Single-cell transcriptomics analysis of proliferative diabetic retinopathy fibrovascular membranes reveals AEBP1 as fibrogenesis modulator

Abstract

The management of preretinal fibrovascular membranes, a devastating complication of advanced diabetic retinopathy (DR), remains challenging. We characterized the molecular profile of cell populations in these fibrovascular membranes to identify potentially new therapeutic targets. Preretinal fibrovascular membranes were surgically removed from patients and submitted for single-cell RNA-Seq (scRNA-Seq). Differential gene expression was implemented to define the transcriptomics profile of these cells and revealed the presence of endothelial, inflammatory, and stromal cells. Endothelial cell reclustering identified subclusters characterized by noncanonical transcriptomics profile and active angiogenesis. Deeper investigation of the inflammatory cells showed a subcluster of macrophages expressing proangiogenic cytokines, presumably contributing to angiogenesis. The stromal cell cluster included a pericyte-myofibroblast transdifferentiating subcluster, indicating the involvement of pericytes in fibrogenesis. Differentially expressed gene analysis showed that Adipocyte Enhancer-binding Protein 1, AEBP1 , was significantly upregulated in myofibroblast clusters, suggesting that this molecule may have a role in transformation. Cell culture experiments with human retinal pericytes (HRP) in high-glucose condition confirmed the molecular transformation of pericytes toward myofibroblastic lineage. AEBP1 siRNA transfection in HRP reduced the expression of profibrotic markers in high glucose. In conclusion, AEBP1 signaling modulates pericyte-myofibroblast transformation, suggesting that targeting AEBP1 could prevent scar tissue formation in advanced DR.

Single‐cell RNA sequencing in exploring the pathogenesis of diabetic retinopathy

“…Besides, SPP1 was observed significantly enriched in this activated microglial cluster compared with other cell types, in accordance with the findings from animal models by Bai et al. 56 However, in a study by Corano‐Scheri et al., 37 a cluster of macrophages showing high expression of pro‐angiogenetic chemokines, such as CXCL1, CXCL2 and CCL2, was identified, instead of microglia. The authors claimed that they were unable to replicate the conclusion of Hu et al.…”

“…Subsequent experiments verified that Col1a1 was increased in pericytes of the OIR retina, and its silencing suppressed ocular angiogenesis and pericyte‒myofibroblast transition during capillary remodelling. In another study by Corano‐Scheri et al., 37 an intermediate cluster expressing genes overlapping with both pericytes and myofibroblasts was identified, suggesting that cells transitioned from a pericyte origin towards a myofibroblastic identity, with an upregulated profibrotic molecule, AEBP1 , that modulates the process. Considering that this transition may further aggravate fibrosis and contraction of FVMs resulting in tractional retinal detachment, AEBP1 could serve as a potential therapeutic target for preventing scar tissue formation in DR.…”

“…Corano‐Scheri et al. 37 conducted a ligand‒receptor analysis between ECs and other cells. ECs communicate with macrophages, pericytes and myofibroblasts via molecules involved in the Notch pathway, which is essential for angiogenesis.…”

“…As shown in Table 1 , the application of scRNA‐seq to the study of DR has seen significant advancements. 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 …”

Editorial: Ocular fibrosis: molecular and cellular mechanisms and treatment modalities

“…Recent studies identifying the source of myofibroblasts, the key cell type driving fibrogenesis, have led to the identification of perivascular supporting cells in many tissues in response to damage including diabetic retinopathy and age-related macular degeneration ( 7 – 9 ). However, the details of mechanisms for this selective transition of pericytes to myofibroblasts and the source of mediators involved in fibrogenesis need further investigation.…”