Abstract
Purpose :
Neovascularization is a common complication in proliferative retinopathies. Bone marrow-derived cells migrate to the retina during this event, yet the role of these migratory cells in the pathogenesis of retinal neovascularization remains controversial. The main focus of this study is to use single cell RNA sequencing (scRNAseq) analysis to uncover the phenotypic changes in bone marrow-derived cells in a mouse model of neovascularization.
Methods :
We used single cell RNA seq 10X genomics data analysis of peripheral blood mononuclear cells and compared the gene expression profiles of different cell clusters. Oxygen-induced retinopathy (OIR) was used as a reliable model for neovascularization. OIR was induced in mice by exposing C57BL/6 litters to 75% oxygen from P7-P12. These pups were then removed to room air and on P17 whole blood samples were collected for analysis. Age-matched room air (RA) pups were used as controls. Ficoll-Paque density gradient centrifugation method was used to isolate bone marrow-derived cells within 2 hours post blood collection. A 10X chromium system was used to process 5’ scRNAseq per sample containing 5000 cells. NovaSeq 6000 with 150 bp end reads were used to sequence libraries. Further data analysis was performed using 10X Genomics software (Cell Ranger and Loupe browser).
Results :
scRNAseq data analysis revealed significant changes in differentiation of bone marrow-derived cells isolated from P17 OIR compared to RA controls. In addition, we identified a cell population that appeared only in the OIR samples and was positive for the MRC1 gene suggesting differentiation to macrophage-like cells. Interestingly, these cells are highly positive for certain wound healing genes including FN1 and also express anti-inflammatory cytokines, including SLP1, which may be inhibitory for neovascularization.
Conclusions :
We observed a phenotypic differentiation and changes in cell behavior in bone marrow-derived cells in a model of retinal neovascularization. These cells are macrophage-like and overexpress certain genes that code for anti-angiogenic factors and thus may have therapeutic potential in neovascularization diseases of the retina.
This is a 2020 ARVO Annual Meeting abstract.