A2E Distribution in RPE Granules in Human Eyes.

Journal Article (Journal Article)

A2E (N-retinylidene-N-retinylethanolamine) is a major fluorophore in the RPE (retinal pigment epithelium). To identify and characterize A2E-rich RPE lipofuscin, we fractionated RPE granules from human donor eyes into five fractions (F1-F5 in ascending order of density) by discontinuous sucrose density gradient centrifugation. The dry weight of each fraction was measured and A2E was quantified by liquid chromatography/mass spectrometry (LC/MS) using a synthetic A2E homolog as a standard. Autofluorescence emission was characterized by a customer-built spectro-fluorometer system. A significant A2E level was detected in every fraction, and the highest level was found in F1, a low-density fraction that makes up half of the total weight of all RPE granules, contains 67% of all A2E, and emits 75% of projected autofluorescence by all RPE granules. This group of RPE granules, not described previously, is therefore the most abundant RPE lipofuscin granule population. A progressive decrease in autofluorescence was observed from F2 to F4, whereas no autofluorescence emission was detected from the heavily pigmented F5. The identification of a novel and major RPE lipofuscin population could have significant implications in our understanding of A2E and lipofuscin in human RPE.

Full Text

Duke Authors

Cited Authors

  • Guan, Z; Li, Y; Jiao, S; Yeasmin, N; Rosenfeld, PJ; Dubovy, SR; Lam, BL; Wen, R

Published Date

  • March 20, 2020

Published In

Volume / Issue

  • 25 / 6

PubMed ID

  • 32244898

Pubmed Central ID

  • 32244898

Electronic International Standard Serial Number (EISSN)

  • 1420-3049

Digital Object Identifier (DOI)

  • 10.3390/molecules25061413

Language

  • eng

Conference Location

  • Switzerland