Vitamin D attenuates diabetic myocardial injury via the Erbb4/ferroptosis axis

BackgroundHyperglycemia and hyperlipidemia lead to the ferroptosis, well as the phosphorylation of Erbb4, and thereby increase the risk of cardiac hypertrophy. Thus, our investigation aims to explore whether vitamin D could mitigate diabetic cardiac injury through modulation of the Erbb4/ferroptosis axis. Methods and resultsKKAy mice fed on a high-fat diet were utilized to construct the prediabetic model, which showed an up-regulated phosphorylation of Erbb4, with concurrent ferroptosis in cardiac tissues. Following the intervention with vitamin D for 16 weeks, the activity of Erbb4/YAP signaling was suppressed and the severeness of ferroptosis was improved. Meanwhile disturbances in glucose-lipid metabolism and insulin secretion induced by high fat were alleviated, along with improvements in cardiac hypertrophy and myocardial function. Moreover, we established an in vitro damage model by introducing H9c2 myocardial cells to high glucose (HG, 33.3 mM) and palmitic acid (PA, 0.25 mM). Unsurprisingly, similar results have been acquired after vitamin D supplementation. Subsequently, selective inhibitors of Erbb4 (Dacomitinib) and ferroptosis (Ferrostatin-1) were applied to evaluate the efficiency of Erbb4 signaling on modulating ferroptosis in vitro, and conclusively confirming that inhibiting of Erbb4 indeed reduce ferroptosis under HG and PA stimulus. Additionally, treatment of vitamin D was found to reduce cardiomyocyte hypertrophy and prevent cell death by inhibiting Erbb4 activity. Interestingly, the combined intervention of Vitamin D and Dacomitinib exerted a synergistic effect on ameliorating the abnormal conditions. ConclusionsOur study unveils, the correlation between Erbb4 and ferroptosis in diabetic heart. Providing evidences that vitamin D supplementation can improve ferroptosis related diabetic cardiac injury through inactivation of Erbb4. Proposing that the combination treatment of vitamin D and Erbb4 inhibitors may emerge as a highly feasible clinical strategy for diabetic myocardial injury.