Murine 3T3 cell lines constitute a standard model system for in vitro study of mammalian adipogenesis although they do not faithfully reflect the biology of the human adipose cells. Several human adipose cell lines and strains have been used to recapitulate human adipogenesis in vitro, but to date there is no generally accepted in vitro model for human adipogenesis. We obtained a clonal strain of human subcutaneous adipose stromal cells, IPI-SA3-C4, and characterized its utility as an in vitro model for human subcutaneous adipogenesis. IPI-SA3-C4 cells showed a high proliferative potential for at least 30 serial passages, reached 70 cumulative population doublings and exhibited a population doubling time of 47 h and colony forming efficiency of 12% at the 57th cumulative population doublings. IPI-SA3-C4 cells remained diploid (46XY) even at the 56th cumulative population doublings and expressed the pluripotency markers POU5F1, NANOG, KLF4, and MYC even at 50th cumulative population doublings. Under specific culture conditions, IPI-SA3-C4 cells displayed cellular hallmarks and molecular markers of adipogenic, osteogenic, and chondrogenic lineages and showed adipogenic capacity even at the 66th cumulative population doublings. These characteristics show IPI-SA3-C4 cells as a promising potential model for human subcutaneous adipogenesis in vitro.
Keywords: Adipogenesis; Cellular model; Chondrogenesis; Human subcutaneous preadipocytes; Osteogenesis.