Biological Roles of PPAR-γ and C/EBP on Adipogenesis and SCD-1 Gene Expression

它展示了C/EBP家族蛋白和PPAR-γ在脂蛋白分化方面的重要作用。However，每个分子的精确作用都没有被定义。为了研究这一问题，我们移植了C/EBP-β和δ双knockout小鼠胚胎纤维块，其中包含腺病毒载体的小鼠PPAR-γ2 （pAdex-mPPARγ2）。当pAdex-mPPARγ 2转染的细胞被troglitazone或15-deoxy-△ D112.14 D1-PGJ 2时，它们将显示出adipocyte表型被固定为油红O的成熟。内源性三聚氰胺含量和SCD-1和aP 2 mRNA水平的这些细胞没有产生差异，与被转染的野生小鼠胚胎纤维块相比，与pAdex-mPPARγ2。However， LPL和GLUT 4 mRNA水平明显低于这些细胞。因此，单独使用PPAR-γ2的表达可以在C/EBP-β和C/EBP-γ的缺失中诱导脂蛋白差异，也可以使用C/EBP-β和/或C/EBP-δ对某些脂蛋白-特定基因表达的重要性。

It is shown that C/EBP family proteins and PPAR-γ play important roles on adipocyte differentiation. However, the precise roles of each molecule have not been defined. To explore this issue, we transfected C/EBP-β and -δ double knockout mouse embryonic fibroblasts with adenovirus vector containing mouse PPAR-γ2 (pAdex-mPPARγ2). When the pAdex-mPPARγ2-transfected cells were stimulated with troglitazone or 15-deoxy-△ィイD112.14ィエD1-PGJ2, they became to show mature adipocyte phenotype stained with oil-red-O. Intracellular triglyceride content and SCD-1 and aP2 mRNA levels of these cells did not differ, compared with wild-type mouse embryonic fibroblasts transfected with pAdex-mPPARγ2. However, LPL and GLUT4 mRNA levels were significantly lower in these cells. Thus, forced expression of PPAR-γ2 alone can induce adipocyte differentiation in the absence of C/EBP-β and C/EBP-γ, although C/EBP-β and /or C/EBP-δ are important for the expression of some adipocyte-specific genes.