Tenascin-C induces transdifferentiation of retinal pigment epithelial cells in proliferative vitreoretinopathy.

ABSTRACT

Proliferation and transdifferentiation of the retinal pigment epithelium (RPE) are hallmarks of proliferative vitreoretinopathy (PVR); however, the critical regulators of this process remain to be elucidated. Here, we investigated the role of tenascin-C in PVR development. In vitro, exposure of human ARPE-19 (hRPE) cells to TGF-ß2 increased tenascin-C expression. Tenascin-C was shown to be involved in TGF-ß2-induced transdifferentiation of hRPE cells, which was inhibited by pretreatment with tenascin-C siRNA. In PVR mouse models, a marked increase in the expression of tenascin-C mRNA and protein was observed. Additionally, immunofluorescence analysis demonstrated a dramatic increase in the colocalization of tenascin-C with RPE65 or α-smooth muscle actin(α-SMA) in the epiretinal membranes of patients with PVR. There was also abundant expression of integrin αV and ß-catenin in the PVR membranes. ICG-001, a ß-catenin inhibitor, efficiently attenuated PVR progression in a PVR animal model. These findings suggest that tenascin-C is secreted by transdifferentiated RPE cells and promotes the development of PVR via the integrin αV and ß-catenin pathways. Therefore, tenascin-C could be a potential therapeutic target for the inhibition of epiretinal membrane development associated with PVR.