Effect of high glucose on toll-like receptor 4 expression and LPS-induced proinflammatory cytokine production in hepatic stellate cells in vitro / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of high glucose on the expressions of toll-like receptor 4 (TLR4) and proinflammatory cytokine production induced by lipopolysaccharide (LPS) in hepatic stellate cells in vitro.</p><p><b>METHODS</b>Hepatic stellate cell line T6 was cultured in vitro and stimulated by high glucose. The mRNA and protein expression of TLR4 were detected by RT-PCR and Western blotting, respectively. After a 24-h pretreatment with high or low glucose, the cells were stimulated with LPS for 2 h, and Western blotting was used to detect the nuclear translocation of nuclear factor-κB (NF-κB); at 24 h of LPS exposure, the cells were examined for MCP-1 and IL-6 mRNA and protein expression levels with RT-PCR and ELISA, respectively.</p><p><b>RESULTS</b>High glucose significantly increased the mRNA and protein expressions of TLR4 (P<0.01) in a time- and dose-dependent manner. High glucose promoted NF-κB nuclear translocation and significantly enhanced the expression and secretion of both MCP-1 and IL-6 (P<0.01). Pretreatment with high glucose significantly promoted LPS-induced NF-κB nuclear translocation (P<0.01) and the mRNA expression and secretion of MCP-1 and IL-6.</p><p><b>CONCLUSIONS</b>High glucose can increase TLR4 mRNA and protein expressions in hepatic stellate cells and promote LPS-induced NF-κB activation and production of proinflammatory cytokines.</p>