p53基因在亚砷酸钠致人胚胎肺成纤维细胞凋亡中的作用

摘要

目的 探讨p53、Bax、bcl-2基因在亚砷酸钠(NaAs02)致人胚胎肺成纤维细胞(HELF)凋亡中的作用.方法 分别取转染了p53质粒HELF细胞(p53组)、转染了PC质粒的HELF细胞(PC组)、常规培养的HELF细胞(正常组),在6孔板中培养48 h后,分别加入0、3、9、15 mmoL/L NaAsO2溶液,培养24 h后,用real-time PCR法检测p53、Bax、bcl-2 mRNA基因表达水平,采用免疫组织化学SABC法检测p53、Bax、bcl-2基因蛋白表达水平;用流式细胞仪检测细胞凋亡情况.结果 p53组细胞p53基因mRNA表达水平(0.51±0.29)低于PC组及正常组[(1.32±0.26),(1.00±0.20),P均<0.05],p53组p53基因蛋白表达水平[(4.10±1.20)%]低于PC组和正常组[(8.00±1.63)%、(7.90±1.79)%,P均<0.05];p53组、PC组、正常组在染砷0、3、9、15 mmol/L时,细胞凋亡率[(0.57±0.28)%、(22.91±4.86)%、(40.05±3.93)%、(44.87±3.58)%,(0.65±0.24)%、(14.09±3.49)%、(20.31±3.66)%、(32.42±3.63)%,(0.56±0.25)%、(12.14±3.70)%、(19.61±3.63)%、(30.43±2.83)%]、Bax mRNA表达水平[(12.73±3.96)、(25.12±6.42)、(104.96±26.77)、(154.04±3052),(14.63±3.57)、(36.75±3.67)、(272.26±66.11)、(846.12±243.36),(14.75±5.65)、(37.22±11.27)、(278.51±37.42)、(861.67±369.29)]、Bax蛋白表达水平[(15.07±0.83)%、(23.79±3.99)%、(3851±158)%、(53.86±124)%,(15.43±1.45)%、(36.11±1.37)%、(56.86±1.97)%、(76.09±2.01)%,(15.20±1.03)%、(35.25±1.09)%、(55.56±2.17)%、(74.48±2.85)%]均随着染毒剂量的增加而增高(P均<0.05),而bcl-2 mRNA表达水平[(443.00±244.47)、(156.79±53.18)、(62.13±13.66)、(23.10±6.44),(420.55±110.77)、(48.15±10.02)、(14.91±6.53)、(7.54±2.62),(577.75±123.22)、(49.68±10.11)、(12.41±1.28)、(7.22±1.89)]、bcl-2蛋白表达水平[(47.20±3.77)%、(41.80±2.94)%、(36.00±2.36)%、(29.00±2.91)%,(45.90±4.15)%、(35.70±2.77)%、(29.80±2.78)%、(24.80±2.66)%,(46.70±3.47)%、(36.20±2.90)%、(30.10±3.21)%、(25.10±2.28)%]均随着染毒剂量的增加而降低(P均<0.05);在染砷3、9、15 mmol/L时,p53组的细胞凋亡率、bcl-2 mRNA表达水平、bcl-2蛋白表达水平均高于同一染砷剂量的正常组和PC组(P均<0.05),而Bax mRNA表达水平、Bax基因蛋白表达水平均低于同一染砷剂量的正常组和PC组(P均<0.05).结论 p53基因减少了NaAsO2致HELF的凋亡,可能是通过改变部分凋亡途径实现.%Objective To investigate the p53,Bax,bcl-2 gene in NaAsO2-induced human embryonic lung fibroblasts(HELF)apoptosis.Methods HELF was divided into HELF cells transfected with p53 plasmid(p53 group),HELF cells transfected with PC plasmid(PC group)and normal cultured HELF cells(normal group).The mRNA expression of p53,Bax and bcl-2 gene was detected by real-time PCR,the protein expression of p53,Bax and bcl-2 was assessed by immunohistochemical SABC and the cell apoptosis of HELF was detected by flow cytometry(FCM),in a 6-well plate and cultured for 48 hours,which was exposed to different doses(0,3,9,15mmol/L)NaAsO2 for 24 hours.Results The p53 gene mRNA expression level of p53 group(0.51±0.29)was lower than that of the normal group and PC group [ (1.00 ± 0.20), (1.32 ± 0.26), all P < 0.05 ]. The p53 protein expression level of p53 group(4.10 ± 1.20) was lower than the PC group and normal group[ (8.00 ± 1.63), (7.90 ± 1.79), allP < 0.05]. In p53 group, PC group, normal group exposed to 0,3,9,15 mmol/L NaAsO2 doses, the apoptotic rate [(0.57 ± 0.28)%, (22.91 ± 4.86)%, (40.05 ± 3.93)%, (44.87 ± 3.58)%; (0.65 ± 0.24)%, (14.09 ± 3.49)%,(20.31 ± 3.66)%, (32.42 ± 3.63)%; (0.56 ± 0.25)%, (12.14 ± 3.70)%, (19.61 ± 3.63)%, (30.43 ± 2.83)%], Bax mRNA expression level[(12.73 ± 3.96), (25.12 ± 6.42), (104.96 ± 26.77), (154.04 ± 30.52); (14.63 ± 3.57),(36.75 ± 3.67), (272.26 ± 66.11), (846.12 ± 243.36); (14.75 ± 5.65), (37.22 ± 11.27), (278.51 ± 37.42),(861.67 ± 369.29) ], Bax protein expression level [ ( 15.07 ± 0.83 ) %, ( 23.79 ± 3.99 ) %, (38.51 ± 1.58 ) %, (53.86 ±1.74)%;(15.43 ± 1.45)%,(36.11 ± 1.37)%, (56.86 ± 1.97)%, (76.09 ± 2.01)%; (15.20 ± 1.03)%,(35.25 ±1.09)%, (55.56 ± 2.17)%, (74.48 ± 2.85)% ] was respectively increased in a dose-dependent manner with the increased concentration of NaAsO2(all P < 0.05). The bel-2 mRNA expression level [ (443.00 ± 244.47), (156.79 ±53.18), (62.13 ± 13.66), (23.10 ± 6.44); (420.55 ± 110.77), (48.15 ± 10.02), (14.91 ± 6.53), (7.54 ± 2.62);(577.75 ± 123.22), (49.68 ± 10.11), (12.41 ± 1.28), (7.22 ± 1.89)], bcl-2 protein expression level[(47.20 ±3.77)%, (41.80 ± 2.94)%, (36.00 ± 2.36)%, (29.00 ± 2.91)%; (45.90 ± 4.15)%, (35.70 ± 2.77)%, (29.80 ±2.78)%, (24.80 ± 2.66)% ; (46.70 ± 3.47)%, (36.20 ± 2.90)%, (30.10 ± 3.21)%, (25.10 ± 2.28)% ] wasdecreased in a dose-dependent manner with the increased concentration of NaAsO2(all P < 0.05 ). In 3,9,15 mmol/L NaAsO2, apoptotic rate of p53 group, mRNA expression of bcl-2, protein expression of bcl-2 was higher than that ofnormal group and PC group, respectively (all P < 0.05), but mRNA expression of Bax, protein expression of Bax was respeetivelylower than that normal group and the PC group(P < 0.05 ). Conclusion p53 gene reduced the apoptosis induced by NaAsO2 in HELF, possibly by changing the apoptosis pathway.