Inhibition of GRK2 reduced doxorubicin-induced oxidative stress and apoptosis through upregulating ADH1

Patients undergoing anti-cancer therapy with doxorubicin (DOX) face the risk of cumulative, irreversible cardiotoxicity. In failing hearts, the overexpressed and activated G protein-coupled receptor kinase 2 (GRK2) initiates pathological signaling, leading to cardiomyocyte death. This study aimed to investigate the potential role of GRK2 in DOX-induced cardiotoxicity (DIC).

Mice were administered intraperitoneal injections of DOX (5 mg/kg) weekly for four weeks to induce DIC. Small interfering RNAs (siRNAs) targeting GRK2, ADH1, and PABPC1 were employed in H9c2 cells. Oxidative stress and cell apoptosis were assessed using Reactive Oxygen Species (ROS) staining and TUNEL staining, respectively. Co-immunoprecipitation (Co-IP) was utilized to detect the interaction between GRK2 and PABPC1. RNA immunoprecipitation (RIP) assay was employed to evaluate the binding between PABPC1 and ADH1 mRNA.

GRK2 was found to be upregulated in DOX-treated mouse hearts and H9c2 cells. Cardiomyocyte-specific GRK2 knockout partially mitigated oxidative stress, apoptosis, and cardiac dysfunction. Additionally, GRK2 knockdown attenuated DOX-induced oxidative damage and apoptosis both in vivo and in H9c2 cells. Furthermore, a reduction in ADH1 expression was observed in DOX-treated hearts and cardiomyocytes, with a pronounced increase following GRK2 knockdown. Notably, the beneficial effects of GRK2 knockdown in H9c2 cells were abolished after ADH1 knockdown. Mechanistically, GRK2 knockdown promoted the binding of PABPC1 to ADH1 mRNA, thereby inhibiting the degradation of ADH1 mRNA. Increased ADH1 expression alleviated DOX-induced oxidative stress and apoptosis in cardiomyocytes.

In conclusion, our study demonstrates that targeting GRK2 may represent a promising therapeutic strategy for mitigating DOX-associated cardiotoxicity.