AEBP1 modulates pericyte-myofibroblast transdifferentiation in proliferative diabetic retinopathy

Abstract

Purpose : The treatment of advanced complications of fibrosis in diabetic retinopathy (DR) remains challenging. We wanted to characterize the molecular profile of the cell populations in fibrovascular membranes from patients with DR to find new targets.

Methods : 4 fibrovascular membranes were surgically removed from patients with proliferative DR and submitted to scRNASeq. Differential gene expression was performed to define the transcriptomic profile of these cells. Human retinal pericytes (HRP) were cultured in high glucose condition for 24-48h and qPCR for profibrotic markers was performed.

Results : scRNASeq revealed the presence of endothelial cells, inflammatory cells, and stromal cells. Endothelial cell re-clustering depicted the presence of abnormal cells, in particular stalk cells, showing the expression of markers not commonly expressed, such as ESM1 and VEGFC. Deeper investigation of the inflammatory cells showed a sub-cluster of macrophages expressing pro-angiogenic cytokines such as CXCL1-2-3-8, CCL2-3, ANXA2and VEGFA, presumably cells actively contributing to exacerbate the pro-angiogenic environment. The stromal cell cluster revealed the presence of a pericyte-myofibroblast transdifferentiating cluster, suggesting the involvement of pericytes in fibrogenesis. Differentially expressed gene analysis revealed that Adipocyte Enhancer-binding Protein 1, AEBP1, was significantly upregulated in myofibroblast clusters (Fig. 1). Cell culture experiments in high glucose culture condition confirmed the molecular changes of pericytes toward myofibroblast lineage. The expression of profibrotic markers such as COL1A1, LUM, THBS2 and AEBP1 were significantly up regulated as early as after 24h and the pericyte marker CSPG4 was significantly downregulated. siRNA transfection to downregulate AEBP1 significantly reduced the expression of the profibrotic markers in high glucose (n=3; p<0.001) (Fig.2).

Conclusions : AEBP1 signaling modulates pericyte-myofibroblast transdifferentiation, suggesting that targeting AEBP1 could provide a new approach to prevent such transdifferentiation and scar tissue formation in DR.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Fig. 1 Trajectory inference in stromal clusters (A). Violin plot of AEBP1 expressionin stromal clusters (B).

 

Fig. 2 Profibrotic marker expression in human retinal pericytes in normal and high glucose medium (A) and after siAEBP1 transfection (B) *p<0.05; **p<0.01; ***p<0.001.