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Updated: Jul 10, 2026
Fast and Specific Assessment of the Halogenating Peroxidase Activity in Leukocyte-enriched Blood Samples
Published on: July 28, 2016
A fluorescent probe for the detection of myeloperoxidase activity in atherosclerosis-associated macrophages
Joanna Shepherd1, Scott A Hilderbrand, Peter Waterman
1Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02215, USA.
Abstract:
The myeloperoxidase (MPO)-derived oxidant hypochlorous acid (HOCl/OCl(-)) is implicated in the pathogenesis of atherosclerosis and other inflammatory states. We have synthesized an imaging probe, sulfonaphthoaminophenyl fluorescein (SNAPF), that selectively reacts with HOCl. SNAPF detects HOCl produced by stimulated MPO-expressing cells cultured from human whole blood, as well as HOCl from bone marrow (BM)-derived macrophages isolated from transgenic mice that express human MPO. Two lines of evidence indicate that SNAPF permits the in vivo imaging of HOCl production. First, we used this approach to demonstrate HOCl production by neutrophils in experimental murine peritonitis. Second, we detected HOCl production by MPO expressing cells in human atherosclerotic arteries. Thus, fluorescence reflectance imaging by SNAPF may provide a valuable noninvasive molecular imaging tool for implicating HOCl and MPO in the damage of inflamed tissues.
Insights
A new imaging probe, sulfonaphthoaminophenyl fluorescein (SNAPF), can detect hypochlorous acid (HOCl) produced by inflammatory cells. This tool visualizes HOCl in animal models and human arteries, aiding atherosclerosis research.
Area of Science:
- Biomedical imaging
- Molecular imaging
- Inflammation research
Background:
- Myeloperoxidase (MPO)-derived hypochlorous acid (HOCl) contributes to atherosclerosis and inflammatory diseases.
- Existing methods for HOCl detection are limited in vivo.
Purpose of the Study:
- To develop and validate a novel imaging probe, SNAPF, for selective detection of HOCl.
- To assess the utility of SNAPF for in vivo imaging of HOCl production in inflammatory conditions.
Main Methods:
- Synthesis of sulfonaphthoaminophenyl fluorescein (SNAPF) probe.
- Detection of HOCl in stimulated MPO-expressing cells and bone marrow-derived macrophages.
- In vivo imaging of HOCl production in experimental murine peritonitis.
- Detection of HOCl in human atherosclerotic arteries using fluorescence reflectance imaging.
Main Results:
- SNAPF selectively reacts with HOCl.
- SNAPF successfully detected HOCl produced by MPO-expressing cells in vitro.
- In vivo studies demonstrated HOCl production by neutrophils in murine peritonitis.
- HOCl production by MPO-expressing cells was visualized in human atherosclerotic arteries.
Conclusions:
- SNAPF is a valuable tool for detecting HOCl produced by MPO-expressing cells.
- Fluorescence reflectance imaging with SNAPF enables noninvasive molecular imaging of HOCl in vivo.
- This approach can help implicate HOCl and MPO in inflammatory tissue damage, particularly in atherosclerosis.
