Abstract：When mature adipocytes are subjected to an in vitro dedifferentiation strategy referred to as ceiling culture, these mature adipocytes can revert to a more primitive phenotype and gain cell proliferative ability. We refer to these cells as dedifferentiated fat (DFAT) cells. Because of those cells possessing multilineage differentiation potential, dedifferentiation has become a significant research topic in recent years. Here we firstly isolated pig mature adipocytes and indentified them by GENMED staining.Then, in order to clarify the mechanism of mature adipocyte dedifferentiation, a novel ceiling culture model was developed and the mRNA expression of marker genes during dedifferentiation couse was analysized using Real-time PCR. Finally, we assessed the effect of 1 μmol/L rosiglitazone on mature adipocyte dedifferentiation. The results showed that 98.7% of isolated cells were mononuclear mature adipocytes and these adipocytes could efficiently dedifferentiate into DFAT cells under a novel ceiling culture model. During the course of dedifferentiation, the mRNA levels of adipogenic marker peroxisome proliferator activated receptor γ (PPARγ), adipocyte-type fatty acid-binding protein (aP2) and lipoprotein lipase (LPL) were up-regulated by 8, 3 and 7.5 folds, respectively. While the lipolytic marker hormone-sensitive lipase (HSL) and Adipose triglyceride lipase (ATGL) were increased about 40 and 10 folds in mRNA level, respectively. In addition, the dedifferentiation was remarkably suppressed by treatment with 1 μmol/mL rosiglitazone. These results indicate that it is mainly a lipolytic course companying with little ability of adipogenesis that mature adipocytes dedifferentiate into DFAT cells, and this will provide new theoretical reference for future research.
