TLR4-P38MAPK信号通路在LPS诱导BV2细胞中的表达及意义

Expression and significance of TLR4-P38MAPK signaling pathway in the LPS-induced BV2 microglia

目的观察LPS诱导小胶质细胞后信号通路Toll样受体4(TLR4)-p38蛋白激酶(p38MAPK)的表达及意义。方法体外培养BV2小胶质细胞,分为对照组、LPS诱导组(LPS刺激12h及24h)及SB203580干预组(LPS+SB203580诱导12h及24h),应用ELISA法检测各组TNF-α、IL-6水平,RT-PCR法检测各组TLR4mRNA和p38MAPK mRNA的表达变化。结果 LPS诱导组细胞分泌TNF-α、IL-6水平显著提高,诱导24h后细胞上清液含量分别为(513.67±14.05)pg/mg和(396.84±15.41)pg/mg。给予SB203580抑制剂后TLR4mRNA和p38MAPK mRNA表达明显减弱,细胞分泌TNF-α、IL-6含量表达与感染组比较也明显降低。结论 LPS刺激小胶质细胞可引起TLR4-p38MAPK信号通路的活化并释放炎性细胞因子,而SB203580则对其有明显的抑制作用,证明TLR4-p38MAPK信号通路与小胶质细胞的炎性活化密切相关。

Objective To investigate the effect and significance of TLR2mRNA and p38MAPK mRNA signaling pathway expressed in the LPS-induced BV2 microglia.Methods The routinely cultured BV2microglia in vitro were divided into control group,LPS stimulation group（stimulation lasting 12 and 24 hours）and SB203580 plus LPS treatment group（stimulation lasting 12 and 24 hours）.We determined the levels of TNF alpha and IL-6 by ELISA method,and detected the group difference of TLR4mRNA and p38MAPK mRNA by RT-PCR method.Results Compared with those in the control group,the expressions of TLR4mRNA and p38MAPK mRNA in the LPS-induced microglia were significantly increased,which were especially obvious after 24-hour stimulation,TNF-αwas（513.67±14.05）pg/mg,IL-6 was（396.84±15.41）pg/mg.Treatment with SB203580 could effectively inhibit TLR4mRNA and p38 MAPK mRNA expressions in BV2microglia,the concentrations of TNF-αand IL-6 markedly decreased when compared with those in the infected group.Conclusion The TLR4-p38MAPK signaling pathway can be activated by LPS in BV2microglia,leading the releasing of inflammatory cytokines.And the SB203580 significantly inhibits the signaling pathway,demonstrating the close relation between the TLR4-p38MAPK signaling pathway and inflammatory activation of microglia.