1
|
Gandhi PS, Zivkovic M, Østergaard H, Bonde AC, Elm T, Løvgreen MN, Schluckebier G, Johansson E, Olsen OH, Olsen EHN, de Bus IA, Bloem K, Alskär O, Rea CJ, Bjørn SE, Schutgens RE, Sørensen B, Urbanus RT, Faber JH. A bispecific antibody approach for the potential prophylactic treatment of inherited bleeding disorders. NATURE CARDIOVASCULAR RESEARCH 2024; 3:166-185. [PMID: 39196196 DOI: 10.1038/s44161-023-00418-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 12/19/2023] [Indexed: 08/29/2024]
Abstract
Inherited bleeding disorders such as Glanzmann thrombasthenia (GT) lack prophylactic treatment options. As a result, serious bleeding episodes are treated acutely with blood product transfusions or frequent, repeated intravenous administration of recombinant activated coagulation factor VII (rFVIIa). Here we describe HMB-001, a bispecific antibody designed to bind and accumulate endogenous FVIIa and deliver it to sites of vascular injury by targeting it to the TREM (triggering receptor expressed on myeloid cells)-like transcript-1 (TLT-1) receptor that is selectively expressed on activated platelets. In healthy nonhuman primates, HMB-001 prolonged the half-life of endogenous FVIIa, resulting in its accumulation. Mouse bleeding studies confirmed antibody-mediated potentiation of FVIIa hemostatic activity by TLT-1 targeting. In ex vivo models of GT, HMB-001 localized FVIIa on activated platelets and potentiated fibrin-dependent platelet aggregation. Taken together, these results indicate that HMB-001 has the potential to offer subcutaneous prophylactic treatment to prevent bleeds in people with GT and other inherited bleeding disorders, with a low-frequency dosing regimen.
Collapse
Affiliation(s)
| | - Minka Zivkovic
- Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | | | | | | | | | | | | | - Ole H Olsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Karien Bloem
- Sanquin Diagnostic Services, Amsterdam, Netherlands
| | | | | | | | - Roger E Schutgens
- Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands
| | | | - Rolf T Urbanus
- Center for Benign Haematology, Thrombosis and Haemostasis, Van Creveldkliniek, University Medical Center Utrecht, Utrecht University, Utrecht, Netherlands.
| | | |
Collapse
|
2
|
Schmidt DE, Truedsson Å, Strålfors A, Hojbjerg JA, Soutari N, Holmström M, Ranta S, Letelier A, Bowyer A, Ljung R, Antovic J, Bruzelius M. Clinical Implications of Discrepancy between One-Stage Clotting and Chromogenic Factor IX Activity in Hemophilia B. Thromb Haemost 2024; 124:32-39. [PMID: 37494968 DOI: 10.1055/a-2142-0262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
BACKGROUND Discrepancy in factor IX activity (FIX:C) between one-stage assay (OSA) and chromogenic substrate assay (CSA) in patients with hemophilia B (PwHB) introduces challenges for clinical management. AIM To study the differences in FIX:C using OSA and CSA in moderate and mild hemophilia B (HB), their impact on classification of severity, and correlation with genotype. METHODS Single-center study including 21 genotyped and clinically characterized PwHB. FIX:C by OSA was measured using ActinFSL (Siemens) and CSA by Biophen (Hyphen). In addition, in vitro experiments with wild-type FIX were performed. Reproducibility of CSA was assessed between three European coagulation laboratories. RESULTS FIX:C by CSA was consistently lower than by OSA, with 10/17 PwHB having a more severe hemophilia type by CSA. OSA displayed a more accurate description of the clinical bleeding severity, compared with CSA. A twofold difference between OSA:CSA FIX:C was present in 12/17 PwHB; all patients had genetic missense variants in the FIX serine protease domain. Discrepancy was also observed with diluted normal plasma, most significant for values below 0.10 IU/mL. Assessment of samples with low FIX:C showed excellent reproducibility of the CSA results between the laboratories. CONCLUSION FIX:C was consistently higher by OSA compared with the CSA. Assessing FIX:C by CSA alone would have led to diagnosis of a more severe hemophilia type in a significant proportion of patients. Our study suggests using both OSA and CSA FIX:C together with genotyping to classify HB severity and provide essential information for clinical management.
Collapse
Affiliation(s)
- David E Schmidt
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
- Paediatric Coagulation, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Åsa Truedsson
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
| | - Annelie Strålfors
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Johanne Andersen Hojbjerg
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Nida Soutari
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Margareta Holmström
- Coagulation Unit, Department of Hematology, Karolinska University Hospital, Stockholm, Sweden
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Susanna Ranta
- Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
- Paediatric Coagulation, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Anna Letelier
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Annette Bowyer
- Department of Coagulation, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Rolf Ljung
- Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Jovan Antovic
- Clinical Chemistry, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Maria Bruzelius
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Coagulation Unit, Department of Hematology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
3
|
De Pablo-Moreno JA, Miguel-Batuecas A, Rodríguez-Merchán EC, Liras A. Treatment of congenital coagulopathies, from biologic to biotechnological drugs: The relevance of gene editing (CRISPR/Cas). Thromb Res 2023; 231:99-111. [PMID: 37839151 DOI: 10.1016/j.thromres.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 09/09/2023] [Accepted: 10/02/2023] [Indexed: 10/17/2023]
Abstract
Congenital coagulopathies have, throughout the history of medicine, been a focus of scientific study and of great interest as they constitute an alteration of one of the most important and conserved pathways of evolution. The first therapeutic strategies developed to address them were aimed at restoring the blood components lost during hemorrhage by administering whole blood or plasma. Later on, the use of cryoprecipitates was a significant breakthrough as it made it possible to decrease the volumes of blood infused. In the 1970' and 80', clotting factor concentrates became the treatment and, from the 1990's to the present day, recombinant factors -with increasingly longer half-lives- have taken over as the treatment of choice for certain coagulopathies in a seamless yet momentous transition from biological to biotechnological drugs. The beginning of this century, however, saw the emergence of new advanced (gene and cell) treatments, which are currently transforming the therapeutic landscape. The possibility to use cells and viruses as well as specific or bispecific antibodies as medicines is likely to spark a revolution in the world of pharmacology where therapies will be individualized and have long-term effects. Specifically, attention is nowadays focused on the development of gene editing strategies, chiefly those based on CRISPR/Cas technology. Rare coagulopathies such as hemophilia A and B, or even ultra-rare ones such as factor V deficiency, could be among those deriving the greatest benefit from these new developments.
Collapse
Affiliation(s)
- Juan A De Pablo-Moreno
- Department of Genetic, Physiology and Microbiology, Biology School, Complutense University of Madrid, Spain
| | - Andrea Miguel-Batuecas
- Department of Genetic, Physiology and Microbiology, Biology School, Complutense University of Madrid, Spain
| | - E Carlos Rodríguez-Merchán
- Osteoarticular Surgery Research, Hospital La Paz Institute for Health Research-IdiPAZ (La Paz University Hospital-Autonomous University of Madrid), Spain
| | - Antonio Liras
- Department of Genetic, Physiology and Microbiology, Biology School, Complutense University of Madrid, Spain.
| |
Collapse
|
4
|
Radic CP, Abelleyro MM, Ziegler B, Marchione VD, Nevado J, Lapunzina P, Sciuccati G, Neme D, Rossetti LC, Bonduel M, De Brasi CD. Haemophilia B, severe childhood obesity and other extra-haematological features associated with similar 4Mb-deletions on Xq27: Clinical findings, molecular insights and literature update. Haemophilia 2023; 29:844-854. [PMID: 36930806 DOI: 10.1111/hae.14779] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/19/2023]
Abstract
INTRODUCTION Haemophilia B (HB) is associated with pathogenic variants in F9. Hemizygous deletions encompassing the entire F9 and proximate genes may express extra-haematological clinical phenotypes. AIM To analyse the genotype/phenotype correlations in two unrelated boys with severe early childhood obesity (SCO), global developmental delay (GDD) and similar bleeding phenotype associated with comparable Xq27 deletions spanning the entire F9 and proximate genes, and characterise the pathogenic events estimating the most likely mutational mechanism involved. METHODS Entire F9-deletions were detected in three hemizygous unrelated probands with HB: two cases, C#1/C#2, presented SCO and GDD and a control patient (Co), who only had severe bleeding symptoms. Dense SNP-array and case-specific STS walking scan allowed characterisation of the deletion breakpoints. Extensive use of bioinformatics, statistics and clinical databases allowed the investigation of genotype-phenotype associations. RESULTS Patients C#1/C#2 and Co resulted in a complete F9 and additional gene deletions of variable extensions on Xq26.3-Xq27.2 (C#1/C#2/Co: 4.3Mb/3.9Mb/160Kb). C#1/C#2 common deleted gene SOX3 is directly associated with SCO, GDD and pituitary hypothyroidism (PH) whilst C#2 extra-deleted gene MAGEC2 indirectly relates to anal atresia (AA). Breakpoint analysis revealed the involvement of the mechanisms of Alu/Alu recombination for the first time in HB and non-homologous or alternative end-joining. CONCLUSION Our results represent the first report of unrelated patients with HB, SCO and GDD. This study and the literature update expand the spectrum of clinical findings and molecular insights observed in patients with HB caused by complete F9 and nearby SOX3 and MAGEC2 gene deletions, which may configure a contiguous gene syndrome.
Collapse
Affiliation(s)
- Claudia P Radic
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Miguel M Abelleyro
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Betiana Ziegler
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Vanina D Marchione
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Julián Nevado
- Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz, Universidad Autónoma, Madrid, Spain.,CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Pablo Lapunzina
- Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz, Universidad Autónoma, Madrid, Spain.,CIBERER, Centro de Investigación Biomédica en Red de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Gabriela Sciuccati
- Servicio de Hematología y Oncología, Hospital de Pediatría Prof. Dr Juan P. Garrahan (HPJG), CABA, Argentina
| | - Daniela Neme
- Fundación de la Hemofilia Alfredo Pavlovsky (FHAP), Hematology, Soler, Ciudad de Buenos Aires, Argentina
| | - Liliana C Rossetti
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina
| | - Mariana Bonduel
- Servicio de Hematología y Oncología, Hospital de Pediatría Prof. Dr Juan P. Garrahan (HPJG), CABA, Argentina
| | - Carlos D De Brasi
- Laboratorio de Genética Molecular de la Hemofilia (GMH), Instituto de Medicina Experimental (IMEX, CONICET-Academia Nacional de Medicina (ANM)), Buenos Aires, Argentina.,Instituto de Investigaciones Hematológicas Mariano R. Castex (IIHEMA, ANM), Buenos Aires, Argentina
| |
Collapse
|
5
|
Shen G, Gao M, Cao Q, Li W. The Molecular Basis of FIX Deficiency in Hemophilia B. Int J Mol Sci 2022; 23:2762. [PMID: 35269902 PMCID: PMC8911121 DOI: 10.3390/ijms23052762] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/15/2022] Open
Abstract
Coagulation factor IX (FIX) is a vitamin K dependent protein and its deficiency causes hemophilia B, an X-linked recessive bleeding disorder. More than 1000 mutations in the F9 gene have been identified in hemophilia B patients. Here, we systematically summarize the structural and functional characteristics of FIX and the pathogenic mechanisms of the mutations that have been identified to date. The mechanisms of FIX deficiency are diverse in these mutations. Deletions, insertions, duplications, and indels generally lead to severe hemophilia B. Those in the exon regions generate either frame shift or inframe mutations, and those in the introns usually cause aberrant splicing. Regarding point mutations, the bleeding phenotypes vary from severe to mild in hemophilia B patients. Generally speaking, point mutations in the F9 promoter region result in hemophilia B Leyden, and those in the introns cause aberrant splicing. Point mutations in the coding sequence can be missense, nonsense, or silent mutations. Nonsense mutations generate truncated FIX that usually loses function, causing severe hemophilia B. Silent mutations may lead to aberrant splicing or affect FIX translation. The mechanisms of missense mutation, however, have not been fully understood. They lead to FIX deficiency, often by affecting FIX's translation, protein folding, protein stability, posttranslational modifications, activation to FIXa, or the ability to form functional Xase complex. Understanding the molecular mechanisms of FIX deficiency will provide significant insight for patient diagnosis and treatment.
Collapse
Affiliation(s)
- Guomin Shen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Meng Gao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Qing Cao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang 471023, China; (M.G.); (Q.C.)
- School of Basic Medical Science, Henan University of Science and Technology, Luoyang 471023, China
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
6
|
Astermark J, Wojciechowski P, Aballéa S, Hakimi Z, Nazir J, Klamroth R. Efficacy of rFIXFc versus rIX-FP for the Treatment of Patients with Hemophilia B: Matching-Adjusted Indirect Comparison of B-LONG and PROLONG-9FP Trials. J Blood Med 2021; 12:613-621. [PMID: 34285621 PMCID: PMC8286734 DOI: 10.2147/jbm.s312885] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/22/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose In patients with hemophilia B, treatment with extended half-life (EHL) recombinant factor IX allows for longer dosing intervals while providing equal or superior bleeding protection compared with standard half-life products. This enables flexible, individualized treatment schedules, which reduce the burden of prophylaxis and improve patient outcomes. This analysis compared the efficacy of recombinant factor IX Fc fusion protein (rFIXFc) and recombinant factor IX albumin fusion protein (rIX-FP), two EHL therapies approved for prophylaxis and treatment of bleeding in hemophilia B. Patients and Methods Matching-adjusted indirect treatment comparison (MAIC) was used to adjust the between-treatment differences in baseline characteristics. Individual patient data for rFIXFc (B-LONG) were matched to aggregated data for rIX-FP (PROLONG-9FP) followed by statistical comparison for estimated annualized bleeding rate (ABR) using a Poisson regression model with adjustment for over dispersion. Data were analyzed according to treatment regimen prior to study entry: prior prophylaxis (rFIXFc, n=48; rIX-FP, n=40) or prior episodic treatment (n=43 and n=19, respectively). Relative treatment effects are presented as incidence rate ratios (IRR) with 95% confidence intervals (CI). Results After adjustment for baseline characteristics, estimated ABR observed for rFIXFc and rIX-FP was not significantly different in patients on prior prophylaxis (1.87 versus 1.58; IRR 1.18, 95% CI 0.67–2.10) or prior episodic (2.25 versus 2.22; IRR 1.01 95% CI 0.40–2.57) regimens. Conclusion This MAIC analysis shows that the estimated ABR for rFIXFc-treated patients from B-LONG was similar to that of rIX-FP-treated patients from PROLONG-9FP and, therefore, indicates that the two EHL therapies provide similar efficacy when used as prophylaxis for patients with hemophilia B. Trough levels differ between the two products (1–3% [targeted] versus 20% [observed], respectively), suggesting that trough level is not a surrogate indicator when ABR is used as a criterion for clinical efficacy when comparing these FIX products in hemophilia B.
Collapse
Affiliation(s)
- Jan Astermark
- Department of Translational Medicine, Lund University, and Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Malmö, Sweden
| | | | | | | | | | - Robert Klamroth
- Department of Internal Medicine, Hemophilia Treatment Centre, Vivantes Klinikum im Friedrichshain, Berlin, Germany
| |
Collapse
|
7
|
Kihlberg K, Baghaei F, Bruzelius M, Funding E, Andre Holme P, Lassila R, Nummi V, Ranta S, Osooli M, Berntorp E, Astermark J. Treatment outcomes in persons with severe haemophilia B in the Nordic region: The B-NORD study. Haemophilia 2021; 27:366-374. [PMID: 33780113 DOI: 10.1111/hae.14299] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/01/2021] [Accepted: 03/06/2021] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Data on outcome in persons with haemophilia B (PwHB) are limited and mainly extrapolated from studies of haemophilia A (HA). AIM To characterize treatment outcomes in persons with severe HB in the Nordic region, with a focus on joint health, compared with matched controls with HA. METHODS PwHB attending haemophilia centres in Denmark, Finland, Norway and Sweden were enrolled and matched with controls with HA. Joint assessment using Haemophilia Joint Health Score (HJHS) and ultrasound according to Haemophilia Early Arthropathy Detection protocol (HEAD-US) was conducted. Adherence was evaluated using the Validated Haemophilia Regimen Treatment Adherence Scale (VERITAS). RESULTS Seventy-nine males with HB, with median age of 30 years (range 1-75), were enrolled. Eleven patients (14%) had a history of or current inhibitor. Twenty-nine PwHB (37%) reported joint bleeds during the prior year, and 35% had previously undergone joint surgery. Ninety-five per cent were on prophylaxis, and 70% used recombinant concentrates, with a median factor consumption of 3,900 IU/kg/year for standard half-life products. Only two patients had a VERITAS score corresponding to 'non-adherence'. Joint health, assessed with HJHS, showed a significant lower score among PwHB compared with HA controls, explained by a difference in the 18-49 age group, without observed differences in older or younger subgroups. The HEAD-US scores were overall low. CONCLUSION The Nordic cohort of PwHB is well treated by prophylaxis, but the goal of zero bleeds for all is not reached. Our findings suggest that patients with severe HB suffer from a milder arthropathy than patients with severe HA.
Collapse
Affiliation(s)
- Kristina Kihlberg
- Clinical Coagulation Research, Department of Translational Medicine, Lund University, Malmö, Sweden.,Department of Haematology, Oncology and Radiation Physics, Centre for Thrombosis and Haemostasis, Skåne University Hospital, Malmö, Sweden
| | - Fariba Baghaei
- Department of Medicine/Hematology and Coagulation, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Maria Bruzelius
- Department of Haematology, Karolinska University Hospital, Stockholm, Sweden.,Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
| | - Eva Funding
- Department of Hematology, Rigshospitalet, Copenhagen, Denmark.,Institute of Clinical Medicine, Copenhagen University, Copenhagen, Denmark
| | - Pål Andre Holme
- Department of Haematology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Riitta Lassila
- Department of Hematology, Coagulation Disorders Unit, Comprehensive Cancer Centre, Helsinki University Hospital, Helsinki, Finland.,Research Program in Systems Oncology, Faculty of Medicine, Helsinki University, Helsinki, Finland
| | - Vuokko Nummi
- Department of Hematology, Coagulation Disorders Unit, Comprehensive Cancer Centre, Helsinki University Hospital, Helsinki, Finland.,Research Program in Systems Oncology, Faculty of Medicine, Helsinki University, Helsinki, Finland
| | - Susanna Ranta
- Pediatric Coagulation, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Mehdi Osooli
- Center for Primary Health Care Research, Department of Clinical Sciences, Lund University, Malmö, Sweden
| | - Erik Berntorp
- Clinical Coagulation Research, Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Jan Astermark
- Clinical Coagulation Research, Department of Translational Medicine, Lund University, Malmö, Sweden.,Department of Haematology, Oncology and Radiation Physics, Centre for Thrombosis and Haemostasis, Skåne University Hospital, Malmö, Sweden
| |
Collapse
|
8
|
Gao W, Xu Y, Liu H, Gao M, Cao Q, Wang Y, Cui L, Huang R, Shen Y, Li S, Yang H, Chen Y, Li C, Yu H, Li W, Shen G. Characterization of missense mutations in the signal peptide and propeptide of FIX in hemophilia B by a cell-based assay. Blood Adv 2020; 4:3659-3667. [PMID: 32766856 PMCID: PMC7422117 DOI: 10.1182/bloodadvances.2020002520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 07/06/2020] [Indexed: 11/20/2022] Open
Abstract
Many mutations in the signal peptide and propeptide of factor IX (FIX) cause hemophilia B. A FIX variants database reports 28 unique missense mutations in these regions that lead to FIX deficiency, but the underlying mechanism is known only for the mutations on R43 that interfere with propeptide cleavage. It remains unclear how other mutations result in FIX deficiency and why patients carrying the same mutation have different bleeding tendencies. Here, we modify a cell-based reporter assay to characterize the missense mutations in the signal peptide and propeptide of FIX. The results show that the level of secreted conformation-specific reporter (SCSR), which has a functional γ-carboxyglutamate (Gla) domain of FIX, decreases significantly in most mutations. The decreased SCSR level is consistent with FIX deficiency in hemophilia B patients. Moreover, we find that the decrease in the SCSR level is caused by several distinct mechanisms, including interfering with cotranslational translocation into the endoplasmic reticulum, protein secretion, γ-carboxylation of the Gla domain, and cleavage of the signal peptide or propeptide. Importantly, our results also show that the SCSR levels of most signal peptide and propeptide mutations increase with vitamin K concentration, suggesting that the heterogeneity of bleeding tendencies may be related to vitamin K levels in the body. Thus, oral administration of vitamin K may alleviate the severity of bleeding tendencies in patients with missense mutations in the FIX signal peptide and propeptide regions.
Collapse
Affiliation(s)
- Wenwen Gao
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Yaqi Xu
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Hongli Liu
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Meng Gao
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Qing Cao
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Yiyi Wang
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Longteng Cui
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Rong Huang
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Yan Shen
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Sanqiang Li
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Haiping Yang
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
- First Affiliated Hospital, Henan University of Science and Technology, Luoyang, People's Republic of China
| | - Yixiang Chen
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| | - Chaokun Li
- Sino-UK Joint Laboratory for Brain Function and Injury, School of Basic Medical Sciences, and
| | - Haichuan Yu
- Department of Biochemistry and Molecular Biology, School of Medical Laboratory, Xinxiang Medical University, Xinxiang, People's Republic of China; and
| | - Weikai Li
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Guomin Shen
- Department of Medical Genetics, Institute of Hemostasis and Thrombosis, School of Basic Medical Sciences, and
| |
Collapse
|