Abstract
Purpose :
To investigate whether endothelial remodeling in physiological and pathological angiogenesis of the retina is associated with interactions of pericyte to endothelial cell
Methods :
On post-natal (P) P4, P7, P14, and P18 of control mice, and P14, and P18 of oxygen-induced retinopathy (OIR) mice, the eyes were enucleated. The vascular formation in the physiological and pathological angiogenesis of the retina was evaluated through fluorescein angiography using FITC-dextran. Immunohistochemistry for CD31, GFAP, NG2, SMA, PDGFR, ZO-1, occludin, claudin-5, and E-/N-/R- cadherin was performed on cross-sections of the control and OIR retina. In addition, western blot analysis for the each factor was done using whole retina. Using microfluidic device, sprouting angiogenesis of the fibrin-attached PC-EC mixture was induced, followed by fixing and labelling by immunofluorescence staining after 5 days of culture, then analyzed quantitatively by image analysis obtained by confocal microscopy.
Results :
During early postnatal days (P4, P8), vessels sprouted radially from optic disc to ora serrata in the nerve fiber layer, where endothelial tube was covered by pericyte and astrocyte except the vascular forefront. With development of retinal layers, deep and vascular plexus on inner and outer plexiform layer were formed, where the vessel was composed of endothelial cells and pericyte. Even in tufts of OIR, contact of pericyte to endothelial cell was detected. On the contact of pericyte and endothelial cells, PDGFR beta expression as well as N-cadherin were observed, which was interestingly expressed on both cells. In microfluidic in vitro model of PC-EC under angiogenesis, oxygen concentration altered expression level of proteins that regulate pericyte-endothelial interaction such as N-cadherin and PDGFR beta.
Conclusions :
Our data demonstrates that endothelial remodeling in physiological and pathological angiogenesis of the retina is associated with interactions of pericyte to endothelial cell. Given that, in addition to environmental condition such as oxygen concentration, the direct contact of pericyte to endothelial cell could contribute to physiological and pathological angiogenesis in the retina.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.