Gene expression profile of the murine ischemic retina and its response to Aflibercept (VEGF-Trap)

Jesús Eduardo Rojo Arias,József Jászai

doi:10.1038/s41598-021-94500-1

Abstract

Ischemic retinal dystrophies are leading causes of acquired vision loss. Although the dysregulated expression of the hypoxia-responsive VEGF-A is a major driver of ischemic retinopathies, implication of additional VEGF-family members in their pathogenesis has led to the development of multivalent anti-angiogenic tools. Designed as a decoy receptor for all ligands of VEGFR1 and VEGFR2, Aflibercept is a potent anti-angiogenic agent. Notwithstanding, the molecular mechanisms mediating Aflibercept’s efficacy remain only partially understood. Here, we used the oxygen-induced retinopathy (OIR) mouse as a model system of pathological retinal vascularization to investigate the transcriptional response of the murine retina to hypoxia and of the OIR retina to Aflibercept. While OIR severely impaired transcriptional changes normally ensuing during retinal development, analysis of gene expression patterns hinted at alterations in leukocyte recruitment during the recovery phase of the OIR protocol. Moreover, the levels of Angiopoietin-2, a major player in the progression of diabetic retinopathy, were elevated in OIR tissues and consistently downregulated by Aflibercept. Notably, GO term, KEGG pathway enrichment, and expression dynamics analyses revealed that, beyond regulating angiogenic processes, Aflibercept also modulated inflammation and supported synaptic transmission. Altogether, our findings delineate novel mechanisms potentially underlying Aflibercept’s efficacy against ischemic retinopathies.

Highlights

Retinopathy of prematurity (ROP) and proliferative diabetic retinopathy (PDR) are prominent microvasculopathies that severely compromise retinal function[1]
We used the mouse model of oxygen-induced retinopathy (OIR) to investigate the transcriptional changes undergone by retinal cells in response to hypoxia and to subsequent anti-angiogenic therapy
We administered AFL, a recombinant decoy receptor neutralizing the ligands of VEGF receptor 1 (VEGFR1) and VEGFR2, at a dose of 25 mg/kg body weight to mice subjected to the OIR protocol

Summary

Introduction

Retinopathy of prematurity (ROP) and proliferative diabetic retinopathy (PDR) are prominent microvasculopathies that severely compromise retinal function[1]. The identification of the vascular endothelial growth factor A (VEGF-A) as a hypoxia-responsive driver of pathological angiogenesis[5] in the retina[6,7] and in tumours[8] led to the development of multiple pharmacological compounds for its neutralization Despite their efficacy in the treatment of c ancer[9,10] and neovascular retinopathies[11,12], VEGF-A inhibitors exhibited unforeseen side effects and limitations, including toxicity, short systemic life-times, and limited diffusion across the tissue[3,11,13]. By conducting cross-comparisons between time-points and treatment schedules, our results hint at the involvement of leukocytes during the recovery phase of the OIR protocol (in line with recent reports24), and at positive effects of AFL on synaptic transmission in OIR retinas, where its administration seems to protect retinal ganglion cells (RGCs) from hypoxic damage

Methods

Results

Conclusion