scholarly journals Glycine Protects H9C2 Cardiomyocytes from High Glucose- and Hypoxia/Reoxygenation-Induced Injury via Inhibiting PKCβ2 Activation and Improving Mitochondrial Quality

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yuan Zhang ◽  
Wating Su ◽  
Qiongxia Zhang ◽  
Jinjin Xu ◽  
Huimin Liu ◽  
...  
Keyword(s):  
Cell Viability ◽  
High Glucose ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
H9c2 Cells ◽  
Sod Activity ◽  
Cyt C ◽  
Ldh Release ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

Background. Patients with diabetes are more vulnerable to myocardial ischemia reperfusion injury (IRI), which is involved in PKCβ2 activation and mitochondrial dysfunction. Glycine has been documented as a cytoprotective agent to attenuate diabetes-related abnormalities and reduce myocardial IRI, but the underlying mechanisms are still unclear. We determined whether glycine could attenuate high glucose- (HG-) and hypoxia/reoxygenation- (H/R-) induced injury by inhibiting PKCβ2 activation and improving mitochondrial quality in cultured H9C2 cells. Methods. H9C2 cells were either exposed to low glucose (LG) or HG conditions with or without treatment of glycine or CGP53353 (a selective inhibitor of PKCβ2) for 48 h, then subjected to 4 h of hypoxia followed by 2 h of reoxygenation (H/R). Cell viability, lactate dehydrogenase (LDH) release, mitochondrial membrane potential (MMP), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) concentration were detected using corresponding commercial kits. Mitochondrial quality control-related proteins (LC-3II, Mfn-2, and Cyt-C) and PKCβ2 activation were detected by Western blot. Results. HG stimulation significantly decreased cell viability and SOD activity and increased LDH release, MDA production, and PKCβ2 activation as compared to LG group, all of which changes were further increased by H/R insult. Glycine or CGP53353 treatment significantly reduced the increase of LDH release, MDA production, PKCβ2 activation, and Cyt-C expression and the decrease of cell viability, SOD activity, MMP, Mfn-2 expression, and LC-3II/LC-3I ratio induced by HG and H/R stimulation. Conclusions. Supplementary glycine protects H9C2 cells from HG- and H/R-induced cellular injury by suppressing PKCβ2 activation and improving mitochondria quality.

scholarly journals Knockdown of Tripartite Motif 8 Protects H9C2 Cells Against Hypoxia/Reoxygenation-Induced Injury Through the Activation of PI3K/Akt Signaling Pathway

2020 ◽  
Vol 29 ◽  
pp. 096368972094924
Author(s):  
Xiaoyan Dang ◽  
Yong Qin ◽  
Changwei Gu ◽  
Jiangli Sun ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Signaling Pathway ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
H9c2 Cells ◽  
Loss Of Function ◽  
Akt Signaling Pathway ◽  
Tripartite Motif ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

Tripartite motif 8 (TRIM8) is a member of the TRIM protein family that has been found to be implicated in cardiovascular disease. However, the role of TRIM8 in myocardial ischemia/reperfusion (I/R) has not been investigated. We aimed to explore the effect of TRIM8 on cardiomyocyte H9c2 cells exposed to hypoxia/reoxygenation (H/R). We found that TRIM8 expression was markedly upregulated in H9c2 cells after stimulation with H/R. Gain- and loss-of-function assays proved that TRIM8 knockdown improved cell viability of H/R-stimulated H9c2 cells. In addition, TRIM8 knockdown suppressed reactive oxygen species production and elevated the levels of superoxide dismutase and glutathione peroxidase. Knockdown of TRIM8 suppressed the caspase-3 activity, as well as caused significant increase in bcl-2 expression and decrease in bax expression. Furthermore, TRIM8 overexpression exhibited apposite effects with knockdown of TRIM8. Finally, knockdown of TRIM8 enhanced the activation of PI3K/Akt signaling pathway in H/R-stimulated H9c2 cells. Inhibition of PI3K/Akt by LY294002 reversed the effects of TRIM8 knockdown on cell viability, oxidative stress, and apoptosis of H9c2 cells. These present findings defined TRIM8 as a therapeutic target for attenuating and preventing myocardial I/R injury.

scholarly journals (Pro)renin Receptor Contributes to Hypoxia/Reoxygenation-Induced Apoptosis and Autophagy in Myocardial Cells via the β-Catenin Signaling Pathway

2020 ◽  
pp. 427-438
Author(s):  
X GAO ◽  
S ZHANG ◽  
D WANG ◽  
Y CHENG ◽  
Y JIANG ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cell Counting ◽  
H9c2 Cells ◽  
Related Factors ◽  
Myocardial Ischemia Reperfusion ◽  
Induced Apoptosis ◽  
Hypoxia Reoxygenation

(Pro)renin receptor (PRR) contributes to regulating many physiological and pathological processes; however, the role of PRR-mediated signaling pathways in myocardial ischemia/reperfusion injury (IRI) remains unclear. In this study, we used an in vitro model of hypoxia/reoxygenation (H/R) to mimic IRI and carried out PRR knockdown by siRNA and PRR overexpression using cDNA in H9c2 cells. Cell proliferation activity was examined by MTT and Cell Counting Kit-8 (CCK-8) assays. Apoptosis-related factors, autophagy markers and β-catenin pathway activity were assessed by real-time PCR and western blotting. After 24 h of hypoxia followed by 2 h of reoxygenation, the expression levels of PRR, LC3B-I/II, Beclin1, cleaved caspase-3, cleaved caspase-9 and Bax were upregulated, suggesting that apoptosis and autophagy were increased in H9c2 cells. Contrary to the effects of PRR downregulation, the overexpression of PRR inhibited proliferation, induced apoptosis, increased the expression of pro-apoptotic factors and autophagy markers, and promoted activation of the β-catenin pathway. Furthermore, all these effects were reversed by treatment with the β-catenin antagonist DKK-1. Thus, we concluded that PRR activation can trigger H/R-induced apoptosis and autophagy in H9c2 cells through the β-catenin signaling pathway, which may provide new therapeutic targets for the prevention and treatment of myocardial IRI.

scholarly journals Inhibition of DNMT-1 alleviates ferroptosis through NCOA4 mediated ferritinophagy during diabetes myocardial ischemia/reperfusion injury

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wenyuan Li ◽  
Wei Li ◽  
Yao Wang ◽  
Yan Leng ◽  
Zhongyuan Xia
Keyword(s):  
High Glucose ◽  
Myocardial Injury ◽  
Cell Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
H9c2 Cell ◽  
Nuclear Receptor Coactivator ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

AbstractThe purpose of this study was to investigate whether inhibition of DNA (cytosine-5)-methyltransferase 1 (DNMT-1) alleviated ferroptosis through nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy during diabetes myocardial (DM) ischemia/reperfusion (I/R) injury (IRI). Rat DM + sham (DS), I/R, and DM + I/R (DIR), H9c2 cell high glucose (HG), hypoxia reoxygenation (H/R), and high-glucose hypoxia reoxygenation (HH/R) models were established. DNMT-1 inhibitor 5-Aza-2’-deoxycytidine (5-aza-CdR) was administered to rat and cell models. The protein level of DNMT-1, NCOA4, FTH, GPX4, Beclin-1, and P62 was detected by western blotting. Compared with normal sham (NS) group, myocardial tissue was injured in DS and I/R models. The level of DNMT-1, NCOA4, and ferroptosis was increased. Moreover, the cell injury was more serious in rat DIR or HH/R model. 5-Aza-CdR could reduce NCOA4-mediated ferritinophagy and myocardial injury in DIR and HH/R models. Moreover, the siRNA for NCOA4 could also reduce the level of ferritinophagy and cell injury in HH/R model. 5-Aza-CdR enhanced the protective effect for NCOA4-siRNA in the process of cell injury. Inhibition of DNMT-1 could reduce ferroptosis during DIR, which the NCOA4-mediated ferritinophagy might be regulated.

MiR-421 inhibition protects H9c2 cells against hypoxia/reoxygenation-induced oxidative stress and apoptosis by targeting Sirt3

Perfusion ◽  
2019 ◽  
Vol 35 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Yu Liu ◽  
Xi-Ming Qian ◽  
Qi-Cai He ◽  
Jia-Kan Weng
Keyword(s):  
Superoxide Dismutase ◽  
Lactate Dehydrogenase ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Activator Protein 1 ◽  
H9c2 Cells ◽  
Expression Levels ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Hypoxia Reoxygenation

Background: MicroRNAs (miRNAs) are involved in myocardial ischemia-reperfusion injury. miRNA-421 (miR-421) plays a significant role in the initiation of apoptosis and myocardial infarction. However, the molecular regulation of miR-421 in myocardial ischemia-reperfusion injury requires further elucidation. Methods: An in vitro hypoxia/reoxygenation model was established, and the expression levels of miR-421 and Sirtuin-3 (Sirt3) in H9c2 cells were quantified using quantitative real-time polymerase chain reaction. Flow cytometry was employed to measure the effects of miR-421 on myocardial apoptosis induced by hypoxia/reoxygenation. The activity of lactate dehydrogenase and superoxide dismutase and levels of malondialdehyde were measured. The binding sites of miR-421 on Sirt3 were predicted using TargetScan software. A luciferase reporter assay was used to validate the direct targeting of Sirt3 with miR-421. Protein expression levels of Sirt3 and its downstream proteins were evaluated using Western blot analysis. Results: Exposure of H9c2 cells to hypoxia/reoxygenation led to increased apoptosis, levels of malondialdehyde and lactate dehydrogenase, and decreased levels of superoxide dismutase. miR-421 knockdown resulted in decreased apoptosis, levels of lactate dehydrogenase and malondialdehyde, and increased superoxide dismutase levels in H9c2 cells. Hypoxia/reoxygenation significantly decreased the relative expression levels of Sirt3. Down-regulation of Sirt3 resulted from overexpression of miR-421, which directly targeted Sirt3. Knockdown of miR-421 up-regulated Sirt3 expression, inhibited activation of the Jun N-terminal kinase/activator protein 1 pathway and caspase 9/3-dependent cell death. Conclusion: The miR-421-Sirt3-Jun N-terminal kinase/activator protein 1 axis is a novel molecular mechanism that accommodates hypoxia/reoxygenation-induced oxidative stress and apoptosis and provides a new direction for the study and treatment of hypoxia/reoxygenation.

scholarly journals Dexmedetomidine attenuates the injury of H9C2 cardiomyocytes under Hypoxia/reoxygenation condition partly through the inhibition of endoplasmic reticulum stress

2020 ◽  
Author(s):  
Zhipeng Zhu ◽  
Xiaoyan Ling ◽  
Hongmei Zhou ◽  
Caijun Zhang
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Viability ◽  
Cell Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Cell Counting ◽  
H9c2 Cells ◽  
Caspase 12 ◽  
Hypoxia Reoxygenation

BackgroundMyocardial ischemia-reperfusion injury (MIRI) has been confirmed to induce endoplasmic reticulum stress(ERS) during downstream cascade reaction when myocardial cell function keep deteriorating to a certain degree. The fact of matter is the clinical inconsistence with experimental outcomes still exist due to the mechanism has not been entirely clarified. Dexmedetomidine (DEX), a new generation anti-inflammatory and organ protector, has been testified can attenuate the IRI of heart. This study aimed to find out if DEX had the capacity to protect the injured cardiomyocytes under in vitro hypoxia/reoxygenation circumstance and if the ERS was totally or partly intervened.MethodsH9C2 cells were subjected to cytotoxicity detection for 24h with DEX normally cultivated in several different concentrations. The proper hypoxia/reoxygenation (H/R) model parameter were concluded by the cell viability and injuries by cell counting kit-8(CCK8) and lactate dehydrogenase (LDH) release, when undergoing hypoxic condition for 3 h and reoxygenated for 3h, 6h,12h, and 24h, respectively. Also, the above index was assessed for H/R cardiomyocytes cultivated by various concentrations of DEX. The apoptosis, expression of) Glucose-regulated protein 78(GRP78), C/EBP homologous protein (CHOP), and caspase-12 were also examined in all groups.Results1, 5 and 10 μM DEX in normal culture could significantly promote the proliferation of H9C2 (> 80%); the activity of H9c2 cells decreased to 62.67% (P < 0.05) at 3h of reoxygenation and to 36% at 6h of reoxygenation followed by 3h anoxic treatment; The cell viability of H9c2 cells in H/R groups incubated with 1 μM DEX increased 61.3%, and the LDH concentration in the supernatant was effectively lowered (−13.7, P < 0.05); H/R dramatically decreased the proportion of flow cytometry apoptosis and increased the expression of GRP78, CHOP and caspase-12, while both DEX and 4-phenyl butyric acid (4-PBA) could significantly reverse those above indicators. Additionally, DEX could induce deeper alterations than 4-PBA on the basis of H/R.Conclusion1 μM DEX can dramatically attended the cell injuries, apoptosis, the expression of GRP78, CHOP and caspase-12 of H9C2 induced by 3h’ hypoxia and 3h’s reoxygenation. moreover, the functions of DEX went beyond the inhibition of ERS under this situation.

scholarly journals N-n-Butyl Haloperidol Iodide Ameliorates Cardiomyocytes Hypoxia/Reoxygenation Injury by Extracellular Calcium-Dependent and -Independent Mechanisms

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yanmei Zhang ◽  
Gaoyong Chen ◽  
Shuping Zhong ◽  
Fuchun Zheng ◽  
Fenfei Gao ◽  
...  
Keyword(s):  
Cell Viability ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Extracellular Calcium ◽  
Camp Content ◽  
Calcium Dependent ◽  
Reoxygenation Injury ◽  
Myocardial Ischemia Reperfusion ◽  
Pka Pathway ◽  
Hypoxia Reoxygenation

N-n-butyl haloperidol iodide (F2) has been shown to antagonize myocardial ischemia/reperfusion injury by blocking calcium channels. This study explores the biological functions of ERK pathway in cardiomyocytes hypoxia/reoxygenation injury and clarifies the mechanisms by which F2ameliorates cardiomyocytes hypoxia/reoxygenation injury through the extracellular-calcium-dependent and -independent ERK1/2-related pathways. In extracellularcalcium-containing hypoxia/reoxygenation cardiomyocytes, PKCαand ERK1/2 were activated, Egr-1 protein level and cTnI leakage increased, and cell viability decreased. The ERK1/2 inhibitors suppressed extracellular-calcium-containing-hypoxia/reoxygenation-induced Egr-1 overexpression and cardiomyocytes injury. PKCαinhibitor downregulated extracellularcalcium-containing-hypoxia/reoxygenation-induced increase in p-ERK1/2 and Egr-1 expression. F2downregulated hypoxia/reoxygenation-induced elevation of p-PKCα, p-ERK1/2, and Egr-1 expression and inhibited cardiomyocytes damage. The ERK1/2 and PKCαactivators antagonized F2’s effects. In extracellular-calcium-free-hypoxia/reoxygenation cardiomyocytes, ERK1/2 was activated, LDH and cTnI leakage increased, and cell viability decreased. F2and ERK1/2 inhibitors antagonized extracellular-calcium-free-hypoxia/reoxygenation-induced ERK1/2 activation and suppressed cardiomyocytes damage. The ERK1/2 activator antagonized F2’s above effects. F2had no effect on cardiomyocyte cAMP content or PKA and Egr-1 expression. Altogether, ERK activation in extracellular-calcium-containing and extracellular-calcium-free hypoxia/reoxygenation leads to cardiomyocytes damage. F2may ameliorate cardiomyocytes hypoxia/reoxygenation injury by regulating the extracellular-calcium-dependent PKCα/ERK1/2/Egr-1 pathway and through the extracellular-calcium-independent ERK1/2 activation independently of the cAMP/PKA pathway or Egr-1 overexpression.

scholarly journals Propofol postconditioning ameliorates hypoxia/reoxygenation induced H9c2 cell apoptosis and autophagy via upregulating forkhead transcription factors under hyperglycemia

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rong-Hui Han ◽  
He-Meng Huang ◽  
Hong Han ◽  
Hao Chen ◽  
Fei Zeng ◽  
...  
Keyword(s):  
Transcription Factors ◽  
High Glucose ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Underlying Mechanism ◽  
Cardiac Cells ◽  
H9c2 Cell ◽  
Protective Effects ◽  
H9c2 Cells ◽  
Hypoxia Reoxygenation

Abstract Background Administration of propofol, an intravenous anesthetic with antioxidant property, immediately at the onset of post-ischemic reperfusion (propofol postconditioning, P-PostC) has been shown to confer cardioprotection against ischemia–reperfusion injury, while the underlying mechanism remains incompletely understood. The FoxO transcription factors are reported to play critical roles in activating cardiomyocyte survival signaling throughout the process of cellular injuries induced by oxidative stress and are also involved in hypoxic postconditioning mediated neuroprotection, however, the role of FoxO in postconditioning mediated protection in the heart and in particular in high glucose condition is unknown. Methods Rat heart-derived H9c2 cells were exposed to high glucose (HG) for 48 h (h), then subjected to hypoxia/reoxygenation (H/R, composed of 8 h of hypoxia followed by 12 h of reoxygenation) in the absence or presence of postconditioning with various concentrations of propofol (P-PostC) at the onset of reoxygenation. After having identified the optical concentration of propofol, H9c2 cells were subjected to H/R and P-PostC in the absence or presence of FoxO1 or FoxO3a gene silencing to explore their roles in P-PostC mediated protection against apoptotic and autophagic cell deaths under hyperglycemia. Results The results showed that HG with or without H/R decreased cell viability, increased lactate dehydrogenase (LDH) leakage and the production of reactive oxygen species (ROS) in H9c2 cells, all of which were significantly reversed by propofol (P-PostC), especially at the concentration of 25 µmol/L (P25) (all P < 0.05, NC vs. HG; HG vs. HG + HR; HG + HR + P12.5 or HG + HR + P25 or HG + HR + P50 vs. HG + HR). Moreover, we found that propofol (P25) decreased H9c2 cells apoptosis and autophagy that were concomitant with increased FoxO1 and FoxO3a expression (all P < 0.05, HG + HR + P25 vs. HG + HR). The protective effects of propofol (P25) against H/R injury were reversed by silencing FoxO1 or FoxO3a (all P < 0.05, HG + HR + P25 vs. HG + HR + P25 + siRNA-1 or HG + HR + P25 + siRNA-5). Conclusion It is concluded that propofol postconditioning attenuated H9c2 cardiac cells apoptosis and autophagy induced by H/R injury through upregulating FoxO1 and FoxO3a under hyperglycemia.

scholarly journals LncRNA LSINCT5/miR-222 regulates myocardial ischemia‑reperfusion injury through PI3K/AKT pathway

2021 ◽  
Author(s):  
Xueying Tong ◽  
Jiajuan Chen ◽  
Wei Liu ◽  
Hui Liang ◽  
Hezhong Zhu
Keyword(s):  
Myocardial Ischemia ◽  
Cell Viability ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Akt Signaling ◽  
Akt Pathway ◽  
Akt Signaling Pathway ◽  
Myocardial Ischemia Reperfusion Injury ◽  
Myocardial Ischemia Reperfusion

AbstractCardiovascular diseases rank the top cause of morbidity and mortality worldwide and are usually associated with blood reperfusion after myocardial ischemia/reperfusion injury (MIRI), which often causes severe pathological damages and cardiomyocyte apoptosis. LSINCT5 expression in the plasma of MI patients (n = 53), healthy controls (n = 42) and hypoxia-reoxygenation (HR)-treated cardiomyocyte AC16 cells was examined using qRT-PCR. The effects of LSINCT5 on cell viability and apoptosis were detected by MTT and flow cytometry, respectively. The expression of apoptosis-related proteins Bcl2, Bax and caspase 3 were tested by Western blot. The interaction between LSINCT5 and miR-222 was predicted by bioinformatic analysis. Moreover, changes in viability and apoptosis of AC16 cells co-transfected with siLSINCT5 and miR-222 inhibitor after HR treatment were examined. At last, the expression of proteins in PI3K/AKT pathway, namely PTEN, PI3K and AKT, was examined to analyze the possible pathway participating in LSINCT5-mediated MI/RI. Our study showed that LSINCT5 expression was upregulated in the plasma of MI patients and HR-treated AC16 cells. LSINCT5 overexpression significantly decreased cell viability and apoptosis. Luciferase reporter gene assay and RNA pulldown assay showed that LSINCT5 was a molecular sponge of miR-222. MiR-222 silencing in AC16 cells simulated the phenotypes of MIRI patients and HR-treated cells, indicating that LSINCT5 functions via miR-222 to regulate proliferation and apoptosis of HR-treated AC16 cells. We also showed that proteins of PI3K/AKT signaling pathway were affected in HR-treated AC16 cells, and LSINTC5 knockdown rescued these effects. LncRNA LSINCT5 was upregulated during MI pathogenesis, and LSINCT5 regulated MIRI possibly via a potential LSINCT5/miR-222 axis and PI3K/AKT signaling pathway. Our findings may provide novel evidence for MIRI prevention.

Overexpression of miR-431 attenuates hypoxia/reoxygenation-induced myocardial damage via autophagy-related 3

2020 ◽  
Author(s):  
Kang Zhou ◽  
Yan Xu ◽  
Qiong Wang ◽  
Lini Dong
Keyword(s):  
Cell Viability ◽  
Cell Apoptosis ◽  
Myocardial Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Myocardial Damage ◽  
Protective Role ◽  
Human Cardiomyocytes ◽  
Hypoxia Reoxygenation

Abstract Myocardial injury is still a serious condition damaging the public health. Clinically, myocardial injury often leads to cardiac dysfunction and, in severe cases, death. Reperfusion of the ischemic myocardial tissues can minimize acute myocardial infarction (AMI)-induced damage. MicroRNAs are commonly recognized in diverse diseases and are often involved in the development of myocardial ischemia/reperfusion injury. However, the role of miR-431 remains unclear in myocardial injury. In this study, we investigated the underlying mechanisms of miR-431 in the cell apoptosis and autophagy of human cardiomyocytes in hypoxia/reoxygenation (H/R). H/R treatment reduced cell viability, promoted cell apoptotic rate, and down-regulated the expression of miR-431 in human cardiomyocytes. The down-regulation of miR-431 by its inhibitor reduced cell viability and induced cell apoptosis in the human cardiomyocytes. Moreover, miR-431 down-regulated the expression of autophagy-related 3 (ATG3) via targeting the 3ʹ-untranslated region of ATG3. Up-regulated expression of ATG3 by pcDNA3.1-ATG3 reversed the protective role of the overexpression of miR-431 on cell viability and cell apoptosis in H/R-treated human cardiomyocytes. More importantly, H/R treatments promoted autophagy in the human cardiomyocytes, and this effect was greatly alleviated via miR-431-mimic transfection. Our results suggested that miR-431 overexpression attenuated the H/R-induced myocardial damage at least partly through regulating the expression of ATG3.

scholarly journals Metformin Protects H9C2 Cardiomyocytes from High-Glucose and Hypoxia/Reoxygenation Injury via Inhibition of Reactive Oxygen Species Generation and Inflammatory Responses: Role of AMPK and JNK

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Mingyan Hu ◽  
Ping Ye ◽  
Hua Liao ◽  
Manhua Chen ◽  
Feiyan Yang
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Viability ◽  
High Glucose ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Compound C ◽  
Hypoxia Reoxygenation

Metformin is a first-line drug for the management of type 2 diabetes. Recent studies suggested cardioprotective effects of metformin against ischemia/reperfusion injury. However, it remains elusive whether metformin provides direct protection against hypoxia/reoxygenation (H/R) injury in cardiomyocytes under normal or hyperglycemic conditions. This study in H9C2 rat cardiomyoblasts was designed to determine cell viability under H/R and high-glucose (HG, 33 mM) conditions and the effects of cotreatment with various concentrations of metformin (0, 1, 5, and 10 mM). We further elucidated molecular mechanisms underlying metformin-induced cytoprotection, especially the possible involvement of AMP-activated protein kinase (AMPK) and Jun NH(2)-terminal kinase (JNK). Results indicated that 5 mM metformin improved cell viability, mitochondrial integrity, and respiratory chain activity under HG and/or H/R (P<0.05). The beneficial effects were associated with reduced levels of reactive oxygen species generation and proinflammatory cytokines (TNF-α, IL-1α, and IL-6) (P<0.05). Metformin enhanced phosphorylation level of AMPK and suppressed HG + H/R induced JNK activation. Inhibitor of AMPK (compound C) or activator of JNK (anisomycin) abolished the cytoprotective effects of metformin. In conclusion, our study demonstrated for the first time that metformin possessed direct cytoprotective effects against HG and H/R injury in cardiac cells via signaling mechanisms involving activation of AMPK and concomitant inhibition of JNK.

Sign in / Sign up

Export Citation Format

Share Document