Purpose: To investigate the biosynthesis of resolvins E1 and D1 (RvE1 and RvD1) in choroid-retinal endothelial cells (CRECs) and leukocytes under inflammatory conditions and to define the mechanisms of anti-inflammatory actions of RvE1 and RvD1 in CRECs and leukocytes, cells crucial to posterior ocular inflammation.
Methods: RvE1, RvD1, and markers of their biosynthesis were determined by lipidomic analysis. After CRECs or cocultures of CRECs and leukocytes were treated with RvE1 or RvD1 and inflammatory stimuli, inflammatory signaling molecules were quantified by Western blot analysis, ELISA, or protein array. Transmigration of polymorphonuclear leukocytes (PMNs) across CRECs monolayers was quantified.
Results: Inflammatory stimulation increased the biosynthesis of RvE1 and RvD1 from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively, in coculture of CRECs and leukocytes. CRECs alone did not produce RvE1 and RvD1. RvE1 or RvD1 inhibited the expressions of vascular cell adhesion molecule-1, IL-8, macrophage inflammatory protein-1beta, regulated on activation normal T cell expressed and secreted, and tumor necrosis factor-alpha from CRECs or cocultures of CRECs and leukocytes. RvD1 reduced prostaglandin E(2) generation from CRECs. However, neither resolvin affected cyclooxygenase-2 formation. Treating CRECs or PMNs with RvE1 or RvD1 inhibited PMN transmigration across CREC barriers.
Conclusions: The interplay of inflammatory stimuli-activated CRECs and leukocytes biosynthesizes RvE1 and RvD1 from EPA and DHA. These resolvins inhibit inflammatory signaling from CRECs and leukocytes and inflammatory activity as PMN transmigration across CRECs barriers. Thus, these resolvins and their biosynthesis pathways are potential targets for novel treatment of inflammatory ocular diseases.