Angiostatic effect of CXCR3 expressed on choroidal neovascularization.

PURPOSE: Several recent studies suggest that some chemokines/chemokine receptors are involved in choroidal neovascularization (CNV). CXCR3 was the focus of the present study because microarray analysis for murine laser-induced CNV model showed the increased expression of CXCR3. The purpose of this study was to evaluate the effect of CXCR3 on CNV. METHODS: Microarray analysis was performed for the mouse eyes with laser-induced CNV. CXCR3 expressions on the CNV were evaluated by immunohistochemistry and real-time RT-PCR. CNV was compared between CXCR3-deficient mice and wild-type mice, between mice treated with anti-CXCR3/anti-IP-10 neutralizing antibody and mice treated with control IgG. Macrophage recruitment into CNV was also investigated. Ocular expressions of vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), C-C chemokine ligand-2 (CCL2), and complement component-3 (C3) were evaluated by real-time PCR. RESULTS: Microarray analysis and real-time RT-PCR revealed the elevation of CXCR3 and IP-10 in laser-treated mouse eyes compared with control eyes. Immunohistochemistry showed CXCR3 expression on the endothelial cells of CNV. Laser-induced CNV of CXCR3-deficient mice was significantly larger, with greater leakage in fluorescein angiography, and with greater macrophage-infiltration compared with wild-type mice (P < 0.01). Intravitreal injection of anti-CXCR3/anti-IP-10 neutralizing antibody exacerbated CNV. The CCL2 expression in the laser-treated eyes of CXCR3-deficient mice was higher than in those of wild-type mice (P < 0.05), whereas VEGF, PEDF, and C3 showed no differences. CONCLUSIONS: These results suggested that CXCR3 expressed on CNV could have an angiostatic effect on it.