Flt3 Regulation in the Mononuclear Phagocyte System Promotes Ocular Neovascularization

Figure 1

Immunofluorescence staining for Flt3 and GSA-Lectin detection in C57BL/6 control, OIR model, rho/VEGF transgenic, CNV model, and rho/rtTA-TRE/VEGF transgenic retinas. Mice were euthanized, and enucleated eyes were submitted to fixation and preparation to generate frozen sections. Immunofluorescence for Flt3 (red) and lectin (green) showed high expression of Flt3 in the OIR model, subretinal NV model, CNV model, and RD model retinas (arrowheads) with NV progression (A–E). Merged images showed colocalization of Flt3 and lectin. Scale bar: 500 μm. (A) Double immunofluorescence staining of Flt3 by Cy3-conjugated secondary antibodies (red) and GSA-Lectin (green) in flat-mounted control retina at P18. (B) Double immunofluorescence staining of Flt3 (red) and GSA-Lectin (green) in flat-mounted OIR retina samples at P18. Areas of staining for Flt3 increased during the pathological progression of OIR. (C) Eye specimens from P21 transgenic mice overexpressing VEGF in photoreceptors (rho/VEGF mice) showed Flt3 staining in the inner plexiform layer and colocalization with GSA-Lectin. (D) Staining of a section from a D14 CNV model showed Flt3 staining, while GSA-Lectin staining of the same section showed vascular staining. (E) Ocular sections from 5- to 8-week-old transgenic mice (rho/rtTA-TRE/VEGF) showed increased Flt3 staining in the inner layer and a close association with vascular staining.