Evaluating Semaglutide's Protection in H/R - Injured AC16 Cardiomyocytes: Oxidative Stress, Inflammation, Apoptosis, and Autophagy Insights.

OBJECTIVE: Semaglutide shows potential in cardiovascular protection, yet its specific role and mechanism in H/R injury are unclear. Given the role of autophagy in cardiomyocyte protection and the unclear mechanism of semaglutide in H/R - induced injury, this study aims to assess semaglutide's protective effects on AC16 cardiomyocytes in an H/R model and probe its mechanism, focusing on autophagy. METHODS: AC16 cardiomyocytes were subjected to H/R to simulate H/R injury. Cells were divided into five groups: Control, H/R, H/R+Semaglutide, H/R+ Semaglutide+Rapamycin (autophagy activator), and H/R+Semaglutide+3-Methyladenine (3-MA, autophagy inhibitor). Cell viability, injury (LDH release), oxidative stress (MDA, SOD), and inflammation (IL-6, TGF-β) were assessed. Protein levels of cleaved caspase-3, caspase-9, Bax, Bcl-2, and the autophagy-related protein FUNDC1 were analyzed by Western blot. RESULTS: H/R treatment significantly decreased cell viability and increased LDH release, indicating severe cellular injury (< 0.05). Semaglutide treatment effectively restored cell viability and reduced LDH release. Furthermore, Semaglutide significantly attenuated H/R-induced oxidative stress, as shown by decreased MDA levels and restored SOD activity (< 0.05). The inflammatory response, characterized by elevated IL-6 and TGF-β, was also markedly suppressed by Semaglutide (< 0.05). Flow cytometry analysis revealed that Semaglutide significantly reduced the apoptosis rate. Western blotting confirmed that Semaglutide downregulated pro-apoptotic proteins (cleaved caspase-3, caspase-9, Bax) and upregulated the anti-apoptotic protein Bcl-2. Importantly, Semaglutide increased the expression of FUNDC1. The protective effects were enhanced by Rapamycin and attenuated by 3-MA, indicating that autophagy is involved in the cardioprotection. CONCLUSION: Semaglutide shows substantial protective efficacy in safeguarding AC16 from H/R-triggered injury. It operates by mitigating oxidative stress, dampening inflammatory processes, inhibiting apoptotic pathways. Importantly, this investigation revealed that the cardioprotective effect, to a considerable degree, mediated through its promotion of autophagy.