[Neovascularization and HGF: neovascularization in proliferative diabetic retinopathy and intraocular HGF]

Human hepatocyte growth factor (hHGF) has a strong angioneogenetic action. The present study was designed to investigate the possible involvement of hHGF in neovascularization in proliferative diabetic retinopathy by measuring vitreous hHGF concentration, and to examine the gene expression of hHGF in retinal Müller cells, which are presumed to play a role in proliferative diabetic retinopathy. Patients who had undergone pars plana vitrectomy were studied (33 diabetic patients with proliferative retinopathy and 20 nondiabetic subjects). The mean vitreous hHGF concentration was higher (p < 0.0001) in diabetic subjects with proliferative retinopathy (5.7 +/- 0.7 ng/ml) than in nondiabetic subjects (1.6 +/- 0.2 ng/ml). Furthermore, diabetic subjects with iris neovascularization, which is suggestive of advanced retinal ischemia, showed higher values of mean vitreous hHGF concentration than those without iris neovascularization (7.3 +/- 1.2 ng/ml [n = 14] vs. 4.5 +/- 0.7 ng/ml [n = 19], p < 0.01). Expression of hHGF gene was detected in cultured human Müller cells. Our results indicate that hHGF may be produced in the eye by retinal cells such as Müller cells and may play a role in neovascularization of proliferative diabetic retinopathy.