C/Ebp Beta Converts Bovine Fibroblasts To Adipocytes Without Hormone Cocktail Induction

Background: Adipogenesis and fibrogenesis can be considered as a competitive process in muscle, which may affect the intramuscular fat deposition. The CCAAT/enhancer-binding protein beta (C/EBP beta) plays an important role in adipogenesis, which is well-characterized in mice, but little known in bovine so far.Results: In this study, real-time qPCR revealed that the level of C/EBP beta was increased during the developmental stages of bovine and adipogenesis process of preadipocytes. Overexpression of C/EBP beta promoted bovine fibroblast proliferation through mitotic clonal expansion (MCE), a necessary process for initiating adipogenesis, by significantly downregulating levels of p21 and p27 (p < 0.01). Also, the PPAR gamma expression was inhibited during the MCE stage (p < 0.01). 31.28% of transfected fibroblasts adopted lipid-laden adipocyte morphology after 8 d. Real-time qPCR showed that C/EBP beta activated the transcription of early stage adipogenesis markers C/EBP alpha and PPAR gamma. Expression of ACC alpha, FASN, FABP4 and LPL was also significantly upregulated, while the expression of LEPR was weakened.Conclusions: It was concluded C/EBP beta can convert bovine fibroblasts into adipocytes without hormone induction by initiating the MCE process and promoting adipogenic genes expression, which may provide new insights into the potential functions of C/EBP beta in regulating intramuscular fat deposition in beef cattle. (C) 2021 Pontificia Universidad Catolica de Valparaiso. Production and hosting by Elsevier B.V.