OBJECTIVETo explore the dedifferentiation phenomenon of human mature adipocytes cultured in vitro and to discuss the possibility of using dedifferentiation adipocytes (DA) as seed cells.

METHODSMature adipocytes and ASCs were harvested from human fat aspirates. Mature adipocytes were cultured and induced to DA by ceiling adherent culture method. Cell morphology were observed during the whole process. Viabilities of DA and ASCs were compared by MTT chromatometry and cell growth curves were drawn based on it. Cell surface markers of DA and ASCs were detected by flow cytometry. The adipogenic, osteogenic and chondrogenic ability of DA and ASCs were assessed by oil red O staining, alizarin bordeaux staining and alcian blue staining, respectively.

RESULTSHuman mature adipocytes can dedifferentiate into fibroblast-shaped DA. MTT chromatometry assay demonstrated that DA and ASCs both had strong reproductive activity, with no significant difference between them. Flow cytometry assay demonstrated that both DA and ASCs expressed HLA-ABC, CD29 and CD44, while didn't express CD45, CD34 and CD106. After two weeks of adipogenic differentiation, lipid droplets could be displayed by oil red O staining in both DA and ASCs. After two weeks of osteogenic differentiation, calcium salts mineralization in DA and ASCs could be detected by alizarin bordeaux staining. After two weeks of chondrogenic differentiation, matrix of cartilage cells in DA and ASCs could be detected by alcian blue staining.

CONCLUSIONSMature adipocytes can be dedifferentiated into DA in vitro. DA has strong reproductive activity, as well as osteogenic, chondrogenic ability and strong adipogenic ability. It expresses some of the stem cell-related cell surface proteins and is a promising seed cell for adipose tissue engineering.