%0 Journal Article
%T PPAR¦Ã Regulates Genes Involved in Triacylglycerol Synthesis and Secretion in Mammary Gland Epithelial Cells of Dairy Goats
%A Hengbo Shi
%A Jun Luo
%A Jiangjiang Zhu
%A Jun Li
%A Yuting Sun
%A Xianzi Lin
%A Liping Zhang
%A Dawei Yao
%A Huaiping Shi
%J PPAR Research
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/310948
%X To explore the function of PPAR¦Ã in the goat mammary gland, we cloned the whole cDNA of the PPAR¦Ã gene. Homology alignments revealed that the goat PPAR¦Ã gene is conserved among goat, bovine, mouse, and human. Luciferase assays revealed that rosiglitazone enhanced the activity of the PPAR¦Ã response element (PPRE) in goat mammary epithelial cells (GMECs). After rosiglitazone (ROSI) treatment of GMECs, there was a significant ( ) increase in the expression of genes related to triacylglycerol synthesis and secretion: LPL, FASN, ACACA, PLIN3, FABP3, PLIN2, PNPLA2, NR1H3, SREBF1, and SCD. The decreases in expression observed after knockdown of PPAR¦Ã relative to the control group (Ad-NC) averaged 65%, 52%, 67%, 55%, 65%, 58%, 85%, 43%, 50%, and 24% for SCD, DGAT1, AGPAT6, SREBF1, ACACA, FASN, FABP3, SCAP, ATGL, and PLIN3, respectively. These results provide direct evidence that PPAR¦Ã plays a crucial role in regulating the triacylglycerol synthesis and secretion in goat mammary cells and underscore the functional importance of PPAR¦Ã in mammary gland tissue during lactation. 1. Introduction Lactation is a process highly demanding of lipid synthesis and transport. Although peroxisome proliferator-activated receptor ¦Ã (PPAR¦Ã) is known to promote lipogenesis and adipogenesis in adipose tissue [1], its role in the lactating mammary gland is less clear. Many candidate genes that regulate lipid synthesis have been identified during the lactation cycle [2]. Researchers have evaluated the expression profiles of 54 genes associated with bovine milk fat synthesis through various periods during lactation and built a regulatory network [3]. Their data showed that PPAR¦Ã might be the main factor that regulates the nuclear transcription factor, sterol regulatory element-binding transcription factor 1 (SREBF1), which also affects the expression of some fatty acid metabolism genes during lactation [3, 4]. Much data have been published regarding PPAR¦Ã¡¯s role in milk fat synthesis in bovine [5¨C7], while there is a lack of data on its role in the dairy goat. Whether PPAR¦Ã also plays the same critical role in regulation of milk fatty acid synthesis during the lactation process in dairy goat remains to be determined. In the present study, we first identified the sequence of PPAR¦Ã in dairy goat mammary tissue and evaluated the activity of the PPRE via luciferase assays. Its function in dairy goat mammary epithelial cells (GMECs) was also investigated through the use of the pharmaceutical ligand rosiglitazone (ROSI) and adenovirus-mediated RNA interference. 2. Materials and Methods
%U http://www.hindawi.com/journals/ppar/2013/310948/