Uric acid induces inflammatory injury in HK-2 cells via PI3K/AKT/NF-κB signaling pathway / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the effects and underlying mechanisms of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/NF-κB signaling pathway in human kidney-2(HK-2) cells of hyperuricemic nephropathy.Methods:HK-2 cells were cultured in vitro and randomly divided into control group and experimental group. The experimental group was induced by high uric acid (720 μmol/L) immersion for 48 h to establish a cell model of hyperuricemic nephropathy in vitro and subsequently divided into hyperuricemic group, overexpressed protease activated receptor 2 (PAR2) and knockdown PAR2 group. The expressions of PAR2, PI3K, AKT, NF-κB mRNA were measured by real-time PCR. The expressions of PAR2, PI3K, AKT and NF-κB protein were measured by Western blotting. The expressions of tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), pro-interleukin-1β (pro-IL-1β), interleukin-1β (IL-1β) and transforming growth factor-β1 (TGF-β1) were detected by enzyme linked immunosorbent assay (ELISA). Results:(1) Compared with the control group, the expressions of PAR2, PI3K, AKT and NF-κB mRNA and protein in hyperuricemic group were significantly increased (all P<0.05), the expressions of TNF-α, MCP-1, IL-6, pro-IL-1β, IL-1β and TGF-β1 in the supernatant in hyperuricemic group were significantly increased (all P<0.01). (2) Compared with the hyperuricemic group, the expressions of PAR2, PI3K, AKT and NF-κB mRNA and protein in overexpressed PAR2 group were significantly increased (all P<0.05), the expressions of TNF-α, MCP-1, IL-6, IL-1β and TGF-β1 in the supernatant were significantly increased (all P<0.05). (3) Compared with the hyperuricemic group, the expression of PAR2, PI3K, AKT and NF-κB mRNA and protein in knockdown PAR2 group were significantly decreased (all P<0.05), the expressions of IL-6, pro-IL-1β, IL-1β and TGF-β1 in the supernatant were significantly decreased (all P<0.05). Conclusions:In the process of uric acid-induced HK-2 cell damage, uric acid significantly up-regulates the expression of PI3K/AKT/NF-κB signaling pathway by activating PAR2, leading to a marked increase in inflammatory damage. Knocking down PAR2 inhibits the expression of PI3K/AKT/NF-κB signaling pathway, which can effectively reduce the inflammatory damage of HK-2 cells.