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Zhang K, Zhang H, Yu D, Pan J, Wang M, Xie H. Clinical and functional characterization of rare compound heterozygous mutations in the SERPINC1 gene causing severe thrombophilia. Gene 2024; 897:148085. [PMID: 38104950 DOI: 10.1016/j.gene.2023.148085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/23/2023] [Accepted: 12/13/2023] [Indexed: 12/19/2023]
Abstract
INTRODUCTION Hereditary antithrombin (AT) deficiency is a rare autosomal dominant disorder with significant clinical heterogeneity. In the study, we identified a patient with AT deficiency caused by compound heterozygous mutations in the SERPINC1 gene. METHODS A total of 9 individuals from three generations were investigated. The mutations were identified by direct sequencing of SERPINC1. Multiple in silico tools were programmed to predict the conservation of mutations and the effect on the AT structure. The coagulation state was evaluated by the thrombin generation assay. Recombinant AT was overexpressed in HEK293T cells; the mRNA level was determined using RT-qPCR. Western blotting, ELISA, and immunocytofluorescence were applied to characterize the recombinant AT protein. RESULTS The proband was a 26-year-old male who experienced recurrent venous thrombosis. He presented the type I deficiency with 33 % AT activity and a synchronized decrease in AT antigen. Genetic screening revealed that he carried a heterozygous c.318_319insT (p.Asn107*) in exon 2 and a heterozygous c.922G > T (p.Gly308Cys) in exon 5, both of which were completely conserved in homologous species and resulted in enhanced thrombin generation capability. Hydrophobicity analysis suggested that the p.Gly308Cys mutation may interfere with the hydrophobic state of residues 307-313. In vitro expression studies indicated that the levels of the recombinant protein AT-G308C decreased to 46.98 % ± 2.94 % and 41.35 % ± 1.48 % in transfected cell lysates and media, respectively. After treatment with a proteasome inhibitor (MG132), the quantity of AT-G308C protein in the cytoplasm was replenished to a level comparable to that of the wild type. The mRNA level of AT-N107* was significantly reduced and the recombinant protein AT-N107* was not detected in either the lysate or the culture media. CONCLUSION These two mutations were responsible for the AT defects and clinical phenotypes of the proband. The p.Gly308Cys mutation could lead to proteasome-dependent degradation of the AT protein in the cytoplasm by altering local residue hydrophobicity. The c.318_319insT could eliminate aberrant transcripts by triggering nonsense-mediated mRNA degradation. Both mutations resulted in type I AT deficiency.
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Affiliation(s)
- Ke Zhang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Haiyue Zhang
- Department of Clinical Laboratory, The First Hospital of Jiaxing & The Affiliated Hospital of Jiaxing University, Jiaxing, China.
| | - Dandan Yu
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Jingye Pan
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Mingshan Wang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
| | - Haixiao Xie
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
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Wang HL, Ruan DD, Wu M, Ji YY, Hu XX, Wu QY, Zhang YP, Lin B, Hu YN, Wang H, Tang Y, Fang ZT, Luo JW, Liao LS, Gao MZ. Identification and characterization of two SERPINC1 mutations causing congenital antithrombin deficiency. Thromb J 2023; 21:3. [PMID: 36624481 PMCID: PMC9830717 DOI: 10.1186/s12959-022-00443-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 12/22/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Antithrombin (AT) is the main physiological anticoagulant involved in hemostasis. Hereditary AT deficiency is a rare autosomal dominant thrombotic disease mainly caused by mutations in SERPINC1, which was usually manifested as venous thrombosis and pulmonary embolism. In this study, we analyzed the clinical characteristics and screened for mutant genes in two pedigrees with hereditary AT deficiency, and the functional effects of the pathogenic mutations were evaluated. METHODS Candidate gene variants were analyzed by next-generation sequencing to screen pathogenic mutations in probands, followed by segregation analysis in families by Sanger sequencing. Mutant and wild-type plasmids were constructed and transfected into HEK293T cells to observe protein expression and cellular localization of SERPINC1. The structure and function of the mutations were analyzed by bioinformatic analyses. RESULTS The proband of pedigree A with AT deficiency carried a heterozygous frameshift mutation c.1377delC (p.Asn460Thrfs*20) in SERPINC1 (NM000488.3), a 1377C base deletion in exon 7 resulting in a backward shift of the open reading frame, with termination after translation of 20 residues, and a different residue sequence translated after the frameshift. Bioinformatics analysis suggests that the missing amino acid sequence caused by the frameshift mutation might disrupt the disulfide bond between Cys279 and Cys462 and affect the structural function of the protein. This newly discovered variant is not currently included in the ClinVar and HGMD databases. p.Arg229* resulted in a premature stop codon in exon 4, and bioinformatics analysis suggests that the truncated protein structure lost its domain of interaction with factor IX (Ala414 site) after the deletion of nonsense mutations. However, considering the AT truncation protein resulting from the p.Arg229* variant loss a great proportion of the molecule, we speculate the variant may affect two functional domains HBS and RCL and lack of the corresponding function. The thrombophilia and decreased-AT-activity phenotypes of the two pedigrees were separated from their genetic variants. After lentiviral plasmid transfection into HEK293T cells, the expression level of AT protein decreased in the constructed c.1377delC mutant cells compared to that in the wild-type, which was not only reduced in c.685C > T mutant cells but also showed a significant band at 35 kDa, suggesting a truncated protein. Immunofluorescence localization showed no significant differences in protein localization before and after the mutation. CONCLUSIONS The p.Asn460Thrfs*20 and p.Arg229* variants of SERPINC1 were responsible for the two hereditary AT deficiency pedigrees, which led to AT deficiency by different mechanisms. The p.Asn460Thrfs*20 variant is reported for the first time.
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Affiliation(s)
- Han-lu Wang
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Dan-dan Ruan
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Min Wu
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Yuan-yuan Ji
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Xing-xing Hu
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Cardiovascular Medicine, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Qiu-yan Wu
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Yan-ping Zhang
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Bin Lin
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Ya-nan Hu
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China
| | - Hang Wang
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Cardiovascular Surgery, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Yi Tang
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Interventional Radiology, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Zhu-ting Fang
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Interventional Radiology, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Jie-wei Luo
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Li-sheng Liao
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Hematology, Fujian Provincial Hospital, Fuzhou, 350001 China
| | - Mei-zhu Gao
- grid.415108.90000 0004 1757 9178Fujian Provincial Hospital, Shengli Clinical Medical College of Fujian Medical University, Fuzhou, 350001 China ,grid.415108.90000 0004 1757 9178Department of Nephrology, Fujian Provincial Hospital, Fuzhou, 350001 China
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Jiang W, Deng M, Gan C, Wang L, Mao H, Li Q. A novel missense mutation in TNFAIP3 causes haploinsufficiency of A20. Cell Immunol 2021; 371:104453. [PMID: 34808442 DOI: 10.1016/j.cellimm.2021.104453] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/09/2021] [Accepted: 10/31/2021] [Indexed: 01/28/2023]
Abstract
A20, encoded by TNFAIP3, is an effective anti-inflammatory molecule that plays a crucial role in inhibiting NF-κB signal transmission and is linked to multiple inflammatory diseases. It has been reported that the haploinsufficiency of A20 (HA20) caused by multiple base mutations in TNFAIP3 shows early-onset spontaneous Behçet-like disease. However, the mechanisms by which A20 mutations involved in inflammatory disease are incompletely defined. Herein, we reported a novel TNFAIP3 (c.1804A > T, p.T602S) variation, which has not been reported before. Summarizing the patient's immunodeficiency phenotype, we aimed to delineate the underlying mechanism for regulation of inflammation and immunity. Candidate genes associated with the Behçet-like phenotypes of the patient were screened and identified by using whole-exome and sanger sequencing. Functional studies were performed in A20(c.1804A > T, p.T602S) patient-derived peripheral blood mononuclear cells (PBMCs) and THP-1 cell lines by lentivirus mediating stable over-expression of A20 and A20(c.1804A > T, p.T602S) to analyze the activity of NF-κB signaling pathway. The clinical manifestations in patients with syndrome are Behçet-like disorder, and sequencing revealed heterozygous mutation in TNFAIP3 (c.1804A > T, p.T602S). Functional tests found that the PBMCs of the patient and his family carrying this heterozygous variant stimulated by LPS, TNF-α, or IL-1β, increased the levels of inflammatory factors and induced over-activation of the canonical NF-κB signaling pathway. Similar results were also observed in the stable transduction THP-1 (A20, c.1804A>T) cell line stimulated by LPS, TNF-α or IL-1β. The novel loss-of-function A20 variation (c.1804A > T, p.T602S) causes over-activation of the canonical NF-κB signaling pathway and fail to terminate NF-κB signaling in response to stimulation by inflammatory cytokines. The variation triggers a dominantly-inherited Behçet-like disorder caused by haploinsufficiency of the A20 protein. Identification of the novel A20 mutation attaches great importance to prenatal diagnosis and fetal therapeutic intervention, drastically reducing the risk of newborns suffering from HA20.
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Affiliation(s)
- Wei Jiang
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China
| | - Mengyue Deng
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China
| | - Chun Gan
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China
| | - Li Wang
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China
| | - Huawei Mao
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China; Department of Rheumatology and Immunology, Beijing Children's Hospital, Capital Medical University, Beijing, PR China
| | - Qiu Li
- Pediatric Research Institute, Chongqing Key Laboratory of Pediatrics, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, PR China; National Clinical Research Center for Child Health and Disorders, Chongqing, PR China; China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Chongqing, PR China.
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Lu Y, Villoutreix BO, Biswas I, Ding Q, Wang X, Rezaie AR. Antithrombin Resistance Rescues Clotting Defect of Homozygous Prothrombin-Y510N Dysprothrombinemia. Thromb Haemost 2021; 122:679-691. [PMID: 34256393 PMCID: PMC8755856 DOI: 10.1055/a-1549-6407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A patient with hematuria in our clinic was diagnosed with urolithiasis. Analysis of the patient's plasma clotting time indicated that both activated partial thromboplastin time (52.6 seconds) and prothrombin time (19.4 seconds) are prolonged and prothrombin activity is reduced to 12.4% of normal, though the patient exhibited no abnormal bleeding phenotype and a prothrombin antigen level of 87.9%. Genetic analysis revealed the patient is homozygous for prothrombin Y510N mutation. We expressed and characterized the prothrombin-Y510N variant in appropriate coagulation assays and found that the specificity constant for activation of the mutant zymogen by factor Xa is impaired approximately fivefold. Thrombin generation assay using patient's plasma and prothrombin-deficient plasma supplemented with either wild-type or prothrombin-Y510N revealed that both peak height and time to peak for the prothrombin mutant are decreased; however, the endogenous thrombin generation potential is increased. Further analysis indicated that the thrombin mutant exhibits resistance to antithrombin and is inhibited by the serpin with approximately 12-fold slower rate constant. Protein C activation by thrombin-Y510N was also decreased by approximately 10-fold; however, thrombomodulin overcame the catalytic defect. The Na+-concentration-dependence of the amidolytic activities revealed that the dissociation constant for the interaction of Na+ with the mutant has been elevated approximately 20-fold. These results suggest that Y510 (Y184a in chymotrypsin numbering) belongs to network of residues involved in binding Na+. A normal protein C activation by thrombin-Y510N suggests that thrombomodulin modulates the conformation of the Na+-binding loop of thrombin. The clotting defect of thrombin-Y510N appears to be compensated by its markedly lower reactivity with antithrombin, explaining patient's normal hemostatic phenotype.
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Affiliation(s)
- Yeling Lu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States.,Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bruno O Villoutreix
- INSERM 1141, NeuroDiderot, Université de Paris, Hôpital Robert-Debré, Paris, France
| | - Indranil Biswas
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States
| | - Qiulan Ding
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xuefeng Wang
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Alireza R Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States.,Department of Biochemistry and Molecular Biology, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
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Rezaie AR, Giri H. Anticoagulant and signaling functions of antithrombin. J Thromb Haemost 2020; 18:3142-3153. [PMID: 32780936 PMCID: PMC7855051 DOI: 10.1111/jth.15052] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 07/25/2020] [Accepted: 08/04/2020] [Indexed: 12/19/2022]
Abstract
Antithrombin (AT) is a major plasma glycoprotein of the serpin superfamily that regulates the proteolytic activity of the procoagulant proteases of both intrinsic and extrinsic pathways. Two important structural features that participate in the regulatory function of AT include a mobile reactive center loop that binds to active site of coagulation proteases, trapping them in the form of inactive covalent complexes, and a basic D-helix that binds to therapeutic heparins and heparan sulfate proteoglycans (HSPGs) on vascular endothelial cells. The binding of D-helix of AT by therapeutic heparins promotes the reactivity of the serpin with coagulation proteases by several orders of magnitude by both a conformational activation of the serpin and a template (bridging) mechanism. In addition to its essential anticoagulant function, AT elicits a potent anti-inflammatory signaling response when it binds to distinct vascular endothelial cell HSPGs, thereby inducing prostacyclin synthesis. Syndecans-4 has been found as a specific membrane-bound HSPG receptor on endothelial cells that relays the signaling effect of AT to the relevant second messenger molecules in the signal transduction pathways inside the cell. However, following cleavage by coagulation proteases and/or by spontaneous conversion to a latent form, AT loses both its anti-inflammatory activity and high-affinity interaction with heparin and HSPGs. Interestingly, these low-affinity heparin conformers of AT elicit potent proapoptotic and antiangiogenic activities by also binding to specific HSPGs by unknown mechanisms. This review article will summarize current knowledge about mechanisms through which different conformers of AT exert their serine protease inhibitory and intracellular signaling functions in these biological pathways.
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Affiliation(s)
- Alireza R. Rezaie
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Hemant Giri
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
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