Document Detail


Tnfaip8 is an essential gene for the regulation of glucocorticoid-mediated apoptosis of thymocytes.
MedLine Citation:
PMID:  19730441     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Glucocorticoids have significant immunoregulatory actions on thymocytes and T cells and act by binding and activating cytosolic glucocorticoid receptors, which translocate to the nucleus and control gene expression through binding to specific response elements in target genes. Glucocorticoids promote cell death by activating an apoptotic program that requires transcriptional regulation. We set out to identify genes that are crucial to the process of glucocorticoid-mediated thymocyte apoptosis. Freshly isolated murine primary thymocytes were treated with dexamethasone, mRNA isolated and used to screen DNA microarrays. A set of candidate genes with upregulated expression was identified and selected members assayed in reconstituted fetal thymic organ culture (FTOC). Fetal liver-derived hematopoietic progenitor cells (HPCs) were infected with retroviruses expressing individual genes then used to repopulate depleted fetal thymic lobes. Reconstituted FTOCs expressing the gene Tnfaip8 were treated with dexamethasone and shown to be greatly sensitized to dexamethasone. Retrovirus-mediated RNA interference was applied to knock down Tnfaip8 expression in HPCs and these were used to reconstitute FTOCs. We observed that downregulating the expression of Tnfaip8 alone was sufficient to effectively protect thymocytes against glucocorticoid-induced apoptosis. We propose that Tnfaip8 is crucial in regulating glucocorticoid-mediated apoptosis of thymocytes.
Authors:
M J Woodward; J de Boer; S Heidorn; M Hubank; D Kioussis; O Williams; H J M Brady
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-09-04
Journal Detail:
Title:  Cell death and differentiation     Volume:  17     ISSN:  1476-5403     ISO Abbreviation:  Cell Death Differ.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-01-11     Completed Date:  2010-07-13     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9437445     Medline TA:  Cell Death Differ     Country:  England    
Other Details:
Languages:  eng     Pagination:  316-23     Citation Subset:  IM    
Affiliation:
Molecular Haematology and Cancer Biology Unit, University College London Institute of Child Health, London, UK.
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MeSH Terms
Descriptor/Qualifier:
Animals
Apoptosis / drug effects,  physiology*
Apoptosis Regulatory Proteins / genetics*,  metabolism*
Dexamethasone / metabolism*,  pharmacology
Glucocorticoids / metabolism*,  pharmacology
Mice
Organ Culture Techniques
RNA Interference
Retroviridae / genetics
Stromal Cells / cytology,  drug effects,  physiology
T-Lymphocytes / cytology,  drug effects,  physiology
Thymus Gland / cytology*,  physiology*
Transcriptional Activation / drug effects,  immunology
Tumor Necrosis Factor-alpha / metabolism
Grant Support
ID/Acronym/Agency:
//Medical Research Council
Chemical
Reg. No./Substance:
0/Apoptosis Regulatory Proteins; 0/Glucocorticoids; 0/TNFAIP8 protein, mouse; 0/Tumor Necrosis Factor-alpha; 50-02-2/Dexamethasone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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