Preadipocyte function and aging: Links between age-related changes in cell dynamics and altered fat tissue function

OBJECTIVE: To review recent findings about changes with age in the replication and differentiation of preadipocytes, the progenitor cells in fat tissue that are capable of differentiating into fat cells, and to examine possible links between these alterations and age-related changes in fat tissue function. DESIGN: A survey and analysis of recent literature concerning changes in preadipocyte and fat cell function with age. CONCLUSIONS: Intrinsic aging changes in fat cells and preadipocytes as well as in factors extrinsic to fat tissue (such as food intake and absorption and hormonal status) contribute to age-related alterations in fat tissue function and cellularity. Changes with age in preadipocyte number, replicative potential, and capacity for differentiation, which may be linked to aging changes in fat cell size, number, and function, have been identified. The decline in preadipocyte capacity for differentiation and the associated decline in fat cell lipogenic capacity may be particularly important in contributing to the decrease in fat mass and alterations in fat tissue function that occur between middle- and old age. These declines result from blunting of the changes in gene expression that occur during preadipocyte differentiation and map, in turn, be related to altered regulation of particular transcription factors that control the preadipocyte differentiation program and maintenance of fat cell function.