Fig. 4

FINS-mediated CE proliferation is augmented by photoreceptor degeneration in Msx1-Cre^ERT2;Rosa26-tdTomato mice. A Schematic of the lineage tracing paradigm in tamoxifen-treated Msx1-Cre^ERT2;Rosa26-tdTomato mice used to investigate the effects of MNU injury and/or FINS (FGF2 + Insulin + Noggin + anti-sFRP2) treatment on ciliary epithelium proliferation, migration and differentiation. The injection period was followed by tissue fixation and IHC analysis at Day 31. Groups included: Naïve control = no injection; PBS = intravitreal PBS; PBS + MNU = intravitreal PBS and i.p. MNU; FINS = intravitreal FINS; FINS + MNU = intravitreal FINS and i.p. MNU. B Quantification of outer nuclear layer (ONL) thickness in eyes from mice of the indicated conditions. (p < 0.001; N = 6 eyes per group). Each data point represents a single eye. C-G Representative images of Hoechst nuclear-stained eye cross-sections from mice of the indicated conditions. RGCL = retinal ganglion cell layer; yellow indicators. INL = inner nuclear layer; blue indicators. ONL = outer nuclear layer; red indicators. H Quantification of Pax6⁺EdU⁺ co-labeled cells relative to total CE area in eyes from mice of the indicated conditions. There was a significant effect of treatment (p < 0.001) and a significant effect of MNU injury (p = 0.035). N = 6 eyes per group. Each data point represents a single eye. I-M Brightfield and fluorescence overlay images of Msx1-tdTomato expression and EdU labeling in eyes from mice of the indicated conditions. White arrows indicate Msx1-tdTomato⁺EdU⁺ co-labeled cells in the ciliary epithelium. Yellow arrowheads indicate Msx1-tdTomato⁺EdU⁺ co-labeled cells in the retina. Straight dashed line indicates the border between the ciliary epithelium (CE) and the neural retina (NR). Dashed line box indicates high magnification inset. Statistics: Two-way ANOVAs with Holm-Sidak posthoc tests except where stated otherwise. Means ± SEMs indicated. * = p < 0.05