[Study on the expressions and roles of renal heat shock protein 72 and Toll-like receptor 4 in hepatorenal syndrome in rat].

ABSTRACT

OBJECTIVE: To explore the expressions and roles of renal heat shock protein 72(HSP72) and Toll-like receptor 4(TLR4) during development of hepatorenal syndrome in rat. METHODS: Following bile duct ligation (BDL), a biliary cirrhosis and hepatorenal syndrome rat model was reproduced. The blood, the renal and hepatic tissues of the rats were examined at 1, 2, 4 and 6 weeks (6 rats were used in each week) after BDL. Blood was withdrawn from the femoral vein and centrifuged. The plasma concentrations of alanine aminotransferase (ALT), total bilirubin (TBil), blood urea nitrogen (BUN) and creatinine (Cr) were measured, and those of the HSP72 and tumor necrosis factor-alpha (TNF-alpha) were assessed with enzyme linked immunosorbent assay (ELISA). After weighing liver and kidney and expressions of HSP72 and TLR4 in renal tissue were determined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. All data were compared with control group (C group). RESULTS: The plasma levels of ALT, TBil at each week and of BUN, Cr at 4 and 6 weeks were increased significantly (all P<0.05). The concentration of plasma HSP72 and the expressions of renal HSP72 mRNA and protein were lower (especially at 4 and 6 weeks, both P<0.01) in BDL rats compared with sham operation rats. But the plasma TNF-alpha levels and renal TLR4 (mRNA and protein) expressions were significantly higher than those of sham operation rats (all P<0.01). CONCLUSION: Decreased expression of renal HSP72 may contribute to activate the TLR4- initiating inflammatory signal pathway, attributing partly to the pathogenesis of hepatorenal syndrome in biliary cirrhosis.