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Palmitic acid increases the abundance of mRNA of genes involved in de novo synthesis of fat in mammary explants from lactating ewes

Carraro, P.C., Da Silva, E.D., Oliveira, D.E.
Small ruminant research 2019 v.174 pp. 99-102
acetyl-CoA carboxylase, biopsy, bovine serum albumin, complementary DNA, culture media, epithelial cells, ewes, explants, fatty acid-binding proteins, fatty-acid synthase, gene expression, gene expression regulation, genes, lactating females, lactation, mammary glands, messenger RNA, milk, milk fat, palmitic acid, physiological transport, polymerase chain reaction, stearoyl-CoA desaturase
Culture of mammary cells with palmitic acid (PA) has shown contradictory results for gene expression of enzymes involved in de novo synthesis pathway. The objective of this study was to evaluate the effects of PA on the mRNA abundance of enzymes involved in de novo fatty acid (FA) synthesis pathway, acetyl-CoA carboxylase alpha from promoters II and III (ACACA-α PII and ACACA-α PIII), fatty acid synthase (FASN), fatty acid internalization (CD36 molecule), intracellular transport (fatty acid binding proteins; FABP3 and FABP4) and desaturation (stearoyl-CoA desaturase 1; SCD1) of FA during milk fat synthesis. Mammary explants obtained through biopsy from three Lacaune ewes with 40 days in milk (DIM) were used. The explants were cultured for 24 h using the following treatments: Control (culture medium + bovine serum albumin (BSA, 98%) and Palmitic Acid (culture medium + 75 μM of C16:0 - 99%). Immediately after incubation, total RNA was extracted, complementary DNA was synthesized, and quantitative real time polymerase chain reaction was performed. The PA treatment upregulated the mRNA expression levels of ACACA-α PIII, ACACA-α PII, and FASN by 1.5, 1.3, and 1.3 fold, respectively, compared to Control. The gene expression levels of CD36, FABP3, FABP4, and SCD1 were not affected by the PA treatment. Thus, PA treatment upregulated the mRNA expression of genes codifying proteins involved in the de novo synthesis pathway.