Apelin is essential for the development of laser-induced choroidal neovascularization model

The apelin was reported to be involved in angiogenesis. This study investigated its role in the development of experimental choroidal neovascularization (CNV) model. Lentivirus-mediated short hairpin RNA (shRNA) targeting the rat apelin gene (Apelin-RNAi-LV) and control shRNA (NC-RFP-LV) were designed and employed. Experimental CNV rat models induced by laser photocoagulation were randomly assigned to be intravitreally injected with phosphatebuffered saline (PBS), NC-RFP-LV and Apelin-RNAi-LV. The expression of apelin was evaluated by RT-PCR analysis, western-blot analysis, and immunofluorescence staining. The laser-induced CNV tissue was assessed qualitatively and quantitatively by histopathological sections, fundus fluorescein angiography, and choroidal flat mounts. The gene expression of apelin was upregulated during CNV formation in a time-dependent manner. By silencing the apelin gene, the expression of apelin was downregulated significantly, and the laser-induced CNV was inhibited obviously. Our study suggests that the apelin may play an important role in the development of laser-induced CNV, and it may act as a novel therapeutic option to inhibit CNV formation.