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

• DOI: 10.1007/s00216-014-8353-z
• Publication Date: 2014-12-03T07:05:44Z
• Authors: Tatiana B. Feldman; Marina A. Yakovleva; Patimat M. Arbukh...; Sergey A. Borzenok; Alexey S. Kononikhin; Igor A. Popov; Evgeny N. Nikolaev; Mikhail A. Ostrovsky
• Keywords: Adult; 0301 basic medicine; Aging; Adolescent; Retinal Pigment Epithelium; Middle Aged; Photochemical Processes; Models, Biological; Lipofuscin; Retinoids; Young Adult; 03 medical and health sciences; Cadaver; Humans; Oxidation-Reduction; Chromatography, High Pressure Liquid; Aged; Fluorescent Dyes

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.