Salvianolic Acid A Protects H9C2 Cardiomyocytes from Doxorubicin-Induced Damage by Inhibiting NFKB1 Expression Thereby Downregulating Long-Noncoding RNA (lncRNA) Plasmacytoma Variant Translocation 1 (PVT1)

BACKGROUND: A cardioprotective effect of salvianolic acid A (SalA) has been described, but it is unknown whether SalA can protect cardiomyocytes against doxorubicin (Dox)-induced cardiotoxicity. This study aimed to investigate whether SalA could inhibit Dox-induced apoptosis in H9C2 cells and to uncover the potential mechanism. MATERIAL/METHODS: H9C2 cardiomyocytes exposed to Dox were treated with SalA or not, and then cell viability, apoptosis, and the expression of nuclear factor-κB (NF-κB) signaling were detected by Cell Counting Kit-8, TUNEL staining, and western blot assays, respectively. Nuclear factor kappa B subunit 1 (NFKB1) was overexpressed in H9C2 cells, and then alterations in cell viability and apoptosis in H9C2 cells co-treated with Dox and SalA were investigated. RESULTS: SalA (2, 10, and 50 μM) had no effect on H9C2 cell viability, while Dox reduced cell viability in a concentration-dependent manner. In addition, SalA rescued Dox-decreased cell viability. Dox also triggered apoptosis as evidenced by an increased ratio of TUNEL-positive cells, enhanced expression of pro-apoptotic proteins, and reduced expression of anti-apoptotic protein BCL-2, which were all partially blocked by SalA co-treatment. The proteins involved in NF-κB signaling including IκBα, IKKα, IKKβ, and p65 were activated by Dox but inactivated by SalA co-treatment. Moreover, Dox increased NFKB1 mRNA and nuclear expression, which was blocked by SalA. NFKB1 could bind to plasmacytoma variant translocation 1 (PVT1) and upregulate PVT1 expression. Mechanistically, the overexpression of NFKB1 blocked the inhibitory effect of SalA on Dox-induced cell viability impairment and apoptosis. CONCLUSIONS: We demonstrated that SalA may exert a protective effect against Dox-induced H9C2 injury and apoptosis via inhibition of NFKB1 expression, thereby downregulating lncRNA PVT1.