Abstract
Purpose: To investigate a possible involvement of CD24 in vascular remodeling and angiogenesis in retinopathy of prematurity (ROP) in a mouse model of oxygen-induced retinopathy.
Materials and methods: 17 CD24 knockout (KO) and 12 wild-type (WT) C57BL/6 mice were used. Group 1 mice were exposed to oxygen concentrations of 75 ± 2% from postnatal day (P) 7 to P12. Group 2 mice were raised in room air. At P17, all mice underwent fluorescein-conjugated-dextran perfusion and were sacrificed. The flat-mounted retinas were scored manually and digitally by a new computerized algorithm, according to blood vessel obliteration, tortuosity, vascular tufts and neovascularization formation.
Results: Fifty four retinal whole mounts were available for analysis and scoring. Group 1 retinas had significantly higher values of vaso-obliteration, tufts, neovascularization, vessel tortuosity and higher mean retinopathy scores than Group 2 retinas (KO mice: 9.0 ± 0.27 vs. 0.74 ± 0.2, respectively, P < 0.0001; WT mice: 7.58 ± 0.40 vs. 1.17 ± 0.27, respectively, P < 0.0001). Manual scoring in Group 1 revealed higher values of neovascularization, tortuosity and mean retinopathy scores in KO mice vs. WT mice (9.0 ± 0.27 vs. 7.58 ± 0.40, respectively, P = 0.009). Digital scoring revealed a higher neovascularization score in KO mice as well (13.72 ± 0.82% vs. 8.06 ± 0.27%, P < 0.0001). All mice had similar vaso-obliteration areas. There were no significant differences between KO and WT mice in Group 2.
Conclusions: Absence of CD24 may have a deleterious effect on angiogenesis occurring in the second stage of ROP development, though its role in vessel obliteration during the first stage of ROP is probably limited.
ACKNOWLEDGMENTS
Andreas Stahl, MD, the Lois Smith Lab, Harvard Medical School, Children’s Hospital Boston. For incorporation of a new algorithm for quantification of green retinas into the SWIFT_NV method. This study was supported by a grant from the Claire and Amedee Maratier Institute for the Study of Blindness and Visual Disorders, Tel-Aviv University.
Declaration of interest: The authors report no declaration of interest. The authors alone are responsible for the content and writing of this paper.