Protective Effects of NaHS/miR-133a-3p on Lipopolysaccharide-Induced Cardiomyocytes Injury

Abstract

Objective. The aim of this study was to investigate the effects of sodium hydrosulfide (NaHS) on Lipopolysaccharide (LPS)-induced cardiomyocyte injury in H9c2 cells. Methods. H9c2 cardiomyocytes cultivated with medium containing 10 μg/mL LPS were used to recapitulate the phenotypes of those in sepsis. Two sequential experiments were performed. The first contained a control group, a LPS group, and a LPS + NaHS group, with the aim to assure the protective effects of NaHS on LPS-treated cardiomyocytes. The second experiment added a fourth group, the LPS + NaHS + miR-133a-3p inhibition group, with the aim to preliminarily explore whether miR-133-3p exerts a protective function downstream of NaHS. The adenosine triphosphate (ATP) kit was used to detect ATP content; real-time quantitative polynucleotide chain reaction (qPCR) was used to measure the levels of mammalian targets of rapamycin (mTOR), AMP-dependent protein kinase (AMPK), and miR-133a-3p, and Western blot (WB) was used to detect protein levels of mTOR, AMPK, myosin-like Bcl2 interacting protein (Beclin-1), microtubule-associated protein 1 light chain 3 (LC3I/II), and P62 (sequestosome-1, sqstm-1/P62). Results. Compared with the control group, the expressions of miR-133a-3p ( $P$  < 0.001), P62 ( $P$  < 0.001), and the content of ATP ( $P$  < 0.001) decreased, while the expressions of Beclin-1 ( $P$  = 0.023) and LC3I/II ( $P$  = 0.048) increased in the LPS group. Compared with the LPS group, the expressions of miR-133a-3p ( $P$  < 0.001), P62 ( $P$  < 0.001), and the content of ATP ( $P$  < 0.001) in the NaHS + LPS group increased, while the expressions of Beclin-1 ( $P$  = 0.023) and LC3I/II ( $P$  = 0.022) decreased. Compared with the NaHS + LPS group, the expression levels of miR-133a-3p ( $P$  < 0.001), P62 ( $P$  = 0.001), and the content of ATP ( $P$  < 0.001) in the LPS + NaHS + miR-133a-3p inhibition group were downregulated, and the expression levels of Beclin-1 ( $P$  = 0.012) and LC3I/II ( $P$  = 0.010) were upregulated. The difference was statistically significant. There was no significant difference in the expression of AMPK and mTOR between groups. Conclusion. Our research demonstrated that NaHS relieved LPS-induced myocardial injury in H9c2 by promoting the expression of miR-133a-3p, inhibiting autophagy in cardiomyocytes, and restoring cellular ATP levels.