肝X受体激动剂T0901317对小鼠肺上皮细胞衰老的影响

Effects of hepatic X receptor agonist T0901317 on lung epithelial cell senescence in mice

目的探讨肝X受体(LXRs)激动剂T0901317对TNF-β1诱导的小鼠肺上皮细胞衰老相关基因表达的影响。方法将培养的MLE-12细胞分为A组(MLE12+PBS)、B组(MLE-12+10 ng/m L TGF-β1)、C组(MLE-12+100 n M T0901317)、D组(MLE-12+10 ng/m L TGF-β1+100 n M T0901317)。流式细胞术检测各组细胞端粒长度、细胞周期及ROS;RT-q PCR检测LXRα、LXRβ、p-16、p-21、ABCA1、ABCG1、SREBP-1的mRNA表达情况;Westernblot检测LXRα、LXRβ、p-16、p-21、ABCA1、ABCG1、SREBP-1的蛋白表达情况。结果端粒酶长度流式测定结果显示,与A组比较,B组、D组的荧光强度减弱,D组荧光强度较B组增强(P<0.05);细胞周期结果显示,与A组比较,B组细胞的G0/G1期比例增加,G2期比例减少,与B组比较,D组细胞的G0/G1期比例降低,G2期比例增加(P均<0.05);DCFH-DA荧光探针流式检测结果显示,与A组比较,B组、D组产生的ROS含量增加,D组较B组减少(P<0.05);RT-q PCR检测结果显示,与A组比较,p21和p16mRNA在B组表达显著升高,LXRα、LXRβ、ABCA1、ABCG1、SREBP-1 mRNA表达均降低(P均<0.05);LXRα和LXRβmRNA在C组表达较A组显著升高(P<0.05);Western-blot检测结果显示,与A组比较,p21和p16蛋白在B组表达显著升高,LXRα、LXRβ、ABCA1、ABCG1、SREBP-1的蛋白表达均降低(P<0.05);LXRα和LXRβ蛋白在C组表达较A组显著升高(P<0.05)。结论T0901317可活化LXRs,抑制上皮细胞衰老基因的表达,明显减少端粒长度缩短,延缓衰老。

Objective To investigate the effect of X receptor agonist T0901317 on the expression of senescence associated genes in mouse lung epithelial cells induced by TNF-beta1. Methods The cultured MLE-12 cells were divided into group A（ MLE12 ＋ PBS）,group B（ MLE-12 ＋ 10 ng/m L TGF-beta1）,group C（ MLE-12 ＋ 100 n M T0901317）,and group D（ MLE-12 ＋ 10 ng/m L TGF-beta1 ＋ 100 n M T0901317）. The telomere length,cell cycle and ROS in each group were measured by flow cytometry. It was detected the expression of RT-q PCR LXR alpha,LXR beta,P-16,P-21,ABCA1,ABCG1,SREBP-1 mRNA. Western-blot（ WB） was used to detect the expression of LXR alpha,LXR beta,p16,p21,ABCA1,ABCG1,SREBP-1 protein. Results Telomere length measured by using flow cytometry results showed that compared with group A,decreased the fluorescence intensity of group B and group D,group D had enhanced fluorescence intensity compared with group B,all P〈0. 05. Cell cycle results showed that compared with group A,group B,G0/G1 phase cell percentage increased,G2 ratio decreased,compared with group B,group D,G0/G1 phase cell percentage decreased,G2 ratio increased,all P〈0. 05. DCFH-DA fluorescence with flow cytometry showed,compared with group A,group B and group D had increased the amount of ROS in group D was lower than group B,all P〈0. 05. RT-q PCR test results showed that compared with group A,the expression of p21 and p16 mRNA in group B was significantly increased,the expression of LXR alpha,LXR beta,ABCA1,ABCG1,SREBP-1 mRNA was decreased,all P〈0. 05. The expression of LXR alpha and LXR beta mRNA in group C were higher than those of group A（ P〈0. 05）. WB detection the results showed that compared with group A,p21 and p16 protein expression in group B was significantly increased,the expression of LXR alpha,LXR beta,ABCA1,ABCG1 and SREBP-1 protein were decreased,all P〈0. 05. LXR alpha and LXR beta protein expression in group C than in group A increased significantly（ P〈0. 05）. Conclusion T0901317 activates LXRs,inhibits the expression of epithelial cell senescence genes,decreases telomere length,and delays senescence.