Macrophages take up triacylglycerol-rich emulsions at a faster rate upon co-incubation with native and modified LDL: An investigation on the role of natural chylomicrons in atherosclerosis

Macrophages take up triacylglycerol-rich emulsions at a faster rate upon co-incubation with native and modified LDL: An investigation on the role of natural chylomicrons in atherosclerosis

Autor Carvalho, Marcia DT Google Scholar
Harada, Lila M. Google Scholar
Gidlund, Magnus Google Scholar
Ketelhuth, Daniel FJ Google Scholar
Boschcov, Paulo Autor UNIFESP Google Scholar
Quintão, Eder Carlos Rocha Autor UNIFESP Google Scholar
Instituição Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Resumo Chylomicrons play a role in atherosclerosis, however, because the mechanisms involved in the cell uptake of these particles are not fully understood, investigations were carried out using a radioactively labeled protein-free triacylglycerol-rich emulsion incubated with peritoneal macrophages obtained from normal and apoE-knockout mice. Experiments were done in the presence of substances that inhibit several endocytic processes: EDTA for low density lipoprotein receptor, fucoidan for scavenger receptor, cytochalasin B for phagocytosis, and a lipopolysaccharide for lipoprotein lipase. in addition, triacylglycerol-rich emulsions were also prepared in the presence of native or modified radioactively labeled low density lipoprotein particles that are known to accumulate in the arterial intima. Probucol was also used to prevent the possible role played by an antioxidant in triacylglycerol-rich emulsion uptake. We have shown that triacylglycerol-rich emulsion alone is taken up by a coated-pit-dependent mechanism, mediated by macrophage secretion of apolipoprotein E. Furthermore, native, aggregated, acetylated, and moderately macrophage-oxidized low density lipoprotein stimulate the uptake of a triacylglycerol-rich emulsion through several mechanisms such as an actin-dependent pathway, scavenger receptors, and lipolysis mediated by lipoprotein lipase. On the other hand, in spite of the interaction of low density lipoprotein forms with a triacylglycerol-rich emulsion, the cellular triacylglycerol-rich emulsion uptake is impaired by copper-oxidized low density lipoprotein, possibly due to its diminished affinity towards lipoprotein lipase. We have also shown that macrophages take up aggregated low density lipoprotein better than the acetylated or oxidized forms of low density lipoprotein. (C) 2001 Wiley-Liss, Inc.
Palavra-chave triacylglycerol-rich emulsions
ethylenediaminetetraacetic acid
low density lipoprotein
fucoidan
cytochalasin B
lipopolysaccharide
Idioma Inglês
Data de publicação 2002-01-01
Publicado em Journal of Cellular Biochemistry. New York: Wiley-liss, v. 84, n. 2, p. 309-323, 2002.
ISSN 0730-2312 (Sherpa/Romeo, fator de impacto)
Publicador Wiley-Blackwell
Extensão 309-323
Fonte http://dx.doi.org/10.1002/jcb.10020
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:000172911000011
Endereço permanente http://repositorio.unifesp.br/handle/11600/26692

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