Linked Life Data

9381981

Source:http://linkedlifedata.com/resource/pubmed/id/9381981

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1997-11-10
pubmed:abstractText
The enzymes and substrates involved in phosphoinositide signal transduction which have been detected in the nucleus of several cell types have been demonstrated to be responsive to agonists. The complexity of this aspect of inositide function has been previously analyzed in some cell models characterized by a mitogenic or differentiating response to specific factors. An interesting experimental model is represented by human derived osteosarcoma Saos-2 cells, characterized by the expression of high affinity receptors for interleukin 1 alpha (IL-1 alpha), which is one of the most potent stimulators of bone resorption. In particular, we investigated the earliest intracellular events following the binding of IL-1 alpha to its receptor, involving the inositide signal transduction pathway. Saos-2 cells present a partitioning of the phosphoinositidase (PLC) isoforms; in fact, the nucleus contains both PLC beta 1 and gamma 1, while the cytoplasm contains almost exclusively the gamma 1 isoform. IL-1 alpha evokes a rapid and transient increase of the PLC beta 1 activity in the nucleus, which causes the hydrolysis of phosphatidylinositol mono- and bis-phosphate. In response to IL-1 alpha, not only the canonical inositol lipid pathway appears to be involved; also the 3'-phosphorylated lipids generated by phosphatidylinositol 3-kinase (PI 3-K), which may act as second messengers, appear to be affected. In fact, Saos-2 cells present a nuclear PI 3-K activity which can be enhanced by the IL-1 alpha treatment. Among the possible targets of the second messengers released by the nuclear PLC beta 1 activation, we found that some protein kinase C isoforms, namely the epsilon and zeta, which are present within the nucleus, are activated after IL-1 alpha exposure. These activated PKC isoforms, in turn, could modulate the activity of the transcription factor NFkB, which, 5 min after IL-1 alpha treatment, has already translocated to the nucleus and bound to DNA to promote gene activation. The actual role of the inositide pathway in the Saos-2 cell function has also been investigated by utilizing cell clones transfected with the mouse sequence of the PLC beta 1.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0065-2571
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
351-75
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Nuclear lipid-dependent signal transduction in human osteosarcoma cells.
pubmed:affiliation
Institute of Cytomorphology, CNR Chieti, Bologna Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't