多氯联苯对大鼠间充质干细胞c-myc和-βcatenin表达的影响

EFFECTS OF POLYCHLORINATED BIPHENYLs ON c-myc AND β-catenin EXPRESSION OF MESENCHYMAL STEM CELLS IN RAT

目的探讨多氯联苯(polychlorinated biphenyls,PCBs)对大鼠间充质干细胞((mesenchy-mal cells,MSCs)功能的影响,为深入研究环境激素对MSCs功能的影响提供依据。方法实验分为对照组、低剂量组(10-7mol/L PCB126)和高剂量组(10-6mol/L PCB126)共3个组。PCB126作用MSCs不同时间后,采用MTT方法检测细胞增殖率,免疫荧光化学方法评价细胞c-myc和-βcatenin的表达,RT-PCR分析c-myc和-βcatenin mRNA的表达,Western blot分析细胞c-myc和-βcatenin蛋白的表达。结果随着PCB126作用时间的延长,细胞增殖率显著增加(P<0.01)。低剂量组12 h时,c-myc和-βcatenin的阳性率分别为50.0%、51.3%,24 h的阳性率分别为67.8%、73.3%;高剂量组12 h时,c-myc和-βcatenin的阳性率分别为54.6%5、1.8%,24 h的阳性率分别为73.0%、74.9%,与对照组(10.0%、16.7%)相比差异有显著性(P<0.01);2个剂量组c-myc和-βcateninmRNA表达丰度在多数时间明显高于对照组(P<0.01);高剂量组24 h时,-βcatenin蛋白表达显著上调(P<0.01);在相同时间,高剂量组-βcatenin蛋白表达水平高于低剂量组(P<0.01)。结论 PCB126影响MSCs生物学功能。

Objective To study the effects of polychlorinated biphenyls（PCBs） on the function of rat mesenchymal stem cells（MSCs）,so as to provide the theoretical basis for further studying the effect of environmental hormone on MSCs.Methods The experimental animals were divided into control group,low-dose group（10-7mol/L PCB126）,and high dose group（10-6mol/L PCB126）.The methods,such as MTT methods,immunofluorescence chemical assay,RTPCR and Western blot were used to analyze the cellular growth rate,expression of c-myc and β-catenin,as well as their mRNA and protein expression respectively at different exposure times.Results The cellular growth rate was increased as the time exposed to PCBs prolonged.In low dose group,the positive rate of c-myc and β-catenin were 50.0%,51.3% respectively for 12 h exposure time,and 67.8%,73.3% for 24 h.In high dose group,the positive rate of c-myc and β-catenin were 54.6%,51.8% for 12 h,and 73.0%,74.9% for 24 h,all of which were higher than those in control group（10.0%,16.7% respectively） （P0.01）.The expression of c-myc and β-catenin mRNA were higher in both low and high groups than in control group（P0.01） at most of the exposure time.In high dose group,β-catenin protein expression were significantly upregulated for 24 h（P0.01） The expression of c-myc and β-catenin protein were higher in high dose group than in low dose group（P0.01）.Conclusion PCB126 could affect MSCs biological function.