Reduction of Laser-Induced Choroidal Neovascularization in Mice With Erythropoietin RNA Interference.

PURPOSE: The purpose of this study was to evaluate the pathological involvement of erythropoietin (EPO) in experimental choroidal neovascularization (CNV) and its association with neovascular age-related macular degeneration (AMD) and polypoidal choroidal vasculopathy (PCV) in the Chinese population.

METHODS

Treatment effect of recombinant EPO protein were assessed by human umbilical vein endothelial cell (HUVEC) proliferation, migration, and tube formation, and ex vivo choroid-sprouting ability. The effect of intravitreal injection of Epo siRNA against neovascularization was evaluated in the laser-induced CNV mouse model. In addition, the association of EPO variants with neovascular AMD and PCV was determined.

RESULTS

Exogenous supplementation of EPO significantly enhanced the migration and tube formation of HUVECs and promoted ex vivo choroid sprouting in mouse retinal pigment epithelium (RPE)-choroid-sclera complex culture. In the experimental CNV mouse model, Epo expression was found to be significantly upregulated by 3.5-folds in RPE-choroid-sclera complex at day 10 after laser induction as compared to the baseline. Immunofluorescence analysis showed that Epo was mainly expressed around the vascular endothelial cells in the RPE-choroid-sclera complex. Intravitreal injection of siRNA targeting Epo reduced 40% Epo expression and 40% CNV lesion areas as compared to the scramble control. However, EPO variants were not associated with neovascular AMD nor PCV in the Chinese population.

CONCLUSIONS

This study revealed the promotion of human endothelial cell tube formation in vitro and choroid sprouting ex vivo by EPO, and the reduction of laser-induced CNV in vivo by Epo RNA interference.

TRANSLATIONAL RELEVANCE: Targeting EPO could be a potential additional treatment for CNV-related diseases.