Abstract 9481: Inhibition of Apoptosis and Ferroptosis Signaling Pathways Alleviates Myocardial Ischemia-Reperfusion Injury in Rats Through Modulation of Mitochondrial Function

Introduction: Apoptosis and ferroptosis have been implicated in cardiac ischemia/reperfusion (I/R) injury. Inhibitors of apoptosis (Z-VAD) and ferroptosis (FER-1) have been shown to protect the heart in several cardiovascular disorders. However, the impacts of Z-VAD, FER-1, and combined therapy during cardiac I/R injury have not been elucidated. Hypothesis: Z-VAD and FER-1 provide cardioprotection by reducing myocardial cell injury and improving cardiac function. The combined treatment exerts better benefits than either single regimen. Methods: Male rats (n=25) were equally divided into 5 groups: sham, vehicle, Z-VAD at 3.3 mg/kg, FER-1 at 2 mg/kg, and combined FER-1 and Z-VAD. All treatments were intravenously injected to the rats 15 min before ischemia. Left anterior descending coronary was ligated for 30 min, followed by 120-min reperfusion in all animals except the sham group. Left ventricular ejection fraction (LVEF), infarct size, mitochondrial reactive oxygen species (ROS) production, and protein expressions of apoptosis and ferroptosis were determined. Results: Cardiac I/R injury led to cardiac mitochondrial dysfunction and cell death, contributed to infarct size expansion and LV dysfunction (Fig 1A-D). Z-VAD, FER-1 and combined treatments markedly increased %LVEF, reduced ROS levels and infarct size (the %reduction is 42.9%, 41.4%, and 47.7%, respectively, compared with vehicle). Cleaved caspase 3 (apoptosis) and ACSL4 (ferroptosis) expression levels were also reduced in those rats. The combined treatment did not show a significant advantage, compared with either single regimen (Fig 1A-D). Conclusions: Inhibitors of either apoptosis or ferroptosis similarly reduced cardiac mitochondrial dysfunction, apoptosis and ferroptosis, resulting in decreased infarct size, and finally leading to improved LV function. These findings indicate that ferroptosis could be a novel therapeutic target for cardioprotection in cardiac I/R injury.