HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Factor VIII ectopically expressed in platelets: efficacy in hemophilia A treatment.

Abstract
Activated platelets release their granule content in a concentrated fashion at sites of injury. We examined whether ectopically expressed factor VIII in developing megakaryocytes would be stored in alpha-granules and whether its release from circulating platelets would effectively ameliorate bleeding in a factor VIIInull mice model. Using the proximal glycoprotein 1b alpha promoter to drive expression of a human factor VIII cDNA construct, transgenic lines were established. One line had detectable human factor VIII that colocalizes with von Willebrand factor in platelets. These animals had platelet factor VIII levels equivalent to 3% to 9% plasma levels, although there was no concurrent plasma human factor VIII detectable. When crossed onto a factor VIIInull background, whole blood clotting time was partially corrected, equivalent to a 3% correction level. In a cuticular bleeding time study, these animals also had only a partial correction, but in an FeCl3 carotid artery, thrombosis assay correction was equivalent to a 50% to 100% level. These studies show that factor VIII can be expressed and stored in platelet alpha-granules. Our studies also suggest that platelet-released factor VIII is at least as potent as an equivalent plasma level and perhaps even more potent in an arterial thrombosis model.
AuthorsHelen V Yarovoi, Dubravka Kufrin, Don E Eslin, Michael A Thornton, Sandra L Haberichter, Qizhen Shi, Hua Zhu, Rodney Camire, Steve S Fakharzadeh, M Anna Kowalska, David A Wilcox, Bruce S Sachais, Robert R Montgomery, Mortimer Poncz
JournalBlood (Blood) Vol. 102 Issue 12 Pg. 4006-13 (Dec 01 2003) ISSN: 0006-4971 [Print] United States
PMID12881300 (Publication Type: Journal Article)
Chemical References
  • Factor VIII
Topics
  • Animals
  • Blood Coagulation Tests
  • Blood Platelets (metabolism, ultrastructure)
  • Carotid Arteries
  • Cytoplasmic Granules (chemistry)
  • Disease Models, Animal
  • Factor VIII (administration & dosage, biosynthesis, genetics)
  • Genetic Therapy (methods)
  • Hemophilia A (therapy)
  • Hemorrhage (prevention & control, therapy)
  • Humans
  • Mice
  • Mice, Transgenic
  • Microscopy, Confocal
  • Sequence Deletion
  • Thrombosis (prevention & control, therapy)

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: