Linked Life Data

9657746

Source:http://linkedlifedata.com/resource/pubmed/id/9657746

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-8-6
pubmed:abstractText
The addition of thrombopoietin (TPO) to HEL cells, cultured in a chemically defined serum-free medium, induced a rapid and dose-dependent phosphorylation of the transcription factor CREB on serine133 (PSer133), as detected by Western blot analysis. TPO also significantly increased the transactivation of CRE-dependent promoter, as determined in transient transfection experiments. On the other hand, neither erythropoietin (Epo; 1 to 10 U) nor hemin (10 (-7) mol/L) were able to significantly stimulate CREB-PSer133 or to activate CRE-promoter in HEL cells. Although pharmacological inhibitors of protein kinase C (chelerytrine and BIM) and protein kinase A (H-89) failed to block the TPO-mediated CREB phosphorylation, a specific inhibitor of the mitogen-activated protein kinases (PD98059) completely blocked the ability of TPO to stimulate CREB-PSer133. Moreover, PD98059 significantly decreased the ability of TPO to upregulate the surface expression of the alphaIIIbbeta3 megakaryocytic marker in HEL cells. In parallel, primary CD34+ hematopoietic cells were seeded in liquid cultures supplemented with 100 ng/mL of TPO and examined by immunofluorescence for the coexpression of alphaIIIbbeta3 and CREB-PSer133 at various time points. High levels of nuclear CREB-PSer133 were unequivocally demonstrated in alphaIIIbbeta3+ cells, including morphologically recognizable megakaryocytes. Taken together, these data suggest that CREB plays a role in modulating the expression of genes critical for megakaryocyte differentiation and that the TPO-mediated CREB phosphorylation seems to be regulated via mitogen-activated protein kinases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-4971
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
92
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
472-80
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
The induction of megakaryocyte differentiation is accompanied by selective Ser133 phosphorylation of the transcription factor CREB in both HEL cell line and primary CD34+ cells.
pubmed:affiliation
Institute of Human Anatomy, University of Ferrara, Ferrara, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't