title: Slit-miR-218-Robo axis regulates retinal neovascularization.
abstract: miR-218 is an important intronic microRNA (miRNA or miR) which is known to regulate angiogenesis in tumors. The present study aimed to investigate the effects of miR-218, as well as its host genes, Slit2 and Slit3, on oxygen-induced retinal neovascularization (RNV) and to explore the associated mechanisms of action. For this purpose, a mouse model of oxygen-induced retinopathy (OIR) was established. The expression levels of miR-218-1 and miR-218-2, as well as those of their host genes, Slit2 and Slit3, were determined by RT-qPCR. Fluorescein angiography was performed on the retinas of the mice with OIR, and RNV was quantified by H&E staining in order to evaluate the effect of pCDH-CMV-miR-218 intravitreal injection on RNV in the mouse model of OIR. Roundabout, axon guidance receptor, homolog 1 (Robo1) expression was detected in mouse retinal vascular endothelial cells expressing high or low levels of miR-218 and in retinal tissues from mice with OIR by western blot analysis. Cell migration was evaluated by a scratch wound assay. We noted that in the mice with OIR, the expression level of miR-218 was significantly downregulated. We also noted that Robo1 expression was suppressed by miR-218. Furthermore, in the mice with OIR, the expression level of miR-218 was significantly downregulated, and that of miR-218-1 and its host gene, Slit2, was concomitantly downregulated as well. The restoration of miR-218 inhibited retinal angiogenesis by targeting Robo1. Taken together, our findings suggest that the Slit2-miR-218-Robo1 axis contributes to the inhibition of retinal angiogenesis and that miR-218 may be a new therapeutic target for preventing RNV.
authors.affiliation: Tianjin Eye Hospital, Heping, Tianjin 300020, P.R. China.
authors.forename: Yichun
authors.initials: Y
authors.lastname: Kong
authors.affiliation: Key Laboratory of Hormones and Development, Ministry of Health, Heping, Tianjin 300070, P.R. China.
authors.forename: Bei
authors.initials: B
authors.lastname: Sun
authors.affiliation: Tianjin Eye Hospital, Heping, Tianjin 300020, P.R. China.
authors.forename: Quanhong
authors.initials: Q
authors.lastname: Han
authors.affiliation: Tianjin Eye Hospital, Heping, Tianjin 300020, P.R. China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Han
authors.affiliation: Tianjin Eye Hospital, Heping, Tianjin 300020, P.R. China.
authors.forename: Yuchuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Tianjin Eye Hospital, Heping, Tianjin 300020, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D002460:Cell Line; D002465:Cell Movement; D005786:Gene Expression Regulation; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000473:pathology*; D015861:Retinal Neovascularization / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000097905:Roundabout Proteins; D000098552:Slit Homolog 2 Protein
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D035683:MicroRNAs; D009419:Nerve Tissue Proteins; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins; D000098552:Slit Homolog 2 Protein; C547684:MIRN218 microRNA, mouse; C432251:Slit3 protein, mouse