Abstract
Methods::
Two non-human primates were injected intravitreally with 1.25 ug / 50ul VEGF and a third served as the naïve control. Animals were enucleated at Day 3 or Day 7 after VEGF injection. Retinal pro-inflammatory factor release was assessed by two methods: 1) immunohistological analysis and 2) Luminex panel of antigens, inflammatory cytokines, chemokines, growth factors, and other cellular markers.
Results::
VEGF caused profound histological alterations of the retina characterized by foveal edema, segmental retinal detachment, hemorrhage, transient pigmentation and cellular infiltration. Most infiltrating cells were myeloperoxidase (MPO)-reactive polymorphonuclear neutrophils in focal areas of the retina at day 3, but which were absent by day 7. Concurrently, MPO and IL-8 levels increased significantly in homogenized retinal tissue at day3 but returned to near normal by day 7. Sparse CD-3+ T cells and even fewer CD-68+ macrophages were present in the retina only at day 7. These changes were accompanied by significantly increased levels of MCP-1 IL-1ra, MIP-1beta, IFN-gamma, IL-16, IL-1beta, PAI-1 TNF-RII and endothelin at day 3, with reduced levels by day 7.
Conclusions::
VEGF caused acute retinal inflammation associated with infiltration of predominantly MPO-reactive neutrophils and moderate expression of several proinflammatory proteins, including MPO and IL-8.
Keywords: inflammation • retinal neovascularization • immunohistochemistry