Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-1-16
pubmed:abstractText
The potential involvement of cellular calcium in the signalling pathway of tumour necrosis factor-alpha (TNF) was assessed in L929 cells using 45Ca2+ and confocal laser scanning microscopy with fluorescence calcium indicators. Our data indicate that the effect of TNF on intracellular Ca2+ mobilization is a slow process with no discernible increase in the cytosolic free Ca2+ concentration ([Ca2+]c) and intranuclear Ca2+ level ([Ca2+]n) within the 1st min of TNF (25 ng/ml) administration. However, prolonged exposure (2 h) of L929 cells to TNF brought about pronounced increase in cytosolic and intranuclear [Ca2+] even in the absence of external Ca2+. The increase in intracellular [Ca2+] was more apparent when cells were treated with thapsigargin, an inhibitor of microsomal Ca2+-ATPase. Interestingly, most of the Ca2+ released was around and confined to the nucleus. Following the pretreatment of cells with thapsigargin, a synergistic killing effect was obtained when cells were cultured with TNF. The use of 45Ca2+ also revealed that TNF enhanced the 45Ca2+ uptake in a time-dependent manner. Calcium channel blockers, verapamil and diltiazem, could alleviate both the TNF-mediated 45Ca2+-uptake and killing activity. Our results therefore suggest that an increase in cellular Ca2+ is a crucial factor in the TNF cytotoxicity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0030-2414
pubmed:author
pubmed:issnType
Print
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
55-62
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Slow increase in intranuclear and cytosolic free calcium concentrations in L929 cells is important in tumour necrosis factor-alpha-mediated cell death.
pubmed:affiliation
Department of Biochemistry, Chinese University of Hong Kong, Shatin.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't