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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1984 Jun;81(12):3883–3887. doi: 10.1073/pnas.81.12.3883

Modification of low density lipoprotein by endothelial cells involves lipid peroxidation and degradation of low density lipoprotein phospholipids.

U P Steinbrecher, S Parthasarathy, D S Leake, J L Witztum, D Steinberg
PMCID: PMC345326  PMID: 6587396

Abstract

Low density lipoprotein (LDL) incubated with cultured endothelial cells from rabbit aorta or human umbilical vein is altered in several ways (EC-modified): (i) It is degraded by macrophages much faster than LDL similarly incubated in the absence of cells or incubated with fibroblasts. (ii) Its electrophoretic mobility is increased. (iii) Its density is increased. We report here that antioxidants completely prevent these changes. We also report that these changes do not take place if transition metals in the medium are chelated with EDTA. During EC-modification as much as 40% of the LDL phosphatidylcholine is degraded to lysophosphatidylcholine by a phospholipase A2-like activity. When incubation conditions in the absence of cells were selected to favor oxidation--for example, by extending the time of incubation of LDL at low concentrations, or by increasing the Cu2+ concentration--LDL underwent changes very similar to those occurring in the presence of cells, including degradation of phosphatidylcholine. Hence, some phospholipase activity appears to be associated with the isolated LDL used in these studies. The results suggest a complex process in which endothelial cells modify LDL by mechanisms involving generation of free radicals and action of phospholipase (s).

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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