Effect of rosiglitazone on the secretion of chemokines in renal tubular epithelial cells stimulated by lipopolysaccharide and the possible mechanism / 中华肾脏病杂志

ABSTRACT

Objective To investigate the inhibitory effect and mechanism of rosiglitazone on chemokines secretion in renal tubular epithelial cells (HK-2) stimulated by lipopolysaccharide (LPS). Methods Cells were divided into four groups control (CON), LPS (1 mg/L),rosiglitazone (10 μmol/L), rosiglitazone (10 μmol/L) +LPS (1 mg/L). MCP-1 and IL-8 expression was measured using real time PCR and ELISA. PPARγ was knockdown by RNAi to investigate whether the inhibitory effect of rosiglitazone was PPARγ-dependent or -independent. The NF-κB in nucleus was detected by Western blotting. The DNA binding activity of NF-κB was determined by electrophoretic mobility shift assay. Results Compared with CON group, the expressions of IL-8 and MCP-1 were increased by (4.30±0.45) and (4.80±1.29) times in mRNA level, (1.39±0.18)and (2.11 ±0.47) times in protein level, respectively, in LPS-stimulated HK-2 cells (P＜0.05).Application of rosiglitazone followed by LPS significantly reduced IL-8 and MCP-1 secretion compared with LPS group (decreasing by 66.37% and 71.88% in mRNA levels, while 41.68% and 47.87% in protein levels) (P＜0.05). In pcDNATM 6.2-GW/EmGFP-miPPARγ transfected cells, IL-8and MCP-1 only were decreased by 18.16% and 16.83% in mRNA level, while 11.39% and 11.86%% in protein level in rosiglitazone pretreated group, showing no significant difference compared with LPS group. Rosiglitazone did not block NF-κB nuclear translocation while significantly inhibiting the DNA binding activity of NF-κB. Conclusions Rosiglitazone inhibits the expressions of MCP-1 and IL-8 via a PPARγ-dependent mechanism in HK-2 cells, resulting from inhibition the DNA binding activity of NF-κB.