Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, 05508-000 São Paulo, SP, Brazil.
Mol Cell Endocrinol. 2012 Mar 5;350(1):118-24. doi: 10.1016/j.mce.2011.12.002. Epub 2011 Dec 9.
Iodine is a critical element involved in thyroid hormone synthesis. Its efflux into the follicular lumen is thought to occur, in part, through pendrin at the apical membrane of thyrocytes. This study attempted to investigate whether iodide administration affects SLC26A4 mRNA expression in rat thyroid and in PCCl3 cells. Rats and cells were treated or not with NaI from 30 min up to 48 h. One group was concomitantly treated with sodium perchlorate. SLC26A4 mRNA expression was also investigated in PCCl3 cells treated with actinomycin D prior to NaI treatment. Iodide administration significantly increased SLC26A4 mRNA content in both models. The simultaneous administration of NaI and perchlorate, as well as the treatment of PCCl3 cells with actinomycin D prevented this effect, indicating that intracellular iodide is essential for this event, which appears to be triggered by transcriptional mechanisms. These data show that intracellular iodide rapidly upregulates SLC26A4 mRNA expression.
碘是甲状腺激素合成中不可或缺的元素。人们认为，碘从甲状腺滤泡腔中的外流部分是通过甲状腺细胞顶膜上的 pendrin 发生的。本研究试图探讨碘化物给药是否会影响大鼠甲状腺和 PCCl3 细胞中 SLC26A4 mRNA 的表达。用 NaI 处理大鼠和细胞 30 分钟至 48 小时。一组同时用高氯酸钠处理。在给予 NaI 之前，还在 PCCl3 细胞中用放线菌 D 处理以研究 SLC26A4 mRNA 的表达。碘化物给药显著增加了两种模型中 SLC26A4 mRNA 的含量。同时给予 NaI 和高氯酸钠，以及用放线菌 D 处理 PCCl3 细胞均可阻止这种作用，表明细胞内碘是该事件所必需的，该事件似乎是由转录机制触发的。这些数据表明，细胞内碘可快速上调 SLC26A4 mRNA 的表达。
