Production of recombinant Von Willebrand factor by CHO cells cultured in macroporous microcarriers

Recombinant Chinese hamster ovary cells producing Von Willebrand factor have been successfully grown in gelatin macroporous microcarriers (Cultispher-G). Serum-free cultures were maintained in 1, 4, and 10 liter fermentors for more than two months. Comparative studies with Cytodex-3 microcarriers have been performed in 1 liter fermentors. The lower specific Von Willebrand factor productivity of CHO cells cultivated on Cultispher-G were offset by higher cell densities (10⁷–2×10⁷ cells/ml). Volumetric Von Willebrand factor productivity was influenced by oxygen concentration, and remained stable during scale-up from 1 to 10 liter fermentors.     

Rehabilitation management in two siblings with Von Hippel-Lindau syndrome: A case series

Von Hippel Lindau (VHL) is a hereditary multiple neoplasia syndrome. We report a case series of two siblings with Von Hippel Lindau (VHL) disease admitted to the rehabilitation department after surgical excision of Central Nervous System (CNS) haemangioblastomas. These clinical cases present rehabilitation challenges in VHL disease. We present a 39-year-old brother and his 45-year-old sister, with the diagnosis of incomplete spinal cord injury (SCI) associated with VHL syndrome lesions. The female patient was diagnosed with chronic motor incomplete cervical SCI and the male patient with acute motor incomplete thoracic SCI. Our target was to increase their functionality and improve their quality of life. Both underwent a comprehensive inpatient rehabilitation program. Programs were individualized as the female patient was admitted 15 years after her spinal cord surgical intervention, while the male patient’s admission was after 4 months of his surgery.     

Interaction of Shiga Toxin with the A-domains and Multimers of von Willebrand Factor

Shiga toxin (Stx) produced by enterohemorrhagic Escherichia coli causes diarrhea-associated hemolytic-uremic syndrome (DHUS), a severe renal thrombotic microangiopathy. We investigated the interaction between Stx and von Willebrand Factor (VWF), a multimeric plasma glycoprotein that mediates platelet adhesion, activation, and aggregation. Stx bound to ultra-large VWF (ULVWF) secreted from and anchored to stimulated human umbilical vein endothelial cells, as well as to immobilized VWF-rich human umbilical vein endothelial cell supernatant. This Stx binding was localized to the A1 and A2 domain of VWF monomeric subunits and reduced the rate of ADAMTS-13-mediated cleavage of the Tyr¹⁶⁰⁵-Met¹⁶⁰⁶ peptide bond in the A2 domain. Stx-VWF interaction and the associated delay in ADAMTS-13-mediated cleavage of VWF may contribute to the pathophysiology of DHUS.     

Transgenic expression of the von Willebrand A domain of the BONZAI 1/COPINE 1 protein triggers a lesion-mimic phenotype in<Emphasis Type="Italic"> Arabidopsis</Emphasis>

The copines are a newly identified, widely distributed class of Ca²⁺-dependent, phospholipid-binding proteins that may be involved in cellular signaling. The copines have a characteristic domain structure: two C2 domains in the N-terminal region and a von Willebrand A (VWA) domain in the C-terminal region. Studies suggest that copines interact with target protein(s) via their VWA domain and recruit the proteins to a membrane location through the activity of the C2 domains. Arabidopsis thaliana (L.) Heynh. plants with loss-of-function mutations in the BONZAI 1/COPINE 1 (BON1/CPN1) gene display aberrant regulation of defense responses, including development of a lesion-mimic phenotype, an accelerated hypersensitive response, and increased resistance to a bacterial and an oomycetous pathogen. The phenotype of mutants in BON1/CPN1 is both humidity- and temperature-sensitive. In this study, we generated transgenic plants expressing either the VWA or the C2 portions of BON1/CPN1 in the wild-type Columbia-0 (Col-0) genetic background. Transgenic plants expressing the BON1/CPN1 C2 domain portion appeared like wild-type plants. However, transgenic plants expressing the BON1/CPN1 VWA domain exhibited a lesion-mimic phenotype that partially phenocopied bon1/cpn1 mutant plants. Our data suggest that BON1/CPN1 VWA domain fragments may interfere with the function of the full-length endogenous BON1/CPN1 protein, possibly by competing with the full-length BON1/CPN1 protein for association with target proteins normally bound to the full-length BON1/CPN1 protein.