Time filter

Source Type

Östermalm, Sweden

Henshall T.L.,Karolinska Institutet | Keller A.,Uppsala University | He L.,Uppsala University | Johansson B.R.,Gothenburg University | And 8 more authors.
Arteriosclerosis, Thrombosis, and Vascular Biology | Year: 2015

OBJECTIVE - : Vascular smooth muscle cells (VSMC) are important for contraction, blood flow distribution, and regulation of blood vessel diameter, but to what extent they contribute to the integrity of blood vessels and blood-brain barrier function is less well understood. In this report, we explored the impact of the loss of VSMC in the Notch3 mouse on blood vessel integrity in the central nervous system. APPROACH AND RESULTS - : Notch3 mice showed focal disruptions of the blood-brain barrier demonstrated by extravasation of tracers accompanied by fibrin deposition in the retinal vasculature. This blood-brain barrier leakage was accompanied by a regionalized and patchy loss of VSMC, with VSMC gaps predominantly in arterial resistance vessels of larger caliber. The loss of VSMC appeared to be caused by progressive degeneration of VSMC resulting in a gradual loss of VSMC marker expression and a progressive acquisition of an aberrant VSMC phenotype closer to the gaps, followed by enhanced apoptosis and cellular disintegration in the gaps. Arterial VSMC were the only mural cell type that was morphologically affected, despite Notch3 also being expressed in pericytes. Transcriptome analysis of isolated brain microvessels revealed gene expression changes in Notch3 mice consistent with loss of arterial VSMC and presumably secondary transcriptional changes were observed in endothelial genes, which may explain the compromised vascular integrity. CONCLUSIONS - : We demonstrate that Notch3 is important for survival of VSMC, and reveal a critical role for Notch3 and VSMC in blood vessel integrity and blood-brain barrier function in the mammalian vasculature. © 2014 American Heart Association, Inc. Source

Ramstrom M.,Octapharma AB | Sandberg H.,Octapharma AB
European Journal of Mass Spectrometry | Year: 2011

Vitamin K-dependent carboxylation of glutamic acid (Glu) residues into γ-carboxyglutamic acid (Gla) is a post-translational modification essential for normal protein activity of, for example, proteins involved in the blood coagulation system. These proteins may contain as many as 12 sites for γ-carboxylation within a protein sequence of 45 amino acid residues. In the biopharmaceutical industry, powerful analytical techniques are required for identification and localization of modified sites. We present comparatively easy and rapid methods for studies of Gla-containing proteins using recent technology. The performances of two mass spectrometric fragmentation techniques, collision-induced dissociation (CID) and electron transfer dissociation (ETD), were evaluated with respect to γ-carboxylated peptides, applying on-line liquid chromatography-ion trap MS. ETD-MS has so far not been reported for Gla-containing peptides and the applicability of CID for heavily γ-carboxylated proteins has not been evaluated. The anticoagulant protein, protein C, containing nine Gla-sites, was chosen as a model protein. After tryptic digestion, three peptides containing Gla residues were detected by MS: a 1.2 kDa fragment containing two Gla residues, a 4.5 kDa peptide containing seven residues and also the 5.6 kDa tryptic peptide containing all nine Gla residues. Regarding the shortest peptide, both CID and ETD provided extensive peptide sequencing. For the larger peptides, fragmentation by CID resulted in loss of the 44 Da CO2 group, while little additional fragmentation of the peptide chain was observed. In contrast, ETD resulted in comprehensive fragmentation of the peptide backbone. The study demonstrates that the combination of both techniques would be beneficial and complementary for investigation of γ-carboxylated proteins and peptides. © IM Publications LLP 2011. All rights reserved. Source

Winge S.,Octapharma AB | Yderland L.,Octapharma AB | Kannicht C.,Octapharma Molecular Biochemistry | Hermans P.,Thermo Fisher Scientific | And 7 more authors.
Protein Expression and Purification | Year: 2015

Introduction Human-cl rhFVIII (Nuwiq®), a new generation recombinant factor VIII (rFVIII), is the first rFVIII produced in a human cell-line approved by the European Medicines Agency. Aims To describe the development, upscaling and process validation for industrial-scale human-cl rhFVIII purification. Methods and results The purification process involves one centrifugation, two filtration, five chromatography columns and two dedicated pathogen clearance steps (solvent/detergent treatment and 20 nm nanofiltration). The key purification step uses an affinity resin (VIIISelect) with high specificity for FVIII, removing essentially all host-cell proteins with >80% product recovery. The production-scale multi-step purification process efficiently removes process- and product-related impurities and results in a high-purity rhFVIII product, with an overall yield of ∼50%. Specific activity of the final product was >9000 IU/mg, and the ratio between active FVIII and total FVIII protein present was >0.9. The entire production process is free of animal-derived products. Leaching of potential harmful compounds from chromatography resins and all pathogens tested were below the limit of quantification in the final product. Conclusions Human-cl rhFVIII can be produced at 500 L bioreactor scale, maintaining high purity and recoveries. The innovative purification process ensures a high-purity and high-quality human-cl rhFVIII product with a high pathogen safety margin. © 2015 The Authors. Published by Elsevier Inc. Source

Sandberg H.,Octapharma AB | Kannicht C.,Octapharma | Stenlund P.,Octapharma AB | Dadaian M.,Octapharma AB | And 3 more authors.
Thrombosis Research | Year: 2012

Introduction: Hemophilia A is routinely treated by administration of exogenous coagulation factor VIII (FVIII). As safety and efficacy of FVIII products have improved over the years, development of FVIII-neutralizing antibodies (FVIII inhibitors) has emerged as the most serious complication. The new human cell line-derived recombinant human FVIII (human-cl rhFVIII) is the first recombinant FVIII product produced in a human cell line without additive animal proteins, with a goal of minimizing the risk of inhibitor development. Materials and methods: Biochemical analyzes of purity, molecular and functional attributes of the novel human-cl rhFVIII were undertaken for product characterization. Results and conclusions: Human-cl rhFVIII was shown to be highly pure, with host-cell protein and DNA traces comparable to, or lower than, currently marketed recombinant FVIII (rFVIII) products. Human-cl rhFVIII was shown to have high specific FVIII activity and characteristics similar to full-length rFVIII products. Furthermore, no significant discrepancy between one-stage and chromogenic assay results were observed for human-cl rhFVIII, indicating potency ratios of these assays comparable to the full-length rFVIII products. In functional tests, human-cl rhFVIII exhibited physiological thrombin generation and a normal rate of inactivation by activated protein C. Importantly, human-cl rhFVIII displayed higher binding capacity with von Willebrand factor than comparator products, thus minimizing circulating unbound FVIII and further reducing the potential risk of inhibitor development. © 2012 Elsevier Ltd. Source

Niaudet C.,Uppsala University | Hofmann J.J.,Octapharma AB | Mae M.A.,Uppsala University | Jung B.,Uppsala University | And 22 more authors.
PLoS ONE | Year: 2015

Despite its known expression in both the vascular endothelium and the lung epithelium, until recently the physiological role of the adhesion receptor Gpr116/ADGRF5 has remained elusive. We generated a new mouse model of constitutive Gpr116 inactivation, with a large genetic deletion encompassing exon 4 to exon 21 of the Gpr116 gene. This model allowed us to confirm recent results defining Gpr116 as necessary regulator of surfactant homeostasis. The loss of Gpr116 provokes an early accumulation of surfactant in the lungs, followed by a massive infiltration of macrophages, and eventually progresses into an emphysemalike pathology. Further analysis of this knockout model revealed cerebral vascular leakage, beginning at around 1.5 months of age. Additionally, endothelial-specific deletion of Gpr116 resulted in a significant increase of the brain vascular leakage. Mice devoid of Gpr116 developed an anatomically normal and largely functional vascular network, surprisingly exhibited an attenuated pathological retinal vascular response in a model of oxygeninduced retinopathy. These data suggest that Gpr116 modulates endothelial properties, a previously unappreciated function despite the pan-vascular expression of this receptor. Our results support the key pulmonary function of Gpr116 and describe a new role in the central nervous system vasculature. © 2015 Niaudet et al. Source

Discover hidden collaborations