Function of circCAP2 in the Differentiation of Cattle (Bos taurus) Preadipocytes
GAO Yu-Hong1, FENG Xue1, WANG Shu-Zhe1, HU Chun-Li1, LI Fen1, ZHANG Lu-Pei2, YANG Run-Jun3, MA Yun1*
1 Key Laboratory of Ruminant Molecular and Cellular Breeding, Ningxia Hui Autonomous Region/School of Agriculture, Ningxia University, Yinchuan 750021, China; 2 Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing 100193, China; 3 College of Animal Science, Jilin University, Changchun 130062, China
Abstract：circular RNA (circRNA) plays an important role in regulating the proliferation and differentiation of preadipocytes. Previous high-throughput sequencing results showed that the expression of a circular RNA circRNA-cyclase associated actin cytoskeleton regulatory protein 2 (circCAP2) was different before and after the differentiation of Bos taurus preadipocytes. In this study, Sanger sequencing and qPCR were used to identify circCAP2 and analysed its expression pattern to research the mechanism of circCAP2 in the differentiation of preadipocytes. Furthermore, circCAP2 was transfected into preadipocytes by overexpression and interference techniques. The lipid accumulation of adipocytes was detected by oil red O staining, and the expression level of adipogenic marker genes was detected by qPCR. The results showed that circCAP2 was real presence and stably expressed, and was extremely highly expressed in mature adipocytes (P<0.01). The gain-of-function test showed that overexpression of circCAP2 significantly promoted lipid accumulation in preadipocytes, and significantly upregulated peroxisome proliferator activated receptor gamma (PPARγ), fatty acid binding protein 4 (FABP4), CCAAT/enhancer-binding protein α (C/EBPα) and C/EBPβ (P<0.05). However, the loss-of-function test showed that interference with circCAP2 significantly inhibited lipid accumulation in adipocytes, and the expression levels of adipogenic marker genes, PPARγ, FABP4, C/EBPα and C/EBPβ, were significantly down-regulated (P<0.05). In conclusion, these results suggest that circCAP2 may be a positive regulator of the differentiation of cattle preadipocytes, which can be used as a novel marker to improve fat deposition in cattle breeding. This study provides a reference for further exploring the regulatory mechanism of circCAP2 on fat deposition in cattle.
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