miR‐16 exhibits protective function in LPS‐treated cardiomyocytes by targeting DOCK2 to repress cell apoptosis and exert anti‐inflammatory effect

Abstract

This study aims to investigate the effects of microRNA (miR)‐16/dedicator of cytokinesis 2 (DOCK2) on myocarditis. The differences in the expression of genes in acute myocarditis were filtered out across Gene Expression Omnibus (GEO) database. Myocarditis cell model was established by lipopolysaccharide (LPS) stimulation in cardiomyocytes. The association between miR‐16 and DOCK2 was predicted by bioinformatics software and confirmed by dual‐luciferase assay. Polymerase chain reaction and western blot analysis were employed to assess the expression levels of miR‐16 and DOCK2 under different conditions. Cells viability, apoptosis, and inflammatory reaction were evaluated by Cell Counting Kit‐8, flow cytometry, and enzyme‐linked immunosorbent assays. miR‐16, as an upstream regulator of DOCK2, exhibited lower expression in LPS‐induced myocarditis model. More importantly, we revealed that a marked augmentation of miR‐16 promoted the growth of LPS‐stimulated cardiomyocytes, and attenuated cell apoptosis and inflammatory response. However, an increasing expression of DOCK2 inhibited the remission of LPS‐induced myocardial injury caused by miR‐16 mimic. Herein, our results highlighted that upregulation of miR‐16 resulted in the protective effects on LPS‐induced myocardial injury by reducing DOCK2 expression, affording a pair of novel target molecules for ameliorating the symptoms of myocarditis.

LncRNA CAIF suppresses LPS‐induced inflammation and apoptosis of cardiomyocytes through regulating miR‐16 demethylation

“…MiR-16 has also been found to have suppressive effects on inflammation in some diseases. [18][19][20][21] Our study found that, similar to CAI, miR-16 expression was decreased in sepsis-induced CHF patients. In addition, miR-16 expression in AC16 cells decreased with increasing LPS concentration, suggesting that miR-16 might be an inflammatory response resistance factor.…”

Insights from DOCK2 in cell function and pathophysiology

“…Analysis by the GSE35182 and GSE53607 databases showed that DOCK2 was significantly upregulated in myocarditis. And increased expression of DOCK2 was positively correlated with pro-inflammatory factors such as IL-6 and TNF-α ( Wang et al, 2020 ). The study revealed a correlation between miR-16 and DOCK2, with miR-16 expression significantly down-regulated in LPS-induced myocarditis.…”

“…The study revealed a correlation between miR-16 and DOCK2, with miR-16 expression significantly down-regulated in LPS-induced myocarditis. Then miR-16 depletion by inhibitors was followed by an elevated expression of DOCK2 at both mRNA and protein levels ( Wang et al, 2020 ). The miR-16 inhibitor promoted LPS-induced cardiomyocyte apoptosis and attenuated the effect of the miR-16 inhibitor on cardiomyocytes by inhibiting DOCK2 expression, and these phenomena could also be reversed by miR-16mimic treatment ( Wang et al, 2020 ).…”

“…Then miR-16 depletion by inhibitors was followed by an elevated expression of DOCK2 at both mRNA and protein levels ( Wang et al, 2020 ). The miR-16 inhibitor promoted LPS-induced cardiomyocyte apoptosis and attenuated the effect of the miR-16 inhibitor on cardiomyocytes by inhibiting DOCK2 expression, and these phenomena could also be reversed by miR-16mimic treatment ( Wang et al, 2020 ). Furthermore, miR-16 overexpression or miR-16 depletion inhibited or promoted TNF-α, IL-6 and IL-8 expression.…”

“…Furthermore, miR-16 overexpression or miR-16 depletion inhibited or promoted TNF-α, IL-6 and IL-8 expression. These phenomena were reversed by over-expression of DOCK2 or depletion of DOCK2 treatment ( Wang et al, 2020 ). In conclusion, DOCK2 is involved in the development and progression of myocarditis by regulating the expression and secretion of inflammatory factors.…”