minocycline and Reperfusion-Injury

Minocycline is a semi-synthetic tetracycline that inhibits bacterial protein synthesis and hence is used for the treatment of many infectious diseases. Over the years, many other interesting properties of minocycline have been identified and been used to make patents which include anti-inflammatory, anti-apoptotic, matrix metalloproteinase inhibitor and free oxygen radical scavenger activity. Ischemia-reperfusion injury is a concern for almost every clinical specialty and minocycline seems to be an attractive cytoprotective agent that can ameliorate the damage due to these properties. Ischemia-reperfusion injury is a complex process and involves various pathways that lead to cell death. This review focuses on the body of evidence describing various proposed mechanisms of action of minocycline and its current experimental use in various animal models of ischemia-reperfusion injury.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Cytoprotection; Disease Models, Animal; Humans; Minocycline; Patents as Topic; Reperfusion Injury

Animal models of cerebral ischemia have improved our understanding of the pathophysiology and mechanisms involved in stroke, as well as the investigation of potential therapies. The potential of zebrafish to model human diseases has become increasingly evident. The availability of these models allows for an increased understanding of the role of chemical exposure in human conditions and provides essential tools for mechanistic studies of disease. To evaluate the potential neuroprotective properties of minocycline against ischemia and reperfusion injury in zebrafish and compare them with other standardized models. In vitro studies with BV-2 cells were performed, and mammalian transient middle cerebral artery occlusion (tMCAO) was used as a comparative standard with the zebrafish stroke model. Animals were subjected to ischemia and reperfusion injury protocols and treated with minocycline. Infarction size, cytokine levels, oxidative stress, glutamate toxicity, and immunofluorescence for microglial activation, and behavioral test results were determined and compared. Administration of minocycline provided significant protection in the three stroke models in different parameters analyzed. Both experimental models complement each other in their particularities. The proposal also strengthens the findings in the literature in rodent models and allows the validation of alternative models so that they can be used in further research involving diseases with ischemia and reperfusion injury.

Topics: Animals; Brain Ischemia; Disease Models, Animal; Humans; Infarction, Middle Cerebral Artery; Mammals; Minocycline; Neuroprotective Agents; Reperfusion Injury; Stroke; Zebrafish

To examine the neuroprotective effect of minocycline on retinal ischemia-reperfusion (IR) injury in rats and investigate its possible mechanism of action.. Retinal IR injury was established by increasing the intraocular pressure in rats up to 110 mmHg for 60 min. The animals with retinal IR injury were intraperitoneally injected with 22.5 mg/kg minocycline twice a day for 14 days. The control group received the same amount of saline. Subsequently, funduscopic examination, retinal thickness measurement, retinal microvascular morphology, full-field electroretinography (ERG), retinal apoptotic cell count, and remaining retinal ganglion cell (RGC) count were performed. The expression of iNOS, Bax, Bcl2, IL-1α, IL-6, TNF-α, caspase-3, GFAP, Iba-1, Hif-1α, and Nrf2 was examined with real-time PCR and western blotting.. Minocycline treatment prevented IR-induced rat retinal edema and retinal cells apoptosis at the early stage and alleviated retina atrophy, blood vessel tortuosity, functional photoreceptor damage, and RGC degeneration at the late stage of the IR injury. At the molecular level, minocycline affected retinal gene and protein expression induced by IR.. The results suggested that minocycline has a neuroprotective effect on rat retinal IR injury, possibly through anti-inflammation, antiapoptosis, antioxidation, and inhibition of microglial activation.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Biomarkers; Blotting, Western; Cell Count; Cell Survival; Disease Models, Animal; Electroretinography; Eye Proteins; In Situ Nick-End Labeling; Injections, Intraperitoneal; Male; Minocycline; Neuroprotective Agents; Papilledema; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Reperfusion Injury; Retinal Ganglion Cells; Retinal Vessels; Tomography, Optical Coherence

The poor clinical relevance of experimental models of stroke contributes to the translational failure between preclinical and clinical studies testing anti-inflammatory molecules for ischemic stroke. Here, we (i) describe the time course of inflammatory responses triggered by a thromboembolic model of ischemic stroke and (ii) we examine the efficacy of two clinically tested anti-inflammatory drugs: Minocycline or anti-CD49d antibodies (tested in stroke patients as Natalizumab) administered early (1 h) or late (48 h) after stroke onset. Radiological (lesion volume) and neurological (grip test) outcomes were evaluated at 24 h and 5 days after stroke. Immune cell responses peaked 48 h after stroke onset. Myeloid cells (microglia/macrophages, dendritic cells, and neutrophils) were already increased 24 h after stroke onset, peaked at 48 h, and remained increased-although to a lesser extent-5 days after stroke onset. CD8

Topics: Animals; Anti-Inflammatory Agents; Brain; Brain Ischemia; Disease Models, Animal; Ischemic Stroke; Male; Mice; Minocycline; Natalizumab; Reperfusion Injury; Thromboembolism

Testicular torsion is a serious urological disease leading to testicular damage. This study aimed to assess the effect of minocycline on testicular ischaemia/reperfusion (I/R) injury caused by testicular torsion/detorsion. Male adult Wistar rats (n = 32) were assigned into four groups of sham, I/R, I/R + minocycline and minocycline. I/R injury was induced by two sets of surgical operations, including the rotation of the left testis (720°, counterclockwise), followed by detorsion after 4 hr. The administration of minocycline was carried out 30 min before detorsion and then continued for 8 weeks. At the end of the 8th week, rats were killed and sampling was done. Johnson's score, the height of seminiferous tubule epithelium, the mean seminiferous tubule diameter, as well as biochemical parameters, SOD, GPx and CAT, were significantly enhanced in the I/R + minocycline group compared with the I/R group. The administration of minocycline led to a marked decrease in expression levels of Caspase-3, Bax, IL-1β and TNF-α genes, and a remarkable increase in expression levels of Bcl-2, 3β-HSD and 17β-HSD3 genes compared with the I/R group. Administration of minocycline could also reduce the rate of germ cell apoptosis (TUNEL staining). Hence, minocycline was useful in the management of testicular torsion/detorsion.

Topics: Animals; Humans; Ischemia; Male; Malondialdehyde; Minocycline; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Spermatic Cord Torsion; Testis

Mammalian target of rapamycin (mTOR) has been evidenced as a multimodal therapy in the pathophysiological process of Acute Ischemic Stroke (AIS). However, the pathway that minocycline targets mTOR signaling is not fully defined in the AIS pathogenesis. This study aims at the roles of minocycline on the mTOR signaling in the AIS process and further discovers the underlying mechanisms of minocycline involved in the following change of mTOR signaling-autophagy.. Cerebral ischemia/reperfusion (CIR) rat animal models were established with the transient suture occlusion into the middle cerebral artery. Minocycline (50mg/kg) was given by intragastric administration. The Morris water maze was used to test the cognitive function of animals. Immunohistochemistry and immunofluorescence were introduced for testing the levels of synaptophysin and PSD-95. Western blot was conducted for investigating the levels of mTOR, p-mTOR (Ser2448), p70S6, p-p70S6 (Thr389), eEF2k, p-eEF2k (Ser366), p-eIF4B (Ser406), LC3, p62, synaptophysin and PSD-95.. Minocycline prevents the cognitive decline of the MCAO stroke rats. Minocycline limits the expression of p-mTOR (Ser2448) and the downstream targets of mTOR [p70S6, p-p70S6 (Thr389), eEF2k, p-eEF2k (Ser366) and p-eIF4B (Ser406)] (P<0.01), while minocycline has no influence on mTOR. LC3-II abundance and the LC3-II/I ratio were upregulated in the hippocampus of the MCAO stroke rats by the minocycline therapy (P<0.01). p62 was downregulated in the hippocampus from the MCAO stroke rats administrated with minocycline therapy(P<0.01). The levels of SYP and PSD-95 were upregulated in the brain of the MCAO stroke rats administrated with minocycline therapy.. Minocycline prevents cognitive deficits via inhibiting mTOR signaling and enhancing the autophagy process, and promoting the expression of pre- and postsynaptic proteins (synaptophysin and PSD-95) in the brain of the MCAO stroke rats. The potential neuroprotective role of minocycline in the process of cerebral ischemia may be related to mitigating ischemia-induced synapse injury via inhibiting the activation of mTOR signaling.

Topics: Animals; Autophagy; Brain; Brain Ischemia; Male; Minocycline; Neuroprotective Agents; Rats; Rats, Wistar; Reperfusion Injury; Signal Transduction; TOR Serine-Threonine Kinases

Stroke induced white matter injury can induce marked neurological deficits even after relatively small infarcts, due to the tightly packed nature of white matter tracts especially in certain areas in the brain. Many drugs which were successful in the pre-clinical trials failed in clinical trials, which was attributed in part to the focus on grey matter injury completely and ignoring their effect on white matter. In this work we selected two known neuroprotective drugs (minocycline and progesterone) and examined their effect on white matter injury after focal cerebral ischemia/reperfusion injury in rats. Focal cerebral ischemia was induced in male Wistar rats (one-hour ischemia followed by reperfusion). Progesterone and minocycline were administered immediately after reperfusion onset. Infarct size, microglial activation and white matter injury were assessed and compared between the treatment and no-treatment groups and Sham operated animals. Our data showed that both progesterone and minocycline reduced infarct size, microglial activation and white matter injury. This work shows a new neuroprotective mechanism of both drugs, via white matter injury reduction, that can be exploited for stroke management. While the utility of either drugs as a sole agent in the management of stroke is questionable, there is a value of using either drugs as an adjuvant therapy to traditional stroke therapy, making use of the white matter protective effect that would improve outcome and facilitate healing after stroke.

Topics: Animals; Brain Ischemia; Female; Male; Minocycline; Neuroprotective Agents; Progesterone; Rats; Rats, Wistar; Reperfusion Injury; Stroke; White Matter

Topics: Animals; Anti-Bacterial Agents; Cell Death; Death; Indium Radioisotopes; Minocycline; Rabbits; Reperfusion Injury; Tomography, Emission-Computed, Single-Photon

The aim of this study was to investigate the effect of minocycline (MC) on the survival of retinal ganglion cells (RGCs) in an ischemic-reperfusion (I/R) injury model of retinal degeneration.. Retinal I/R injury was induced in the left eye of mice for 60 min by maintaining intraocular pressure at 90 mmHg. Low- or high-dose MC (20 or 100 mg/kg, respectively) was administered by intravenous injection at 5 min after the retinal ischemic insult and then administered once daily until the mice were euthanized. RGCs and microglial cells were counted using immunofluorescence staining. Functional changes in the RGCs were evaluated using electroretinography. The visual function was assessed using an optokinetic test.. The data demonstrated that the effect of MC was dose dependent. Low-dose MC showed protective effects, with reduced RGC loss and microglial activation, while the high-dose MC showed damage effects, with more RGC loss and microglial activation when compared with the vehicle group. The electroretinography and optokinetic test results were consistent with the morphologic observations.. These data suggested that appropriate concentrations of MC can protect the retina against retinal ischemic-reperfusion injury, while excessive MC has detrimental effects.

Topics: Animals; Disease Models, Animal; Drug Administration Schedule; Electroretinography; Ependymoglial Cells; Hormesis; Intraocular Pressure; Male; Mice; Minocycline; Neuroprotective Agents; Primary Cell Culture; Reperfusion Injury; Retinal Degeneration; Retinal Ganglion Cells; Vision, Ocular

Spinal microglia and astrocytes are the main responders to the inflammatory cascade and process pain through various neural interactions. CXCL10 is a late-phase protein that accelerates arteriogenesis during reperfusion through CXCR3. However, the early-phase expression (within 72 h postoperatively) of CXCL10 and CXCR3 during the development of ischemia-reperfusion (IR)-induced inflammatory pain remains unclear. We investigated whether this chemokine pair participates in glial interactions during early-phase IR injury.. A rat model was induced by an 8-min occlusion of the aortic arch. Temporal assessments of mechanical and thermal allodynia and the protein levels of CXCL10 and CXCR3 were determined through measurements of paw withdrawal thresholds (PWTs) and paw withdrawal latencies (PWLs) and Western blotting assays. The co-localization of various cells with glial cells was detected by double immunofluorescence. The effects of CXCL10/CXCR3 on glial interactions were explored by intrathecal treatment with specific inhibitors (AMD487, minocycline and fluorocitrate) and recombinant CXCL10, and subsequent release of cytokines was assessed by ELISAs.. The IR injury initiated bimodal allodynia within 72 h of reperfusion, as illustrated by two W-shape trends in the PWTs and PWLs with two minima at 12 and 48 h post-IR. Allodynia was highly correlated with overexpression of CXCL10 and CXCR3, which were expressed in microglia at the early stage and in both microglia and astrocytes at the late stage, as shown by increased CXCL10 and CXCR3 immunoreactivities and double-labeled cells. AMD487 and minocycline injections exerted comparable inhibitory effects on CXCR3 and Iba-1 and on GFAP immunoreactivity at 12 and 48 h post-IR, and these inhibitory effects were only observed at 48 h following fluorocitrate injection. The levels of TNF-α and IL-6 showed variations in concert with the changes in Iba-1 and GFAP immunoreactivities. Recombinant CXCL10 injection reversed the abovementioned effects.. The results showed that CXCL10/CXCR3 are involved in bimodal inflammatory pain during early-phase IR injury. The sequential activation of and crosstalk between microglia and astrocytes mediated through CXCR3 upregulation suggested that treatments targeting specific cell types are important in post-IR allodynia.

Topics: Animals; Astrocytes; Calcium-Binding Proteins; Chemokine CXCL10; Disease Models, Animal; Glial Fibrillary Acidic Protein; Hyperalgesia; Microfilament Proteins; Microglia; Minocycline; Rats; Rats, Sprague-Dawley; Receptors, CXCR3; Reperfusion Injury; Spinal Cord

Memory deficit is the most visible symptom of cerebral ischemia that is associated with loss of pyramidal cells in CA1 region of the hippocampus. Oxidative stress and inflammation may be involved in the pathogenesis of ischemia/reperfusion (I/R) damage. Minocycline, a semi-synthetic tetracycline derived antibiotic, has anti-inflammatory and antioxidant properties. We evaluated the neuroprotective effect of minocycline on memory deficit induced by cerebral I/R in rat. I/R was induced by occlusion of common carotid arteries for 20min. Minocycline (40mg/kg, i.p.) was administered once daily for 7days after I/R. Learning and memory were assessed using the Morris water maze test. Nissl staining was used to evaluate the viability of CA1 pyramidal cells. The effects of minocycline on the microglial activation was also investigated by Iba1 (Ionized calcium binding adapter molecule 1) immunostaining. The content of malondialdehyde (MDA) and pro-inflammatory cytokines (IL-1β and TNF-α) in the hippocampus were measured by thiobarbituric acid reaction substances method and ELISA, respectively. Minocycline reduced the increase in escape latency time and in swimming path length induced by cerebral I/R. Furthermore, the ischemia-induced reduction in time spent in the target quadrant during the probe trial was increased by treatment with minocycline. Histopathological results indicated that minocycline prevented pyramidal cells death and microglial activation induced by I/R. Minocycline also reduced the levels of MDA and pro-inflammatory cytokines in the hippocampus in rats subjected to I/R. Minocycline has neuroprotective effects on memory deficit induced by cerebral I/R in rat, probably via its anti-inflammatory and antioxidant properties.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Brain Ischemia; Cognitive Dysfunction; Disease Models, Animal; Hippocampus; Inflammation; Ischemic Attack, Transient; Learning; Male; Memory; Memory Disorders; Minocycline; Neuroprotective Agents; Oxidants; Oxidative Stress; Pyramidal Cells; Rats; Rats, Wistar; Reperfusion; Reperfusion Injury; Tumor Necrosis Factor-alpha

Cerebral ischemia leads to multifaceted injury to the brain. A polytherapeutic drug that can be administered immediately after reperfusion may increase protection to the brain by simultaneously targeting multiple deleterious cascades. This study evaluated efficacy of the combination of three clinically approved drugs: lamotrigine, minocycline, and lovastatin, using two mouse models: global and focal cerebral ischemia induced by transient occlusion of the common carotid arteries or the middle cerebral artery, respectively. In vitro, the combination drug, but not single drug, protected neurons against oxygen-glucose deprivation (OGD)-induced cell death. The combination drug simultaneously targeted cell apoptosis and DNA damage induced by ischemia. Besides acting on neurons, the combination drug suppressed inflammatory processes in microglia and brain endothelial cells induced by ischemia. In a transient global ischemia model, the combination drug, but not single drug, suppressed microglial activation and inflammatory cytokine production, and reduced neuronal damage. In a transient focal ischemia model, the combination drug, but not single drug, attenuated brain infarction, suppressed infiltration of peripheral neutrophils, and reduced neurological deficits following ischemic stroke. In summary, the combination drug confers a broad-spectrum protection against ischemia/reperfusion (I/R) injury and could be a promising approach for early neuroprotection after out-of-hospital cardiac arrest or ischemic stroke.

Topics: Animals; Apoptosis; Brain; Brain Ischemia; Drug Therapy, Combination; Female; Lamotrigine; Lovastatin; Mice; Mice, Inbred C57BL; Minocycline; Neurons; Neuroprotective Agents; Reperfusion Injury; Triazines

Retinal ischemia-reperfusion (IR) injury causes irreversible loss of neurons and ultimately leads to permanent visual impairment and blindness. The cellular response under this pathological retinal condition is less clear. Using genetically modified mice, we systematically examined the behavior of microglia/macrophages after injury. We show that IR leads to activation of microglia/macrophages indicated by migration and proliferation of resident microglia and recruitment of circulating monocytes. IR-induced microglia/macrophages associate with apoptotic retinal neurons. Very interestingly, neuron loss can be mitigated by minocycline treatment. Minocycline induces Il4 expression and M2 polarization of microglia/macrophages. IL4 neutralization dampens minocycline-induced M2 polarization and neuroprotection. Given a well-established safety profile as an antibiotic, our results provide a rationale for using minocycline as a therapeutic agent for treating ischemic retinal degeneration.

Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Male; Mice; Mice, Inbred C57BL; Microglia; Minocycline; Neuroprotection; Reperfusion Injury; Retina; Retinal Degeneration

Cerebral ischemia leads to memory impairment that is associated with loss of hippocampal CA1 pyramidal neurons. Neuroinflammation and oxidative stress may be implicated in the pathogenesis of ischemia/reperfusion damage. Minocycline has anti-inflammatory and antioxidant properties. We investigated the neuroprotective effects of minocycline in rats subjected to cerebral ischemia/reperfusion injury. Thirty male rats were divided into three groups: control, sham, and minocycline-pretreated group. Minocycline (40 mg/kg) was injected intraperitoneally immediately before surgery, and then ischemia was induced by occlusion of common carotid arteries for 20 min. Seven days after reperfusion, the Morris water-maze task was used to evaluate memory. Nissl staining was also performed to analyze pyramidal cell damage. We measured the contents of malondialdehyde and proinflammatory cytokines in the hippocampus by the thiobarbituric acid method and enzyme-linked immunosorbent assay, respectively. Microglial activation was also investigated by Iba1 immunostaining. The results showed that pretreatment with minocycline prevented memory impairment induced by cerebral ischemia/reperfusion. Minocycline pretreatment also significantly attenuated ischemia-induced pyramidal cell death and microglial activation in the CA1 region and reduced the levels of malondialdehyde and proinflammatory cytokines (interleukin-1β and tumor necrosis factor-α) in the hippocampus of ischemic rats. Minocycline showed neuroprotective effects on cerebral ischemia-induced memory deficit probably through its anti-inflammatory and antioxidant activities.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Brain Ischemia; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Inflammation; Male; Maze Learning; Memory Disorders; Minocycline; Neuroprotective Agents; Oxidative Stress; Rats; Reperfusion Injury

Minocycline, a broad-spectrum tetracycline antibiotic, has shown anti-inflammatory and neuroprotective effects in ischemic brain injury. The present study seeks to determine whether monocyte chemotactic protein-induced protein 1 (MCPIP1), a recently identified modulator of inflammatory reactions, is involved in the cerebral neuroprotection conferred by minocycline treatment in the animal model of focal cerebral ischemia and to elucidate the mechanisms of minocycline-induced ischemic brain tolerance.. Focal cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 2 h in male C57BL/6 mice and MCPIP1 knockout mice followed by 24- or 48-h reperfusion. Twelve hours before ischemia or 2 h after MCAO, mice were injected intraperitoneally with 90 mg/kg of minocycline hydrochloride. Thereafter, the animals were injected twice a day, at a dose of 90 mg/kg after ischemia until sacrificed. Transcription and expression of MCPIP1 gene was monitored by quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemistry. The neurobehavioral scores, infarction volumes, and proinflammatory cytokines in brain and NF-κB signaling were evaluated after ischemia/reperfusion.. MCPIP1 protein and mRNA levels significantly increased in mouse brain undergoing minocycline pretreatment. Minocycline treatment significantly attenuated the infarct volume, neurological deficits, and upregulation of proinflammatory cytokines in the brain of wild type mice after MCAO. MCPIP1-deficient mice failed to evoke minocycline-treatment-induced tolerance compared with that of the control MCPIP1-deficient group without minocycline treatment. Similarly, in vitro data showed that minocycline significantly induced the expression of MCPIP1 in primary neuron-glial cells, cortical neurons, and reduced oxygen glucose deprivation (OGD)-induced cell death. The absence of MCPIP1 blocked minocycline-induced protection on neuron-glial cells and cortical neurons treated with OGD.. Our in vitro and in vivo studies demonstrate that MCPIP1 is an important mediator of minocycline-induced protection from brain ischemia.

Topics: Animals; Brain Edema; Brain Infarction; Cells, Cultured; Cytokines; Disease Models, Animal; Gene Expression Regulation; Glial Fibrillary Acidic Protein; Glucose; Hypoxia; Infarction, Middle Cerebral Artery; Mice; Mice, Inbred C57BL; Mice, Knockout; Minocycline; Neurologic Examination; Neurons; Neuroprotective Agents; Phosphopyruvate Hydratase; Reperfusion Injury; Ribonucleases; Time Factors

To observe the effects of minocycline on morphology and the expression of synaptophysin in cortical tissues of rats after cerebral ischemia reperfusion injury.. 36 male SD rats were randomly divided into 3 groups: sham group, model group [ischemia reperfusion (I/R)] and minocycline (Min) group (treated with minocycline for 14 d, 3 mg/kg, 2 times/d ). Middle cerebral artery occlusion (MCAO) was used to established as focal cerebral I/R model. At 14 d after I/R. Neurological functional recovery was evaluated using the staircase test, the cell morphology in cortex was evaluated by HE staining, the neurite growth was observed by immunostaining with anti-microtubule-associated protein-2 (MAP-2) antibody, the expression of synaptophysin in pei-infarct region was tested by Western blot.. In the sham group, the rats did not show any neurological deficits. The neurons in the cortex were arranged in neat rows and the morphology were normal, the MAP-2 positive neurons showed longer neuronal processes than the model group. Compared to the model group, minocycline significantly improved forelimb motor function, increased the expression of synaptophysin and the number of MAP-2-positive cells in peri-infarct region (P < 0.05).. Minocycline could improve the neurite regrowth and the expression of synaptophysin of neuron in ischemic cortex, promote neurological functional recovery of rats after MCAO, which is related to regulate the neuronal plasticity.

Topics: Animals; Brain Ischemia; Male; Minocycline; Neuronal Plasticity; Neurons; Rats; Rats, Sprague-Dawley; Recovery of Function; Reperfusion Injury; Synaptophysin

Cerebral hyperperfusion (CHP) is a potential complication of superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis for moyamoya disease (MMD), and optimal postoperative management has not yet been established. Minocycline, a neuroprotective antibiotic agent, plays a role in blocking matrix metalloproteinase 9 (MMP-9), which contributes to edema formation and hemorrhagic conversion after cerebral ischemia-reperfusion. Patients with MMD have been shown to have increased serum MMP-9 levels.. To examine the effect of minocycline on the prevention of postoperative CHP after STA-MCA anastomosis for MMD.. N-isopropyl-p-[I]iodoamphetamine single-photon emission computed tomography was performed 1 and 7 days after STA-MCA anastomosis on 109 hemispheres in 86 consecutive patients with MMD (ages, 9-69 years; mean, 37.2 years). Postoperative systolic blood pressure was strictly maintained at lower than 130 mm Hg in all 109 surgeries. The most 60 recent hemispheres were managed by the intraoperative and postoperative intravenous administration of minocycline hydrochloride (200 mg/d). The incidence of focal neurological deterioration (FND) due to CHP was then compared with that in 36 patients undergoing 49 surgeries managed without minocycline.. FND due to CHP was observed in 4 operated hemispheres in patients treated without minocycline (4/49, 8.16%), and in none in the minocycline-treated group (0/60) (P = .0241). Multivariate analysis revealed that minocycline administration (P < .001), surgery on the left hemisphere (P = .031), and a smaller recipient artery diameter (P < .001) significantly correlated with FND due to CHP.. The administration of minocycline with strict blood pressure control may represent secure and effective postoperative management to prevent symptomatic CHP after STA-MCA anastomosis for MMD.

Topics: Adolescent; Adult; Aged; Anastomosis, Surgical; Blood Pressure Determination; Brain; Cerebral Revascularization; Cerebrovascular Disorders; Child; Female; Humans; Male; Middle Aged; Middle Cerebral Artery; Minocycline; Moyamoya Disease; Neuroprotective Agents; Postoperative Care; Postoperative Complications; Radionuclide Imaging; Reperfusion Injury; Temporal Arteries; Young Adult

To explore the protective eff ect of minocycline on hepatic ischemia-reperfusion injury (IRI) in rats and the underlying mechanisms.. A total of 54 male Sprague-Dawley rats were randomly divided into 3 groups: the sham-operated group (control group), the ischemic-reperfusion (IR group), and the minocycline preconditioning group (n=18 per group). The rats in the minocycline preconditioning group were given minocycline (45 mg/kg) by gastric irrigation at 36 h before operation and then were subsequently administered with minocycline (22.5 mg/kg) at every 12 h. Th e rats were sacrifi ced at 2, 6, 24 h after reperfusion. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. HE staining of liver tissues was performed to detect the histological changes, and the degree of liver IRI according to Suzuki score were calculated. The levels of malondialdehyde (MDA) and myeloperoxidase (MPO) were determined by spectrophotometer; the mRNA expression of tumor necrosis factor-α (TNF-α) and interleukin-1 beta (IL-1β) in the liver were measured by real-time PCR; Dickkopf-1 (DKK-1) and beta-catenin (β-catenin) protein expression in the liver were detected by Western blot.. After 2, 6, 24 h reperfusion, compared with the IR group, the liver function (ALT, AST and LDH) in the minocycline group was significantly improved (all P<0.05); the Suzuki's scores and the levels of hepatic TNF-α and IL-1β mRNA were significantly decreased (all P<0. 05); the MDA and MPO levels the liver were decreased (both P<0.05); the protein expression of hepatic DKK-1 was decreased (P<0.05), while the protein expression of β-catenin was increased (P<0.05).. Minocycline can alleviate the ischemic-reperfusion injury mainly through reducing oxidative stress and inhibiting the release of pro-inflammatory cytokines depends on the activation of the Wnt/β-catenin signaling pathway in the liver.

Topics: Alanine Transaminase; Animals; Aspartate Aminotransferases; beta Catenin; Intercellular Signaling Peptides and Proteins; Interleukin-1beta; Ischemic Preconditioning; L-Lactate Dehydrogenase; Liver; Male; Malondialdehyde; Minocycline; Oxidative Stress; Peroxidase; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Reperfusion Injury; Tumor Necrosis Factor-alpha

Paraplegia remains a devastating complication of thoracoabdominal aortic procedures resulting from spinal cord ischemia and reperfusion injury (SCIR). Pharmacologic interventions have not proven efficacious in attenuating this injury, with poor understanding of the underlying mechanisms. The resident macrophages, or microglia in the spinal cord, may play a significant role in SCIR. The macrolide antibiotic, minocycline, has been shown in stroke models to inhibit microglial activation. This study hypothesized that microglial inhibition by minocycline after SCIR will attenuate injury with preservation of motor function.. Mature male C57Bl/6 mice underwent 4 minutes of thoracic aortic occlusion with reperfusion. Mice receiving minocycline 30 minutes before ischemia and daily thereafter (90 mg/kg and 45 mg/kg, respectively) were compared with mice receiving vehicle controls. Hind-limb motor function was measured at 12-hour intervals, with spinal cord harvest for histologic and immunologic comparison at 60 hours.. Minocycline treatment significantly preserved hind limb motor function in all mice (n = 7) compared with complete paralysis in all untreated mice (n = 8), reaching significance from 24 hours of reperfusion through 60 hours. Immunofluorescent staining for Iba-1 revealed significant inhibition of microglial activation by minocycline treatment. Vehicle control sections demonstrated a greater degree of apoptosis compared with minocycline-treated spinal cord sections.. Minocycline limits microglial activation, paralleling functional preservation after aortic cross-clamping. These data suggest functional microglia contribute to reperfusion injury after spinal cord ischemia. The effects of minocycline demonstrate a potential pharmacological therapy as well as demonstrating a potential cellular target in preventing paraplegia after aortic intervention.

Topics: Animals; Inflammation; Male; Mice; Mice, Inbred C57BL; Microglia; Minocycline; Motor Activity; Nerve Degeneration; Reperfusion Injury; Spinal Cord Ischemia; Tumor Necrosis Factor-alpha

Minocycline, a tetracycline-derived compound, mitigates damage caused by ischemia/reperfusion (I/R) injury. Here, 19 tetracycline-derived compounds were screened in comparison to minocycline for their ability to protect hepatocytes against damage from chemical hypoxia and I/R injury. Cultured rat hepatocytes were incubated with 50μM of each tetracycline-derived compound 20 min prior to exposure to 500μM iodoacetic acid plus 1mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs-Ringer-HEPES buffer at pH6.2 for 4h prior to reoxygenation at pH7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca(2+) uptake was measured in isolated rat liver mitochondria incubated with Fluo-5N. Cell killing after 120 min of chemical hypoxia measured by propidium iodide (PI) fluorometry was 87%, which decreased to 28% and 42% with minocycline and doxycycline, respectively. After I/R, cell killing at 120 min decreased from 79% with vehicle to 43% and 49% with minocycline and doxycycline. No other tested compound decreased killing. Minocycline and doxycycline also inhibited mitochondrial Ca(2+) uptake and suppressed the Ca(2+)-induced mitochondrial permeability transition (MPT), the penultimate cause of cell death in reperfusion injury. Ru360, a specific inhibitor of the mitochondrial calcium uniporter (MCU), also decreased cell killing after hypoxia and I/R and blocked mitochondrial Ca(2+) uptake and the MPT. Other proposed mechanisms, including mitochondrial depolarization and matrix metalloprotease inhibition, could not account for cytoprotection. Taken together, these results indicate that minocycline and doxycycline are cytoprotective by way of inhibition of MCU.

Topics: Animals; Anti-Bacterial Agents; Calcium; Calcium Channels; Doxycycline; Hepatocytes; Hypoxia; Iron; Male; Minocycline; Mitochondria, Liver; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Tetracycline

Many retinal diseases are associated with vascular dysfunction accompanied by neuroinflammation. We examined the ability of minocycline (Mino), a tetracycline derivative with anti-inflammatory and neuroprotective properties, to prevent vascular permeability and inflammation following retinal ischemia-reperfusion (IR) injury, a model of retinal neurodegeneration with breakdown of the blood-retinal barrier (BRB).. Male Sprague-Dawley rats were subjected to 45 min of pressure-induced retinal ischemia, with the contralateral eye serving as control. Rats were treated with Mino prior to and following IR. At 48 h after reperfusion, retinal gene expression, cellular inflammation, Evan's blue dye leakage, tight junction protein organization, caspase-3 activation, and DNA fragmentation were measured. Cellular inflammation was quantified by flow-cytometric evaluation of retinal tissue using the myeloid marker CD11b and leukocyte common antigen CD45 to differentiate and quantify CD11b+/CD45low microglia, CD11b+/CD45hi myeloid leukocytes and CD11bneg/CD45hi lymphocytes. Major histocompatibility complex class II (MHCII) immunoreactivity was used to determine the inflammatory state of these cells.. Mino treatment significantly inhibited IR-induced retinal vascular permeability and disruption of tight junction organization. Retinal IR injury significantly altered mRNA expression for 21 of 25 inflammation- and gliosis-related genes examined. Of these, Mino treatment effectively attenuated IR-induced expression of lipocalin 2 (LCN2), serpin peptidase inhibitor clade A member 3 N (SERPINA3N), TNF receptor superfamily member 12A (TNFRSF12A), monocyte chemoattractant-1 (MCP-1, CCL2) and intercellular adhesion molecule-1 (ICAM-1). A marked increase in leukostasis of both myeloid leukocytes and lymphocytes was observed following IR. Mino treatment significantly reduced retinal leukocyte numbers following IR and was particularly effective in decreasing the appearance of MHCII+ inflammatory leukocytes. Surprisingly, Mino did not significantly inhibit retinal cell death in this model.. IR induces a retinal neuroinflammation within hours of reperfusion characterized by inflammatory gene expression, leukocyte adhesion and invasion, and vascular permeability. Despite Mino significantly inhibiting these responses, it failed to block neurodegeneration.

Topics: Animals; Blood-Retinal Barrier; Capillary Permeability; Fluorescent Antibody Technique; Gene Expression; Inflammation; Male; Minocycline; Nerve Degeneration; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Reperfusion Injury; Retina

The aim of this study was to assess the effects of minocycline on cerebral ischemia-reperfusion (I/R) injury in rats. The study was carried out on 24 male Wistar albino rats, weighing 200-250 g, which were divided into three groups: (i) control (n = 8), (ii) I/R (n = 8) and (iii) I/R + minocycline (n = 8). Minocycline was administrated at a dose of 90 mg/kg p.o. to the I/R group 48, 24 and 1 h before ischemia. Following bilateral exposure of the common carotid arteries by anterior cervical dissection and separation of the vagus nerve, I/R injury was performed by occlusion. Following reperfusion, malondialdehyde (MDA), superoxide dismutase, glutathione peroxidase and catalase levels in the blood and brain tissue, and creatine kinase (CK), CK-BB, lactate dehydrogenase (LDH), neuron-specific enolase (NSE) and protein S100β levels in the blood were measured and the histopathological changes were monitored. Regarding histopathological evaluation, symptoms of degeneration were significantly improved in the I/R + minocycline group compared to the I/R-only group. Statistical analysis of the biochemical parameters revealed significant differences in MDA (p < 0.001), nitric oxide (p < 0.05), CK (p < 0.05) and CK-MB (p < 0.05) levels between the I/R + minocycline group and the I/R group. According to the literature, the effect of minocycline is firstly assessed by LDH, CK-MB, NSE and S-100β analysis in addition to antioxidant status and histopathological analysis.

Topics: Animals; Brain; Brain Ischemia; Male; Minocycline; Neuroprotective Agents; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Minocycline has been recently implicated in protection against focal cerebral ischemia reperfusion (I/R), but the protective effects on neurobehavioral abnormalities remains contradictory. In the present study, we investigate whether minocycline improves axonal regeneration and neurological function recovery by inhibiting the expression of the repulsive guidance molecular A (RGMa) after focal cerebral ischemia reperfusion. Male Sprague-Dawley (SD) rats were subjected to occlusion of the right middle cerebral artery (MCAO) for 2 h and 3 mg kg⁻¹ minocycline was injected intravenously immediately after reperfusion twice a day for 14 days. The staircase test and modified neurological severity score (mNSS) were performed to evaluate functional outcome and blood-brain barrier (BBB) permeability was assessed by Evan's blue dye extravasation (EB) at the expected time point. The expression of RGMa in ischemic cortex was measured by immunohistochemical staining and Western blot 2 weeks after MCAO. Neurofilament protein 200 (NF-200) immunohistochemical staining was used to assess axonal damage. Treatment with minocycline at a dose of 3 mg kg⁻¹ via the caudal vein significantly reduced the extravasation of EB, elevated mNSS and improved forelimb motor function as assessed by the staircase test when compared to the I/R group (P < 0.05). Moreover, axonal regrowth was enhanced in the minocycline treatment group when compared to the I/R group (P < 0.05). In addition, minocycline significantly reduced the expression of RGMa protein 2 weeks after MCAO as assessed by both immunostaining and Western blot. Our studies suggest that early minocycline treatment promotes neurological functional recovery and axonal regeneration in rats after MCAO, which might be mediated by down-regulating RGMa expression.

Topics: Animals; Axons; Brain Ischemia; Cerebral Cortex; GPI-Linked Proteins; Male; Membrane Proteins; Middle Cerebral Artery; Minocycline; Nerve Regeneration; Nerve Tissue Proteins; Neurofilament Proteins; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Recovery of Function; Reperfusion Injury

This study examined the protective effect of ischemic postconditioning (IPoC) and minocycline postconditioning (MT) on myocardial ischemia-reperfusion (I/R) injury in atherosclerosis (AS) animals and the possible mechanism. Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model. AS rabbits were randomly divided into 3 groups: (1) I/R group, the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h; (2) IPoC group, the myocardial ischemia lasted for 35 min, and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles (R20s/I20s×3)], and then reperfusion was sustained for 12 h; (3) MT group, minocycline was intravenously injected 10 min before reperfusion. The blood lipids, malondialdehyde (MDA), superoxide dismutase (SOD), soluble cell adhesion molecule (sICAM), myeloperoxidase (MPO), and cardiac troponin T (cTnT) were biochemically determined. The myocardial infarction size (IS) and apoptosis index (AI) were measured by pathological examination. The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the AS models were successfully established. The myocardial IS, the plasma levels of MDA, sICAM, MPO and cTnT, and the enzymatic activity of MPO were significantly decreased, and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group (P<0.05 for all). The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group (all P<0.05). It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits, and the mechanisms involved anti-oxidation, anti-inflammation, up-regulation of bcl-2 expression and down-regulation of caspase-3 expression. Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.

Topics: Animals; Atherosclerosis; Ischemic Preconditioning, Myocardial; Male; Minocycline; Myocardial Reperfusion Injury; Rabbits; Reperfusion Injury

Matrix metalloproteinases (MMPs) are endopeptidases that degrade extracellular matrix and involved in ischemic organ injuries. The present study was designed to determine the role of MMP-2 in the development of ischemic acute kidney injury (AKI). AKI was induced in MMP-2 wild-type (MMP-2(+/+)) mice by 30, 60, 90, and 120 min renal ischemia and reperfusion. Renal histology, expression and activity of MMP-2 and MMP-9, and renal function were examined during the development of AKI. AKI was also induced in MMP-2-deficient (MMP-2(-/-)) mice and MMP-2(+/+) mice treated with inhibitor of MMPs (minocycline and synthetic peptide MMP inhibitor). In MMP-2(+/+) mice, MMP-2 and MMP-9 activities increased significantly at 2 to 24 h, peaked at 6 h, after reperfusion. Immunohistochemical analysis identified MMP-2 in the interstitium around tubules and peritubular capillaries in the outer medulla. Acute tubular injury (ATI), including apoptosis and necrosis, was evident in the outer medulla at 24 h, along with renal dysfunction. As ischemia period increases, MMP-2 and MMP-9 activities at 6 h and severity of AKI at 24 h increased depending on the duration of ischemia between 30 and 120 min. However, the kidneys of MMP-2(-/-) mice showed minimal ATI; serum creatinine 24 h after reperfusion was significantly low in these mice. Inhibitors of MMPs reduced ATI and improved renal dysfunction at 24 h. We conclude that MMPs, especially MMP-2 have a pathogenic role in ischemia-reperfusion AKI, and that inhibitors of MMPs can protect against ischemic AKI.

Topics: Animals; Apoptosis; Creatinine; Immunohistochemistry; Kidney; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Matrix Metalloproteinase Inhibitors; Mice; Mice, Knockout; Minocycline; Necrosis; Reperfusion Injury; Time Factors

A prospective, randomized laboratory investigation.. To investigate whether administration of minocycline attenuates hind-limb motor dysfunction and gray and white matter injury after spinal cord ischemia.. Minocycline, a semisynthetic tetracycline antibiotic, has been shown to have neuroprotective effects in models of focal and global cerebral ischemia. However, there have been no data available regarding the effects of minocycline in a model of spinal cord ischemia.. Thirty-six rats were randomly allocated to one of three groups; control (C) group (n = 11), minocycline (M) group (n = 13), or sham group (n = 12). Minocycline or saline was intraperitoneally administered for 3 days beginning at 12 hours before 10 minutes of spinal cord ischemia or sham operation. Spinal cord ischemia was induced with intraaortic balloon catheter and blood withdrawal. Seventy-two hours after reperfusion, hind-limb motor functions were assessed using Basso, Beattie, Bresnahan (BBB) Scale (0 = paraplegia, 21 = normal). For histologic assessments, the gray and white matter injury was evaluated using the number of normal neurons and the extents of vacuolations in the white matter, respectively. Activated microglia was also evaluated using Iba-1 immunohistochemistry.. BBB scores and the numbers of normal neurons in the M group were significantly higher than those in the C group. The percentage areas of vacuolations in the white matter and the number of Iba-1 positive cells were significantly lower in the M group compared with those in the C group.. The results indicated that minocycline administration improved hind-limb motor function and attenuated gray and white matter injury and microglial activation after spinal cord ischemia in rats.

Topics: Animals; Anti-Bacterial Agents; Calcium-Binding Proteins; Central Nervous System; Hindlimb; Immunohistochemistry; Microfilament Proteins; Minocycline; Neurons; Prospective Studies; Random Allocation; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Spinal Cord Ischemia

The purpose of this study was to investigate the effects of minocycline on the renal dysfunction and injury caused by bilateral ischemia/reperfusion (I/R) of murine kidneys in vivo.. Male C57BL/6 mice were administered minocycline (45 mg/kg i.v.) or saline (0.9%, v/v, NaCl) 36 hours prior to I/R. Mice were subjected to bilateral renal ischemia (35 min) followed by reperfusion (6 hours). Serum creatinine (sCr) and blood urea nitrogen (BUN) levels were measured. Additionally, renal superoxide dismutase (SOD) levels, malondialdehyde (MDA) levels and myeloperoxidase (MPO) activity were determined. The expression of intercellular adhesion molecule-1 (ICAM-1), caspase-3, caspase-8 and caspase-9 was determined using real time RT-PCR and Western blot analysis.. Minocycline administration significantly reduced the increases in sCr and BUN caused by I/R, indicating attenuation of renal dysfunction and injury, and reduced histological evidence of renal damage caused by I/R. Minocycline administration also markedly reduced the evidence of oxidative stress (MPO activity, SOD and MDA levels), inflammation (ICAM-1 expression and MPO activity) and apoptosis (caspase-3, caspase-8 and caspase-9 expression) in mouse kidneys subjected to I/R.. These findings provide good evidence that minocycline can reduce the renal dysfunction and injury caused by I/R of the kidney. Its mechanism may involve suppression of apoptosis, inflammatory response and oxidative stress.

Topics: Animals; Base Sequence; Blotting, Western; Disease Models, Animal; DNA Primers; Kidney; Male; Mice; Mice, Inbred C57BL; Minocycline; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction

Topics: Animals; Calcium; Humans; Liver Transplantation; Minocycline; Mitochondria, Liver; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Permeability; Rats; Reperfusion Injury; Temperature

There is an increase in reactive oxygen and nitrogen species in cardiomyocytes during myocardial ischemia/reperfusion injury. This leads to oxidative DNA damage and activation of nuclear repair enzymes such as poly(ADP-ribose) polymerase-1 (PARP-1). PARP-1 activation promotes DNA repair under normal conditions. However, excessive activation of PARP-1 leads to cell death. We report that PARP-1 enzymatic activity is directly inhibited by minocycline, and we propose that one mechanism of minocycline cardioprotection is the result of PARP-1 inhibition. Using cultured adult rat cardiac myocytes, we evaluated the mechanism of minocycline protection in which PARP-1 activation was induced by simulated ischemia/reperfusion injury using oxygen–glucose deprivation.We found an increase in reactive oxygen species production, PARP-1 activation, and PARP-1-mediated cell death after simulated ischemia/reperfusion. Cell death was significantly reduced by the PARP inhibitors 3, 4-dihydro-5-[4-(1-piperidinyl)butoxy]-1(2H)-isoquinolinone (10 μM) and PJ-34 (500 nM) or by minocycline (500 nM). Cellular NAD(+) depletion and poly(ADP-ribose) formation, which are biochemical markers of PARP-1 activation, were also blocked by minocycline. Finally, simulated ischemia/reperfusion led to induction of the mitochondrial permeability transition, which was prevented by minocycline. Therefore, we propose that the protective effect of minocycline on cardiac myocyte survival is the result of inhibition of PARP-1 activity.

Topics: Animals; Cardiotonic Agents; Cell Death; Cells, Cultured; Enzyme Inhibitors; Male; Minocycline; Myocytes, Cardiac; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Rats; Reperfusion Injury

Graft failure after liver transplantation may involve mitochondrial dysfunction. We examined whether prevention of mitochondrial injury would improve graft function. Orthotopic rat liver transplantation was performed after 18 hours' cold storage in University of Wisconsin solution and treatment with vehicle, minocycline, tetracycline, or N-methyl-4-isoleucine cyclosporin (NIM811) of explants and recipients. Serum alanine aminotransferase (ALT), necrosis, and apoptosis were assessed 6 hours after implantation. Mitochondrial polarization and cell viability were assessed by intravital microscopy. Respiration and the mitochondrial permeability transition (MPT) were assessed in isolated rat liver mitochondria. After transplantation with vehicle or tetracycline, ALT increased to 5242 U/L and 4373 U/L, respectively. Minocycline and NIM811 treatment decreased ALT to 2374 U/L and 2159 U/L, respectively (P < 0.01). Necrosis and terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) also decreased from 21.4% and 21 cells/field, respectively, after vehicle to 10.1% and 6 cells/field after minocycline and to 8.7% and 5.2 cells/field after NIM811 (P < 0.05). Additionally, minocycline decreased caspase-3 activity in graft homogenates (P < 0.05). Long-term graft survival was 27% and 33%, respectively, after vehicle and tetracycline treatment, which increased to 60% and 70% after minocycline and NIM811 (P < 0.05). In isolated mitochondria, minocycline and NIM811 but not tetracycline blocked the MPT. Minocycline blocked the MPT by decreasing mitochondrial Ca(2+) uptake, whereas NIM811 blocks by interaction with cyclophilin D. Intravital microscopy showed that minocycline and NIM811 preserved mitochondrial polarization and cell viability after transplantation (P < 0.05).. Minocycline and NIM811 attenuated graft injury after rat liver transplantation and improved graft survival. Minocycline and/or NIM811 might be useful clinically in hepatic surgery and transplantation.

Topics: Adenosine Diphosphate; Alanine Transaminase; Animals; Anti-Bacterial Agents; Apoptosis; Calcium; Cyclosporine; Graft Survival; Liver; Liver Transplantation; Male; Minocycline; Mitochondria; Mitochondrial Diseases; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Necrosis; Rats; Rats, Inbred Lew; Reperfusion Injury; Tetracycline

Reperfusion injury is a complication of recanalization therapies after focal cerebral ischemia. The disruption of the blood-brain barrier (BBB) caused by up-regulated metalloproteinases (MMPs) can lead to edema and hemorrhage. Middle cerebral artery occlusion (MCAO=90 min) and reperfusion (R=24 h vs. 5 days) was induced in male Wistar rats. Rats were randomized in four groups: (1) control (C), (2) twice daily minocycline (30 mg/kg bodyweight) every day (M), (3) hypothermia (33 degrees C) for 4 h starting 60 min after occlusion (H), (4) combination of groups 2 and 3 (MH). Serial MRI was performed regarding infarct evolution and BBB disruption, MMP-2 and MMP-9 were assessed by zymography of serum and ischemic brain tissue, and a functional neuroscore was done at 24 h and 5 days. M and H reduced both infarct sizes, volume and signal intensity of BBB breakdown and improved neuroscore at all points in time to the same extent. This was most likely due to inhibition of MMP-2 and MMP-9. The presence of MMP-9 at 24 h or MMP-2 at 5 days in brain tissue correlated with BBB breakdown whereas serum MMP-2- and -9 showed no relationship with BBB breakdown. The combination MH had a small but not significantly additional effect over the single treatments. Minocycline seems to be as neuroprotective as hypothermia in the acute and subacute phase after cerebral ischemia. One essential mechanism is the inhibition of MMPs. The combination therapy is only slightly superior. The net effect of MMPs inhibition up to 5 days after focal cerebral ischemia is still beneficial.

Topics: Acute Disease; Animals; Anti-Bacterial Agents; Blood-Brain Barrier; Brain Edema; Brain Ischemia; Disease Models, Animal; Disease Progression; Hypothermia, Induced; Infarction, Middle Cerebral Artery; Intracranial Hemorrhages; Magnetic Resonance Imaging; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Metalloproteases; Minocycline; Neuroprotective Agents; Rats; Rats, Wistar; Reperfusion Injury; Time Factors

Early reperfusion after an ischemic stroke can cause blood-brain barrier injury with subsequent cerebral edema and devastating brain hemorrhage. These complications of early reperfusion, which result from excess production of reactive oxygen species, significantly limit the benefits of stroke therapies. In this article, we use a novel animal model that facilitates identification of specific components of the reperfusion injury process, including vascular injury and secondary brain damage, and allows assessment of therapeutic interventions.. Knock-out (KO) mice containing 50% manganese-superoxide dismutase activity (SOD2-KO) and transgenic mice overexpressing SOD2 undergo transient focal ischemia and reperfusion followed by assessment of infarct, edema, hemorrhage rates, metalloproteinase activation, and microvascular injury.. SOD2-KO mice demonstrate delayed (>24h) blood-brain barrier breakdown associated with activation of matrix metalloproteinases, inflammation, and high brain hemorrhage rates. These adverse consequences are absent in wild-type littermates and minocycline-treated SOD2-KO animals. Increased hemorrhage rates also are absent in SOD2 overexpressors, which have reduced vascular endothelial cell death. Finally, we show that the tight junction membrane protein, occludin, is an early and specific target in oxidative stress-induced microvascular injury.. This model is ideal for studying ischemia/reperfusion-induced vascular injury and secondary brain hemorrhage and offers a unique opportunity to evaluate antioxidant-based neurovascular protective strategies as potential adjunct treatments to currently approved stroke therapies such as thrombolysis and endovascular clot retrieval.

Topics: Animals; Blood-Brain Barrier; Blotting, Western; Brain; Brain Ischemia; Cerebral Hemorrhage; Disease Models, Animal; Enzyme Inhibitors; In Situ Nick-End Labeling; Matrix Metalloproteinase 9; Mice; Mice, Knockout; Mice, Transgenic; Minocycline; Oxidative Stress; Reperfusion Injury; Superoxide Dismutase

Effective stroke therapies require recanalization of occluded cerebral blood vessels; however, early reperfusion can cause BBB (blood-brain barrier) injury, leading to cerebral oedema and/or devastating brain haemorrhage. These complications of early reperfusion, which result from excess production of ROS (reactive oxygen species), significantly limit the benefits of stroke therapies. Here, we summarize some of the findings that lead to the development of a novel animal model that facilitates identification of specific free radical-associated components of the reperfusion injury process and allows therapeutic interventions to be assessed. In this model, KO (knockout) mice containing 50% activity of the mitochondrial antioxidant manganese-SOD (superoxide dismutase) (SOD2-KO) undergo transient focal ischaemia followed by reperfusion. These animals have delayed (>24 h) BBB breakdown associated with activation of matrix metalloproteinase-9, inflammation and a high brain haemorrhage rate. These adverse consequences are absent from wild-type littermates, SOD2 overexpressors and minocycline-treated SOD2-KO animals. In addition, using microvessel isolations following in vivo ischaemia/reperfusion, we were able to show that the tight junction membrane protein, occludin, is an early and specific target in ROS-mediated microvascular injury. This new model is ideal for studying ischaemia/reperfusion-induced vascular injury and secondary brain damage and offers a unique opportunity to evaluate free radical-based neurovascular protective strategies.

Topics: Animals; Anti-Inflammatory Agents; Brain Injuries; Disease Models, Animal; Endothelium, Vascular; Humans; Matrix Metalloproteinase 9; Mice; Minocycline; Reactive Oxygen Species; Reperfusion Injury; Tight Junctions

Tetracyclines exhibit significant anti-inflammatory properties, inhibit matrix metalloproteinases (MMPs), and are protective in models of ischemia-reperfusion injury (IRI). Both inflammatory cascades and MMP activation have been demonstrated to modulate microvascular permeability. Because increased microvascular permeability occurs during IRI in a variety of organ systems including the kidney, we hypothesized that minocycline, a semisynthetic tetracycline, would diminish microvascular leakage during renal IRI. To test this hypothesis, we used intravital 2-photon microscopy to examine leakage of fluorescent dextrans from the vasculature in a rodent model of IRI. Minocycline significantly reduced the extent of dextran (500 kDa) leakage from the renal microvasculature 24 h after ischemia. Although minocycline diminished leukocyte accumulation in the kidney following ischemia, areas of leukocyte accumulation did not correlate with areas of microvascular permeability in either the saline- or minocycline-pretreated animals. Minocycline diminished the perivascular increase in MMP-2 and MMP-9, as well as the increase in MMP-2 activity 24 h after ischemia. ABT-518, a specific inhibitor of MMP-2 and MMP-9, also significantly reduced the extent of dextran (500 kDa) leakage from the renal microvasculature 24 h after ischemia. Our results indicate that minocycline mitigates the renal microvascular permeability defect following IRI. This effect is spatially distinct from the effect of minocycline on leukocyte accumulation and may be related to diminished activity of MMPs on the integrity of the perivascular matrix.

Topics: Acute Kidney Injury; Animals; Capillary Permeability; Kidney; Leukocytes; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Minocycline; Rats; Rats, Sprague-Dawley; Reperfusion Injury

The incidence of neonatal stroke is high and currently there are no strategies to protect the neonatal brain from stroke or reduce the sequelae. Agents capable of modifying inflammatory processes hold promise. We set out to determine whether delayed administration of one such agent, minocycline, protects the immature brain in a model of transient middle cerebral artery (MCA) occlusion in 7-day-old rat pups. Injury volume in minocycline (45 mg/kg/dose, beginning at 2 h after MCA occlusion) and vehicle-treated pups was determined 24 h and 7 days after onset of reperfusion. Accumulation of activated microglia/macrophages, phosphorylation of mitogen-activated protein kinase (MAPK) p38 in the brain, and concentrations of inflammatory mediators in plasma and brain were determined at 24 h. Minocycline significantly reduced the volume of injury at 24 h but not 7 days after transient MCA occlusion. The beneficial effect of minocycline acutely after reperfusion was not associated with changed ED1 phenotype, nor was the pattern of MAPK p38 phosphorylation altered. Minocycline reduced accumulation of IL-1beta and CINC-1 in the systemic circulation but failed to affect the increased levels of IL-1beta, IL-18, MCP-1 or CINC-1 in the injured brain tissue. Therefore, minocycline provides early but transient protection, which is largely independent of microglial activation or activation of the MAPK p38 pathway.

Topics: Animals; Anti-Bacterial Agents; Brain; Brain Chemistry; Chemokines; Cytokines; Enzyme Activation; Female; Immunohistochemistry; Macrophage Activation; Minocycline; Neuroprotective Agents; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Rats; Rats, Sprague-Dawley; Reperfusion Injury

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

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