Fig. 5

TERT promoted GDF11 activation of Smad2/3 signaling in old CD133⁺/VEGFR2⁺ cells. a–e Western blot analysis of Smad2/3, Bcl2, and caspase 3 protein expression under various conditions. a Representative western blots of the protein levels of Smad2/3, Bcl2, caspase 3, and phosphorylation of eNOS and Smad2/3 in the CD133⁺/VEGFR2⁺ cells receiving rhGDF11, SB431542, or adTERT. b–e Quantitative analysis of expression of phosphorylated Smad2/3 (b, c), Bcl2 (d), and caspase 3 (e) in cells pre-transfected with vehicle (WT) or adTERT (adTERT) plus rhGDF11 or SB431542. All data represent means ± s.e.m. p < 0.05: *vs. vehicle, ^†vs. rhGDF11 addition, ^‡vs. rhGDF1and SB431542 addition, ^§vs. adTERT addition, ^||vs. rhGDF11 and adTERT addition (n = 10 per group). f CD133⁺/VEGFR2⁺ cells transfected with vehicle or adTERT were treated for 24 h with rhGDF11 or SB431542 before immunofluorescence labeling of Bcl2 (red) and Smad2/3 (green). DAPI indicates the nucleus of cells. Scale bars = 50 µm