Inhibition of lncRNA XIST Improves Myocardial I/R Injury by Targeting miR-133a through Inhibition of Autophagy and Regulation of SOCS2

Abstract

The objective of this study was to investigate the role of lncRNA XIST and its relationship with miR-133a in myocardial I/R injury. H9C2 cells treated by hypoxia/reoxygenation (H/R) were used to establish an in vitro I/R model. The small interfering RNA (siRNA) for XIST and miR-133 mimics, inhibitor, and suppressor of cytokine signaling (SOCS2) recombinant plasmids were used to transfect the cells. Cell apoptosis was determined by flow cytometry analysis, and cell viability was used for 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide (MTT) assay. The dual-luciferase reporter assay was performed to confirm binding between XIST and miR-133a, as well as miR-133a and SOCS2. To inhibit or overexpress XIST, miR-133a, or SOCS2 in I/R mice, we used recombinant lentivirus vectors and adenovirus vectors for tail vein injection. The expression of XIST, miR-133a, and SOCS2 was determined by quantitative real-time PCR, and LC3 I/II and Beclin1 was determined by western blotting. The expression of XIST and SOCS2 was significantly upregulated, whereas the miR-133a level was remarkably downregulated in both H/R H9C2 cells and I/R mice myocardial tissues. In both H/R H9C2 cells and I/R mice, the inhibition of XIST led to decreased apoptosis and autophagy, and inhibition of miR-133a reversed these effects. Similarly, overexpression of miR-133a resulted in reduced apoptosis and autophagy, which were reversed by overexpression of SOCS2. The inhibition of XIST and overexpression of miR-133a also promote cell viability of H/R cells. The dual-luciferase reporter assay significantly showed that XIST directly targeted on miR-133a, and miR-133a directly targeted on SOCS2. The inhibition of XIST could improve myocardial I/R injury by regulation of the miR-133a/SOCS2 axis and inhibition of autophagy.

Total Glucosides of Paeony Alleviate Cell Apoptosis and Inflammation by Targeting the Long Noncoding RNA XIST/MicroRNA-124-3p/ITGB1 Axis in Renal Ischemia/Reperfusion Injury

“…Interference of XIST exerts protective functions in IRI. XIST knockdown restrains cell apoptosis and autophagy in myocardial tissues of IRI mice [ 43 ]. XIST silencing reduces the levels of TNF- α and IL-6 in a rat acute kidney injury model caused by I/R [ 17 ].…”

Retracted: Long non‐coding RNA XIST binding to let‐7c‐5p contributes to rheumatoid arthritis through its effects on proliferation and differentiation of osteoblasts via regulation of STAT3

“…In addition, a previous study has revealed the elevation in lncRNA XIST expression in myocardial I/R injury. 38 Moreover, lncRNA XIST is reported to be negatively correlated with miR-449a expression. 39 Accumulating evidence has suggested that the deregulation of miRs exerts great effects on the development and progression of RA.…”

Autophagy in cardiovascular diseases: role of noncoding RNAs

“…miR-133a directly targets SOCS2 to suppress apoptosis and autophagy and promote cell viability. 92 XIST knockdown inhibits autophagy and cell apoptosis through the downregulation of miR-133a and attenuation of the MI area after I/R injury. 92 …”