A2E, a byproduct of the visual cycle
Open accessAbstract
A substantial portion of the lipofuscin that accumulates with age and in some retinal disorders in retinal pigment epithelial (RPE) cells, forms as a consequence of light-related vitamin A recycling. Major constituents of RPE lipofuscin are the di-retinal conjugate A2E and its photoisomers. That the accretion of A2E has consequences for the cell, with the adverse effects of A2E being attributable to its amphiphilic structure and its photoreactivity, is consistent with evidence of an association between atrophic age-related macular degeneration (AMD) and excessive lipofuscin accumulation.
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Lipofuscin bodies provide a fluorescent marker for quantification in the living eye and can serve as long-lasting evidence of excessive past accumulation of all-trans-retinal.
“These bodies provide a useful fluorescent marker for lipofuscin quantification in the living eye, which can serve as long-lasting evidence of excessive past accumulation of all-trans-retinal.539−541”
From Chemistry of the Retinoid (Visual) Cycle (2014) · cites this paper as [539]
The Introduction (page unavailable) says RPE lipofuscin produces fundus fluorescence, can be monitored in the living eye, and accumulates because it cannot be enzymatically degraded. Section 2 (page unavailable) links increased availability of all-trans-retinal to formation of a lipofuscin precursor. The paper does not establish that the fluorescence specifically identifies excessive past accumulation of all-trans-retinal, rather than lipofuscin formed through ordinary visual-cycle activity. (LLM, conf=0.82)
Experimental — accuracy not yet measuredAnother sign of aging is the accumulation of lipofuscin, an undegradable fluorescent material; in the RPE, accumulation of lipofuscin may be due in large part to incomplete digestion of shed photoreceptor discs.
“Another sign of aging is the accumulation of lipofuscin, an undegradable fluorescent material; in the RPE, accumulation of lipofuscin may be due in large part to incomplete digestion of shed photoreceptor discs (142).”
From Unraveling a Multifactorial Late-Onset Disease: From Genetic Susceptibility to Disease Mechanisms for Age-Related Macular Degeneration (2009) · cites this paper as [142]
The major component of lipofuscin is N-retinylidene-N-retinylethanol-amine (A2E), a quaternary amine and retinoid byproduct of the visual cycle.
“The major component of lipofuscin is N-retinylidene-N-retinylethanol-amine (A2E), a quaternary amine and retinoid byproduct of the visual cycle.130”
From Age-related macular degeneration (2008) · cites this paper as [130]
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References 82 · Cited by 318
Research works printed but not linked: 2
- Ben-Shabat, S., Itagaki, Y., Jockusch, S., Sparrow, J. R., Turro, N. J., & Nakanishi, K. (2002). Formation of a nona-oxirane from A2E, a lipofuscin fluorophore related to macular degeneration, and evidence of singlet oxygen involvement. Angewandte Chemie- International Edition, 41, 814-817.
- Ben-Shabat, S., Parish, C. A., Vollmer, H. R., Itagaki, Y., Fishkin, N., Nakanishi, K., & Sparrow, J. R. (2002). Biosynthetic studies of A2E, a major fluorophore of RPE lipofuscin. Journal of Biological Chemistry, 277, 7183-7190.
- Authors
- Sparrow, J. R., Fishkin, N., Zhou, J., Cai, B., Jang, Y. P., Krane, S., Itagaki, Y., & Nakanishi, K.
- Affiliations
- Columbia University Irving Medical Center (US)
- Columbia University (US)
- Corresponding author
- Sparrow, Janet R.
- Venue
- Vision Research
- Publisher
- Elsevier BV
- Published
- 2003-12
- Volume
- 43
- Issue
- 28
- Pages
- 2983-2990
- ISSN
- 0042-6989 (ISSN-L)
- OpenAlex
- W2044627868
- Cited by
- 318
- References
- 82
- Citations by year
- 2026: 12 · 2025: 13 · 2024: 6 · 2023: 7 · 2022: 16 · 2021: 12 · 2020: 24 · 2019: 15 · 2018: 12 · 2017: 11 · 2016: 15 · 2015: 21 · 2014: 9 · 2013: 13 · 2012: 15
- FWCI
- 4.44
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- Locations
- Vision Research (publishedVersion)
- PubMed (publishedVersion)
- Funders
- American Health Assistance Foundation
- Research to Prevent Blindness
- Macula Vision Research Foundation
- National Institutes of Health
- National Eye Institute (R01EY012951, EY 12951)
- National Institute of General Medical Sciences (GM-36564, R01GM036564)
- Topics
- Health Sciences › Medicine › Ophthalmology › Retinal Diseases and Treatments
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Retinal Development and Disorders
- Health Sciences › Medicine › Biochemistry › Antioxidant Activity and Oxidative Stress
- Keywords
- A2E, lipofuscin, visual cycle, retinal pigment epithelium, photoisomers, photoreactivity, age-related macular degeneration, retinal degeneration, lipofuscin accumulation
- MeSH terms
- Atrophy, Humans, Light, Lipofuscin, Macular Degeneration, Pigment Epithelium of Eye, Pyridinium Compounds, Retina, Retinaldehyde, Retinoids, Vitamin A
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