Fatp1 deficiency affects retinal light response and dark adaptation, and induces age-related alterations

PLoS One. 2012;7(11):e50231. doi: 10.1371/journal.pone.0050231. Epub 2012 Nov 16.

Abstract

FATP1 is involved in lipid transport into cells and in intracellular lipid metabolism. We showed previously that this protein interacts with and inhibits the limiting-step isomerase of the visual cycle RPE65. Here, we aimed to analyze the effect of Fatp1-deficiency in vivo on the visual cycle, structure and function, and on retinal aging. Among the Fatp family members, we observed that only Fatp1 and 4 are expressed in the control retina, in both the neuroretina and the retinal pigment epithelium. In the neuroretina, Fatp1 is mostly expressed in photoreceptors. In young adult Fatp1(-/-) mice, Fatp4 expression was unchanged in retinal pigment epithelium and reduced two-fold in the neuroretina as compared to Fatp1(+/+) mice. The Fatp1(-/-) mice had a preserved retinal structure but a decreased electroretinogram response to light. These mice also displayed a delayed recovery of the b-wave amplitude after bleaching, however, visual cycle speed was unchanged, and both retinal pigment epithelium and photoreceptors presented the same fatty acid pattern compared to controls. In 2 year-old Fatp1(-/-) mice, transmission electron microscopy studies showed specific abnormalities in the retinas comprising choroid vascularization anomalies and thickening of the Bruch membrane with material deposits, and sometimes local disorganization of the photoreceptor outer segments. These anomalies lead us to speculate that the absence of FATP1 accelerates the aging process.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / genetics*
  • Aging / physiology
  • Animals
  • DNA Primers / genetics
  • Dark Adaptation / genetics
  • Dark Adaptation / physiology*
  • Electroretinography
  • Fatty Acid Transport Proteins / deficiency
  • Fatty Acid Transport Proteins / metabolism*
  • Fatty Acids / metabolism
  • Fluorescence
  • Histological Techniques
  • Light*
  • Mice
  • Mice, Knockout
  • Microscopy, Electron, Transmission
  • Polymerase Chain Reaction
  • Retina / metabolism
  • Retina / radiation effects*
  • Retina / ultrastructure
  • Retinal Pigment Epithelium / metabolism
  • Rhodopsin / metabolism
  • Statistics, Nonparametric
  • cis-trans-Isomerases / metabolism

Substances

  • DNA Primers
  • Fatty Acid Transport Proteins
  • Fatty Acids
  • Slc27a1 protein, mouse
  • Slc27a4 protein, mouse
  • Rhodopsin
  • retinoid isomerohydrolase
  • cis-trans-Isomerases

Grants and funding

This work was supported by private foundations (Fédération des Aveugles et Handicapés Visuels de France, IRRP, UNADEV, SOS Rétinite), University of Montpellier (UM1 and UM2), the Région Languedoc Roussillon, the French Ministry for National Education and Inserm. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.