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Postprandial apoE Isoform and Conformational Changes Associated with VLDL Lipolysis Products Modulate Monocyte Inflammation

den Hartigh, Laura J.; Altman, Robin; Hutchinson, Romobia; Petrlova, Jitka LU ; Budamagunta, Madhu S.; Tetali, Sarada D.; Lagerstedt, Jens LU ; Voss, John C. and Rutledge, John C. (2012) In PLoS ONE 7(11).
Abstract
Objective: Postprandial hyperlipemia, characterized by increased circulating very low-density lipoproteins (VLDL) and circulating lipopolysaccharide (LPS), has been proposed as a mechanism of vascular injury. Our goal was to examine the interactions between postprandial lipoproteins, LPS, and apoE3 and apoE4 on monocyte activation. Methods and Results: We showed that apoE3 complexed to phospholipid vesicles attenuates LPS-induced THP-1 monocyte cytokine expression, while apoE4 increases expression. ELISA revealed that apoE3 binds to LPS with higher affinity than apoE4. Electron paramagnetic resonance (EPR) spectroscopy of site-directed spin labels placed on specific amino acids of apoE3 showed that LPS interferes with conformational... (More)
Objective: Postprandial hyperlipemia, characterized by increased circulating very low-density lipoproteins (VLDL) and circulating lipopolysaccharide (LPS), has been proposed as a mechanism of vascular injury. Our goal was to examine the interactions between postprandial lipoproteins, LPS, and apoE3 and apoE4 on monocyte activation. Methods and Results: We showed that apoE3 complexed to phospholipid vesicles attenuates LPS-induced THP-1 monocyte cytokine expression, while apoE4 increases expression. ELISA revealed that apoE3 binds to LPS with higher affinity than apoE4. Electron paramagnetic resonance (EPR) spectroscopy of site-directed spin labels placed on specific amino acids of apoE3 showed that LPS interferes with conformational changes normally associated with lipid binding. Specifically, compared to apoE4, apoE bearing the E3-like R112 -> Ser mutation displays increased self association when exposed to LPS, consistent with a stronger apoE3-LPS interaction. Additionally, lipolysis of fasting VLDL from normal human donors attenuated LPS-induced TNF alpha secretion from monocytes to a greater extent than postprandial VLDL, an effect partially reversed by blocking apoE. This effect was reproduced using fasting VLDL lipolysis products from e3/e3 donors, but not from e4/e4 subjects, suggesting that apoE3 on fasting VLDL prevents LPS-induced inflammation more readily than apoE4. Conclusion: Postprandial apoE isoform and conformational changes associated with VLDL dramatically modulate vascular inflammation. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
7
issue
11
publisher
Public Library of Science
external identifiers
  • wos:000317185400007
  • scopus:84870338015
ISSN
1932-6203
DOI
10.1371/journal.pone.0050513
language
English
LU publication?
yes
id
58cde0c6-57d4-4c51-8cce-fed072edbb2e (old id 3749561)
date added to LUP
2013-06-03 08:39:19
date last changed
2017-01-01 05:34:15
@article{58cde0c6-57d4-4c51-8cce-fed072edbb2e,
  abstract     = {Objective: Postprandial hyperlipemia, characterized by increased circulating very low-density lipoproteins (VLDL) and circulating lipopolysaccharide (LPS), has been proposed as a mechanism of vascular injury. Our goal was to examine the interactions between postprandial lipoproteins, LPS, and apoE3 and apoE4 on monocyte activation. Methods and Results: We showed that apoE3 complexed to phospholipid vesicles attenuates LPS-induced THP-1 monocyte cytokine expression, while apoE4 increases expression. ELISA revealed that apoE3 binds to LPS with higher affinity than apoE4. Electron paramagnetic resonance (EPR) spectroscopy of site-directed spin labels placed on specific amino acids of apoE3 showed that LPS interferes with conformational changes normally associated with lipid binding. Specifically, compared to apoE4, apoE bearing the E3-like R112 -> Ser mutation displays increased self association when exposed to LPS, consistent with a stronger apoE3-LPS interaction. Additionally, lipolysis of fasting VLDL from normal human donors attenuated LPS-induced TNF alpha secretion from monocytes to a greater extent than postprandial VLDL, an effect partially reversed by blocking apoE. This effect was reproduced using fasting VLDL lipolysis products from e3/e3 donors, but not from e4/e4 subjects, suggesting that apoE3 on fasting VLDL prevents LPS-induced inflammation more readily than apoE4. Conclusion: Postprandial apoE isoform and conformational changes associated with VLDL dramatically modulate vascular inflammation.},
  articleno    = {e50513},
  author       = {den Hartigh, Laura J. and Altman, Robin and Hutchinson, Romobia and Petrlova, Jitka and Budamagunta, Madhu S. and Tetali, Sarada D. and Lagerstedt, Jens and Voss, John C. and Rutledge, John C.},
  issn         = {1932-6203},
  language     = {eng},
  number       = {11},
  publisher    = {Public Library of Science},
  series       = {PLoS ONE},
  title        = {Postprandial apoE Isoform and Conformational Changes Associated with VLDL Lipolysis Products Modulate Monocyte Inflammation},
  url          = {http://dx.doi.org/10.1371/journal.pone.0050513},
  volume       = {7},
  year         = {2012},
}