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Macrophages release plasma membrane-derived particles rich in accessible cholesterol.
- Source :
-
Proceedings of the National Academy of Sciences of the United States of America . 9/4/2018, Vol. 115 Issue 36, pE8499-E8508. 10p. - Publication Year :
- 2018
-
Abstract
- Macrophages are generally assumed to unload surplus cholesterol through direct interactions between ABC transporters on the plasma membrane and HDLs, but they have also been reported to release cholesterol-containing particles. How macrophagederived particles are formed and released has not been clear. To understand the genesis of macrophage-derived particles, we imaged mouse macrophages by EM and nanoscale secondary ion mass spectrometry (nanoSIMS). By scanning EM, we found that large numbers of 20- to 120-nm particles are released from the fingerlike projections (filopodia) of macrophages. These particles attach to the substrate, forming a "lawn" of particles surrounding macrophages. By nanoSIMS imaging we showed that these particles are enriched in the mobile and metabolically active accessible pool of cholesterol (detectable by ALO-D4, a modified version of a cholesterol-binding cytolysin). The cholesterol content of macrophagederived particles was increased by loading the cells with cholesterol or by adding LXR and RXR agonists to the cell-culture medium. Incubating macrophages with HDL reduced the cholesterol content of macrophage-derived particles. We propose that release of accessible cholesterol-rich particles from the macrophage plasma membrane could assist in disposing of surplus cholesterol and increase the efficiency of cholesterol movement to HDL. [ABSTRACT FROM AUTHOR]
- Subjects :
- *MACROPHAGES
*CHOLESTEROL
*LIPOPROTEINS
*BLOOD lipoproteins
*VESICLES (Cytology)
Subjects
Details
- Language :
- English
- ISSN :
- 00278424
- Volume :
- 115
- Issue :
- 36
- Database :
- Academic Search Index
- Journal :
- Proceedings of the National Academy of Sciences of the United States of America
- Publication Type :
- Academic Journal
- Accession number :
- 131670298
- Full Text :
- https://doi.org/10.1073/pnas.1810724115