Reduced glutathione ameliorates acute kidney injury by inhibiting ferroptosis

Abstract

Reduced glutathione (RGSH) can participate in the redox process in the body and inhibit damage to important organs caused by free radicals. Due to its broad biological effects, in addition to its clinical applications in treatment of liver diseases, RGSH is also used in the treatment of numerous other diseases, such as malignant tumors and nerve, urological and digestion diseases. However, there are few reports of RGSH being used in treatment of acute kidney injury (AKI), and the mechanism of its action in AKI is not clear. To assess the possible mechanism of RGSH inhibition in AKI, a mouse AKI model and HK-2 cell ferroptosis model were built to perform in vitro and in vivo experiments. The levels of blood urea nitrogen (BUN) and malondialdehyde (MDA) before and after the RGSH treatment were assessed, and the pathological changes of the kidneys were assessed using hematoxylin and eosin staining. Immunohistochemical (IHC) methods were used to evaluate the expressions of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase (GPX4) in the kidney tissues, reverse transcription-quantitative PCR and western blotting were used to assess the levels of ferroptosis marker factors in the kidney tissues and HK-2 cells, and flow cytometry was used to assess cell death. The results indicated that, RGSH intervention reduced the BUN and serum MDA levels, and ameliorated glomerular damage and the level of renal structure damage in the mouse model. IHC results demonstrated that RGSH intervention could significantly reduce the ACSL4 mRNA expression level and inhibit iron accumulation, and significantly upregulate the GPX4 mRNA expression level. Moreover, RGSH could inhibit ferroptosis induced by ferroptosis inducers erastin and RSL3 in HK-2 cells. Cell assay results demonstrated that RGSH could improve the lipid oxide level and cell viability, and inhibit cell death, so as to ameliorate the effects of AKI. These results suggested that RGSH could ameliorate AKI by inhibiting ferroptosis, which indicates RGSH as a promising therapeutic strategy for the treatment of AKI.