RUNX1 promotes pathological retinal angiogenesis through von Willebrand factor

Runt-related transcription factor 1 (RUNX1) is a key transcriptional regulator for angiogenesis, and its pharmacological inhibition attenuates retinal pathological angiogenesis. However, the functional mechanisms by which RUNX1 promotes angiogenesis, especially at the protein level, remain poorly understood.

Using an oxygen-induced retinopathy (OIR) model and a RUNX1 inhibition (Ro5-3335) injection model, we tested the effects of RUNX1 inhibition on neovascular formation. Retinas from mice were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in Data-Independent Acquisition (DIA) mode. In vitro experiments were conducted to assess the effects of von Willebrand factor (vWF) on the migration and sprouting of RUNX1 overexpression endothelial cells (RUNX1-OE).

In total, 465 differentially expressed proteins (DEPs) were identified, comprising 295 up-regulated proteins and 170 down-regulated proteins. The bioinformatic analysis revealed significant enrichment in pathways critical to retinal angiogenesis, including extracellular matrix (ECM)-receptor interaction, focal adhesion, and actin cytoskeleton regulation. Following RUNX1 inhibition, we identified 57 overlapping DEPs whose dysregulation was reversed. These rescued proteins showed strong enrichment in ECM-receptor interaction signaling. Notably, vWF, an endothelial-related marker, was identified as a downstream target protein of RUNX1 and was found to be involved in retinal pathological angiogenesis.

Our present findings establish RUNX1 as a promising therapeutic target for retinal pathological angiogenesis, with its effect mediated via the vWF axis.