Insulin Signaling in Insulin Receptor Substrate (IRS)-1-Deficient Brown Adipocytes Requirement of IRS-1 for Lipid Synthesis

摘要

Immortalized fetal brown adipocyte cell lines have been generated from homozygous (-/-) and heterozy- gous (+/-) insulin receptor substrate (IRS)-1-defi- cient mice, as well as from wild-type mice (+/+). Under growing condition, these cell lines maintained the expression of the adipogenic marker fatty acid syn- thase and uncoupling protein-1, a tissue-specific ther- mogenic marker. The IRS-1 (-/-) brown adipocytes lacked IRS-1 protein expression and had a significant increase in IRS-2 protein expression.