Comparison of age related parameters in AT-MSCs isolated from young and aged donors. (A, B) Gene profiling of AT-MSCs indicate that gene expression of p16 and p21 is higher is AT-MSCs isolated from aged as compared to young donors. Data is shown as fold-induction as compared to untreated control cells. (C, D) Similarly, aged cultures show senescent features as determined by SA-β-gal staining compared to young cultures (data shown as percent positive cells). Concomitant with these features young AT-MSCs have higher level of SOD (E; data shown as absorbance values) and viability after stress (F; data shown as percent viable cells). Results are expressed as Mean ± Standard deviation. *P < 0.01 for young AT-MSCs versus aged AT-MSCs. AT-MSCs: adipose tissue derived mesenchymal stem cells, SA-β-gal: senescence associated beta galactosidase.