Regulation of FAT/CD36 mRNA gene expression by long chain fatty acids in the differentiated 3T3-L1 cells.
Defects in fatty acid translocase (FAT/CD36) have been identified as a major factor in insulin resistance and defective fatty acid and glucose metabolism. Therefore, understanding of the regulation of FAT/CD36 expression and function is important for a potential therapeutic target for type II diabetes. We differentiated 3T3-L1 preadipocytes into matured adipocytes and examined the roles of insulin and long chain fatty acids on FAT/CD36 expression and function. Our results indicate that FAT/CD36 mRNA expression was not detected at preadipocyte but was significantly increased at matured adipocyte. In fully differentiated 3T3-L1 adipocytes, insulin significantly increased FAT/CD36 mRNA and protein expression in a dose dependent manner. The free fatty acid stearic acid reduced FAT/CD36 mRNA expression while the non-metabolizable free fatty acid alpha-bromopalmitate (2-BP) significantly increased FAT/CD36 mRNA and protein expression. Isoproterenol, in contrast, dose-dependently reduced FAT/CD36 mRNA expression and increased free fatty acid release. Mechanism analysis indicated that the effect of insulin and 2-BP on the FAT/CD36 mRNA gene expression may be mediated through activation of PPAR-gamma, suggesting that FAT/CD36 may have important implications in the pathophysiology of defective fatty acid metabolism.
Yang
Yingkui
Y
Department of Surgery, University of Alabama at Birmingham, Birmingham, AL 35205, USA.
Chen
Min
M
Loux
Tara J
TJ
Harmon
Carroll M
CM
D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D018955:CD36 Antigens / Q000235:genetics*; D002460:Cell Line; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005227:Fatty Acids / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects*; D007328:Insulin / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D051379:Mice; D010168:Palmitates / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013229:Stearic Acids / Q000494:pharmacology
D018955:CD36 Antigens; D005227:Fatty Acids; D007328:Insulin; D010168:Palmitates; D012333:RNA, Messenger; D013229:Stearic Acids; C022776:2-bromopalmitate; C031183:stearic acid; D007545:Isoproterenol