摘要目的 观察不同碘营养水平时胰岛素样生长因子Ⅰ(IGF-Ⅰ)和转化生长因子βⅠ(TGF-β1)对胎盘绒毛滋养层细胞(HPT-8)钠碘转运体(NIS)及pendrin mRNA表达的影响.方法 体外培养HPT-8细胞,取对数生长期细胞接种于细胞培养瓶,待细胞贴壁后根据加入培养液的不同碘含量(0、5、50、500、5000 μg/L)分为低碘1组、低碘2组、对照组、高碘1组和高碘2组.培养24h后,每组细胞再以原来的碘水平,分别加入IGF-Ⅰ(0.050 mg/L)、TGF-β1 (0.001 mg/L),即碘+IGF-Ⅰ和碘+TGF-β1.继续培养24 h后,提取细胞总RNA,反转录合成cDNA,采用实时荧光定量PCR方法检测HPT-8细胞NIS及pendrin mRNA的表达.结果 HPT-8细胞NIS mRNA的表达:在不同碘水平,单纯加碘时NIS mRNA表达组间比较差异有统计学意义(F=3.612,P＜0.01).其中低碘1组(0.44±0.21)NIS mRNA表达显著低于对照组(1.25±0.77,P＜ 0.01).在相同碘水平时,低碘1组、高碘1组NIS mRNA表达组内比较差异有统计学意义(F值分别为13.632、6.900,P均＜0.01).其中在低碘1组,碘+ IGF-Ⅰ(1.13±0.38)和碘+TGF-β1 (0.81±0.34) NIS mRNA表达高于单纯加碘(0.44±0.21,P＜ 0.01或＜0.05);在高碘1组,碘+TGF-β1 (0.62±0.30) NIS mRNA表达显著低于单纯加碘(1.23±0.91,P＜ 0.01).HPT-8细胞pendrin mRNA的表达:在不同碘水平,单纯加碘时pendrin mRNA表达组间比较差异有统计学意义(F=12.717,P＜0.01).其中低碘1组(0.59±0.15) pendrin mRNA表达显著低于对照组(1.03±0.14,P＜ 0.01),高碘1组(1.29±0.31)高于对照组(P＜0.05).在相同碘水平时,低碘1组、低碘2组、对照组、高碘1组pendrin mRNA表达组内比较差异有统计学意义(F值分别为12.588、4.588、8.679、8.445,P均＜0.01).其中在低碘1组、低碘2组和对照组,碘+IGF-Ⅰ(1.68±0.82、1.51±0.79、1.50±0.51) pendrin mRNA表达均高于单纯加碘(0.59±0.15、0.89±0.22、1.03±0.14,P均＜0.01);在高碘1组,碘+TGF-β1 (0.78±0.20) pendrin mRNA表达显著低于单纯加碘(1.29±0.31,P＜ 0.01).结论 在碘缺乏情况下,HPT-8细胞NIS、pendrin mRNA表达下降,摄碘能力下降;在轻度碘过量时,HPT-8细胞pendrin mRNA表达增加,摄碘能力增强.细胞因子IGF-Ⅰ及TGF-β1对于HPT-8细胞的碘转运能力均有一定的调节作用,即碘缺乏时增加碘的摄入,在碘过量时减少碘的摄入.

abstractsObjective To observe the effects of insulin-like growth factor-Ⅰ (IGF-Ⅰ) and transforming growth factor-β1 (TGF-β1) on the expressions of sodium iodide symporter(NIS) and pendrin mRNA in a placental villous trophoblast cell line(HPT-8) exposed to different levels of iodine.Methods HPT-8 cells were cultured in vitro in the culture flask and divided into low iodine group-Ⅰ (LI-Ⅰ),low iodine group-Ⅱ (LI-Ⅱ),control group,high iodine group-Ⅰ (HI-Ⅰ) and high iodine group-Ⅱ (HI-Ⅱ) that exposed to different concentrations of iodine (0,5,50,500,5000 μg/L).After cell cultured for 24 h,the followings were added to the culture medium:iodine plus IGF-Ⅰ(0.050 mg/L),iodine plus TGF-β1 (0.001 mg/L).After cultured for another 24 h,total RNA was extracted,the expressions of NIS and pendrin mRNA of HPT-8 cells were determined by real-time quantitative PCR.Results The expression of NIS mRNA in HPT-8 cells:at different levels of iodine,the differences of NIS mRNA expression between groups were statistically significant in group with iodine alone(F =3.612,P ＜ 0.01).The expression of NIS mRNA in LI-Ⅰ group(0.44 ± 0.21) was significantly lower than that of control group(1.25 ± 0.77,P＜ 0.01).At the same level of iodine,in LI-Ⅰ group and HI-Ⅰ group,the differences of NIS mRNA expression within groups were statistically significant (F =13.632,6.900,all P ＜ 0.01).In LI-Ⅰ group,the expressions of NIS mRNA were higher in iodine plus IGF-Ⅰ(1.13 ± 0.38) and iodine plus TGF-β1 (0.81 ± 0.34) than that of pure iodine(0.44 ± 0.21,P ＜ 0.01 or ＜ 0.05);in HI-Ⅰ group,the expression of NIS mRNA was lower in iodine plus TGF-β1 (0.62 ± 0.30) than that of pure iodine(1.23 ± 0.91,P ＜ 0.01).The expression of pendrin mRNA in HPT-8 cells:at different levels of iodine,the differences of pendrin mRNA expression between groups were statistically significant in group with iodine alone(F =12.717,P ＜ 0.01).The expression of pendrin mRNA in LI-Ⅰ group(0.59 ± 0.15) was significantly lower than that of control group(1.03 ± 0.14,P ＜ 0.01) ; HI-Ⅰ group(1.29 ± 0.31) was higher than control group(P ＜ 0.05).At the same level of iodine,the differences of pendrin mRNA expression within groups were statistically significant in LI-Ⅰ,LI-Ⅱ,control and HI-Ⅰ groups (F=12.588,4.588,8.679,8.445,all P ＜ 0.01).In LI-Ⅰ,LI-Ⅱ and control groups,the expressions of pendrin mRNA were significantly higher in iodine plus IGF-Ⅰ(1.68 ± 0.82,1.51 ± 0.79,1.50 ± 0.51) than that of pure iodine(0.59 ± 0.15,0.89 ± 0.22,1.03 ± 0.14,all P ＜ 0.01); in HI-Ⅰ group,the expression of pendrin mRNA was significantly lower in iodine plus TGF-β1 (0.78 ± 0.20) than that of pure iodine(1.29 ± 0.31,P ＜ 0.01).Conclusions In the case of iodine deficiency,the mRNA expressions of NIS and pendrin in HPT-8 cells are decreased and the iodine uptake ability is decreased; the expression of pendrin mRNA in HPT-8 cells is increased and placental iodine uptake is increased under the conditions of mild iodine excessive.IGF-Ⅰ and TGF-β1 play a role in the placental iodine uptake through increasing iodine uptake under the conditions of iodine deficiency and decreasing iodine uptake under the conditions of iodine excessive.