The effect of rPEDF and its mutants on PEDF-induced neurotrophic activity. (A) Retinoblastoma Y-79 cells (2.5 × 105 cells/mL) were incubated with rPEDF or the rPEDF mutants (all at 20 nM) in MEM supplemented with 2 mM l-glutamine, antibiotics, and 0.1% ITS. After 7 days in culture, the cells were transferred onto poly-d-lysine–coated plates, and their morphology and differentiation state were visualized by a Nikon TE2000U inverted microscope equipped with a 10 ×/0.3 objective lens and connected to a DVC camera (Nikon, Melville, NY) and DVC C-View v.22 for Windows XP (DVC, Indianapolis, IN) at various times. The Y-79 morphology at 7 days after attachment is shown. (B) Quantitative analysis of the results presented in panel A is presented as a mean ± SD (n = 3). Student t test was used to analyze statistical significance of the differences between cells treated with rPEDF and cells treated with the various PEDF forms (*P < .01; **P < .05). dia indicates diameter.
