Figure 8. Apoptotic cell death in the rat lens epithelial explants

The photographs represent a control (A) and a TGF-β2/FGF-2 (B) treated rat epithelial explant. The scale bar represents 100 μm. The TUNEL-positive nuclei are present as green nuclei while DAPI staining of normal cell nuclei is present as blue. The control explant exhibited only a few TUNEL-positive nuclei while the TGF-β2/FGF-2 treated epithelial explants show a greater number of TUNEL-positive nuclei located in the plaques (yellow arrows). The bar graph represents the percentage of apoptotic nuclei per 150 cells for control, FGF-2, TGF-β2, and TGF-β2/FGF-2 treated lens epithelial explant extracts from normal culture and heat shocked conditions. A total of three lens epithelial explants from each of the eight treatment groups were used for TUNEL analysis. Statistical analysis (ANOVA: p is less than or equal to 0.05) shows that there is a significant treatment effect. The heat shocked control (2.3%±0.6%) epithelial explants demonstrate less apoptotic cell death than the control (4.3%±0.5%) explants under normal cultured conditions, but the decrease is not significant. FGF-2 treatment (normal, 1.9%±0.6%; heat shocked, 0.8%±0.2%) induced significant decrease of apoptotic cell death relative to the normal control epithelial explants (marked with a "+" sign). The normal TGF-β2 (7.5%±0.8%) and TGF-β2/FGF-2 (normal, 9.6%±0.6%; heat shocked, 6.8%±0.5%) explants demonstrated a significant increase of cell death. The increase of cell death in the heat shocked TGF-β2 (4.6%±0.7%) explants is not significantly different from normal control explants (marked with a black dot). The asterisk indicates that the heat shocked TGF-β2 and TGF-β2/FGF-2 explants demonstrated significantly lower apoptotic cell death than the same treatment groups under normal culture conditions.