miR-148a and miR-17-5p synergistically regulate milk TAG synthesis via PPARGC1A and PPARA in goat mammary epithelial cells

• Published in: RNA biology Vol. 14; no. 3; pp. 326 - 338
• Main Authors: Chen, Zhi, Luo, Jun, Sun, Shuang, Cao, Duoyao, Shi, Huaiping, Loor, Juan J.
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 04.03.2017
• Subjects: 3' Untranslated Regions; Animals; Base Pairing; Epithelial Cells - metabolism; Female; Gene Expression Profiling; Gene Expression Regulation; Goats; High-Throughput Nucleotide Sequencing; Lipid Metabolism - genetics; Mammary Glands, Animal - metabolism; MicroRNAs - genetics; Milk - metabolism; miR-148a; miR-17-5p; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - genetics; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha - metabolism; PPAR alpha - genetics; PPAR alpha - metabolism; PPARA; PPARGC1A; Research Paper; RNA Interference; RNA, Messenger - genetics; triacylglycerol synthesis; triacylglycerol synthesis; miR-17–5p; PPARA; PPARGC1A; miR-148a
• ISSN: 1547-6286; 1555-8584
• DOI: 10.1080/15476286.2016.1276149

MicroRNA (miRNA) are a class of '18-25' nt RNA molecules which regulate gene expression and play an important role in several biologic processes including fatty acid metabolism. Here we used S-Poly (T) and high-throughput sequencing to evaluate the expression of miRNA and mRNA during early-lactation and in the non-lactating ("dry") period in goat mammary gland tissue. Results indicated that miR-148a, miR-17-5p, PPARGC1A and PPARA are highly expressed in the goat mammary gland in early-lactation and non-lactating periods. Utilizing a Luciferase reporter assay and Western Blot, PPARA, an important regulator of fatty acid oxidation, and PGC1a (PPARGC1A), a major regulator of fat metabolism, were demonstrated to be targets of miR-148a and miR-17-5p in goat mammary epithelial cells (GMECs). It was also revealed that miR-148a expression can regulate PPARA, and miR-17-5p represses PPARGC1A in GMECs. Furthermore, the overexpression of miR-148a and miR-17-5p promoted triacylglycerol (TAG) synthesis while the knockdown of miR-148a and miR-17-5p impaired TAG synthesis in GMEC. These findings underscore the importance of miR-148a and miR-17-5p as key components in the regulation of TAG synthesis. In addition, miR-148a cooperates with miR-17-5p to regulate fatty acid metabolism by repressing PPARGC1A and PPARA in GMECs. Further studies on the functional role of miRNAs in lipid metabolism of ruminant mammary cells seem warranted.