Effect of different exogenous fatty acids on the cytosolic triacylglycerol content in bovine mammary cells

Abstract

The objective of this study was to determine how cytosolic triacylglycerols (TAG) are stored in mammary cells and whether this depends on the individual chemical configuration of fatty acids (FA). This objective was accomplished by addition of different FA to a FA-free medium used to culture mammary alveolar cells-large T antigen cells (MAC-T). Treatments consisted of adding FA (palmitate, stearate, oleate, linoleate, rumenic acid [CLA], elaidate and vaccinate) solutions to the medium at 100, 200, 300 and 400 mmol/L concentrations for a 24-h incubation period. At the end of each incubation period, cytosolic TAG, DNA and protein contents were measured. Palmitate, vaccenate, linoleate and CLA increased ( P < 0.05) cytosolic TAG (μg/mg protein). Palmitate and CLA increased ( P < 0.05) cytosolic TAG adjusted for DNA content. Overall, effects on cytosolic TAG accumulation depended on individual FA structure (chain length, degree of saturation, and number and orientation of FA double bonds). In addition, the long-chain FA used in this study did not have a detrimental effect on MAC-T cells as indicated by cytosolic protein and DNA contents reflecting their biological role in lipid accumulation.

Effects of dietary polyunsaturated fatty acid sources on expression of lipid-related genes in bovine milk somatic cells

“…Supplementation at 2.7% DM with 18-carbon unsaturated FA such as rapeseed oil (rich in C18:1 cis-9), soybean oil (rich in C18:2 cis n-6), and linseed oil (C18:3 n-3), has inhibited de novo synthesis FA, which reduces expression of INSIG1 5 . In this study, SO provided 50 g/100 g of C18:2 cis n-6, whereas FO was composed (g/100 g) mostly of C18:2 cis n-6 (16), C20:5 n-3 (16), C20:5 n-3 (5), and C22:6 n-3 (8).…”

“…In fact, those alterations were observed in different biological functions, such as FA synthesis ( ACACA ), acetate and FA activation and intra-cellular transport ( FABP3 , FABP4 ), lipid droplet formation ( PLIN2 ), and transcription regulation ( THRSP ), and this was observed over a period of 63 days of lipid supplementation with either palm oil (as a saturated FA source) or olive oil (as an unsaturated FA source). We have also reported that at in vitro level, responses of mammary gland cells to lipid supplementation will depend on individual FA structure, such as chain length, degree of saturation, and orientation of FA double bonds 8 .…”

Effects of exogenous C18 unsaturated fatty acids on milk lipid synthesis in bovine mammary epithelial cells

“…Oleate and linoleate were reported to significantly upregulate TAG synthesis in BMECs, and C18 UFAs at a concentration lower than 100 μM could increase the accumulation of TAG (Yonezawa et al ., 2004; Cui et al ., 2012). A recent study in Mac-T cells showed similar results and that UFA treatment increased cytosolic TAG accumulation (Vargas-Bello-Pérez et al ., 2018). Moreover, Green et al .…”

“…In accordance with our study showing that the cellular oleic acid and total UFA concentrations were higher following incubation with a mixture of oleic, linoleic and linolenic acids, Vargas-Bello-Pérez et al . (2019) showed that the single addition of oleate increased cytosolic MUFAs and UFAs in Mac-T cells. Together with the present results, these findings suggest that oleic acid serves as a potent regulator of FA unsaturation in BMECs.…”

Goat Milk Foodomics. Dietary Supplementation of Sunflower Oil and Rapeseed Oil Modify Milk Amino Acid and Organic Acid Profiles in Dairy Goats

“…The most practical way to modulate milk fatty acids (FAs) toward a healthier profile for human consumption is by the supplementation of animal feed with vegetable oils ( 3 – 5 ). The chemical changes in milk FA profile depend on the FA profile of vegetable oil supplement, such as length of FA chain, degree of unsaturation, and orientation of FA double bonds as shown in an in vitro study performed on goat mammary gland cells ( 6 ).…”