Synergistic Cytokine Signaling Drives Angiofibrotic Gene Pathways in Primary Human Retinal Endothelial Cells.

Neovascularization of the posterior eye is a progressive disease state, marked by an inflammatory initiation, angiogenic growth, and subsequent fibrotic degeneration of endothelial cells (ECs). Although implicated in age-related macular degeneration and proliferative diabetic retinopathy as a leading cause of irreversible vision loss worldwide, the mechanisms underpinning retinal EC dysregulation in neovascularization and fibrosis are not well understood. This study presents a transcriptomic investigation of cultured primary human microvascular retinal EC dysregulation following exposure to 10 ng/mL of six retinal neovascularization-associated signaling molecules [IL-6, tumor necrosis factor-α, transforming growth factor (TGF)-β1, TGF-β2, thrombin, and vascular endothelial growth factor-A] both individually and as a combined treatment for 24 hours. Tumor necrosis factor-α, thrombin, and TGF-β2 alone induced significant enhancement of inflammatory and angiofibrotic pathways, including phosphatidylinositol 3-kinase/Akt, NF-κB, and SMAD. BGN, CD34, COL1A2, CXCL8, IGFBP5, INHBA, SERPINE1, SNAI1, TGFB2, and TNFSF11 were identified as having overlapping, nodal roles in the pathologic dysfunction of retinal ECs. Cotreatment with all six ligands significantly enhanced differential gene expression, revealing 889 unique differentially expressed genes. Using a novel network-based gene correlation engine, GeneBunny, the cocktail group was found to mimic published retinal and choroidal EC transcriptomes from tissue of patients with age-related macular degeneration more accurately than individual treatment groups. These findings provide a biologically relevant characterization of the pathologic mechanisms driven by key retinal neovascularization-associated signaling molecules in retinal, enabling the identification of novel anti-fibrotic therapeutic targets.