Involvement of CD24 in Angiogenesis in a Mouse Model of Oxygen-Induced Retinopathy

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.

KEYWORDS::

• CD24
• oxygen-induced retinopathy
• retinopathy of prematurity
• angiogenesis

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.