Apoptosis of human adipocytes in vitro.

Large increases in fat stores involve an increase in adipocyte number via the replication and differentiation of preadipocytes, with the resultant cell gain widely regarded as irreversible. To date, there has been no clearly defined process or mechanism reported by which adipocyte deletion may occur. Here, we show that human adipocytes undergo apoptosis following growth factor deprivation or mild heat injury in vitro, thus demonstrating a cellular mechanism by which normal adipocyte loss could occur in vivo. The findings have implications for the understanding of adipose tissue kinetics and its derangement as well as for the potential development of methods for modifying fat store size.