Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport
Previous studies have shown that cholesterol in atherosclerotic plaques is present in both intracellular and extracellular forms. In the current study, we investigated a mechanism for extracellular cholesterol accumulation and examined the capacity of this pool of cholesterol to be removed by choles...
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| Format: | Article |
| Language: | English |
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Elsevier
2010-08-01
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| Series: | Journal of Lipid Research |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520370668 |
| _version_ | 1818740428513476608 |
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| author | Daniel S. Ong Joshua J. Anzinger Francisco J. Leyva Noa Rubin Lia Addadi Howard S. Kruth |
| author_facet | Daniel S. Ong Joshua J. Anzinger Francisco J. Leyva Noa Rubin Lia Addadi Howard S. Kruth |
| author_sort | Daniel S. Ong |
| collection | DOAJ |
| description | Previous studies have shown that cholesterol in atherosclerotic plaques is present in both intracellular and extracellular forms. In the current study, we investigated a mechanism for extracellular cholesterol accumulation and examined the capacity of this pool of cholesterol to be removed by cholesterol acceptors, a step in reverse cholesterol transport. Human monocyte-derived macrophages differentiated with macrophage-colony stimulating factor were incubated with acetylated LDL to allow cholesterol enrichment and processing. These macrophages were subsequently labeled with a monoclonal antibody that specifically detects ordered cholesterol arrays, revealing the presence of unesterified cholesterol-rich microdomains on the cell surfaces and in the extracellular matrix. Similar unesterified cholesterol-rich microdomains were present in human atherosclerotic plaques. Actin microfilaments functioned in microdomain deposition or maintenance, and Src family kinases regulated transfer of these microdomains from the cell surface onto the extracellular matrix. Mediators of reverse cholesterol transport, apolipoprotein A-I (apoA-I), and HDL were capable of removing these extracellular un-esterified cholesterol-rich microdomains. However, apoA-I removed the microdomains only when macrophages were present. ApoA-I removal of microdomains was blocked by glyburide and inhibitor of ATP-binding cassette transporter A1 (ABCA1) function. In summary, cultures of cholesterol-enriched human monocyte-derived macrophages generate extracellular unesterified cholesterol-rich microdomains, which can subsequently be removed by cholesterol acceptors and therefore potentially function in reverse cholesterol transport. |
| first_indexed | 2024-12-18T01:40:34Z |
| format | Article |
| id | doaj.art-c05975d4407d477bb186852cad50d010 |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-18T01:40:34Z |
| publishDate | 2010-08-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-c05975d4407d477bb186852cad50d0102022-12-21T21:25:21ZengElsevierJournal of Lipid Research0022-22752010-08-0151823032313Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transportDaniel S. Ong0Joshua J. Anzinger1Francisco J. Leyva2Noa Rubin3Lia Addadi4Howard S. Kruth5Section of Experimental Atherosclerosis, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1422; Clinical Research Training Program, National Institutes of Health, Bethesda, MD 20892Section of Experimental Atherosclerosis, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1422Section of Experimental Atherosclerosis, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1422Department of Structural Biology, Weizmann Institute of Science, 76100, Rehovot, IsraelDepartment of Structural Biology, Weizmann Institute of Science, 76100, Rehovot, IsraelTo whom correspondence should be addressed; Section of Experimental Atherosclerosis, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1422Previous studies have shown that cholesterol in atherosclerotic plaques is present in both intracellular and extracellular forms. In the current study, we investigated a mechanism for extracellular cholesterol accumulation and examined the capacity of this pool of cholesterol to be removed by cholesterol acceptors, a step in reverse cholesterol transport. Human monocyte-derived macrophages differentiated with macrophage-colony stimulating factor were incubated with acetylated LDL to allow cholesterol enrichment and processing. These macrophages were subsequently labeled with a monoclonal antibody that specifically detects ordered cholesterol arrays, revealing the presence of unesterified cholesterol-rich microdomains on the cell surfaces and in the extracellular matrix. Similar unesterified cholesterol-rich microdomains were present in human atherosclerotic plaques. Actin microfilaments functioned in microdomain deposition or maintenance, and Src family kinases regulated transfer of these microdomains from the cell surface onto the extracellular matrix. Mediators of reverse cholesterol transport, apolipoprotein A-I (apoA-I), and HDL were capable of removing these extracellular un-esterified cholesterol-rich microdomains. However, apoA-I removed the microdomains only when macrophages were present. ApoA-I removal of microdomains was blocked by glyburide and inhibitor of ATP-binding cassette transporter A1 (ABCA1) function. In summary, cultures of cholesterol-enriched human monocyte-derived macrophages generate extracellular unesterified cholesterol-rich microdomains, which can subsequently be removed by cholesterol acceptors and therefore potentially function in reverse cholesterol transport.http://www.sciencedirect.com/science/article/pii/S0022227520370668atherosclerosisunesterifiedmacrophage-colony stimulating factorSrc family kinaseactinapolipoprotein A-I |
| spellingShingle | Daniel S. Ong Joshua J. Anzinger Francisco J. Leyva Noa Rubin Lia Addadi Howard S. Kruth Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport Journal of Lipid Research atherosclerosis unesterified macrophage-colony stimulating factor Src family kinase actin apolipoprotein A-I |
| title | Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| title_full | Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| title_fullStr | Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| title_full_unstemmed | Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| title_short | Extracellular cholesterol-rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| title_sort | extracellular cholesterol rich microdomains generated by human macrophages and their potential function in reverse cholesterol transport |
| topic | atherosclerosis unesterified macrophage-colony stimulating factor Src family kinase actin apolipoprotein A-I |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520370668 |
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