Abstract
Purpose :
Ischemic retinopathies are significant causes of vision loss. A strategy to repair damaged vasculature and reperfuse the hypoxic retina is a valid and important goal. Many groups have sought to harness the reparative potential of endothelial progenitors in a cell therapy strategy. In the current study, we have built upon our previous work showing that endothelial colony forming cells (ECFCs) can integrate into the murine vasculature and drive a regrowth of patent vessels in the ischaemic retina. Based on transcriptomics of hypoxia-exposed ECFCs we have identified that miR-130 regulates angiogenesis-related gene expression events. The current study has sought to determine the role of miR-130 in ECFCs and whether this miRNA can be manipulated to improve vascular repair.
Methods :
ECFCs were isolated from umbilical cord blood and categorised via flow cytometry, as well as cellular morphology. Cells were fixed and stained for vinculin to identify focal adhesions (FA). FA were then enumerated, and the cells adhesion assessed via a modified MTT assay. Overexpression (OE) of miR-130 or a control-mimic (c-mim) was then induced in ECFCs, the effect of this OE was then assessed. These, miR-130 OE ECFCs were applied to the ex vivo choroidal explant model to assess their ability to interact with, and possibly improve, sprouting choroidal vasculature. Explants were imaged daily to determine total sprouting distance. In the murine oxygen-induced retinopathy (OIR) model miR-130 OE or c-mim OE ECFCs were administered intravitreally and the impact on ischemic retinopathy assessed.
Results :
Cells OE miR-130 had a greater number of FA compared to untreated cells and C-mim OE cells (P<0.001) as well as greater adhesion (P<0.05). In the ex vivo choroid angiogenesis model, explants exposed to miR-130 OE cells had a significantly greater sprouting distance (P=<0.001) than explants grown in co-culture with C-mim OE cells, non-transfected cells or no cell controls. In the murine OIR model, administration of miR-130 OE cells led to a reduction in the avascular area of retinas that was significantly greater than that achieved by non-transfected control cells (P<0.05).
Conclusions :
Whilst ECFCs have previously demonstrated vasoreparative potential in the eye, an ability to improve their function in the ischaemic retina would be valuable. Augmentation of ECFCs via miR-130 OE enhances the efficacy of this cell therapy.
This is a 2021 ARVO Annual Meeting abstract.