Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-2-27
pubmed:abstractText
Apoptosis of inflammatory cells and their subsequent clearance (efferocytosis) by macrophages (Mphis) are key mechanisms orchestrating successful resolution of inflammation. Although the powerful proinflammatory agents lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNF-alpha) influence rates of inflammatory cell apoptosis, little is known about their effects on efferocytosis. We have demonstrated that LPS and TNF-alpha potently inhibit efferocytosis of neutrophils by monocyte-derived Mphis. Inhibition was both concentration and time dependent, although the effect of TNF-alpha was more rapid. We have found that soluble TNF receptor-I attenuated LPS inhibition of phagocytosis, indicating that TNF-alpha production is critical. Inhibition of efferocytosis by LPS was found to be positively associated with Mphi production of TNF-alpha, but negatively with interleukin-10 (IL-10) release. A critical role for IL-10 in the regulation of phagocytosis was suggested by 2 important findings: LPS inhibition was observed more rapidly in the presence of an anti-human IL-10 receptor-alpha antibody, and efferocytosis by IL-10-deficient Mphis was markedly reduced compared to wild-type Mphis. Furthermore, exogenous IL-10 and glucocorticoids reversed inhibitory effects of LPS on efferocytosis via suppression of TNF-alpha production. We suggest that efferocytosis is regulated in an autocrine manner by pro- and anti-inflammatory mediators, and the inflammatory milieu determines whether inflammation successfully resolves.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
844-54
pubmed:meshHeading
pubmed-meshheading:18971259-Animals, pubmed-meshheading:18971259-Anti-Inflammatory Agents, pubmed-meshheading:18971259-Apoptosis, pubmed-meshheading:18971259-Dose-Response Relationship, Drug, pubmed-meshheading:18971259-Erythrocytes, pubmed-meshheading:18971259-Gene Expression Regulation, pubmed-meshheading:18971259-Glucocorticoids, pubmed-meshheading:18971259-Humans, pubmed-meshheading:18971259-Immunoglobulin G, pubmed-meshheading:18971259-Inflammation, pubmed-meshheading:18971259-Interleukin-10, pubmed-meshheading:18971259-Lipopolysaccharides, pubmed-meshheading:18971259-Macrophages, pubmed-meshheading:18971259-Mice, pubmed-meshheading:18971259-Mice, Knockout, pubmed-meshheading:18971259-Neutrophils, pubmed-meshheading:18971259-Phagocytosis, pubmed-meshheading:18971259-Purines, pubmed-meshheading:18971259-Tumor Necrosis Factor-alpha
pubmed:year
2009
pubmed:articleTitle
Macrophage phagocytosis of apoptotic neutrophils is critically regulated by the opposing actions of pro-inflammatory and anti-inflammatory agents: key role for TNF-alpha.
pubmed:affiliation
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh Medical School, 47 Little France Crescent, Edinburgh, Scotland, EH16 4TJ UK. s.michlewska@sms.ed.ac.uk
pubmed:publicationType
Journal Article