Abstract
Purpose: :
To use metabolomic and transcriptomic analysis, immunohistochemistry and confocal microscopy to assess the trophic rescue effect of human umbilical cord blood (HCB)-derived myeloid progenitor cells in a model of OIR.
Methods: :
CD14+ cells were freshly isolated from HCB, characterized by flow cytometry, infected with Adenovirus 5-GFP, injected intravitreally and visualized by confocal microscopy. Rescue was evaluated on p17 by quantifying areas of vaso-obliteration and neovascularization (NV). A panel of 60 genes was used to analyze and quantify the expression of human and mouse genes in mouse retinas after the injection of human cells. Metabolites were extracted and identified in OIR and normal retinas at p12, p15 and p18 and evaluated for the ability to induce toxicity and apoptosis of astrocytes and endothelial cells in vitro and in vivo.
Results: :
On day 0 CD14+ cells are a heterogeneous population expressing both myeloid progenitor (CD33 and CD44) and endothelial (VEGFR-2) cell specific antigens. Using the OIR model, we show that Ad5-GFP CD14+ cells: (1) target sites of retinal NV and significantly enhance vascular repair; (2) induce expression of mouse angiogenic cytokines such as FGF a and b, IL-8 and TGFα in OIR retinas; (3) up regulate the expression of human anti oxidative stress genes as Catalase 1, Beta-glucuronidase, Superoxide dismutase-1; (4) reduce apoptotic events by expressing anti apoptotic genes as BCL2, AKT1, IFI6, IFI1; and (5) decrease the production of toxic metabolites such as β-epoxycholesterol and 7-ketocholesterol to levels observed in control, non-OIR retinas.
Conclusions: :
We have characterized human CB-derived CD14+ cells that target retinal vasculature and provide trophic rescue in a model of OIR. Metabolomic analysis confirmed the transcriptomic profile. CD14+ cells regulate events leading to the production of several metabolites toxic for EC and glia in OIR retinas and continue to express monocyte and dendritic cell markers (CD163, CD68, CD209, HLDRA) after injection into the mouse retinas subjected to OIR.
Keywords: retina • retinopathy of prematurity • hypoxia