Vwf K1362A resulted in failure of protein synthesis in mice
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Von Willebrand factor (VWF) is synthesized in megakaryocytes and endothelial cells (ECs) and has two main roles: to carry and protect coagulation factor VIII (FVIII) from degradation by forming VWF–FVIII complex; and to mediate platelet adhesion and aggregation at sites of vascular injury. Previous research using the HEK293 cell line revealed that the VWF K1362 mutation interacted directly with platelet glycoprotein Ib (GPIb). Vwf K1362A knock-in (KI) mice were therefore generated to verify the in vivo function of residue 1362 in binding to platelet GPIb. The Cre-loxP system was employed to introduce the Vwf K1362A mutation systemically in mice. In blood coagulation analysis, the VWF antigen (VWF:Ag) of Lys1362Ala KI homozygous (homo) mice was below the sensitivity of detection by enzyme-linked immunosorbent assay. FVIII activities (FVIII:C) were 47.9 ± 0.3 and 3.3 ± 0.3% (K1362A heterozygous (hetero) and K1362A KI homo mice, respectively) compared to wild-type mice. Immunohistochemical staining analysis revealed that VWF protein did not exist in ECs of K1362A KI homo mice. These results indicated that VWF protein synthesis of K1362A was impaired after transcription in mice. K1362 seems to represent a very important position not only for VWF function, but also for VWF synthesis in mice.
KeywordsVon Willebrand factor Mouse model Genetic mutation
We would like to thank NPO Biotechnology Research and Development for technical assistance. We wish to thank the staff of the Division of Experimental Animals at Nagoya University Graduate School of Medicine for their technical support. We are also grateful to Kimiko Sannodo for obtaining blood from mice and PCR typing.
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Conflict of interest
This research was supported by JSPS KAKENHI Grant Number JP 22591059 and Novartis Research Grants.
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