Stimulation of CYP450-Mediated omega-3 Docosahexaenoic Acid (DHA) Metabolism via MFSD2A as a Novel Therapy for Inflammatory Bowel Disease

Background and Aims: New evidences indicate that defects in pro-resolving pathways might underlie the pathogenesis of IBD. The resolution process is regulated by lipid mediators, such as those derived from the w-3 docosahexaenoic acid (DHA), whose esterified form is transported by the Major Facilitator Superfamily Domain containing 2A (MFSD2A) through the endothelium of brain, retina, and placenta. We investigated if and how MFSD2A may modulate the lipid metabolism of gut endothelial cells, thus promoting the resolution of intestinal inflammation. Methods Lipidomic analysis was performed by Liquid chromatography-mass spectrometry on both mucosal biopsies and primary human intestinal microvascular endothelial cells (HIMEC) isolated from surgical specimens of active, drug-induced resolving patients and healthy non-IBD subjects. By using a lentiviral strategy, healthy HIMEC were transduced with a lentivirus carrying GFP-tagged MFSD2A overexpressing vector (MFSD2A-OE), and assayed for their angiogenic properties and response to inflammatory stimuli. Adoptive transfer of human circulating endothelial progenitor cells (ECFCs), genetically engineered to overexpress MFSD2A, was performed in CD1 nude colitic mice, along with orally administered DHA. Results The lipidomic analysis revealed a reduced percentage of pro-resolving metabolites derived from Cytochrome P450 epoxygenation of DHA (epoxy-DHA derivatives) in the inflamed mucosa, when compared with samples from healthy and resolving tissues (1,40% ±0,09 vs 0,85%± 0,15 over total fatty acids; p<0,05). Interestingly, we found that reduced level of epoxy DHA-derivatives in active tissues correlated with lower amounts of MFSD2A compared to resolving mucosa (2±0,3 vs 1±0,1; p<0,01). MFSD2A, found exclusively expressed by gut endothelium, exerted pro-resolving effects in HIMEC in terms of reduced pro-inflammatory markers and anti-angiogenic functions, and promoted the release of beneficial epoxy-DHA derivatives. Transplantation of engineered human MFSD2A-OE ECFCs in DHA-fed colitic mice, resulted in amelioration of intestinal inflammation, through the stimulation of epoxy-DHA derivative release in the inflamed mucosa. These pro-resolving effects of MFSD2A were completely abolished by CYP2C inhibitor both in vitro and in vivo, demonstrating that protective functions exerted by MFSD2A depends on epoxy metabolites of DHA. Conclusion Our study provides not only important insights into the molecular mechanisms regulating resolution of intestinal inflammation, but also a strong rationale for the development of novel therapeutic strategies to treat IBD. Our cellbased therapeutic approach may help a selective cohort of non-responding patients, with the potential advantage of avoiding immune suppression, and using natural endogenous pathways to resolve inflammation.