DEX Inhibits H/R-induced Cardiomyocyte Ferroptosis by the miR-141-3p/lncRNA TUG1 Axis.

Background:  Ferroptosis is emerging as a critical pathway in ischemia/reperfusion (I/R) injury, contributing to compromised cardiac function and predisposing individuals to sepsis and myocardial failure. The study investigates the underlying mechanism of dexmedetomidine (DEX) in hypoxia/reoxygenation (H/R)-induced ferroptosis in cardiomyocytes, aiming to identify novel targets for myocardial I/R injury treatment.

Methods:  H9C2 cells were subjected to H/R and treated with varying concentrations of DEX. Additionally, H9C2 cells were transfected with miR-141-3p inhibitor followed by H/R treatment. Levels of miR-141-3p, long noncoding RNA (lncRNA) taurine upregulated 1 (TUG1), Fe²⁺, glutathione (GSH), and malondialdehyde were assessed. Reactive oxygen species (ROS) generation was measured via fluorescent labeling. Expression of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4 (ACSL4) was determined using Western blot. The interaction between miR-141-3p and lncRNA TUG1 was evaluated through RNA pull-down assay and dual-luciferase reporter gene assays. The stability of lncRNA TUG1 was assessed using actinomycin D.

Results:  DEX ameliorated H/R-induced cardiomyocyte injury and elevated miR-141-3p expression in cardiomyocytes. DEX treatment increased cell viability, Fe²⁺, and ROS levels while decreasing ACSL4 protein expression. Furthermore, DEX upregulated GSH and GPX4 protein levels. miR-141-3p targeted lncRNA TUG1, reducing its stability and overall expression. Inhibition of miR-141-3p or overexpression of lncRNA TUG1 partially reversed the inhibitory effect of DEX on H/R-induced ferroptosis in cardiomyocytes.

Conclusion:  DEX mitigated H/R-induced ferroptosis in cardiomyocytes by upregulating miR-141-3p expression and downregulating lncRNA TUG1 expression, unveiling a potential therapeutic strategy for myocardial I/R injury.