1
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Trégouët DA, Morange PE. Next-generation sequencing strategies in venous thromboembolism: in whom and for what purpose? J Thromb Haemost 2024; 22:1826-1834. [PMID: 38641321 DOI: 10.1016/j.jtha.2024.04.004] [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: 02/13/2024] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/21/2024]
Abstract
This invited review follows the oral presentation "To Sequence or Not to Sequence, That Is Not the Question; But 'When, Who, Which and What For?' Is" given during the State of the Art session "Translational Genomics in Thrombosis: From OMICs to Clinics" of the International Society on Thrombosis and Haemostasis 2023 Congress. Emphasizing the power of next-generation sequencing technologies and the diverse strategies associated with DNA variant analysis, this review highlights the unresolved questions and challenges in their implementation both for the clinical diagnosis of venous thromboembolism and in translational research.
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Affiliation(s)
- David-Alexandre Trégouët
- University of Bordeaux, Institut National de la Santé et de la Recherche Médicale, Bordeaux Population Health Research Center, Unité Mixte de Recherche 1219, Bordeaux, France.
| | - Pierre-Emmanuel Morange
- Cardiovascular and Nutrition Research Center (Centre de Recherche en CardioVasculaire et Nutrition), Institut National de la Santé et de la Recherche Médicale, Institut National de Recherche pour l'agriculture, l' Alimentation et l'Environnement, Aix-Marseille University, Marseille, France
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2
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Xu F, Zhou X, Jin Y, Yang L, Pan J, Wang M, Chen X. Analysis of PROS1 mutations and clinical characteristics in three Chinese families with hereditary protein S deficiency. Ann Hematol 2024; 103:653-662. [PMID: 38175252 DOI: 10.1007/s00277-023-05607-6] [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: 11/15/2023] [Accepted: 12/21/2023] [Indexed: 01/05/2024]
Abstract
We report three heterozygous PROS1 mutations that caused type I protein S deficiency in three unrelated Chinese families. We measured protein S activity and antigen levels for all participants, screened them for mutations in the PROS1 gene. And we employed the calibrated automated thrombin generation (CAT) method to investigate thrombin generation. Numerous bioinformatics tools were utilized to analyze the conservation, pathogenicity of mutation, and spatial structure of the protein S. Phenotyping analysis indicated that all three probands exhibited simultaneous reduced levels of PS:A, TPS:Ag, and FPS:Ag. Genetic testing revealed that proband A harbored a heterozygous c.458_458delA (p.Lys153Serfs*6) mutation in exon 5, proband B carried a heterozygous c.1687C>T (p.Gln563stop) mutation in exon 14, and proband C exhibited a heterozygous c.200A>C (p.Glu67Ala) mutation in exon 2. Bioinformatic analysis predicted that the p.Lys153Serfs*6 frameshift mutation and the p.Gln563stop nonsense mutation in the protein S were classified as "disease-causing." The identification of the novel mutation p.Lys153Serfs*6 in PROS1 enriches the Human Genome Database. Our research suggests that these three mutations (p.Lys153Serfs*6, p.Gln563stop, and p.Glu67Ala) are possibly responsible for the decreased level of protein S in the three families. Furthermore, the evidence also supports the notion that individuals who are asymptomatic but have a family history of PSD can benefit from genetic analysis of the PROS1 gene.
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Affiliation(s)
- Fei Xu
- 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, Zhejiang, China
| | - Xingxing Zhou
- 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, Zhejiang, China
| | - Yanhui Jin
- 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, Zhejiang, China
| | - Lihong Yang
- 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, Zhejiang, 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, Zhejiang, 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, Zhejiang, China
| | - Xiaoli Chen
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou, Zhejiang, 325000, China.
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3
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Soukarieh O, Tillet E, Proust C, Dupont C, Jaspard-Vinassa B, Soubrier F, Goyenvalle A, Eyries M, Trégouët DA. uAUG creating variants in the 5'UTR of ENG causing Hereditary Hemorrhagic Telangiectasia. NPJ Genom Med 2023; 8:32. [PMID: 37848456 PMCID: PMC10582052 DOI: 10.1038/s41525-023-00378-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023] Open
Abstract
Hereditary Hemorrhagic Telangiectasia (HHT) is a rare, autosomal dominant, vascular disorder. About 80% of cases are caused by pathogenic variants in ACVRL1 (also known as ALK1) and ENG, with the remaining cases being unexplained. We identified two variants, c.-79C>T and c.-68G>A, in the 5'UTR of ENG in two unrelated patients. They create upstream AUGs at the origin of upstream overlapping open reading frames (uoORFs) ending at the same stop codon. To assess the pathogenicity of these variants, we performed functional assays based on the expression of wild-type and mutant constructs in human cells and evaluated their effect on ALK1 activity in a BMP-response element assay. This assay is mandatory for molecular diagnosis and has been so far only applied to coding ENG variants. These variants were associated with a decrease of protein levels in HeLa and HUVEC cells and a decreased ability to activate ALK1. We applied the same experiments on three additional uoORF-creating variants (c.-142A>T, c.-127C>T and c.-10C>T) located in the 5'UTR of ENG and previously reported in HHT patients. We found that all the analyzed variants alter protein levels and function. Additional experiments relying on an artificial deletion in our mutated constructs show that identified uAUGs could initiate the translation indicating that the associated effect is translation-dependent. Overall, we have identified two 5'UTR ENG variations in HHT patients and shed new light on the role of upstream ORFs on ENG regulation. Our findings contribute to the amelioration of molecular diagnosis in HHT.
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Affiliation(s)
- Omar Soukarieh
- Univ. Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR 1219, F-33000, Bordeaux, France.
- Univ. Bordeaux, INSERM, BMC, U1034, F-33600, Pessac, France.
| | - Emmanuelle Tillet
- INSERM UMR U1292, Laboratoire BIOSANTE, Université Grenoble Alpes, Inserm, CEA, Grenoble, France
| | - Carole Proust
- Univ. Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR 1219, F-33000, Bordeaux, France
| | - Charlène Dupont
- Univ. Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR 1219, F-33000, Bordeaux, France
| | | | - Florent Soubrier
- Département de Génétique, Hôpital Pitié-Salpêtrière, Sorbonne Université, Assistance Publique-Hôpitaux de Paris, Paris, France
- Sorbonne Université, INSERM, UMR_S 1166, Institute of Cardiometabolism And Nutrition (ICAN), Paris, France
| | | | - Mélanie Eyries
- Département de Génétique, Hôpital Pitié-Salpêtrière, Sorbonne Université, Assistance Publique-Hôpitaux de Paris, Paris, France
- Sorbonne Université, INSERM, UMR_S 1166, Institute of Cardiometabolism And Nutrition (ICAN), Paris, France
| | - David-Alexandre Trégouët
- Univ. Bordeaux, INSERM, Bordeaux Population Health Research Center, UMR 1219, F-33000, Bordeaux, France
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4
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA (NEW YORK, N.Y.) 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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5
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Coursimault J, Cassinari K, Lecoquierre F, Quenez O, Coutant S, Derambure C, Vezain M, Drouot N, Vera G, Schaefer E, Philippe A, Doray B, Lambert L, Ghoumid J, Smol T, Rama M, Legendre M, Lacombe D, Fergelot P, Olaso R, Boland A, Deleuze JF, Goldenberg A, Saugier-Veber P, Nicolas G. Deep intronic NIPBL de novo mutations and differential diagnoses revealed by whole genome and RNA sequencing in Cornelia de Lange syndrome patients. Hum Mutat 2022; 43:1882-1897. [PMID: 35842780 DOI: 10.1002/humu.24438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/23/2022] [Accepted: 07/09/2022] [Indexed: 01/25/2023]
Abstract
Cornelia de Lange syndrome (CdLS; MIM# 122470) is a rare developmental disorder. Pathogenic variants in 5 genes explain approximately 50% cases, leaving the other 50% unsolved. We performed whole genome sequencing (WGS) ± RNA sequencing (RNA-seq) in 5 unsolved trios fulfilling the following criteria: (i) clinical diagnosis of classic CdLS, (ii) negative gene panel sequencing from blood and saliva-isolated DNA, (iii) unaffected parents' DNA samples available and (iv) proband's blood-isolated RNA available. A pathogenic de novo mutation (DNM) was observed in a CdLS differential diagnosis gene in 3/5 patients, namely POU3F3, SPEN, and TAF1. In the other two, we identified two distinct deep intronic DNM in NIPBL predicted to create a novel splice site. RT-PCRs and RNA-Seq showed aberrant transcripts leading to the creation of a novel frameshift exon. Our findings suggest the relevance of WGS in unsolved suspected CdLS cases and that deep intronic variants may account for a proportion of them.
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Affiliation(s)
- Juliette Coursimault
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Kévin Cassinari
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - François Lecoquierre
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Olivier Quenez
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Sophie Coutant
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Céline Derambure
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Myriam Vezain
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Nathalie Drouot
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Gabriella Vera
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Elise Schaefer
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Anaïs Philippe
- Service de Génétique Médicale, Institut de Génétique Médicale d'Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Bérénice Doray
- Service de Génétique Médicale, Centre Hospitalier Universitaire Félix Guyon, Bellepierre Saint Denis, France
| | - Laëtitia Lambert
- Service de Génétique Clinique, CHRU NANCY, F-54000 France, UMR INSERM U 1256 N-GERE, F-54000, Nancy, France
| | - Jamal Ghoumid
- Université de Lille, ULR7364 RADEME, CHU Lille, Clinique de Génétique « Guy Fontaine », and FHU-G4 Génomique, F-59000, Lille, France
| | - Thomas Smol
- Université de Lille, ULR7364 RADEME, CHU Lille, Institut de Génétique Médicale, and FHU-G4 Génomique, F-59000, Lille, France
| | - Mélanie Rama
- Institut de Génétique Médicale, CHU de Lille, France
| | - Marine Legendre
- Service de Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Didier Lacombe
- INSERM U1211, Université de Bordeaux; Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Patricia Fergelot
- INSERM U1211, Université de Bordeaux; Génétique Médicale, CHU de Bordeaux, Bordeaux, France
| | - Robert Olaso
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057, Evry, France
| | - Anne Boland
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057, Evry, France
| | - Jean-François Deleuze
- Université Paris-Saclay, CEA, Centre National de Recherche en Génomique Humaine (CNRGH), 91057, Evry, France
| | - Alice Goldenberg
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Pascale Saugier-Veber
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
| | - Gaël Nicolas
- Normandie Univ, UNIROUEN, Inserm U1245 and CHU Rouen, Department of Genetics and reference center for developmental disorders, FHU-G4 Génomique, F-76000, Rouen, France
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6
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Soukarieh O, Meguerditchian C, Proust C, Aïssi D, Eyries M, Goyenvalle A, Trégouët DA. Common and Rare 5′UTR Variants Altering Upstream Open Reading Frames in Cardiovascular Genomics. Front Cardiovasc Med 2022; 9:841032. [PMID: 35387445 PMCID: PMC8977850 DOI: 10.3389/fcvm.2022.841032] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/21/2022] [Indexed: 01/16/2023] Open
Abstract
High-throughput sequencing (HTS) technologies are revolutionizing the research and molecular diagnosis landscape by allowing the exploration of millions of nucleotide sequences at an unprecedented scale. These technologies are of particular interest in the identification of genetic variations contributing to the risk of rare (Mendelian) and common (multifactorial) human diseases. So far, they have led to numerous successes in identifying rare disease-causing mutations in coding regions, but few in non-coding regions that include introns, untranslated (UTR), and intergenic regions. One class of neglected non-coding variations is that of 5′UTR variants that alter upstream open reading frames (upORFs) of the coding sequence (CDS) of a natural protein coding transcript. Following a brief summary of the molecular bases of the origin and functions of upORFs, we will first review known 5′UTR variations altering upORFs and causing rare cardiovascular disorders (CVDs). We will then investigate whether upORF-affecting single nucleotide polymorphisms could be good candidates for explaining association signals detected in the context of genome-wide association studies for common complex CVDs.
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Affiliation(s)
- Omar Soukarieh
- INSERM, Bordeaux Population Health, U1219, Molecular Epidemiology of Vascular and Brain Disorders, University of Bordeaux, Bordeaux, France
- *Correspondence: Omar Soukarieh,
| | - Caroline Meguerditchian
- INSERM, Bordeaux Population Health, U1219, Molecular Epidemiology of Vascular and Brain Disorders, University of Bordeaux, Bordeaux, France
| | - Carole Proust
- INSERM, Bordeaux Population Health, U1219, Molecular Epidemiology of Vascular and Brain Disorders, University of Bordeaux, Bordeaux, France
| | - Dylan Aïssi
- INSERM, Bordeaux Population Health, U1219, Molecular Epidemiology of Vascular and Brain Disorders, University of Bordeaux, Bordeaux, France
| | - Mélanie Eyries
- Department of Genetics, Pitié-Salpêtrière Hospital, Assistance Publique-Hôpitaux de Paris, Sorbonne Université, Paris, France
| | | | - David-Alexandre Trégouët
- INSERM, Bordeaux Population Health, U1219, Molecular Epidemiology of Vascular and Brain Disorders, University of Bordeaux, Bordeaux, France
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7
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Larsen OH, Kjaergaard AD, Hvas AM, Nissen PH. Genetic Variants in the Protein S ( PROS1 ) Gene and Protein S Deficiency in a Danish Population. TH OPEN 2021; 5:e479-e488. [PMID: 34729451 PMCID: PMC8553426 DOI: 10.1055/s-0041-1736636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/08/2021] [Indexed: 12/01/2022] Open
Abstract
Protein S (PS) deficiency is a risk factor for venous thromboembolism (VTE) and can be caused by variants of the gene encoding PS (
PROS1
). This study aimed to evaluate the clinical value of molecular analysis of the
PROS1
gene in PS-deficient participants. We performed Sanger sequencing of the coding region of the
PROS1
gene and multiplex ligation-dependent probe amplification to exclude large structural rearrangements. Free PS was measured by a particle-enhanced immunoassay, while PS activity was assessed by a clotting method.
A total of 87 PS-deficient participants and family members were included. In 22 index participants, we identified 13
PROS1
coding variants. Five variants were novel. In 21 index participants, no coding sequence variants or structural rearrangements were identified. The free PS level was lower in index participants carrying a
PROS1
variant compared with index participants with no variant (0.51 [0.32–0.61] vs. 0.62 [0.57–0.73] × 10
3
IU/L;
p
< 0.05). The p.(Thr78Met) variant was associated with only slightly decreased free PS levels (0.59 [0.53–0.66] × 10
3
IU/L) compared with the p.(Glu390Lys) variant (0.27 [0.24–0.37] × 10
3
IU/L,
p
< 0.01). The frequency of VTE in participants with a coding
PROS1
variant was 43 and 17% in the group with normal
PROS1
gene (
p
= 0.05).
In conclusion, we report 13
PROS1
coding variants including five novel variants. PS levels differ by
PROS1
variant and the frequency of VTE was higher when a coding
PROS1
variant was present. Hence, molecular analysis of the
PROS1
gene may add clinical value in the diagnostic work-up of PS deficiency.
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Affiliation(s)
- Ole Halfdan Larsen
- Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Alisa D Kjaergaard
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Anne-Mette Hvas
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Peter H Nissen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark
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8
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Abstract
PURPOSE OF REVIEW Protein S (PS) is an essential natural anticoagulant. PS deficiency is a major contributor to acquired hypercoagulability. Acquired hypercoagulability causes myocardial infarction, stroke, and deep vein thrombosis in millions of individuals. Yet, despite its importance in hemostasis, PS is the least understood anticoagulant. Even after 40 years since PS was first described, we are still uncovering information about how PS functions. The purpose of this review is to highlight recent findings that advance our understanding of the functions of PS and explain hypercoagulability caused by severe PS deficiency. RECENT FINDINGS PS has long been described as a cofactor for Activated Protein C (APC) and Tissue Factor Pathway Inhibitor (TFPI). However, a recent report describes direct inhibition of Factor IXa (FIXa) by PS, an activity of PS that had been completely overlooked. Thrombophilia is becoming a more frequently reported disorder. Hereditary PS deficiency is an anticoagulant deficiency that results eventually in thrombophilia. In addition, PS deficiency is a predisposing factor for venous thromboembolism (VTE), but an effect of PS deficiency in arterial thrombosis, such as arterial ischemic stroke, is uncertain. Plasma PS concentration decreases in pregnant women. Inherited thrombophilias are important etiologies for recurrent pregnancy loss, and anticoagulation therapy is of benefit to women with recurrent pregnancy loss who had documented only PS deficiency.Hypoxia is a risk factor for VTE, and hypoxia downregulates plasma PS level. Importantly, COVID-19 can lead to hypoxemia because of lung damage from IL6-driven inflammatory responses to the viral infection. Because hypoxia decreases the abundance of the key anticoagulant PS, we surmise that the IL6-induced cytokine explosion combined with hypoxemia causes a drop in PS level that exacerbates the thrombotic risk in COVID-19 patients. SUMMARY This review is intended to advance understanding of the anticoagulant function of an important plasma protein, PS. Despite 40+ years of research, we have not had a complete description of PS biology as it pertains to control of blood coagulation. However, the picture of PS function has become sharper with the recent discovery of FIXa inhibition by PS. Hemostasis mediated by PS now includes regulation of FIXa activity alongside the cofactor activities of PS in the TFPI/APC pathways. In addition, the direct inhibition of FIXa by PS suggests that PS, particularly a small derivative of PS, could be used to treat individuals with PS deficiencies or abnormalities that cause thrombotic complications.
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Affiliation(s)
- Rinku Majumder
- Department of Biochemistry & Molecular Biology, Louisiana State University Health Sciences Center, New Orleans, Louisiana, USA
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