Sacubitril/valsartan attenuated myocardial inflammation, fibrosis, apoptosis and promoted autophagy in doxorubicin-induced cardiotoxicity mice via regulating the AMPKα-mTORC1 signaling pathway

Abstract

This study aimed to investigate the potential cardioprotective effects of sacubitril/valsartan (Sac/Val) in mice with doxorubicin (DOX)-induced cardiomyopathy, a common manifestation of cancer therapy-related cardiac dysfunction (CTRCD) associated with DOX. A total of thirty-two mice were equally classified into 4 groups: control group, DOX (total 24 mg/kg), Sac/Val (80 mg/kg), and Sac/Val + DOX (Sac/Val was given from seven days before doxorubicin administration). Neonatal rat ventricular myocytes was exposed to 5 µM of DOX for 6 h in vitro to mimic the in vivo conditions. A variety of techniques were used to investigate cardiac inflammation, fibrosis, apoptosis, and autophagy, including western blot, real-time quantitative PCR (RT-qPCR), immunohistochemistry, and fluorescence. Mice with DOX-induced cardiotoxicity displayed impaired systolic and diastolic function, characterized by elevated levels of cardiac inflammation, fibrosis, cardiomyocyte hypertrophy, apoptosis, and autophagy inhibition in the heart. Treatment with Sac/Val partially reversed these effects. In comparison to the control group, the protein expression of NLRP3, caspase-1, collagen I, Bax, cleaved caspase-3, and P62 were significantly increased, while the protein expression of Bcl-2 and LC3-II were significantly decreased in the myocardial tissues of the Dox-induced cardiomyopathy group. The administration of Sac/Val demonstrated the potential to partially reverse alterations in protein expression within the myocardium of mice with DOX-induced cardiotoxicity by modulating the AMPKα-mTORC1 signaling pathway and suppressing oxidative stress. Additionally, Sac/Val treatment may mitigate Dox-induced apoptosis and inhibition of autophagy in primary cardiomyocytes. Sac/Val seems to be cardioprotective against DOX-induced cardiotoxicity in the pre-treatment mice model. These findings could be attributed to the anti-inflammatory, antioxidant, anti-apoptotic, and de-autophagy effects of Sac/Val through regulation of the AMPKα-mTORC1 signaling pathway.

Keywords: Apoptosis; Cardiotoxicity; Doxorubicin; Sacubitril/valsartan.