Linked Life Data

11435291

Source:http://linkedlifedata.com/resource/pubmed/id/11435291

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-7-3
pubmed:abstractText
The Quebec platelet disorder (QPD) is an autosomal dominant platelet disorder associated with delayed bleeding and alpha-granule protein degradation. The degradation of alpha-granule, but not plasma, fibrinogen in patients with the QPD led to the investigation of their platelets for a protease defect. Unlike normal platelets, QPD platelets contained large amounts of fibrinolytic serine proteases that had properties of plasminogen activators. Western blot analysis, zymography, and immunodepletion experiments indicated this was because QPD platelets contained large amounts of urokinase-type plasminogen activator (u-PA) within a secretory compartment. u-PA antigen was not increased in all QPD plasmas, whereas it was increased more than 100-fold in QPD platelets (P <.00009), which contained increased u-PA messenger RNA. Although QPD platelets contained 2-fold more plasminogen activator inhibitor 1 (PAI-1) (P <.0008) and 100-fold greater u-PA-PAI-1 complexes (P <.0002) than normal platelets, they contained excess u-PA activity, predominantly in the form of two chain (tcu-PA), which required additional PAI-1 for full inhibition. There was associated proteolysis of plasminogen in QPD platelets, to forms that comigrated with plasmin. When similar amounts of tcu-PA were incubated with normal platelet secretory proteins, many alpha-granule proteins were proteolyzed to forms that resembled degraded QPD platelet proteins. These data implicate u-PA in the pathogenesis of alpha-granule protein degradation in the QPD. Although patients with the QPD have normal to increased u-PA levels in their plasma, without evidence of systemic fibrinogenolysis, their increased platelet u-PA could contribute to bleeding by accelerating fibrinolysis within the hemostatic plug. QPD is the only inherited bleeding disorder in humans known to be associated with increased u-PA.
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
98
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
257-65
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Platelets from patients with the Quebec platelet disorder contain and secrete abnormal amounts of urokinase-type plasminogen activator.
pubmed:affiliation
Departments of Pathology and Molecular Medicine, and Medicine, McMaster University, Hamilton, Ontario, Quebec, Canada. haywdrc@mcmaster.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't