Submitted to: Lipids Journal
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/18/2007
Publication Date: 1/10/2008
Citation: Deiuliis, J., Shin, J., Bae, D., Azain, M.J., Barb, C.R., Lee, K. 2008. Developmental, hormonal, and nutritional regulation of expression of porcine adipose tissue triglyceride lipase (pATGL) gene. Lipids Journal. 43(3):215-225. Interpretive Summary: The newly identified enzyme, adipose triglyceride lipase (ATGL) breaks down stored lipid in fat cells to be used in energy metabolism. This is the first report to characterize porcine ATGL gene sequence and characterize ATGL gene and protein expression. ATGL expression in fat cells increased with development, feed restriction, and responded to metabolic hormones such as insulin. AGTL plays a role in fat cell function and whole body metabolism. Therefore, understanding the interaction of ATGL with fat cell function and metabolism is necessary in order to develop new methods to increase the efficiency of red meat production with out affecting quality.
Technical Abstract: Adipose triglyceride lipase (ATGL) is a newly identified lipase. We report for the first time the porcine ATGL sequence and characterize ATGL gene and protein expression in vitro and in vivo. Adult pig tissue expresses ATGL at high levels in the white adipose and muscle tissue relative to other tested tissues. We show that within the white adipose tissue ATGL is expressed at higher levels in the fat than the stromal-vascular fraction. Additionally, ATGL expression increases dramatically in the subcutaneous adipose during development and maturation of the adipose as well as during in vitro adipogenesis. Peroxisome proliferator-activated receptor gamma is highly expressed concomitant with ATGL gene expression, suggesting a possible role in the regulation of ATGL by adipogenic regulators. In vitro treatment of differentiated primary pig preadipocytes with metabolic hormones allowed us to conclude that ATGL transcript levels are hormone sensitive. Insulin treatment, as well as activators of lipolysis such as epinephrine and forskolin, decreased ATGL gene expression. In order to characterize ATGL expression changes in vivo, we feed-restricted twelve adult gilts and collected subcutaneous and peri-renal fat tissues. ATGL gene and protein levels were increased in both fat depots. Our data shows that ATGL expression reacts to hormonal stimuli and plays a role in catecholamine-induced lipolysis in porcine as it does in mice.