April 2011
Volume 52, Issue 14
Free
ARVO Annual Meeting Abstract  |   April 2011
A2E And Lipofuscin Are Present In The Retinal Pigment Epithelium Of Nrl-/- Mice
Author Affiliations & Notes
  • Nicholas Boyer
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Daniel Higbee
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Lorie R. Blakeley
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Zsolt Ablonczy
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Rosalie K. Crouch
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Yiannis Koutalos
    Ophthalmology, Medical University of South Carolina, Charleston, South Carolina
  • Footnotes
    Commercial Relationships  Nicholas Boyer, None; Daniel Higbee, None; Lorie R. Blakeley, None; Zsolt Ablonczy, None; Rosalie K. Crouch, None; Yiannis Koutalos, None
  • Footnotes
    Support  NIH grants EY014850 (YK), EY004939 (RKC), EY020661 (ZA/RKC), EY019065 (ZA), EY014793 (MUSC vision core), Foundation Fighting Blindness, Research to Prevent Blindness
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 3645. doi:https://doi.org/
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Nicholas Boyer, Daniel Higbee, Lorie R. Blakeley, Zsolt Ablonczy, Rosalie K. Crouch, Yiannis Koutalos; A2E And Lipofuscin Are Present In The Retinal Pigment Epithelium Of Nrl-/- Mice. Invest. Ophthalmol. Vis. Sci. 2011;52(14):3645. doi: https://doi.org/.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: : To examine the A2E and lipofuscin content of the retinal pigment epithelium (RPE) of Nrl-/- mice, the retinas of which contain only cone-like photoreceptors. A2E, a major component of lipofuscin, has been suggested to be formed as a byproduct of reactions involving the visual pigment chromophore. Nrl-/- photoreceptor cells have outer segments which are small, contain only cone pigments, and have cone-like responses when stimulated by light.

Methods: : Nrl-/- mice of various ages were kept in cyclic light. Organic solvent extracts from Nrl-/- RPE-choroid samples were analyzed by HPLC and mass spectrometry (nano-LC-MS/MS). The results were compared against a synthetic A2E standard for confirmation of identity. Whole eyecups (with retina removed) were flattened and lipofuscin levels were measured at 10x magnification on a Leica Laser Scanning Confocal fluorescence microscope (ex= 488 nm, emission collected from 565-725 nm). Sample preparation was carried out under dim red light.

Results: : Comparison of Nrl-/- RPE-choroid extracts with a synthetic A2E standard by HPLC showed that the extracts contain a peak with the same retention time and absorbance spectra as A2E (dual absorbance max at ~335 and 440 nm). Mass spectrometry data showed a peak at 592 m/z, corresponding to A2E, with a matching MS/MS fragmentation pattern, confirming the presence of A2E in Nrl-/- RPE. The amount of A2E measured by HPLC was lower than that measured from wild type RPE. Data from fluorescence microscopy show total Nrl-/- RPE fluorescence to be less than that of wild type mice. The fluorescence emission spectrum of lipofuscin granules in Nrl-/- RPE has a broad peak with max~620 similar to that of granules in wild type.

Conclusions: : Lipofuscin and A2E accumulate in the RPE of Nrl-/- mice as they do in mice with rod photoreceptors, but in lower total amounts. This is consistent with the lower amount of chromophore-containing pigment in Nrl-/- retinas. Our data demonstrate that cone visual pigments can contribute to the production of lipofuscin and A2E in the RPE. Support: NIH grants R01 EY014850 (YK), R01 EY004939 (RKC), R21 EY020661 (ZA/RKC), EY019065 (ZA), R24 EY14793 (MUSC vision core), Foundation Fighting Blindness, Inc. (Owings Mills, MD) (RKC); and unrestricted awards to the Departments of Ophthalmology at MUSC from Research to Prevent Blindness (RPB; New York); RKC is an RPB Senior Scientific Investigator.

Keywords: retinal pigment epithelium • retinoids/retinoid binding proteins • ipofuscin 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×