The role of tenascin-C in the mouse model of laser-induced choroidal neovascularization

Abstract

Purpose: Tenascin-C has been shown to be highly expressed in the choroidal fibrovascular membranes (FVMs) from patients with age-related macular degeneration (AMD). However, its exact roles in the pathogenesis of choroidal FVMs remain elusive. The purpose of this study was to investigate the role of tenascin-C in choroidal FVM formation.

Methods: Adult C57BL/6J mice underwent retinal laser photocoagulation to induce choroidal neovascularization (CNV). The eyeballs were enucleated from 1 to 28 days after laser photocoagulation. Cryostat sections were prepared for immunofluorescence staining using anti-tenascin-C, anti-αSMA , and anti-CD31 antibodies. The mRNA and protein levels of tenascin-C in the retinal pigment epithelium (RPE)-choroid complex were examined by real-time PCR and enzyme-linked immunosorbent assay (ELISA), respectively. Cultured human RPE cells were treated with TGF-β2 for 24 hours, and tenascin-C expression was determined by real-time PCR. Proliferation in RPE cells stimulated with tenascin-C was measured using bromodeoxyu-ridine (BrdU)-ELISA.

Results: Both mRNA and protein expression of tenascin-C in the RPE-choroid complex of the mouse model of laser-induced CNV was dramatically increased on day 3 and day 14 by real-time PCR and ELISA, respectively. Double immunofluorescence analyses showed that tenascin-C was co-stained with both αSMA and CD31 around choroidal FVMs in the model. In vitro, TGF-β2 markedly induced expression of tenascin-C in RPE cells, and tenascin-C promoted the proliferation of RPE cells.

Conclusions: Tenascin-C produced by vascular endothelial cells and myofibroblasts may play a role in promoting choroidal FVM fromation in an autocrine/paracrine manner.

Keywords: 453 choroid: neovascularization • 412 age-related macular degeneration