Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation

Janet L Funk, Kenneth R. Feingold, Arthur H. Moser, Carl Grunfeld

Research output: Contribution to journalArticle

112 Citations (Scopus)

Abstract

A role for immune and inflammatory processes in the induction of atherosclerotic lesions is emerging. These studies were undertaken to determine whether activation by lipopolysaccharide (LPS) enhances the ability of macrophages to become foam cells. Since LPS activation inhibits scavenger receptor activity, we studied the ability of LPS-activated RAW 264.7 macrophages to accumulate lipid from a variety of lipid particles that are not ligands for the scavenger receptor. Macrophages activated by LPS, in the absence of lipid particles, accumulated triglyceride, but not cholesterol ester (CE). The addition of Soyacal, a triglyceride-rich particle, further enhanced this LPS-stimulated triglyceride accumulation. LPS activation similarly enhanced CE accumulation almost 3-fold from two CE-rich lipoproteins, βVLDL and LDL, as compared with controls. The unstimulated control cells only accumulated significant CE from βVLDL and not LDL. LPS-enhanced lipid accumulation was dependent on LPS dose and began after 8-12 h of incubation. LPS increased the degradation of 125I-labelled LDL and the cell-associated 125I-labelled LDL at 37°C by 1.8-fold. Degradation remained saturable, consistent with a receptor-mediated process. Antioxidants did not inhibit LPS-induced CE accumulation from LDL. Thus, activation of RAW 264.7 macrophages enhanced their ability to accumulate lipid from a variety of lipid particles and to become foam cells. These data suggest a potential role for infections, and LPS in particular, in atherogenesis.

Original languageEnglish (US)
Pages (from-to)67-82
Number of pages16
JournalAtherosclerosis
Volume98
Issue number1
DOIs
StatePublished - Jan 4 1993
Externally publishedYes

Fingerprint

Foam Cells
Lipopolysaccharides
Macrophages
Lipids
Cholesterol Esters
Scavenger Receptors
Triglycerides
VLDL Lipoproteins
LDL Lipoproteins
Atherosclerosis
Antioxidants

Keywords

  • Atherosclerosis
  • Beta-very low density lipoprotein (βVLDL)
  • Foam cells
  • Lipopolysaccharide
  • Low density lipoprotein (LDL)
  • Macrophages

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation. / Funk, Janet L; Feingold, Kenneth R.; Moser, Arthur H.; Grunfeld, Carl.

In: Atherosclerosis, Vol. 98, No. 1, 04.01.1993, p. 67-82.

Research output: Contribution to journalArticle

Funk, Janet L ; Feingold, Kenneth R. ; Moser, Arthur H. ; Grunfeld, Carl. / Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation. In: Atherosclerosis. 1993 ; Vol. 98, No. 1. pp. 67-82.
@article{2e2d10d8d60d4d669def860838dc16fc,
title = "Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation",
abstract = "A role for immune and inflammatory processes in the induction of atherosclerotic lesions is emerging. These studies were undertaken to determine whether activation by lipopolysaccharide (LPS) enhances the ability of macrophages to become foam cells. Since LPS activation inhibits scavenger receptor activity, we studied the ability of LPS-activated RAW 264.7 macrophages to accumulate lipid from a variety of lipid particles that are not ligands for the scavenger receptor. Macrophages activated by LPS, in the absence of lipid particles, accumulated triglyceride, but not cholesterol ester (CE). The addition of Soyacal, a triglyceride-rich particle, further enhanced this LPS-stimulated triglyceride accumulation. LPS activation similarly enhanced CE accumulation almost 3-fold from two CE-rich lipoproteins, βVLDL and LDL, as compared with controls. The unstimulated control cells only accumulated significant CE from βVLDL and not LDL. LPS-enhanced lipid accumulation was dependent on LPS dose and began after 8-12 h of incubation. LPS increased the degradation of 125I-labelled LDL and the cell-associated 125I-labelled LDL at 37°C by 1.8-fold. Degradation remained saturable, consistent with a receptor-mediated process. Antioxidants did not inhibit LPS-induced CE accumulation from LDL. Thus, activation of RAW 264.7 macrophages enhanced their ability to accumulate lipid from a variety of lipid particles and to become foam cells. These data suggest a potential role for infections, and LPS in particular, in atherogenesis.",
keywords = "Atherosclerosis, Beta-very low density lipoprotein (βVLDL), Foam cells, Lipopolysaccharide, Low density lipoprotein (LDL), Macrophages",
author = "Funk, {Janet L} and Feingold, {Kenneth R.} and Moser, {Arthur H.} and Carl Grunfeld",
year = "1993",
month = "1",
day = "4",
doi = "10.1016/0021-9150(93)90224-I",
language = "English (US)",
volume = "98",
pages = "67--82",
journal = "Atherosclerosis",
issn = "0021-9150",
publisher = "Elsevier Ireland Ltd",
number = "1",

}

TY - JOUR

T1 - Lipopolysaccharide stimulation of RAW 264.7 macrophages induces lipid accumulation and foam cell formation

AU - Funk, Janet L

AU - Feingold, Kenneth R.

AU - Moser, Arthur H.

AU - Grunfeld, Carl

PY - 1993/1/4

Y1 - 1993/1/4

N2 - A role for immune and inflammatory processes in the induction of atherosclerotic lesions is emerging. These studies were undertaken to determine whether activation by lipopolysaccharide (LPS) enhances the ability of macrophages to become foam cells. Since LPS activation inhibits scavenger receptor activity, we studied the ability of LPS-activated RAW 264.7 macrophages to accumulate lipid from a variety of lipid particles that are not ligands for the scavenger receptor. Macrophages activated by LPS, in the absence of lipid particles, accumulated triglyceride, but not cholesterol ester (CE). The addition of Soyacal, a triglyceride-rich particle, further enhanced this LPS-stimulated triglyceride accumulation. LPS activation similarly enhanced CE accumulation almost 3-fold from two CE-rich lipoproteins, βVLDL and LDL, as compared with controls. The unstimulated control cells only accumulated significant CE from βVLDL and not LDL. LPS-enhanced lipid accumulation was dependent on LPS dose and began after 8-12 h of incubation. LPS increased the degradation of 125I-labelled LDL and the cell-associated 125I-labelled LDL at 37°C by 1.8-fold. Degradation remained saturable, consistent with a receptor-mediated process. Antioxidants did not inhibit LPS-induced CE accumulation from LDL. Thus, activation of RAW 264.7 macrophages enhanced their ability to accumulate lipid from a variety of lipid particles and to become foam cells. These data suggest a potential role for infections, and LPS in particular, in atherogenesis.

AB - A role for immune and inflammatory processes in the induction of atherosclerotic lesions is emerging. These studies were undertaken to determine whether activation by lipopolysaccharide (LPS) enhances the ability of macrophages to become foam cells. Since LPS activation inhibits scavenger receptor activity, we studied the ability of LPS-activated RAW 264.7 macrophages to accumulate lipid from a variety of lipid particles that are not ligands for the scavenger receptor. Macrophages activated by LPS, in the absence of lipid particles, accumulated triglyceride, but not cholesterol ester (CE). The addition of Soyacal, a triglyceride-rich particle, further enhanced this LPS-stimulated triglyceride accumulation. LPS activation similarly enhanced CE accumulation almost 3-fold from two CE-rich lipoproteins, βVLDL and LDL, as compared with controls. The unstimulated control cells only accumulated significant CE from βVLDL and not LDL. LPS-enhanced lipid accumulation was dependent on LPS dose and began after 8-12 h of incubation. LPS increased the degradation of 125I-labelled LDL and the cell-associated 125I-labelled LDL at 37°C by 1.8-fold. Degradation remained saturable, consistent with a receptor-mediated process. Antioxidants did not inhibit LPS-induced CE accumulation from LDL. Thus, activation of RAW 264.7 macrophages enhanced their ability to accumulate lipid from a variety of lipid particles and to become foam cells. These data suggest a potential role for infections, and LPS in particular, in atherogenesis.

KW - Atherosclerosis

KW - Beta-very low density lipoprotein (βVLDL)

KW - Foam cells

KW - Lipopolysaccharide

KW - Low density lipoprotein (LDL)

KW - Macrophages

UR - http://www.scopus.com/inward/record.url?scp=0027500143&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027500143&partnerID=8YFLogxK

U2 - 10.1016/0021-9150(93)90224-I

DO - 10.1016/0021-9150(93)90224-I

M3 - Article

VL - 98

SP - 67

EP - 82

JO - Atherosclerosis

JF - Atherosclerosis

SN - 0021-9150

IS - 1

ER -