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.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 甲状腺滤泡形成需要碘的吸收和释放到甲状腺滤泡腔。 碘离子的顶端排出被认为是由Pendrin介导的，Pendrin是一种由SLC 26 A4基因编码的阴离子交换剂。 然而，一些证据表明，在甲状腺中存在顶端碘流出的替代途径。 通过研究现有的文献，以及通过挖掘微阵列数据库，我们确定了可能介导碘外流的转运蛋白。 这些包括囊性纤维化跨膜传导调节器（CFTR）和ClC-5，一种Cl-/H+交换器，这两种物质以前都在甲状腺组织中被发现。 从野生型和CFTR -/-猪甲状腺生长极化原代培养物，以便于使用短路电流（Isc）测量以及125 I通量评价阴离子转运。 Isc研究表明存在cAMP激活的阴离子（氯离子和碘离子）分泌，其在CFTR-/-猪甲状腺培养物中被消除。 野生型甲状腺表达SLC 26 A7，另一种候选阴离子转运蛋白，基于mRNA和蛋白质水平的测量，分别使用qRT-PCR和免疫印迹。 有趣的是，SLC 26 A7蛋白表达在CFTR -/-甲状腺培养物中被消除，尽管mRNA表达没有显著差异。 SLC 26 A7电流的生物物理学和药理学特征将在表达系统中进一步检查，所得信息不仅用于探测其在甲状腺培养物中的极化表达，还用于探测其对碘化物分泌的功能影响。 此外，使用极化原代培养物的未来研究将测试ClC-5和/或SLC 26 A7 shRNA敲除的效果，以评估它们对载体碘转运的相对贡献。