bay-11-7082 and Reperfusion-Injury

Stroke is the most common cerebrovascular disease with high morbidity and mortality around the world. However, the underlying mechanisms involved in nerve injury and cerebral ischaemia/reperfusion (I/R) during cerebrovascular disease are still not completely clear. In the present study, we investigate the role of kinesin family member 2 (KIF2) in the neuroprotection after cerebral I/R injury. KIF2 was aberrantly expressed in the cerebral tissues from middle cerebral artery occlusion (MCAO) rat model in a time dependent manner. A similar changing pattern was found in the cultured hypoxic neurons as well as SK-N-SH cells in vitro. Compared to the control, KIF2 inhibition significantly increased the level of malonic dialdehyde (MDA), and reduced the level of superoxide dismutase (SOD) as well as glutathione peroxidase (GSH-px) activity in cerebral tissues of MCAO rat model. The reactive oxygen species (ROS) level was also up-regulated after KIF2 siRNA knockdown in cultured hypoxic SK-N-SH cells. The apoptosis rates of hypoxic neurons and SK-N-SH cells as well as activated-caspase-3 level were obviously increased after KIF2 silencing. Furthermore, we found that the nuclear factor-kappa B (NF-κB) pathway was involved in KIF2-mediated neuroprotection after cerebral I/R injury, and induced apoptosis of hypoxic SK-N-SH cells by KIF2 silencing could be attenuated by the specific inhibitor BAY11-7082 of NF-κB. In conclusion, we demonstrate that KIF2 could mediate the neuroprotection in cerebral I/R injury by inhibiting activation of NF-κB pathway. This might provide a novel therapeutic target for cerebral I/R injury.

Topics: Animals; Brain Ischemia; Cell Line, Tumor; Humans; Kinesins; Male; Neuroprotection; NF-kappa B; Nitriles; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction; Sulfones

Topics: Animals; Caspases; Cell Line; Cell Survival; Gene Expression Regulation; Male; Malondialdehyde; Mice; Mice, Inbred C57BL; Myocardial Ischemia; Myocytes, Cardiac; Nitriles; Protective Agents; Reactive Oxygen Species; Reperfusion Injury; Silybin; Sulfones

Intestinal ischemia-reperfusion (I/R) injury causes inflammation and tissue damage and contributes to high morbidity and mortality, but the underlying mechanism remains elusive and effective therapies are still lacking. We report here a critical role of the microRNA 682 (miR-682) as a key regulator and therapeutic target in intestinal I/R injury. MiR-682 was markedly induced in intestinal epithelial cells (IECs) during intestinal ischemia in mice and in the human colonic epithelial cells during hypoxia, but was undetected rapidly after intestinal reperfusion in IEC of mice. MiR-682 induction during hypoxia was modulated by hypoxia-inducible factor-1α (HIF-1α). On lentivirus-mediated miR-682 overexpression in vivo during intestinal reperfusion or miR-682 mimic transfection in vitro during hypoxia, miR-682 decreased the expression of phosphatase and tensin homolog (PTEN) and subsequently activated nuclear translocation of nuclear factor kappa B (NF-κB) p65. Consequently, NF-κB activation by miR-682-mediated PTEN downregulation prevented reactive oxygen species (ROS) induction, inflammatory reaction, mitochondrial-mediated apoptosis and IEC apoptosis. The effect of miR-682-mediated PTEN/NF-κB pathway on IECs resulted in protection against intestinal I/R injury in mice. However, NF-κB chemical inhibitor reversed miR-682-mediated decreased PTEN expression, ROS induction, inflammation and IEC apoptosis. Collectively, these results identify a novel miR-682/PTEN/NF-κBp65 signaling pathway in IEC injury induced by I/R that could be targeted for therapy.

Topics: Animals; Apoptosis; Epithelial Cells; Gene Expression Regulation; Genetic Vectors; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Intestine, Small; Lentivirus; Mice; Mice, Inbred C57BL; MicroRNAs; Mitochondria; Nitriles; Organometallic Compounds; Phenanthrolines; Primary Cell Culture; PTEN Phosphohydrolase; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Sulfones; Survival Analysis; Transcription Factor RelA

We investigated the role of the nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome during testis ischemia and reperfusion injury (TI/R) in wild-type (WT) and NLRP3 knock-out (KO) mice. WT and KO mice underwent 1 hour testicular ischemia followed by 4 hours and 1 and 7 days of reperfusion or a sham TI/R. Furthermore, two groups of WT mice were treated at the beginning of reperfusion and up to 7 days with two inflammasome inhibitors, BAY 11-7082 (20 mg/kg i.p.) or Brilliant Blue G (45.5 mg/kg i.p.), or vehicle. Animals were killed with a pentobarbital sodium overdose at 4 hours and 1 and 7 days, and bilateral orchidectomies were performed. Biochemical and morphologic studies were carried out in all groups. TI/R in WT mice significantly increased caspase-1 and interleukin (IL)-1β mRNA after 4 hours and IL-18 mRNA at 1 day of reperfusion (P ≤ 0.05). There was also a significant increase in caspase-3 and terminal deoxynucleotidyl transferase-mediated digoxigenin-deoxyuridine nick-end labeling-positive cells, marked histologic damage, and altered spermatogenesis in WT mice in both testes after 1 and 7 days of reperfusion. KO TI/R mice, WT TI/R BAY 11-7082, and Brilliant Blue G treated mice showed a significant reduced IL-1β and IL-18 mRNA expression, blunted caspase-1 and -3 expression, minor histologic damages, low terminal deoxynucleotidyl transferase-mediated digoxigenin-deoxyuridine nick-end labeling activity, and preserved spermatogenesis. These data suggest that the activation of NLRP3 plays a key role in TI/R, and its inhibition might represent a therapeutic target for the management of patients with unilateral testicular torsion.

Topics: Animals; Apoptosis; Carrier Proteins; Caspase 1; Caspase 3; Inflammasomes; Interleukin-18; Interleukin-1beta; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitriles; NLR Family, Pyrin Domain-Containing 3 Protein; Orchiectomy; Reperfusion Injury; Rosaniline Dyes; Spermatogenesis; Sulfones; Testicular Diseases; Testis

Despite advancements in renal replacement therapy, the mortality rate for acute kidney injury (AKI) remains unacceptably high, likely due to remote organ injury. Kidney ischemia-reperfusion injury (IRI) activates cellular and soluble mediators that incite a distinct pulmonary proinflammatory and proapoptotic response. Tumor necrosis factor receptor 1 (TNFR1) has been identified as a prominent death receptor activated in the lungs during ischemic AKI. We hypothesized that circulating TNF-α released from the postischemic kidney induces TNFR1-mediated pulmonary apoptosis, and we aimed to elucidate molecular pathways to programmed cell death. Using an established murine model of kidney IRI, we characterized the time course for increased circulatory and pulmonary TNF-α levels and measured concurrent upregulation of pulmonary TNFR1 expression. We then identified TNFR1-dependent pulmonary apoptosis after ischemic AKI using TNFR1-/- mice. Subsequent TNF-α signaling disruption with Etanercept implicated circulatory TNF-α as a key soluble mediator of pulmonary apoptosis and lung microvascular barrier dysfunction during ischemic AKI. We further elucidated pathways of TNFR1-mediated apoptosis with NF-κB (Complex I) and caspase-8 (Complex II) expression and discovered that TNFR1 proapoptotic signaling induces NF-κB activation. Additionally, inhibition of NF-κB (Complex I) resulted in a proapoptotic phenotype, lung barrier leak, and altered cellular flice inhibitory protein signaling independent of caspase-8 (Complex II) activation. Ischemic AKI activates soluble TNF-α and induces TNFR1-dependent pulmonary apoptosis through augmentation of the prosurvival and proapoptotic TNFR1 signaling pathway. Kidney-lung crosstalk after ischemic AKI represents a complex pathological process, yet focusing on specific biological pathways may yield potential future therapeutic targets.

Topics: Acute Kidney Injury; Animals; Apoptosis; Capillary Permeability; CASP8 and FADD-Like Apoptosis Regulating Protein; Caspase 3; Caspase 8; Creatinine; Etanercept; Immunoglobulin G; Ischemia; Kidney; Lung; Lung Injury; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Nitriles; Protein Isoforms; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type I; Reperfusion Injury; Signal Transduction; Sulfones; Tumor Necrosis Factor-alpha

Despite development of therapeutic modalities, myocardial ischemia-reperfusion (I/R) injury remains an important cause of cardiac dysfunction. Multiple strategies exist experimentally, but few are clinically available. Nuclear factor kappa-B (NF-κB) is a key transcription factor in the inflammatory response and is implicated in I/R injury. We hypothesized that the NFκB inhibitor BAY 11-7082 (BAY) would decrease the extent of injury after myocardial I/R. Hypoxia-reoxygenation (H/R) was induced in rat neonatal cardiomyocytes with or without BAY pretreatment. NF-κB activation, vascular cell adhesion molecule (VCAM)-1, and monocyte chemoattractant protein (MCP)-1 were assayed by immunocytochemistry, Western blot or reverse transcriptase-polymerase chain reaction (RT-PCR). Sprague-Dawley rats (n = 7) were administered BAY (130 µg/kg) and I/R was induced by ligation of the left anterior descending artery (LAD) for 30 minutes followed by reperfusion. Infarct size was analyzed after 24 hours. At 2 weeks, echocardiography was performed to evaluate ventricular function and hearts were analyzed for fibrosis and apoptosis. BAY treatment inhibited NF-κB p65 activation, as well as VCAM-1 and MCP-1 expression induced by H/R in cardiomyocytes. Compared with control rats, BAY pretreated rats showed reduced infarct size. Echocardiograms demonstrated preserved systolic function as a fractional shortening in the BAY+I/R group (P < 0.05). Fibrosis was reduced in the BAY+I/R group (P < 0.05) and apoptosis was also reduced in the BAY+I/R group (P < 0.05).In the rat myocardial I/R injury model, BAY significantly reduced the infarct size, and preserved myocardial function. These data demonstrate that a currently available and well-tolerated inhibitor of NF-κB can decrease the risk of myocardial injury associated with I/R.

Topics: Animals; Apoptosis; Blotting, Western; Cells, Cultured; Chemokine CCL2; Disease Models, Animal; Immunohistochemistry; Inflammation; Myocytes, Cardiac; NF-kappa B; Nitriles; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Sulfones

We provide the first report of direct effects of resistin upon haemodynamic and neurohumoral parameters in isolated perfused rat heart preparations. Pre-conditioning with 1 nmol L-1 recombinant human resistin prior to ischaemia significantly impaired contractile recovery during reperfusion, compared with vehicle-infused hearts (P<0.05, n=12). This was accompanied by a significant increase in both A-type and B-type natriuretic peptides (P<0.05, n=12 both ANP and BNP vs vehicle), creatine kinase, and tumour necrosis factor-alpha (TNF-alpha) release in resistin-infused hearts. Resistin had no significant effect on myocardial glucose uptake. Co-infusion of resistin with Bay 11 7082 (an NF-kappaB inhibitor) improved contractile recovery following ischaemia and reduced both natriuretic peptide and creatine kinase release. This is the first evidence indicating resistin impairs cardiac recovery following ischaemia, stimulates cardiac TNF-alpha secretion, and modulates reperfusion release of natriuretic peptides and biochemical markers of myocardial damage. A TNF-alpha signalling related mechanism is suggested as one component underlying these effects.

Topics: Animals; Creatine Kinase; Enzyme Inhibitors; Glucose; Humans; Male; Myocardial Ischemia; Myocardium; Nitriles; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Resistin; Sulfones; Tumor Necrosis Factor-alpha