Klf6 aggravates myocardial ischemia/reperfusion injury by activating Acsl4-mediated ferroptosis.

Abstract

Ferroptosis is closely related to myocardial ischemia/reperfusion (I/R) damage. Kruppel-like factor 6 (Klf6) can aggravate renal I/R injury. We aimed to elucidate the role of Klf6 in myocardial I/R damage as well as its potential mechanism. Myocardial I/R mice model and hypoxia/reoxygenation (H/R)-treated HL-1 cells were established. The levels of Fe²⁺ , MDA, lipid ROS, and ferroptosis-related proteins were measured for assessing ferroptosis. Infarct area, H&E staining, cardiac function, and cell viability were detected for evaluating myocardial injury. Immunohistochemistry, immunofluorescence, western blot, and RT-qPCR were applied for detecting the levels of related genes. The m6A modification of Klf6, as well as the relationships between Klf6 and Mettl3, Igf2bp2, or Acsl4 promoter, was evaluated using MeRIP, RNA immunoprecipitation, RNA pull-down, chromatin immunoprecipitation, and luciferase reporter assay accordingly.Klf6 protein and mRNA levels, as well as Klf6 m6A modification, were elevated in HL-1 cells subjected to H/R and in the heart tissues from I/R mice. In H/R-challenged HL-1 cells, the binding relationships between Klf6 mRNA and Igf2bp2 or Mettl3 were confirmed; moreover, Igf2bp2 or Mettl3 knockdown decreased the Klf6 level and inhibited Klf6 mRNA stability. Klf6 knockdown restrained H/R-triggered cell viability loss, improved I/R-induced myocardial injury, and inhibited ferroptosis in myocardial I/R damage models. Klf6 directly bound to the Acsl4 promoter and positively regulated its expression. Acsl4 overexpression compromised the Klf6 knockdown-generated protective effect in HL-1 cells.m6A modification-regulated Klf6 aggravated myocardial I/R damage through activating Acsl4-mediated ferroptosis, thereby providing one potential target for the treatment of myocardial I/R.