促甲状腺激素、雌二醇、催乳素对不同碘营养水平哺乳期小鼠乳腺细胞钠碘转运体mRNA表达的影响

The effects of thyroid-stimulating hormone, estradiol and prolactin on sodlum/iodide symporter mRNA expression in mouse lactating mammary gland cells under different iodine levels

目的观察不同碘营养水平哺乳期小鼠乳腺细胞钠碘转运体（NIS）mRNA的表达及促甲状腺激素（TSH）、雌二醇（E2）、催乳素（PRL）对哺乳期小鼠乳腺细胞NISmRNA表达的影响。方法将体外培养哺乳期小鼠乳腺细胞分为5组，分别用含0、5、50（对照）、3000、10000μg／L碘水平的培养液（碘酸钾配制）刺激24h。每组细胞在原有碘水平条件下，进行4种方式培养：单纯碘、碘＋TSH（10μg／L）、碘＋E2（100μg／L）、碘＋PRL（100μg／L），24h后收集细胞。采用实时荧光定量PCR法检测各组乳腺细胞NISmRNA表达。结果单纯碘（0、5μg／L）组乳腺细胞NISmRNA表达（0．0165±0．0016、0．0158±0．0027）明显高于单纯碘（50μg/L）组（0．0119±0．0010，P均〈0．01）；碘（0μg／L）＋TSH组乳腺细胞NISmRNA表达（0．0216±0．0024）明显高于单纯碘（0μg／L）组（0．0t65±0．0016，P〈0．01）；碘（0、5、50、3000、10000μg／L）＋E2组NISmRNA表达（0．0234±0．0045、0．0188±0．0012、0．0153．4-0．0014、0．0130±0．0013、0．0124±0．0006）明显高于相应碘水平的单纯碘组（0．0165±0．0016、0．0158±0．0027、0．0119±0．0010、0．0098±0．0010、0．0106±0．0007，P均〈0．05）；碘（0、50、3000μg／L）＋PRL组NISmRNA表达（0．0190±0．0012、0．0147±0．0013、0．0118±0．0012）明显高于相应碘水平的单纯碘组（0．0165±0．0016、0．0119±0．0010、0．0098±0．0010，P均〈0．05）。结论在重度碘缺乏时TSH对乳腺细胞NISmRNA表达有上调作用：在不同碘营养水平时E2、PRL对乳腺细胞NISmRNA表达同样有上调作用。

Objective The present study investigated the sodium/iodide symporter mRNA expression in mouse lactating mammary gland cells under different iodine levels and the effects of thyroid-stimulating hormone （TSH）, estradiol （E2） and prolactin （PRL） on NIS mRNA expression in mouse lactating mammary gland cells. Methods Mouse lactating mammary gland cells were cultured in vitro and stimulated with different concentrations of iodine （0, 5, 50, 3 000, 10 000 μg/L; 50 μg/L was the control group） for 24 h, and the followings were added to the culture medium,iodine plus TSH （10μg/L）, iodine plus E2 （100 μg/L） and iodine plus PRL （100 μg/L）. After cultured for another 24 h, total RNA was extracted, the expression of NIS mRNA in mouse lactating mammary gland cells weredetected by real-time quantitative PCR. Results The NIS mRNA expression levels of the mammary gland cells stimulated with 0, 5 μg/L of iodine （0.016 5 ± 0.001 6, 0.015 8 ± 0.002 7） were significantly higher than that of the control group （0.011 9 ± 0.001 0, all P 〈 0.01）. Under the iodine concentration of 0 μg/L, the NIS mRNA expression level in the iodine plus TSH group （0.021 6 ± 0.002 4） was significantly higher than that of the cells with iodine alone （0.016 5 ±0.001 6, P〈 0.01）. The NIS mRNA expression in the iodine （0, 5, 50, 3 000, 10 000 μg/L） plus E2 groups （0.023 4±0.004 5, 0.018 8 ＋± 0.001 2, 0.015 3± 0.001 4, 0.013 0 ± 0.001 3, 0.012 4 ± 0.000 6） were significantly higher than those of the cells with iodine alone （0.016 5 ± 0.001 6, 0.015 8 ± 0.002 7, 0.011 9± 0.001 0, 0.009 8± 0.001 0, 0.010 6 ±0.000 7, all P 〈 0.05）. The expression of NIS mRNA in the iodine （0, 50, 3 000μg/L） plus PRL groups （0.019 0 ± 0.001 2, 0.014 7 ± 0.001 3, 0.011 8 ±0.001 2） were higher than that of iodine alone group under 0, 50, 3 000 μg/L iodine concentrations （0.016 5 ± 0.001 6, 0.011 9 ± 0.001 0, 0.009 8 ± 0.001 0, all P 〈 0.05）. Conclusions TSH has up-regulated the NIS mRNA expression in mammary gland cells under the condition of severe iodine deficiency. At different levels of iodine nutrition, E2 and PRL have stimulated the NIS mRNA expression.