大肠杆菌脂多糖影响Toll样受体4在人牙髓细胞的表达  

Expression of Toll like receptor 4(TLR4) in human dental pulp cells is regulated by E.coli lipopolysaccharide

作　　者：蒋宏伟[1] 凌均棨[1] 任邦鹏[1] 

机构地区：[1]广州中山大学附属口腔医院牙体牙髓科,510055

出　　处：《实用口腔医学杂志》2007年第1期31-35,共5页Journal of Practical Stomatology

摘　　要：目的:探讨大肠杆菌脂多糖(lippolysacchaide,LPS)对体外培养的人牙髓细胞(human dental pulp cells,HDPCs)Toll样受体4(Toll-likereceptor4,TLR4)表达的影响及TLR4在LPS对牙髓细胞激活中的作用。方法:以大肠杆菌LPS刺激体外培养的人牙髓细胞,运用实时荧光定量RT-PCR和免疫荧光技术分别检测牙髓细胞TLR4mRNA和蛋白的表达。利用抗体阻断和ELISA方法观察TLR4在LPS激活牙髓细胞释放IL-1β中的作用。结果:正常牙髓细胞不表达TLR4,1×10-4g/L大肠杆菌LPS作用HDPCs6、12、24h后均可见TLR4在胞膜/胞质的表达,胞核并不表达TLR4。FQRT-PCR结果表明LPS能明显上调牙髓细胞TLR4mRNA的表达(P<0.001),并具有LPS浓度依赖性。抗体阻断和ELISA结果证实LPS能激活牙髓细胞释放IL-1β(P<0.01),抗TLR4单抗能明显抑制LPS对HDPCs的激活(P<0.05)。结论:正常人牙髓细胞不表达TLR4,大肠杆菌LPS能诱导牙髓细胞表达TLR4mRNA和蛋白。TLR4介导了LPS对牙髓细胞的活化,在LPS对牙髓细胞激活效应中具有重要作用。Objective：To investigate the effects of E. coli lipopolysaccharide（LPS） stimulus on the synthesis of TLR4 protein and its mRNA expression in human dental pulp cells（ HDPCs）, and to explore the roles of TLR4 on the activation of HDPCs induced by LPS. Methods：The expressions of TLR4 mRNA and the synthesis of TLR4 protein in HDPCs induced by LPS were detected by real-time fluorescence quantitative RT-PCR（ FQ RT- PCR） and immunofluorescence technique. IL-113 concentrations in the supernatant of cultured HDPCs pretreated with TLR4 antibody were assayed with ELISA. Results： The expressions of TLR4 could not be detected in normal HDPCs. After being stimulated with 1 × 10^-4 g/L LPS for 6,12 or 24 h, immunostaining showed that TLR4 was expressed in cytomembrane and cytoplasm of HDPCs, while in nucleus the expressions were negative. FQ RT-PCR showed their expressions significantly increased after being stimulated with LPS （ P 〈 0.001 ）, and this trend continued with increasing LPS concentrations. ELISA testified LPS can improve IL-113 concentrations in the supernatant of cultured HDPCs（ P 〈 0.01 ）. The antibody of TLR4 can obviously decrease the production of IL-113 induced by LPS（ P 〈 0.05）. Conclusions：The expressions of TLR4 were not detected in normal HDPCs. After stimulation with E. coli LIPS, HDPCs increased the synthesis of TLR4 protein and its mRNA expression. These results indicate that TLR4 may play a pivotal role in the activation of HDPCs induced by E. coli LPS.

关 键 词：TOLL样受体4 脂多糖类 牙髓细胞 

分 类 号：R78[医药卫生—口腔医学]