Effects of Free Linolenic Acid on Transcription of mRNAs of Genes Related to Fatty Acid Metabolism in Mammary Epithelial Cells of Dairy Cows

This experiment was conducted to study the effects of free linolenic acid (LNA) on the targeted genes of mammary epithelial cells of dairy cows cultured in vitro,which were related to fatty acid metabolism.In the cultured epithelial cells,the control group was supplemented with BSA replacing FBS,and treatments were supplemented with both BSA and LNA at different concentrations.The experiment lasted for 36 h,and the technique RT-qPCR was used to analyse the transcription level of targeted genes.The results showed as follows:1) 0.625～5.000 μmol/L LNA significantly upregulated the transcription of CD36 gene (P0.01),and higher (≥5 μmol/L) LNA downregulated the transcription of acyl-CoA synthetase-isoform-1 and fatty acid-binding protein-3 genes (P0.01).2) The transcription level of fatty acid biosynthesis genes had a dose response with LNA.Higher concentration of LNA (≥5 μmol/L) decreased the transcription of fatty acid synthase and stearoyl CoA desaturase-1 genes (P0.01).3) The extent of LNA concentration did not affect the transcription of proxiomepro liferater ctivatedreceptor-gama gene (P0.05),but sterol response element binding protein gene was very sensitive to LNA (P0.01).This study suggests that long-chain fatty acid LNA inhibits the expression of fatty acid endogenous synthesis genes;however,CD36 plays an important role in the transportation process of fatty acids into the mammary epithelial cells of dairy cows.