Research Paper Volume 7, Issue 3 pp 152—166
Serum from calorie-restricted animals delays senescence and extends the lifespan of normal human fibroblasts in vitro
Figure 2. CR serum reduces SA-β-gal activity in normal human diploid fibroblasts. (A and B) Representative photomicrographs of SA-β-gal staining (left panels) of IMR-90 fibroblasts at PDL 21 and 55 (A) and of WI-38, fibroblasts at PDL 24 and 40 (B). Data were obtained from cells cultured in medium supplemented with 10% FBS. Original magnification: X100. Graphs on the right show the average percentage of β-gal positive cells shown in left panels, and represent the average -/+ SEM from three independent experiments. * = statistically significant (p<0.05) for early vs. late passage. (C and D) Representative photomicrographs of SA-β-gal staining (left panels) of IMR-90 (PDL37) fibroblasts (C) and WI-38 (PDL36) cells (D) cultured for one week in the presence of AL (upper panels) or CR serum (lower panels). Original magnification: X100. Graphs on the right show the average percentage of β-gal positive cells shown in left panels. Data represent the average -/+ SEM from three independent experiments. * = statistically significant (p<0.05) CR vs. AL.