase)-9 and -3 were significantly enhanced in brain tissues. Astragalus extract significantly increased neurocyte survival and decreased the apoptosis rate as well as down-regulated the expression of p-JNK1/2, Cyt C, caspase-9, and caspase-3. These results suggest that Astragalus extract has neuroprotective effects against nerve injury after cerebral ischemia-reperfusion, and the underlying mechanism may be associated with improved cellular energy metabolism, inhibition of JNK signal transduction pathway activation, and then suppression of the mitochondrial apoptosis pathway.

Topics: Animals; Apoptosis; Astragalus Plant; Brain Ischemia; CA1 Region, Hippocampal; Caspase 3; Caspase 9; Cytochromes c; Energy Metabolism; JNK Mitogen-Activated Protein Kinases; Male; Mice; Mice, Inbred C57BL; Neurons; Neuroprotective Agents; Plant Extracts; Reperfusion Injury

High levels of reactive oxygen species inflict oxidative damage on various cellular components that eventually culminate in a variety of diseases. This study investigated the cytoprotective effects of a nucleic acid-based health product (Squina [Hong Kong, China] DNA) against oxidative stress, particularly in neuronal cells. Adult female Sprague-Dawley rats were treated with Squina DNA, and changes in mitochondrial antioxidant status and functional capacity were assessed by the activities of antioxidant enzymes and ATP generation capacity in brain, heart ventricular, kidney, skeletal muscle, and liver tissues of control and Squina DNA-treated rats. The effects of Squina DNA pretreatment on brain/neuronal cell injury were investigated in a rat model of cerebral ischemia/reperfusion (I/R) injury and a neuroblastoma SH-SY5Y cell model of β-amyloid (Aβ) protein fragment 25-35-induced toxicity. Long-term Squina DNA treatment caused dose-dependent increases in mitochondrial antioxidant status and functional capacity in rat brain, heart ventricular, kidney, skeletal muscle, and liver tissues. Squina DNA pretreatment significantly prevented I/R injury in brain tissue. The cerebroprotection was associated with a reversal of I/R-induced impairment in mitochondrial antioxidant status and disruption in membrane integrity. Squina DNA ethanol extract also significantly inhibited the Aβ-induced apoptosis in SH-SY5Y neuronal cells, as evidenced by less caspase 3 and caspase 9 activation as well as mitochondrial cytochrome c release in Aβ-challenged cells. Squina DNA may enhance the resistance of tissues and cells to oxidative stress, particularly in pathological conditions such as stroke and aging-related neurodegenerative diseases.

Topics: Amyloid beta-Peptides; Animals; Antioxidants; Apoptosis; Biological Products; Brain; Brain Ischemia; Caspases; Cell Line, Tumor; Cytochromes c; DNA; Dose-Response Relationship, Drug; Female; Heart Ventricles; Kidney; Liver; Mitochondria; Mitochondrial Membranes; Muscle, Skeletal; Neurodegenerative Diseases; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Salmon; Stroke

Flurbiprofen acts as a nonselective inhibitor for cyclooxygenases (COX-1 and COX-2), but its impact on hepatic ischemia/reperfusion (I/R) injury remains unclear. Mice were randomized into sham, I/R and flurbiprofen (Flurb) groups. The hepatic artery and portal vein to the left and median liver lobes were occluded for 90 min and unclamped for reperfusion to establish a model of segmental (70%) warm hepatic ischemia. Pretreatment of animals with flurbiprofen prior to I/R insult significantly decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), and prevented hepatocytes from I/R-induced apoptosis/necrosis. Moreover, flurbiprofen dramatically inhibited mitochondrial permeability transition (MPT) pore opening, and thus prevented mitochondrial-related cell death and apoptosis. Mechanistic studies revealed that flurbiprofen markedly inhibited glycogen synthase kinase (GSK)-3β activity and increased phosphorylation of GSK-3β at Ser9, which, consequently, could modulate the adenine nucleotide translocase (ANT)-cyclophilin D (CyP-D) complex and the susceptibility to MPT induction. Therefore, administration of flurbiprofen prior to hepatic I/R ameliorates mitochondrial and hepatocellular damage through inhibition of MPT and inactivation of GSK-3β, and provides experimental evidence for clinical use of flurbiprofen to protect liver function in surgical settings in addition to its conventional use for pain relief.

Topics: Animals; Calcium; Caspase 3; Caspase 9; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase Inhibitors; Cyclophilins; Cytochromes c; Enzyme Activation; Flurbiprofen; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Liver; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial ADP, ATP Translocases; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Peptidyl-Prolyl Isomerase F; Phosphorylation; Protein Binding; Reperfusion Injury; Signal Transduction

We previously reported the administration of a potent cytochrome P450 inhibitor, sulfaphenazole (SPZ), to suppress oxidative stress and the extension of myocardial infarct size in a rat model of cardiac ischemia-reperfusion (I/R). The aim of this study was to investigate the effects of SPZ on the myocardial cell apoptosis induced by I/R in rats. I/R injury was evoked by ligation of the left anterior descending coronary artery for 1 h, followed by reperfusion for 3 h. TUNEL-positive nuclei were detected and nucleosomal DNA fragmentation was observed 3 h after reperfusion. The administration of SPZ largely suppressed the cardiac DNA fragmentation induced by I/R. A pan-caspase inhibitor, z-VAD-fmk, had no effect on DNA fragmentation. Caspase-3/7 was not activated 3 h after reperfusion. Decreases in the mitochondrial membrane potential and cytochrome c release from the mitochondria to cytosol were detected 3 h after reperfusion. The expression levels of BimEL and Noxa were elevated 3 h after reperfusion. These phenomena were suppressed by the administration of SPZ. Taken together, treatment with SPZ could attenuate the myocardial cell apoptosis accompanied with I/R by inhibiting the mitochondrial dysfunction due to decreases in the expression of BimEL and Noxa.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Bcl-2-Like Protein 11; Caspase 3; Caspase 7; Cytochromes c; Cytosol; DNA Fragmentation; In Situ Nick-End Labeling; Male; Membrane Potential, Mitochondrial; Membrane Proteins; Mitochondria; Myocardial Reperfusion Injury; Myocytes, Cardiac; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury; Sulfaphenazole

Our recent studies have shown that ischemia/reperfusion (I/R) produces significant necrosis and apoptosis in the cells of skeletal muscle. Our previous studies also demonstrated that melatonin provides significant protection against superoxide generation, endothelial dysfunction, and cell death in the skeletal muscle after I/R. Mitochondria are essential for cell survival, because of their roles as ATP producers as well as regulators of cell death. However, the efficacy of melatonin on I/R-induced mitochondrial dysfunction in the skeletal muscle in vivo has not been demonstrated in the literature.. Vascular pedicle isolated rat gracilis muscle model was used. After 4 h of ischemia followed by 24 h of reperfusion, gracilis muscle was harvested, and mitochondrial as well as cytosolic fractions were isolated. Mitochondrial dysfunction was determined by the alteration of mitochondrial membrane potential and the release of the proapoptotic protein, cytochrome c. Three groups were designed; sham I/R, I/R-V (I/R with vehicle), and I/R-Mel (I/R with melatonin). Melatonin or vehicle was given intravenously 10 min prior to reperfusion and 10 min after reperfusion.. We found that the capability of uptake of fluorescent JC-1 dye in skeletal muscle cells was substantially improved in I/R-Mel group compared with I/R-V group. Melatonin significantly inhibited the outflow of cytochrome c from mitochondria to cytoplasm, which was demonstrated in the I/R-V group.. Melatonin significantly attenuates I/R-induced mitochondrial dysfunction, such as the depolarization of mitochondrial membrane potential and the release of the proapoptotic protein, cytochrome c, from the mitochondria.

Topics: Animals; Antioxidants; Benzimidazoles; Carbocyanines; Cytochromes c; Fluorescent Dyes; Male; Melatonin; Membrane Potential, Mitochondrial; Mitochondria, Muscle; Muscle, Skeletal; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Superoxides

Ischemia-reperfusion injury (IRI) is responsible for primary liver dysfunction and failure after transplantation. The mitochondrial pathway appears to be involved in liver ischemia-reperfusion injury. Mitochondrial ATP-sensitive K (mitoK(ATP)) channels play a central role in protecting the heart from injury in ischemic preconditioning. The selective mitoK(ATP) channel agonist diazoxide potently reduced mitochondrial injury by preventing cytochrome c loss from the intermembrane space. Therefore, this study sought to determine whether diazoxide can attenuate ischemia-reperfusion injury induced by orthotopic liver transplantation (OLT) in mice. Furthermore, it was found that up-regulation of the Bcl-2 gene is a mechanism of diazoxide cytoprotection.. Donors were treated with diazoxide, Bcl-2 siRNA, or diazoxide + Bcl-2 siRNA and vehicle 10 min or 24 h before liver harvesting. Liver grafts were then orthotopically transplanted into their corresponding recipients.. Liver injury, as judged by transaminase level and histologic examination, was significantly lower in the diazoxide group compared with vehicle controls. The percentage of apoptotic cells and the amount of cytochrome c in the cytosol 6 h after transplant were also markedly reduced in diazoxide-treated grafts compared with vehicle-treated controls. Diazoxide notably up-regulated expression of Bcl-2, while siRNA knockdown of Bcl-2 abolished the cytoprotective effects of diazoxide.. Diazoxide attenuated graft injury after mouse liver transplantation. One mechanism of diazoxide protection involves the induction of Bcl-2, an anti-apoptotic protein. Diazoxide might be useful clinically in hepatic surgery and transplantation.

Topics: Animals; Apoptosis; Cytochromes c; Cytosol; Diazoxide; Liver; Liver Transplantation; Male; Mice; Mice, Inbred BALB C; Mitochondria, Liver; Models, Animal; Potassium Channels; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; RNA, Small Interfering; Signal Transduction; Transplantation, Homologous; Up-Regulation

NADPH oxidase is a major complex that produces reactive oxygen species (ROSs) during the ischemic period and aggravates brain damage and cell death after ischemic injury. Although many approaches have been tested for preventing production of ROSs by NADPH oxidase in ischemic brain injury, the regulatory mechanisms of NADPH oxidase activity after cerebral ischemia are still unclear. The aim of this study is identifying apocynin as a critical modulator of NADPH oxidase and elucidating its role as a neuroprotectant in an experimental model of brain ischemia in rat. Treatment of apocynin 5min before of reperfusion attenuated cerebral ischemia in rats. Administration of apocynin showed marked reduction in infarct size compared with that of control rats. Medial carotid artery occlusion (MCAo)-induced cerebral ischemia was also associated with an increase in, nitrotyrosine formation, as well as IL-1β expression, IκB degradation and ICAM expression in ischemic regions. These expressions were markedly inhibited by the treatment of apocynin. We also demonstrated that apocynin reduces levels of apoptosis (TUNEL, Bax and Bcl-2 expression) resulting in a reduction in the infarct volume in ischemia-reperfusion brain injury. This new understanding of apocynin induced adaptation to ischemic stress and inflammation could suggest novel avenues for clinical intervention during ischemic and inflammatory diseases.

Topics: Acetophenones; Animals; Apoptosis; bcl-2-Associated X Protein; Brain; Cytochromes c; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation, Enzymologic; I-kappa B Proteins; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Intercellular Adhesion Molecule-1; Interleukin-1beta; Male; NADPH Oxidases; Neurologic Examination; Peptide Fragments; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury; Tyrosine

P53 upregulated modulator of apoptosis (PUMA) plays an important role in mediating cell death. However, the role of PUMA in cardiomyocyte death induced by hypoxia/reoxygenation (H/R) and its molecular mechanism still remain enigmatic. Here, we used the in vitro model to elucidate the effects of PUMA on H/R-induced cardiomyocyte apoptosis as well as the underlying mechanisms. We reported that H/R could upregulate the expression of PUMA accompanied by the elevation of cardiomyocyte apoptosis. Interestingly, inhibition of endogenous PUMA expression by PUMA siRNA or p53 inhibitor repressed H/R-induced cardiomyocyte apoptosis. Furthermore, we found H/R stimulated the associations of PUMA apoptosis repressor with caspase recruitment domain (ARC) and consequently attenuated the associations of ARC with caspase 8, resulting in caspase 8 activation. Also, H/R stimulated cytochrome C release and caspase 3 activation. However, these stimulating effects of H/R disappeared upon knockdown of endogenous PUMA. Our data reveal that PUMA participates in H/R-triggered cardiomyocyte apoptosis by interfering with mitochondrial pathway.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; Benzothiazoles; Caspase 3; Caspase 8; Cells, Cultured; Cytochromes c; Hypoxia; Membrane Potential, Mitochondrial; Mitochondria, Heart; Muscle Proteins; Myocytes, Cardiac; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Toluene

The role of p53 in inducing apoptosis following acute kidney injury is well-established; however, the molecular mechanisms remain largely unknown. We report here that the p53 proapoptotic target Siva and its receptor CD27, a member of the tumor necrosis factor receptor family, are upregulated following renal ischemia-reperfusion injury (IRI). Inhibition of Siva using antisense oligonucleotides conferred functional and morphological protection, and it prevented apoptosis postrenal IRI in mice. Renal IRI in CD27-deficient mice displayed functional protection and partial inhibition of apoptosis, suggesting an incomplete role for CD27 in Siva-mediated apoptosis. To further elucidate mechanisms by which Siva elicits apoptosis, in vitro studies were performed. In Siva-transfected LLC-PK(1)cells, Siva is persistently expressed in the nucleus at 3 h onwards and its translocation to mitochondria and the plasma membrane occurred at 6 h. Moreover, Siva overexpression induced mitochondrial permeability, cytochrome c release, caspase-8 and -9 activation, translocation of apoptosis-inducing factor (AIF) to the nucleus, and apoptosis. Inhibition of Siva in ischemic kidneys prevented mitochondrial release of cytochrome c and AIF. These data indicate that Siva function is pivotal in regulating apoptosis in the pathology of renal IRI. Targeting Siva may offer a potential therapeutic strategy for renal IRI.

Topics: Analysis of Variance; Animals; Apoptosis; Apoptosis Inducing Factor; Apoptosis Regulatory Proteins; Caspase 8; Caspase 9; Cell Hypoxia; Cytochromes c; Disease Models, Animal; Enzyme Activation; Intracellular Signaling Peptides and Proteins; Kidney; LLC-PK1 Cells; Male; Mice; Mice, 129 Strain; Mice, Knockout; Mitochondrial Membranes; Oligonucleotides, Antisense; Permeability; Protein Transport; Recombinant Fusion Proteins; Reperfusion Injury; Swine; Time Factors; Transfection; Tumor Necrosis Factor Receptor Superfamily, Member 7; Tumor Suppressor Protein p53

Because myocardial infarction is a major cause of morbidity and mortality worldwide, protecting the heart from the ischaemia and reperfusion (I/R) damage is the focus of intense research. Based on our in vitro findings showing that TVP1022 (the S-enantiomer of rasagiline, an anti-Parkinsonian drug) possesses cardioprotective effects, in the present study we investigated the hypothesis that TVP1022 can attenuate myocardial damage in an I/R model in rats.. The model consisted of 30-min occlusion of the left anterior descending artery followed by 4 or 24 h reperfusion. In addition, we investigated the possible mechanisms of cardioprotection in H9c2 cells and neonatal rat ventricular myocytes (NRVM) exposed to oxidative stress induced by H(2) O(2) .. TVP1022 (20 and 40 mg·kg(-1) ) administered 5 min before reperfusion followed by an additional dose 4 h after reperfusion reduced the infarct size and attenuated the decline in ventricular function. TVP1022 also attenuated I/R-induced deterioration in cardiac mitochondrial integrity evaluated by mitochondrial swelling capacity. In vitro, using H9c2 cells and NRVM, TVP1022 attenuated both serum free- and H(2) O(2) -induced damage, preserved mitochondrial membrane potential and Bcl-2 levels, inhibited mitochondrial cytochrome c release and the increase in cleaved caspase 9 and 3 levels, and enhanced the phosphorylation of protein kinase C and glycogen synthase kinase-3β.. TVP1022 provided cardioprotection in a model of myocardial infarction, and therefore should be considered as a novel adjunctive therapy for attenuating myocardial damage resulting from I/R injuries.

Topics: Animals; Cardiotonic Agents; Caspase 3; Caspase 9; Cells, Cultured; Cytochromes c; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Indans; Male; Membrane Potentials; Mitochondria; Myocardial Infarction; Myocardium; Protein Kinase C; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Tannic acid (TA) inhibits nicotinamide adenine dinucleotide phosphate (NADPH)-cytochrome P450 reductase (CPR) activity, which is measured by reduction of cytochrome c, in rat liver microsomes (RLMs). In the current study, we noticed that TA directly reduces cytochrome c in the absence of microsomes, thus confounding the CPR activity assay. A method is presented that measures CPR activity in the presence of TA by subtracting the cytochrome c reduction in the absence of NADPH (TA effect) from that in the presence of NADPH (TA plus CPR effect). The method was used to determine the inhibitory effect of TA in RLMs, recombinant CPR enzyme, and primary hepatocytes. Additionally, application of TA in a study of role of CPR in a primary rat hepatocyte model of ischemia-reperfusion (IR) was investigated. TA showed concentration-dependent, complete inhibition of CPR with half maximal inhibitory concentration (IC(50) ) values of 58.2 μM in RLMs and 54.6 and 275 μM in primary rat hepatocytes in the absence and presence of serum in the medium, respectively. Additionally, inhibition of CPR by TA was associated with a significant reduction in reactive oxygen species and cell death after IR injury. These data may be useful in future studies using TA as an inhibitor of CPR in microsomes and primary hepatocytes.

Topics: Animals; Artifacts; Biological Assay; Cell Hypoxia; Cells, Cultured; Culture Media, Serum-Free; Cytochromes c; Dose-Response Relationship, Drug; Hepatocytes; Male; Microsomes, Liver; NADPH-Ferrihemoprotein Reductase; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Tannins

Hexokinase (HK), the rate-limiting enzyme in glycolysis, controls cell survival by promoting metabolism and/or inhibiting apoptosis. Since HK isoforms I and II have mitochondrial targeting sequences, we attempted to separate the protective effects of HK on cell metabolism from those on apoptosis. We exposed renal epithelial cells to metabolic stress causing ATP depletion in the absence of glucose and found that this activated glycogen synthase kinase 3β (GSK3β) and Bax caused mitochondrial membrane injury and apoptosis. ATP depletion led to a progressive HK II dissociation from mitochondria, released mitochondrial apoptosis inducing factor and cytochrome c into the cytosol, activated caspase-3, and reduced cell survival. Compared with control, adenoviral-mediated HK I or II overexpression improved cell survival following stress, but did not prevent GSK3β or Bax activation, improve ATP content, or reduce mitochondrial fragmentation. HK I or HK II overexpression increased mitochondria-associated isoform-specific HK content, and decreased mitochondrial membrane injury and apoptosis after stress. In vivo, HK II localized exclusively to the proximal tubule. Ischemia reduced total renal HK II content and dissociated HK II from proximal tubule mitochondria. In cells overexpressing HK II, Bax and HK II did not interact before or after stress. While the mechanism by which HK antagonizes Bax-mediated apoptosis is unresolved by these studies, one possible scenario is that the two proteins compete for a common binding site on the outer mitochondrial membrane.

Topics: Adenosine Triphosphate; Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Cell Survival; Cells, Cultured; Cytochromes c; Disease Models, Animal; Epithelial Cells; Glucose; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hexokinase; Kidney Diseases; Kidney Tubules, Proximal; Mice; Mitochondrial Membranes; Opossums; Protein Transport; Reperfusion Injury; Signal Transduction; Stress, Physiological; Time Factors; Transfection

Cardiomyocyte apoptosis is an important remodeling event contributing to heart failure and adiponectin may mediate cardioprotective effects at least in part via attenuating apoptosis. Here we used hypoxia-reoxygenation (H/R) induced apoptosis in H9c2 cells to examine the effect of adiponectin and cellular mechanisms of action. We first used TUNEL labeling in combination with laser scanning cytometry to demonstrate that adiponectin prevented H/R-induced DNA fragmentation. The anti-apoptotic effect of adiponectin was also verified via attenuation of H/R-induced phosphatidylserine exposure using annexin V binding. H/R-induced apoptosis via the mitochondrial-mediated intrinsic pathway of apoptosis as assessed by cytochrome c release into cytosol and caspase-3 activation, both of which were attenuated by adiponectin. Mechanistically, we demonstrated that adiponectin enhanced anti-oxidative potential in these cells which led to attenuation of the increase in intracellular reactive oxygen species (ROS) caused by H/R. To further address the mechanism of adiponctins anti-apoptotic effects we used siRNA to efficiently knockdown adiponectin receptor (AdipoR1) expression and found that this attenuated the protective effects of adiponectin on ROS production and caspase 3 activity. Knockdown of APPL1, an important intracellular binding partner for AdipoR, also significantly reduced the ability of adiponectin to prevent H/R-induced ROS generation and caspase 3 activity. In summary, H/R-induced ROS generation and activation of the intrinsic apoptotic pathway was prevented by adiponectin via AdipoR1/APPL1 signaling and increased anti-oxidant potential.

Topics: Adaptor Proteins, Signal Transducing; Adiponectin; Animals; Annexin A5; Antioxidants; Apoptosis; Base Sequence; Carrier Proteins; Caspase 3; Cell Hypoxia; Cell Line; Cytochromes c; DNA Fragmentation; Gene Knockdown Techniques; Mitochondria; Myocytes, Cardiac; Nerve Tissue Proteins; Oxygen; Rats; Reactive Oxygen Species; Receptors, Adiponectin; Reperfusion Injury; RNA, Small Interfering

1. Calcium-sensing receptors (CaSR) exist in a variety of tissues. In 2010, we first identified its functional expression in Buffalo rat liver (BRL) cells and demonstrated that the activation of CaSR was involved in an increased intracellular calcium through the Gq subunit-phospholipase C-inositol triphosphate pathway. However, its role and related mechanism in hepatic ischaemia/reperfusion (I/R) injury is still unclear. 2. Therefore, in the present study, BRL cells were incubated in ischaemia-mimetic solution for 4 h, then reincubated in the normal culture medium for 10 h to establish a simulated I/R model. We assayed the apoptotic ratio of BRL cells by flow cytometry and Hoechst 33342 staining; analyzed the expression of CaSR, cytochrome c (Cyt-c), caspase-3, Bcl-2, Bax, extracellular signal-regulated protein kinase (ERK), and p38 by Western blotting; and measured the concentration of intracellular calcium by laser-scanning confocal microscopy. 3. The results showed that simulated I/R increased the expression of CaSR and induced apoptosis in BRL cells. GdCl(3), a specific activator of CaSR, further increased CaSR expression, intracellular calcium, and apoptosis in BRL cells during I/R. The activation of CaSR downregulated Bcl-2 expression, upregulated Cyt-c, caspase-3, and Bax expressions, and promoted p38 and ERK-1/2 phosphorylation. 4. In conclusion, increased CaSR expression plays a vital role in apoptosis induced by I/R injury, in which its mechanism is related with calcium overload and the activation of the mitochondrial and mitogen-activated protein kinase apoptotic pathways. The regulation of CaSR activity might serve as a novel pharmacological target to prevent and treat liver disease.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Calcium; Caspase 3; Cells, Cultured; Cytochromes c; Extracellular Signal-Regulated MAP Kinases; GTP-Binding Protein alpha Subunits, Gq-G11; Hepatocytes; Inositol Polyphosphate 5-Phosphatases; p38 Mitogen-Activated Protein Kinases; Phosphoric Monoester Hydrolases; Rats; Rats, Inbred BUF; Receptors, Calcium-Sensing; Reperfusion Injury; Signal Transduction; Type C Phospholipases

Recently, nitrite has been rediscovered as a physiologically relevant storage reservoir of nitric oxide in blood and it can readily be converted to nitric oxide under hypoxic and acidic conditions. In this study, the authors evaluated the therapeutic efficacy of nitrite on reperfusion-induced microcirculatory alterations and mitochondrial dysfunction in the microvasculature of skeletal muscle.. The authors used a vascular pedicle isolated rat cremaster model that underwent 4 hours of warm ischemia followed by 2 hours or 17 hours of reperfusion. At 5 minutes before reperfusion, normal saline, sodium nitrite (0.20 μM/minute/kg), or nitrite mixed with 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxyl (potassium salt) (0.2 mg/minute/kg) was infused into the microcirculation of ischemic cremaster by means of intraarterial infusion. Ischemia-reperfusion-induced microcirculatory alterations were measured after 2 hours of reperfusion. Microvasculature of the cremaster muscle including the vascular pedicle was harvested to determine the mitochondrial dysfunction. The blood concentration of methemoglobin was also measured to determine the toxicity of nitrite.. The authors found that nitrite significantly attenuated ischemia-reperfusion-induced vasoconstriction, arteriole stagnation, and capillary no-reflow in the early phase of reperfusion and the depolarization of mitochondrial membrane potential and cytochrome c release in the late phase of reperfusion. Nitrite-induced protection was significantly blocked by a nitric oxide scavenger (potassium salt). The methemoglobin results showed that the doses of nitrite we used in the present study were safe.. The supplementation of a low dose of nitrite, directly into the microcirculation of ischemic muscle through local intraarterial infusion, significantly attenuated ischemia-reperfusion-induced microcirculatory alterations in vivo and mitochondrial dysfunction in vitro in the microvasculature of skeletal muscle.

Topics: Analysis of Variance; Animals; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Ischemia; Male; Membrane Potentials; Methemoglobin; Microcirculation; Mitochondria, Muscle; Muscle, Skeletal; Nitrites; Random Allocation; Rats; Rats, Sprague-Dawley; Reference Values; Reperfusion Injury

Although magnolol is cytoprotective against warm ischemia/reperfusion injury, its effect on cold preservation has not been fully investigated. This study aimed at examining whether magnolol maintains the liver graft integrity after cold preservation and elucidating the underlying mechanisms in terms of apoptotic signaling under both normothermic and hypothermic conditions. After being preserved in Ringer's lactate (RL) at 4 degrees C for 6h ex vivo, the magnolol-treated grafts demonstrated significantly higher AST, ALT, and LDH levels in perfusates than those from negative controls. TUNEL staining showed no difference in the number of apoptotic nuclei in both groups, whereas a more intense apoptotic signal in magnolol-treated grafts was shown as compared with the controls. In vitro data showed no significant difference in viability of RL-preserved clone-9 hepatocytes between the magnolol-treated and control groups, while magnolol pretreatment at 30min before cold preservation prominently induced hepatocyte cell death. RT-PCR and Western blotting analyses revealed a suppression in Bcl-2, but an up-regulation in Bax expression in clone-9 cells after magnolol treatment. Magnolol suppressed the ratios of NF-kappaB to I-kappaBalpha protein contents and I-kappaBalpha phosphorylation induced by TNF-alpha, and potentiated mitochondrial cytochrome c release and subsequent caspase-3 cleavage. Conversely, caspase-3 inhibitor attenuated magnolol-induced hepatotoxicity. We concluded that magnolol could not protect liver grafts from cold ischemia/reperfusion injury. High concentration of magnolol under serum-reduced conditions attenuates NF-kappaB-mediated signaling and induces intrinsic apoptotic pathway, thereby inducing in vitro hepatotoxicity.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Biphenyl Compounds; Blotting, Western; Caspase 3; Chemical and Drug Induced Liver Injury; Cold Temperature; Cryopreservation; Cytochromes c; I-kappa B Proteins; In Situ Nick-End Labeling; Lignans; Liver; Liver Transplantation; Magnolia; Male; Mitochondria; NF-kappa B; Plant Bark; Plant Extracts; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; Serum; Signal Transduction; Tumor Necrosis Factor-alpha

Acetaminophen, a popular analgesic and antipyretic, has been found to be effective against neuronal cell death in in vivo and in vitro models of neurological disorders. Acute neuronal death has been attributed to loss of mitochondrial permeability transition coupled with mitochondrial dysfunction. The potential impact of acetaminophen on acute injury from cerebral ischemia-reperfusion has not been studied. We investigated the effects of acetaminophen on cerebral ischemia-reperfusion-induced injury using a transient global forebrain ischemia model. Male Sprague-Dawley rats received 15mg/kg of acetaminophen intravenously during ischemia induced by hypovolemic hypotension and bilateral common carotid arterial occlusion, which was followed by reperfusion. Acetaminophen reduced tissue damage, degree of mitochondrial swelling, and loss of mitochondrial membrane potential. Acetaminophen maintained mitochondrial cytochrome c content and reduced activation of caspase-9 and incidence of apoptosis. Our data show that acetaminophen reduces apoptosis via a mitochondrial-mediated mechanism in an in vivo model of cerebral ischemia-reperfusion. These findings suggest a novel role for acetaminophen as a potential stroke therapeutic.

Topics: Acetaminophen; Animals; Apoptosis; Brain; Brain Ischemia; Carotid Artery Diseases; Caspase 9; Cytochromes c; Disease Models, Animal; Hypotension; Male; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Swelling; Neuroprotective Agents; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors

To investigate the protective effects of ginsenoside Rb(3), a triterpenoid saponin isolated from the leaves of Panax notoginseng, on ischemic and reperfusion injury model of PC12 cells and elucidate the related mechanisms.. PC12 cells exposed to oxygen and glucose deprivation (OGD) and restoration (OGD-Rep) were used as an in vitro model of ischemia and reperfusion. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) leakage were used to evaluate the protective effects of ginsenoside Rb(3). Cellular apoptosis and mitochondrial membrane potential (MMP) were analyzed using flow cytometry. Intracellular calcium ion concentration ([Ca(2+)](i)) was detected using fluorophotometer system. Caspase-3, -8, and -9 activities were measured using assay kits with an ELISA reader. Western blotting assay was used to evaluate the release of cytochrome c and expression of caspase-3, Bcl-2 and Bax proteins.. It was shown that ginsenoside Rb(3) (0.1-10 micromol/L) significantly increased cell viability and inhibited LDH release in a dose-dependent manner on the ischemic model. In addition, ginsenoside Rb(3) also significantly inhibited ischemic injury-induced apoptosis, [Ca(2+)](i) elevation, and decrease of MMP. Meanwhile, pretreatment with ginsenoside Rb(3) significantly induced an increase of Bcl-2 protein expression and a decrease of cytosolic cytochrome c, cleaved-caspase 3 and Bax protein expression, the caspase-3, -8, and -9 activity were also inhibited.. The results indicated that ginsenoside Rb(3) could markedly protected OGD-Rep induced ischemic injury and the mechanisms maybe related to its suppression of the intracellular Ca(2+) elevation and inhibition of apoptosis and caspase activity. Ginsenoside Rb(3) could be a promising candidate in the development of a novel class of anti-ischemic agent.

Topics: Animals; bcl-2-Associated X Protein; Calcium; Caspases; Cell Hypoxia; Cell Survival; Cytochromes c; Cytoprotection; Ginsenosides; Glucose; L-Lactate Dehydrogenase; Membrane Potential, Mitochondrial; Oxygen; Panax notoginseng; PC12 Cells; Proto-Oncogene Proteins c-bcl-2; Rats; Reperfusion Injury

Volatile anesthetic ischemic postconditioning reduces infarct size following ischemia/reperfusion. Whether phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3 beta (GSK3β) is causal for cardioprotection by postconditioning is controversial. We therefore investigated the impact of PKB/Akt and GSK3β in isolated perfused rat hearts subjected to 40 min of ischemia followed by 1 h of reperfusion. 2.0% sevoflurane (1.0 minimum alveolar concentration) was administered at the onset of reperfusion in 15 min as postconditioning. Western blot analysis was used to determine phosphorylation of PKB/Akt and its downstream target GSK3β after 1 h of reperfusion. Mitochondrial and cytosolic content of cytochrome C checked by western blot served as a marker for mitochondrial permeability transition pore opening. Sevoflurane postconditioning significantly improved functional cardiac recovery and decreased infarct size in isolated rat hearts. Compared with unprotected hearts, sevoflurane postconditioning-induced phosphorylation of PKB/Akt and GSK3β were significantly increased. Increase of cytochrome C in mitochondria and decrease of it in cytosol is significant when compared with unprotected ones which have reversal effects on cytochrome C. The current study presents evidence that sevoflurane-induced cardioprotection at the onset of reperfusion are partly through activation of PKB/Akt and GSK3β.

Topics: Animals; Blotting, Western; Cytochromes c; Enzyme Activation; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hemodynamics; In Vitro Techniques; Ischemic Postconditioning; Male; Methyl Ethers; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Myocardium; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Wistar; Reperfusion Injury; Sevoflurane

This study examined the time-dependent effects of a cell permeable SOD mimetic, MnTMPyP, on mitochondrial function in renal ischemia-reperfusion injury (IRI). Male SD rats were subject to either sham operation or bilateral renal ischemia for 45 min followed by reperfusion for 1, 4 or 24 h. A sub-set of animals was treated with either saline vehicle or 5 mg/Kg of MnTMPyP (i.p.). EPR measurements showed that at 1-h reperfusion MnTMPyP prevented a decrease in aconitase activity (p < 0.05) and attenuated the increase in the high spin heme at g = 6 and oxidation of 4Fe4S to 3Fe4S signal at g = 2.015 (p < 0.01). MnTMPyP was effective in preventing loss of mitochondrial complexes and prevented the loss of cytochrome c and Smac/Diablo from mitochondria early in reperfusion. Following 24 h of reperfusion MnTMPyP was effective in attenuating caspase-3 and blocking apoptosis (p < 0.05). In conclusion, MnTMPyP has biphasic effects in renal IRI, inhibiting mitochondrial dysfunction at the early phases of reperfusion and prevention of apoptosis following longer durations of reperfusion.

Topics: Aconitate Hydratase; Animals; Antioxidants; Apoptosis; Apoptosis Regulatory Proteins; Carrier Proteins; Caspase 3; Cytochromes c; Drug Evaluation, Preclinical; Electron Spin Resonance Spectroscopy; Heme; In Situ Nick-End Labeling; Kidney; Male; Metalloporphyrins; Mitochondria; Mitochondrial Proteins; Oxidation-Reduction; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase; Time Factors

Certain determinants of ischemic resistance in the Brown Norway rat strain have been proposed, but no studies to date have focused on the role of the Wnt pathway in the ischemic resistance mechanism. We performed a comparative genomic study in Brown Norway vs. Sprague-Dawley rats. Selective manipulations of the Wnt pathway in vivo and in vitro allowed us to study whether the action of the Wnt pathway on apoptosis through the regulation of osteopontin was critical to the maintenance of inherent ischemic resistance mechanisms. The results revealed a major gene upregulation of the Wnt family in Brown Norway rats after renal ischemia-reperfusion. Manipulation of the Wnt signaling cascade by selective antibodies increased mitochondrial cytochrome c release and caspase 3 activity. The antiapoptotic role of Wnt was mediated by osteopontin, a direct Wnt target gene. Osteopontin was reduced by Wnt antibody administration in vivo, and osteopontin gene silencing in vitro significantly increased mitochondrial cytochrome c release. The overexpression of Wnt pathway genes detected in Brown Norway rats is critical in the maintenance of their inherent ischemic resistance. Activation of the Wnt signaling cascade reduces mitochondrial cytochrome c release and caspase 3 activity through the action of osteopontin.

Topics: Animals; Antibodies; Apoptosis; Caspase 3; Cell Line; Cytochromes c; Disease Models, Animal; Gene Expression Profiling; Kidney; Male; Mitochondria; Oligonucleotide Array Sequence Analysis; Osteopontin; Rats; Rats, Inbred BN; Rats, Sprague-Dawley; Reperfusion Injury; RNA Interference; Species Specificity; Transfection; Wnt Proteins

The present study aimed to investigate the change of cytochrome c in postconditioning-attenuated ischemia-reperfusion (I/R)-induced mucosal apoptosis in rat intestine compared with ischemic preconditioning (IPC). Using rat model of intestine I/R injury, male Sprague-Dawley rats weighing 220-250 g were divided into 4 groups which were Sham operation group, I/R group, IPC group and ischemic postconditioning (IPOST) group. In these groups, I/R procedure was performed by the occlusion of the superior mesenteric artery (SMA) for 45 min followed by reperfusion for 1 h. In Sham group, there was no intervention. In IPC group, SMA was occluded for 5 min and reperfused for 5 min, for two cycles, before the prolonged occlusion. In IPOST group, three cycles of 30-s reperfusion and 30-s reocclusion were preceded at the start of reperfusion. After the reperfusion, the small intestines were sampled for experimental detection. Intestinal mucosal mitochondrial membrane potential was detected by confocal laser scanning microscopy. Expressions of cytochrome c and caspase-3 proteins were detected using Western-blot method. The apoptosis of intestinal mucosal cells was determined with agarose gel electrophoresis and deoxynucleotidyl transferase mediated dUTP-biotin nick-end labeling (TUNEL) technique. Compared with I/R group, the mitochondrial membrane potentials and the expressions of cytochrome c protein were significantly increased, while the expressions of caspase-3 and the apoptotic rates were decreased in IPOST and IPC groups (P<0.05). There were no significant differences between IPOST and IPC groups (P>0.05). These data provide substantial evidence that IPOST attenuates I/R-induced mucosal apoptosis by reducing the release of cytochrome c from mitochondria in the rat small intestine.

Topics: Animals; Apoptosis; Cytochromes c; Intestinal Mucosa; Intestines; Ischemic Postconditioning; Male; Membrane Potential, Mitochondrial; Mitochondria; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Indirubin-3'-oxime is an indirubin analogue that shows favorable inhibitory activity targeting glycogen synthase kinase 3beta (GSK-3beta). In this study, we evaluated if acute treatment with indirubin-3'-oxime (Ind) prevents hepatic ischemia/reperfusion (I/R) damage. Wistar rats were subjected to 150 min of 70% warm ischemia and 16 h of reperfusion. In the treated group 1 microM indirubin-3'-oxime was administered in the hepatic artery 30 min before ischemia. Acute treatment with Ind decreased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) levels, comparatively to I/R livers. Bax translocation to the mitochondria and cytochrome c release were higher in I/R livers. Ind treatment significantly attenuated Bax translocation and preserved mitochondrial cytochrome c content. Ind also protected mitochondria from calcium-induced mitochondrial permeability transition (MPT), as well as the decrease in state 3 mitochondrial respiration, the delay in the repolarization after a phosphorylative cycle and the decrease in ATP content caused by I/R. By addressing GSK-3beta activity and phosphorylated GSK-3beta at Ser(9) content in liver homogenates and isolated mitochondria, data suggests that inhibition of GSK-3beta by indirubin-3'-oxime prevents the increase in mitochondrial phosphorylated GSK-3beta at Ser(9) induced by I/R, thus correlating with MPT inhibition and preservation of cytochrome c content. Pre-treatment with indirubin-3'-oxime in conditions of hepatic I/R, protects the liver by maintaining mitochondrial function and hepatic energetic balance.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; bcl-2-Associated X Protein; Cytochromes c; Enzyme Inhibitors; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Indoles; L-Lactate Dehydrogenase; Liver; Liver Function Tests; Male; Mitochondria; Oximes; Permeability; Rats; Rats, Wistar; Reperfusion Injury

Though recent studies have reported the importance of several endogenous cytoprotective factors including heat shock protein 70 (HSP70) that protect intestinal epithelial cells (IECs) from the effects of stress and injury, the exact mechanism of HSP70 underlying cytoprotection against hypoxia/reoxygenation induced IEC injury remains unclear. The present study was designed to investigate the possible mechanisms by which HSP70 protected IECs against hypoxia/reoxygenation injury and focused on the effects of HSP70 on IEC apoptosis induced by hypoxia/reoxygenation injury. Recombinant adenoviruses (Ad-HSP70) were transfected into the intestinal epithelial cell line in vitro and then suffered from 90 min of hypoxia followed by 60 min of reoxygenation. The LDH leaking, apoptosis, and mitochondrial membrane potential (Psi(m)) were evaluated after hypoxia/reoxygenation. The expression of HSP70, cytochrome c and Bcl-2 protein was determined by Western blot or immunofluorescence analysis. The results show that HSP70 protein was highly expressed in the IECs at 48h following Ad-HSP70 transfection. HSP70 overexpression could reduce LDH leakage and cell apoptosis in IECs following hypoxia/reoxygenation injury. Furthermore, the overexpression of HSP70 significantly reversed the decrease of mitochondrial membrane potential and the release of mitochondrial cytochrome c in IECs during hypoxia/reoxygenation. HSP70 overexpression was also associated with the increasing expression of Bcl-2 protein in IECs during hypoxia/reoxygenation. We conclude that HSP70 protects IECs against hypoxia/reoxygenation induced apoptosis through increasing Bcl-2 expression, which in turn could inhibit the mitochondria-related apoptotic pathway that involves the disruption of the Psi(m) and release of cytochrome c from mitochondria.

Topics: Animals; Apoptosis; Blotting, Western; Cell Hypoxia; Cell Line; Cytochromes c; HSP70 Heat-Shock Proteins; Humans; Intestinal Diseases; Intestinal Mucosa; Lactate Dehydrogenases; Membrane Potential, Mitochondrial; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Rats; Reperfusion Injury; Transfection; Up-Regulation

Ischemic brain is particularly susceptible to free radicals mediated secondary neuronal damage, especially mitochondrial dysfunctions. Chinese Herbal Medicine with antioxidant properties is believed to have potential therapeutic effect. Leonurine, an alkaloid present in Herba Leonuri (HL), has shown biological effects such as antioxidant, anticoagulant, anti-apoptosis and protection against ischemic heart disease. In this study, neuroprotective effects of leonurine against cerebral ischemia/reperfusion-induced mitochondrial dysfunctions in cortex were evaluated. We used transient rat middle cerebral artery occlusion (MCAO) model of brain ischemia. The rats were treated with their respective treatments for 1 week prior to the MCAO. We found that leonurine significantly improved neurological outcome and reduced ischemia/reperfusion (I/R)-induced cerebral infarction 24 h after MCAO. Leonurine decreased reactive oxygen species (ROS) level in mitochondria isolated from ischemic cortex, which was increased by MCAO. Terminal deoxyuridine triphosphate (dUTP) Nick-End Labeling (TUNEL) staining showed anti-apoptotic effect of leonurine on ischemic cortex. Western blot analysis showed a marked decrease in the expression of Bax and an increase of Bcl-2 as a result of leonurine treatment. The attenuation of mitochondrial membrane swelling, restore of mitochondrial membrane potential and content of cytochrome c (Cyt-C) in mitochondria isolated from ischemic cortex could also be observed in leonurine treated group. The findings of this study suggest that leonurine has promising therapeutic effect for ischemic stroke treatment through antioxidant and anti-apoptotic mechanisms.

Topics: Animals; Antioxidants; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Brain Ischemia; Cerebral Cortex; Cerebral Infarction; Cytochromes c; Disease Models, Animal; Drugs, Chinese Herbal; Gallic Acid; In Situ Nick-End Labeling; Leonurus; Male; Membrane Potential, Mitochondrial; Mitochondria; Mitochondrial Membranes; Neuroprotective Agents; Oxidative Stress; Phytotherapy; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

To investigate the effects of cyclosporine A (CsA), a powerful inhibitor of mitochondrial permeability transition pore (MPTP), on pneumocyte apoptosis, the release of cytochrome C and the activity of caspase-3 after lung ischemia/reperfusion, and explore the mechanisms.. Single lung in situ ischemia/reperfusion animal model was used. 30 SD rats were randomly divided into three groups (n = 10): sham (S) group, ischemia/reperfusion (I/R) group and cyclosporine A (CsA) group. Apoptosis of pneumocyte was assessed by TUNEL method, cytochrome C (CytC) in cytoplasm was detected by immunohistochemistry techniques, and the activity of caspase-3 was measured with spectrophotometer.. The content of CytC in cytoplasm, the activity of caspase-3, and the value of apoptosis index (AI) in ischemia/reperfusion group were evidently higher than that in S group (P < 0.01). CsA suppressed apoptosis as well as CytC release and caspase-3 activity (P < 0.01).. CsA can prevent the release of cytochrome C, block the apoptosis of pneumocyte accordingly maybe by closing the MPTP.

Topics: Alveolar Epithelial Cells; Animals; Apoptosis; Caspase 3; Cyclosporine; Cytochromes c; Lung; Male; Rats; Rats, Sprague-Dawley; Reperfusion Injury

During partial hepatectomy, ischemia-reperfusion (I/R) is commonly applied in clinical practice to reduce blood flow. Steatotic livers show impaired regenerative response and reduced tolerance to hepatic injury. We examined the effects of tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (PBA) in steatotic and non-steatotic livers during partial hepatectomy under I/R (PH+I/R). Their effects on the induction of unfolded protein response (UPR) and endoplasmic reticulum (ER) stress were also evaluated. We report that PBA, and especially TUDCA, reduced inflammation, apoptosis and necrosis, and improved liver regeneration in both liver types. Both compounds, especially TUDCA, protected both liver types against ER damage, as they reduced the activation of two of the three pathways of UPR (namely inositol-requiring enzyme and PKR-like ER kinase) and their target molecules caspase 12, c-Jun N-terminal kinase and C/EBP homologous protein-10. Only TUDCA, possibly mediated by extracellular signal-regulated kinase upregulation, inactivated glycogen synthase kinase-3β. This is turn, inactivated mitochondrial voltage-dependent anion channel, reduced cytochrome c release from the mitochondria and caspase 9 activation and protected both liver types against mitochondrial damage. These findings indicate that chemical chaperones, especially TUDCA, could protect steatotic and non-steatotic livers against injury and regeneration failure after PH+I/R.

Topics: Activating Transcription Factor 6; Animals; Caspase 12; Cytochromes c; Endoplasmic Reticulum; Fatty Liver; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Heat-Shock Proteins; Hepatectomy; JNK Mitogen-Activated Protein Kinases; Liver; Mitochondria; Phenylbutyrates; Rats; Rats, Zucker; Reperfusion Injury; Taurochenodeoxycholic Acid; Unfolded Protein Response; Voltage-Dependent Anion Channels

Cerebral ischemia-reperfusion injury is the main reason for the loss of neurons in the ischemic cerebrovascular disease. Therefore, to deeply understand its pathogenesis and find a new target is the key issue to be solved. This research aimed to investigate the neuroprotective effects of salvianolic acid B (SalB) against oxygen-glucose deprivation/reperfusion (OGD/RP) damage in primary rat cortical neurons.. The primary cultures of neonatal Wister rats were randomly divided into the control group, the OGD/RP group and the SalB-treatment group (10 mg/L). The cell model was established by depriving of oxygen and glucose for 3 hours and reperfusion for 3 hours and 24 hours, respectively. The neuron viability was determined by MTT assay. The level of cellular reactive oxygen species (ROS) was detected by fluorescent labeling method and spin trapping technique respectively. The activities of neuronal Mn-superoxide dismutase (Mn-SOD), catalase (CAT) and glutathione peroxidase (GSH-PX) were assayed by chromatometry. The mitochondria membrane potential (ΔΨ(m)) was quantitatively analyzed by flow cytometry. The release rate of cytochrome c was detected by Western blotting. The neuronal ultrastructure was observed by transmission electron microscopy. Statistical significance was evaluated by analysis of variance (ANOVA) followed by Student-Newman-Keuls test.. OGD/RP increased the level of cellular ROS, but decreased the cell viability and the activities of Mn-SOD, CAT and GSH-PX; SalB treatment significantly reduced the level of ROS (P < 0.05); and enhanced the cell viability (P < 0.05) and the activities of these antioxidases (P < 0.05). Additionally, OGD/RP induced the fluorescence value of ΔΨ(m) to diminish and the release rate of cytochrome c to rise notably; SalB markedly elevated the level of ΔΨ(m) (P < 0.01) and depressed the release rate of cytochrome c (P < 0.05); it also ameliorated the neuronal morphological injury.. The neuroprotection of SalB may be attributed to the elimination of ROS and the inhibition of apoptosis.

Topics: Animals; Apoptosis; Benzofurans; Catalase; Cells, Cultured; Cerebral Cortex; Cytochromes c; Glutathione Peroxidase; Hypoxia-Ischemia, Brain; Membrane Potential, Mitochondrial; Neuroprotective Agents; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase

The p53 tumor suppressor gene plays a crucial role in mediating apoptotic cell death in renal ischemia-reperfusion injury (IRI). To further elucidate the p53-dependent pathway, we investigated the role of the p53 apoptosis effector related to PMP-22 (PERP), an apoptosis-associated p53 transcriptional target. PERP mRNA and protein are highly induced in the outer medullary proximal tubular cells (PTC) of ischemic kidneys postreperfusion at 3, 12, and 24 h in a p53-dependent manner. In PTC, overexpression of PERP augmented the rate of apoptosis following hypoxia by inducing mitochondrial permeability and subsequent release of cytochrome c, apoptosis-inducing factor (AIF), and caspase 9 activation. In addition, silencing of the PERP gene with short hairpin RNA prevented apoptosis in hypoxia-mediated injury by precluding mitochondrial dysfunction and consequent cytochrome c and AIF translocation. These data suggest that PERP is a key effector of p53-mediated apoptotic pathways and is a potential therapeutic target for renal IRI.

Topics: Animals; Apoptosis; Apoptosis Inducing Factor; Caspase 9; Cell Hypoxia; Cytochromes c; Disease Models, Animal; Enzyme Activation; Epithelial Cells; Kidney; LLC-PK1 Cells; Male; Membrane Proteins; Mice; Mice, Knockout; Mitochondria; Mitochondrial Membranes; Permeability; Reperfusion Injury; RNA Interference; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Swine; Time Factors; Transfection; Tumor Suppressor Protein p53

This study examined the hypothesis that apoptotic inhibition via mitochondrial pathway was involved in hyperbaric oxygen preconditioning (HBO-PC)-induced neuroprotection on ischemia-reperfusion injury in rat brain. Male Sprague-Dawley rats (250 approximately 280 g, n=144) were divided into control, middle cerebral artery occlusion (MCAO) for 90 min, and HBO-PC plus MCAO groups. HBO-PC was conducted four times by giving 100% oxygen at 2.5 atm absolute (ATA), for 1 h at 12 h intervals for 2 days. At 24 h after the last HBO-PC, MCAO was performed and at 24 h after MCAO, neurological function, brain water content, infarct volume, and cell death were evaluated. Enzymatic activity of capase-3 and -9, and expression of cytochrome c, Bcl-2 and Bax proteins were performed in the samples from hippocampus, ischemic penumbra and core of the brain cortex, respectively. HBO-PC reduced brain edema, decreased infarction volume, and improved neurological recovery. HBO-PC reduced cytoplasm cytochrome c levels, decreased caspase enzyme activity, upregulated the ratio of Bcl-2 and Bax expression, and abated the apoptosis of ischemic tissue. HBO-PC protects brain tissues from ischemia-reperfusion injury by suppressing mitochondrial apoptotic pathways.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain; Caspase 3; Caspase 9; Cerebral Cortex; Cytochromes c; Hippocampus; Hyperbaric Oxygenation; Infarction, Middle Cerebral Artery; Male; Mitochondria; Motor Activity; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Water

Renal injury is a severe and extremely common complication that occurs early in neonates with asphyxia. Reperfusion injury has been suggested as the cause of kidney damage during resuscitation of neonatal asphyxia. Previous studies have demonstrated that postasphyxial serum from neonates with asphyxia may result in apoptosis of renal tubular cells. However, the mechanisms that mediate renal tubular cell apoptosis induced by postasphyxial serum remain poorly understood.. In this report we investigate the intracellular signal transduction mechanisms that operate during injury of renal tubular cells induced by postasphyxial serum in neonates.. Cultured human renal proximal tubular cells HK-2 cell were exposed to 10% fetal calf serum (normal control), 20% postasphyxial serum or 20% postasphyxial serum with pyrrolidine dithiocarbamate (PDTC). The expression of both BAD and BAX in the cytoplasm was detected by immunohistochemistry. The mitochondria membrane potential (Deltapsim) was examined by confocal microscopy, and the release of the apoptogenic mitochondrial proteins cytochrome C and AIF was assessed by Western blot analysis.. Loss of mitochondria membrane potential was detected in HK-2 cells treated with 20% postasphyxial serum as compared to cells in normal serum or PTDC-pretreated cells in 20% postasphyxial serum. A significant increase of Bad and Bax protein expression was also detected, along with the release of cytochrome C and AIF from mitochondria to cytosol in the postasphyxial serum treated cells, but not in the normal or PTDC-pretreated control cells.. Our findings suggest that postasphyxial serum may induce renal tubular cell apoptosis through the mitochondrial pathway, and its intracellular signal transduction mechanism includes the activation of nuclear factor-kappaB.

Topics: Apoptosis; Asphyxia Neonatorum; bcl-2-Associated X Protein; bcl-Associated Death Protein; Cell Line; Cytochromes c; Cytoplasm; Humans; Immunohistochemistry; Infant, Newborn; Kidney Diseases; Kidney Tubules; Kidney Tubules, Proximal; Membrane Potential, Mitochondrial; NF-kappa B; Pyrrolidines; Reperfusion Injury; Serum; Signal Transduction; Thiocarbamates

To determine the involvement of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in cytoprotection, we subjected N2-A cells to oxygen-glucose deprivation followed by reoxygenation (H-R). Following H-R insults, H(2)O(2) production was increased while cell viability declined, which was accompanied by loss of mitochondrial membrane potential (MMP), cytochrome c release, caspases 9 and 3 activation, poly(ADP-ribose)polymerase (PARP) cleavage and apoptosis. Rosiglitazone up to 5 microM protected cell viability, normalized MMP, and prevented apoptotic signals. The protective effect of rosiglitazone was abrogated by GW9662, a PPAR-gamma antagonist, or a specific PPAR-gamma small interference RNA (siRNA) but not a control scRNA. PPAR-gamma overexpression alone was effective in maintaining MMP and preventing apoptosis and its protective effect was also abrogated by PPAR-gamma siRNA or GW9662. To elucidate the mechanism by which PPAR-gamma protects MMP and prevents apoptosis, we analyzed Bcl-2, Bcl-xl, and phosphorylated Bad (p-Bad). H-R suppressed them. Rosiglitazone or PPAR-gamma overexpression restored them via PPAR-gamma. Rosiglitazone or PPAR-gamma overexpression preserved phosphorylated Akt and 3-phosphoinositide-dependent kinase-1 (PDK-1) in a PPAR-gamma dependent manner. These results indicate that ligand-activated PPAR-gamma protects N2-A cells against H-R damage by enhancing Bcl-2/Bcl-xl and maintaining p-Bad via preservation of p-Akt.

Topics: 3-Phosphoinositide-Dependent Protein Kinases; Anilides; Animals; Apoptosis; bcl-Associated Death Protein; bcl-X Protein; Caspase 3; Caspase 9; Cell Hypoxia; Cell Line, Tumor; Cell Survival; Cytochromes c; Cytoprotection; Dose-Response Relationship, Drug; Glucose; Hydrogen Peroxide; Membrane Potential, Mitochondrial; Mice; Mitochondria; Neuroblastoma; Phosphorylation; Poly(ADP-ribose) Polymerases; PPAR gamma; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; RNA Interference; RNA, Small Interfering; Rosiglitazone; Thiazolidinediones; Time Factors; Transfection; Up-Regulation

Prolonged ischemia amplified iscehemia/reperfusion (IR) induced renal apoptosis and autophagy. We hypothesize that ischemic conditioning (IC) by a briefly intermittent reperfusion during a prolonged ischemic phase may ameliorate IR induced renal dysfunction. We evaluated the antioxidant/oxidant mechanism, autophagy and apoptosis in the uninephrectomized Wistar rats subjected to sham control, 4 stages of 15-min IC (I15 x 4), 2 stages of 30-min IC (I30 x 2), and total 60-min ischema (I60) in the kidney followed by 4 or 24 hours of reperfusion. By use of ATP assay, monitoring O2-. amounts, autophagy and apoptosis analysis of rat kidneys, I60 followed by 4 hours of reperfusion decreased renal ATP and enhanced reactive oxygen species (ROS) level and proapoptotic and autophagic mechanisms, including enhanced Bax/Bcl-2 ratio, cytochrome C release, active caspase 3, poly-(ADP-ribose)-polymerase (PARP) degradation fragments, microtubule-associated protein light chain 3 (LC3) and Beclin-1 expression and subsequently tubular apoptosis and autophagy associated with elevated blood urea nitrogen and creatinine level. I30 x 2, not I15 x 4 decreased ROS production and cytochrome C release, increased Manganese superoxide dismutase (MnSOD), Copper-Zn superoxide dismutase (CuZnSOD) and catalase expression and provided a more efficient protection than I60 against IR induced tubular apoptosis and autophagy and blood urea nitrogen and creatinine level. We conclude that 60-min renal ischemia enhanced renal tubular oxidative stress, proapoptosis and autophagy in the rat kidneys. Two stages of 30-min ischemia with 3-min reperfusion significantly preserved renal ATP content, increased antioxidant defense mechanisms and decreased ischemia/reperfusion enhanced renal tubular oxidative stress, cytosolic cytochrome C release, proapoptosis and autophagy in rat kidneys.

Topics: Aldehydes; Animals; Antioxidants; Apoptosis; Autophagy; Blood Urea Nitrogen; Creatinine; Cysteine Proteinase Inhibitors; Cytochromes c; Female; Ischemic Preconditioning; Isoenzymes; Kidney; NADPH Oxidases; Nephrectomy; Oxidative Stress; Peroxidase; Rats; Rats, Wistar; Reactive Oxygen Species; Reperfusion Injury; Superoxide Dismutase

Our previous studies showed that the assembly of the GluR6-PSD95-mixed lineage kinase 3 (MLK3) signaling module played an important role in rat ischemic brain injury. In this study, we aimed to elucidate whether ischemic preconditioning could downregulate the assembly of the GluR6-PSD95-MLK3 signaling module and suppress the activation of MLK3, MKK4/7, and c-Jun N-terminal kinase (JNK). As a result, ischemic preconditioning could not only inhibit the assembly of the GluR6-PSD95-MLK3 signaling module, diminish the phosphorylation of the transcription factor c-Jun, downregulate Fas ligand expression, attenuate the phosphorylation of 14-3-3 and Bcl-2 and the translocation of Bax to mitochondria, but also increase the release of cytochrome c and the activation of caspase-3. In contrast, both GluR6 antisense ODNs (oligodeoxynucleotides) and 6,7,8,9-tetrahydro-5-nitro-1 H-benz[g]indole-2,3-dione-3-oxime (NS102), an antagonist of GluR6 receptor, prevented the above effects of preconditioning, which shows that suppressing the expression of GluR6 or inhibiting GluR6 activity contributes negatively to preconditioning-induced ischemia tolerance. Taken together, our results indicate that preconditioning can inhibit the over-assembly of the GluR6-PSD95-MLK3 signaling module and the JNK3 activation. GluR6 subunit-containing kainite receptors play an important role in the preconditioning-induced neuronal survival and provide new insight into stroke therapy.

Topics: 14-3-3 Proteins; Animals; Apoptosis; Brain Ischemia; Caspase 3; Cell Nucleus; Cytochromes c; Disks Large Homolog 4 Protein; Enzyme Activation; Fas Ligand Protein; GluK2 Kainate Receptor; Hippocampus; Intracellular Signaling Peptides and Proteins; Ischemic Preconditioning; Male; MAP Kinase Kinase Kinases; Membrane Proteins; Mitogen-Activated Protein Kinase 10; Mitogen-Activated Protein Kinase Kinase Kinase 11; Mitogen-Activated Protein Kinase Kinases; Neurons; Phosphorylation; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Receptors, Kainic Acid; Reperfusion Injury; Signal Transduction

The mechanism of mitochondrial damage, a key contributor to renal tubular cell death during acute kidney injury, remains largely unknown. Here, we have demonstrated a striking morphological change of mitochondria in experimental models of renal ischemia/reperfusion and cisplatin-induced nephrotoxicity. This change contributed to mitochondrial outer membrane permeabilization, release of apoptogenic factors, and consequent apoptosis. Following either ATP depletion or cisplatin treatment of rat renal tubular cells, mitochondrial fragmentation was observed prior to cytochrome c release and apoptosis. This mitochondrial fragmentation was inhibited by Bcl2 but not by caspase inhibitors. Dynamin-related protein 1 (Drp1), a critical mitochondrial fission protein, translocated to mitochondria early during tubular cell injury, and both siRNA knockdown of Drp1 and expression of a dominant-negative Drp1 attenuated mitochondrial fragmentation, cytochrome c release, caspase activation, and apoptosis. Further in vivo analysis revealed that mitochondrial fragmentation also occurred in proximal tubular cells in mice during renal ischemia/reperfusion and cisplatin-induced nephrotoxicity. Notably, both tubular cell apoptosis and acute kidney injury were attenuated by mdivi-1, a newly identified pharmacological inhibitor of Drp1. This study demonstrates a rapid regulation of mitochondrial dynamics during acute kidney injury and identifies mitochondrial fragmentation as what we believe to be a novel mechanism contributing to mitochondrial damage and apoptosis in vivo in mouse models of disease.

Topics: Adenosine Triphosphate; Animals; Apoptosis; Caspase Inhibitors; Cell Line; Cells, Cultured; Cisplatin; Cytochromes c; Dynamins; Enzyme Inhibitors; GTP Phosphohydrolases; Imaging, Three-Dimensional; Kidney Tubular Necrosis, Acute; Kidney Tubules, Proximal; Male; Mice; Mice, Inbred C57BL; Microtubule-Associated Proteins; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Rats; Reperfusion Injury; RNA, Small Interfering; Sodium Azide

Ghrelin is known to promote neuronal defense and survival against ischemic injury by inhibiting apoptotic processes. In the present study, we investigated the role of prostate apoptosis response-4 (Par-4), a proapoptotic gene the expression of which is increased after ischemic injury, in ghrelin-mediated neuroprotection during middle cerebral artery occlusion (MCAO). Both ghrelin and des-acyl ghrelin protected cortical neurons from ischemic injury. Ghrelin receptor specific antagonist abolished the protective effects of ghrelin, whereas those of des-acyl ghrelin were preserved, suggesting the involvement of a receptor that is distinct from GHS-R1a. The expression of Par-4 was increased by MCAO, which was attenuated by ghrelin and des-acyl ghrelin treatments. Both ghrelin and des-acyl ghrelin increased the Bcl-2/Bax ratio, prevented cytochrome c release, and inhibited caspase-3 activation. Our data indicate that des-acyl ghrelin, as well as ghrelin, protect cortical neurons against ischemic injury through the inhibition of Par-4 expression and apoptotic molecules in mitochondrial pathway.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2-Associated X Protein; Brain Ischemia; Caspase 3; Cytochromes c; Ghrelin; Infarction, Middle Cerebral Artery; Male; Neurons; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Receptors, Ghrelin; Reperfusion Injury

To investigate the effect of dauricine on the apoptosis of neuronal cells and the expression of apoptosis-related proteins in the brain penumbra of rats induced by transient focal cerebral ischemia-reperfusion injury.. Male SD rats were randomly divided into five groups: sham group (Sham), model group (Model), and Dauricine groups of low, middle and high doses. To make the transient focal cerebral ischemia-reperfusion injury model, the middle cerebral artery on the right side of rat was occluded by inserting a nylon suture through the internal carotid artery for 1 h, followed by reperfusion for 24 h after withdrawing the suture. Dauricine groups, different doses of Dauricine (2.5, 5, 10 mg x kg(-1) as low, middle and high dose respectively) were administered intraperitoneally at the beginning of the cerebral ischemia, and at 11 h and 23 h after reperfusion. At the same time, Sham group and Model group was administered saline as controls. Brain samples of rats were treated with paraformaldehyde perfusion fixation 24 h after blood reperfusion and then collected for making pathological sections. Apoptotic changes of neuronal cells in the brain penumbra of rat were evaluated in situ by terminal deoxyribonucleotidyl transferasemediated dUTP-digoxigenin nick end-labelling (TUNEL). Cytochrome C (Cyt-C) release and the expression of caspase -3 and caspase -9 proteins of the ischemic-reperfusion brain tissue were determined by immunohistochemistry assay.. TUNEL-positive cells in groups of middle and high doses of dauricine (18.9 +/- 2.02 and 15.9 +/- 2.9 cells/mm2 respectively) decreased significantly compared with model group (25.5 +/- 3.3 cells/mm2, P<0.05). Cyt-C release and the expression of caspase-3 and caspase-9 proteins in groups of middle and high doses of dauricine were also inhibited compared with Model group (P<0.01).. The mechanism of the neuroprotective effect of dauricine after cerebral ischemia-reperfusion injury may parly, related with an inhibition of neuronal cells apoptosis in the penumbra.

Topics: Animals; Apoptosis; Benzylisoquinolines; Caspases; Cytochromes c; Dose-Response Relationship, Drug; Gene Expression Regulation; Ischemic Attack, Transient; Male; Neuroprotective Agents; Rats; Reperfusion Injury; Tetrahydroisoquinolines

Ischemic brain is highly vulnerable to free radicals mediated secondary neuronal damage especially mitochondrial dysfunctions. Present study investigated the neuroprotective effect of S-allyl L-cysteine (SAC), a water soluble compound from garlic, against cerebral ischemia/reperfusion (I/R)-induced mitochondrial dysfunctions in hippocampus (HIP). We used transient rat middle cerebral artery occlusion (MCAO) model of brain ischemia. SAC (300 mg/kg) was given twice intraperitoneally: 15 min pre-occlusion and 2 h post-occlusion at the time of reperfusion. SAC significantly restored ATP content and the activity of mitochondrial respiratory complexes in SAC treated group which were severely altered in MCAO group. A marked decrease in calcium swelling was observed as a result of SAC treatment. Western blot analysis showed a marked decrease in cytochrome c release as a result of SAC treatment. The status of mitochondrial glutathione (GSH) and glucose 6-phosphate dehydrogenase (G6-PD) was restored by SAC treatment with a significant decrease in mitochondrial lipid peroxidation (LPO), protein carbonyl (PC) and H2O2 content. SAC significantly improved neurological deficits assessed by different scoring methods as compared to MCAO group. Also, the brain edema was significantly reduced. The findings of this study suggest the ability of SAC in functional preservation of ischemic neurovascular units and its therapeutic relevance in the treatment of ischemic stroke.

Topics: Animals; Blotting, Western; Brain Edema; Calcium; Cysteine; Cytochromes c; Electron Transport Chain Complex Proteins; Glutathione; Hippocampus; Hydrogen Peroxide; Infarction, Middle Cerebral Artery; Lipid Peroxidation; Male; Mitochondria; Motor Activity; Neuroprotective Agents; Protein Carbonylation; Rats; Rats, Wistar; Reperfusion Injury; Severity of Illness Index

Although anoxic preconditioning (APC) in the myocardium has been investigated for many years, its physiological mechanism is still not completely understood. Increasing evidence indicates that transiently increased resistance to ischemic damage following APC is dependent on de novo proteins synthesis. However, the key effector pathway(s) associated with APC still remains unclear. The proto-oncogene Pim kinase belongs to a serine/threoine protein kinase family, consists of Pim-1, Pim-2 and Pim-3 and has been implicated in stimulating cell growth and inhibiting cell apoptosis. Therefore we assumed that Pim-3 expression might be aberrantly induced in cardiomyocytes that were subjected to anoxia/reoxygenation (A/R) injury and that Pim-3 might also contribute to cardio-protection after APC. To address this hypothesis, we cloned a Pim-3 expression vector, transfected it into rat cardiomyocytes, and examined Pim-3 expression in rat cardiomyocytes that were subjected to A/R injury. Moreover, we studied the role of three major MAPK pathways, e.g. p38 MAPK, JNK, and ERK1/2, in order to evaluate the molecular mechanism underlying Pim-3 up-regulation and A/R induced cardiomyocyte injury. Our experiments showed that APC induced an up-regulation of Pim-3 and the transfection of Pim-3 gene into the cardiomyocytes attenuated A/R injury. The inhibition of p38 MAPK by SB203580 abolished both the Pim-3 up-regulation and the cardio-protection provided by APC. Overall, these results suggest that APC could act to protect the heart from A/R injury with cooperation from the proto-oncogene Pim-3; in addition, it up-regulates Pim-3 expression through a p38 MAPK signaling pathway.

Topics: Animals; Apoptosis; Cell Hypoxia; Cell Survival; Cytochromes c; Gene Expression Regulation; In Situ Nick-End Labeling; Ischemic Preconditioning, Myocardial; L-Lactate Dehydrogenase; MAP Kinase Signaling System; Myocytes, Cardiac; p38 Mitogen-Activated Protein Kinases; Protein Serine-Threonine Kinases; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Apoptosis as well as necrosis may play an important role in hepatic ischemia/reperfusion (I/R) injury. Interleukin 10 (IL-10), a Th2 type cytokine, modulates inflammatory responses by inhibiting the production of proinflammatory cytokines. The study focused on cytoprotective and antiapoptotic pathways to assess mechanisms by which gene transduction of human IL-10 (hIL-10) may renders grafts resistant to the cold I/R injury.. Adenoviruses encoding hIL-10 or beta-galactosidase (LacZ) were injected via the superior mesenteric vein into prospective donor animals. The donor liver was harvested 48h after transduction, and stored for 12h at 4 degrees C lactated Ringer's solution prior to being transplanted. Graft survival, liver function, the degree of necrosis and apoptosis, and the molecules of apoptotic networks were assessed.. Ad-hIL-10 pretreatment significantly prolonged the survival of liver grafts by improving liver function, preserving hepatocyte integrity and architecture, and depressing intrahepatic apoptosis and necrosis. In addition, Ad-hIL-10 pretreatment diminished the release of cytochrome c from mitochondria into cytoplasm and caspase-3 activity, with simultaneous up-regulated of antioxidant HO-1 and anti-antiapoptotic Bcl-2 molecules.. Adenoviral gene transfer of hIL-10 ameliorated cold I/R injury by decreasing hepatic necrosis and apoptosis. The underlying mechanism of cytoprotective effects may at least be involved with the inhibition of caspase-3 activity and mitochondrial cytochrome c release, and the up-regulation of antiapoptotic (Bcl-2) and antioxidant (HO-1) molecules.

Topics: Adenoviridae; Animals; Apoptosis; Cold Temperature; Cryoprotective Agents; Cytochromes c; Genetic Therapy; Graft Survival; Hepatocytes; Humans; Interleukin-10; Liver Transplantation; Necrosis; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Recent studies have shown that kainate (KA) receptors are involved in neuronal cell death induced by seizure, which is mediated by the GluR6.PSD-95.MLK3 signaling module and subsequent JNK activation. In our previous studies, we demonstrated the neuroprotective role of a GluR6 c-terminus containing peptide against KA or cerebral ischemia-induced excitotoxicity in vitro and in vivo. Here, we first report that overexpression of the PDZ1 domain of PSD-95 protein exerts a protective role against neuronal death induced by cerebral ischemia-reperfusion in vivo and can prevent neuronal cell death induced by oxygen-glucose deprivation. Further studies show that overexpression of PDZ1 can perturb the interaction of GluR6 with PSD-95 and suppress the assembly of the GluR6.PSD-95.MLK3 signaling module and therefore inhibit JNK activation. Thus, it not only inhibits phosphorylation of c-Jun and down-regulates Fas ligand expression but also inhibits phosphorylation of 14-3-3 and decreases Bax translocation to mitochondria, decreases the release of cytochrome c, and decreases caspase-3 activation. Overall, the essential role of the PDZ1 domain of PSD-95 in apoptotic cell death in neurons provides an experimental foundation for gene therapy of neurodegenerative diseases with overexpression of the PDZ1 domain.

Topics: Analysis of Variance; Animals; bcl-2-Associated X Protein; Blotting, Western; Cell Death; Cell Fractionation; Cell Line; Cells, Cultured; Cytochromes c; Disks Large Homolog 4 Protein; Glucose; GluK2 Kainate Receptor; Hippocampus; Humans; Hypoxia; Immunohistochemistry; In Situ Nick-End Labeling; Intracellular Signaling Peptides and Proteins; JNK Mitogen-Activated Protein Kinases; Male; Membrane Proteins; Mitochondria; Neurons; Phosphorylation; Protein Transport; Rats; Rats, Sprague-Dawley; Receptors, Kainic Acid; Reperfusion Injury; Signal Transduction; Subcellular Fractions

Nitric oxide ((.)NO) generated by the dissociation of S-nitrosoglutathione or added as gaseous solution, inhibits the oxidation of exogenous NADH supported by the activity of the cytosolic NADH/cyto-c electron transport pathway. The inhibition is immediate, very strong, higher at lower oxygen concentration, independent on the (.)NO concentration and remains constant as long as (.)NO is no more available and then is spontaneously removed. The data obtained, not in contrast with those reported with isolated cytochrome oxidase (Cox), strengthen a new concept: reduced cytochrome c (cyto-c) and (.)NO behave as two substrates of Cox, which promotes their oxidation with molecular oxygen as a co-substrate. In the presence of (.)NO, Cox exhibits the property of switching from cyto-c oxidase to (.)NO oxidase activity. With an "all or nothing" process Cox becomes an efficient (.)NO scavenger. The persistence of membrane potential, even in the presence of high inhibition of oxygen uptake, could be tentatively correlated to the protective effect of (.)NO on the ischaemic-reperfusion injury.

Topics: Animals; Cytochromes c; Cytosol; Dose-Response Relationship, Drug; Electron Transport Complex IV; Membrane Potential, Mitochondrial; Mitochondria, Liver; NAD; Nitric Oxide; Oxygen; Protein Transport; Rats; Rats, Wistar; Reperfusion Injury

NAD+ acts not only as a cofactor for cellular respiration but also as a substrate for NAD(+)-dependent enzymes, such as Sirt1. The cellular NAD+ synthesis is regulated by both the de novo and the salvage pathways. Nicotinamide phosphoribosyltransferase (Nampt) is a rate-limiting enzyme in the salvage pathway.. Here we investigated the role of Nampt in mediating NAD+ synthesis in cardiac myocytes and the function of Nampt in the heart in vivo.. Expression of Nampt in the heart was significantly decreased by ischemia, ischemia/reperfusion and pressure overload. Upregulation of Nampt significantly increased NAD+ and ATP concentrations, whereas downregulation of Nampt significantly decreased them. Downregulation of Nampt increased caspase 3 cleavage, cytochrome c release, and TUNEL-positive cells, which were inhibited in the presence of Bcl-xL, but did not increase hairpin 2-positive cells, suggesting that endogenous Nampt negatively regulates apoptosis but not necrosis. Downregulation of Nampt also impaired autophagic flux, suggesting that endogenous Nampt positively regulates autophagy. Cardiac-specific overexpression of Nampt in transgenic mice increased NAD+ content in the heart, prevented downregulation of Nampt, and reduced the size of myocardial infarction and apoptosis in response to prolonged ischemia and ischemia/reperfusion.. Nampt critically regulates NAD+ and ATP contents, thereby playing an essential role in mediating cell survival by inhibiting apoptosis and stimulating autophagic flux in cardiac myocytes. Preventing downregulation of Nampt inhibits myocardial injury in response to myocardial ischemia and reperfusion. These results suggest that Nampt is an essential gatekeeper of energy status and survival in cardiac myocytes.

Topics: Adenosine Triphosphate; Animals; Animals, Newborn; Apoptosis; Autophagy; bcl-X Protein; Caspase 3; Cells, Cultured; Cytochromes c; Cytokines; Disease Models, Animal; Energy Metabolism; Mice; Mice, Transgenic; Myocardial Ischemia; Myocytes, Cardiac; NAD; Nicotinamide Phosphoribosyltransferase; Rats; Rats, Wistar; Reperfusion Injury; RNA Interference; RNA, Messenger

Stroke is the third leading cause of death in the United States, yet no neuroprotective agents for treatment are clinically available. There is a pressing need to understand the signaling molecules that mediate ischemic cell death and identify novel neuroprotective targets. Cyclopentenone isoprostanes (IsoPs), formed after free radical-mediated peroxidation of arachidonic acid, are used as markers of stress, but their bioactivity is poorly understood. We have recently shown that 15-A(2t)-IsoP is a potent neurotoxin in vitro and increases the free radical burden in neurons. In this work, we demonstrate that 15-A(2t)-IsoP is abundantly produced in stroke-infarcted human cortical tissue. Using primary neuronal cultures we found that minimally toxic exposure to 15-A(2t)-IsoP does not alter ATP content, but in combination with oxygen glucose deprivation resulted in a significant hyperpolarization of the mitochondrial membrane and dramatically increased neuronal cell death. In the presence of Ca(2+), 15-A(2t)-IsoP led to a rapid induction of the permeability transition pore and release of cytochrome c. Taken with our previous work, these data support a model in which ischemia causes generation of reactive oxygen species, calcium influx, lipid peroxidation, and 15-A(2t)-IsoP formation. These factors combine to enhance opening of the permeability transition pore leading to cell death subsequent to mitochondrial cytochrome c release. These data are the first documentation of significant 15-A(2t)-IsoP formation after acute ischemic stroke and suggest that the addition of 15-A(2t)-IsoP to in vitro models of ischemia may help to more fully recapitulate stroke injury.

Topics: Animals; Calcium; Cells, Cultured; Cytochromes c; Dose-Response Relationship, Drug; Humans; Lipid Peroxidation; Mass Spectrometry; Mitochondria; Neurons; Prostaglandins A; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Stroke; Time Factors

Although it is becoming increasingly common to accept livers from older donors for transplantation, old livers are more damaged by hepatic ischemia and reperfusion injury (HIRI) than young livers. We hypothesized that this age-related susceptibility to HIRI is due to increased hepatocellular apoptosis driven by tumor necrosis factor alpha (TNFalpha). Young (6-week-old) and old (60-week-old) mice underwent 60 minutes of hepatic ischemia and increasing periods of reperfusion. TNFalpha was determined by enzyme-linked immunosorbent assay. Liver injury (enzyme release), apoptosis (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-digoxigenin nick-end labeling staining, cytochrome C release, and caspase activation), and necrosis (hematoxylin and eosin staining) were assessed. We assessed the impact of apoptosis by blocking TNFalpha production or effect (pentoxifylline and TNFalpha receptor knockout), inhibiting apoptotic pathways (caspase inhibition), or imposing a hepatic protective strategy [glucose infusion with ischemic preconditioning (Glc/PC)]. In comparison with young livers, old livers subjected to HIRI had more pronounced liver aspartate aminotransferase release (6200 versus 3900 U/L, P = 0.02), necrosis (45% versus 25%, P = 0.03), and apoptosis with increased 30-minute TNFalpha release (19.02 versus 10.62 pg/mg, P = 0.03). Eliminating TNFalpha production reversed the effect of age, as did inhibition of apoptotic pathways with caspase inhibition. Glc/PC of old mice attenuated TNFalpha release (9.56 versus 19.02 pg/mg, P = 0.001) and age-related exaggerated HIRI and improved survival (60% versus 0%). In conclusion, the age-related susceptibility to HIRI is driven by an exaggerated induction of TNFalpha-dependent hepatocellular apoptosis. Targeting the apoptotic cascade has implications for the older donor liver population.

Topics: Aging; Animals; Apoptosis; Caspase 3; Cytochromes c; Disease Models, Animal; In Situ Nick-End Labeling; Ischemic Preconditioning; Liver; Liver Transplantation; Macrophages, Peritoneal; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Necrosis; Receptors, Tumor Necrosis Factor, Type I; Reperfusion Injury; Survival Rate; Tumor Necrosis Factor-alpha; Up-Regulation

Ischemic preconditioning (IPC) and anesthetic-induced preconditioning against myocardial infarction are mediated via protein kinase B. Pim-1 kinase acts downstream of protein kinase B and was recently shown to regulate cardiomyocyte survival. The authors tested the hypothesis that IPC and anesthetic-induced preconditioning are mediated by Pim-1 kinase.. Pentobarbital-anesthetized male C57Black/6 mice were subjected to 45 min of coronary artery occlusion and 3 h of reperfusion. Animals received no intervention, Pim-1 kinase inhibitor II (10 microg/g intraperitoneally), its vehicle dimethyl sulfoxide (10 microl/g intraperitoneally), or 1.0 minimum alveolar concentration desflurane alone or in combination with Pim-1 kinase inhibitor II (10 microg/g intraperitoneally). IPC was induced by three cycles of 5 min ischemia-reperfusion each, and animals received IPC either alone or in combination with Pim-1 kinase inhibitor II (10 microg/g intraperitoneally). Infarct size was determined with triphenyltetrazolium chloride, and area at risk was determined with Evans blue (Sigma-Aldrich, Taufkirchen, Germany). Protein expression of Pim-1 kinase, Bad, phospho-Bad, and cytosolic content of cytochrome c were measured using Western immunoblotting.. Infarct size in the control group was 47 + or - 2%. Pim-1 kinase inhibitor II (44 + or - 2%) had no effect on infarct size. Desflurane (17 + or - 3%) and IPC (19 + or - 2%) significantly reduced infarct size compared with control (both P < 0.05 vs. control). Blockade of Pim-1 kinase completely abrogated desflurane-induced preconditioning (43 + or - 3%), whereas IPC (35 + or - 3%) was blocked partially. Desflurane tended to reduce cytosolic content of cytochrome c, which was abrogated by Pim-1 kinase inhibitor II.. These data suggest that Pim-1 kinase mediates at least in part desflurane-induced preconditioning and IPC against myocardial infarction in mice.

Topics: Anesthetics, Inhalation; Animals; bcl-Associated Death Protein; Blood Pressure; Blotting, Western; Cytochromes c; Data Interpretation, Statistical; Desflurane; Enzyme Activation; Heart Rate; Ischemic Preconditioning, Myocardial; Isoflurane; Male; Mice; Mice, Inbred C57BL; Myocardial Infarction; Myocardium; Proto-Oncogene Proteins c-pim-1; Reperfusion Injury; Signal Transduction

In response to ischemic/hypoxic preconditioning, tissues/organs exhibit protective responses to subsequent and severe ischemic stress. We hypothesized that repetitive hypoxic preconditioning (RHP) may provide long-lasting protection than single preconditioning against ischemia/reperfusion injury in rat kidneys through hypoxia-induced factor (HIF)-1-dependent pathway.. For RHP induction, female Wistar rats were subjected to intermittent hypoxic exposure (380 Torr) 15 hr/day for 28 days.. RHP increased renal HIF-1 alpha mRNA and protein expression and triggered HIF-1 alpha-dependent renal Bcl-2 protein expression in a time-dependent manner. When returning to normoxia, increased RHP exposure prolonged renal Bcl-2 expression. Forty-five minutes of renal ischemia with 4 hr of reperfusion enhanced O2- levels and proapoptotic mechanisms, including enhanced cytosolic Bax translocation to mitochondria, release of cytochrome c to cytosol, activation of caspase 3, poly-(ADP-ribose)-polymerase fragments, tubular apoptosis, blood urea nitrogen, and creatinine level. RHP treatment depressed renal O2- production, mitochondrial Bax translocation and cytochrome c release, and tubular apoptosis. In the primary tubular cultures from RHP-treated kidneys, antisense oligodeoxyribonucleotides of bcl-2 abrogated this protection.. RHP activates an HIF-1 alpha-dependent signaling cascade leading to an increase in Bcl-2 protein expression, an inhibition in cytosolic Bax and mitochondrial cytochrome c translocation, and a hypoxic/ischemia tolerance against renal ischemia/reperfusion injury.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Blood Urea Nitrogen; Caspase 3; Cells, Cultured; Creatinine; Cytochromes c; Disease Models, Animal; Female; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Kidney; Kidney Diseases; Mitochondria; Oligodeoxyribonucleotides, Antisense; Oxidative Stress; Poly Adenosine Diphosphate Ribose; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger; Signal Transduction; Superoxides; Time Factors; Up-Regulation

To explore the effect of propofol preconditioning on cardiomyocyte apoptosis and cytochrome C release from mitochondria during mild hypothermic ischemia/reperfusion in isolated rat hearts.. 50 isolated SD rat hearts perfused on Langendorff apparatus were randomly divided into 5 groups (n=10): control group (C), DMSO group (D), 3 different concentrations of propofol groups of 25 micromol x L(-1) (P1), 50 micromol x L(-1) (P2), 100 micromol x L(-1) (P3) propofol respectively. All of the isolated rat hearts were subjected to 31 degrees C mild hypothermic ischemia for 55 min followed by 60 min reperfusion. The D, P1, P2, P3 groups were preconditioned by perfusing with K-H solution containing 20 micromol x L(-1) DMSO and 25, 50, 100 micromol x L(-1) propofol respectively for 10 min and then followed by 5 min K-H solution washing out before ischemia. The preconditioning procedure was repeated twice. Hemodynamics of the hearts was recorded after equilibration(baseline values) immediately before ischemia, 30 min and 60 min after reperfusion respectively. Cardiomyocyte apoptosis rate and contents of cytosolic and mitochondrial cytochrome C were measured at the end of reperfusion.. After 30 min and 60 min reperfusion, LVEDP was significantly lower and LVDP was significantly higher in P3 group than those in C group ( P < 0.05, P < 0.01). Compared with C group, cardiomyocyte apoptosis rate of the hearts decreased significantly in P2,P3 groups at the end of reperfusion (P < 0.05, P < 0.01). Cytochrome C level increased significantly in mitochondria but decreased significantly in cytosol in P2, P3 groups as compared with C group (P < 0.05, P < 0.01).. Propofol preconditioning decreased cardiomyocyte apoptosis, protected the heart against 31 degrees C mild hypothermic ischemia/reperfusion injury by attenuation of the release of cytochrome C from mitochondria to cytosol.

Topics: Animals; Apoptosis; Cytochromes c; Hypothermia, Induced; In Vitro Techniques; Ischemic Preconditioning; Male; Mitochondria, Heart; Myocardium; Propofol; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury

The critical event of the intrinsic pathway of apoptosis following transient global brain ischemia is the release of cytochrome c from the mitochondria. In vitro studies have shown that insulin can signal specifically via phosphatidylinositol-3-OH-kinase (PI3-K) and Akt to prevent cytochrome c release. Therefore, insulin may exert its neuroprotective effects during brain reperfusion by blocking cytochrome c release. We hypothesized that insulin acts through PI3-K, Akt, and Bcl-2 family proteins to inhibit cytochrome c release following transient global brain ischemia. We found that a single bolus of insulin given immediately upon reperfusion inhibited cytochrome c release for at least 24 h, and produced a fivefold improvement in neuronal survival at 14 days. Moreover, insulin's ability to inhibit cytochrome c release was completely dependent on PI3-K signaling and insulin induces phosphorylation of Akt through PI3-K. In untreated animals, there was an increase in mitochondrial Bax at 6 h of reperfusion, and Bax binding to Bcl-X(L) was disrupted at the mitochondria. Insulin prevented both these events in a PI3-K-dependent manner. In summary, insulin regulates cytochrome c release through PI3-K likely by activating Akt, promoting the binding between Bax and Bcl-X(L), and by preventing Bax translocation to the mitochondria.

Topics: Animals; bcl-2-Associated X Protein; bcl-X Protein; Brain Ischemia; Cytochromes c; Insulin; Male; Phosphatidylinositol 3-Kinases; Protein Binding; Rats; Rats, Long-Evans; Reperfusion Injury; Signal Transduction

Ischemic postconditioning (Postcond) is defined as a series of intermittent interruptions of blood flow in the early phase of reperfusion that mechanically alters the hydrodynamics of reperfusion. A recent study showed that Postcond reduced infarct size in cerebral ischemia/reperfusion (I/R) injury. However, little is known about the mechanisms of Postcond in cerebral I/R injury. In the present study, we investigated the effects of Postcond in focal cerebral I/R injury in the rat middle cerebral artery occlusion model.. Adult male Sprague-Dawley rats were treated with Postcond after 60 minutes of occlusion (beginning of reperfusion). Neurologic scores and infarct volumes were assessed at 24 and 72 hours. Oxidative stress was evaluated by malondialdehyde assay, and apoptosis-related molecules were studied by Western blotting.. Postcond treatment upregulated Bcl-2 and heat-shock protein 70 expression and downregulated cytochrome c release to the cytosol, Bax translocation to the mitochondria, and caspase-3 activity. Postcond treatment also reduced infarct volumes and oxidative stress levels and improved neurologic scores compared with the I/R-only group.. These findings indicate that Postcond inhibits focal cerebral I/R injury. This neuroprotective effect is likely achieved by antiapoptotic mechanisms.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Brain Ischemia; Caspase 3; Cytochromes c; Disease Models, Animal; Down-Regulation; HSP70 Heat-Shock Proteins; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Ischemic Preconditioning; Male; Oxidative Stress; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; RNA, Messenger; Up-Regulation

Recent studies have suggested that neuronal apoptosis in cerebral ischemia could arise from dysfunction of endoplasmic reticulum (ER) and mitochondria. B-cell lymphoma/leukemia-2 gene (Bcl-2) has been described as an inhibitor both in programmed cell death (PCD) and ER dysfunction during apoptosis, and the Bcl-2 family play a key role in regulating the PCD, both locally at the ER and from a distance at the mitochondrial membrane. However, its signal pathways and concrete mechanisms in endoplasmic reticulum-initiated apoptosis remain incompletely understood. We therefore investigate whether ischemia/reperfusion (I/R) causes neuronal apoptosis in part via cross-talk between ER and mitochondria or not, and how the overexpression of Bcl-2 prevents this form of cell death. Here we show that analogous I/R-induced cell death occurs consequent to interactions of ER stress and mitochondrial death pathways. The participation of the mitochondrial pathway was demonstrated by the release of cytochrome C (cyt C) from mitochondrial into cytoplasmic fractions and caspase-9 cleavage. The involvement of ER stress was further supported by the observable increase of glucose-regulated protein 78(GRP78)/BiP expression and caspase-12 activity. Furthermore, prior to these changes, swelling of the ER lumen and dissociation of ribosomes from rough ER were detected by electron microscopy. Bcl-2 overexpression inhibits the release of cyt C and the activation of caspase-9/-8/-3 but not caspase-12 based on the results of Western blot. These suggest that cross-talk between ER and mitochondria participate in neuronal damage after ischemia/reperfusion. Bcl-2 overexpression could suppress I/R-induced neuronal apoptosis via influencing mitochondrial integrity.

Topics: Animals; Apoptosis; Blotting, Western; Caspases; Cells, Cultured; Cerebral Cortex; Cytochromes c; Endoplasmic Reticulum; Microscopy, Electron, Transmission; Mitochondria; Neurons; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Up-Regulation

Although mesenchymal stem cells (MSCs) are being tested for cardiac repair, the majority of transplanted cells undergo apoptosis in the ischaemic heart because of the effects of ischaemia/reperfusion, poor blood supply and other pro-apoptotic factors. Several experimental and clinical studies have suggested that cyclosporin A (CsA) treatment reduces apoptosis in human endothelial cells and neurocytes. However, the effect of CsA on the apoptosis in MSCs is still unclear. In this study, we investigated whether CsA could inhibit hypoxia/ reoxygenation (H/R)-induced apoptosis in MSCs. MSCs pre-incubated with or without CsA were subjected to 6 h of hypoxia followed by 12 h of reoxygenation. Our data showed that pre-incubation with 0.5-5 microM CsA dose-dependently protected the MSCs from H/R injury, as evidenced by decreased apoptosis and increased cell viability. CsA inhibited the H/R-induced translocation of cytochrome c, increased bcl-2 expression and restored mitochondrial membrane potential. CsA also increased the expression of p-BAD. We propose that preincubation MSCs with CsA inhibits MSC apoptosis through the mitochondrial and BAD pathway.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; bcl-Associated Death Protein; Cell Survival; Cyclosporine; Cytochromes c; Enzyme Activation; Hypoxia; Male; Membrane Potential, Mitochondrial; Mesenchymal Stem Cells; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; NFATC Transcription Factors; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

The purpose of this study was to determine the effects of diazoxide on apoptosis and the relative mechanisms in a model of brain injury induced by cerebral ischemia/reperfusion (I/R) during deep hypothermia.. Three-week-old Sprague-Dawley male rats were randomly and equitably divided into sham-operated group, placebo-treated group and diazoxide-treated group respectively. Specific examination of the regional cerebral blood flow (rCBF) was measured in the three groups continuously during the operation by laser Doppler flowmetry. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) was showed DNA fragmentation. The mRNA expressions of cytochrome c and full-length caspase-3 were determined by RT-PCR, while the protein expressions of cytochrome c and cleaved caspase-3 were determined by immunohistochemistry at 1 h, 6 h, 24 h, 72 h and 7 days after I/R, respectively. Cytosolic release of cytochrome c at 24 h after I/R was also confirmed by Western blot.. rCBF was significantly decreased in both of placebo-treated and diazoxide-treated group just after ischemia in the time interval 0-5 min, and had no obvious changes in all the time intervals during the operation. Diazoxide preconditioning significantly decreased the percentage of TUNEL-positive staining cells. The mRNA expressions of cytochrome c and full-length caspase-3 in diazoxide-treated group were significantly decreased. In addition, diazoxide provided a significant reduction in the protein expressions of cytochrome c and cleaved caspase-3.. These results suggested that the neuroprotective effects of diazoxide against cerebral I/R injury during deep hypothermia correlated with the reduction of DNA fragmentation, prevention of mitochondrial cytochrome c release and inhibition of caspase-3 activation.

Topics: Analysis of Variance; Animals; Brain Injuries; Caspase 3; Cerebrovascular Circulation; Cytochromes c; Diazoxide; Disease Models, Animal; Gene Expression Regulation; Hypothermia, Induced; In Situ Nick-End Labeling; Laser-Doppler Flowmetry; Male; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Time Factors

Nortriptyline, an antidepressant, was identified as a strong inhibitor of mitochondrial permeability transition by our screening of a library of 1040 drugs. Because mitochondrial permeability transition and consequent mitochondrial dysfunction have been implicated in acute neuronal death, we proposed to investigate the possible neuroprotective effects of nortriptyline in cerebral ischemia.. The effects of nortriptyline were first studied in oxygen/glucose deprivation-induced death of primary cerebrocortical neurons, a cellular model of cerebral ischemia. Mitochondrial membrane potential, mitochondrial factor release, and caspase 3 activation were evaluated after its treatment. Nortriptyline was also studied in a mouse model, which was established by occlusion of the middle cerebral artery. The infarct volume, neurological function, and biochemical events were examined in the absence or the presence of nortriptyline.. Nortriptyline inhibits oxygen/glucose deprivation-induced cell death, loss of mitochondrial membrane potential, downstream release of mitochondrial factors, and activation of caspase 3 in primary cerebrocortical neurons. Furthermore, it decreases infarct size and improves neurological scores after middle cerebral artery occlusion in mice.. The ability of nortriptyline to inhibit mitochondrial factor release and caspase activation and further protect the animals correlates to its inhibitory effect on mitochondrial permeability transition in isolated mitochondria. This study indicated that nortriptyline is neuroprotective against cerebral ischemia. It also suggested mitochondrial permeability transition might be a valuable therapeutic target for acute neurodegeneration.

Topics: Adrenergic Uptake Inhibitors; Animals; Apoptosis Inducing Factor; Apoptosis Regulatory Proteins; Calcium; Carrier Proteins; Cell Death; Cerebral Cortex; Cytochromes c; Glucose; Infarction, Middle Cerebral Artery; Male; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Proteins; Neurons; Neuroprotective Agents; Nortriptyline; Oxygen; Recovery of Function; Reperfusion Injury

Recent studies suggest that besides the L-type calcium channel, two calcium channels on the endoplasmic reticulum (ER), the inositol 1,4,5-trisphosphate receptor (InsP3R) and ryanodine receptor (RyR), may play a role in the apoptotic process of renal tubular cells induced by ischemia/reperfusion (I/R) injury. We used antimycin A to induce cell I/R injury in vitro and found an elevation of the cytosolic calcium concentration and consequently apoptosis. Blocking either the L-type calcium channel with nicardipine or the InsP3R with TMB-8 can inhibit cytochrome c release, activate caspase 3 and decrease the apoptotic cell number. However, blocking the RyR with dantrolene had no effect. We further found that Ca(2+) influx through the L-type channel is needed for the opening of the InsP3R which activates a cascade of Ca(2+) release from the ER store. To test these blockers in vivo, in a rat renal I/R model, pretreatment with nicardipine and TMB-8, but not dantrolene, can protect renal function. Taken together, our results suggest that after I/R injury, Ca(2+) influx through the L-type calcium channel triggers the Ca(2+) release from the InsP3R and finally induces apoptosis. The InsP3R could be a new target for the treatment of renal I/R injury.

Topics: Animals; Antimycin A; Apoptosis; Blood Pressure; Calcium; Calcium Channel Blockers; Calcium Channels, L-Type; Cells, Cultured; Cytochromes c; Dantrolene; DNA Fragmentation; Endoplasmic Reticulum; Epithelial Cells; Inositol 1,4,5-Trisphosphate Receptors; Kidney Tubules, Proximal; Male; Malondialdehyde; Muscle Relaxants, Central; Rats; Rats, Wistar; Reperfusion Injury; Ryanodine Receptor Calcium Release Channel; Superoxide Dismutase; Urothelium

Ischemic postconditioning has been found to decrease brain infarct area and spinal cord ischemic injury. In this study, we tested the hypothesis that ischemic postconditioning reduces global cerebral ischemia/reperfusion-induced structural and functional injury in rats.. Ten-minute global ischemia was induced by 4-vessel occlusion in male Sprague-Dawley rats. The animals underwent postconditioning consisting of 3 cycles of 15-second/15-second (Post-15/15), 30-second/30-second (Post-30/30), or 60-second/15-second (Post-60/15) reperfusion/reocclusion or 15-second/15-second reperfusion/reocclusion applied after a 45-second reperfusion (Post-45-15/15).. Ten minutes of ischemia and 7 days of reperfusion destroyed 85.8% of CA1 hippocampal neurons and 64.1% of parietal cortical neurons. Three cycles of Post-15/15, Post-30/30, and Post-45-15/15 reperfusion/reocclusion markedly reduced neuronal loss after 7 days or 3 weeks of reperfusion and diminished the deficiency in spatial learning and memory. After reperfusion, a period of hyperperfusion followed by hypoperfusion was observed, both of which were blocked by postconditioning. The cytosolic level of cytochrome c increased significantly after 48 hours of reperfusion, and this was inhibited by Post-15/15, Post-30/30, and Post-45-15/15. However, 3 cycles of 60-second/15-second reperfusion/reocclusion failed to protect against neuronal damage, behavioral deficit, or cytochrome c translocation.. Our data provide the first evidence that an appropriate ischemic postconditioning strategy has neuroprotective effects against global cerebral ischemia/reperfusion injury and a consequent behavioral deficit and that these protective effects are associated with its ability to improve disturbed cerebral blood flow and prevent cytochrome c translocation.

Topics: Animals; Brain Ischemia; Cell Count; Cerebrovascular Circulation; Cytochromes c; Cytoprotection; Cytosol; Hippocampus; Ischemic Preconditioning; Male; Maze Learning; Memory; Neurons; Parietal Lobe; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Swimming; Time Factors

To evaluate development of brain injury after hind limbs ischemia/reperfusion (LI/R) in rats, and the effect of MK801 on the brain injury following LI/R.. The limbs ischemia/reperfusion model was established in rats. The MDA contents were evaluated in each group, apoptotic cells were detected with TUNEL, the expression of apoptosis-associated protein, such as bcl-2, cytoC and caspase-3 were determined with immunohistochemistry and Western-blot.. The contents of MDA in brain tissue increased significantly following LI/R. The expression of bcl-2, cytoC, Caspase-3 was increased than those in the control group (P < 0.01) following LI/R significantly. The expression of Caspase-3 was increased 24 h after the onset of reperfusion. The expression of Caspase-3, bcl-2 gene was quite obvious in the midbrain red nucleus region. MK801 inhibited the expression of bcl-2, cytoC, Caspase-3 obviously.. The excessive apoptosis and apoptosis-associated factors could play an important role in the brain injury following LI/R in rat, MK801 might decrease the production of free radical and the excite toxicity of glutamate, inhibit the expression of apoptosis associated protein and reduce the occurrence of apoptosis.

Topics: Animals; Apoptosis; Brain Injuries; Caspase 3; Cytochromes c; Dizocilpine Maleate; Extremities; Ischemia; Male; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Ischemia-reperfusion injury is a determinant in liver injury occurring during surgical procedures, ischemic states, and multiple organ failure. The pre-existing nutritional status of the liver, i.e., fasting, might contribute to the extent of tissue injury. This study investigated whether Intralipid, a solution containing soybean oil, egg phospholipids, and glycerol, could protect ex vivo perfused livers of fasting rats from anoxia-reoxygenation injury.. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Isolated livers were perfused with glucose 5.5 and 15 mM, and two different concentrations of Intralipid, i.e., 0.5:100 and 1:100 (v/v) Intralipid 10%:medium (n = 5 in each group). The experiment consisted of perfusion for 15 min, warm anoxia for 60 min, and reoxygenation during 60 min. Hepatic enzymes, potassium, glucose, lactate, bilirubin, dienes, trienes, and cytochrome-c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in biopsies.. Intralipid attenuated transaminases, lactate dehydrogenase, potassium, diene, and triene release in the perfusate (dose-dependant) during the reoxygenation phase when compared with glucose-treated groups. The concentration of cytochrome-c in the medium was the highest in the 5.5-mM glucose group. The glycogen content was low in all livers at the start of the experiment.. Intralipid presents, under the present experimental conditions, a better protective effect than glucose in anoxia-reoxygenation injury of the rat liver.

Topics: Animals; Bilirubin; Blood Glucose; Cytochromes c; Dose-Response Relationship, Drug; Fasting; Fat Emulsions, Intravenous; Female; Hepatectomy; Humans; Liver; Liver Glycogen; Nutritional Status; Organ Culture Techniques; Oxygen; Perfusion; Random Allocation; Rats; Rats, Wistar; Reperfusion Injury

The small intestine is highly sensitive to ischaemia-reperfusion (I/R) induced injury which is associated with high morbidity and mortality. Apoptosis, or programmed cell death, is a major mode of cell death occurring during I/R induced injury. However, the mechanisms by which I/R cause apoptosis in the small intestine are poorly understood. p53 upregulated modulator of apoptosis (PUMA) is a p53 downstream target and a member of the BH3-only group of Bcl-2 family proteins. It has been shown that PUMA plays an essential role in apoptosis induced by a variety of stimuli in different tissues through a mitochondrial pathway.. The role of PUMA in I/R induced injury and apoptosis in the small intestine was investigated. The mechanisms by which PUMA is regulated in I/R induced intestinal apoptosis were also studied.. Ischaemia was induced by superior mesenteric artery occlusion in the mouse small intestine. Induction of PUMA in response to ischaemia alone, or ischaemia followed by reperfusion (I/R), was examined. I/R induced intestinal apoptosis and injury were compared between PUMA knockout and wild-type mice. The mechanisms of I/R induced and PUMA mediated apoptosis were investigated through analysis of caspase activation, cytosolic release of mitochondrial cytochrome c and alterations of the proapoptotic Bcl-2 family proteins Bax and Bak. To determine whether PUMA is induced by reactive oxygen species and/or reactive nitrogen species generated by I/R, superoxide dismutase (SOD) and N-nitro-l-arginine methyl ester (L-NAME) were used to treat animals before I/R. To determine whether p53 is involved in regulating PUMA during I/R induced apoptosis, PUMA induction and apoptosis in response to I/R were examined in p53 knockout mice.. PUMA was markedly induced following I/R in the mucosa of the mouse small intestine. I/R induced intestinal apoptosis was significantly attenuated in PUMA knockout mice compared with that in wild-type mice. I/R induced caspase 3 activation, cytochrome c release, Bax mitochondrial translocation and Bak multimerisation were also inhibited in PUMA knockout mice. SOD or L-NAME significantly blunted I/R induced PUMA expression and apoptosis. Furthermore, I/R induced PUMA expression and apoptosis in the small intestine were not affected in the p53 knockout mice.. Our data demonstrated that PUMA is activated by oxidative stress in response to I/R to promote p53 independent apoptosis in the small intestine through the mitochondrial pathway. Inhibition of PUMA is potentially useful for protecting against I/R induced intestinal injury and apoptosis.

Topics: Animals; Apoptosis; Apoptosis Regulatory Proteins; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Caspase 3; Cytochromes c; DNA Fragmentation; Intestine, Small; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Reperfusion Injury; Tumor Suppressor Protein p53; Tumor Suppressor Proteins

Gentamicin, a widely used antibiotic for the treatment of bacterial infection, can cause nephrotoxicity. Tetramethylpyrazine (TMP) is a compound purified from the rhizome of Ligusticum wallichi (Chuanxiong) and has been found to protect against ischaemia-reperfusion injury, nephritis and alcohol-induced toxicity in rat kidneys.. We used rat renal tubular cells (RTCs), NRK-52E, in this study. The cytotoxicity of gentamicin was checked with transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) staining, and the generation of reactive oxygen species was measured using the fluorescent probe 2,7-dichlorofluorescein. We evaluated several apoptotic parameters: cleaved caspase levels, tumour necrosis factor (TNF-alpha) excretion and nuclear factor Kappa B (NF-kappaB) activity. We also examined the TMP protective effect on gentamicin-induced apoptosis in rat kidneys.. The results of this study showed that gentamicin was found to markedly induce apoptosis in NRK-52E cells in a dose-dependent manner; that TMP expressed a dose-dependent protective effect against gentamicin-induced apoptosis; that pre-treatment of the cells with 50 or 100 microM of TMP effectively decreased the reactive oxygen species formation induced by gentamicin; that TMP was found to inactivate the gentamicin-stimulated activities of caspase-3, caspase-8 and caspase-9, to inhibit gentamicin-induced release of cytochrome c, as well as to raise the expression of Bcl-x(L); that TMP inhibited the gentamicin-induced TNF-alpha excretion, and inactivated the transcription factor NF-kappaB; and that the TMP treatment significantly reduced apoptotic injury in rat RTCs.. Based on the results of this study, we suggest that TMP can attenuate gentamicin-induced oxidative stress and apoptotic injury in rat RTCs, and that its character may have therapeutic potential for patients with renal diseases.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; bcl-X Protein; Blotting, Western; Caspase 3; Caspase 8; Caspase 9; Caspase Inhibitors; Cytochromes c; Disease Models, Animal; DNA; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Gene Expression; Gentamicins; In Situ Nick-End Labeling; Kidney Tubules, Proximal; Ligusticum; Male; NF-kappa B; Oxidative Stress; Pyrazines; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Tumor Necrosis Factor-alpha; Vasodilator Agents

Ischemia-reperfusion (IR) of the testis results in germ-cell-specific apoptosis (GCA) and a reduction in daily sperm production. This has been correlated with and is dependent upon neutrophil recruitment to the testis. In a rat model of testicular IR, this has also been correlated with an increase in reactive oxygen species (ROS). We have investigated ROS in the mouse testis after IR and determined whether the observed GCA is mediated via a mitochondrial caspase-9-dependent pathway involving the upstream mediators caspase 2 and BAX. Mice were subjected to a 2-h period of testicular ischemia followed by reperfusion. An accumulation of 8-isoprostane, a marker of oxidative stress, occurred 4 h after reperfusion. Activation of a mitochondrial dependent pathway to GCA after testicular IR was determined based on the observations that both BAX and caspase 2 translocated to the mitochondria, and that an increase occurred in cytoplasmic cytochrome c. Moreover, microinfusion of a specific caspase 9 inhibitor significantly reduced active caspase 3 after testicular IR and the number of apoptotic germ cells. These results suggest that oxidative stress products accumulate in the testis following IR and demonstrate that the observed GCA is stimulated through a mitochondrial caspase-9-dependent pathway. The identification of the germ-cell apoptotic pathway induced after testicular IR, including the key players in the pathway subsequent to ROS (BAX, caspase 9, and caspase 2), aids our understanding of IR injury in the testis and provides a wider background for the development of therapeutic interventions to rescue testis function.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 2; Caspase 3; Caspase 9; Cytochromes c; Dinoprost; Male; Mice; Mice, Inbred C57BL; Mitochondria; Oxidative Stress; Reperfusion Injury; Spermatic Cord Torsion; Spermatozoa; Testis

Massive Ca(2+) accumulation in mitochondria, plus the stimulating effect of an inducing agent, i.e., oxidative stress, induces the so-called permeability transition, which is characterized by the opening of a nonspecific pore. This work was aimed at studying the influence of thyroid hormone on the opening of such a nonspecific pore in kidney mitochondria, as induced by an oxidative stress. To meet this objective, membrane permeability transition was examined in mitochondria isolated from kidney of euthyroid and hypothyroid rats, after a period of ischemia/reperfusion. It was found that mitochondria from hypothyroid rats were able to retain accumulated Ca(2+) to sustain a transmembrane potential after Ca(2+) addition, as well as to maintain matrix NAD(+) and membrane cytochrome c content. The protective effect of hypothyroidism was clearly opposed to that occurring in ischemic reperfused mitochondria from euthyroid rats. Our findings demonstrate that these mitochondria were unable to preserve selective membrane permeability, except when cyclosporin A was added. It is proposed that the protection is conferred by the low content of cardiolipin found in the inner membrane. This phospholipid is required to switch adenine nucleotide translocase from specific carrier to a non-specific pore.

Topics: Animals; bcl-2-Associated X Protein; Calcium; Cardiolipins; Cyclosporine; Cytochromes c; Disease Models, Animal; Hypothyroidism; Injections, Intraperitoneal; Kidney; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Membranes; Mitochondrial Permeability Transition Pore; NAD; Oxidative Stress; Rats; Reperfusion Injury; Thyroidectomy

Activation of alpha(1)-adrenergic receptors (alpha(1)-ARs) mimics ischemic preconditioning (IP). However, the subtypes of alpha(1)-ARs involved and the protective mechanisms are not entirely clear. Here we tested the hypothesis that preservation of mitochondrial integrity, in particular, Ca(2+) homeostasis via the epsilon isoform of protein kinase C (PKCepsilon) and mitoK(ATP) channels, may underlie the basis of alpha(1B)-AR-triggered cardioprotection.. Indo-1 fluorescence in adult rat cardiomyocytes was used as an index of cytosolic ([Ca(2+)](c)) or mitochondrial free Ca(2+) concentration ([Ca(2+)](m)), and cell shortening was measured simultaneously. Cells were subjected to 20 min of simulated ischemia followed by 30 min of reperfusion (I/R).. Activation of a(1)-ARs by phenylephrine significantly decreased I/R-induced [Ca(2+)](c) and [Ca(2+)](m) overload, mitochondrial cytochrome c release and ATP reduction, and improved Ca(2+) transients and cell shortening. These protective effects were markedly inhibited by blockade of alpha(1B)-AR (chloroethylclonidine) but not alpha(1A)-AR (5'-methylurapidil) or alpha(1D)-AR (BMY 7378). Moreover, phenylephrine-afforded protection on the [Ca(2+)](m), [Ca(2+)](c), and cell shortening was lost when mitoK(ATP) channels were inhibited with 5-hydroxydecanoate and PKCepsilon with PKCepsilon V(1-2). However, PKCepsilon V(1-2) did not affect the mitoK(ATP) channel opener diazoxide-induced protection on these parameters.. These findings indicate that phenylephrine-induced protection on [Ca(2+)](m) homeostasis is mediated by selective activation of alpha(1B)-AR via mitoK(ATP) channel opening and PKCepsilon activation. Mitochondrial function appears to be a determinant of [Ca(2+)](c) and contractile function during I/R injury.

Topics: Adenosine Triphosphate; Adrenergic alpha-1 Receptor Antagonists; Adrenergic alpha-Antagonists; Animals; Calcium; Cell Size; Clonidine; Cytochromes c; Decanoic Acids; Diazoxide; Hydroxy Acids; Male; Mitochondria, Heart; Myocardial Ischemia; Myocytes, Cardiac; Phenylephrine; Potassium Channel Blockers; Potassium Channels; Protein Kinase C-epsilon; Rats; Rats, Sprague-Dawley; Receptors, Adrenergic, alpha-1; Reperfusion Injury; Vasodilator Agents

Cerebral ischemic pre-conditioning (IPC) is capable of protecting hippocampal neurons from ischemia/reperfusion (I/R) injury. In the current study, we investigated the role of activated caspase-9 in the protective process induced by IPC and related it to cytochrome c release and apoptosis.. I/R injury was induced by a four-vessel occlusion model in Wistar rats which were randomly divided into ischemia/reperfusion group (I/R), ischemic pre-conditioning + I/R group (IPC + I/R) and control group. Histologic changes in the pyramidal layer of the hippocampal CA1 region were determined by hematoxylin and eosin (H&E) staining. The relative proportion of apoptotic neurons in this area was assessed with TUNEL staining. The redistribution of cytochrome c and activation of caspase-9 were detected in the same area with immunohistochemistry and Western blotting respectively.. Compared to the I/R group, IPC increased the number of surviving neurons in the hippocampal CA1 region (p<0.001), markedly reduced the number of apoptotic pyramidal neurons (p<0.001), inhibited the release of cytochrome c from mitochondria to cytoplasm (p<0.001 for positively stained neurons) and decreased the amount of activated caspase-9 (p<0.001).. These findings confirm that IPC is capable of protecting neurons from injury by apoptosis. The release of cytochrome c to the cytosol demonstrates that the mitochondrial pathway was involved, and the reduction in this release caused by IPC was clearly associated with reduced caspase-9 activation. Together, these results suggest that IPC protects neurons via action on the mitochondrial/caspase-9 pathway of apoptosis.

Topics: Analysis of Variance; Animals; Apoptosis; Caspase 9; Cytochromes c; Disease Models, Animal; Enzyme Activation; Hippocampus; In Situ Nick-End Labeling; Ischemic Preconditioning; Male; Pyramidal Cells; Rats; Rats, Wistar; Reperfusion Injury

We incubated neonatal Sprague-Dawley rat cardiomyocytes in primary culture in a medium simulating ischemia (consisting of hypoxia plus serum deprivation) for 2 h, then re-incubated them for 24 h in normal culture medium to establish a model of simulated ischemia/reperfusion (I/R) injury. Apoptotic cell death was measured by MTT assay, TUNEL staining and flow cytometry. Morphological alterations were assessed by transmission electron microscopy, the expression of caspases-3 and -9 and Bcl-2 and the release of cytochrome c by Western blotting, and the intracellular free-calcium concentration ([Ca2+]i) by laser confocal scanning microscopy. The results showed that pretreatment with 10 micromol/l spermine or spermidine significantly inhibited apoptosis in the I/R cells, suppressed the expression of caspases-3 and -9 and cytochrome c release, up-regulated Bcl-2 expression and decreased [Ca2+]i. However, pretreatment with 10 micromol/l putrescine had the opposite effects. Evidence for this "double-edged" effect of polyamines on apoptosis in I/R-injured cardiomyocytes is presented for the first time. It may suggest a novel pharmacological target for preventing and treating cardiac ischemia/reperfusion injury.

Topics: Animals; Animals, Newborn; Apoptosis; Calcium; Caspases; Cells, Cultured; Cytochromes c; Microscopy, Electron, Transmission; Myocytes, Cardiac; Polyamines; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Ischemia-reperfusion (I/R) injury is a commonly encountered clinical problem in liver surgery and transplantation. The pathogenesis of I/R injury is multifactorial, but mitochondrial Ca(2+) overload plays a central role. We have previously defined a novel pathway for mitochondrial Ca(2+) handling and now further characterize this pathway and investigate a novel Ca(2+)-channel inhibitor, 2-aminoethoxydiphenyl borate (2-APB), for preventing hepatic I/R injury. The effect of 2-APB on cellular and mitochondrial Ca(2+) uptake was evaluated in vitro by using (45)Ca(2+). Subsequently, 2-APB (2 mg/kg) or vehicle was injected into the portal vein of anesthetized rats either before or following 1 h of inflow occlusion to 70% of the liver. After 3 h of reperfusion, liver injury was assessed enzymatically and histologically. Hep G2 cells transfected with green fluorescent protein-tagged cytochrome c were used to evaluate mitochondrial permeability. 2-APB dose-dependently blocked Ca(2+) uptake in isolated liver mitochondria and reduced cellular Ca(2+) accumulation in Hep G2 cells. In vivo I/R increased liver enzymes 10-fold, and 2-APB prevented this when administered pre- or postischemia. 2-APB significantly reduced cellular damage determined by hematoxylin and eosin and terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling staining of liver tissue. In vitro I/R caused a dissociation between cytochrome c and mitochondria in Hep G2 cells that was prevented by administration of 2-APB. These data further establish the role of cellular Ca(2+) uptake and subsequent mitochondrial Ca(2+) overload in I/R injury and identify 2-APB as a novel pharmacological inhibitor of liver I/R injury even when administered following a prolonged ischemic insult.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; Boron Compounds; Calcium; Calcium Channel Blockers; Calcium Radioisotopes; Cell Death; Cell Line, Tumor; Cytochromes c; Disease Models, Animal; Dose-Response Relationship, Drug; Humans; L-Lactate Dehydrogenase; Liver; Male; Mitochondria, Liver; Mitochondrial Membranes; Permeability; Rats; Rats, Sprague-Dawley; Recombinant Fusion Proteins; Reperfusion Injury; Time Factors; Transfection

Nitrite (NO(2)(-)) is an intrinsic signaling molecule that is reduced to NO during ischemia and limits apoptosis and cytotoxicity at reperfusion in the mammalian heart, liver, and brain. Although the mechanism of nitrite-mediated cytoprotection is unknown, NO is a mediator of the ischemic preconditioning cell-survival program. Analogous to the temporally distinct acute and delayed ischemic preconditioning cytoprotective phenotypes, we report that both acute and delayed (24 h before ischemia) exposure to physiological concentrations of nitrite, given both systemically or orally, potently limits cardiac and hepatic reperfusion injury. This cytoprotection is associated with increases in mitochondrial oxidative phosphorylation. Remarkably, isolated mitochondria subjected to 30 min of anoxia followed by reoxygenation were directly protected by nitrite administered both in vitro during anoxia or in vivo 24 h before mitochondrial isolation. Mechanistically, nitrite dose-dependently modifies and inhibits complex I by posttranslational S-nitrosation; this dampens electron transfer and effectively reduces reperfusion reactive oxygen species generation and ameliorates oxidative inactivation of complexes II-IV and aconitase, thus preventing mitochondrial permeability transition pore opening and cytochrome c release. These data suggest that nitrite dynamically modulates mitochondrial resilience to reperfusion injury and may represent an effector of the cell-survival program of ischemic preconditioning and the Mediterranean diet.

Topics: Aconitate Hydratase; Administration, Oral; Animals; Cytochromes c; Cytoprotection; Electron Transport; Electron Transport Complex I; Enzyme Activation; Ion Channel Gating; Ischemic Preconditioning; Liver; Male; Mice; Mice, Inbred C57BL; Mitochondria; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Molecular Mimicry; Myocardial Reperfusion Injury; Nitrites; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

Apoptosis, a predominant cause of neuronal death after stroke, can be executed in a caspase-dependent or apoptosis inducing factor (AIF)-dependent manner. Herpes simplex virus (HSV) vectors expressing caspase inhibitors p35 and crmA have been shown to be neuroprotective against various excitotoxic insults. Here we further evaluated the possible neuroprotective role of p35 and crmA in a rat stroke model. Overexpression of p35, but not crmA, significantly increased neuronal survival. Results of double immunofluorescence staining indicate that compared with neurons infected with crmA or control vectors, p35-infected neurons had less active caspase-3 expression, cytosolic cytochrome c and nuclear AIF translocation.

Topics: Analysis of Variance; Animals; Apoptosis; Apoptosis Inducing Factor; beta-Galactosidase; Bromodeoxyuridine; Cell Count; Cytochromes c; Disease Models, Animal; Indoles; Infarction, Middle Cerebral Artery; Male; Microscopy, Confocal; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Serpins; Simplexvirus; Viral Proteins

Kidney proximal tubules exhibit decreased ATP and reduced, but not absent, mitochondrial membrane potential (Deltapsi(m)) during reoxygenation after severe hypoxia. This energetic deficit, which plays a pivotal role in overall cellular recovery, cannot be explained by loss of mitochondrial membrane integrity, decreased electron transport, or compromised F1F0-ATPase and adenine nucleotide translocase activities. Addition of oleate to permeabilized tubules produced concentration-dependent decreases of Deltapsi(m) measured by safranin O uptake (threshold for oleate = 0.25 microM, 1.6 nmol/mg protein; maximal effect = 4 microM, 26 nmol/mg) that were reversed by delipidated BSA (dBSA). Cell nonesterified fatty acid (NEFA) levels increased from <1 to 17.4 nmol/mg protein during 60- min hypoxia and remained elevated at 7.6 nmol/mg after 60 min reoxygenation, at which time ATP had recovered to only 10% of control values. Safranin O uptake in reoxygenated tubules, which was decreased 85% after 60-min hypoxia, was normalized by dBSA, which improved ATP synthesis as well. dBSA also almost completely normalized Deltapsi(m) when the duration of hypoxia was increased to 120 min. In intact tubules, the protective substrate combination of alpha-ketoglutarate + malate (alpha-KG/MAL) increased ATP three- to fourfold, limited NEFA accumulation during hypoxia by 50%, and lowered NEFA during reoxygenation. Notably, dBSA also improved ATP recovery when added to intact tubules during reoxygenation and was additive to the effect of alpha-KG/MAL. We conclude that NEFA overload is the primary cause of energetic failure of reoxygenated proximal tubules and lowering NEFA substantially contributes to the benefit from supplementation with alpha-KG/MAL.

Topics: Adenosine Triphosphate; Animals; Cell Membrane Permeability; Cytochromes c; Fatty Acids, Nonesterified; Female; In Vitro Techniques; Kidney Tubules, Proximal; Mitochondria; Phenazines; Rabbits; Reperfusion Injury; Serum Albumin, Bovine

Expression and activity of the germinal center kinase, Ste20-like kinase (SLK), are increased during kidney development and recovery from ischemic acute renal failure. In this study, we characterize the activation and functional role of SLK. SLK underwent dimerization via the C-terminal domain, and dimerization enhanced SLK activity. In contrast, the C-terminal domain of SLK did not dimerize with a related kinase, Mst1, and did not affect Mst1 activity. Phosphorylation/dephosphorylation of SLK were not associated with changes in kinase activity. SLK induced phosphorylation of apoptosis signal-regulating kinase-1 (ASK1) and increased ASK1 activity, indicating that ASK1 is a substrate of SLK. Moreover, SLK stimulated phosphorylation of p38 mitogen-activated protein kinase via ASK1, but not c-Jun N-terminal kinase nor extracellular signal-regulated kinase. Chemical anoxia and recovery during re-exposure to glucose (ischemia-reperfusion injury in cell culture) stimulated SLK activity. Overexpression of SLK enhanced anoxia/recovery-induced apoptosis, release of cytochrome c, and activities of caspase-8 and -9, and apoptosis was reduced significantly with p38 and caspase-9 inhibitors. Induction of the endoplasmic reticulum stress response by anoxia/recovery or tunicamycin (monitored by induction of Bip or Grp94 expression, phosphorylation of eukaryotic translation initiation factor 2alpha subunit, expression of CHOP, and activation of caspase-12) was attenuated in cells that overexpress SLK. Thus, SLK is an anoxia/recovery-dependent kinase that is activated via homodimerization and that signals via ASK1 and p38 to promote apoptosis. Attenuation of the protective aspects of the endoplasmic reticulum stress response by SLK may contribute to its proapoptotic effect.

Topics: Animals; Apoptosis; Calcium; Caspase 12; Caspase 9; Caspase Inhibitors; Caspases; Catalytic Domain; Cell Cycle; Cell Line; Chlorocebus aethiops; COS Cells; Cytochromes c; Densitometry; Dimerization; DNA, Complementary; Dogs; Endoplasmic Reticulum; Enzyme Activation; Eukaryotic Initiation Factor-2; Germinal Center Kinases; Glucose; Hepatocyte Growth Factor; HSP70 Heat-Shock Proteins; Immunoblotting; Immunoprecipitation; Ionophores; JNK Mitogen-Activated Protein Kinases; MAP Kinase Kinase Kinase 5; Membrane Proteins; Nerve Tissue Proteins; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Protein Serine-Threonine Kinases; Protein Structure, Tertiary; Proto-Oncogene Proteins; Rats; Reperfusion Injury; Tunicamycin

To investigate a possible mechanism responsible for anti-apoptotic effects of melatonin and provide theoretical evidences for clinical therapy.. Ischemia-reperfusion mediated neuronal cell injury model was constructed in cerebellar granule neurons (CGNs) by deprivation of glucose, serum and oxygen in media. After ischemia, melatonin was added to the test groups to reach differential concentration during reperfusion. DNA fragmentation, mitochondrial transmembrane potential, mitochondrial cytochrome c release and caspase-3 activity were observed after subjecting cerebellar granule neurons to oxygen-glucose deprivation (OGD).. The results showed that OGD induced typical cell apoptosis change, DNA ladder and apoptosis-related alterations in mitochondrial functions including depression of mitochondrial transmembrane potential (its maximal protection ratio was 73.26%) and release of cytochrome c (its maximal inhibition ratio was 42.52%) and the subsequent activation of caspase-3 (its maximal protection ratio was 59.32%) in cytoplasm. Melatonin reduced DNA damage and inhibited release of mitochondrial cytochrome c and activation of caspase-3. Melatonin can strongly prevent the OGD-induced loss of the mitochondria membrane potential.. Our findings suggested that the direct inhibition of mitochondrial pathway might essentially contribute to its anti-apoptotic effects in neuronal ischemia-reperfusion.

Topics: Animals; Apoptosis; Blotting, Western; Caspase 3; Caspases; Cerebellum; Cytochromes c; Cytoplasm; DNA Fragmentation; Glucose; Immunoblotting; Melatonin; Membrane Potentials; Mitochondria; Neurons; Nitric Oxide Synthase Type I; Oxygen; Rats; Rats, Sprague-Dawley; Reperfusion; Reperfusion Injury; Time Factors

Loss in mitochondrial function and induction of mitochondrial-mediated apoptosis occur as a result of cardiac ischemia/reperfusion. Brief and repeated cycles of ischemia/reperfusion, termed ischemic preconditioning, prevent or minimize contractile dysfunction and apoptosis associated with prolonged episodes of cardiac ischemia and reperfusion. The effects of preconditioning on various indices of ischemia/reperfusion-induced alterations in mitochondrial function and structure were therefore explored. Utilizing an in vivo rat model data is provided indicating that preconditioning completely prevents cardiac ischemia/reperfusion-induced: (1) loss in the activity of the redox sensitive Krebs cycle enzyme alpha-ketoglutarate dehydrogenase; (2) declines in NADH-linked ADP-dependent mitochondrial respiration; (3) insertion of the pro-apoptotic Bcl-2 protein Bax into the mitochondrial membrane; and (4) release of cytochrome c into the cytosol. The results of the current study indicate that preconditioning prevents specific alterations in mitochondrial structure and function that are known to impact cellular viability and provide insight into the collective benefits of preconditioning.

Topics: Animals; Cells, Cultured; Cytochromes c; Ischemic Preconditioning; Male; Mitochondria, Heart; Oxygen; Rats; Rats, Inbred F344; Reperfusion Injury; Treatment Outcome

In the last decade, various groups have found evidence of nitric oxide production by mitochondrial nitric oxide synthase (mNOS) in a range of experimental models. However, little is known about the role of mNOS in renal ischemia-reperfusion (I/R) injury and its possible involvement in the apoptotic pathway. We analyzed the role of mNOS in apoptosis promotion in rat kidney I/R and its direct implication through experiments in which isolated kidney mitochondria were subjected to hypoxia/reoxygenation. Results showed that neuronal NOS located in the inner mitochondrial membrane is upregulated during renal I/R and that this upregulation, together with the increase in nitric oxide production, is involved in the generation of intramitochondrial peroxynitrite, which in turn leads to cytochrome c release and apoptosis induction in renal I/R.

Topics: Animals; Apoptosis; Biomarkers; Blotting, Western; Cytochromes c; Densitometry; Enzyme Inhibitors; Ischemia; Kidney; Male; Mitochondria; NG-Nitroarginine Methyl Ester; Nitric Oxide Synthase Type I; Nitrites; Peroxynitrous Acid; Rats; Rats, Wistar; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; Time Factors; Up-Regulation

The overall goal of this study was to determine the molecular basis by which mixed-lineage kinase 3 (MLK3) kinase and its signaling pathways are negatively regulated by the pro-survival Akt pathway in cerebral ischemia. We demonstrated that tyrosine phosphorylation of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) underlies the increased Akt-Ser473 phosphorylation by orthovanadate. Co-immunoprecipitation analysis revealed that endogenous Akt physically interacts with Rac1 in the hippocampal CA1 region, and this interaction is promoted on tyrosine phosphatase inhibition. The elevated Akt activation can deactivate MLK3 by phosphorylation at the Ser71 residue of Rac1, a small Rho family of guanidine triphosphatases required for MLK3 autophosphorylation. Subsequently, inhibition of c-Jun N-terminal kinase 3 (JNK3) results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c and activation of caspase 3. At the same time, the expression of Fas-ligand decreases in the CA1 region after inhibition of c-Jun activation. The neuroprotective effect of Akt activation is significant in the CA1 region after global cerebral ischemia. Our results suggest that the activation of the pro-apoptotic MLK3/JNK3 cascade induced by ischemic stress can be suppressed through activation of the anti-apoptotic phosphatidylinositol 3-kinase/Akt pathway, which provides a direct link between Akt and the family of stress-activated kinases.

Topics: 14-3-3 Proteins; Animals; bcl-2-Associated X Protein; Biological Transport; Brain Ischemia; Caspase 3; Caspases; Cytochromes c; Cytosol; Enzyme Activation; Enzyme Inhibitors; Fas Ligand Protein; Hippocampus; Male; MAP Kinase Kinase Kinases; Membrane Glycoproteins; Mitochondria; Mitogen-Activated Protein Kinase 10; Mitogen-Activated Protein Kinase Kinase Kinase 11; Neuroprotective Agents; Phosphorylation; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; rac1 GTP-Binding Protein; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Tumor Necrosis Factor Inhibitors; Tyrosine; Vanadates

Although p53 is a key modulator of cellular stress responses, the mechanism of p53-mediated apoptosis is ambiguous. p53 can mediate apoptosis in response to death stimuli by transcriptional activation of proapoptotic genes and transcriptional-independent mechanisms. Recent studies have shown that the p53 protein can directly induce permeabilization of the outer mitochondrial membrane by forming a inhibitory complex with a protective Bcl-2 family protein, resulting in cytochrome c release. However, how the mitochondrial p53 pathway mediates neuronal apoptosis after cerebral ischemia remains unclear. We examined the interaction between the mitochondrial p53 pathway and vulnerable hippocampal CA1 neurons in rats using a transient global cerebral ischemia (tGCI) model. Western blot analysis and immunofluorescent staining revealed mitochondrial p53 translocation after tGCI in the hippocampal CA1 neurons. Coimmunoprecipitation revealed that translocated p53 bound to Bcl-X(L) in the mitochondrial fraction. To examine the effect of a specific p53 inhibitor on the mitochondrial p53 pathway and apoptotic cell death after tGCI, we intravenously administered pifithrin-alpha (PFT). Mitochondrial p53 translocation and interaction between p53 and Bcl-X(L) were prevented by treatment with PFT. Moreover, cytochrome c release from mitochondria and subsequent apoptotic CA1 neuronal death were decreased with PFT treatment. These results suggest that the mitochondrial p53 pathway is one of the novel mechanisms mediating delayed death of vulnerable hippocampal CA1 neurons after tGCI.

Topics: Animals; Apoptosis; Cells, Cultured; Cytochromes c; Hippocampus; Male; Mitochondria; Neurons; Protein Transport; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Tumor Suppressor Protein p53

In ischemia-reperfusion injuries, elevated calcium and reactive oxygen species (ROS) induce mitochondrial permeability transition (mPT), which plays a pivotal role in mediating damages and cell death. Inhibition of mPT decreases necrotic cell death; however, during reperfusion, the continuous production of ROS may contribute to the temporary opening of the pore and thus the onset of the delayed apoptotic cell death. Based on amiodarone structure, we developed the first SOD-mimetic mPT inhibitor (HO-3538) that can eliminate ROS in the microenvironment of the permeability pore. In isolated mitochondria, HO-3538 inhibited mPT and the release of proapoptotic mitochondrial proteins. It had a ROS scavenging effect and antiapoptotic effect in a cardiomyocyte line and it diminished release of mitochondrial proapoptotic proteins. Furthermore, HO-3538 significantly enhanced the recovery of mitochondrial energy metabolism and functional cardiac parameters; decreased infarct size, lipid peroxidation, and protein oxidation; and suppressed necrotic as well as apoptotic cell death pathways in Langendorff-perfused hearts. In these respects it was somewhat superior to its two constituents, amiodarone and a pyrrol-derivative free radical scavenger. These data suggest that the SOD-mimetic mPT inhibitors are ideal candidates for drug development for the alleviation of postinfarct myocardial injuries.

Topics: Amiodarone; Animals; Apoptosis; Cytochromes c; Humans; Ischemia; Jurkat Cells; Magnetic Resonance Spectroscopy; Mice; Mitochondria; Myocardial Infarction; Necrosis; Rats; Rats, Wistar; Reperfusion Injury; Superoxide Dismutase

Cold ischemia--warm reperfusion (CI/WR) injury of liver transplantation involves hepatocyte cell death, the nature and underlying mechanisms of which remain unclear. Isolated hepatocytes and isolated perfused livers were used to determine the prevalence of necrosis and apoptosis as well as mitochondrial dysfunction. In isolated cells, propidium iodide and Hoechst 33342 staining showed a cold-storage, time-dependent increase in necrosis, whereas apoptosis was minimal even after 48 h of hypothermia. Nonetheless, a progressive loss of mitochondrial membrane potential was observed. Translocation of mitochondrial cytochrome c toward microsomes occurred within 24 h of CI/WR, with cytochrome c reaching the cytosol later. Mitochondria isolated from whole livers subjected to CI/WR also display reduced metabolic parameters and increased susceptibility to swelling. These events are associated with increased activity of major initiator (caspase 9) and effector (caspase 3) caspases. The results demonstrate that CI/WR induces mitochondrial dysfunction in isolated cells and in the whole organ; only in the latter is that sufficient to trigger the classical mitochondrial pathway of apoptosis. Our study also provides evidence for the involvement of endoplasmic reticulum stress in CI/WR hepatocyte injury. Combined protection of mitochondria and endoplasmic reticulum may thus represent an innovative therapeutic avenue to enhance liver graft viability and functional integrity.

Topics: Adenosine; Allopurinol; Animals; Caspase 3; Caspase 9; Caspases; Cell Death; Cold Temperature; Cytochromes c; Glutathione; Hepatocytes; In Vitro Techniques; Insulin; Liver; Liver Transplantation; Male; Membrane Potentials; Mitochondria; Mitochondrial Swelling; Organ Preservation; Organ Preservation Solutions; Raffinose; Rats; Rats, Wistar; Reperfusion Injury

Non-heart-beating donors are expected to ameliorate shortages of donors for organ transplantation. The issue of preventing warm ischemic injury after circulatory arrest must be investigated. In the current study, we investigated whether isoflurane inhalation during warm ischemia could attenuate ischemia reperfusion injury (IRI) of the lung.. An isolated perfused rat lung model was used. The rats were allocated into four groups: the no ischemia group; the ischemia-1 minimum alveolar concentration (MAC) iso group (ventilation with air and 1.38% isoflurane); the Ischemia-3MAC iso group (ventilation with air and 4.2% isoflurane); and the Ischemia-no treatment group (ventilation with only air). Lungs were subjected to 50 min of ischemia at 37 degrees C. Physiological lung functions were measured after reperfusion in experiment one. Mitochondrial control ratio (RCR), cytochrome-c release from mitochondria, and caspase activities just after warm ischemia were measured in experiment two.. Pulmonary functions in the Ischemia-1MAC iso group were significantly greater than those in the Ischemia-no treatment group for experiment one. There were no dose-dependent effects between 1MAC and 3MAC isoflurane. In experiment two, RCR in the Ischemia-1MAC iso group was significantly greater than that in the Ischemia-no treatment group. Cytochrome-c release and caspase-9 activity in the Ischemia-1MAC iso group were significantly decreased compared to those in the Ischemia-no treatment group.. Isoflurane inhalation attenuates warm IRI with the protection of mitochondria. Our results suggest that isoflurane inhalation after circulatory arrest can be a simple and effective method to protect the lung against warm ischemia.

Topics: Administration, Inhalation; Anesthetics, Inhalation; Animals; Blood Circulation; Caspase 9; Cell Respiration; Cytochromes c; Heart Arrest; In Vitro Techniques; Isoflurane; Lung; Mitochondria; Rats; Reperfusion Injury; Vascular Resistance; Warm Ischemia; Weight Gain

c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, is activated in response to a number of extracellular stimuli, including inflammatory cytokines, UV irradiation and ischaemia. A large body of evidence supports a role for JNK signalling in stress-induced apoptosis. It has been hypothesized that JNK may contribute to the apoptotic response by regulating the intrinsic cell death pathway involving the mitochondria. Here, we examined the role of the JNK signalling pathway in hippocampal CA1 apoptotic neurones following transient ischaemia in gerbils. We showed early activation of death receptor-dependent apoptosis (caspase-8 activation 2 days after ischaemia) and a biphasic activation of caspase-3 and caspase-9 after ischaemia. Activation of the mitochondrial pathway, as measured by cytochrome c release, appeared as a late event (5-7 days after ischaemia). AS601245, a novel JNK inhibitor, antagonized activation of both pathways and significantly protected CA1 neurones from cell death. Our results suggest a key role of JNK in the control of death receptor and mitochondrial-dependent apoptosis after transient ischaemia.

Topics: Acetonitriles; Analysis of Variance; Animals; Apoptosis; Benzothiazoles; Caspases; Cytochromes c; Enzyme Activation; Gerbillinae; Hippocampus; In Situ Nick-End Labeling; Ischemic Attack, Transient; JNK Mitogen-Activated Protein Kinases; Male; Mitochondria; Neurons; Reperfusion Injury; Thiazoles; Time Factors

Although ischemia reperfusion (I/R) induces apoptotic damage of mammalian small intestine, the molecular mechanism is largely unknown. We investigated the appearance of apoptosis at various time-points (0-24 h) of reperfusion after 1-h ischemia and the expression of various apoptosis-related proteins, such as Bcl-2, Bax, Fas, Fas ligand (FasL), activated caspase-3, and cytochrome c, immunohistochemically in rat small intestine. As assessed by TUNEL and electron microscopy, apoptotic cells were increased at 3 h of reperfusion in all intestinal parts (villous epithelium, crypt epithelium, and stroma of intestine). Moreover, the TUNEL-positive cells in the stroma were later identified as T cells. The expression of Fas and FasL as well as activated caspase-3 was markedly increased at 3 h of reperfusion in the stroma. In the villous epithelium, a transient decrease in Bcl-2 expression was found while in the crypt epithelium, Fas expression was induced. Finally, intraperitoneal injection of leupeptin (an SH-protease inhibitor) after I/R resulted in a significant inhibition of the induction of apoptosis in the stroma and crypt epithelium. Our results indicate that the triggering molecules of apoptosis in the I/R rat small intestine may vary depending on cell type and that the use of a broad-spectrum protease inhibitor may reduce intestinal damage.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Caspase 3; Caspase Inhibitors; Caspases; Cytochromes c; Fas Ligand Protein; Immunohistochemistry; In Situ Nick-End Labeling; Intestine, Small; Leupeptins; Membrane Glycoproteins; Microscopy, Electron; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury

Hepatic ischemia followed by reperfusion (I/R) is a major clinical problem during transplantation, liver resection for tumor, and circulatory shock, producing apoptosis and necrosis. Although several intracellular signal molecules are induced following I/R including NF-kappaB and c-Jun N terminal kinase (JNK), their roles in I/R injury are largely unknown. The aim of this study is to assess the role of JNK during warm I/R injury using novel selective JNK inhibitors.. Male Wistar rats (200+/-25 g) are pretreated with vehicle or with one of three compounds (CC0209766, CC0223105, and CC-401), which are reversible, highly selective, ATP-competitive inhibitors of JNK. In the first study, rats are assessed for survival using a model of ischemia to 70% of the liver for 90 min followed by 30% hepatectomy of the non-ischemic lobes and then reperfusion. In the second study, rats are assessed for liver injury resulting from 60 or 90 min of ischemia followed by reperfusion with analysis over time of hepatic histology, serum ALT, hepatic caspase-3 activation, cytochrome c release, and lipid peroxidation.. In the I/R survival model, vehicle-treated rats have a 7-day survival of 20-40%, while rats treated with the three different JNK inhibitors have survival rates of 60-100% (P<0.05). The decrease in mortality correlates with improved hepatic histology and serum ALT levels. Vehicle treated rats have pericentral necrosis, neutrophil infiltration, and some apoptosis in both hepatocytes and sinusoidal endothelial cells, while JNK inhibitors significantly decrease both types of cell death. JNK inhibitors decrease caspase-3 activation, cytochrome c release from mitochondria, and lipid peroxidation. JNK inhibition transiently blocks phosphorylation of c-Jun at an early time point after reperfusion, and AP-1 activation is also substantially blocked. JNK inhibition blocks the upregulation of the pro-apoptotic Bak protein and the degradation of Bid.. Thus, JNK inhibitors decrease both necrosis and apoptosis, suggesting that JNK activity induces cell death by both pathways.

Topics: Animals; Apoptosis; Caspase 3; Caspases; Cytochromes c; Cytoplasm; Disease Models, Animal; Enzyme Inhibitors; JNK Mitogen-Activated Protein Kinases; Lipid Peroxidation; Liver; Male; Mitochondria; Necrosis; Rats; Rats, Wistar; Reperfusion Injury; Tumor Necrosis Factor-alpha

Ischemia/reperfusion induces oxidative injury to proximal and distal renal tubular cells. We hypothesize that Bcl-2 protein augmentation with adenovirus vector mediated bcl-2 (Adv-bcl-2) gene transfer may improve ischemia/reperfusion induced renal proximal and distal tubular apoptosis through the mitochondrial control of Bax and cytochrome C translocation. Twenty-four hours of Adv-bcl-2 transfection to proximal and distal tubular cells in vitro upregulated Bcl-2/Bax ratio and inhibited hypoxia/reoxygenation induced cytochrome C translocation, O(2) (-) production and tubular apoptosis. Intra-renal arterial Adv-bcl-2 administration with renal venous clamping augmented Bcl-2 protein of rat kidney in vivo in a time-dependent manner. The maximal Bcl-2 protein expression appeared at 7 days after Adv-bcl-2 administration and the primary location of Bcl-2 augmentation was in proximal and distal tubules, but not in glomeruli. With a real-time monitoring O(2) (-) production and apoptosis analysis of rat kidneys, ischemia/reperfusion increased renal O(2) (-) level, potentiated proapoptotic mechanisms, including decrease in Bcl-2/Bax ratio, increases in caspase 3 expression and poly-(ADP-ribose)-polymerase fragments and subsequent proximal and distal tubular apoptosis. However, Adv-bcl-2 administration significantly enhanced Bcl-2/Bax ratio, decreased ischemia/reperfusion induced O(2) (-) amount, inhibited proximal and distal tubular apoptosis and improved renal function. Our results suggest that Adv-bcl-2 gene transfer significantly reduces ischemia/reperfusion induced oxidative injury in the kidney.

Topics: Adenoviridae; Animals; Apoptosis; Caspases; Cytochromes c; Female; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Humans; Kidney Diseases; Kidney Tubules, Distal; Kidney Tubules, Proximal; Oxidative Stress; Poly(ADP-ribose) Polymerases; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury

Increased permeability and reduced cerebral endothelial cell (CEC) viability induced by oxidative stress are the hallmarks of the blood-brain barrier disruption. In our experiments hydrogen peroxide (H2O2, 0.5 mM) induced a continuous decrease of the transendothelial electrical resistance (TEER) and resulted in intercellular gap formations in cultured rat CECs. Adrenomedullin (AM) increased TEER, enhanced peripheral localization of F-actin bands and attenuated the increased permeability induced by H2O2. Furthermore, AM treatment preserved mitochondrial membrane potential, attenuated cytochrome c release, and consequently improved CEC viability in H2O2 treated cultures. These results suggest that AM treatment protects CECs against oxidative injury.

Topics: Actins; Adrenomedullin; Animals; Blood-Brain Barrier; Brain; Cell Survival; Cells, Cultured; Cytochromes c; Dose-Response Relationship, Drug; Endothelial Cells; Hydrogen Peroxide; Membrane Potentials; Microscopy, Fluorescence; Mitochondria; Oxidants; Oxidative Stress; Peptides; Permeability; Rats; Rats, Wistar; Reperfusion Injury; Telencephalon; Time Factors

Aging-related changes of tubular cell apoptosis and its mechanisms in renal ischemia/reperfusion (I/R) injury are unclear. In the present study, aged (27-month-old) and young (3-month-old) Wistar rats were used to investigate aging-related tubular cell apoptosis in the setting of renal I/R injury. The renal I/R model was induced by clamping bilateral renal arteries for 30 minutes followed by reperfusion for 18 hours. Cyclosporine A (CsA, 2 mg/kg) or mycophenolate mofetil (MMF, 20 mg/kg/d) was used before ischemia. Age-matched sham-operated rats served as controls. We found that tubular cell apoptosis increased more significantly in aged rats than in young rats after renal I/R. More pronounced increases of Bax/Bcl-2 ratio, cytosolic cytochrome c, and caspase-9, which are involved in mitochondria-mediated apoptosis, were found in aged rats than in young rats, and were associated with a more pronounced decrease in superoxide dismutase activity and increase of malondialdehyde content. However, increases of tumor necrosis factor-alpha and caspase-8, two components of death receptor-mediated apoptosis, showed no aging-related differences. Interfering mitochondria and death receptor pathways with CsA and MMF, respectively, reduced the apoptosis in both age groups, whereas CsA was more effective in aged rats. Our results have demonstrated that there was an aging-related increase of tubular cell apoptosis in the renal I/R model, which may be, at least partly, due to an enhanced mitochondrial pathway resulting possibly from increased oxidative stress.

Topics: Aging; Animals; Apoptosis; bcl-2-Associated X Protein; Blotting, Northern; Blotting, Western; Caspases; Creatinine; Cytochromes c; Disease Models, Animal; Genes, bcl-2; In Situ Nick-End Labeling; Kidney; Kidney Tubules; Lipid Peroxidation; Male; Malondialdehyde; Mitochondria; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger; Severity of Illness Index; Superoxide Dismutase; Tumor Necrosis Factor-alpha

Normothermic ischemia-reperfusion is a determinant in liver injury occurring during surgical procedures, ischemic state, and multiple organ failure. The preexisting nutritional status of the liver might contribute to the extent of tissue injury and primary nonfunction. The aim of this study was to determine the role of starvation on hepatic ischemia-reperfusion injury in normal rat livers.. Rats were randomly divided into two groups: one had free access to food, the other was fasted for 16 h. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Two modes of perfusion were applied in each series of rats, fed and fasting. In the ischemia-reperfusion mode, the experiment consisted of perfusion for 15 min, warm ischemia for 60 min, and reperfusion during 60 min. In the nonischemia mode, perfusion was maintained during the 135-min study period. Five rats were included in each experimental condition, yielding a total of 20 rats. Liver enzymes, potassium, glucose, lactate, free radicals, i.e., dienes and trienes, and cytochrome c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in tissue biopsies.. Transaminases, lactate dehydrogenase, potassium, and free radical concentrations were systematically higher in fasting rats in both conditions, with and without ischemia. Cytochrome c was higher after reperfusion in the fasting rats. Glucose and lactate concentrations were greater in the fed group. The glycogen content decreased in both groups during the experiment but was markedly lower in the fasting rats.. In fed rats, liver injury was moderate, whereas hepatocytes integrity was notably impaired both after continuous perfusion and warm ischemia in fasting animals. Reduced glycogen store in hepatocytes may explain reduced tolerance.

Topics: Animals; Bilirubin; Biomarkers; Blood Glucose; Cytochromes c; Enzyme-Linked Immunosorbent Assay; Enzymes; Female; Glycogen; Hepatectomy; In Vitro Techniques; Lactic Acid; Liver; Liver Function Tests; Liver Glycogen; Nutritional Status; Oxidative Stress; Perfusion; Potassium; Rats; Rats, Wistar; Reperfusion Injury

Thrombospondin 1 (TSP-1) is a matricellular protein that inhibits angiogenesis and causes apoptosis in vivo and in vitro in several cancerous cells and tissues. Here we identify TSP-1 as the molecule with the highest induction level at 3 hours of IR injury in rat and mouse kidneys subjected to ischemia/reperfusion (IR) injury using the DNA microarray approach. Northern hybridizations demonstrated that TSP-1 expression was undetectable at baseline, induced at 3 and 12 hours, and returned to baseline levels at 48 hours of reperfusion. Immunocytochemical staining identified the injured proximal tubules as the predominant sites of expression of TSP-1 in IR injury and showed colocalization of TSP-1 with activated caspase-3. Addition of purified TSP-1 to normal kidney proximal tubule cells or cells subjected to ATP depletion in vitro induced injury as demonstrated by cytochrome c immunocytochemical staining and caspase-3 activity. The deleterious role of TSP-1 in ischemic kidney injury was demonstrated directly in TSP-1 null mice, which showed significant protection against IR injury-induced renal failure and tubular damage. We propose that TSP-1 is a novel regulator of ischemic damage in the kidney and may play an important role in the pathophysiology of ischemic kidney failure.

Topics: Adenosine Triphosphate; Animals; Binding Sites; Blotting, Northern; Blotting, Western; Caspase 3; Caspases; CD36 Antigens; Colorimetry; Cytochromes c; DNA, Complementary; Enzyme Activation; Gene Deletion; Immunoblotting; Immunohistochemistry; In Situ Nick-End Labeling; Ischemia; Kidney; Kidney Tubules; Male; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Nucleic Acid Hybridization; Oligonucleotide Array Sequence Analysis; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Thrombospondin 1; Time Factors

Ischemia-reperfusion is a critical event in the development of primary graft dysfunctions after liver transplantations. Ischemia-reperfusion causes cell injuries which are related to the successive cold preservation-warm reperfusion (CPWR) periods required by the graft. Recent evidences suggest that oxidative stress plays an important role in the development of these injuries and that mitochondrial dysfunctions are involved. The purpose of this study was to investigate the effect of the natural phytoalexin resveratrol on the prevention of liver injuries induced by 40-h cold preservation followed by a warm reperfusion. CPWR induced liver mitochondrial and cellular damages as attested by the increase in lipid peroxidation of liver membranes, the alteration of oxidative phosphorylation parameters, mitochondrial swelling and the activation of the cellular markers of necrosis and apoptosis, i.e., lactate dehydrogenase (LDH) leakage, mitochondrial cytochrome c release and caspase activation. Resveratrol inhibits lipid peroxidation and protects mitochondrial functions. It improves respiratory chain activity and prevents opening of the permeability transition pore, allowing better recovery of ATP energetic charge. Resveratrol also limits the activation of the cellular markers of necrosis and apoptosis. These protective effects could be related to the antioxidant properties of the drug but also to its membrane-stabilizing activity. Indeed, further experiments demonstrate that resveratrol is able to prevent the release of cytochrome c caused by oxygen deprivation in isolated liver mitochondria. These data demonstrate that resveratrol ameliorates the liver injury induced by CPWR and appears as a promising drug to improve the primary function of the grafted liver after transplantation.

Topics: Adenosine Triphosphate; Animals; Antioxidants; Apoptosis; Caspases; Cold Temperature; Cytochromes c; Dose-Response Relationship, Drug; In Vitro Techniques; L-Lactate Dehydrogenase; Lipid Peroxidation; Liver; Male; Mitochondria, Liver; Mitochondrial Membranes; Mitochondrial Swelling; Necrosis; Oxidative Phosphorylation; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Resveratrol; Stilbenes; Time Factors

Ischemic preconditioning (I/P) and methylprednisolone (MP) have been suggested to protect against ischemia-reperfusion (IR) injury, which results in an increased tolerance against organ hypoxia.. Before 45 minutes of hepatic ischemia, male Wistar rats were pretreated with either I/P (5/30 minutes) or MP (30 mg/kg BW). The degree of IR injury and the postischemic inflammatory (leukocyte infiltration, myeloperoxidase, intercellular adhesion molecule-1) and apoptotic (TUNEL, caspase 3, cytochrome C) activity was measured in both groups and compared with non-pretreated (ischemic) animals.. Histology and enzyme release revealed that I/P and MP treatment provided significant protection as compared with ischemic controls. TUNEL-positive cells, as well as caspase 3 and cytochrome C expression, were clearly reduced in hepatic tissue of MP-treated animals and partially reduced in I/P-treated animals when compared with ischemic animals. The inflammatory response was considerably reduced in MP- and I/P-treated animals, especially in the early period after ischemia. NF-kappaB/Rel-binding activity was increased after I/P and decreased in MP-treated animals, whereas ischemic controls showed a constant binding activity.. MP (probably by downregulation of NF-kappaB-binding activity) and I/P attenuated the postischemic apoptotic and inflammatory response. Both treatments equally reduced IR-related hepatocellular damage, and, thus, may also be applied equally in surgery involving warm organ hypoxia.

Topics: Animals; Anti-Inflammatory Agents; Apoptosis; Caspase 3; Caspases; Cytochromes c; Gene Expression Regulation; Hot Temperature; In Situ Nick-End Labeling; Intercellular Adhesion Molecule-1; Ischemic Preconditioning; Leukocytes; Liver; Male; Methylprednisolone; NF-kappa B; Peroxidase; Rats; Rats, Wistar; Reperfusion Injury

Mitochondrial calcium (mCa + 2) overload occurs during cold preservation and is an integral part of mitochondrial-dependent apoptotic pathways. We investigated the role of mCa + 2 overload in cell death following hypothermic storage using HepG2 cells stored in normoxic-hypothermic (4 degrees C) or hypoxic (< 0.1% O2)-hypothermic Belzer storage solution. Cells were stored for 6 h, with or without 10 microM ruthenium red (mCa + 2 uniporter inhibitor) followed by rewarming in oxygenated media at 37 degrees C. Cytoplasmic cytochrome c levels were studied by Western analysis and by fluorescent microscopy after transfection of cytochrome c-GFP expression plasmid. Immunofluorescence determined the intracellular, spatio-temporal distribution of Bax, and TUNEL staining was used to evaluate cell death after 180 min of rewarming. Caspase activation was evaluated using Western analysis and a caspase 3 activity assay. Bax translocation, cytochrome c release, and early rewarming cell death occurred following hypothermic storage and were exacerbated by hypoxia. Caspase 3 activation did not occur following hypothermic storage. Blockade of mCa + 2 uptake prevented Bax translocation, cytochrome c release, and early rewarming cell death. These studies demonstrate that mCa + 2 uptake during hypothermic storage, both hypoxic and normoxic, contributes to early rewarming apoptosis by triggering Bax translocation to mitochondria and cytochrome c release.

Topics: Apoptosis; bcl-2-Associated X Protein; Calcium; Caspase 3; Caspases; Cryopreservation; Cytochromes c; Hepatoblastoma; Humans; Indicators and Reagents; Mitochondria; Protein Transport; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Reperfusion Injury; Ruthenium Red; Tumor Cells, Cultured

This study is aimed at investigating the novel use of minocycline for cardiac protection during ischemia/reperfusion (I/R) injury, as well as its mechanism of action.. Minocycline is a tetracycline with anti-inflammatory properties, which is used clinically for the treatment of diseases such as urethritis and rheumatoid arthritis. Experimentally, minocycline has also been shown to be neuroprotective in animal models of cerebral ischemia and to delay progression and improve survival in mouse models of neurodegenerative diseases.. We studied 62 rat intact hearts exposed to I/R and cell cultures of neonatal and adult rat ventricular myocytes.. Minocycline significantly reduced necrotic and apoptotic cell death, both in neonatal and adult myocytes, not only when given prior to hypoxia (p < 0.001), but also at reoxygenation (p < 0.05). Moreover, in the intact heart exposed to I/R, in vivo treatment with minocycline promoted hemodynamic recovery (p < 0.001) and cell survival, with reduction of infarct size (p < 0.001), cardiac release of creatine phosphokinase (p < 0.001), and apoptotic cell death (p < 0.001). In regard to its antiapoptotic mechanism of action, minocycline significantly reduced the expression level of initiator caspases, increased the ratio of XIAP to Smac/DIABLO at both the messenger RNA and protein level, and prevented mitochondrial release of cytochrome c and Smac/DIABLO (all, p < 0.05). These synergistic actions dramatically prevent the post-ischemic induction of caspase activity associated with cardiac I/R injury.. Because of its safety record and multiple novel mechanisms of action, minocycline may be a valuable cardioprotective agent to ameliorate cardiac dysfunction and cell loss associated with I/R injury.

Topics: Animals; Animals, Newborn; Anti-Bacterial Agents; Apoptosis; Apoptosis Regulatory Proteins; Carrier Proteins; Caspase Inhibitors; Cells, Cultured; Cytochromes c; Down-Regulation; Enzyme Inhibitors; Minocycline; Mitochondria, Heart; Mitochondrial Proteins; Myocardial Infarction; Myocardial Ischemia; Myocytes, Cardiac; Oxygen; Proteins; Rats; Rats, Sprague-Dawley; Reperfusion Injury; X-Linked Inhibitor of Apoptosis Protein

Ischemic preconditioning provides a way of protecting organs from damage inflicted with prolonged ischemia-reperfusion. In this study, we investigated the mechanism of ischemic preconditioning involved in inhibition of prolonged ischemia-reperfusion-induced mucosal apoptosis in rat small intestine. Ischemic preconditioning was triggered by a transient occlusion of the superior mesenteric artery followed by reperfusion. Ischemia-reperfusion was induced by 60-min occlusion of the superior mesenteric artery followed by 60-min reperfusion in the small intestine. Ischemia-reperfusion alone induced mucosal apoptosis and mitochondrial respiratory dysfunction via promoted reactive oxygen species generation, reduced mitochondrial glutathione oxidation, increased mitochondrial lipid peroxidation, reduced mitochondrial membrane potential, and enhanced release of cytochrome c from mitochondria to activate caspase-9 and caspase-6 in the small intestine. Pretreatment with 20-min ischemia followed by 5-min reperfusion significantly inhibited the prolonged ischemia-reperfusion-induced mucosal apoptosis by 30%. Ischemic preconditioning ameliorated mitochondrial respiratory dysfunction by 50%, reduced reactive oxygen species generation by 38%, and suppressed mitochondrial lipid peroxidation by 36%, resulting in improvement of the mitochondrial membrane potential and prevention of cytochrome c release as well as caspase-6 activation. Results suggest that ischemic preconditioning attenuated ischemia-reperfusion-induced mucosal apoptosis partly by inhibiting the reactive oxygen species-mediated mitochondria-dependent pathway in the rat small intestine.

Topics: Animals; Apoptosis; Blotting, Western; Cytochromes c; DNA; DNA Fragmentation; Electrophoresis, Agar Gel; In Situ Nick-End Labeling; Intestinal Mucosa; Intestine, Small; Ischemic Preconditioning; Lipid Peroxidation; Male; Membrane Potentials; Mitochondria; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Sulfhydryl Compounds

A possible mechanism for D-cis-diltiazem (diltiazem)-mediated improvement of the contractile function of ischemic/reperfused hearts was examined. Thirty-five-min ischemia/60-min reperfusion recovered little the left ventricular developed pressure (LVDP) and decreased myocardial high-energy phosphates (HEPs). Ischemia induced an accumulation of tissue Na+ content, an increase in cytochrome c in the cytosolic fraction, and a decrease in the oxygen consumption rate (OCR) in perfused hearts. Treatment of the heart with 1 microM diltiazem for the last 3-min of pre-ischemia did not affect the decrease in HEPs during ischemia, whereas that with 3 microM partially attenuated the decrease in ATP, suggesting that 3 microM diltiazem exerted energy-sparing effect. Treatment with 1 microM diltiazem enhanced the post-ischemic recovery of LVDP associated with attenuation of the ischemia-induced accumulation of tissue Na+, increase in cytochrome c in the cytosolic fraction, and decrease in myocardial OCR, and restoration of the myocardial HEPs during reperfusion. Combined treatment with diltiazem and a Na+/H+ exchange inhibitor, but not a Na+ channel blocker, facilitated the attenuation of Na+ accumulation in the ischemic heart and the enhancement of the post-ischemic recovery of LVDP. Sodium lactate, a possible metabolite in ischemic hearts, and sodium chloride increased the Na+ concentration in mitochondria, released cytochrome c into incubation medium, and reduced the mitochondrial respiration. Treatment of isolated mitochondria with diltiazem failed to attenuate the sodium lactate- and sodium chloride-induced alterations. These results suggest that the cardioprotection of diltiazem may be exerted via attenuating cytosolic Na+ overload through Na+ channels in the ischemic heart, leading to preservation of mitochondrial functional ability during ischemia, followed by improvement of post-ischemic energy production and contractile recovery.

Topics: Animals; Calcium; Cardiotonic Agents; Cardiovascular Agents; Cytochromes c; Diltiazem; Drug Interactions; Ischemia; Male; Mitochondria; Myocardial Contraction; Myocardial Reperfusion Injury; Myocardium; Oxygen Consumption; Phosphates; Rats; Rats, Wistar; Reperfusion Injury; Respiration; Sodium; Sodium Channel Blockers; Sodium-Hydrogen Exchangers

We designed this experimental study to determine the optimal cycle for intermittent inflow occlusion during liver resection. A cycle of intermittent clamping (IC) for 15 minutes of ischemia followed by reperfusion for 5 minutes during liver resection is currently the most popular protocol used by experienced liver centers. As each period of reperfusion is associated with bleeding, longer periods of clamping would be advantageous. However, the longest safe duration of successive ischemia is unknown. Three groups of mice were subjected to a total liver ischemic period for 90 minutes; 2 groups underwent IC for 15 or 30 minutes, respectively, followed by 5 minutes of reperfusion, while the control group was subjected to continuous inflow occlusion only. The degree of tissue injury was assessed using biochemical and histological markers, as well as animal survival. While serious injury was observed in the continuous clamping group, both IC groups were associated with minimal injury, including lesser degrees of apoptosis and necrosis. All animals survived in the IC groups, while all animals died following 90 minutes of continuous inflow occlusion. In conclusion, intermittent portal pedicle clamping with 15- or 30-minute cycles is highly protective. A period of 30 minutes clamping should be preferred, since this would decrease the amount of blood loss associated with each cycle. This data should be confirmed in humans, and may represent a change in the current practice of hepatic surgery.

Topics: Animals; Apoptosis; Caspase 3; Caspases; Constriction; Cytochromes c; Hemostasis, Surgical; Liver; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron; Necrosis; Portal System; Reperfusion Injury; Survival Analysis; Time Factors

Tetracyclines exhibit significant anti-inflammatory properties in a variety of rheumatologic and dermatologic conditions. They have also been shown to inhibit apoptosis in certain neurodegenerative disorders. Because ischemic renal injury is characterized by both apoptosis and inflammation, we investigated the therapeutic potential of tetracyclines in a rat model of renal ischemia-reperfusion. Male Sprague-Dawley rats underwent bilateral renal artery clamp for 30 min followed by reperfusion and received either minocycline or saline for 36 h before ischemia. Minocycline reduced tubular cell apoptosis 24 h after ischemia as determined by terminal transferase-mediated dUTP nick end-labeling staining and nuclear morphology. It also decreased cytochrome c release into the cytoplasm and reduced upregulation of p53 and Bax after ischemia. The minocycline-treated group showed a significant reduction in tubular injury and cast formation. In addition, minocycline reduced the number of infiltrating leukocytes, decreased leukocyte chemotaxis both in vitro and ex vivo, and downregulated the expression of ICAM-1. Serum creatinine 24-h postischemia was significantly reduced in the minocycline-treated group. We conclude that minocycline has potent antiapoptotic and anti-inflammatory properties and protects renal function in this model of ischemia-reperfusion. Tetracyclines are among the safest and best-studied antibiotics. They are thus attractive candidates for the therapy of human ischemic acute renal failure.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; bcl-2-Associated X Protein; Chemotaxis, Leukocyte; Cytochromes c; Cytosol; Disease Models, Animal; Kidney; Kidney Diseases; Leukocytes; Male; Minocycline; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tumor Suppressor Protein p53; Up-Regulation

Reactive oxygen species (ROS) play a key role in promoting mitochondrial cytochrome c release and induction of apoptosis. ROS induce dissociation of cytochrome c from cardiolipin on the inner mitochondrial membrane (IMM), and cytochrome c may then be released via mitochondrial permeability transition (MPT)-dependent or MPT-independent mechanisms. We have developed peptide antioxidants that target the IMM, and we used them to investigate the role of ROS and MPT in cell death caused by t-butylhydroperoxide (tBHP) and 3-nitropropionic acid (3NP). The structural motif of these peptides centers on alternating aromatic and basic amino acid residues, with dimethyltyrosine providing scavenging properties. These peptide antioxidants are cell-permeable and concentrate 1000-fold in the IMM. They potently reduced intracellular ROS and cell death caused by tBHP in neuronal N(2)A cells (EC(50) in nm range). They also decreased mitochondrial ROS production, inhibited MPT and swelling, and prevented cytochrome c release induced by Ca(2+) in isolated mitochondria. In addition, they inhibited 3NP-induced MPT in isolated mitochondria and prevented mitochondrial depolarization in cells treated with 3NP. ROS and MPT have been implicated in myocardial stunning associated with reperfusion in ischemic hearts, and these peptide antioxidants potently improved contractile force in an ex vivo heart model. It is noteworthy that peptide analogs without dimethyltyrosine did not inhibit mitochondrial ROS generation or swelling and failed to prevent myocardial stunning. These results clearly demonstrate that overproduction of ROS underlies the cellular toxicity of tBHP and 3NP, and ROS mediate cytochrome c release via MPT. These IMM-targeted antioxidants may be very beneficial in the treatment of aging and diseases associated with oxidative stress.

Topics: Amino Acid Motifs; Animals; Antioxidants; Caco-2 Cells; Calcium; Cardiolipins; Cell Death; Cell Survival; Cytochromes c; Humans; Hydrogen Peroxide; Intracellular Membranes; Liver; Male; Mice; Mitochondria; Mitochondria, Liver; Nitro Compounds; Oxidative Stress; Oxygen; Oxygen Consumption; Peptides; Propionates; Reactive Oxygen Species; Reperfusion; Reperfusion Injury; tert-Butylhydroperoxide; Time Factors; Tyrosine

Glutamate is the only amino acid extracted by healthy myocardium in net amounts, with uptake further increased during hypoxic or ischemic conditions. Glutamate supplementation provides cardioprotection from hypoxic and reperfusion injury through several metabolic pathways that depend upon adequate transport of glutamate into the mitochondria. Glutamate transport across the inner mitochondrial membrane is a key component of the malate/aspartate shuttle. Glutamate transport in the brain has been well characterized since the discovery of the excitatory amino acid transporter (EAAT) family. We hypothesize that a protein similar to EAAT1 found in brain may function as a glutamate transporter in cardiac mitochondria. Rat heart total RNA was screened by reverse transcriptase-polymerase chain reaction with an array of primer pairs derived from the rat brain EAAT1 cDNA sequence, yielding a 3786-bp cDNA comprising a 1638-bp open reading frame identical to rat brain EAAT1 with flanking 5'- and 3'-untranslated regions. Northern blot analysis confirmed a 4-kb mRNA product in rat heart and brain, with greater abundance in brain. A protein of the predicted approximate 60-kD size was recognized in myocardial lysates by an anti-EAAT1 polyclonal antibody produced against an amino-terminal peptide from human EAAT1. The protein enriched in rat heart mitochondria by immunoblot, co-localized with the mitochondrial protein cytochrome c by immunohistochemistry, and further localized to the inner mitochondrial membrane upon digitonin fractionation of the mitochondria. In myocytes overexpressing EAAT1, activity of the malate/aspartate shuttle increased by 33% compared to non-transfected cells (P = 0.004). These data indicate that EAAT1 is expressed in myocardial mitochondria, and functions in the malate/aspartate shuttle, suggesting a role for EAAT1 in myocardial glutamate metabolism.

Topics: Adenoviridae; Animals; Aspartic Acid; Blotting, Northern; Brain; Cells, Cultured; Coloring Agents; Cytochromes c; Digitonin; DNA, Complementary; Excitatory Amino Acid Transporter 1; Genetic Vectors; Glutamic Acid; Hypoxia; Immunoblotting; Immunohistochemistry; Malates; Microscopy, Fluorescence; Mitochondria; Mitochondria, Heart; Myocardium; Open Reading Frames; Rats; Rats, Inbred WKY; Rats, Sprague-Dawley; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Messenger; Subcellular Fractions; Tetrazolium Salts; Thiazoles; Transfection

Heart attacks caused by occlusion of coronary arteries are often treated by mechanical or enzymatic removal of the occlusion and reperfusion of the ischemic heart. It is now recognized that reperfusion per se contributes to myocardial damage, and there is a great interest in identifying the molecular basis of this damage. We recently showed that inhibiting protein kinase Cdelta (PKCdelta) protects the heart from ischemia and reperfusion-induced damage. Here, we demonstrate that PKCdelta activity and mitochondrial translocation at the onset of reperfusion mediates apoptosis by facilitating the accumulation and dephosphorylation of the pro-apoptotic BAD (Bcl-2-associated death promoter), dephosphorylation of Akt, cytochrome c release, PARP (poly(ADP-ribose) polymerase) cleavage, and DNA laddering. Our data suggest that PKCdelta activation has a critical proapoptotic role in cardiac responses following ischemia and reperfusion.

Topics: Animals; Apoptosis; bcl-Associated Death Protein; bcl-X Protein; Carrier Proteins; Caspase 3; Caspases; Cytochromes c; Enzyme Activation; Humans; In Situ Nick-End Labeling; In Vitro Techniques; Male; Mitochondria; Myocardial Ischemia; Myocardium; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerases; Protein Kinase C; Protein Kinase C-delta; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proteins; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Wistar; Reperfusion Injury; Signal Transduction

Subsarcolemmal mitochondria sustain progressive damage during myocardial ischemia. Ischemia decreases the content of the mitochondrial phospholipid cardiolipin accompanied by a decrease in cytochrome c content and a diminished rate of oxidation through cytochrome oxidase. We propose that during ischemia mitochondria produce reactive oxygen species at sites in the electron transport chain proximal to cytochrome oxidase that contribute to the ischemic damage. Isolated, perfused rabbit hearts were treated with rotenone, an irreversible inhibitor of complex I in the proximal electron transport chain, immediately before ischemia. Rotenone pretreatment preserved the contents of cardiolipin and cytochrome c measured after 45 min of ischemia. The rate of oxidation through cytochrome oxidase also was improved in rotenone-treated hearts. Inhibition of the electron transport chain during ischemia lessens damage to mitochondria. Rotenone treatment of isolated subsarcolemmal mitochondria decreased the production of reactive oxygen species during the oxidation of complex I substrates. Thus, the limitation of electron flow during ischemia preserves cardiolipin content, cytochrome c content, and the rate of oxidation through cytochrome oxidase. The mitochondrial electron transport chain contributes to ischemic mitochondrial damage that in turn augments myocyte injury during subsequent reperfusion.

Topics: Animals; Cardiolipins; Cytochromes c; Electron Transport; Electron Transport Complex I; Electron Transport Complex IV; Hydrogen Peroxide; In Vitro Techniques; Mitochondria; Myocardial Ischemia; Myocardium; Oxidants; Rabbits; Reactive Oxygen Species; Reperfusion Injury; Rotenone; Uncoupling Agents

To investigate the effects of beta-aescin on apoptosis induced by transient focal brain ischemia in rats.. Rats were pretreated with beta-aescin for 7 d and then subjected to brain ischemia/reperfusion (I/R) injury induced by a middle cerebral artery occlusion. After 2 h ischemia and 24 h reperfusion, Hematoxylin-Eosin (HE) staining, in situ end-labeling of nuclear DNA fragmentation (TUNEL) were employed to determine the level of apoptosis. The expressions of caspase-3 and Bcl-2 in the cortex were determined by immunohistochemistry and Western blot. The release of cytochrome c was analyzed by Western blot.. The increased numbers of HE- and TUNEL-positive staining cells were significantly observed at 24 h after reperfusion. The immunoreactivity was inhibited by beta-aescin (30, 60 mg/kg) (P<0.01 or P<0.05 vs vehicle-treated). After cerebral I/R, cytochrome c was released into the cytosol and caspase-3 was activated, whereas Bcl-2 expression was inhibited. beta-Aescin (30, 60 mg/kg) markedly inhibited the expression of caspase-3 and the release of cytochrome c, and up-regulated the expression of Bcl-2 (P<0.05, P<0.01 vs vehicle-treated).. beta-Aescin could potently inhibit caspase-3 activation and the release of cytochrome c, increasing the expression of Bcl-2 after cerebral I/R in rats. These findings on the inhibitory effects of beta-aescin on brain ischemic injury-induced apoptosis might have important theoretical basis for the treatment on ischemic cerebrovascular diseases.

Topics: Animals; Apoptosis; Brain Ischemia; Caspase 3; Caspases; Cerebral Cortex; Cytochromes c; Escin; Infarction, Middle Cerebral Artery; Male; Mitochondria; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Apoptosis as well as necrosis may play an important role in hepatic ischemia/reperfusion (I/R) injury. Akt, a serine-threonine protein kinase, is known to promote cell survival. We investigated whether gene transfer of constitutively active or dominant negative Akt could affect hepatic I/R injury.. Hepatic I/R injury was induced in rats by Pringle's maneuver for 20 min followed by reperfusion. Adenoviruses encoding a constitutively active form of Akt (myrAkt), a dominant negative form of Akt (dnAkt), or beta-galactosidase (LacZ) were injected through the tail vein 72 h before hepatic I/R.. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) staining demonstrated a significant increase in the positive cells 240 min after reperfusion. Immunoblotting with phospho-Akt antibody showed phosphorylation of Akt from 90 to 180 min after reperfusion. The expression of myrAkt reduced the number of TUNEL-positive cells and hepatic necrosis around the central veins in the liver after reperfusion. This expression also significantly inhibited the increase in serum alanine aminotransferase (297 +/- 131 IU/L, P < 0.05) 120 min after I/R, compared with increases in uninfected (1761 +/- 671 IU/L), LacZ adenovirus (1528 +/- 671 IU/L)-, and dnAkt adenovirus (1342 +/- 485 IU/L)-infected rats. MyrAkt expression phosphorylated Bad and inhibited the release of cytochrome-c after reperfusion. No difference in nuclear translocation of nuclear factor (NF)-kappaB, p65 was seen among the three groups of rats, however.. Adenoviral gene transfer of myrAkt could inhibit apoptotic cell death and subsequent hepatic I/R injury in the rat, through Bad, not NF-kappaB.

Topics: Adenoviridae; Alanine Transaminase; Animals; Apoptosis; bcl-Associated Death Protein; BH3 Interacting Domain Death Agonist Protein; Carrier Proteins; Cytochromes c; Cytoplasm; Gene Transfer Techniques; Immunoblotting; In Situ Nick-End Labeling; Liver; Liver Circulation; Male; Mitochondria; Necrosis; NF-kappa B; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Reperfusion Injury

Reperfusion of myocardial tissue can result in programmed cell death. Nevertheless, relatively little information exists concerning pathways initiated in vivo that ultimately commit cardiac cells to apoptosis during ischemia/reperfusion. The goal of the present study was to determine whether mitochondrial-mediated mechanisms of apoptosis are initiated during in vivo cardiac ischemia/reperfusion. We provide evidence that the content of cytochrome c in the cytosol increases exclusively during reperfusion. Over the same time interval Bax, a pro-apoptotic protein implicated in release of cytochrome c from mitochondria, was found to disappear from cytosolic extracts. This was associated with the appearance of tightly associated Bax in the mitochondrial fraction. Cytochrome c from reperfused cytosolic extracts is present as a high molecular weight oligomer consistent with formation of the apoptosome. In addition, pro-caspase-9 was found to disappear exclusively during reperfusion. Therefore, the results of the current study indicate that the mitochondrial-mediated pathway of apoptosis is initiated as a result of in vivo cardiac ischemia/reperfusion.

Topics: Animals; Apoptosis; bcl-2-Associated X Protein; Blotting, Western; Caspase 9; Caspases; Cytochromes c; Cytosol; Electrophoresis, Polyacrylamide Gel; Male; Mitochondria; Mitochondria, Heart; Myocardial Reperfusion; Protein Transport; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Inbred F344; Reperfusion; Reperfusion Injury; Time Factors

Post-hemorrhagic shock mesenteric lymph (PHSML) has been linked with neutrophil (PMN) priming, endothelial cell (EC) activation, and acute lung injury (ALI) in rodent models. We have previously identified the lipid fraction of PHSML as containing the causative agent(s). Due to the lesson learned from the rodent gut bacterial translocation experience, we sought to confirm this phenomenon using a large animal model; hypothesizing that lymph collected from the porcine gut following ischemia/reperfusion (I/R) would cause PMN priming.. Mesenteric lymph was collected from adult pigs before, during, and for 2 hours after non-lethal hemorrhagic shock (mean arterial pressure = 30 mm Hg x 45 minutes). Whole lymph and the extracted lipid fractions of the lymph were then added to isolated human and porcine PMNs and superoxide production was measured by cytochrome C reduction.. Hemorrhagic shock profoundly affected mesenteric lymph flow from baseline (pre-shock) flow rates of 75.63 +/- 8.86 mL/hr to 49.38 +/- 5.76 mL/hr during shock and increasing to 253.38 +/- 27.62 mL/hr after 2 hours of resuscitation. Human PMNs exposed to both whole lymph (PHSML) and its extracted lipids (PHSML Lipid) collected 2 hours after shock exhibited more than a two-fold increase in superoxide release upon activation compared with pre-shock samples: PHSML- 6.27 +/- 0.83 versus 2.56 +/- 0.60 nmolO2(-)/ 3.75 cells/mL/min, respectively (p = 0.007), PHSML Lipid- 4.93 +/- 0.34 versus 2.49 +/- 0.11 nmolO2(-)/ 3.75 cells/mL/min (p < 0.001). Similarly, porcine PMNs exhibited close to a two-fold activation when exposed to the lymph and lipid fraction: PHSML- 4.51 +/- 0.42 versus 1.06 +/- 0.28 nmolO2(-)/ 3.75 cells/mL/min (p = 0.008), PHSML Lipid-4.80 +/- 0.81 versus 1.55 +/- 0.23 nmolO2(-)/ 3.75 cells/mL/min (p = 0.002).. Mesenteric lymphatics serve as the conduit for inflammatory mediators elaborated by the post-ischemic gut in both small and large animal models. Further, the causal agent(s) exist in the lipid fraction of the lymph and are active on both human and animal PMNs.

Topics: Animals; Cytochromes c; Disease Models, Animal; Lipids; Lymphatic System; Neutrophils; Rats; Reperfusion Injury; Shock, Hemorrhagic; Shock, Traumatic; Splanchnic Circulation; Superoxides; Swine

To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (deltapsim) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn't completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can't completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.

Topics: Animals; Apoptosis; Caspase 3; Caspases; Cytochromes c; Mice; Mitochondria; Neuroblastoma; Neurons; Reperfusion Injury; Tumor Cells, Cultured

Transient focal ischaemia by middle cerebral artery occlusion (MCAO) may produce cell death, but the mechanisms leading to cell death differ in the infarct core and in the penumbra, the immediate zone surrounding the infarct core. In the present study, transient focal ischaemia to adult rats was produced by intraluminal occlusion of the middle cerebral artery for 1 h followed by 0 h (n=6), 1 h (n=10), 4 h (n=8), 6 h (n=2) and 12 h (n=3) of reperfusion. The present model of ischaemia causes a large cortico-striatal infarct extending through the mediolateral cortex and dorsolateral striatum at 12 h. The expression and subcellular distribution of several proteins involved in apoptosis have been examined in the penumbra and in the infarct core by using combined methods of immunohistochemistry, cell subfractionation and Western blotting. Transient focal ischaemia by MCAO results in activation of complex signal pathways for cell death in the penumbra. Increased expression of Bcl-2 and Bax, but not of Bcl-x, occurs in the penumbra at the time when Bax translocates from the cytosol to the mitochondria, cytochrome c is released to the cytoplasm and active caspase-3 is expressed. Bax translocation, cytochrome c release and active caspase-3 are observed at 4 h, but not at 1 h, following reperfusion, and together indicate activation of the caspase-dependent pathway of apoptosis in the penumbra. In contrast, reduced Bax expression but not Bax translocation and cytochrome c release occurs in the infarct core, thus suggesting apoptosis signals restricted to the penumbra. In addition, increased expression of an apoptosis-inducing factor in the cytoplasm and nuclei of selected cells shows, for the first time, activation of the caspase-independent mitochondrial pathway in the penumbra following transient focal ischaemia and reperfusion.

Topics: Animals; Apoptosis; Apoptosis Inducing Factor; bcl-2-Associated X Protein; bcl-X Protein; Blotting, Western; Brain Ischemia; Caspases; Cytochromes c; Cytosol; Enzyme Activation; Flavoproteins; Immunohistochemistry; Infarction, Middle Cerebral Artery; Male; Membrane Proteins; Mitochondria; Neuroglia; Neurons; Protein Transport; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-bcl-2; Rats; Reperfusion Injury; Time Factors