Astragaloside IV protects renal tubular epithelial cells with hypoxia reoxygenation by regulating Th1/Th2 balance

Abstract

Objective To investigate the molecular mechanism of immune regulation of astragaloside Ⅳ(Ast) on hypoxia reoxygenation renal tubular epithelial cells (HK-2 cells). Methods HK-2 cells were divided into normal cell group, hypoxia reoxygenation group, and hypoxia reoxygenation + Ast group. The anoxic environment was simulated in the incubating container with anaerobic incubation bag.Hypoxia reoxygenation HK-2 cell group was treated with hypoxia for 1 h and then reoxygenated for 1 h; in hypoxia reoxygenated HK-2 cells + Ast group, hypoxia reoxygenated HK-2 cells were added to 250 mg/L astragaloside solution; normal group was cultured under normal conditions. After 24 hours, cells were observed directly under the inverted microscope. The expression of TNF-α, IFN-γ, IL-4 and IL-10 mRNA was detected by RT-PCR.The apoptosis rate of each group was detected by Annexin V/PI staining and flow cytometry. Results Compared with the hypoxia reoxygenation group, the number of cells in the hypoxia reoxygenation + Ast treatment group was significantly increased, the growth state was improved and the apoptosis rate was decreased. Compared with the normal control group, hypoxia-reoxygenation group increased the levels of Th1 cytokines (TNF-α and IFN-γ) and Th2 cytokines (IL-4 and IL-10)(P<0.01). The increase of Th2 cytokines was higher than that of Th1 cytokines, and the Th1/Th2 ratio was decreased. Compared with the hypoxia-reoxygenation group, hypoxia-reoxygenated cells and Ast-treated group had decreased levels of Th1-type and Th2-type cytokines (P<0.05), and the Th2-type cytokines showed a greater decrease than Th1-type cytokines. Conclusions Astragaloside Ⅳ can improve Th1/Th2 imbalance by affecting secretion of various cytokines, and has a protective effect on hypoxia-reoxygenating renal tubular epithelial cells. Key words: Acute kidney injury; Hypoxia reoxygenation; Renal tubular epithelial