Fatty Acid Binding Proteins-Ligand Specificity

描述（由申请人提供）：长链脂肪酸（LCFAs）和LCFA- coas是脂质代谢的重要代谢中间体，也是参与LCFA、脂蛋白和/或葡萄糖代谢的核转录因子（ppar, HNF4alpha）的配体调节剂。尽管体外纯化脂肪酸结合蛋白（FABPs）和/或培养中过表达转化细胞的研究表明，FABPs在LCFA代谢中具有功能，但个体FABPs在体内的生理作用尚不清楚。肝细胞大量表达三种结合LCFAs和LCFA-CoAs的蛋白：肝脂肪酸结合蛋白（L-FABP）、甾醇载体蛋白-2 （SCP-2）和甾醇载体蛋白-x （SCP-x）。该应用程序的目的是：(i)单独消除LCFA/LCFA- coa结合蛋白的合成，并在指示的情况下，在基因消融的小鼠中繁殖；（ii）研究这些蛋白在培养肝细胞和体内直链和支链LCFAs代谢中的个体作用；（iii）研究LCFA/LCFA- coa结合蛋白可能发挥作用的两种潜在的核调节机制。具体目的集中在培养的肝细胞和基因靶向小鼠上，研究：

DESCRIPTION (provided by applicant): Long chain fatty acids (LCFAs) and LCFA-CoAs serve as important metabolic intermediates in lipid metabolism and as ligand regulators of nuclear transcription factors (PPARalpha, HNF4alpha) involved in LCFA, lipoprotein, and/or glucose metabolism. Although studies with purified fatty acid binding proteins (FABPs) in vitro and/or with overexpressed, transformed cells in culture suggest functions in LCFA metabolism, physiological roles of individual FABPs in vivo are unresolved. Liver cells (hepatocytes) express three proteins in abundance that bind both LCFAs and LCFA-CoAs: liver fatty acid-binding protein (L-FABP), sterol carrier protein-2 (SCP-2), and sterol carrier protein-x (SCP-x). The objective of this application is to: (i) eliminate synthesis of LCFA/LCFA-CoA binding proteins individually, and where indicated, multiply in gene-ablated mice; (ii) examine individual role(s) of these proteins in metabolism of straight- and branched-chain LCFAs in cultured hepatocytes and in vivo; and (iii) examine two potential nuclear regulatory mechanism(s) whereby the LCFA/LCFA-CoA binding proteins may exert effects. The specific aims are focused on cultured hepatocyes and gene-targeted mice to examine: Aim 1. LCFA uptake and intracellular LCFA/LCFA-CoA transport in hepatocytes cultured from gene-ablated mice and in vivo. Aim 2. Trafficking of L-FABP, LCFAs/LCFA-CoAs to nuclei, distribution within nuclei, and interaction with PPARalpha and HNF4alpha in cultured hepatocytes from control and gene-ablated mice. Aim 3. Oxidation of LCFAs in mitochondria, peroxisomes, and endoplasmic reticulum of cultured hepatocytes from gene-ablated mice and in vivo. Aim 4. Esterification for storage or secretion in cultured hepatocytes from gene-ablated mice and in vivo. With the growing awareness of interrelationships between intracellular fatty acid and glucose metabolism, results from these studies will contribute to our understanding of factors involved in diabetes as well as diseases of lipid metabolism, including atherosclerosis, obesity, and heart disease.