碘对体外培养哺乳期乳腺细胞钠碘转运体表达的作用及肿瘤坏死因子α对其的影响

Effect of tumor necrosis factor-α with different levels of iodine on expression of Na^＋I^- symporter in cultured lactating mammary cells

目的 观察不同碘营养水平时体外培养哺乳期乳腺细胞钠碘转运体（NIS）表达水平,以及肿瘤坏死因子α（TNF-α）对其的影响作用.方法 体外培养小鼠原代哺乳期乳腺细胞,分为低碘1组、低碘2组、适碘组、高碘1组、高碘2组,分别加入含碘0、5、50、3000、10 000μg/L的DEME/F12培养液培养24 h,然后部分换成含对应剂量的碘加TNF-α（10-2 mg/L）的DEME/F12培养液,继续培养24 h.用实时荧光定量PCR方法检测哺乳期乳腺细胞NIS mRNA表达水平,并用In-Cell Western方法检测NIS蛋白表达水平.结果 单纯加碘时低碘1组[（64.66±14.99）×10-4]乳腺细胞NIS mRNA表达水平高于适碘组[（22.76±7.36）×10-4,P＜0.05],高碘1组[（10.18±3.53）×10-4]、高碘2组[（8.59±2.89）×10-4]低于适碘组（P均＜0.05）;随着碘剂量升高,乳腺细胞NIS mRNA表达水平呈下降趋势.在碘加TNF-α时,低碘1组、低碘2组、适碘组[（2.72±0.45）、（2.69±0.68）、（1.80±0.67）×10-4]乳腺细胞NIS mRNA表达水平低于单纯加碘时对应各组[（64.66±14.99）、（29.82±4.47）、（22.76±7.36）×10-4,P均＜0.05];高碘1组[（6.58±2.87）×10-4]、高碘2组[（7.04±.1.36）×10-4]高于适碘组（P均＜0.05）;随着碘缺乏和碘过量程度加重,乳腺细胞NIS mRNA表达水平呈上升趋势.随着碘剂量升高,单纯加碘时乳腺细胞NIS蛋白表达水平呈下降趋势.碘加TNF-α时各组乳腺细胞NIS蛋白表达水平与单纯加碘时对应各组比较有降低的趋势.碘加TNF-α时,随着碘缺乏和碘过量程度加重,乳腺细胞NIS蛋白表达水平均呈上升趋势.结论 随着碘剂量升高,哺乳期乳腺细胞NIS mRNA和蛋白表达水平均呈下降趋势.TNF-α对不同碘营养水平下哺乳期乳腺细胞NIS mRNA和蛋白表达具有抑制作用.

Objective To observe the expression of Na＋/I- symporter（NIS） in cultured lactating mammary cells with different levels of iodine and the effect of tumor necrosis factor-α（TNF-α）. Methods Original generation of mouse lactating mammary cells cultured in vitro were divided into low iodine group Ⅰ （LI-Ⅰ）, low iodine group Ⅱ （LI-Ⅱ）, adequate iodine group（AI）, high iodine group Ⅰ（HI-Ⅰ）, and high iodine group Ⅱ（HI-Ⅱ）. Cells were cultured in DEME/F12 culture medium for 24 h with different concentrations of iodine （0,5,50,3000 and 10 000 μg/L, respectively）, and TNF-α（ 10-2 mg/L） was added to some of cultured cells for 24 h. The expression of NIS mRNA of lactating mammary cells was determined by real-time quantitative PCR and the expression of NIS protein was detected by In-Cell Western. Results In iodine alone group, the expression of NIS mRNA in LI-Ⅰ group [ （64.66 ± 14.99） x 10-4] was higher than that of AI group[ （22.76 ± 7.36） × 10-4, P 〈 0.01 ]; HI-I group[ （10.18 ±3.53） × 10-4] and HI-Ⅱ group[ （8.59 ± 2.89） × 10-4] were lower than that of AI group（all P 〈 .0.05）; With increased iodine concentration, the expression of NIS mRNA decreased. The expression of NIS mRNA in LI-Ⅰ group [（2.72 ± 0.45） × 10-4], LI-Ⅱ group[ （2.69 ± 0.68） × 10-4] and AI group[（1.80 ± 0.67） × 10-4] with iodine plus TNF-o were all lower than that of LI-Ⅰ group, LI-Ⅱ group[ （29.82 ± 4.47 ） × 10-4], and AI group without TNF-α （all P 〈 0.01）. In iodine plus TNF-α, the expression of NIS mRNA in HI-Ⅰ group[（6.58 ± 2.87） × 10-4] and HI-Ⅱ[（7.04 ± 1.36） × 10-4] group were all higher than that of AI group（all P 〈 0.05）; With increased iodine deficiency or iodine excess, the expression of NIS mRNA increased. With increased iodine concentration, the expression of NIS protein decreased in iodine alone group. The expression of NIS protein in iodine plus TNF-α was all lower than that in iodine alone group. In iodine plus TNF-α, the expression of NIS protein increased in both iodine deficiency and iodine excess conditions. Conclusions Iodine may decrease the expression of NIS mRNA and protein of lactating mammary cells. The expression of NIS mRNA and protein of lactating mammary cells was inhibited by TNF-α under different levels of iodine.