Figure 10.

Norrin induces survival in cultured RGC-5 cells. A, B, Quantification of cell number in differentiated RGC-5 cells after incubation for 24 h in serum-free medium with and without Norrin (A; mean ± SEM of 3 independent experiments; n ≥ 48; ***p < 0.001) or with 40 ng/ml Norrin with or without 100 ng/ml DKK-1 (B; mean ± SEM of 3 independent experiments; n ≥ 32; **p < 0.001). C, Western blot analysis for β-catenin in nuclear proteins from differentiated RGC-5 cells after incubation with Norrin (40 ng/ml) for 3 h. D, Quantitative real-time RT-PCR for neurotrophic growth factors in RNA of differentiated RGC-5 cells after incubation for 7 h with 20 or 40 ng/ml Norrin, and in untreated controls (mean ± SEM; n ≥ 4). E, Quantification of cell number in differentiated RGC-5 cells after incubation for 24 h in serum-free medium or after treatment with serum-free conditioned (cond.) cell culture medium of Müller cells that were preincubated with and without 40 ng/ml Norrin (mean ± SEM of 3 independent experiments; n ≥ 28; **p < 0.01; ***p < 0.001).