牛PPARγ基因对脂肪细胞增殖分化的影响

Impact of cattle PPARγ expression on adipocyte proliferation and differentiation

取郏县红牛第6和第7肋骨间肌间脂肪组织为试验材料,分离并培养原代前体脂肪细胞。在诱导分化牛前体脂肪细胞过程中,添加终浓度为1μmol/L的吡格列酮对脂肪细胞进行药物干预,上调过氧化物酶体增殖物激活受体γ(peroxisome proliferations actirated receptorγ,PPARγ)基因的表达后,通过MTT检测牛前体脂肪的增殖;油红O提取比色法检测牛前体脂肪细胞分化过程中脂滴的分泌;利用real-time PCR技术检测PPARγ基因表达上调后其他参与脂肪分化相关基因的表达情况。结果显示:吡格列酮药物干预后,PPARγ基因表达明显上调(P<0.01);PPARγ基因的表达上调后,牛脂肪细胞的增殖能力下降,分化能力增强;脂肪分化相关基因C/EBPA、SREBP11、FABPA、PLIN1、LPL和IGFBP2的表达量明显上调(P<0.05),GATA2和FAS基因的表达量没有发生明显变化。结果表明:PPARγ基因的表达可显著影响脂肪细胞的增殖与分化,可能与肉牛脂肪沉积有一定的关系。

To explore the influence and mechanism of the cattle PPAR7 on cow adipocyte prolifera- tion and differentiation,and analyze the regulating-controlling principles of cattle PPARγ gene in lipid metabolism. Jiaxian red cattle tissue speciments were obtained from the subcutaneous adipose tissue on the sixth and seventh ribs, then isolated and cultured preadipocytes in vitro. The expres- sion of PPARγgene was enhanced though added a final concentration of 1 μmol/L of pioglieta- zone, then we determined the prolifetation and differentiation of adipocytes by MTT assay and Oil Red O staining extraction assay,respectively. After PPARγ gene was upregulated, the expression level of other genes involved adipocyte differentiation was detected by real-time PCR analyses. The results that upregulating PPARrγ gene increased cattle adipocyte proliferateion and decreased cell differentiation drug intervention increased expression of PPARγ gene（P〈0.01）, mean while the expression levels of classic PPARγ target gene CEBPA, SREBP1, FABPA, PLIN1, LPL, and IGFBP2 is also significantly induced（P〈0.05）. In summary,PPARγ gene expression can signifi- cantly affect the proliferation and differentiation of adipocyte ceils, which maybe is related to with beef fat deposition.