FIG. 8.

Exogenous bFGF exerted differential effect on the adipogenic differentiation of hMSCs depending on the timing of its application. Cells were plated at equal density across all treatment groups (six replicate wells per treatment group) as well as before treatment initiation in each experimental set. For each treatment group, bFGF was applied in AIM at the indicated time window (rinsed off at the end of treatment), and cells were in AIM alone on the remaining days. Control group was treated with AIM only. OilRedO quantification, adipocyte counts, and DAPI nuclei counts were determined at the end of the 12-day AIM treatment. (A) bFGF enhanced cellular proliferation across all stages of adipogenic differentiation of hMSCs, but only promoted adipogenesis during days 0–2 by increasing the total number of cells committing to adipocytes. Between days 3 and 6, bFGF inhibited adipogenesis by reducing the total number of adipocytes, while after day 6, bFGF had insignificant effect in terms of total accumulation of fat oil droplets based on OilRedO quantification, but the number of recognizable adipocytes was significantly reduced. Data were derived from the average of four independent replicates of the whole experimental set, with 6 wells per group and a total of 256 OilRedO and 256 DAPI images processed for each treatment group. (B) Representative whole well images of each treatment group taken at the end of 12-day adipogenic induction. *P < 0.01, **P < 0.05 (n = 4). bFGF, basic fibroblast growth factor. Color images available online at www.liebertpub.com/scd