Membrane-type frizzled-related protein regulates lipidome and transcription for photoreceptor function

FASEB J. 2020 Jan;34(1):912-929. doi: 10.1096/fj.201902359R. Epub 2019 Nov 28.

Abstract

Molecular decision-makers of photoreceptor (PRC) membrane organization and gene regulation are critical to understanding sight and retinal degenerations that lead to blindness. Using Mfrprd6 mice, which develop PRC degeneration, we uncovered that membrane-type frizzled-related protein (MFRP) participates in docosahexaenoic acid (DHA, 22:6) enrichment in a manner similar to adiponectin receptor 1 (AdipoR1). Untargeted imaging mass spectrometry demonstrates cell-specific reduction of phospholipids containing 22:6 and very long-chain polyunsaturated fatty acids (VLC-PUFAs) in Adipor1-/- and Mfrprd6 retinas. Gene expression of pro-inflammatory signaling pathways is increased and gene-encoding proteins for PRC function decrease in both mutants. Thus, we propose that both proteins are necessary for retinal lipidome membrane organization, visual function, and to the understanding of the early pathology of retinal degenerative diseases.

Keywords: Adipor1; RPE cell; VLC‐PUFAs; inflammatory signaling; matrix‐assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS); retinal degenerations.

Publication types

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

MeSH terms

  • Animals
  • Cell Membrane / metabolism*
  • Electroretinography
  • Eye Proteins / metabolism*
  • Female
  • Gene Expression Regulation*
  • Inflammation
  • Lipidomics*
  • Male
  • Mass Spectrometry
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Receptors, Adiponectin / metabolism*
  • Retina / metabolism*
  • Retinal Degeneration / metabolism
  • Retinal Pigment Epithelium / metabolism
  • Signal Transduction
  • Tomography, Optical Coherence

Substances

  • Eye Proteins
  • Membrane Proteins
  • Mfrp protein, mouse
  • Receptors, Adiponectin
  • adiponectin receptor 1, mouse