Dexmedetomidine Attenuates Hypoxia/Reoxygenation Injury of H9C2 Myocardial Cells by Upregulating miR-146a Expression via the MAPK Signal Pathway

Pharmacology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Yi Chu ◽  
Jiwei Teng ◽  
Pin Feng ◽  
Hui Liu ◽  
Fangfang Wang ◽  
...  

<b><i>Introduction and Objective:</i></b> Dexmedetomidine (Dex) and a number of miRNAs contribute to ischemia/reperfusion injury. We aimed to explore the role of Dex and miR-146a on myocardial cells injured by hypoxia/reoxygenation (H/R). <b><i>Method:</i></b> H9C2 cells were injured by H/R. Cell viability was tested using the cell counting kit-8. Lactate dehydrogenase (LDH) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) levels were determined using commercial kits. Flow cytometry was performed to determine apoptosis rate and reactive oxygen species (ROS) level. Protein and mRNA levels were assessed using Western blot and qPCR. <b><i>Results:</i></b> miR-146a expression and cell viability of H9C2 cells were downregulated under the circumstance of H/R injury. The tendency could be reversed by Dex, which could also upregulate SOD activity and decrease apoptosis, LDH activity, MDA, 78-kDa glucose-regulated protein (GRP78), and C/EBP homologous protein (CHOP) levels of H9C2 cells. GRP78, CHOP levels, and cell viability were negatively modulated by miR-146a. Dex elevated cell viability, catalase, MnSOD, and NAD(P)H dehydrogenase (NQO1) levels but suppressed apoptosis rate, GRP78, and CHOP levels by increasing miR-146a expression and downregulating ROS, phosphorylation of p38, and extracellular signal-regulated kinases 1/2 levels. By using SB203580 (SB), the p38 mitogen-activated protein kinase (MAPK) inhibitor, Dex or the inhibition of miR-146 upregulated cell viability but downregulated GRP78 and CHOP levels. <b><i>Conclusion:</i></b> Dex might regulate miR-146a expression, which could further modulate the endoplasmic reticulum stress and oxidative stress and eventually affect the cell viability and apoptosis of myocardial cells injured by H/R via the MAPK signal pathway.

2020 ◽  
Author(s):  
Zhipeng Zhu ◽  
Xiaoyan Ling ◽  
Hongmei Zhou ◽  
Caijun Zhang

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.


2020 ◽  
Author(s):  
Junyu Zhao ◽  
Qian Zhu ◽  
Man Shang ◽  
Miao Liu ◽  
Yilu Wang ◽  
...  

Abstract Background Microvesicles (MVs) are submicron membrane vesicles as mediators of intercellular communication. The aim of our study was to investigate protective mechanism of circulating MVs derived from ischemic preconditioning (IPC-MVs) on myocardial I/R injury. Results Administration of IPC-MVs reduced infarct size and activity of lactate dehydrogenase (LDH) in myocardial I/R injury in vivo. Meanwhile, IPC-MVs could increase cell viability and reduce LDH activity in hypoxia/reoxygenation (H/R) injured H9c2 cells in vitro. Microarray analysis demonstrated that miR-133a-3p expression in IPC-MVs increased apparently compared with Sham-MVs. We found that miR-133a-3p increased cell viability, decreased LDH activity and apoptosis , as well as suppressed H/R-induced endoplasmic reticulum stress (ERS). MVs induced by hypoxic preconditioning enriched with FAM-miR-133a-3p allowed the transfer of miR-133a-3p to target cells. In addition, miR-133a-3p was significantly increased in H/R injured H9c2 cells by treatment with IPC-MVs. Epidermal growth factor receptor (EGFR) is a target gene of miR-133a-3p. AG1478 (EGFR inhibitor) significantly increased cell viability, decreased LDH activity and ERS-induced apoptosis in H9c2 cells under H/R injury. Conclusions The findings of this study showed that IPC-MVs exerted cardioprotective effects by transferring miR-133a-3p into H/R injured cardiomyocytes targeting EGFR, thus attenuating ERS-induced apoptosis. MiR-133a-3p transferred by IPC-MVs may provide a novel therapy for myocardial I/R injury.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xin Liu ◽  
Hong Bian ◽  
Qing-Li Dou ◽  
Xian-Wen Huang ◽  
Wu-Yuan Tao ◽  
...  

Ginkgetin, the extract of Ginkgo biloba leaves, has been reported to exert preventive and therapeutic effects on cardiovascular disease. However, little is known about its role in myocardial ischemia-reperfusion injury (MIRI). The present study aimed to unveil the function of ginkgetin in cardiomyocytes subjected to hypoxia/reoxygenation (H/R) injury. Cell Counting Kit-8 (CCK-8) was employed to evaluate the impact of ginkgetin on cell viability in the absence or presence of H/R. Proinflammatory cytokines and malondialdehyde (MDA), reactive oxygen species (SOD), and lactate dehydrogenase (LDH) were determined via corresponding kits. In addition, flow cytometry was performed to detect apoptotic level. Western blot analysis was utilized to estimate caspase-3 and cytochrome C. Ginkgetin had no significant effect on cell viability; however, it could enhance viability of H9C2 cells exposed to H/R. Inflammation and oxidative stress induced by H/R injury were relieved via pretreatment with ginkgetin. Preconditioning of ginkgetin also decreased apoptotic rate and the protein levels of caspase-3, cytochrome C under H/R condition. Furthermore, 2-HBA, an inducer of caspase-3, was used for the activation of caspase-3 signaling pathway. It was found that induction of caspase-3 eliminated the protective effect of ginkgetin on H9C2 cells exposed to H/R. These results indicated that ginkgetin attenuated inflammation, oxidative stress, and apoptosis. These protective roles of ginkgetin may attribute to caspase-3 dependent pathway.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yuan Zhang ◽  
Wating Su ◽  
Qiongxia Zhang ◽  
Jinjin Xu ◽  
Huimin Liu ◽  
...  

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Chuanliang Liu ◽  
Jieqiong Zhang ◽  
Xuejie Lun ◽  
Lei Li

Objective. To explore the effect and related mechanism of LncRNA PVT1 on hypoxia-induced cardiomyocyte injury. Methods. PVT1RNA and miR-214-3p levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell vitality and apoptosis were, respectively, evaluated by Cell Counting Kit-8 (CCK-8) and flow cytometry analysis. Starbase and Dual luciferase reporter (DLR) gene assay was employed to validate the interaction between miR-214-3p and PVT1. Results. PVT1 was statistically upregulated, and miR-214-3p was statistically downregulated in hypoxia-induced H9c2 cells. The survival rate of H9c2 cells induced by hypoxia decreased statistically, while the apoptosis rate increased statistically ( P < 0.05 ). PVT1 knockdown upregulated the hypoxia-induced H9c2 cell viability and inhibited apoptosis. DLR assay verified the targeting relationship between PVT1 and miR-214-3p. In addition, miR-214-3p inhibitors reversed the viability of H9c2 cells with PVT1 knockout and promoted apoptosis. Conclusion. Silencing PVT1 can enhance the hypoxia-induced H9c2 cell viability and inhibit apoptosis, providing a potential target for the treatment of cardiovascular diseases.


2018 ◽  
Vol 48 (6) ◽  
pp. 2483-2492 ◽  
Author(s):  
Xinling Zhang ◽  
Chunxiang Zhang ◽  
Nan Wang ◽  
Yan Li ◽  
Debing Zhang ◽  
...  

Background/Aims: Acute myocardial infarction is a serious disease with high morbidity and mortality. microRNAs (miRNAs) have been proved to play an important role in modulating myocardial ischemia and reperfusion injury. Hence, in this study, we constructed H9c2 cell model to elucidate the roles of microRNA-486 (miR-486) in preventing hypoxia-induced damage in H9c2 cells. Methods: H9c2 cells were cultured in hypoxic incubator with 1% O2 to simulate hypoxia and/or transfected with miR-486 mimic, scramble, anti-miR-486, si-N-myc downstream-regulated gene 2 (NDRG2) and their corresponding negative controls (NC). Effects of miR-486 and/or NDRG2 dysregulation on hypoxia-induced myocardial injury in H9c2 cells were investigated by evaluating cell viability, migration, invasion and apoptosis using Cell Counting Kit-8 (CCK-8), transwell assay, flow cytometry, respectively. The proteins expression and RNA expression were detected by western blot and quantitative real time polymerase chain reaction (qRT-PCR), respectively. Results: Hypoxia treatment induced damage in H9c2 cells by decreasing cell viability, migration and invasion and increasing cell apoptosis. Moreover, hypoxia inhibited the expression of miR-486 in H9c2 cells. Overexpression of miR-486 alleviated hypoxia-induced myocardial injury in H9c2 cells, while suppression of miR-486 further aggravated hypoxia-induced injury. Furthermore, NDRG2 expression was negatively regulated by miR-486, and NDRG2 was confirmed as a target of miR-486. Knockdown of NDRG2 alleviated the effects of miR-486 suppression on hypoxia-induced myocardial injury. Besides, knockdown of NDRG2 markedly inhibited the activation of c-Jun N-terminal kinase (JNK) /c-jun and nuclear factor κB (NF-κB) signaling pathways in hypoxia-induced H9c2 cells. Conclusion: Our findings indicate that miR-486 may alleviate hypoxia-induced myocardial injury possibly by targeting NDRG2 to inactivate JNK/c-jun and NF-κB signaling pathways. miR-486 may be a potential target for treating ischemic myocardial injury following acute myocardial infarction.


2020 ◽  
Vol 29 ◽  
pp. 096368972094924
Author(s):  
Xiaoyan Dang ◽  
Yong Qin ◽  
Changwei Gu ◽  
Jiangli Sun ◽  
Rui Zhang ◽  
...  

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.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Xue-bin Cao ◽  
Zhi-hao Jiang ◽  
Lei Dong ◽  
Yu Zheng ◽  
Yang Li

Salidroside, a phenyl-propanoid glycoside isolated from the medicinal plant Rhodiola rosea, has potent cardioprotective effects, especially against myocardial hypoxia and reoxygenation injury. However, the molecular mechanism underlying its action is still unclear. The aim of this study was to determine the effect of salidroside on sodium channel current (INa) and transient outward potassium channel current (Ito) in H9C2 cardiomyocytes. H9C2 cells were subcultured under anoxic conditions to mimic myocardial hypoxia and subsequently treated with salidroside. Whole cell patch clamp was performed to determine the effect of hypoxia/reoxygenation and salidroside on myocardial electrophysiological properties. In the differentiated H9C2 cells, hypoxia/reoxygenation reduced INa and Ito amplitude, while salidroside significantly restored both and altered the INa and Ito activation/inactivation kinetics in a dose-dependent manner. Our findings demonstrate that salidroside protects myocardial cells against hypoxia-reoxygenation by restoring the function of sodium and potassium channels.


2021 ◽  
Author(s):  
Yu-jia Huang ◽  
Hai-ying Tong ◽  
Xian-ju Huang ◽  
Xin-Cai Xiao ◽  
Yue Dong ◽  
...  

Abstract Anshen Buxin Liuwei pill (ABLP), a Mongolian medicinal formula, composed of the six medicinal materials of Mongolian medicine Bos taurus domesticus Gmelin, Choerospondias axillaris (Roxb. ) Burtt et Hill, Myristica fragrans Houtt., Eugenia caryophµllata Thunb., Aucklandia lappa Decne., Liqui dambar formosana Hance, is considered to have a therapeutic effect on the symptoms such as coronary heart disease, angina pectoris, arrhythmia, depression and irritability, palpitation, and shortness of breath. Therefore, the present study was employed a network pharmacology approach to identify the potentially active ingredients and to evaluate the protective effect of ABLP on hypoxia/reoxygenation (HR)-induced H9c2 cardiomyocytes, and its influence on cell viability, apoptosis, oxidative stress. H9c2 cardiomyocytes were used to construct a HR injury model. CCK-8 assay and AnnexinV-FITC cell apoptosis assays were used for cell viability and cell apoptosis determination. The levels of LDH, SOD, MDA, CAT, CK, GSH-Px, Na+-K+-ATPase, and Ca2+-ATPase in the cells were determined to assess the effect of ABLP. the mRNA levels of Sirtuin3 (Sirt3) and Cytochrome C (Cytc) in H9c2 cells were determined by quantitative real-time PCR. The finding of this study indicates that HR treatment cells began to shrink from the spindle in an irregular shape with some floated in the medium, well by increasing the therapeutic dose of ABLP (5 µg/mL, 25 µg/mL, and 50 µg/mL), the cells gradually reconverted in a concentration-dependent manner. The release of CK in HR-treated cells was significantly increased, indicating that ABLP exerts a protective effect in H9c2 cells against HR injury and can improve the mitochondrial energy metabolism and mitochondrial function integrity. The present study scrutinized the cardio-protective effect of ABLP against the HR-induced H9c2 cells injury through antioxidant and mitochondrion pathways. ABLP could be a promising therapeutic drug for the treatment of myocardial ischemic cardiovascular disease. The results will provide reasonable information for clinical use of the ABLP.


2020 ◽  
pp. 427-438
Author(s):  
X GAO ◽  
S ZHANG ◽  
D WANG ◽  
Y CHENG ◽  
Y JIANG ◽  
...  

(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.


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