Immunohistologic study of interleukin-1, transforming growth factor-β, and α-smooth muscle actin in lens epithelial cells in diabetic eyes

PURPOSE: To assess the effects of the cytokines interleukin-1 (IL-1), transforming growth factor-beta (TGF-beta), and alpha-smooth muscle actin (alpha-SMA) in lens epithelial cells (LECs) in normal and diabetic eyes. SETTING: Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan. METHODS: Ten eyes of 10 patients with diabetic mellitus and 20 normal eyes of 20 patients with senile cataract were studied. The anterior lens capsules with LECs obtained by capsulotomy during cataract surgery were cultured. The LECs obtained immediately after surgery and on the third day of culture were immunohistologically studied to assess the activities of the cytokines. RESULTS: Interleukin-1 and TGF-beta staining showed a low level activity in some LECs in diabetic eyes but only a minimum level of activity in those in normal eyes. During culture, LECs in diabetic eyes became small and transformed into fusiform and fibroblast-like cells, and these cells were strongly stained for IL-1 and TGF-beta. Normal eyes showed little changes in cell morphology and were weakly stained for IL-1 and TGF-beta. Both with culture and with no culture, a-SMA showed only minimal activity in both diabetic and normal eyes, with no difference. CONCLUSION: Lens epithelial cells after cataract surgery had low IL-1 and TGF-beta activities, and these activities increased during culture. Diabetic eyes showed higher cytokine activities and more marked morphologic changes than normal eyes, suggesting that increased proliferative activity and increased cytokine activity of LECs contribute to strong anterior capsule contraction in diabetic eyes.