不同碘水平时促甲状腺激素、人绒毛膜促性腺激素、雌二醇对胎盘绒毛滋养层细胞pendrin mRNA表达的影响

摘要

Objective To observe the expression of pendrin mRNA and ability of iodine uptake in a placental villous trophoblast cell line(HPT-8) cultured in vitro with different levels of iodine and the effects of thyroid stimulating hormone(TSH),human chorionic gonadotrophin(HCG) and estradiol(E2).Methods HPT-8 cells were cultured in six-well plates and divided into low iodine group 1 (LI-1),low iodine group 2(LI-2),adequate iodine group (AI),high iodine group 1 (HI-1) and high iodine group 2 (HI-2) based on iodine concentrations (0,5,50,500,5000 μg/L) added to the culture medium.After cultured for 24 h,the followings were added to the culture medium:pure iodine,iodine plus TSH(0.01 mg/L),iodine plus HCG(5000 U/L),iodine plus E2(0.1 mg/L) and iodine plus TSH,HCG,E2,respectively,then cultured for another 24 h.The expression of pendrin mRNA of HPT-8 cells was determined by real-time quantitative PCR.Results At different levels of iodine,the differences of pendrin mRNA expression between groups were statistically significant in groups with iodine alone,iodine plus TSH,iodine plus E2 and iodine plus TSH,HCG and E2(F =8.43,9.91,30.37,7.34,all P ＜ 0.01).In groups with iodine alone,the expression in LI-1 group(1.00 ± 0.11) was significantly lower than that in AI group(1.37 ± 0.19,P ＜ 0.01),and HI-2 group(1.67 ± 0.25) was higher than AI group(P ＜ 0.05).In groups with iodine plus E2,the expression of pendrin mRNA in HI-2 group (13.37 ± 6.48) was significantly higher than that of AI group(1.95 ± 0.61,P ＜ 0.01).In groups with iodine plus HCG,TSH and E2,the expression of pendrin mRNA in LI-2 group(2.26 ± 1.32) was significantly higher than that of AI group(1.06 ± 0.33,P ＜ 0.01).At the same level of iodine,the differences of pendrin mRNA expression within groups were statistically significant in LI-1,AI,HI-1,HI-2 groups(F=10.98,11.59,6.70,33.06,all P＜ 0.01).In HI-1 group,the expression was lower in iodine plus TSH,HCG and E2(1.10 ± 0.26) than pure iodine (1.49 ± 0.41,P ＜ 0.05).In HI-2 group,iodine plus E2(13.37 ± 6.48) was higher than the pure iodine(1.33 ± 0.28,P ＜ 0.01).Conclusions HPT-8 cells have increased expression of pendrin mRNA and promote iodine uptake under mild iodine deficiency conditions,but under severe iodine deficiency conditions,HPT-8 cells are in a decompensated state and have decreased expression of pendrin mRNA,the ability of iodine uptake is decreased.HCG and TSH play a week role in HPT-8 cells iodine uptake,whereas E2 promotes iodine uptake under severe iodine excess with significantly increased expression of pendrin mRNA obviously.When the three hormones are administrated together,the ability of iodine uptake is increased under mild iodine deficiency conditions and decreased under mild iodine excess.%目的 观察不同碘营养水平时促甲状腺激素(TSH)、人绒毛膜促性腺激素(HCG)、雌二醇(E2)对体外培养人早孕胎盘绒毛滋养细胞(HPT-8)pendrin mRNA表达,即摄碘能力的影响.方法 采用细胞培养的方法,体外培养HPT-8细胞.取对数生长期细胞接种于六孔培养板,待细胞贴壁后按照加入培养液的含碘量不同(0、5、50、500、5000 μg/L)分为低碘1组、低碘2组、适碘组、高碘1组、高碘2组.培养24 h后,每组细胞再以原来的碘水平,在5种条件下进行培养:单纯碘、碘+ TSH(0.01 mg/L)、碘+HCG(5000 U/L)、碘+E2(0.1mg/L)和碘+HCG(5000 U/L)+ TSH(0.01 mg/L)+E2(0.1 mg/L).继续培养24 h后,提取细胞总RNA,反转录合成cDNA,通过实时荧光定量PCR方法检测HPT-8细胞pendrin mRNA表达水平.结果 在不同碘营养水平,单纯加碘、碘+ TSH、碘+E2、碘+HCG+ TSH+ E2时HPT-8细胞pendrin mRNA表达组间比较差异有统计学意义(F值分别为8.43、9.91、30.37、7.34,P均＜0.01).其中单纯加碘时,低碘1组(1.00±0.11)pendrin mRNA表达显著低于适碘组(1.37±0.19,P＜ 0.01),低碘2组(1.67±0.25)高于适碘组(P＜0.05)；碘+E2时,高碘2组(13.37±6.48)pendrin mRNA表达显著高于适碘组(1.95±0.61,P＜0.01)；碘+HCG+ TSH+ E2时,低碘2组(2.26±1.32)pendrin mRNA表达显著高于适碘组(1.06±0.33,P＜ 0.01).在相同碘营养水平时,低碘1组、适碘组、高碘1组、高碘2组pendrin mRNA表达组内比较差异有统计学意义(F值分别为10.98、11.59、6.70、33.06,P均＜0.01).其中在高碘1组,碘+HCG+ TSH+ E2(1.10±0.26)pendrin mRNA表达低于单纯加碘(1.49±0.41,P＜0.05)；在高碘2组,碘+E2(13.37±6.48)pendrin mRNA表达显著高于单纯加碘(1.33±0.28,P＜ 0.01).结论 轻度碘缺乏条件下,HPT-8细胞处于代偿状态,pendrin mRNA表达增加,摄碘能力增强,重度碘缺乏条件下,HPT-8细胞处于失代偿状态,pendrin mRNA表达下降,摄碘能力下降.HCG和TSH对HPT-8细胞摄碘能力调控的意义不大,E2在重度高碘时,HPT-8细胞pendrin mRNA表达明显增加,摄碘能力增强最为明显.三种激素共同作用时,在轻度碘缺乏时上调HPT-8细胞摄碘能力,轻度碘过量时下调HPT-8细胞摄碘能力.