Lipoprotein Lipase, Tissue Expression and Effects on Genes Related to Fatty Acid Synthesis in Goat Mammary Epithelial Cells

Abstract

Lipoprotein lipase (LPL) serves as a central factor in hydrolysis of triacylglycerol and uptake of free fatty acids from the plasma. However, there are limited data concerning the action of LPL on the regulation of milk fat synthesis in goat mammary gland. In this investigation, we describe the cloning and sequencing of the LPL gene from Xinong Saanen dairy goat mammary gland, along with a study of its phylogenetic relationships. Sequence analysis showed that goat LPL shares similarities with other species including sheep, bovine, human and mouse. LPL mRNA expression in various tissues determined by RT-qPCR revealed the highest expression in white adipose tissue, with lower expression in heart, lung, spleen, rumen, small intestine, mammary gland, and kidney. Expression was almost undetectable in liver and muscle. The expression profiles of LPL gene in mammary gland at early, peak, mid, late lactation, and the dry period were also measured. Compared with the dry period, LPL mRNA expression was markedly greater at early lactation. However, compared with early lactation, the expression was lower at peak lactation and mid lactation. Despite those differences, LPL mRNA expression was still greater at peak, mid, and late lactation compared with the dry period. Using goat mammary epithelial cells (GMEC), the in vitro knockdown of LPL via shRNA or with Orlistat resulted in a similar degree of down-regulation of LPL (respectively). Furthermore, knockdown of LPL was associated with reduced mRNA expression of SREBF1, FASN, LIPE and PPARG but greater expression of FFAR3. There was no effect on ACACA expression. Orlistat decreased expression of LIPE, FASN, ACACA, and PPARG, and increased FFAR3 and SREBF1 expression. The pattern of LPL expression was similar to the changes in milk fat percentage in lactating goats. Taken together, results suggest that LPL may play a crucial role in fatty acid synthesis.

Plasma biochemical and minerals parameters in Arbia goats of a semi-arid region of North-Eastern Algeria during different stages of production

“…In contrast to our findings, other researchers reported non-significant changes between early, mid and late lactation in black goat (DARWESH et al, 2013), and in valfortorina goats (CASAMASSIMA et al, 2007), whereas triglyceride tended to increase as Montefalcone goats advanced in stages of lactation (CASAMASSIMA et al, 2007). The decrease in triglyceride levels could be the result of the use of fat reserve mobilization for milk production (WANG-SHENG et al, 2014). The decrease in triglycerides during early lactation found in the present study could not be an indicator of negative energy because during this period glucose did not decrease compared to before pregnancy, which means the animals were in a positive energy status.…”

Carcass traits, fatty acid composition, gene expression, oxidative stability and quality attributes of different muscles in Dorper lambs fed Nigella sativa seeds, Rosmarinus officinalis leaves and their combination

“…LPL is the rate limiting enzyme for the import of triglyceride (TAG) derived FAs by muscle, for utilization, and adipose tissue, for storage, and plays an important role in the differentiation and maturation of adipose cells [ 28 ]. Lipoprotein lipase serves as a central factor in hydrolysis of triacylglycerol and uptake of free FAs from the plasma [ 29 ]. Moreover, it controls the triglycerides partitioning between adipose tissue and muscles [ 30 ].…”

Specificity Protein 1 Regulates Gene Expression Related to Fatty Acid Metabolism in Goat Mammary Epithelial Cells

“…Six Xinong Saanen dairy goats (four years old, third parity) were selected and divided into two groups of three to conduct the main project (Experimental Farm of the Northwest A&F University, Yangling, China). For one group, all three goats were slaughtered during the lactation period (100 days), tissue samples (lungs, small intestine, muscle, spleen, mammary gland, subcutaneous fat, stomach, kidney, liver and heart) were rapidly collected, and rinsed with DEPC (Sigma, St. Louis, MO, USA) sterile water, and were then used for tissue expression determination of the SP1 gene [ 37 , 38 , 39 , 40 ]. Dry-off period was presumed from 300 days after calving to the next calving.…”