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Immunology - Ophthalmology

Suppression and Regression of Choroidal Neovascularization in Mice by a Novel CCR2 Antagonist, INCB3344
Published: Monday, December 19, 2011
Author: Ping Xie et al.

by Ping Xie, Motohiro Kamei, Mihoko Suzuki, Nagakazu Matsumura, Kentaro Nishida, Susumu Sakimoto, Hirokazu Sakaguchi, Kohji Nishida


To investigate the effect of an intravitreally administered CCR2 antagonist, INCB3344, on a mouse model of choroidal neovascularization (CNV).


CNV was induced by laser photocoagulation on Day 0 in wild type mice. INCB3344 or vehicle was administered intravitreally immediately after laser application. On Day 14, CNV areas were measured on retinal pigment epithelium (RPE)-choroid flat mounts and histopathologic examination was performed on 7 ┬Ám-thick sections. Macrophage infiltration was evaluated by immunohistochemistry on RPE-choroid flat mounts and quantified by flow cytometry on Day 3. Expression of vascular endothelial growth factor (VEGF) protein in RPE-choroid tissue was examined by immunohistochemistry and ELISA, VEGF mRNA in sorted macrophages in RPE-choroid tissue was examine by real-time PCR and expression of phosphorylated extracellular signal-regulated kinase (p-ERK 1/2) in RPE-choroid tissue was measured by Western blot analysis on Day 3. We also evaluated the efficacy of intravitreal INCB3344 to spontaneous CNV detected in Cu, Zn-superoxide dismutase (SOD1) deficient mice. Changes in CNV size were assessed between pre- and 1week post-INCB3344 or vehicle administration in fundus photography and fluorescence angiography (FA).


The mean CNV area in INCB3344-treated mice decreased by 42.4% compared with the vehicle-treated control mice (p<0.001). INCB3344 treatment significantly inhibited macrophage infiltration into the laser-irradiated area (p<0.001), and suppressed the expression of VEGF protein (p?=?0.012), VEGF mRNA in infiltrating macrophages (p<0.001) and the phosphorylation of ERK1/2 (p<0.001). The area of spontaneous CNV in Sod1-/- mice regressed by 70.35% in INCB3344-treated animals while no change was detected in vehicle-treated control mice (p<0.001).


INCB3344 both inhibits newly forming CNV and regresses established CNV. Controlling inflammation by suppressing macrophage infiltration and angiogenic ability via the CCR-2/MCP-1 signal may be a useful therapeutic strategy for treating CNV associated with age-related macular degeneration.