Phillygenin ameliorates myocardial ischemia-reperfusion injury by inhibiting cuproptosis via the autophagy-lysosome degradation of CTR1

Abstract

Myocardial ischemia-reperfusion injury (MI/RI) is a major contributor to poor outcomes after revascularization in patients with myocardial infarction, largely due to the absence of targeted therapies. Phillygenin (PHI), a bioactive compound isolated from Forsythia suspensa, has been found to confer various pharmacological properties, including anti-inflammatory, hepatoprotective, and renal protective effects. However, the specific role of PHI in MI/RI remains largely unclear. Thus, this study aims to investigate whether PHI exerted cardioprotective effects against MI/RI, and if so, to elucidate the underlying molecular mechanisms. Hypoxia/reoxygenation (H/R) models in H9c2 cardiomyocytes and MI/RI mouse models were established. PHI intervention markedly improved cardiac function, reduced myocardial infarct size, and attenuated cardiomyocyte damage in MI/RI mice. PHI treatment significantly reversed H/R-induced cellular injury and mitochondrial dysfunction in cultured cardiomyocytes. Notably, PHI administration significantly mitigated myocardial cuproptosis, rather than pyroptosis and ferroptosis. Specifically, PHI reduced cardiomyocyte cuproptosis by downregulating the protein expression of ferredoxin 1 (FDX1) and lipoyl synthase (LIAS), and suppressing copper accumulation. Induction of cuproptosis abolished the cardiac benefits of PHI in vivo and in vitro. Mechanistically, PHI promoted the lysosomal localization and degradation of the copper transporter 1 (CTR1), thus alleviating cuproptosis, inflammation, oxidative stress, and mitochondrial injury in cardiomyocytes. Overall, PHI may be a promising therapeutic agent for the alleviation of MI/RI-induced cardiac dysfunction through the inhibition of cuproptosis via facilitating the transfer of CTR1 to the lysosome for degradation.

Keywords: Autophagy; Cuproptosis; Lysosome; Mitochondrial function; Myocardial ischemia-reperfusion injury; Oxidative stress.