You are here

  • Home
  • Archive
  • Volume 93, Issue 8
  • Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium

Article Text

Article menu
Download PDFPDF
Original Article
Laboratory science
Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium
  1. K G Duncan1,
  2. K Hosseini1,
  3. K R Bailey1,2,
  4. H Yang1,
  5. R J Lowe1,
  6. M T Matthes1,
  7. J P Kane3,
  8. M M LaVail1,
  9. D M Schwartz1,2,
  10. J L Duncan1
  1. 1
    Department of Ophthalmology, University of California, San Francisco, California, USA
  2. 2
    Veterans Affairs Medical Center, San Francisco, California, USA
  3. 3
    Cardiovascular Research Institute, University of California, San Francisco, California, USA
  1. Correspondence to Dr D M Schwartz, Box 0730, University of California, San Francisco, CA 94143-0730, USA; schwartz7{at}mindspring.com

Abstract

Aims: Excessive lipid accumulation in Bruch’s membrane (BrM) is a hallmark of ageing, the major risk factor for age-related macular degeneration (AMD). Retinal pigment epithelial (RPE) cells may utilise reverse cholesterol transport (RCT) activity to move lipid into BrM, mediated through ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI).

Methods: ABCA1 expression was assessed by reverse transcription polymerase chain reaction (RT-PCR) and western blotting of human RPE cell extracts. Lipid transport assays were performed using radiolabelled photoreceptor outer segments (POS). ABCA1 and SR-BI expression was examined in normal mouse eyes by immunofluorescence staining. BrMs of ABCA1 and SR-BI heterozygous mice were examined microscopically.

Results: Human RPE cells expressed ABCA1 mRNA and protein. The ABCA1 and SR-BI inhibitor glyburide (also known as glibenclamide) abolished basal transport of POS-derived lipids in RPE cells in the presence of high-density lipoprotein. Mouse retina and RPE expressed ABCA1 and SR-BI. SR-BI was highly expressed in RPE. BrMs were significantly thickened in SR-BI heterozygous mice, but not in ABCA1 heterozygous mice.

Conclusion: RPE cells express ABCA1 and SR-BI. This implies a significant role for SR-BI and ABCA1 in lipid transport and RCT in the retina and RPE.

https://doi.org/10.1136/bjo.2008.144006

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    View Full Text

    Footnotes

    • Funding Supported by a Physician Scientist Award (JLD); Unrestricted Grant from Research to Prevent Blindness – a Career Development Award (JLD); Center Grant from the Foundation Fighting Blindness (MML, JLD); the Dennis Jahnigen Career Development Scholars Award (JLD); NIH-NEI grants EY00415 (JLD), EY01919 and EY002162 (MML); That Man May See, Inc. (MML, JLD); The Bernard A. Newcomb Macular Degeneration Fund (JLD); Hope for Vision (JLD); and the Karl Kirchgessner Foundation (JLD).

    • Competing interests None declared.

    • Ethics approval All procedures were approved by the University of California San Francisco Institutional Animal Care and Use Committee.