矽尘对小鼠肺组织TLR4 mRNA与RelA mRNA表达的影响

Effects of silica dust on expression of TLR4 mRNA and RelA mRNA in lung tissue in mice

[目的]探讨矽尘对小鼠肺组织TOLL样受体4(TLR4)mRNA与核因子-κB p65(RelA)mRNA表达的影响。[方法]将40只小鼠随机分成4组,每组10只,分别为2、4、8 h暴露组(即每天吸入染尘2、4、8 h)和对照组(不染尘)。染尘20 d后,取肺组织,应用实时荧光定量PCR法(RT-q PCR)测定各组TLR4 mRNA和RelA mRNA的表达。[结果]对照组与3个暴露组TLR4 mRNA表达量的中位数分别为0.89、1.22、4.89、7.21,4个组间的差异有统计学意义(χ~2=4.93,P=0.02);4、8 h暴露组与对照组的差异有统计学意义(P<0.05),2 h暴露组与对照组的差异无统计学意义(P>0.05)。对照组和3个暴露组RelA mR NA表达量分别为0.96、1.33、2.23、3.04,4个组间差异有统计学意义(χ~2=6.35,P=0.00);4、8 h暴露组与对照组的差异有统计学意义(P<0.05),2 h暴露组与对照组的差异无统计学意义(P>0.05)。TLR4 mRNA与RelA mRNA两者之间具有相关性(r=0.99,P=0.00)。[结论]矽尘染毒后小鼠肺组织TLR4 mRNA和RelA mRNA的表达上调,提示TLR4/RelA信号通路激活。

[Objective] To investigate the effects of silica dust on the expression of TLR4 mRNA and RelA mRNA in lung tissue of experimental mice. [Methods] Forty mice were randomly divided into four groups with 10 mice in each group ：control group（not exposed to silica dust）, and 2, 4, and 8 h exposure groups（exposed to silica dust for 2, 4, and 8 h every day, respectively）. After 20 days of exposure, lung tissues were dissected to detect the expression of TLR4 mRNA and RelA mRNA by RT-q PCR technology. [Results] The median expression levels of TLR4 mRNA in the control group and three exposure groups were 0.89, 1.22, 4.89, and 7.21, respectively（χ^2=4.93, P=0.02）. Compared with the control group, the expression levels of TLR4 mRNA in the 4 h and 8 h exposure groups were both different（P〈0.05）, but that in the 2 h exposure group showed no significant changes（P〈0.05）. The expression levels of RelA mRNA in the control group and three exposure groups were 0.96, 1.33, 2.23, and 3.04, respectively（χ^2=6.35, P=0.00）. Compared with the control group, the expression levels of RelA mRNA in the 4 h and 8 h exposure groups were both significantly different（P〈0.05）, but that in the 2 h exposure group showed no significant changes（P〈0.05）. The expression levels of TLR4 mRNA and RelA mRNA showed a significant correlation（r=0.99, P=0.00）. [Conclusion] The elevated expressions of TLR4 mRNA and RelA mRNA in the lung tissue of mice exposed to silica dust indicate the activation of TLR4/RelA signaling pathway.