Description
Retinopathy of prematurity (ROP) is a disorder of the developing retina of preterm infants. ROP can lead to blindness due to abnormal angiogenesis that is the result of suspended vascular development and vaso-obliteration leading to severe retinal stress and hypoxia. We tested the hypothesis that a combined treatment with two human progenitor populations, the CD34+ cells, bone marrow-derived, and the endothelial colony-forming cells (ECFCs) synergistically protected the developing retinal vasculature in a murine model of ROP, the oxygen-induced retinopathy (OIR)., CD34+ cells alone, ECFCs alone, or a combination thereof were injected intravitreally at either P5 or P12 and pups were euthanized at P17. Retinas from OIR mice injected with ECFCs or the combined treatment revealed formation of the deep vascular plexus (DVP) while still in hyperoxia, with normal appearing connections between the superficial vascular plexus (SVP) and the DVP. The combination therapy prevented aberrant retinal neovascularization and was more effective anatomically and functionally at rescuing the ischemia phenotype than either cell type alone. The beneficial effect of the cell combination was the result of their ability to orchestrate an acceleration of vascular development and more rapid ensheathment of pericytes on the developing vessels.