Fatty acid transport and its regulation

脂肪酸转运及其调控

• 批准号: 7006136
• 负责人: Harvey F Lodish
• 金额: $ 41.67万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7006136
• 关键词: antisense nucleic acid; fatty acid metabolism; fatty acid synthase; fatty acid transport; gene expression; genetically modified animals; hormone regulation /control mechanism; insulin; laboratory mouse; lipid metabolism; long chain fatty acid; molecular cloning; protein isoforms; protein protein interaction; protein structure function; transport proteins; tumor necrosis factor alpha

We have cloned and characterized five mammalian fatty acid transport proteins (FATPs). FATP1 is expressed at high levels in heart, adipocytes, muscle, and brain. FATP4 is expressed predominantly in the brush border of the absorptive small intensive epithelial cells and is essential for uptake of LCFAs. Human FATP6 is expressed exclusively in heart muscle and its level is elevated in hypertrophic tissue. Our overall goal is to understand the molecular mechanism of fatty acid transport and its regulation. We focus on the FATPs as well as other proteins implicated in fatty acid transport: the "scavenger" receptors CD36 and SRI-BI; LACS (long chain fatty acyl CoA synthetase); and cytosolic FABPs (fatty acid binding proteins), and their roles in fatty acid transport in heart, adipocytes, and intestinal epithelial cells. Our specific aims are to 1) Determine whether these proteins functional synergize to enhance the transports of LCFAs by cultured cells and whether, depending on the transport mechanism involved, fatty acids are esterified to CoA upon entry. 2) Determine whether stable physical interactions occur between various FATPs, FABPs, SR-BI/CD36, and LACS. 3) Determine by antisense experiments which protein is rate-limiting for adipocyte LCFA uptake, both in the absence and presence of insulin. 4) Determine how insulin stimulates and TNF-alpha inhibits LCFA uptake by adipocytes 5) Clone and study the putative purine homologue of the cardiac-specific human FATP6. 6) Depending on the results obtained, use expression model systems to test the roles of FATP1, FATP4, and other proteins in LCFA uptake and determine the role of these proteins in whole-mouse lipid metabolism. Thus we will 1) Determine the expression pattern of these candidate fatty acid transport proteins within the developing and adult murine heart. 2) Using both FATP1 knockout and transgenic FATP1 over-expressing mice, determine the role of FATP1 in LCFA, uptake and lipid metabolism by adipose tissue and heart and striated muscle. 3) Using gene knock-out mice, determine the role of FAT4, SR- BI, and CD36 in uptake of LCFAs from the small intestine by the absorptive epithelial cells.

我们克隆并表征了五种哺乳动物脂肪酸转运蛋白（FATP）。 FATP1 在心脏、脂肪细胞、肌肉和大脑中高水平表达。 FATP4 主要在吸收性小密集上皮细胞的刷状缘中表达，对于 LCFA 的摄取至关重要。人类 FATP6 仅在心肌中表达，并且其水平在肥大组织中升高。我们的总体目标是了解脂肪酸运输的分子机制及其调节。我们重点关注 FATP 以及与脂肪酸转运有关的其他蛋白质：“清道夫”受体 CD36 和 SRI-BI； LACS（长链脂肪酰辅酶A合成酶）；和胞质 FABP（脂肪酸结合蛋白），及其在心脏、脂肪细胞和肠上皮细胞脂肪酸转运中的作用。我们的具体目标是 1) 确定这些蛋白质是否在功能上协同作用以增强培养细胞对 LCFA 的转运，以及根据所涉及的转运机制，脂肪酸在进入时是否被酯化为 CoA。 2)确定各种FATP、FABP、SR-BI/CD36和LACS之间是否发生稳定的物理相互作用。 3) 通过反义实验确定在存在和不存在胰岛素的情况下哪种蛋白质对脂肪细胞 LCFA 的摄取具有限速作用。 4) 确定胰岛素如何刺激和 TNF-α 抑制脂肪细胞对 LCFA 的摄取 5) 克隆并研究心脏特异性人 FATP6 的推定嘌呤同系物。 6) 根据获得的结果，使用表达模型系统测试 FATP1、FATP4 和其他蛋白质在 LCFA 摄取中的作用，并确定这些蛋白质在全小鼠脂质代谢中的作用。因此，我们将 1) 确定这些候选脂肪酸转运蛋白在发育中和成年小鼠心脏内的表达模式。 2) 使用 FATP1 敲除和转基因 FATP1 过表达小鼠，确定 FATP1 在脂肪组织、心脏和横纹肌的 LCFA、摄取和脂质代谢中的作用。 3) 使用基因敲除小鼠，确定 FAT4、SR-BI 和 CD36 在吸收性上皮细胞从小肠摄取 LCFA 中的作用。