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 ◽  
...  

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.

STEMedicine ◽  
2021 ◽  
Vol 2 (6) ◽  
pp. e87
Author(s):  
Jin Cheng ◽  
Qing Zou ◽  
Yugang Xue

Background: Nerol was reported as a natural anti-oxidant product and its protective effects against cardiovascular diseases have been documented. Our current study was designed to explore the cardioprotective effect of Nerol on hypoxia/reoxygenation (H/R)-induced production of reactive oxygen species (ROS) and cell apoptosis in H9c2 cells. The potential molecular mechanisms were further investigated. Methods: The cells were treated with 2.5 or 5 µM Nerol before or after H/R. Lactate dehydrogenase (LDH) release, cell viability, oxidative stress markers, and apoptotic proteins were assessed by cell counting kit-8, LDH release assay, commercial kits, and Western blot, respectively. To explore the underlying mechanism, the phosphorylation of p85 and p38, regulatory subunits of phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinase (MAPK), was evaluated by Western blot. To further confirm that the PI3K/AKT signaling pathway participated in the cardiomyocyte protection, H9c2 cells were treated with 5 µM Nerol in the presence or absence of 5 µM BEZ235 or LY294002 followed by H/R treatment. Results: H/R remarkably induced apoptosis, LDH release and ROS production. The cell viability was suppressed via inhibiting the PI3K/AKT signaling pathway activation. By contrast, pretreatment with Nerol can neutralize these effects by activating the PI3K/AKT signaling pathway. With the addition of BEZ235 or LY294002, the inhibitory effects of Nerol were abolished. Conclusion: Nerol provided promising cardioprotective effect against H/R-induced injuries in H9c2 cells by activating the PI3K/AKT pathway.


Author(s):  
Xueying Tong ◽  
Jiajuan Chen ◽  
Wei Liu ◽  
Hui Liang ◽  
Hezhong Zhu

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.


2018 ◽  
Vol 47 (6) ◽  
pp. 2589-2601 ◽  
Author(s):  
Xiangyan Li ◽  
Qingxia Huang ◽  
Manying Wang ◽  
Xiuci Yan ◽  
Xinying Song ◽  
...  

Background/Aims: A series of reports revealed that autophagy and apoptosis exerted detrimental effects on the pathology of cardiac ischemia/reperfusion (I/R) injury. Ginsenoside compound K (CK), a major intestinal metabolite underlying the pharmacological actions of orally administered ginseng, has a protective effect against myocardial I/R injury. However, the molecular mechanisms by which CK protects against I/R injury remain unclear. In this study, we hypothesized that the cardioprotective effects of CK against I/R injury are mediated by inhibiting autophagy/apoptosis-related signaling pathways in H9c2 cardiomyocyte cells. Methods: H9c2 cells were incubated with CK and exposed to I/R. Cell viability and damage was analyzed by MTT and lactate dehydrogenase assays. Reactive oxygen species (ROS) generation, mitochondrial damage, and cell apoptosis were analyzed by flow cytometry and TUNEL staining. The expression of autophagy, apoptosis, and related signaling proteins was analyzed by Western blotting and immunofluorescence staining. Results: CK pretreatment promoted cell viability and attenuated ROS accumulation and intracellular mitochondrial damage induced by I/R injury Moreover, CK reduced autophagy by regulating the formation of phagocytic precursors to autophagosomes and also inhibited apoptosis through a mitochondrial-mediated pathway. Additionally the cardioprotective effect of CK against I/R injury was mainly through the activation of the PI3K-Akt signaling pathway. Conclusions: CK pretreatment inhibits autophagy-mediated apoptosis induced by I/R injury through the activation of the PI3K-Akt signaling pathway, which reveals that CK may be one of the key bioactive ingredients of ginseng for the treatment of myocardial I/R injury.


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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