Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-3-17
pubmed:abstractText
To determine whether the type 2 iodothyronine deiodinase (D2), the principal central nervous system enzyme converting T(4) to biologically active T(3), is regulated in tanycytes by immune activation, D2 activity was measured in the mediobasal hypothalamus (MBH) 4, 12, and 24 h after administration of bacterial lipopolysaccharide (LPS) and compared with D2 levels in the cortex and anterior pituitary of rats. In contrast to D2 activity in the cortex and anterior pituitary that showed a steady linear increase over 24 h, which was coincident with a decline in thyroid hormone and TSH levels, D2 activity peaked in the MBH 12 h after LPS administration. By in situ hybridization, the increased D2 mRNA synthesis induced by LPS was specifically localized to tanycytes lining the third ventricle. In vitro assays in HC11 and HEK-293 cells demonstrated that the p65 subunit of nuclear factor-kappaB markedly increased both rat and human D2 genes (dio2) as analyzed by promoter assays. No activation of human dio2 was observed when an 83-bp minimal promoter was used. We propose that LPS or LPS-induced cytokines directly induce D2 mRNA in tanycytes. The ensuing MBH-specific D2-mediated local thyrotoxicosis may suppress the hypothalamus-pituitary-thyroid axis by local feedback inhibition of hypophysiotropic TRH and/or TSH and contribute to the mechanism of central hypothyroidism associated with infection.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
145
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1649-55
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:14684601-Animals, pubmed-meshheading:14684601-Body Temperature, pubmed-meshheading:14684601-Cerebral Cortex, pubmed-meshheading:14684601-Enzyme Induction, pubmed-meshheading:14684601-Hormones, pubmed-meshheading:14684601-Humans, pubmed-meshheading:14684601-Hypothalamus, Middle, pubmed-meshheading:14684601-Iodide Peroxidase, pubmed-meshheading:14684601-Lipopolysaccharides, pubmed-meshheading:14684601-Male, pubmed-meshheading:14684601-NF-kappa B, pubmed-meshheading:14684601-Pituitary Gland, Anterior, pubmed-meshheading:14684601-Promoter Regions, Genetic, pubmed-meshheading:14684601-RNA, Messenger, pubmed-meshheading:14684601-Rats, pubmed-meshheading:14684601-Rats, Sprague-Dawley, pubmed-meshheading:14684601-Time Factors, pubmed-meshheading:14684601-Transcription Factor RelA
pubmed:year
2004
pubmed:articleTitle
Lipopolysaccharide induces type 2 iodothyronine deiodinase in the mediobasal hypothalamus: implications for the nonthyroidal illness syndrome.
pubmed:affiliation
Department of Endocrine and Behavioral Neurobiology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't