miR-27a suppresses triglyceride accumulation and affects gene mRNA expression associated with fat metabolism in dairy goat mammary gland epithelial cells

• Published in: Gene 2013-05, Vol.521 (1), p.15-23
• Main Authors: Lin, Xian-zi, Luo, Jun, Zhang, Li-ping, Wang, Wei, Shi, Heng-bo, Zhu, Jiang-jiang
• Format: Article
• Language: English
• Subjects: Animals; epithelial cells; Epithelial Cells - metabolism; Epithelial Cells - physiology; Fatty acid composition; Fatty Acids - metabolism; Fatty Acids, Unsaturated - metabolism; Female; Gene Expression Regulation; gene overexpression; genes; goat milk; goats; Goats - genetics; Goats - metabolism; lactation; lipid metabolism; Lipid Metabolism - genetics; mammary glands; Mammary Glands, Animal - cytology; Mammary Glands, Animal - physiology; messenger RNA; MicroRNA; MicroRNAs - genetics; Milk - chemistry; Milk - metabolism; milk fat; Milk triglyceride; nucleotides; prolactin; Prolactin - metabolism; RNA, Messenger; saturated fatty acids; triacylglycerols; Triglycerides - genetics; Triglycerides - metabolism; unsaturated fatty acids
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2013.03.050

MicroRNAs (miRNAs), a well-defined group of small RNAs containing about 22 nucleotides, participate in various biological metabolic processes. miR-27a is a miRNA that is known to regulate fat synthesis and differentiation in preadipocyte cells. However, little is known regarding the role that miR-27a plays in regulating goat milk fat synthesis. In this study, we determined the miR-27a expression profile in goat mammary gland and found that miR-27a expression was correlated with the lactation cycle. Additionally, prolactin promoted miR-27a expression in goat mammary gland epithelial cells. Further functional analysis showed that over-expression of miR-27a down-regulated triglyceride accumulation and decreased the ratio of unsaturated/saturated fatty acid in mammary gland epithelial cells. miR-27a also significantly affected mRNA expression related to milk fat metabolism. Specifically, over-expression of miR-27a reduced gene mRNA expression associated with triglyceride synthesis by suppressing PPARγ protein levels. This study provides the first experimental evidence that miR-27a regulates triglyceride synthesis in goat mammary gland epithelial cells and improves our understanding about the importance of miRNAs in milk fat synthesis. •A correlation exists between miR-27a and milk triglyceride accumulation in goat.•miR-27a expression correlates with lactation cycle and prolactin concentration.•Over-expression of miR-27a decreases triglyceride and fatty acid contents.•Over-expressed miR-27a suppresses the ratio of unsaturated/saturated fatty acid.•miR-27a significantly affects gene mRNA expression related to milk fat metabolism.