Age affects the paracrine activity and differentiation potential of human adipose-derived stem cells

Stem cell therapy is considered a novel treatment modality for critical diseases. Adipose tissue is a rich and easily accessible source of stem cells. Adipose-derived stem cells (ADSCs) can be expanded ex vivo and possess characteristics similar to those derived from the bone marrow. However, the quality of ADSCs can be affected by age, underlying disease or the lifestyle of individuals. The aim of the present study was to explore the association between age and ADSC activity, including paracrine and differentiation potential. Adipose tissues from young (age <30 years) and elderly (age >70 years) groups were obtained, and ADSCs from each group were cultured in vitro. The effect of age on ADSC activity was investigated in vitro by evaluating the proliferation rate, adipo/osteogenic differentiation potential and cytokine profile using ELISA. The results revealed that increased age reduced cell activity and increased the doubling time of ADSCs, without causing profound morphological changes. The paracrine action of ADSCs was markedly altered by increased age, as demonstrated by reduced expression levels of vascular endothelial growth factor, stromal cell-derived factor-1 alpha and hepatocyte growth factor. Differentiation of ADSCs into osteoblasts or adipocytes rarely occurred in the elderly group compared with the young group. Overall, these results indicate that age may affect the cellular function of ADSCs and should be considered prior to ADSC transplantation.