Correction of bleeding symptoms in von Willebrand factor-deficient mice by liver-expressed von Willebrand factor mutants.
OBJECTIVE
von Willebrand Factor (vWF) structure-function relationship has been studied only in vitro. To investigate the physiological importance of particular vWF domains, we have introduced mutations into murine vWF (mvWF) cDNA inhibiting vWF binding to glycoprotein (Gp) Ib, GpIIbIIIa, and to fibrillar collagen.


RESULTS
We delivered wild-type (WT) or mutant mvWF cDNA into vWF-deficient (Vwf-/-) mice using hydrodynamic injection and assessed whether hemorrhagic symptoms could be corrected. Hydrodynamic gene transfer resulted in high expression of plasma mvWF 24 hours after injection (438+/-63% for 50 microg of cDNA). Factor VIII activity was normalized in Vwf-/- mice injected with mvWF cDNA and multimerization was achieved. Bleeding time was corrected after injection of WT mvWF cDNA in Vwf-/- mice whereas noninjected mice did not stop bleeding. Injection of the GpIIbIIIa and the collagen binding mutants in Vwf-/- mice also resulted in a correction of bleeding time whereas mice injected with the GpIb binding mutant were bleeding for as long they were observed, although blood loss was decreased compared with noninjected mice (61+/-21 microL versus 232+/-63 microL).


CONCLUSIONS
Our model allows the rapid in vivo evaluation of specific mutations on plasma vWF function.
Marx
Isabelle
I
INSERM U770, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cedex, France.
Lenting
Peter J
PJ
Adler
Thure
T
Pendu
Ronan
R
Christophe
Olivier D
OD
Denis
Cécile V
CV
D000818:Animals; D001760:Bleeding Time; D001780:Blood Coagulation Tests; D018076:DNA, Complementary / Q000032:analysis; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D012016:Reference Values; D012680:Sensitivity and Specificity; D014842:von Willebrand Diseases / Q000235:genetics / Q000628:therapy*; D014841:von Willebrand Factor / Q000235:genetics / Q000494:pharmacology*
D018076:DNA, Complementary; D014841:von Willebrand Factor