| 1. |
- Cartwright, Ashley, et al.
(författare)
-
Characterization of large in-frame von Willebrand factor deletions highlights differing pathogenic mechanisms
- 2020
-
Ingår i: Blood Advances. - 2473-9529 .- 2473-9537. ; 4:13, s. 2979-2990
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Tidskriftsartikel (refereegranskat)abstract
- Copy number variation (CNV) is known to cause all von Willebrand disease (VWD) types, although the associated pathogenic mechanisms involved have not been extensively studied. Notably, in-frame CNV provides a unique opportunity to investigate how specific von Willebrand factor (VWF) domains influence the processing and packaging of the protein. Using multiplex ligation-dependent probe amplification, this study determined the extent to which CNV contributed to VWD in the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease cohort, highlighting in-frame deletions of exons 3, 4-5, 32-34, and 33-34. Heterozygous in vitro recombinant VWF expression demonstrated that, although deletion of exons 3, 32-34, and 33-34 all resulted in significant reductions in total VWF (P < .0001, P < .001, and P < .01, respectively), only deletion of exons 3 and 32-34 had a significant impact on VWF secretion (P < .0001). High-resolution microscopy of heterozygous and homozygous deletions confirmed these observations, indicating that deletion of exons 3 and 32-34 severely impaired pseudo-Weibel-Palade body (WPB) formation, whereas deletion of exons 33-34 did not, with this variant still exhibiting pseudo-WPB formation similar to wild-type VWF. In-frame deletions in VWD, therefore, contribute to pathogenesis via moderate or severe defects in VWF biosynthesis and secretion.
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| 2. |
- Cartwright, Ashley, et al.
(författare)
-
Characterization of large in-frame von Willebrand factor deletions highlights differing pathogenic mechanisms
- 2020
-
Ingår i: Blood Advances. - : Elsevier BV. - 2473-9529 .- 2473-9537. ; 4:13, s. 2979-2990
-
Tidskriftsartikel (refereegranskat)abstract
- Copy number variation (CNV) is known to cause all von Willebrand disease (VWD) types, although the associated pathogenic mechanisms involved have not been extensively studied. Notably, in-frame CNV provides a unique opportunity to investigate how specific von Willebrand factor (VWF) domains influence the processing and packaging of the protein. Using multiplex ligation-dependent probe amplification, this study determined the extent to which CNV contributed to VWD in the Molecular and Clinical Markers for the Diagnosis and Management of Type 1 von Willebrand Disease cohort, highlighting in-frame deletions of exons 3, 4-5, 32-34, and 33-34. Heterozygous in vitro recombinant VWF expression demonstrated that, although deletion of exons 3, 32-34, and 33-34 all resulted in significant reductions in total VWF (P < .0001, P < .001, and P < .01, respectively), only deletion of exons 3 and 32-34 had a significant impact on VWF secretion (P < .0001). High-resolution microscopy of heterozygous and homozygous deletions confirmed these observations, indicating that deletion of exons 3 and 32-34 severely impaired pseudo-Weibel-Palade body (WPB) formation, whereas deletion of exons 33-34 did not, with this variant still exhibiting pseudo-WPB formation similar to wild-type VWF. In-frame deletions in VWD, therefore, contribute to pathogenesis via moderate or severe defects in VWF biosynthesis and secretion.
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| 3. |
- Mufti, Ahmad H, et al.
(författare)
-
The common VWF single nucleotide variants c.2365A>G and c.2385T>C modify VWF biosynthesis and clearance
- 2018
-
Ingår i: Blood Advances. - 2473-9529 .- 2473-9537. ; 2:13, s. 1585-1594
-
Tidskriftsartikel (refereegranskat)abstract
- Plasma levels of von Willebrand factor (VWF) vary considerably in the general population and this variation has been linked to several genetic and environmental factors. Genetic factors include 2 common single nucleotide variants (SNVs) located in VWF, rs1063856 (c.2365A>G) and rs1063857 (c.2385T>C), although to date the mechanistic basis for their association with VWF level is unknown. Using genotypic/phenotypic information from a European healthy control population, in vitro analyses of recombinant VWF expressing both SNVs, and in vivo murine models, this study determined the precise nature of their association with VWF level and investigated the mechanism(s) involved. Possession of either SNV corresponded with a significant increase in plasma VWF in healthy controls (P < .0001). In vitro expression confirmed this observation and highlighted an independent effect for each SNV (P < .0001 and P < .01, respectively), despite close proximity and strong linkage disequilibrium between them both. The influence of c.2365A>G on VWF levels was also confirmed in vivo. This increase in VWF protein corresponded to an increase in VWF messenger RNA (mRNA) resulting, in part, from prolonged mRNA half-life. In addition, coinheritance of both SNVs was associated with a lower VWF propeptide-to-VWF antigen ratio in healthy controls (P < .05) and a longer VWF half-life in VWF knockout mice (P < .0001). Both SNVs therefore directly increase VWF plasma levels through a combined influence on VWF biosynthesis and clearance, and may have an impact on disease phenotype in both hemostatic and thrombotic disorders.
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| 4. |
- Mufti, Ahmad H, et al.
(författare)
-
The common VWF single nucleotide variants c.2365A>G and c.2385T>C modify VWF biosynthesis and clearance
- 2018
-
Ingår i: Blood Advances. - : Elsevier BV. - 2473-9529 .- 2473-9537. ; 2:13, s. 1585-1594
-
Tidskriftsartikel (refereegranskat)abstract
- Plasma levels of von Willebrand factor (VWF) vary considerably in the general population and this variation has been linked to several genetic and environmental factors. Genetic factors include 2 common single nucleotide variants (SNVs) located in VWF, rs1063856 (c.2365A>G) and rs1063857 (c.2385T>C), although to date the mechanistic basis for their association with VWF level is unknown. Using genotypic/phenotypic information from a European healthy control population, in vitro analyses of recombinant VWF expressing both SNVs, and in vivo murine models, this study determined the precise nature of their association with VWF level and investigated the mechanism(s) involved. Possession of either SNV corresponded with a significant increase in plasma VWF in healthy controls (P < .0001). In vitro expression confirmed this observation and highlighted an independent effect for each SNV (P < .0001 and P < .01, respectively), despite close proximity and strong linkage disequilibrium between them both. The influence of c.2365A>G on VWF levels was also confirmed in vivo. This increase in VWF protein corresponded to an increase in VWF messenger RNA (mRNA) resulting, in part, from prolonged mRNA half-life. In addition, coinheritance of both SNVs was associated with a lower VWF propeptide-to-VWF antigen ratio in healthy controls (P < .05) and a longer VWF half-life in VWF knockout mice (P < .0001). Both SNVs therefore directly increase VWF plasma levels through a combined influence on VWF biosynthesis and clearance, and may have an impact on disease phenotype in both hemostatic and thrombotic disorders.
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