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LDL Cholesterol Uptake Assay Using Live Cell Imaging Analysis with Cell Health Monitoring
Published on: November 17, 2018
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Human mast cell neutral proteases generate modified LDL particles with increased proteoglycan binding.
Katariina Maaninka1, Su Duy Nguyen1, Mikko I Mäyränpää2
1Wihuri Research Institute, Biomedicum 1, Haartmaninkatu 8, 00290 Helsinki, Finland.
Atherosclerosis
|April 29, 2018
Summary
Mast cells release cathepsin G, which modifies LDL and enhances its binding to proteoglycans, potentially promoting atherosclerosis. This study highlights mast cell proteases
Area of Science:
- Cardiovascular Biology
- Immunology
- Proteomics
Background:
- Atherogenesis involves low-density lipoprotein (LDL) interaction with the extracellular matrix.
- Proteolytic modification of LDL can intensify this interaction.
- Mast cells (MCs) in atherosclerotic lesions release neutral proteases upon activation.
Purpose of the Study:
- To investigate the capacity of mast cell proteases to cleave apolipoprotein B-100 (apoB-100) in LDL.
- To determine the effect of MC proteases on LDL binding to proteoglycans.
Main Methods:
- Differentiated human mast cells (MCs) in vitro and activated them to generate conditioned medium.
- Incubated LDL with MC-conditioned medium or individual MC proteases.
- Assessed LDL binding to proteoglycans and atherosclerotic plaques ex vivo.
- Detected MC proteases in human coronary artery lesions using immunofluorescence and qPCR.
Main Results:
- Activated human MCs released tryptase, chymase, carboxypeptidase A3, cathepsin G, and granzyme B.
- Cathepsin G most effectively degraded apoB-100, induced LDL fusion, and enhanced LDL binding to proteoglycans and atherosclerotic lesions.
- Lesional MCs in human coronary arteries were found to contain cathepsin G, with its expression correlating with tryptase and chymase.
Conclusions:
- Cathepsin G in human atherosclerotic lesions primarily originates from mast cells.
- Activated mast cells may contribute to atherogenesis by increasing LDL retention within lesions.
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