Novel Regulators of Retina Neovascularization: A Proteomics Approach

The purpose of this
study was to identify proteins that regulate
vascular remodeling in an ROP mouse model. Pups were subjected to
fluctuating oxygen levels and retinas sampled during vessel regression
(PN12) or neovascularization (PN17) for comparative SWATH-MS proteomics
using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We
developed a human retinal endothelial cell (HREC) ROP correlate to
validate the expression of retina neovascular-specific markers. A
total of 5191 proteins were identified in OIR retinas with 498 significantly
regulated in elevated oxygen and 345 after a return to normoxia. A
total of 122 proteins were uniquely regulated during vessel regression
and 69 during neovascularization (FC ≥ 1.5; p ≤ 0.05), with several validated by western blot analyses.
Expressions of 56/69 neovascular-specific proteins were confirmed
in hypoxic HRECs with 23 regulated in the same direction as OIR neovascular
retinas. These proteins control angiogenesis-related processes including
matrix remodeling, cell migration, adhesion, and proliferation. RNAi
and transfection overexpression studies confirmed that VASP and ECH1,
showing the highest levels in hypoxic HRECs, promoted human umbilical
vein (HUVEC) and HREC cell proliferation, while SNX1 and CD109, showing
the lowest levels, inhibited their proliferation. These proteins are
potential biomarkers and exploitable intervention tools for vascular-related
disorders. The proteomics data set generated has been deposited to
the ProteomeXchange/iProX Consortium with the Identifier:PXD029208.