Cited by 35Retinal Diseases and TreatmentsRetinal Development and DisordersAntioxidant Activity and Oxidative Stress

Bisretinoids of the Retina: Photo-Oxidation, Iron-Catalyzed Oxidation, and Disease Consequences

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Kim, Hye Jin, Montenegro, Diego, Zhao, Jin, Sparrow, Janet R.·2021·Antioxidants

Abstract

The retina and, in particular, retinal pigment epithelial cells are unusual for being encumbered by exposure to visible light, while being oxygen-rich, and also amassing photoreactive molecules. These fluorophores (bisretinoids) are generated as a byproduct of the activity of vitamin A aldehyde—the chromophore necessary for vision. Bisretinoids form in photoreceptor cells due to random reactions of two molecules of vitamin A aldehyde with phosphatidylethanolamine; bisretinoids are subsequently transferred to retinal pigment epithelial (RPE) cells, where they accumulate in the lysosomal compartment with age. Bisretinoids can generate reactive oxygen species by both energy and electron transfer, and they become photo-oxidized and photolyzed in the process. While these fluorescent molecules are accrued by RPE cells of all healthy eyes, they are also implicated in retinal disease.

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Crossref · 10.3390/antiox10091382

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  • In the membranes of outer photoreceptor segments, nonenzymatically formed toxic bisretinoids are converted upon phagocytosis in the acidic environment of RPE phagolysosomes to bisretinoid pyridinium compound A2E and related bisretinoids.

    “In the membranes of outer photoreceptor segments are nonenzymatically formed toxic bisretinoids. Upon phagocytosis, these bisretinoids are in the acidic environment of RPE phagolysosomes converted to bisretinoid pyridinium compound A2E and related bisretinoids [54,69,70,71,72,73,74].”

    From The Role of Vitamin A in Retinal Diseases (2022) · cites this paper as [72]

    Section 2 states that bisretinoids form nonenzymatically in photoreceptor outer segments and identifies A2PE as the immediate precursor of A2E. The Conclusions say the compounds reach the RPE in phagocytosed outer-segment membrane. The paper does not say that the bisretinoids generally are converted to A2E and related compounds in the acidic environment of RPE phagolysosomes. (LLM, conf=0.85)

    Experimental — accuracy not yet measured
  • Although abundant lipofuscin accumulation is involved in the aetiology of certain retinal diseases such as AMD, Best disease and ABCA4-retinopathy, it also accumulates at a lower level with age in the RPE of healthy eyes.

    “Although abundant lipofuscin accumulation is involved in the aetiology of certain retinal diseases (e.g., AMD, Best disease and ABCA4-retinopathy), it accumulates at a lower level also with age in the RPE of healthy eyes [9,72,73,74,75].”

    From The Role of Vitamin A in Retinal Diseases (2022) · cites this paper as [72]

    Section 2 says bisretinoid fluorophores accumulate throughout life and are measurable in the RPE. Section 8 reports elevated lipofuscin-related signals in ABCA4-associated Stargardt disease and within Best disease lesions, but describes the Best disease increase as likely secondary rather than established as a cause. It also reports lipofuscin-related signals in studied AMD groups as similar to or lower than those in age-matched healthy eyes, not abundantly elevated. Page numbers were not available in our copy. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

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Authors
Kim, H. J., Montenegro, D., Zhao, J., & Sparrow, J. R.
Affiliations
Columbia University Irving Medical Center (US)
Corresponding author
Sparrow, Janet R.
Venue
Antioxidants
Publisher
MDPI AG
Published
2021-08-29
Volume
10
Issue
9
Pages
1382
ISSN
2076-3921 (ISSN-L)
OpenAlex
W3197408017
Cited by
35
References
134
Citations by year
2026: 4 · 2025: 8 · 2024: 5 · 2023: 8 · 2022: 10
FWCI
0.98
Type
journal article
Language
en
Open access
Locations
  • Antioxidants (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, other-oa)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • National Eye Institute (EY028131, EY012951, EY024091, P30EY019007)
  • Research to Prevent Blindness (The Department of Ophthalmology Columbia University)
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
bisretinoids, vitamin A aldehyde, retinal pigment epithelium, photoreceptors, photooxidation, iron-catalyzed oxidation, reactive oxygen species, photolysis, lysosomal accumulation, retinal disease, phosphatidylethanolamine, energy transfer, electron transfer

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