REGULATION OF NA TRANSPORT FUNCTION BY CFTR IN THYROID EPITHELIAL CELLS

CFTR对甲状腺上皮细胞NA转运功能的调节

• 批准号: 8167825
• 负责人: PEYING FONG
• 金额: $ 19.71万
• 依托单位: KANSAS STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8167825
• 关键词: Anion Transport Proteins; Anions; Apical; Chloride Ion; Chlorides; Computer Retrieval of Information on Scientific Projects Database; Cyclic AMP; Cystic Fibrosis Transmembrane Conductance Regulator; Databases; Epithelial; Evaluation; Family suidae; Funding; Future; Genes; Grant; Immunoblotting; Institution; Iodides; Literature; Measurement; Mediating; Messenger RNA; Mining; Pathway interactions; Proteins; Regulation; Relative (related person); Research; Research Personnel; Resources; Source; System; Testing; Thyroid Gland; Tissues; United States National Institutes of Health; base; mRNA Expression; protein expression; small hairpin RNA; uptake

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Thyroid hormonogenesis requires iodide uptake and release into the thyroid follicular lumen. The apical exit of iodide is thought to be mediated by Pendrin, an anion exchanger encoded by the SLC26A4 gene. However, several lines of evidence suggest that alternative pathways for apical iodide efflux exist in the thyroid gland. By researching the existing literature, as well as by mining microarray databases, we identified transporters that potentially mediate iodide efflux. These include the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) and ClC-5, a Cl-/H+ exchanger, both of which previously have been identified in thyroid tissue. Polarized primary cultures were grown from wild type and CFTR -/- pig thyroids to facilitate evaluations of anion transport using short-circuit current (Isc) measurements as well as 125I fluxes. Isc studies indicate the presence of cAMP-activated anion (chloride and iodide) secretion that is abolished in CFTR-/- pig thyroid cultures. Wild type thyroid expresses SLC26A7, another candidate anion transport protein, based on measurements of both the mRNA and protein levels, using qRT-PCR and immunoblotting, respectively. Interestingly, SLC26A7 protein expression is abolished in CFTR -/- thyroid cultures, although mRNA expression did not differ significantly. The biophysical and pharmacological profile of SLC26A7 currents will be further examined in expression systems and resultant information exploited to probe not only its polarized expression in thyroid cultures, but also its functional impact on iodide secretion. In addition, future studies using polarized primary cultures will test the effects of ClC-5 and/or SLC26A7 shRNA knockdown, to evaluate their relative contributions to vectorial iodide transport.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 甲状腺激素生成需要吸收碘并将其释放到甲状腺滤泡腔中。 碘化物的顶端排出被认为是由 Pendrin 介导的，Pendrin 是一种由 SLC26A4 基因编码的阴离子交换剂。 然而，一些证据表明甲状腺中存在顶端碘流出的替代途径。 通过研究现有文献以及挖掘微阵列数据库，我们确定了可能介导碘化物流出的转运蛋白。 其中包括囊性纤维化跨膜电导调节器 (CFTR) 和 ClC-5（一种 Cl-/H+ 交换器），这两种物质先前已在甲状腺组织中被发现。 极化原代培养物是从野生型和 CFTR -/- 猪甲状腺中培养出来的，以便于使用短路电流 (Isc) 测量以及 125I 通量来评估阴离子传输。 Isc 研究表明存在 cAMP 激活的阴离子（氯离子和碘离子）分泌，这种分泌在 CFTR-/- 猪甲状腺培养物中被消除。 野生型甲状腺表达 SLC26A7，这是另一种候选阴离子转运蛋白，基于分别使用 qRT-PCR 和免疫印迹测量的 mRNA 和蛋白质水平。 有趣的是，SLC26A7 蛋白表达在 CFTR -/- 甲状腺培养物中被消除，尽管 mRNA 表达没有显着差异。 将在表达系统中进一步检查 SLC26A7 电流的生物物理和药理学特征，并利用所得信息不仅探测其在甲状腺培养物中的极化表达，而且探测其对碘化物分泌的功能影响。 此外，未来使用极化原代培养物的研究将测试 ClC-5 和/或 SLC26A7 shRNA 敲低的效果，以评估它们对矢量碘化物转运的相对贡献。