Downregulation of VEGFA and VEGFB blocks hypoxia-induced retinal EC proliferation and neovascularization. (A-E) All the conditions were the same as in Figure 5 except that the mice pups were administered with control, VEGFA, or VEGFB siRNA. Retinal EC proliferation and neovascularization were measured as described in “Materials and methods.” (A) Retinal EC proliferation was detected by coimmunofluorescence staining of the retinal sections for CD31 and Ki67. The right column shows the higher magnification (×40) of the selected areas (rectangular boxes) from the images shown in the left column. (B) Retinal EC proliferation was measured by counting CD31- and Ki67-positive cells that extended anterior to the inner limiting membrane per section (n = 6 eyes, 3 sections/eye). (C) Retinal vascularization is shown in the first row. Neovascularization is highlighted with red color in the second row. The third row shows selected rectangular areas of the images shown in the first row under ×10 original magnification. (D) The bar graph shows quantification of retinal vascularization. (E) The bar graph shows quantification of retinal neovascularization. The values are presented as mean ± SD (n = 6 retinas). *P < .01 vs normoxia + control siRNA; ^§P < .01 vs hypoxia + control siRNA.