Effects Of BMP2 On The Differentiation Of Porcine Preadipocyte And Its Mechanism

In the practice of animal production, adipose tissue has been more concerned, and the distribution and the deposition of fat affect the meat quality. It is hoped that the meat is delicious, tasty, and juicy, which requires a moderate fat content in muscles. Meanwhile, adipose tissue is also an endocrine organ, of which the secretion of leptin, adipokines, interleukins, and adiponectin is involved in the regulation of energy metabolism. Moderate amount of fat is beneficial to human body and excess fat intake can cause metabolic syndrome and obesity, diabetes, hypertension, and other common diseases of modern society.BMP2, an acid hydrophobic protein, is a secreted protein with a highly conserved sequence. In recent years, studies on mesenchymal stem cells, preadipocytes, and embryonic stem cells have found that BMP2 plays an important role in adipogenesis. Currently, studies on the induction effects of BMP2 on the differentiation of preadipocytes are mainly focused on the preadipocyte cell lines, and this promoting effect can be enhanced by the application of PPAR agonists. In this study, suitable concentrations of BMP2 were added during the culture of the isolated primary porcine preadipocytes in vitro to promote the differentiation of thses cells into mature cells and to explore the key molecular pathway and mechanism of the BMP2 in the process of the differentiation of preadipocytes into mature cells by the deep sequencing technology.Porcine preadipocytes were firstly isolated from piglet subcutaneous, cultured and induced to differentiate in vitro. During the differentiation, appropriate concentrations of BMP2 were added and the differentiation degree of preadipocytes was identified by oil red O staining and fluorescence quantitative PCR method. The results showed that the addition of 50ng/ml BMP2 upregulated the m RNA expressions of PPARγ,C/EBPα, and a P2 in preadipocytes and promoted the preadipocyte differentiation and lipid deposition.After the screening of the optimal adding concentration, the differentially expressed genes between BMP2-treated group and untreated group was screened out in this study suing the high-throughput sequencing technology, and the sequencing results were verified by real-time fluorescence quantitative PCR. The results showed that the expression levels of a total of 692 genes in the BMP2-treated group were significantly different from those of the untreated group, in which 447 were up-regulated and 245 were down-regulated. Pathway analysis showed that the differential genes were mainly involved in cell growth and differentiation, the PPARγ regulatory pathway, and immune response.Then, the specific functions of differentially expressed genes RGS2 and FAD3 were intensively studied by RNAi technology in this study. The expression of RGS2 gene was knockdown by the transfection of si RNA in the process of in vitro culture and differentiation of porcine preadipocytes and the results showed that the reduced m RNA expression of RGS2 gene could inhibit the differentiation of porcine preadipocytes and lipid deposition. Similarly, the knockdown of the m RNA expression of FAD3 gene in porcine preadipocytes could promote the differentiation of the cells.Therefore, in this study, the promoting effect of BMP2 on the differentiation of porcine preadipocytes and lipid deposition was defined; a large number of molecular pathways mediated by BMP2 have been identified, which influence the differentiation of porcine preadipocytes; the promoting effect of RGS2 gene on the differentiation of porcine preadipocytes and the inhibitory effect of FAD3 on the differentiation of porcine preadipocytes were explored. These results provide a theoretical basis for the in-depth understanding of the function of BMP2 gene and the mechanism of preadipocyte differentiation and lipid deposition.