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 5. Over-expression of SIRT1 in normal human diploid fibroblasts delays senescence. (A) Representative immunoblots for SIRT1 (upper panel) and β-actin (lower panel) proteins from IMR-90 (PDL 48) and WI-38 (PDL 41) cells 24 hours after transfection with either pSIRT1 (second and fourth lane) or a control plasmid (vector; first and third lanes) and cultured in medium supplemented with 10 % FBS. (B) Representative phase-contrast photomicrographs of IMR-90 cells (PDL 48) and WI-38 cells (PDL 41) two weeks after transfection with either pSIRT1 or vector control. Original magnification: X200.