ZLY032 mediated activation of Notch1/Hes1 signaling inhibits cardiomyocyte ferroptosis to protect against myocardial Ischemia-Reperfusion injury in mice.

Myocardial ischemia/reperfusion (I/R) injury seriously compromises patients' prognosis and survival rates. Accumulating evidence shows that ferroptosis is intricately involved in myocardial I/R injury. The activation of Notch1 exerts a protective effect on the heart. However, whether it plays a cardioprotective role by inhibiting cardiomyocyte ferroptosis and what the underlying mechanisms are remain unclear. Here, we found that activating the Notch1/Hes1 signaling pathway during the ischemia/reperfusion (I/R) can effectively inhibit the levels of lipid peroxidation and oxidative stress in cardiomyocytes, thereby suppressing myocardial ferroptosis. In addition, we identified a small molecule compound, ZLY032, which is an agonist of PPARδ and possesses anti-inflammatory and antioxidant activities. Treatment with ZLY032 potently alleviated I/R-mediated cardiac contractile impairment, decreased the infarct area and mitigated cardiomyocyte ferroptosis. Mechanistically, the Notch intracellular domain (NICD)interacts with GPX4 to inhibit its degradation. As a PPARδ agonist, ZLY032 activates the Notch1/Hes1 signaling pathway in a PPARδ-dependent manner, thereby inhibiting myocardial ferroptosis and exerting a cardioprotective effect. In conclusion, our study elucidates that Notch1 inhibits cardiomyocyte ferroptosis by modulating the protein stability of GPX4. Moreover, ZLY032 serves as a novel protective agent against myocardial ischemia-reperfusion injury， exerts its effects by relying on PPARδ-mediated upregulation of the Notch1/Hes1 signaling pathway and the subsequent reinforcement of GPX4 protein stability, highlighting the potential of ZLY032 as a promising therapeutic agent for treating myocardial I/R injury.