scholarly journals Bone marrow mesenchymal stem cell-secreted exosomes carrying microRNA-125b protect against myocardial ischemia reperfusion injury via targeting SIRT7

2019 ◽  
Vol 465 (1-2) ◽  
pp. 103-114 ◽  
Author(s):  
Qi Chen ◽  
Yu Liu ◽  
Xueyan Ding ◽  
Qinfeng Li ◽  
Fuyu Qiu ◽  
...  

AbstractMicroRNA-125b (miR-125b) reduces myocardial infarct area and restrains myocardial ischemia reperfusion injury (I/R). In this study, we aimed to investigate the effect of bone marrow mesenchymal stem cell (BMSC)-derived exosomes carrying miR-125b on I/R rats. The myocardial I/R model in rats was constructed by ligation of the left anterior descending coronary artery (LAD). Rats were randomly divided into I/R and Sham group. Lv-cel-miR-67 (control) or Lv-miR-125b was transfected into BMSCs. Exosomes were extracted from transfected BMSCs, and separately named BMSC-Exo-67, BMSC-Exo-125b, and BMSC-Exo. MTT assay and flow cytometry were used to detect the viability and apoptosis of I/R myocardium cells, respectively. The expression of cell apoptosis proteins and the levels of inflammatory factors were examined by Western blot and ELISA assay, respectively. The target relationship between miR-125b and SIRT7 was predicted by using StarBase3.0, and was confirmed by using dual-luciferase reporter gene assay. qRT-PCR, immunohistochemistry staining, and Western blot were used to evaluate the expression of SIRT7 in myocardium tissues in I/R rats. BMSC-derived exosomes were successfully isolated and identified by TEM and positive expression of CD9 and CD63. The expression of miR-125b was down-regulated in I/R myocardium tissues and cells. BMSC-Exo-125b significantly up-regulated miR-125b in I/R myocardium cells. The intervention of BMSC-Exo-125b significantly increased the cell viability, decreased the apoptotic ratio, down-regulated Bax and caspase-3, up-regulated Bcl-2, and decreased the levels of IL-1β, IL-6, and TNF-α in I/R myocardium cells. SIRT7 was a target of miR-125b, and BMSC-Exo-125b significantly down-regulated SIRT7 in myocardium cells. In addition, the injection of BMSC-Exo-125b alleviated the pathological damages and down-regulated SIRT7 in myocardium tissues of I/R rats. BMSC-derived exosomes carrying miR-125b protected against myocardial I/R by targeting SIRT7.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Liang Zong ◽  
Weixin Wang

Objective. This project is aimed at investigating whether CircANXA2 can promote the apoptosis of myocardial cells by inhibiting miR-133 expression and thereby participate in the development of myocardial ischemia-reperfusion injury. Materials and Method. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of CircANXA2 in H9c2 cells after hypoxia/reoxygenation (H/R) treatment. Evaluation of myocardial injury markers in H9c2 cells was performed using commercial kits, including lactate dehydrogenase (LDH), malonaldehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidation (GSH-PX). MTT analysis and flow cytometry were used to detect myocardial cell proliferation and apoptosis, respectively. Western blot was used to detect the protein expression of apoptosis-related genes. Result. qRT-PCR results showed that compared with the control, the expression of CircANXA2 was upregulated and the expression level of miR-133 was significantly decreased in H/R-treated H9c2 cells. CircANXA2 overexpression increased LDH, MDA, SOD, and GSH-PX activity in H/R-treated H9c2 cells. At the same time, CircANXA2 overexpression inhibited the proliferation of H/R-treated cells, and CircANXA2 was able to induce cardiomyocyte apoptosis. Western blot results showed that after overexpression of CircANXA2, the proapoptotic genes Bax and cytochrome C was upregulated, while the antiapoptotic gene Bcl-2 was downregulated. In H9c2 cells, upregulating miR-133 can reverse the inhibition of proliferation induced by CircANXA2 overexpression and increase apoptosis. Conclusions. CircANXA2 promotes cardiomyocyte apoptosis in myocardial ischemia-reperfusion injury by inhibiting the expression of miR-133. CircANXA2 may be a potential target for myocardial ischemia-reperfusion injury.


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