Aim of the study
This study aimed to investigate whether GAS, an active ingredient of G. elata Blume, can alleviate CP-induced AKI and to explore its underlying mechanisms. Materials and
Conclusions
GAS alleviated CP-induced AKI by inhibiting ferroptosis via the SIRT1/FOXO3A/GPX4 signaling pathway. The results offer new insights into the development of new anti-AKI drugs from traditional Chinese medicine.
Methods
Experiments were conducted with a CP-induced AKI mouse model and an immortalized human renal tubular epithelial cell line (HK-2). Serum creatinine, Periodic acid-Schiff staining, tissue iron, glutathione, malondialdehyde, and 4-Hydroxynonenal were detected in serum and kidney samples to observe whether GAS inhibits CP-induced tubule ferroptosis. The drug target was verified by detecting the effects of GAS on sirtuin-1 (SIRT1) activity in vitro. Transcriptional regulation of glutathione peroxidase 4 (GPX4) by forkhead box O3A (FOXO3A) was verified by siRNA knockdown, overexpression, and chromatin immunoprecipitation. The effects of FOXO3A, SIRT1, and GAS on CP-induced ferroptosis were measured with propidium iodide, dihydroethidium, monobromobimane, and dipyrromethene boron difluoride staining in HK-2 cells. The relationship between GAS and the SIRT1/FOXO3A/GPX4 pathway was studied using Western blotting.
Results
GAS treatment inhibited CP-induced reactive oxygen species, lipid peroxidation, and tubule death in the cell and animal models. GAS activated SIRT1 in vitro. The SIRT1 inhibitor blocked the protective role of GAS in reducing lipid peroxidation in HK-2 cells. FOXO3A transcriptionally regulated GPX4 expression and inhibited CP-induced cell ferroptosis. Compared to CP-damaged mouse kidneys, GAS-treated mice demonstrated significantly increased SIRT1 and GPX4 expression levels, decreased CP-induced acetylation of FOXO3A, and inhibited lipid peroxidation and cell death. Conclusions: GAS alleviated CP-induced AKI by inhibiting ferroptosis via the SIRT1/FOXO3A/GPX4 signaling pathway. The results offer new insights into the development of new anti-AKI drugs from traditional Chinese medicine.