Qishen Yiqi dropping pills improve isoproterenol-induced cardiomyocyte hypertrophy by regulating X-inactive specific transcript (XIST) expression in rats

BACKGROUND: This study aimed to explore the potential mechanism of Qishen Yiqi dropping pills (QYDPs) in the treatment of chronic heart failure (CHF) by regulating the expression of lncRNAs during CHF. METHODS: Differences in the expression of the long non-coding RNA (lncRNA), X-inactive specific transcript (XIST), in an isoproterenol (ISO)-induced cardiomyocyte hypertrophy model treated with QYDPs was analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). A cell counting kit-8 (CCK8) assay, flow cytometry (FCM), and enzyme linked immunosorbent assay (ELISA) were used to analyze the protective effects of QYDPs on the proliferation rate, apoptosis, myocardial enzyme, oxidative stress, and inflammation of cardiomyocytes, as well as the molecular mechanism of XIST. RESULTS: Our results showed that in the ISO-induced cardiomyocyte hypertrophy model, XIST expression and apoptosis were increased, the cell proliferation rate was decreased, and myocardial enzyme levels increased [i.e., increased lactate dehydrogenase (LDH) and creatine kinase (CK) levels]. Furthermore, cellular oxidative stress [i.e., increased malondialdehyde (MDA) levels and decreased superoxide dismutase (SOD) levels] and inflammatory response [i.e., increased interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α protein secretion] were also promoted. QYDP treatment effectively mitigated the effects of ISO induction. Subsequently, we found that suppressing XIST expression reversed the effect of ISO induction, whereas overexpression (ov) of XIST enhanced the effect of ISO induction. Finally, this study confirmed that QYDP treatment improved the ISO-induced decrease in proliferation, apoptosis, and promotion of oxidative stress and inflammatory response in cardiomyocytes, whereas ov of XIST partially negated the effect of QYDPs. CONCLUSIONS: QYDPs protected H9c2 cells from ISO-induced damage by downregulating XIST expression.