The effect of salvianolate on cardiomyocyte remodeling improvement after myocardial infarction through calcineurin/nuclear factor C3 of the activated T cell/B-myosin heavy chain pathway regulation.

Abstract

Enormous evidences in clinic and experimental studies have demonstrated that salvianolate (Sal) could treat cardiovascular diseases such as myocardial infarction (MI), but the underlying mechanism was still needed to be explored. This study aims to investigate the effect of Sal on cardiomyocyte remodeling after MI in rats and explore whether the possible mechanism was related to decreasing the β-myosin heavy chain (β-MHC) expression in cardiomyocytes via the calcineurin (CaN)/nuclear factor C3 of the activated T cell (NFATc3) pathway. Both MI model and angiotensin II induced primary myocardial cells obtained from rats were used in this study. After treatment with Sal, the cardiac function was assessed by color Doppler echocardiography, while MI area, myocardial cell area and heart mass index (HMI) were analyzed via Masson and hematoxylin and eosin staining (HE) stain, respectively. Additionally, CaN activity, and CaN, NFATc3, β-MHC mRNA and protein expressions in myocardial tissue and myocardial cells were tested via corresponding methods, mainly including real-time fluorescence-based quantitative polymerase chain reaction (RT-qPCR), Western blot (WB), immunohistochemistry and fluorescence staining analysis. As a result we obtained the high dose of Sal in vivo could perform beneficial effects on cardiomyocyte remodeling of MI rats, mainly manifesting as improving fractional shortening and ejection fraction rates, reducing the MI area, myocardial cross-sectional area and HMI (P<0.05, 0.01), inhibiting the activity of CaN in myocardial tissue, down-regulating b-MHC mRNA and protein expressions, and decreasing the nuclear translocation of NFATc3 (P<0.05). In the in vitro experiments, 10 μmol/L of Sal could inhibit the increase of the myocardial cell area and CaN activity, down-regulate the mRNA and protein of CaN A subunit, β-MHC; and inhibit the nuclear translocation of NFATc3 (P<0.05, 0.01). In conclusion: use of Sal can improve cardiomyocyte remodeling and down-regulate the expression of β-MHC in cardiomyocytes, of which the mechanism might be related to the reduction of the nuclear translocation of NFATc3 as well as the down-regulation of CaNA subunit expression and/or the inhibition of CaN activity. The results will provide a laboratory basis for the clinical application of Sal.