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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2010-8-5
pubmed:abstractText
NKT cells are remarkably abundant in mouse liver. Compelling experimental evidence has suggested that NKT cells are involved in the pathogenesis of many liver diseases. Activation of NKT cells with alpha-galactosylceramide (alpha-GalCer) causes liver injury through mechanisms that are not well understood. We undertook studies to characterize the key pathways involved in alpha-GalCer-induced liver injury. We found that expression of the transcription factor IFN regulatory factor 1 (IRF-1) in mouse liver was dramatically upregulated by alpha-GalCer treatment. Neutralization of either TNF-alpha or IFN-gamma inhibited alpha-GalCer-mediated IRF-1 upregulation. alpha-GalCer-induced liver injury was significantly suppressed in IRF-1 knockout mice or in wild-type C56BL/6 mice that received a microRNA specifically targeting IRF-1. In contrast, overexpression of IRF-1 greatly potentiated alpha-GalCer-induced liver injury. alpha-GalCer injection also induced a marked increase in hepatic inducible NO synthase expression in C56BL/6 mice, but not in IRF-1 knockout mice. Inducible NO synthase knockout mice exhibited significantly reduced liver injury following alpha-GalCer treatment. Finally, we demonstrated that both NKT cells and hepatocytes expressed IRF-1 in response to alpha-GalCer. However, it appeared that the hepatocyte-derived IRF-1 was mainly responsible for alpha-GalCer-induced liver injury, based on the observation that inhibition of IRF-1 by RNA interference did not affect alpha-GalCer-induced NKT cell activation. Our findings revealed a novel mechanism of NKT cell-mediated liver injury in mice, which has implications in the development of human liver diseases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1550-6606
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
185
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2536-43
pubmed:meshHeading
pubmed-meshheading:20624945-Animals, pubmed-meshheading:20624945-Blotting, Western, pubmed-meshheading:20624945-Flow Cytometry, pubmed-meshheading:20624945-Galactosylceramides, pubmed-meshheading:20624945-Gene Expression, pubmed-meshheading:20624945-Gene Knockout Techniques, pubmed-meshheading:20624945-Hepatocytes, pubmed-meshheading:20624945-Interferon Regulatory Factor-1, pubmed-meshheading:20624945-Interferon-gamma, pubmed-meshheading:20624945-Liver, pubmed-meshheading:20624945-Liver Diseases, pubmed-meshheading:20624945-Lymphocyte Activation, pubmed-meshheading:20624945-Male, pubmed-meshheading:20624945-Mice, pubmed-meshheading:20624945-Mice, Inbred C57BL, pubmed-meshheading:20624945-Mice, Knockout, pubmed-meshheading:20624945-Natural Killer T-Cells, pubmed-meshheading:20624945-Nitric Oxide Synthase Type II, pubmed-meshheading:20624945-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:20624945-Tumor Necrosis Factor-alpha
pubmed:year
2010
pubmed:articleTitle
A critical role for IFN regulatory factor 1 in NKT cell-mediated liver injury induced by alpha-galactosylceramide.
pubmed:affiliation
Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural