Fig. 3. Inhibition of TGFß signaling restores proliferation in addback conditions. (A) Quantification of nestin⁺/BrdU⁺ cells shows restoration of proliferation to near control levels (white bar; 24.9±2.4%) in the presence of TGFßRII-Fc and 5 million retinal cells (dark gray bar; 24.4±1.8%) compared with 5 million cells alone (light gray bar; 15±2.2%). Neither ActivinRII-Fc nor BMPRIB-Fc had a significant effect on proliferation (black bars). (B) Quantification of CRALBP⁺/BrdU⁺ cells shows TGFßRII-Fc restores proliferation of CRALBP⁺ Müller glial cells in the presence of 5 million retinal cells (dark gray bar; 41.7±3.9%), compared with 5 million cells alone (light gray bar; 23±2.8%), neither ActivinRII-Fc, nor BMPRIB-Fc affected glial proliferation in this assay (black bars). Error bars=s.e.m. ^*P<0.02, ^**P<.005 pairwise comparisons (Student's t-test).