MicroRNA-15a Regulates the Differentiation of Intramuscular Preadipocytes by Targeting <i>ACAA1</i>, <i>ACOX1</i> and <i>SCP2</i> in Chickens

• Main Authors: Guoxi Li, Shouyi Fu, Yi Chen, Wenjiao Jin, Bin Zhai, Yuanfang Li, Guirong Sun, Ruili Han, Yanbin Wang, Yadong Tian, Hong Li, Xiangtao Kang
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: International Journal of Molecular Sciences
• Subjects: miR-15a; chicken intramuscular preadipocytes; differentiation; <i>ACAA1</i>; <i>ACOX1</i>; <i>SCP2</i>
• Online Access: https://www.mdpi.com/1422-0067/20/16/4063

Our previous studies showed that microRNA-15a (miR-15a) was closely related to intramuscular fat (IMF) deposition in chickens; however, its regulatory mechanism remains unclear. Here, we evaluated the expression characteristics of miR-15a and its relationship with the expression of acetyl-CoA acyltransferase 1 (<i>ACAA1</i>), acyl-CoA oxidase 1 (<i>ACOX1</i>) and sterol carrier protein 2 (<i>SCP2</i>) by qPCR analysis in Gushi chicken breast muscle at 6, 14, 22, and 30 weeks old, where we performed transfection tests of miR-15a mimics in intramuscular preadipocytes and verified the target gene of miR-15a in chicken fibroblasts (DF1). The miR-15a expression level at 30 weeks increased 13.5, 4.5, and 2.7-fold compared with the expression levels at 6, 14, and 22 weeks, respectively. After 6 days of induction, miR-15a over-expression significantly promoted intramuscular adipogenic differentiation and increased cholesterol and triglyceride accumulation in adipocytes. Meanwhile, 48 h after transfection with miR-15a mimics, the expression levels of <i>ACAA1</i>, <i>ACOX1</i> and <i>SCP2</i> genes decreased by 56.52%, 31.18% and 37.14% at the mRNA level in intramuscular preadipocytes. In addition, the co-transfection of miR-15a mimics and <i>ACAA1</i>, <i>ACOX1</i> and <i>SCP2</i> 3&#8242;UTR (untranslated region) dual-luciferase vector significantly inhibited dual-luciferase activity in DF1 cells. Taken together, our data demonstrate that miR-15a can reduce fatty acid oxidation by targeting <i>ACAA1</i>, <i>ACOX1</i>, and <i>SCP2</i>, which subsequently indirectly promotes the differentiation of chicken intramuscular preadipocytes.