Variability of cholesterol accessibility in human red blood cells measured using a bacterial cholesterol-binding toxin

  1. Rima S Chakrabarti
  2. Sally A Ingham
  3. Julia Kozlitina
  4. Austin Gay
  5. Jonathan C Cohen
  6. Arun Radhakrishnan
  7. Helen H Hobbs  Is a corresponding author
  1. Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, United States
  2. University of Texas Southwestern Medical Center, United States

Abstract

Cholesterol partitions into accessible and sequestered pools in cell membranes. Here we describe a new assay using fluorescently-tagged anthrolysin O, a cholesterol-binding bacterial toxin, to measure accessible cholesterol in human red blood cells (RBCs). Accessible cholesterol levels were stable within individuals but varied >10-fold among individuals. Significant variation was observed among ethnic groups (Blacks>Hispanics>Whites). Variation in accessibility of RBC cholesterol was unrelated to the cholesterol content of RBCs or plasma, but was associated with the phospholipid composition of the RBC membranes and with plasma triglyceride levels. Pronase treatment of RBCs only modestly altered cholesterol accessibility. Individuals on hemodialysis, who have an unexplained increase in atherosclerotic risk, had significantly higher RBC cholesterol accessibility. Our data indicate that RBC accessible cholesterol is a stable phenotype with significant inter-individual variability. Factors both intrinsic and extrinsic to the RBC contribute to variation in its accessibility. This assay provides a new tool to assess cholesterol homeostasis among tissues in humans.

Article and author information

Author details

  1. Rima S Chakrabarti

    Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
  2. Sally A Ingham

    Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
  3. Julia Kozlitina

    Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
  4. Austin Gay

    Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
  5. Jonathan C Cohen

    Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
  6. Arun Radhakrishnan

    Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7266-7336
  7. Helen H Hobbs

    Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
    For correspondence
    helen.hobbs@utsouthwestern.edu
    Competing interests
    Helen H Hobbs, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8700-9897

Funding

Howard Hughes Medical Institute

  • Rima S Chakrabarti
  • Sally A Ingham
  • Helen H Hobbs

National Institutes of Health (PO1 HL20948)

  • Austin Gay
  • Jonathan C Cohen
  • Arun Radhakrishnan
  • Helen H Hobbs

Welch Foundation (I-1793)

  • Arun Radhakrishnan

American Heart Association (12SDG12040267)

  • Arun Radhakrishnan

National Institutes of Health (5T32-GM008203)

  • Austin Gay

National Institutes of Health (UL1TR001105)

  • Julia Kozlitina
  • Helen H Hobbs

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Stephen G Young, University of California, Los Angeles, United States

Ethics

Human subjects: All study protocols were approved by the Institutional Review Board (IRB) of the University of Texas Southwestern Medical Center, and all subjects provided written informed consent. Each participant completed a detailed staff-administered survey, including questions about socioeconomic status, medical history and medication use. Ancestry was self-reported.

Version history

  1. Received: November 16, 2016
  2. Accepted: January 28, 2017
  3. Accepted Manuscript published: February 7, 2017 (version 1)
  4. Accepted Manuscript updated: February 8, 2017 (version 2)
  5. Version of Record published: February 23, 2017 (version 3)

Copyright

© 2017, Chakrabarti et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Rima S Chakrabarti
  2. Sally A Ingham
  3. Julia Kozlitina
  4. Austin Gay
  5. Jonathan C Cohen
  6. Arun Radhakrishnan
  7. Helen H Hobbs
(2017)
Variability of cholesterol accessibility in human red blood cells measured using a bacterial cholesterol-binding toxin
eLife 6:e23355.
https://doi.org/10.7554/eLife.23355

Share this article

https://doi.org/10.7554/eLife.23355

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