Role and mechanism of ABL1 in myocardial necroptosis and cardiac ischemia/reperfusion injury

Abstract

BACKGROUND: ABL1 is involved in the regulation of multiple cellular processes, yet its functions within the cardiovascular system remains largely unexplored. In particular, its role in cardiac ischemia/reperfusion injury and necroptosis has not been reported. OBJECTIVE: To investigate the role of ABL1 in cardiac ischemia/reperfusion injury and myocardial necroptosis, as well as the underlying molecular mechanisms. METHODS: (1) Animal experiment: C57BL/6J mice were randomly divided into four groups: sham surgery group, ischemia/reperfusion group, ABL1 knockdown + ischemia/reperfusion group, and ABL1 negative control + ischemia/reperfusion group. Lentiviral vectors targeting ABL1 were injected in situ into the myocardium. One week later, ischemia/reperfusion injury was induced by ligation of the left anterior descending coronary artery followed by reperfusion. ABL1 protein expression, cardiac function, myocardial fibrosis, and cardiomyocyte surface area were assessed. (2) Cell experiment: H9c2 cells were divided into four groups: negative control cell line + PBS, ABL1 knockdown cell line + PBS, negative control cell line + H2O2 500 µmol/L, and ABL1 knockdown cell line + H2O2 500 µmol/L. Additionally, H9c2 cells were divided into five groups: negative control cell line + PBS, negative control cell line + H2O2 500 µmol/L, ABL1 knockdown cell line + H2O2 500 µmol/L, ABL1 knockdown cell line + Parkin overexpression adenovirus + H2O2 500 µmol/L, and ABL1 knockdown cell line + Parkin negative control adenovirus + H2O2 500 µmol/L. Cell viability, necroptosis, reactive oxygen species levels, and mitochondrial membrane potential were measured. Expression of ABL1, Parkin, and cyclophilin D was detected, and the interaction between ABL1 and Parkin was examined. RESULTS AND CONCLUSION: (1) ABL1 protein expression was significantly downregulated in the mouse cardiac ischemia/reperfusion model. (2) Knockdown of ABL1 exacerbated ischemia/reperfusion-induced cardiac dysfunction, as evidenced by decreased left ventricular ejection fraction and fractional shortening, and increased left ventricular end-systolic and end-diastolic diameters. (3) Knockdown of ABL1 promoted ischemia/reperfusion-induced myocardial fibrosis and aggravated ventricular remodeling. (4) ABL1 protein expression was significantly downregulated in the cardiomyocyte oxidative stress model. (5) Knockdown of ABL1 exacerbated oxidative stress-induced cell viability loss, necroptosis, and reactive oxygen species accumulation. (6) ABL1 regulated mitochondrial membrane permeability, modulated the expression of Parkin and cyclophilin D, and regulated cellular oxidative stress levels by targeting Parkin. (7) These results indicate that ABL1 expression is significantly downregulated in both in vivo ischemia/reperfusion and in vitro oxidative stress models, and knockdown of ABL1 aggravates cardiac ischemia/reperfusion injury and cardiomyocyte oxidative stress injury, acting through the Parkin-CypD pathway.

1. Introduction

Ischemic heart disease is one of the leading causes of global health burden and mortality. Although reperfusion therapies such as thrombolysis and percutaneous coronary intervention are effective in restoring blood flow, they can paradoxically exacerbate myocardial injury, leading to cardiac dysfunction, arrhythmias, fibrosis, and heart failure. This phenomenon is known as myocardial ischemia/reperfusion injury. Despite advances in treatment, effective interventions to prevent or reverse this injury remain limited.

Traditionally, necrosis was considered a passive and uncontrolled process. However, recent studies have revealed that necrosis can be regulated through specific molecular mechanisms, termed necroptosis. Necroptosis is characterized by cell swelling and plasma membrane rupture, leading to the release of damage-associated molecular patterns (DAMPs) and subsequent inflammation. It is mediated by extrinsic death receptor pathways and intrinsic mitochondrial pathways, and contributes to various cardiac diseases. For instance, in diabetic cardiomyopathy, necroptosis plays a major role, and its inhibition with Necrostatin-1 has shown protective effects.