Heat shock protein 22 alleviates doxorubicin-induced kidney injury by suppressing oxidative stress and apoptosis

This study investigated the effects of heat shock protein 22 (HSP22) against doxorubicin (DOX)-induced kidney injury. Mice were randomly assigned to four groups: CON, ad-HSP22, DOX, and ad-HSP22 + DOX. Adeno-associated virus carrying the HSP22 gene (ad-HSP22) was administered via tail vein injection for four weeks, followed by intraperitoneal simulation with DOX (20 mg/kg) for another five days. Upon euthanasia, ELISA, histological staining (H&E, IHC, DHE, and TUNEL), and western blot analyses were employed to assess relevant markers. Serum biomarkers of kidney injury, SCr, and BUN, were upregulated after DOX administration but normalized with HSP22 overexpression. Pathological changes induced by DOX were also reversed by HSP22 overexpression in H&E, IHC, DHE, and TUNEL stains. DOX-induced upregulation of NOX-2 and NOX-4 and downregulation of SOD-1 and SOD-2 were reversed by HSP22 overexpression. Similarly, DOX-induced increases in Bax and decrease in Bcl-2 were attenuated by HSP22 overexpression. The study further demonstrated that the Nrf2/HO-1 signaling pathway was activated by HSP22 overexpression. In vitro experiments corroborated the findings from in vivo experiments. In conclusion, HSP22 alleviates DOX-induced kidney injury by suppressing oxidative stress and apoptosis, primarily through the activation of the Nrf2/HO-1 signaling pathway. These results suggest HSP22 as a potential therapeutic target for DOX-induced kidney injury.