Abstract
Lipid droplet proteins of the PAT (perilipin, adipophilin, and TIP47) family regulate cellular neutral lipid stores. We have studied a new member of this family, PAT-1, and found that it is expressed in highly oxidative tissues. We refer to this protein as "OXPAT." Physiologic lipid loading of mouse liver by fasting enriches OXPAT in the lipid droplet tissue fraction. OXPAT resides on lipid droplets with the PAT protein adipophilin in primary cardiomyocytes. Ectopic expression of OXPAT promotes fatty acid-induced triacylglycerol accumulation, long-chain fatty acid oxidation, and mRNAs associated with oxidative metabolism. Consistent with these observations, OXPAT is induced in mouse adipose tissue, striated muscle, and liver by physiological (fasting), pathophysiological (insulin deficiency), pharmacological (peroxisome proliferator-activated receptor [PPAR] agonists), and genetic (muscle-specific PPARα overexpression) perturbations that increase fatty acid utilization. In humans with impaired glucose tolerance, PPARγ agonist treatment induces adipose OXPAT mRNA. Further, adipose OXPAT mRNA negatively correlates with BMI in nondiabetic humans. Our collective data in cells, mice, and humans suggest that OXPAT is a marker for PPAR activation and fatty acid oxidation. OXPAT likely contributes to adaptive responses to the fatty acid burden that accompanies fasting, insulin deficiency, and overnutrition, responses that are defective in obesity and type 2 diabetes.
Document Type
Article
Publication Date
12-2006
Digital Object Identifier (DOI)
10.2337/db06-0399
Repository Citation
Wolins, Nathan E.; Quaynor, Benjamin K.; Skinner, James R.; Tzekov, Anatoly; Croce, Michelle A.; Gropler, Matthew C.; Varma, Vijayalakshmi; Yao-Borengasser, Aiwei; Rasouli, Neda; Kern, Philip A.; Finck, Brian N.; and Bickel, Perry E., "OXPAT/PAT-1 is a PPAR-Induced Lipid Droplet Protein that Promotes Fatty Acid Utilization" (2006). Clinical and Translational Science Faculty Publications. 38.
https://uknowledge.uky.edu/ccts_facpub/38
