Intermittent fasting attenuates inflammasome activity in ischemic stroke.

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Fann, David Yang-Wei; Santro, Tomislav; Manzanero, Silvia; Widiapradja, Alexander; Cheng, Yi-Lin; Lee, Seung-Yoon; Chunduri, Prasad; Jo, Dong-Gyu; Stranahan, Alexis M; Mattson, Mark P; Arumugam, Thiruma V

2014-07-01

Recent findings have revealed a novel inflammatory mechanism that contributes to tissue injury in cerebral ischemia mediated by multi-protein complexes termed inflammasomes. Intermittent fasting (IF) can decrease the levels of pro-inflammatory cytokines in the periphery and brain. Here we investigated the impact of IF (16h of food deprivation daily) for 4months on NLRP1 and NLRP3 inflammasome activities following cerebral ischemia. Ischemic stroke was induced in C57BL/6J mice by middle cerebral artery occlusion, followed by reperfusion (I/R). IF decreased the activation of NF-κB and MAPK signaling pathways, the expression of NLRP1 and NLRP3 inflammasome proteins, and both IL-1β and IL-18 in the ischemic brain tissue. These findings demonstrate that IF can attenuate the inflammatory response and tissue damage following ischemic stroke by a mechanism involving suppression of NLRP1 and NLRP3 inflammasome activity. Copyright © 2014 Elsevier Inc. All rights reserved.

Isoflurane administration before ischemia and during reperfusion attenuates ischemia/reperfusion-induced injury of isolated rabbit lungs.

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Liu, R; Ishibe, Y; Ueda, M; Hang, Y

1999-09-01

To investigate the effects of isoflurane on ischemia/ reperfusion (IR)-induced lung injury, we administered isoflurane before ischemia or during reperfusion. Isolated rabbit lungs were divided into the following groups: control (n = 6), perfused and ventilated for 120 min without ischemia; ISO-control (n = 6), 1 minimum alveolar anesthetic concentration (MAC) isoflurane was administered for 30 min before 120 min continuous perfusion; IR (n = 6), ischemia for 60 min, followed by 60 min reperfusion; IR-ISO1 and IR-ISO2, ischemia followed by reperfusion and 1 MAC (n = 6) or 2 MAC (n = 6) isoflurane for 60 min; ISO-IR (n = 6), 1 MAC isoflurane was administered for 30 min before ischemia, followed by IR. During these maneuvers, we measured total pulmonary vascular resistance (Rt), coefficient of filtration (Kfc), and lung wet to dry ratio (W/D). The results indicated that administration of isoflurane during reperfusion inhibited an IR-induced increase in Kfc and W/D ratio. Furthermore, isoflurane at 2 MAC, but not 1 MAC, significantly inhibited an IR-induced increase in Rt. The administration of isoflurane before ischemia significantly attenuated the increase in IR-induced Kfc, W/D, and Rt. Our results suggest that the administration of isoflurane before ischemia and during reperfusion protects against ischemia-reperfusion-induced injury in isolated rabbit lungs.

Momordica charantia polysaccharides could protect against cerebral ischemia/reperfusion injury through inhibiting oxidative stress mediated c-Jun N-terminal kinase 3 signaling pathway.

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Gong, Juanjuan; Sun, Fumou; Li, Yihang; Zhou, Xiaoling; Duan, Zhenzhen; Duan, Fugang; Zhao, Lei; Chen, Hansen; Qi, Suhua; Shen, Jiangang

2015-04-01

Momordica charantia (MC) is a medicinal plant for stroke treatment in Traditional Chinese Medicine, but its active compounds and molecular targets are unknown yet. M. charantia polysaccharide (MCP) is one of the important bioactive components in MC. In the present study, we tested the hypothesis that MCP has neuroprotective effects against cerebral ischemia/reperfusion injury through scavenging superoxide (O2(-)), nitric oxide (NO) and peroxynitrite (ONOO(-)) and inhibiting c-Jun N-terminal protein kinase (JNK3) signaling cascades. We conducted experiments with in vivo global and focal cerebral ischemia/reperfusion rat models and in vitro oxygen glucose deprivation (OGD) neural cells. The effects of MCP on apoptotic cell death and infarction volume, the bioactivities of scavenging O2(-), NO and ONOO(-), inhibiting lipid peroxidation and modulating JNK3 signaling pathway were investigated. Major results are summarized as below: (1) MCP dose-dependently attenuated apoptotic cell death in neural cells under OGD condition in vitro and reduced infarction volume in ischemic brains in vivo; (2) MCP had directing scavenging effects on NO, O2(-) and ONOO(-) and inhibited lipid peroxidation; (3) MCP inhibited the activations of JNK3/c-Jun/Fas-L and JNK3/cytochrome C/caspases-3 signaling cascades in ischemic brains in vivo. Taken together, we conclude that MCP could be a promising neuroprotective ingredient of M. charantia and its mechanisms could be at least in part attributed to its antioxidant activities and inhibiting JNK3 signaling cascades during cerebral ischemia/reperfusion injury. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relation between reperfusion and hemorrhagic transformation in acute ischemic stroke

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Horsch, Alexander D. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Rijnstate Hospital, Department of Radiology, Arnhem (Netherlands); Dankbaar, Jan Willem; Niesten, Joris M.; Seeters, Tom van; Schaaf, Irene C. van der; Velthuis, Birgitta K. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Graaf, Yolanda van der [Julius Center for Health Sciences and Primary Care, Utrecht (Netherlands); Kappelle, L.J. [University Medical Center, Department of Neurology, Utrecht Stroke Center, Utrecht (Netherlands); Collaboration: DUST investigators

2015-12-15

Intravenous recombinant tissue plasminogen activator (IV-rtPA) is given in acute ischemic stroke patients to achieve reperfusion. Hemorrhagic transformation (HT) is a serious complication of IV-rtPA treatment and related to blood-brain barrier (BBB) injury. It is unclear whether HT occurs secondary to reperfusion in combination with ischemic BBB injury or is caused by the negative effect of IV-rtPA on BBB integrity. The aim of this study was to establish the association between reperfusion and the occurrence of HT. From the DUST study, patients were selected with admission and follow-up non-contrast CT (NCCT) and CT perfusion (CTP) imaging, and a perfusion deficit in the middle cerebral artery territory on admission. Reperfusion was categorized qualitatively as reperfusion or no-reperfusion by visual comparison of admission and follow-up CTP. Occurrence of HT was assessed on follow-up NCCT. The association between reperfusion and occurrence of HT on follow-up was estimated by calculating odds ratios (ORs) and 95 % confidence intervals (CIs) with additional stratification for IV-rtPA treatment. Inclusion criteria were met in 299 patients. There was no significant association between reperfusion and HT (OR 1.2 95%CI 0.5-3.1). In patients treated with IV-rtPA (n = 203), the OR was 1.3 (95%CI 0.4-4.0), and in patients not treated with IV-rtPA (n = 96), the OR was 0.8 (95%CI 0.1-4.5). HT occurred in 14 % of the IV-rtPA patients and in 7 % of patients without IV-rtPA (95%CI of difference -1 to 14 %). Our results suggest that the increased risk of HT after acute ischemic stroke treatment is not dependent on the reperfusion status. (orig.)

CURRENT REPERFUSION THERAPY POSSIBILITIES IN MYOCARDIAL INFARCTION AND ISCHEMIC STROKE

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E. V. Konstantinova

2015-01-01

Full Text Available Myocardial infarction and ischemic stroke remain to be of the greatest medical and social importance because of their high prevalence, disability, and mortality rates. Intractable thrombotic occlusion of the respective artery leads to the formation of an ischemic lesion focus in the tissue of the heart or brain. Emergency reperfusion serves to decrease a necrotic focus, makes its formation reversible, and reduces patient death rates. The paper considers main reperfusion therapy lines: medical (with thrombolytic drugs and mechanical (with primary interventions one and their combination in treating patients with acute myocardial and cerebral ischemia. Each reperfusion procedure is discussed in view of its advantages, disadvantages, available guidelines, and possibilities of real clinical practice. Tenecteplase is assessed in terms of its efficacy, safety, and capacities for bolus administration, which allows its use at any hospital and at the pre-hospital stage. Prehospital thrombolysis permits reperfusion therapy to bring much closer to the patient and therefore aids in reducing time to reperfusion and in salvaging as much the myocardial volume as possible. The rapidest recovery of myocardial and cerebral perfusion results in a decreased necrotic area and both improved immediate and late prognosis. The results of randomized clinical trials studying the possibilities of the medical and mechanical methods to restore blood flow are analyzed in the context of evidence-based medicine. The reason why despite the available contraindications, limited efficiency, and the risk of hemorrhagic complications, thrombolytic therapy remains the method of choice for prehospital reperfusion, an alternative to primary percutaneous coronary intervention (PCI if it cannot be carried out in patients with myocardial infarction at the stated time, and the only treatment ischemic stroke treatment that has proven its efficiency and safety in clinical trials is under

Postconditioning attenuates acute intestinal ischemia–reperfusion injury

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Ilker Sengul

2013-03-01

Full Text Available The aim of this study was to test the hypothesis that postconditioning (POC would reduce the detrimental effects of the acute intestinal ischemia–reperfusion (I/R compared to those of the abrupt onset of reperfusion. POC has a protective effect on intestinal I/R injury by inhibiting events in the early minutes of reperfusion in rats. Twenty-four Wistar–Albino rats were subjected to the occlusion of superior mesenteric artery for 30 minutes, then reperfused for 120 minutes, and randomized to the four different modalities of POC: (1 control (no intervention; (2 POC-3 (three cycles of 10 seconds of reperfusion–reocclusion, 1 minute total intervention; (3 POC-6 (six cycles of 10 seconds of reperfusion–reocclusion, 2 minutes total intervention; and (4 sham operation (laparotomy only. The arterial blood samples [0.3 mL total creatine kinase (CK and 0.6 mL malondialdehyde (MDA] and the intestinal mucosal MDA were collected from each after reperfusion. POC, especially POC-6, was effective in attenuating postischemic pathology by decreasing the intestinal tissue MDA levels, serum total CK activity, inflammation, and total histopathological injury scores. POC exerted a protective effect on the intestinal mucosa by reducing the mesenteric oxidant generation, lipid peroxidation, and neutrophil accumulation. The six-cycle algorithm demonstrated the best protection.

Pre-ischemic mitochondrial substrate constraint by inhibition of malate-aspartate shuttle preserves mitochondrial function after ischemia-reperfusion

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Jespersen, Nichlas Riise; Yokota, Takashi; Støttrup, Nicolaj Brejnholt

2017-01-01

KEY POINTS: Pre-ischaemic administration of aminooxiacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against ischaemia-reperfusion injury. The underlying mechanism remains unknown. We examined whether transient inhibition of the MAS during ischaemia......, but not IPC, reduced the myocardial interstitial concentration of tricarboxylic acid cycle intermediates at the onset of reperfusion. The results obtained in the present study demonstrate that metabolic regulation by inhibition of the MAS at the onset of reperfusion may be beneficial for the preservation...... of mitochondrial function during late reperfusion in an IR-injured heart. ABSTRACT: Mitochondrial dysfunction plays a central role in ischaemia-reperfusion (IR) injury. Pre-ischaemic administration of aminooxyacetate (AOA), an inhibitor of the malate-aspartate shuttle (MAS), provides cardioprotection against IR...

MCT1 and MCT4 Expression During Myocardial Ischemic-Reperfusion Injury in the Isolated Rat Heart

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Yi Zhu

2013-09-01

Full Text Available Background/Aims: Myocardium ischemia-reperfusion (I/R injury can be caused by imbalances in cellular metabolism. Lactate, transported by monocarboxylate transporters (MCTs, has been implicated as a mechanism in this process. The present study was designed to investigate the expression and functional role of MCTs in rat hearts during ischemia and reperfusion. Methods: Langendorff-perfused rat hearts were subjected to 20 minutes stabilization, 30 minutes of global ischemia and 60 minutes reperfusion. Hearts were collected serially for detecting expression changes in MCT1, MCT4 during myocardial I/R injury and lactate concentration was measured. Post-ischemic left ventricular function and infract size were determined at end-point, followed by the pretreatment of D-lactate, a competitive inhibitor of MCTs. Results: MCT4 was significantly increased following global ischemia and MCT1 expression was increased during the early stages of reperfusion in isolated rat hearts, while the expression of the ancillary protein CD147 was increased during I/R injury. We determined increases in AMPK phosphorylation status, which was significantly elevated following ischemia and early reperfusion. Blocking monocarboxylate transport by competitive inhibition with D-lactate caused decreased left ventricular performance and increased infarct size. Conclusion: Increased MCT4 expression facilitates lactate extrusion during the ischemic period, while increased MCT1 may facilitate lactate transport into and out of cells simultaneously during early reperfusion, with increases in AMPK phosphorylation status during the myocardial I/R period. Lactate transport by MCTs has a profound protective effect during myocardial ischemia reperfusion injury.

Protective effects of incensole acetate on cerebral ischemic injury.

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Moussaieff, Arieh; Yu, Jin; Zhu, Hong; Gattoni-Celli, Sebastiano; Shohami, Esther; Kindy, Mark S

2012-03-14

The resin of Boswellia species is a major anti-inflammatory agent that has been used for centuries to treat various conditions including injuries and inflammatory conditions. Incensole acetate (IA), a major constituent of this resin, has been shown to inhibit NF-κB activation and concomitant inflammation, as well as the neurological deficit following head trauma. Here, we show that IA protects against ischemic neuronal damage and reperfusion injury in mice, attenuating the inflammatory nature of ischemic damage. IA given post-ischemia, reduced infarct volumes and improved neurological activities in the mouse model of ischemic injury in a dose dependent fashion. The protection from damage was accompanied by inhibition of TNF-α, IL-1β and TGF-β expression, as well as NF-κB activation following injury. In addition, IA is shown to have a therapeutic window of treatment up to 6h after ischemic injury. Finally, the protective effects of IA were partially mediated by TRPV3 channels as determined by the TRPV3 deficient mice and channel blocker studies. This study suggests that the anti-inflammatory and neuroprotective activities of IA may serve as a novel therapeutic treatment for ischemic and reperfusion injury, and as a tool in the ongoing research of mechanisms for neurological damage. Published by Elsevier B.V.

Inhaled nitric oxide pretreatment but not posttreatment attenuates ischemia-reperfusion-induced pulmonary microvascular leak.

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Chetham, P M; Sefton, W D; Bridges, J P; Stevens, T; McMurtry, I F

1997-04-01

Ischemia-reperfusion (I/R) pulmonary edema probably reflects a leukocyte-dependent, oxidant-mediated mechanism. Nitric oxide (NO) attenuates leukocyte-endothelial cell interactions and I/R-induced microvascular leak. Cyclic adenosine monophosphate (cAMP) agonists reverse and prevent I/R-induced microvascular leak, but reversal by inhaled NO (INO) has not been tested. In addition, the role of soluble guanylyl cyclase (sGC) activation in the NO protection effect is unknown. Rat lungs perfused with salt solution were grouped as either I/R, I/R with INO (10 or 50 ppm) on reperfusion, or time control. Capillary filtration coefficients (Kfc) were estimated 25 min before ischemia (baseline) and after 30 and 75 min of reperfusion. Perfusate cell counts and lung homogenate myeloperoxidase activity were determined in selected groups. Additional groups were treated with either INO (50 ppm) or isoproterenol (ISO-10 microM) after 30 min of reperfusion. Guanylyl cyclase was inhibited with 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ-15 microM), and Kfc was estimated at baseline and after 30 min of reperfusion. (1) Inhaled NO attenuated I/R-induced increases in Kfc. (2) Cell counts were similar at baseline. After 75 min of reperfusion, lung neutrophil retention (myeloperoxidase activity) and decreased perfusate neutrophil counts were similar in all groups. (3) In contrast to ISO, INO did not reverse microvascular leak. (4) 8-bromoguanosine 3',5'-cyclic monophosphate (8-br-cGMP) prevented I/R-induced microvascular leak in ODQ-treated lungs, but INO was no longer effective. Inhaled NO attenuates I/R-induced pulmonary microvascular leak, which requires sGC activation and may involve a mechanism independent of inhibition of leukocyte-endothelial cell interactions. In addition, INO is ineffective in reversing I/R-induced microvascular leak.

Platelet aggregation but not activation and degranulation during the acute post-ischemic reperfusion phase in livers with no underlying disease

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van Golen, Rowan F.; Stevens, Katarzyna M.; Colarusso, Pina; Jaeschke, Hartmut; Heger, Michal

2015-01-01

Platelets and P-selectin (CD62P) play an unequivocal role in the pathology of hepatic ischemia/reperfusion (I/R) injury. Inhibition or knock-out of P-selectin or immunodepletion of platelets results in amelioration of post-ischemic inflammation, reduced hepatocellular damage, and improved survival.

Edaravone prevents lung injury induced by hepatic ischemia-reperfusion.

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Uchiyama, Munehito; Tojo, Kentaro; Yazawa, Takuya; Ota, Shuhei; Goto, Takahisa; Kurahashi, Kiyoyasu

2015-04-01

Lung injury is a major clinical concern after hepatic ischemia-reperfusion (I/R), due to the production of reactive oxygen species in the reperfused liver. We investigated the efficacy of edaravone, a potent free-radical scavenger, for attenuating lung injury after hepatic I/R. Adult male Sprague-Dawley rats were assigned to sham + normal saline (NS), I/R + NS, or I/R + edaravone group. Rats in the I/R groups were subjected to 90 min of partial hepatic I/R. Five minutes before reperfusion, 3 mg/kg edaravone was administered to the I/R + edaravone group. After 6 h of reperfusion, we evaluated lung histopathology and wet-to-dry ratio. We also measured malondialdehyde (MDA), an indicator of oxidative stress, in the liver and the lung, as well as cytokine messenger RNA expressions in the reperfused liver and plasma cytokine concentrations. Histopathology revealed lung damages after 6 h reperfusion of partial ischemic liver. Moreover, a significant increase in lung wet-to-dry ratio was observed. MDA concentration increased in the reperfused liver, but not in the lungs. Edaravone administration attenuated the lung injury and the increase of MDA in the reperfused liver. Edaravone also suppressed the reperfusion-induced increase of interleukin-6 messenger RNA expressions in the liver and plasma interleukin-6 concentrations. Edaravone administration before reperfusion of the ischemic liver attenuates oxidative stress in the reperfused liver and the subsequent lung injury. Edaravone may be beneficial for preventing lung injury induced by hepatic I/R. Copyright © 2015 Elsevier Inc. All rights reserved.

Fermented Chinese formula Shuan-Tong-Ling attenuates ischemic stroke by inhibiting inflammation and apoptosis

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Zhi-gang Mei

2017-01-01

Full Text Available The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae (Gegen, salvia miltiorrhiza (Danshen, radix curcuma (Jianghuang, hawthorn (Shanzha, salvia chinensis (Shijianchuan, sinapis alba (Baijiezi, astragalus (Huangqi, panax japonicas (Zhujieshen, atractylodes macrocephala koidz (Baizhu, radix paeoniae alba (Baishao, bupleurum (Chaihu, chrysanthemum (Juhua, rhizoma cyperi (Xiangfu and gastrodin (Tianma, whose aqueous extract was fermented with lactobacillus, bacillus aceticus and saccharomycetes. Shuan-Tong-Ling is a formula used to treat brain diseases including ischemic stroke, migraine, and vascular dementia. Shuan-Tong-Ling attenuated H2O2-induced oxidative stress in rat microvascular endothelial cells. However, the potential mechanism involved in these effects is poorly understood. Rats were intragastrically treated with 5.7 or 17.2 mL/kg Shuan-Tong-Ling for 7 days before middle cerebral artery occlusion was induced. The results indicated Shuan-Tong-Ling had a cerebral protective effect by reducing infarct volume and increasing neurological scores. Shuan-Tong-Ling also decreased tumor necrosis factor-α and interleukin-1β levels in the hippocampus on the ischemic side. In addition, Shuan-Tong-Ling upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of acetylated-protein 53 and Bax. Injection of 5 mg/kg silent information regulator 1 (SIRT1 inhibitor EX527 into the subarachnoid space once every 2 days, four times, reversed the above changes. These results demonstrate that Shuan-Tong-Ling might benefit cerebral ischemia/reperfusion injury by reducing inflammation and apoptosis through activation of the SIRT1 signaling pathway.

Inhibition of Fas-associated death domain-containing protein (FADD protects against myocardial ischemia/reperfusion injury in a heart failure mouse model.

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Qian Fan

Full Text Available As technological interventions treating acute myocardial infarction (MI improve, post-ischemic heart failure increasingly threatens patient health. The aim of the current study was to test whether FADD could be a potential target of gene therapy in the treatment of heart failure.Cardiomyocyte-specific FADD knockout mice along with non-transgenic littermates (NLC were subjected to 30 minutes myocardial ischemia followed by 7 days of reperfusion or 6 weeks of permanent myocardial ischemia via the ligation of left main descending coronary artery. Cardiac function were evaluated by echocardiography and left ventricular (LV catheterization and cardiomyocyte death was measured by Evans blue-TTC staining, TUNEL staining, and caspase-3, -8, and -9 activities. In vitro, H9C2 cells transfected with ether scramble siRNA or FADD siRNA were stressed with chelerythrin for 30 min and cleaved caspase-3 was assessed.FADD expression was significantly decreased in FADD knockout mice compared to NLC. Ischemia/reperfusion (I/R upregulated FADD expression in NLC mice, but not in FADD knockout mice at the early time. FADD deletion significantly attenuated I/R-induced cardiac dysfunction, decreased myocardial necrosis, and inhibited cardiomyocyte apoptosis. Furthermore, in 6 weeks long term permanent ischemia model, FADD deletion significantly reduced the infarct size (from 41.20 ± 3.90% in NLC to 26.83 ± 4.17% in FADD deletion, attenuated myocardial remodeling, improved cardiac function and improved survival. In vitro, FADD knockdown significantly reduced chelerythrin-induced the level of cleaved caspase-3.Taken together, our results suggest FADD plays a critical role in post-ischemic heart failure. Inhibition of FADD retards heart failure progression. Our data supports the further investigation of FADD as a potential target for genetic manipulation in the treatment of heart failure.

Effect of Ischemic Postconditioning and Atorvastatin in the Prevention of Remote Lung Reperfusion Injury

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Carlos Henrique Marques dos Santos

Full Text Available Abstract Objective: The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods: We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R, ischemic postcondictioning (IPC, postconditioning + atorvastatin (IPC+A, atorvastatin (A and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia and posterior clamp removal (reperfusion, 70 minutes. In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue to grade 4 (intense lesion. Results: The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01. Conclusion: Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.

Vildagliptin reduces cardiac ischemic-reperfusion injury in obese orchiectomized rats.

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Pongkan, Wanpitak; Pintana, Hiranya; Jaiwongkam, Thidarat; Kredphoo, Sasiwan; Sivasinprasasn, Sivaporn; Chattipakorn, Siriporn C; Chattipakorn, Nipon

2016-10-01

Obesity and testosterone deprivation are associated with coronary artery disease. Testosterone and vildagliptin (dipeptidyl peptidase-4 inhibitors) exert cardioprotection during ischemic-reperfusion (I/R) injury. However, the effect of these drugs on I/R heart in a testosterone-deprived, obese, insulin-resistant model is unclear. This study investigated the effects of testosterone and vildagliptin on cardiac function, arrhythmias and the infarct size in I/R heart of testosterone-deprived rats with obese insulin resistance. Orchiectomized (O) or sham operated (S) male Wistar rats were divided into 2 groups to receive normal diet (ND) or high-fat diet (HFD) for 12 weeks. Orchiectomized rats in each diet were divided to receive testosterone (2 mg/kg), vildagliptin (3 mg/kg) or the vehicle daily for 4 weeks. Then, I/R was performed by a 30-min left anterior descending coronary artery ligation, followed by a 120-min reperfusion. LV function, arrhythmia scores, infarct size and cardiac mitochondrial function were determined. HFD groups developed insulin resistance at week 12. At week 16, cardiac function was impaired in NDO, HFO and HFS rats, but was restored in all testosterone- and vildagliptin-treated rats. During I/R injury, arrhythmia scores, infarct size and cardiac mitochondrial dysfunction were prominently increased in NDO, HFO and HFS rats, compared with those in NDS rats. Treatment with either testosterone or vildagliptin similarly attenuated these impairments during I/R injury. These finding suggest that both testosterone replacement and vildagliptin share similar efficacy for cardioprotection during I/R injury by decreasing the infarct size and attenuating cardiac mitochondrial dysfunction caused by I/R injury in testosterone-deprived rats with obese insulin resistance. © 2016 Society for Endocrinology.

Conditioning techniques and ischemic reperfusion injury in relation to on-pump cardiac surgery

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Holmberg, Fredrik Eric Olof; Ottas, Konstantin Alex; Andreasen, Charlotte

2014-01-01

OBJECTIVES: The objective was to investigate the potential protective effects of two conditioning methods, on myocardial ischemic and reperfusion injury in relation to cardiac surgery. DESIGN: Totally 68 patients were randomly assigned to either a control group (n = 23), a remote ischemic...

CTGF/CCN2 Postconditioning Increases Tolerance of Murine Hearts towards Ischemia-Reperfusion Injury.

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Kaasbøll, Ole Jørgen; Moe, Ingvild Tronstad; Ahmed, Mohammad Shakil; Stang, Espen; Hagelin, Else Marie Valbjørn; Attramadal, Håvard

2016-01-01

Previous studies of ischemia-reperfusion injury (IRI) in hearts from mice with cardiac-restricted overexpression of CCN2 have shown that CCN2 increases tolerance towards IRI. The objectives of this study were to investigate to what extent post-ischemic administration of recombinant human CCN2 (rhCCN2) would limit infarct size and improve functional recovery and what signaling pathways are involved. Isolated mice hearts were perfused ad modum Langendorff, subjected to no-flow, global ischemia, and subsequently, exposed to mammalian cell derived, full-length (38-40kDa) rhCCN2 (250 nM) or vehicle during the first 15 min of a 60 min reperfusion period. Post-ischemic administration of rhCCN2 resulted in attenuation of infarct size from 58 ± 4% to 34 ± 2% (p concentration-dependent increase of cardiac phospho-GSK3β (serine-9) contents. We demonstrate that post-ischemic administration of rhCCN2 increases the tolerance of ex vivo-perfused murine hearts to IRI. Mechanistically, this postconditioning effect of rhCCN2 appeared to be mediated by activation of the reperfusion injury salvage kinase pathway as demonstrated by sensitivity to PI3 kinase inhibition and increased CCN2-induced phosphorylation of GSK3β (Ser-9). Thus, the rationale for testing rhCCN2-mediated post-ischemic conditioning of the heart in more complex models is established.

Overview of Experimental and Clinical Findings regarding the Neuroprotective Effects of Cerebral Ischemic Postconditioning.

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Ma, Di; Feng, Liangshu; Deng, Fang; Feng, Jia-Chun

2017-01-01

Research on attenuating the structural and functional deficits observed following ischemia-reperfusion has become increasingly focused on the therapeutic potential of ischemic postconditioning. In recent years, various methods and animal models of ischemic postconditioning have been utilized. The results of these numerous studies have indicated that the mechanisms underlying the neuroprotective effects of ischemic postconditioning may involve reductions in the generation of free radicals and inhibition of calcium overload, as well as the release of endogenous active substances, alterations in membrane channel function, and activation of protein kinases. Here we review the novel discovery, mechanism, key factors, and clinical application of ischemic postconditioning and discuss its implications for future research and problem of clinical practice.

Effects of Remote Ischemic Conditioning Methods on Ischemia-Reperfusion Injury in Muscle Flaps: An Experimental Study in Rats

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Durdane Keskin

2017-09-01

Full Text Available Background The aim of this study was to investigate the effects of remote ischemic conditioning on ischemia-reperfusion injury in rat muscle flaps histopathologically and biochemically. Methods Thirty albino rats were divided into 5 groups. No procedure was performed in the rats in group 1, and only blood samples were taken. A gracilis muscle flap was elevated in all the other groups. Microclamps were applied to the vascular pedicle for 4 hours in order to achieve tissue ischemia. In group 2, no additional procedure was performed. In groups 3, 4, and 5, the right hind limb was used and 3 cycles of ischemia-reperfusion for 5 minutes each (total, 30 minutes was applied with a latex tourniquet (remote ischemic conditioning. In group 3, this procedure was performed before flap elevation (remote ischemic preconditoning. In group 4, the procedure was performed 4 hours after flap ischemia (remote ischemic postconditioning. In group 5, the procedure was performed after the flap was elevated, during the muscle flap ischemia episode (remote ischemic perconditioning. Results The histopathological damage score in all remote conditioning ischemia groups was lower than in the ischemic-reperfusion group. The lowest histopathological damage score was observed in group 5 (remote ischemic perconditioning. Conclusions The nitric oxide levels were higher in the blood samples obtained from the remote ischemic perconditioning group. This study showed the effectiveness of remote ischemic conditioning procedures and compared their usefulness for preventing ischemia-reperfusion injury in muscle flaps.

Effects of Remote Ischemic Conditioning Methods on Ischemia-Reperfusion Injury in Muscle Flaps: An Experimental Study in Rats.

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Keskin, Durdane; Unlu, Ramazan Erkin; Orhan, Erkan; Erkilinç, Gamze; Bogdaycioglu, Nihal; Yilmaz, Fatma Meric

2017-09-01

The aim of this study was to investigate the effects of remote ischemic conditioning on ischemia-reperfusion injury in rat muscle flaps histopathologically and biochemically. Thirty albino rats were divided into 5 groups. No procedure was performed in the rats in group 1, and only blood samples were taken. A gracilis muscle flap was elevated in all the other groups. Microclamps were applied to the vascular pedicle for 4 hours in order to achieve tissue ischemia. In group 2, no additional procedure was performed. In groups 3, 4, and 5, the right hind limb was used and 3 cycles of ischemia-reperfusion for 5 minutes each (total, 30 minutes) was applied with a latex tourniquet (remote ischemic conditioning). In group 3, this procedure was performed before flap elevation (remote ischemic preconditoning). In group 4, the procedure was performed 4 hours after flap ischemia (remote ischemic postconditioning). In group 5, the procedure was performed after the flap was elevated, during the muscle flap ischemia episode (remote ischemic perconditioning). The histopathological damage score in all remote conditioning ischemia groups was lower than in the ischemic-reperfusion group. The lowest histopathological damage score was observed in group 5 (remote ischemic perconditioning). The nitric oxide levels were higher in the blood samples obtained from the remote ischemic perconditioning group. This study showed the effectiveness of remote ischemic conditioning procedures and compared their usefulness for preventing ischemia-reperfusion injury in muscle flaps.

Effects Of Ischemic Preconditioning On The Renal Ischemia- Reperfusion Injury

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Anyamanesh S

2003-07-01

Full Text Available  During kidney and other organ transplantation, the organ to be transplanted, must inevitably remain out of the body with little or no blood perfusion at all for a long period of time (ischemia. These events have been suggested to cause the formation of oxygen- derived free radicals (OFR. Reperfusion (reintroduction of blood flow will further exacerbate the initial damage caused by the ischemic insult and may result in the production of free radicals. The aim of this study was to investigate whether induction of brief periods of renal artery occlusion (ischemic pre¬conditioning, IPC can provide protection from the effects of a subsequent period of ischemia and reperfusion (IR in the rat kidney."nMaterials and Methods: In this regard, 28 white, male rats were randomly and equally divided into four groups: Control (sham- operated, IPC alone, IR alone (30 min ischemia followed by 10 min reperfusion, and IPC- IR. Preconditioning involved the sequential clamping of the right renal artery for 5 min and declamping for 5 min for a total of 3 cycles. To demonstrate the effectiveness of IPC regimen, vitamin E as an endogenous antioxidant and an index of lipid peroxidation was measured by HPLC after its extraction from right renal venous plasma and right renal tissue."nResults: Results of this study showed that the amount of vitamin E of renal tissue and venous plasma in the IR group had a significant decrease when compared to the control group (P< 0.0001. Whereas the amount of this vitamin in both renal tissue and venous plasma of the IPC- IR group was significantly higher than that in the IR group (P< 0.0001, but did not show any significant difference with the control group."nConclusion: In this study, preconditioning method prevented the reduction of the endogenous antioxidant (Vit. E in encountering the following sustained ischemic insult. Therefore, we suggest that ischemic preconditioning can be used to protect the Vit. E level of kidney from its

Tranexamic Acid Does Not Influence Cardioprotection by Ischemic Preconditioning and Remote Ischemic Preconditioning

NARCIS (Netherlands)

van Caster, Patrick; Eiling, Sandra; Boekholt, Yvonne; Behmenburg, Friederike; Dorsch, Marianne; Heinen, André; Hollmann, Markus W.; Huhn, Ragnar

2018-01-01

Prior studies have suggested that the antifibrinolytic drug aprotinin increases the infarct size after ischemia and reperfusion (I/R) and attenuates the effect of ischemic preconditioning (IPC). Aprotinin was replaced by tranexamic acid (TXA) in clinical practice. Here, we investigated whether TXA

Involvement of adenosine and standardization of aqueous extract of garlic (Allium sativum Linn.) on cardioprotective and cardiodepressant properties in ischemic preconditioning and myocardial ischemia-reperfusion induced cardiac injury

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Sharma, Ashish Kumar; Munajjam, Arshee; Vaishnav, Bhawna; Sharma, Richa; Sharma, Ashok; Kishore, Kunal; Sharma, Akash; Sharma, Divya; Kumari, Rita; Tiwari, Ashish; Singh, Santosh Kumar; Gaur, Samir; Jatav, Vijay Singh; Srinivasan, Barthu Parthi; Agarwal, Shyam Sunder

2012-01-01

The present study investigated the effect of garlic (Allium sativum Linn.) aqueous extracts on ischemic preconditioning and ischemia-reperfusion induced cardiac injury, as well as adenosine involvement in ischemic preconditioning and garlic extract induced cardioprotection. A model of ischemia-reperfusion injury was established using Langendorff apparatus. Aqueous extract of garlic dose was standardized (0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0.07%, 0.05%, 0.03%, 0.01%), and the 0.05% dose was found to be the most effective. Higher doses (more than 0.05%) were highly toxic, causing arrhythmia and cardiodepression, whereas the lower doses were ineffective. Garlic exaggerated the cardioprotective effect of ischemic preconditioning. The cardioprotective effect of ischemic preconditioning and garlic cardioprotection was significantly attenuated by theophylline (1,000 µmol/L) and 8-SPT (10 mg/kg, i.p.) and expressed by increased myocardial infarct size, increased LDH level, and reduced nitrite and adenosine levels. These findings suggest that adenosine is involved in the pharmacological and molecular mechanism of garlic induced cardioprotection and mediated by the modulation of nitric oxide. PMID:23554727

Limb Remote Ischemic Postconditioning Reduces Ischemia-Reperfusion Injury by Inhibiting NADPH Oxidase Activation and MyD88-TRAF6-P38MAP-Kinase Pathway of Neutrophils

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Gangling Chen

2016-11-01

Full Text Available Limb remote ischemic postconditioning (LRIP has been confirmed to reduce the ischemia-reperfusion injury but its mechanisms are still not clear. This study clarified the mechanism of LRIP based on the nicotinamide-adenine dinucleotide phosphate (NADPH oxidase and Myeloid differentiation factor 88 (MyD88-Tumor necrosis factor (TNF receptor-associated factor 6 (TRAF6-P38 pathway of neutrophils. Rat middle cerebral artery occlusion (MCAO model was used in this study. Ischemia-reperfusion injury was carried out by MCAO 1.5 h followed by 24 h reperfusion. LRIP operation was performed to the left femoral artery at 0, 1 or 3 h after reperfusion. Behavioral testing, including postural reflex test, vibrissae-elicited forelimb placing test and tail hang test, showed that LRIP operated at 0 h of reperfusion could significantly ameliorate these behavioral scores. Pathological examinations, infarct size, Myeloperoxidase (MPO activity showed that LRIP operated at 0 h of reperfusion could significantly ameliorate the pathological scores, reduce the infarct size and MPO activity in the brain and increase the MPO activity in the left leg. By using Neutrophil counting, immunofluorescence and real-time PCR techniques, we found that LRIP operated at 0 h of reperfusion could reduce neutrophil counts in the peripheral blood and downregulate the activation of neutrophil in the peripheral blood and rat brain. Western blots revealed that MyD88, TRAF6, p38 mitogen-activated protein kinase (p38-MAPK in neutrophils and the phosphorylation of p47phox (Ser 304 and Ser 345 in neutrophil could be downregulated by LRIP. Our study suggests that LRIP inhibits the number and activation of neutrophils in the rat brain and peripheral blood linked to down-regulating the activation of NADPH oxidase in neutrophils by MyD88/TRAF6/p38-MAPK pathway.

Ischemic preconditioning effect of prodromal angina is attenuated in acute myocardial infarction patients with hypertensive left ventricular hypertrophy

International Nuclear Information System (INIS)

Takeuchi, Toshiharu; Kikuchi, Kenjiro; Hasebe, Naoyuki; Ishii, Yoshinao

2011-01-01

Several animal experiments on acute myocardial infarction (AMI) have shown that the cardioprotective effects of ischemic preconditioning are more significant in hypertensive subjects. However, because there are no clinical data on the impact of hypertension on ischemic preconditioning in patients with AMI, whether clinical ischemic preconditioning of prodromal angina was beneficial in AMI patients with hypertension was investigated in the present study. 125 patients with a first anterior AMI who had undergone successful reperfusion therapy were divided into 2 groups, with or without hypertension, and into 2 further subgroups based on the presence or absence of prodromal angina. Dual-isotope (thallium-201(TL)/Tc-99m pyrophosphate) single-photon emission computed tomography (SPECT) was performed within 1 week of reperfusion therapy. Left ventricular (LV) function and LV mass index (LVMI) were measured by left ventriculography and echocardiography, respectively. In patients without hypertension, prodromal angina resulted in significantly less myocardial damage on TL-SPECT, better LV ejection fraction and a greater myocardial blush grade compared to patients without prodromal angina. However, these cardioprotective effects of prodromal angina were significantly diminished in hypertensive patients. Importantly, the myocardial salvage effects of prodromal angina showed a significant negative correlation with LVMI, which was significantly greater in hypertensive patients. The cardioprotective effects of prodromal angina were attenuated in patients with hypertension. Hypertensive LV hypertrophy may crucially limit the effects of ischemic preconditioning in AMI. (author)

A quantitative spatiotemporal analysis of microglia morphology during ischemic stroke and reperfusion

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Morrison Helena W

2013-01-01

Full Text Available Abstract Background Microglia cells continuously survey the healthy brain in a ramified morphology and, in response to injury, undergo progressive morphological and functional changes that encompass microglia activation. Although ideally positioned for immediate response to ischemic stroke (IS and reperfusion, their progressive morphological transformation into activated cells has not been quantified. In addition, it is not well understood if diverse microglia morphologies correlate to diverse microglia functions. As such, the dichotomous nature of these cells continues to confound our understanding of microglia-mediated injury after IS and reperfusion. The purpose of this study was to quantitatively characterize the spatiotemporal pattern of microglia morphology during the evolution of cerebral injury after IS and reperfusion. Methods Male C57Bl/6 mice were subjected to focal cerebral ischemia and periods of reperfusion (0, 8 and 24 h. The microglia process length/cell and number of endpoints/cell was quantified from immunofluorescent confocal images of brain regions using a skeleton analysis method developed for this study. Live cell morphology and process activity were measured from movies acquired in acute brain slices from GFP-CX3CR1 transgenic mice after IS and 24-h reperfusion. Regional CD11b and iNOS expressions were measured from confocal images and Western blot, respectively, to assess microglia proinflammatory function. Results Quantitative analysis reveals a significant spatiotemporal relationship between microglia morphology and evolving cerebral injury in the ipsilateral hemisphere after IS and reperfusion. Microglia were both hyper- and de-ramified in striatal and cortical brain regions (respectively after 60 min of focal cerebral ischemia. However, a de-ramified morphology was prominent when ischemia was coupled to reperfusion. Live microglia were de-ramified, and, in addition, process activity was severely blunted proximal to

Attenuation of ischemia/reperfusion-induced inhibition of the rapid component of delayed rectifier potassium current by Isosteviol through scavenging reactive oxygen species.

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Yin, Chunxia; Chen, Yaoxu; Wu, Huanlin; Xu, Danping; Tan, Wen

2017-12-01

Isosteviol has been demonstrated to play a protective role during ischemia reperfusion (I/R) myocardial infarction. However, the underlying electrophysiological mechanisms of isosteviol are still unknown. Our previous study showed that the rapid component of the delayed rectifier potassium channel (I Kr ) plays an important role in the prolongation of I/R-induced QT interval-related arrhythmia. This study aimed to investigate whether isosteviol could attenuate I/R-induced prolongation of the action potential duration (APD) along with inhibition of I Kr , and we aimed to clarify the electrophysiological mechanism of isosteviol to determine its cardioprotective effects in guinea pigs. We observed that the APD 90 were 298.5±41.6ms in control, 528.6±56.7ms during I/R, and reduced to 327.8±40.5ms after 10μmol/L of isosteviol treatment. The I Kr currents were 1.44±0.06 pA·pF -1 in the control group, 0.50±0.07pA·pF -1 during I/R, and recovered to 1.20±0.12pA·pF -1 after 10μmol/L of isoteviol treatment. Moreover, isosteviol reduced the over-production of reactive oxygen species (ROS) during I/R. Importantly, isosteviol does not affect the I Kr and human ether-a-go-go-related gene currents of normal cardiomyocytes. It attenuated the I/R-induced inhibition of I Kr due to reduced over-production of ROS. Furthermore, isosteviol is safe and has no cardiotoxicity, and it might be beneficial for coronary reperfusion therapy. Copyright © 2017. Published by Elsevier B.V.

Farnesoid X Receptor Activation Attenuates Intestinal Ischemia Reperfusion Injury in Rats.

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Laurens J Ceulemans

Full Text Available The farnesoid X receptor (FXR is abundantly expressed in the ileum, where it exerts an enteroprotective role as a key regulator of intestinal innate immunity and homeostasis, as shown in pre-clinical models of inflammatory bowel disease. Since intestinal ischemia reperfusion injury (IRI is characterized by hyperpermeability, bacterial translocation and inflammation, we aimed to investigate, for the first time, if the FXR-agonist obeticholic acid (OCA could attenuate intestinal ischemia reperfusion injury.In a validated rat model of intestinal IRI (laparotomy + temporary mesenteric artery clamping, 3 conditions were tested (n = 16/group: laparotomy only (sham group; ischemia 60min+ reperfusion 60min + vehicle pretreatment (IR group; ischemia 60min + reperfusion 60min + OCA pretreatment (IR+OCA group. Vehicle or OCA (INT-747, 2*30mg/kg was administered by gavage 24h and 4h prior to IRI. The following end-points were analyzed: 7-day survival; biomarkers of enterocyte viability (L-lactate, I-FABP; histology (morphologic injury to villi/crypts and villus length; intestinal permeability (Ussing chamber; endotoxin translocation (Lipopolysaccharide assay; cytokines (IL-6, IL-1-β, TNFα, IFN-γ IL-10, IL-13; apoptosis (cleaved caspase-3; and autophagy (LC3, p62.It was found that intestinal IRI was associated with high mortality (90%; loss of intestinal integrity (structurally and functionally; increased endotoxin translocation and pro-inflammatory cytokine production; and inhibition of autophagy. Conversely, OCA-pretreatment improved 7-day survival up to 50% which was associated with prevention of epithelial injury, preserved intestinal architecture and permeability. Additionally, FXR-agonism led to decreased pro-inflammatory cytokine release and alleviated autophagy inhibition.Pretreatment with OCA, an FXR-agonist, improves survival in a rodent model of intestinal IRI, preserves the gut barrier function and suppresses inflammation. These results turn

Hsp20 Protects against Oxygen-Glucose Deprivation/Reperfusion-Induced Golgi Fragmentation and Apoptosis through Fas/FasL Pathway

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Bingwu Zhong

2015-01-01

Full Text Available Cerebral ischemia-reperfusion injury plays an important role in the development of tissue injury after acute ischemic stroke. Finding effective neuroprotective agents has become a priority in the treatment of ischemic stroke. The Golgi apparatus (GA is a pivotal organelle and its protection is an attractive target in the treatment of cerebral ischemia-reperfusion injury. Protective effects of Hsp20, a potential cytoprotective agent due to its chaperone-like activity and involvement in regulation of many vital processes, on GA were assessed in an ischemia-reperfusion injury model. Mouse neuroblastoma Neuro2a (N2a cells were subjected to oxygen-glucose deprivation/reperfusion (OGDR insult. OGDR induces Golgi fragmentation, apoptosis, and p115 cleavage in N2a cells. However, transfection with Hsp20 significantly attenuates OGDR-induced Golgi fragmentation and apoptosis. Hsp20 interacts with Bax, decreases FasL and Bax expression, and inhibits caspases 3 and p115 cleavage in N2a cells exposed to OGDR. Our data demonstrate that increased Hsp20 expression protects against OGDR-induced Golgi fragmentation and apoptosis, likely through interaction with Bax and subsequent amelioration of the OGDR-induced elevation in p115 cleavage via the Fas/FasL signaling pathway. This neuroprotective potential of Hsp20 against OGDR insult and the underlying mechanism will pave the way for its potential clinical application for cerebral ischemia-reperfusion related disorders.

Prdx6 Upregulation by Curcumin Attenuates Ischemic Oxidative Damage via SP1 in Rats after Stroke

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Gongwei Jia

2017-01-01

Full Text Available Background. The role of Peroxiredoxin 6 (Prdx6 in brain ischemia remains unclear. Curcumin (Cur treatment elicits neuroprotective effects against cerebral ischemic injury, and the associated mechanisms may involve Prdx6. In this study, we investigated whether Prdx6 and the transcription factor specific protein 1 (SP1 were involved in the antioxidant effect of Cur after stoke. Methods. Focal cerebral ischemic injury was induced by transient middle cerebral artery occlusion for 2 hours in male Sprague-Dawley rats treated with or without Prdx6 siRNA. Expression of Prdx6 in the penumbra was assessed by Real-Time PCR (RT-PCR, Western blot analysis, and immunoflourescent staining. In addition, infarct volume, neurological deficit score, and oxidative stress were evaluated. Prdx6 levels were also determined in the presence and absence of SP1 antagonist mithramycin A (MTM-A. Results. Cur treatment upregulated Prdx6 protein expression and the number of Prdx6-positive neuronal cells 24 hours after reperfusion. Cur treatment also attenuated oxidative stress and induced neuroprotective effects against ischemic damage, whereas the beneficial effects of Cur treatment were lost in animals treated with Prdx6-siRNA. Prdx6 upregulation by Cur treatment was abolished by SP1 antagonists MTM. Conclusions. Prdx6 upregulation by Cur treatment attenuates ischemic oxidative damage through SP1 induction in rats after stroke. This represents a novel mechanism of Cur-induced neuroprotection against cerebral ischemia.

Ischemic Conditioning as a Hemostatic Intervention in Surgery and Cardiac Procedures: A Systematic Review

DEFF Research Database (Denmark)

Krag, Andreas Engel; Hvas, Anne-Mette

2017-01-01

did not increase operative bleeding. In conclusion, ischemic conditioning reduced platelet activity without increasing the risk of bleeding in patients undergoing surgery or cardiac procedures. Limited evidence supports the proposal that ischemic conditioning reduces the incidence of arterial......Ischemic conditioning induced by nonlethal cycles of tissue ischemia and reperfusion attenuates ischemia–reperfusion injury. The objective of this study is to systematically review the effects of local and remote ischemic conditioning on laboratory parameters of hemostasis and the clinical outcomes......, thromboembolism, and bleeding were extracted for qualitative synthesis. In total, 69 studies were included; of these, 53 were randomized controlled trials (RCTs) and 11 were meta-analyses. Local and remote ischemic conditioning reduced platelet activation in patients undergoing cardiac procedures. Local ischemic...

Possible involvement of caveolin in attenuation of cardioprotective effect of ischemic preconditioning in diabetic rat heart

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Singh Manjeet

2011-07-01

Full Text Available Abstract Background Nitric oxide (NO has been noted to produce ischemic preconditioning (IPC-mediated cardioprotection. Caveolin is a negative regulator of NO, which inhibits endothelial nitric oxide synthase (eNOS by making caveolin-eNOS complex. The expression of caveolin is increased during diabetes mellitus (DM. The present study was designed to investigate the involvement of caveolin in attenuation of the cardioprotective effect of IPC during DM in rat. Methods Experimental DM was induced by single dose of streptozotocin (50 mg/Kg, i.p, and animals were used for experiments four weeks later. Isolated heart was mounted on Langendorff's apparatus, and was subjected to 30 min of global ischemia and 120 min of reperfusion. IPC was given by four cycles of 5 min of ischemia and 5 min of reperfusion with Kreb's-Henseleit solution (K-H. Extent of injury was measured in terms of infarct size by triphenyltetrazolium chloride (TTC staining, and release of lactate dehydrogenase (LDH and creatin kinase-MB (CK-MB in coronary effluent. The cardiac release of NO was noted by measuring the level of nitrite in coronary effluent. Results IPC- induced cardioprotection and release of NO was significantly decreased in diabetic rat heart. Pre-treatment of diabetic rat with daidzein (DDZ a caveolin inhibitor (0.2 mg/Kg/s.c, for one week, significantly increased the release of NO and restored the attenuated cardioprotective effect of IPC. Also perfusion of sodium nitrite (10 μM/L, a precursor of NO, significantly restored the lost effect of IPC, similar to daidzein in diabetic rat. Administration of 5-hydroxy deaconate (5-HD, a mito KATP channel blocker, significantly abolished the observed IPC-induced cardioprotection in normal rat or daidzein and sodium nitrite perfused diabetic rat heart alone or in combination. Conclusions Thus, it is suggested that attenuation of the cardioprotection in diabetic heart may be due to decrease the IPC mediated release of NO in

Involvement of CCR-2 chemokine receptor activation in ischemic preconditioning and postconditioning of brain in mice.

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Rehni, Ashish K; Singh, Thakur Gurjeet

2012-10-01

The present study has been designed to investigate the potential role of CCR-2 chemokine receptor in ischemic preconditioning as well as postconditioning induced reversal of ischemia-reperfusion injury in mouse brain. Bilateral carotid artery occlusion of 17 min followed by reperfusion for 24h was employed in present study to produce ischemia and reperfusion induced cerebral injury in mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was evaluated using elevated plus-maze test and Morris water maze test. Rota rod test was employed to assess motor incoordination. Bilateral carotid artery occlusion followed by reperfusion produced cerebral infarction and impaired memory and motor co-ordination. Three preceding episodes of bilateral carotid artery occlusion for 1 min and reperfusion of 1 min were employed to elicit ischemic preconditioning of brain, while three episodes of bilateral carotid artery occlusion for 10s and reperfusion of 10s immediately after the completion of were employed to elicit ischemic postconditioning of brain. Both prior ischemic preconditioning as well as ischemic postconditioning immediately after global cerebral ischemia prevented markedly ischemia-reperfusion-induced cerebral injury as measured in terms of infarct size, loss of memory and motor coordination. RS 102895, a selective CCR-2 chemokine receptor antagonist, attenuated the neuroprotective effect of both the ischemic preconditioning as well as postconditioning. It is concluded that the neuroprotective effect of both ischemic preconditioning as well as ischemic postconditioning may involve the activation of CCR-2 chemokine receptors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Pharmacological prevention of reperfusion injury in acute myocardial infarction. A potential role for adenosine as a therapeutic agent.

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Quintana, Miguel; Kahan, Thomas; Hjemdahl, Paul

2004-01-01

The concept of reperfusion injury, although first recognized from animal studies, is now recognized as a clinical phenomenon that may result in microvascular damage, no-reflow phenomenon, myocardial stunning, myocardial hibernation and ischemic preconditioning. The final consequence of this event is left ventricular (LV) systolic dysfunction leading to increased morbidity and mortality. The typical clinical case of reperfusion injury occurs in acute myocardial infarction (MI) with ST segment elevation in which an occlusion of a major epicardial coronary artery is followed by recanalization of the artery. This may occur either spontaneously or by means of thrombolysis and/or by primary percutaneous coronary intervention (PCI) with efficient platelet inhibition by aspirin (acetylsalicylic acid), clopidogrel and glycoprotein IIb/IIIa inhibitors. Although the pathophysiology of reperfusion injury is complex, the major role that neutrophils play in this process is well known. Neutrophils generate free radicals, degranulation products, arachidonic acid metabolites and platelet-activating factors that interact with endothelial cells, inducing endothelial injury and neutralization of nitrous oxide vasodilator capacity. Adenosine, through its multi-targeted pharmacological actions, is able to inhibit some of the above-mentioned detrimental effects. The net protective of adenosine in in vivo models of reperfusion injury is the reduction of the infarct size, the improvement of the regional myocardial blood flow and of the regional function of the ischemic area. Additionally, adenosine preserves the post-ischemic coronary flow reserve, coronary blood flow and the post-ischemic regional contractility. In small-scale studies in patients with acute MI, treatment with adenosine has been associated with smaller infarcts, less no-reflow phenomenon and improved LV function. During elective PCI adenosine reduced ST segment shifts, lactate production and ischemic symptoms. During the

PARP Inhibition Attenuates Histopathological Lesion in Ischemia/Reperfusion Renal Mouse Model after Cold Prolonged Ischemia

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Raimundo M. G. del Moral

2013-01-01

Full Text Available We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN and other renal lesions related to prolonged cold ischemia/reperfusion (IR in kidneys preserved at 4°C in University of Wisconsin (UW solution. Material and Methods. We used 30 male Parp1+/+ wild-type and 15 male Parp10/0 knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinylbutoxyl]-1(2H-isoquinolinone (DPQ at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ. We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp10/0 knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

A novel therapy to attenuate acute kidney injury and ischemic allograft damage after allogenic kidney transplantation in mice.

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Faikah Gueler

Full Text Available Ischemia followed by reperfusion contributes to the initial damage to allografts after kidney transplantation (ktx. In this study we tested the hypothesis that a tetrapeptide EA-230 (AQGV, might improve survival and attenuate loss of kidney function in a mouse model of renal ischemia/reperfusion injury (IRI and ischemia-induced delayed graft function after allogenic kidney transplantation. IRI was induced in male C57Bl/6N mice by transient bilateral renal pedicle clamping for 35 min. Treatment with EA-230 (20-50mg/kg twice daily i.p. for four consecutive days was initiated 24 hours after IRI when acute kidney injury (AKI was already established. The treatment resulted in markedly improved survival in a dose dependent manner. Acute tubular injury two days after IRI was diminished and tubular epithelial cell proliferation was significantly enhanced by EA-230 treatment. Furthermore, CTGF up-regulation, a marker of post-ischemic fibrosis, at four weeks after IRI was significantly less in EA-230 treated renal tissue. To learn more about these effects, we measured renal blood flow (RBF and glomerular filtration rate (GFR at 28 hours after IRI. EA-230 improved both GFR and RBF significantly. Next, EA-230 treatment was tested in a model of ischemia-induced delayed graft function after allogenic kidney transplantation. The recipients were treated with EA-230 (50 mg/kg twice daily i.p. which improved renal function and allograft survival by attenuating ischemic allograft damage. In conclusion, EA-230 is a novel and promising therapeutic agent for treating acute kidney injury and preventing IRI-induced post-transplant ischemic allograft injury. Its beneficial effect is associated with improved renal perfusion after IRI and enhanced regeneration of tubular epithelial cells.

Remote Ischemic Conditioning to Protect against Ischemia-Reperfusion Injury: A Systematic Review and Meta-Analysis

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Brevoord, Daniel; Kranke, Peter; Kuijpers, Marijn; Weber, Nina; Hollmann, Markus; Preckel, Benedikt

2012-01-01

Background Remote ischemic conditioning is gaining interest as potential method to induce resistance against ischemia reperfusion injury in a variety of clinical settings. We performed a systematic review and meta-analysis to investigate whether remote ischemic conditioning reduces mortality, major adverse cardiovascular events, length of stay in hospital and in the intensive care unit and biomarker release in patients who suffer from or are at risk for ischemia reperfusion injury. Methods and Results Medline, EMBASE and Cochrane databases were searched for randomized clinical trials comparing remote ischemic conditioning, regardless of timing, with no conditioning. Two investigators independently selected suitable trials, assessed trial quality and extracted data. 23 studies in patients undergoing cardiac surgery (15 studies), percutaneous coronary intervention (four studies) and vascular surgery (four studies), comprising in total 1878 patients, were included in this review. Compared to no conditioning, remote ischemic conditioning did not reduce mortality (odds ratio 1.22 [95% confidence interval 0.48, 3.07]) or major adverse cardiovascular events (0.65 [0.38, 1.14]). However, the incidence of myocardial infarction was reduced with remote ischemic conditioning (0.50 [0.31, 0.82]), as was peak troponin release (standardized mean difference −0.28 [−0.47, −0.09]). Conclusion There is no evidence that remote ischemic conditioning reduces mortality associated with ischemic events; nor does it reduce major adverse cardiovascular events. However, remote ischemic conditioning did reduce the incidence of peri-procedural myocardial infarctions, as well as the release of troponin. PMID:22860077

Blockade of Death Ligand TRAIL Inhibits Renal Ischemia Reperfusion Injury

International Nuclear Information System (INIS)

Adachi, Takaomi; Sugiyama, Noriyuki; Gondai, Tatsuro; Yagita, Hideo; Yokoyama, Takahiko

2013-01-01

Renal ischemia-reperfusion injury (IRI) is a leading cause of acute kidney injury (AKI). Many investigators have reported that cell death via apoptosis significantly contributed to the pathophysiology of renal IRI. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor superfamily, and induces apoptosis and inflammation. However, the role of TRAIL in renal IRI is unclear. Here, we investigated whether TRAIL contributes to renal IRI and whether TRAIL blockade could attenuate renal IRI. AKI was induced by unilateral clamping of the renal pedicle for 60 min in male FVB/N mice. We found that the expression of TRAIL and its receptors were highly upregulated in renal tubular cells in renal IRI. Neutralizing anti-TRAIL antibody or its control IgG was given 24 hr before ischemia and a half-dose booster injection was administered into the peritoneal cavity immediately after reperfusion. We found that TRAIL blockade inhibited tubular apoptosis and reduced the accumulation of neutrophils and macrophages. Furthermore, TRAIL blockade attenuated renal fibrosis and atrophy after IRI. In conclusion, our study suggests that TRAIL is a critical pathogenic factor in renal IRI, and that TRAIL could be a new therapeutic target for the prevention of renal IRI

Ischemic preconditioning fails to confer additional protection against ischemia-reperfusion injury in the hypothyroid rat heart.

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Mourouzis, I; Dimopoulos, A; Saranteas, T; Tsinarakis, N; Livadarou, E; Spanou, D; Kokkinos, A D; Xinaris, C; Pantos, C; Cokkinos, D V

2009-01-01

There is accumulating evidence showing that ischemic preconditioning (PC) may lose its cardioprotective effect in the diseased states. The present study investigated whether PC can be effective in hypothyroidism, a clinical condition which is common and often accompanies cardiac diseases such as heart failure and myocardial infarction. Hypothyroidism was induced in rats by 3-week administration of 6n-propyl-2-thiouracil in water (0.05 %). Normal and hypothyroid hearts (HYPO) were perfused in Langendorff mode and subjected to 20 min of zero-flow global ischemia and 45 min of reperfusion. A preconditioning protocol (PC) was also applied prior to ischemia. HYPO hearts had significantly improved post-ischemic recovery of left ventricular developed pressure, end-diastolic pressure and reduced lactate dehydrogenase release. Furthermore, phospho-JNK and p38 MAPK levels after ischemia and reperfusion were 4.0 and 3.0 fold lower in HYPO as compared to normal hearts (Phearts. PC improved the post-ischemic recovery of function and reduced the extent of injury in normal hearts but had no additional effect on the hypothyroid hearts. This response, in the preconditioned normal hearts, resulted in 2.5 and 1.8 fold smaller expression of the phospho-JNK and phospho-p38 MAPK levels at the end of reperfusion, as compared to non-PC hearts (Phearts, no additional reduction in the phosphorylation of these kinases was observed after PC. Hypothyroid hearts appear to be tolerant to ischemia-reperfusion injury. This response may be, at least in part, due to the down-regulation of ischemia-reperfusion induced activation of JNKs and p38 MAPK kinases. PC is not associated with further reduction in the activation of these kinases in the hypothyroid hearts and fails to confer added protection in those hearts.

Heme Oxygenase-1 Gene Therapy Provides Cardioprotection Via Control of Post-Ischemic Inflammation: An Experimental Study in a Pre-Clinical Pig Model.

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Hinkel, Rabea; Lange, Philipp; Petersen, Björn; Gottlieb, Elena; Ng, Judy King Man; Finger, Stefanie; Horstkotte, Jan; Lee, Seungmin; Thormann, Michael; Knorr, Maike; El-Aouni, Chiraz; Boekstegers, Peter; Reichart, Bruno; Wenzel, Philip; Niemann, Heiner; Kupatt, Christian

2015-07-14

Heme oxygenase-1 (HO-1) is an inducible stress-responsive enzyme converting heme to bilirubin, carbon monoxide, and free iron, which exerts anti-inflammatory and antiapoptotic effects. Although efficient cardioprotection after HO-1 overexpression has been reported in rodents, its role in attenuating post-ischemic inflammation is unclear. This study assessed the efficacy of recombinant adenoassociated virus (rAAV)-encoding human heme oxygenase-1 (hHO-1) in attenuating post-ischemic inflammation in a murine and a porcine ischemia/reperfusion model. Murine ischemia was induced by 45 min of left anterior descending occlusion, followed by 24 h of reperfusion and functional as well as fluorescent-activated cell sorting analysis. Porcine hearts were subjected to 60 min of ischemia and 24h of reperfusion before hemodynamic and histologic analyses were performed. Human microvascular endothelial cells transfected with hHO-1 displayed an attenuated interleukin-6 and intercellular adhesion molecule 1 expression, resulting in reduced monocytic THP-1 cell recruitment in vitro. In murine left anterior descending occlusion and reperfusion, the post-ischemic influx of CD45(+) leukocytes, Ly-6G(+) neutrophils, and Ly-6C(high) monocytes was further exacerbated in HO-1-deficient hearts and reversed by rAAV.hHO-1 treatment. Conversely, in our porcine model of ischemia, the post-ischemic influx of myeloperoxidase-positive neutrophils and CD14(+) monocytes was reduced by 49% and 87% after rAAV.hHO-1 transduction, similar to hHO-1 transgenic pigs. Functionally, rAAV.hHO-1 and hHO-1 transgenic left ventricles displayed a smaller loss of ejection fraction than control animals. Whereas HO-1 deficiency exacerbates post-ischemic cardiac inflammation in mice, hHO-1 gene therapy attenuates inflammation after ischemia and reperfusion in murine and porcine hearts. Regional hHO-1 gene therapy provides cardioprotection in a pre-clinical porcine ischemia/reperfusion model. Copyright © 2015 American

CTGF/CCN2 Postconditioning Increases Tolerance of Murine Hearts towards Ischemia-Reperfusion Injury.

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Ole Jørgen Kaasbøll

Full Text Available Previous studies of ischemia-reperfusion injury (IRI in hearts from mice with cardiac-restricted overexpression of CCN2 have shown that CCN2 increases tolerance towards IRI. The objectives of this study were to investigate to what extent post-ischemic administration of recombinant human CCN2 (rhCCN2 would limit infarct size and improve functional recovery and what signaling pathways are involved.Isolated mice hearts were perfused ad modum Langendorff, subjected to no-flow, global ischemia, and subsequently, exposed to mammalian cell derived, full-length (38-40kDa rhCCN2 (250 nM or vehicle during the first 15 min of a 60 min reperfusion period.Post-ischemic administration of rhCCN2 resulted in attenuation of infarct size from 58 ± 4% to 34 ± 2% (p < 0.001 which was abrogated by concomitant administration of the PI3 kinase inhibitor LY294002 (45 ± 3% vs. 50 ± 3%, ns. In congruence with reduction of infarct size rhCCN2 also improved recovery of left ventricular developed pressure (p < 0.05. Western blot analyses of extracts of ex vivo-perfused murine hearts also revealed that rhCCN2 evoked concentration-dependent increase of cardiac phospho-GSK3β (serine-9 contents.We demonstrate that post-ischemic administration of rhCCN2 increases the tolerance of ex vivo-perfused murine hearts to IRI. Mechanistically, this postconditioning effect of rhCCN2 appeared to be mediated by activation of the reperfusion injury salvage kinase pathway as demonstrated by sensitivity to PI3 kinase inhibition and increased CCN2-induced phosphorylation of GSK3β (Ser-9. Thus, the rationale for testing rhCCN2-mediated post-ischemic conditioning of the heart in more complex models is established.

Reperfusion is a more accurate predictor of follow-up infarct volume than recanalization: a proof of concept using CT in acute ischemic stroke patients.

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Soares, Bruno P; Tong, Elizabeth; Hom, Jason; Cheng, Su-Chun; Bredno, Joerg; Boussel, Loic; Smith, Wade S; Wintermark, Max

2010-01-01

The purpose of this study was to compare recanalization and reperfusion in terms of their predictive value for imaging outcomes (follow-up infarct volume, infarct growth, salvaged penumbra) and clinical outcome in acute ischemic stroke patients. Twenty-two patients admitted within 6 hours of stroke onset were retrospectively included in this study. These patients underwent a first stroke CT protocol including CT-angiography (CTA) and perfusion-CT (PCT) on admission, and similar imaging after treatment, typically around 24 hours, to assess recanalization and reperfusion. Recanalization was assessed by comparing arterial patency on admission and posttreatment CTAs; reperfusion, by comparing the volumes of CBV, CBF, and MTT abnormality on admission and posttreatment PCTs. Collateral flow was graded on the admission CTA. Follow-up infarct volume was measured on the discharge noncontrast CT. The groups of patients with reperfusion, no reperfusion, recanalization, and no recanalization were compared in terms of imaging and clinical outcomes. Reperfusion (using an MTT reperfusion index >75%) was a more accurate predictor of follow-up infarct volume than recanalization. Collateral flow and recanalization were not accurate predictors of follow-up infarct volume. An interaction term was found between reperfusion and the volume of the admission penumbra >50 mL. Our study provides evidence that reperfusion is a more accurate predictor of follow-up infarct volume in acute ischemic stroke patients than recanalization. We recommend an MTT reperfusion index >75% to assess therapy efficacy in future acute ischemic stroke trials that use perfusion-CT.

The pro-resolving lipid mediator Maresin 1 protects against cerebral ischemia/reperfusion injury by attenuating the pro-inflammatory response

International Nuclear Information System (INIS)

Xian, Wenjing; Wu, Yan; Xiong, Wei; Li, Longyan; Li, Tong; Pan, Shangwen; Song, Limin; Hu, Lisha; Pei, Lei; Yao, Shanglong

2016-01-01

Inflammation plays a crucial role in acute ischemic stroke pathogenesis. Macrophage-derived Maresin 1 (MaR1) is a newly uncovered mediator with potent anti-inflammatory abilities. Here, we investigated the effect of MaR1 on acute inflammation and neuroprotection in a mouse brain ischemia reperfusion (I/R) model. Male C57 mice were subjected to 1-h middle cerebral artery occlusion (MCAO) and reperfusion. By the methods of 2,3,5-triphenyltetrazolium chloride, haematoxylin and eosin or Fluoro-Jade B staining, neurological deficits scoring, ELISA detection, immunofluorescence assay and western blot analysis, we found that intracerebroventricular injection of MaR1 significantly reduced the infarct volume and neurological defects, essentially protected the brain tissue and neurons from injury, alleviated pro-inflammatory reactions and NF-κB p65 activation and nuclear translocation. Taken together, our results suggest that MaR1 significantly protects against I/R injury probably by inhibiting pro-inflammatory reactions. - Highlights: • MaR1 significantly protects against ischemia reperfusion injury. • MaR1 inhibits pro-inflammatory cytokines and chemokines and reducing glial activation and neutrophil infiltration. • These effects at least partially occurred via suppression of the NF-κB p65 signalling pathway.

The pro-resolving lipid mediator Maresin 1 protects against cerebral ischemia/reperfusion injury by attenuating the pro-inflammatory response

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Xian, Wenjing [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Wu, Yan [Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Xiong, Wei [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Li, Longyan [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Li, Tong [Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Pan, Shangwen [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Song, Limin [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Hu, Lisha [Department of Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Pei, Lei [Department of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); Yao, Shanglong, E-mail: ysltian@163.com [Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan (China); and others

2016-03-25

Inflammation plays a crucial role in acute ischemic stroke pathogenesis. Macrophage-derived Maresin 1 (MaR1) is a newly uncovered mediator with potent anti-inflammatory abilities. Here, we investigated the effect of MaR1 on acute inflammation and neuroprotection in a mouse brain ischemia reperfusion (I/R) model. Male C57 mice were subjected to 1-h middle cerebral artery occlusion (MCAO) and reperfusion. By the methods of 2,3,5-triphenyltetrazolium chloride, haematoxylin and eosin or Fluoro-Jade B staining, neurological deficits scoring, ELISA detection, immunofluorescence assay and western blot analysis, we found that intracerebroventricular injection of MaR1 significantly reduced the infarct volume and neurological defects, essentially protected the brain tissue and neurons from injury, alleviated pro-inflammatory reactions and NF-κB p65 activation and nuclear translocation. Taken together, our results suggest that MaR1 significantly protects against I/R injury probably by inhibiting pro-inflammatory reactions. - Highlights: • MaR1 significantly protects against ischemia reperfusion injury. • MaR1 inhibits pro-inflammatory cytokines and chemokines and reducing glial activation and neutrophil infiltration. • These effects at least partially occurred via suppression of the NF-κB p65 signalling pathway.

Putative role of ischemic postconditioning in a rat model of limb ischemia and reperfusion: involvement of hypoxia-inducible factor-1α expression

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Wang, T. [Department of Anesthesiology, Shuyang People' s Hospital, JiangSu (China); Zhou, Y.T. [Department of General Surgery, Shuyang People' s Hospital, JiangSu (China); Chen, X.N. [Institute of Pathophysiology, School of Basic Medical Sciences, LanZhou University, Lanzhou, Gansu (China); Zhu, A.X. [Department of Pharmacy, Shuyang People' s Hospital, JiangSu (China)

2014-07-25

Hypoxia-inducible factor-1α (HIF-1α) is one of the most potent angiogenic growth factors. It improves angiogenesis and tissue perfusion in ischemic skeletal muscle. In the present study, we tested the hypothesis that ischemic postconditioning is effective for salvaging ischemic skeletal muscle resulting from limb ischemia-reperfusion injury, and that the mechanism involves expression of HIF-1α. Wistar rats were randomly divided into three groups (n=36 each): sham-operated (group S), hindlimb ischemia-reperfusion (group IR), and ischemic postconditioning (group IPO). Each group was divided into subgroups (n=6) according to reperfusion time: immediate (0 h, T{sub 0}), 1 h (T{sub 1}), 3 h (T{sub 3}), 6 h (T{sub 6}), 12 h (T{sub 12}), and 24 h (T{sub 24}). In the IPO group, three cycles of 30-s reperfusion and 30-s femoral aortic reocclusion were carried out before reperfusion. At all reperfusion times (T{sub 0}-T{sub 24}), serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities, as well as interleukin (IL)-6, IL-10, and tumor necrosis factor-α (TNF-α) concentrations, were measured in rats after they were killed. Histological and immunohistochemical methods were used to assess the skeletal muscle damage and HIF-1α expression in skeletal muscle ischemia. In groups IR and IPO, serum LDH and CK activities and TNF-α, IL-6, and IL-10 concentrations were all significantly increased compared to group S, and HIF-1α expression was up-regulated (P<0.05 or P<0.01). In group IPO, serum LDH and CK activities and TNF-α and IL-6 concentrations were significantly decreased, IL-10 concentration was increased, HlF-1α expression was down-regulated (P<0.05 or P<0.01), and the pathological changes were reduced compared to group IR. The present study suggests that ischemic postconditioning can reduce skeletal muscle damage caused by limb ischemia-reperfusion and that its mechanisms may be related to the involvement of HlF-1α in the limb ischemia-reperfusion injury

Ghrelin protects the heart against ischemia/reperfusion injury via inhibition of TLR4/NLRP3 inflammasome pathway.

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Wang, Qin; Lin, Ping; Li, Peng; Feng, Li; Ren, Qian; Xie, Xiaofeng; Xu, Jing

2017-10-01

The aim of this study was to investigate the cardioprotective effects of ghrelin against myocardial ischemia/reperfusion (I/R) injury and the underlying mechanism. Sprague-Dawley rats were randomized into Sham, I/R and I/R+ghrelin groups. After 30 minutes ischemia, ghrelin (8nmol/kg) was injected intraperitoneally at the time of reperfusion in the I/R+ghrelin group. Then hemodynamic parameters were observed at 24h after reperfusion. Ghrelin exhibited dramatic improvement in cardiac functions, as manifested by increased LVSP and ±dP/dt max and decreased LVDP. At 24h after reperfusion, ghrelin significantly attenuated the myocardial infarction area and apoptosis, accompanied with a decrease in the levels of the myocyte injury marker enzymes. Oxidative stress injury and inflammatory response were also relieved by ghrelin. Western blot showed that the expression of TLR4, NLRP3, and caspase-1 were obviously increased in I/R group, while ghrelin significantly inhibited the I/R-induced TLR4, NLRP3, and caspase-1 expression. Ghrelin could inhibit the increased protein levels of NLRP3, caspase-1, and IL-1β induced by lipopolysacharide in primary cultured cardiomyocytes of neonatal rats. Ghrelin protected the heart against I/R injury by inhibiting oxidative stress and inflammation via TLR4/NLRP3 signaling pathway. Our results might provide new strategy and target for treatment of myocardial ischemia/reperfusion injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Overview of Experimental and Clinical Findings regarding the Neuroprotective Effects of Cerebral Ischemic Postconditioning

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Ma, Di; Feng, Liangshu; Deng, Fang; Feng, Jia-Chun

2017-01-01

Research on attenuating the structural and functional deficits observed following ischemia-reperfusion has become increasingly focused on the therapeutic potential of ischemic postconditioning. In recent years, various methods and animal models of ischemic postconditioning have been utilized. The results of these numerous studies have indicated that the mechanisms underlying the neuroprotective effects of ischemic postconditioning may involve reductions in the generation of free radicals and ...

RP105 Protects Against Apoptosis in Ischemia/Reperfusion-Induced Myocardial Damage in Rats by Suppressing TLR4-Mediated Signaling Pathways

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Jun Yang

2015-07-01

Full Text Available Background: Myocardial apoptosis is heavily implicated in the myocardial damage caused by ischemia-reperfusion (I/R. Toll-like receptor 4 (TLR4 is a potent inducer of these apoptotic cascades. In contrast, the radioprotective 105 kDa protein (RP105 is a specific negative regulator of TLR4 signaling pathways. However, the precise mechanisms by which RP105 inhibits myocardium apoptosis via TLR4-associated pathways during I/R is not fully understood. Methods: We utilized a rat model of myocardial ischemic reperfusion injury (MIRI. Animals were pre-treated with Ad-EGFP adenovirus, Ad-EGFP-RP105 adenovirus, saline, or nothing (sham. After three days, rats underwent a 30min left anterior descending coronary artery occlusion and a 4h reperfusion. Mycardial tissue was assessed by immunohistochemistry, TUNEL-staining, Western blot, quantitative RT-PCR, and a morphometric assay. Results: RP105 overexpression resulted in a reduction in infarct size, fewer TUNEL-positive cardiomyocytes, and a reduction in mitochondrial-associated apoptosis cascade activity. Further, RP105 overexpression repressed I/R-induced myocardial injury by attenuating myocardial apoptosis. This was mediated by inhibiting TLR4 activation and the phosphorylation of P38MAPK and the downstream transcription factor AP-1. Conclusion: RP105 overexpression leads to the de-activation of TLR4, P38MAPK, and AP-1 signaling pathways, and subsequently represses apoptotic cascades and ensuing damage of myocardial ischemic reperfusion. These findings may become the basis of a novel therapeutic approach for reducing of cardiac damage caused by MIRI.

Low-energy shock wave preconditioning reduces renal ischemic reperfusion injury caused by renal artery occlusion.

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Xue, Yuquan; Xu, Zhibin; Chen, Haiwen; Gan, Weimin; Chong, Tie

2017-07-01

To evaluate whether low energy shock wave preconditioning could reduce renal ischemic reperfusion injury caused by renal artery occlusion. The right kidneys of 64 male Sprague Dawley rats were removed to establish an isolated kidney model. The rats were then divided into four treatment groups: Group 1 was the sham treatment group; Group 2, received only low-energy (12 kv, 1 Hz, 200 times) shock wave preconditioning; Group 3 received the same low-energy shock wave preconditioning as Group 2, and then the left renal artery was occluded for 45 minutes; and Group 4 had the left renal artery occluded for 45 minutes. At 24 hours and one-week time points after reperfusion, serum inducible nitric oxide synthase (iNOS), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), creatinine (Cr), and cystatin C (Cys C) levels were measured, malondialdehyde (MDA) in kidney tissue was detected, and changes in nephric morphology were evaluated by light and electron microscopy. Twenty-four hours after reperfusion, serum iNOS, NGAL, Cr, Cys C, and MDA levels in Group 3 were significantly lower than those in Group 4; light and electron microscopy showed that the renal tissue injury in Group 3 was significantly lighter than that in Group 4. One week after reperfusion, serum NGAL, KIM-1, and Cys C levels in Group 3 were significantly lower than those in Group 4. Low-energy shock wave preconditioning can reduce renal ischemic reperfusion injury caused by renal artery occlusion in an isolated kidney rat model.

Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy

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Ming-Shuo Sun

2018-01-01

Full Text Available Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.

Inhibition of Long Chain Fatty Acyl-CoA Synthetase (ACSL) and Ischemia Reperfusion Injury

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Prior, Allan M.; Zhang, Man; Blakeman, Nina; Datta, Palika; Pham, Hung; Young, Lindon H.; Weis, Margaret T.; Hua, Duy H.

2014-01-01

Various triacsin C analogs, containing different alkenyl chains and carboxylic acid bioisoteres including 4-aminobenzoic acid, isothiazolidine dioxide, hydroxylamine, hydroxytriazene, and oxadiazolidine dione, were synthesized and their inhibitions of long chain fatty acyl-CoA synthetase (ACSL) were examined. Two methods, a cell-based assay of ACSL activity and an in situ [14C]-palmitate incorporation into extractable lipids were used to study the inhibition. Using an in vivo leukocyte recruitment inhibition protocol, the translocation of one or more cell adhesion molecules from the cytoplasm to the plasma membrane on either the endothelium or leukocyte or both was inhibited by inhibitors 1, 9, and triacsin C. The results suggest that inhibition of ACSL may attenuate the vascular inflammatory component associated with ischemia reperfusion injury and lead to a decrease of infarct expansion. PMID:24480468

Protection of Ischemic and Reperfused Rat Heart by Aqueous Extract of Urtica Dioica

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D Shackebaei

2010-09-01

Full Text Available Background: Urtica dioica (U.D has widely been used in traditional medicine for its hypotensive and vasodilatory effects. The objective of this study was to clarify the effects of aqueous extract of Urtica dioica on isolated ischemia- reperfused heart.Methods: The heart of male wistar rats were isolated and perfused according to langendorff method. In the control group (n = 13 the hearts were subjected to three steps of stabilization (30 min, normothermic global ischemia (40 min and reperfusion (45 min. In addition, before and after ischemia, the aqueous extract of U.D (200 mg/ml was added to perfusion solution in the test group (n=14. Different cardiac variables including left ventricular pressure, heart rate and coronary flow were measured and rate pressure product was calculated.Results: Results showed that left ventricular pressure (59.11±4.7 and rate pressure product (13680±1136 in 45th minute of reperfusion in the test group were significantly (P=0.0187 and 0.0321 respectively greater than the control group (39.1±6.0, 9480±1480 respectively. These findings indicated decreased cardiac damage following ischemia in the test group, compared with that of control group.Conclusion: Results of the present study showed that the aqueous extract of U.D, increased the tolerance of isolated rat hearts against ischemic damage. This effect can be explained by potent antioxidant activity of the U.D extract, suggesting its clinical use in ischemic heart disease.

Neuroprotective effect of TAT-14-3-3ε fusion protein against cerebral ischemia/reperfusion injury in rats.

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Yuanjun Zhu

Full Text Available Stroke is the major cause of death and disability worldwide, and the thrombolytic therapy currently available was unsatisfactory. 14-3-3ε is a well characterized member of 14-3-3 family, and has been reported to protect neurons against apoptosis in cerebral ischemia. However, it cannot transverse blood brain barrier (BBB due to its large size. A protein transduction domain (PTD of HIV TAT protein, is capable of delivering a large variety of proteins into the brain. In this study, we generated a fusion protein TAT-14-3-3ε, and evaluated its potential neuroprotective effect in rat focal ischemia/reperfusion (I/R model. Western blot analysis validated the efficient transduction of TAT-14-3-3ε fusion protein into brain via a route of intravenous injection. TAT-14-3-3ε pre-treatment 2 h before ischemia significantly reduced cerebral infarction volume and improved neurologic score, while post-treatment 2 h after ischemia was less effective. Importantly, pre- or post-ischemic treatment with TAT-14-3-3ε significantly increased the number of surviving neurons as determined by Nissl staining, and attenuated I/R-induced neuronal apoptosis as showed by the decrease in apoptotic cell numbers and the inhibition of caspase-3 activity. Moreover, the introduction of 14-3-3ε into brain by TAT-mediated delivering reduced the formation of autophagosome, attenuated LC3B-II upregulation and reversed p62 downregulation induced by ischemic injury. Such inhibition of autophagy was reversed by treatment with an autophagy inducer rapamycin (RAP, which also attenuated the neuroprotective effect of TAT-14-3-3ε. Conversely, autophagy inhibitor 3-methyladenine (3-MA inhibited I/R-induced the increase in autophagic activity, and attenuated I/R-induced brain infarct. These results suggest that TAT-14-3-3ε can be efficiently transduced into brain and exert significantly protective effect against brain ischemic injury through inhibiting neuronal apoptosis and autophagic

Hexokinase cellular trafficking in ischemia-reperfusion and ischemic preconditioning is altered in type I diabetic heart

NARCIS (Netherlands)

Gurel, Ebru; Ustunova, Savas; Kapucu, Aysegul; Yilmazer, Nadim; Eerbeek, Otto; Nederlof, Rianne; Hollmann, Markus W.; Demirci-Tansel, Cihan; Zuurbier, Coert J.

2013-01-01

Diabetes mellitus (DM) has been reported to alter the cardiac response to ischemia-reperfusion (IR). In addition, cardioprotection induced by ischemic preconditioning (IPC) is often impaired in diabetes. We have previously shown that the subcellular localisation of the glycolytic enzyme hexokinase

Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

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Vaez, Haleh; Samadzadeh, Mehrban; Zahednezhad, Fahimeh; Najafi, Moslem

2012-01-01

Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H) solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2%) for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (Phoney. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2%) markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (Phoney in global ischemia showed protective effects against ischemia/reperfusion (I/R) injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects. PMID:24312792

The possible protective effects of dipyridamole on ischemic reperfusion injury of priapism

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Ersagun Karaguzel

2016-02-01

Full Text Available ABSTRACT Purpose To investigate the protective effects against ischemia reperfusion injury of dipyridamole in a model of induced priapism in rats. Materials and Methods Twenty-four male Sprague-Dawley rats were divided into four groups, control, P/R, P/R+DMSO and P/R+D. 3ml blood specimens were collected from vena cava inferior in order to determine serum MDA, IMA, TAS, TOS and OSI values, and penile tissue was taken for histopathological examination in control group. Priapism was induced in P/R group. After 1h, priapism was concluded and 30 min reperfusion was performed. In P/R+DMSO group 1ml/kg DMSO was administered intraperitoneally 30 min before reperfusion, while in P/R+D group 10mg/kg dipyridamole was administered intraperitoneally 30 min before reperfusion. Blood and penis specimens were collected after the end of 30 min reperfusion period. Sinusoidal area (µm2, tears in tunica albuginea and injury parameters in sinusoidal endothelium of penis were investigated. Results Histopathological examination revealed no significant changes in term of sinusoidal area. A decrease in tears was observed in P/R+D group compared to P/R group (p0.05. There were no significant differences in MDA and IMA values between groups. A significant increase in TOS and OSI values was observed in P/R+D group compared to P/R group. A significant decrease in TAS levels was observed in P/R+D group compared to the P/R group. Conclusions The administration of dipyridamole before reperfusion in ischemic priapism model has a potential protective effect against histopathological injury of the penis.

Polyol pathway and modulation of ischemia-reperfusion injury in Type 2 diabetic BBZ rat hearts

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Guberski Dennis

2008-10-01

Full Text Available Abstract We investigated the role of polyol pathway enzymes aldose reductase (AR and sorbitol dehydrogenase (SDH in mediating injury due to ischemia-reperfusion (IR in Type 2 diabetic BBZ rat hearts. Specifically, we investigated, (a changes in glucose flux via cardiac AR and SDH as a function of diabetes duration, (b ischemic injury and function after IR, (c the effect of inhibition of AR or SDH on ischemic injury and function. Hearts isolated from BBZ rats, after 12 weeks or 48 weeks diabetes duration, and their non-diabetic littermates, were subjected to IR protocol. Myocardial function, substrate flux via AR and SDH, and tissue lactate:pyruvate (L/P ratio (a measure of cytosolic NADH/NAD+, and lactate dehydrogenase (LDH release (a marker of IR injury were measured. Zopolrestat, and CP-470,711 were used to inhibit AR and SDH, respectively. Myocardial sorbitol and fructose content, and associated changes in L/P ratios were significantly higher in BBZ rats compared to non-diabetics, and increased with disease duration. Induction of IR resulted in increased ischemic injury, reduced ATP levels, increases in L/P ratio, and poor cardiac function in BBZ rat hearts, while inhibition of AR or SDH attenuated these changes and protected hearts from IR injury. These data indicate that AR and SDH are key modulators of myocardial IR injury in BBZ rat hearts and that inhibition of polyol pathway could in principle be used as a therapeutic adjunct for protection of ischemic myocardium in Type 2 diabetic patients.

Huperzine A attenuates hepatic ischemia reperfusion injury via anti-oxidative and anti-apoptotic pathways.

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Xu, Zhe; Wang, Yang

2014-08-01

Hepatic ischemia reperfusion (HI/R) injury may occur during liver transplantation and remains a serious concern in clinical practice. Huperzine A (HupA), an alkaloid isolated from the Chinese traditional medicine Huperzia serrata, has been demonstrated to possess anti‑oxidative and anti‑apoptotic properties. In the present study, a rat model of HI/R was established by clamping the hepatic artery, the hepatoportal vein and the bile duct with a vascular clamp for 30 min followed by reperfusion for 6 h under anesthesia. HupA was injected into the tail vein 5 min prior to the induction of HI/R at doses of 167 and 500 µg/kg. The histopathological assessment of the liver was performed using hematoxylin and eosin staining. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assayed in the serum samples. The tissue levels of superoxide dismutase (SOD), catalase (CAT), malondiadehyde (MDA) and glutathione (GSH) were also measured spectrophotometrically. Furthermore, the protein expression of caspase‑3, Bcl‑2 and Bax in hepatic tissues was detected via western blot analysis. Treatment of Wistar rats with HupA at doses of 167 and 500 µg/kg markedly attenuated HI/R injury as observed histologically. In addition, the significant reductions of serum ALT and AST were observed in HupA‑treated ischemic rats. Furthermore, HupA treatment enhanced the activity of hepatic tissue SOD, CAT and GSH, but decreased the MDA tissue content. Western blot analysis revealed elevated levels of Bcl‑2 expression but decreased Bax and caspase‑3 tissue expression at the protein level in the HupA‑treated group. The present data suggest that HupA attenuates the HI/R injury of rats through its anti‑oxidative and anti‑apoptotic signaling pathways.

Lebetin 2, a Snake Venom-Derived Natriuretic Peptide, Attenuates Acute Myocardial Ischemic Injury through the Modulation of Mitochondrial Permeability Transition Pore at the Time of Reperfusion.

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Bochra Tourki

Full Text Available Cardiac ischemia is one of the leading causes of death worldwide. It is now well established that natriuretic peptides can attenuate the development of irreversible ischemic injury during myocardial infarction. Lebetin 2 (L2 is a new discovered peptide isolated from Macrovipera lebetina venom with structural similarity to B-type natriuretic peptide (BNP. Our objectives were to define the acute cardioprotective actions of L2 in isolated Langendorff-perfused rat hearts after regional or global ischemia-reperfusion (IR. We studied infarct size, left ventricular contractile recovery, survival protein kinases and mitochondrial permeability transition pore (mPTP opening in injured myocardium. L2 dosage was determined by preliminary experiments at its ability to induce cyclic guanosine monophosphate (cGMP release without changing hemodynamic effects in normoxic hearts. L2 was found to be as effective as BNP in reducing infarct size after the induction of either regional or global IR. Both peptides equally improved contractile recovery after regional IR, but only L2 increased coronary flow and reduced severe contractile dysfunction after global ischemia. Cardioprotection afforded by L2 was abolished after isatin or 5-hydroxydecanote pretreatment suggesting the involvement of natriuretic peptide receptors and mitochondrial KATP (mitoKATP channels in the L2-induced effects. L2 also increased survival protein expression in the reperfused myocardium as evidenced by phosphorylation of signaling pathways PKCε/ERK/GSK3β and PI3K/Akt/eNOS. IR induced mitochondrial pore opening, but this effect was markedly prevented by L2 treatment. These data show that L2 has strong cardioprotective effect in acute ischemia through stimulation of natriuretic peptide receptors. These beneficial effects are mediated, at least in part, by mitoKATP channel opening and downstream activated survival kinases, thus delaying mPTP opening and improving IR-induced mitochondrial

Arctigenin attenuates ischemic stroke via SIRT1-dependent inhibition of NLRP3 inflammasome.

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Zhang, Shimeng; Jiang, Liangjun; Che, Fengyuan; Lu, Yucheng; Xie, Zhongxiang; Wang, Hao

2017-11-04

Arctigenin (ARC), a phenylpropanoid dibenzylbutyrolactone lignan derived from Arctium lappa L, has been reported to protect against cerebral ischemia injury in rats, but the underlying mechanism is unclear. In this study, we investigated whether ARC ameliorated ischemic stroke by inhibiting NLRP3 inflammasome-derived neuroinflammation and whether SIRT1 signaling was involved in this process. ARC (20 mg/kg) or vehicle were intraperitoneally injected to Sprague-Dawley rats for 3 days before middle cerebral artery occlusion (MCAO) surgery performed. The infarct volume, neurological score, brain water content, neuroinflammation, NLRP3 inflammasome activation and SIRT1 protein expression were assessed. Furthermore, we also investigated whether ARC protected against cerebral ischemia via SIRT1-dependent inhibition of NLRP3 inflammasome by administrating EX527, a specific SIRT1 inhibitor, under oxygen-glucose deprivation (OGD) condition. We found that ARC pretreatment decreased infarct volume, neurological score and brain water content. Moreover, ARC treatment effectively inhibited cerebral ischemia induced NLRP3 inflammasome activation and IL-1β, IL-18 secretion both in vivo and in vitro. Futhermore, ARC treatment activated Silent information regulator 1 (SIRT1) singnaling in the brain. Importantly, suppress of SIRT1 reversed the inhibitory effect of ARC on NLRP3 inflammasome activation. Taken together our results demonstrated that ARC may confer protection against ischemic stroke by inhibiting NLRP3 inflammasome activation. The activation of SIRT1 signaling pathway may contribute to the neuroprotection of ARC in MCAO. Copyright © 2017 Elsevier Inc. All rights reserved.

Investigation of the role of non-selective calcium channel blocker (flunarizine) on cerebral ischemic-reperfusion associated cognitive dysfunction in aged mice.

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Gulati, Puja; Muthuraman, Arunachalam; Kaur, Parneet

2015-04-01

The present study was designed to investigate the role of flunarizine (a non-selective calcium channel blocker) on cerebral ischemic-reperfusion associated cognitive dysfunction in aged mice. Bilateral carotid artery occlusion of 12min followed by reperfusion for 24h was given to induce cerebral injury in male Swiss mice. The assessment of learning & memory was performed by Morris water maze test; motor in-coordination was evaluated by rota rod, lateral push and inclined beam walking tests; cerebral infarct size was quantified by triphenyltetrazolium chloride staining. In addition, reduced glutathione (GSH), total calcium and acetylcholinesterase (AChE) activity were also estimated in aged brain tissue. Donepezil treated group served as a positive control in this study. Ischemia reperfusion (I/R) injury produced significant increase in cerebral infarct size. A significant loss of memory along with impairment of motor performance was also noted. Further, I/R injury also produced significant increase in levels of total calcium, AChE activity and decrease in GSH levels. Pretreatment of flunarizine significantly attenuated I/R induced infarct size, behavioral and biochemical changes. Hence, it may be concluded that, a non-selective calcium channel blocker can be useful in I/R associated cognitive dysfunction due to its anti-oxidant, anti-infarct and modulatory actions of neurotransmitters & calcium channels. Copyright © 2015 Elsevier Inc. All rights reserved.

Neuroprotective effect of curcumin on spinal cord in rabbit model with ischemia/reperfusion.

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Liu, Zhi-Qiang; Xing, Shan-Shan; Zhang, Wei

2013-03-01

Ischemic/reperfusion (I/R) injury of the spinal cord is a serious complication that can result from thoracoabdominal aortic surgery. To investigate the neuroprotective effect of curcumin against I/R injury in a rabbit model. A total of 36 rabbits were randomly divided into three groups: sham, I/R, and curcumin-treated group. Rabbits were subject to 30-min aortic occlusion to induce transient spinal cord ischemia. Neurological function was observed after reperfusion and spinal cord segment (L3-L5) was collected for histopathological evaluation. Malondialdehyde (MDA) and total superoxide dismutase (SOD) activity were also assayed. Rabbits in I/R group were induced to paraplegia. While after 48-hour treatment, compared with I/R group, curcumin significantly improved neurological function, reduced cell apoptosis and MDA levels as well as increased SOD activity (P curcumin, at least in an animal model, can attenuate transient spinal cord ischemic injury potentially via reducing oxidative damage, which may provide a novel approach in the treatment of spinal cord ischemic injury.

Electroacupuncture ameliorates post-stroke learning and memory through minimizing ultrastructural brain damage and inhibiting the expression of MMP-2 and MMP-9 in cerebral ischemia-reperfusion injured rats.

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Lin, Ruhui; Yu, Kunqiang; Li, Xiaojie; Tao, Jing; Lin, Yukun; Zhao, Congkuai; Li, Chunyan; Chen, Li-Dian

2016-07-01

The aim of the present study was to investigate the potential neuroprotective effects of electroacupuncture (EA) in the treatment of cerebral ischemia/reperfusion (I/R) injury, and to elucidate the association between this neuroprotective effect and brain ultrastructure and expression of matrix metalloproteinase (MMP)‑2 and 9. Rats underwent focal cerebral I/R injury by arterial ligation and received in vivo therapeutic EA at the Baihui (DU20) and Shenting (DU24) acupoints. The therapeutic efficacy was then evaluated following the surgery. The results of the current study demonstrated that EA treatment significantly ameliorated neurological deficits and reduced cerebral infarct volume compared with I/R injured rats. Furthermore, EA improved the learning and memory ability of rats following I/R injury, inhibited blood brain barrier breakdown and reduced neuronal damage in the ischemic penumbra. Furthermore, EA attenuated ultrastructural changes in the brain tissue following ischemia and inhibited MMP‑2/MMP‑9 expression in cerebral I/R injured rats. The results suggest that EA ameliorates anatomical deterioration, and learning and memory deficits in rats with cerebral I/R injury.

Dexrazoxane Shows No Protective Effect in the Acute Phase of Reperfusion during Myocardial Infarction in Pigs.

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Kamat, Pranitha; Vandenberghe, Stijn; Christen, Stephan; Bongoni, Anjan K; Meier, Bernhard; Rieben, Robert; Khattab, Ahmed A

2016-01-01

Calcium and iron overload participate in the mechanisms of ischemia/reperfusion (I/R) injury during myocardial infarction (MI). Calcium overload induces cardiomyocyte death by hypercontraction, while iron catalyses generation of reactive oxygen species (ROS). We therefore hypothesized that dexrazoxane, an intracellular metal chelator, would attenuate I/R injury. MI was induced in pigs by occlusion of the left anterior descending artery for 1 hour followed by 2 hours reperfusion. Thirty minutes before reperfusion either 5 mg/ml dexrazoxane (n = 5) or saline (n = 5) was infused intravenously. Myocardial necrosis as percentage of the area at ischemic risk was found to be similar in both groups (77.2 ± 18% for dexrazoxane and 76.4 ± 14% for saline group) as determined by triphenyl tetrazolium chloride staining of the ischemic myocardium. Also, serum levels of troponin-I were similar in both groups. A conductance catheter was used to measure left ventricular pressure and volume at all times. Markers for tissue damage due to ROS (HNE), endothelial cell activation (CD31) and inflammation (IgG, C3b/c, C5b9, MCP-1) were assessed on tissue and/or in serum. No significant differences were observed between the groups for the parameters analyzed. To conclude, in this clinically relevant model of early reperfusion after acute myocardial ischemia, dexrazoxane lacked attenuating effects on I/R injury as shown by the measured parameters.

Aquaporin-4 inhibition mediates piroxicam-induced neuroprotection against focal cerebral ischemia/reperfusion injury in rodents.

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Bhattacharya, Pallab; Pandey, Anand Kumar; Paul, Sudip; Patnaik, Ranjana; Yavagal, Dileep R

2013-01-01

Aquaporin-4(AQP4) is an abundant water channel protein in brain that regulates water transport to maintain homeostasis. Cerebral edema resulting from AQP4 over expression is considered to be one of the major determinants for progressive neuronal insult during cerebral ischemia. Although, both upregulation and downregulation of AQP4 expression is associated with brain pathology, over expression of AQP4 is one of the chief contributors of water imbalance in brain during ischemic pathology. We have found that Piroxicam binds to AQP4 with optimal binding energy value. Thus, we hypothesized that Piroxicam is neuroprotective in the rodent cerebral ischemic model by mitigating cerebral edema via AQP4 regulation. Rats were treated with Piroxicam OR placebo at 30 min prior, 2 h post and 4 h post 60 minutes of MCAO followed by 24 hour reperfusion. Rats were evaluated for neurological deficits and motor function just before sacrifice. Brains were harvested for infarct size estimation, water content measurement, biochemical analysis, RT-PCR and western blot experiments. Piroxicam pretreatment thirty minutes prior to ischemia and four hour post reperfusion afforded neuroprotection as evident through significant reduction in cerebral infarct volume, improvement in motor behavior, neurological deficit and reduction in brain edema. Furthermore, ischemia induced surge in levels of nitrite and malondialdehyde were also found to be significantly reduced in ischemic brain regions in treated animals. This neuroprotection was found to be associated with inhibition of acid mediated rise in intracellular calcium levels and also downregulated AQP4 expression. Findings of the present study provide significant evidence that Piroxicam acts as a potent AQP4 regulator and renders neuroprotection in focal cerebral ischemia. Piroxicam could be clinically exploited for the treatment of brain stroke along with other anti-stroke therapeutics in future.

Inhibition of miR-15 Protects Against Cardiac Ischemic Injury

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Hullinger, Thomas G.; Montgomery, Rusty L.; Seto, Anita G.; Dickinson, Brent A.; Semus, Hillary M.; Lynch, Joshua M.; Dalby, Christina M.; Robinson, Kathryn; Stack, Christianna; Latimer, Paul A.; Hare, Joshua M.; Olson, Eric N.; van Rooij, Eva

2012-01-01

Rationale Myocardial infarction (MI) is a leading cause of death worldwide. Because endogenous cardiac repair mechanisms are not sufficient for meaningful tissue regeneration, MI results in loss of cardiac tissue and detrimental remodeling events. MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression in a sequence dependent manner. Our previous data indicate that miRNAs are dysregulated in response to ischemic injury of the heart and actively contribute to cardiac remodeling after MI. Objective This study was designed to determine whether miRNAs are dysregulated on ischemic damage in porcine cardiac tissues and whether locked nucleic acid (LNA)-modified anti-miR chemistries can target cardiac expressed miRNAs to therapeutically inhibit miR-15 on ischemic injury. Methods and Results Our data indicate that the miR-15 family, which includes 6 closely related miRNAs, is regulated in the infarcted region of the heart in response to ischemia-reperfusion injury in mice and pigs. LNA-modified chemistries can effectively silence miR-15 family members in vitro and render cardiomyocytes resistant to hypoxia-induced cardiomyocyte cell death. Correspondingly, systemic delivery of miR-15 anti-miRs dose-dependently represses miR-15 in cardiac tissue of both mice and pigs, whereas therapeutic targeting of miR-15 in mice reduces infarct size and cardiac remodeling and enhances cardiac function in response to MI. Conclusions Oligonucleotide-based therapies using LNA-modified chemistries for modulating cardiac miRNAs in the setting of heart disease are efficacious and validate miR-15 as a potential therapeutic target for the manipulation of cardiac remodeling and function in the setting of ischemic injury. PMID:22052914

Effects of calcium antagonist and free radical scavengers on ischemic and reperfused myocardium due to acute occlusion of coronary arteries

International Nuclear Information System (INIS)

Ohsuzu, Fumitaka; Sakata, Nobuhiro; Yanagida, Shigeki

1988-01-01

The Langendorff perfused rat heart was used to investigate whether ischemic and reperfused injury could be protected by anti-free radical intervention alone or combined treatment with calcium antagonist. Hearts were subjected to 10 min. of aerobic perfusion with Krebs-Henseleit solution (K-H) and then randomized into three groups (GP): Control group received only K-H, FRS group K-H with superoxide dismutase (24 IU/ml) and catalase (22 IU/ml) and Combined group the same solution of FRS group with verapamil (10'-'7M) for 10 min; and three groups were subjected to 20 min. of global ischemia; and each group was reperfused by the prior perfusate for 20 min. LV developed pressure (DP) and heart rate (HR) were measured by an intraventricular baloon. Phosphorus-31 NMR spectroscopy allowed continuous monitoring of myocardial phosphocreatine (PCr), inorganic phosphate (Pi) and β-ATP content. Each group consisted of 5 experiments. PCr in Combined group was significantly higher than that of Control group with significantly higher values of DP and DPxHR compared to Combined group in the early phase of ischemia. By the middle phase of reperfusion, significant reduction in Pi was found only in Combined group with the reduction of HR. However, no significant difference of β-ATP was found between Control group and Combined group through ischemia and reperfusion. These results suggest that free radical scavengers alone could not protect ischemic and reperfused myocardium from injury, but that the reduction of oxygen consumption by verapamil might be predominantly effective in preventing myocardial damage partially from ischemia and reperfusion. (author)

Peculiarities of reaction of HIF-1α protein of the hippocampus neurons in rats with experimental diabetes mellitus in the dynamics of ischemic-reperfusion damage of the brain

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T. M. Boychuk

2016-12-01

Higher State Educational Establishment of Ukraine “Bukovinian State medical University”, Chernivtsi, Ukraine   Abstract Introduction. The role of the transcriptional factor Hif-1α in pathogenesis of hypoxic damages and diabetes mellitus (DM is proved, although molecular mechanisms underlying the basis of this factor dysfunction in association with DM with ischemic-reperfusion damage of the brain remain unknown. Objective. The objective of this investigation was to study the content of Hif-1α protein in the hippocampus neurons of rats with experimental DM in the dynamics of ischemic-reperfusion damage of the brain. Results. In rats without DM 20 minute ischemia with one hour reperfusion increases the content of Hif-1α protein in all the fields of the hippocampus. On the 12th day of ischemic-reperfusion period in the hippocampus CA2-CA4 fields the values of certain examined indices of the activity of Hif-1α transcriptional factor continue to increase, and in СА1field they normalize or approach to the values of animals in the control group.  In rats with DM during early post-ischemic period there are no changes of Hif-1α protein content in CA1 field, in CA2 field there are signs of its reduced activity, in CA3 field they are limited by the reaction of one index, in CA4 field they are of a similar character with those of the control rats under experimental conditions.  On the 12th day of ischemic-reperfusion period in CA1 field all the indices of activity of Hif-1α transcriptional factor increase exceeding corresponding indices by absolute values in animals of the control group under the same experimental conditions, in СА2 and СА3 fields changes of the examined parameters are limited as compared to the same ones in animals from the control group, in CA4 field values that were increased in the control group decrease. Conclusions. Diabetes mellitus restricts reaction of Hif-1α protein on ischemia-reperfusion inn the neurons of СА1-СА3 fields in

Accumulation of polymorphonuclear leukocytes in reperfused ischemic canine myocardium: relation with tissue viability assessed by fluorine-18-2-deoxyglucose uptake

International Nuclear Information System (INIS)

Wijns, W.; Melin, J.A.; Leners, N.

1988-01-01

Polymorphonuclear leukocytes may participate in reperfusion injury. Whether leukocytes affect viable or only irreversibly injured tissue is not known. Therefore, we assessed the accumulation of 111In-labeled leukocytes in tissue samples characterized as either ischemic but viable or necrotic by metabolic, histochemical, and ultrastructural criteria. Six open-chest dogs received left anterior descending coronary occlusion for 2 hr followed by 4 hr reperfusion. Myocardial blood flow was determined by microspheres and autologous 111In-labeled leukocytes were injected intravenously. Fluorine-18-2-deoxyglucose, a tracer of exogenous glucose utilization, was injected 3 hr after reperfusion. The dogs were killed 4 hr after reperfusion. The risk and the necrotic regions were assessed following in vivo dye injection and postmortem tetrazolium staining. Myocardial samples were obtained in the ischemic but viable, necrotic and normal zones, and counted for 111In and 18F activity. Compared to normal, leukocytes were entrapped in necrotic regions (111In activity: 207 +/- 73%) where glucose uptake was decreased (26 +/- 15%). A persistent glucose uptake, marker of viability, was mainly seen in risk region (135 +/- 85%) where leukocytes accumulation was moderate in comparison to normal zone (146 +/- 44%). Thus, the glucose uptake observed in viable tissue is mainly related to myocytes metabolism and not to leukocytes metabolism

The Potential of Tetrandrine as a Protective Agent for Ischemic Stroke

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Sheng-Hong Tseng

2011-09-01

Full Text Available Stroke is one of the leading causes of mortality, with a high incidence of severe morbidity in survivors. The treatment to minimize tissue injury after stroke is still unsatisfactory and it is mandatory to develop effective treatment strategies for stroke. The pathophysiology of ischemic stroke is complex and involves many processes including energy failure, loss of ion homeostasis, increased intracellular calcium level, platelet aggregation, production of reactive oxygen species, disruption of blood brain barrier, and inflammation and leukocyte infiltration, etc. Tetrandrine, a bisbenzylisoquinoline alkaloid, has many pharmacologic effects including anti-inflammatory and cytoprotective effects. In addition, tetrandrine has been found to protect the liver, heart, small bowel and brain from ischemia/reperfusion injury. It is a calcium channel blocker, and can inhibit lipid peroxidation, reduce generation of reactive oxygen species, suppress the production of cytokines and inflammatory mediators, inhibit neutrophil recruitment and platelet aggregation, which are all devastating factors during ischemia/reperfusion injury of the brain. Because tetrandrine can counteract these important pathophysiological processes of ischemic stroke, it has the potential to be a protective agent for ischemic stroke.

Dexrazoxane Shows No Protective Effect in the Acute Phase of Reperfusion during Myocardial Infarction in Pigs.

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Pranitha Kamat

Full Text Available Calcium and iron overload participate in the mechanisms of ischemia/reperfusion (I/R injury during myocardial infarction (MI. Calcium overload induces cardiomyocyte death by hypercontraction, while iron catalyses generation of reactive oxygen species (ROS. We therefore hypothesized that dexrazoxane, an intracellular metal chelator, would attenuate I/R injury. MI was induced in pigs by occlusion of the left anterior descending artery for 1 hour followed by 2 hours reperfusion. Thirty minutes before reperfusion either 5 mg/ml dexrazoxane (n = 5 or saline (n = 5 was infused intravenously. Myocardial necrosis as percentage of the area at ischemic risk was found to be similar in both groups (77.2 ± 18% for dexrazoxane and 76.4 ± 14% for saline group as determined by triphenyl tetrazolium chloride staining of the ischemic myocardium. Also, serum levels of troponin-I were similar in both groups. A conductance catheter was used to measure left ventricular pressure and volume at all times. Markers for tissue damage due to ROS (HNE, endothelial cell activation (CD31 and inflammation (IgG, C3b/c, C5b9, MCP-1 were assessed on tissue and/or in serum. No significant differences were observed between the groups for the parameters analyzed. To conclude, in this clinically relevant model of early reperfusion after acute myocardial ischemia, dexrazoxane lacked attenuating effects on I/R injury as shown by the measured parameters.

Transcranial diffuse optical assessment of the microvascular reperfusion after thrombolysis for acute ischemic stroke.

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Delgado-Mederos, Raquel; Gregori-Pla, Clara; Zirak, Peyman; Blanco, Igor; Dinia, Lavinia; Marín, Rebeca; Durduran, Turgut; Martí-Fàbregas, Joan

2018-03-01

In this pilot study, we have evaluated bedside diffuse optical monitoring combining diffuse correlation spectroscopy and near-infrared diffuse optical spectroscopy to assess the effect of thrombolysis with an intravenous recombinant tissue plasminogen activator (rtPA) on cerebral hemodynamics in an acute ischemic stroke. Frontal lobes of five patients with an acute middle cerebral artery occlusion were measured bilaterally during rtPA treatment. Both ipsilesional and contralesional hemispheres showed significant increases in cerebral blood flow, total hemoglobin concentration and oxy-hemoglobin concentration during the first 2.5 hours after rtPA bolus. The increases were faster and higher in the ipsilesional hemisphere. The results show that bedside optical monitoring can detect the effect of reperfusion therapy for ischemic stroke in real-time.

Impaired cardiac ischemic tolerance in spontaneously hypertensive rats is attenuated by adaptation to chronic and acute stress.

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Ravingerová, T; Bernátová, I; Matejíková, J; Ledvényiová, V; Nemčeková, M; Pecháňová, O; Tribulová, N; Slezák, J

2011-01-01

Chronic hypertension may have a negative impact on the myocardial response to ischemia. On the other hand, intrinsic ischemic tolerance may persist even in the pathologically altered hearts of hypertensive animals, and may be modified by short- or long-term adaptation to different stressful conditions. The effects of long-term limitation of living space (ie, crowding stress [CS]) and brief ischemia-induced stress on cardiac response to ischemia/reperfusion (I/R) injury are not yet fully characterized in hypertensive subjects. The present study was designed to test the influence of chronic and acute stress on the myocardial response to I/R in spontaneously hypertensive rats (SHR) compared with their effects in normotensive counterparts. In both groups, chronic, eight-week CS was induced by caging five rats per cage in cages designed for two rats (200 cm(2)/rat), while controls (C) were housed four to a cage in cages designed for six animals (480 cm(2)/rat). Acute stress was evoked by one cycle of I/R (5 min each, ischemic preconditioning) before sustained I/R in isolated Langendorff-perfused hearts of normotensive and SHR rats. At baseline conditions, the effects of CS were manifested only as a further increase in blood pressure in SHR, and by marked limitation of coronary perfusion in normotensive animals, while no changes in heart mechanical function were observed in any of the groups. Postischemic recovery of contractile function, severity of ventricular arrhythmias and lethal injury (infarction size) were worsened in the hypertrophied hearts of C-SHR compared with normotensive C. However, myo-cardial stunning and reperfusion-induced ventricular arrhythmias were attenuated by CS in SHR, which was different from deterioration of I/R injury in the hearts of normotensive animals. In contrast, ischemic preconditioning conferred an effective protection against I/R in both groups, although the extent of anti-infarct and anti-arrhythmic effects was lower in SHR. Both

Nicotinamide mononucleotide inhibits post-ischemic NAD(+) degradation and dramatically ameliorates brain damage following global cerebral ischemia.

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Park, Ji H; Long, Aaron; Owens, Katrina; Kristian, Tibor

2016-11-01

Nicotinamide adenine dinucleotide (NAD(+)) is an essential cofactor for multiple cellular metabolic reactions and has a central role in energy production. Brain ischemia depletes NAD(+) pools leading to bioenergetics failure and cell death. Nicotinamide mononucleotide (NMN) is utilized by the NAD(+) salvage pathway enzyme, nicotinamide adenylyltransferase (Nmnat) to generate NAD(+). Therefore, we examined whether NMN could protect against ischemic brain damage. Mice were subjected to transient forebrain ischemia and treated with NMN or vehicle at the start of reperfusion or 30min after the ischemic insult. At 2, 4, and 24h of recovery, the proteins poly-ADP-ribosylation (PAR), hippocampal NAD(+) levels, and expression levels of NAD(+) salvage pathway enzymes were determined. Furthermore, animal's neurologic outcome and hippocampal CA1 neuronal death was assessed after six days of reperfusion. NMN (62.5mg/kg) dramatically ameliorated the hippocampal CA1 injury and significantly improved the neurological outcome. Additionally, the post-ischemic NMN treatment prevented the increase in PAR formation and NAD(+) catabolism. Since the NMN administration did not affect animal's temperature, blood gases or regional cerebral blood flow during recovery, the protective effect was not a result of altered reperfusion conditions. These data suggest that administration of NMN at a proper dosage has a strong protective effect against ischemic brain injury. Published by Elsevier Inc.

Neuroprotective Effects of Psalmotoxin-1, an Acid-Sensing Ion Channel (ASIC) Inhibitor, in Ischemia Reperfusion in Mouse Eyes.

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Dibas, Adnan; Millar, Cameron; Al-Farra, Abraham; Yorio, Thomas

2018-03-29

The purpose of the current study is to assess changes in the expression of Acid-Sensing Ion Channel (ASIC)1a and ASIC2 in retinal ganglion cells (RGCs) after retinal ischemia and reperfusion (I/R) injury and to test if inhibition of ASIC1a provides RGC neuroprotection. Transient ischemia was induced in one eye of C57BL/6 mice by raising intraocular pressure to 120 mmHg for 60 min followed by retinal reperfusion by restoring normal pressure. RGC function was measured by Pattern electroretinography (PERG). In addition, retinal ASIC1a and ASIC2 were observed by immunohistochemistry and western blot. Changes in calpain, fodrin, heat shock protein 70 (HSP70), Brn3a, super oxide dismutase-1 (SOD1), catalase, and glutathione perioxidase-4 (GPX4) protein levels were assessed by western blot. RGC numbers were measured by immunohistochemistry on whole retinal flat mounts using anti-RNA binding protein with multiple splicing (RBPMS) antibodies. Intravitreal injection of psalmotoxin-1, a selective ASIC1a blocker, was used to assess the neuroprotective effect of ASIC1a inhibition. Levels of ASIC1a and ASIC2 after I/R increased in RGCs. Upregulation of ASIC1a but not ASIC2 was attenuated by intravitreal injection of psalmotoxin-1. I/R induced activation of calpain and degradation of fodrin, HSP70, and reduction in Brn3a. In contrast, while psalmotoxin-1 attenuated calpain activation and increased Brn3a levels, it failed to block HSP70 degradation. Unlike SOD1 protein which was reduced, catalase protein levels increased after I/R. Psalmotoxin-1, although not affecting SOD1 and GPX4, increased catalase levels significantly. Psalmotoxin-1 also increased RBPMS-labeled RGCs following I/R as judged by immunohistochemistry of retinal flat mounts. Finally, psalmotoxin-1 enhanced the amplitude of PERG following I/R, suggesting partial rescue of RGC function. Psalmotoxin-1 appears to exert a neuroprotective effect under ischemic insults and targeting inhibition of ASICs may represent a

Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

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Haleh Vaez

2012-08-01

Full Text Available Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13. The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2% for 15 min and was resumed until the end of 120 min with normal K/H solution. Results: In the control group, VEBs number was 784±199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83±23 (P<0.001, 138±48 (P<0.01, 142±37 (P<0.001 and 157±40 (P<0.01, respectively. Number and duration of VT and time spent in reversible VF were also reduced by honey. In the control group, the infarct size was 54.1±7.8%, however; honey (0.25, 0.5, 1 and 2% markedly lowered the value to 12.4±2.4, 12.7±3.3, 11.3±2.6 and 7.9±1.7 (P<0.001, respectively. Conclusion: Postischemic administration of natural honey in global ischemia showed protective effects against ischemia/reperfusion (I/R injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects.

Activated protein C attenuates acute ischaemia reperfusion injury in skeletal muscle.

LENUS (Irish Health Repository)

Dillon, J P

2012-02-03

Activated protein C (APC) is an endogenous anti-coagulant with anti-inflammatory properties. The purpose of the present study was to evaluate the effects of activated protein C in the setting of skeletal muscle ischaemia reperfusion injury (IRI). IRI was induced in rats by applying rubber bands above the levels of the greater trochanters bilaterally for a period of 2h followed by 12h reperfusion. Treatment groups received either equal volumes of normal saline or activated protein C prior to tourniquet release. Following 12h reperfusion, muscle function was assessed electrophysiologically by electrical field stimulation. The animals were then sacrificed and skeletal muscle harvested for evaluation. Activated protein C significantly attenuated skeletal muscle reperfusion injury as shown by reduced myeloperoxidase content, wet to dry ratio and electrical properties of skeletal muscle. Further in vitro work was carried out on neutrophils isolated from healthy volunteers to determine the direct effect of APC on neutrophil function. The effects of APC on TNF-alpha stimulated neutrophils were examined by measuring CD18 expression as well as reactive oxygen species generation. The in vitro work demonstrated a reduction in CD18 expression and reactive oxygen species generation. We conclude that activated protein C may have a protective role in the setting of skeletal muscle ischaemia reperfusion injury and that this is in part mediated by a direct inhibitory effect on neutrophil activation.

Curcumin inhibits neuronal and vascular degeneration in retina after ischemia and reperfusion injury.

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Leilei Wang

Full Text Available Neuron loss, glial activation and vascular degeneration are common sequelae of ischemia-reperfusion (I/R injury in ocular diseases. The present study was conducted to explore the ability of curcumin to inhibit retinal I/R injury, and to investigate underlying mechanisms of the drug effects.Different dosages of curcumin were administered. I/R injury was induced by elevating the intraocular pressure for 60 min followed by reperfusion. Cell bodies, brn3a stained cells and TUNEL positive apoptotic cells in the ganglion cell layer (GCL were quantitated, and the number of degenerate capillaries was assessed. The activation of glial cells was measured by the expression level of GFAP. Signaling pathways including IKK-IκBα, JAK-STAT1/3, ERK/MAPK and the expression levels of β-tubulin III and MCP-1 were measured by western blot analysis. Pre-treatment using 0.01%-0.25% curcumin in diets significantly inhibited I/R-induced cell loss in GCL. 0.05% curcumin pre-treatment inhibited I/R-induced degeneration of retinal capillaries, TUNEL-positive apoptotic cell death in the GCL, brn3a stained cell loss, the I/R-induced up-regulation of MCP-1, IKKα, p-IκBα and p-STAT3 (Tyr, and down-regulation of β-tubulin III. This dose showed no effect on injury-induced GFAP overexpression. Moreover, 0.05% curcumin administered 2 days after the injury also showed a vaso-protective effect.Curcumin protects retinal neurons and microvessels against I/R injury. The beneficial effects of curcumin on neurovascular degeneration may occur through its inhibitory effects on injury-induced activation of NF-κB and STAT3, and on over-expression of MCP-1. Curcumin may therefore serve as a promising candidate for retinal ischemic diseases.

Exogenous Gene Transmission of Isocitrate Dehydrogenase 2 Mimics Ischemic Preconditioning Protection.

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Kolb, Alexander L; Corridon, Peter R; Zhang, Shijun; Xu, Weimin; Witzmann, Frank A; Collett, Jason A; Rhodes, George J; Winfree, Seth; Bready, Devin; Pfeffenberger, Zechariah J; Pomerantz, Jeremy M; Hato, Takashi; Nagami, Glenn T; Molitoris, Bruce A; Basile, David P; Atkinson, Simon J; Bacallao, Robert L

2018-04-01

Ischemic preconditioning confers organ-wide protection against subsequent ischemic stress. A substantial body of evidence underscores the importance of mitochondria adaptation as a critical component of cell protection from ischemia. To identify changes in mitochondria protein expression in response to ischemic preconditioning, we isolated mitochondria from ischemic preconditioned kidneys and sham-treated kidneys as a basis for comparison. The proteomic screen identified highly upregulated proteins, including NADP+-dependent isocitrate dehydrogenase 2 (IDH2), and we confirmed the ability of this protein to confer cellular protection from injury in murine S3 proximal tubule cells subjected to hypoxia. To further evaluate the role of IDH2 in cell protection, we performed detailed analysis of the effects of Idh2 gene delivery on kidney susceptibility to ischemia-reperfusion injury. Gene delivery of IDH2 before injury attenuated the injury-induced rise in serum creatinine ( P <0.05) observed in controls and increased the mitochondria membrane potential ( P <0.05), maximal respiratory capacity ( P <0.05), and intracellular ATP levels ( P <0.05) above those in controls. This communication shows that gene delivery of Idh2 can confer organ-wide protection against subsequent ischemia-reperfusion injury and mimics ischemic preconditioning. Copyright © 2018 by the American Society of Nephrology.

The pathways by which mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury

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Chun Luo

2015-01-01

Full Text Available Several studies have demonstrated that mild hypothermia exhibits a neuroprotective role and it can inhibit endothelial cell apoptosis following ischemia/reperfusion injury by decreasing casp-ase-3 expression. It is hypothesized that mild hypothermia exhibits neuroprotective effects on neurons exposed to ischemia/reperfusion condition produced by oxygen-glucose deprivation. Mild hypothermia significantly reduced the number of apoptotic neurons, decreased the expression of pro-apoptotic protein Bax and increased mitochondrial membrane potential, with the peak of anti-apoptotic effect appearing between 6 and 12 hours after the injury. These findings indicate that mild hypothermia inhibits neuronal apoptosis following ischemia/reperfusion injury by protecting the mitochondria and that the effective time window is 6-12 hours after ischemia/reperfusion injury

Ligustrazine monomer against cerebral ischemia-reperfusion injury

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Hai-jun Gao

2015-01-01

Full Text Available Ligustrazine (2,3,5,6-tetramethylpyrazine is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mechanism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administration, and the most effective mode of administration for clinical treatment of cerebral ischemia/reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine administration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[(1,1-dimethylethyloxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC195 after cerebral ischemia were better than ligustrazine.

High plasma concentrations of asymmetric dimethylarginine inhibit ischemic cardioprotection in hypercholesterolemic rats

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Landim, M.B.P.; Dourado, P.M.M.; Casella-Filho, A.; Chagas, A.C.P.; Luz, P.L. da

2013-01-01

A low concentration of nitric oxide associated with a high concentration of asymmetric dimethylarginine (ADMA) can explain the lack of ischemic cardioprotection observed in the presence of hypercholesterolemia. The objective of the present study was to evaluate the effect of hypercholesterolemia on ischemic pre- and postconditioning and its correlation with plasma concentrations of ADMA. Male Wistar rats (6-8 weeks old) fed a 2% cholesterol diet (n = 21) for 8 weeks were compared to controls (n = 25) and were subjected to experimental myocardial infarction and reperfusion, with ischemic pre- and postconditioning. Total cholesterol and ADMA were measured in plasma before the experimental infarct and the infarct area was quantified. Weight, total cholesterol and plasma ADMA (means ± SE; 1.20 ± 0.06, 1.27 ± 0.08 and 1.20 ± 0.08 vs 0.97 ± 0.04, 0.93 ± 0.05 and 0.97 ± 0.04 µM) were higher in animals on the hypercholesterolemic diet than in controls, respectively. Cardioprotection did not reduce infarct size in the hypercholesterolemic animals (pre: 13.55% and post: 8% compared to 7.95% observed in the group subjected only to ischemia and reperfusion), whereas infarct size was reduced in the animals on a normocholesterolemic diet (pre: 8.25% and post: 6.10% compared to 12.31%). Hypercholesterolemia elevated ADMA and eliminated the cardioprotective effects of ischemic pre- and postconditioning in rats

High plasma concentrations of asymmetric dimethylarginine inhibit ischemic cardioprotection in hypercholesterolemic rats

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Landim, M.B.P.; Dourado, P.M.M.; Casella-Filho, A.; Chagas, A.C.P.; Luz, P.L. da [Unidade de Aterosclerose, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

2013-05-10

A low concentration of nitric oxide associated with a high concentration of asymmetric dimethylarginine (ADMA) can explain the lack of ischemic cardioprotection observed in the presence of hypercholesterolemia. The objective of the present study was to evaluate the effect of hypercholesterolemia on ischemic pre- and postconditioning and its correlation with plasma concentrations of ADMA. Male Wistar rats (6-8 weeks old) fed a 2% cholesterol diet (n = 21) for 8 weeks were compared to controls (n = 25) and were subjected to experimental myocardial infarction and reperfusion, with ischemic pre- and postconditioning. Total cholesterol and ADMA were measured in plasma before the experimental infarct and the infarct area was quantified. Weight, total cholesterol and plasma ADMA (means ± SE; 1.20 ± 0.06, 1.27 ± 0.08 and 1.20 ± 0.08 vs 0.97 ± 0.04, 0.93 ± 0.05 and 0.97 ± 0.04 µM) were higher in animals on the hypercholesterolemic diet than in controls, respectively. Cardioprotection did not reduce infarct size in the hypercholesterolemic animals (pre: 13.55% and post: 8% compared to 7.95% observed in the group subjected only to ischemia and reperfusion), whereas infarct size was reduced in the animals on a normocholesterolemic diet (pre: 8.25% and post: 6.10% compared to 12.31%). Hypercholesterolemia elevated ADMA and eliminated the cardioprotective effects of ischemic pre- and postconditioning in rats.

The cardioprotective efficacy of TVP1022 against ischemia/reperfusion injury and cardiac remodeling in rats.

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Malka, Assaf; Ertracht, Offir; Bachner-Hinenzon, Noa; Reiter, Irina; Binah, Ofer

2016-12-01

Following acute myocardial infarction (MI), early and successful reperfusion is the most effective strategy for reducing infarct size and improving the clinical outcome. However, immediate restoration of blood flow to the ischemic zone results in myocardial damage, defined as "reperfusion-injury". Whereas we previously reported that TVP1022 (the S-isomer of rasagiline, FDA-approved anti-Parkinson drug) decreased infarct size 24 h post ischemia reperfusion (I/R) in rats, in this study we investigated the chronic cardioprotective efficacy of TVP1022 14 days post-I/R. To simulate the clinical settings of acute MI followed by reperfusion therapy, we employed a rat model of left anterior descending artery occlusion for 30 min followed by reperfusion and a follow-up for 14 days. TVP1022 was initially administered postocclusion-prereperfusion, followed by chronic daily administrations. Cardiac performance and remodeling were evaluated using customary and advanced echocardiographic methods, hemodynamic measurements by Millar Mikro-Tip ® catheter, and histopathological techniques. TVP1022 administration markedly decreased the remodeling process as illustrated by attenuation of left ventricular enlargement and cardiac hypertrophy (both at the whole heart and the cellular level). Furthermore, TVP1022 inhibited cardiac fibrosis and reduced ventricular BNP levels. Functionally, TVP1022 treatment preserved cardiac wall motion. Specifically, the echocardiographic and most of the direct hemodynamic measures were pronouncedly improved by TVP1022. Collectively, these findings indicate that TVP1022 provides prominent cardioprotection against I/R injury and post-MI remodeling in this I/R model.

Lipopolysaccharide preconditioning protects hepatocytes from ischemia/reperfusion injury (IRI through inhibiting ATF4-CHOP pathway in mice.

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Jianhua Rao

Full Text Available BACKGROUND: Low-dose lipopolysaccharide (LPS preconditioning-induced liver protection has been demonstrated during ischemia-reperfusion injury (IRI in several organs but has not been sufficiently elucidated underlying causal mechanism. This study investigated the role of low-dose LPS preconditioning on ATF4-CHOP pathway as well as the effects of the pathway on tissue injury and inflammation in a mouse model of liver partial-warm IRI. METHODS: LPS (100 µg/kg/d was injected intraperitoneally two days before ischemia. Hepatic injury was evaluated based on serum alanine aminotransferase levels, histopathology, and caspase-3 activity. The ATF4-CHOP pathway and its related apoptotic molecules were investigated after reperfusion. The role of LPS preconditioning on apoptosis and ATF4-CHOP pathway was examined in vitro. Moreover, the effects of the ATF4-CHOP pathway on apoptosis, Caspase-12, and Caspase-3 were determined with ATF4 small interfering RNA (siRNA. Inflammatory cytokine expression was also checked after reperfusion. Inflammatory cytokines and related signaling pathways were analyzed in vitro in macrophages treated by LPS preconditioning or ATF4 siRNA. RESULTS: LPS preconditioning significantly attenuated liver injury after IRI. As demonstrated by in vitro experiments, LPS preconditioning significantly reduced the upregulation of the ATF4-CHOP pathway and inhibited Caspase-12 and Caspase-3 activation after IRI. Later experiments showed that ATF4 knockdown significantly suppressed CHOP, cleaved caspase-12 and caspase-3 expression, as well as inhibited hepatocellular apoptosis. In addition, in mice pretreated with LPS, TNF-α and IL-6 were inhibited after reperfusion, whereas IL-10 was upregulated. Similarly, low-dose LPS significantly inhibited TNF-α, IL-6, ATF4-CHOP pathway, NF-κB pathway, and ERK1/2 in high-dose LPS-stimulated macrophages, whereas IL-10 and cytokine signaling (SOCS-3 suppressor were induced. Importantly, ATF4 siRNA is

Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

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Xia, D.Y.; Li, W.; Qian, H.R.; Yao, S.; Liu, J.G.; Qi, X.K.

2013-01-01

Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis

Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

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Xia, D.Y. [Department of Neurology, Navy General Hospital of PLA, Beijing (China); Li, W. [General Hospital of Shenyang Military Command, Department of Neurology, Shenyang, China, Department of Neurology, General Hospital of Shenyang Military Command, Shenyang (China); Qian, H.R.; Yao, S.; Liu, J.G.; Qi, X.K. [Department of Neurology, Navy General Hospital of PLA, Beijing (China)

2013-08-10

Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

Effect of limb ischemic preconditioning on myocardial apoptosis-related proteins in ischemia-reperfusion injury

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GAO, JIANZHI; ZHAO, LINJING; WANG, YONGLING; TENG, QINGLEI; LIANG, LIDONG; ZHANG, JINYING

2013-01-01

The aim of this study was to investigate the effect of limb ischemic preconditioning (LIPC) on myocardial apoptosis in myocardial ischemia-reperfusion injury (MIRI), as well as the regulation of caspase-3 and the B cell lymphoma 2 (Bcl-2) gene in LIPC. A total of 50 rats were divided randomly into 5 groups (n=10). Four rats in each group were drawn out for detection of apoptosis. The sham, MIRI and LIPC groups underwent surgery without additional treatment. In the LY294002 group, LY294002 pre...

Inhibition of Notch signaling by Dll4-Fc promotes reperfusion of acutely ischemic tissues

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Liu, Ren [Department of Pathology, University of Southern California, Los Angeles (United States); Trindade, Alexandre [Centro Interdisciplinar de Investigacao em Sanidade Animal (CIISA), Lisbon Technical University, Lisbon (Portugal); Instituto Gulbenkian de Ciencia, Oeiras (Portugal); Sun, Zhanfeng [Department of Vascular Surgery, 2nd Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang (China); Kumar, Ram; Weaver, Fred A. [Department of Surgery, University of Southern California, Los Angeles (United States); Krasnoperov, Valery; Naga, Kranthi [Vasgene Therapeutics, Los Angeles, CA (United States); Duarte, Antonio [Centro Interdisciplinar de Investigacao em Sanidade Animal (CIISA), Lisbon Technical University, Lisbon (Portugal); Instituto Gulbenkian de Ciencia, Oeiras (Portugal); Gill, Parkash S., E-mail: parkashg@usc.edu [Department of Pathology, University of Southern California, Los Angeles (United States)

2012-02-03

Highlights: Black-Right-Pointing-Pointer Low dose Dll4-Fc increases vascular proliferation and overall perfusion. Black-Right-Pointing-Pointer Low dose Dll4-Fc helps vascular injury recovery in hindlimb ischemia model. Black-Right-Pointing-Pointer Low dose Dll4-Fc helps vascular injury recovery in skin flap model. Black-Right-Pointing-Pointer Dll4 heterozygous deletion promotes vascular injury recovery. Black-Right-Pointing-Pointer Dll4 overexpression delays vascular injury recovery. -- Abstract: Notch pathway regulates vessel development and maturation. Dll4, a high-affinity ligand for Notch, is expressed predominantly in the arterial endothelium and is induced by hypoxia among other factors. Inhibition of Dll4 has paradoxical effects of reducing the maturation and perfusion in newly forming vessels while increasing the density of vessels. We hypothesized that partial and/or intermittent inhibition of Dll4 may lead to increased vascular response and still allow vascular maturation to occur. Thus tissue perfusion can be restored rapidly, allowing quicker recovery from ischemia or tissue injury. Our studies in two different models (hindlimb ischemia and skin flap) show that inhibition of Dll4 at low dose allows faster recovery from vascular and tissue injury. This opens a new possibility for Dll4 blockade's therapeutic application in promoting recovery from vascular injury and restoring blood supply to ischemic tissues.

Neuroprotective effect of hydroxy safflor yellow A against cerebral ischemia-reperfusion injury in rats: putative role of mPTP.

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Ramagiri, Sruthi; Taliyan, Rajeev

2016-01-01

Hydroxy safflor yellow A (HSYA) has been translated clinically for cardiovascular diseases. HSYA is also greatly acknowledged for its protective effects against cerebral ischemic-reperfusion (I/R) injury. Although the precise mechanism of cerebral I/R injury is not fully understood, oxygen-derived free radicals and mitochondrial permeability transition pore (mPTP) opening during I/R injury are widely recognized as an important contributor to neuronal injury. Thus, we speculated that the neuroprotective effects of HSYA against cerebral I/R injury may be associated with mPTP modulation. Induction of I/R injury was achieved by 60 min of middle cerebral artery occlusion, followed by reperfusion for 24 h. For behavior and cognitive assessment, neurological scoring (NSS), rotarod, and Y-maze task were performed. Oxidative damage was measured in terms of markers such as malondialdehyde, reduced glutathione, and catalase levels and cerebral infarct volumes were quantified using 2,3,5-triphenyl tetrazolinium chloride staining. I/R injury-induced inflammation was determined using tumor necrosis factor-α (TNF-α) levels. Animals exposed to I/R injury showed neurological severity, functional and cognitive disability, elevated oxidative markers, and TNF-α levels along with large infarct volumes. HSYA treatment during onset of reperfusion ameliorated performance in NSS, rotarod and Y-maze attenuated oxidative damage, TNF-α levels, and infarction rate. However, treatment with carboxyatractyloside, an mPTP opener, 20 min before HSYA, attenuated the protective effect of HSYA. Our study confirmed that protective effect of HSYA may be conferred through its free radical scavenger action followed by inhibiting the opening of mPTP during reperfusion and HSYA might act as a promising therapeutic agent against cerebral I/R injury.

Glycogen synthase kinase-3 inhibition attenuates fibroblast activation and development of fibrosis following renal ischemia-reperfusion in mice

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Shailendra P. Singh

2015-08-01

Full Text Available Glycogen synthase kinase-3β (GSK3β is a serine/threonine protein kinase that plays an important role in renal tubular injury and regeneration in acute kidney injury. However, its role in the development of renal fibrosis, often a long-term consequence of acute kidney injury, is unknown. Using a mouse model of renal fibrosis induced by ischemia-reperfusion injury, we demonstrate increased GSK3β expression and activity in fibrotic kidneys, and its presence in myofibroblasts in addition to tubular epithelial cells. Pharmacological inhibition of GSK3 using TDZD-8 starting before or after ischemia-reperfusion significantly suppressed renal fibrosis by reducing the myofibroblast population, collagen-1 and fibronectin deposition, inflammatory cytokines, and macrophage infiltration. GSK3 inhibition in vivo reduced TGF-β1, SMAD3 activation and plasminogen activator inhibitor-1 levels. Consistently in vitro, TGF-β1 treatment increased GSK3β expression and GSK3 inhibition abolished TGF-β1-induced SMAD3 activation and α-smooth muscle actin (α-SMA expression in cultured renal fibroblasts. Importantly, overexpression of constitutively active GSK3β stimulated α-SMA expression even in the absence of TGF-β1 treatment. These results suggest that TGF-β regulates GSK3β, which in turn is important for TGF-β–SMAD3 signaling and fibroblast-to-myofibroblast differentiation. Overall, these studies demonstrate that GSK3 could promote renal fibrosis by activation of TGF-β signaling and the use of GSK3 inhibitors might represent a novel therapeutic approach for progressive renal fibrosis that develops as a consequence of acute kidney injury.

Inhibition of microRNA-153 protects neurons against ischemia/reperfusion injury in an oxygen-glucose deprivation and reoxygenation cellular model by regulating Nrf2/HO-1 signaling.

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Ji, Qiong; Gao, Jianbo; Zheng, Yan; Liu, Xueli; Zhou, Qiangqiang; Shi, Canxia; Yao, Meng; Chen, Xia

2017-07-01

MicroRNAs are emerging as critical regulators in cerebral ischemia/reperfusion injury; however, their exact roles remain poorly understood. miR-153 is reported to be a neuron-related miRNA involved in neuroprotection. In this study, we aimed to investigate the precise role of miR-153 in regulating neuron survival during cerebral ischemia/reperfusion injury using an oxygen-glucose deprivation and reoxygenation (OGD/R) cellular model. We found that miR-153 was significantly upregulated in neurons subjected to OGD/R treatment. Inhibition of miR-153 significantly attenuated OGD/R-induced injury and oxidative stress in neurons. Nuclear factor erythroid 2-related factor 2 (Nrf2) was identified as a target gene of miR-153. Inhibition of miR-153 significantly promoted the expression of Nrf2 and heme oxygenase-1 (HO-1). However, silencing of Nrf2 significantly blocked the protective effects of miR-153 inhibition. Our study indicates that the inhibition of miR-153 protects neurons against OGD/R-induced injury by regulating Nrf2/HO-1 signaling and suggests a potential therapeutic target for cerebral ischemia/reperfusion injury. © 2017 Wiley Periodicals, Inc.

Targeting reactive nitrogen species: a promising therapeutic strategy for cerebral ischemia-reperfusion injury.

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Chen, Xing-miao; Chen, Han-sen; Xu, Ming-jing; Shen, Jian-gang

2013-01-01

Ischemic stroke accounts for nearly 80% of stroke cases. Recanalization with thrombolysis is a currently crucial therapeutic strategy for re-building blood supply, but the thrombolytic therapy often companies with cerebral ischemia-reperfusion injury, which are mediated by free radicals. As an important component of free radicals, reactive nitrogen species (RNS), including nitric oxide (NO) and peroxynitrite (ONOO(-)), play important roles in the process of cerebral ischemia-reperfusion injury. Ischemia-reperfusion results in the production of nitric oxide (NO) and peroxynitrite (ONOO(-)) in ischemic brain, which trigger numerous molecular cascades and lead to disruption of the blood brain barrier and exacerbate brain damage. There are few therapeutic strategies available for saving ischemic brains and preventing the subsequent brain damage. Recent evidence suggests that RNS could be a therapeutic target for the treatment of cerebral ischemia-reperfusion injury. Herein, we reviewed the recent progress regarding the roles of RNS in the process of cerebral ischemic-reperfusion injury and discussed the potentials of drug development that target NO and ONOO(-) to treat ischemic stroke. We conclude that modulation for RNS level could be an important therapeutic strategy for preventing cerebral ischemia-reperfusion injury.

Ischemia postconditioning and mesenchymal stem cells engraftment synergistically attenuate ischemia reperfusion-induced lung injury in rats.

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Chen, Shuchen; Chen, Liangwan; Wu, Xiaonan; Lin, Jiangbo; Fang, Jun; Chen, Xiangqi; Wei, Shijin; Xu, Jianxin; Gao, Qin; Kang, Mingqiang

2012-11-01

It has been reported that ischemic postconditioning (IPO) or mesenchymal stem cell (MSC) engraftment could protect organs from ischemia/reperfusion (I/R) injury. We investigated the synergetic effects of combined treatment on lung injury induced by I/R. Adult Sprague-Dawley rats were randomly assigned to one of the following groups: sham-operated control, I/R, IPO, MSC engraftment, and IPO plus MSC engraftment. Lung injury was assessed by arterial blood gas analysis, the wet/dry lung weight ratio, superoxide dismutase level, malondialdehyde content, myeloperoxidase activity, and tissue histologic changes. Cytokine expression was detected using real-time polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay. Cell apoptosis was determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end assay and annexin V staining. MSC engraftment or IPO alone markedly attenuated the lung wet/dry weight ratio, malondialdehyde and myeloperoxidase production, and lung pathologic injury and enhanced arterial partial oxygen pressure, superoxide dismutase content, inhibited pro-inflammatory cytokine levels, and decreased cell apoptosis in lung tissue, compared with the I/R group. In contrast, IPO pretreatment enhanced the protective effects of MSC on I/R-induced lung injury compared with treatment alone. Moreover, in the combined treatment group, the number of MSC engraftments in the lung tissue was increased, associated with enhanced survival of MSCs compared with MSC treatment alone. Additional investigation showed that IPO treatment increased expression of vascular endothelial growth factor and stromal cell-derived factor-1 in I/R lung tissue. IPO might contribute to the homing and survival of transplanted MSCs and enhance their therapeutic effects through improvement of the microenvironment of I/R injury. Copyright © 2012 Elsevier Inc. All rights reserved.

Retention and clearance of C-11 palmitic acid in ischemic and reperfused canine myocardium

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Schwaiger, M.; Schelbert, H.R.; Keen, R.; Vinten-Johansen, J.; Hansen, H.; Selin, C.; Barrio, J.; Huang, S.C.; Phelps, M.E.

1985-01-01

Free fatty acids are the major energy source for cardiac muscle. Oxidation of fatty acid decreases or even ceases during ischemia. Its recovery after transient ischemia remains largely unexplored. Using intracoronary carbon-11 palmitic acid as a tracer of myocardial fatty acid metabolism in an open chest dog model, retention and clearance of tracer in myocardium were evaluated at control, during ischemia and after reperfusion following a 20 minute occlusion of the left anterior descending coronary artery. Myocardial C-11 time-activity curves were analyzed with biexponential curve-fitting routines yielding fractional distribution and clearance half-times of C-11 palmitic acid in myocardial tissue. In animals with permanent occlusion and intracoronary injection of C-11 palmitic acid distal to the occlusion site, the relative size and half-time of the early clearance curve component differed markedly from control values and did not change with ongoing ischemia. Conversely, in animals with only 20 minutes of coronary occlusion, the relative size of the early C-11 clearance phase was still significantly depressed at 20 and 90 minutes of reperfusion but returned to control level at 180 minutes. Tissue C-11 clearance half-times remained significantly prolonged throughout the reperfusion period. Regional function in reperfused myocardium monitored with ultrasonic crystals recovered slowly and was still less than control after 3 hours of reperfusion. The data indicate that after transient ischemia, myocardial fatty acid metabolism fails to recover immediately. Because the metabolic recovery occurs in parallel with recovery of regional function, C-11 palmitic acid in conjunction with positron tomography may be useful for studying regional fatty acid metabolism noninvasively after an ischemic injury, and may be helpful in identifying reversible tissue injury

Isoproterenol reduces ischemia-reperfusion lung injury despite beta-blockade.

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Takashima, Seiki; Schlidt, Scott A; Koukoulis, Giovanna; Sevala, Mayura; Egan, Thomas M

2005-06-01

If lungs could be retrieved from non-heart-beating donors (NHBDs), the shortage of lungs for transplantation could be alleviated. The use of lungs from NHBDs is associated with a mandatory warm ischemic interval, which results in ischemia-reperfusion injury upon reperfusion. In an earlier study, rat lungs retrieved 2-h postmortem from NHBDs had reduced capillary leak measured by filtration coefficient (Kfc) when reperfused with isoproterenol (iso), associated with an increase in lung tissue levels of cyclic AMP (cAMP). The objective was to determine if this decrease in Kfc was because of beta-stimulation, or would persist despite beta-blockade. Donor rats were treated intraperitoneally with beta-blockade (propranolol or pindolol) or carrier, sacrificed, and lungs were retrieved immediately or 2 h postmortem. The lungs were reperfused with or without iso and the beta-blockers in the reperfusate. Outcome measures were Kfc, wet:dry weight ratio (W/D), lung levels of adenine nucleotides and cAMP. Lungs retrieved immediately after death had normal Kfc and W/D. After 2 h of ischemia, Kfc and W/D were markedly elevated in controls (no drug) and lungs reperfused with beta-blockers alone. Isoproterenol-reperfusion decreased Kfc and W/D significantly (P < 0.01) even in the presence of beta-blockade. Lung cAMP levels were increased only with iso in the absence of beta-blockade. The attenuation of ischemia-reperfusion injury because of iso occurs even in the presence of beta-blockade, and may not be a result of beta-stimulated increased cAMP.

The synergetic effect of edaravone and borneol in the rat model of ischemic stroke.

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Wu, Hai-Yin; Tang, Ying; Gao, Li-Yan; Sun, Wei-Xiang; Hua, Yao; Yang, Shi-Bao; Zhang, Zheng-Ping; Liao, Gao-Yong; Zhou, Qi-Gang; Luo, Chun-Xia; Zhu, Dong-Ya

2014-10-05

Free radical production contributes to the early ischemic response and the neuroinflammatory response to injury initiates the second wave of cell death following ischemic stroke. Edaravone is a free radical scavenger, and borneol has shown anti-inflammatory effect. We investigated the synergistic effect of these two drugs in the rat model of transient cerebral ischemia. Edaravone scavenged OH, NO and ONOO─ concentration-dependently, and borneol inhibited ischemia/reperfusion-induced tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) expressions. In the rat model of transient cerebral ischemia and reperfusion, the combination of edaravone and borneol significantly ameliorated ischemic damage with an optimal proportion of 4:1. Emax (% inhibition) of edaravone, borneol and two drugs in combination was 55.7%, 65.8% and 74.3% respectively. ED50 of edaravone and borneol was 7.17 and 0.36 mg/kg respectively. When two drugs in combination, ED50 was 0.484 mg/kg, in which edaravone was 0.387 mg/kg (ineffective dose) and borneol was 0.097 mg/kg (ineffective dose). Combination index (CI)edaravone and borneol. The combination exhibited a therapeutic time window of 6h in ischemia/reperfusion model, and significantly ameliorated damages in permanent ischemia model. Moreover, two drugs in combination promoted long-term effect, including improved elemental vital signs, sensorimotor functions and spatial cognition. Our results suggest that the combination of edaravone and borneol have a synergistic effect for treating ischemic stroke. Copyright © 2014 Elsevier B.V. All rights reserved.

Ebselen pretreatment attenuates ischemia/reperfusion injury and prevents hyperglycemia by improving hepatic insulin signaling and β-cell survival in gerbils.

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Park, S; Kang, S; Kim, D S; Shin, B K; Moon, N R; Daily, J W

2014-08-01

Transient carotid artery occlusion causes ischemia/reperfusion (I/R) injury resulting in neuron and pancreatic β-cell death with consequential post-stroke hyperglycemia, which can lead to diabetes and may accelerate the development of Alzheimer's disease. Antioxidants have been shown to protect against the I/R injury and destruction of neurons. However, it is unknown whether the protection against I/R injury extends to the pancreatic β-cells. Therefore, we investigated whether treatment with ebselen, a glutathione peroxidase mimic, prevents neuronal and β-cell death following I/R in gerbils susceptible to stroke. After 28 days post artery occlusion, there was widespread neuronal cell death in the CA1 of the hippocampus and elevated IL-1β and TNF-α levels. Pretreatment with ebselen prevented the death by 56% and attenuated neurological damage (abnormal eyelid drooping, hair bristling, muscle tone, flexor reflex, posture, and walking patterns). Ischemic gerbils also exhibited impaired glucose tolerance and insulin sensitivity which induced post-stroke hyperglycemia associated with decreased β-cell mass due to increased β-cell apoptosis. Ebselen prevented the increased β-cell apoptosis, possibly by decreasing IL-1β and TNF-α in islets. Ischemia also attenuated hepatic insulin signaling, and expression of GLUT2 and glucokinase, whereas ebselen prevented the attenuation and suppressed gluconeogenesis by decreasing PEPCK expression. In conclusion, antioxidant protection by ebselen attenuated I/R injury of neurons and pancreatic β-cells and prevented subsequent impairment of glucose regulation that could lead to diabetes and Alzheimer's disease.

Real-time ischemic condition monitoring in normoglycemic and hyperglycemic rats

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Choi, Samjin; Kang, Sung Wook; Lee, Gi-Ja; Chae, Su-Jin; Park, Hun-Kuk; Choi, Seok Keun; Chung, Joo-Ho

2010-01-01

An increase in excitotoxic amino acid glutamate (GLU) concentration associated with neuronal damage might be the cause of the ischemic damage observed in stroke patients suffering from hyperglycemia. However, the effect has never been investigated by real-time in vivo monitoring. Therefore, this study examined the effects of the functional responses of ischemia-evoked electroencephalography (EEG), cerebral blood flow (%CBF) and ΔGLU in hyperglycemia through real-time in vivo monitoring. Five Sprague-Dawley rats were treated with streptozocin (hyperglycemia) and five normal rats were used as the controls. Global ischemia was induced using an 11-vessel occlusion model. The experimental protocols consisting of 10 min pre-ischemic, 10 min ischemic and 40 min reperfusion periods were applied to both groups. Under these conditions, the responses of the ischemia-evoked EEG, %CBF and ΔGLU were monitored in real time. The EEG showed flat patterns during ischemia followed by poor recovery during reperfusion. The peak reperfusion %CBF was decreased significantly in the hyperglycemia group compared to the control group (p < 0.05, n = 5). The extracellular ΔGLU releases increased significantly during ischemia (p < 0.0001, n = 5) and reperfusion (p < 0.001, n = 5) in the hyperglycemia group compared to the control group. The decrease in reperfusion %CBF during short-term hyperglycemia might be related to the increased plasma osmolality, decreased adenosine levels and swollen endothelial cells with decreased vascular luminal diameters under hyperglycemic conditions. And, the increase in ΔGLU during short-term hyperglycemia might be related to the neurotoxic effects of the high extracellular concentrations of ΔGLU and the inhibition of GLU uptake

Activation of proteolytic enzymes and depression of the sarcolemmal Na+/K+-ATPase in ischemia-reperfused heart may be mediated through oxidative stress.

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Singh, Raja B; Hryshko, Larry; Freed, Darren; Dhalla, Naranjan S

2012-02-01

We tested whether the activation of proteolytic enzymes, calpain, and matrix metalloproteinases (MMPs) during ischemia-reperfusion (I/R) is mediated through oxidative stress. For this purpose, isolated rat hearts were subjected to a 30 min global ischemia followed by a 30 min reperfusion. Cardiac function was monitored and the activities of Na(+)/K(+)-ATPase, Mg(2+)-ATPase, calpain, and MMP were measured. Depression of cardiac function and Na(+)/K(+)-ATPase activity in I/R hearts was associated with increased calpain and MMP activities. These alterations owing to I/R were similar to those observed in hearts perfused with hypoxic medium, H(2)O(2) and xanthine plus xanthine oxidase. The I/R-induced changes were attenuated by ischemic preconditioning as well as by perfusing the hearts with N-acetylcysteine or mercaptopropionylglycine. Inhibition of MMP activity in hearts treated with doxycycline depressed the I/R-induced changes in cardiac function and Na(+)/K(+)-ATPase activity without affecting the calpain activation. On the other hand, inhibition of calpain activity upon treatment with leupeptin or MDL 28170 significantly reduced the MMP activity in addition to attenuating the I/R-induced alterations in cardiac function and Na(+)/K(+)-ATPase activity. These results suggest that the I/R-induced depression in Na(+)/K(+)-ATPase and cardiac function may be a consequence of the increased activities of both calpain and MMP because of oxidative stress in the heart.

Real-time monitoring of nitric oxide (NO) and pO2 levels under ischemic conditions associated with small bowel ischemia/reperfusion injury using selective electrodes for NO and oxygen molecules.

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Watanabe, T; Owada, S; Kobayashi, H; Ishiuchi, A; Nakano, H; Asakuta, T; Shimamura, T; Asano, T; Koizumi, S; Jinnouchi, Y; Katayama, M; Kamibayasi, M; Murakami, E; Otsubo, T

2007-12-01

The present study demonstrated the feasibility of monitoring nitric oxide (NO) and pO2 levels under ischemic conditions associated with small bowel ischemia/reperfusion (I/R) injury through the use of selective electrodes for NO and oxygen molecules. NO levels gradually increased during ischemia. When reperfusion was started, the NO level decreased suddenly and returned to pre-ischemia values within 10 minutes. After clamping, pO2 decreased rapidly. When reperfusion was started, pO2 increased suddenly, returning to pre-ischemia values within 10 minutes. We concluded that it is feasible to monitor NO and pO2 levels under ischemic conditions of small bowel I/R injury through the use of electrodes selective for NO and oxygen molecules.

Agmatine attenuates intestinal ischemia and reperfusion injury by reducing oxidative stress and inflammatory reaction in rats.

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Turan, Inci; Ozacmak, Hale Sayan; Ozacmak, V Haktan; Barut, Figen; Araslı, Mehmet

2017-11-15

Oxidative stress and inflammatory response are major factors causing several tissue injuries in intestinal ischemia and reperfusion (I/R). Agmatine has been reported to attenuate I/R injury of various organs. The present study aims to analyze the possible protective effects of agmatine on intestinal I/R injury in rats. Four groups were designed: sham control, agmatine-treated control, I/R control, and agmatine-treated I/R groups. IR injury of small intestine was induced by the occlusion of the superior mesenteric artery for half an hour to be followed by a 3-hour-long reperfusion. Agmatine (10mg/kg) was administered intraperitoneally before reperfusion period. After 180min of reperfusion period, the contractile responses to both carbachol and potassium chloride (KCl) were subsequently examined in an isolated-organ bath. Malondialdehyde (MDA), reduced glutathione (GSH), and the activity of myeloperoxidase (MPO) were measured in intestinal tissue. Plasma cytokine levels were determined. The expression of the intestinal inducible nitric oxide synthase (iNOS) was also assessed by immunohistochemistry. The treatment with agmatine appeared to be significantly effective in reducing the MDA content and MPO activity besides restoring the content of GSH. The treatment also attenuated the histological injury. The increases in the I/R induced expressions of iNOS, IFN-γ, and IL-1α were brought back to the sham control levels by the treatment as well. Our findings indicate that the agmatine pretreatment may ameliorate reperfusion induced injury in small intestine mainly due to reducing inflammatory response and oxidative stress. Copyright © 2017 Elsevier Inc. All rights reserved.

Brief exposure to carbon monoxide preconditions cardiomyogenic cells against apoptosis in ischemia-reperfusion

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Kondo-Nakamura, Mihoko; Shintani-Ishida, Kaori; Uemura, Koichi; Yoshida, Ken-ichi

2010-01-01

We examined whether and how pretreatment with carbon monoxide (CO) prevents apoptosis of cardioblastic H9c2 cells in ischemia-reperfusion. Reperfusion (6 h) following brief ischemia (10 min) induced cytochrome c release, activation of caspase-9 and caspase-3, and apoptotic nuclear condensation. Brief CO pretreatment (10 min) or a caspase-9 inhibitor (Z-LEHD-FMK) attenuated these apoptotic changes. Ischemia-reperfusion increased phosphorylation of Akt at Ser472/473/474, and this was enhanced by CO pretreatment. A specific Akt inhibitor (API-2) blunted the anti-apoptotic effects of CO in reperfusion. In normoxic cells, CO enhanced O 2 - generation, which was inhibited by a mitochondrial complex III inhibitor (antimycin A) but not by a NADH oxidase inhibitor (apocynin). The CO-enhanced Akt phosphorylation was suppressed by an O 2 - scavenger (Tiron), catalase or a superoxide dismutase (SOD) inhibitor (DETC). These results suggest that CO pretreatment induces mitochondrial generation of O 2 - , which is then converted by SOD to H 2 O 2 , and subsequent Akt activation by H 2 O 2 attenuates apoptosis in ischemia-reperfusion.

Limb Remote Ischemic Conditioning: Mechanisms, Anesthetics, and the Potential for Expanding Therapeutic Options

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Chen, Gangling; Thakkar, Mrugesh; Robinson, Christopher; Doré, Sylvain

2018-01-01

Novel and innovative approaches are essential in developing new treatments and improving clinical outcomes in patients with ischemic stroke. Remote ischemic conditioning (RIC) is a series of mechanical interruptions in blood flow of a distal organ, following end organ reperfusion, shown to significantly reduce infarct size through inhibition of oxidation and inflammation. Ischemia/reperfusion (I/R) is what ultimately leads to the irreversible brain damage and clinical picture seen in stroke patients. There have been several reports and reviews about the potential of RIC in acute ischemic stroke; however, the focus here is a comprehensive look at the differences in the three types of RIC (remote pre-, per-, and postconditioning). There are some limited uses of preconditioning in acute ischemic stroke due to the unpredictability of the ischemic event; however, it does provide the identification of biomarkers for clinical studies. Remote limb per- and postconditioning offer a more promising treatment during patient care as they can be harnessed during or after the initial ischemic insult. Though further research is needed, it is imperative to discuss the importance of preclinical data in understanding the methods and mechanisms involved in RIC. This understanding will facilitate translation to a clinically feasible paradigm for use in the hospital setting. PMID:29467715

99mTc-Annexin-V uptake in a rat model of variable ischemic severity and reperfusion time

International Nuclear Information System (INIS)

Taki, Junichi; Higuchi, Takahiro; Kawashima, Atsuhiro; Muramori, Akira; Nakajima, Kenichi; Tait, J.F.; Matsunari, Ichiro; Vanderheyden, J.L.; Strauss, H.W.

2007-01-01

The background of this study was to determine whether mild to moderate ischemia that is not severe enough to induce myocardial infarction will cause myocardial cell damage or apoptosis, the 99m Tc-Annexin-V (Tc-A) uptake was studied in groups of rats with various intervals of coronary occlusion and reperfusion times. After left coronary artery occlusion for 15 min (n=23), 10 min (n=23), or 5 min (n=12), Tc-A (80-150 MBq) was injected at 0.5, 1.5, 6, or 24 h after reperfusion. One hour later, to verify the area at risk, 201 Tl (0.74 MBq) was injected just after left coronary artery re-occlusion and the rats were killed 1 min later. Dual tracer autoradiography was performed to assess Tc-A uptake and area at risk. In all 5-min occlusion and reperfusion models, no significant Tc-A uptake was observed in the area at risk. Tc-A uptake ratios in the 15-min and 10-min ischemia models were 4.46±3.16 and 2.02±0.47 (p=0.078) at 0.5 h after reperfusion, 3.49±1.78 and 1.47±0.11 (p<0.05) at 1.5 h after reperfusion, 1.60±0.43 and 1.34±0.23 (p=0.24) at 6 h after reperfusion, 1.50±0.33 and 1.28±0.33 (p=0.099) at 24 h after reperfusion, respectively. With 15-min ischemia, in 3 of the 5 rats there were a few micro-foci of myocardial cell degeneration and cell infiltration in less than 1% of the ischemic area at 24 h after reperfusion. No significant histological change was observed in rats with 10-min or 5-min ischemia. The data indicate that Tc-A binding depends on the severity of ischemia even without a significant amount of histological change or infarction. (author)

Resistance to Reperfusion Injury Following Short Term Postischemic Administration of Natural Honey in Globally Ischemic Isolated Rat Heart

OpenAIRE

Haleh Vaez; Mehrban Samadzadeh; Fahimeh Zahednezhad; Moslem Najafi

2012-01-01

Purpose: Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods: Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibra...

Mitochondrial events responsible for morphine's cardioprotection against ischemia/reperfusion injury

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He, Haiyan; Huh, Jin; Wang, Huihua; Kang, Yi; Lou, Jianshi; Xu, Zhelong

2016-01-01

Morphine may induce cardioprotection by targeting mitochondria, but little is known about the exact mitochondrial events that mediate morphine's protection. We aimed to address the role of the mitochondrial Src tyrosine kinase in morphine's protection. Isolated rat hearts were subjected to 30 min ischemia and 2 h of reperfusion. Morphine was given before the onset of ischemia. Infarct size and troponin I release were measured to evaluate cardiac injury. Oxidative stress was evaluated by measuring mitochondrial protein carbonylation and mitochondrial ROS generation. HL-1 cells were subjected to simulated ischemia/reperfusion and LDH release and mitochondrial membrane potential (ΔΨm) were measured. Morphine reduced infarct size as well as cardiac troponin I release which were aborted by the selective Src tyrosine kinase inhibitors PP2 and Src-I1. Morphine also attenuated LDH release and prevented a loss of ΔΨm at reperfusion in a Src tyrosine kinase dependent manner in HL-1 cells. However, morphine failed to reduce LDH release in HL-1 cells transfected with Src siRNA. Morphine increased mitochondrial Src phosphorylation at reperfusion and this was abrogated by PP2. Morphine attenuated mitochondrial protein carbonylation and mitochondrial superoxide generation at reperfusion through Src tyrosine kinase. The inhibitory effect of morphine on the mitochondrial complex I activity was reversed by PP2. These data suggest that morphine induces cardioprotection by preventing mitochondrial oxidative stress through mitochondrial Src tyrosine kinase. Inhibition of mitochondrial complex I at reperfusion by Src tyrosine kinase may account for the prevention of mitochondrial oxidative stress by morphine. - Highlights: • Morphine induced mito-Src phosphorylation and reduced infarct size in rat hearts. • Morphine failed to reduce I/R-induced LDH release in Src-silencing HL-1 cells. • Morphine prevented mitochondria damage caused by I/R through Src. • Morphine reduced

Arterially perfused neurosphere-derived cells distribute outside the ischemic core in a model of transient focal ischemia and reperfusion in vitro.

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Chiara Pastori

Full Text Available BACKGROUND: Treatment with neural stem cells represents a potential strategy to improve functional recovery of post-ischemic cerebral injury. The potential benefit of such treatment in acute phases of human ischemic stroke depends on the therapeutic viability of a systemic vascular delivery route. In spite of the large number of reports on the beneficial effects of intracerebral stem cells injection in experimental stroke, very few studies demonstrated the effectiveness of the systemic intravenous delivery approach. METODOLOGY/PRINCIPAL FINDINGS: We utilized a novel in vitro model of transient focal ischemia to analyze the brain distribution of neurosphere-derived cells (NCs in the early 3 hours that follow transient occlusion of the medial cerebral artery (MCA. NCs obtained from newborn C57/BL6 mice are immature cells with self-renewal properties that could differentiate into neurons, astrocytes and oligodendrocytes. MCA occlusion for 30 minutes in the in vitro isolated guinea pig brain preparation was followed by arterial perfusion with 1x10(6 NCs charged with a green fluorescent dye, either immediately or 60 minutes after reperfusion onset. Changes in extracellular pH and K(+ concentration during and after MCAO were measured through ion-sensitive electrodes. CONCLUSION/SIGNIFICANCE: It is demonstrated that NCs injected through the vascular system do not accumulate in the ischemic core and preferentially distribute in non-ischemic areas, identified by combined electrophysiological and morphological techniques. Direct measurements of extracellular brain ions during and after MCA occlusion suggest that anoxia-induced tissue changes, such as extracellular acidosis, may prevent NCs from entering the ischemic area in our in vitro model of transitory focal ischemia and reperfusion suggesting a role played by the surrounding microenviroment in driving NCs outside the ischemic core. These findings strongly suggest that the potential beneficial effect

Experimental chronic kidney disease attenuates ischemia-reperfusion injury in an ex vivo rat lung model.

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Chung-Kan Peng

Full Text Available Lung ischemia reperfusion injury (LIRI is one of important complications following lung transplant and cardiopulmonary bypass. Although patients on hemodialysis are still excluded as lung transplant donors because of the possible effects of renal failure on the lungs, increased organ demand has led us to evaluate the influence of chronic kidney disease (CKD on LIRI. A CKD model was induced by feeding Sprague-Dawley rats an adenine-rich (0.75% diet for 2, 4 and 6 weeks, and an isolated rat lung in situ model was used to evaluate ischemia reperfusion (IR-induced acute lung injury. The clinicopathological parameters of LIRI, including pulmonary edema, lipid peroxidation, histopathological changes, immunohistochemistry changes, chemokine CXCL1, inducible nitric oxide synthase (iNOS, proinflammatory and anti-inflammatory cytokines, heat shock protein expression, and nuclear factor-κB (NF-κB activation were determined. Our results indicated that adenine-fed rats developed CKD as characterized by increased blood urea nitrogen and creatinine levels and the deposition of crystals in the renal tubules and interstitium. IR induced a significant increase in the pulmonary arterial pressure, lung edema, lung injury scores, the expression of CXCL1 mRNA, iNOS level, and protein concentration of the bronchial alveolar lavage fluid (BALF. The tumor necrosis factor-α levels in the BALF and perfusate; the interleukin-10 level in the perfusate; and the malondialdehyde levels in the lung tissue and perfusate were also significantly increased by LIRI. Counterintuitively, adenine-induced CKD significantly attenuated the severity of lung injury induced by IR. CKD rats exhibited increased heat shock protein 70 expression and decreased activation of NF-κB signaling. In conclusion, adenine-induced CKD attenuated LIRI by inhibiting the NF-κB pathway.

Dynamin-Related Protein 1 Inhibitors Protect against Ischemic Toxicity through Attenuating Mitochondrial Ca2+ Uptake from Endoplasmic Reticulum Store in PC12 Cells

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Ye Tian

2014-02-01

Full Text Available Intracellular calcium homeostasis disorder and mitochondrial dysfunction are involved in many acute and chronic brain diseases, including ischemic brain injury. An imbalance in mitochondrial fission and fusion is one of the most important structural abnormalities found in a large number of mitochondrial dysfunction related diseases. Here, we investigated the effects of mitochondrial division inhibitor A (mdivi A and mdivi B, two small molecule inhibitors of mitochondrial fission protein dunamin-related protein 1 (Drp-1, in neuronal injury induced by oxygen-glucose deprivation (OGD in PC12 cells. We found that mdivi A and mdivi B inhibited OGD-induced neuronal injury through attenuating apoptotic cell death. These two inhibitors also preserved mitochondrial function, as evidenced by reduced reactive oxygen species (ROS generation and cytochrome c release, as well as prevented loss of mitochondrial membrane potential (MMP. Moreover, mdivi A and mdivi B significantly suppressed mitochondrial Ca2+ uptake, but had no effect on cytoplasmic Ca2+ after OGD injury. The results of calcium imaging and immunofluorescence staining showed that Drp-1 inhibitors attenuated endoplasmic reticulum (ER Ca2+ release and prevented ER morphological changes induced by OGD. These results demonstrate that Drp-1 inhibitors protect against ischemic neuronal injury through inhibiting mitochondrial Ca2+ uptake from the ER store and attenuating mitochondrial dysfunction.

The protective effect of ischemic preconditioning on rat testis

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Ciralik Harun

2007-12-01

Full Text Available Abstract Background It has been demonstrated that brief episodes of sublethal ischemia-reperfusion, so-called ischemic preconditioning, provide powerful tissue protection in different tissues such as heart, brain, skeletal muscle, lung, liver, intestine, kidney, retina, and endothelial cells. Although a recent study has claimed that there are no protective effects of ischemic preconditioning in rat testis, the protective effects of ischemic preconditioning on testicular tissue have not been investigated adequately. The present study was thus planned to investigate whether ischemic preconditioning has a protective effect on testicular tissue. Methods Rats were divided into seven groups that each contained seven rats. In group 1 (control group, only unilateral testicular ischemia was performed by creating a testicular torsion by a 720 degree clockwise rotation for 180 min. In group 2, group 3, group 4, group 5, group 6, and group 7, unilateral testicular ischemia was performed for 180 min following different periods of ischemic preconditioning. The ischemic preconditioning periods were as follows: 10 minutes of ischemia with 10 minutes of reperfusion in group 2; 20 minutes of ischemia with 10 minutes of reperfusion in group 3; 30 minutes of ischemia with 10 minutes of reperfusion in group 4; multiple preconditioning periods were used (3 × 10 min early phase transient ischemia with 10 min reperfusion in all episodes in group 5; multiple preconditioning periods were used (5, 10, and 15 min early phase transient ischemia with 10 min reperfusion in all episodes in group 6; and, multiple preconditioning periods were used (10, 20, and 30 min early phase transient ischemia with 10 min reperfusion in all episodes in group 7. After the ischemic protocols were carried out, animals were sacrificed by cervical dislocation and testicular tissue samples were taken for biochemical measurements (protein, malondialdehyde, nitric oxide and histological examination

Beneficial effect of medicinal plants on the contractility of post-hypoxic isolated guinea pig atria - Potential implications for the treatment of ischemic-reperfusion injury

NARCIS (Netherlands)

Bipat, Robbert; Toelsie, Jerry R.; Magali, Indira; Soekhoe, Rubaina; Stender, Karin; Wangsawirana, Angelique; Oedairadjsingh, Krishan; Pawirodihardjo, Jennifer; Mans, Dennis R. A.

Context Ischemic-reperfusion injury is accompanied by a decreased contractility of the myocardium. Positive-inotropic agents have proven useful for treating this condition but may exert serious side-effects.Objective In this study, aqueous preparations from Abelmoschus esculentus L. Moench

Protection of Liver as a Remote Organ after Renal Ischemia-Reperfusion Injury by Renal Ischemic Postconditioning

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Behjat Seifi

2014-01-01

Full Text Available This study was designed to investigate the protective effects of local renal ischemic postconditioning (POC on liver damage after renal ischemia-reperfusion (IR injury. Male rats were divided into three groups  (n=8. They underwent a right nephrectomy before induction of 45 minutes of left kidney ischemia or sham operation. POC was performed by four cycles of 10 seconds of ischemia and 10 seconds of reperfusion just at the beginning of 24 hours of reperfusion. Then blood and liver samples were collected to measure serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, and liver oxidative stress parameters including superoxide dismutase (SOD activity and malondialdehyde (MDA level. Renal IR caused a significant increase in liver functional indices as demonstrated by increased serum AST and ALT compared to sham group. These parameters reduced significantly in POC group compared to IR group. Liver MDA levels increased and SOD activity decreased in IR group compared to sham group. Induction of POC reduced the elevated liver MDA levels and increased the reduced liver SOD activity. These results revealed that renal IR injury causes liver damage as a remote organ and POC protects liver from renal IR injury by a modification in the hepatic oxidative stress status.

Arctigenin protects focal cerebral ischemia-reperfusion rats through inhibiting neuroinflammation.

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Fan, Tao; Jiang, Wei Long; Zhu, Jian; Feng Zhang, Yu

2012-01-01

Stroke is the third leading cause of death in industrialized countries and the most important cause of acquired adult disability. Many evidences suggest that inflammation accounts for the progression of cerebral ischemic injury. Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignin isolated from certain plants, has shown anti-inflammatory activity against diabetes and Alzheimer's disease. In this study, we tested whether arctigenin can protect middle cerebral artery occluded (MCAO) rats. Male Sprague-Dawley rats were pretreated with arctigenin or vehicle for 7 d before being subjected to transient occlusion of middle cerebral artery and reperfusion. Rats were evaluated at 24 h after MCAO for neurological deficit scoring. Furthermore, the mechanism of the anti-inflammatory effect of arctigenin was investigated with a focus on inflammatory cells, proinflammatory cytokines, and transcriptional factors. Arctigenin significantly reduced cerebral infarction and improved neurological outcome. Arctigenin suppressed the activation of microglia and decreased the expression of interleukin (IL)- 1β and tumor necrosis factor (TNF)-α. These results revealed that arctigenin has a promising therapeutic effect in ischemic stroke treatment through an anti-inflammatory mechanism.

Administration of FTY720 during Tourniquet-Induced Limb Ischemia Reperfusion Injury Attenuates Systemic Inflammation

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Anthony D. Foster

2017-01-01

Full Text Available Acute ischemia-reperfusion injury (IRI of the extremities leads to local and systemic inflammatory changes which can hinder limb function and can be life threatening. This study examined whether the administration of the T-cell sequestration agent, FTY720, following hind limb tourniquet-induced skeletal muscle IRI in a rat model would attenuate systemic inflammation and multiple end organ injury. Sprague-Dawley rats were subjected to 1 hr of ischemia via application of a rubber band tourniquet. Animals were randomized to receive an intravenous bolus of either vehicle control or FTY720 15 min after band placement. Rats (n=10/time point were euthanized at 6, 24, and 72 hr post-IRI. Peripheral blood as well as lung, liver, kidney, and ischemic muscle tissue was analyzed and compared between groups. FTY720 treatment markedly decreased the number of peripheral blood T cells (p<0.05 resulting in a decreased systemic inflammatory response and lower serum creatinine levels and had a modest but significant effect in decreasing the transcription of injury-associated target genes in multiple end organs. These findings suggest that early intervention with FTY720 may benefit the treatment of IRI of the limb. Further preclinical studies are necessary to characterize the short-term and long-term beneficial effects of FTY720 following tourniquet-induced IRI.

The administration of hydrogen sulphide prior to ischemic reperfusion has neuroprotective effects in an acute stroke model.

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Chul-Woong Woo

Full Text Available Emerging evidence has suggested that hydrogen sulfide (H2S may alleviate the cellular damage associated with cerebral ischemia/reperfusion (I/R injury. In this study, we assessed using 1H-magnetic resonance imaging/magnetic resonance spectroscopy (1H-MRI/MRS and histologic analysis whether H2S administration prior to reperfusion has neuroprotective effects. We also evaluated for differences in the effects of H2S treatment at 2 time points. 1H-MRI/MRS data were obtained at baseline, and at 3, 9, and 24 h after ischemia from 4 groups: sham, control (I/R injury, sodium hydrosulfide (NaHS-30 and NaHS-1 (NaHS delivery at 30 and 1 min before reperfusion, respectively. The total infarct volume and the midline shift at 24 h post-ischemia were lowest in the NaHS-1, followed by the NaHS-30 and control groups. Peri-infarct volume was significantly lower in the NaHS-1 compared to NaHS-30 and control animals. The relative apparent diffusion coefficient (ADC in the peri-infarct region showed that the NaHS-1 group had significantly lower values compared to the NaHS-30 and control animals and that NaHS-1 rats showed significantly higher relative T2 values in the peri-infarct region compared to the controls. The relative ADC value, relative T2 value, levels of N-acetyl-L-aspartate (NAA, and the NAA, glutamate, and taurine combination score (NGT in the ischemic core region at 24 h post-ischemia did not differ significantly between the 2 NaHS groups and the control except that the NAA and NGT values were higher in the peri-infarct region of the NaHS-1 animals at 9 h post-ischemia. In the ischemic core and peri-infarct regions, the apoptosis rate was lowest in the NaHS-1 group, followed by the NaHS-30 and control groups. Our results suggest that H2S treatment has neuroprotective effects on the peri-infarct region during the evolution of I/R injury. Furthermore, our findings indicate that the administration of H2S immediately prior to reperfusion produces the

Kallikrein-like amidase activity in renal ischemia and reperfusion

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M.D. Carattino

2000-05-01

Full Text Available We assessed a kallikrein-like amidase activity probably related to the kallikrein-kinin system, as well as the participation of leukocyte infiltration in renal ischemia and reperfusion. Male C57BL/KSJmdb mice were subjected to 20 or 60 min of ischemia and to different periods of reperfusion. A control group consisted of sham-operated mice, under similar conditions, except for ischemia induction. Kallikrein-like amidase activity, Evans blue extravasation and myeloperoxidase activity were measured in kidney homogenates, previously perfused with 0.9% NaCl. Plasma creatinine concentration increased only in the 60-min ischemic group. After 20 min of ischemia and 1 or 24 h of reperfusion, no change in kallikrein-like amidase activity or Evans blue extravasation was observed. In the mice subjected to 20 min of ischemia, edema was evident at 1 h of reperfusion, but kidney water content returned to basal levels after 24 h of reperfusion. In the 60-min ischemic group, kallikrein-like amidase activity and Evans blue extravasation showed a similar significant increase along reperfusion time. Kallikrein-like amidase activity increased from 4 nmol PNA mg protein-1 min-1 in the basal condition to 15 nmol PNA mg protein-1 min-1 at 10 h of reperfusion. For dye extravasation the concentration measured was near 200 µg of Evans blue/g dry tissue in the basal condition and 1750 µg of Evans blue/g dry tissue at 10 h of reperfusion. No variation could be detected in the control group. A significant increase from 5 to 40 units of DAbs 655 nm g wet tissue-1 min-1 in the activity of the enzyme myeloperoxidase was observed in the 60-min ischemic group, when it was evaluated after 24 h of reperfusion. Histological analysis of the kidneys showed migration of polymorphonuclear leukocytes from the vascular bed to the interstitial tissue in the 60-min ischemic group after 24 h of reperfusion. We conclude that the duration of ischemia is critical for the development of damage

Brief exposure to carbon monoxide preconditions cardiomyogenic cells against apoptosis in ischemia-reperfusion

Energy Technology Data Exchange (ETDEWEB)

Kondo-Nakamura, Mihoko [Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Shintani-Ishida, Kaori, E-mail: kaori@m.u-tokyo.ac.jp [Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Uemura, Koichi; Yoshida, Ken-ichi [Department of Forensic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2010-03-12

We examined whether and how pretreatment with carbon monoxide (CO) prevents apoptosis of cardioblastic H9c2 cells in ischemia-reperfusion. Reperfusion (6 h) following brief ischemia (10 min) induced cytochrome c release, activation of caspase-9 and caspase-3, and apoptotic nuclear condensation. Brief CO pretreatment (10 min) or a caspase-9 inhibitor (Z-LEHD-FMK) attenuated these apoptotic changes. Ischemia-reperfusion increased phosphorylation of Akt at Ser472/473/474, and this was enhanced by CO pretreatment. A specific Akt inhibitor (API-2) blunted the anti-apoptotic effects of CO in reperfusion. In normoxic cells, CO enhanced O{sub 2}{sup -} generation, which was inhibited by a mitochondrial complex III inhibitor (antimycin A) but not by a NADH oxidase inhibitor (apocynin). The CO-enhanced Akt phosphorylation was suppressed by an O{sub 2}{sup -} scavenger (Tiron), catalase or a superoxide dismutase (SOD) inhibitor (DETC). These results suggest that CO pretreatment induces mitochondrial generation of O{sub 2}{sup -}, which is then converted by SOD to H{sub 2}O{sub 2}, and subsequent Akt activation by H{sub 2}O{sub 2} attenuates apoptosis in ischemia-reperfusion.

Effect of arginase inhibition on ischemia-reperfusion injury in patients with coronary artery disease with and without diabetes mellitus.

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Oskar Kövamees

Full Text Available Arginase competes with nitric oxide synthase for their common substrate L-arginine. Up-regulation of arginase in coronary artery disease (CAD and diabetes mellitus may reduce nitric oxide bioavailability contributing to endothelial dysfunction and ischemia-reperfusion injury. Arginase inhibition reduces infarct size in animal models. Therefore the aim of the current study was to investigate if arginase inhibition protects from endothelial dysfunction induced by ischemia-reperfusion in patients with CAD with or without type 2 diabetes (NCT02009527.Male patients with CAD (n = 12 or CAD + type 2 diabetes (n = 12, were included in this cross-over study with blinded evaluation. Endothelium-dependent vasodilatation was assessed by flow-mediated dilatation (FMD of the radial artery before and after 20 min ischemia-reperfusion during intra-arterial infusion of the arginase inhibitor (Nω-hydroxy-nor-L-arginine, 0.1 mg/min or saline.The forearm ischemia-reperfusion was well tolerated. Endothelium-independent vasodilatation was assessed by sublingual nitroglycerin. Ischemia-reperfusion decreased FMD in patients with CAD from 12.7±5.2% to 7.9±4.0% during saline administration (P<0.05. Nω-hydroxy-nor-L-arginine administration prevented the decrease in FMD in the CAD group (10.3±4.3% at baseline vs. 11.5±3.6% at reperfusion. Ischemia-reperfusion did not significantly reduce FMD in patients with CAD + type 2 diabetes. However, FMD at reperfusion was higher following nor-NOHA than following saline administration in both groups (P<0.01. Endothelium-independent vasodilatation did not differ between the occasions.Inhibition of arginase protects against endothelial dysfunction caused by ischemia-reperfusion in patients with CAD. Arginase inhibition may thereby be a promising therapeutic strategy in the treatment of ischemia-reperfusion injury.

Succinate-induced neuronal mitochondrial fission and hexokinase II malfunction in ischemic stroke: Therapeutical effects of kaempferol.

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Wu, Bin; Luo, Hong; Zhou, Xu; Cheng, Cai-Yi; Lin, Lin; Liu, Bao-Lin; Liu, Kang; Li, Ping; Yang, Hua

2017-09-01

Mitochondrial dysfunction is known as one of causative factors in ischemic stroke, leading to neuronal cell death. The present work was undertaken to investigate whether succinate induces neuron apoptosis by regulating mitochondrial morphology and function. In neurons, oxygen-glucose deprivation induced succinate accumulation due to the reversal of succinate dehydrogenase (SDH) activation, leading to mitochondrial fission. Kaempferol inhibited mitochondrial fission and maintained mitochondrial HK-II through activation of Akt, and thereby protected neurons from succinate-mediated ischemi injury. Knockdown of Akt2 with siRNA diminished the effect of kaempferol, indicating that kaempferol suppressed dynamin-related protein 1 (Drp1) activation and promoted HK-II mitochondrial binding dependently on Akt. Moreover, we demonstrated that kaempferol potentiated autophagy during oxygen and glucose deprivation, contributing to protecting neuron survival against succinate insult. In vivo, oral administration of kaempferol in mice attenuated the infract volume after ischemic and reperfusion (I/R) injury and reproduced the similar mitochondrial protective effect in the brain infract area. This study indicates that succinate accumulation plays a pivotal role in I/R injury-induced neuronal mitochondrial dysfunction, and suggests that modulation of Drp1 phosphorylation might be potential therapeutic strategy to protect neuron mitochondrial integrity and treat ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancement of Na/K pump activity by chronic intermittent hypobaric hypoxia protected against reperfusion injury.

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Guo, Hui-Cai; Guo, Fang; Zhang, Li-Nan; Zhang, Rong; Chen, Qing; Li, Jun-Xia; Yin, Jian; Wang, Yong-Li

2011-06-01

Chronic intermittent hypobaric hypoxia (CIHH) has been shown to attenuate intracellular Na(+) accumulation and Ca(2+) overload during ischemia and reperfusion (I/R), both of which are closely related to the outcome of myocardial damage. Na/K pump plays an essential role in maintaining the equilibrium of intracellular Na(+) and Ca(2+) during I/R. It has been shown that enhancement of Na/K pump activity by ischemic preconditioning may be involved in the cardiac protection. Therefore, we tested whether Na/K pump was involved in the cardioprotection by CIHH. We found that Na/K pump current in cardiac myocytes of guinea pigs exposed to CIHH increased 1.45-fold. The K(1) and f(1), which reflect the portion of α(1)-isoform of Na/K pump, dramatically decreased or increased, respectively, in CIHH myocytes. Western blot analysis revealed that CIHH increased the protein expression of the α(1)-isoform by 76%, whereas the protein expression of the α(2)-isoform was not changed significantly. Na/K pump current was significantly suppressed in simulated I/R, and CIHH preserved the Na/K pump current. CIHH significantly improved the recovery of cell length and contraction during reperfusion. Furthermore, inhibition of Na/K pump by ouabain attenuated the protective effect afforded by CIHH. Collectively, these data suggest that the increase of Na/K pump activity following CIHH is due to the upregulating α(1)-isoform of Na/K pump, which may be one of the mechanisms of CIHH against I/R-induced injury.

Protective Effect of Hesperetin and Naringenin against Apoptosis in Ischemia/Reperfusion-Induced Retinal Injury in Rats

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Selcuk Kara

2014-01-01

Full Text Available Purpose. Hesperetin and naringenin are naturally common flavonoids reported to have antioxidative effects. This study was performed to investigate whether either hesperetin or naringenin has a protective effect against apoptosis on retinal ischemia/reperfusion (I/R injury. Methods. Retinal I/R was induced by increasing the intraocular pressure to 150 mmHg for 60 minutes. Thirty-three male Wistar albino rats were randomised into 5 groups named control, I/R + sham, I/R + solvent (DMSO, I/R + hesperetin, and I/R + naringenin. Animals were given either hesperetin, naringenin, or the solvent intraperitoneally immediately following reperfusion. Thickness of retinal layers and retinal cell apoptosis were detected by histological analysis, tunel assay, and immunohistochemistry assay. Results. Hesperetin and naringenin attenuated the I/R-induced apoptosis of retinal cells in the inner and outer nuclear cells of the rat retina. Retinal layer thickness of the naringenin treatment group was significantly thicker than that of the hesperetin, sham, and solvent groups (P<0.05. Conclusions. Hesperetin and naringenin can prevent harmful effects induced by I/R injury in the rat retina by inhibiting apoptosis of retinal cells, which suggests that those flavanones have a therapeutic potential for the protection of ocular ischemic diseases.

Carbonic anhydrase inhibitor attenuates ischemia-reperfusion induced acute lung injury.

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Chou-Chin Lan

Full Text Available Ischemia-reperfusion (IR-induced acute lung injury (ALI is implicated in several clinical conditions including lung transplantation, cardiopulmonary bypass surgery, re-expansion of collapsed lung from pneumothorax or pleural effusion and etc. IR-induced ALI remains a challenge in the current treatment. Carbonic anhydrase has important physiological function and influences on transport of CO2. Some investigators suggest that CO2 influences lung injury. Therefore, carbonic anhydrase should have the role in ALI. This study was undertaken to define the effect of a carbonic anhydrase inhibitor, acetazolamide (AZA, in IR-induced ALI, that was conducted in a rat model of isolated-perfused lung with 30 minutes of ischemia and 90 minutes of reperfusion. The animals were divided into six groups (n = 6 per group: sham, sham + AZA 200 mg/kg body weight (BW, IR, IR + AZA 100 mg/kg BW, IR + AZA 200 mg/kg BW and IR+ AZA 400 mg/kg BW. IR caused significant pulmonary micro-vascular hyper-permeability, pulmonary edema, pulmonary hypertension, neutrophilic sequestration, and an increase in the expression of pro-inflammatory cytokines. Increases in carbonic anhydrase expression and perfusate pCO2 levels were noted, while decreased Na-K-ATPase expression was noted after IR. Administration of 200mg/kg BW and 400mg/kg BW AZA significantly suppressed the expression of pro-inflammatory cytokines (TNF-α, IL-1, IL-6 and IL-17 and attenuated IR-induced lung injury, represented by decreases in pulmonary hyper-permeability, pulmonary edema, pulmonary hypertension and neutrophilic sequestration. AZA attenuated IR-induced lung injury, associated with decreases in carbonic anhydrase expression and pCO2 levels, as well as restoration of Na-K-ATPase expression.

Neuroprotective effect of gadolinium: a stretch-activated calcium channel blocker in mouse model of ischemia-reperfusion injury.

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Gulati, Puja; Muthuraman, Arunachalam; Jaggi, Amteshwar S; Singh, Nirmal

2013-03-01

The present study was designed to investigate the potential of gadolinium, a stretch-activated calcium channel blocker in ischemic reperfusion (I/R)-induced brain injury in mice. Bilateral carotid artery occlusion of 12 min followed by reperfusion for 24 h was given to induce cerebral injury in male Swiss mice. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was assessed using Morris water maze test and motor incoordination was evaluated using rota-rod, lateral push, and inclined beam walking tests. In addition, total calcium, thiobarbituric acid reactive substance (TBARS), reduced glutathione (GSH), and acetylcholinesterase (AChE) activity were also estimated in brain tissue. I/R injury produced a significant increase in cerebral infarct size. A significant loss of memory along with impairment of motor performance was also noted. Furthermore, I/R injury also produced a significant increase in levels of TBARS, total calcium, AChE activity, and a decrease in GSH levels. Pretreatment of gadolinium significantly attenuated I/R-induced infarct size, behavioral and biochemical changes. On the basis of the present findings, we can suggest that opening of stretch-activated calcium channel may play a critical role in ischemic reperfusion-induced brain injury and that gadolinium has neuroprotective potential in I/R-induced injury.

PKA Inhibitor H89 (N-[2-p-bromocinnamylamino-ethyl]-5-isoquinolinesulfonamide Attenuates Synaptic Dysfunction and Neuronal Cell Death following Ischemic Injury

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Juhyun Song

2015-01-01

Full Text Available The cyclic AMP-dependent protein kinase (PKA, which activates prosurvival signaling proteins, has been implicated in the expression of long-term potentiation and hippocampal long-term memory. It has come to light that H89 commonly known as the PKA inhibitor have diverse roles in the nervous system that are unrelated to its role as a PKA inhibitor. We have investigated the role of H89 in ischemic and reperfusion injury. First, we examined the expression of postsynaptic density protein 95 (PSD95, microtubule-associated protein 2 (MAP2, and synaptophysin in mouse brain after middle cerebral artery occlusion injury. Next, we examined the role of H89 pretreatment on the expression of brain-derived neurotrophic factor (BDNF, PSD95, MAP2, and the apoptosis regulators Bcl2 and cleaved caspase-3 in cultured neuroblastoma cells exposed to hypoxia and reperfusion injury. In addition, we investigated the alteration of AKT activation in H89 pretreated neuroblastoma cells under hypoxia and reperfusion injury. The data suggest that H89 may contribute to brain recovery after ischemic stroke by regulating neuronal death and proteins related to synaptic plasticity.

Arginase induction and activation during ischemia and reperfusion and functional consequences for the heart

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Klaus-Dieter eSchlüter

2015-03-01

Full Text Available Induction and activation of arginase is among the fastest responses of the heart to ischemic events. Induction of arginase expression and enzyme activation under ischemic conditions shifts arginine consumption from nitric oxide formation (NO to the formation of ornithine and urea. In the heart such a switch in substrate utilisation reduces the impact of the NO/cGMP-pathway on cardiac function that requires intact electromechanical coupling but at the same time it induces ornithine-dependent pathways such as the polyamine metabolism. Both effects significantly reduce the recovery of heart function during reperfusion and thereby limits the success of reperfusion strategies. In this context, changes in arginine consumption trigger cardiac remodelling in an unfavourable way and increases the risk of arrhythmia, specifically in the initial post-ischemic period in which arginase activity is dominating. However, during the entire ischemic period arginase activation might be a meaningful adaptation that is specifically relevant for reperfusion following prolonged ischemic periods. Therefore, a precise understanding about the underlying mechanism that leads to arginase induction as well as of it’s mechanistic impact on post-ischemic hearts is required for optimizing reperfusion strategies. In this review we will summarize our current understanding of these processes and give an outlook about possible treatment options for the future.

Prophylactic Treatment with Cerium Oxide Nanoparticles Attenuate Hepatic Ischemia Reperfusion Injury in Sprague Dawley Rats

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Nandini D.P.K. Manne

2017-07-01

Full Text Available Background: Hepatic ischemia reperfusion is one the main causes for graft failure following transplantation. Although, the molecular events that lead to hepatic failure following ischemia reperfusion (IR are diverse and complex, previous studies have shown that excessive formation of reactive oxygen species (ROS are responsible for hepatic IR injury. Cerium oxide (CeO2 nanoparticles have been previously shown to act as an anti-oxidant and anti-inflammatory agent. Here, we evaluated the protective effects of CeO2 nanoparticles on hepatic ischemia reperfusion injury. Methods: Male Sprague Dawley rats were randomly assigned to one of the four groups: Control, CeO2 nanoparticle only, hepatic ischemia reperfusion (IR group and hepatic ischemia reperfusion (IR plus CeO2 nanoparticle group (IR+ CeO2. Partial warm hepatic ischemia was induced in left lateral and median lobes for 1h, followed by 6h of reperfusion. Animals were sacrificed after 6h of reperfusion and blood and tissue samples were collected and processed for various biochemical experiments. Results: Prophylactic treatment with CeO2 nanoparticles (0.5mg/kg i.v (IR+CeO2 group 1 hour prior to hepatic ischemia and subsequent reperfusion injury lead to a decrease in serum levels of alanine aminotransaminase and lactate dehydrogenase at 6 hours after reperfusion. These changes were accompanied by significant decrease in hepatocyte necrosis along with reduction in several serum inflammatory markers such as macrophage derived chemokine, macrophage inflammatory protein-2, KC/GRO, myoglobin and plasminogen activator inhibitor-1. However, immunoblotting demonstrated no significant changes in the levels of apoptosis related protein markers such as bax, bcl2 and caspase 3 in IR and IR+ CeO2 groups at 6 hours suggesting necrosis as the main pathway for hepatocyte death. Conclusion: Taken together, these data suggest that CeO2 nanoparticles attenuate IR induced cell death and can be used as a prophylactic

Prior intake of Brazil nuts attenuates renal injury induced by ischemia and reperfusion

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Natassia Alberici Anselmo

2018-04-01

Full Text Available ABSTRACT Introduction: Ischemia-reperfusion (IR injury results from inflammation and oxidative stress, among other factors. Because of its anti-inflammatory and antioxidant properties, the Brazil nut (BN might attenuate IR renal injury. Objective: The aim of the present study was to investigate whether the intake of BN prevents or reduces IR kidney injury and inflammation, improving renal function and decreasing oxidative stress. Methods: Male Wistar rats were distributed into six groups (N=6/group: SHAM (control, SHAM treated with 75 or 150 mg of BN, IR, and IR treated with 75 or 150 mg of BN. The IR procedure consisted of right nephrectomy and occlusion of the left renal artery with a non-traumatic vascular clamp for 30 min. BN was given daily and individually for 7 days before surgery (SHAM or IR and maintained until animal sacrifice (48h after surgery. We evaluated the following parameters: plasma creatinine, urea, and phosphorus; proteinuria, urinary output, and creatinine clearance; plasmatic TBARS and TEAC; kidney expression of iNOS and nitrotyrosine, and macrophage influx. Results: Pre-treatment with 75 mg of BN attenuated IR-induced renal changes, with elevation of creatinine clearance and urinary output, reducing proteinuria, urea, and plasmatic phosphorus as well as reducing kidney expression of iNOS, nitrotyrosine, and macrophage influx. Conclusion: Low intake of BN prior to IR-induced kidney injury improves renal function by inhibition of macrophage infiltration and oxidative stress.

Electroacupunctre improves motor impairment via inhibition of microglia-mediated neuroinflammation in the sensorimotor cortex after ischemic stroke.

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Liu, Weilin; Wang, Xian; Yang, Shanli; Huang, Jia; Xue, Xiehua; Zheng, Yi; Shang, Guanhao; Tao, Jing; Chen, Lidian

2016-04-15

Electroacupuncture (EA) is one of the safety and effective therapies for improving neurological and sensorimotor impairment via blockade of inappropriate inflammatory responses. However, the mechanisms of anti-inflammation involved is far from been fully elucidated. Focal cerebral ischemic stroke was administered by the middle cerebral artery occlusion and reperfusion (MCAO/R) surgery. The MCAO/R rats were accepted EA treatment at the LI 11 and ST 36 acupoints for consecutive 3days. The neurological outcome, animal behaviors test and molecular biology assays were used to evaluate the MCAO/R model and therapeutic effect of EA. EA treatment for MCAO rats showed a significant reduction in the infarct volumes accompanied by functional recovery in mNSS outcomes, motor function performances. The possible mechanisms that EA treatment attenuated the over-activation of Iba-1 and ED1 positive microglia in the peri-infract sensorimotor cortex. Simultaneously, both tissue and serum protein levels of the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were decreased by EA treatment in MCAO/R injured rats. The levels of inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) were decreased in the peri-infract sensorimotor cortex and blood serum of MCAO/R injured rats after EA treatment. Furthermore, we found that EA treatment prevented from the nucleus translocation of NF-κB p65 and suppressed the expression of p38 mitogen-activated protein kinase (p38 MAPK) and myeloid differentiation factor 88 (MyD88) in the peri-infract sensorimotor cortex. The findings from this study indicated that EA improved the motor impairment via inhibition of microglia-mediated neuroinflammation that invoked NF-κB p65, p38 MAPK and MyD88 produced proinflammatory cytokine in the peri-infract sensorimotor cortex of rats following ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Reno-Cerebral Reflex Activates the Renin-Angiotensin System, Promoting Oxidative Stress and Renal Damage After Ischemia-Reperfusion Injury.

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Cao, Wei; Li, Aiqing; Li, Jiawen; Wu, Chunyi; Cui, Shuang; Zhou, Zhanmei; Liu, Youhua; Wilcox, Christopher S; Hou, Fan Fan

2017-09-01

A kidney-brain interaction has been described in acute kidney injury, but the mechanisms are uncertain. Since we recently described a reno-cerebral reflex, we tested the hypothesis that renal ischemia-reperfusion injury (IRI) activates a sympathetic reflex that interlinks the renal and cerebral renin-angiotensin axis to promote oxidative stress and progression of the injury. Bilateral ischemia-reperfusion activated the intrarenal and cerebral, but not the circulating, renin-angiotensin system (RAS), increased sympathetic activity in the kidney and the cerebral sympathetic regulatory regions, and induced brain inflammation and kidney injury. Selective renal afferent denervation with capsaicin or renal denervation significantly attenuated IRI-induced activation of central RAS and brain inflammation. Central blockade of RAS or oxidative stress by intracerebroventricular (ICV) losartan or tempol reduced the renal ischemic injury score by 65% or 58%, respectively, and selective renal afferent denervation or reduction of sympathetic tone by ICV clonidine decreased the score by 42% or 52%, respectively (all p renal damage and dysfunction persisted after controlling blood pressure with hydralazine. This study uncovered a novel reflex pathway between ischemic kidney and the brain that sustains renal oxidative stress and local RAS activation to promote ongoing renal damage. These data suggest that the renal and cerebral renin-angiotensin axes are interlinked by a reno-cerebral sympathetic reflex that is activated by ischemia-reperfusion, which contributes to ischemia-reperfusion-induced brain inflammation and worsening of the acute renal injury. Antioxid. Redox Signal. 27, 415-432.

3H-1,2-Dithiole-3-thione as a novel therapeutic agent for the treatment of ischemic stroke through Nrf2 defense pathway.

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Kuo, Ping-Chang; Yu, I-Chen; Scofield, Barbara A; Brown, Dennis A; Curfman, Eric T; Paraiso, Hallel C; Chang, Fen-Lei; Yen, Jui-Hung

2017-05-01

Cerebral ischemic stroke accounts for more than 80% of all stroke cases. During cerebral ischemia, reactive oxygen species produced in brain tissue induce oxidative stress and inflammatory responses. D3T, the simplest compound of the cyclic, sulfur-containing dithiolethiones, is found in cruciferous vegetables and has been reported to induce antioxidant genes and glutathione biosynthesis through activation of Nrf2. In addition to antioxidant activity, D3T was also reported to possess anti-inflammatory effects. In this study, we evaluated the therapeutic potential of D3T for the treatment of ischemic stroke and investigated the mechanisms underlying the protective effects of D3T in ischemic stroke. Mice subjected to transient middle cerebral artery occlusion/reperfusion (tMCAO/R) were administered with vehicle or D3T to evaluate the effect of D3T in cerebral brain injury. We observed D3T reduced infarct size, decreased brain edema, lessened blood-brain barrier disruption, and ameliorated neurological deficits. Further investigation revealed D3T suppressed microglia (MG) activation and inhibited peripheral inflammatory immune cell infiltration of CNS in the ischemic brain. The protective effect of D3T in ischemic stroke is mediated through Nrf2 induction as D3T-attenuated brain injury was abolished in Nrf2 deficient mice subjected to tMCAO/R. In addition, in vitro results indicate the induction of Nrf2 by D3T is required for its suppressive effect on MG activation and cytokine production. In summary, we demonstrate for the first time that D3T confers protection against ischemic stroke, which is mediated through suppression of MG activation and inhibition of CNS peripheral cell infiltration, and that the protective effect of D3T in ischemic stroke is dependent on the activation of Nrf2. Copyright © 2017 Elsevier Inc. All rights reserved.

Hypercholesterolemic myocardium is vulnerable to ischemia-reperfusion injury and refractory to sevoflurane-induced protection.

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Yong Xu

Full Text Available Recent studies have demonstrated that volatile anesthetic postconditioning confers myocardial protection against ischemia-reperfusion (IR injury through activation of the reperfusion injury salvage kinase (RISK pathway. As RISK has been shown to be impaired in hypercholesterolemia. Therefore, we investigate whether anesthetic-induced cardiac protection was maintained in hypercholesterolemic rats. In the present study, normocholesteolemic or hypercholesterolemic rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. Animals received 2.4% sevoflurane for 5 min or 3 cycles of 10-s ischemia/10-s reperfusion. The hemodynamic parameters, including left ventricular developed pressure, left ventricular end-diastolic pressure and heart rate, were continuously monitored. The infarct size, apoptosis, p-Akt, p-ERK1/2, p-GSK3β were determined. We found that both sevoflurane and ischemic postconditioning significantly improved heart pump function, reduced infarct size and increased the phosphorylation of Akt, ERK1/2 and their downstream target of GSK3β in the healthy rats. In the hypercholesterolemic rats, neither sevoflurane nor ischemic postconditioning improved left ventricular hemodynamics, reduced infarct size and increased the phosphorylated Akt, ERK1/2 and GSK3β. In contrast, GSK inhibitor SB216763 conferred cardioprotection against IR injury in healthy and hypercholesterolemic hearts. In conclusions, hyperchoesterolemia abrogated sevoflurane-induced cardioprotection against IR injury by alteration of upstream signaling of GSK3β and acute GSK inhibition may provide a novel therapeutic strategy to protect hypercholesterolemic hearts against IR injury.

Identification of ischemic regions in a rat model of stroke.

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Popp, Anke; Jaenisch, Nadine; Witte, Otto W; Frahm, Christiane

2009-01-01

Investigations following stroke first of all require information about the spatio-temporal dimension of the ischemic core as well as of perilesional and remote affected tissue. Here we systematically evaluated regions differently impaired by focal ischemia. Wistar rats underwent a transient 30 or 120 min suture-occlusion of the middle cerebral artery (MCAO) followed by various reperfusion times (2 h, 1 d, 7 d, 30 d) or a permanent MCAO (1 d survival). Brains were characterized by TTC, thionine, and immunohistochemistry using MAP2, HSP72, and HSP27. TTC staining reliably identifies the infarct core at 1 d of reperfusion after 30 min MCAO and at all investigated times following 120 min and permanent MCAO. Nissl histology denotes the infarct core from 2 h up to 30 d after transient as well as permanent MCAO. Absent and attenuated MAP2 staining clearly identifies the infarct core and perilesional affected regions at all investigated times, respectively. HSP72 denotes perilesional areas in a limited post-ischemic time (1 d). HSP27 detects perilesional and remote impaired tissue from post-ischemic day 1 on. Furthermore a simultaneous expression of HSP72 and HSP27 in perilesional neurons was revealed. TTC and Nissl staining can be applied to designate the infarct core. MAP2, HSP72, and HSP27 are excellent markers not only to identify perilesional and remote areas but also to discriminate affected neuronal and glial populations. Moreover markers vary in their confinement to different reperfusion times. The extent and consistency of infarcts increase with prolonged occlusion of the MCA. Therefore interindividual infarct dimension should be precisely assessed by the combined use of different markers as described in this study.

Effects of compound Shenhua tablet on renal tubular Na+-K+-ATPase in rats with acute ischemic reperfusion injury.

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Yang, Yue; Wei, Ri-bao; Zheng, Xiao-yong; Qiu, Qiang; Cui, Shao-yuan; Yin, Zhong; Shi, Suo-zhu; Chen, Xiang-mei

2014-03-01

To observe the effect of Compound Shenhua Tablet (, SHT) on the sodium-potassium- exchanging adenosinetriphosphatase (Na(+)-K(+)-ATPase) in the renal tubular epithelial cells of rats with acute ischemic reperfusion and to investigate the mechanisms underlying the effects of SHT on renal ischemic reperfusion injury (RIRI). Fifty male Wistar rats were randomly divided into the sham surgery group, model group, astragaloside group [150 mg/(kg·d)], SHT low-dose group [1.5 g/(kg·d)] and SHT high-dose group [3.0 g/(kg·d)], with 10 rats in each group. After 1 week of continuous intragastric drug administration, surgery was performed to establish the model. At either 24 or 72 h after the surgery, 5 rats in each group were sacrificed, blood biochemistry, renal pathology, immunoblot and immunohistochemical examinations were performed, and double immunofluorescence staining was observed under a laser confocal microscope. Compared with the sham surgery group, the serum creatinine (SCr) and blood urea nitrogen (BUN) levels were significantly increased, Na(+)-K(+)-ATPase protein level was decreased, and kidney injury molecule-1 (KIM-1) protein level was increased in the model group after the surgery (P<0.01 or P<0.05). Compared with the model group, the SCr, BUN, pathological scores, Na(+)-K(+)-ATPase, and the KIM-1 protein level of the three treatment groups were significantly improved at 72 h after the surgery (P<0.05 or P<0.01). And the SCr, BUN of the SHT low- and high-dose groups, and the pathological scores of the SHT high-dose group were significantly lower than those of the astragaloside group (P<0.05). The localizations of Na(+)-K(+)-ATPase and megalin of the model group were disrupted, with the distribution areas overlapping with each other and alternately arranged. The severity of the disruption was slightly milder in three treatment groups compared with that of the model group. The results of immunofluorescence staining showed that the SHT high-dose group had a

Magnetic resonance imaging in acute ischemic stroke

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Ohta, Kouichi [Mito Red Cross Hospital (Japan)

2000-01-01

This paper summarizes current MRI technology used in the diagnosis of acute cerebral infarction and discusses tasks for further improvement of MRI technology. First, the principles and methods of MRI imaging are described in terms of 1) diffusion-weighted imaging (DWI) and ADC maps, 2) perfusion imaging, 3) the fluid-attenuated inversion recovery (FLAIR) method, and 4) MR angiography (MRA). Then, the actual use of MRI in the early phase of ischemic cerebrovascular disorders is discussed focusing on general MRI procedures, cases in which an ischemic lesion dose not yield a high signal with DWI in the acute phase, and chronological changes in DWI signal strength and ADC. Third, chronological changes in acute cerebrovascular disorder in an animal model of local cerebral ischemia are summarized in terms of expansion of reduced ADC areas and ischemic penumbras in the acute phase of cerebral ischemia. Finally, chronological changes in acute ischemic disorders in patients with cerebrovascular disorders are assessed by reviewing the development of reduced ADC and expansion of DWI lesions. Whether MRI can identify cerebral tissues that can be rescued by the reperfusion method by examining the mismatchs between perfusion images and DWI, relative CBV, and ADC is also discussed. (K.H.)

Fisetin Confers Cardioprotection against Myocardial Ischemia Reperfusion Injury by Suppressing Mitochondrial Oxidative Stress and Mitochondrial Dysfunction and Inhibiting Glycogen Synthase Kinase 3β Activity

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Karthi Shanmugam

2018-01-01

Full Text Available Acute myocardial infarction (AMI is the leading cause of morbidity and mortality worldwide. Timely reperfusion is considered an optimal treatment for AMI. Paradoxically, the procedure of reperfusion can itself cause myocardial tissue injury. Therefore, a strategy to minimize the reperfusion-induced myocardial tissue injury is vital for salvaging the healthy myocardium. Herein, we investigated the cardioprotective effects of fisetin, a natural flavonoid, against ischemia/reperfusion (I/R injury (IRI using a Langendorff isolated heart perfusion system. I/R produced significant myocardial tissue injury, which was characterized by elevated levels of lactate dehydrogenase and creatine kinase in the perfusate and decreased indices of hemodynamic parameters. Furthermore, I/R resulted in elevated oxidative stress, uncoupling of the mitochondrial electron transport chain, increased mitochondrial swelling, a decrease of the mitochondrial membrane potential, and induction of apoptosis. Moreover, IRI was associated with a loss of the mitochondrial structure and decreased mitochondrial biogenesis. However, when the animals were pretreated with fisetin, it significantly attenuated the I/R-induced myocardial tissue injury, blunted the oxidative stress, and restored the structure and function of mitochondria. Mechanistically, the fisetin effects were found to be mediated via inhibition of glycogen synthase kinase 3β (GSK3β, which was confirmed by a biochemical assay and molecular docking studies.

Fisetin Confers Cardioprotection against Myocardial Ischemia Reperfusion Injury by Suppressing Mitochondrial Oxidative Stress and Mitochondrial Dysfunction and Inhibiting Glycogen Synthase Kinase 3β Activity.

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Shanmugam, Karthi; Ravindran, Sriram; Kurian, Gino A; Rajesh, Mohanraj

2018-01-01

Acute myocardial infarction (AMI) is the leading cause of morbidity and mortality worldwide. Timely reperfusion is considered an optimal treatment for AMI. Paradoxically, the procedure of reperfusion can itself cause myocardial tissue injury. Therefore, a strategy to minimize the reperfusion-induced myocardial tissue injury is vital for salvaging the healthy myocardium. Herein, we investigated the cardioprotective effects of fisetin, a natural flavonoid, against ischemia/reperfusion (I/R) injury (IRI) using a Langendorff isolated heart perfusion system. I/R produced significant myocardial tissue injury, which was characterized by elevated levels of lactate dehydrogenase and creatine kinase in the perfusate and decreased indices of hemodynamic parameters. Furthermore, I/R resulted in elevated oxidative stress, uncoupling of the mitochondrial electron transport chain, increased mitochondrial swelling, a decrease of the mitochondrial membrane potential, and induction of apoptosis. Moreover, IRI was associated with a loss of the mitochondrial structure and decreased mitochondrial biogenesis. However, when the animals were pretreated with fisetin, it significantly attenuated the I/R-induced myocardial tissue injury, blunted the oxidative stress, and restored the structure and function of mitochondria. Mechanistically, the fisetin effects were found to be mediated via inhibition of glycogen synthase kinase 3 β (GSK3 β ), which was confirmed by a biochemical assay and molecular docking studies.

The cardioprotective efficacy of TVP1022 in a rat model of ischaemia/reperfusion.

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Ertracht, Offir; Liani, Esti; Bachner-Hinenzon, Noa; Bar-Am, Orit; Frolov, Luba; Ovcharenko, Elena; Awad, Huda; Blum, Shany; Barac, Yaron; Amit, Tamar; Adam, Dan; Youdim, Moussa; Binah, Ofer

2011-06-01

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. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

Allowable warm ischemic time and morphological and biochemical changes in uterine ischemia/reperfusion injury in cynomolgus macaque: a basic study for uterus transplantation.

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Kisu, Iori; Umene, Kiyoko; Adachi, Masataka; Emoto, Katsura; Nogami, Yuya; Banno, Kouji; Itagaki, Iori; Kawamoto, Ikuo; Nakagawa, Takahiro; Narita, Hayato; Yoshida, Atsushi; Tsuchiya, Hideaki; Ogasawara, Kazumasa; Aoki, Daisuke

2017-10-01

How long is the allowable warm ischemic time of the uterus and what morphological and biochemical changes are caused by uterine ischemia/reperfusion injury in cynomolgus macaques? Warm ischemia in the uterus of cynomolgus macaques is tolerated for up to 4 h and reperfusion after uterine ischemia caused no further morphological and biochemical changes. Uterus transplantation is a potential option for women with uterine factor infertility. The allowable warm ischemic time and ischemia/reperfusion injury of the uterus in humans and non-human primates is unknown. This experimental study included 18 female cynomolgus macaques with periodic menstruation. Animals were divided into six groups of three monkeys each: a control group and groups with uterine ischemia for 0.5, 1, 2, 4 and 8 h. Biopsies of uterine tissues were performed before blood flow blockage, after each blockage time, and after reperfusion for 3 h. Blood sampling was performed after each blockage time, and after reperfusion for 5, 15 and 30 min for measurement of biochemical data. Resumption of menstruation was monitored after the surgical procedure. Morphological, physiological and biochemical changes after ischemia and reperfusion were evaluated. Mild muscle degeneration and zonal degeneration were observed in all animals subjected to warm ischemia for 4 or 8 h, but there were no marked differences in the appearance of specimens immediately after ischemia and after reperfusion for 3 h in animals subjected to 4 or 8 h of warm ischemia. There were no significant changes in any biochemical parameters at any time point in each group. Periodical menstruation resumed in all animals with warm ischemia up to 4 h, but did not recover in animals with warm ischemia for 8 h with atrophic uteri. Warm ischemia in actual transplantation was not exactly mimicked in this study because uteri were not perfused, cooled, transplanted or reanastomosed with vessels. Results in non-human primates cannot always be extrapolated to

Hyper-attenuating brain lesions on CT after ischemic stroke and thrombectomy are associated with final brain infarction.

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Cabral, F B; Castro-Afonso, L H; Nakiri, G S; Monsignore, L M; Fábio, Src; Dos Santos, A C; Pontes-Neto, O M; Abud, D G

2017-12-01

Purpose Hyper-attenuating lesions, or contrast staining, on a non-contrast brain computed tomography (NCCT) scan have been investigated as a predictor for hemorrhagic transformation after endovascular treatment of acute ischemic stroke (AIS). However, the association of hyper-attenuating lesions and final ischemic areas are poorly investigated in this setting. The aim of the present study was to assess correlations between hyper-attenuating lesions and final brain infarcted areas after thrombectomy for AIS. Methods Data from patients with AIS of the anterior circulation who underwent endovascular treatment were retrospectively assessed. Images of the brain NCCT scans were analyzed in the first hours and late after treatment. The hyper-attenuating areas were compared to the final ischemic areas using the Alberta Stroke Program Early CT Score (ASPECTS). Results Seventy-one of the 123 patients (65.13%) treated were included. The association between the hyper-attenuating region in the post-thrombectomy CT scan and final brain ischemic area were sensitivity (58.3% to 96.9%), specificity (42.9% to 95.6%), positive predictive values (71.4% to 97.7%), negative predictive values (53.8% to 79.5%), and accuracy values (68% to 91%). The highest sensitivity values were found for the lentiform (96.9%) and caudate nuclei (80.4%) and for the internal capsule (87.5%), and the lowest values were found for the M1 (58.3%) and M6 (66.7%) cortices. Conclusions Hyper-attenuating lesions on head NCCT scans performed after endovascular treatment of AIS may predict final brain infarcted areas. The prediction appears to be higher in the deep brain regions compared with the cortical regions.

Resveratrol alleviates cerebral ischemia/reperfusion injury in rats by inhibiting NLRP3 inflammasome activation through Sirt1-dependent autophagy induction.

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He, Qi; Li, Zhenyu; Wang, Yueting; Hou, Yanghao; Li, Lingyu; Zhao, Jing

2017-09-01

Resveratrol has been reported to protect against cerebral ischemia/reperfusion (I/R) injury in rats, but the underlying mechanism is unclear. In the current study, we examined whether resveratrol ameliorates cerebral I/R injury by inhibiting NLRP3 inflammasome-derived inflammation and whether autophagy is involved in this process. In addition, we explored the role of Sirt1 in resveratrol-mediated protective effects. To answer these questions, healthy male Sprague-Dawley rats were exposed to middle cerebral artery occlusion for 1h followed by 24h reperfusion. We found that cerebral I/R increased levels of activated NLRP3 inflammasome, caspase-1, IL-1β, and IL-18 and enhanced autophagy activity (ratio of LC3B-II/LC3B-I and p62/SQSTM1). Treatment with resveratrol, a specific Sirt1 agonist, attenuated I/R-induced NLRP3 inflammasome-derived inflammation but upregulated autophagy. Furthermore, resveratrol treatment clearly reduced cerebral infarct volume, decreased brain water content, and improved neurological scores. In addition, inhibition of autophagy using 3-MA intracerebroventricular injection blocked the inhibitory effect of resveratrol on NLRP3 inflammasome activation. Finally, Sirt1 knockdown with siRNA significantly blocked resveratrol-induced enhancement of autophagy activity and suppression of NLRP3 inflammasome activation. In conclusion, our results demonstrate that resveratrol protects against cerebral I/R injury by inhibiting NLRP3 inflammasome activation through Sirt1-dependent autophagy activity. Copyright © 2017. Published by Elsevier B.V.

Uptake and distribution of a labeled fatty acid in a canine model of ischemia with and without reperfusion

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Devous, M.D. Sr.

1985-01-01

The relationship between regional myocardial blood flow (RMBF) and the regional distribution of 15-(4-iodophenyl)-9-methyl pentadecanoic acid (9-MPDA) was studied in a canine model of myocardial ischemia with and without reperfusion. Group 1 dogs received 135 min of left anterior descending coronary artery (LAD) occlusion; Group 2 dogs received 90 min of LAD occlusion and 45 min of reflow; and Group 3 dogs received 90 min of LAD occlusion and 3.5 hr of reperfusion. All animals received 9-MPDA 15 min prior to sacrifice, and tracer microspheres prior to occlusion, 5 and 80 min after occlusion, 15 min after reperfusion, and 15 min before the end of reperfusion. In Group 1 (permanent ischemia), 9-MPDA distribution was closely correlated with RMBF both 5 and 80 min after occlusion. In Group 2, 9-MPDA uptake was most closely correlated with reperfusion RMBF rather than ischemic RMBF. However, in 1 animal with good reperfusion, 9-MPDA uptake was reduced and was correlated with ischemic blood flow measured 5 min after occlusion. In Group 3, 9-MPDA uptake was correlated with RMBF measured during the ischemic period and not with reperfusion RMBF. It appears that 9-MPDA uptake is determined by RMBF when flow is limited, or early in reperfusion. With prolonged reperfusion, 9-MPDA uptake is significantly reduced in the ischemic zone in the presence of normal flow. This finding implies that the uptake of this fatty acid during reperfusion is related to myocardial damage (myocardial metabolism?) and not to RMBF

Predicting ischemic mitral regurgitation in patients with acute ST-elevation myocardial infarction: Does time to reperfusion really matter and what is the role of collateral circulation?

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Valuckiene, Zivile; Budrys, Povilas; Jurkevicius, Renaldas

2016-01-15

Ischemic mitral regurgitation (MR) is an adverse prognostic factor. We aimed to assess the role of time delay from symptom onset to reperfusion, and the impact of collateral circulation to incidence of MR in relation to established echocardiographic and clinical risk factors. Patients with STEMI presenting within 12 h from symptom onset and treated with primary percutaneous coronary intervention (PPCI) at Hospital of Lithuanian University of Health Sciences were enrolled. Echocardiography was performed after PPCI. Based on MR grade, patients were divided into no significant MR (NMR, grade 0-I MR, N = 102) and ischemic MR (IMR, grade ≥ 2 MR, N = 71) groups. Well-developed collaterals were defined as grade ≥ 2 by Rentrop classification. Continuous variables were compared by independent samples Student's T-test. Multivariate logistic regression analysis was used to identify independent predictors of ischemic MR. Time to reperfusion, MI localization, TIMI flow before/after PCI was similar between the groups. IMR group patients were elder, more often females and non-smokers, had lower body mass index, higher prevalence of multi-vessel coronary artery disease (CAD), better-developed collateral supply, greater left ventricular end-diastolic diameter index, left atrial index, pulmonary artery systolic pressure and lower ejection fraction. Multivariate logistic regression analysis revealed that ischemic MR is predicted by female gender, well-developed collateral supply, presence of multi-vessel CAD, and lower EF. In acute STEMI significant MR is unrelated to ischemic time and is predicted by female gender, lower EF, multi-vessel CAD and well-developed collateral supply to the infarct region.

Advanced glycation end-product (AGE)-albumin from activated macrophage is critical in human mesenchymal stem cells survival and post-ischemic reperfusion injury.

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Son, Myeongjoo; Kang, Woong Chol; Oh, Seyeon; Bayarsaikhan, Delger; Ahn, Hyosang; Lee, Jaesuk; Park, Hyunjin; Lee, Sojung; Choi, Junwon; Lee, Hye Sun; Yang, Phillip C; Byun, Kyunghee; Lee, Bonghee

2017-09-14

Post-ischemic reperfusion injury (PIRI) triggers an intense inflammatory response which is essential for repair but is also implicated in pathogenesis of post-ischemic remodeling in several organs in human. Stem cell therapy has recently emerged as a promising method for treatment of PIRI in human. However, satisfactory results have not been reported due to severe loss of injected stem cells in PIRI including critical limb ischemia (CLI). For investigating the advanced glycation end-product-albumin (AGE-albumin) from activated macrophages is critical in both muscle cell and stem cell death, we evaluated the recovery of PIRI-CLI by injection of human bone marrow derived mesenchymal stem cells (hBD-MSCs) with or without soluble receptor for AGEs (sRAGE). Our results showed that activated M1 macrophages synthesize and secrete AGE-albumin, which induced the skeletal muscle cell death and injected hBD-MSCs in PIRI-CLI through RAGE increase. Combined injection of sRAGE and hBD-MSCs resulted in enhanced survival of hBD-MSCs and angiogenesis in PIRI-CLI mice. Taken together, AGE-albumin from activated macrophages is critical for both skeletal muscle cell and hBD-MSCs death in PIRI-CLI. Therefore, the inhibition of AGE-albumin from activated macrophages could be a successful therapeutic strategy for treatment of PIRI including CLI with or without stem cell therapy.

X-ray phase-contrast tomography of renal ischemia-reperfusion damage.

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Astrid Velroyen

Full Text Available The aim of the study was to investigate microstructural changes occurring in unilateral renal ischemia-reperfusion injury in a murine animal model using synchrotron radiation.The effects of renal ischemia-reperfusion were investigated in a murine animal model of unilateral ischemia. Kidney samples were harvested on day 18. Grating-Based Phase-Contrast Imaging (GB-PCI of the paraffin-embedded kidney samples was performed at a Synchrotron Radiation Facility (beam energy of 19 keV. To obtain phase information, a two-grating Talbot interferometer was used applying the phase stepping technique. The imaging system provided an effective pixel size of 7.5 µm. The resulting attenuation and differential phase projections were tomographically reconstructed using filtered back-projection. Semi-automated segmentation and volumetry and correlation to histopathology were performed.GB-PCI provided good discrimination of the cortex, outer and inner medulla in non-ischemic control kidneys. Post-ischemic kidneys showed a reduced compartmental differentiation, particularly of the outer stripe of the outer medulla, which could not be differentiated from the inner stripe. Compared to the contralateral kidney, after ischemia a volume loss was detected, while the inner medulla mainly retained its volume (ratio 0.94. Post-ischemic kidneys exhibited severe tissue damage as evidenced by tubular atrophy and dilatation, moderate inflammatory infiltration, loss of brush borders and tubular protein cylinders.In conclusion GB-PCI with synchrotron radiation allows for non-destructive microstructural assessment of parenchymal kidney disease and vessel architecture. If translation to lab-based approaches generates sufficient density resolution, and with a time-optimized image analysis protocol, GB-PCI may ultimately serve as a non-invasive, non-enhanced alternative for imaging of pathological changes of the kidney.

Dietary broccoli sprouts protect against myocardial oxidative damage and cell death during ischemia-reperfusion.

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Akhlaghi, Masoumeh; Bandy, Brian

2010-09-01

Cruciferous vegetables are known for antioxidant and anti-carcinogenic effects. In the current study we asked whether dietary broccoli sprouts can protect the heart from ischemia-reperfusion. Rats were fed either control diet (sham and control groups) or a diet mixed with 2% dried broccoli sprouts for 10 days. After 10 days the isolated hearts were subjected to ischemia for 20 min and reperfusion for 2 h, and evaluated for cell death, oxidative damage, and Nrf2-regulated phase 2 enzyme activities. Broccoli sprouts feeding inhibited markers of necrosis (lactate dehydrogenase release) and apoptosis (caspase-3 activity) by 78-86%, and decreased indices of oxidative stress (thiobarbituric acid reactive substances and aconitase inactivation) by 82-116%. While broccoli sprouts increased total glutathione and activities of the phase 2 enzymes glutamate cysteine ligase and quinone reductase in liver, they did not affect these in ischemic-reperfused heart. While the mechanism is not clear, the results show that a relatively short dietary treatment with broccoli sprouts can strongly protect the heart against oxidative stress and cell death caused by ischemia-reperfusion.

Novel resveratrol analogues attenuate renal ischemic injury in rats

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Khader, Adam; Yang, Weng-Lang; Kuncewitch, Michael; Prince, Jose M.; Marambaud, Philippe; Nicastro, Jeffrey; Coppa, Gene F.; Wang, Ping

2014-01-01

Background Renal ischemia-reperfusion (I/R) is a severe clinical complication with no specific treatment. Resveratrol has been shown as a promising experimental agent in renal I/R due to its effect on cellular energy metabolism, oxidative stress, and inflammation. Recently, we identified two biologically active resveratrol analogues (RSVAs), RSVA405 and RSVA314. We hypothesized that both RSAVs would attenuate I/R-induced renal injury. Methods Adult male rats were subjected to renal I/R through bilateral renal pedicle clamping for 60 min, followed by reperfusion. RSVA405 (3 mg/kg BW), RSVA314 (3 mg/kg BW), or vehicle (10% DMSO and 33% Solutol in PBS) was administered by intraperitoneal injection 1 h prior to ischemia. Blood and renal tissues were collected 24 h after I/R for evaluation. Results Administration of RSVA405 and RSVA314 significantly reduced the serum levels of renal dysfunction and injury markers, including creatinine, blood urea nitrogen, aspartate aminotransferase, and lactate dehydrogenase, compared to vehicle. The protective effect of RSVA405 and RSVA314 was also reflected on histologic evaluation. Both RSVAs reduced the number of apoptotic cells by more than 60% as determined by TUNEL assay, compared to vehicle. The renal ATP levels of the vehicle group was decreased to 52.4% of control, while those of the RSVA405 and RSVA314 groups were restored to 72.3% and 79.6% of control, respectively. Both RSVAs significantly reduced the protein expression of inducible nitric oxide synthase and nitrotyrosine, and the mRNA levels of TNF-α, IL-6 and IL-1β. Conclusions RSVA405 and RSVA314 attenuate I/R-induced renal injury through the modulation of energy metabolism, oxidative stress, and inflammation. PMID:25214260

Cyclical blood flow restriction resistance exercise: a potential parallel to remote ischemic preconditioning?

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Sprick, Justin D; Rickards, Caroline A

2017-11-01

Remote ischemic preconditioning (RIPC) is characterized by the cyclical application of limb blood flow restriction and reperfusion and has been shown to protect vital organs during a subsequent ischemic insult. Blood flow restriction exercise (BFRE) similarly combines bouts of blood flow restriction with low-intensity exercise and thus could potentially emulate the protection demonstrated by RIPC. One concern with BFRE, however, is the potential for an augmented rise in sympathetic outflow due to greater activation of the exercise pressor reflex. Because of the use of lower workloads, however, we hypothesized that BFRE would elicit an attenuated increase in sympathetic outflow [assessed via plasma norepinephrine (NE) and mean arterial pressure (MAP)] and middle cerebral artery velocity (MCAv) when compared with conventional exercise (CE). Fifteen subjects underwent two leg press exercise interventions: 1 ) BFRE-220 mmHg bilateral thigh occlusion at 20% 1 rep-max (1RM), and 2 ) CE-65% 1RM without occlusion. Each condition consisted of 4 × 5-min cycles of exercise, with 3 × 10-reps in each cycle. Five minutes of rest and reperfusion (for BFRE) followed each cycle. MAP increased with exercise ( P exercise ( P exercise only ( P = 0.07). Plasma NE concentration increased with CE only ( P exercise ( P ≤ 0.02). The attenuated sympathetic response, combined with similar cerebrovascular responses, suggest that cyclical BFRE could be explored as an alternative to CE in the clinical setting. Copyright © 2017 the American Physiological Society.

Discovery of 3-n-butyl-2,3-dihydro-1H-isoindol-1-one as a potential anti-ischemic stroke agent

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Lan Z

2015-06-01

Full Text Available Zujian Lan, Xiaoyu Xu, Wenkai Xu, Jin Li, Zengrong Liang, Xuefei Zhang, Ming Lei, Chunshun Zhao School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, People’s Republic of China Abstract: To develop novel anti-ischemic stroke agents with better therapeutic efficacy and bioavailability, we designed and synthesized a series of 3-alkyl-2,3-dihydro-1H-isoindol-1-ones compounds (3a–i derivatives, one of which (3d exhibited the strongest inhibitory activity for the adenosine diphosphate-induced and arachidonic acid-induced platelet aggregation. This activity is superior to that of 3-n-butylphthalide and comparable with aspirin and edaravone. Meanwhile, 3d not only exhibited a potent activity in scavenging free radicals and improving the survival of HT22 cells against the reactive oxygen species-mediated cytotoxicity in vitro but also significantly attenuated the ischemia/reperfusion-induced oxidative stress in ischemic rat brains. Results from transient middle cerebral artery occlusion and permanent middle cerebral artery occlusion model, indicated that 3d could significantly reduce infarct size, improve neurobehavioral deficits, and prominently decrease attenuation of cerebral damage. Most importantly, 3d possessed a very high absolute bioavailability and was rapidly distributed in brain tissue to keep high plasma drug concentration for the treatment of ischemic strokes. In conclusion, our findings suggest that 3-alkyl-2,3-dihydro-1H-isoindol-1-ones, a novel series of compounds, might be candidate drugs for the treatment of acute ischemic strokes, and 3d may be a promising therapeutic agent for the primary and secondary prevention of ischemic stroke. Keywords: stroke, platelet aggregation, ischemia/reperfusion, middle cerebral artery occlusion, 3-alkyl-2,3-dihydro-1H-isoindol-1-ones

Effect of X-Ray Attenuation of Arterial Obstructions on Intravenous Thrombolysis and Outcome after Ischemic Stroke.

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Grant Mair

Full Text Available To assess whether the x-ray attenuation of intra-arterial obstruction measured on non-contrast CT in ischemic stroke can predict response to thrombolysis and subsequent functional outcome.The Third International Stroke Trial (IST-3 was a multicenter randomized-controlled trial of intravenous thrombolysis (rt-PA given within six hours of ischemic stroke. Ethical approval and informed consent were obtained. In a subgroup of 109 IST-3 patients (38 men, median age 82 years, a single reader, masked to all clinical and other imaging data, manually measured x-ray attenuation (Hounsfield Units, HU on non-contrast CT at the location of angiographically-proven intra-arterial obstructions, pre-randomization and at 24-48 hour follow-up. We calculated change in attenuation between scans. We assessed the impact of pre-randomization arterial obstruction attenuation on six-month functional outcome.Most arterial obstructions (64/109, 59% were hyperattenuating (mean 51.0 HU. Compared with control, treatment with rt-PA was associated with a greater, but non-significant, reduction in obstruction attenuation at follow-up (-8.0 HU versus -1.4 HU in patients allocated control, p = 0.117. In multivariable ordinal regression analysis controlled for patient age, stroke severity, location and extent of obstruction, time from stroke onset to baseline scan and rt-PA treatment allocation, the attenuation of pre-randomization arterial obstruction was not independently associated with six-month outcome (odds ratio = 0.99, 95% confidence interval = 0.94-1.03, p = 0.516.In ischemic stroke, the x-ray attenuation of the arterial obstruction may decline more rapidly from baseline to 24-48 hours following treatment with thrombolysis but we found no evidence that baseline arterial obstruction attenuation predicts six-month outcome.

Mitochondrial events responsible for morphine's cardioprotection against ischemia/reperfusion injury

Energy Technology Data Exchange (ETDEWEB)

He, Haiyan [Department of Physiology & Pathophysiology, Tianjin Medical University, Tianjin 300070 (China); Department of Pharmacology, Tianjin Medical University, Tianjin 300070 (China); Huh, Jin [Department of Anesthesia and Pain Medicine, Medical College, Kangwon National University, Chuncheon City (Korea, Republic of); Wang, Huihua [Department of Anesthesiology, The Second Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province (China); Kang, Yi; Lou, Jianshi [Department of Pharmacology, Tianjin Medical University, Tianjin 300070 (China); Xu, Zhelong, E-mail: zxu@tmu.edu.cn [Department of Physiology & Pathophysiology, Tianjin Medical University, Tianjin 300070 (China)

2016-01-01

Morphine may induce cardioprotection by targeting mitochondria, but little is known about the exact mitochondrial events that mediate morphine's protection. We aimed to address the role of the mitochondrial Src tyrosine kinase in morphine's protection. Isolated rat hearts were subjected to 30 min ischemia and 2 h of reperfusion. Morphine was given before the onset of ischemia. Infarct size and troponin I release were measured to evaluate cardiac injury. Oxidative stress was evaluated by measuring mitochondrial protein carbonylation and mitochondrial ROS generation. HL-1 cells were subjected to simulated ischemia/reperfusion and LDH release and mitochondrial membrane potential (ΔΨm) were measured. Morphine reduced infarct size as well as cardiac troponin I release which were aborted by the selective Src tyrosine kinase inhibitors PP2 and Src-I1. Morphine also attenuated LDH release and prevented a loss of ΔΨm at reperfusion in a Src tyrosine kinase dependent manner in HL-1 cells. However, morphine failed to reduce LDH release in HL-1 cells transfected with Src siRNA. Morphine increased mitochondrial Src phosphorylation at reperfusion and this was abrogated by PP2. Morphine attenuated mitochondrial protein carbonylation and mitochondrial superoxide generation at reperfusion through Src tyrosine kinase. The inhibitory effect of morphine on the mitochondrial complex I activity was reversed by PP2. These data suggest that morphine induces cardioprotection by preventing mitochondrial oxidative stress through mitochondrial Src tyrosine kinase. Inhibition of mitochondrial complex I at reperfusion by Src tyrosine kinase may account for the prevention of mitochondrial oxidative stress by morphine. - Highlights: • Morphine induced mito-Src phosphorylation and reduced infarct size in rat hearts. • Morphine failed to reduce I/R-induced LDH release in Src-silencing HL-1 cells. • Morphine prevented mitochondria damage caused by I/R through Src. • Morphine

Cocktail treatment, a promising strategy to treat acute cerebral ischemic stroke?

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Li-jun Liang

2016-01-01

Full Text Available Up to now, over 1,000 experimental treatments found in cells and rodents have been difficult to translate to human ischemic stroke. Since ischemia and reperfusion, two separate stages of ischemic stroke, have different pathophysiological mechanisms leading to brain injury, a combination of protective agents targeting ischemia and reperfusion respectively may obtain substantially better results than a single agent. Normobaric hyperoxia (NBO has been shown to exhibit neuro- and vaso-protective effects by improving tissue oxygenation when it is given during ischemia, however the effect of NBO would diminish when the duration of ischemia and reperfusion was extended. Therefore, during reperfusion drug treatment targeting inflammation, oxidative stress and free radical scavenger would be a useful adjuvant to extend the therapeutic window of tissue plasminogen activator, the only United States Food and Drug Administration (FDA approved treatment for acute ischemic stroke. In this review, we discussed the neuro- and vaso-protective effects of NBO and recent finding of combining NBO with other drugs.

Protection against Oxygen-Glucose Deprivation/Reperfusion Injury in Cortical Neurons by Combining Omega-3 Polyunsaturated Acid with Lyciumbarbarum Polysaccharide.

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Shi, Zhe; Wu, Di; Yao, Jian-Ping; Yao, Xiaoli; Huang, Zhijian; Li, Peng; Wan, Jian-Bo; He, Chengwei; Su, Huanxing

2016-01-13

Ischemic stroke, characterized by the disturbance of the blood supply to the brain, is a severe worldwide health threat with high mortality and morbidity. However, there is no effective pharmacotherapy for ischemic injury. Currently, combined treatment is highly recommended for this devastating injury. In the present study, we investigated neuroprotective effects of the combination of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) and Lyciumbarbarum polysaccharide (LBP) on cortical neurons using an in vitro ischemic model. Our study demonstrated that treatment with docosahexaenoic acid (DHA), a major component of the ω-3 PUFAs family, significantly inhibited the increase of intracellular Ca(2+) in cultured wild type (WT) cortical neurons subjected to oxygen-glucose deprivation/reperfusion (OGD/R) injury and promoted their survival compared with the vehicle-treated control. The protective effects were further confirmed in cultured neurons with high endogenous ω-3 PUFAs that were isolated from fat-1 mice, in that a higher survival rate was found in fat-1 neurons compared with wild-type neurons after OGD/R injury. Our study also found that treatment with LBP (50 mg/L) activated Trk-B signaling in cortical neurons and significantly attenuated OGD/R-induced cell apoptosis compared with the control. Notably, both combining LBP treatment with ω-3 PUFAs administration to WT neurons and adding LBP to fat-1 neurons showed enhanced effects on protecting cortical neurons against OGD/R injury via concurrently regulating the intracellular calcium overload and neurotrophic pathway. The results of the study suggest that ω-3 PUFAs and LBP are promising candidates for combined pharmacotherapy for ischemic stroke.

Novel monohydroxamate drugs attenuate myocardial reperfusion-induced arrhythmias

DEFF Research Database (Denmark)

Collis, C S; Rice-Evans, C; Davies, Michael Jonathan

1996-01-01

the first 5 min of reperfusion were quantified. Drugs (all at 150 microM) were introduced during the last 2 min of ischaemia and remained throughout reperfusion. Although the monohydroxamate- and desferrioxamine-treated hearts showed a reduction in the incidence of ventricular tachycardia and fibrillation...

The flavonoid fisetin attenuates postischemic immune cell infiltration, activation and infarct size after transient cerebral middle artery occlusion in mice

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Gelderblom, Mathias; Leypoldt, Frank; Lewerenz, Jan; Birkenmayer, Gabriel; Orozco, Denise; Ludewig, Peter; Thundyil, John; Arumugam, Thiruma V; Gerloff, Christian; Tolosa, Eva; Maher, Pamela; Magnus, Tim

2012-01-01

The development of the brain tissue damage in ischemic stroke is composed of an immediate component followed by an inflammatory response with secondary tissue damage after reperfusion. Fisetin, a flavonoid, has multiple biological effects, including neuroprotective and antiinflammatory properties. We analyzed the effects of fisetin on infarct size and the inflammatory response in a mouse model of stroke, temporary middle cerebral artery occlusion, and on the activation of immune cells, murine primary and N9 microglial and Raw264.7 macrophage cells and human macrophages, in an in vitro model of inflammatory immune cell activation by lipopolysaccharide (LPS). Fisetin not only protected brain tissue against ischemic reperfusion injury when given before ischemia but also when applied 3 hours after ischemia. Fisetin also prominently inhibited the infiltration of macrophages and dendritic cells into the ischemic hemisphere and suppressed the intracerebral immune cell activation as measured by intracellular tumor necrosis factor α (TNFα) production. Fisetin also inhibited LPS-induced TNFα production and neurotoxicity of macrophages and microglia in vitro by suppressing nuclear factor κB activation and JNK/Jun phosphorylation. Our findings strongly suggest that the fisetin-mediated inhibition of the inflammatory response after stroke is part of the mechanism through which fisetin is neuroprotective in cerebral ischemia. PMID:22234339

Evaluation of the gender difference in the protective effects of ischemic postconditioning on ischemia-reperfusion-induced acute kidney injury in rats

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Atefeh Mahmoudi

2013-11-01

Full Text Available Background: Several studies indicate that gender differences exist in tolerance of the kidney to ischemia reperfusion (IR injury. Recently, postconditioning (POC, induction of brief repetitive periods of IR, has been introduced to reduce the extent of the damage to the kidney. This method was shown to attenuate renal IR injury by modifying oxidative stress and reducing lipid peroxidation. Considering the gender effect on the results of several treatment methods, in this study, we investigated the impact of gender on the protective effect of POC on the rat kidney.Methods: In this study, after right nephrectomy, 48 male and female rats were randomly divided into 6 groups of 8 rats: In IR group, with the use of bulldog clamp, 45 minutes of left renal artery ischemia was induced followed by 24 hours of reperfusion. In the sham group, all of the above surgical procedures were applied except that IR was not induced. In the POC group, after the induction of 45 minutes ischemia, 4 cycles of 10 seconds of intermittent ischemia and reperfusion were applied before restoring of blood to the kidney. 24 hours later, serum and renal tissue samples were collected for renal functional monitoring and oxidative stress evaluation.Results: Postconditioning attenuated renal dysfunction considering the significant decrease in plasma creatinine and BUN compared with IR group only in male rats (P<0.05. Also, POC attenuated oxidative stress in male rats’ kidney tissues as demonstrated by a significantly reduced malondialdehyde (MDA level and increased superoxide dismutase (SOD activity (P<0.05. In female rats, there were no changes in functional markers and oxidative stress status in POC group compared to IR group. Conclusion: Considering gender difference, POC had protective effect against IR injury by attenuating functional and oxidative stress markers in male rat kidneys. This protective effect was not seen in female rats.

The application of remote ischemic conditioning in cardiac surgery [version 1; referees: 3 approved

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Zeljko J. Bosnjak

2017-06-01

Full Text Available Perioperative myocardial ischemia and infarction are the leading causes of morbidity and mortality following anesthesia and surgery. The discovery of endogenous cardioprotective mechanisms has led to testing of new methods to protect the human heart. These approaches have included ischemic pre-conditioning, per-conditioning, post-conditioning, and remote conditioning of the myocardium. Pre-conditioning and per-conditioning include brief and repetitive periods of sub-lethal ischemia before and during prolonged ischemia, respectively; and post-conditioning is applied at the onset of reperfusion. Remote ischemic conditioning involves transient, repetitive, non-lethal ischemia and reperfusion in one organ or tissue (remote from the heart that renders myocardium more resistant to lethal ischemia/reperfusion injury. In healthy, young hearts, many conditioning maneuvers can significantly increase the resistance of the heart against ischemia/reperfusion injury. The large multicenter clinical trials with ischemic remote conditioning have not been proven successful in cardiac surgery thus far. The lack of clinical success is due to underlying risk factors that interfere with remote ischemic conditioning and the use of cardioprotective agents that have activated the endogenous cardioprotective mechanisms prior to remote ischemic conditioning. Future preclinical research using remote ischemic conditioning will need to be conducted using comorbid models.

Inhibition of coagulation and inflammation by activated protein C or antithrombin reduces intestinal ischemia/reperfusion injury in rats

NARCIS (Netherlands)

Schoots, Ivo G.; Levi, Marcel; van Vliet, Arlène K.; Maas, Adrie M.; Roossink, E. H. Paulina; van Gulik, Thomas M.

2004-01-01

Objective: To examine whether administration of activated protein C or antithrombin reduces local splanchnic derangement of coagulation and inflammation and attenuates intestinal dysfunction and injury following intestinal ischemia/reperfusion. Design: Randomized prospective animal study. Setting:

Canine study on myocardial ischemic memory with 18F-FDG PET/CT imaging

International Nuclear Information System (INIS)

Xie Boqia; Yang Minfu; Dou Kefei; Han Chunlei; Tian Yi; Zhang Ping; Yang Zihe; Yin Jiye; Wang Hao

2012-01-01

Objective: To explore whether the existence and duration of ischemia measured by dynamic 18 F-FDG PET/CT imaging correlated with the extent of myocardial ischemia in a canine model of myocardial ischemia-reperfusion. Methods: Canine coronary artery occlusion was carried out for 20 min (n=4) and for 40 min (n=4) followed by 24 h of open-artery reperfusion. All dogs underwent dynamic 18 F-FDG PET/CT and 99 Tc m -MIBI SPECT imaging at baseline and 1 h and 24 h after reperfusion.Quantitative analysis of myocardial 18 F-FDG uptake was performed using Carimas Core software,and the extraction ratio of 18 F-FDG (K) was calculated by the ratio of 18 F-FDG uptake rate in the ischemic area (k ischemia ) and normoperfused region (k normoperfused ). Echocardiographic data were also acquired between each PET/CT imaging study to detect the wall motion in the ischemic and normoperfused myocardium. Paired t test and non-parametric statistical tests, measured by SPSS 19.0, were used to analyze the data. Results: Coronary occlusion produced sustained, abnormal wall motion in the ischemic region for more than 1 h. Similar K values were demonstrated between the 20 min and 40 min groups at baseline (1.02 ±0.06 and 1.03 ±0.05, Z=-0.29, P>0.05). At 1 h after reperfusion, the reperfusion regions showed normal perfusion but with increased 18 F-FDG uptake, which was higher in the 40 min ischemic group than in the 20 min ischemic group (2.31 ±0.13 and 1.87 ±0.09, Z=-2.31, P<0.05). At 24 h after reperfusion, however, only the 40 min ischemic group showed slightly higher 18 F-FDG uptake than baseline (1.15 ± 0.02 and 1.03 ±0.05, t=4.32, P<0.05), whereas no significant difference was found in the 20 min ischemic group (1.05 ± 0.04 and 1.02 ± 0.06, t=0.87, P>0.05). Histological examination of the ischemic myocardium from both groups revealed neatly arranged cells without interstitial edema, hemorrhage nor inflammatory response. Conclusions: Myocardial 'ischemic memory' was

R56865 IS ANTIFIBRILLATORY IN REPERFUSED ISCHEMIC GUINEA-PIG HEARTS, EVEN WHEN GIVEN ONLY DURING REPERFUSION

NARCIS (Netherlands)

SCHEUFLER, E; MOZES, A; GUTTMANN, [No Value; WILFFERT, B

R56865 was previously characterized as an inhibitor of Na and Ca overload that has beneficial effects during ischemia and reperfusion. An isolated guinea-pig heart preparation was subjected to 60 minutes of ischemia and 60 minutes of reperfusion. R56865 was given before ischemia and with the onset

Sodium 4-Phenylbutyrate Attenuates Myocardial Reperfusion Injury by Reducing the Unfolded Protein Response.

Science.gov (United States)

Takatori, Osamu; Usui, Soichiro; Okajima, Masaki; Kaneko, Shuichi; Ootsuji, Hiroshi; Takashima, Shin-Ichiro; Kobayashi, Daisuke; Murai, Hisayoshi; Furusho, Hiroshi; Takamura, Masayuki

2017-05-01

The unfolded protein response (UPR) plays a pivotal role in ischemia-reperfusion (I/R) injury in various organs such as heart, brain, and liver. Sodium 4-phenylbutyrate (PBA) reportedly acts as a chemical chaperone that reduces UPR. In the present study, we evaluated the effect of PBA on reducing the UPR and protecting against myocardial I/R injury in mice. Male C57BL/6 mice were subjected to 30-minute myocardial I/R, and were treated with phosphate-buffered saline (as a vehicle) or PBA. At 4 hours after reperfusion, mice treated with PBA had reduced serum cardiac troponin I levels and numbers of apoptotic cells in left ventricles (LVs) in myocardial I/R. Infarct size had also reduced in mice treated with PBA at 48 hours after reperfusion. At 2 hours after reperfusion, UPR markers, including eukaryotic initiation of the factor 2α-subunit, activating transcription factor-6, inositol-requiring enzyme-1, glucose-regulated protein 78, CCAAT/enhancer-binding protein (C/EBP) homologous protein, and caspase-12, were significantly increased in mice treated with vehicle compared to sham-operated mice. Administration of PBA significantly reduced the I/R-induced increases of these markers. Cardiac function and dimensions were assessed at 21 days after I/R. Sodium 4-phenylbutyrate dedicated to the improvement of cardiac parameters deterioration including LV end-diastolic diameter and LV fractional shortening. Consistently, PBA reduced messenger RNA expression levels of cardiac remodeling markers such as collagen type 1α1, brain natriuretic peptide, and α skeletal muscle actin in LV at 21 days after I/R. Unfolded protein response mediates myocardial I/R injury. Administration of PBA reduces the UPR, apoptosis, infarct size, and preserved cardiac function. Hence, PBA may be a therapeutic option to attenuate myocardial I/R injury in clinical practice.

Protective effect of nicotinamide adenine dinucleotide (NAD+) against spinal cord ischemia-reperfusion injury via reducing oxidative stress-induced neuronal apoptosis.

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Xie, Lei; Wang, Zhenfei; Li, Changwei; Yang, Kai; Liang, Yu

2017-02-01

As previous studies demonstrate that oxidative stress and apoptosis play crucial roles in ischemic pathogenesis and nicotinamide adenine dinucleotide (NAD + ) treatment attenuates oxidative stress-induced cell death among primary neurons and astrocytes as well as significantly reduce cerebral ischemic injury in rats. We used a spinal cord ischemia injury (SCII) model in rats to verify our hypothesis that NAD + could ameliorate oxidative stress-induced neuronal apoptosis. Adult male rats were subjected to transient spinal cord ischemia for 60min, and different doses of NAD + were administered intraperitoneally immediately after the start of reperfusion. Neurological function was determined by Basso, Beattie, Bresnahan (BBB) scores. The oxidative stress level was assessed by superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The degree of apoptosis was analyzed by deoxyuridinetriphosphate nick-end labeling (TUNEL) staining and protein levels of cleaved caspase-3 and AIF (apoptosis inducing factor). The results showed that NAD + at 50 or 100mg/kg significantly decreased the oxidative stress level and neuronal apoptosis in the spinal cord of ischemia-reperfusion rats compared with saline, as accompanied with the decreased oxidative stress, NAD + administration significantly restrained the neuronal apoptosis after ischemia injury while improved the neurological and motor function. These findings suggested that NAD + might protect against spinal cord ischemia-reperfusion via reducing oxidative stress-induced neuronal apoptosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Identification of early irreversible damage area in a rat model of cerebral ischemia and reperfusion].

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Liu, S; Guo, Y

2000-02-01

To observe the early neuron ischemic damage in focal cerebral ischemia/reperfusion with histostaining methods of argyrophil III (AG III), Toludine blue(TB), and H&E, and to make out the 'separating line' between the areas of reversible and irreversible early ischemic damage. Forty-two male Wistar rats were randomly divided into the following groups: pseudo-surgical, blank-control, O2R0(occluded for 2 hours and reperfused for 0 hour), O2R0.5, O2R2, O2R4, O2R24. There were 6 rats in each group. Rats in experimental groups were suffered focal cerebral ischemia/reperfusion through a nylon suture method. After a special processor for tissue manage, the brain were coronal sectioned and stained with H&E, TB, and AG III. The area where dark neurons dwell in (ischemic core) were calculated with image analysis system. The success rate of ischemic model for this experiment is 90%. After being stained with argyrophil III method, normal neurons appear yellow or pale brown, which is hardly distinguished from the pale brown background. The ischemic neuron stained black, and has collapsed body and "corkscrew-like" axon or dentries, which were broken to some extent. The neuropil in the dark neurons dwelt area appears gray or pale black, which is apparently different from the pale brown neighborhood area. The distribution of dark neurons in cortex varies according to different layers, and has a character of columnar form. The dark neurons present as early as 2 hours ischemia without reperfusion with AG III method. AG III stain could selectively display early ischemic neurons, the area dwelt by dark neurons represent early ischemic core. Dark neuron is possibly the irreversibly damaged neuron. Identification of dark neurons could be helpful in the discrimination between early ischemic center and penumbra.

Attenuation of ischemia-reperfusion injury by sevoflurane postconditioning involves protein kinase B and glycogen synthase kinase 3 beta activation in isolated rat hearts.

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Fang, Neng-Xin; Yao, Yun-Tai; Shi, Chun-Xia; Li, Li-Huan

2010-12-01

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.

Oxidative stress in ischemia and reperfusion

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Sinning, Christoph; Westermann, Dirk; Clemmensen, Peter

2017-01-01

Oxidative stress remains a major contributor to myocardial injury after ischemia followed by reperfusion (I/R) as the reperfusion of the myocardial infarction (MI) area inevitably leads to a cascade of I/R injury. This review focused on concepts of the antioxidative defense system and elucidates......, the different mechanisms through which myocardial protection can be addressed, like ischemic postconditioning in myocardial infarction or adjunctive measures like targeted temperature management as well as new theories, including the role of iron in I/R injury, will be discussed....

Calreticulin Binds to Fas Ligand and Inhibits Neuronal Cell Apoptosis Induced by Ischemia-Reperfusion Injury

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Beilei Chen

2015-01-01

Full Text Available Background. Calreticulin (CRT can bind to Fas ligand (FasL and inhibit Fas/FasL-mediated apoptosis of Jurkat T cells. However, its effect on neuronal cell apoptosis has not been investigated. Purpose. We aimed to evaluate the neuroprotective effect of CRT following ischemia-reperfusion injury (IRI. Methods. Mice underwent middle cerebral artery occlusion (MCAO and SH-SY5Y cells subjected to oxygen glucose deprivation (OGD were used as models for IRI. The CRT protein level was detected by Western blotting, and mRNA expression of CRT, caspase-3, and caspase-8 was measured by real-time PCR. Immunofluorescence was used to assess the localization of CRT and FasL. The interaction of CRT with FasL was verified by coimmunoprecipitation. SH-SY5Y cell viability was determined by MTT assay, and cell apoptosis was assessed by flow cytometry. The measurement of caspase-8 and caspase-3 activity was carried out using caspase activity assay kits. Results. After IRI, CRT was upregulated on the neuron surface and bound to FasL, leading to increased viability of OGD-exposed SH-SY5Y cells and decreased activity of caspase-8 and caspase-3. Conclusions. This study for the first time revealed that increased CRT inhibited Fas/FasL-mediated neuronal cell apoptosis during the early stage of ischemic stroke, suggesting it to be a potential protector activated soon after IRI.

Sodium phenylbutyrate ameliorates focal cerebral ischemic/reperfusion injury associated with comorbid type 2 diabetes by reducing endoplasmic reticulum stress and DNA fragmentation.

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Srinivasan, Krishnamoorthy; Sharma, Shyam S

2011-11-20

Endoplasmic reticulum (ER) stress has been postulated to play a crucial role in the pathophysiology of cerebral ischemic/reperfusion (I/R) injury and diabetes. Diabetes is a major risk factor and also common amongst the people who suffer from stroke. In this study, we have investigated the neuroprotective potential of sodium 4-phenylbutyrate (SPB; 30-300mg/kg), a chemical chaperone by targeting ER stress in a rat model of transient focal cerebral ischemia associated with comorbid type 2 diabetes. Intraperitoneal treatment with SPB (100 and 300mg/kg) significantly ameliorated brain I/R damage as evidenced by reduction in cerebral infarct and edema volume. It also significantly improved the functional recovery of various neurobehavioral impairments (neurological deficit score, grip strength and rota rod) evoked by I/R compared with vehicle-treatment. Further, SPB (100mg/kg) significantly reduced the DNA fragmentation as shown by prominent reduction in terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells. This effect was observed concomitantly with significant attenuation in upregulation of 78kDa glucose regulated protein (GRP78), CCAAT/enhancer binding protein homologous protein or growth arrest DNA damage-inducible gene 153 (CHOP/GADD153) and activation of caspase-12, specific markers of ER stress/apoptosis. The neuroprotection observed with SPB was independent of its effect on cerebral blood flow and blood glucose. In conclusion, this study demonstrates the neuroprotective effect of SPB owing to amelioration of ER stress and DNA fragmentation. It also suggest that targeting ER stress might offer a promising therapeutic approach and benefits against ischemic stroke associated with comorbid type 2 diabetes. Copyright © 2011 Elsevier B.V. All rights reserved.

Time to Angiographic Reperfusion and Clinical Outcome after Acute Ischemic Stroke in the Interventional Management of Stroke Phase III (IMS III) Trial: A Validation Study

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Khatri, Pooja; Yeatts, Sharon D.; Mazighi, Mikael; Broderick, Joseph P.; Liebeskind, David S.; Demchuk, Andrew M.; Amarenco, Pierre; Carrozzella, Janice; Spilker, Judith; Foster, Lydia D.; Goyal, Mayank; Hill, Michael D.; Palesch, Yuko Y.; Jauch, Edward C.; Haley, E. Clarke; Vagal, Achala; Tomsick, Thomas A.

2014-01-01

BACKGROUND The IMS III Trial did not demonstrate clinical benefit of the endovascular approach compared to IV rt-PA alone for moderate or severe ischemic strokes (NIHSS≥8) enrolled within three hours of stroke onset. Late reperfusion of tissue that is no longer salvageable may be one explanation, as suggested by prior exploratory studies showing an association between time to reperfusion and good clinical outcome. We sought to validate this relationship in the large-scale IMS III trial, and consider its implications for future endovascular trials. METHODS The analysis consisted of the endovascular cohort with proximal arterial occlusions in the anterior circulation that achieved angiographic reperfusion (TICI 2–3) during the endovascular procedure (within 7 hours from the onset of symptoms). Logistic regression was used to model good clinical outcome (90-day modified Rankin 0–2) as a function of the time to reperfusion, and prespecified variables were considered for adjustment. FINDINGS Among 240 proximal vessel occlusions, angiographic reperfusion (TICI 2–3) was achieved in 182 (76%). Mean time to reperfusion was 325 minutes (range 180–418 minutes). Longer time for reperfusion was associated with a decreased likelihood of good clinical outcome (RR [95% CI] for every 30 minute delay: unadjusted 0·85 [0·77–0·94]; adjusted 0·88 [0·80–0·98]). INTERPRETATION We confirm that delay in time to angiographic reperfusion leads to a decreased likelihood of good clinical outcome. Achieving rapid reperfusion may be critical for the successes of future acute endovascular trials. FUNDING: NIH/NINDS (study sponsor), Genentech Inc. (study drug - intra-arterial t-PA), EKOS Corp. (device), Concentric Inc. (device), Cordis Neurovascular, Inc. (device), and Boehringer Ingelheim (European Investigator Meeting support). PMID:24784550

Ischemic preconditioning improves mitochondrial tolerance to experimental calcium overload.

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Crestanello, Juan A; Doliba, Nicolai M; Babsky, Andriy M; Doliba, Natalia M; Niibori, Koki; Whitman, Glenn J R; Osbakken, Mary D

2002-04-01

Ca(2+) overload leads to mitochondrial uncoupling, decreased ATP synthesis, and myocardial dysfunction. Pharmacologically opening of mitochondrial K(ATP) channels decreases mitochondrial Ca(2+) uptake, improving mitochondrial function during Ca(2+) overload. Ischemic preconditioning (IPC), by activating mitochondrial K(ATP) channels, may attenuate mitochondrial Ca(2+) overload and improve mitochondrial function during reperfusion. The purpose of these experiments was to study the effect of IPC (1) on mitochondrial function and (2) on mitochondrial tolerance to experimental Ca(2+) overload. Rat hearts (n = 6/group) were subjected to (a) 30 min of equilibration, 25 min of ischemia, and 30 min of reperfusion (Control) or (b) two 5-min episodes of ischemic preconditioning, 25 min of ischemia, and 30 min of reperfusion (IPC). Developed pressure (DP) was measured. Heart mitochondria were isolated at end-Equilibration (end-EQ) and at end-Reperfusion (end-RP). Mitochondrial respiratory function (state 2, oxygen consumption with substrate only; state 3, oxygen consumption stimulated by ADP; state 4, oxygen consumption after cessation of ADP phosphorylation; respiratory control index (RCI, state 3/state 4); rate of oxidative phosphorylation (ADP/Deltat), and ADP:O ratio) was measured with polarography using alpha-ketoglutarate as a substrate in the presence of different Ca(2+) concentrations (0 to 5 x 10(-7) M) to simulate Ca(2+) overload. IPC improved DP at end-RP. IPC did not improve preischemic mitochondrial respiratory function or preischemic mitochondrial response to Ca(2+) loading. IPC improved state 3, ADP/Deltat, and RCI during RP. Low Ca(2+) levels (0.5 and 1 x 10(-7) M) stimulated mitochondrial function in both groups predominantly in IPC. The Control group showed evidence of mitochondrial uncoupling at lower Ca(2+) concentrations (1 x 10(-7) M). IPC preserved state 3 at high Ca(2+) concentrations. The cardioprotective effect of IPC results, in part, from

Effect of ischemic preconditioning in skeletal muscle measured by functional magnetic resonance imaging and spectroscopy: a randomized crossover trial

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Bartko Johann

2011-06-01

Full Text Available Abstract Background Nuclear magnetic resonance (NMR imaging and spectroscopy have been applied to assess skeletal muscle oxidative metabolism. Therefore, in-vivo NMR may enable the characterization of ischemia-reperfusion injury. The goal of this study was to evaluate whether NMR could detect the effects of ischemic preconditioning (IPC in healthy subjects. Methods Twenty-three participants were included in two randomized crossover protocols in which the effects of IPC were measured by NMR and muscle force assessments. Leg ischemia was administered for 20 minutes with or without a subsequent impaired reperfusion for 5 minutes (stenosis model. IPC was administered 4 or 48 hours prior to ischemia. Changes in 31phosphate NMR spectroscopy and blood oxygen level-dependent (BOLD signals were recorded. 3-Tesla NMR data were compared to those obtained for isometric muscular strength. Results The phosphocreatine (PCr signal decreased robustly during ischemia and recovered rapidly during reperfusion. In contrast to PCr, the recovery of muscular strength was slow. During post-ischemic stenosis, PCr increased only slightly. The BOLD signal intensity decreased during ischemia, ischemic exercise and post-ischemic stenosis but increased during hyperemic reperfusion. IPC 4 hours prior to ischemia significantly increased the maximal PCr reperfusion signal and mitigated the peak BOLD signal during reperfusion. Conclusions Ischemic preconditioning positively influenced muscle metabolism during reperfusion; this resulted in an increase in PCr production and higher oxygen consumption, thereby mitigating the peak BOLD signal. In addition, an impairment of energy replenishment during the low-flow reperfusion was detected in this model. Thus, functional NMR is capable of characterizing changes in reperfusion and in therapeutic interventions in vivo. Trial Registration ClinicalTrials.gov: NCT00883467

Lysine and arginine reduce the effects of cerebral ischemic insults and inhibit glutamate-induced neuronal activity in rats

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Takashi Kondoh

2010-06-01

Full Text Available Intravenous administration of arginine was shown to be protective against cerebral ischemic insults via nitric oxide production and possibly via additional mechanisms. The present study aimed at evaluating the neuroprotective effects of oral administration of lysine (a basic amino acid, arginine, and their combination on ischemic insults (cerebral edema and infarction and hemispheric brain swelling induced by transient middle cerebral artery occlusion/reperfusion in rats. Magnetic resonance imaging and 2,3,5-triphenyltetrazolium chloride staining were performed two days after ischemia induction. In control animals, the major edematous areas were observed in the cerebral cortex and striatum. The volumes associated with cortical edema were significantly reduced by lysine (2.0 g/kg, arginine (0.6 g/kg, or their combined administration (0.6 g/kg each. Protective effects of these amino acids on infarction were comparable to the inhibitory effects on edema formation. Interestingly, these amino acids, even at low dose (0.6 g/kg, were effective to reduce hemispheric brain swelling. Additionally, the effects of in vivo microiontophoretic (juxtaneuronal applications of these amino acids on glutamate-evoked neuronal activity in the ventromedial hypothalamus were investigated in awake rats. Glutamate-induced neuronal activity was robustly inhibited by microiontophoretic applications of lysine or arginine onto neuronal membranes. Taken together, our results demonstrate the neuroprotective effects of oral ingestion of lysine and arginine against ischemic insults (cerebral edema and infarction, especially in the cerebral cortex, and suggest that suppression of glutamate-induced neuronal activity might be the primary mechanism associated with these neuroprotective effects.

Alpha-2 agonist attenuates ischemic injury in spinal cord neurons.

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Freeman, Kirsten A; Puskas, Ferenc; Bell, Marshall T; Mares, Joshua M; Foley, Lisa S; Weyant, Michael J; Cleveland, Joseph C; Fullerton, David A; Meng, Xianzhong; Herson, Paco S; Reece, T Brett

2015-05-01

Paraplegia secondary to spinal cord ischemia-reperfusion injury remains a devastating complication of thoracoabdominal aortic intervention. The complex interactions between injured neurons and activated leukocytes have limited the understanding of neuron-specific injury. We hypothesize that spinal cord neuron cell cultures subjected to oxygen-glucose deprivation (OGD) would simulate ischemia-reperfusion injury, which could be attenuated by specific alpha-2a agonism in an Akt-dependent fashion. Spinal cords from perinatal mice were harvested, and neurons cultured in vitro for 7-10 d. Cells were pretreated with 1 μM dexmedetomidine (Dex) and subjected to OGD in an anoxic chamber. Viability was determined by MTT assay. Deoxyuridine-triphosphate nick-end labeling staining and lactate dehydrogenase (LDH) assay were used for apoptosis and necrosis identification, respectively. Western blot was used for protein analysis. Vehicle control cells were only 59% viable after 1 h of OGD. Pretreatment with Dex significantly preserves neuronal viability with 88% viable (P control cells by 50% (P neuron cell culture, OGD mimics neuronal metabolic derangement responsible for paraplegia after aortic surgery. Dex preserves neuronal viability and decreases apoptosis in an Akt-dependent fashion. Dex demonstrates clinical promise for reducing the risk of paraplegia after high-risk aortic surgery. Copyright © 2015 Elsevier Inc. All rights reserved.

Inhibition of PKR protects against H2O2-induced injury on neonatal cardiac myocytes by attenuating apoptosis and inflammation.

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Wang, Yongyi; Men, Min; Xie, Bo; Shan, Jianggui; Wang, Chengxi; Liu, Jidong; Zheng, Hui; Yang, Wengang; Xue, Song; Guo, Changfa

2016-12-08

Reactive oxygenation species (ROS) generated from reperfusion results in cardiac injury through apoptosis and inflammation, while PKR has the ability to promote apoptosis and inflammation. The aim of the study was to investigate whether PKR is involved in hydrogen peroxide (H 2 O 2 ) induced neonatal cardiac myocytes (NCM) injury. In our study, NCM, when exposed to H 2 O 2 , resulted in persistent activation of PKR due to NCM endogenous RNA. Inhibition of PKR by 2-aminopurine (2-AP) or siRNA protected against H 2 O 2 induced apoptosis and injury. To elucidate the mechanism, we revealed that inhibition of PKR alleviated H 2 O 2 induced apoptosis companied by decreased caspase3/7 activity, BAX and caspase-3 expression. We also revealed that inhibition of PKR suppressed H 2 O 2 induced NFκB pathway and NLRP3 activation. Finally, we found ADAR1 mRNA and protein expression were both induced after H 2 O 2 treatment through STAT-2 dependent pathway. By gain and loss of ADAR1 expression, we confirmed ADAR1 modulated PKR activity. Therefore, we concluded inhibition of PKR protected against H 2 O 2 -induced injury by attenuating apoptosis and inflammation. A self-preservation mechanism existed in NCM that ADAR1 expression is induced by H 2 O 2 to limit PKR activation simultaneously. These findings identify a novel role for PKR/ADAR1 in myocardial reperfusion injury.

17β-Estradiol prevents cell death and mitochondrial dysfunction by estrogen receptor-dependent mechanism in astrocytes following oxygen-glucose deprivation/reperfusion

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Guo, Jiabin; Duckles, Sue P.; Weiss, John H.; Li, Xuejun; Krause, Diana N.

2012-01-01

17β-estradiol (E2) has been shown to protect against ischemic brain injury, yet its targets and the mechanisms are unclear. E2 may exert multiple regulatory actions on astrocytes that may greatly contribute to its ability to protect the brain. Mitochondria are recognized to play central roles in the development of injury during ischemia. Increasing evidence indicates that mitochondrial mechanisms are critically involved in E2-mediated protection. In this study, the effect of E2 and the role of mitochondria were evaluated in primary cultures of astrocytes subjected to an ischemia-like condition of oxygen-glucose deprivation (OGD)/reperfusion. We showed that E2 treatment significantly protects against OGD/reperfusion-induced cell death as determined by cell viability, apoptosis and lactate dehydrogenase leakage. The protective effects of E2 on astrocytic survival were blocked by an estrogen receptor (ER) antagonist (ICI 182,780), and were mimicked by an estrogen receptor (ER) agonist selective for ERα (PPT), but not by an ER agonist selective for ERβ (DPN). OGD/reperfusion provoked mitochondria dysfunction as manifested by an increase of cellular reactive oxygen species production, loss of mitochondrial membrane potential and depletion of ATP. E2 pretreatment significantly inhibited OGD/reperfusion-induced mitochondrial dysfunction, and this effect was also blocked by ICI 182,780. Therefore, we concluded that E2 provides direct protection to astrocytes from ischemic injury by an ER-dependent mechanism, highlighting an important role for ERα. Estrogen protects against mitochondria dysfunction at the early phase of ischemic injury. However, overall implications for protection against brain ischemia and its complex sequelae await further exploration. PMID:22554613

Sevoflurane mitigates shedding of hyaluronan from the coronary endothelium, also during ischemia/reperfusion: an ex vivo animal study

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Chen C

2016-04-01

Full Text Available Congcong Chen,1,3 Daniel Chappell,2,3 Thorsten Annecke,2,3 Peter Conzen,2 Matthias Jacob,2,3 Ulrich Welsch,4 Bernhard Zwissler,2 Bernhard F Becker3 1Department of Anesthesiology, Second Affiliated Hospital of Zhejiang University, Hangzhou, People's Republic of China; 2Clinic of Anesthesiology, Ludwig-Maximilians-University, Munich, Germany; 3Walter-Brendel-Centre of Experimental Medicine, Ludwig-Maximilians-University, Munich, Germany; 4Institute of Anatomy, Ludwig-Maximilians-University, Munich, Germany Abstract: Glycosaminoglycan hyaluronan (HA, a major constituent of the endothelial glycocalyx, helps to maintain vascular integrity. Preconditioning the heart with volatile anesthetic agents protects against ischemia/reperfusion injury. We investigated a possible protective effect of sevoflurane on the glycocalyx, especially on HA. The effect of pre-ischemic treatment with sevoflurane (15 minutes at 2% vol/vol gas on shedding of HA was evaluated in 28 isolated, beating guinea pig hearts, subjected to warm ischemia (20 minutes at 37°C followed by reperfusion (40 minutes, half with and half without preconditioning by sevoflurane. HA concentration was measured in the coronary effluent. Over the last 20 minutes of reperfusion hydroxyethyl starch (1 g% was continuously infused and the epicardial transudate collected over the last 5 minutes for measuring the colloid extravasation. Additional hearts were fixed by perfusion after the end of reperfusion for immunohistology and electron microscopy. Sevoflurane did not significantly affect post-ischemic oxidative stress, but strongly inhibited shedding of HA during the whole period, surprisingly even prior to ischemia. Immunohistology demonstrated that heparan sulfates and SDC1 of the glycocalyx were also preserved by sevoflurane. Electron microscopy revealed shedding of glycocalyx caused by ischemia and a mostly intact glycocalyx in hearts exposed to sevoflurane. Coronary vascular permeability of the

Evaluation of Pulmonary Reperfusion Injury in Rats Undergoing Mesenteric Ischemia and Reperfusion and Protective Effect of Postconditioning on this Process

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Carlos Henrique Marques dos Santos

2015-10-01

Full Text Available ABSTRACT INTRODUCTION: Some publications have demonstrated the presence of lung reperfusion injury in mesenteric ischemia and reperfusion (I/R, but under to diverse methods. Postconditioning has been recognized as effective in preventing reperfusion injury in various organs and tissues. However, its effectiveness has not been evaluated in the prevention of lung reperfusion injury after mesenteric ischemia and reperfusion. OBJECTIVE: To evaluate the presence of pulmonary reperfusion injury and the protective effect of ischemic postconditioning on lung parenchyma in rats submitted to mesenteric ischemia and reperfusion. METHODS: Thirty Wistar rats were distributed into three groups: group A (10 rats, which was held mesenteric ischemia (30 minutes and reperfusion (60 minutes; group B (10 rats, ischemia and reperfusion, interspersed by postconditioning with two alternating cycles of reperfusion and reocclusion, for two minutes each; and group C (10 rats, ischemia and reperfusion interleaved by postconditioning with four alternating cycles of reperfusion and reocclusion of 30 seconds each. Finally, it was resected the upper lung lobe for histological analysis. RESULTS: There were mild lung lesions (grade 1 in all samples. There was no statistical difference between groups 1 and 2 (P >0.05. CONCLUSION: The mesenteric ischemia and reperfusion in rats for thirty and sixty minutes, respectively, caused mild reperfusion injury in lung. Postconditioning was not able to minimize the remote reperfusion injury and there was no difference comparing two cycles of two minutes with four cycles of 30 seconds.

Novel Targets for Treating Ischemia-Reperfusion Injury in the Liver

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Weili Yang

2018-04-01

Full Text Available Liver ischemia-reperfusion injury (IRI is a major complication of hemorrhagic shock, liver transplantation, and other liver surgeries. It is one of the leading causes for post-surgery hepatic dysfunction, always leading to morbidity and mortality. Several strategies, such as low-temperature reperfusion and ischemic preconditioning, are useful for ameliorating liver IRI in animal models. However, these methods are difficult to perform in clinical surgeries. It has been reported that the activation of peroxisome proliferator activated receptor gamma (PPARγ protects the liver against IRI, but with unidentified direct target gene(s and unclear mechanism(s. Recently, FAM3A, a direct target gene of PPARγ, had been shown to mediate PPARγ’s protective effects in liver IRI. Moreover, noncoding RNAs, including LncRNAs and miRNAs, had also been reported to play important roles in the process of hepatic IRI. This review briefly discussed the roles and mechanisms of several classes of important molecules, including PPARγ, FAM3A, miRNAs, and LncRNAs, in liver IRI. In particular, oral administration of PPARγ agonists before liver surgery or liver transplantation to activate hepatic FAM3A pathways holds great promise for attenuating human liver IRI.

Protective effect of Na(+)/Ca (2+) exchange blocker KB-R7943 on myocardial ischemia-reperfusion injury in hypercholesterolemic rats.

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Lv, Yan; Ren, Yongkui; Sun, Lufan; Wang, Shaojun; Wei, Minjie; Jia, Dalin

2013-06-01

Reverse-mode activation of the Na(+)/Ca(2+) exchanger (NCX) during reperfusion following ischemia contributes to Ca(2+) overload and cardiomyocyte injury. KB-R7943, a selective reverse-mode NCX inhibitor, reduces lethal reperfusion injury under non-ischemic conditions. However, the effectiveness of this compound under ischemic conditions is unclear. In the present study, we studied the effects of KB-R7943 in an animal model of hyperlipidemia. We further assessed whether the K ATP (+) channels are involved in potential protective mechanisms of KB-R7943. Twelve rats were fed normal chow, while 48 animals were fed a high cholesterol diet. The hearts from the control and hypercholesterolemic rats were subjected to 25 min of global ischemia followed by a 120-min reperfusion. Before this, hearts from hypercholesterolemic rats either received no intervention (cholesterol control group) or were pre-treated with 1 μM KB-R7943 and 0.3 μM of K ATP (+) blocker glibenclamide or glibenclamide alone. The infarction sizes (triphenyltetrazolium assay) were 35 ± 5.0 % in the control group, 46 ± 8.7 % in the cholesterol control group (p KB-R7943 group (p KB-R7943 and glibenclamide group, and 47 ± 8.5 % in the glibenclamide group (p KB-R7943 attenuated the magnitude of cell apoptosis (p KB-R7943 reduces the infarction size and apoptosis in hyperlipidemic animals through the activation of K ATP (+) channels.

No evidence for activated autophagy in left ventricular myocardium at early reperfusion with protection by remote ischemic preconditioning in patients undergoing coronary artery bypass grafting.

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Nilgün Gedik

Full Text Available Remote ischemic preconditioning (RIPC by repeated brief limb ischemia/reperfusion reduces myocardial injury in patients undergoing coronary artery bypass grafting (CABG. Activation of signal transducer and activator of transcription 5 (STAT5 in left ventricular (LV myocardium at early reperfusion is associated with such protection. Autophagy, i.e., removal of dysfunctional cellular components through lysosomes, has been proposed as one mechanism of cardioprotection. Therefore, we analyzed whether or not the protection by RIPC is associated with activated autophagy.CABG patients were randomized to undergo RIPC (3×5 min blood pressure cuff inflation/5 min deflation or placebo (cuff deflated before skin incision (n = 10/10. Transmural myocardial biopsies were taken from the LV before cardioplegia (baseline and at early (5-10 min reperfusion. RIPC-induced protection was reflected by decreased serum troponin I concentration area under the curve (194±17 versus 709±129 ng/ml × 72 h, p = 0.002. Western blotting for beclin-1-phosphorylation and protein expression of autophagy-related gene 5-12 (ATG5-12 complex, light chain 3 (LC3, parkin, and p62 was performed. STAT3-, STAT5- and extracellular signal-regulated protein kinase 1/2 (ERK1/2-phosphorylation was used as positive control to confirm signal activation by ischemia/reperfusion.Signals of all analyzed autophagy proteins did not differ between baseline and early reperfusion and not between RIPC and placebo. STAT5-phosphorylation was greater at early reperfusion only with RIPC (2.2-fold, p = 0.02. STAT3- and ERK1/2-phosphorylation were greater at early reperfusion with placebo and RIPC (≥2.7-fold versus baseline, p≤0.05.Protection through RIPC in patients undergoing CABG surgery does not appear to be associated with enhanced autophagy in LV myocardium at early reperfusion.

Pre-Ischemic Treadmill Training for Prevention of Ischemic Brain Injury via Regulation of Glutamate and Its Transporter GLT-1

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Jingchun Guo

2012-07-01

Full Text Available Pre-ischemic treadmill training exerts cerebral protection in the prevention of cerebral ischemia by alleviating neurotoxicity induced by excessive glutamate release following ischemic stroke. However, the underlying mechanism of this process remains unclear. Cerebral ischemia-reperfusion injury was observed in a rat model after 2 weeks of pre-ischemic treadmill training. Cerebrospinal fluid was collected using the microdialysis sampling method, and the concentration of glutamate was determined every 40 min from the beginning of ischemia to 4 h after reperfusion with high-performance liquid chromatography (HPLC-fluorescence detection. At 3, 12, 24, and 48 h after ischemia, the expression of the glutamate transporter-1 (GLT-1 protein in brain tissues was determined by Western blot respectively. The effect of pre-ischemic treadmill training on glutamate concentration and GLT-1 expression after cerebral ischemia in rats along with changes in neurobehavioral score and cerebral infarct volume after 24 h ischemia yields critical information necessary to understand the protection mechanism exhibited by pre-ischemic treadmill training. The results demonstrated that pre-ischemic treadmill training up-regulates GLT-1 expression, decreases extracellular glutamate concentration, reduces cerebral infarct volume, and improves neurobehavioral score. Pre-ischemic treadmill training is likely to induce neuroprotection after cerebral ischemia by regulating GLT-1 expression, which results in re-uptake of excessive glutamate.

17β-Estradiol prevents cell death and mitochondrial dysfunction by an estrogen receptor-dependent mechanism in astrocytes after oxygen-glucose deprivation/reperfusion.

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Guo, Jiabin; Duckles, Sue P; Weiss, John H; Li, Xuejun; Krause, Diana N

17β-Estradiol (E2) has been shown to protect against ischemic brain injury, yet its targets and the mechanisms are unclear. E2 may exert multiple regulatory actions on astrocytes that may greatly contribute to its ability to protect the brain. Mitochondria are recognized as playing central roles in the development of injury during ischemia. Increasing evidence indicates that mitochondrial mechanisms are critically involved in E2-mediated protection. In this study, the effects of E2 and the role of mitochondria were evaluated in primary cultures of astrocytes subjected to an ischemia-like condition of oxygen-glucose deprivation (OGD)/reperfusion. We showed that E2 treatment significantly protects against OGD/reperfusion-induced cell death as determined by cell viability, apoptosis, and lactate dehydrogenase leakage. The protective effects of E2 on astrocytic survival were blocked by an estrogen receptor (ER) antagonist (ICI-182,780) and were mimicked by an ER agonist selective for ERα (PPT), but not by an ER agonist selective for ERβ (DPN). OGD/reperfusion provoked mitochondrial dysfunction as manifested by an increase in cellular reactive oxygen species production, loss of mitochondrial membrane potential, and depletion of ATP. E2 pretreatment significantly inhibited OGD/reperfusion-induced mitochondrial dysfunction, and this effect was also blocked by ICI-182,780. Therefore, we conclude that E2 provides direct protection to astrocytes from ischemic injury by an ER-dependent mechanism, highlighting an important role for ERα. Estrogen protects against mitochondrial dysfunction at the early phase of ischemic injury. However, overall implications for protection against brain ischemia and its complex sequelae await further exploration. Copyright © 2012 Elsevier Inc. All rights reserved.

Cardioprotective effect of the Hibiscus rosa sinensis flowers in an oxidative stress model of myocardial ischemic reperfusion injury in rat

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Gauthaman, Karunakaran K; Saleem, Mohamed TS; Thanislas, Peter T; Prabhu, Vinoth V; Krishnamoorthy, Karthikeyan K; Devaraj, Niranjali S; Somasundaram, Jayaprakash S

2006-01-01

Background The present study investigates the cardioprotective effects of Hibiscus rosa sinensis in myocardial ischemic reperfusion injury, particularly in terms of its antioxidant effects. Methods The medicinal values of the flowers of Hibiscus rosa sinensis (Chinese rose) have been mentioned in ancient literature as useful in disorders of the heart. Dried pulverized flower of Hibiscus rosa sinensis was administered orally to Wistar albino rats (150–200 gms) in three different doses [125, 250 and 500 mg/kg in 2% carboxy methyl cellulose (CMC)], 6 days per week for 4 weeks. Thereafter, rats were sacrificed; either for the determination of baseline changes in cardiac endogenous antioxidants [superoxide dismutase, reduced glutathione and catalase] or the hearts were subjected to isoproterenol induced myocardial necrosis. Results There was significant increase in the baseline contents of thiobarbituric acid reactive substances (TBARS) [a measure of lipid per oxidation] with both doses of Hibiscus Rosa sinensis. In the 250 mg/kg treated group, there was significant increase in superoxide dismutase, reduced glutathione, and catalase levels but not in the 125 and 500 mg/kg treated groups. Significant rise in myocardial thiobarbituric acid reactive substances and loss of superoxide dismutase, catalase and reduced glutathione (suggestive of increased oxidative stress) occurred in the vehicle treated hearts subjected to in vivo myocardial ischemic reperfusion injury. Conclusion It may be concluded that flower of Hibiscus rosa sinensis (250 mg/kg) augments endogenous antioxidant compounds of rat heart and also prevents the myocardium from isoproterenol induced myocardial injury. PMID:16987414

Genetic inhibition of CETP, ischemic vascular disease and mortality, and possible adverse effects

DEFF Research Database (Denmark)

Johannsen, Trine Holm; Frikke-Schmidt, Ruth; Schou, Jesper

2012-01-01

This study tested whether genetic variation in the CETP gene is consistent with a protective effect of cholesteryl ester transfer protein (CETP) inhibition on risk of ischemic events and on total mortality, without the adverse effects reported for torcetrapib.......This study tested whether genetic variation in the CETP gene is consistent with a protective effect of cholesteryl ester transfer protein (CETP) inhibition on risk of ischemic events and on total mortality, without the adverse effects reported for torcetrapib....

Hybrid approach of ventricular assist device and autologous bone marrow stem cells implantation in end-stage ischemic heart failure enhances myocardial reperfusion

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Khayat Andre

2011-01-01

Full Text Available Abstract We challenge the hypothesis of enhanced myocardial reperfusion after implanting a left ventricular assist device together with bone marrow mononuclear stem cells in patients with end-stage ischemic cardiomyopathy. Irreversible myocardial loss observed in ischemic cardiomyopathy leads to progressive cardiac remodelling and dysfunction through a complex neurohormonal cascade. New generation assist devices promote myocardial recovery only in patients with dilated or peripartum cardiomyopathy. In the setting of diffuse myocardial ischemia not amenable to revascularization, native myocardial recovery has not been observed after implantation of an assist device as destination therapy. The hybrid approach of implanting autologous bone marrow stem cells during assist device implantation may eventually improve native cardiac function, which may be associated with a better prognosis eventually ameliorating the need for subsequent heart transplantation. The aforementioned hypothesis has to be tested with well-designed prospective multicentre studies.

The expression of endothelial and inducible nitric oxide synthase and apoptosis in intestinal ischemia and reperfusion injury under the action of ischemic preconditioning and pentoxifylline.

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Oliveira, Teresinha Regina Ribeiro de; Oliveira, Geraldo Ferreira de; Simões, Ricardo Santos; Feitosa, Suellen Maurim; Tikazawa, Eduardo Hiroshi; Monteiro, Hugo Pequeno; Fagundes, Djalma José; Taha, Murched Omar

2017-11-01

To investigate the expression of nitric oxide synthase (NOS) and apoptosis associated with ischemic preconditioning (IPC) and pentoxifylline (PTX) in intestinal ischemia (I) and reperfusion (R) injury. Thirty male rats were assigned to 5 groups: (CG), no clamping of the superior mesenteric artery (90 minutes); (IR-SS) saline + ischemia (30 minutes) + reperfusion (60 minutes); (IR-PTX) PTX + ischemia (30 minutes) + reperfusion (60 minutes); (IPC-IR-SS) 5 minutes of ischemia + 5 minutes of reperfusion (IPC) + saline + I(30 minutes)+R(60 minutes); and (IPC-IR-PTX) IPC + PTX + I(30 minutes)+ R(60 minutes). The application of IPC and PTX showed a significantly lower immunohistochemistry reaction for active caspase-3 (P0.05). The NOS-2 expression (qRTPCR) in the IR-PTX group (P<0.05) was higher than the values for the IPC+IR-SS and IPC-IR-PTX groups. The NOS-3 expression was significantly upper in the IPC-IR-PTX group than in the CG (P<0.05), the IR-SS (P<0.05) and the IR-PTX (P<0.05) groups. The BCL-2 and active caspase-3 showed beneficial effects on PTX and IPC. The expression of NOS-2 and NOS-3 in the IPC and IPC-PTX groups showed no synergistic effect.

Agonist of inward rectifier K+ channels enhances the protection of ischemic postconditioning in isolated rat hearts.

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Liao, Z; Feng, Z; Long, C

2014-07-01

Selective inhibition of inward rectifier K + channels could abolish the protection mediated by ischemic preconditioning, but the roles of these channels in ischemic postconditioning have not been well characterized. Our study aims to evaluate the effect of inward rectifier K + channels on the protection induced by ischemic postconditioning. Langendorff-perfused rat hearts (n=8 per group) were split into four groups: postconditioning hearts (IPO group); ischemic postconditioning with BaCl 2 hearts (PB group); ischemic postconditioning with zacopride hearts (PZ group); and without ischemic postconditioning (CON group). After suffering 30 minutes of global ischemia, groups IPO, PB and PZ went through 10 seconds of ischemic postconditioning with three different perfusates: respectively, Krebs-Henseleit buffer (IPO group); 20 μmol/L BaCl 2 (antagonist of the channel, PB group); 1 μmol/L zacopride (agonist of the channel, PZ group). At the end of reperfusion, the myocardial performance was better preserved in the PZ group than the other three groups. The PB group showed no significant differences from the CON group. Our study has shown that the I K1 channel agonist zacopride is associated with the enhancement of ischemic postconditioning. © The Author(s) 2014.

Acute reperfusion without recanalization

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Makris, Nikolaos; Chamard, Leila; Mikkelsen, Irene K

2017-01-01

Acute reperfusion despite persistent arterial occlusion may occur in up to 30% of ischemic stroke patients. Recruitment of leptomeningeal collaterals may explain this phenomenon. Using dynamic susceptibility-contrast perfusion imaging (DSC-PI), we assessed acute changes in collateral flow among...... patients without recanalization. From a multicenter prospective database (I-KNOW), 46 patients with magnetic resonance angiography visible occlusion in whom both reperfusion and recanalization were assessed within 6 h of onset were identified. Maps of collateral flow at arterial, capillary and late venous...... phases were generated from DSC-PI through inter-frame registration, baseline signal subtraction and temporal summation, and graded blind to all other relevant clinical and radiological data using the Higashida scale. Flow direction and the acute evolution of collaterals were evaluated against...

Study on the Mechanism of mTOR-Mediated Autophagy during Electroacupuncture Pretreatment against Cerebral Ischemic Injury

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Zhou-Quan Wu

2016-01-01

Full Text Available This study is aimed at investigating the association between the electroacupuncture (EA pretreatment-induced protective effect against early cerebral ischemic injury and autophagy. EA pretreatment can protect cerebral ischemic and reperfusion injuries, but whether the attenuation of early cerebral ischemic injury by EA pretreatment was associated with autophagy is not yet clear. This study used the middle cerebral artery occlusion model to monitor the process of ischemic injury. For rats in the EA pretreatment group, EA pretreatment was conducted at Baihui acupoint before ischemia for 30 min for 5 consecutive days. The results suggested that EA pretreatment significantly increased the expression of autophagy in the cerebral cortical area on the ischemic side of rats. But the EA pretreatment-induced protective effects on the brain could be reversed by the specific inhibitor 3-methyladenine of autophagy. Additionally, the Pearson correlation analysis indicated that the impact of EA pretreatment on p-mTOR (2481 was negatively correlated with its impact on autophagy. In conclusion, the mechanism of EA pretreatment at Baihui acupoint against cerebral ischemic injury is mainly associated with the upregulation of autophagy expression, and its regulation of autophagy may depend on mTOR-mediated signaling pathways.

O2 free radicals: cause of ischemia-reperfusion injury to cardiac Na+-K+-ATPase

International Nuclear Information System (INIS)

Kim, M.S.; Akera, T.

1987-01-01

The role of O2 free radicals in the reduction of sarcolemmal Na+-K+-ATPase, which occurs during reperfusion of ischemic heart, was examined in isolated guinea pig heart using exogenous scavengers of O2 radicals and an inhibitor of xanthine oxidase. Ischemia and reperfusion reduced Na+-K+-ATPase activity and specific [3H]ouabain binding to the enzyme in ventricular muscle homogenates and also markedly lowered sodium pump activity estimated from ouabain-sensitive 86Rb+ uptake by ventricular muscle slices. These effects of ischemia and reperfusion were prevented to various degrees by O2-radical scavengers, such as superoxide dismutase, catalase, dimethyl-sulfoxide, histidine, or vitamin E or by the xanthine oxidase inhibitor, allopurinol. The degree of protection afforded by these agents paralleled that of reduction in enhanced lipid peroxidation of myocardial tissue as estimated from malondialdehyde production. These results strongly suggest that O2 radicals play a crucial role in the injury to sarcolemmal Na+-K+-ATPase during reperfusion of ischemic heart

O2 free radicals: cause of ischemia-reperfusion injury to cardiac Na+-K+-ATPase

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Kim, M.S.; Akera, T.

1987-02-01

The role of O2 free radicals in the reduction of sarcolemmal Na+-K+-ATPase, which occurs during reperfusion of ischemic heart, was examined in isolated guinea pig heart using exogenous scavengers of O2 radicals and an inhibitor of xanthine oxidase. Ischemia and reperfusion reduced Na+-K+-ATPase activity and specific (3H)ouabain binding to the enzyme in ventricular muscle homogenates and also markedly lowered sodium pump activity estimated from ouabain-sensitive 86Rb+ uptake by ventricular muscle slices. These effects of ischemia and reperfusion were prevented to various degrees by O2-radical scavengers, such as superoxide dismutase, catalase, dimethyl-sulfoxide, histidine, or vitamin E or by the xanthine oxidase inhibitor, allopurinol. The degree of protection afforded by these agents paralleled that of reduction in enhanced lipid peroxidation of myocardial tissue as estimated from malondialdehyde production. These results strongly suggest that O2 radicals play a crucial role in the injury to sarcolemmal Na+-K+-ATPase during reperfusion of ischemic heart.

Improving reconstituted HDL composition for efficient post-ischemic reduction of ischemia reperfusion injury.

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Marie-Claude Brulhart-Meynet

Full Text Available New evidence shows that high density lipoproteins (HDL have protective effects beyond their role in reverse cholesterol transport. Reconstituted HDL (rHDL offer an attractive means of clinically exploiting these novel effects including cardioprotection against ischemia reperfusion injury (IRI. However, basic rHDL composition is limited to apolipoprotein AI (apoAI and phospholipids; addition of bioactive compound may enhance its beneficial effects.The aim of this study was to investigate the role of rHDL in post-ischemic model, and to analyze the potential impact of sphingosine-1-phosphate (S1P in rHDL formulations.The impact of HDL on IRI was investigated using complementary in vivo, ex vivo and in vitro IRI models. Acute post-ischemic treatment with native HDL significantly reduced infarct size and cell death in the ex vivo, isolated heart (Langendorff model and the in vivo model (-48%, p<0.01. Treatment with rHDL of basic formulation (apoAI + phospholipids had a non-significant impact on cell death in vitro and on the infarct size ex vivo and in vivo. In contrast, rHDL containing S1P had a highly significant, protective influence ex vivo, and in vivo (-50%, p<0.01. This impact was comparable with the effects observed with native HDL. Pro-survival signaling proteins, Akt, STAT3 and ERK1/2 were similarly activated by HDL and rHDL containing S1P both in vitro (isolated cardiomyocytes and in vivo.HDL afford protection against IRI in a clinically relevant model (post-ischemia. rHDL is significantly protective if supplemented with S1P. The protective impact of HDL appears to target directly the cardiomyocyte.

Role of Extracellular RNA and TLR3‐Trif Signaling in Myocardial Ischemia–Reperfusion Injury

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Chen, Chan; Feng, Yan; Zou, Lin; Wang, Larry; Chen, Howard H.; Cai, Jia‐Yan; Xu, Jun‐Mei; Sosnovik, David E.; Chao, Wei

2014-01-01

Background Toll‐like receptor 3 (TLR3) was originally identified as the receptor for viral RNA and represents a major host antiviral defense mechanism. TLR3 may also recognize extracellular RNA (exRNA) released from injured tissues under certain stress conditions. However, a role for exRNA and TLR3 in the pathogenesis of myocardial ischemic injury has not been tested. This study examined the role of exRNA and TLR3 signaling in myocardial infarction (MI), apoptosis, inflammation, and cardiac dysfunction during ischemia‐reperfusion (I/R) injury. Methods and Results Wild‐type (WT), TLR3−/−, Trif−/−, and interferon (IFN) α/β receptor‐1 deficient (IFNAR1−/−) mice were subjected to 45 minutes of coronary artery occlusion and 24 hours of reperfusion. Compared with WT, TLR3−/− or Trif−/− mice had smaller MI and better preserved cardiac function. Surprisingly, unlike TLR(2/4)‐MyD88 signaling, lack of TLR3‐Trif signaling had no impact on myocardial cytokines or neutrophil recruitment after I/R, but myocardial apoptosis was significantly attenuated in Trif−/− mice. Deletion of the downstream IFNAR1 had no effect on infarct size. Importantly, hypoxia and I/R led to release of RNA including microRNA from injured cardiomyocytes and ischemic heart, respectively. Necrotic cardiomyocytes induced a robust and dose‐dependent cytokine response in cultured cardiomyocytes, which was markedly reduced by RNase but not DNase, and partially blocked in TLR3‐deficient cardiomyocytes. In vivo, RNase administration reduced serum RNA level, attenuated myocardial cytokine production, leukocytes infiltration and apoptosis, and conferred cardiac protection against I/R injury. Conclusion TLR3‐Trif signaling represents an injurious pathway during I/R. Extracellular RNA released during I/R may contribute to myocardial inflammation and infarction. PMID:24390148

Neuroprotection of ebselen against ischemia/reperfusion injury involves GABA shunt enzymes.

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Seo, Jeong Yeol; Lee, Choong Hyun; Cho, Jun Hwi; Choi, Jung Hoon; Yoo, Ki-Yeon; Kim, Dae Won; Park, Ok Kyu; Li, Hua; Choi, Soo Young; Hwang, In Koo; Won, Moo-Ho

2009-10-15

Seleno-organic compound, ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), is a substrate with radical-scavenging activity. In this study, we observed the neuroprotective effects of ebselen against ischemic damage and on GABA shunt enzymes such as glutamic acid decarboxylase 67 (GAD67), GABA transaminse (GABA-T) and succinic semialdehyde dehydrogenase (SSADH) in the hippocampal CA1 region after 5 min of transient forebrain ischemia in gerbils. For this, vehicle (physiological saline) or ebselen was administered 30 min before or after ischemia/reperfusion and sacrificed 4 days after ischemia/reperfusion. The administration of ebselen significantly reduced the neuronal death in the CA1 region induced by ischemia/reperfusion. In addition, treatment with ebselen markedly elevated GAD67, GABA-T and SSADH immunoreactivity and their protein levels compared to that in the vehicle-treated group, respectively. These results suggest that ebselen protects neurons from ischemic damage via control of the expressions of GABA shunt enzymes to enter the TCA cycle.

Effect of limb ischemic preconditioning on myocardial apoptosis-related proteins in ischemia-reperfusion injury

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GAO, JIANZHI; ZHAO, LINJING; WANG, YONGLING; TENG, QINGLEI; LIANG, LIDONG; ZHANG, JINYING

2013-01-01

The aim of this study was to investigate the effect of limb ischemic preconditioning (LIPC) on myocardial apoptosis in myocardial ischemia-reperfusion injury (MIRI), as well as the regulation of caspase-3 and the B cell lymphoma 2 (Bcl-2) gene in LIPC. A total of 50 rats were divided randomly into 5 groups (n=10). Four rats in each group were drawn out for detection of apoptosis. The sham, MIRI and LIPC groups underwent surgery without additional treatment. In the LY294002 group, LY294002 preconditioning was administered 15 min before reperfusion. In the LY294002+LIPC group, following LIPC, LY294002 was administered 15 min before reperfusion. The relative expression of myocardial Bcl-2 and caspase-3 mRNA and the apoptotic index for each group were determined by reverse transcription-polymerase chain reaction (RT-PCR) and terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL), respectively. The ultrastructure of the cardiac muscle tissues was observed by election microscopy. Compared with the sham group, the expression of caspase-3 mRNA in the MIRI group significantly increased (P<0.05) and the expression of Bcl-2 mRNA clearly decreased. Compared with the MIRI group, LIPC reduced the expression of caspase-3 and increased the expression of Bcl-2 mRNA (P<0.05). There were no significant differences between the LY294002+LIPC group and the MIRI group. Compared with the sham group, the apoptotic index of myocardial cells in the MIRI group significantly increased (P<0.05). Compared with the MIRI group, LIPC significantly decreased the apoptotic index of myocardial cells (P<0.05) and LY294002 increased the apoptotic index of myocardial cells. Compared with the LIPC group, LY294002+LIPC significantly increased the apoptotic index of myocardial cells (P<0.05). There were no significant differences between the LY294002+LIPC and MIRI groups. In conclusion, LIPC increased the expression of Bcl-2 and decreased caspase-3 mRNA and

Protective effects of alkaloid extract from Leonurus heterophyllus on cerebral ischemia reperfusion injury by middle cerebral ischemic injury (MCAO) in rats.

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Liang, Hao; Liu, Ping; Wang, Yunshan; Song, Shuliang; Ji, Aiguo

2011-07-15

The neuronal damage following cerebral ischemia is a serious risk to stroke patients. The aim of this study was to investigate the neuroprotective effects of alkaloid extract from Leonurus heterophyllus (LHAE) on cerebral ischemic injury. After 24 h of reperfusion following ischemia for 2 h induced by middle cerebral artery occlusion (MCAO), some rats were intraperitoneally administered different doses of LHAE (3.6, 7.2, 14.4 mg/kg, respectively). Neurological examination was measured in all animals. Infarct volume, myeloperoxidase (MPO) activity, levels of nitrate/nitrite metabolite (NO) and apoptosis ratio of nerve fiber in brain were determined. The results showed that LHAE at 7.2 mg/kg or 14.4 mg/kg exerted significantly decreasing neurological deficit scores and reducing the infarct volume on rats with focal cerebral ischemic injury (pagent. Further studies are warranted to assess the efficacy and safety of LHAE in patients. Copyright © 2011 Elsevier GmbH. All rights reserved.

Paeoniflorin, a Monoterpene Glycoside, Protects the Brain from Cerebral Ischemic Injury via Inhibition of Apoptosis.

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Zhang, Yuqin; Li, Huang; Huang, Mingqing; Huang, Mei; Chu, Kedan; Xu, Wei; Zhang, Shengnan; Que, Jinhua; Chen, Lidian

2015-01-01

Paeoniflorin (PF) is a principal bioactive component, which exhibits many pharmacological effects, including protection against ischemic injury. This paper aimed to investigate the protective effect of PF both in vivo and in vitro. Middle cerebral artery occlusion (MCAO) was performed on male Sprague-Dawley (SD) rat for 2 h, and different doses of PF or vehicle were administered 2 h after reperfusion. Rats were sacrificed after 7 days treatment of PF/vehicle. PF treatment for 7 days ameliorated MCAO-induced neurological deficit and decreased the infarct area. Further study demonstrated that PF inhibited the over-activation of astrocytes and apoptosis of neurons, and PF promoted up-regulation of neuronal specific marker neuron-specific nuclear (NeuN) and microtubule-associated protein 2 (MAP-2) in brain. Moreover, NMDA-induced neuron apoptosis was employed. The in vitro study revealed that PF treatment protected against NMDA-induced cell apoptosis and neuronal loss via up-regulation of neuronal specific marker NeuN, MAP-2 and Bcl-2 and the down-regulation Bax. Taken together, the present study demonstrates that PF produces its protective effect by inhibiting the over-activation of astrocytes, apoptosis of neurons and up-regulation of neuronal specific marker NeuN, MAP-2, and B-cell lymphoma-2 (Bcl-2), and down-regulation Bax. Our study reveals that PF may be a potential neuroprotective agent for stroke and can provide basic data for clinical use.

Low dose of L-glutamic acid attenuated the neurological dysfunctions and excitotoxicity in bilateral common carotid artery occluded mice.

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Ramanathan, Muthiah; Abdul, Khadar K; Justin, Antony

2016-10-01

Glutamate, an excitatory neurotransmitter in the brain, produces excitotoxicity through its agonistic action on postsynaptic N-methyl-D-aspartate receptor, resulting in neurodegeneration. We hypothesized that the administration of low doses of glutamate in cerebral ischemia could attenuate the excitotoxicity in neurons through its autoreceptor regulatory mechanism, and thereby control neurodegeneration. To test the hypothesis, the effect of L-glutamic acid (L-GA) 400 μmol/l/kg was evaluated in a bilateral common carotid artery occlusion-induced global ischemic mouse model. Memantine was used as a positive control. Global ischemia in mice was induced by occlusion of both the common carotid artery (bilateral common carotid artery occlusion) for 20 min, followed by reperfusion injury. L-GA was infused slowly through the tail vein 30 min before the surgery and every 24 h thereafter until the end of the experiment. The time-dependent change in cerebral blood flow was monitored using a laser Doppler image analyzer. The neurotransmitters glutamate and γ-aminobutyric acid (GABA) and the neurobiochemicals ATP, glutathione, and nitric oxide were measured in the different regions of brain at 0, 24, 48, and 72 h after reperfusion injury. L-GA increased locomotor activity, muscle coordination, and cerebral blood flow in ischemic mice at 72 h after ischemic insult. L-GA reduced glutamate levels in the cortex, striatum, and hippocampus at 72 h, whereas GABA levels were elevated in all three brain regions studied. Further, L-GA elevated glutathione levels and attenuated nitric oxide levels, but failed to restore ATP levels 72 h after ischemia-reperfusion. We conclude that the gradual reduction of glutamate along with elevation of GABA in different brain regions could have contributed toward the neuroprotective effect of L-GA. Hence, a slow infusion of a low dose of L-GA could be beneficial in controlling excitotoxicity-induced neurodegeneration following ischemia.

Ischemia-reperfusion histopathology alterations of the rabbit intestinal wall with and without ischemic preconditioning Alterações histopatológicas da parede intestinal de coelhos na isquemia-reperfusão com e sem precondicionamento isquêmico

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Otoni Moreira Gomes

2011-08-01

Full Text Available PURPOSE: To evaluate the histopathology alterations of the intestinal mucosa of rabbits submitted to mesenteric artery ischemia and reperfusion with and without ischemic preconditioning. METHODS: Two groups of ten male New Zealand white rabbits body (weight 2.2-3.0, average 2.5 kg. For mesenteric ischemia induction in all animals the small bowel and mesentery were cut 30cm and 60cm far from the gastroduodenal pyloric transition before the proximal mesenteric artery occlusion. In the Group 1 animals, the proximal mesenteric artery was occluded for 45 min with an atraumatic vascular clamp, followed by reperfusion for 30 min. In the Group 2 the 45 min ischemic phase was preceded by three cycles of ischemia (2 minutes each alternated with three cycles of reperfusion (2 minutes each. For istopathology study small bowel biopsies were obtained before ischemia (control, after 45 min of mesenteric ischemia and at 30 min. of mesenteric artery reperfusion. RESULTS: In the Group I animals, the followings histopathology grade results were observed: t1, mean 2,8; t2, mean 3,3. Using the Kruskal-Wallis non-parameter test, differences between t0 and t1 and t0 and t2 were significants (p0.05. In the Group 2 animals histopathology grade results were: t1 mean 2,6 and t2, mean 2,1. Differences between t0 and t1, t0 and t2 were significant (p0.05 between results of t1 in both groups but histopathology injury observed in Group 1 t2 biopsies were higher (pOBJETIVO: Avaliar as alterações histopatológicas da mucosa intestinal de coelhos submetidos a isquemia-reperfusão com e sem precondicionamento isquêmicol. MÉTODOS: Foram estudados dois grupos de dez coelhos Nova Zelândia machos com pesos variáveis entre 2,2 e 3,0 kg (média de 2,5 kg de peso corpóreo. Para indução da isquemia, em todos os animais, o intestino delgado e o mesentério foram seccionados 30 cm e 60 cm após a transição pilórica gastroduodenal, antes da oclusão da artéria mesent

Imaging of rat cerebral ischemia-reperfusion injury using99mTc-labeled duramycin

International Nuclear Information System (INIS)

Zhang Yuqing; Stevenson, Gail D.; Barber, Christy; Furenlid, Lars R.; Barrett, Harrison H.; Woolfenden, James M.; Zhao Ming; Liu Zhonglin

2013-01-01

Objectives: Prompt identification of necrosis and apoptosis in the infarct core and penumbra region is critical in acute stroke for delineating the underlying ischemic/reperfusion molecular pathologic events and defining therapeutic alternatives. The objective of this study was to investigate the capability of 99m Tc-labeled duramycin in detecting ischemia-reperfusion injury in rat brain after middle cerebral artery (MCA) occlusion. Methods: Ischemic cerebral injury was induced in ten rats by vascular insertion of a nylon suture in the left MCA for 3 hr followed by 21–24 hr reperfusion. After i.v. injection of 99m Tc-duramycin (1.0-3.5 mCi), dynamic cerebral images were acquired for 1 hr in six rats using a small-animal SPECT imager. Four other rats were imaged at 2 hr post-injection. Ex vivo images were obtained by autoradiography after sacrifice. Histologic analyses were performed to assess cerebral infarction and apoptosis. Results: SPECT images showed that 99m Tc-duramycin uptake in the left cerebral hemisphere was significantly higher than that in the right at 1 and 2 hr post-injection. The level of radioactive uptake in the ischemic brain varied based on ischemic severity. The average ratio of left cerebral hot-spot uptake to right hemisphere radioactivity, as determined by computerized ROI analysis, was 4.92 ± 0.79. Fractional washout at 1 hr was 38.2 ± 4.5% of peak activity for left cerebral hot-spot areas and 80.9 ± 2.0% for remote control areas (P 99m Tc-duramycin SPECT imaging may be useful for detecting and quantifying ongoing apoptotic neuronal cell loss induced by ischemia-reperfusion injury.

KLF5 overexpression attenuates cardiomyocyte inflammation induced by oxygen-glucose deprivation/reperfusion through the PPARγ/PGC-1α/TNF-α signaling pathway.

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Li, Yang; Li, Jian; Hou, Zhiwen; Yu, Yang; Yu, Bo

2016-12-01

The primary physiological function of Krüppel-like zinc-finger transcription factor (KLF5) is the regulation of cardiovascular remodeling. Vascular remodeling is closely related to the amelioration of various ischemic diseases. However, the underlying correlation of KLF5 and ischemia is not clear. In this study, we aim to investigate the role of KLF5 in myocardial ischemia reperfusion (IR) injury and the potential mechanisms involved. Cultured H9C2 cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/Rep) to mimic myocardial IR injury in vivo. Expressions of KLF5 and PPARγ were distinctly inhibited, and PGC-1α expression was activated at 24h after myocardial OGD/Rep injury. After myocardial OGD/Rep injury, we found that KLF5 overexpression down-regulated levels of TNF-α, IL-1β, IL-6 and IL-8. Through the analysis of lactate dehydrogenase (LDH) release, we demonstrate that KLF5 overexpression reduced the release of OGD/Rep-induced LDH. KLF5 overexpression significantly enhanced cell activity and decreased cell apoptosis during OGD/Rep injury. Compared with the OGD/Rep group, cells overexpressing KLF5 showed anti-apoptotic effects, such as decreased expression of Bax and cleaved caspase-3 as well as increased Bcl-2 expression. KLF5 overexpression activated PPARγ, a protein involved in OGD/Rep injury, and increased levels of PGC-1α, while TNF-α expression was remarkably inhibited. In addition, GW9662, a PPARγ receptor antagonist, reversed the expression of PPARγ/PGC-1α/TNF-α and cell activity induced by KLF5 overexpression. The effects of KLF5 overexpression on PPARγ/PGC-1α/TNF-α and cell activity were abolished by co-treatment with GW9662. Taken together, these results suggest that KLF5 can efficiently alleviate OGD/Rep-induced myocardial injury, perhaps through regulation of the PPARγ/PGC-1α/TNF-α pathway. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

[Approach to the relationship between the changes of the content of free zinc in hippocampus and ischemic neuronal damage].

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Zhou, Zhu-Juan; Zheng, Jian; He, Ying

2002-08-01

To make approach to the relationship between the changes of free zinc and ischemic neuronal damage in hippocampus after forebrain ischemia/reperfusion. The models of forebrain ischemia/reperfusion were established in rats. The contents of free Zn2+ were measured by TSQ fluorescence method. The Zn2+ chelator (CaEDTA) was injected into lateral ventricles in order to evaluate the effect of free Zn2+ on ischemic neuronal damage. (1) Zn2+ fluorescence in the hilus of dentate gyrus, CA3 region and the stratum radiatum and stratum oriens of CA1 decreased slightly at forty-eight hours after reperfusion. From seventy-two hours to ninety-six hour after reperfusion, the decreased fluorescence gradually returned to the normal level, but some fluorescence dots were found in pyramidal neurons of CA1 and the hilus of dentate gyrus. Seven days after reperfusion, all the changes of the fluorescence almost recovered. (2) The cell membrane-impermeable Zn2+ chelator CaEDTA could reduce the intracellular concentration of free Zn2+ and reduced neuronal damage after forebrain ischemia/reperfusion. (1) The synaptic vesicle Zn2+ released and then translocated into postsynaptic neurons after forebrain ischemia/reperfusion and played a role in ischemic neuronal damage. (2) The cell membrane-impermeable chelator CaEDTA could provide neuroprotection.

The role of heme oxygenase-1 in drug metabolizing dysfunction in the alcoholic fatty liver exposed to ischemic injury

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Won [Department of Pharmacology, Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju 52727 (Korea, Republic of); Kang, Jung-Woo [School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 16419 (Korea, Republic of); Lee, Sun-Mee, E-mail: sunmee@skku.edu [School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do 16419 (Korea, Republic of)

2016-02-01

This study was designed to investigate the role of heme oxygenase-1 (HO-1) in hepatic drug metabolizing dysfunction after ischemia/reperfusion (IR) in alcoholic fatty liver (AFL). Rats were fed a Lieber–DeCarli diet for five weeks to allow for development of AFL and were then subjected to 90 min of hepatic ischemia and 5 h of reperfusion. Rats were pretreated with hemin (HO-1 inducer) or ZnPP (HO-1 inhibitor) for 16 h and 3 h before hepatic ischemia. After hepatic IR, ethanol diet (ED)-fed rats had higher serum aminotransferase activities and more severe hepatic necrosis compared to the control diet (CD)-fed rats. These changes were attenuated by hemin and exacerbated by ZnPP. The activity and gene expression of HO-1 and its transcription factor (Nrf2) level increased significantly after 5 h of reperfusion in CD-fed rats but not in ED-fed rats. After reperfusion, cytochrome P450 (CYP) 1A1, 1A2, and 2B1 activities were reduced to levels lower than those observed in sham group, whereas CYP2E1 activity increased. The decrease in CYP2B1 activity and the increase in CYP2E1 activity were augmented after hepatic IR in ED-fed animals. These changes were significantly attenuated by hemin but aggravated by ZnPP. Finally, CHOP expression and PERK phosphorylation, microsomal lipid peroxidation, and levels of proinflammatory mediators increased in ED-fed rats compared to CD-fed rats after reperfusion. These increases were attenuated by hemin. Our results suggest that AFL exacerbates hepatic drug metabolizing dysfunction during hepatic IR via endoplasmic reticulum stress and lipid peroxidation and this is associated with impaired HO-1 induction. - Highlights: • Endogenous HO-1 is generated in insufficient quantities in steatotic ischemic injury. • Impaired HO-1 induction leads to excessive ER stress response and lipid peroxidation. • Alcoholic steatosis exacerbates IR-induced hepatic drug-metabolizing dysfunction. • HO-1 induction is required for appropriate medication

Myocardial thallium-201 kinetics and regional flow alterations with 3 hours of coronary occlusion and either rapid reperfusion through a totally patent vessel or slow reperfusion through a critical stenosis

International Nuclear Information System (INIS)

Granato, J.E.; Watson, D.D.; Flanagan, T.L.; Beller, G.A.

1987-01-01

Myocardial thallium-201 kinetics and regional blood flow alterations were examined in a canine model using 3 hours of coronary occlusion and different methods of reperfusion. Group I comprised 10 dogs undergoing a 3 hour left anterior descending artery occlusion and no reperfusion. Group II comprised seven dogs undergoing 3 hours of left anterior descending artery occlusion and rapid reperfusion through a totally patent vessel. Group III comprised 10 dogs undergoing 3 hours of left anterior descending artery occlusion and slow reperfusion through a residual stenosis. All dogs received 1.5 mCi of thallium-201 after 40 minutes of coronary occlusion. During occlusion and 2 hours of reperfusion, serial hemodynamic, blood flow and myocardial thallium-201 activity measurements were made. The relative thallium-201 gradient (normal zone minus ischemic zone activity when initial normal activity is expressed as 100%) during left anterior descending coronary occlusion was similar in all groups. Group I, 87 +/- 3%; Group II, 78 +/- 6%; Group III, 83 +/- 6% (p = NS). After 2 hours of either method of reperfusion, the final relative gradient had decreased to a similar level (Group II, 51 +/- 9%; Group III, 42 +/- 6%). These values were not significantly different from the final relative thallium-201 gradient seen in dogs undergoing a sustained 3 hour occlusion (Group I, 55 +/- 5%). After 2 hours of reperfusion, both methods of reflow were associated with similar degrees of ''no reflow.'' Transmural flows in the central ischemic zone were 89 +/- 10% of normal in Group II and 71 +/- 6% of normal in Group III after reperfusion, with both flows substantially higher than the relative thallium-201 activities in these dogs

Sustained benefit of temporary limited reperfusion in skeletal muscle following ischemia

International Nuclear Information System (INIS)

Anderson, R.J.; Cambria, R.; Kerr, J.; Hobson, R.W. II

1990-01-01

Limiting the rate of reperfusion blood flow following prolonged ischemia in skeletal muscle has been shown beneficial. However, the persistence of this benefit with reinstitution of normal blood flow remains undefined. We investigated the role of temporary limited reperfusion on ischemia-reperfusion injury in an isolated gracilis muscle model in six anesthetized dogs. Both gracilis muscles were subjected to 6 hr of ischemia followed by 2 hr of reperfusion. Reperfusion blood flow was limited for the first hour in one gracilis muscle to its preischemic rate followed by a second hour of normal reperfusion (LR/NR). The contralateral muscle underwent 2 hr of normal reperfusion (NR/NR). Muscle injury was quantified by technetium-99m pyrophosphate (TcPyp) uptake and by histochemical staining using triphenyltetrazolium chloride (TTC) with planimetry of the infarct size. Capillary permeability was evaluated by muscle weight gain. Results are reported as the mean +/- SEM. These data demonstrate a sustained benefit from temporary limited reperfusion. This methodology should be considered in the surgical management of the acutely ischemic limb

Normal versus sickle red blood cells: hemodynamic and permeability characteristics in reperfusion lung injury.

Science.gov (United States)

Haynes, J; Seibert, A; Shah, A; Taylor, A

1990-01-01

Decreased deformability and increased internal viscosity of the sickle red blood cell (SRBC) contribute to abnormal flow in the microcirculation. Since the lungs are commonly affected in sickle cell disease, we compared the hemodynamics of the normal human red blood cell (NRBC) with the SRBC in the pulmonary circulation. The SRBC has decreased antioxidant enzyme activities compared with the NRBC. Thus, using the capillary filtration coefficient (Kfc), we determined the ability of the NRBC and the SRBC to attenuate the increased permeability and resulting edema seen in the oxidant stress of reperfusion lung injury (RLI). We found that lungs perfused with a 5% SRBC perfusate had higher pulmonary arterial pressures (Ppa) and resistances than lungs perfused with a 5% NRBC perfusate. Lungs made ischemic and reperfused with a physiologic cell-free perfusate resulted in a significant increase (P less than .05) in Kfc compared with the preischemic Kfc (.45 +/- .06 to 1.4 +/- 22 mL.min-1.cm H2O.100 g-1). In lungs reperfused with 5% RBC-containing perfusates, the Kfc did not change from preischemic Kfc with NRBCs and decreased from the preischemic Kfc with SRBCs. These findings suggest that the SRBC causes physiologically significant increases in Ppa and resistances and the SRBC, like the NRBC, offers apparent protection in RLI.

Remote Ischemic Conditioning

Science.gov (United States)

Heusch, Gerd; Bøtker, Hans Erik; Przyklenk, Karin; Redington, Andrew; Yellon, Derek

2014-01-01

In remote ischemic conditioning (RIC) brief, reversible episodes of ischemia with reperfusion in one vascular bed, tissue or organ confer a global protective phenotype and render remote tissues and organs resistant to ischemia/reperfusion injury. The peripheral stimulus can be chemical, mechanical or electrical and involves activation of peripheral sensory nerves. The signal transfer to the heart or other organs is through neuronal and humoral communications. Protection can be transferred, even across species, with plasma-derived dialysate and involves nitric oxide, stromal derived factor-1α, microRNA-144, but also other, not yet identified factors. Intracardiac signal transduction involves: adenosine, bradykinin, cytokines, and chemokines, which activate specific receptors; intracellular kinases; and mitochondrial function. RIC by repeated brief inflation/deflation of a blood pressure cuff protects against endothelial dysfunction and myocardial injury in percutaneous coronary interventions, coronary artery bypass grafting and reperfused acute myocardial infarction. RIC is safe and effective, noninvasive, easily feasible and inexpensive. PMID:25593060

Sustained nonoxidative glucose utilization and depletion of glycogen in reperfused canine myocardium

International Nuclear Information System (INIS)

Schwaiger, M.; Neese, R.A.; Araujo, L.

1989-01-01

Ischemically injured reperfused myocardium is characterized by increased 18F-fluorodeoxyglucose uptake as demonstrated by positron emission tomography. To elucidate the metabolic fate of exogenous glucose entering reperfused myocardium, D-[6-14C] glucose and L-[U-13C] lactate were used to determine glucose uptake, glucose oxidation and the contribution of exogenous glucose to lactate production. The pathologic model under investigation consisted of a 3 h balloon occlusion of the left anterior descending coronary artery followed by 24 h of reperfusion in canine myocardium. The extent and severity of myocardial injury after the ischemia and reperfusion were assessed by histochemical evaluation (triphenyltetrazolium chloride and periodic acid-Schiff stains). Thirteen intervention and four control dogs were studied. The glucose uptake in the occluded/reperfused area was significantly enhanced compared with that in control dogs (0.40 +/- 0.14 versus 0.15 +/- 0.10 mumol/ml, respectively). In addition, a significantly greater portion of the glucose extracted immediately entered glycolysis in the intervention group (75%) than in the control dogs (33%). The activity of the nonoxidative glycolytic pathway was markedly increased in the ischemically injured reperfused area, as evidenced by the four times greater lactate release in this area compared with the control value. The dual carbon-labeled isotopes showed that 57% of the exogenous glucose entering glycolysis was being converted to lactate. Exogenous glucose contributed to greater than 90% of the observed lactate production. This finding was confirmed by the histochemical finding of sustained glycogen depletion in the occlusion/reperfusion area. The average area of glycogen depletion (37%) significantly exceeded the average area of necrosis

Gradual reintroduction of oxygen reduces reperfusion injury in cat stomach

International Nuclear Information System (INIS)

Perry, M.A.; Wadhwa, S.S.

1988-01-01

Recent studies have shown that oxygen-derived free radicals are responsible for a major portion of ischemia-reperfusion injury in the stomach. The oxygen radicals are produced during perfusion when oxygen delivery to the tissue increases. In the present study the authors investigate the effect on mucosal injury of regulating the rate of reintroduction of oxygen to the stomach after ischemia. Local gastric ischemia was achieved by reducing celiac artery pressure to 30 mmHg for 1 h. Ischemic injury was assessed by measuring the loss of 51 Cr-labeled red blood cells across the gastric mucosa. Mucosal blood loss was negligible before and during the ischemia period but increased during reperfusion. When blood flow to the stomach was gradually returned to normal after ischemia, the mucosal blood loss was reduced. If the stomach was vascularly perfused with low Po 2 blood for 1 h after ischemia before being returned to normal arterial perfusion, the mucosal blood loss was also reduced. When the stomach was made hypoxemic for 1 h rather than ischemic by perfusing the vasculature with low Po 2 blood then reperfused with normoxic blood, there was very little mucosal bleeding. The data indicate that gastric mucosal bleeding after ischemia is reduced if the tissue is returned slowly to a normal Po 2 . These findings support the concept that reperfusion injury is due largely to the production of oxygen radicals. The low level of injury produced by hypoxemia indicates that hypoxia per se makes only a minor contribution to reperfusion injury in the stomach

Interstitial pO2 in ischemic penumbra and core are differentially affected following transient focal cerebral ischemia in rats.

Science.gov (United States)

Liu, Shimin; Shi, Honglian; Liu, Wenlan; Furuichi, Takamitsu; Timmins, Graham S; Liu, Ke Jian

2004-03-01

Stroke causes heterogeneous changes in tissue oxygenation, with a region of decreased blood flow, the penumbra, surrounding a severely damaged ischemic core. Treatment of acute ischemic stroke aims to save this penumbra before its irreversible damage by continued ischemia. However, effective treatment remains elusive due to incomplete understanding of processes leading to penumbral death. While oxygenation is central in ischemic neuronal death, it is unclear exactly what actual changes occur in interstitial oxygen tension (pO2) in ischemic regions during stroke, particularly the penumbra. Using the unique capability of in vivo electron paramagnetic resonance (EPR) oximetry to measure localized interstitial pO2, we measured both absolute values, and temporal changes of pO2 in ischemic penumbra and core during ischemia and reperfusion in a rat model. Ischemia rapidly decreased interstitial pO2 to 32% +/- 7.6% and 4% +/- 0.6% of pre-ischemic values in penumbra and core, respectively 1 hour after ischemia. Importantly, whilst reperfusion restored core pO2 close to its pre-ischemic value, penumbral pO2 only partially recovered. Hyperoxic treatment significantly increased penumbral pO2 during ischemia, but not in the core, and also increased penumbral pO2 during reperfusion. These divergent, important changes in pO2 in penumbra and core were explained by combined differences in cellular oxygen consumption rates and microcirculation conditions. We therefore demonstrate that interstitial pO2 in penumbra and core is differentially affected during ischemia and reperfusion, providing new insights to the pathophysiology of stroke. The results support normobaric hyperoxia as a potential early intervention to save penumbral tissue in acute ischemic stroke.

Effect of a critical coronary stenosis on myocardial neutrophil accumulation during ischemia and early reperfusion in dogs

International Nuclear Information System (INIS)

Richard, V.J.; Brooks, S.E.; Jennings, R.B.; Reimer, K.A.

1989-01-01

In many experimental models of ischemia and reperfusion, reperfusion is performed abruptly, allowing full reactive hyperemia to occur. In the clinical setting, however, reperfusion after thrombolysis is often limited by residual stenosis. Some experimental models attempt to mimic this situation with a critical stenosis. The purpose of this study was to determine whether preventing reactive hyperemia during the initial phase of reperfusion would modify the transmural distribution of myocardial blood flow or the myocardial accumulation of polymorphonuclear leukocytes (PMNs). The left circumflex artery was occluded for 90 minutes and then reperfused for 60 minutes in anesthetized, open-chest dogs. Autologous PMNs were isolated, labeled with 111In, and reinjected 1 hour before coronary occlusion. 125I-labeled albumin was injected simultaneously to correct for 111In associated with plasma proteins and to permit calculation of the number of PMNs in the inner, middle, and outer thirds of nonischemic and ischemic-reperfused tissue. The presence of a critical stenosis abolished reactive hyperemia during the first 5 minutes of reperfusion, but did not substantially affect blood flow measured after 55 minutes of reperfusion. In both groups, there was a significant accumulation of PMNs in all layers of the ischemic-reperfused bed compared with the nonischemic bed, and the magnitude of this PMN accumulation was not altered by the presence of a critical stenosis. Moreover, infarct size, estimated by triphenyl tetrazolium chloride (TTC) loss after 60 minutes of reperfusion, was not affected by the presence of a critical stenosis. Thus, the presence of a critical stenosis abolished the hyperemic blood flow after reperfusion but did not influence the early PMN response to ischemia and reperfusion or the early loss of TTC staining

Ursolic acid reduces the metalloprotease/anti-metalloprotease imbalance in cerebral ischemia and reperfusion injury.

Science.gov (United States)

Wang, Yanzhe; He, Zhiyi; Deng, Shumin

2016-01-01

Activators of PPARs, particularly PPARγ, may be effective neuroprotective drugs against inflammatory responses in cerebral ischemia and reperfusion injury. Ursolic acid (UA) may act as a PPARγ agonist and serve as an anti-inflammatory agent. In this study, we used a rat middle cerebral artery occlusion and reperfusion model to examine how UA acts as a neuroprotective agent to modulate the metalloprotease/anti-metalloprotease balance. The middle cerebral artery occlusion and reperfusion model (occlusion for 2 hours followed by reperfusion for 48 hours) was induced in male Sprague Dawley rats. UA was administered intragastrically 0.5, 24, and 47 hours after reperfusion. Bisphenol A diglycidyl ether (a PPARγ antagonist) was intraperitoneally administered 1, 24.5, and 47.5 hours after reperfusion. Forty-eight hours after reperfusion, neurological deficits and infarct volume were estimated. The PPARγ level and the metalloprotease/anti-metalloprotease balance were examined by Western blotting and immunohistochemistry. The activation of MAPK signaling pathways was also assessed. UA-treated (5, 10, or 20 mg/kg) rats showed significant improvement in neurological deficit score, infarct volume, and the number of intact neurons compared with control rats (Pprotective effects in a dose-dependent manner. Co-treatment with UA and bisphenol A diglycidyl ether completely abolished the UA-induced changes in PPARγ expression; however UA continued to exert a significant but partial neuroprotective effect. UA can act as a PPARγ agonist to improve the metalloprotease/anti-metalloprotease balance, possibly by inhibiting the activation of the MAPK signaling pathway, thereby attenuating cerebral ischemia and reperfusion injury. Therefore, UA may serve as a novel neuroprotective therapeutic agent.

The mechanism of Intralipid®-mediated cardioprotection complex IV inhibition by the active metabolite, palmitoylcarnitine, generates reactive oxygen species and activates reperfusion injury salvage kinases.

Directory of Open Access Journals (Sweden)

Phing-How Lou

Full Text Available Intralipid® administration at reperfusion elicits protection against myocardial ischemia-reperfusion injury. However, the underlying mechanisms are not fully understood.Sprague-Dawley rat hearts were exposed to 15 min of ischemia and 30 min of reperfusion in the absence or presence of Intralipid® 1% administered at the onset of reperfusion. In separate experiments, the reactive oxygen species (ROS scavenger N-(2-mercaptopropionyl-glycine was added either alone or with Intralipid®. Left ventricular work and activation of Akt, STAT3, and ERK1/2 were used to evaluate cardioprotection. ROS production was assessed by measuring the loss of aconitase activity and the release of hydrogen peroxide using Amplex Red. Electron transport chain complex activities and proton leak were measured by high-resolution respirometry in permeabilized cardiac fibers. Titration experiments using the fatty acid intermediates of Intralipid® palmitoyl-, oleoyl- and linoleoylcarnitine served to determine concentration-dependent inhibition of complex IV activity and mitochondrial ROS release.Intralipid® enhanced postischemic recovery and activated Akt and Erk1/2, effects that were abolished by the ROS scavenger N-(2-mercaptopropionylglycine. Palmitoylcarnitine and linoleoylcarnitine, but not oleoylcarnitine concentration-dependently inhibited complex IV. Only palmitoylcarnitine reached high tissue concentrations during early reperfusion and generated significant ROS by complex IV inhibition. Palmitoylcarnitine (1 µM, administered at reperfusion, also fully mimicked Intralipid®-mediated protection in an N-(2-mercaptopropionyl-glycine -dependent manner.Our data describe a new mechanism of postconditioning cardioprotection by the clinically available fat emulsion, Intralipid®. Protection is elicited by the fatty acid intermediate palmitoylcarnitine, and involves inhibition of complex IV, an increase in ROS production and activation of the RISK pathway.

Effect of electroacupuncture on TRPM7 mRNA expression after cerebral ischemia/reperfusion in rats via TrkA pathway.

Science.gov (United States)

Zhao, Li; Shi, Jing; Sun, Ning; Tian, Shunlian; Meng, Xianfang; Liu, Xiaochun; Li, Lingli

2005-01-01

The effect of electroacupuncture (EA) on TRPM7 mRNA expression of focal cerebral ischemia in rats and further the role of EA in the relationship between TRPM7 and trkA pathway was investigated. Thirty SD rats were randomly divided into 5 groups : normal group, ischemia/reperfusion group, EA treated group (ischemic rats with EA treatment), TE infusion group (ischemic rats with EA treatment and TE buffer infusion), AS-ODN group (ischemic rats with EA treatment and antisense trkA oligonucleotide infusion). The stroke animal model was established by the modified method of middle cerebral artery occlusion. Antisense trkA oligonucleotide that blocked NGFs effects was injected into cerebroventricle before EA. The TRPM7 mRNA was detected by RT-PCR method. The results showed that there were low TRPM7 mRNA levels in cortex and hippocampus in normal group. Compared with normal group, TRPM7 mRNA expression was increased significantly in ischemia/reperfusion group (PPM7 mRNA was found in EA treated group in contrast to ischemia/reperfusion group (P<0.05). The expression of TRPM7 mRNA in AS-ODN group was remarkably increased compared with EA treated group and TE infusion group (P<0.05). The results indicated that TRPM7 channels in the ischemic cortex and hippocampus in rats might play a key role in ischemic brain injury. EA could reverse the overexpression of TRPM7 in cerebral ischemia/reperfusion rats. And the inhibitory effect of EA on TRPM7 channels might be through trkA pathway.

Effect of desferrioxamine on reperfusion damage of rat heart ...

African Journals Online (AJOL)

1990-09-01

Sep 1, 1990 ... ... deferrioxamine on rat heart mitochondrial oxidative phosphorylation after normothermic ischemic cardiac arrest and of reperfusion. Res Commun Chem Pathol Pharmacol 1988;. 62: 419-434. IL Sordahl LA, Johnson C, Blailock ZR. Schwartz A. The mitochondrion. Mechods Phannacol1971; 1: 247-286.

Research progress of NLRP3 inflammasome in organ ischemia-reperfusion injury

Directory of Open Access Journals (Sweden)

Pei-lei LI

2017-04-01

Full Text Available Ischemia-reperfusion injury is a common pathophysiological process in organ transplantation, ischemic stroke and organ resection surgery, and also an important factor causing organ dysfunction and severe postoperative complications. How to avoid or mitigate organ ischemia-reperfusion injury has always been a research hotspot. NLRP3 Inflammasome has been considered to be an important link in inflammatory response. It has an indispensable role in maturation process of IL -1βand IL -18. We reviewed the research in recent yeas about the role of NLRP3 Inflammasome in organ ischemia-reperfusion injury in this paper. DOI: 10.11855/j.issn.0577-7402.2017.02.17

The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury.

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Milos R Ljubisavljevic

Full Text Available Although repetitive Transcranial Magnetic Stimulation (rTMS in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS and intermittent (iTBS theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS and pattern (cTBS vs. iTBS. The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss

The Effects of Different Repetitive Transcranial Magnetic Stimulation (rTMS) Protocols on Cortical Gene Expression in a Rat Model of Cerebral Ischemic-Reperfusion Injury

Science.gov (United States)

Ljubisavljevic, Milos R.; Javid, Asma; Oommen, Joji; Parekh, Khatija; Nagelkerke, Nico; Shehab, Safa; Adrian, Thomas E.

2015-01-01

Although repetitive Transcranial Magnetic Stimulation (rTMS) in treatment of stroke in humans has been explored over the past decade the data remain controversial in terms of optimal stimulation parameters and the mechanisms of rTMS long-term effects. This study aimed to explore the potential of different rTMS protocols to induce changes in gene expression in rat cortices after acute ischemic-reperfusion brain injury. The stroke was induced by middle cerebral artery occlusion (MCAO) with subsequent reperfusion. Changes in the expression of 96 genes were examined using low-density expression arrays after MCAO alone and after MCAO combined with 1Hz, 5Hz, continuous (cTBS) and intermittent (iTBS) theta-burst rTMS. rTMS over the lesioned hemisphere was given for two weeks (with a 2-day pause) in a single daily session and a total of 2400 pulses. MCAO alone induced significant upregulation in the expression of 44 genes and downregulation in 10. Two weeks of iTBS induced significant increase in the expression of 52 genes. There were no downregulated genes. 1Hz and 5Hz had no significant effects on gene expression, while cTBS effects were negligible. Upregulated genes included those involved in angiogenesis, inflammation, injury response and cellular repair, structural remodeling, neuroprotection, neurotransmission and neuronal plasticity. The results show that long-term rTMS in acute ischemic-reperfusion brain injury induces complex changes in gene expression that span multiple pathways, which generally promote the recovery. They also demonstrate that induced changes primarily depend on the rTMS frequency (1Hz and 5Hz vs. iTBS) and pattern (cTBS vs. iTBS). The results further underlines the premise that one of the benefits of rTMS application in stroke may be to prime the brain, enhancing its potential to cope with the injury and to rewire. This could further augment its potential to favorably respond to rehabilitation, and to restore some of the loss functions. PMID

Hemorheological changes in ischemia-reperfusion: an overview on our experimental surgical data.

Science.gov (United States)

Nemeth, Norbert; Furka, Istvan; Miko, Iren

2014-01-01

Blood vessel occlusions of various origin, depending on the duration and extension, result in tissue damage, causing ischemic or ischemia-reperfusion injuries. Necessary surgical clamping of vessels in vascular-, gastrointestinal or parenchymal organ surgery, flap preparation-transplantation in reconstructive surgery, as well as traumatological vascular occlusions, all present special aspects. Ischemia and reperfusion have effects on hemorheological state by numerous ways: besides the local metabolic and micro-environmental changes, by hemodynamic alterations, free-radical and inflammatory pathways, acute phase reactions and coagulation changes. These processes may be harmful for red blood cells, impairing their deformability and influencing their aggregation behavior. However, there are still many unsolved or non-completely answered questions on relation of hemorheology and ischemia-reperfusion. How do various organ (liver, kidney, small intestine) or limb ischemic-reperfusionic processes of different duration and temperature affect the hemorheological factors? What is the expected magnitude and dynamics of these alterations? Where is the border of irreversibility? How can hemorheological investigations be applied to experimental models using laboratory animals in respect of inter-species differences? This paper gives a summary on some of our research data on organ/tissue ischemia-reperfusion, hemorheology and microcirculation, related to surgical research and experimental microsurgery.

Possible role of opioids and KATP channels in neuroprotective effect of postconditioning in mice.

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Pateliya, Bharat Bhai; Singh, Nirmal; Jaggi, Amteshwar Singh

2008-09-01

The present study was designed to investigate the possible role of opioids and K(ATP) channels in ischemic postconditioning-induced reversal of global cerebral ischemia and reperfusion (I/R) induced neuronal injury. Mice were subjected to global ischemia by bilateral carotid artery occlusion for 10 min followed by reperfusion for 24 h, to produce neuronal injury. Ischemic postconditioning was induced by three episodes of carotid artery occlusion and reperfusion of 10 s each, immediately after global ischemia. Morphine postconditioning was induced by administration of morphine (5 mg/kg i.v.), 5 min prior to reperfusion. Naloxone (5 mg/kg i.v.), opioid receptor antagonist, and glibenclamide (5 mg/kg i.v.), K(ATP) channel blocker were administered 10 min before global ischemia. Extent of cerebral injury was assessed by measuring cerebral infarct size using triphenyl tetrazolium chloride (TTC) staining. Short-term memory was evaluated using the elevated plus maze test, while degree of motor incoordination was evaluated using inclined beam-walking, rota-rod and lateral push tests. Bilateral carotid artery occlusion followed by reperfusion resulted in significant increase in infarct size, impairment in short-term memory and motor co-ordination. Ischemic/morphine postconditioning significantly attenuated I/R induced neuronal injury and behavioural alterations. Pretreatments with naloxone and glibenclamide attenuated the neuroprotective effects of ischemic/morphine postconditioning. It may be concluded that ischemic/morphine postconditioning protects I/R induced cerebral injury via activating opioid receptor and K(ATP) channel opening.

Thiamet G mediates neuroprotection in experimental stroke by modulating microglia/macrophage polarization and inhibiting NF-κB p65 signaling.

Science.gov (United States)

He, Yating; Ma, Xiaofeng; Li, Daojing; Hao, Junwei

2017-08-01

Inflammatory responses are accountable for secondary injury induced by acute ischemic stroke (AIS). Previous studies indicated that O-GlcNAc modification (O-GlcNAcylation) is involved in the pathology of AIS, and increase of O-GlcNAcylation by glucosamine attenuated the brain damage after ischemia/reperfusion. Inhibition of β-N-acetylglucosaminidase (OGA) with thiamet G (TMG) is an alternative option for accumulating O-GlcNAcylated proteins. In this study, we investigate the neuroprotective effect of TMG in a mouse model of experimental stroke. Our results indicate that TMG administration either before or after middle cerebral artery occlusion (MCAO) surgery dramatically reduced infarct volume compared with that in untreated controls. TMG treatment ameliorated the neurological deficits and improved clinical outcomes in neurobehavioral tests by modulating the expression of pro-inflammatory and anti-inflammatory cytokines. Additionally, TMG administration reduced the number of Iba1 + cells in MCAO mice, decreased expression of the M1 markers, and increased expression of the M2 markers in vivo. In vitro, M1 polarization of BV2 cells was inhibited by TMG treatment. Moreover, TMG decreased the expression of iNOS and COX2 mainly by suppressing NF-κB p65 signaling. These results suggest that TMG exerts a neuroprotective effect and could be useful as an anti-inflammatory agent for ischemic stroke therapy.

No improvement of neuronal metabolism in the reperfusion phase with melatonin treatment after hypoxic-ischemic brain injury in the neonatal rat.

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Berger, Hester R; Morken, Tora Sund; Vettukattil, Riyas; Brubakk, Ann-Mari; Sonnewald, Ursula; Widerøe, Marius

2016-01-01

Mitochondrial impairment is a key feature underlying neonatal hypoxic-ischemic (HI) brain injury and melatonin is potentially neuroprotective through its effects on mitochondria. In this study, we have used (1) H and (13) C NMR spectroscopy after injection of [1-(13) C]glucose and [1,2-(13) C]acetate to examine neuronal and astrocytic metabolism in the early reperfusion phase after unilateral HI brain injury in 7-day-old rat pups, exploring the effects of HI on mitochondrial function and the potential protective effects of melatonin on brain metabolism. One hour after hypoxia-ischemia, astrocytic metabolism was recovered and glycolysis was normalized, whereas mitochondrial metabolism in neurons was clearly impaired. Pyruvate carboxylation was also lower in both hemispheres after HI. The transfer of glutamate from neurons to astrocytes was higher whereas the transfer of glutamine from astrocytes to neurons was lower 1 h after HI in the contralateral hemisphere. Neuronal metabolism was equally affected in pups treated with melatonin (10 mg/kg) immediately after HI as in vehicle treated pups indicating that the given dose of melatonin was not capable of protecting the neuronal mitochondria in this early phase after HI brain injury. However, any beneficial effects of melatonin might have been masked by modulatory effects of the solvent dimethyl sulfoxide on cerebral metabolism. Neuronal and astrocytic metabolism was examined by (13) C and (1) H NMR spectroscopy in the early reperfusion phase after unilateral hypoxic-ischemic brain injury and melatonin treatment in neonatal rats. One hour after hypoxia-ischemia astrocytic mitochondrial metabolism had recovered and glycolysis was normalized, whereas mitochondrial metabolism in neurons was impaired. Melatonin treatment did not show a protective effect on neuronal metabolism. © 2015 International Society for Neurochemistry.

Milrinone-induced postconditioning reduces hepatic ischemia-reperfusion injury in rats: the roles of phosphatidylinositol 3-kinase and nitric oxide.

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Toyoda, Tomomi; Tosaka, Shinya; Tosaka, Reiko; Maekawa, Takuji; Cho, Sungsam; Eguchi, Susumu; Nakashima, Masahiro; Sumikawa, Koji

2014-01-01

Ischemic postconditioning (PostC) protects the liver against ischemia-reperfusion (IR) injury. Milrinone, a phosphodiesterase 3 inhibitor, has been reported to exhibit preconditioning properties against hepatic IR injury; however, its PostC properties remain unknown. This study investigated whether milrinone has PostC properties against hepatic IR injury and the roles of phosphatidylinositol 3-kinase (PI3K) and nitric oxide synthase (NOS). Male Wistar rats were separated into six groups: (1) group S: animals that underwent sham operation without ischemia, (2) group C: ischemia followed by reperfusion with no other intervention, (3) group M: milrinone administered immediately after reperfusion, (4) group MW: wortmannin, a PI3K inhibitor, injected before milrinone administration, (5) group MN: l-NAME, a NOS inhibitor, injected before milrinone administration, and (6) group MD, milrinone administered 30 min after reperfusion. Except for group S, all groups underwent 1 h of warm ischemia of median and left lateral lobes, followed by 5 h of reperfusion. Biochemical liver function analysis and histologic examination were performed. Serum aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels, histologic damage scores, and apoptotic rate in group M were significantly lower than those in group C. The inhibition of PI3K or NOS prevented this protective effect. Milrinone administered 30 min after reperfusion did not show obvious protective effects. Milrinone-induced PostC protects against hepatic IR injury when it is administered immediately after reperfusion, and PI3K and NOS may play an important role in this protective effect. Copyright © 2014 Elsevier Inc. All rights reserved.

Alveolar epithelial fluid transport capacity in reperfusion lung injury after lung transplantation.

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Ware, L B; Golden, J A; Finkbeiner, W E; Matthay, M A

1999-03-01

Reperfusion lung injury is an important cause of morbidity and mortality after orthotopic lung transplantation. The purpose of this study was to investigate the function of the alveolar epithelium in the setting of reperfusion lung injury. Simultaneous samples of pulmonary edema fluid and plasma were collected from eight patients with severe post-transplantation reperfusion edema. The edema fluid to plasma protein ratio was measured, an indicator of alveolar-capillary barrier permeability. The initial edema fluid to plasma protein ratio was > 0.75 in six of eight patients, confirming the presence of increased permeability of the alveolar-capillary barrier. Graft ischemic time was positively correlated with the degree of permeability (r = 0.77, p mean +/- SD). Alveolar fluid clearance was calculated from serial samples in six patients. Intact alveolar fluid clearance correlated with less histologic injury, rapid resolution of hypoxemia, and more rapid resolution of radiographic infiltrates. The two patients with no net alveolar fluid clearance had persistent hypoxemia and more severe histologic injury. This study provides the first direct evidence that increased permeability to protein is the usual cause of reperfusion edema after lung transplantation, with longer ischemic times associated with greater permeability to protein in the transplanted lung. The high rates of alveolar fluid clearance indicate that the fluid transport capacity of the alveolar epithelium may be well preserved in the allograft despite reperfusion lung injury. The ability to reabsorb fluid from the alveolar space was a marker of less severe reperfusion injury, whereas the degree of alveolar-capillary barrier permeability to protein was not. Measurement of alveolar fluid clearance may be useful to assess the severity of reperfusion lung injury and to predict outcome when pulmonary edema develops after lung transplantation.

Inhibition of MMP-2 Expression with siRNA Increases Baseline Cardiomyocyte Contractility and Protects against Simulated Ischemic Reperfusion Injury

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Han-Bin Lin

2014-01-01

Full Text Available Matrix metalloproteinases (MMPs significantly contribute to ischemia reperfusion (I/R injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2 in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

Tadalafil enhances the neuroprotective effects of ischemic postconditioning in mice, probably in a nitric oxide associated manner.

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Gulati, Puja; Singh, Nirmal

2014-05-01

This study investigates the modulatory effect of tadalafil, a selective phosphodiesterase (PDE-5) inhibitor, on the neuroprotective effects of ischemic postconditioning (iPoCo) in mice. Bilateral carotid artery occlusion (BCAO) for 12 min followed by reperfusion for 24 h was employed to produce ischemia and reperfusion induced cerebral injury. Cerebral infarct size was measured using TTC staining. Memory was assessed using the Morris water maze test. Degree of motor incoordination was evaluated using inclined beam-walking, rota-rod, and lateral push tests. Brain nitrite/nitrate, acetylcholinesterase activity, TBARS, and glutathione levels were also estimated. BCAO followed by reperfusion produced a significant increase in cerebral infarct size, brain nitrite/nitrate and TBARS levels, and acetylcholinesterase activity along with a reduction in glutathione. Marked impairment of memory and motor coordination was also noted. iPoCo consisting of 3 episodes of 10 s carotid artery occlusion and reperfusion instituted immediately after BCAO significantly decreased infarct size, memory impairment, motor incoordination, and altered biochemistry. Pretreatment with tadalafil mimicked the neuroprotective effects of iPoCo. The tadalafil-induced neuroprotective effects were significantly attenuated by l-NAME, a nonselective NOS inhibitor. We concluded that tadalafil mimics the neuroprotective effects of iPoCo, probably through a nitric oxide dependent pathway, and PDE-5 could be a target of interest with respect to the neuroprotective mechanism of iPoCo.

Mathematical Modeling of Ischemia-Reperfusion Injury and Postconditioning Therapy.

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Fong, D; Cummings, L J

2017-11-01

Reperfusion (restoration of blood flow) after a period of ischemia (interruption of blood flow) can paradoxically place tissues at risk of further injury: so-called ischemia-reperfusion injury or IR injury. Recent studies have shown that postconditioning (intermittent periods of further ischemia applied during reperfusion) can reduce IR injury. We develop a mathematical model to describe the reperfusion and postconditioning process following an ischemic insult, treating the blood vessel as a two-dimensional channel, lined with a monolayer of endothelial cells that interact (respiration and mechanotransduction) with the blood flow. We investigate how postconditioning affects the total cell density within the endothelial layer, by varying the frequency of the pulsatile flow and the oxygen concentration at the inflow boundary. We find that, in the scenarios we consider, the pulsatile flow should be of high frequency to minimize cellular damage, while oxygen concentration at the inflow boundary should be held constant, or subject to only low-frequency variations, to maximize cell proliferation.

Cardioprotective effect of breviscapine: inhibition of apoptosis in H9c2 cardiomyocytes via the PI3K/Akt/eNOS pathway following simulated ischemia/reperfusion injury.

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Wang, Jun; Ji, Shu-Yun; Liu, Si-Zhu; Jing, Rui; Lou, Wei-Juan

2015-09-01

Breviscapine (BE) is a standardized Chinese herbal medicine extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used to treat cardiovascular and cerebrovascular diseases. However, there are no reports on the protective effects and underlying molecular mechanisms of BE action on myocardial ischemia/reperfusion (MI/R)-induced cardiomyocyte apoptosis. In the present study, we aimed to confirm the cardioprotective effect of BE from MI/R injury in vivo, and investigate the potential molecular mechanisms against simulated ischemia/reperfusion (SI/R)-induced cardiomyocyte apoptosis in vitro. The rat model of MI/R injury was induced by 30 min of transient vessel occlusion followed by 3 h of reperfusion. BE significantly reduced the myocardium infarct size and production of cardiac troponin (cTnl) in serum. In an in vitro experiment, H9c2 cardiomyocytes were incubated with vehicle or ischemic buffer during hypoxia; then, they were reoxygenated with or without BE. BE markedly improved the cell viability and decreased lactate dehydrogenase (LDH) release. We confirmed the anti-apoptotic effect of BE with the Hoechst 33258 staining assay, and this effect was associated with an increase in Bcl-2 and a decrease in active caspase-3 expression. Western blot analysis also showed that BE increased the phosphorylation of Akt and eNOS in H9c2 cells, and the protective effects of BE were partially inhibited by the phosphatidylinositol 3'-kinase (PI3K) specific inhibitor LY294002. Our results suggested that BE could provide significant cardioprotection against MI/R injury, and the potential mechanisms might involve suppression of cardiomyocyte apoptosis through activating the PI3K/Akt/eNOS signaling pathway.

Argon inhalation attenuates retinal apoptosis after ischemia/reperfusion injury in a time- and dose-dependent manner in rats.

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Felix Ulbrich

Full Text Available Retinal ischemia and reperfusion injuries (IRI permanently affect neuronal tissue and function by apoptosis and inflammation due to the limited regenerative potential of neurons. Recently, evidence emerged that the noble gas Argon exerts protective properties, while lacking any detrimental or adverse effects. We hypothesized that Argon inhalation after IRI would exert antiapoptotic effects in the retina, thereby protecting retinal ganglion cells (RGC of the rat's eye.IRI was performed on the left eyes of rats (n = 8 with or without inhaled Argon postconditioning (25, 50 and 75 Vol% for 1 hour immediately or delayed after ischemia (i.e. 1.5 and 3 hours. Retinal tissue was harvested after 24 hours to analyze mRNA and protein expression of Bcl-2, Bax and Caspase-3, NF-κB. Densities of fluorogold-prelabeled RGCs were analyzed 7 days after injury in whole-mounts. Histological tissue samples were prepared for immunohistochemistry and blood was analyzed regarding systemic effects of Argon or IRI. Statistics were performed using One-Way ANOVA.IRI induced RGC loss was reduced by Argon 75 Vol% inhalation and was dose-dependently attenuated by lower concentrations, or by delayed Argon inhalation (1504±300 vs. 2761±257; p<0.001. Moreover, Argon inhibited Bax and Bcl-2 mRNA expression significantly (Bax: 1.64±0.30 vs. 0.78±0.29 and Bcl-2: 2.07±0.29 vs. 0.99±0.22; both p<0.01, as well as caspase-3 cleavage (1.91±0.46 vs. 1.05±0.36; p<0.001. Expression of NF-κB was attenuated significantly. Immunohistochemistry revealed an affection of Müller cells and astrocytes. In addition, IRI induced leukocytosis was reduced significantly after Argon inhalation at 75 Vol%.Immediate and delayed Argon postconditioning protects IRI induced apoptotic loss of RGC in a time- and dose-dependent manner, possibly mediated by the inhibition of NF-κB. Further studies need to evaluate Argon's possible role as a therapeutic option.

Potential neuroprotective effects of acupuncture stimulation on diabetes mellitus in a global ischemic rat model

International Nuclear Information System (INIS)

Choi, Samjin; Lee, Gi-Ja; Chae, Su-Jin; Kang, Sung Wook; Park, Hun-Kuk; Yin, Chang-Shik; Lee, Seung-Hoon; Choi, Seok Keun

2010-01-01

Acupuncture (ACU) is known to be effective in ischemia treatment, and glutamate (GLU) excitotoxicity is an important factor in neuronal cell death. We observed the effect of ACU on cerebral blood flow (%CBF) and ΔGLU (the changes in GLU release) in the ischemic stroke rat model of diabetic mellitus (DM). A global ischemia was induced using the eleven-vessel occlusion (11-VO) method in 14 Sprague-Dawley rats (DM), which were randomly divided into two groups: the control group and the ACU-treatment group. Extracellular ΔGLU was assessed using an intra-cerebral biosensor system measuring 256 samples per second, simultaneously with %CBF and electroencephalogram. ACU stimulation was applied to ACU points GB34 and GB39 during the ischemic period. Twenty-three diagnostic parameters were proposed first for a detailed analysis of changes in %CBF and GLU release during ischemia/reperfusion. ACU rats showed a significant decrease in ischemic (p < 0.05) and reperfusion %CBF (p < 0.0001) than control rats, and a significantly larger decrease in ischemic ΔGLU (p < 0.05) and peak level of reperfusion ΔGLU (p < 0.005) than control rats. From these results, we suggest that ACU stimulation is responsible for the potential protection of neurons through suppression of %CBF response in the increased plasma osmolality and extracellular ΔGLU in diabetic rats under ischemic conditions

Cardiac-specific expression of the tetracycline transactivator confers increased heart function and survival following ischemia reperfusion injury.

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Laila Elsherif

Full Text Available Mice expressing the tetracycline transactivator (tTA transcription factor driven by the rat α-myosin heavy chain promoter (α-MHC-tTA are widely used to dissect the molecular mechanisms involved in cardiac development and disease. However, these α-MHC-tTA mice exhibit a gain-of-function phenotype consisting of robust protection against ischemia/reperfusion injury in both in vitro and in vivo models in the absence of associated cardiac hypertrophy or remodeling. Cardiac function, as assessed by echocardiography, did not differ between α-MHC-tTA and control animals, and there were no noticeable differences observed between the two groups in HW/TL ratio or LV end-diastolic and end-systolic dimensions. Protection against ischemia/reperfusion injury was assessed using isolated perfused hearts where α-MHC-tTA mice had robust protection against ischemia/reperfusion injury which was not blocked by pharmacological inhibition of PI3Ks with LY294002. Furthermore, α-MHC-tTA mice subjected to coronary artery ligation exhibited significantly reduced infarct size compared to control animals. Our findings reveal that α-MHC-tTA transgenic mice exhibit a gain-of-function phenotype consisting of robust protection against ischemia/reperfusion injury similar to cardiac pre- and post-conditioning effects. However, in contrast to classical pre- and post-conditioning, the α-MHC-tTA phenotype is not inhibited by the classic preconditioning inhibitor LY294002 suggesting involvement of a non-PI3K-AKT signaling pathway in this phenotype. Thus, further study of the α-MHC-tTA model may reveal novel molecular targets for therapeutic intervention during ischemic injury.

[Protective effects of luteolin on neurons against oxygen-glucose deprivation/reperfusion injury via improving Na+/K+ -ATPase activity].

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Fang, Lumei; Zhang, Mingming; Ding, Yuemin; Fang, Yuting; Yao, Chunlei; Zhang, Xiong

2010-04-01

Luteolin, a flavone, has considerable neuroprotective effects by its anti-oxidative mechanism. However, it is still unclear whether luteolin can protect neurons against oxygen-glucose deprivation/reperfusion (OGD/R) induced injury. After 2 hours oxygen-glucose deprivation and 24 hours reperfusion treatment in primary cultured hippocampal neurons, the neuron viability, survival rate and apoptosis rate were evaluated by MTT assay, lactate dehydrogenase (LDH) leakage assay and Hoechst staining, respectively. The activity of Na+/K+ -ATPase was examined in cultured neurons or in the hippocampus of SD rats treated by 10 minutes global cerebral ischemia and followed 24 hours reperfusion. Treatment by OGD/R markedly reduced neuronal viability, increased LDH leakage rate and increased apoptosis rate. Application of luteolin (10-100 micromol x L(-1)) during OGD inhibited OGD/R induced neuron injury and apoptosis in a dose-dependent manner. Compared to the control group or OGP/R-treated neurons, the activity of Na+/K+ -ATPase was significantly suppressed in global ischemia/reperfusion group or OGD/R-treated neurons. Application of luteolin during ischemia or OGD preserved the Na+/K+ -ATPase activity. Furthermore, inhibition of Na+/K+ -ATPase with ouabain attenuated the protective effect afforded by luteolin. The data provide the evidence that luteolin has neuroprotective effect against OGD/R induced injury and the protective effect may be associated with its ability to improve Na+/K+ -ATPase activity after OGD/R.

Receptor for advanced glycation end products involved in lung ischemia reperfusion injury in cardiopulmonary bypass attenuated by controlled oxygen reperfusion in a canine model.

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Rong, Jian; Ye, Sheng; Liang, Meng-ya; Chen, Guang-xian; Liu, Hai; Zhang, Jin-Xin; Wu, Zhong-kai

2013-01-01

Controlled oxygen reperfusion could protect the lung against ischemia-reperfusion injury in cardiopulmonary bypass (CPB) by downregulating high mobility group box 1 (HMGB1), a high affinity receptor of HMGB1. This study investigated the effect of controlled oxygen reperfusion on receptor for advanced glycation end products (RAGE) expression and its downstream effects on lung ischemia-reperfusion injury. Fourteen canines received CPB with 60 minutes of aortic clamping and cardioplegic arrest followed by 90 minutes of reperfusion. Animals were randomized to receive 80% FiO2 during the entire procedure (control group) or to a test group receiving a controlled oxygen reperfusion protocol. Pathologic changes in lung tissues, RAGE expression, serum interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were evaluated. The lung pathologic scores after 25 and 90 minutes of reperfusion were significantly lower in the test group compared with the control group (p RAGE expression, TNF-α, and IL-6 were downregulated by controlled oxygen treatment (p RAGE might be involved in the lung ischemia-reperfusion injury in canine model of CPB, which was downregulated by controlled oxygen reperfusion.

The relationship between myocardial blood flow and myocardial viability after reperfusion. Myocardial viability assessed by 15O-water-PET

International Nuclear Information System (INIS)

Tsukagoshi, Joichi

1994-01-01

The purpose of this study was to examine the relationship between myocardial blood flow and myocardial viability in the ischemic canine myocardium after reperfusion. Transient ischemia was induced by 60-, 90-, and 180-minute occlusion of the left anterior descending coronary artery. Myocardial blood flow (MBF) was measured in the areas in which regional contractility was severely impaired (ehocardiographically akinetic or dyskinetic) in the early reperfusion period by 15 O-water positron emission tomography (PET) 12 hours and 4 weeks after reperfusion. An MBF ratio of ischemic to nonischemic regions 12 hours after reperfusion was inversely correlated with the amount of histologically determined tissue necrosis (r=-0.74). The regional contractility recovered 4 weeks later in the areas where an MBF ratio was 0.48 or greater, but did not recover in the areas with a lower MBF ratio. Thus, myocardial viability can be appropriately predicted in the early phase of myocardial perfusion by PET with 15 O-water even in the absence of metabolic imaging. (author)

Therapeutic hypothermia reduces intestinal ischemia/reperfusion ...

African Journals Online (AJOL)

The detached intestinal epithelial cells in hypothermia group showed ... of apoptosis than those in normothermia group at 4 h (17.30 ± 2.56 vs. ... intestinal ischemia/reperfusion (IR) injury, which could be attenuated by therapeutic hypothermia.

A Nitric Oxide-Donor Furoxan Moiety Improves the Efficacy of Edaravone against Early Renal Dysfunction and Injury Evoked by Ischemia/Reperfusion

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Fausto Chiazza

2015-01-01

Full Text Available Edaravone (5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, EDV is a free-radical scavenger reduces organ ischemic injury. Here we investigated whether the protective effects of EDV in renal ischemia/reperfusion (I/R injury may be enhanced by an EDV derivative bearing a nitric oxide- (NO- donor furoxan moiety (NO-EDV. Male Wistar rats were subjected to renal ischemia (45 minutes, followed by reperfusion (6 hours. Administration of either EDV (1.2–6–30 µmol/kg, i.v. or NO-EDV (0.3–1.2–6 µmol/kg, i.v. dose-dependently attenuated markers of renal dysfunction (serum urea and creatinine, creatinine clearance, urine flow, urinary N-acetyl-β-D-glucosaminidase, and neutrophil gelatinase-associated lipocalin/lipocalin-2. NO-EDV exerted protective effects in the dose-range 1.2–6 µmol/kg, while a higher dose (30 µmol/kg was needed to obtain protection by EDV. Both EDV and NO-EDV modulated tissue markers of oxidative stress and lipid peroxidation. NO-EDV, but not EDV, activated endothelial NO synthase (NOS and blunted I/R-induced upregulation of inducible NOS, secondary to modulation of Akt and NF-κB activation, respectively. Besides NO-EDV administration inhibited I/R-induced IL-1β, IL-18, IL-6, and TNF-α overproduction. Overall, these findings demonstrate that the NO-donor moiety contributes to the protection against early renal I/R injury and suggest that NO-donor EDV codrugs are worthy of additional study as innovative pharmacological tools.

Combining remote ischemic preconditioning and aerobic exercise: a novel adaptation of blood flow restriction exercise.

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Sprick, Justin D; Rickards, Caroline A

2017-11-01

Remote ischemic preconditioning (RIPC) can attenuate tissue damage sustained by ischemia-reperfusion injury. Blood flow restriction exercise (BFRE) restricts blood flow to exercising muscles. We implemented a novel approach to BFRE with cyclical bouts of blood flow restriction-reperfusion, reflecting the RIPC model. A concern about BFRE, however, is potential amplification of the exercise pressor reflex, which could be unsafe in at-risk populations. We hypothesized that cyclical BFRE would elicit greater increases in sympathetic outflow and arterial pressure than conventional exercise (CE) when performed at the same relative intensity. We also assessed the cerebrovascular responses due to potential implementation of BFRE in stroke rehabilitation. Fourteen subjects performed treadmill exercise at 65-70% maximal heart rate with and without intermittent BFR (4 × 5-min intervals of bilateral thigh-cuff pressure followed by 5-min reperfusion periods). Mean arterial pressure (MAP), plasma norepinephrine (NE), and middle and posterior cerebral artery velocities (MCAv and PCAv) were compared between trials. As expected, BFRE elicited higher concentration NE compared with CE (1249 ± 170 vs. 962 ± 114 pg/ml; P = 0.06). Unexpectedly, however, there were no differences in MAP between conditions (overall P = 0.33), and MAP was 4-5 mmHg lower with BFRE versus CE during the reperfusion periods ( P ≤ 0.05 for reperfusion periods 3 and 4 ). There were no differences in MCAv or PCAv between trials ( P ≥ 0.22), suggesting equivalent cerebrometabolic demand. The exaggerated sympathoexcitatory response with BFRE was not accompanied by higher MAP, likely because of the cyclical reperfusions. This cyclical BFRE paradigm could be adapted to cardiac or stroke rehabilitation, where exercising patients could benefit from the cardio and cerebro protection associated with RIPC. Copyright © 2017 the American Physiological Society.

Probucol plus cilostazol attenuate hypercholesterolemia‑induced exacerbation in ischemic brain injury via anti-inflammatory effects.

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Kim, Ji Hyun; Hong, Ki Whan; Bae, Sun Sik; Shin, Yong-Il; Choi, Byung Tae; Shin, Hwa Kyoung

2014-09-01

Probucol, a lipid-lowering agent with anti-oxidant properties, is involved in protection against atherosclerosis, while cilostazol, an antiplatelet agent, has diverse neuroprotective properties. In this study, we investigated the anti-inflammatory effects of probucol and cilostazol on focal cerebral ischemia with hypercholesterolemia. Apolipoprotein E (ApoE) knockout (KO) mice were fed a high-fat diet (HFD) with or without 0.3% probucol and/or 0.2% cilostazol for 10 weeks. To assess the protective effects of the combined therapy of probucol and cilostazol on ischemic injury, the mice received 40 min of middle cerebral artery occlusion (MCAO). Infarct volumes, neurobehavioral deficits and neuroinflammatory mediators were subsequently evaluated 48 h after reperfusion. Probucol alone and probucol plus cilostazol significantly decreased total- and low-density lipoprotein (LDL)-cholesterol in ApoE KO with HFD. MCAO resulted in significantly larger infarct volumes in ApoE KO mice provided with HFD compared to those fed a regular diet, although these volumes were significantly reduced in the probucol plus cilostazol group. Consistent with a smaller infarct size, probucol alone and the combined treatment of probucol and cilostazol improved neurological and motor function. In addition, probucol alone and probucol plus cilostazol decreased MCP-1 expression and CD11b and GFAP immuno-reactivity in the ischemic cortex. These findings suggested that the inhibitory effects of probucol plus cilostazol in MCP-1 expression in the ischemic brain with hypercholesterolemia allowed the identification of one of the mechanisms responsible for anti-inflammatory action. Probucol plus cilostazol may therefore serve as a therapeutic strategy for reducing the impact of stroke in hypercholesterolemic subjects.

Effects of defibrotide, a novel oligodeoxyribonucleotide, on ischaemia and reperfusion injury of the rat liver.

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Kim, Kwang Joon; Shin, Yong Kyoo; Song, Jin Ho; Oh, Byung Kwon; Choi, Myung Sup; Sohn, Uy Dong

2002-02-01

1. The purpose of this study was to investigate the protective effects of defibrotide, a single-stranded polydeoxyribonucleotide, on ischaemia-reperfusion injury to the liver using a rat model. 2. Ischaemia of the left and median lobes was created by total inflow occlusion for 30 min followed by 60 min of reperfusion. Hepatic injury was assessed by the release of liver enzymes (alanine transferase, ALT and lactic dehydrogenase, LDH). Hepatic oxidant stress was measured by superoxide production, lipid peroxidation and nitrite/nitrate formation. Leukocyte-endothelium interaction and Kupffer cell mobilization were quantified by measuring hepatic myeloperoxidase (MPO), polymorphonuclear leukocyte adherence to superior mesenteric artery (SMA) and immunostaining of Kupffer cell. 3. Defibrotide treatment resulted in a significant inhibition of postreperfusion superoxide generation, lipid peroxidation, serum ALT activity, serum LDH activity, MPO activity, serum nitrite/nitrate level, leukocyte adherence to SMA, and Kupffer cell mobilization, indicating a significant attenuation of hepatic dysfunction. 4. A significant correlation existed between liver ischaemia/reperfusion and hepatic injury, suggesting that liver ischaemia/reperfusion injury is mediated predominantly by generation of oxygen free radicals and mobilization of Kupffer cells. 5. We conclude that defibrotide significantly protects the liver against liver ischaemia/reperfusion injury by interfering with Kupffer cell mobilization and formation of oxygen free radicals. This study provides strong evidence that defibrotide has important beneficial effects on acute inflammatory tissue injury such as that occurring in the reperfusion of the ischaemic liver.

Protective perioperative strategy using a third generation hydroxyethyl starch during surgery in a murine model of liver reperfusion injury Estratégia protetora perioperatória usando um hidroxietilamido de terceira geração para expansão volêmica durante a cirurgia em modelo murino de lesão de reperfusão hepática

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Dora Catré

2011-12-01

Full Text Available PURPOSE: To investigate whether a third generation colloid, hydroxyethyl starch (HES 130/0.4, used for perioperative fluid therapy, protects the rat liver against the late-phase response of ischemia/reperfusion injury (IRI and if inhibition of neutrophil hepatic infiltration plays a part in this mechanism. METHODS: Wistar rats were used (8 in each group. Three groups had IRI induced by lobar vascular occlusion (60 minutes and reperfusion (24 hours and received HES (13 mL/kg iv, 7.5% saline (HS (13 mL/kg iv or no fluid. Three other groups were sham-operated and received the same fluid as the test groups. After 24 hours of reperfusion, blood was drawn for alanine aminotransferase (ALT quantification and ischemic liver samples were taken for histological study (hematoxylin and eosin and chloroacetate staining of neutrophils. RESULTS: HES treatment attenuated the elevation in serum ALT (P=0.001 and reduced the extent of hepatocellular necrosis (P0.05. CONCLUSION: Hydroxyethyl starch suppresses inflammatory response and ameliorates the late-phase response of hepatic ischemia/reperfusion injury.OBJETIVO: Investigar se um colóide de terceira geração (HES 130/0.4, utilizado para fluidoterapia perioperatória, protege o fígado de rato contra a resposta da fase tardia de isquemia/reperfusão e se a inibição da infiltração hepática de neutrófilos desempenha um papel neste mecanismo. MÉTODOS: Foram utilizados ratos Wistar (8 em cada grupo. Três grupos tiveram lesão de isquemia/reperfusão (IRI induzida por oclusão vascular lobar (60 minutos e reperfusão (24 horas e receberam HES (13 ml / kg iv, soro fisiológico a 7,5% (HS (13 ml / kg iv ou nenhum fluido. Três outros grupos foram sham-operados e receberam o mesmo tipo de fluido dos grupos de teste. Após 24 horas de reperfusão, o sangue foi retirado para quantificação da alanina aminotransferase (ALT e amostras de fígado isquêmico foram retiradas para estudo histológico (hematoxilina e

The incidence of dysphagia in patients receiving cerebral reperfusion therapy poststroke.

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Ribeiro, Priscila W; Cola, Paula C; Gatto, Ana R; da Silva, Roberta G; Luvizutto, Gustavo J; Braga, Gabriel P; Schelp, Arthur O; de Arruda Henry, Maria A C; Bazan, Rodrigo

2014-07-01

The high prevalence of dysphagia after stroke leads to increased mortality, and cerebral reperfusion therapy has been effective in reducing neurologic deficits. The aim of this study was to investigate the severity and evolution of dysphagia and the occurrence of pneumonia in patients submitted to cerebral reperfusion therapy. Seventy ischemic stroke patients were evaluated. Of these, 35 patients (group 1) were submitted to cerebral reperfusion therapy and 35 (group 2) did not receive thrombolytic treatment. The following were evaluated: severity of dysphagia by means of videofluoroscopy, evolution of oral intake rate by means of the Functional Oral Intake Scale, and the occurrence of pneumonia by international protocol. The relation between the severity of dysphagia and the occurrence of pneumonia with the treatment was evaluated through the chi-square test; the daily oral intake rate and its relation to the treatment were assessed by the Mann-Whitney test and considered significant if P is less than .05. The moderate and severe degrees of dysphagia were more frequent (P=.013) among the patients who were not submitted to cerebral reperfusion therapy. The daily oral intake evolved independently of the treatment type, without statistical significance when compared between the groups, whereas pneumonia occurred more frequently in group 2 (28%) in relation to group 1 (11%) and was associated with the worst degrees of dysphagia (P=.045). We can conclude that there is improvement in the oral intake rate in both groups, with lower severity of dysphagia and occurrence of pneumonia in ischemic stroke patients submitted to cerebral reperfusion therapy. Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Ketogenic Diet Improves Brain Ischemic Tolerance and Inhibits NLRP3 Inflammasome Activation by Preventing Drp1-Mediated Mitochondrial Fission and Endoplasmic Reticulum Stress

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Min Guo

2018-03-01

Full Text Available Background: Neuroprotective effects of ketogenic diets (KD have been reported in stroke models, and nucleotide-binding domain (NOD-like receptor protein 3 (NLRP3 inflammasome has also been implicated in the pathogenesis of stroke. This study aimed to investigate the effects of KD on NLRP3 inflammasome and explore the potential molecular mechanisms.Methods: In in vivo study, mice were fed with KD for 3 weeks and then subjected to middle cerebral artery occlusion/reperfusion (MCAO/R-injury. In in vitro study, SH-SY-5Y cells were treated with β-hydroxybutyrate (BHB followed by oxygen–glucose deprivation/reoxygenation (OGD/R. NLRP3 inflammasome activation and related regulatory mechanisms were evaluated.Results: Mice fed with KD had increased tolerance to MCAO/R. KD inhibited endoplasmic reticulum (ER stress and suppressed TXNIP/NLRP3 inflammasome activation in the brain. The in vitro study showed BHB (10 mM prevented the mitochondrial translocation of dynamin-related protein 1 (Drp1 to inhibit mitochondrial fission. Furthermore, BHB decreased reactive oxygen species (ROS generation, inhibited ROS-NLRP3 pathway in OGD/R-treated cells, and suppressed ER stress-induced NLRP3 inflammasome activation.Conclusions: KD may suppress ER stress and protect mitochondrial integrity by suppressing the mitochondrial translocation of Drp1 to inhibit NLRP3 inflammasome activation, thus exerting neuroprotective effects. Our findings provide evidence for the potential application of KD in the prevention of ischemic stroke.

[Molecular mechanisms of ischemic-reperfusion syndrome and its personalized therapy].

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Grebenchikov, O A; Likhvantsev, V V; Plotnikov, E Iu; Silachev, D N; Pevzner, I B; Zorova, L D; Zorov, D B

2014-01-01

Cardiovascular pathologies are the major causes of morbidity and mortality in the world. Cessation of the blood flow in large vessels, supplying tissues with oxygen and substrates, leads to ischemic conditions accompanied by unwanted shifts of oxidative metabolism and rise of the reactive oxygen species (ROS) generation. Small amounts of ROS are essential elements of the cell metabolism, however pathological elevation of ROS jeopardizes the survival of cells, organs and even organisms. Paradoxically, blood flow restoration during prolonged ischemia leads to oxidative stress that is often fatal for a live system. Oxygen paradox appears to be a limiting factor in clinical practice that intuitively seeks for immediate and complete restoration of a damaged blood flow. Mitochondrion is a major ROS source and a key element of pro-apoptotic signaling, however it is clear, that mitochondria are the main target for anti-ischemic treatment. In the present review we consider two ways of such anti-ischemic strategy, bringing ischemic tolerance to the organ through mitochondrial involvement, such as intrinsic, biological, or artificial, pharmacological adaptive systems (preconditioning). The latter is aimed to simulate elements and high efficiency of intrinsic protective system. The role of antioxidants in anti-ischemic therapy and their effects on preconditioning signaling are discussed in the review.

Retinal reperfusion in diabetic retinopathy following treatment with anti-VEGF intravitreal injections.

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Levin, Ariana M; Rusu, Irene; Orlin, Anton; Gupta, Mrinali P; Coombs, Peter; D'Amico, Donald J; Kiss, Szilárd

2017-01-01

The aim of this study is to report peripheral reperfusion of ischemic areas of the retina on ultra-widefield fluorescein angiography (UWFA) following anti-vascular endothelial growth factor (VEGF) intravitreal injections in patients treated for diabetic retinopathy. This study is a retrospective review of 16 eyes of 15 patients with diabetic retinopathy, who received anti-VEGF intravitreal injections and underwent pre- and postinjection UWFA. The main outcome measured was the presence of reperfusion in postinjection UWFA images in areas of the retina that demonstrated nonperfusion in preinjection images. Images were analyzed for reperfusion qualitatively and quantitatively by two graders. Twelve of 16 eyes (75%) or 11 of 15 patients (73.3%) demonstrated reperfusion following anti-VEGF injection. On UWFA, reperfusion was detected both within the field of 7-standard field (7SF) fluorescein angiography and in the periphery outside the 7SF. Four of 16 eyes or 4 of 15 patients did not demonstrate reperfusion, one of which had extensive scarring from prior panretinal photocoagulation. In patients with diabetic retinopathy, treatment with anti-VEGF agents can be associated with reperfusion of areas of nonperfusion, as demonstrated by UWFA.

Gene Expression ‏‏‏‏Profiles of BAD and Bcl-xL in the CA1 Region of the Hippocampus Following Global Ischemic/Reperfusion and FK-506 Administration.

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Badr, Ramak; Hashemi, Mehrdad; Javadi, Gholamreza; Movafagh, Abolfazl; Mahdian, Reza

2015-12-01

The hippocampus is a tiny nub in the mammalian brain that is involved in forming, organizing, and storing memories. Global cerebral ischemia (GCI) and reperfusion induced apoptosis lead to cell injury and death. FK-506 is a strong immunosuppressant drug that has neuroprotective effects on the hypoxic-ischemic effects of brain damage. BAD and Bcl-xL are pro-apoptotic and anti-apoptotic genes, respectively. These genes belong to The B-cell lymphoma-2 (Bcl-2) family. In this study, we assessed the neurotrophic properties of FK-506 on expression of the BAD and Bcl-xL genes in the hippocampus following global ischemia and reperfusion. In the present experimental study, adult male Wistar rats were obtained and housed under standard conditions in the Tehran University of Medical Science in Iran. Rats were equally distributed in groups of three among the following groups: normal control, treated-1 (ischemia/reperfusion), and treated-2 (ischemia/reperfusion followed by FK-506). Global ischemia was induced for animals in the treated-1 and treated-2 groups. In treated-2, two doses of FK-506 were injected: one dose as an IV injection immediately after reperfusion and another as an intra-peritoneal (IP) injection after 48 hours. Then, the hippocampus tissue was removed after anaesthetizing the rats. RNA was isolated, cDNA was synthesized, and real-time PCR was performed. Finally, the obtained data were analyzed statistically (P value ˂ 0.05). The quantitative results of real-time PCR show that the mRNA expression ratio of Bcl-xL down-regulated was 0.75 ± 0.06 in the ischemia/reperfusion group versus 1.57 ± 0.09 in the control group (P value BAD up-regulated in the ischemia/reperfusion + FK506 group was 3.65 ± 0.49 compared to Normal control (1.39 ± 0.09) and Ischemia/reperfusion + FK506 was 1.09 ± 0.20 (P value BAD /Bcl-xL) confirmed that expression of the pro-apoptotic gene significantly decreased (P value ˂ 0.001) under the ischemia/reperfusion condition. In contrast

Pretreatment with Sodium Phenylbutyrate Alleviates Cerebral Ischemia/Reperfusion Injury by Upregulating DJ-1 Protein

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Rui-Xin Yang

2017-06-01

Full Text Available Oxidative stress and mitochondrial dysfunction play critical roles in ischemia/reperfusion (I/R injury. DJ-1 is an endogenous antioxidant that attenuates oxidative stress and maintains mitochondrial function, likely acting as a protector of I/R injury. In the present study, we explored the protective effect of a possible DJ-1 agonist, sodium phenylbutyrate (SPB, against I/R injury by protecting mitochondrial dysfunction via the upregulation of DJ-1 protein. Pretreatment with SPB upregulated the DJ-1 protein level and rescued the I/R injury-induced DJ-1 decrease about 50% both in vivo and in vitro. SPB also improved cellular viability and mitochondrial function and alleviated neuronal apoptosis both in cell and animal models; these effects of SPB were abolished by DJ-1 knockdown with siRNA. Furthermore, SPB improved the survival rate about 20% and neurological functions, as well as reduced about 50% of the infarct volume and brain edema, of middle cerebral artery occlusion mice 23 h after reperfusion. Therefore, our findings demonstrate that preconditioning of SPB possesses a neuroprotective effect against cerebral I/R injury by protecting mitochondrial function dependent on the DJ-1 upregulation, suggesting that DJ-1 is a potential therapeutic target for clinical ischemic stroke.

Pretreatment with Sodium Phenylbutyrate Alleviates Cerebral Ischemia/Reperfusion Injury by Upregulating DJ-1 Protein.

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Yang, Rui-Xin; Lei, Jie; Wang, Bo-Dong; Feng, Da-Yun; Huang, Lu; Li, Yu-Qian; Li, Tao; Zhu, Gang; Li, Chen; Lu, Fang-Fang; Nie, Tie-Jian; Gao, Guo-Dong; Gao, Li

2017-01-01

Oxidative stress and mitochondrial dysfunction play critical roles in ischemia/reperfusion (I/R) injury. DJ-1 is an endogenous antioxidant that attenuates oxidative stress and maintains mitochondrial function, likely acting as a protector of I/R injury. In the present study, we explored the protective effect of a possible DJ-1 agonist, sodium phenylbutyrate (SPB), against I/R injury by protecting mitochondrial dysfunction via the upregulation of DJ-1 protein. Pretreatment with SPB upregulated the DJ-1 protein level and rescued the I/R injury-induced DJ-1 decrease about 50% both in vivo and in vitro . SPB also improved cellular viability and mitochondrial function and alleviated neuronal apoptosis both in cell and animal models; these effects of SPB were abolished by DJ-1 knockdown with siRNA. Furthermore, SPB improved the survival rate about 20% and neurological functions, as well as reduced about 50% of the infarct volume and brain edema, of middle cerebral artery occlusion mice 23 h after reperfusion. Therefore, our findings demonstrate that preconditioning of SPB possesses a neuroprotective effect against cerebral I/R injury by protecting mitochondrial function dependent on the DJ-1 upregulation, suggesting that DJ-1 is a potential therapeutic target for clinical ischemic stroke.

Ischemic preconditioning of the lower extremity attenuates the normal hypoxic increase in pulmonary artery systolic pressure.

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Foster, Gary P; Westerdahl, Daniel E; Foster, Laura A; Hsu, Jeffrey V; Anholm, James D

2011-12-15

Ischemic pre-condition of an extremity (IPC) induces effects on local and remote tissues that are protective against ischemic injury. To test the effects of IPC on the normal hypoxic increase in pulmonary pressures and exercise performance, 8 amateur cyclists were evaluated under normoxia and hypoxia (13% F(I)O(2)) in a randomized cross-over trial. IPC was induced using an arterial occlusive cuff to one thigh for 5 min followed by deflation for 5 min for 4 cycles. In the control condition, the resting pulmonary artery systolic pressure (PASP) increased from a normoxic value of 25.6±2.3 mmHg to 41.8±7.2 mmHg following 90 min of hypoxia. In the IPC condition, the PASP increased to only 32.4±3.1 mmHg following hypoxia, representing a 72.8% attenuation (p=0.003). No significant difference was detected in cycle ergometer time trial duration between control and IPC conditions with either normoxia or hypoxia. IPC administered prior to hypoxic exposure was associated with profound attenuation of the normal hypoxic increase of pulmonary artery systolic pressure. Published by Elsevier B.V.

Attenuation of Cerebral Ischemic Injury in Smad1 Deficient Mice.

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Jamie K Wong

Full Text Available Stroke results in brain tissue damage from ischemia and oxidative stress. Molecular regulators of the protective versus deleterious cellular responses after cerebral ischemia remain to be identified. Here, we show that deletion of Smad1, a conserved transcription factor that mediates canonical bone morphogenetic protein (BMP signaling, results in neuroprotection in an ischemia-reperfusion (I/R stroke model. Uninjured mice with conditional deletion of Smad1 in the CNS (Smad1 cKO displayed upregulation of the reactive astrocyte marker GFAP and hypertrophic morphological changes in astrocytes compared to littermate controls. Additionally, cultured Smad1(-/- astrocytes exhibited an enhanced antioxidant capacity. When subjected to I/R injury by transient middle cerebral artery occlusion (tMCAO, Smad1 cKO mice showed enhanced neuronal survival and improved neurological recovery at 7 days post-stroke. This neuroprotective phenotype is associated with attenuated reactive astrocytosis and neuroinflammation, along with reductions in oxidative stress, p53 induction, and apoptosis. Our data suggest that Smad1-mediated signaling pathway is involved in stroke pathophysiology and may present a new potential target for stroke therapy.

Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury.

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Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

2015-01-01

Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury.

Repetitive stimulation of autophagy-lysosome machinery by intermittent fasting preconditions the myocardium to ischemia-reperfusion injury

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Godar, Rebecca J; Ma, Xiucui; Liu, Haiyan; Murphy, John T; Weinheimer, Carla J; Kovacs, Attila; Crosby, Seth D; Saftig, Paul; Diwan, Abhinav

2015-01-01

Autophagy, a lysosomal degradative pathway, is potently stimulated in the myocardium by fasting and is essential for maintaining cardiac function during prolonged starvation. We tested the hypothesis that intermittent fasting protects against myocardial ischemia-reperfusion injury via transcriptional stimulation of the autophagy-lysosome machinery. Adult C57BL/6 mice subjected to 24-h periods of fasting, every other day, for 6 wk were protected from in-vivo ischemia-reperfusion injury on a fed day, with marked reduction in infarct size in both sexes as compared with nonfasted controls. This protection was lost in mice heterozygous null for Lamp2 (coding for lysosomal-associated membrane protein 2), which demonstrate impaired autophagy in response to fasting with accumulation of autophagosomes and SQSTM1, an autophagy substrate, in the heart. In lamp2 null mice, intermittent fasting provoked progressive left ventricular dilation, systolic dysfunction and hypertrophy; worsening cardiomyocyte autophagosome accumulation and lack of protection to ischemia-reperfusion injury, suggesting that intact autophagy-lysosome machinery is essential for myocardial homeostasis during intermittent fasting and consequent ischemic cardioprotection. Fasting and refeeding cycles resulted in transcriptional induction followed by downregulation of autophagy-lysosome genes in the myocardium. This was coupled with fasting-induced nuclear translocation of TFEB (transcription factor EB), a master regulator of autophagy-lysosome machinery; followed by rapid decline in nuclear TFEB levels with refeeding. Endogenous TFEB was essential for attenuation of hypoxia-reoxygenation-induced cell death by repetitive starvation, in neonatal rat cardiomyocytes, in-vitro. Taken together, these data suggest that TFEB-mediated transcriptional priming of the autophagy-lysosome machinery mediates the beneficial effects of fasting-induced autophagy in myocardial ischemia-reperfusion injury. PMID:26103523

Melatonin attenuates lung injury in a hind limb ischemia–reperfusion rat model

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Hamed Takhtfooladi

2015-01-01

Full Text Available Objective: This study evaluated the protective antioxidant effect of melatonin on lung injury as a remote organ after skeletal muscle ischemia–reperfusion in rats. Methods: Thirty male Wistar rats were allocated randomly into three experimental groups: operated with no ischemia (Sham group, ischemia–reperfusion group and ischemia–reperfusion + melatonin group. Hind limb ischemia was induced by clamping the femoral artery. After 2 h ischemia, the clamp was removed and the animal underwent 24 h reperfusion. Rats in the ischemia–reperfusion + melatonin group received melatonin (10 mg/kg i.v., immediately before the clamp was removed. At the end of the trial, animals were euthanized and the lungs were removed for water content determination, histopathological and biochemical studies. Results: In the ischemia–reperfusion + melatonin group, tissues showed less intense histological abnormalities such as neutrophilic infiltration, intra-alveolar hemorrhage and edema compared with the ischemia–reperfusion group. Histopathologically, there was a significant difference (P < 0.05 between the two groups. The lung water content in the ischemia–reperfusion + melatonin group was significantly lower than the ischemia–reperfusion group (P < 0.05. Lung tissue myeloperoxidase (MPO activity and nitric oxide (NO level were significantly (P < 0.05 increased by ischemia–reperfusion. The increase in these parameters was reduced by melatonin.Comparing the ischemia–reperfusion + melatonin group with the sham group, no significant increase in all analyzed aspects of the research was observed. Conclusions: These findings suggest that melatonin has preventive effects in lung tissue injury after transient femoral artery occlusion. Keywords: Melatonin, Ischemia–reperfusion, Lung remote injury, Histopathology, Myeloperoxidase, Nitric oxide

Salidroside pretreatment attenuates apoptosis and autophagy during hepatic ischemia–reperfusion injury by inhibiting the mitogen-activated protein kinase pathway in mice

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Feng J

2017-07-01

Full Text Available Jiao Feng,1,* Qinghui Zhang,2,* Wenhui Mo,3,* Liwei Wu,1 Sainan Li,1 Jingjing Li,1 Tong Liu,1 Shizan Xu,4 Xiaoming Fan,5 Chuanyong Guo1 1Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, 2Department of Clinical Laboratory, Kunshan First People’s Hospital Affiliated to Jiangsu University, Kunshan, JiangSu, 3Department of Gastroenterology, Minhang Hospital, Fudan University, Shanghai, 4Department of Gastroenterology, Shanghai Tenth People’s Hospital, School of Clinical Medicine of Nanjing Medical University, Shanghai, 5Department of Gastroenterology, Jinshan Hospital of Fudan University, Jinshan, Shanghai, China *These authors contributed equally to this work Abstract: Ischemia–reperfusion injury (IRI contributes to liver damage in many clinical situations, such as liver resection and liver transplantation. In the present study, we investigated the effects of the antioxidant, anti-inflammatory, and anticancer agent salidroside (Sal on hepatic IRI in mice. The mice were randomly divided into six groups: normal control, Sham, Sal (20 mg/kg, IRI, IRI + Sal (10 mg/kg, and IRI + Sal (20 mg/kg. We measured liver enzymes, proinflammatory cytokines, TNF-α and interleukin-6, and apoptosis- and autophagy-related marker proteins at 2, 8, and 24 hours after reperfusion. Components of mitogen-activated protein kinase (MAPK signaling, including P-38, jun N-terminal kinase (JNK, and extracellular signal-regulated kinase (ERK, were also measured using an MAPK activator anisomycin to deduce their roles in hepatic IRI. Our results show that Sal safely protects hepatocytes from IRI by reducing levels of liver enzymes in the serum. These findings were confirmed by histopathology. We concluded that Sal protects hepatocytes from IRI partly by inhibiting the activation of MAPK signaling, including the phosphorylation of P38, JNK, and ERK. This ameliorates inflammatory reactions, apoptosis, and

Ethyl Pyruvate Ameliorates Hepatic Ischemia-Reperfusion Injury by Inhibiting Intrinsic Pathway of Apoptosis and Autophagy

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Miao Shen

2013-01-01

Full Text Available Background. Hepatic ischemia-reperfusion (I/R injury is a pivotal clinical problem occurring in many clinical conditions such as transplantation, trauma, and hepatic failure after hemorrhagic shock. Apoptosis and autophagy have been shown to contribute to cell death in hepatic I/R injury. Ethyl pyruvate, a stable and simple lipophilic ester, has been shown to have anti-inflammatory properties. In this study, the purpose is to explore both the effect of ethyl pyruvate on hepatic I/R injury and regulation of intrinsic pathway of apoptosis and autophagy. Methods. Three doses of ethyl pyruvate (20 mg/kg, 40 mg/kg, and 80 mg/kg were administered 1 h before a model of segmental (70% hepatic warm ischemia was established in Balb/c mice. All serum and liver tissues were obtained at three different time points (4 h, 8 h, and 16 h. Results. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, and pathological features were significantly ameliorated by ethyl pyruvate (80 mg/kg. The expression of Bcl-2, Bax, Beclin-1, and LC3, which play an important role in the regulation of intrinsic pathway of apoptosis and autophagy, was also obviously decreased by ethyl pyruvate (80 mg/kg. Furthermore, ethyl pyruvate inhibited the HMGB1/TLR4/ NF-κb axis and the release of cytokines (TNF-α and IL-6. Conclusion. Our results showed that ethyl pyruvate might attenuate to hepatic I/R injury by inhibiting intrinsic pathway of apoptosis and autophagy, mediated partly through downregulation of HMGB1/TLR4/ NF-κb axis and the competitive interaction with Beclin-1 of HMGB1.

Edaravone attenuates neuronal apoptosis in hypoxic-ischemic brain damage rat model via suppression of TRAIL signaling pathway.

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Li, Chunyi; Mo, Zhihuai; Lei, Junjie; Li, Huiqing; Fu, Ruying; Huang, Yanxia; Luo, Shijian; Zhang, Lei

2018-06-01

Edaravone is a new type of oxygen free radical scavenger and able to attenuate various brain damage including hypoxic-ischemic brain damage (HIBD). This study was aimed at investigating the neuroprotective mechanism of edaravone in rat hypoxic-ischemic brain damage model and its correlation with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling pathway. 75 seven-day-old Sprague-Dawley neonatal rats were equally divided into three groups: sham-operated group (sham), HIBD group and HIBD rats injected with edaravone (HIBD + EDA) group. Neurological severity and space cognitive ability of rats in each group were evaluated using Longa neurological severity score and Morris water maze testing. TUNEL assay and flow cytometry were used to determine brain cell apoptosis. Western blot was used to estimate the expression level of death receptor-5 (DR5), Fas-associated protein with death domain (FADD), caspase 8, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax). In addition, immunofluorescence was performed to detect caspase 3. Edaravone reduced neurofunctional damage caused by HIBD and improved the cognitive capability of rats. The above experiment results suggested that edaravone could down-regulate the expression of active caspase 3 protein, thereby relieving neuronal apoptosis. Taken together, edaravone could attenuate neuronal apoptosis in rat hypoxic-ischemic brain damage model via suppression of TRAIL signaling pathway, which also suggested that edaravone might be an effective therapeutic strategy for HIBD clinical treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cardioprotection against experimental myocardial ischemic injury using cornin

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Y. Xu

2016-01-01

Full Text Available Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt.

Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

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Y. Wang

2013-09-01

Full Text Available Quercetin (Que, a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group: sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05. Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05. Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

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Wang, Y.; Zhang, Z.Z.; Wu, Y.; Ke, J.J.; He, X.H.; Wang, Y.L. [Department of Anesthesiology, Zhongnan Hospital, Wuhan University, Wuhan (China)

2013-09-24

Quercetin (Que), a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R) injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group): sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05). Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05). Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

Sulforaphane exerts neuroprotective effects via suppression of the inflammatory response in a rat model of focal cerebral ischemia.

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Ma, Li-Li; Xing, Guo-Ping; Yu, Yin; Liang, Hui; Yu, Tian-Xia; Zheng, Wei-Hong; Lai, Tian-Bao

2015-01-01

Inflammatory damage plays an important role in cerebral ischemic pathogenesis and may represent a promising target for treatment. Sulforaphane exerts protective effects in a rat model of focal cerebral ischemia/reperfusion injury by alleviating brain edema. However, the possible mechanisms of sulforaphane after cerebral ischemia/reperfusion injury have not been fully elucidated. Therefore, in the present study, we investigated the effect of sulforaphane on inflammatory reaction and the potential molecular mechanisms in cerebral ischemia rats. We found that sulforaphane significantly attenuated the blood-brain barrier (BBB) disruption; decreased the levels of pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-1β; reduced the nitric oxide (NO) levels and inducible nitric oxide synthase (iNOS) activity; inhibited the expression of iNOS and cyclooxygenase-2 (COX-2). In addition, sulforaphane inhibits the expression of p-NF-κB p65 after focal cerebral ischemia-reperfusion injury. Taken together, our results suggest that sulforaphane suppresses the inflammatory response via inhibiting the NF-κB signaling pathway in a rat model of focal cerebral ischemia, and sulforaphane may be a potential therapeutic agent for the treatment of cerebral ischemia injury.

Ultrasound Imaging of Mouse Fetal Intracranial Hemorrhage Due to Ischemia/Reperfusion

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Kenichi Funamoto

2017-05-01

Full Text Available Despite vast improvement in perinatal care during the 30 years, the incidence rate of neonatal encephalopathy remains unchanged without any further Progress towards preventive strategies for the clinical impasse. Antenatal brain injury including fetal intracranial hemorrhage caused by ischemia/reperfusion is known as one of the primary triggers of neonatal injury. However, the mechanisms of antenatal brain injury are poorly understood unless better predictive models of the disease are developed. Here we show a mouse model for fetal intracranial hemorrhage in vivo developed to investigate the actual timing of hypoxia-ischemic events and their related mechanisms of injury. Intrauterine growth restriction mouse fetuses were exposed to ischemia/reperfusion cycles by occluding and opening the uterine and ovarian arteries in the mother. The presence and timing of fetal intracranial hemorrhage caused by the ischemia/reperfusion were measured with histological observation and ultrasound imaging. Protein-restricted diet increased the risk of fetal intracranial hemorrhage. The monitoring of fetal brains by ultrasound B-mode imaging clarified that cerebral hemorrhage in the fetal brain occurred after the second ischemic period. Three-dimensional ultrasound power Doppler imaging visualized the disappearance of main blood flows in the fetal brain. These indicate a breakdown of cerebrovascular autoregulation which causes the fetal intracranial hemorrhage. This study supports the fact that the ischemia/reperfusion triggers cerebral hemorrhage in the fetal brain. The present method enables us to noninvasively create the cerebral hemorrhage in a fetus without directly touching the body but with repeated occlusion and opening of the uterine and ovarian arteries in the mother.

Electroacupuncture ameliorates cognitive impairment through inhibition of NF-κB-mediated neuronal cell apoptosis in cerebral ischemia-reperfusion injured rats.

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Feng, Xiaodong; Yang, Shanli; Liu, Jiao; Huang, Jia; Peng, Jun; Lin, Jiumao; Tao, Jing; Chen, Lidian

2013-05-01

Cognitive impairment is a serious mental deficit following stroke that severely affects the quality of life of stroke survivors. Nuclear factor‑κB (NF-κB)-mediated neuronal cell apoptosis is involved in the development of post-stroke cognitive impairment; therefore, it has become a promising target for the treatment of impaired cognition. Acupuncture at the Baihui (DU20) and Shenting (DU24) acupoints is commonly used in China to clinically treat post‑stroke cognitive impairment; however, the precise mechanism of its action is largely unknown. In the present study, we evaluated the therapeutic efficacy of electroacupuncture against post-stroke cognitive impairment and investigated the underlying molecular mechanisms using a rat model of focal cerebral ischemia-reperfusion (I/R) injury. Electroacupuncture at Baihui and Shenting was identified to significantly ameliorate neurological deficits and reduce cerebral infarct volume. Additionally, electroacupuncture improved learning and memory ability in cerebral I/R injured rats, demonstrating its therapeutic efficacy against post-stroke cognitive impairment. Furthermore, electroacupuncture significantly suppressed the I/R-induced activation of NF-κB signaling in ischemic cerebral tissues. The inhibitory effect of electroacupuncture on NF-κB activation led to the inhibition of cerebral cell apoptosis. Finally, electroacupuncture markedly downregulated the expression of pro-apoptotic Bax and Fas, two critical downstream target genes of the NF-κB pathway. Collectively, our findings suggest that inhibition of NF-κB‑mediated neuronal cell apoptosis may be one mechanism via which electroacupuncture at Baihui and Shenting exerts a therapeutic effect on post-stroke cognitive impairment.

Oxidized tissue proteins after intestinal reperfusion injury in rats

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Schanaider Alberto

2005-01-01

Full Text Available PURPOSE: To analyse if the carbonyl proteins measurement could be validated as a method that allows the identification of an intestinal oxidative stress after ischemia and reperfusion injury. METHODS: Twenty-five male Wistar rats (n =21 weighting 200 to 250g were divided into three groups. Group I - control (n = 10. Group II - sham (n = 5 and Group III (n = 10 subjected to 60 minutes of intestinal ischemia and equal period of reperfusion. For this purpose it was clamped the superior mesenteric artery in its distal third. Histological changes and carbonyl protein levels were determined in the samples of all groups. In group III, samples of both normal and reperfused ileal segment were studied. RESULTS: All the reperfused segments showed mucosal and submucosal swelling and inflammatory infiltrate of the lamina propria. Levels of carbonyl protein rose in group III, including in the non-ischemic segments. The sensitivity and specificity of the carbonyl protein tissue levels were respectively 94% and 88%. CONCLUSION: The carbonyl protein method is a useful biologic marker of oxidative stress after the phenomenon of intestinal ischemia and reperfusion in rats. It was also noteworthy that the effects of oxidative stress could be seen far from the locus of the primary injury.

NMR studies of myocardial energy metabolism and ionic homeostasis during ischemia and reperfusion

International Nuclear Information System (INIS)

Kirkels, J.H.

1989-01-01

In this study several aspects of myocardial energy metabolism and ionic homeostasis during ischemia and reperfusion were investigated in isolated perfused rat hearts, regionally ischemic rabbit hearts, and ex vivo human donor hearts during long term hypothermic cardioplegia. Phosphorus-31 nuclear magnetic resonance ( 31 P NMR) spectroscopy was used as a powerful tool to non-destructively follow the time course in changes in intracellular high-energy phosphates, (creatine phosphate and ATP), inorganic phosphate, and pH. In addition, changes in intracellular free magnesium were followed during ischemia and reperfusion. Sodium-23 ( 23 Na) NMR spectroscopy was used to study intracellular sodium during ischemia and reperfusion and during calcium-free perfusion. (author). 495 refs.; 33 figs.; 11 tabs

Oxidative Stress and Lung Ischemia-Reperfusion Injury

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Renata Salatti Ferrari

2015-01-01

Full Text Available Ischemia-reperfusion (IR injury is directly related to the formation of reactive oxygen species (ROS, endothelial cell injury, increased vascular permeability, and the activation of neutrophils and platelets, cytokines, and the complement system. Several studies have confirmed the destructiveness of the toxic oxygen metabolites produced and their role in the pathophysiology of different processes, such as oxygen poisoning, inflammation, and ischemic injury. Due to the different degrees of tissue damage resulting from the process of ischemia and subsequent reperfusion, several studies in animal models have focused on the prevention of IR injury and methods of lung protection. Lung IR injury has clinical relevance in the setting of lung transplantation and cardiopulmonary bypass, for which the consequences of IR injury may be devastating in critically ill patients.

Changes in electrical activity of heart during ischemic–reperfusion injury modified by the administration of antidepressants

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Vicen M.

2016-09-01

Full Text Available The aim of our work was to investigate the effect of amitriptyline, citalopram and venlafaxine on the heart during ischemic- reperfusion (l-R injury. Amitriptyline prolonged both QRS complex and QTc interval duration; citalopram and venlafaxine prolonged only QTc interval duration. Amitriptyline worked most proarrhythmogenic, citalopram least; venlafaxine increased the heart rate during ischemia; however, prolonged QTc interval at the beginning of reperfusion was followed by serious dysrhythmias.

Increased expression of IRE1α and stress-related signal transduction proteins in ischemia-reperfusion injured retina

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Natsuyo Hata

2008-08-01

Full Text Available Natsuyo Hata1, Toshiyuki Oshitari1,2, Akiko Yokoyama1,3, Yoshinori Mitamura1, Shuichi Yamamoto11Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan; 2Department of Ophthalmology, Kimitsu Central Hospital, Kisarazu City, Chiba, Japan; 3Department of Ophthalmology, Inoue Memorial Hospital, Chuo-ku, Chiba, JapanAbstract: The purpose of this study was to determine whether the expression of ER stress-related factors IRE1α, apoptosis signal-regulating kinase 1 (ASK1, SAPK/ERK kinase 1 (SEK1 and c-Jun N-terminal kinase (JNK is associated with the damaged retinal neurons induced by ischemia-reperfusion injury. After 60 minutes of ischemia, the rat retinas were reperfused, and retinas were isolated and fixed after 6, 9, 12, 18, and 24 hours, and 2, 5, and 9 days of reperfusion. Cryosections were immunostained with Fluoro-Jade B, a degenerating neuron marker to label degenerating neurons. Semi-quantitative analysis of the expression of IRE1α, ASK1, SEK1, and JNK were performed in both control and ischemic retinas. In ischemic retinas, the intensities of IRE1α immunoreactivity in the ganglion cell layer (GCL were significantly higher than in the control retinas. In ischemic retinas, the numbers of SEK1-, ASK1-, and JNK-positive cells were significantly increased in the GCL compared to those in the control retinas. In addition, the cells that were positive for SEK1-, ASK1-, and JNK were also positive for Fluoro-Jade B-positive cells. These results indicate that the increased expression of ER stress-related factors was, in part, associated with the retinal neuronal abnormalities after ischemia-reperfusion injury in rat retinas.Keywords: endoplasmic reticulum, IRE1α, apoptosis signal-regulating kinase 1, SAPK/ERK kinase 1, c-Jun N-terminal kinase, Fluoro-Jade B, ischemia-reperfusion injury

Ischemia and reperfusion of the lung tissues induced increase of lung permeability and lung edema is attenuated by dimethylthiourea (PP69).

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Chen, K H; Chao, D; Liu, C F; Chen, C F; Wang, D

2010-04-01

This study sought to determine whether oxygen radical scavengers of dimethylthiourea (DMTU), superoxide dismutase (SOD), or catalase (CAT) pretreatment attenuated ischemia-reperfusion (I/R)-induced lung injury. After isolation from a Sprague-Dawley rat, the lungs were perfused through the pulmonary artery cannula with rat whole blood diluted 1:1 with a physiological salt solution. An acute lung injury was induced by 10 minutes of hypoxia with 5% CO2-95% N2 followed by 65 minutes of ischemia and then 65 minutes of reperfusion. I/R significantly increased microvascular permeability as measured by the capillary filtration coefficient (Kfc), lung weight-to-body weight ratio (LW/BW), and protein concentration in bronchoalveolar lavage fluid (PCBAL). DMTU pretreatment significantly attenuated the acute lung injury. The capillary filtration coefficient (P<.01), LW/BW (P<.01) and PCBAL (P<.05) were significantly lower among the DMTU-treated rats than hosts pretreated with SOD or CAT. The possible mechanisms of the protective effect of DMTU in I/R-induced lung injury may relate to the permeability of the agent allowing it to scavenge intracellular hydroxyl radicals. However, whether superoxide dismutase or catalase antioxidants showed protective effects possibly due to their impermeability of the cell membrane not allowing scavenging of intracellular oxygen radicals. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Acute stress decreases but chronic stress increases myocardial sensitivity to ischemic injury in rodents

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Eric D Eisenmann

2016-04-01

Full Text Available Cardiovascular disease is the largest cause of mortality worldwide, and stress is a significant contributor to the development of cardiovascular disease. The relationship between acute and chronic stress and cardiovascular disease is well-evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia-reperfusion injury. Conversely, chronic stress is arrythmogenic and increases sensitivity to myocardial ischemia-reperfusion injury. Few studies have examined the impact of validated animal models of stress-related psychological disorders on the ischemic heart. This review examines the work that has been completed using rat models to study the effects of stress on myocardial sensitivity to ischemic injury. Utilization of animal models of stress-related psychological disorders is critical in the prevention and treatment of cardiovascular disorders in patients experiencing stress-related psychiatric conditions.

Reduction of myocardial ischemia-reperfusion injury by mechanical tissue resuscitation using sub-atmospheric pressure.

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Argenta, Louis C; Morykwas, Michael J; Mays, Jennifer J; Thompson, Edreca A; Hammon, John W; Jordan, James E

2010-03-01

Reperfusion-induced injury after myocardial infarction is associated with a well-defined sequence of early and late cardiomyocyte death. Most present attempts to ameliorate this sequence focus on a single facet of the complex process in an attempt to salvage cardiomyocytes. We examined, as proof of concept, the effects of mechanical tissue resuscitation (MTR) with controlled negative pressure on myocardial injury following acute myocardial infarction. Anesthetized swine were subjected to 75 minutes of left coronary artery occlusion and three hours of reperfusion. Animals were assigned to one of three groups: (A) untreated control; treatment of involved myocardium for 180 minutes of MTR with (B) -50 mmHg, or (C) -125 mmHg. All three groups were subjected to equivalent ischemic stress. Treatment of the ischemic area with MTR for 180 minutes significantly (p control: 9.3 +/- 1.8% (-50 mmHg) and 11.9 +/- 1.2% (-125 mmHg) versus 26.4 +/- 2.1% (control). Total area of cell death was reduced by 65% with -50 mmHg treatment and 55% in the -125 mmHg group. Treatment of ischemic myocardium with MTR, for a controlled period of time during reperfusion, successfully reduced the extent of myocardial death after acute myocardial infarction. These data provide evidence that MTR using subatmospheric pressure may be a simple, efficacious, nonpharmacological, mechanical strategy for decreasing cardiomyocyte death following myocardial infarction, which can be delivered in the operating room.

Huang-Lian-Jie-Du-Decotion induced protective autophagy against the injury of cerebral ischemia/reperfusion via MAPK-mTOR signaling pathway.

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Wang, Peng-Ran; Wang, Jun-Song; Zhang, Chao; Song, Xing-Fang; Tian, Na; Kong, Ling-Yi

2013-08-26

Huang-Lian-Jie-Du-Decotion (HLJDD, Hwangryun-Hae-Dok-Decotion in Japan), an ancient antipyretic and detoxifying traditional Chinese medicine formula, was reported to have protective effect on ischemic stroke. To investigate the therapeutic effect of HLJDD on ischemic stroke and explore its mode of action. A model of ischemic stroke in the rat was established after transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Rats were assigned randomly to groups of control, sham, transient ischemia/reperfusion (I/R), and three treatment groups by HLJDD at 2.5, 5.0, 10.0mg/kg. The neurological deficit, the cerebral infarct size, morphology abnormality, biochemical parameters were examined, and the levels of relevant proteins were determined by immunoblotting analysis to evaluate the protective effects of HLJDD on ischemic stroke and explore the underlying mechanism. Compared with I/R group, HLJDD significantly ameliorated neurological deficit and histopathology changes, decreased infarct area, and restored the levels of biochemical indicators including nitric oxide (NO), malondialdehyde (MDA), glutathione (GSH), glutathione disulfide (GSSG), total superoxide dismutase (T-SOD), Cu/Zn-SOD, Mn-SOD and glutathione peroxidase (GSH-PX). HLJDD also notably elevated the levels of microtubule-associated protein 1 light chain 3 (LC3), Beclin-1, and other autophagy related genes (Atgs), promoted the activation of extracellular signal-regulated kinases (ERK), protein kinase B (Akt), 3-phosphoinositide-dependent kinase (PDK1), and inhibited the activation of mammalian target of rapamycin (mTOR), c-Jun N-terminal protein kinases (JNK), p38, phosphatase and tensin homolog (PTEN). HLJDD showed neuroprotective effects on ischemic stroke, at least in part to the induced protective autophagy via the regulation of mitogen-activated protein kinase (MAPK) signals. This Akt-independent protective autophagy is favorable in the treatment of stroke, avoiding unfavorable side

The relationship between myocardial blood flow and myocardial viability after reperfusion. Myocardial viability assessed by [sup 15]O-water-PET

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Tsukagoshi, Joichi (Gunma Univ., Maebashi (Japan). School of Medicine)

1994-09-01

The purpose of this study was to examine the relationship between myocardial blood flow and myocardial viability in the ischemic canine myocardium after reperfusion. Transient ischemia was induced by 60-, 90-, and 180-minute occlusion of the left anterior descending coronary artery. Myocardial blood flow (MBF) was measured in the areas in which regional contractility was severely impaired (ehocardiographically akinetic or dyskinetic) in the early reperfusion period by [sup 15]O-water positron emission tomography (PET) 12 hours and 4 weeks after reperfusion. An MBF ratio of ischemic to nonischemic regions 12 hours after reperfusion was inversely correlated with the amount of histologically determined tissue necrosis (r=-0.74). The regional contractility recovered 4 weeks later in the areas where an MBF ratio was 0.48 or greater, but did not recover in the areas with a lower MBF ratio. Thus, myocardial viability can be appropriately predicted in the early phase of myocardial perfusion by PET with [sup 15]O-water even in the absence of metabolic imaging. (author).

A porcine ex vivo lung perfusion model with maximal argon exposure to attenuate ischemia-reperfusion injury

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An Martens

2017-01-01

Full Text Available Argon (Ar is a noble gas with known organoprotective effects in rodents and in vitro models. In a previous study we failed to find a postconditioning effect of Ar during ex vivo lung perfusion (EVLP on warm-ischemic injury in a porcine model. In this study, we further investigated a prolonged exposure to Ar to decrease cold ischemia-reperfusion injury after lung transplantation in a porcine model with EVLP assessment. Domestic pigs (n = 6/group were pre-conditioned for 6 hours with 21% O 2 and 79% N 2 (CONTR or 79% Ar (ARG. Subsequently, lungs were cold flushed and stored inflated on ice for 18 hours inflated with the same gas mixtures. Next, lungs were perfused for 4 hours on EVLP (acellular while ventilated with 12% O 2 and 88% N 2 (CONTR group or 88% Ar (ARG group. The perfusate was saturated with the same gas mixture but with the addition of CO 2 to an end-tidal CO 2 of 35-45 mmHg. The saturated perfusate was drained and lungs were perfused with whole blood for an additional 2 hours on EVLP. Evaluation at the end of EVLP did not show significant effects on physiologic parameters by prolonged exposure to Ar. Also wet-to-dry weight ratio did not improve in the ARG group. Although in other organ systems protective effects of Ar have been shown, we did not detect beneficial effects of a high concentration of Ar on cold pulmonary ischemia-reperfusion injury in a porcine lung model after prolonged exposure to Ar in this porcine model with EVLP assessment.

Dietary nitrate attenuates renal ischemia-reperfusion injuries by modulation of immune responses and reduction of oxidative stress.

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Yang, Ting; Zhang, Xing-Mei; Tarnawski, Laura; Peleli, Maria; Zhuge, Zhengbing; Terrando, Niccolo; Harris, Robert A; Olofsson, Peder S; Larsson, Erik; Persson, A Erik G; Lundberg, Jon O; Weitzberg, Eddie; Carlstrom, Mattias

2017-10-01

Ischemia-reperfusion (IR) injury involves complex pathological processes in which reduction of nitric oxide (NO) bioavailability is suggested as a key factor. Inorganic nitrate can form NO in vivo via NO synthase-independent pathways and may thus provide beneficial effects during IR. Herein we evaluated the effects of dietary nitrate supplementation in a renal IR model. Male mice (C57BL/6J) were fed nitrate-supplemented chow (1.0mmol/kg/day) or standard chow for two weeks prior to 30min ischemia and during the reperfusion period. Unilateral renal IR caused profound tubular and glomerular damage in the ischemic kidney. Renal function, assessed by plasma creatinine levels, glomerular filtration rate and renal plasma flow, was also impaired after IR. All these pathologies were significantly improved by nitrate. Mechanistically, nitrate treatment reduced renal superoxide generation, pro-inflammatory cytokines (IL-1β, IL-6 and IL-12 p70) and macrophage infiltration in the kidney. Moreover, nitrate reduced mRNA expression of pro-inflammatory cytokines and chemo attractors, while increasing anti-inflammatory cytokines in the injured kidney. In another cohort of mice, two weeks of nitrate supplementation lowered superoxide generation and IL-6 expression in bone marrow-derived macrophages. Our study demonstrates protective effect of dietary nitrate in renal IR injury that may be mediated via modulation of oxidative stress and inflammatory responses. These novel findings suggest that nitrate supplementation deserve further exploration as a potential treatment in patients at high risk of renal IR injury. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Growth Arrest-Specific Protein 6 is Hepatoprotective Against Ischemia/Reperfusion Injury

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Llacuna, Laura; Bárcena, Cristina; Bellido-Martín, Lola; Fernández, Laura; Stefanovic, Milica; Marí, Montserrat; García-Ruiz, Carmen; Fernández-Checa, José C.; de Frutos, Pablo García; Morales, Albert

2010-01-01

Growth arrest-specific gene 6 (GAS6) promotes growth and cell survival during tissue repair and development in different organs, including the liver. However, the specific role of GAS6 in liver ischemia/reperfusion (I/R) injury has not been previously addressed. Here, we report an early increase in serum GAS6 levels following I/R exposure. Moreover, unlike wild type mice, Gas6-/- mice were highly sensitive to partial hepatic I/R, with 90% of mice dying within 12 hours of reperfusion due to massive hepatocellular injury. I/R induced early hepatic AKT phosphorylation in wild type but not in Gas6-/- mice, without significant changes in JNK phosphorylation or nuclear NF-κB translocation, whereas hepatic IL-1β and TNF mRNA levels were higher in Gas6-/- mice compared to wild type mice. In line with the in vivo data, in vitro studies indicated that GAS6 induced AKT phosphorylation in primary mouse hepatocytes protecting them from hypoxia-induced cell death, while GAS6 diminished lipopolysaccharide (LPS)-induced cytokine expression (IL-1β and TNF) in murine macrophages. Finally, in vivo recombinant GAS6 treatment not only rescued GAS6 knockout mice from I/R-induced severe liver damage, but also attenuated hepatic damage in wild type mice following I/R. In conclusion, our data uncover GAS6 as a new player in liver I/R injury, emerging as a potential therapeutic target to reduce post-ischemic hepatic damage. PMID:20730776

Insulin Preconditioning Elevates p-Akt and Cardiac Contractility after Reperfusion in the Isolated Ischemic Rat Heart

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Tamaki Sato

2014-01-01

Full Text Available Insulin induces cardioprotection partly via an antiapoptotic effect. However, the optimal timing of insulin administration for the best quality cardioprotection remains unclear. We tested the hypothesis that insulin administered prior to ischemia provides better cardioprotection than insulin administration after ischemia. Isolated rat hearts were prepared using Langendorff method and divided into three groups. The Pre-Ins group (Pre-Ins received 0.5 U/L insulin prior to 15 min no-flow ischemia for 20 min followed by 20 min of reperfusion. The Post-Ins group (Post-Ins received 0.5 U/L insulin during the reperfusion period only. The control group (Control was perfused with KH buffer throughout. The maximum of left ventricular derivative of pressure development (dP/dt(max was recorded continuously. Measurements of TNF-α and p-Akt in each time point were assayed by ELISA. After reperfusion, dP/dt(max in Pre-Ins was elevated, compared with Post-Ins at 10 minutes after reperfusion and Control at all-time points. TNF-α levels at 5 minutes after reperfusion in the Pre-Ins were lower than the others. After 5 minutes of reperfusion, p-Akt was elevated in Pre-Ins compared with the other groups. Insulin administration prior to ischemia provides better cardioprotection than insulin administration only at reperfusion. TNF-α suppression is possibly mediated via p-Akt leading to a reduction in contractile myocardial dysfunction.

Molecular Mechanisms Responsible for Neuron-Derived Conditioned Medium (NCM-Mediated Protection of Ischemic Brain.

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Chi-Hsin Lin

Full Text Available The protective value of neuron-derived conditioned medium (NCM in cerebral ischemia and the underlying mechanism(s responsible for NCM-mediated brain protection against cerebral ischemia were investigated in the study. NCM was first collected from the neuronal culture growing under the in vitro ischemic condition (glucose-, oxygen- and serum-deprivation or GOSD for 2, 4 or 6 h. Through the focal cerebral ischemia (bilateral CCAO/unilateral MCAO animal model, we discovered that ischemia/reperfusion (I/R-induced brain infarction was significantly reduced by NCM, given directly into the cistern magna at the end of 90 min of CCAO/MCAO. Immunoblocking and chemical blocking strategies were applied in the in vitro ischemic studies to show that NCM supplement could protect microglia, astrocytes and neurons from GOSD-induced cell death, in a growth factor (TGFβ1, NT-3 and GDNF and p-ERK dependent manner. Brain injection with TGFβ1, NT3, GDNF and ERK agonist (DADS alone or in combination, therefore also significantly decreased the infarct volume of ischemic brain. Moreover, NCM could inhibit ROS but stimulate IL-1β release from GOSD-treated microglia and limit the infiltration of IL-β-positive microglia into the core area of ischemic brain, revealing the anti-oxidant and anti-inflammatory activities of NCM. In overall, NCM-mediated brain protection against cerebral ischemia has been demonstrated for the first time in S.D. rats, due to its anti-apoptotic, anti-oxidant and potentially anti-glutamate activities (NCM-induced IL-1β can inhibit the glutamate-mediated neurotoxicity and restriction upon the infiltration of inflammatory microglia into the core area of ischemic brain. The therapeutic potentials of NCM, TGFβ1, GDNF, NT-3 and DADS in the control of cerebral ischemia in human therefore have been suggested and require further investigation.

Detection of focal hypoxic-ischemic injury and neuronal stress in a rodent model of unilateral MCA occlusion/reperfusion using radiolabeled annexin V

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Mari, Carina; Goris, Michael L. [Division of Nuclear Medicine, Department of Radiology, Stanford University Hospital, CA 94305, Stanford (United States); Karabiyikoglu, Murat; Yenari, Midori Anne [Departments of Neurosurgery and Neurology, Stanford University Hospital, CA 94305, Stanford (United States); Tait, Jonathan F. [Department of Laboratory Medicine, University of Washington Medical Center, WA 98195-7110, Seattle (United States); Blankenberg, Francis G. [Division of Nuclear Medicine, Department of Radiology, Stanford University Hospital, CA 94305, Stanford (United States); Division of Pediatric Radiology, Department of Radiology, Stanford University, Lucile Salter Packard Children' s Hospital, 725 Welch Road, Room 1673, CA 94305, Palo Alto (United States)

2004-05-01

In this study we wished to determine whether technetium-99m annexin V, an in vivo marker of cellular injury and death, could be used to noninvasively monitor neuronal injury following focal middle cerebral artery (MCA) occlusion/reperfusion injury. Sixteen adult male Sprague-Dawley rats (along with four controls) underwent left (unilateral) MCA intraluminal beaded thread occlusion for 2 h followed by reperfusion. One hour following tail vein injection of 5-10 mCi of {sup 99m}Tc-annexin V, animals underwent either single-photon emission computerized tomography (SPECT) or autoradiography followed by immunohistochemical analyses. There was abnormal, bilateral, multifocal uptake of {sup 99m}Tc-annexin V in each cerebral hemisphere as seen by both SPECT and autoradiography at 4 h and 1, 3, and 7 days after initiation of occlusion. The average maximal annexin V uptake at 4 h was 310%{+-}85% and 365%{+-}151% above control values (P<0.006) within the right and left hemispheres, respectively, peaking on day 3 with values of 925%{+-}734% and 1,194%{+-}643% (P<0.03) that decreased by day 7 to 489%{+-}233% and 785%{+-}225% (P<0.01). Total lesional volume of the left hemisphere was 226%, 261%, and 451% (P<0.03) larger than the right at 4, 24, and 72 h after injury, respectively. Annexin V localized to the cytoplasm of injured neurons ipsilateral to the site of injury as well as to otherwise normal-appearing neurons of the contralateral hemisphere as confirmed by dual fluorescent microscopy. It is concluded that there is abnormal bilateral, multifocal annexin V uptake, greater on the left than on the right side, within 4 h of unilateral left MCA ischemic injury and that the uptake peaks at 3 days and decreases by 7 days after injury. This pattern suggests that neuronal stress may play a role in the response of the brain to focal injury and be responsible for annexin V uptake outside the region of ischemic insult. (orig.)

Neuroprotective Effect of the Ginsenoside Rg1 on Cerebral Ischemic Injury In Vivo and In Vitro Is Mediated by PPARγ-Regulated Antioxidative and Anti-Inflammatory Pathways

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Yang Li

2017-01-01

Full Text Available The ginsenoside Rg1 exerts a neuroprotective effect during cerebral ischemia/reperfusion injury. Rg1 has been previously reported to improve PPARγ expression and signaling, consequently enhancing its regulatory processes. Due to PPARγ’s role in the suppression of oxidative stress and inflammation, Rg1’s PPARγ-normalizing capacity may play a role in the observed neuroprotective action of Rg1 during ischemic brain injury. We utilized a middle cerebral artery ischemia/reperfusion injury model in rats in addition to an oxygen glucose deprivation model in cortical neurons to elucidate the mechanisms underlying the neuroprotective effects of Rg1. We found that Rg1 significantly increased PPARγ expression and reduced multiple indicators of oxidative stress and inflammation. Ultimately, Rg1 treatment improved neurological function and diminished brain edema, indicating that Rg1 may exert its neuroprotective action on cerebral ischemia/reperfusion injury through the activation of PPARγ signaling. In addition, the present findings suggested that Rg1 was a potent PPARγ agonist in that it upregulated PPARγ expression and was inhibited by GW9662, a selective PPARγ antagonist. These findings expand our previous understanding of the molecular basis of the therapeutic action of Rg1 in cerebral ischemic injury, laying the ground work for expanded study and clinical optimization of the compound.

The effect of aloe vera on ischemia--Reperfusion injury of sciatic nerve in rats.

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Guven, Mustafa; Gölge, Umut Hatay; Aslan, Esra; Sehitoglu, Muserref Hilal; Aras, Adem Bozkurt; Akman, Tarik; Cosar, Murat

2016-04-01

Aloe vera is compound which has strong antioxidant and anti-inflammatory effects. We investigated the neuroprotective role of aloe vera treatment in rats with experimental sciatic nerve ischemia/reperfusion injury. Twenty-eight male Wistar Albino rats were divided equally into 4 groups. Groups; Control group (no surgical procedure or medication), sciatic nerve ischemia/reperfusion group, sciatic nerve ischemia/reperfusion+aloe vera group and sciatic nerve ischemia/reperfusion+methylprednisolone group. Ischemia was performed by clamping the infrarenal abdominal aorta. 24 hours after ischemia, all animals were sacrificed. Sciatic nerve tissues were also examined histopathologically and biochemically. Ischemic fiber degeneration significantly decreased in the pre-treated with aloe vera and treated with methylprednisolone groups, especially in the pre-treated with aloe vera group, compared to the sciatic nerve ischemia/reperfusion group (paloe vera group was not statistically different compared to the MP group (p>0.05). Aloe vera is effective neuroprotective against sciatic nerve ischemia/reperfusion injury via antioxidant and anti-inflammatory properties. Also aloe vera was found to be as effective as MP. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Reperfusion promotes mitochondrial dysfunction following focal cerebral ischemia in rats.

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Jun Li

Full Text Available BACKGROUND AND PURPOSE: Mitochondrial dysfunction has been implicated in the cell death observed after cerebral ischemia, and several mechanisms for this dysfunction have been proposed. Reperfusion after transient cerebral ischemia may cause continued and even more severe damage to the brain. Many lines of evidence have shown that mitochondria suffer severe damage in response to ischemic injury. The purpose of this study was to observe the features of mitochondrial dysfunction in isolated mitochondria during the reperfusion period following focal cerebral ischemia. METHODS: Male Wistar rats were subjected to focal cerebral ischemia. Mitochondria were isolated using Percoll density gradient centrifugation. The isolated mitochondria were fixed for electron microscopic examination; calcium-induced mitochondrial swelling was quantified using spectrophotometry. Cyclophilin D was detected by Western blotting. Fluorescent probes were used to selectively stain mitochondria to measure their membrane potential and to measure reactive oxidative species production using flow cytometric analysis. RESULTS: Signs of damage were observed in the mitochondrial morphology after exposure to reperfusion. The mitochondrial swelling induced by Ca(2+ increased gradually with the increasing calcium concentration, and this tendency was exacerbated as the reperfusion time was extended. Cyclophilin D protein expression peaked after 24 hours of reperfusion. The mitochondrial membrane potential was decreased significantly during the reperfusion period, with the greatest decrease observed after 24 hours of reperfusion. The surge in mitochondrial reactive oxidative species occurred after 2 hours of reperfusion and was maintained at a high level during the reperfusion period. CONCLUSIONS: Reperfusion following focal cerebral ischemia induced significant mitochondrial morphological damage and Ca(2+-induced mitochondrial swelling. The mechanism of this swelling may be mediated by

[The protective action of nimodipine on the ischemic myocardium].

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Tsorin, I B; Kazanova, G V; Kirsanova, G Iu; Chirkova, E Iu; Chichkanov, G G

1992-01-01

The experiments with unconscious cats and dogs have demonstrated that the calcium antagonist nimodipine has a profound anti-ischemic property. The drug reduces the average value of ST-segment elevation in multiple epicardial ECG leads, during acute myocardial ischemia. Nimodipine maintains cardiac pump and contractile functions, elevates ATP levels in the arbitrarily intact and ischemic myocardium of the left ventricle during 40-min occlusion and 60-min reperfusion of the coronary artery. The protective action of the drug is unassociated with enhanced collateral coronary circulation.

Heme oxygenase-1 mediates the protective effects of ischemic preconditioning on mitigating lung injury induced by lower limb ischemia-reperfusion in rats.

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Peng, Tsui-Chin; Jan, Woan-Ching; Tsai, Pei-Shan; Huang, Chun-Jen

2011-05-15

Lower limb ischemia-reperfusion (I/R) imposes oxidative stress, elicits inflammatory response, and subsequently induces acute lung injury. Ischemic preconditioning (IP), a process of transient I/R, mitigates the acute lung injury induced by I/R. We sought to elucidate whether the protective effects of IP involve heme oxygenase-1 (HO-1). Adult male rats were randomized to receive I/R, I/R plus IP, I/R plus IP plus the HO-1 inhibitor tin protoporphyrin (SnPP) (n = 12 in each group). Control groups were run simultaneously. I/R was induced by applying rubber band tourniquet high around each thigh for 3 h followed by reperfusion for 3 h. To achieve IP, three cycles of bilateral lower limb I/R (i.e., ischemia for 10 min followed by reperfusion for 10 min) were performed. IP was performed immediately before I/R. After sacrifice, degree of lung injury was determined. Histologic findings, together with assays of leukocyte infiltration (polymorphonuclear leukocytes/alveoli ratio and myeloperoxidase activity) and lung water content (wet/dry weight ratio), confirmed that I/R induced acute lung injury. I/R also caused significant inflammatory response (increases in chemokine, cytokine, and prostaglandin E(2) concentrations), imposed significant oxidative stress (increases in nitric oxide and malondialdehyde concentrations), and up-regulated HO-1 expression in lung tissues. IP significantly enhanced HO-1 up-regulation and, in turn, mitigated oxidative stress, inflammatory response, and acute lung injury induced by I/R. In addition, the protective effects of IP were counteracted by SnPP. The protective effects of IP on mitigating acute lung injury induced by lower limb I/R are mediated by HO-1. Copyright © 2011 Elsevier Inc. All rights reserved.

Therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemia/reperfusion injury in rats.

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Guo, Chao; Zhu, Yanrong; Weng, Yan; Wang, Shiquan; Guan, Yue; Wei, Guo; Yin, Ying; Xi, Miaomaio; Wen, Aidong

2014-01-01

Breviscapine injection is a Chinese herbal medicine standardized product extracted from Erigeron breviscapus (Vant.) Hand.-Mazz. It has been widely used for treating cardiovascular and cerebrovascular diseases. However, the therapeutic time window and the action mechanism of breviscapine are still unclear. The present study was designed to investigate the therapeutic time window and underlying therapeutic mechanism of breviscapine injection against cerebral ischemic/reperfusion injury. Sprague-Dawley rats were subjected to middle cerebral artery occlusion for 2h followed by 24h of reperfusion. Experiment part 1 was used to investigate the therapeutic time window of breviscapine. Rats were injected intravenously with 50mg/kg breviscapine at different time-points of reperfusion. After 24h of reperfusion, neurologic score, infarct volume, brain water content and serum level of neuron specific enolase (NSE) were measured in a masked fashion. Part 2 was used to explore the therapeutic mechanism of breviscapine. 4-Hydroxy-2-nonenal (4-HNE), 8-hydroxyl-2'- deoxyguanosine (8-OHdG) and the antioxidant capacity of ischemia cortex were measured by ELISA and ferric-reducing antioxidant power (FRAP) assay, respectively. Immunofluorescence and western blot analysis were used to analyze the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Part 1: breviscapine injection significantly ameliorated neurologic deficit, reduced infarct volume and water content, and suppressed the levels of NSE in a time-dependent manner. Part 2: breviscapine inhibited the increased levels of 4-HNE and 8-OHdG, and enhanced the antioxidant capacity of cortex tissue. Moreover, breviscapine obviously raised the expression of Nrf2 and HO-1 proteins after 24h of reperfusion. The therapeutic time window of breviscapine injection for cerebral ischemia/reperfusion injury seemed to be within 5h after reperfusion. By up-regulating the expression of Nrf2/HO-1 pathway

Involvement of Rho-kinase in cold ischemia-reperfusion injury after liver transplantation in rats.

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Shiotani, Satoko; Shimada, Mitsuo; Suehiro, Taketoshi; Soejima, Yuji; Yosizumi, Tomoharu; Shimokawa, Hiroaki; Maehara, Yoshihiko

2004-08-15

Reperfusion of ischemic tissues is known to cause the generation of reactive oxygen species (ROS) with resultant tissue damage. However, the sources of ROS in reperfused tissues are not fully characterized. We hypothesized that the small GTPase Rho and its target effector Rho-kinase/ROK/ROCK are involved in the oxidative burst in reperfused tissue with resultant reperfusion injury. In an in vivo rat model of liver transplantation using cold ischemia for 12 hr followed by reperfusion, a specific Rho-kinase inhibitor, fasudil (30 mg/kg), was administered orally 1 hr before the transplantation. Fasudil suppressed the ischemia-reperfusion (I/R)-induced generation of ROS after reperfusion (P<0.01) and also suppressed the release of inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta) 3 hr after reperfusion, resulting in a significant reduction of I/R-induced hepatocellular injury (P<0.05), necrosis, apoptosis (P<0.01), and neutrophil infiltration (P<0.0001) 12 hr after reperfusion. All animals receiving a graft without fasudil died within 3 days, whereas 40% of those receiving fasudil survived (P<0.001). The present study demonstrates that Rho-kinase-mediated production of ROS and inflammatory cytokines are substantially involved in the pathogenesis of hepatocellular necrosis and apoptosis induced by cold I/R in vivo and that Rho-kinase may be regarded as a novel therapeutic target for the disorder.

The role of curcumin on intestinal oxidative stress, cell proliferation and apoptosis after ischemia/reperfusion injury in rats.

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Yucel, Ahmet Fikret; Kanter, Mehmet; Pergel, Ahmet; Erboga, Mustafa; Guzel, Ahmet

2011-12-01

The aim of this study was to demonstrate the role of curcumin on oxidative stress, cell proliferation and apoptosis in the rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ curcumin; each group contain 10 animals. Sham group animals underwent laparotomy without I/R injury. After I/R groups animals underwent laparotomy, 1 h of superior mesenteric artery ligation were followed by 1 h of reperfusion. In the curcumin group, 3 days before I/R, curcumin (100 mg/kg) was administered by gastric gavage. All animals were sacrificed at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation in all groups. Curcumin treatment significantly decreased the elevated tissue malondialdehyde levels and increased of reduced superoxide dismutase, and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological injury including mucosal erosions and villous congestion and hemorrhage. Curcumin treatment significantly attenuated the severity of intestinal I/R injury, with inhibiting of I/R-induced apoptosis and cell proliferation. These results suggest that curcumin treatment has a protective effect against intestinal damage induced by intestinal I/R. This protective effect is possibly due to its ability to inhibit I/R-induced oxidative stress, apoptosis and cell proliferation.

Retinal reperfusion in diabetic retinopathy following treatment with anti-VEGF intravitreal injections

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Levin AM

2017-01-01

Full Text Available Ariana M Levin, Irene Rusu, Anton Orlin, Mrinali P Gupta, Peter Coombs, Donald J D’Amico, Szilárd Kiss Department of Ophthalmology, Weill Cornell Medical College, New York, NY, USA Purpose: The aim of this study is to report peripheral reperfusion of ischemic areas of the retina on ultra-widefield fluorescein angiography (UWFA following anti-vascular endothelial growth factor (VEGF intravitreal injections in patients treated for diabetic retinopathy. Methods: This study is a retrospective review of 16 eyes of 15 patients with diabetic retinopathy, who received anti-VEGF intravitreal injections and underwent pre- and postinjection UWFA. The main outcome measured was the presence of reperfusion in postinjection UWFA images in areas of the retina that demonstrated nonperfusion in preinjection images. Images were analyzed for reperfusion qualitatively and quantitatively by two graders. Results: Twelve of 16 eyes (75% or 11 of 15 patients (73.3% demonstrated reperfusion following anti-VEGF injection. On UWFA, reperfusion was detected both within the field of 7-standard field (7SF fluorescein angiography and in the periphery outside the 7SF. Four of 16 eyes or 4 of 15 patients did not demonstrate reperfusion, one of which had extensive scarring from prior panretinal photocoagulation. Conclusion: In patients with diabetic retinopathy, treatment with anti-VEGF agents can be associated with reperfusion of areas of nonperfusion, as demonstrated by UWFA. Keywords: anti-VEGF, diabetes, diabetic retinopathy, ischemia, perfusion, reperfusion

Remote Ischemic Postconditioning (RIPC) of the Upper Arm Results in Protection from Cardiac Ischemia-Reperfusion Injury Following Primary Percutaneous Coronary Intervention (PCI) for Acute ST-Segment Elevation Myocardial Infarction (STEMI).

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Cao, Bangming; Wang, Haipeng; Zhang, Chi; Xia, Ming; Yang, Xiangjun

2018-02-19

BACKGROUND The aim of this study was to evaluate the role of remote ischemic postconditioning (RIPC) of the upper arm on protection from cardiac ischemia-reperfusion injury following primary percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). MATERIAL AND METHODS Eighty patients with STEMI were randomized into two groups: primary PCI (N=44) and primary PCI+RIPC (N=36). RIPC consisted of four cycles of 5 minutes of occlusion and five minutes of reperfusion by cuff inflation and deflation of the upper arm, commencing within one minute of the first PCI balloon dilatation. Peripheral venous blood samples were collected before PCI and at 0.5, 8, 24, 48, and 72 hours after PCI. Levels of creatine kinase-MB (CK-MB), serum creatinine (Cr), nitric oxide (NO), and stromal cell-derived factor-1α (SDF-1α) were measured. The rates of acute kidney injury (AKI) and the estimated glomerular filtration rate (eGFR) were calculated. RESULTS Patients in the primary PCI+RIPC group, compared with the primary PCI group, had significantly lower peak CK-MB concentrations (PPCI in patients with acute STEMI might provide cardiac and renal protection from ischemia-reperfusion injury via the actions of SDF-1α, and NO.

Detection of viable myocardium in canine model with myocardial ischemia and ischemia-reperfusion by 125I-BMIPP: relation to regional blood flow

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Huang Gang; Zhao Huiyang; Shen Xuedong; Li Qing; Yuan Jimin; Zhu Cuiying

1999-01-01

Objective: The effects of BMIPP (β-methyl-iodophenyl pentadecanoic acid) on detecting viable myocardium and the relation between regional blood flow and the uptake of BMIPP were evaluated in canine model of myocardial ischemia and ischemia-reperfusion. Methods: 12 open-chest dogs under anesthesia were divided into two groups. Group I (ischemia group) had left circumflex coronary arterial occlusion for 2 h and group II (ischemia-reperfusion group) was occluded for 1 h and followed by 2 h reperfusion. Myocardial blood flow was measured with 99 Tc m -microspheres. 30 min after intravenous injection of 125 I-BMIPP and 99 Tc m -microspheres, the heart was excised rapidly and stained with Evans blue and NBT. Tissue samples (divided into approximately 1 g) of left ventricle were obtained, weighed and counted for 125 I and 99 Tc m . Regional blood flow and the uptake of BMIPP were expressed as percentages of average values in non-ischemic myocardium (two to three tissue samples) from the normal myocardium. Results: In ischemic myocardium (NBT positive samples), the uptake of BMIPP was relatively higher compared with regional blood flow [(67 +- 23)% vs (42 +- 19)%, P 0.05]. In ischemia-reperfusion group, regional blood flow was increased in ischemic and necrotic tissues, but the uptake of BMIPP was not enhanced with the increasing blood flow. Conclusions: BMIPP uptake seems to provide metabolic information independent of regional blood flow. The mismatching between regional blood flow and BMIPP uptake may indicate myocardial viability in the regions of hypoperfusion and the uptake of BMIPP in ischemic myocardium was related to existence of cellular metabolism

Mitochondria as Key Targets of Cardioprotection in Cardiac Ischemic Disease: Role of Thyroid Hormone Triiodothyronine

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Francesca Forini

2015-03-01

Full Text Available Ischemic heart disease is the major cause of mortality and morbidity worldwide. Early reperfusion after acute myocardial ischemia has reduced short-term mortality, but it is also responsible for additional myocardial damage, which in the long run favors adverse cardiac remodeling and heart failure evolution. A growing body of experimental and clinical evidence show that the mitochondrion is an essential end effector of ischemia/ reperfusion injury and a major trigger of cell death in the acute ischemic phase (up to 48–72 h after the insult, the subacute phase (from 72 h to 7–10 days and chronic stage (from 10–14 days to one month after the insult. As such, in recent years scientific efforts have focused on mitochondria as a target for cardioprotective strategies in ischemic heart disease and cardiomyopathy. The present review discusses recent advances in this field, with special emphasis on the emerging role of the biologically active thyroid hormone triiodothyronine (T3.

Mitochondria as key targets of cardioprotection in cardiac ischemic disease: role of thyroid hormone triiodothyronine.

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Forini, Francesca; Nicolini, Giuseppina; Iervasi, Giorgio

2015-03-19

Ischemic heart disease is the major cause of mortality and morbidity worldwide. Early reperfusion after acute myocardial ischemia has reduced short-term mortality, but it is also responsible for additional myocardial damage, which in the long run favors adverse cardiac remodeling and heart failure evolution. A growing body of experimental and clinical evidence show that the mitochondrion is an essential end effector of ischemia/ reperfusion injury and a major trigger of cell death in the acute ischemic phase (up to 48-72 h after the insult), the subacute phase (from 72 h to 7-10 days) and chronic stage (from 10-14 days to one month after the insult). As such, in recent years scientific efforts have focused on mitochondria as a target for cardioprotective strategies in ischemic heart disease and cardiomyopathy. The present review discusses recent advances in this field, with special emphasis on the emerging role of the biologically active thyroid hormone triiodothyronine (T3).

Pharmacokinetic Study of Piracetam in Focal Cerebral Ischemic Rats.

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Paliwal, Pankaj; Dash, Debabrata; Krishnamurthy, Sairam

2018-04-01

Cerebral ischemia affects hepatic enzymes and brain permeability extensively. Piracetam was investigated up to phase III of clinical trials and there is lack of data on brain penetration in cerebral ischemic condition. Thus, knowledge of the pharmacokinetics and brain penetration of piracetam during ischemic condition would aid to improve pharmacotherapeutics in ischemic stroke. Focal cerebral ischemia was induced by middle cerebral artery occlusion for 2 h in male Wistar rats followed by reperfusion. After 24 h of middle cerebral artery occlusion or 22 h of reperfusion, piracetam was administered for pharmacokinetic, brain penetration, and pharmacological experiments. In pharmacokinetic study, blood samples were collected at different time points after 200-mg/kg (oral) and 75-mg/kg (intravenous) administration of piracetam through right external jugular vein cannulation. In brain penetration study, the cerebrospinal fluid, systemic blood, portal blood, and brain samples were collected at pre-designated time points after 200-mg/kg oral administration of piracetam. In a separate experiment, the pharmacological effect of the single oral dose of piracetam in middle cerebral artery occlusion was assessed at a dose of 200 mg/kg. All the pharmacokinetic parameters of piracetam including area under curve (AUC 0-24 ), maximum plasma concentration (C max ), time to reach the maximum plasma concentration (t max ), elimination half-life (t 1/2 ), volume of distribution (V z ), total body clearance, mean residence time, and bioavailability were found to be similar in ischemic stroke condition except for brain penetration. Piracetam exposure (AUC 0-2 ) in brain and CSF were found to be 2.4- and 3.1-fold higher, respectively, in ischemic stroke compared to control rats. Piracetam significantly reduced infarct volume by 35.77% caused by middle cerebral artery occlusion. There was no change in the pharmacokinetic parameters of piracetam in the ischemic stroke model except for

Sevoflurane postconditioning against cerebral ischemic neuronal injury is abolished in diet-induced obesity: role of brain mitochondrial KATP channels.

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Yang, Zecheng; Chen, Yunbo; Zhang, Yan; Jiang, Yi; Fang, Xuedong; Xu, Jingwei

2014-03-01

Obesity is associated with increased infarct volumes and adverse outcomes following ischemic stroke. However, its effect on anesthetic postconditioning‑induced neuroprotection has not been investigated. The present study examined the effect of sevoflurane postconditioning on focal ischemic brain injury in diet‑induced obesity. Sprague‑Dawley rats were fed a high‑fat diet (HF; 45% kcal as fat) for 12 weeks to develop obesity syndrome. Rats fed a low‑fat diet (LF; 10% kcal as fat) served as controls. The HF or LF‑fed rats were subjected to focal cerebral ischemia for 60 min, followed by 24 h of reperfusion. Postconditioning was performed by exposure to sevoflurane for 15 min immediately at the onset of reperfusion. The involvement of the mitochondrial KATP (mitoKATP) channel was analyzed by the administration of a selective inhibitor of 5‑hydroxydecanoate (5‑HD) prior to sevoflurane postconditioning or by administration of diazoxide (DZX), a mitoKATP channel opener, instead of sevoflurane. The cerebral infarct volume, neurological score and motor coordination were evaluated 24 h after reperfusion. The HF‑fed rats had larger infarct volumes, and lower neurological scores than the LF‑fed rats and also failed to respond to neuroprotection by sevoflurane or DZX. By contrast, sevoflurane and DZX reduced the infarct volumes and improved the neurological scores and motor coordination in the LF‑fed rats. Pretreatment with 5‑HD inhibited sevoflurane‑induced neuroprotection in the LF‑fed rats, whereas it had no effect in the HF‑fed rats. Molecular studies demonstrated that the expression of Kir6.2, a significant mitoKATP channel component, was reduced in the brains of the HF‑fed rats compared with the LF‑fed rats. The results of this study indicate that diet‑induced obesity eliminates the ability of anesthetic sevoflurane postconditioning to protect the brain against cerebral ischemic neuronal injury, most likely due to an impaired brain

Preventive Treatment with Ketamine Attenuates the Ischaemia-Reperfusion Response in a Chronic Postischaemia Pain Model

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Suryamin Liman

2015-01-01

Full Text Available Ischemia and inflammation may be pathophysiological mechanisms of complex regional pain syndrome (CRPS. Ketamine has proposed anti-inflammatory effects and has been used for treating CRPS. This study aimed to evaluate anti-inflammatory and analgesic effects of ketamine after ischaemia-reperfusion injury in a chronic postischaemia pain (CPIP model of CRPS-I. Using this model, ischemia was induced in the hindlimbs of male Sprague-Dawley rats. Ketamine, methylprednisolone, or saline was administered immediately after reperfusion. Physical effects, (oedema, temperature, and mechanical and cold allodynia in the bilateral hindpaws, were assessed from 48 hours after reperfusion. Fewer (56% rats in the ketamine group developed CPIP at the 48th hour after reperfusion (nonsignificant. Ketamine treated rats showed a significantly lower temperature in the ischaemic hindpaw compared to saline (P<0.01 and methylprednisolone (P<0.05 groups. Mechanical and cold allodynia were significantly lower in the ischaemic side in the ketamine group (P<0.05. Proinflammatory cytokines TNF-α and IL-2 were significantly lower at the 48th hour after reperfusion in ketamine and methylprednisolone groups, compared to saline (all P<0.05. In conclusion, immediate administration of ketamine after an ischaemia-reperfusion injury can alleviate pain and inflammation in the CPIP model and has potential to treat postischaemic pain.

Delayed perfusion phenomenon in a rat stroke model at 1.5 T MR: An imaging sign parallel to spontaneous reperfusion and ischemic penumbra?

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Chen Feng [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Radiology, Zhong Da Hospital, Southeast University, 87 Ding Jia Qiao Road, Nanjing 210009, Jiangsu Province (China); Suzuki, Yasuhiro [Department of Molecular and Cellular Medicine, Faculty of Medicine, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Pharmacology, Hamamatsu University School of Medicine, 1-20-1 Handayama, 431-3192 Hamamatsu (Japan); Nagai, Nobuo [Department of Molecular and Cellular Medicine, Faculty of Medicine, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Sun Xihe [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Department of Radiology, the Affiliated Hospital of Weifang Medical University, Weifang 261031, Shandong Province (China); Coudyzer, Walter [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Yu Jie [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Marchal, Guy [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium); Ni Yicheng [Department of Radiology, University Hospitals, Catholic University of Leuven, Herestraat 49, B-3000 Leuven (Belgium)]. E-mail: Yicheng.Ni@med.kuleuven.ac.be

2007-01-15

Introduction: Delayed perfusion (DP) sign at MR imaging was reported in stroke patients. We sought to experimentally elucidate its relation to spontaneous reperfusion and ischemic penumbra. Methods: Stroke was induced by photothrombotic occlusion of middle cerebral artery in eight rats and studied up to 72 h using a 1.5 T MR scanner with T2 weighted imaging (T2WI), diffusion weighted imaging (DWI), and dynamic susceptibility contrast-enhanced perfusion weighted imaging (DSC-PWI). Relative signal intensity (rSI), relative lesion volume (rLV), relative cerebral blood flow (rCBF), PWI{sub rLV}-DWI{sub rLV} mismatch (penumbra) and DP{sub rLV} were quantified and correlated with neurological deficit score (NDS), triphenyl tetrazolium chloride (TTC) staining, microangiography (MA) and histopathology. Results: The rSI and rLV characterized this stroke model on different MRI sequences and time points. DSC-PWI reproduced cortical DP in all rats, where rCBF evolved from 88.9% at 1 h through 64.9% at 6 h to 136.3% at 72 h. The PWI{sub rLV}-DWI{sub rLV} mismatch reached 10 {+-} 5.4% at 1 h, remained positive through 12 h and decreased to -3.3 {+-} 4.5% at 72 h. The incidence and rLV of the DP were well correlated with those of the penumbra (p < 0.01, r {sup 2} = 0.85 and p < 0.0001, r {sup 2} = 0.96, respectively). Shorter DP durations and more collateral arterioles occurred in rats without (n = 4) than with (n = 4) cortex involvement (p < 0.05). Rats without cortex involvement tended to earlier reperfusion and a lower NDS. Microscopy confirmed MRI, MA and TTC findings. Conclusions: In this rat stroke model, we reproduced clinically observed DP on DSC-PWI, confirmed spontaneous reperfusion, and identified the penumbra extending to 12 h post-ischemia, which appeared interrelated.

Genistein attenuates brain damage induced by transient cerebral ischemia through up-regulation of ERK activity in ovariectomized mice.

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Wang, Shiquan; Wei, Haidong; Cai, Min; Lu, Yan; Hou, Wugang; Yang, Qianzi; Dong, Hailong; Xiong, Lize

2014-01-01

Stroke has severe consequences in postmenopausal women. As replacement therapy of estrogen have various adverse effects and the undermined outcomes. Genistein, a natural phytoestrogen, has been suggested to be a potential neuroprotective agent for such stroke patients. However, the role of genistein and its underlying mechanism in ovariectomized mice has not yet been evaluated. In the present study, ovariectomized mice were treated with genistein (10 mg/kg) or vehicle daily for two weeks before developing transient cerebral ischemia (middle cerebral artery occlusion). The neurological manifestation was evaluated, and infarct volumes were demonstrated by 2,3,5-triphenyltetrazolium chloride staining at 24 h after reperfusion. In addition, phosphorylation of extracellular signal-regulated kinase (ERK) was detected by Western blotting and immunofluorescence staining, and cellular apoptosis was evaluated in the ischemic penumbra. We found that treatment with genistein reduced infarct volumes, improved neurological outcomes and attenuated cellular apoptosis at 24 h after reperfusion. ERK1/2 showed increased phosphorylation by genistein treatment after reperfusion, and an ERK1/2 inhibitor U0126 abolished this protective effect of genistein in terms of infarct volumes, neurological scores and cellular apoptosis. Our findings indicate that treatment with genistein can reduce the severity of subsequent stroke episodes, and that this beneficial function is associated with ERK activation.

Impact of ischemic preconditioning on functional sympatholysis during handgrip exercise in humans.

NARCIS (Netherlands)

Horiuchi, M.; Endo, J.; Thijssen, D.H.J.

2015-01-01

Repeated bouts of ischemia followed by reperfusion, known as ischemic preconditioning (IPC), is found to improve exercise performance. As redistribution of blood from the inactive areas to active skeletal muscles during exercise (i.e., functional sympatholysis) is important for exercise performance,

Acute effects of remote ischemic preconditioning on cutaneous microcirculation - a controlled prospective cohort study

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Kraemer Robert

2011-11-01

Full Text Available Abstract Background Therapeutic strategies aiming to reduce ischemia/reperfusion injury by conditioning tissue tolerance against ischemia appear attractive not only from a scientific perspective, but also in clinics. Although previous studies indicate that remote ischemic intermittent preconditioning (RIPC is a systemic phenomenon, only a few studies have focused on the elucidation of its mechanisms of action especially in the clinical setting. Therefore, the aim of this study is to evaluate the acute microcirculatory effects of remote ischemic preconditioning on a distinct cutaneous location at the lower extremity which is typically used as a harvesting site for free flap reconstructive surgery in a human in-vivo setting. Methods Microcirculatory data of 27 healthy subjects (25 males, age 24 ± 4 years, BMI 23.3 were evaluated continuously at the anterolateral aspect of the left thigh during RIPC using combined Laser-Doppler and photospectrometry (Oxygen-to-see, Lea Medizintechnik, Germany. After baseline microcirculatory measurement, remote ischemia was induced using a tourniquet on the contralateral upper arm for three cycles of 5 min. Results After RIPC, tissue oxygen saturation and capillary blood flow increased up to 29% and 35% during the third reperfusion phase versus baseline measurement, respectively (both p = 0.001. Postcapillary venous filling pressure decreased statistically significant by 16% during second reperfusion phase (p = 0.028. Conclusion Remote intermittent ischemic preconditioning affects cutaneous tissue oxygen saturation, arterial capillary blood flow and postcapillary venous filling pressure at a remote cutaneous location of the lower extremity. To what extent remote preconditioning might ameliorate reperfusion injury in soft tissue trauma or free flap transplantation further clinical trials have to evaluate. Trial registration ClinicalTrials.gov: NCT01235286

Amelioration of cognitive, motor and endogenous defense functions with silymarin, piracetam and protocatechuic acid in the cerebral global ischemic rat model.

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Muley, Milind M; Thakare, Vishnu N; Patil, Rajesh R; Bafna, Pallavi A; Naik, Suresh R

2013-07-19

The neuroprotective activities of silymarin, piracetam and protocatechuic acid ethyl ester (PCA) on cerebral global ischemic/reperfusion were evaluated in a rat model. A midline ventral incision was made in the throat region. The right and left common carotid arteries were located and a bilateral common carotid artery occlusion (BCCAO) was performed for 30min using atraumatic clamps followed by a 24h period of reperfusion. Neurological/behavioral functions (cognitive and motor), endogenous defense systems (lipid peroxidation, glutathione, catalase, and superoxide dismutase), reduced water content and infarct size and histopathological alterations were then studied. Silymarin and PCA treatments significantly improved cognitive, motor and endogenous defense functions, histopathological alterations, and, reduced both water content and infarct size compared to the vehicle-treated ischemic control group. Piracetam treatment improved neurological and histopathological alterations, reduced water content and infarct size, but failed to restore/prevent the impaired endogenous defense functions significantly. Silymarin showed better neuroprotection than piracetam and PCA in experimentally induced global ischemic/reperfusion and was able to facilitate mnemonic performance. Copyright © 2013 Elsevier Inc. All rights reserved.

Inhibition of NF-κB activity in the hypothalamic paraventricular nucleus attenuates hypertension and cardiac hypertrophy by modulating cytokines and attenuating oxidative stress

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Yu, Xiao-Jing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Zhang, Dong-Mei [Department of Physiology, Dalian Medical University, Dalian 116044 (China); Jia, Lin-Lin; Qi, Jie; Song, Xin-Ai; Tan, Hong [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Cui, Wei [Department of Endocrinology and Metabolism, First Affiliated Hospital of Xi' an Jiaotong University, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China); Chen, Wensheng [Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Qin, Da-Nian, E-mail: dnqin@stu.edu.cn [Department of Physiology, Shantou University Medical College, Shantou 515041 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University School of Basic Medical Sciences, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University Health Science Center, Xi' an 710061 (China)

2015-05-01

We hypothesized that chronic inhibition of NF-κB activity in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), attenuating nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase in the PVN of young spontaneously hypertensive rats (SHR). Young normotensive Wistar–Kyoto (WKY) and SHR rats received bilateral PVN infusions with NF–κB inhibitor pyrrolidine dithiocarbamate (PDTC) or vehicle for 4 weeks. SHR rats had higher mean arterial pressure and cardiac hypertrophy as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, cardiomyocyte diameters of the left cardiac ventricle, and mRNA expressions of cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC). These SHR rats had higher PVN levels of proinflammatory cytokines (PICs), reactive oxygen species (ROS), the chemokine monocyte chemoattractant protein-1 (MCP-1), NAD(P)H oxidase activity, mRNA expression of NOX-2 and NOX-4, and lower PVN IL-10, and higher plasma levels of PICs and NE, and lower plasma IL-10. PVN infusion of NF-κB inhibitor PDTC attenuated all these changes. These findings suggest that NF-κB activation in the PVN increases sympathoexcitation and hypertensive response, which are associated with the increases of PICs and oxidative stress in the PVN; PVN inhibition of NF-κB activity attenuates PICs and oxidative stress in the PVN, thereby attenuates hypertension and cardiac hypertrophy. - Highlights: • Spontaneously hypertensive rats exhibit neurohormonal excitation in the PVN. • PVN inhibition of NF-κB attenuates hypertension-induced cardiac hypertrophy. • PVN inhibition of NF-κB attenuates hypertension-induced neurohormonal excitation. • PVN inhibition of NF-κB attenuates hypertension-induced imbalance of cytokines

Action of iloprost and PGE1 on global ischemic and reperfused myocardium: a 31P-NMR-study.

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Pissarek, M; Gründer, W; Keller, T; Goos, H; Mest, H J; Krause, E G

1988-01-01

The influence of iloprost, PGE1 and of the combined application of iloprost and PGE1 on high energy phosphate contents was investigated in isolated rat hearts perfused aerob at 37 degrees C in Langendorff mode. Changes in creatine phosphate, ATP and inorganic phosphate were registered during 20 minutes of global ischemia and 56 minutes of reperfusion with 31P-NMR-spectroscopic methods starting drug application prior to ischemia simultaneously with onset of heart perfusion. Most effective in preservation of high energy phosphates was the combined application of PGE1 and iloprost resulting in a creatine phosphate/inorganic phosphate ratio of 103.2 +/- 30.9% of pre-ischemia values compared to 52.5 +/- 6.1% in control group without drug application 0-5 minutes after onset of reperfusion, 148.8 +/- 24.8% vs 78.8 +/- 15.2% at 6-11 minutes of reperfusion and 116.6 +/- 16% vs 68.9 +/- 12.7% at 12-17 minutes of reperfusion. The same trend was observed employing ATP/inorganic phosphate ratio. The improved energy state in reperfused hearts following application of PGE1 and iloprost in combination is presumed to be supported by a reduction of the loss of high energy phosphates (HEP) during global ischemia and by a cytoprotective effect of iloprost immediately after starting reperfusion.

Comparison of the effects of dexmedetomidine administered at two different times on renal ischemia/reperfusion injury in rats

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Edip Gonullu

2014-05-01

Full Text Available Background and objectives: We investigated the effect of dexmedetomidine on ischemic renal failure in rats. Methods: In the present study, 26 male adult Wistar albino rats weighting 230–300 g were randomly separated into four groups: sham-operated (n = 5, ischemia reperfusion (IR (IR group, n = 7, IR/reperfusion treatment with dexmedetomidine (Dex. R group, n = 7 and IR/pre-ischemic treatment with dexmedetomidine (Dex. I group, n = 7. In the first group, sham operation was achieved and renal clamps were not applied. For the IR group, renal ischemia was induced by occlusion of the bilateral renal arteries and veins for 60 min followed by reperfusion for 24 h. For the Dex. R and Dex. I groups, the same surgical procedure as in the IR group was performed, and dexmedetomidine (100 mcg/kg intraperitoneal was administrated at the 5th min after reperfusion and before ischemia. At the end of reperfusion, blood samples were drawn, the rats were sacrificed, and the left kidney was processed for histopathology. Results: The blood urea nitrogen (BUN levels in groups Dex. R and Dex. I were significantly lower than in the IR group (p = 0.015, p = 0.043, although urine flow was significantly higher in group Dex. R (p = 0.003. The renal histopathological score in the IR group was significantly higher than in the other groups. There was no significant difference between the Dex. R and Dex. I groups. Conclusions: The results were shown that administration of dexmedetomidine reduced the renal IR injury histomorphologically. Administration of dexmedetomidine in the reperfusion period was considered as more effective due to increase in urinary output and decrease in BUN levels. Keywords: Kidney, Ischemia/reperfusion, Dexmedetomidine, Acute renal failure

Multimodality imaging demonstrates trafficking of liposomes preferentially to ischemic myocardium

International Nuclear Information System (INIS)

Lipinski, Michael J.; Albelda, M. Teresa; Frias, Juan C.; Anderson, Stasia A.; Luger, Dror; Westman, Peter C.; Escarcega, Ricardo O.; Hellinga, David G.; Waksman, Ron; Arai, Andrew E.; Epstein, Stephen E.

2016-01-01

Introduction: Nanoparticles may serve as a promising means to deliver novel therapeutics to the myocardium following myocardial infarction. We sought to determine whether lipid-based liposomal nanoparticles can be shown through different imaging modalities to specifically target injured myocardium following intravenous injection in an ischemia–reperfusion murine myocardial infarction model. Methods: Mice underwent ischemia–reperfusion surgery and then either received tail-vein injection with gadolinium- and fluorescent-labeled liposomes or no injection (control). The hearts were harvested 24 h later and underwent T1 and T2-weighted ex vivo imaging using a 7 Tesla Bruker magnet. The hearts were then sectioned for immunohistochemistry and optical fluorescent imaging. Results: The mean size of the liposomes was 100 nm. T1-weighted signal intensity was significantly increased in the ischemic vs. the non-ischemic myocardium for mice that received liposomes compared with control. Optical imaging demonstrated significant fluorescence within the infarct area for the liposome group compared with control (163 ± 31% vs. 13 ± 14%, p = 0.001) and fluorescent microscopy confirmed the presence of liposomes within the ischemic myocardium. Conclusions: Liposomes traffic to the heart and preferentially home to regions of myocardial injury, enabling improved diagnosis of myocardial injury and could serve as a vehicle for drug delivery.

Multimodality imaging demonstrates trafficking of liposomes preferentially to ischemic myocardium

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Lipinski, Michael J., E-mail: mjlipinski12@gmail.com [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States); Albelda, M. Teresa [GIBI2" 3" 0, Grupo de Investigación Biomédica en Imagen, IIS La Fe, Valencia (Spain); Frias, Juan C. [Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, Valencia (Spain); Anderson, Stasia A. [Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Luger, Dror; Westman, Peter C.; Escarcega, Ricardo O.; Hellinga, David G.; Waksman, Ron [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States); Arai, Andrew E. [Advanced Cardiovascular Imaging Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Epstein, Stephen E. [MedStar Heart and Vascular Institute, MedStar Washington Hospital Center, Washington, DC (United States)

2016-03-15

Introduction: Nanoparticles may serve as a promising means to deliver novel therapeutics to the myocardium following myocardial infarction. We sought to determine whether lipid-based liposomal nanoparticles can be shown through different imaging modalities to specifically target injured myocardium following intravenous injection in an ischemia–reperfusion murine myocardial infarction model. Methods: Mice underwent ischemia–reperfusion surgery and then either received tail-vein injection with gadolinium- and fluorescent-labeled liposomes or no injection (control). The hearts were harvested 24 h later and underwent T1 and T2-weighted ex vivo imaging using a 7 Tesla Bruker magnet. The hearts were then sectioned for immunohistochemistry and optical fluorescent imaging. Results: The mean size of the liposomes was 100 nm. T1-weighted signal intensity was significantly increased in the ischemic vs. the non-ischemic myocardium for mice that received liposomes compared with control. Optical imaging demonstrated significant fluorescence within the infarct area for the liposome group compared with control (163 ± 31% vs. 13 ± 14%, p = 0.001) and fluorescent microscopy confirmed the presence of liposomes within the ischemic myocardium. Conclusions: Liposomes traffic to the heart and preferentially home to regions of myocardial injury, enabling improved diagnosis of myocardial injury and could serve as a vehicle for drug delivery.

Effects of anti-tumor necrosis factor-alpha and anti-intercellular adhesion molecule-1 antibodies on ischemia/reperfusion lung injury.

Science.gov (United States)

Chiang, Chi-Huei

2006-10-31

Inhibition of neutrophil activation and adherence to endothelium by antibodies to tumor necrosis factor-alpha (TNF-alpha) and intercellular adhesion molecules (ICAM-1), respectively, might attenuate ischemia-reperfusion injury (I/R). I/R was conducted in an isolated rat lung model. Anti-TNF-alpha antibody and/or anti-ICAM-1 antibody were added before ischemia or after reperfusion. Hemodynamic changes, lung weight gain (LWG), capillary filtration coefficients (Kfc), and pathologic changes were assessed to evaluate the severity of I/R. The LWG, Kfc, pathological changes and lung injury score of treatment groups with anti-TNF-alpha antibody treatment, either pre-ischemia or during reperfusion, were less than those observed in control groups. Similar findings were found in group treated with anti-ICAM-1 antibody or combination therapy during reperfusion. In contrast, pre-I/R treatment with anti-ICAM-1 antibody induced severe lung edema and failure to complete the experimental procedure. No additional therapeutic effect was found in combination therapy. We conclude that TNF-alpha and ICAM-1 play important roles in I/R. Anti-TNF-alpha antibody has therapeutic and preventive effects on I/R. However, combined therapy with anti-TNF-alpha antibody and anti-ICAM-1 antibody may have no additive effect and need further investigation.

A novel imidazopyridine derivative, X22, prevents the retinal ischemia-reperfusion injury via inhibition of MAPKs.

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Bian, Yang; Ren, Luqing; Wang, Lei; Xu, Shanmei; Tao, Jianjian; Zhang, Xiuhua; Huang, Yi; Qian, Yuanyuan; Zhang, Xin; Song, Zongming; Wu, Wencan; Wang, Yi; Liang, Guang

2015-06-01

Inflammation is a pathological hallmark of ischemia reperfusion (I/R) injury. The present study was conducted to explore the ability of a new anti-inflammatory compound, X22, to attenuate retinal I/R injury via cytokine-inhibitory mechanism. For the in vitro experiment, ARPE-19 cells were pretreated with X22 (5 or 10 μM) or saline for 2 h, followed by stimulation with tert-butyl hydroperoxide (TBHP, 1000 μM) for an indicated amount of time. The expression of inflammatory mediators, cell viability, and cell apoptosis were evaluated. For the in vivo experiment, the rats were randomized to receive treatment with saline or X22 (0.1 μM/kg, 3 μL) before the induction of I/R injury. Histological evaluation, apoptosis of retinal cells, macrophage infiltration, and retina functional changes were further determined. Our data showed that pretreatment with X22 significantly inhibited TBHP-induced inflammatory cytokine expression in ARPE-19 cells. The anti-inflammatory activity of X22 may be associated with its inhibition on MAPKs, rather than NF-κB. Subsequently, our data proved that TBHP induced apoptosis in ARPE-19 cells, while pretreatment of X22 significantly suppressed TBHP-caused ARPE-19 apoptosis. Finally, the in vivo data revealed that X22 administration maintained better inner retinal layer structures, reduced apoptosis of retinal ganglion cell, and improved retinal function in retinal I/R rat models, which were accompanied with a remarkable decrease in retinal macrophage infiltration. These results suggest that the novel compound X22 is a potential agent for the treatment of retinal I/R-related diseases via the MAPKs-targeting anti-inflammatory mechanism and deserves the further development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pretreatment with soluble ST2 reduces warm hepatic ischemia/reperfusion injury

International Nuclear Information System (INIS)

Yin Hui; Huang Baojun; Yang Heng; Huang Yafei; Xiong Ping; Zheng Fang; Chen Xiaoping; Chen Yifa; Gong Feili

2006-01-01

The interleukin-1 receptor-like protein ST2 exists in both membrane-bound (ST2L) and soluble form (sST2). ST2L has been found to play an important regulatory role in Th2-type immune response, but the function of soluble form of ST2 remains to be elucidated. In this study, we report the protective effect of soluble ST2 on warm hepatic ischemia/reperfusion injury. We constructed a eukaryotic expression plasmid, psST2-Fc, which expresses functional murine soluble ST2-human IgG1 Fc (sST2-Fc) fusion protein. The liver damage after ischemia/reperfusion was significantly attenuated by the expression of this plasmid in vivo. sST2-Fc remarkably inhibited the activation of Kupffer cells and the production of proinflammatory mediators TNF-α and IL-6. Furthermore, the levels of TLR4 mRNA and the nuclear translocation of NF-κB were also suppressed by pretreatment with sST2-Fc. These results thus identified soluble ST2 as a negative regulator in hepatic I/R injury, possibly via ST2-TLR4 pathway

Edaravone, a free radical scavenger, attenuates cerebral infarction and hemorrhagic infarction in rats with hyperglycemia.

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Okamura, Koichi; Tsubokawa, Tamiji; Johshita, Hiroo; Miyazaki, Hiroshi; Shiokawa, Yoshiaki

2014-01-01

Thrombolysis due to acute ischemic stroke is associated with the risk of hemorrhagic infarction, especially after reperfusion. Recent experimental studies suggest that the main mechanism contributing to hemorrhagic infarction is oxidative stress caused by disruption of the blood-brain barrier. Edaravone, a free radical scavenger, decreases oxidative stress, thereby preventing hemorrhagic infarction during ischemia and reperfusion. In this study, we investigated the effects of edaravone on hemorrhagic infarction in a rat model of hemorrhagic transformation. We used a previously established hemorrhagic transformation model of rats with hyperglycemia. Hyperglycemia was induced by intraperitoneal injection of glucose to all rats (n  =  20). The rats with hyperglycemia showed a high incidence of hemorrhagic infarction. Middle cerebral artery occlusion (MCAO) for 1.5 hours followed by reperfusion for 24 hours was performed in edaravone-treated rats (n  =  10) and control rats (n  =  10). Upon completion of reperfusion, both groups were evaluated for infarct size and hemorrhage volume and the results obtained were compared. Edaravone significantly decreased infarct volume, with the average infarct volume in the edaravone-treated rats (227.6 mm(3)) being significantly lower than that in the control rats (264.0 mm(3)). Edaravone treatment also decreased the postischemic hemorrhage volumes (53.4 mm(3) in edaravone-treated rats vs 176.4 mm(3) in controls). In addition, the ratio of hemorrhage volume to infarct volume was lower in the edaravone-treated rats (23.5%) than in the untreated rats (63.2%). Edaravone attenuates cerebral infarction and hemorrhagic infarction in rats with hyperglycemia.

Roles for C-X-C chemokines and C5a in lung injury after hindlimb ischemia-reperfusion

DEFF Research Database (Denmark)

Bless, N M; Warner, R L; Padgaonkar, V A

1999-01-01

We evaluated the roles of the C-X-C chemokines cytokine-induced neutrophil chemoattractant (CINC) and macrophage inflammatory protein-2 (MIP-2) as well as the complement activation product C5a in development of lung injury after hindlimb ischemia-reperfusion in rats. During reperfusion, CD11b...... and CD18, but not CD11a, were upregulated on neutrophils [bronchoalveolar lavage (BAL) and blood] and lung macrophages. BAL levels of CINC and MIP-2 were increased during the ischemic and reperfusion periods. Treatment with either anti-CINC or anti-MIP-2 IgG significantly reduced lung vascular......, 58, and 23%, respectively (P MIP-2 as well as the complement activation product C5a are required for lung neutrophil recruitment and full induction of lung injury after hindlimb ischemia-reperfusion in rats....

Effect of baicalin on toll-like receptor 4-mediated ischemia/reperfusion inflammatory responses in alcoholic fatty liver condition

International Nuclear Information System (INIS)

Kim, Seok-Joo; Lee, Sun-Mee

2012-01-01

Alcoholic fatty liver is susceptible to secondary stresses such as ischemia/reperfusion (I/R). Baicalin is an active component extracted from Scutellaria baicalensis, which is widely used in herbal preparations for treatment of hepatic diseases and inflammatory disorders. This study evaluated the potential beneficial effect of baicalin on I/R injury in alcoholic fatty liver. Rats were fed an alcohol liquid diet or a control isocaloric diet for 5 weeks, and then subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Baicalin (200 mg/kg) was intraperitoneally administered 24 and 1 h before ischemia. After reperfusion, baicalin attenuated the increases in serum alanine aminotransferase activity, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels in alcoholic fatty liver. The increased levels of TNF-α and IL-6 mRNA expression and inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions increased after reperfusion, which were higher in ethanol-fed animals, were attenuated by baicalin. In ethanol-fed animals, baicalin attenuated the increases in toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 protein expressions and the nuclear translocation of NF-κB after reperfusion. In conclusion, our findings suggest that baicalin ameliorates I/R-induced hepatocellular damage by suppressing TLR4-mediated inflammatory responses in alcoholic fatty liver. -- Highlights: ► Baicalin attenuates hepatic I/R-induced inflammation in alcoholic fatty liver. ► Baicalin downregulates TLR4, MyD88 expression during I/R in alcoholic fatty liver. ► Baicalin attenuates NF-κB nuclear translocation during I/R in alcoholic fatty liver.

Hypoxic Air Inhalation and Ischemia Interventions Both Elicit Preconditioning Which Attenuate Subsequent Cellular Stress In vivo Following Blood Flow Occlusion and Reperfusion.

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Barrington, James H; Chrismas, Bryna C R; Gibson, Oliver R; Tuttle, James; Pegrum, J; Govilkar, S; Kabir, Chindu; Giannakakis, N; Rayan, F; Okasheh, Z; Sanaullah, A; Ng Man Sun, S; Pearce, Oliver; Taylor, Lee

2017-01-01

Ischemic preconditioning (IPC) is valid technique which elicits reductions in femoral blood flow occlusion mediated reperfusion stress (oxidative stress, Hsp gene transcripts) within the systemic blood circulation and/or skeletal muscle. It is unknown whether systemic hypoxia, evoked by hypoxic preconditioning (HPC) has efficacy in priming the heat shock protein (Hsp) system thus reducing reperfusion stress following blood flow occlusion, in the same manner as IPC. The comparison between IPC and HPC being relevant as a preconditioning strategy prior to orthopedic surgery. In an independent group design, 18 healthy men were exposed to 40 min of (1) passive whole-body HPC (FiO 2 = 0.143; no ischemia. N = 6), (2) IPC (FiO 2 = 0.209; four bouts of 5 min ischemia and 5 min reperfusion. n = 6), or (3) rest (FiO 2 = 0.209; no ischemia. n = 6). The interventions were administered 1 h prior to 30 min of tourniquet derived femoral blood flow occlusion and were followed by 2 h subsequent reperfusion. Systemic blood samples were taken pre- and post-intervention. Systemic blood and gastrocnemius skeletal muscle samples were obtained pre-, 15 min post- (15PoT) and 120 min (120PoT) post-tourniquet deflation. To determine the cellular stress response gastrocnemius and leukocyte Hsp72 mRNA and Hsp32 mRNA gene transcripts were determined by RT-qPCR. The plasma oxidative stress response (protein carbonyl, reduced glutathione/oxidized glutathione ratio) was measured utilizing commercially available kits. In comparison to control, at 15PoT a significant difference in gastrocnemius Hsp72 mRNA was seen in HPC (-1.93-fold; p = 0.007) and IPC (-1.97-fold; p = 0.006). No significant differences were observed in gastrocnemius Hsp32 and Hsp72 mRNA, leukocyte Hsp72 and Hsp32 mRNA, or oxidative stress markers ( p > 0.05) between HPC and IPC. HPC provided near identical amelioration of blood flow occlusion mediated gastrocnemius stress response (Hsp72 mRNA), compared to an established IPC

Hypoxic Air Inhalation and Ischemia Interventions Both Elicit Preconditioning Which Attenuate Subsequent Cellular Stress In vivo Following Blood Flow Occlusion and Reperfusion

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James H. Barrington

2017-08-01

Full Text Available Ischemic preconditioning (IPC is valid technique which elicits reductions in femoral blood flow occlusion mediated reperfusion stress (oxidative stress, Hsp gene transcripts within the systemic blood circulation and/or skeletal muscle. It is unknown whether systemic hypoxia, evoked by hypoxic preconditioning (HPC has efficacy in priming the heat shock protein (Hsp system thus reducing reperfusion stress following blood flow occlusion, in the same manner as IPC. The comparison between IPC and HPC being relevant as a preconditioning strategy prior to orthopedic surgery. In an independent group design, 18 healthy men were exposed to 40 min of (1 passive whole-body HPC (FiO2 = 0.143; no ischemia. N = 6, (2 IPC (FiO2 = 0.209; four bouts of 5 min ischemia and 5 min reperfusion. n = 6, or (3 rest (FiO2 = 0.209; no ischemia. n = 6. The interventions were administered 1 h prior to 30 min of tourniquet derived femoral blood flow occlusion and were followed by 2 h subsequent reperfusion. Systemic blood samples were taken pre- and post-intervention. Systemic blood and gastrocnemius skeletal muscle samples were obtained pre-, 15 min post- (15PoT and 120 min (120PoT post-tourniquet deflation. To determine the cellular stress response gastrocnemius and leukocyte Hsp72 mRNA and Hsp32 mRNA gene transcripts were determined by RT-qPCR. The plasma oxidative stress response (protein carbonyl, reduced glutathione/oxidized glutathione ratio was measured utilizing commercially available kits. In comparison to control, at 15PoT a significant difference in gastrocnemius Hsp72 mRNA was seen in HPC (−1.93-fold; p = 0.007 and IPC (−1.97-fold; p = 0.006. No significant differences were observed in gastrocnemius Hsp32 and Hsp72 mRNA, leukocyte Hsp72 and Hsp32 mRNA, or oxidative stress markers (p > 0.05 between HPC and IPC. HPC provided near identical amelioration of blood flow occlusion mediated gastrocnemius stress response (Hsp72 mRNA, compared to an established IPC

Function and mechanism of toll-like receptors in cerebral ischemic tolerance: from preconditioning to treatment

OpenAIRE

Wang, Peng-Fei; Xiong, Xiao-Yi; Chen, Jing; Wang, Yan-Chun; Duan, Wei; Yang, Qing-Wu

2015-01-01

Increasing evidence suggests that toll-like receptors (TLRs) play an important role in cerebral ischemia-reperfusion injury. The endogenous ligands released from ischemic neurons activate the TLR signaling pathway, resulting in the production of a large number of inflammatory cytokines, thereby causing secondary inflammation damage following cerebral ischemia. However, the preconditioning for minor cerebral ischemia or the preconditioning with TLR ligands can reduce cerebral ischemic injury b...

Comparison of the effects of dexmedetomidine administered at two different times on renal ischemia/reperfusion injury in rats

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Edip Gonullu

2014-06-01

Full Text Available Background and objectives: We investigated the effect of dexmedetomidine on ischemic renal failure in rats. Methods: In the present study, 26 male adult Wistar albino rats weighting 230-300 g were randomly separated into four groups: sham-operated (n = 5, ischemia reperfusion (IR (IR group, n = 7, IR/reperfusion treatment with dexmedetomidine (Dex. R group, n = 7 and IR/pre-ischemic treatment with dexmedetomidine (Dex. I group, n = 7. In the first group, sham operation was achieved and renal clamps were not applied. For the IR group, renal ischemia was induced by occlusion of the bilateral renal arteries and veins for 60 min followed by reperfusion for 24 h. For the Dex. R and Dex. I groups, the same surgical procedure as in the IR group was performed, and dexmedetomidine (100 mcg/kg intraperitoneal was administrated at the 5th min after reperfusion and before ischemia. At the end of reperfusion, blood samples were drawn, the rats were sacrificed, and the left kidney was processed for histopathology. Results: The blood urea nitrogen (BUN levels in groups Dex. R and Dex. I were significantly lower than in the IR group (p = 0.015, p = 0.043, although urine flow was significantly higher in group Dex. R (p = 0.003. The renal histopathological score in the IR group was significantly higher than in the other groups. There was no significant difference between the Dex. R and Dex. I groups. Conclusions: The results were shown that administration of dexmedetomidine reduced the renal IR injury histomorphologically. Administration of dexmedetomidine in the reperfusion period was considered as more effective due to increase in urinary output and decrease in BUN levels.

Two-photon imaging during prolonged middle cerebral artery occlusion in mice reveals recovery of dendritic structure after reperfusion.

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Li, Ping; Murphy, Timothy H

2008-11-12

Filament occlusion of the middle cerebral artery (MCA) is a well accepted animal model of focal ischemia. Advantages of the model are relatively long occlusion times and a large penumbra region that simulates aspects of human stroke. Here, we use two-photon and confocal microscopy in combination with regional measurement of blood flow using laser speckle to assess the spatial relationship between the borders of the MCA ischemic territory and loss of dendrite structure, as well as the effect of reperfusion on dendritic damage in adult YFP (yellow fluorescent protein) and GFP (green fluorescent protein) C57BL/6 transgenic mice with fluorescent (predominantly layer 5) neurons. By examining the spatial extent of dendritic damage, we determined that 60 min of MCA occlusion produced a core with severe structural damage that did not recover after reperfusion (begins approximately 3.8 mm lateral to midline), a reversibly damaged area up to 0.6 mm medial to the core that recovered after reperfusion (penumbra), and a relatively structurally intact area ( approximately 1 mm wide; medial penumbra) with hypoperfusion. Loss of structure was preceded by a single ischemic depolarization 122.1 +/- 10.2 s after occlusion onset. Reperfusion of animals after 60 min of ischemia was not associated with exacerbation of damage (reperfusion injury) and resulted in a significant restoration of blebbed dendritic structure, but only within approximately 0.6 mm lateral of the dendritic damage structural border. In summary, we find that recovery of dendritic structure can occur after reperfusion after even 60 min of ischemia, but is likely restricted to a relatively small penumbra region with partial blood flow or oxygenation.

Histone acetylation and CREB binding protein are required for neuronal resistance against ischemic injury.

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Ferah Yildirim

Full Text Available Epigenetic transcriptional regulation by histone acetylation depends on the balance between histone acetyltransferase (HAT and deacetylase activities (HDAC. Inhibition of HDAC activity provides neuroprotection, indicating that the outcome of cerebral ischemia depends crucially on the acetylation status of histones. In the present study, we characterized the changes in histone acetylation levels in ischemia models of focal cerebral ischemia and identified cAMP-response element binding protein (CREB-binding protein (CBP as a crucial factor in the susceptibility of neurons to ischemic stress. Both neuron-specific RNA interference and neurons derived from CBP heterozygous knockout mice showed increased damage after oxygen-glucose deprivation (OGD in vitro. Furthermore, we demonstrated that ischemic preconditioning by a short (5 min subthreshold occlusion of the middle cerebral artery (MCA, followed 24 h afterwards by a 30 min occlusion of the MCA, increased histone acetylation levels in vivo. Ischemic preconditioning enhanced CBP recruitment and histone acetylation at the promoter of the neuroprotective gene gelsolin leading to increased gelsolin expression in neurons. Inhibition of CBP's HAT activity attenuated neuronal ischemic preconditioning. Taken together, our findings suggest that the levels of CBP and histone acetylation determine stroke outcome and are crucially associated with the induction of an ischemia-resistant state in neurons.

Ethanol extracts from Portulaca oleracea L. attenuated ischemia/reperfusion induced rat neural injury through inhibition of HMGB1 induced inflammation

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Zheng, Chenggang; Liu, Chen; Wang, Wanyin; Tang, Gusheng; Dong, Liwei; Zhou, Juan; Zhong, Zhengrong

2016-01-01

It is well demonstrated that the high mobility group box 1 (HMGB1) mediated inflammation has been implicated as one of the important causes for brain damage induced by cerebral ischemia/reperfusion (I/R). In the present study, we assessed the neuro-protective and anti-inflammation effects of the ethanol extracts from Portulaca oleracea L. (EEPO) against cerebral I/R injury in the rat transient middle cerebral artery occlusion (tMCAO) model. Rats were administrated with their respective treatment for 7 days before the MCA occlusion. After that, rats were intraperitoneal injection with chloral hydrate and sacrificed by decapitation, then the serum and brain tissue were collected. The neurological deficit score, infarct size and brain edema were tested. The levels of serum cytokine as TNF-α, IL-1β, INF-γ, IL-6, and HMGB1 and LDH were detected. The protein level of tissue or nucleus HMGB1, IκB and p-p65 were tested, too. The results showed that pretreatment with EEPO significantly decreased the neurological deficit score, infarct size and brain edema. Moreover, EEPO decreased rat serum cytokine level and rat right cortices p-p65 and IκB protein level. In conclusion all these results suggested that pretreatment with EEFPO provided significant protection against cerebral I/R injury in rats might by virtue of its anti-inflammation property through inhibition of increase of neuleus HMGB1. PMID:27904702

Multivariate prediction of spontaneous repetitive responses in ventricular myocardium exposed in vitro to simulated ischemic conditions.

Science.gov (United States)

Schiariti, M; Puddu, P E; Rouet, R

1994-06-01

Guinea-pig ventricular myocardium was partly exposed to normal Tyrode's superfusion and partly to altered conditions (using modified Tyrode's solution) set to simulate acute myocardial ischemia (PO2 80 +/- 10 mmHg; no glucose; pH 7.00 +/- 0.05; K+ 12 mM). Using a double-chamber tissue bath and standard microelectrode technique, the occurrence of spontaneous repetitive responses was investigated during simulated ischemia (occlusion) and after reperfusing the previously ischemic superfused tissue with normal Tyrode's solution (reperfusion). In 62 experiments (42 animals) the effects of: (1) duration of simulated ischemia (1321 +/- 435 s), (2) stimulation rate (1002 +/- 549 ms) and (3) number of successive simulated ischemic periods (occlusions) (1.58 +/- 0.92) on: (1) resting membrane potential, (2) action potential amplitude, (3) duration of 50 and 90% action potentials and (4) maximal upstroke velocity of action potential were studied. All variables were considered as gradients (delta) between normal and ischemic tissue. Both during occlusion and upon reperfusion, spontaneous repetitive responses were coded as single, couplets, salvos (three to nine and > 10) or total spontaneous repetitive responses (coded present when at least one of the above-mentioned types was seen). The incidence of total spontaneous repetitive responses was 31% (19/62) on occlusion and 85% (53/62) upon reperfusion. Cox's models (forced and stepwise) were used to predict multivariately the occurrence of arrhythmic events considered as both total spontaneous repetitive responses and as separate entities. These models were applicable since continuous monitoring of the experiments enabled exact timing of spontaneous repetitive response onset during both occlusion and reperfusion. In predicting reperfusion spontaneous repetitive responses, total spontaneous repetitive responses and blocks observed during the occlusion period were also considered. Total occlusion spontaneous repetitive responses

Ischemic Stroke: Advances in Diagnosis and Management.

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Cassella, Courtney R; Jagoda, Andy

2017-11-01

Acute ischemic stroke carries the risk of morbidity and mortality. Since the advent of intravenous thrombolysis, there have been improvements in stroke care and functional outcomes. Studies of populations once excluded from thrombolysis have begun to elucidate candidates who might benefit and thus should be engaged in the process of shared decision-making. Imaging is evolving to better target the ischemic penumbra salvageable with prompt reperfusion. Availability and use of computed tomography angiography identifies large-vessel occlusions, and new-generation endovascular therapy devices are improving outcomes in these patients. With this progress in stroke treatment, risk stratification tools and shared decision-making are fundamental. Copyright © 2017 Elsevier Inc. All rights reserved.

The Prognostic Value of a Four-Dimensional CT Angiography-Based Collateral Grading Scale for Reperfusion Therapy in Acute Ischemic Stroke Patients.

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Zhang, Sheng; Chen, Weili; Tang, Huan; Han, Quan; Yan, Shenqiang; Zhang, Xiaocheng; Chen, Qingmeng; Parsons, Mark; Wang, Shaoshi; Lou, Min

2016-01-01

Leptomeningeal collaterals, which affects tissue fate, are still challenging to assess. Four-dimensional CT angiography (4D CTA) originated from CT perfusion (CTP) provides the possibility of non-invasive and time-resolved assessment of leptomeningeal collateral flow. We sought to develop a comprehensive rating system to integrate the speed and extent of collateral flow on 4D CTA, and investigate its prognostic value for reperfusion therapy in acute ischemic stroke (AIS) patients. We retrospectively studied 80 patients with M1 ± internal carotid artery (ICA) occlusion who had baseline CTP before intravenous thrombolysis. The velocity and extent of collaterals were evaluated by regional leptomeningeal collateral score on peak phase (rLMC-P) and temporally fused intensity projections (tMIP) (rLMC-M) on 4D CTA, respectively. The cutoffs of rLMC-P and rLMC-M score for predicting good outcome (mRS score ≤ 2) were integrated to develop the collateral grading scale (CGS) (rating from 0-2). The CGS score was correlated with 3-months mRS score (non-recanalizers: ρ = -0.495, p = 0.01; recanalizers: ρ = -0.671, p < 0.001). Patients with intermediate or good collaterals (CGS score of 1 and 2) who recanalized were more likely to have good outcome than those without recanalization (p = 0.038, p = 0.018), while there was no significant difference in outcome in patients with poor collaterals (CGS score of 0) stratified by recanalization (p = 0.227). Identification of collaterals based on CGS may help to select good responders to reperfusion therapy in patients with large artery occlusion.

Role of TRPV1 channels in ischemia/reperfusion-induced acute kidney injury.

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Lan Chen

Full Text Available OBJECTIVES: Transient receptor potential vanilloid 1 (TRPV1 -positive sensory nerves are widely distributed in the kidney, suggesting that TRPV1-mediated action may participate in the regulation of renal function under pathophysiological conditions. Stimulation of TRPV1 channels protects against ischemia/reperfusion (I/R-induced acute kidney injury (AKI. However, it is unknown whether inhibition of these channels is detrimental in AKI or not. We tested the role of TRPV1 channels in I/R-induced AKI by modulating these channels with capsaicin (TRPV1 agonist, capsazepine (TRPV1 antagonist and using Trpv1-/- mice. METHODS AND RESULTS: Anesthetized C57BL/6 mice were subjected to 25 min of renal ischemia and 24 hrs of reperfusion. Mice were pretreated with capsaicin (0.3 mg/kg body weight or capsazepine (50 mg/kg body weight. Capsaicin ameliorated the outcome of AKI, as measured by serum creatinine levels, tubular damage,neutrophil gelatinase-associated lipocalin (NGAL abundance and Ly-6B.2 positive polymorphonuclear inflammatory cells in injured kidneys. Neither capsazepine nor deficiency of TRPV1 did deteriorate renal function or histology after AKI. Measurements of endovanilloids in kidney tissue indicate that 20-hydroxyeicosatetraeonic acid (20-HETE or epoxyeicosatrienoic acids (EETs are unlikely involved in the beneficial effects of capsaicin on I/R-induced AKI. CONCLUSIONS: Activation of TRPV1 channels ameliorates I/R-induced AKI, but inhibition of these channels does not affect the outcome of AKI. Our results may have clinical implications for long-term safety of renal denervation to treat resistant hypertension in man, with respect to the function of primary sensory nerves in the response of the kidney to ischemic stimuli.

Noscapine protects OLN-93 oligodendrocytes from ischemia-reperfusion damage: Calcium and nitric oxide involvement.

Science.gov (United States)

Nadjafi, S; Ebrahimi, S-A; Rahbar-Roshandel, N

2015-12-01

This study was carried out to evaluate the effects of noscapine, a benzylisoquinoline alkaloid from opium poppy, on oligodendrocyte during ischemia/reperfusion-induced excitotoxic injury. Changes in intracellular calcium levels due to chemical ischemia and nitric oxide (NO) production during ischemia/reperfusion were evaluated as the hallmarks of ischemia-derived excitotoxic event. OLN-93 cell line (a permanent immature rat oligodendrocyte) was used as a model of oligodendrocyte. 30- or 60-minute-oxygen-glucose deprivation/24 hours reperfusion were used to induce excitotoxicity. MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay was used to evaluate cell viability. Ratiometric fluorescence microscopy using Ca(2+)-sensitive indicator Fura-2/AM was utilized to assess intracellular calcium levels. NO production was evaluated by Griess method. Noscapine (4 μM) significantly attenuated intracellular Ca(2+) elevation (P < 0.001). Also, noscapine significantly decreased NO production during a 30-minute oxygen-glucose deprivation/reperfusion (P < 0.01). The inhibitory effect of noscapine (4 μM) on intracellular Ca(2+) was greater than ionotropic glutamate receptors antagonists. Noscapine is protective against ischemia/reperfusion-induced excitotoxic injury in OLN-93 oligodendrocyte. This protective effect seems to be related to attenuation of intracellular Ca(2+) overload and NO production.

A pathophysiological role of TRPV1 in ischemic injury after transient focal cerebral ischemia in mice

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Miyanohara, Jun [Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University (Japan); Shirakawa, Hisashi, E-mail: shirakaw@pharm.kyoto-u.ac.jp [Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University (Japan); Sanpei, Kazuaki [Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University (Japan); Nakagawa, Takayuki [Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University (Japan); Department of Clinical Pharmacology and Therapeutics, Kyoto University Hospital (Japan); Kaneko, Shuji [Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University (Japan)

2015-11-20

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel with high Ca{sup 2+} permeability, which functions as a polymodal nociceptor activated by heat, protons and several vanilloids, including capsaicin and anandamide. Although TRPV1 channels are widely distributed in the mammalian brain, their pathophysiological roles in the brain remain to be elucidated. In this study, we investigated whether TRPV1 is involved in cerebral ischemic injury using a middle cerebral artery (MCA) occlusion model in wild-type (WT) and TRPV1-knockout (KO) mice. For transient ischemia, the left MCA of C57BL/6 mice was occluded for 60 min and reperfused at 1 and 2 days after ischemia. We found that neurological and motor deficits, and infarct volumes in TRPV1-KO mice were lower than those of WT mice. Consistent with these results, intracerebroventricular injection of a TRPV1 antagonist, capsazepine (20 nmol), 30 min before the onset of ischemia attenuated neurological and motor deficits and improved infarct size without influencing cerebral blood flow in the occluded MCA territory. The protective effect of capsazepine on ischemic brain damage was not observed in TRPV1-KO mice. WT and TRPV1-KO mice did not show any differences with respect to the increased number of Iba1-positive microglia/macrophages, GFAP-positive astrocytes, and Gr1-positive neutrophils at 1 and 2 days after cerebral ischemia. Taken together, we conclude that brain TRPV1 channels are activated by ischemic stroke and cause neurological and motor deficits and infarction after brain ischemia. - Highlights: • We investigated whether TRPV1 is involved in transient ischemic brain damage in mice. • Neurological deficits and infarct volumes were lower in TRPV1-KO mice than in WT mice. • Injection of a TRPV1 antagonist, capsazepine, attenuated neurological deficits and improved infarct size. • No differences in astrocytic or microglial activation were observed between WT and TRPV1-KO mice.

A pathophysiological role of TRPV1 in ischemic injury after transient focal cerebral ischemia in mice

International Nuclear Information System (INIS)

Miyanohara, Jun; Shirakawa, Hisashi; Sanpei, Kazuaki; Nakagawa, Takayuki; Kaneko, Shuji

2015-01-01

Transient receptor potential vanilloid 1 (TRPV1) is a non-selective cation channel with high Ca"2"+ permeability, which functions as a polymodal nociceptor activated by heat, protons and several vanilloids, including capsaicin and anandamide. Although TRPV1 channels are widely distributed in the mammalian brain, their pathophysiological roles in the brain remain to be elucidated. In this study, we investigated whether TRPV1 is involved in cerebral ischemic injury using a middle cerebral artery (MCA) occlusion model in wild-type (WT) and TRPV1-knockout (KO) mice. For transient ischemia, the left MCA of C57BL/6 mice was occluded for 60 min and reperfused at 1 and 2 days after ischemia. We found that neurological and motor deficits, and infarct volumes in TRPV1-KO mice were lower than those of WT mice. Consistent with these results, intracerebroventricular injection of a TRPV1 antagonist, capsazepine (20 nmol), 30 min before the onset of ischemia attenuated neurological and motor deficits and improved infarct size without influencing cerebral blood flow in the occluded MCA territory. The protective effect of capsazepine on ischemic brain damage was not observed in TRPV1-KO mice. WT and TRPV1-KO mice did not show any differences with respect to the increased number of Iba1-positive microglia/macrophages, GFAP-positive astrocytes, and Gr1-positive neutrophils at 1 and 2 days after cerebral ischemia. Taken together, we conclude that brain TRPV1 channels are activated by ischemic stroke and cause neurological and motor deficits and infarction after brain ischemia. - Highlights: • We investigated whether TRPV1 is involved in transient ischemic brain damage in mice. • Neurological deficits and infarct volumes were lower in TRPV1-KO mice than in WT mice. • Injection of a TRPV1 antagonist, capsazepine, attenuated neurological deficits and improved infarct size. • No differences in astrocytic or microglial activation were observed between WT and TRPV1-KO mice.

Neuroprotective effects of orientin on oxygen-glucose deprivation/reperfusion-induced cell injury in primary culture of rat cortical neurons.

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Tian, Tian; Zeng, Junan; Zhao, Guangyu; Zhao, Wenjing; Gao, Songyi; Liu, Li

2018-01-01

Orientin (luteolin-8-C-glucoside) is a phenolic compound found abundantly in millet, juice, and peel of passion fruit and has been shown to have antioxidant properties. In the present study, we explored the effects of orientin on oxygen-glucose deprivation/reperfusion (OGD/RP)-induced cell injury in primary culture of rat cortical neurons using an in vitro model of neonatal ischemic brain injury. The reduced cell viability and elevated lactate dehydrogenase leakage were observed after OGD/RP exposure, which were then reversed by orientin (10, 20, and 30 µM) pretreatment in a dose-dependent manner. Additionally, OGD/RP treatment resulted in significant oxidative stress, accompanied by enhanced intracellular reactive oxygen species (ROS) generation, and obvious depletion in the activities of intracellular Mn-superoxide dismutase, catalase, and glutathione peroxidase antioxidases. However, these effects were dose dependently restored by orientin pretreatment. We also found that orientin pretreatment dose dependently suppressed [Ca 2+ ] i increase and mitochondrial membrane potential dissipation caused by OGD/RP in primary culture of rat cortical neurons. Western blot analysis showed that OGD/RP exposure induced a distinct decrease of Bcl-2 protein and a marked elevation of Bax, caspase-3, and cleaved caspase-3 proteins; whereas these effects were dose dependently reversed by orientin incubation. Both the caspase-3 activity and the apoptosis rate were increased under OGD/RP treatment, but was then dose dependently down-regulated by orientin (10, 20, and 30 µM) incubation. Moreover, orientin pretreatment dose dependently inhibited OGD/RP-induced phosphorylation of JNK and ERK1/2. Notably, JNK inhibitor SP600125 and ERK1/2 inhibitor PD98059 also dramatically attenuated OGD/RP-induced cell viability loss and ROS generation, and further, orientin failed to protect cortical neurons with the interference of JNK activator anisomycin or ERK1/2 activator FGF-2. Taken

Protective effects of angiopoietin-like 4 on the blood-brain barrier in acute ischemic stroke treated with thrombolysis in mice.

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Zhang, Bin; Xu, Xiaofeng; Chu, Xiuli; Yu, Xiaoyang; Zhao, Yuwu

2017-04-03

Given the risk of blood-brain barrier damage (BBB) caused by ischemic and tissue plasminogen activator thrombolysis, the preservation of vascular integrity is important. Angiopoietin-like 4 (ANGPTL4), a protein secreted in hypoxia, is involved in the regulation of vascular permeability. We hypothesized that Angptl4 might exert a protective effect in thrombolysis through stabilizing blood-brain barrier and inhibit hyper-permeability. We investigated the role of Angptl4 in stroke using a transient focal cerebral ischemia mouse model. The treated mice were administered Angptl4 1h after the ischemic event upon reperfusion. Our results showed that Angptl4 combined with thrombolysis greatly reduced the infarct volume and consequent neurological deficit. Western blot analyses and gelatin zymography revealed that Angptl4 protected the integrity of the endothelium damaged by thrombolysis. Angptl4 inhibited the up-regulation of vascular endothelial growth factor (VEGF) in the vascular endothelium after stroke, which was suppressed by counteracting VEGFR signaling and diminishing downstream Src signaling, and led to the increased stability of junctions and improved endothelial cell barrier integrity. These findings demonstrated that Angptl4 protects the permeability of the BBB damaged by ischemic and thrombolysis. Suggested that Angptl4 might be a promising target molecule in therapies for vasoprotection after thrombolysis treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Study on pretreatment of FPS-1 in rats with hepatic ischemia-reperfusion injury.

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Lin, Shiqing; Liu, Kexuan; Wu, Weikang; Chen, Chao; Wang, Zhi; Zhang, Xuanhong

2009-01-01

This study was designed to determine whether FPS-1, the water-soluble polysaccharide isolated from fuzi, protected against hepatic damage in hepatic ischemia-reperfusion injury in rats, and its mechanism. SD rats were subjected to 60 min of hepatic ischemia, followed by 120 min reperfusion. FPS-1 (160 mg/kg/day) was administered orally for 5 days before ischemia-reperfusion injury in treatment group. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin (ALB) were assayed to evaluate liver functions. Liver samples were taken for histological examination and determination of malondialdehyde (MDA), superoxide dismutase (SOD), that catalase (CAT) in liver. Na(+)-K(+)-ATPase and Ca(2+)-ATPase in mitochondria were measured with colorimetry method. Morphological changes were also investigated by using both light microscopy and electron microscopy (EM). In addition, apoptosis and oncosis were detected by Annexin V-FITC/PI immunofluorescent flow cytometry analysis. Serum AST and ALT levels were elevated in groups exposed to ischemia-reperfusion (p FPS-1 reversed all these biochemical parameters as well as histological alterations, evidently by increased SOD, CAT, reduced MDA and histological scores compared to the model group (p FPS-1 could attenuate the necrotic states by the detection of immunofluorescent flow cytometry analysis. Pretreatment with FPS-1 reduced hepatic ischemia-reperfusion injury through its potent antioxidative effects and attenuation of necrotic states.

Salvia miltiorrhiza Bunge (Danshen) extract attenuates permanent cerebral ischemia through inhibiting platelet activation in rats.

Science.gov (United States)

Fei, Yu-Xiang; Wang, Si-Qi; Yang, Li-Jian; Qiu, Yan-Ying; Li, Yi-Ze; Liu, Wen-Yuan; Xi, Tao; Fang, Wei-Rong; Li, Yun-Man

2017-07-31

/PKC signaling pathway. SCED attenuates cerebral ischemic injury. The possible mechanism is that SCED inhibits thrombosis formation, platelet aggregation and activation of PLC/PKC pathway. On this basis, this new extract could be a promising agent to inhibit thrombosis formation and protect against cerebral ischemia injury. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Ursolic acid reduces the metalloprotease/anti-metalloprotease imbalance in cerebral ischemia and reperfusion injury

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Wang Y

2016-05-01

significant but partial neuroprotective effect. Conclusion: UA can act as a PPARγ agonist to improve the metalloprotease/anti-metalloprotease balance, possibly by inhibiting the activation of the MAPK signaling pathway, thereby attenuating cerebral ischemia and reperfusion injury. Therefore, UA may serve as a novel neuroprotective therapeutic agent. Keywords: brain ischemia, ursolic acid, peroxisome proliferator-activated receptors, matrix metalloproteases

Pulmonary Morphological Changes in the Simulation and Treatment of Lower Limb Ischemic and Perfusion Lesions

Directory of Open Access Journals (Sweden)

V. I. Sergiyenko

2006-01-01

Full Text Available Objective: to investigate pulmonary morphological changes in animals with limb ischemic and reperfusion lesions, which were treated with hemocarboperfusion on sodium hypochlorite-modified sorbents.Materials and methods. The investigation was conducted on 94 mature mongrel male dogs with 4-hour limb ischemia and subsequent reperfusion. Limb ischemia was induced by applying a tourniquet to the isolated vascular fascicle of an experimental limb proximal to the origin of the deep artery of the thigh. Following 4 hours, reperfusion was made, by removing the tourniquet. Three hours of the initiation of reperfusion, one-hour hemocarboperfusion was performed thrice for 72 hours. Lung biopsy samples were used for morphological studies. Morphological changes were evaluated, by employing the hematoxylin- and eosin-stained semifine sections. The visceral histological pattern was assessed by a light trinocular microscope (OLYMPUS, Japan (microscope objective 10.Results. The development of 4-hour limb ischemia is accompanied by significant microcirculatory disorders in the lungs that exhibit dyscirculatory and dystrophic processes concurrent with the signs of tissue dyscomplexation without the signs of an inflammatory reaction. In the reperfusion period, there was a significant progression of lung tissue morphological changes corresponding to the pattern of phase 2 respiratory distress syndrome. Sodium hypochlorite-modified CKN-1K sorbent hemocarboperfusion resulted in a virtually complete restoration of the lung architectonics in the presence of insignificant microcirculato-ry and ventilatory disorders. After standard hemocarboperfusion, the lung tissue may be defined as a slightly reduced pattern of acute pulmonary lesion.Conclusion. Sodium hypochlorite-modified CKN-1K sorbent hemocarboperfusion is an effective technique in abolishing ischemic and reperfusion lesions. 

Mitochondrial Bioenergetics During Ischemia and Reperfusion.

Science.gov (United States)

Consolini, Alicia E; Ragone, María I; Bonazzola, Patricia; Colareda, Germán A

2017-01-01

During ischemia and reperfusion (I/R) mitochondria suffer a deficiency to supply the cardiomyocyte with chemical energy, but also contribute to the cytosolic ionic alterations especially of Ca 2+ . Their free calcium concentration ([Ca 2+ ]m) mainly depends on mitochondrial entrance through the uniporter (UCam) and extrusion in exchange with Na + (mNCX) driven by the electrochemical gradient (ΔΨm). Cardiac energetic is frequently estimated by the oxygen consumption, which determines metabolism coupled to ATP production and to the maintaining of ΔΨm. Nevertheless, a better estimation of heart energy consumption is the total heat release associated to ATP hydrolysis, metabolism, and binding reactions, which is measurable either in the presence or the absence of oxygenation or perfusion. Consequently, a mechano-calorimetrical approach on isolated hearts gives a tool to evaluate muscle economy. The mitochondrial role during I/R depends on the injury degree. We investigated the role of the mitochondrial Ca 2+ transporters in the energetic of hearts stunned by a model of no-flow I/R in rat hearts. This chapter explores an integrated view of previous and new results which give evidences to the mitochondrial role in cardiac stunning by ischemia o hypoxia, and the influence of thyroid alterations and cardioprotective strategies, such as cardioplegic solutions (high K-low Ca, pyruvate) and the phytoestrogen genistein in both sex. Rat ventricles were perfused in a flow-calorimeter at either 30 °C or 37 °C to continuously measure the left ventricular pressure (LVP) and total heat rate (Ht). A pharmacological treatment was done before exposing to no-flow I and R. The post-ischemic contractile (PICR as %) and energetical (Ht) recovery and muscle economy (Eco: P/Ht) were determined during stunning. The functional interaction between mitochondria (Mit) and sarcoplasmic reticulum (SR) was evaluated with selective mitochondrial inhibitors in hearts reperfused with Krebs-10 m

Intracellular sodium hydrogen exchange inhibition and clinical myocardial protection.

Science.gov (United States)

Mentzer, Robert M; Lasley, Robert D; Jessel, Andreas; Karmazyn, Morris

2003-02-01

Although the mechanisms underlying ischemia/reperfusion injury remain elusive, evidence supports the etiologic role of intracellular calcium overload and oxidative stress induced by reactive oxygen species. Activation of the sodium hydrogen exchanger (NHE) is associated with intracellular calcium accumulation. Inhibition of the NHE-1 isoform may attenuate the consequences of this injury. Although there is strong preclinical and early clinical evidence that NHE inhibitors may be cardioprotective, definitive proof of this concept in humans awaits the results of ongoing clinical trials.

Attenuation of ischemia-reperfusion-induced alterations in intracellular Ca2+ in cardiomyocytes from hearts treated with N-acetylcysteine and N-mercaptopropionylglycine.

Science.gov (United States)

Saini-Chohan, Harjot K; Dhalla, Naranjan S

2009-12-01

This study was undertaken to test whether Ca(2+)-handling abnormalities in cardiomyocytes after ischemia-reperfusion (I/R) are prevented by antioxidants such as N-acetyl L-cysteine (NAC), which is known to reduce oxidative stress by increasing the glutathione redox status, and N-(2-mercaptopropionyl)-glycine (MPG), which scavenges both peroxynitrite and hydroxyl radicals. For this purpose, isolated rat hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion, and cardiomyocytes were prepared to monitor changes in the intracellular concentration of free Ca(2+) ([Ca(2+)](i)). Marked depression in the left ventricular developed pressure and elevation in the left ventricular end-diastolic pressure in I/R hearts were attenuated by treatment with NAC or MPG. Cardiomyocytes obtained from I/R hearts showed an increase in the basal level of [Ca(2+)](i) as well as augmentation of the low Na(+)-induced increase in [Ca(2+)](i), with no change in the KCl-induced increase in [Ca(2+)](i). These I/R-induced alterations in Ca(2+) handling by cardiomyocytes were attenuated by treatment of hearts with NAC or MPG. Furthermore, reduction in the isoproterenol-, ATP-, ouabain-, and caffeine-induced increases in [Ca(2+)](i) in cardiomyocytes from I/R hearts were limited by treatment with NAC or MPG. The increases in the basal [Ca(2+)](i), unlike the KCl-induced increase in [Ca(2+)](i), were fully or partially prevented by both NAC and MPG upon exposing cardiomyocytes to hypoxia-reoxygenation, H(2)O(2), or a mixture of xanthine and xanthine oxidase. These results suggest that improvement in cardiac function of I/R hearts treated with NAC or MPG was associated with attenuation of changes in Ca(2+) handling by cardiomyocytes, and the results support the view that oxidative stress due to oxyradical generation and peroxynitrite formation plays an important role in the development of intracellular Ca(2+) overload in cardiomyocytes as a consequence of I/R injury.

Inhibition of TNF-α in hypothalamic paraventricular nucleus attenuates hypertension and cardiac hypertrophy by inhibiting neurohormonal excitation in spontaneously hypertensive rats

Energy Technology Data Exchange (ETDEWEB)

Song, Xin-Ai; Jia, Lin-Lin [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Cui, Wei [Department of Endocrinology and Metabolism, First Affiliated Hospital of Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Zhang, Meng [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Chen, Wensheng [Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi' an 710032 (China); Yuan, Zu-Yi [Department of Cardiovascular Medicine, First Affiliated Hospital of Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Guo, Jing [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Li, Hui-Hua [Key Laboratory of Remodeling-related Cardiovascular Diseases, Department of Pathology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069 (China); Zhu, Guo-Qing [Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Physiology, Nanjing Medical University, Nanjing 210029 (China); Liu, Hao, E-mail: haoliu75@163.com [Department of Neurosurgery, First Affiliated Hospital of Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China); Kang, Yu-Ming, E-mail: ykang@mail.xjtu.edu.cn [Department of Physiology and Pathophysiology, Xi' an Jiaotong University Cardiovascular Research Center, Xi' an Jiaotong University School of Medicine, Xi' an 710061 (China)

2014-11-15

We hypothesized that chronic inhibition of tumor necrosis factor-alpha (TNF-α) in the hypothalamic paraventricular nucleus (PVN) delays the progression of hypertension and attenuates cardiac hypertrophy by up-regulating anti-inflammatory cytokines, reducing pro-inflammatory cytokines (PICs), decreasing nuclear factor-κB (NF-κB) p65 and NAD(P)H oxidase activities, as well as restoring the neurotransmitters balance in the PVN of spontaneously hypertensive rats (SHR). Adult normotensive Wistar–Kyoto (WKY) and SHR rats received bilateral PVN infusion of a TNF-α blocker (pentoxifylline or etanercept) or vehicle for 4 weeks. SHR rats showed higher mean arterial pressure and cardiac hypertrophy compared with WKY rats, as indicated by increased whole heart weight/body weight ratio, whole heart weight/tibia length ratio, left ventricular weight/tibia length ratio, and cardiac atrial natriuretic peptide (ANP) and beta-myosin heavy chain (β-MHC) mRNA expressions. Compared with WKY rats, SHR rats had higher PVN levels of tyrosine hydroxylase, PICs, the chemokine monocyte chemoattractant protein-1 (MCP-1), NF-κB p65 activity, mRNA expressions of NOX-2 and NOX-4, and lower PVN levels of IL-10 and 67-kDa isoform of glutamate decarboxylase (GAD67), and higher plasma norepinephrine. PVN infusion of pentoxifylline or etanercept attenuated all these changes in SHR rats. These findings suggest that SHR rats have an imbalance between excitatory and inhibitory neurotransmitters, as well as an imbalance between pro- and anti-inflammatory cytokines in the PVN; and chronic inhibition of TNF-α in the PVN delays the progression of hypertension by restoring the balances of neurotransmitters and cytokines in the PVN, and attenuating PVN NF-κB p65 activity and oxidative stress, thereby attenuating hypertension-induced sympathetic hyperactivity and cardiac hypertrophy. - Highlights: • Spontaneously hypertensive rats exhibit neurohormonal excitation in the PVN. • PVN inhibition of

Inhibition of CD147 (Cluster of Differentiation 147) Ameliorates Acute Ischemic Stroke in Mice by Reducing Thromboinflammation.

Science.gov (United States)

Jin, Rong; Xiao, Adam Y; Chen, Rui; Granger, D Neil; Li, Guohong

2017-12-01

Inflammation and thrombosis currently are recognized as critical contributors to the pathogenesis of ischemic stroke. CD147 (cluster of differentiation 147), also known as extracellular matrix metalloproteinase inducer, can function as a key mediator of inflammatory and immune responses. CD147 expression is increased in the brain after cerebral ischemia, but its role in the pathogenesis of ischemic stroke remains unknown. In this study, we show that CD147 acts as a key player in ischemic stroke by driving thrombotic and inflammatory responses. Focal cerebral ischemia was induced in C57BL/6 mice by a 60-minute transient middle cerebral artery occlusion. Animals were treated with anti-CD147 function-blocking antibody (αCD147) or isotype control antibody. Blood-brain barrier permeability, thrombus formation, and microvascular patency were assessed 24 hours after ischemia. Infarct size, neurological deficits, and inflammatory cells invaded in the brain were assessed 72 hours after ischemia. CD147 expression was rapidly increased in ischemic brain endothelium after transient middle cerebral artery occlusion. Inhibition of CD147 reduced infarct size and improved functional outcome on day 3 after transient middle cerebral artery occlusion. The neuroprotective effects were associated with (1) prevented blood-brain barrier damage, (2) decreased intravascular fibrin and platelet deposition, which in turn reduced thrombosis and increased cerebral perfusion, and (3) reduced brain inflammatory cell infiltration. The underlying mechanism may include reduced NF-κB (nuclear factor κB) activation, MMP-9 (matrix metalloproteinase-9) activity, and PAI-1 (plasminogen activator inhibitor-1) expression in brain microvascular endothelial cells. Inhibition of CD147 ameliorates acute ischemic stroke by reducing thromboinflammation. CD147 might represent a novel and promising therapeutic target for ischemic stroke and possibly other thromboinflammatory disorders. © 2017 American Heart

Bicarbonate modulates oxidative and functional damage in ischemia-reperfusion.

Science.gov (United States)

Queliconi, Bruno B; Marazzi, Thire B M; Vaz, Sandra M; Brookes, Paul S; Nehrke, Keith; Augusto, Ohara; Kowaltowski, Alicia J

2013-02-01

The carbon dioxide/bicarbonate (CO(2)/HCO(3)(-)) pair is the main biological pH buffer. However, its influence on biological processes, and in particular redox processes, is still poorly explored. Here we study the effect of CO(2)/HCO(3)(-) on ischemic injury in three distinct models (cardiac HL-1 cells, perfused rat heart, and Caenorhabditis elegans). We found that, although various concentrations of CO(2)/HCO(3)(-) do not affect function under basal conditions, ischemia-reperfusion or similar insults in the presence of higher CO(2)/HCO(3)(-) resulted in greater functional loss associated with higher oxidative damage in all models. Because the effect of CO(2)/HCO(3)(-) was observed in all models tested, we believe this buffer is an important determinant of oxidative damage after ischemia-reperfusion. Copyright © 2012 Elsevier Inc. All rights reserved.

Spontaneous Reperfusion after In Situ Thromboembolic Stroke in Mice

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Cho, Tae-Hee; Bolbos, Radu; Langlois, Jean-Baptiste; Hermitte, Laure; Wiart, Marlène; Berthezène, Yves; Nighoghossian, Norbert

2012-01-01

Injection of thrombin into the middle cerebral artery (MCA) of mice has been proposed as a new model of thromboembolic stroke. The present study used sequential multiparametric Magnetic Resonance Imaging (MRI), including Magnetic Resonance Angiography (MRA), Diffusion-Weighted Imaging (DWI) and Perfusion-Weighted Imaging (PWI), to document MCA occlusion, PWI-DWI mismatch, and lesion development. In the first experiment, complete MCA occlusion and reproducible hypoperfusion were obtained in 85% of animals during the first hour after stroke onset. In the second experiment, 80% of animals showed partial to complete reperfusion during a three-hour follow-up. Spontaneous reperfusion thus contributed to the variability in ischemic volume in this model. The study confirmed the value of the model for evaluating new thrombolytic treatments, but calls for extended MRI follow-up at the acute stage in therapeutic studies. PMID:23166825

Endothelium-targeted overexpression of heat shock protein 27 ameliorates blood–brain barrier disruption after ischemic brain injury

Science.gov (United States)

Jiang, Xiaoyan; Zhang, Lili; Pu, Hongjian; Hu, Xiaoming; Zhang, Wenting; Cai, Wei; Gao, Yanqin; Leak, Rehana K.; Keep, Richard F.; Bennett, Michael V. L.; Chen, Jun

2017-01-01

The damage borne by the endothelial cells (ECs) forming the blood–brain barrier (BBB) during ischemic stroke and other neurological conditions disrupts the structure and function of the neurovascular unit and contributes to poor patient outcomes. We recently reported that structural aberrations in brain microvascular ECs—namely, uncontrolled actin polymerization and subsequent disassembly of junctional proteins, are a possible cause of the early onset BBB breach that arises within 30–60 min of reperfusion after transient focal ischemia. Here, we investigated the role of heat shock protein 27 (HSP27) as a direct inhibitor of actin polymerization and protectant against BBB disruption after ischemia/reperfusion (I/R). Using in vivo and in vitro models, we found that targeted overexpression of HSP27 specifically within ECs—but not within neurons—ameliorated BBB impairment 1–24 h after I/R. Mechanistically, HSP27 suppressed I/R-induced aberrant actin polymerization, stress fiber formation, and junctional protein translocation in brain microvascular ECs, independent of its protective actions against cell death. By preserving BBB integrity after I/R, EC-targeted HSP27 overexpression attenuated the infiltration of potentially destructive neutrophils and macrophages into brain parenchyma, thereby improving long-term stroke outcome. Notably, early poststroke administration of HSP27 attached to a cell-penetrating transduction domain (TAT-HSP27) rapidly elevated HSP27 levels in brain microvessels and ameliorated I/R-induced BBB disruption and subsequent neurological deficits. Thus, the present study demonstrates that HSP27 can function at the EC level to preserve BBB integrity after I/R brain injury. HSP27 may be a therapeutic agent for ischemic stroke and other neurological conditions involving BBB breakdown. PMID:28137866

Global brain ischemia and reperfusion.

Science.gov (United States)

White, B C; Grossman, L I; O'Neil, B J; DeGracia, D J; Neumar, R W; Rafols, J A; Krause, G S

1996-05-01

Brain damage accompanying cardiac arrest and resuscitation is frequent and devastating. Neurons in the hippocampus CA1 and CA4 zones and cortical layers III and V are selectively vulnerable to death after injury by ischemia and reperfusion. Ultrastructural evidence indicates that most of the structural damage is associated with reperfusion, during which the vulnerable neurons develop disaggregation of polyribosomes, peroxidative damage to unsaturated fatty acids in the plasma membrane, and prominent alterations in the structure of the Golgi apparatus that is responsible for membrane assembly. Reperfusion is also associated with vulnerable neurons with prominent production of messenger RNAs for stress proteins and for the proteins of the activator protein-1 complex, but these vulnerable neurons fail to efficiently translate these messages into the proteins. The inhibition of protein synthesis during reperfusion involves alteration of translation initiation factors, specifically serine phosphorylation of the alpha-subunit of eukaryotic initiation factor-2 (elF-2 alpha). Growth factors--in particular, insulin--have the potential to reverse phosphorylation of elF-2 alpha, promote effective translation of the mRNA transcripts generated in response to ischemia and reperfusion, enhance neuronal defenses against radicals, and stimulate lipid synthesis and membrane repair. There is now substantial evidence that the insulin-class growth factors have neuron-sparing effects against damage by radicals and ischemia and reperfusion. This new knowledge may provide a fundamental basis for a rational approach to "cerebral resuscitation" that will allow substantial amelioration of the often dismal neurologic outcome now associated with resuscitation from cardiac arrest.

Role of necroptosis in autophagy signaling during hepatic ischemia and reperfusion

Energy Technology Data Exchange (ETDEWEB)

Hong, Jeong-Min; Kim, Seok-Joo; Lee, Sun-Mee, E-mail: sunmee@skku.edu

2016-10-01

Ischemia and reperfusion (I/R) is a complex phenomenon involving massive inflammation and cell death. Necroptosis refers to a newly described cell death as “programmed necrosis” that is controlled by receptor-interacting protein kinase (RIP) 1 and RIP3, which is involved in the pathogenesis of several inflammatory diseases. Autophagy is an essential cytoprotective system that is rapidly activated in response to various stimuli and involves crosstalk between different modes of cell death and inflammation. In this study, we investigated pattern changes in necroptosis and its role in autophagy signaling during hepatic I/R. Male C57BL/6 mice were subjected to 60 min of ischemia followed by 3 h reperfusion. Necrostatin-1 (Nec-1, a necroptosis inhibitor; 1.65 mg/kg) was administered intraperitoneally 5 min before reperfusion. Hepatic I/R significantly increased the level of RIP3, phosphorylated RIP1 and RIP3 protein expression, and RIP1/RIP3 necrosome formation, which were attenuated by Nec-1. I/R also significantly increased serum levels of alanine aminotransferase, tumor necrosis factor-α, and interleukin-6, which were attenuated by Nec-1. Meanwhile, hepatic I/R activated autophagy and mitophagy, as evidenced by increased LC3-II, PINK1, and Parkin, and decreased sequestosome 1/p62 protein expression. Nec-1 attenuated these changes and attenuated the increased levels of autophagy-related protein (ATG) 3, ATG7, Rab7, and cathepsin B protein expression during hepatic I/R. Moreover, hepatic I/R activated the extracellular signal-regulated kinase (ERK) pathway, and Nec-1 attenuated this increase. Taken together, our findings suggest that necroptosis contributes to hepatic damage during I/R, which induces autophagy via ERK activation. - Highlights: • Hepatic I/R induces RIP1/RIP3-dependent necroptosis. • Necroptosis contributes to hepatic I/R injury. • Necroptosis activates autophagic flux via ERK activation during hepatic I/R.

Endogenous and natural complement inhibitor attenuates myocardial injury and arterial thrombogenesis

DEFF Research Database (Denmark)

Pavlov, Vasile I; Skjoedt, Mikkel-Ole; Siow Tan, Ying

2012-01-01

BACKGROUND: Coagulation disorders and reperfusion of ischemic myocardium are major causes of morbidity and mortality. Lectin pathway initiation complexes are composed of multimolecular carbohydrate recognition subcomponents and 3 lectin pathway-specific serine proteases. We have recently shown th...

Experimental study of the molecular mechanisms of myocardial ischemic memory with 18F-FDG PET/CT imaging

International Nuclear Information System (INIS)

Xie Boqia; Yang Minfu; Ye Jue; Yang Zihe; Dou Kefei; Tian Yi; Han Chunlei

2012-01-01

This study was aimed to explore whether the changes of mRNA and the existence and duration of ischemic 18 F-FDG uptake correlate with the extent of myocardial ischemia in ischemia-reperfusion canine model. The 20-minute (n= 4) and 40-minute (n=4) coronary artery occlusion followed by 24 h of open-artery reperfusion in canine model were per- formed. All dogs underwent fasting (>12 h) dynamic 18 F-FDG PET/CT and 99 Tc m -MIBI SPECT imaging at baseline, 1 h and 24 h after reperfusion. When all imaging were completed, myocardial samples from the ischemic and nonischemic region were obtained, and the mRNA expression of glucose transporter-l (GLUT-1), glucose transporter-4 (GLUT-4), and heart-fatty acid binding protein (H-FABP) were estimated by Real Time PCR. There was no difference in the ratio of hypoperfused region/nomoperfused region of 18 F-FDG up- take between the 20-minute group and 40-minute group at baseline. When examined at 1 h, increased 18 F-FDG uptake was observed in the 40-minute group. When estimated at 24 h, only the 40-minute group showed slightly higher 18 F-FDG uptake than baseline, whereas no such difference was demonstrated in the 20-minute group. Similar mRNA expression of GLUT-1, GLUT-4 and H-FABP were demonstrated in the nonischemic regions between the 2 groups, whereas increased expressions of GLUT-1 and GLUT-4, and decreased H-FABP mRNA were demonstrated in the ischemic regions. The changes of mRNA expression were more obvious in the 40 minute group than in the 20-minute group. The results showed that the existence and persistent period of ischemic 18 F-FDG uptake (ischemic memory) was correlated with the extent of myocardial ischemia. (authors)

Ischemic preconditioning protects against gap junctional uncoupling in cardiac myofibroblasts.

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Sundset, Rune; Cooper, Marie; Mikalsen, Svein-Ole; Ytrehus, Kirsti

2004-01-01

Ischemic preconditioning increases the heart's tolerance to a subsequent longer ischemic period. The purpose of this study was to investigate the role of gap junction communication in simulated preconditioning in cultured neonatal rat cardiac myofibroblasts. Gap junctional intercellular communication was assessed by Lucifer yellow dye transfer. Preconditioning preserved intercellular coupling after prolonged ischemia. An initial reduction in coupling in response to the preconditioning stimulus was also observed. This may protect neighboring cells from damaging substances produced during subsequent regional ischemia in vivo, and may preserve gap junctional communication required for enhanced functional recovery during subsequent reperfusion.

Sex-dependent effects of chronic psychosocial stress on myocardial sensitivity to ischemic injury.

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Rorabaugh, Boyd R; Krivenko, Anna; Eisenmann, Eric D; Bui, Albert D; Seeley, Sarah; Fry, Megan E; Lawson, Joseph D; Stoner, Lauren E; Johnson, Brandon L; Zoladz, Phillip R

2015-01-01

Individuals with post-traumatic stress disorder (PTSD) experience many debilitating symptoms, including intrusive memories, persistent anxiety and avoidance of trauma-related cues. PTSD also results in numerous physiological complications, including increased risk for cardiovascular disease (CVD). However, characterization of PTSD-induced cardiovascular alterations is lacking, especially in preclinical models of the disorder. Thus, we examined the impact of a psychosocial predator-based animal model of PTSD on myocardial sensitivity to ischemic injury. Male and female Sprague-Dawley rats were exposed to psychosocial stress or control conditions for 31 days. Stressed rats were given two cat exposures, separated by a period of 10 days, and were subjected to daily social instability throughout the paradigm. Control rats were handled daily for the duration of the experiment. Rats were tested on the elevated plus maze (EPM) on day 32, and hearts were isolated on day 33 and subjected to 20 min ischemia and 2 h reperfusion on a Langendorff isolated heart system. Stressed male and female rats gained less body weight relative to controls, but only stressed males exhibited increased anxiety on the EPM. Male, but not female, rats exposed to psychosocial stress exhibited significantly larger infarcts and attenuated post-ischemic recovery of contractile function compared to controls. Our data demonstrate that predator stress combined with daily social instability sex-dependently increases myocardial sensitivity to ischemic injury. Thus, this manipulation may be useful for studying potential mechanisms underlying cardiovascular alterations in PTSD, as well as sex differences in the cardiovascular stress response.

Erdosteine and ebselen as useful agents in intestinal ischemia/reperfusion injury.

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Tunc, Turan; Uysal, Bulent; Atabek, Cuneyt; Kesik, Vural; Caliskan, Bahadir; Oztas, Emin; Ersoz, Nail; Oter, Sukru; Guven, Ahmet

2009-08-01

Reactive oxygen and nitrogen species generated during reperfusion of the tissue are characteristic of ischemia/reperfusion (I/R) injury. The purpose of the present study was to investigate whether erdosteine and ebselen, molecules with antioxidant properties and peroxynitrite scavenging capability, respectively, can reduce oxidative stress and histological damage in the rat small bowel subjected to mesenteric I/R injury. Forty Sprague-Dawley rats were divided into five groups equally: sham, I/R, I/R plus erdosteine, I/R plus ebselen, and I/R plus erdosteine and ebselen. Intestinal ischemia for 45 min and reperfusion for 3 d were carried out. Ileal specimens were obtained to determine the tissue levels of malondialdehide (MDA), protein carbonyl content (PCC), superoxide dismutase (SOD), glutathione peroxidase (GPx), nitrite/nitrate (NO(x)) level and histological changes. Intestinal I/R resulted in increased tissue MDA, PCC, and NO(x) levels and decreased SOD and GPx activities. Both erdosteine and ebselen alone significantly decreased MDA, PCC, and NO(x) levels and increased antioxidant enzymes activities, but all values were different from control. These changes almost returned to control values in the group treated with erdostein and ebselen. Histopathologically, the intestinal injury in rats treated with erdosteine and ebselen as well as combination were less than I/R group. Both erdosteine and ebselen were able to attenuate I/R injury of the intestine via inhibition of lipid peroxidation and protein oxidation, maintenance of antioxidant, and free radical scavenger properties. Nevertheless, combination treatment showed more promising results, suggesting that scavenging peroxynitrite nearby antioxidant activity is important in preventing intestinal I/R injury.

Role of Epinephrine and Extracorporeal Membrane Oxygenation in the Management of Ischemic Refractory Ventricular Fibrillation

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Jason A. Bartos, MD, PhD

2017-06-01

Full Text Available Summary: Extracorporeal membrane oxygenation (ECMO is used in cardiopulmonary resuscitation (CPR of refractory cardiac arrest. The authors used a 2 × 2 study design to compare ECMO versus CPR and epinephrine versus placebo in a porcine model of ischemic refractory ventricular fibrillation (VF. Pigs underwent 5 min of untreated VF and 10 min of CPR, and were randomized to receive epinephrine versus placebo for another 35 min. Animals were further randomized to left anterior descending artery (LAD reperfusion at minute 45 with ongoing CPR versus venoarterial ECMO cannulation at minute 45 of CPR and subsequent LAD reperfusion. Four-hour survival was improved with ECMO whereas epinephrine showed no effect. Key Words: advanced cardiopulmonary life support, cardiac arrest, cardiopulmonary resuscitation, ECMO, extracorporeal membrane oxygenation, ischemic refractory ventricular fibrillation, ST-segment elevation myocardial infarction, ventricular fibrillation

Reduction in Hexokinase II Levels Results in Decreased Cardiac Function and Altered Remodeling After Ischemia/Reperfusion Injury

NARCIS (Netherlands)

Wu, Rongxue; Smeele, Kirsten M.; Wyatt, Eugene; Ichikawa, Yoshihiko; Eerbeek, Otto; Sun, Lin; Chawla, Kusum; Hollmann, Markus W.; Nagpal, Varun; Heikkinen, Sami; Laakso, Markku; Jujo, Kentaro; Wasserstrom, J. Andrew; Zuurbier, Coert J.; Ardehali, Hossein

2011-01-01

Rationale: Cardiomyocytes switch substrate utilization from fatty acid to glucose under ischemic conditions; however, it is unknown how perturbations in glycolytic enzymes affect cardiac response to ischemia/reperfusion (I/R). Hexokinase (HK)II is a HK isoform that is expressed in the heart and can

Remote Ischemic Preconditioning and Outcomes of Cardiac Surgery.

OpenAIRE

Hausenloy, DJ; Candilio, L; Evans, R; Ariti, C; Jenkins, DP; Kolvekar, S; Knight, R; Kunst, G; Laing, C; Nicholas, J; Pepper, J; Robertson, S; Xenou, M; Clayton, T; Yellon, DM

2015-01-01

: Whether remote ischemic preconditioning (transient ischemia and reperfusion of the arm) can improve clinical outcomes in patients undergoing coronary-artery bypass graft (CABG) surgery is not known. We investigated this question in a randomized trial. : We conducted a multicenter, sham-controlled trial involving adults at increased surgical risk who were undergoing on-pump CABG (with or without valve surgery) with blood cardioplegia. After anesthesia induction and before surgical incision, ...

An engineered S1P chaperone attenuates hypertension and ischemic injury.

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Swendeman, Steven L; Xiong, Yuquan; Cantalupo, Anna; Yuan, Hui; Burg, Nathalie; Hisano, Yu; Cartier, Andreane; Liu, Catherine H; Engelbrecht, Eric; Blaho, Victoria; Zhang, Yi; Yanagida, Keisuke; Galvani, Sylvain; Obinata, Hideru; Salmon, Jane E; Sanchez, Teresa; Di Lorenzo, Annarita; Hla, Timothy

2017-08-15

Endothelial dysfunction, a hallmark of vascular disease, is restored by plasma high-density lipoprotein (HDL). However, a generalized increase in HDL abundance is not beneficial, suggesting that specific HDL species mediate protective effects. Apolipoprotein M-containing HDL (ApoM + HDL), which carries the bioactive lipid sphingosine 1-phosphate (S1P), promotes endothelial function by activating G protein-coupled S1P receptors. Moreover, HDL-bound S1P is limiting in several inflammatory, metabolic, and vascular diseases. We report the development of a soluble carrier for S1P, ApoM-Fc, which activated S1P receptors in a sustained manner and promoted endothelial function. In contrast, ApoM-Fc did not modulate circulating lymphocyte numbers, suggesting that it specifically activated endothelial S1P receptors. ApoM-Fc administration reduced blood pressure in hypertensive mice, attenuated myocardial damage after ischemia/reperfusion injury, and reduced brain infarct volume in the middle cerebral artery occlusion model of stroke. Our proof-of-concept study suggests that selective and sustained targeting of endothelial S1P receptors by ApoM-Fc could be a viable therapeutic strategy in vascular diseases. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Electroacupuncture improves cerebral blood flow and attenuates moderate ischemic injury via Angiotensin II its receptors-mediated mechanism in rats.

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Li, Jing; He, Jiaojun; Du, Yuanhao; Cui, Jingjun; Ma, Ying; Zhang, Xuezhu

2014-11-11

To investigate the effects and potential mechanism of electroacupuncture intervention on expressions of Angiotensin II and its receptors-mediated signaling pathway in experimentally induced cerebral ischemia. Totally 126 male Wistar rats were randomly divided into control group, model group and EA group. The latter two were further divided into ten subgroups (n = 6) following Middle Cerebral Artery Occlusion (MCAO). Changes in regional cerebral blood flow (rCBF) and expressions of Angiotensin II and its receptors (AT1R, AT2R), as well as effector proteins in phosphatidyl inositol signal pathway were monitored before and at different times after MCAO. MCAO-induced decline of ipsilateral rCBF was partially suppressed by electroacupuncture, and contralateral blood flow was also superior to that of model group. Angiotensin II level was remarkably elevated immediately after MCAO, while electroacupuncture group exhibited significantly lower levels at 1 to 3 h and the value was significantly increased thereafter. The enhanced expression of AT1R was partially inhibited by electroacupuncture, while increased AT2R level was further induced. Electroacupuncture stimulation attenuated and postponed the upregulated-expressions of Gq and CaM these upregulations. ELISA results showed sharply increased expressions of DAG and IP3, which were remarkably neutralized by electroacupuncture. MCAO induced significant increases in expression of Angiotensin II and its receptor-mediated signal pathway. These enhanced expressions were significantly attenuated by electroacupuncture intervention, followed by reduced vasoconstriction and improved blood supply in ischemic region, and ultimately conferred beneficial effects on cerebral ischemia.

Importance of tissue perfusion in ST segment elevation myocardial infarction patients undergoing reperfusion strategies: role of adenosine.

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Forman, Mervyn B; Jackson, Edwin K

2007-11-01

High risk ST segment elevation myocardial infarction (STEMI) patients undergoing reperfusion therapy continue to exhibit significant morbidity and mortality due in part to myocardial reperfusion injury. Importantly, preclinical studies demonstrate that progressive microcirculatory failure (the "no-reflow" phenomenon) contributes significantly to myocardial reperfusion injury. Diagnostic techniques to measure tissue perfusion have validated this concept in humans, and it is now clear that abnormal tissue perfusion occurs frequently in STEMI patients undergoing reperfusion therapy. Moreover, because tissue perfusion correlates poorly with epicardial blood flow (TIMI flow grade), clinical studies show that tissue perfusion is an independent predictor of early and late mortality in STEMI patients and is associated with infarct size, ventricular function, CHF and ventricular arrhythmias. The mechanisms responsible for abnormal tissue perfusion are multifactorial and include both mechanical obstruction and vasoconstrictor humoral factors. Adenosine, an endogenous nucleoside, maintains microcirculatory flow following reperfusion by activating four well-characterized extracellular receptors. Because activation of adenosine receptors attenuates the mechanical and functional mechanisms leading to the "no reflow" phenomenon and activates other cardioprotective pathways as well, it is not surprising that both experimental and clinical studies show striking myocardial salvage with intravenous infusions of adenosine administered in the peri-reperfusion period. For example, a post hoc analysis of the AMISTAD II trial indicates a significant reduction in 1 and 6-month mortality in STEMI patients undergoing reperfusion therapy who are treated with adenosine within 3 hours of symptoms. In conclusion, adenosine's numerous cardioprotective effects, including attenuation of the "no-reflow" phenomenon, support its use in high risk STEMI undergoing reperfusion.

Effect of Curcuma longa and Ocimum sanctum on myocardial apoptosis in experimentally induced myocardial ischemic-reperfusion injury

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Mohanty, Ipseeta; Arya, Dharamvir Singh; Gupta, Suresh Kumar

2006-01-01

Background In the present investigation, the effect of Curcuma longa (Cl) and Ocimum sanctum (Os) on myocardial apoptosis and cardiac function was studied in an ischemia and reperfusion (I-R) model of myocardial injury. Methods Wistar albino rats were divided into four groups and orally fed saline once daily (sham, control IR) or Cl (100 mg/kg; Cl-IR) or Os (75 mg/kg; Os-IR) respectively for 1 month. On the 31st day, in the rats of the control IR, Cl-IR and Os-IR groups LAD occlusion was undertaken for 45 min, and reperfusion was allowed for 1 h. The hemodynamic parameters{mean arterial pressure (MAP), heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular peak positive (+) LVdP/dt (rate of pressure development) and negative (-) LVdP/dt (rate of pressure decline)} were monitored at pre-set points throughout the experimental duration and subsequently, the animals were sacrificed for immunohistopathological (Bax, Bcl-2 protein expression & TUNEL positivity) and histopathological studies. Results Chronic treatment with Cl significantly reduced TUNEL positivity (p < 0.05), Bax protein (p < 0.001) and upregulated Bcl-2 (p < 0.001) expression in comparison to control IR group. In addition, Cl demonstrated mitigating effects on several myocardial injury induced hemodynamic {(+)LVdP/dt, (-) LVdP/dt & LVEDP} and histopathological perturbations. Chronic Os treatment resulted in modest modulation of the hemodynamic alterations (MAP, LVEDP) but failed to demonstrate any significant antiapoptotic effects and prevent the histopathological alterations as compared to control IR group. Conclusion In the present study, significant cardioprotection and functional recovery demonstrated by Cl may be attributed to its anti-apoptotic property. In contrast to Os, Cl may attenuate cell death due to apoptosis and prevent the impairment of cardiac performance. PMID:16504000

[The relationship between ischemic preconditioning-induced infarction size limitation and duration of test myocardial ischemia].

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Blokhin, I O; Galagudza, M M; Vlasov, T D; Nifontov, E M; Petrishchev, N N

2008-07-01

Traditionally infarction size reduction by ischemic preconditioning is estimated in duration of test ischemia. This approach limits the understanding of real antiischemic efficacy of ischemic preconditioning. Present study was performed in the in vivo rat model of regional myocardial ischemia-reperfusion and showed that protective effect afforded by ischemic preconditioning progressively decreased with prolongation of test ischemia. There were no statistically significant differences in infarction size between control and preconditioned animals when the duration of test ischemia was increased up to 1 hour. Preconditioning ensured maximal infarction-limiting effect in duration of test ischemia varying from 20 to 40 minutes.

The Cardioprotective Effects of Citric Acid and L-Malic Acid on Myocardial Ischemia/Reperfusion Injury

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Tang, Xilan; Liu, Jianxun; Dong, Wei; Li, Peng; Li, Lei; Lin, Chengren; Zheng, Yongqiu; Hou, Jincai; Li, Dan

2013-01-01

Organic acids in Chinese herbs, the long-neglected components, have been reported to possess antioxidant, anti-inflammatory, and antiplatelet aggregation activities; thus they may have potentially protective effect on ischemic heart disease. Therefore, this study aims to investigate the protective effects of two organic acids, that is, citric acid and L-malic acid, which are the main components of Fructus Choerospondiatis, on myocardial ischemia/reperfusion injury and the underlying mechanisms. In in vivo rat model of myocardial ischemia/reperfusion injury, we found that treatments with citric acid and L-malic acid significantly reduced myocardial infarct size, serum levels of TNF-α, and platelet aggregation. In vitro experiments revealed that both citric acid and L-malic acid significantly reduced LDH release, decreased apoptotic rate, downregulated the expression of cleaved caspase-3, and upregulated the expression of phosphorylated Akt in primary neonatal rat cardiomyocytes subjected to hypoxia/reoxygenation injury. These results suggest that both citric acid and L-malic acid have protective effects on myocardial ischemia/reperfusion injury; the underlying mechanism may be related to their anti-inflammatory, antiplatelet aggregation and direct cardiomyocyte protective effects. These results also demonstrate that organic acids, besides flavonoids, may also be the major active ingredient of Fructus Choerospondiatis responsible for its cardioprotective effects and should be attached great importance in the therapy of ischemic heart disease. PMID:23737849

S100B protein in serum is elevated after global cerebral ischemic injury

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Bao-di Sun; Hong-mei Liu; Shi-nan Nie

2013-01-01

BACKGROUND:S100B protein in patients with cardiac arrest,hemorrhagic shock and other causes of global cerebral ischemic injury will be dramatically increased.Ischemic brain injury may elevate the level of serum S100 B protein and the severity of brain damage.METHODS:This article is a critical and descriptive review on S100 B protein in serum after ischemic brain injury.We searched Pubmed database with key words or terms such as 'S100B protein', 'cardiac arrest', 'hemorrhagic shock' and 'ischemia reperfusion injury' appeared in the last five years.RESULTS:S100B protein in patients with cardiac arrest,hemorrhagic shock and other causes of ischemic brain injury will be dramatically increased.Ischemic brain injury elevated the level of serum S100 B protein,and the severity of brain damage.CONCLUSION:The level of S100 B protein in serum is elevated after ischemic brain injury,but its mechanism is unclear.

Neuroprotective effects of SMADs in a rat model of cerebral ischemia/reperfusion

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Fang-fang Liu

2015-01-01

Full Text Available Previous studies have shown that up-regulation of transforming growth factor β1 results in neuroprotective effects. However, the role of the transforming growth factor β1 downstream molecule, SMAD2/3, following ischemia/reperfusion remains unclear. Here, we investigated the neuroprotective effects of SMAD2/3 by analyzing the relationships between SMAD2/3 expression and cell apoptosis and inflammation in the brain of a rat model of cerebral ischemia/reperfusion. Levels of SMAD2/3 mRNA were up-regulated in the ischemic penumbra 6 hours after cerebral ischemia/reperfusion, reached a peak after 72 hours and were then decreased at 7 days. Phosphorylated SMAD2/3 protein levels at the aforementioned time points were consistent with the mRNA levels. Over-expression of SMAD3 in the brains of the ischemia/reperfusion model rats via delivery of an adeno-associated virus containing the SMAD3 gene could reduce tumor necrosis factor-α and interleukin-1β mRNA levels, down-regulate expression of the pro-apoptotic gene, capase-3, and up-regulate expression of the anti-apoptotic protein, Bcl-2. The SMAD3 protein level was negatively correlated with cell apoptosis. These findings indicate that SMAD3 exhibits neuroprotective effects on the brain after ischemia/reperfusion through anti-inflammatory and anti-apoptotic pathways.

Dual Gas Treatment With Hydrogen and Carbon Monoxide Attenuates Oxidative Stress and Protects From Renal Ischemia-Reperfusion Injury.

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Nishida, T; Hayashi, T; Inamoto, T; Kato, R; Ibuki, N; Takahara, K; Takai, T; Yoshikawa, Y; Uchimoto, T; Saito, K; Tanda, N; Kouno, J; Minami, K; Uehara, H; Hirano, H; Nomi, H; Okada, Y; Azuma, H

Hydrogen (H 2 ) and carbon monoxide (CO) gas are both reported to reduce reactive oxygen species and alleviate tissue ischemia-reperfusion (I-R) injury. The present study was conducted to evaluate the effects of a mixture of H 2 gas and CO gas (dual gas) in comparison with hydrogen gas (H 2 : 2%) alone on I-R renal injury (composition of dual gas; N 2 : 77.8%; O 2 : 20.9%; H 2 : 1.30%; CO: 250 parts per million). Adult male Sprague-Dawley rats (body weight 250-280 g) were divided into 5 groups: (1) sham operation control, (2) dual gas inhalation (dual treatment) without I-R treatment, (3) I-R renal injury, (4) H 2 gas alone inhalation (H 2 treatment) with I-R renal injury, and (5) dual treatment with I-R renal injury. I-R renal injury was induced by clamping the left renal artery and vein for 45 minutes followed by reperfusion, and then contralateral nephrectomy was performed 2 weeks later. Renal function was markedly decreased at 24 hours after reperfusion, and thereafter the effects of dual gas were assessed by histologic examination and determination of the superoxide radical, together with functional and molecular analyses. Pathologic examination of the kidney of I-R rats revealed severe renal damage. Importantly, cytoprotective effects of the dual treatment in comparison with H 2 treatment and I-R renal injury were observed in terms of superoxide radical scavenging activity and histochemical features. Rats given dual treatment and I-R renal injury showed significant decreases in blood urea nitrogen. Increased expression of several inflammatory cytokines (tumor necrosis factor-α, interleukin-6, intracellular adhesion molecule-1, nuclear factor-κB, hypoxia inducible factor-1α, and heme oxygenase-1) was attenuated by the dual treatment. Dual gas inhalation decreases oxidative stress and markedly improves I-R-induced renal injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of FK506 on Hippocampal CA1 Cells Following Transient Global Ischemia/Reperfusion in Wistar Rat

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Zahra-Nadia Sharifi

2012-01-01

Full Text Available Transient global cerebral ischemia causes loss of pyramidal cells in CA1 region of hippocampus. In this study, we investigated the neurotrophic effect of the immunosuppressant agent FK506 in rat after global cerebral ischemia. Both common carotid arteries were occluded for 20 minutes followed by reperfusion. In experimental group 1, FK506 (6 mg/kg was given as a single dose exactly at the time of reperfusion. In the second group, FK506 was administered at the beginning of reperfusion, followed by its administration intraperitoneally (IP 6, 24, 48, and 72 hours after reperfusion. FK506 failed to show neurotrophic effects on CA1 region when applied as a single dose of 6 mg/kg. The cell number and size of the CA1 pyramidal cells were increased, also the number of cell death decreased in this region when FK506 was administrated 48 h after reperfusion. This work supports the possible use of FK506 in treatment of ischemic brain damage.

Sildenafil citrate protects skeletal muscle of ischemia-reperfusion injury: immunohistochemical study in rat model

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Dinani Matoso Fialho de Oliveira Armstrong

2013-04-01

Full Text Available PURPOSE: To investigate the effect of sildenafil citrate (SC on skeletal muscle ischemia-reperfusion (IR injury in rats. METHODS: Adult male Wistar rats were randomized into three groups: vehicle-treated control (CTG, sildenafil citrate-treated (SCG, and sham group (SG. CTG and SCG had femoral artery occluded for 6 hours. Saline or 1 mg/kg of SC was given 5.5 hours after occlusion. SG had a similar procedure without artery occlusion. Soleus muscle samples were acquired 4 or 24h after the reperfusion. Immunohistochemistry caspase-3 analysis was used to estimate apoptosis using the apoptotic ratio (computed as positive/negative cells. Wilcoxon rank-sum or Kruskal-Wallis tests were used to assess differences among groups. RESULTS: Eighteen animals were included in the 4h reperfusion groups and 21 animals in the 24h reperfusion groups. The mean apoptotic ratio was 0.18±0.1 for the total cohort; 0.14±0.06 for the 4h reperfusion groups and 0.19±0.08 for the 24h groups (p<0.05. The SCG had lower caspase-3 ratio compared to the control groups at the 24h reperfusion time point (p<0.05. CONCLUSION: Sildenafil citrate administration after the onset of the ischemic injury reduces IR-induced cellular damage in skeletal muscle in this rat hindlimb ischemia model.

Anti neuroinflammatory effect of Vildagliptin in ischaemia-reperfusion induced cerebral infarction in normal and STZ induced type-II diabetic rats

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Kaleru Purnachander

2016-03-01

Full Text Available Diabetes is one of the major risk factor for cerebral ischemic stroke. Increased base line levels of oxidative stress in diabetes will lead to cerebral ischemic damage. In pathological conditions such as cerebral ischemia/reperfusion injury, free radicals cause oxidative stress and inflammation leading to increased injury of brain. Inflammation is one of the major pathological mechanisms involved in cerebral ischemia and reperfusion injury. Vildagliptin newer anti-diabetic drug of the class DPP-4 inhibitors is reported to have anti-inflammatory properties apart from its antihyperglycemic activity. Therefore the aim of the present study is to evaluate the anti-inflammatory effect of Vildagliptin against cerebral infarction induced ischemia reperfusion injury in normal and STZ induced diabetic Wistar rats. Cerebral infarction was induced by bilateral common carotid artery occlusion followed by 4 hr reperfusion. Percent infarction, inflammatory markers such as MPO, TNF-α, IL-6 and IL-10 were analysed. Treatment with Vildagliptin for a period of four weeks produced significant reduction in percent cerebral infarct volume. Vildagliptin at 10 mg/kg dose, showed significant reduction in markers like MPO, TNF-α, IL-6 and IL-1β in diabetic group when compared to normal group and in contrast significant increase in anti-inflammatory marker like IL-10 levels. Vildagliptin showed significant cerebroprotective effect by antiinflammatory mechanisms.

Protective effect of tetraethyl pyrazine against focal cerebral ischemia/reperfusion injury in rats: therapeutic time window and its mechanism.

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Jia, Jie; Zhang, Xi; Hu, Yong-Shan; Wu, Yi; Wang, Qing-Zhi; Li, Na-Na; Wu, Cai-Qin; Yu, Hui-Xian; Guo, Qing-Chuan

2009-03-01

Tetramethyl pyrazine has been considered an effective agent in treating neurons ischemia/reperfusion injury, but the mechanism of its therapeutic effect remains unclear. This study was to explore the therapeutic time window and mechanism of tetramethyl pyrazine on temporary focal cerebral ischemia/reperfusion injury. Middle cerebral artery occlusion was conducted in male Sprague-Dawley rats and 20 mg/kg of tetramethyl pyrazine was intraperitoneally injected at different time points. At 72 h after reperfusion, all animals' neurologic deficit scores were evaluated. Cerebrums were removed and cerebral infarction volume was measured. The expression of thioredoxin and thioredoxin reductase mRNA was determined at 6 and 24 h after reperfusion. Cerebral infarction volume and neurological deficit scores were significantly decreased in the group with tetramethyl pyrazine treatment. The expression of thioredoxin-1/thioredoxin-2 and thioredoxin reductase-1/thioredoxin reductase-2 was significantly decreased in rats with ischemia/reperfusion injury, while it was increased by tetramethyl pyrazine administration. Treatment with tetramethyl pyrazine, within 4 h after reperfusion, protects the brain from ischemic reperfusion injury in rats. The neuroprotective mechanism of tetramethyl pyrazine treatment is, in part, mediated through the upregulation of thioredoxin transcription.

The role of Toll-like receptors in retinal ischemic diseases

Institute of Scientific and Technical Information of China (English)

Wen-Qin Xu; Yu-Sheng Wang

2016-01-01

Toll-like receptors(TLRs) are commonly referred to a series of evolutionary conserved receptors which recognize and respond to various microbes and endogenous ligands.Growing evidence has demonstrated that the expression of TLRs in the retina is regulated during retinal ischemic diseases,including ischemia-reperfusion injury,glaucoma,diabetic retinopathy(DR) and retinopathy of prematurity(ROP).TLRs can be expressed in multiple cells in the retina,such as glial cells,retinal pigment epithelium(RPE),as well as photoreceptor cells and endothelium cells.Activation of TLRs in retina could initiate a complex signal transduction cascade,induce the production of inflammatory cytokines and regulate the level of costimulatory molecules,which play prominent roles in the pathogenesis of retinal ischemic diseases.In this review,we summarized current studies about the relationship between TLRs and ischemic retinopathy.A greater understanding of the effect of TLRs on ischemic injuries may contribute to the development of specific TLR targeted therapeutic strategies in these conditions.

Reduced ischemia-reperfusion injury with isoproterenol in non-heart-beating donor lungs.

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Jones, D R; Hoffmann, S C; Sellars, M; Egan, T M

1997-05-01

Transplantation of lungs retrieved from non-heart-beating donors could expand the donor pool. Recent studies suggest that the ischemia-reperfusion injury (IRI) to the lung can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, as measured by Kfc, in lungs retrieved from non-heart-beating donors and reperfused with or without isoproterenol (iso). Using an in situ isolated perfused lung model, lungs were retrieved from non-heart-beating donor rats ventilated with O2 or not at varying intervals after death. The lungs were reperfused with or without iso (10 microM). Kfc, lung viability, and pulmonary hemodynamics were measured, and tissue levels of adenine nucleotides and cAMP were measured by HPLC. Iso-reperfusion decreased Kfc significantly (P Kfc in non-iso-reperfused (r = 0.65) and iso-perfused (r = 0.84) lungs. cAMP levels increased significantly with iso-reperfusion. cAMP levels correlated with Kfc (r = 0.87) in iso-reperfused lungs. Iso-reperfusion of lungs retrieved from non-heart-beating donor rats results in decreased capillary permeability and increased lung tissue cAMP levels. Pharmacologic augmentation of tissue TAN and cAMP levels may further ameliorate the increased capillary permeability seen in lungs retrieved from non-heart-beating donors.

Oridonin attenuates Aβ1-42-induced neuroinflammation and inhibits NF-κB pathway.

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Sulei Wang

Full Text Available Neuroinflammation induced by beta-amyloid (Aβ plays a critical role in the pathogenesis of Alzheimer's disease (AD, and inhibiting Aβ-induced neuroinflammation serves as a potential strategy for the treatment of AD. Oridonin (Ori, a compound of Rabdosia rubescens, has been shown to exert anti-inflammatory effects. In this study, we demonstrated that Ori inhibited glial activation and decreased the release of inflammatory cytokines in the hippocampus of Aβ1-42-induced AD mice. In addition, Ori inhibited the NF-κB pathway and Aβ1-42-induced apoptosis. Furthermore, Ori could attenuate memory deficits in Aβ1-42-induced AD mice. In conclusion, our study demonstrated that Ori inhibited the neuroinflammation and attenuated memory deficits induced by Aβ1-42, suggesting that Ori might be a promising candidate for AD treatment.

Neuroprotective role of nanoencapsulated quercetin in combating ischemia-reperfusion induced neuronal damage in young and aged rats.

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Aparajita Ghosh

Full Text Available Cerebral stroke is the leading cause of death and permanent disability among elderly people. In both humans and animals, cerebral ischemia damages the nerve cells in vulnerable regions of the brain, viz., hippocampus, cerebral cortex, cerebellum, and hypothalamus. The present study was conducted to evaluate the therapeutic efficacy of nanoencapsulated quercetin (QC in combating ischemia-reperfusion-induced neuronal damage in young and aged Swiss Albino rats. Cerebral ischemia was induced by occlusion of the common carotid arteries of both young and aged rats followed by reperfusion. Nanoencapsulated quercetin (2.7 mg/kg b wt was administered to both groups of animals via oral gavage two hours prior to ischemic insults as well as post-operation till day 3. Cerebral ischemia and 30 min consecutive reperfusion caused a substantial increase in lipid peroxidation, decreased antioxidant enzyme activities and tissue osmolality in different brain regions of both groups of animals. It also decreased mitochondrial membrane microviscosity and increased reactive oxygen species (ROS generation in different brain regions of young and aged rats. Among the brain regions studied, the hippocampus appeared to be the worst affected region showing increased upregulation of iNOS and caspase-3 activity with decreased neuronal count in the CA1 and CA3 subfields of both young and aged rats. Furthermore, three days of continuous reperfusion after ischemia caused massive damage to neuronal cells. However, it was observed that oral treatment of nanoencapsulated quercetin (2.7 mg/kg b wt resulted in downregulation of iNOS and caspase-3 activities and improved neuronal count in the hippocampal subfields even 3 days after reperfusion. Moreover, the nanoformulation imparted a significant level of protection in the antioxidant status in different brain regions, thus contributing to a better understanding of the given pathophysiological processes causing ischemic neuronal damage.

Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

International Nuclear Information System (INIS)

Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D.; Lemasters, John J.

2013-01-01

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 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (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. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective tetracyclines protect

Minocycline and doxycycline, but not other tetracycline-derived compounds, protect liver cells from chemical hypoxia and ischemia/reperfusion injury by inhibition of the mitochondrial calcium uniporter

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Schwartz, Justin; Holmuhamedov, Ekhson; Zhang, Xun; Lovelace, Gregory L.; Smith, Charles D. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Lemasters, John J., E-mail: JJLemasters@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC (United States); Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC (United States)

2013-11-15

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 50 μM of each tetracycline-derived compound 20 min prior to exposure to 500 μM iodoacetic acid plus 1 mM KCN (chemical hypoxia). In other experiments, hepatocytes were incubated in anoxic Krebs–Ringer–HEPES buffer at pH 6.2 for 4 h prior to reoxygenation at pH 7.4 (simulated I/R). Tetracycline-derived compounds were added 20 min prior to reperfusion. Ca{sup 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{sup 2+} uptake and suppressed the Ca{sup 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{sup 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. - Highlights: • Minocycline and doxycycline are the only cytoprotective tetracyclines of those tested • Cytoprotective tetracyclines inhibit the MPT and mitochondrial calcium and iron uptake. • Cytoprotective

Evidence for the role of histaminergic pathways in neuroprotective mechanism of ischemic postconditioning in mice.

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Kaur, Indresh; Kumar, Amit; Jaggi, Amteshwar S; Singh, Nirmal

2017-08-01

The present study has been designed to investigate the possible role of histaminergic pathway in neuroprotective mechanism of ischemic postconditioning (iPoCo). Bilateral carotid artery occlusion (BCAO) for 12 min followed by reperfusion for 24 h was employed to produce I/R-induced cerebral injury in National Institutes of Health mice mice. iPoCo involving three episodes of carotid artery occlusion and reperfusion of 10 sec each was instituted immediately after BCAO just before prolonged reperfusion. Cerebral infarct size was measured using triphenyltetrazolium chloride staining. Memory was evaluated using Morris water maze test. Rotarod test, inclined beam-walking test, and neurological severity score (NSS) were performed to assess motor incoordination and sensorimotor abilities. Brain acetylcholine esterase (AChE) activity, brain myeloperoxidase (MPO) activity, brain thiobarbituric acid-reactive species (TBARS), and glutathione level (GSH) were also estimated. BCAO produced a significant rise in cerebral infarct size and NSS along with impairment of memory and motor coordination and biochemical alteration (↑AChE, ↑MPO ↓GSH, and ↑TBARS). iPoCo attenuated the deleterious effect of BCAO on infarct size, memory, NSS, motor coordination, and biochemical markers. Pretreatment of carnosine (a histamine [HA] precursor) potentiated the neuroprotective effects of iPoCo, whereas pretreatment of ketotifen (HA H1 receptor blocker and mast cell stabilizer) abolished the protective effects of iPoCo as well as that of carnosine on iPoCo. It may be concluded that neuroprotective effect of iPoCo probably involves activation of histaminergic pathways. © 2017 Société Française de Pharmacologie et de Thérapeutique.

Effect of liver ischemic preconditioning in cirrhotic rats submitted to hepatic ischemia/reperfusion injury Efeito do pré-condicionamento isquêmico hepático submetidos a lesão de isquemia/reperfusão do fígado

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Eduardo Garcia Pacheco

2006-01-01

Full Text Available PURPOSE: The main aim of this study was to determine the influence of ischemic preconditioning (IPC on rat liver cirrhosis. METHODS: Cirrhosis was induced in Wistar rats by occlusion of the hepatic duct. The animals were divided into four groups of six animals each: non-cirrhotic group (simulated operation only, cirrhotic control group (simulated operation in cirrhotic rats, I/R group (40-minute ischemia without IPC, and IPC group (cirrhotic rats with ischemia, previously submitted to IPC. The IPC procedure consisted of partial hepatic ischemia for five minutes, followed by 10 minutes of reperfusion. In the case of the IPC group, the animals were submitted to liver ischemia for 40 minutes after the preconditioning procedure, followed by 2 hours of reperfusion. Blood samples were collected for measurement of serum aminotransferases (ALT and AST. The respiratory control ratio (RCR, the mitochondrial membrane potential (MMP, and malondialdehyde (MDA values in the hepatic tissue were analyzed. Nonparametric statistical analysis was used and a value of pOBJETIVO: O objetivo deste estudo foi determinar a influência do pré-condicionamento isquêmico (IPC em fígados de ratos cirróticos. MÉTODOS: A cirrose hepática foi induzida em ratos Wistar machos (250 a 300g por oclusão, durante 30 dias, do ducto hepático comum.A seguir, os animais cirróticos foram divididos em três grupos de seis; Grupo controle cirrótico (operação simulada para isquemia/reperfusão/pré-condicionamento, Grupo I/R, isquemia de 40 minutos sem pré-condicionamento (IPC e grupo IPC com isquemia precedida por IPC. O IPC consistiu de uma isquemia parcial por cinco minutos, seguida por 10 minutos de reperfusão. No grupo IPC, após o pré-condicionamento, os animais foram submetidos à isquemia hepática de 40 minutos seguida de 2 horas de reperfusão. Foram colhidas amostras de sangue para dosagem sérica de aminotransferases (ALT e AST. Razão de controle respiratório (RCR

Protective effect of Urtica dioica L. on renal ischemia/reperfusion injury in rat.

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Sayhan, Mustafa Burak; Kanter, Mehmet; Oguz, Serhat; Erboga, Mustafa

2012-12-01

Renal ischemia-reperfusion (I/R) injury may occur after renal transplantation, thoracoabdominal aortic surgery, and renal artery interventions. This study was designed to investigate the effect of Urtica dioica L. (UD), in I/R induced renal injury. A total of 32 male Sprague-Dawley rats were divided into four groups: control, UD alone, I/R and I/R + UD; each group contain 8 animals. A rat model of renal I/R injury was induced by 45-min occlusion of the bilateral renal pedicles and 24-h reperfusion. In the UD group, 3 days before I/R, UD (2 ml/kg/day intraperitoneal) was administered by gastric gavage. All animals were sacrificed at the end of reperfusion and kidney tissues samples were obtained for histopathological investigation in all groups. To date, no more histopathological changes on intestinal I/R injury in rats by UD treatment have been reported. Renal I/R caused severe histopathological injury including tubular damage, atrophy dilatation, loss of brush border and hydropic epithelial cell degenerations, renal corpuscle atrophy, glomerular shrinkage, markedly focal mononuclear cell infiltrations in the kidney. UD treatment significantly attenuated the severity of intestinal I/R injury and significantly lowered tubulointerstitial damage score than the I/R group. The number of PCNA and TUNEL positive cells in the control and UD alone groups was negligible. When kidney sections were PCNA and TUNEL stained, there was a clear increase in the number of positive cells in the I/R group rats in the renal cortical tissues. However, there is a significant reduction in the activity of PCNA and TUNEL in kidney tissue of renal injury induced by renal I/R with UD therapy. Our results suggest that administration of UD attenuates renal I/R injury. These results suggest that UD treatment has a protective effect against renal damage induced by renal I/R. This protective effect is possibly due to its ability to inhibit I/R induced renal damage, apoptosis and cell proliferation.

Flurbiprofen, a Cyclooxygenase Inhibitor, Protects Mice from Hepatic Ischemia/Reperfusion Injury by Inhibiting GSK-3β Signaling and Mitochondrial Permeability Transition

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Fu, Hailong; Chen, Huan; Wang, Chengcai; Xu, Haitao; Liu, Fang; Guo, Meng; Wang, Quanxing; Shi, Xueyin

2012-01-01

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. PMID:22714712

Anti-inflammatory and antioxidant effects of infliximab in a rat model of intestinal ischemia/reperfusion injury.

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Pergel, Ahmet; Kanter, Mehmet; Yucel, Ahmet Fikret; Aydin, Ibrahim; Erboga, Mustafa; Guzel, Ahmet

2012-11-01

The aim of this study was to investigate the possible protective effects of infliximab on oxidative stress, cell proliferation and apoptosis in the rat intestinal mucosa after ischemia/reperfusion (I/R). A total of 30 male Wistar albino rats were divided into three groups: sham, I/R and I/R+ infliximab; each group comprised 10 animals. Sham group animals underwent laparotomy without I/R injury. I/R groups after undergoing laparotomy, 1 hour of superior mesenteric artery ligation occurred, which was followed by 1 hour of reperfusion. In the infliximab group, 3 days before I/R, infliximab (3 mg/kg) was administered intravenously. All animals were killed at the end of reperfusion and intestinal tissues samples were obtained for biochemical and histopathological investigation in all groups. To date, no biochemical and histopathological changes have been reported regarding intestinal I/R injury in rats due to infliximab treatment. Infliximab treatment significantly decreased the elevated tissue malondialdehyde levels and increased reduced superoxide dismutase and glutathione peroxidase enzyme activities in intestinal tissues samples. I/R caused severe histopathological injury including mucosal erosions, inflammatory cell infiltration, necrosis, hemorrhage, and villous congestion. Infliximab treatment significantly attenuated the severity of intestinal I/R injury, inhibiting I/R-induced apoptosis, and cell proliferation. Because of its anti-inflammatory and antioxidant effects, infliximab pretreatment may have protective effects on the experimental intestinal I/R model of rats.

Reducing mitochondrial bound hexokinase II mediates transition from non-injurious into injurious ischemia/reperfusion of the intact heart

NARCIS (Netherlands)

R. Nederlof (Rianne); Gürel-Gurevin, E. (Ebru); O. Eerbeek (Otto); C. Xie (Chaoqin); Deijs, G.S.; Konkel, M. (Moritz); Hu, J. (Jun); N.C. Weber (Nina); C. Schumacher (Cees); A. Baartscheer (Antonius); E.G. Mik (Egbert); M.W. Hollmann (Markus); F.G. Akar (Fadi); C.J. Zuurbier (Coert J.)

2016-01-01

textabstractIschemia/reperfusion (I/R) of the heart becomes injurious when duration of the ischemic insult exceeds a certain threshold (approximately ≥20 min). Mitochondrial bound hexokinase II (mtHKII) protects against I/R injury, with the amount of mtHKII correlating with injury. Here, we examine

Caffeine Mitigates Lung Inflammation Induced by Ischemia-Reperfusion of Lower Limbs in Rats

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Wei-Chi Chou

2015-01-01

Full Text Available Reperfusion of ischemic limbs can induce inflammation and subsequently cause acute lung injury. Caffeine, a widely used psychostimulant, possesses potent anti-inflammatory capacity. We elucidated whether caffeine can mitigate lung inflammation caused by ischemia-reperfusion (IR of the lower limbs. Adult male Sprague-Dawley rats were randomly allocated to receive IR, IR plus caffeine (IR + Caf group, sham-operation (Sham, or sham plus caffeine (n=12 in each group. To induce IR, lower limbs were bilaterally tied by rubber bands high around each thigh for 3 hours followed by reperfusion for 3 hours. Caffeine (50 mg/kg, intraperitoneal injection was administered immediately after reperfusion. Our histological assay data revealed characteristics of severe lung inflammation in the IR group and mild to moderate characteristic of lung inflammation in the IR + Caf group. Total cells number and protein concentration in bronchoalveolar lavage fluid of the IR group were significantly higher than those of the IR + Caf group (P<0.001 and P=0.008, resp.. Similarly, pulmonary concentrations of inflammatory mediators (tumor necrosis factor-α, interleukin-1β, and macrophage inflammatory protein-2 and pulmonary myeloperoxidase activity of the IR group were significantly higher than those of the IR + Caf group (all P<0.05. These data clearly demonstrate that caffeine could mitigate lung inflammation induced by ischemia-reperfusion of the lower limbs.

Manipulations of core temperatures in ischemia-reperfusion lung injury in rabbits.

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Chang, Hung; Huang, Kun-Lun; Li, Min-Hui; Hsu, Ching-Wang; Tsai, Shih-Hung; Chu, Shi-Jye

2008-01-01

The present study was designed to determine the effect of various core temperatures on acute lung injury induced by ischemia-reperfusion (I/R) in our isolated rabbit lung model. Typical acute lung injury was successfully induced by 30 min of ischemia followed by 90 min of reperfusion observation. The I/R elicited a significant increase in pulmonary arterial pressure, microvascular permeability (measured by using the capillary filtration coefficient, Kfc), Delta Kfc ratio, lung weight gain and the protein concentration of the bronchoalveolar lavage fluid. Mild hypothermia significantly attenuated acute lung injury induced by I/R, all parameters having decreased significantly (p<0.05); conversely, mild hyperthermia did not further exacerbate acute lung injury. These experimental data suggest that mild hypothermia significantly ameliorated acute lung injury induced by ischemia-reperfusion in rabbits.

Guidelines for acute ischemic stroke treatment: part II: stroke treatment

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Sheila Cristina Ouriques Martins

2012-11-01

Full Text Available The second part of these Guidelines covers the topics of antiplatelet, anticoagulant, and statin therapy in acute ischemic stroke, reperfusion therapy, and classification of Stroke Centers. Information on the classes and levels of evidence used in this guideline is provided in Part I. A translated version of the Guidelines is available from the Brazilian Stroke Society website (www.sbdcv.com.br.

Myocardial thallium-201 kinetics during coronary occlusion and reperfusion: influence of method of reflow and timing of thallium-201 administration

International Nuclear Information System (INIS)

Granato, J.E.; Watson, D.D.; Flanagan, T.L.; Gascho, J.A.; Beller, G.A.

1986-01-01

Thallium-201 (201Tl) uptake and redistribution kinetics were examined in an open-chest canine preparation of occlusion and reperfusion. Seven dogs (group I) underwent 3 hr of sustained occlusion and received 1.5 mCi of 201Tl after 40 min of occlusion of the left anterior descending coronary artery (LAD). Group II (n = 18) underwent 60 min of LAD occlusion followed by sudden and total release of the ligature. Group IIa (n = 8) received intravenous 201Tl during occlusion of the LAD, whereas group IIb (n = 10) received intravenous 201Tl at the time of peak reflow. Group III dogs (n = 26) also underwent 60 min of LAD occlusion that was followed by gradual reflow through a residual critical stenosis. Animals in this group also received 201Tl either before (IIIa; n = 16) or after reflow was established (IIIb; n = 10). In group I, the relative 201Tl gradient (nonischemic minus ischemic activity) decreased from 88 +/- 8% (mean +/- SEM) to 59 +/- 6% during 3 hr of coronary occlusion (p = .034). After rapid and total reperfusion (group IIa), this gradient decreased from 71 +/- 6% during occlusion to 26 +/- 5% after reflow (p less than .001). After slow reperfusion through a residual stenosis (group IIIa), the gradient decreased from 81 +/- 5% to 31 +/- 5% (p less than .001) (p = .56 compared with group IIa). In rapidly reperfused dogs receiving intravenous thallium during peak reflow (IIb), initial 201Tl activity in the ischemic zone was 155 +/- 20% of initial normal activity and fell to 93 +/- 13% of normal after 2 hr of reperfusion. In dogs reperfused slowly through a critical stenosis (IIIb), which received 201Tl during reflow, 201Tl activity soon after reflow was 94 +/- 4% of initial normal and decreased to 80 +/- 6% at 2 hr of reperfusion (p = .10). There was histochemical evidence of necrosis in the biopsy region in 80% of the 20 dogs subjected to triphenyl tetrazolium chloride staining

Actualities on molecular pathogenesis and repairing processes of cerebral damage in perinatal hypoxic-ischemic encephalopathy

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Praticò Andrea D

2010-09-01

Full Text Available Abstract Hypoxic-ischemic encephalopathy (HIE is the most important cause of cerebral damage and long-term neurological sequelae in the perinatal period both in term and preterm infant. Hypoxic-ischemic (H-I injuries develop in two phases: the ischemic phase, dominated by necrotic processes, and the reperfusion phase, dominated by apoptotic processes extending beyond ischemic areas. Due to selective ischemic vulnerability, cerebral damage affects gray matter in term newborns and white matter in preterm newborns with the typical neuropathological aspects of laminar cortical necrosis in the former and periventricular leukomalacia in the latter. This article summarises the principal physiopathological and biochemical processes leading to necrosis and/or apoptosis of neuronal and glial cells and reports recent insights into some endogenous and exogenous cellular and molecular mechanisms aimed at repairing H-I cerebral damage.

Distribution of carbon flux within fatty acid utilization during myocardial ischemia and reperfusion

International Nuclear Information System (INIS)

Nellis, S.H.; Liedtke, A.J.; Renstrom, B.

1991-01-01

Twenty-nine intact, working pig hearts were extracorporeally perfused and divided into two study groups (16 Aerobic and 13 Ischemic/Reflow hearts). Step function, equilibrium labeling with [14C]palmitate was used to develop uptake and washout curves of radioactive fatty acid products contained in coronary effluent during either aerobic perfusion or reperfusion after ischemia (60% reduction in left anterior descending coronary flow for 30 minutes). Left anterior descending control flows were slightly overperfused in Aerobic hearts (18% higher than in Ischemic/Reflow hearts); otherwise, circumflex and right coronary flows, left ventricular pressure, and serum fatty acids and blood sugar levels were comparable between groups. As expected in Ischemic/Reflow hearts, recovery of regional systolic shortening and myocardial oxygen consumption in reperfusion was only modestly impaired (-20% and -19%, respectively, not significant and p less than 0.011 compared with preischemic values, not significant from Aerobic hearts). The only significant metabolized product to be released from labeled fatty acid utilization in either group was 14CO2. A smaller fatty acid pool also was measured and accounted for by that contained in the coronary intravascular volume. The authors could determine no significant back diffusion of fatty acids from myocardium in either perfusion condition. Uptake time constants of the early phase of 14CO2 production also were virtually identical in both groups (19.9 ± 3.2 versus 16.7 ± 3.2 minutes in Aerobic and Ischemic/Reflow hearts, respectively) and strongly correlated with hemodynamics as described by heart rate. In washout studies, tissue radioactivity in the aqueous soluble and fatty acid pools declined in both study groups, and counts in complex lipids and cholesterol/cholesteryl esters remained steady, whereas those in triacylglycerols varied

Risk of ischemic stroke after an acute myocardial infarction in patients with diabetes mellitus.

Science.gov (United States)

Jakobsson, Stina; Bergström, Lisa; Björklund, Fredrik; Jernberg, Tomas; Söderström, Lars; Mooe, Thomas

2014-01-01

Incidence, any trend over time, and predictors of ischemic stroke after an acute myocardial infarction (AMI) in diabetic patients are unknown. Data for 173,233 unselected patients with an AMI, including 33,503 patients with diabetes mellitus, were taken from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (RIKS-HIA) during 1998 to 2008. Ischemic stroke events were recorded during 1 year of follow-up. Patients with diabetes mellitus more often had a history of cardiovascular disease, received less reperfusion therapy, and were treated with acetylsalicylic acid, P2Y12 inhibitors, and statins to a lesser extent compared with patients without diabetes mellitus. However, the use of evidence-based therapies increased markedly in both groups during the study period. The incidence of ischemic stroke during the first year after AMI decreased from 7.1% to 4.7% in patients with diabetes mellitus and from 4.2% to 3.7% in patients without diabetes mellitus. Risk reduction was significantly larger in the diabetic subgroup. Reperfusion therapy, acetylsalicylic acid, P2Y12 inhibitors, and statins were independently associated with the reduced stroke risk. Ischemic stroke is a fairly common complication after an AMI in patients with diabetes mellitus, but the risk of stroke has decreased during recent years. The increased use of evidence-based therapies contributes importantly to this risk reduction, but there is still room for improvement.

Chronic exposure to zinc oxide nanoparticles increases ischemic-reperfusion injuries in isolated rat hearts

Energy Technology Data Exchange (ETDEWEB)

Milivojević, Tamara; Drobne, Damjana; Romih, Tea; Mali, Lilijana Bizjak [University of Ljubljana, Department of Biology, Biotechnical Faculty (Slovenia); Marin, Irena; Lunder, Mojca; Drevenšek, Gorazd, E-mail: gorazd.drevensek@mf.uni-lj.si [University of Ljubljana, Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine (Slovenia)

2016-10-15

The use of zinc oxide nanoparticles (ZnO NPs) in numerous products is increasing, although possible negative implications of their long-term consumption are not known yet. Our aim was to evaluate the chronic, 6-week oral exposure to two different concentrations of ZnO NPs on isolated rat hearts exposed to ischemic-reperfusion injury and on small intestine morphology. Wistar rats of both sexes (n = 18) were randomly divided into three groups: (1) 4 mg/kg ZnO NPs, (2) 40 mg/kg ZnO NPs, and (3) control. After 6 weeks of treatment, the hearts were isolated, the left ventricular pressure (LVP), the coronary flow (CF), the duration of arrhythmias and the lactate dehydrogenase release rate (LDH) were measured. A histological investigation of the small intestine was performed. Chronic exposure to ZnO NPs acted cardiotoxic dose-dependently. ZnO NPs in dosage 40 mg/kg maximally decreased LVP (3.3-fold) and CF (2.5-fold) and increased the duration of ventricular tachycardia (all P < 0.01) compared to control, whereas ZnO NPs in dosage 4 mg/kg acted less cardiotoxic. Goblet cells in the small intestine epithelium of rats, treated with 40 mg ZnO NPs/kg, were enlarged, swollen and numerous, the intestinal epithelium width was increased. Unexpectedly, ZnO NPs in both dosages significantly decreased LDH. A 6-week oral exposure to ZnO NPs dose-dependently increased heart injuries and caused irritation of the intestinal mucosa. A prolonged exposure to ZnO NPs might cause functional damage to the heart even with exposures to the recommended daily doses, which should be tested in future studies.

Update on Inflammatory Biomarkers and Treatments in Ischemic Stroke

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Aldo Bonaventura

2016-11-01

Full Text Available After an acute ischemic stroke (AIS, inflammatory processes are able to concomitantly induce both beneficial and detrimental effects. In this narrative review, we updated evidence on the inflammatory pathways and mediators that are investigated as promising therapeutic targets. We searched for papers on PubMed and MEDLINE up to August 2016. The terms searched alone or in combination were: ischemic stroke, inflammation, oxidative stress, ischemia reperfusion, innate immunity, adaptive immunity, autoimmunity. Inflammation in AIS is characterized by a storm of cytokines, chemokines, and Damage-Associated Molecular Patterns (DAMPs released by several cells contributing to exacerbate the tissue injury both in the acute and reparative phases. Interestingly, many biomarkers have been studied, but none of these reflected the complexity of systemic immune response. Reperfusion therapies showed a good efficacy in the recovery after an AIS. New therapies appear promising both in pre-clinical and clinical studies, but still need more detailed studies to be translated in the ordinary clinical practice. In spite of clinical progresses, no beneficial long-term interventions targeting inflammation are currently available. Our knowledge about cells, biomarkers, and inflammatory markers is growing and is hoped to better evaluate the impact of new treatments, such as monoclonal antibodies and cell-based therapies.

Chronic heat improves mechanical and metabolic response of trained rat heart on ischemia and reperfusion.

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Levy, E; Hasin, Y; Navon, G; Horowitz, M

1997-05-01

Cardiac mechanics and metabolic performance were studied in isolated perfused hearts of rats subjected to a combined chronic stress of heat acclimation and swimming training (EXAC) or swimming training alone (EX). Diastolic (DP) and systolic pressures (SP), coronary flow (CF), and oxygen consumption were measured during normoperfusion (80 mmHg), and the appearance of ischemic contracture (IC), DP, and SP were measured during progressive graded ischemia, total ischemia (TI), and reperfusion insults. ATP, phosphocreatine, and intracellular pH were measured during TI and reperfusion with 31P nuclear magnetic resonance spectroscopy. During normoperfusion, SP and cardiac efficiency (derived from rate-pressure product-oxygen consumption relationships) were the highest in the 2-mo EXAC hearts (P pool and there was a delayed decline in intracellular pH. On reperfusion, these hearts also displayed improved ATP and phosphocreatine recovery, the 2-mo EXAC heart demonstrating significantly faster high-energy phosphate salvage, improved diastolic function, and pulse pressure recovery. The data attest to the beneficial effects of heat acclimation on cardiac mechanics of trained rats during normoperfusion and cardiac protection on ischemia and reperfusion. Possibly, energy sparing, lesser acidosis, and shorter duration of IC on ischemia and improved energy salvage on reperfusion contribute synergistically to this potent beneficial effect.

A polymeric micelle magnetic resonance imaging (MRI) contrast agent reveals blood-brain barrier (BBB) permeability for macromolecules in cerebral ischemia-reperfusion injury.

Science.gov (United States)

Shiraishi, Kouichi; Wang, Zuojun; Kokuryo, Daisuke; Aoki, Ichio; Yokoyama, Masayuki

2017-05-10

Blood-brain barrier (BBB) opening is a key phenomenon for understanding ischemia-reperfusion injuries that are directly linked to hemorrhagic transformation. The recombinant human tissue-type plasminogen activator (rtPA) increases the risk of symptomatic intracranial hemorrhages. Recent imaging technologies have advanced our understanding of pathological BBB disorders; however, an ongoing challenge in the pre-"rtPA treatment" stage is the task of developing a rigorous method for hemorrhage-risk assessments. Therefore, we examined a novel method for assessment of rtPA-extravasation through a hyper-permeable BBB. To examine the image diagnosis of rtPA-extravasation for a rat transient occlusion-reperfusion model, in this study we used a polymeric micelle MRI contrast-agent (Gd-micelles). Specifically, we used two MRI contrast agents at 1h after reperfusion. Gd-micelles provided very clear contrast images in 15.5±10.3% of the ischemic hemisphere at 30min after i.v. injection, whereas a classic gadolinium chelate MRI contrast agent provided no satisfactorily clear images. The obtained images indicate both the hyper-permeable BBB area for macromolecules and the distribution area of macromolecules in the ischemic hemisphere. Owing to their large molecular weight, Gd-micelles remained in the ischemic hemisphere through the hyper-permeable BBB. Our results indicate the feasibility of a novel clinical diagnosis for evaluating rtPA-related hemorrhage risks. Copyright © 2017 Elsevier B.V. All rights reserved.

The effects of different anesthesia techniques on free radical production after tourniquet-induced ischemia-reperfusion injury at children's age

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Budić Ivana

2010-01-01

Full Text Available Background/Aim. Reperfusion of previously ischemic tissue leads to injuries mediated by reactive oxygen species. The aim of the study was to investigate the effects of different anesthesia techniques on oxidative stress caused by tourniquetinduced ischemia-reperfusion (IR injury during extremity operations at children's age. Methods. The study included 45 patients American Society of Anesthesiologists (ASA classification I or II, 8 to 17 years of age, undergoing orthopedic procedures that required bloodless limb surgery. The children were randomized into three groups of 15 patients each: general inhalational anesthesia with sevoflurane (group S, total intravenous anesthesia with propofol (group T and regional anesthesia (group R. Venous blood samples were obtained at four time points: before peripheral nerve block and induction of general anesthesia (baseline, 1 min before tourniquet release (BTR, 5 and 20 min after tourniquet release (ATR. Postischemic reperfusion injury was estimated by measurement of concentration of malondialdehyde (MDA in plasma and erythrocytes as well as catalase (CAT activity. Results. Plasma MDA concentration in the group S was significantly higher at 20 min ATR in comparison with the groups T and R (6.78 ± 0.33 μmolL-1-1 vs 4.07 ± 1.53 and 3.22 ± 0.9. μmolL-1-1, respectively. There was a significant difference in MDA concentration in erytrocythes between the groups S and T after 5 min of reperfusion (5.88 ± 0.88 vs 4.27 ± 1.04 nmol/mlEr, p < 0.05. Although not statistically significant, CAT activity was slightly increased as compared to baseline in both groups S and R. In the group T, CAT activity decreased at all time points when compared with baseline, but the observed decrease was only statistically significant at BTR (34.70 ± 9.27 vs 39.69 ± 12.91 UL-1, p < 0.05. Conclusion. Continuous propofol infusion and regional anesthesia techniques attenuate lipid peroxidation and IR injury connected with tourniquet

Dynamic mechanisms of cardiac oxygenation during brief ischemia and reperfusion

International Nuclear Information System (INIS)

Parsons, W.J.; Rembert, J.C.; Bauman, R.P.; Greenfield, J.C. Jr.; Piantadosi, C.A.

1990-01-01

Myocardial oxygenation may be altered markedly by changes in tissue blood flow. During brief ischemia and reperfusion produced by transient occlusion of the left anterior descending artery in 10 open-chest dogs, changes in the oxygenation of tissue hemoglobin (Hb) plus myoglobin (Mb) and the oxidation-reduction (redox) state of mitochondrial cytochrome aa3 were monitored continuously using near-infrared spectroscopy. The nondestructive optical technique indicated that coronary occlusion produced an abrupt drop in tissue oxygen stores (tHb02 + Mb02), tissue blood volume (tBV), and the oxidation level of cytochrome aa3. Changes in the cytochrome oxidation state were related inversely to transmural collateral blood flow within the ischemic region (r = 0.77) measured with radiolabeled microspheres. Furthermore, there was a direct relationship (r = 0.91) between collateral blood flow and the tissue level of desaturated Hb and Mb (tHb + Mb). Reperfusion after 2 min of ischemia led to a synchronous overshoot of baseline in coronary flow and tBV followed by supranormal increases in tHb + Mb02 and the oxidation level of cytochrome aa3. The tHb + Mb level increased transiently during reperfusion. This response correlated inversely with collateral flow during ischemia (r = 0.91). Accordingly, the time required to reach peak tHb + Mb levels was shortest in dogs with high collateral flows (r = 0.75). Thus collateral blood flow partially sustains myocardial oxygenation during coronary artery occlusion and influences tissue reoxygenation early during reperfusion

The remote ischemic preconditioning algorithm: effect of number of cycles, cycle duration and effector organ mass on efficacy of protection.

Science.gov (United States)

Johnsen, Jacob; Pryds, Kasper; Salman, Rasha; Løfgren, Bo; Kristiansen, Steen Buus; Bøtker, Hans Erik

2016-03-01

Remote ischemic preconditioning (rIPC), induced by cycles of transient limb ischemia and reperfusion (IR), is cardioprotective. The optimal rIPC-algorithm is not established. We investigated the effect of cycle numbers and ischemia duration within each rIPC-cycle and the influence of effector organ mass on the efficacy of cardioprotection. Furthermore, the duration of the early phase of protection by rIPC was investigated. Using a tourniquet tightened at the inguinal level, we subjected C57Bl/6NTac mice to intermittent hind-limb ischemia and reperfusion. The rIPC-protocols consisted of (I) two, four, six or eight cycles, (II) 2, 5 or 10 min of ischemia in each cycle, (III) single or two hind-limb occlusions and (IV) 0.5, 1.5, 2.0 or 2.5 h intervals from rIPC to index cardiac ischemia. All rIPC algorithms were followed by 5 min of reperfusion. The hearts were subsequently exposed to 25 min of global ischemia and 60 min of reperfusion in an ex vivo Langendorff model. Cardioprotection was evaluated by infarct size and post-ischemic hemodynamic recovery. Four to six rIPC cycles yielded significant cardioprotection with no further protection by eight cycles. Ischemic cycles lasting 2 min offered the same protection as cycles of 5 min ischemia, whereas prolonged cycles lasting 10 min abrogated protection. One and two hind-limb preconditioning were equally protective. In our mouse model, the duration of protection by rIPC was 1.5 h. These findings indicate that the number and duration of cycles rather than the tissue mass exposed to rIPC determines the efficacy of rIPC.

Phosphatase and tensin homolog-β-catenin signaling modulates regulatory T cells and inflammatory responses in mouse liver ischemia/reperfusion injury.

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Zhu, Qiang; Li, Changyong; Wang, Kunpeng; Yue, Shi; Jiang, Longfeng; Ke, Michael; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Zhang, Feng; Lu, Ling; Ke, Bibo

2017-06-01

The phosphatase and tensin homolog (PTEN) deleted on chromosome 10 plays an important role in regulating T cell activation during inflammatory response. Activation of β-catenin is crucial for maintaining immune homeostasis. This study investigates the functional roles and molecular mechanisms by which PTEN-β-catenin signaling promotes regulatory T cell (Treg) induction in a mouse model of liver ischemia/reperfusion injury (IRI). We found that mice with myeloid-specific phosphatase and tensin homolog knockout (PTEN M-KO ) exhibited reduced liver damage as evidenced by decreased levels of serum alanine aminotransferase, intrahepatic macrophage trafficking, and proinflammatory mediators compared with the PTEN-proficient (floxed phosphatase and tensin homolog [PTEN FL/FL ]) controls. Disruption of myeloid PTEN-activated b-catenin promoted peroxisome proliferator-activated receptor gamma (PPARγ)-mediated Jagged-1/Notch signaling and induced forkhead box P3 (FOXP3)1 Tregs while inhibiting T helper 17 cells. However, blocking of Notch signaling by inhibiting γ-secretase reversed myeloid PTEN deficiency-mediated protection in ischemia/reperfusion-triggered liver inflammation with reduced FOXP3 + and increased retinoid A receptor-related orphan receptor gamma t-mediated interleukin 17A expression in ischemic livers. Moreover, knockdown of β-catenin or PPARγ in PTEN-deficient macrophages inhibited Jagged-1/Notch activation and reduced FOXP3 + Treg induction, leading to increased proinflammatory mediators in macrophage/T cell cocultures. In conclusion, our findings demonstrate that PTEN-β-catenin signaling is a novel regulator involved in modulating Treg development and provides a potential therapeutic target in liver IRI. Liver Transplantation 23 813-825 2017 AASLD. © 2017 by the American Association for the Study of Liver Diseases.

Myocardial ischemic preconditioning upregulated protein 1(Mipu1):zinc finger protein 667 - a multifunctional KRAB/C{sub 2}H{sub 2} zinc finger protein

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Han, D.; Zhang, C. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China); Fan, W.J. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China); The Second Affiliated Hospital, University of South China, Hengyang City, Hunan Province (China); Pan, W.J.; Feng, D.M.; Qu, S.L.; Jiang, Z.S. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China)

2014-10-31

Myocardial ischemic preconditioning upregulated protein 1 (Mipu1) is a newly discovered upregulated gene produced in rats during the myocardial ischemic preconditioning process. Mipu1 cDNA contains a 1824-base pair open reading frame and encodes a 608 amino acid protein with an N-terminal Krüppel-associated box (KRAB) domain and classical zinc finger C{sub 2}H{sub 2} motifs in the C-terminus. Mipu1 protein is located in the cell nucleus. Recent studies found that Mipu1 has a protective effect on the ischemia-reperfusion injury of heart, brain, and other organs. As a nuclear factor, Mipu1 may perform its protective function through directly transcribing and repressing the expression of proapoptotic genes to repress cell apoptosis. In addition, Mipu1 also plays an important role in regulating the gene expression of downstream inflammatory mediators by inhibiting the activation of activator protein-1 and serum response element.

Drug Delivery to the Ischemic Brain

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Thompson, Brandon J.; Ronaldson, Patrick T.

2014-01-01

Cerebral ischemia occurs when blood flow to the brain is insufficient to meet metabolic demand. This can result from cerebral artery occlusion that interrupts blood flow, limits CNS supply of oxygen and glucose, and causes an infarction/ischemic stroke. Ischemia initiates a cascade of molecular events inneurons and cerebrovascular endothelial cells including energy depletion, dissipation of ion gradients, calcium overload, excitotoxicity, oxidative stress, and accumulation of ions and fluid. Blood-brain barrier (BBB) disruption is associated with cerebral ischemia and leads to vasogenic edema, a primary cause of stroke-associated mortality. To date, only a single drug has received US Food and Drug Administration (FDA) approval for acute ischemic stroke treatment, recombinant tissue plasminogen activator (rt-PA). While rt-PA therapy restores perfusion to ischemic brain, considerable tissue damage occurs when cerebral blood flow is re-established. Therefore, there is a critical need for novel therapeutic approaches that can “rescue” salvageable brain tissue and/or protect BBB integrity during ischemic stroke. One class of drugs that may enable neural cell rescue following cerebral ischemia/reperfusion injury is the HMG-CoA reductase inhibitors (i.e., statins). Understanding potential CNS drug delivery pathways for statins is critical to their utility in ischemic stroke. Here, we review molecular pathways associated with cerebral ischemia and novel approaches for delivering drugs to treat ischemic disease. Specifically, we discuss utility of endogenous BBB drug uptake transporters such as organic anion transporting polypeptides (OATPs/Oatps) and nanotechnology-based carriers for optimization of CNS drug delivery. Overall, this chapter highlights state-of-the-art technologies that may improve pharmacotherapy of cerebral ischemia. PMID:25307217

Anchusa italica extract: phytochemical and neuroprotective evaluation on global cerebral ischemia and reperfusion

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Akram Torki

2018-06-01

Full Text Available Abstract Stroke is the third leading cause of mortality and disability in industrial countries. Treatment with herbs with antioxidant properties has been reported to be an alternative to the conventional treatments. This study was conducted to investigate the effect of Anchusa italica extract on hippocampal injury induced by transient global cerebral ischemia and reperfusion in the rat. To do so, 50 rats were randomly assigned to five groups; control, sham, ischemia, and 50 or 100 mg/kg of Anchusa italica treated animals. Ischemia was induced by occlusion of carotid artery for 30 minutes. Afterward, behavioral tests and biochemical analyses were conducted. Induction of ischemia/reperfusion caused a decline in learning and passive avoidance memory in rats. Moreover, Anchusa italica caused an increase in learning and improved the passive avoidance memory. Induction of ischemia/reperfusion caused a decrease in the antioxidant capacity of the brain and serum as well as an increase in the malondialdehyde of the brain and serum. Anchusa italica led to an increase in the antioxidant capacity of the brain and serum and decrease in the malondialdehyde of the brain and serum. Overall, because of its protective effects on spatial memory, passive avoidance learning, antioxidant capacity, and lipid peroxidation during ischemia/reperfusion, Anchusa italica might be beneficial in ischemic patients.

Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging

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Tanabe, Kazuaki; Ishibashi, Yutaka; Shimada, Toshio (Shimane Medical Univ., Izumo (Japan)) (and others)

1993-05-01

In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR=0.68[+-]0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR: 1.76[+-]0.34). We conclude that Gd-DTPA-enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration. (author).

Evaluating coronary reperfusion during acute myocardial infarction in a canine model by gadolinium-DTPA-enhanced magnetic resonance imaging

International Nuclear Information System (INIS)

Tanabe, Kazuaki; Ishibashi, Yutaka; Shimada, Toshio

1993-01-01

In previous studies, magnetic resonance imaging (MRI) using contrast agents was found to be useful in distinguishing reperfused infarcts from nonreperfused infarcts. However, there have been only a few detailed studies using consecutive MR images for the assessment of myocardial reperfusion during an acute infarction and also no studies have been performed using a percutaneous transluminal coronary occlusion model (closed chest model). We induced acute myocardial infarction in dogs by occluding and then reperfusing the coronary artery with a balloon catheter. ECG-gated MR images were taken using the spin-echo technique before and after Gd-DTPA injection during both coronary artery occlusion and after reperfusion. We defined the intensity ratio (IR) as the signal intensity at the ischemic area divided by that at the nonischemic area on MR images and compared each image by the IR. Without Gd-DTPA, there was no difference between infarcted and normally perfused myocardium. Infarcted myocardium had a low signal intensity (IR=0.68±0.14) soon after Gd-DTPA injection. This difference diminished with time. After reperfusion the infarcted myocardium had a high signal intensity (IR: 1.76±0.34). We conclude that Gd-DTPA-enhanced MRI can distinguish reperfused from nonreperfused infarcts soon after Gd-DTPA administration. (author)

Maintenance of cAMP in non-heart-beating donor lungs reduces ischemia-reperfusion injury.

Science.gov (United States)

Hoffmann, S C; Bleiweis, M S; Jones, D R; Paik, H C; Ciriaco, P; Egan, T M

2001-06-01

Studies suggest that pulmonary vascular ischemia-reperfusion injury (IRI) can be attenuated by increasing intracellular cAMP concentrations. The purpose of this study was to determine the effect of IRI on capillary permeability, assessed by capillary filtration coeficient (Kfc), in lungs retrieved from non-heart-beating donors (NHBDs) and reperfused with the addition of the beta(2)-adrenergic receptor agonist isoproterenol (iso), and rolipram (roli), a phosphodiesterase (type IV) inhibitor. Using an in situ isolated perfused lung model, lungs were retrieved from NHBD rats at varying intervals after death and either ventilated with O(2) or not ventilated. The lungs were reperfused with Earle's solution with or without a combination of iso (10 microM) and roli (2 microM). Kfc, lung viability, and pulmonary hemodynamics were measured. Lung tissue levels of adenine nucleotides and cAMP were measured by HPLC. Combined iso and roli (iso/roli) reperfusion decreased Kfc significantly (p Kfc in non-iso/roli-reperfused (r = 0.89) and iso/roli-reperfused (r = 0.97) lungs. cAMP levels correlated with Kfc (r = 0.93) in iso/roli-reperfused lungs. Pharmacologic augmentation of tissue TAN and cAMP levels might ameliorate the increased capillary permeability observed in lungs retrieved from NHBDs.

PPARα inhibition modulates multiple reprogrammed metabolic pathways in kidney cancer and attenuates tumor growth.

Science.gov (United States)

Abu Aboud, Omran; Donohoe, Dallas; Bultman, Scott; Fitch, Mark; Riiff, Tim; Hellerstein, Marc; Weiss, Robert H

2015-06-01

Kidney cancer [renal cell carcinoma (RCC)] is the sixth-most-common cancer in the United States, and its incidence is increasing. The current progression-free survival for patients with advanced RCC rarely extends beyond 1-2 yr due to the development of therapeutic resistance. We previously identified peroxisome proliferator-activating receptor-α (PPARα) as a potential therapeutic target for this disease and showed that a specific PPARα antagonist, GW6471, induced apoptosis and cell cycle arrest at G0/G1 in RCC cell lines associated with attenuation of cell cycle regulatory proteins. We now extend that work and show that PPARα inhibition attenuates components of RCC metabolic reprogramming, capitalizing on the Warburg effect. The specific PPARα inhibitor GW6471, as well as a siRNA specific to PPARα, attenuates the enhanced fatty acid oxidation and oxidative phosphorylation associated with glycolysis inhibition, and PPARα antagonism also blocks the enhanced glycolysis that has been observed in RCC cells; this effect did not occur in normal human kidney epithelial cells. Such cell type-specific inhibition of glycolysis corresponds with changes in protein levels of the oncogene c-Myc and has promising clinical implications. Furthermore, we show that treatment with GW6471 results in RCC tumor growth attenuation in a xenograft mouse model, with minimal obvious toxicity, a finding associated with the expected on-target effects on c-Myc. These studies demonstrate that several pivotal cancer-relevant metabolic pathways are inhibited by PPARα antagonism. Our data support the concept that targeting PPARα, with or without concurrent inhibition of glycolysis, is a potential novel and effective therapeutic approach for RCC that targets metabolic reprogramming in this tumor.

Coenzyme Q10 Protects Hippocampal Neurons Against Ischemia/Reperfusion Injury via Modulation of BAX/Bcl-2 Expression

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M Zamani

2012-12-01

Full Text Available Introduction : Preliminary studies confirmed reduction in cell death following treatment with antioxidants. According to this finding we study the relationship between consumption of CoQ10 and expression of bax and bcl2 in hippocampus following ischemia/reperfusion as proteins involved in cell programmed death or apoptosis.Material & methods : We studied the protective role of CoQ10 against Ischemia-Reperfusion. Experimental design includes four groups: intact, ischemic control, sham control and treatment groups with CoQ10. The mice treated with CoQ10 as Pre - Treatment for a week. Then, ischemia induced by common carotid artery ligation and following the reduction in inflammation (a week the mice post-treated with CoQ10.Nissl staining applied to counting necrotic cells of hippocampus and the western blotting performed to measurement the bax and bcl2 expression.Results :. Cell death was significantly lower when mice treated with CoQ10. Bax expression was significantly high in ischemic group but in treatment group was less and reversely the bcl2 expression in ischemic group was lower than treatment and vehicle groups.Conclusion : Ischemia for 15 minutes induced cell death in hippocampus with more potent effect on CA1. CoQ10 intake significantly reduced cell death and prevented the expression of bax while inducing an increase in expression of bcl2.

DIDS prevents ischemic membrane degradation in cultured hippocampal neurons by inhibiting matrix metalloproteinase release.

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Matthew E Pamenter

Full Text Available During stroke, cells in the infarct core exhibit rapid failure of their permeability barriers, which releases ions and inflammatory molecules that are deleterious to nearby tissue (the penumbra. Plasma membrane degradation is key to penumbral spread and is mediated by matrix metalloproteinases (MMPs, which are released via vesicular exocytosis into the extracellular fluid in response to stress. DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid preserves membrane integrity in neurons challenged with an in vitro ischemic penumbral mimic (ischemic solution: IS and we asked whether this action was mediated via inhibition of MMP activity. In cultured murine hippocampal neurons challenged with IS, intracellular proMMP-2 and -9 expression increased 4-10 fold and extracellular latent and active MMP isoform expression increased 2-22 fold. MMP-mediated extracellular gelatinolytic activity increased ∼20-50 fold, causing detachment of 32.1±4.5% of cells from the matrix and extensive plasma membrane degradation (>60% of cells took up vital dyes and >60% of plasma membranes were fragmented or blebbed. DIDS abolished cellular detachment and membrane degradation in neurons and the pathology-induced extracellular expression of latent and active MMPs. DIDS similarly inhibited extracellular MMP expression and cellular detachment induced by the pro-apoptotic agent staurosporine or the general proteinase agonist 4-aminophenylmercuric acetate (APMA. Conversely, DIDS-treatment did not impair stress-induced intracellular proMMP production, nor the intracellular cleavage of proMMP-2 to the active form, suggesting DIDS interferes with the vesicular extrusion of MMPs rather than directly inhibiting proteinase expression or activation. In support of this hypothesis, an antagonist of the V-type vesicular ATPase also inhibited extracellular MMP expression to a similar degree as DIDS. In addition, in a proteinase-independent model of vesicular exocytosis, DIDS

Autophagy and Liver Ischemia-Reperfusion Injury

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Raffaele Cursio

2015-01-01

Full Text Available Liver ischemia-reperfusion (I-R injury occurs during liver resection, liver transplantation, and hemorrhagic shock. The main mode of liver cell death after warm and/or cold liver I-R is necrosis, but other modes of cell death, as apoptosis and autophagy, are also involved. Autophagy is an intracellular self-digesting pathway responsible for removal of long-lived proteins, damaged organelles, and malformed proteins during biosynthesis by lysosomes. Autophagy is found in normal and diseased liver. Although depending on the type of ischemia, warm and/or cold, the dynamic process of liver I-R results mainly in adenosine triphosphate depletion and in production of reactive oxygen species (ROS, leads to both, a local ischemic insult and an acute inflammatory-mediated reperfusion injury, and results finally in cell death. This process can induce liver dysfunction and can increase patient morbidity and mortality after liver surgery and hemorrhagic shock. Whether autophagy protects from or promotes liver injury following warm and/or cold I-R remains to be elucidated. The present review aims to summarize the current knowledge in liver I-R injury focusing on both the beneficial and the detrimental effects of liver autophagy following warm and/or cold liver I-R.

Change in iron metabolism in rats after renal ischemia/reperfusion injury.

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Guang-Liang Xie

Full Text Available Previous studies have indicated that hepcidin, which can regulate iron efflux by binding to ferroportin-1 (FPN1 and inducing its internalization and degradation, acts as the critical factor in the regulation of iron metabolism. However, it is unknown whether hepcidin is involved in acute renal ischemia/reperfusion injury (IRI. In this study, an IRI rat model was established via right renal excision and blood interruption for 45 min in the left kidney, and iron metabolism indexes were examined to investigate the change in iron metabolism and to analyze the role of hepcidin during IRI. From 1 to 24 h after renal reperfusion, serum creatinine and blood urea nitrogen were found to be time-dependently increased with different degrees of kidney injury. Regular variations in iron metabolism indexes in the blood and kidneys were observed in renal IRI. Renal iron content, serum iron and serum ferritin increased early after reperfusion and then declined. Hepcidin expression in the liver significantly increased early after reperfusion, and its serum concentration increased beginning at 8 h after reperfusion. The splenic iron content decreased significantly in the early stage after reperfusion and then increased time-dependently with increasing reperfusion time, and the hepatic iron content showed a decrease in the early stage after reperfusion. The early decrease of the splenic iron content and hepatic iron content might indicate their contribution to the increase in serum iron in renal IRI. In addition, the duodenal iron content showed time-dependently decreased since 12 h after reperfusion in the IRI groups compared to the control group. Along with the spleen, the duodenum might contribute to the decrease in serum iron in the later stage after reperfusion. The changes in iron metabolism indexes observed in our study demonstrate an iron metabolism disorder in renal IRI, and hepcidin might be involved in maintaining iron homeostasis in renal IRI. These

Prevention of reperfusion lung injury by lidocaine in isolated rat lung ventilated with higher oxygen levels.

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Das K

2003-01-01

Full Text Available BACKGROUND: Lidocaine, an antiarrhythmic drug has been shown to be effective against post-ischaemic reperfusion injury in heart. However, its effect on pulmonary reperfusion injury has not been investigated. AIMS: We investigated the effects of lidocaine on a postischaemic reperfused rat lung model. MATERIALS AND METHODS: Lungs were isolated and perfused at constant flow with Krebs-Henseilet buffer containing 4% bovine serum albumin, and ventilated with 95% oxygen mixed with 5% CO2. Lungs were subjected to ischaemia by stopping perfusion for 60 minutes followed by reperfusion for 10 minutes. Ischaemia was induced in normothermic conditions. RESULTS: Postischaemic reperfusion caused significant (p < 0.0001 higher wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure compared to control lungs. Lidocaine, at a dose of 5mg/Kg b.w. was found to significantly (p < 0.0001 attenuate the increase in the wet-to-dry lung weight ratio, pulmonary arterial pressure and peak airway pressure observed in post-ischaemic lungs. CONCLUSION: Lidocaine is effective in preventing post-ischaemic reperfusion injury in isolated, perfused rat lung.

Static inflation attenuates ischemia/reperfusion injury in an isolated rat lung in situ.

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Kao, Shang Jyh; Wang, David; Yeh, Diana Yu-Wung; Hsu, Kang; Hsu, Yung Hsiang; Chen, Hsing I

2004-08-01

Ischemia (I)/reperfusion (R) lung injury is an important clinical issue in lung transplantation. In the present study, we observed the effects of lung static inflation, different perfusates, and ventilatory gas with nitrogen or oxygen on the I/R-induced pulmonary damage. A total of 96 male Sprague-Dawley rats were used. The lung was isolated in situ. In an isolated lung, the capillary filtration coefficient (Kfc), lung weight gain (LWG), lung weight (LW)/body weight (BW) ratio, and protein concentration in BAL fluid (PCBAL) were measured or calculated to evaluate the degree of lung injury. Histologic examinations with hematoxylin-eosin staining were performed. I/R caused lung injury, as reflected by increases in Kfc, LWG, LW/BW, and PCBAL. The histopathologic picture revealed the presence of hyaline membrane formation and the infiltration of inflammatory cells. These values were significantly attenuated by static lung inflation. The I/R lung damage appeared to be less in the lung perfused with whole blood than in the lung perfused with an isotonic solution. Therapy with ventilatory air (ie, nitrogen or oxygen) did not alter the I/R lung damage. The data suggest that lung inflation is protective to I/R injury, irrespective of the type of ventilatory air used for treatment. The preservation of the lung for transplantation is better kept at a static inflation state and perfused with whole blood instead of an isotonic physiologic solution.