苯并芘体外对人胎盘滋养细胞增殖和凋亡的影响及其机制

Effects of benzo(a) pyrene on proliferation and apoptosis in human placental trophoblast cells in vitro and the mechanism

目的探讨苯并芘对滋养细胞的损害作用及其机制。方法通过观察苯并(a)芘[benzo(a) pyrene,BaP]体外对人胎盘滋养细胞系JEG-3细胞增殖和凋亡的影响,并观察对芳香烃受体(aryl hydrocarbon receptor,AhR)及其核转位蛋白(aryl hrdrocarbon receptor nuclear translocator,ARNT)表达的作用。将BaP染毒浓度分成四组:空白对照组、低剂量组、中剂量组、高剂量组,应用不同浓度的BaP处理人胎盘滋养细胞系JEG-3细胞24 h,四甲基偶氮唑盐(3-(4,5-dimethyl-2-thiazoly)-2,5-diphenyl-2-H-tetrazolium bromide,MTT)比色法检测JEG-3细胞增殖率,流式细胞术检测JEG-3细胞凋亡率。实时荧光定量PCR方法检测细胞AhR和ARNT基因mRNA的表达,Western blot检测细胞AhR和ARNT蛋白表达。结果细胞增殖率BaP中剂量组和BaP高剂量组低于空白对照组和BaP低剂量组(P <0. 05),凋亡率BaP中剂量组和BaP高剂量组高于空白对照组和BaP低剂量组(P <0. 05)。BaP低、中、高剂量组AhR基因mRNA表达(1. 71±0. 15、2. 10±0. 17和2. 29±0. 16)和ARNT基因mRNA表达(1. 57±0. 13、1. 96±0. 17和2. 36±0. 15)均高于空白对照组(1. 41±0. 13、1. 28±0. 11)(P <0. 05),呈浓度依赖; BaP低、中、高剂量组AhR蛋白表达(29. 54±2. 34、34. 64±2. 35和39. 96±2. 36)和ARNT蛋白表达(39. 94±2. 37、45. 62±2. 41和51. 52±2. 66)均高于对照组(23. 22±2. 31、34. 28±2. 24、39)(P <0. 05),呈浓度依赖。结论 BaP体外可抑制JEG-3细胞增殖和诱导细胞凋亡,激活AhR通路可能是BaP损伤胎盘滋养细胞的机制之一。

Objective To investigate the damage of benzo(a)pyrene(BaP)to human placental trophoblast cells in vitro by observing the effect of BaP on the proliferation and apoptosis of these cells,and on expressions of aryl hydrocarbon receptor(AhR)and aryl hrdrocarbon receptor nuclear translocator(ARNT).Methods BaP concentrations were divided into four groups:blank control group,low dose group,medium dose group and high dose group.The JEG-3 cells were treated with different concentrations of BaP for 24 h.The MTT assay was used to measure cell growth,and flow cytometry was used to measure cell apoptosis rates.AhR and ARNT mRNA were detected by real-time q PCR,while AhR and ARNT proteins were detected by Western blot.Results The cell proliferation rates in the medium dose group and high dose group were lower than those of the blank control group and low dose group(P<0.05).The apoptotic rate of the medium dose group and high dose group was higher than that of the blank control group and low dose group(P<0.05).The expressions of AhR gene(1.71±0.15、2.10±0.17和2.29±0.16)and ARNT gene(1.57±0.13、1.96±0.17和2.36±0.15)in low,medium and high dose groups of BaP were higher than that in the blank control group(1.41±0.13、1.28±0.11)(P<0.05),which changed in a concentration-dependent manner.The expressions of AhR protein(29.54±2.34、34.64±2.35 and 39.96±2.36)and ARNT protein(39.94±2.37、45.62±2.41 and 51.52±2.66)in low,medium and high dose groups of BaP were higher than those in the control group(23.22±2.31、34.28±2.24、39)(P<0.05),which also changed in a concentration-dependent manner.Conclusions BaP can inhibit the cellular proliferation and induce apoptosis in human placental trophoblast cells in vitro,and the AhR pathway activation may be one of the mechanisms by which BaP damages human placental trophoblast cells.