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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-4-25
pubmed:abstractText
Inflammatory conditions and oxidative stress contribute to the development of atherosclerosis. Nuclear factor E2-related factor 2 (Nrf2) is a redox-sensitive transcription factor known for its antioxidant, anti-inflammatory, and, thus, cell-protective properties. Its role in effecting a deactivated state of oxidized low-density lipoprotein (oxLDL)-generated foam cell macrophages (FCMs), a prevailing cellular phenotype of atherosclerotic lesions, has not been investigated yet. In this study RAW264.7- or mouse peritoneal macrophage-derived FCMs showed reduced mRNA expression of proinflammatory cytokines such as IL-1? and IL-6 and an attenuated production of reactive oxygen species (ROS), as analyzed by hydroethidine in response to lipopolysaccharide (LPS) and compared to LPS-treated control macrophages. In peritoneal FCMs from Nrf2-/- mice (C57BL/6J), the LPS-induced proinflammatory response was restored. OxLDL induced heme oxygenase (HO)-1, which was Nrf2-dependent, and inhibition of HO-1 activity in FCMs using zinc protoporphyrin-IX allowed the cells to regain a proinflammatory phenotype. Mechanistically, oxLDL attenuated ROS-dependent activation of CCAAT/enhancer binding protein (C/EBP) family members in FCMs, thereby reducing cytokine expression. Thus, in FCMs the Nrf2/HO-1 axis intervenes in LPS signaling. ROS production is impaired, C/EBP transactivation is reduced, and consequently the expression of proinflammatory mediators is attenuated, thereby shaping a desensitized FCM phenotype. This macrophage phenotype may be important for the progression of atherosclerosis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
1873-4596
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
50
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1382-91
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Antioxidant signaling via Nrf2 counteracts lipopolysaccharide-mediated inflammatory responses in foam cell macrophages.
pubmed:affiliation
Institute of Biochemistry I/ZAFES, Faculty of Medicine, Goethe-University, 60590 Frankfurt, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't