Figure 3. Silencing of DIRAS3 induces premature senescence in human ASCs. (A) Morphology of ASCs infected with shCntrl and shDIRAS3 was documented using light microscope at 40x magnification. (B and C) ASCs infected with either shDIRAS3 or shControl (shCntrl) expressing lentiviruses were fixed and stained for SA-β-GAL. Percentage of SA-β-GAL positive cells was calculated by scanning 5 low-power magnification fields (n=3). (D) ASCs were transduced by indicated lentiviruses with increasing MOI and cell lysates immunoblotted using phospho-Ser-139 Gamma H2A.X antibody. β-Actin served as a loading control.