Transgene-host cell interactions mediate significant influences on the production, stability, and function of recombinant canine FVIII.

Recombinant FVIII manufacturing is characterized by poor product stability and low yields. Codon-optimization of transgenes accelerates translation by exploiting the synonymous codon usage bias of a species. However, this can alter the performance of the final product.

Analysis of the role of von Willebrand factor, platelet glycoprotein VI-, and α2β1-mediated collagen binding in thrombus formation.

Rare missense mutations in the von Willebrand factor (VWF) A3 domain that disrupt collagen binding have been found in patients with a mild bleeding phenotype. However, the analysis of these aberrant VWF-collagen interactions has been limited. Here, we have developed mouse models of collagen-binding mutants and analyzed the function of the A3 domain using comprehensive in vitro and in vivo approaches.

Omental implantation of BOECs in hemophilia dogs results in circulating FVIII antigen and a complex immune response.

Ex vivo gene therapy strategies avoid systemic delivery of viruses thereby mitigating the risk of vector-associated immunogenicity. Previously, we delivered autologous factor VIII (FVIII)-expressing blood outgrowth endothelial cells (BOECs) to hemophilia A mice and showed that these cells remained sequestered within the implanted matrix and provided therapeutic levels of FVIII. Prior to translating this strategy into the canine (c) model of hemophilia A, we increased cFVIII transgene expression by at least 100-fold with the use of the elongation factor 1 alpha (EF1α) promoter and a strong endothelial enhancer element.

Quantitative and qualitative changes of von Willebrand factor and their impact on mortality in patients with end-stage kidney disease.

von Willebrand factor (vWF) antigen levels are elevated in patients with end-stage kidney disease (ESKD). We determined the quantitative and qualitative abnormalities of vWF and factors influencing vWF proteolysis in participants with ESKD compared with age-matched controls and determined the association between abnormalities in vWF and mortality over 4 years of follow-up. vWF : Ag and von Willebrand factor propeptide (vWFpp) levels, vWF functional activity (vWF :RCo), vWF multimer profiles, ADAMTS-13, thrombospondin 1 (TSP-1), and interleukin 6 (IL-6) were evaluated before and after a single hemodialysis treatment in 55 individuals with vascular disease and an age-matched group of controls (n = 21).

Use of a mouse model to elucidate the phenotypic effects of the von Willebrand factor cleavage mutants, Y1605A/M1606A and R1597W.

Background: von Willebrand Factor (VWF) is tightly regulated by the metalloproteinase ADAMTS13, which cleaves VWF to reduce VWF multimer size and binding affinity for collagen and platelets.

Objective: This study examines two VWF mutations, R1597W (enhanced cleavage) and Y1605A-M1606A (decreased cleavage), to determine their impact on VWF, in addition to ADAMTS13-mediated cleavage.

Methods: In vitro mouse ADAMTS13 digestions were performed on recombinant proteins.