TRANSFORMING GROWTH FACTOR-β AND FIBROBLAST GROWTH FACTOR INDUCE LENS EPITHELIAL EXPLANT METAPLASIA： IMPLICATIONS FOR THE FORMATION OF SUBCAPSULAR OPACIFICATION
摘要
Objective. This study was to investigate the effects of transforming growth factor-β(TGFβ) and fibroblast growth factor (FGF) in the subcapsular opaeification formation of the lens. Methods. Lens epithelial explants from 10-day-old rats were cultured with TGFβ1 or TGFβ2 in the presence of FGF for 5 days, then were examined by light and electron microscopy, and by immunolocalization of α-smooth muscle(α-sm) actin and type Ⅰ collagen. Resets. In TGFβ/FGF-treated explants,extensive proliferation oeeured, with formation of spindle and star-shaped cells. These cells showed ultrastructure and biochemical features of fibroblast or myofibroblast.Prominent Golgi apparatus and rough endoplaie reticulum were observed in scene cells, Intracellular microfilaments with cytoplasmic dense bodies and membrane associated dense bodies, features of smooth muscle cells, were also observed. Some cells showed reactivity to α-sin actin antibody. TGFβ/FGF-treated explants were strongly stained with type I collagen antibody. Conclusion. In the presence of FGF, TGFβ1 and TGFβ2 induced lens epithelial cell(LEC)proliferation and transformation into fibroblast or myofibroblast like ceils, with producing of abundant collagen matrix in the explants. The changes are similar to the metaplasia that oeeurrs in subeapsular opacification of the lens. The findings suggest that TGFβ and FGF plays a role in the pathogenesis of subcapsular opacification of the lens.