HMGB1 in renal ischemic injury

Factors that initiate cellular damage and trigger the inflammatory response cascade and renal injury are not completely understood after renal ischemia-reperfusion injury (IRI). High-mobility group box-1 protein (HMGB1) is a damage-associated molecular pattern molecule that binds to chromatin, but upon signaling undergoes nuclear-cytoplasmic translocation and release from cells. Immunohistochemical and Western blot analysis identified HMGB1 nuclear-cytoplasmic translocation and release from renal cells (particularly vascular and tubular cells) into the venous circulation after IRI. Time course analysis indicated HMGB1 release into the venous circulation progressively increased parallel to increased renal ischemic duration. Ethyl pyruvate (EP) treatment blocked H2O2(oxidative stress)-induced HMGB1 release from human umbilical vein endothelial cells in vitro, and in vivo resulted in nuclear retention and significant blunting of HMGB1 release into the circulation after IRI. EP treatment before IRI improved short-term serum creatinine and albuminuria, proinflammatory cyto-/chemokine release, and long-term albuminuria and fibrosis. The renoprotective effect of EP was abolished when exogenous HMGB1 was injected, suggesting EP's therapeutic efficacy is mediated by blocking HMGB1 translocation and release. To determine the independent effects of circulating HMGB1 after injury, exogenous HMGB1 was administered to healthy animals at pathophysiological dose. HMGB1 administration induced a rapid surge in systemic circulating cyto-/chemokines (including TNF-α, eotaxin, G-CSF, IFN-γ, IL-10, IL-1α, IL-6, IP-10, and KC) and led to mobilization of bone marrow CD34+Flk1+ cells into the circulation. Our results indicate that increased ischemic duration causes progressively enhanced HMGB1 release into the circulation triggering damage/repair signaling, an effect inhibited by EP because of its ability to block HMGB1 nuclear-cytoplasmic translocation.

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Assessing the Efficacy of Dietary Selenomethionine Supplementation in the Setting of Cardiac Ischemia/Reperfusion Injury

Antioxidants ◽

10.3390/antiox8110546 ◽

2019 ◽

Vol 8 (11) ◽

pp. 546 ◽

Cited By ~ 2

Author(s):

Leila Reyes ◽

David P. Bishop ◽

Clare L. Hawkins ◽

Benjamin S. Rayner

Keyword(s):

Cardiac Myocyte ◽

Hypochlorous Acid ◽

Ischemia Reperfusion Injury ◽

Heart Function ◽

Ischemia Reperfusion ◽

Cytosolic Calcium ◽

Cardiac Ischemia ◽

Cellular Damage

Oxidative stress is a major hallmark of cardiac ischemia/reperfusion (I/R) injury. This partly arises from the presence of activated phagocytes releasing myeloperoxidase (MPO) and its production of hypochlorous acid (HOCl). The dietary supplement selenomethionine (SeMet) has been shown to bolster endogenous antioxidant processes as well as readily react with MPO-derived oxidants. The aim of this study was to assess whether supplementation with SeMet could modulate the extent of cellular damage observed in an in vitro cardiac myocyte model exposed to (patho)-physiological levels of HOCl and an in vivo rat model of cardiac I/R injury. Exposure of the H9c2 cardiac myoblast cell line to HOCl resulted in a dose-dependent increase in necrotic cell death, which could be prevented by SeMet supplementation and was attributed to SeMet preventing the HOCl-induced loss of mitochondrial inner trans-membrane potential, and the associated cytosolic calcium accumulation. This protection was credited primarily to the direct oxidant scavenging ability of SeMet, with a minor contribution arising from the ability of SeMet to bolster cardiac myoblast glutathione peroxidase (GPx) activity. In vivo, a significant increase in selenium levels in the plasma and heart tissue were seen in male Wistar rats fed a diet supplemented with 2 mg kg−1 SeMet compared to controls. However, SeMet-supplementation demonstrated only limited improvement in heart function and did not result in better heart remodelling following I/R injury. These data indicate that SeMet supplementation is of potential benefit within pathological settings where excessive HOCl is known to be generated but has limited efficacy as a therapeutic agent for the treatment of heart attack.

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Neuroprotective effect of Indobufen against pyroptosis following cerebral ischemia-reperfusion injury both in vivo and in vitro

10.21203/rs.3.rs-29012/v4 ◽

2020 ◽

Author(s):

Tian Zhang ◽

Dan Xu ◽

Fengyang Li ◽

Rui Liu ◽

Kai Hou ◽

...

Keyword(s):

Cerebral Ischemia ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Therapeutic Effects ◽

Caspase 1 ◽

Cerebral Ischemia Reperfusion

Abstract Background: Indobufen is a new generation of antiplatelet agents and has been shown to have antithrombotic effects in animal models. However, the efficacy of Indobufen on cerebral ischemia/reperfusion (I/R) injury and its mechanisms remain to be investigated. Methods: In this study, the efficacy of Indobufen with both pre- (5days) and post- (15days) treatment on rats suffering middle cerebral artery occlusion/reperfusion (MCAO/R, 2h of ischemia and 24h/15days of reperfusion) was investigated. Furthermore, human umbilical vein endothelial cells (HUVECs) were cultured and underwent oxygen glucose deprivation/reoxygenation (OGD/R) injury for in vitro studies. Relationship between Indobufen and pyroptosis associated NF-κB/Caspase-1/GSDMD pathway was preliminarily discussed. Results: The pharmacodynamic tests revealed that Indobufen ameliorated I/R injury by decreasing the platelet aggregation, infarct size, brain edema and neurologic impairment in rats and rescuing cell apoptosis/pyroptosis in HUVECs. The underlying mechanisms were probably related to pyroptosis suppression by platelet inhibition induced regulation of the NF-κB/Caspase-1/GSDMD pathway.Conclusion: Overall, these studies indicates that Indobufen exerts protective and therapeutic effects against I/R injury by pyroptosis suppression via downregulating NF-κB/Caspase-1/GSDMD pathway.

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Neuroprotective effect of Indobufen against pyroptosis following cerebral ischemia-reperfusion injury both in vivo and in vitro

10.21203/rs.3.rs-29012/v1 ◽

2020 ◽

Author(s):

Tian Zhang ◽

Dan Xu ◽

Fengyang Li ◽

Rui Liu ◽

Kai Hou ◽

...

Keyword(s):

Cerebral Ischemia ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Therapeutic Effects ◽

Caspase 1 ◽

Cerebral Ischemia Reperfusion

Abstract Background: Indobufen is a new generation of antiplatelet agents and has been shown to have antithrombotic effects in animal models. However, the efficacy of Indobufen on cerebral ischemia/reperfusion (I/R) injury and its mechanisms remain to be investigated. Methods: In this study, the efficacy of Indobufen with both pre- and post-treatment on rats suffering middle cerebral artery occlusion/reperfusion (MCAO/R) was investigated. Furthermore, human umbilical vein endothelial cells (HUVECs) were cultured and underwent oxygen glucose deprivation/reoxygenation (OGD/R) injury for in vitro studies. Relationship between Indobufen and pyroptosis associated NF-κB/Caspase-1/GSDMD pathway was preliminarily discussed. Results: The pharmacodynamic tests revealed that Indobufen ameliorated I/R injury by decreasing the platelet aggregation, infarct size, brain edema and neurologic impairment in rats and rescuing cell apoptosis/pyroptosis in HUVECs. The underlying mechanisms were probably related to pyroptosis suppression by regulating the NF-κB/Caspase-1/GSDMD pathway. Conclusion: Overall, these studies indicates that Indobufen exerts protective and therapeutic effects against I/R injury by pyroptosis suppression via downregulating NF-κB/Caspase-1/GSDMD pathway.

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Abstract 98: Reducing Mitochondrial, But Not Cytosolic Iron, Protects The Heart Against Ischemia-reperfusion Injury

Circulation Research ◽

10.1161/res.115.suppl_1.98 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Hsiang-Chun J Chang ◽

Rongxue Wu ◽

Hossein Ardehali

Keyword(s):

Cardiac Function ◽

Iron Homeostasis ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Critical Role ◽

Cellular Damage ◽

Antioxidant Systems ◽

Mitochondrial Iron

Introduction: Iron is essential for the activity of a large number of cellular proteins, but excess free iron can cause cellular damage through production of reactive oxygen species (ROS). Mitochondria are the major site of cellular iron homeostasis, and we recently showed the mitochondrial iron export is mediated by ATP-binding cassette protein-B8 (ABCB8). The role of mitochondrial iron in ischemia-reperfusion (I/R) injury in the heart has not been examined. We hypothesize that mitochondrial iron has a critical role in I/R damage and a reduction of mitochondrial iron is protective against I/R injury through a reduction in ROS. Results: Cardiomyocyte-specific ABCB8 transgenic (TG) mice had significantly lower mitochondrial iron in the heart than nontransgenic (NTG) littermates at baseline, but their cardiac function and the expression of key antioxidant systems were indistinguishable from NTG littermates. To study the role of mitochondrial iron in I/R injury, we subjected ABCB8 TG mice to I/R. TG mice displayed significantly less apoptosis compared to NTG littermates (11.76% vs. 17.63%, p<0.05, n=4-6) and had significantly reduced lipid peroxidation products 48 hours after I/R. To further confirm that our in vivo finding was due to reduced mitochondrial iron, we studied the effect of pharmacological reduction of mitochondrial iron in vitro. 2,2-bipyridyl (BPD) is a mitochondria-accessible iron chelator while deferoxamine (DFO) has poor penetrance into mitochondria. Treating rat cardiomyoblasts H9C2 with BPD but not DFO significantly reduced chelatable mitochondrial iron, as measured by staining cells with rhodamine B-[(1,10-phenanthrolin-5-yl)aminocarbonyl]benzyl ester. In addition, BPD but not DFO pretreatment protected cells against H2O2 induced cell death (p<0.05). BPD treatment in mice decreased baseline mitochondrial iron and significantly preserved cardiac function after I/R. Conclusions: Our findings demonstrate that selective reduction in mitochondrial iron is protective in I/R injury, and show that mitochondrial iron is a source of ROS and cellular damage in I/R. Thus, targeting mitochondrial iron with selective iron chelators, as studied in our system, may provide a novel approach for treatment of ischemic heart disease.

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Interaction between uric acid and HMGB1 translocation and release from endothelial cells

AJP Renal Physiology ◽

10.1152/ajprenal.00520.2011 ◽

2012 ◽

Vol 302 (6) ◽

pp. F730-F741 ◽

Cited By ~ 41

Author(s):

May M. Rabadi ◽

Mei-Chuan Kuo ◽

Tammer Ghaly ◽

Seham M. Rabadi ◽

Mia Weber ◽

...

Keyword(s):

Endothelial Cells ◽

Uric Acid ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Calcium Mobilization ◽

Erk Pathway

We aimed to investigate the potential relationship between alarmins [acting via Toll-like receptor-4 (TLR4)], uric acid (UA), and high-mobility group box-1 protein (HMGB1) during acute kidney injury. UA, which is significantly increased in the circulation following renal ischemia-reperfusion injury (IRI), was used both in vitro and in vivo as an early response-signaling molecule to determine its ability to induce the secretion of HMGB1 from endothelial cells. Treatment of human umbilical vein endothelial cells (HUVEC) with UA resulted in increased HMGB1 mRNA expression, acetylation of nuclear HMGB1, and its subsequent nuclear-cytoplasmic translocation and release into the circulation, as determined by Western blotting and immunofluorescence. Treatment of HUVEC with UA and a calcium mobilization inhibitor (TMB-8) or a MEK/Erk pathway inhibitor (U0126) prevented translocation of HMGB1 from the nucleus, resulting in reduced cytoplasmic and circulating levels of HMGB1. Once released, HMGB1 in autocrine fashion promoted further HMGB1 release while also stimulating NF-κB activity and increased angiopoietin-2 expression and protein release. Transfection of HUVEC with TLR4 small interfering (si) RNA reduced HMGB1 levels during UA and HMGB1 treatment. In summary, UA after IRI mediates the acetylation and release of HMGB1 from endothelial cells by mechanisms that involve calcium mobilization, the MEK/Erk pathway, and activation of TLR4. Once released, HMGB1 promotes its own further cellular release while acting as an autocrine and paracrine to activate both proinflammatory and proreparative mediators.

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The Role of MCPIP1 in Ischemia/Reperfusion Injury-Induced HUVEC Migration and Apoptosis

Cellular Physiology and Biochemistry ◽

10.1159/000430378 ◽

2015 ◽

Vol 37 (2) ◽

pp. 577-591 ◽

Cited By ~ 18

Author(s):

Tiebing Zhu ◽

Qi Yao ◽

Xiaonan Hu ◽

Chen Chen ◽

Honghong Yao ◽

...

Keyword(s):

Cell Migration ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Ischemia Reperfusion ◽

Mitogen Activated Protein Kinase ◽

Mitogen Activated Protein ◽

Myocardial Ischemia Reperfusion ◽

Umbilical Vein Endothelial Cells ◽

And Function

Background/Aims: Monocyte chemotactic protein-induced protein 1 (MCPIP1) plays a crucial role in various cellular processes, including neurogenesis. However, the relationship between MCPIP1 and myocardial ischemia/reperfusion (I/R) injury remained illdefined. In this study, we explored whether the I/R-mediated up-regulation of MCPIP1 is critical in the modulation of both cell migration and apoptosis in human umbilical vein endothelial cells (HUVECs). Methods: Using Western blot analysis and quantitative real-time PCR, the protein expression and mRNA transcription, respectively, of MCPIP1 was detected in HUVECs. To investigate cell migration, an in vitro scratch assay and a nested matrix model were applied. Results: I/R increased the expression of MCPIP1 via the activation of the mitogen-activated protein kinase (MAPK) and PI3K/Akt pathways. I/R increased migration and apoptosis of HUVECs, which were significantly inhibited by MCPIP1 siRNA. Conclusion: These findings suggest that I/R-mediated up-regulation of MCPIP1 regulates migration and apoptosis in HUVECs. Understanding the regulation of MCPIP1 expression and function may aid in the development of an adjunct therapeutic strategy in the treatment of individuals with I/R injury.

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Ethyl Pyruvate Promotes Proliferation of Regulatory T Cells by Increasing Glycolysis

Molecules ◽

10.3390/molecules25184112 ◽

2020 ◽

Vol 25 (18) ◽

pp. 4112

Author(s):

Ivan Koprivica ◽

Dragica Gajić ◽

Nada Pejnović ◽

Verica Paunović ◽

Tamara Saksida ◽

...

Keyword(s):

T Cells ◽

Ischemia Reperfusion Injury ◽

Ethyl Pyruvate ◽

Ischemia Reperfusion ◽

Acid Oxidation ◽

Stable Form ◽

Beneficial Effects ◽

And Function

Ethyl pyruvate (EP), a stable form of pyruvate, has shown beneficial effects in animal models of shock, ischemia/reperfusion injury, and sepsis due to its potent anti-oxidant and anti-inflammatory properties. Our recent study demonstrated that EP application prevented the clinical manifestation of type 1 diabetes in mice by augmenting regulatory T cell (Treg) number and function. Our present study shows that EP increases Treg proliferation and suppressive function (perforin and IL-10 expression) during in vitro differentiation from conventional CD4+CD25− T cells. Enhanced expansion of Treg after EP treatment correlated with increased ATP levels and relied on increased glycolysis. Inhibition of oxidative phosphorylation did not attenuate EP stimulatory effects, suggesting that this metabolic pathway was not mandatory for EP-driven Treg proliferation. Moreover, EP lowered the expression of carnitine palmitoyltransferase I, an enzyme involved in fatty acid oxidation. Further, the stimulatory effect of EP on Treg proliferation was not mediated through inhibition of the mTOR signaling pathway. When given in vivo either intraperitoneally or orally to healthy C57BL/6 mice, EP increased the number of Treg within the peritoneal cavity or gut-associated lymphoid tissue, respectively. In conclusion, EP promotes in vitro Treg proliferation through increased glycolysis and enhances Treg proliferation when administered in vivo.

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Neuroprotective effect of Indobufen against pyroptosis following cerebral ischemia-reperfusion injury both in vivo and in vitro

10.21203/rs.3.rs-29012/v3 ◽

2020 ◽

Author(s):

Tian Zhang ◽

Dan Xu ◽

Fengyang Li ◽

Rui Liu ◽

Kai Hou ◽

...

Keyword(s):

Cerebral Ischemia ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Therapeutic Effects ◽

Caspase 1 ◽

Cerebral Ischemia Reperfusion

Abstract Background: Indobufen is a new generation of antiplatelet agents and has been shown to have antithrombotic effects in animal models. However, the efficacy of Indobufen on cerebral ischemia/reperfusion (I/R) injury and its mechanisms remain to be investigated. Methods: In this study, the efficacy of Indobufen with both pre- (5days) and post- (15days) treatment on rats suffering middle cerebral artery occlusion/reperfusion (MCAO/R, 2h of ischemia and 24h/15days of reperfusion) was investigated. Furthermore, human umbilical vein endothelial cells (HUVECs) were cultured and underwent oxygen glucose deprivation/reoxygenation (OGD/R) injury for in vitro studies. Relationship between Indobufen and pyroptosis associated NF-κB/Caspase-1/GSDMD pathway was preliminarily discussed.Results: The pharmacodynamic tests revealed that Indobufen ameliorated I/R injury by decreasing the platelet aggregation, infarct size, brain edema and neurologic impairment in rats and rescuing cell apoptosis/pyroptosis in HUVECs. The underlying mechanisms were probably related to pyroptosis suppression by platelet inhibition induced regulation of the NF-κB/Caspase-1/GSDMD pathway. Conclusion: Overall, these studies indicates that Indobufen exerts protective and therapeutic effects against I/R injury by pyroptosis suppression via downregulating NF-κB/Caspase-1/GSDMD pathway.

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Neuroprotective effect of Indobufen against pyroptosis following cerebral ischemia-reperfusion injury both in vivo and in vitro

10.21203/rs.3.rs-29012/v2 ◽

2020 ◽

Author(s):

Tian Zhang ◽

Dan Xu ◽

Fengyang Li ◽

Rui Liu ◽

Kai Hou ◽

...

Keyword(s):

Cerebral Ischemia ◽

Ischemia Reperfusion Injury ◽

Umbilical Vein ◽

Neuroprotective Effect ◽

Ischemia Reperfusion ◽

Therapeutic Effects ◽

Caspase 1 ◽

Cerebral Ischemia Reperfusion

Abstract Background: Indobufen is a new generation of antiplatelet agents and has been shown to have antithrombotic effects in animal models. However, the efficacy of Indobufen on cerebral ischemia/reperfusion (I/R) injury and its mechanisms remain to be investigated. Methods: In this study, the efficacy of Indobufen with both pre- (5days) and post- (15days) treatment on rats suffering middle cerebral artery occlusion/reperfusion (MCAO/R, 2h of ischemia and 24h/15days of reperfusion) was investigated. Furthermore, human umbilical vein endothelial cells (HUVECs) were cultured and underwent oxygen glucose deprivation/reoxygenation (OGD/R) injury for in vitro studies. Relationship between Indobufen and pyroptosis associated NF-κB/Caspase-1/GSDMD pathway was preliminarily discussed. Results: The pharmacodynamic tests revealed that Indobufen ameliorated I/R injury by decreasing the platelet aggregation, infarct size, brain edema and neurologic impairment in rats and rescuing cell apoptosis/pyroptosis in HUVECs. The underlying mechanisms were probably related to pyroptosis suppression by platelet inhibition induced regulation of the NF-κB/Caspase-1/GSDMD pathway. Conclusion: Overall, these studies indicates that Indobufen exerts protective and therapeutic effects against I/R injury by pyroptosis suppression via downregulating NF-κB/Caspase-1/GSDMD pathway.

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Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons

Cell Death and Disease ◽

10.1038/s41419-021-03752-2 ◽

2021 ◽

Vol 12 (5) ◽

Author(s):

Anthony R. Anzell ◽

Garrett M. Fogo ◽

Zoya Gurm ◽

Sarita Raghunayakula ◽

Joseph M. Wider ◽

...

Keyword(s):

Cortical Neurons ◽

Ischemia Reperfusion Injury ◽

Mitochondrial Dynamics ◽

Ischemia Reperfusion ◽

Mitochondrial Fission ◽

Conditional Knockout ◽

Mitochondrial Morphology ◽

Primary Neurons ◽

Mitochondrial Fragmentation

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.

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