Dimethyl Fumarate (DMFu) inhibits pathological angiogenesis and increases glycolytic capacity in retinal endothelial cells

Abstract

Purpose : The interplay of inflammation, angiogenesis and metabolic dysfunction plays a key role in the pathogenesis of wet age-related macular degeneration (AMD). We previously showed that dimethyl fumarate (DMFu) exhibited anti-inflammatory properties in retinal pigment epithelial cells. Here, we show the anti-angiogenic effects of DMFu in human microvascular retinal endothelial cells (HRECs) and mouse choroidal explants.

Methods : HRECs (Cell Systems) were cultured in Endothelial Basal Media-2 (EBM-2) BulletKit Medium. The migratory capacity of HRECs was examined using the scratch wound assay in serum-free EBM-2 with/without VEGF (10 ng/ml) and DMFu (80 μM)/DMSO 0.004%. Tube formation was assessed by seeding HRECs on Cultrex-coated plates and images were analyzed using the ImageJ Angiogenesis Analyzer. Bulk RNA seq was performed on HRECs treated with VEGF +/- DMFu/DMSO for 24h. Glycolysis and oxidative phosphorylation (OXPHOS) were examined on Seahorse XFe96. Protein expression of electron transport chain (ETC) complexes was assessed by western blotting. For the choroidal sprouting assay, 1 mm² biopsies of RPE/choroid/sclera were collected from 3-week-old C57BL/6J mice and embedded in Cultrex.

Results : DMFu significantly reduced migration and tube formation (reduced branching and mesh index) even in the presence of VEGF. DMFu robustly inhibited vascular sprouting area in the mouse choroidal sprouting model. Metabolically, DMFu significantly reduced expression of Complex II of the ETC, accompanied by a suppression in maximal OXPHOS and a shift towards increased glycolytic capacity. Heatmap analysis of RNAseq data revealed distinct gene expression profiles induced by DMFu and VEGF individually. The combined treatment of VEGF+DMFu resulted in a gene expression pattern that closely aligned with that induced by DMFu alone, indicating a predominant effect of DMFu in dictating gene expression changes. Furthermore, RNAseq revealed a significant increase in miR-27A with DMFu, a master regulator of metabolic reprogramming.

Conclusions : DMFu exerts its anti-angiogenic effects on endothelial cells through enhancing glycolytic capacity, highlighting the interplay of angiogenesis and metabolic reprogramming. With its FDA-approval for multiple sclerosis and well-established safety profile, DMFu is a contender for rapid drug repurposing for AMD.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.