Elovanoids are novel cell-specific lipid mediators necessary for neuroprotective signaling for photoreceptor cell integrity

Sci Rep. 2017 Jul 13;7(1):5279. doi: 10.1038/s41598-017-05433-7.

Abstract

Docosahexaenoic acid (DHA, 22:6 n-3) is abundant in the retina and is enzymatically converted into pro-homeostatic docosanoids. The DHA- or eicosapentaenoic acid (EPA)-derived 26 carbon fatty acid is a substrate of elongase ELOVL4, which is expressed in photoreceptor cells and generates very long chain (≥C28) polyunsaturated fatty acids including n-3 (VLC-PUFAs,n-3). While ELOVL4 mutations are linked to vision loss and neuronal dysfunctions, the roles of VLC-PUFAs remain unknown. Here we report a novel class of lipid mediators biosynthesized in human retinal pigment epithelial (RPE) cells that are oxygenated derivatives of VLC-PUFAs,n-3; we termed these mediators elovanoids (ELV). ELVs have structures reminiscent of docosanoids but with different physicochemical properties and alternatively-regulated biosynthetic pathways. The structures, stereochemistry, and bioactivity of ELVs were determined using synthetic materials produced by stereo-controlled chemical synthesis. ELVs enhance expression of pro-survival proteins in cells undergoing uncompensated oxidative stress. Our findings unveil a novel autocrine/paracrine pro-homeostatic RPE cell signaling that aims to sustain photoreceptor cell integrity and reveal potential therapeutic targets for retinal degenerations.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Cells, Cultured
  • Eye Proteins / metabolism
  • Fatty Acids, Unsaturated / pharmacology*
  • Humans
  • Male
  • Membrane Proteins / metabolism
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neuroprotection
  • Neuroprotective Agents / pharmacology*
  • Oxidative Stress*
  • Photoreceptor Cells / drug effects*
  • Photoreceptor Cells / metabolism
  • Photoreceptor Cells / pathology
  • Receptors, Adiponectin / physiology*
  • Retinal Pigment Epithelium / drug effects*
  • Retinal Pigment Epithelium / metabolism
  • Retinal Pigment Epithelium / pathology
  • Signal Transduction
  • Young Adult

Substances

  • ELOVL4 protein, human
  • Eye Proteins
  • Fatty Acids, Unsaturated
  • Membrane Proteins
  • Neuroprotective Agents
  • Receptors, Adiponectin
  • adiponectin receptor 1, mouse