Objective: To evaluate the expression of connective tissue growth factor (CTGF) in choroidal neovascular membranes from patients with age-related macular degeneration and the effect of CTGF on choroidal endothelial cell (CEC) function.
Methods: Using immunohistochemical methods, we analyzed CTGF expression in 13 surgically excised choroidal neovascular membranes related to age-related macular degeneration. The expression of CTGF in retinal pigment epithelial and CEC cultures was determined by means of reverse transcriptase polymerase chain reaction and Western blot, and its regulation by vascular endothelial growth factor and transforming growth factor beta was determined. The effects of CTGF on bovine CEC proliferation, attachment, migration, and tube formation were measured.
Results: Vascularized human choroidal neovascular membranes showed strong CTGF immunoreactivity. Double staining disclosed colocalization of CTGF with retinal pigment epithelial cells and CECs. The CTGF induced a significant increase in attachment and migration of CECs; however, it did not stimulate CEC proliferation. The CTGF protein was up-regulated in retinal pigment epithelial cells and CECs by stimulation with transforming growth factor beta and vascular endothelial growth factor, respectively.
Conclusions: The expression of CTGF in choroidal neovascular membranes, its regulation by angiogenic growth factors, and its proangiogenic effects on CEC function suggest that CTGF may play a role in the pathogenesis of choroidal neovascularization. Clinical Relevance Multiple growth factors are involved in the pathogenesis of choroidal neovascularization in age-related macular degeneration.