pH Regulation of Fat Storage in the Nematode Intestine

线虫肠道脂肪储存的 pH 调节

• 批准号: 6952415
• 负责人: Keith Nehrke
• 金额: $ 31.2万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-27 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6952415
• 关键词: Caenorhabditis elegans; RNA interference; Xenopus; acid base balance; acidosis; biological signal transduction; cell line; cholesterol; dietary restriction; fluorescence microscopy; functional /structural genomics; gastrointestinal absorption /transport; gene deletion mutation; genetic mapping; genetic screening; glucose metabolism; lipid metabolism; longevity; membrane transport proteins; microarray technology; mitochondria; oxygen consumption; protein isoforms; protein localization; recombinant proteins; sodium hydrogen exchanger; suppressor mutations

DESCRIPTION (provided by applicant): Deficiencies in Na+/H+ or CI-/HCO3- exchange compromise fluid and electrolyte transport in the mammalian intestine, but the ultimate role of acid-base transport in nutrient uptake processes and lipid metabolism is relatively poorly understood. In addition, little is known regarding how intestinal pHi influences cell signaling events that response to nutrient availability. We hypothesis that pHi acts as a synergistic messenger, and provides a metabolic context through which the actions of diverse cellular and trans-cellular signaling pathways are interpreted. In this application, we offer preliminary evidence linking acid-base transport to fat storage and related signaling events in the nematode C. elegans, and propose the following: Aim 1 involves characterizing the SLC4 and SLC26 CI-/HCO3- homologs in C. elegans by first assessing their distribution, then examining function both in situ, using recombinant protein expression and in vivo, using a genetically encoded pH indicator and RNAi. Aim 2 is designed to test how changes in intestinal pHi affect classic cell signaling processes that regulate fat storage, and conversely what cell signaling processes are involved in conveying the phenotypic effects of cellular acidosis. Aim 3 is designed to utilize genetic, reverse-genetic, and functional genomic assays to identify regulatory proteins that attenuate intracellular pH, as well as the global transcriptional responses to intracellular acidification. The strength of this proposal is that it will use a powerful model system and novel reagents for monitoring pH in living organisms to study fat biology from a unique perspective: that of acid-base homeostasis.

描述（由申请人提供）： Na+/H+ 或 CI-/HCO3- 交换的缺陷会损害哺乳动物肠道中的液体和电解质运输，但酸碱运输在营养吸收过程和脂质代谢中的最终作用尚不清楚。此外，关于肠道 pHi 如何影响响​​应营养可用性的细胞信号事件，人们知之甚少。我们假设 pHi 充当协同信使，并提供代谢背景，通过该代谢背景来解释不同细胞和跨细胞信号通路的作用。在此应用中，我们提供了线虫中酸碱运输与脂肪储存和相关信号事件之间的联系的初步证据，并提出以下建议：目标 1 涉及表征线虫中的 SLC4 和 SLC26 CI-/HCO3- 同源物首先评估它们的分布，然后使用重组蛋白表达在原位检查功能，并使用基因编码的 pH 指示剂和 RNAi 在体内检查功能。目标 2 旨在测试肠道 pHi 的变化如何影响调节脂肪储存的经典细胞信号传导过程，以及反过来，哪些细胞信号传导过程参与传递细胞酸中毒的表型效应。目标 3 旨在利用遗传、反向遗传和功能基因组测定来识别减弱细胞内 pH 的调节蛋白，以及对细胞内酸化的整体转录反应。该提案的优势在于，它将使用强大的模型系统和新颖的试剂来监测活体有机体的 pH 值，从酸碱稳态的独特角度研究脂肪生物学。