1
|
Lombardi S, Testa MF, Pinotti M, Branchini A. Translation termination codons in protein synthesis and disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2022; 132:1-48. [PMID: 36088072 DOI: 10.1016/bs.apcsb.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fidelity of protein synthesis, a process shaped by several mechanisms involving specialized ribosome regions and external factors, ensures the precise reading of sense as well as stop codons (UGA, UAG, UAA), which are usually localized at the 3' of mRNA and drive the release of the polypeptide chain. However, either natural (NTCs) or premature (PTCs) termination codons, the latter arising from nucleotide changes, can undergo a recoding process named ribosome or translational readthrough, which insert specific amino acids (NTCs) or subset(s) depending on the stop codon type (PTCs). This process is particularly relevant for nonsense mutations, a relatively frequent cause of genetic disorders, which impair gene expression at different levels by potentially leading to mRNA degradation and/or synthesis of truncated proteins. As a matter of fact, many efforts have been made to develop efficient and safe readthrough-inducing compounds, which have been challenged in several models of human disease to provide with a therapy. In this view, the dissection of the molecular determinants shaping the outcome of readthrough, namely nucleotide and protein contexts as well as their interplay and impact on protein structure/function, is crucial to identify responsive nonsense mutations resulting in functional full-length proteins. The interpretation of experimental and mechanistic findings is also important to define a possibly clear picture of potential readthrough-favorable features useful to achieve rescue profiles compatible with therapeutic thresholds typical of each targeted disorder, which is of primary importance for the potential translatability of readthrough into a personalized and mutation-specific, and thus patient-oriented, therapeutic strategy.
Collapse
Affiliation(s)
- Silvia Lombardi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Maria Francesca Testa
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
| |
Collapse
|
2
|
Lombardi S, Aaen KH, Nilsen J, Ferrarese M, Gjølberg TT, Bernardi F, Pinotti M, Andersen JT, Branchini A. Fusion of engineered albumin with factor IX Padua extends half-life and improves coagulant activity. Br J Haematol 2021; 194:453-462. [PMID: 34109608 PMCID: PMC8362221 DOI: 10.1111/bjh.17559] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 12/29/2022]
Abstract
The short half‐life of coagulation factor IX (FIX) for haemophilia B (HB) therapy has been prolonged through fusion with human serum albumin (HSA), which drives the neonatal Fc receptor (FcRn)‐mediated recycling of the chimera. However, patients would greatly benefit from further FIX‐HSA half‐life extension. In the present study, we designed a FIX‐HSA variant through the engineering of both fusion partners. First, we developed a novel cleavable linker combining the two FIX activation sites, which resulted in improved HSA release. Second, insertion of the FIX R338L (Padua) substitution conferred hyperactive features (sevenfold higher specific activity) as for FIX Padua alone. Furthermore, we exploited an engineered HSA (QMP), which conferred enhanced human (h)FcRn binding [dissociation constant (KD) 0·5 nM] over wild‐type FIX‐HSA (KD 164·4 nM). In hFcRn transgenic mice, Padua‐QMP displayed a significantly prolonged half‐life (2·7 days, P < 0·0001) versus FIX‐HSA (1 day). Overall, we developed a novel FIX‐HSA protein with improved activity and extended half‐life. These combined properties may result in a prolonged functional profile above the therapeutic threshold, and thus in a potentially widened therapeutic window able to improve HB therapy. This rational engineering of both partners may pave the way for new fusion strategies for the design of engineered biotherapeutics.
Collapse
Affiliation(s)
- Silvia Lombardi
- Department of Life Sciences and Biotechnology and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Kristin H Aaen
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine and Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jeannette Nilsen
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine and Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Mattia Ferrarese
- Department of Life Sciences and Biotechnology and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Torleif T Gjølberg
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine and Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway.,Department of Ophthalmology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology and LTTA Centre, University of Ferrara, Ferrara, Italy
| | - Jan T Andersen
- Department of Immunology, University of Oslo and Oslo University Hospital Rikshospitalet, Oslo, Norway.,Institute of Clinical Medicine and Department of Pharmacology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology and LTTA Centre, University of Ferrara, Ferrara, Italy
| |
Collapse
|
3
|
Hayakawa Y, Tamura S, Suzuki N, Odaira K, Tokoro M, Kawashima F, Hayakawa F, Takagi A, Katsumi A, Suzuki A, Okamoto S, Kanematsu T, Matsushita T, Kojima T. Essential role of a carboxyl-terminal α-helix motif in the secretion of coagulation factor XI. J Thromb Haemost 2021; 19:920-930. [PMID: 33421272 DOI: 10.1111/jth.15242] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 12/28/2020] [Accepted: 01/04/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Coagulation factor XI (FXI) is a plasma serine protease zymogen that contributes to hemostasis. However, the mechanism of its secretion remains unclear. OBJECTIVE To determine the molecular mechanism of FXI secretion by characterizing a novel FXI mutant identified in a FXI-deficient Japanese patient. PATIENT/METHODS The FXI gene (F11) was analyzed by direct sequencing. Mutant recombinant FXI (rFXI) was overexpressed in HEK293 or COS-7 cells. Western blotting and enzyme-linked immunosorbent assay were performed to examine the FXI extracellular secretion profile. Immunofluorescence microscopy was used to investigate the subcellular localization of the rFXI mutant. RESULTS We identified a novel homozygous frameshift mutation in F11 [c.1788dupC (p.E597Rfs*65)], resulting in a unique and extended carboxyl-terminal (C-terminal) structure in FXI. Although rFXI-E597Rfs*65 was intracellularly synthesized, its extracellular secretion was markedly reduced. Subcellular localization analysis revealed that rFXI-E597Rfs*65 was abnormally retained in the endoplasmic reticulum (ER). We generated a series of C-terminal-truncated rFXI mutants to further investigate the role of the C-terminal region in FXI secretion. Serial rFXI experiments revealed that a threonine at position 622, the fourth residue from the C-terminus, was essential for secretion. Notably, Thr622 engages in the formation of an α-helix motif, indicating the importance of the C-terminal α-helix in FXI intracellular behavior and secretion. CONCLUSION FXI E597Rfs*65 results in the pathogenesis of a severe secretory defect resulting from aberrant ER-to-Golgi trafficking caused by the lack of a C-terminal α-helix motif. This study demonstrates the impact of the C-terminal structure, especially the α-helix motif, on FXI secretion.
Collapse
Affiliation(s)
- Yuri Hayakawa
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Shogo Tamura
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Nobuaki Suzuki
- Department of Transfusion Medicine, Nagoya University Hospital, Nagoya, Japan
| | - Koya Odaira
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Mahiru Tokoro
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fumika Kawashima
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Fumihiko Hayakawa
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akira Takagi
- Department of Medical Technology, Shubun University, Ichinomiya, Japan
| | - Akira Katsumi
- Department of Hematology, National Center for Geriatrics and Gerontology, Obu City, Japan
| | - Atsuo Suzuki
- Department of Clinical Laboratory, Nagoya University Hospital, Nagoya, Japan
| | - Shuichi Okamoto
- Department of Hematology and Oncology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Takeshi Kanematsu
- Department of Clinical Laboratory, Nagoya University Hospital, Nagoya, Japan
| | - Tadashi Matsushita
- Department of Transfusion Medicine, Nagoya University Hospital, Nagoya, Japan
- Department of Clinical Laboratory, Nagoya University Hospital, Nagoya, Japan
| | - Tetsuhito Kojima
- Division of Cellular and Genetic Sciences, Department of Integrated Health Sciences, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Aichi Health Promotion Foundation, Nagoya, Japan
| |
Collapse
|
4
|
Branchini A. The carboxyl-terminal region of coagulation serine proteases: A matter of cut and change. J Thromb Haemost 2021; 19:917-919. [PMID: 33792173 DOI: 10.1111/jth.15237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 11/29/2022]
Affiliation(s)
- Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| |
Collapse
|
5
|
Molecular Insights into Determinants of Translational Readthrough and Implications for Nonsense Suppression Approaches. Int J Mol Sci 2020; 21:ijms21249449. [PMID: 33322589 PMCID: PMC7764779 DOI: 10.3390/ijms21249449] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/27/2020] [Accepted: 12/05/2020] [Indexed: 02/07/2023] Open
Abstract
The fidelity of protein synthesis, a process shaped by several mechanisms involving specialized ribosome regions and external factors, ensures the precise reading of sense and stop codons. However, premature termination codons (PTCs) arising from mutations may, at low frequency, be misrecognized and result in PTC suppression, named ribosome readthrough, with production of full-length proteins through the insertion of a subset of amino acids. Since some drugs have been identified as readthrough inducers, this fidelity drawback has been explored as a therapeutic approach in several models of human diseases caused by nonsense mutations. Here, we focus on the mechanisms driving translation in normal and aberrant conditions, the potential fates of mRNA in the presence of a PTC, as well as on the results obtained in the research of efficient readthrough-inducing compounds. In particular, we describe the molecular determinants shaping the outcome of readthrough, namely the nucleotide and protein context, with the latter being pivotal to produce functional full-length proteins. Through the interpretation of experimental and mechanistic findings, mainly obtained in lysosomal and coagulation disorders, we also propose a scenario of potential readthrough-favorable features to achieve relevant rescue profiles, representing the main issue for the potential translatability of readthrough as a therapeutic strategy.
Collapse
|
6
|
Balestra D, Branchini A. Molecular Mechanisms and Determinants of Innovative Correction Approaches in Coagulation Factor Deficiencies. Int J Mol Sci 2019; 20:ijms20123036. [PMID: 31234407 PMCID: PMC6627357 DOI: 10.3390/ijms20123036] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/07/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023] Open
Abstract
Molecular strategies tailored to promote/correct the expression and/or processing of defective coagulation factors would represent innovative therapeutic approaches beyond standard substitutive therapy. Here, we focus on the molecular mechanisms and determinants underlying innovative approaches acting at DNA, mRNA and protein levels in inherited coagulation factor deficiencies, and in particular on: (i) gene editing approaches, which have permitted intervention at the DNA level through the specific recognition, cleavage, repair/correction or activation of target sequences, even in mutated gene contexts; (ii) the rescue of altered pre-mRNA processing through the engineering of key spliceosome components able to promote correct exon recognition and, in turn, the synthesis and secretion of functional factors, as well as the effects on the splicing of missense changes affecting exonic splicing elements; this section includes antisense oligonucleotide- or siRNA-mediated approaches to down-regulate target genes; (iii) the rescue of protein synthesis/function through the induction of ribosome readthrough targeting nonsense variants or the correction of folding defects caused by amino acid substitutions. Overall, these approaches have shown the ability to rescue the expression and/or function of potentially therapeutic levels of coagulation factors in different disease models, thus supporting further studies in the future aimed at evaluating the clinical translatability of these new strategies.
Collapse
Affiliation(s)
- Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121 Ferrara, Italy.
| |
Collapse
|
7
|
Ferrarese M, Baroni M, Della Valle P, Spiga I, Poloniato A, D'Angelo A, Pinotti M, Bernardi F, Branchini A. Missense changes in the catalytic domain of coagulation factor X account for minimal function preventing a perinatal lethal condition. Haemophilia 2019; 25:685-692. [PMID: 30994257 DOI: 10.1111/hae.13761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 03/23/2019] [Accepted: 03/23/2019] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Inherited deficiencies in the coagulation pathway provide diversified models to investigate the molecular bases of perinatal lethality associated with null-like variants. Differently from X-linked haemophilias, homozygous/doubly heterozygous null variants in the rare autosomally inherited deficiency of factor X (FX) might be incompatible with perinatal survival. AIM To provide experimental evidence about the null/close-to-null FX function. METHODS The residual secreted (ELISA) and functional (thrombin generation assays) protein levels associated with the novel nonsense (c.1382G>A; p.Trp461Ter) and missense (c.752T>C; p.Leu251Pro) variants, found in the proposita with life-threatening symptoms at birth, were characterized through recombinant (r)FX expression. RESULTS The rFX-461Ter showed very low secretion and undetectable function. Expression and function of the predicted readthrough-deriving missense variants (rFX-461Tyr, rFX-461Gln) were also severely impaired. These unfavourable features, due to nucleotide and protein sequence constraints, precluded functional readthrough over the 461 stop codon. Differently, the poorly secreted rFX-251Pro variant displayed residual function that was characterized by anti-TFPI aptamer-based amplification or selective inhibition of activated FX function by fondaparinux in plasma and found to be reduced by approximately three orders of magnitude. Similarly to the rFX-251Pro, a group of catalytic domain missense variants cause poorly secreted molecules with modest function in FX-deficient patients with life-threatening symptoms. CONCLUSIONS Our data, contributing to the knowledge of the very severe FX deficiency forms, support life-saving requirement of trace FX function, clearly exemplified by the dysfunctional but not completely inactive rFX-251Pro variant that, albeit with severely reduced function, is compatible with a residual activity ensuring minimal haemostasis and permitting perinatal survival.
Collapse
Affiliation(s)
- Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marcello Baroni
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Patrizia Della Valle
- Coagulation Service and Thrombosis Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Ivana Spiga
- Clinical Molecular Biology Laboratory, IRCCS San Raffaele Hospital, Milan, Italy
| | - Antonella Poloniato
- Neonatology Unit, Mother-Child Department, IRCCS San Raffaele Hospital, Milan, Italy
| | - Armando D'Angelo
- Coagulation Service and Thrombosis Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| |
Collapse
|
8
|
Marchi S, Corricelli M, Branchini A, Vitto VAM, Missiroli S, Morciano G, Perrone M, Ferrarese M, Giorgi C, Pinotti M, Galluzzi L, Kroemer G, Pinton P. Akt-mediated phosphorylation of MICU1 regulates mitochondrial Ca 2+ levels and tumor growth. EMBO J 2018; 38:embj.201899435. [PMID: 30504268 DOI: 10.15252/embj.201899435] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 10/08/2018] [Accepted: 10/15/2018] [Indexed: 12/13/2022] Open
Abstract
Although mitochondria play a multifunctional role in cancer progression and Ca2+ signaling is remodeled in a wide variety of tumors, the underlying mechanisms that link mitochondrial Ca2+ homeostasis with malignant tumor formation and growth remain elusive. Here, we show that phosphorylation at the N-terminal region of the mitochondrial calcium uniporter (MCU) regulatory subunit MICU1 leads to a notable increase in the basal mitochondrial Ca2+ levels. A pool of active Akt in the mitochondria is responsible for MICU1 phosphorylation, and mitochondrion-targeted Akt strongly regulates the mitochondrial Ca2+ content. The Akt-mediated phosphorylation impairs MICU1 processing and stability, culminating in reactive oxygen species (ROS) production and tumor progression. Thus, our data reveal the crucial role of the Akt-MICU1 axis in cancer and underscore the strategic importance of the association between aberrant mitochondrial Ca2+ levels and tumor development.
Collapse
Affiliation(s)
- Saverio Marchi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mariangela Corricelli
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Veronica Angela Maria Vitto
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Sonia Missiroli
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Giampaolo Morciano
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy.,Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy
| | - Mariasole Perrone
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Giorgi
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Lorenzo Galluzzi
- Department of Radiation Oncology, Weill Cornell Medical College, New York, NY, USA.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Guido Kroemer
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France.,Equipe 11 Labellisée Ligue Nationale Contre le Cancer, Centre de Recherche des Cordeliers, Paris, France.,Institut National de la Santé et de la Recherche Médicale, U1138, Paris, France.,Université Pierre et Marie Curie, Paris, France.,Metabolomics and Cell Biology Platforms, Gustave Roussy Cancer Campus, Villejuif, France.,Center of Clinical Investigations in Biotherapies of Cancer (CICBT), Villejuif, France.,Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.,Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden
| | - Paolo Pinton
- Laboratory for Technologies of Advanced Therapies (LTTA), Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy .,Maria Cecilia Hospital, GVM Care & Research, Cotignola, Italy
| |
Collapse
|
9
|
Ferrarese M, Pignani S, Lombardi S, Balestra D, Bernardi F, Pinotti M, Branchini A. The carboxyl-terminal region of human coagulation factor X as a natural linker for fusion strategies. Thromb Res 2018; 173:4-11. [PMID: 30453126 DOI: 10.1016/j.thromres.2018.11.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/29/2018] [Accepted: 11/08/2018] [Indexed: 10/27/2022]
Abstract
Fusion with human serum albumin (HSA), which represents a well-established technique to extend half-life of therapeutic proteins, commonly exploits intervening peptide linkers as key components. Here, we explored the human coagulation factor X (FX) carboxyl-terminal region, previously demonstrated by us to be dispensable for secretion and coagulant activity, as a natural linker for fusion purposes. To test our hypothesis, we compared direct FX-HSA fusion with the designed FX-HSA fusion proteins mimicking the recombinant activated factor VII (rFVIIa)-HSA or factor IX (FIX)-HSA chimeras, both strongly dependent from artificial linkers. Three constructs were produced by direct tandem fusion (FX-HSA) and through flexible (glycine/serine; FX-GS-HSA, mimicking rFVIIa-HSA) or cleavable (incorporating the FX activation site; FX-CL-HSA, mimicking FIX-HSA) linkers. The FX-HSA was efficiently secreted and displayed prolonged plasma persistence in mice. All chimeras possessed remarkable pro-coagulant activity, comparable to FX for FX-HSA (88.7 ± 6.0%) and FX-CL-HSA (98.0 ± 16.4%) or reduced for FX-GS-HSA (55.8 ± 5.4%). Upon incubation with activators, FX-HSA and FX-CL-HSA displayed a correct activation profile while the FX-GS-HSA activation was slightly defective. In fluorogenic-based assays, FX-HSA showed normal activity over time and a specific amidolytic activity (1.0 ± 0.12) comparable to that of FX. Overall, the FX-HSA features indicate that the FX carboxyl-terminal region represents an intrinsic sequence allowing direct tandem fusion. Our results provide the first experimental evidence for i) a coagulation factor fusion protein with biological properties independent from artificial linkers, ii) the suitability of FX carboxyl-terminal region as a natural linker for fusion purposes.
Collapse
Affiliation(s)
- Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Silvia Pignani
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Silvia Lombardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
| |
Collapse
|
10
|
Pignani S, Todaro A, Ferrarese M, Marchi S, Lombardi S, Balestra D, Pinton P, Bernardi F, Pinotti M, Branchini A. The chaperone-like sodium phenylbutyrate improves factor IX intracellular trafficking and activity impaired by the frequent p.R294Q mutation. J Thromb Haemost 2018; 16:2035-2043. [PMID: 29993188 DOI: 10.1111/jth.14236] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Indexed: 12/25/2022]
Abstract
Essentials Missense mutations often impair protein folding, and thus intracellular trafficking and secretion. Cellular models of severe type I hemophilia B were challenged with chaperone-like compounds. Sodium phenylbutyrate improved intracellular trafficking and secretion of the frequent p.R294Q. The increased coagulant activity levels (∼3%) of p.R294Q would ameliorate the bleeding phenotype. SUMMARY Background Missense mutations often impair protein folding and intracellular processing, which can be improved by small compounds with chaperone-like activity. However, little has been done in coagulopathies, where even modest increases of functional levels could have therapeutic implications. Objectives To rescue the expression of factor IX (FIX) variants affected by missense mutations associated with type I hemophilia B (HB) through chaperone-like compounds. Methods Expression studies of recombinant (r)FIX variants and evaluation of secreted levels (ELISA), intracellular trafficking (immunofluorescence) and activity (coagulant assays) before and after treatment of cells with chaperone-like compounds. Results As a model we chose the most frequent HB mutation (p.R294Q, ~100 patients), compared with other recurrent mutations associated with severe/moderate type I HB. Immunofluorescence studies revealed retention of rFIX variants in the endoplasmic reticulum and negligible localization in the Golgi, thus indicating impaired intracellular trafficking. Consistently, and in agreement with coagulation phenotypes in patients, all missense mutations resulted in impaired secretion (< 1% wild-type rFIX). Sodium phenylbutyrate (NaPBA) quantitatively improved trafficking to the Golgi and dose dependently promoted secretion (from 0.3 ± 0.1% to 1.5 ± 0.3%) only of the rFIX-294Q variant. Noticeably, this variant displayed a specific coagulant activity that was higher (~2.0 fold) than that of wild-type rFIX in all treatment conditions. Importantly, coagulant activity was concurrently increased to levels (3.0 ± 0.9%) that, if achieved in patients, would ameliorate the bleeding phenotype. Conclusions Altogether, our data detail molecular mechanisms underlying type I HB and candidate NaPBA as affordable 'personalized' therapeutics for patients affected by the highly frequent p.R294Q mutation, and with reduced access to substitutive therapy.
Collapse
Affiliation(s)
- S Pignani
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - A Todaro
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - M Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - S Marchi
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - S Lombardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - D Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - P Pinton
- Department of Morphology, Surgery and Experimental Medicine, Section of Pathology, Oncology and Experimental Biology, University of Ferrara, Ferrara, Italy
| | - F Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - M Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - A Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| |
Collapse
|
11
|
Ferrarese M, Testa MF, Balestra D, Bernardi F, Pinotti M, Branchini A. Secretion of wild-type factor IX upon readthrough over F9 pre-peptide nonsense mutations causing hemophilia B. Hum Mutat 2018; 39:702-708. [PMID: 29388273 DOI: 10.1002/humu.23404] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 01/16/2018] [Accepted: 01/19/2018] [Indexed: 12/30/2022]
Abstract
Pre-peptide regions of secreted proteins display wide sequence variability, even among highly homologous proteins such as coagulation factors, and are intracellularly removed, thus potentially favoring secretion of wild-type proteins upon suppression of nonsense mutations (translational readthrough). As models we selected F9 nonsense mutations with readthrough-favorable features affecting the pre-peptide and pro-peptide regions of coagulation factor IX (FIX), which cause hemophilia B (HB). Only the p.Gly21Ter (c.61G > T) in the variable pre-peptide hydrophobic core significantly responded (secretion, 4.1 ± 0.5% of wild-type; coagulant activity, 4.0 ± 0.3%) to the readthrough-inducer geneticin. Strikingly, for the p.Gly21Ter mutation, the resulting specific coagulant activity (0.96 ± 0.11) was compatible with normal function, thus suggesting secretion of FIX with wild-type features upon readthrough and removal of pre-peptide. Expression of the predicted readthrough-deriving missense variants (Gly21Trp/Cys/Arg) revealed a preserved specific activity (ranging from 0.84 to 0.98), thus supporting our observation. Conversely, rescue of the p.Cys28Ter (c.84T > A) and p.Lys45Ter (c.133A > T) was prevented by constraints of adjacent cleavage sites, a finding consistent with the association of most missense mutations affecting these regions with severe or moderate HB. Overall, our data indicate that suppression of nonsense mutations in the pre-peptide core preserves mature protein features, thus making this class of mutations preferred candidates for therapeutic readthrough.
Collapse
Affiliation(s)
- Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Maria Francesca Testa
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Dario Balestra
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| |
Collapse
|
12
|
Donadon I, McVey JH, Garagiola I, Branchini A, Mortarino M, Peyvandi F, Bernardi F, Pinotti M. Clustered F8 missense mutations cause hemophilia A by combined alteration of splicing and protein biosynthesis and activity. Haematologica 2017; 103:344-350. [PMID: 29170251 PMCID: PMC5792279 DOI: 10.3324/haematol.2017.178327] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 11/15/2017] [Indexed: 01/01/2023] Open
Abstract
Dissection of pleiotropic effects of missense mutations, rarely investigated in inherited diseases, is fundamental to understanding genotype-phenotype relationships. Missense mutations might impair mRNA processing in addition to protein properties. As a model for hemophilia A, we investigated the highly prevalent F8 c.6046c>t/p.R2016W (exon 19) mutation. In expression studies exploiting lentiviral vectors, we demonstrated that the amino acid change impairs both Factor VIII (FVIII) secretion (antigen 11.0±0.4% of wild-type) and activity (6.0±2.9%). Investigations in patients' ectopic F8 mRNA and with minigenes showed that the corresponding nucleotide change also decreases correct splicing to 70±5%, which is predicted to lower further FVIII activity (4.2±2%), consistently with patients' levels (<1-5%). Masking the mutated exon 19 region by antisense U7snRNA supported the presence of a splicing regulatory element, potentially affected by several missense mutations causing hemophilia A. Among these, the c.6037g>a (p.G2013R) reduced exon inclusion to 41±3% and the c.6053a>g (p.E2018G) to 28±2%, similarly to a variant affecting the 5' splice site (c.6113a>g, p.N2038S, 26±2%), which displayed normal protein features upon recombinant expression. The p.G2013R reduced both antigen (7.0±0.9%) and activity (8.4±0.8%), while the p.E2018G produced a dysfunctional molecule (antigen: 69.0±18.1%; activity: 19.4±2.3%). In conclusion, differentially altered mRNA and protein patterns produce a gradient of residual activity, and clarify genotype-phenotype relationships. Data detail pathogenic mechanisms that, only in combination, account for moderate/severe disease forms, which in turn determine the mutation profile. Taken together we provide a clear example of interplay between mRNA and protein mechanisms of disease that operate in shaping many other inherited disorders.
Collapse
Affiliation(s)
- Irving Donadon
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy.,Human Molecular Genetics, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - John H McVey
- School of Bioscience & Medicine, University of Surrey, Guildford, UK
| | - Isabella Garagiola
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione Luigi Villa, Milan, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy
| | - Mimosa Mortarino
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione Luigi Villa, Milan, Italy
| | - Flora Peyvandi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione Luigi Villa, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Italy .,Laboratorio per le Tecnologie delle Terapie Avanzate, University of Ferrara, Italy
| |
Collapse
|
13
|
Specific factor IX mRNA and protein features favor drug-induced readthrough over recurrent nonsense mutations. Blood 2017; 129:2303-2307. [PMID: 28196793 DOI: 10.1182/blood-2016-09-738641] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 02/11/2017] [Indexed: 12/11/2022] Open
Abstract
Drug-induced readthrough over premature stop codons (PTCs) is a potentially attractive therapy for genetic disorders, but a wide outcome variability has been observed. Through expression studies, we investigated the responsiveness to the readthrough-inducing drug geneticin of 11 rationally selected factor IX (FIX) nonsense mutations, present in 70% (324/469) of hemophilia B (HB) patients with PTCs. Among the predicted readthrough-permissive TGA variants, only 2 (p.W240X and p.R384X) responded with a remarkable rescue of FIX activity. The amounts of rescued full-length FIX protein for the p.W240X (∼9% of recombinant FIX [rFIX]-wild-type [WT]) slightly exceeded activity (5.2 ± 0.6%). FIX antigen for the p.R384X (1.9 ± 0.3%) was remarkably lower than activity (7.5 ± 0.7%). Data indicate novel specific mechanisms producing functional rescue: (1) prevalent reinsertion of the authentic residue (tryptophan), reverting the nonsense effects for the p.W240X, and (2) gain-of-function for the p.R384X, supported by the fourfold increased activity of the most probable readthrough-mediated missense variant (rFIX-R384W). For most PTCs, impaired secretion/function produced by readthrough-mediated amino acid substitutions prevented a significant functional rescue, which requires combinations of favorable FIX messenger RNA (mRNA) sequence and protein features. This rational approach, applicable to other coagulation disorders, helps with interpreting the poor response reported in the few investigated HB patients, and identifies candidate patients eligible for treatment.
Collapse
|
14
|
Branchini A, Ferrarese M, Lombardi S, Mari R, Bernardi F, Pinotti M. Differential functional readthrough over homozygous nonsense mutations contributes to the bleeding phenotype in coagulation factor VII deficiency. J Thromb Haemost 2016; 14:1994-2000. [PMID: 27513915 DOI: 10.1111/jth.13443] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Indexed: 11/29/2022]
Abstract
Essentials Potentially null homozygous Factor(F)7 nonsense mutations are associated to variable bleeding symptoms. Readthrough of p.Ser112X (life-threatening) and p.Cys132X (moderate) stop codons was investigated. Readthrough-mediated insertion of wild-type or tolerated residues produce functional proteins. Functional readthrough over homozygous F7 nonsense mutations contributes to the bleeding phenotype. SUMMARY Background Whereas the rare homozygous nonsense mutations causing factor (F)VII deficiency may predict null conditions that are almost completely incompatible with life, they are associated with appreciable differences in hemorrhagic symptoms. The misrecognition of premature stop codons (readthrough) may account for variable levels of functional full-length proteins. Objectives To experimentally evaluate the basal and drug-induced levels of FVII resulting from the homozygous p.Cys132X and p.Ser112X nonsense mutations that are associated with moderate (132X) or life-threatening (112X) symptoms, and that are predicted to undergo readthrough with (132X) or without (112X) production of wild-type FVII. Methods We transiently expressed recombinant FVII (rFVII) nonsense and missense variants in human embryonic kidney 293 cells, and evaluated secreted FVII protein and functional levels by ELISA, activated FX generation, and coagulation assays. Results The levels of functional FVII produced by p.Cys132X and p.Ser112X mutants (rFVII-132X, 1.1% ± 0.2% of wild-type rFVII; rFVII-112X, 0.5% ± 0.1% of wild-type rFVII) were compatible with the occurrence of spontaneous readthrough, which was magnified by the addition of G418 - up to 12% of the wild-type value for the rFVII-132X nonsense variant. The predicted missense variants arising from readthrough abolished (rFVII-132Trp/Arg) or reduced (rFVII-112Trp/Cys/Arg, 22-45% of wild-type levels) secretion and function. These data suggest that the appreciable rescue of p.Cys132X function was driven by reinsertion of the wild-type residue, whereas the minimal p.Ser112X function was explained by missense changes permitting FVII secretion and function. Conclusions The extent of functional readthrough might explain differences in the bleeding phenotype of patients homozygous for F7 nonsense mutations, and prevent null conditions even for the most readthrough-unfavorable mutations.
Collapse
Affiliation(s)
- A Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
- LTTA Center, University of Ferrara, Ferrara, Italy.
| | - M Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - S Lombardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - R Mari
- Department of Medical Sciences, Center for Hemostasis and Thrombosis, Hematology Section, University of Ferrara, Ferrara, Italy
| | - F Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Center, University of Ferrara, Ferrara, Italy
| | - M Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Center, University of Ferrara, Ferrara, Italy
| |
Collapse
|
15
|
Branchini A, Baroni M, Burini F, Puzzo F, Nicolosi F, Mari R, Gemmati D, Bernardi F, Pinotti M. The carboxyl-terminal region is NOT essential for secreted and functional levels of coagulation factor X. J Thromb Haemost 2015; 13:1468-74. [PMID: 26083275 DOI: 10.1111/jth.13034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/10/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND The homologous coagulation factor X (FX), VII (FVII), IX (FIX) and protein C (PC) display striking differences in the carboxyl-terminus, with that of FX being the most extended. This region is essential for FVII, FIX and PC secretion. OBJECTIVES To provide experimental evidence for the role of the FX carboxyl-terminus. METHODS Recombinant FX (rFX) variants were expressed in multiple eukaryotic cell systems. Protein and activity levels were evaluated by ELISA, coagulant and amidolytic assays. RESULTS AND DISCUSSION Expression of a panel of progressively truncated rFX variants in HEK293 cells revealed that the deletion of up to 21 residues in the carboxyl-terminus did not significantly affect secreted protein levels, as confirmed in HepG2 and BHK21 cells. In contrast, chimeric rFX-FVII variants with swapped terminal residues showed severely reduced levels. The truncated rFX variants revealed normal amidolytic activity, suggesting an intact active site. Intriguingly, these variants, which included that resembling the activated FXβ form once cleaved, also displayed remarkable or normal pro-coagulant capacity in PT- and aPTT-based assays. This supports the hypothesis that subjects with nonsense mutations in the FX carboxyl-terminus, so far never identified, would be asymptomatic. CONCLUSIONS For the first time we demonstrate that the FX carboxyl-terminal region downstream of residue K467 is not essential for secretion and provides a modest contribution to pro-coagulant properties. These findings, which might suggest an involvement of the carboxyl-terminal region in the divergence of the homologous FX, FVII, FIX and PC, help to interpret the mutational pattern of FX deficiency.
Collapse
Affiliation(s)
- A Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Centre, University of Ferrara, Ferrara, Italy
| | - M Baroni
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Centre, University of Ferrara, Ferrara, Italy
| | - F Burini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - F Puzzo
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - F Nicolosi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - R Mari
- Centre for Haemostasis and Thrombosis, Haematology Section, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - D Gemmati
- Centre for Haemostasis and Thrombosis, Haematology Section, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - F Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Centre, University of Ferrara, Ferrara, Italy
| | - M Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
- LTTA Centre, University of Ferrara, Ferrara, Italy
| |
Collapse
|
16
|
Perot E, Enjolras N, Le Quellec S, Indalecio A, Girard J, Negrier C, Dargaud Y. Expression and characterization of a novel human recombinant factor IX molecule with enhanced in vitro and in vivo clotting activity. Thromb Res 2015; 135:1017-24. [PMID: 25795563 DOI: 10.1016/j.thromres.2015.02.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 02/04/2015] [Accepted: 02/24/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Hemophilia B is an inherited X-linked recessive bleeding disorder, due to a defect in human factor IX (FIX). The main treatment for hemophilia B is replacement therapy using FIX concentrates. Prophylactic treatment in severe hemophilia B is very effective but is limited by cost issues. Production of a recombinant FIX (rFIX) with enhanced clotting activity, offering the possibility of fewer infusions and fewer costs with similar efficacy, is one of the current challenges for hemophilia B treatment. The present study focused on an important amino acid sequence known to be involved in the interaction of activated FIX (FIXa) with its cofactor, activated factor VIII (FVIIIa). MATERIALS AND METHODS Using site-directed mutagenesis of glutamate E410 (c240, chymotrypsin numbering), four recombinant FIX-E410 (E410H, A, L and N) mutants were developed and produced by the human hepatoma cell line Huh-7. RESULTS The in-vitro clotting activity of mutant FIX molecules was 3 to 5-fold higher than wild-type recombinant FIX (FIX-WT). FIX-E410H compound showed the highest in-vitro procoagulant activity. Enhanced specific activity was confirmed using thrombin generation assay. FIX-E410H induced 5.2-fold higher thrombin generation than FIX-WT. In hemophilia B mice, we observed significantly higher in-vivo clotting activity and thrombin generating capacity with FIX-E410H compared to FIX-WT. We demonstrated that increased procoagulant activity of FIX-E410H was mainly explained by 2.5- fold enhanced affinity of the mutant for human FVIIIa. CONCLUSION We have engineered and characterized four improved FIX proteins with enhanced in-vitro and in-vivo activity. Future studies are required to evaluate the immunogenicity of FIX-E410.
Collapse
Affiliation(s)
- Eloïse Perot
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France
| | - Nathalie Enjolras
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France
| | - Sandra Le Quellec
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France; Unite d'Hemostase Clinique, Centre Regional de Traitement des Hemophiles, Hopital Cardiologique Louis Pradel, 28Bd du Doyen Jean Lepine, 69500 Bron, France
| | - Alice Indalecio
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France
| | - Jonathan Girard
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France
| | - Claude Negrier
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France; Unite d'Hemostase Clinique, Centre Regional de Traitement des Hemophiles, Hopital Cardiologique Louis Pradel, 28Bd du Doyen Jean Lepine, 69500 Bron, France
| | - Yesim Dargaud
- EA 4174, Hemostase, Inflammation & Sepsis, Universite Lyon1, Faculte de Medecine Laennec, 69372 Lyon cedex 08, France; Unite d'Hemostase Clinique, Centre Regional de Traitement des Hemophiles, Hopital Cardiologique Louis Pradel, 28Bd du Doyen Jean Lepine, 69500 Bron, France.
| |
Collapse
|