Figure 5

Chondrogenic potential of AT-MSCs is compromised by donor age. Differentiation of AT-MSCs was induced chondrogenic induction medium for 21 days in micromass pellet culture. Alcian blue staining was performed for induced AT-MSCs isolated from (A) young, (B) adult and (C) aged individuals. At higher microscopic magnification (shown in insets) the cartilage like tissue appeared to be composed of rounded cells, surrounded by lacunae lying in a proteoglycan rich extracellular matrix. Chondrogenic in vitro potential was quantified by a colorimetric assay in which Alcian blue uptake (blue color) was extracted with 6 M guanidine HCl and absorbance was read at 620 nm. (D1) showing micromass 30 minutes after incubation and (D2) after 120 minutes. (E) absorbance values were significantly higher for young and adult AT-MSCs compared to aged. (F) Quantitative RT-PCR was performed for mRNA expression of aggrecan and collagen type 2. Age related decline in mRNA level was observed for both genes. Results are expressed as mean ± standard deviation. *P < 0.05, **P < 0.01, ***P < 0.001 for young AT-MSCs versus aged AT-MSCs, ^#P for adult versus aged AT-MSCs.