Astragaloside IV Inhibits the Pyroptosis in the Acute Kidney Injury through Targeting the SIRT1/FOXO3a Axis.

Abstract

Acute kidney injury (AKI) is a commonly encountered critical condition in clinical settings, often resulting from sepsis, infections or ischemia. Astragaloside IV (AS-IV) is the primary active component of Astragalus. The functions of Astragalus are mainly related to AS-IV, showing remarkable therapeutic effects in anti-inflammatory, antioxidant, immune-enhancing, and anti-tumor aspects. This study aimed to explore the role of AS-IV in AKI development. Lipopolysaccharide (LPS) was used to stimulate the HK-2 cells and rats to establish the AKI model in vivo and in vitro. After AS-IV treatment, the cell viability, pyroptosis rate, lactate dehydrogenase (LDH) activity, interleukin (IL)-18 and IL-1β contents, and cleaved-caspase-1, GSDMD-N, SIRT, FOXO3a protein levels were detected. Caspase-1 levels were analyzed by immunofluorescence staining. Additionallly, the acetylation levels of FOXO3a were detected by immunoprecipitation and Western blot assays. AS-IV treatment promoted the cell viability, and inhibited the pyroptosis, LDH activity, caspase-1 levels in the LPS stimulated HK-2 cells. AS-IV treatment decreased the IL-18 and IL-1β contents, cleaved-caspase-1 and GSDMD-N protein levels in both LPS stimulated HK-2 cells and rats. Furthermore, after EX527 treatment, a Sirtuin 1 (SIRT1) inhibitor, the role of AS-IV in the LPS stimulated HK-2 cells were reversed. AS-IV treatment increased the protein levels and decreased the acetylation levels of FOXO3a, which was reversed after EX527 treatment. Co-immunoprecipitation (CO-IP) assay and immunofluorescence staining confirmed that SIRT1 interacted with FOXO3a. In conclusion, this research demonstrated that AS-IV treatment inhibited the pyroptosis occurrence in LPS stimulated HK-2 cells and rats. This may be related to the SIRT1 mediated deacetylation of FOXO3a.