Retinyl ester homeostasis in the adipose differentiation-related protein-deficient retina

J Biol Chem. 2008 Sep 5;283(36):25091-102. doi: 10.1074/jbc.M802981200. Epub 2008 Jul 7.

Abstract

The retinal pigmented epithelium (RPE) plays an essential role in vision, including storing and converting retinyl esters of the visual chromophore, 11-cis-retinal. Retinyl ester storage structures (RESTs), specialized lipid droplets within the RPE, take up retinyl esters synthesized in the endoplasmic reticulum. Here we report studies of mice lacking exons 2 and 3 of the gene encoding adipose differentiation-related protein (Adfp), a structural component of RESTs. We found that dark adaptation was slower in Adfp(Delta2-3/Delta2-3) than in Adfp+/+ mice and that Adfp(Delta2-3/Delta2-3) mice had consistently delayed clearances of all-trans-retinal and all-trans-retinol from rod photoreceptor cells. Two-photon microscopy revealed aberrant trafficking of all-trans-retinyl esters in the RPE of Adfp(Delta2-3/Delta2-3) mice, a problem caused by abnormal maintenance of RESTs in the dark-adapted state. Retinyl ester accumulation was also reduced in Adfp(Delta2-3/Delta2-3) as compared with Adfp+/+ mice. These observations suggest that Adfp plays a unique role in vision by maintaining proper storage and trafficking of retinoids within the eye.

Publication types

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

MeSH terms

  • Animals
  • Biological Transport / physiology
  • Dark Adaptation / physiology*
  • Exons / physiology
  • Homeostasis / physiology*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Transgenic
  • Perilipin-2
  • Pigment Epithelium of Eye / cytology
  • Pigment Epithelium of Eye / metabolism*
  • Retinal Rod Photoreceptor Cells / cytology
  • Retinal Rod Photoreceptor Cells / metabolism*
  • Retinaldehyde / genetics
  • Retinaldehyde / metabolism*

Substances

  • Membrane Proteins
  • Perilipin-2
  • Plin2 protein, mouse
  • Retinaldehyde