AIM: To investigate the expression of toll-like receptor 4(TLR4) and MD-2 gene and protein in Kupffer cells (KCs)and their role in ischemia-reperfusion (IR) injury of ratliver graft.METHODS: KCs were isolated at 0 (co...AIM: To investigate the expression of toll-like receptor 4(TLR4) and MD-2 gene and protein in Kupffer cells (KCs)and their role in ischemia-reperfusion (IR) injury of ratliver graft.METHODS: KCs were isolated at 0 (control group), 2, 12,24 h (IR group) following IR in rat liver graft, mRNA expressionof TLR4 and MD-2 was detected by RT-PCR analysis, proteinexpression of TLR4/MD-2 was detected by flow cytometric(FCM) analysis, and tumor necrosis factor-(~ (TNF-(~) levelin supernatant was measured by ELISA. Then isolated KCswere incubated with anti-TLR4 polyclonal antibody (anti-TLR4 group), and TNF-(~ level was measured again.RESULTS: The mRNA and protein expression of TLR4/MD-2 and the level of TNF-(~ in IR group increased significantlyat 2 h following IR, and reached the maximum at 12 h, andslightly decreased at 24 h, but were still significantly higherthan those in the control group (P<O.01). The expression ofthese factors was markedly decreased after anti-TLR4antibody treatment as compared with the IR group (P<O.01).CONCLUSION: Lipopolysaccharide (LPS) following IR canup-regulate TLR4/MD-2 gene and protein expression inKCs, and synthesize cytokine TNF-(~. Anti TLR4 antibodycan inhibit the production of TNF-(~ induced by LPS. TLR4and its partner molecule MD-2 may play an important rolein Kupffer cell activation and IR injury.展开更多
文摘目的探讨脂多糖作用小鼠RAW264.7巨噬细胞24 h内细胞表面TLR4/CD14/MD-2受体复合物表达的变化特点。方法分别用低剂量(100 ng/ml)和高剂量(1 000 ng/ml)脂多糖刺激RAW264.7,应用RT-PCR检测TLR4、CD14、MD-2m RNA水平的变化,ELISA检测细胞上清TNF-α含量的变化。结果低剂量脂多糖下调TLR4 m RNA表达,14 h降至最低,24 h维持在低水平表达;CD14和MD-2 m RNA表达增加。高剂量脂多糖上调TLR4 m RNA表达,1 h上升至高峰,此后维持在高水平表达;CD14和MD-2 m RNA表达也明显增强。高剂量脂多糖作用后TNF-α含量显著高于低剂量脂多糖(P<0.05)。结论高剂量脂多糖逆转低剂量脂多糖下调的TLR4表达,提高TLR4/CD14/MD-2受体复合物的表达水平,放大下游信号转导通路的炎症效应。
基金Supported by the National Natural Science Foundation of China,No.30300337,30200278,30170919
文摘AIM: To investigate the expression of toll-like receptor 4(TLR4) and MD-2 gene and protein in Kupffer cells (KCs)and their role in ischemia-reperfusion (IR) injury of ratliver graft.METHODS: KCs were isolated at 0 (control group), 2, 12,24 h (IR group) following IR in rat liver graft, mRNA expressionof TLR4 and MD-2 was detected by RT-PCR analysis, proteinexpression of TLR4/MD-2 was detected by flow cytometric(FCM) analysis, and tumor necrosis factor-(~ (TNF-(~) levelin supernatant was measured by ELISA. Then isolated KCswere incubated with anti-TLR4 polyclonal antibody (anti-TLR4 group), and TNF-(~ level was measured again.RESULTS: The mRNA and protein expression of TLR4/MD-2 and the level of TNF-(~ in IR group increased significantlyat 2 h following IR, and reached the maximum at 12 h, andslightly decreased at 24 h, but were still significantly higherthan those in the control group (P<O.01). The expression ofthese factors was markedly decreased after anti-TLR4antibody treatment as compared with the IR group (P<O.01).CONCLUSION: Lipopolysaccharide (LPS) following IR canup-regulate TLR4/MD-2 gene and protein expression inKCs, and synthesize cytokine TNF-(~. Anti TLR4 antibodycan inhibit the production of TNF-(~ induced by LPS. TLR4and its partner molecule MD-2 may play an important rolein Kupffer cell activation and IR injury.
