Changes in spectral properties and composition of lipofuscin fluorophores from human-retinal-pigment epithelium with age and pathology

Anal Bioanal Chem. 2015 Feb;407(4):1075-88. doi: 10.1007/s00216-014-8353-z. Epub 2014 Dec 4.

Abstract

Fundus autofluorescence mostly originates from bisretinoid fluorophores in lipofuscin granules, which accumulate in retinal-pigment-epithelium cells with age. The dynamics of accumulation, photo-oxidation, and photodegradation of bisretinoids during aging or in the presence of pathology have been insufficiently investigated. Changes in spectral properties and composition of human lipofuscin-granule fluorophores with age and pathology have now been investigated by a high-performance liquid chromatography method using spectrophotometric and fluorescent detectors connected in series. It was found that: (i) N-retinylidene-N-retinylethanolamine (A2E) fluorescence intensity is not predominant in the chloroform extract of human-cadaver-eye retinal pigment epithelium studied; bisretinoid photo-oxidation and photodegradation products have much higher fluorescent properties; (ii) the relative emission maximum in the fluorescence spectrum of suspended retinal-pigment-epithelium cells obtained from an individual human-cadaver eye without pathology is irrespective of donor age and falls within the range 575 ± 15 nm; in two cadaver eyes with signs of age-related macular degeneration, emission maxima were shifted by 23-36 nm towards the shortwave region; and (iii) the ratio of bisretinoid photo-oxidation and photodegradation products to unoxidized bisretinoids in the chloroform extract of cadaver-eye retinal pigment epithelium increases with donor age, from 0.69 ± 0.03 to 1.32 ± 0.04. The differences in fluorescence properties between chloroform extracts obtained from cadaver eyes with and without signs of age-related macular degeneration could be used to increase the potential of fundus autofluorescence imaging as a noninvasive diagnostic method.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging / metabolism*
  • Aging / pathology*
  • Cadaver
  • Chromatography, High Pressure Liquid
  • Fluorescent Dyes
  • Humans
  • Lipofuscin / chemistry
  • Lipofuscin / metabolism*
  • Lipofuscin / radiation effects
  • Middle Aged
  • Models, Biological
  • Oxidation-Reduction
  • Photochemical Processes
  • Retinal Pigment Epithelium / metabolism*
  • Retinal Pigment Epithelium / pathology*
  • Retinoids / chemistry
  • Retinoids / metabolism*
  • Retinoids / radiation effects
  • Young Adult

Substances

  • A2-E (N-retinylidene-N-retinylethanolamine)
  • Fluorescent Dyes
  • Lipofuscin
  • Retinoids