P1742Experimental ischemic stroke in rats induce myocardial contractile dysfunction in vivo and ex vivo and increase cardiac vulnerability to ischemia-reperfusion injury ex vivo

Background: Ischemia-reperfusion injury (IRI) is one of the major risk factors implicated in morbidity and mortality associated with cardiovascular disease. During cardiac ischemia, the build-up of acidic metabolites results in decreased intracellular and extracellular pH that can reach as low as 6.0-6.5. The resulting tissue acidosis exacerbates ischemic injury and significantly impacts cardiac function. Methods: We used genetic and pharmacological methods to investigate the role of acid sensing ion channel 1a (ASIC1a) in cardiac IRI at the cellular and whole organ level. Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) as well as ex vivo and in vivo models of IRI were used to test the efficacy of ASIC1a inhibitors as pre- and post-conditioning therapeutic agents. Results: Analysis of human complex trait genetics indicate that variants in the ASIC1 genetic locus are significantly associated with cardiac and cerebrovascular ischemic injuries. Using hiPSC-CMs in vitro and murine ex vivo heart models, we demonstrate that genetic ablation of ASIC1a improves cardiomyocyte viability after acute IRI. Therapeutic blockade of ASIC1a using specific and potent pharmacological inhibitors recapitulates this cardioprotective effect. We used an in vivo model of myocardial infarction (MI) and two models of ex vivo donor heart procurement and storage as clinical models to show that ASIC1a inhibition improves post-IRI cardiac viability. Use of ASIC1a inhibitors as pre- or post-conditioning agents provided equivalent cardioprotection to benchmark drugs, including the sodium-hydrogen exchange inhibitor zoniporide. At the cellular and whole organ level, we show that acute exposure to ASIC1a inhibitors has no impact on cardiac ion channels regulating baseline electromechanical coupling and physiological performance. Conclusions: Collectively, our data provide compelling evidence for a novel pharmacological strategy involving ASIC1a blockade as a cardioprotective therapy to improve the viability of hearts subjected to IRI.

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The role of microRNA in modulating myocardial ischemia-reperfusion injury

Physiological Genomics ◽

10.1152/physiolgenomics.00130.2010 ◽

2011 ◽

Vol 43 (10) ◽

pp. 534-542 ◽

Cited By ~ 135

Author(s):

Yumei Ye ◽

Jose R. Perez-Polo ◽

Jinqiao Qian ◽

Yochai Birnbaum

Keyword(s):

Heart Disease ◽

Reperfusion Injury ◽

Fas Ligand ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Therapeutic Targets ◽

In Vitro Models

MicroRNAs (miRNAs) are small (∼22 nt) noncoding single-stranded RNA molecules that downregulate gene expression. Studies have shown that miRNAs control diverse aspects of heart disease, including hypertrophy, remodeling, heart failure, and arrhythmia. Recently, several studies have suggested that miRNAs contribute to ischemia-reperfusion injury by altering key signaling elements, thus making them potential therapeutic targets. By altering the expression of various key elements in cell survival and apoptosis [such as phosphoinositide 3-kinase (PI3K), phosphatase and tensin homolog deleted on chromosome 10 (PTEN), Bcl-2, Mcl-1, heat shock protein (HSP)60, HSP70, HSP20, programmed cell death 4 (Pdcd4), LRRFIP1, Fas ligand (FasL), Sirt-1, etc.], miRNAs alter the response to ischemia-reperfusion injury. Studies using various in vivo, ex vivo, and in vitro models have suggested the possible involvement of miR-1, miR-21, miR-29, miR-92a, miR-133, miR-199a, and miR-320 in ischemia-reperfusion injury and/or remodeling after myocardial infarction. Thus miRNAs could be potential therapeutic targets for the treatment of heart disease. Inhibiting miRNAs by antisense strategies or pharmacological approaches is likely to emerge as an alternative and safe method for conferring short- and intermediate-term protection against ischemia-reperfusion injury.

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Antioxidant network expression abrogates oxidative posttranslational modifications in mice

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.01285.2010 ◽

2011 ◽

Vol 300 (5) ◽

pp. H1960-H1970 ◽

Cited By ~ 14

Author(s):

R. Mital ◽

W. Zhang ◽

M. Cai ◽

Z. M. Huttinger ◽

L. A. Goodman ◽

...

Keyword(s):

Lipid Peroxidation ◽

Myocardial Ischemia ◽

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Fatty Acid Binding ◽

Myocardial Ischemia Reperfusion Injury ◽

Myocardial Ischemia Reperfusion

Antioxidant enzymatic pathways form a critical network that detoxifies ROS in response to myocardial stress or injury. Genetic alteration of the expression levels of individual enzymes has yielded mixed results with regard to attenuating in vivo myocardial ischemia-reperfusion injury, an extreme oxidative stress. We hypothesized that overexpression of an antioxidant network (AON) composed of SOD1, SOD3, and glutathione peroxidase (GSHPx)-1 would reduce myocardial ischemia-reperfusion injury by limiting ROS-mediated lipid peroxidation and oxidative posttranslational modification (OPTM) of proteins. Both ex vivo and in vivo myocardial ischemia models were used to evaluate the effect of AON expression. After ischemia-reperfusion injury, infarct size was significantly reduced both ex vivo and in vivo, ROS formation, measured by dihydroethidium staining, was markedly decreased, ROS-mediated lipid peroxidation, measured by malondialdehyde production, was significantly limited, and OPTM of total myocardial proteins, including fatty acid-binding protein and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a, was markedly reduced in AON mice, which overexpress SOD1, SOD3, and GSHPx-1, compared with wild-type mice. These data demonstrate that concomitant SOD1, SOD3, and GSHPX-1 expression confers marked protection against myocardial ischemia-reperfusion injury, reducing ROS, ROS-mediated lipid peroxidation, and OPTM of critical cardiac proteins, including cardiac fatty acid-binding protein and SERCA2a.

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Astaxanthin Ameliorates Ischemic-Hypoxic-Induced Neurotrophin Receptor p75 Upregulation in the Endothelial Cells of Neonatal Mouse Brains

International Journal of Molecular Sciences ◽

10.3390/ijms20246168 ◽

2019 ◽

Vol 20 (24) ◽

pp. 6168

Author(s):

Min-Hsun Kuo ◽

Hung-Fu Lee ◽

Yi-Fang Tu ◽

Li-Hsuan Lin ◽

Ya-Yun Cheng ◽

...

Keyword(s):

Endothelial Cells ◽

Ischemic Stroke ◽

Reperfusion Injury ◽

Cell Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Neurotrophin Receptor ◽

P75 Neurotrophin Receptor

Ischemic stroke is a leading cause of human death in present times. Two phases of pathological impact occur during an ischemic stroke, namely, ischemia and reperfusion. Both periods include individual characteristic effects on cell injury and apoptosis. Moreover, these conditions can cause severe cell defects and harm the blood-brain barrier (BBB). Also, the BBB components are the major targets in ischemia-reperfusion injury. The BBB owes its enhanced protective roles to capillary endothelial cells, which maintain BBB permeability. One of the nerve growth factor (NGF) receptors initiating cell signaling, once activated, is the p75 neurotrophin receptor (p75NTR). This receptor is involved in both the survival and apoptosis of neurons. Although many studies have attempted to explain the role of p75NTR in neurons, the mechanisms in endothelial cells remain unclear. Endothelial cells are the first cells to encounter p75NTR stimuli. In this study, we found the upregulated p75NTR expression and reductive expression of tight junction proteins after in vivo and in vitro ischemia-reperfusion injury. Moreover, astaxanthin (AXT), an antioxidant drug, was utilized and was found to reduce p75NTR expression and the number of apoptotic cells. This study verified that p75NTR plays a prominent role in endothelial cell death and provides a novel downstream target for AXT.

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Protective role of synthetic HDL from ischemia-reperfusion injury: Ex vivo and in vivo models

Nutrition Metabolism and Cardiovascular Diseases ◽

10.1016/s0939-4753(03)80064-9 ◽

2003 ◽

Vol 13 (5) ◽

pp. 313

Keyword(s):

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Protective Role ◽

In Vivo Models

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Sulforaphane Elicits Protective Effects in Intestinal Ischemia Reperfusion Injury

International Journal of Molecular Sciences ◽

10.3390/ijms21155189 ◽

2020 ◽

Vol 21 (15) ◽

pp. 5189

Author(s):

Zhiquan Chen ◽

Annika Mohr ◽

Barbara Heitplatz ◽

Uwe Hansen ◽

Andreas Pascher ◽

...

Keyword(s):

Reperfusion Injury ◽

Intestinal Ischemia ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Ischemia Reperfusion ◽

Protective Effects ◽

Cellular Interactions ◽

Morphological Alterations ◽

Intestinal Ischemia Reperfusion

Intestinal ischemia reperfusion injury (IRI) is an inherent, unavoidable event of intestinal transplantation, contributing to allograft failure and rejection. The inflammatory state elicited by intestinal IRI is characterized by heightened leukocyte recruitment to the gut, which is amplified by a cross-talk with platelets at the endothelial border. Sulforaphane (SFN), a naturally occurring isothiocyanate, exhibits anti-inflammatory characteristics and has been shown to reduce platelet activation and block leukocyte adhesion. Thus, the aim of this study was to investigate protective effects and mechanism of action of SFN in a murine model of intestinal IRI. Intestinal IRI was induced by superior mesenteric artery occlusion for 30 min, followed by reperfusion for 2 h, 8 h or 24 h. To investigate cellular interactions, leukocytes were in vivo stained with rhodamine and platelets were harvested from donor animals and ex vivo stained. Mice (C57BL/6J) were divided into three groups: (1) control, (2) SFN treatment 24 h prior to reperfusion and (3) SFN treatment 24 h prior to platelet donation. Leukocyte and platelet recruitment was analyzed via intravital microscopy. Tissue was analyzed for morphological alterations in intestinal mucosa, barrier permeability, and leukocyte infiltration. Leukocyte rolling and adhesion was significantly reduced 2 h and 8 h after reperfusion. Mice receiving SFN treated platelets exhibited significantly decreased leukocyte and platelet recruitment. SFN showed protection for intestinal tissue with less damage observed in histopathological and ultrastructural evaluation. In summary, the data presented provide evidence for SFN as a potential therapeutic strategy against intestinal IRI.

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Platelet necrosis mediates ischemic stroke outcome in mice

Blood ◽

10.1182/blood.2019002124 ◽

2020 ◽

Vol 135 (6) ◽

pp. 429-440 ◽

Cited By ~ 7

Author(s):

Frederik Denorme ◽

Bhanu Kanth Manne ◽

Irina Portier ◽

Alicia S. Eustes ◽

Yasuhiro Kosaka ◽

...

Keyword(s):

Ischemic Stroke ◽

Ischemia Reperfusion Injury ◽

Ex Vivo ◽

Infarct Volume ◽

Ischemia Reperfusion ◽

Similar Degree ◽

Cyclophilin D ◽

Wild Type ◽

Neutrophil Depletion

Abstract Dysregulated platelet functions contribute to the development and progression of ischemic stroke. Utilizing mice with a platelet-specific deletion of cyclophilin D (CypD), a mediator of necrosis, we found that platelet necrosis regulates tissue damage and outcomes during ischemic stroke in vivo. Mice with loss of CypD in platelets (CypDplt−/−mice) exhibited significantly enhanced cerebral blood flow, improved neurological and motor functions, and reduced ischemic stroke infarct volume after cerebral ischemia-reperfusion injury. These effects were attributable, at least in part, to platelet-neutrophil interactions. Twenty-four hours after stroke, significantly more circulating platelet-neutrophil aggregates (PNAs) were found in CypDplt+/+ mice. Underscoring the role of platelet necrosis in PNA formation, we observed a significant number of phosphatidylserine (PS)+ platelets in PNAs in CypDplt+/+ mice. In contrast, significantly fewer platelets in PNAs were PS+ in CypDplt−/− counterparts. Accordingly, mice with CypD-deficient platelets had fewer neutrophils and PNAs recruited to their brain following stroke relative to wild-type counterparts. Neutrophil depletion in wild-type mice conferred protection from ischemic stroke to a similar degree as observed in mice with CypD-deficient platelets. Neutrophil depletion in CypDplt−/− mice did not further reduce infarct size. Transmission electron microscopy of ex vivo–formed PNAs revealed a propensity of necrotic platelets to interact with neutrophils. These results suggest that necrotic platelets interact with neutrophils to exacerbate brain injury during ischemic stroke. Because inhibiting platelet necrosis does not compromise hemostasis, targeting platelet CypD may be a potential therapeutic strategy to limit brain damage following ischemic stroke.

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N6-methyladenosine demethylase FTO impairs hepatic ischemia–reperfusion injury via inhibiting Drp1-mediated mitochondrial fragmentation

Cell Death and Disease ◽

10.1038/s41419-021-03622-x ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Ying Dong Du ◽

Wen Yuan Guo ◽

Cong Hui Han ◽

Ying Wang ◽

Xiao Song Chen ◽

...

Keyword(s):

Reperfusion Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Mitochondrial Fragmentation ◽

Hepatic Ischemia ◽

Adeno Associated Virus ◽

Downstream Target ◽

Hepatic Ischemia Reperfusion

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.

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