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Giannakopoulos B, Krilis SA. Domain 5 of Beta 2 glycoprotein I: Friend or foe in health? Context matters. Clin Immunol 2024; 265:110282. [PMID: 38917928 DOI: 10.1016/j.clim.2024.110282] [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: 06/14/2023] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024]
Abstract
Beta 2 glycoprotein I (β2GPI) is the major autoantigen in the antiphospholipid syndrome, an autoimmune disorder characterized by thrombotic and obstetric complications. The autoantibodies that target beta 2 glycoprotein I are pathogenic and contribute to disease pathogenesis. The β2GPI molecule is composed of 5 domains that are numbered 1 through to 5. Autoantibodies bind mainly to domain 1 whereas the majority of the biological functions of the β2GPI molecule in diverse processes such as apoptotic cell clearance, complement regulation, lipopolysaccharide clearance and anticoagulation have been localised to domain 5 and its unique biochemistry, reviewed in this article. The role of purified domain 5 peptide as a potential therapeutic agent in APS and ischemia reperfusion injury is discussed.
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Affiliation(s)
- Bill Giannakopoulos
- Faculty of Medicine and Health, University of New South Wales, St George and Sutherland Campus, Level 2, Pitney Building, Kogarah, Sydney, NSW 2217, Australia; Department of Rheumatology, St George Public Hospital, Kogarah, Sydney, 2217, Australia.
| | - Steven A Krilis
- Faculty of Medicine and Health, University of New South Wales, St George and Sutherland Campus, Level 2, Pitney Building, Kogarah, Sydney, NSW 2217, Australia; Department of Infectious Diseases, Immunology, and Sexual Health, St George Public Hospital, Kogarah, Sydney 2217, Australia.
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2
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Hasdemir HS, Pozzi N, Tajkhorshid E. Atomistic characterization of β2-glycoprotein I domain V interaction with anionic membranes. J Thromb Haemost 2024:S1538-7836(24)00427-6. [PMID: 39047943 DOI: 10.1016/j.jtha.2024.07.010] [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: 03/20/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/27/2024]
Abstract
BACKGROUND Interaction of β2-glycoprotein I (β2GPI) with anionic membranes is crucial in antiphospholipid syndrome (APS), implicating the role of its membrane-binding domain, domain V (DV). The mechanism of DV binding to anionic lipids is not fully understood. OBJECTIVES This study aimed to elucidate the molecular details of β2GPI DV binding to anionic membranes. METHODS We utilized molecular dynamics simulations to investigate the structural basis of anionic lipid recognition by DV. To corroborate the membrane-binding mode identified in the highly mobile membrane mimetic simulations, we conducted additional simulations using a full membrane model. RESULTS The study identified critical regions in DV, namely the lysine-rich loop and the hydrophobic loop, which are essential for membrane association via electrostatic and hydrophobic interactions, respectively. A novel lysine pair contributing to membrane binding was also discovered, providing new insights into β2GPI's membrane interaction. Simulations revealed 2 distinct binding modes of DV to the membrane, with mode 1 characterized by the insertion of the hydrophobic loop into the lipid bilayer, suggesting a dominant mechanism for membrane association. This interaction is pivotal for the pathogenesis of APS, as it facilitates the recognition of β2GPI by antiphospholipid antibodies. CONCLUSION The study advances our understanding of the molecular interactions between β2GPI's DV and anionic membranes, which are crucial for APS pathogenesis. It highlights the importance of specific regions in DV for membrane binding and reveals a predominant binding mode. These findings have significant implications for APS diagnostics and therapeutics, offering a deeper insight into the molecular basis of the syndrome.
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Affiliation(s)
- Hale S Hasdemir
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA; Center for Biophysics and Computational Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Nicola Pozzi
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA. https://www.twitter.com/LabPozzi
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA; Center for Biophysics and Computational Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA; Department of Biochemistry, University of Illinois Urbana-Champaign, Urbana, Illinois, USA.
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3
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Hasdemir HS, Pozzi N, Tajkhorshid E. Atomistic Characterization of Beta-2-Glycoprotein I Domain V Interaction with Anionic Membranes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.585743. [PMID: 38562685 PMCID: PMC10983932 DOI: 10.1101/2024.03.19.585743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Background Interaction of beta-2-glycoprotein I ( β 2 GPI) with anionic membranes is crucial in antiphospholipid syndrome (APS), implicating the role of it's membrane bind-ing domain, Domain V (DV). The mechanism of DV binding to anionic lipids is not fully understood. Objectives This study aims to elucidate the mechanism by which DV of β 2 GPI binds to anionic membranes. Methods We utilized molecular dynamics (MD) simulations to investigate the struc-tural basis of anionic lipid recognition by DV. To corroborate the membrane-binding mode identified in the HMMM simulations, we conducted additional simulations using a full mem-brane model. Results The study identified critical regions in DV, namely the lysine-rich loop and the hydrophobic loop, essential for membrane association via electrostatic and hydrophobic interactions, respectively. A novel lysine pair contributing to membrane binding was also discovered, providing new insights into β 2 GPI's membrane interaction. Simulations revealed two distinct binding modes of DV to the membrane, with mode 1 characterized by the insertion of the hydrophobic loop into the lipid bilayer, suggesting a dominant mechanism for membrane association. This interaction is pivotal for the pathogenesis of APS, as it facilitates the recognition of β 2 GPI by antiphospholipid antibodies. Conclusion The study advances our understanding of the molecular interactions be-tween β 2 GPI's DV and anionic membranes, crucial for APS pathogenesis. It highlights the importance of specific regions in DV for membrane binding and reveals a predominant bind-ing mode. These findings have significant implications for APS diagnostics and therapeutics, offering a deeper insight into the molecular basis of the syndrome.
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Winans T, Oaks Z, Choudhary G, Patel A, Huang N, Faludi T, Krakko D, Nolan J, Lewis J, Blair S, Lai Z, Landas SK, Middleton F, Asara JM, Chung SK, Wyman B, Azadi P, Banki K, Perl A. mTOR-dependent loss of PON1 secretion and antiphospholipid autoantibody production underlie autoimmunity-mediated cirrhosis in transaldolase deficiency. J Autoimmun 2023; 140:103112. [PMID: 37742509 PMCID: PMC10957505 DOI: 10.1016/j.jaut.2023.103112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/26/2023]
Abstract
Transaldolase deficiency predisposes to chronic liver disease progressing from cirrhosis to hepatocellular carcinoma (HCC). Transition from cirrhosis to hepatocarcinogenesis depends on mitochondrial oxidative stress, as controlled by cytosolic aldose metabolism through the pentose phosphate pathway (PPP). Progression to HCC is critically dependent on NADPH depletion and polyol buildup by aldose reductase (AR), while this enzyme protects from carbon trapping in the PPP and growth restriction in TAL deficiency. Although AR inactivation blocked susceptibility to hepatocarcinogenesis, it enhanced growth restriction, carbon trapping in the non-oxidative branch of the PPP and failed to reverse the depletion of glucose 6-phosphate (G6P) and liver cirrhosis. Here, we show that inactivation of the TAL-AR axis results in metabolic stress characterized by reduced mitophagy, enhanced overall autophagy, activation of the mechanistic target of rapamycin (mTOR), diminished glycosylation and secretion of paraoxonase 1 (PON1), production of antiphospholipid autoantibodies (aPL), loss of CD161+ NK cells, and expansion of CD38+ Ito cells, which are responsive to treatment with rapamycin in vivo. The present study thus identifies glycosylation and secretion of PON1 and aPL production as mTOR-dependent regulatory checkpoints of autoimmunity underlying liver cirrhosis in TAL deficiency.
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Affiliation(s)
- T Winans
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - Z Oaks
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - G Choudhary
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - A Patel
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - N Huang
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - T Faludi
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - D Krakko
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - J Nolan
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - J Lewis
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - Sarah Blair
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - Z Lai
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - S K Landas
- Departments of Pathology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - F Middleton
- Departments of Neuroscience, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - J M Asara
- Division of Signal Transduction, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - S K Chung
- Faculty of Medicine, Macau University of Science and Technology, Taipa, Macau
| | - B Wyman
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - P Azadi
- University of Georgia, Athens, GA 30602, USA
| | - K Banki
- Departments of Pathology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA
| | - A Perl
- Departments of Medicine, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Microbiology and Immunology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA; Departments of Biochemistry and Molecular Biology, State University of New York, Norton College of Medicine, Syracuse, NY, 13210, USA.
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Yao WC, Leong KH, Chiu LT, Chou PY, Wu LC, Chou CY, Kuo CF, Tsai SY. The trends in the incidence and thrombosis-related comorbidities of antiphospholipid syndrome: a 14-year nationwide population-based study. Thromb J 2022; 20:50. [PMID: 36050731 PMCID: PMC9434885 DOI: 10.1186/s12959-022-00409-8] [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: 05/23/2022] [Accepted: 08/18/2022] [Indexed: 12/02/2022] Open
Abstract
Background This study aims to provide 14-year nationwide epidemiology data to evaluate the incidence ratio of APS in Taiwan and the condition of comorbidities by analyzing the National Health Insurance Research Database. Methods Nineteen thousand one hundred sixty-three patients newly diagnosed as having APS during the 2000–2013 period and 76,652 controls (with similar distributions of age and sex) were analyzed. Results The incidence of APS increased from 4.87 to 6.49 per 10,000 person-years in the Taiwan population during 2000–2013. The incidence of APS increased with age after 20 years old, especially in the female population, and it rose rapidly after age over 60 years old. In addition, APS cohorts presented a higher proportion of diabetes mellitus, hypertension, hyperlipidemia, stroke, heart failure, atrial fibrillation, myocardial infarction, PAOD, chronic kidney disease, COPD, deep vein thrombosis, pulmonary embolism, SLE, rheumatoid arthritis, Sjogren’s syndrome, and polymyositis. Conclusions Our study indicated an increasing trend in APS incidence among the Taiwanese population and a relationship between APS and potential comorbidities. This large national study found that the APS risk is heavily influenced by sex and age. Thus, the distinctive sex and age patterns might be constructive given exploring potential causal mechanisms. Furthermore, our findings indicate that clinicians should have a heightened awareness of the probability of APS, especially in women in certain age groups presenting with symptoms of APS.
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Affiliation(s)
- Wei-Cheng Yao
- Department of Anesthesiology and Pain Medicine, Min-Sheng General Hospital, Tao-Yuan City, Taiwan
| | - Kam-Hang Leong
- Department of Laboratory Medicine, MacKay Memorial Hospital, No. 92, Sec. 2, Zhongshan N. Rd, Taipei City, 10449, Taiwan.,Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Lu-Ting Chiu
- Management Office for Health Data, China Medical University Hospital, Taichung City, Taiwan
| | - Po-Yi Chou
- Department of Laboratory Medicine, MacKay Memorial Hospital, No. 92, Sec. 2, Zhongshan N. Rd, Taipei City, 10449, Taiwan
| | - Li-Chih Wu
- Department of Laboratory Medicine, MacKay Memorial Hospital, No. 92, Sec. 2, Zhongshan N. Rd, Taipei City, 10449, Taiwan
| | - Chih-Yu Chou
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Chien-Feng Kuo
- Department of Medicine, MacKay Medical College, New Taipei City, Taiwan.,Division of Infectious Diseases, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan.,Department of Nursing, MacKay Junior College of Medicine, Nursing and Management, New Taipei City, Taiwan
| | - Shin-Yi Tsai
- Department of Laboratory Medicine, MacKay Memorial Hospital, No. 92, Sec. 2, Zhongshan N. Rd, Taipei City, 10449, Taiwan. .,Department of Medicine, MacKay Medical College, New Taipei City, Taiwan. .,Institute of Biomedical Sciences, MacKay Medical College, New Taipei City, Taiwan. .,Institute of Long-Term Care, MacKay Medical College, New Taipei City, Taiwan. .,Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.
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Asif S, Bali A, Dang AK, Gonzalez DA, Kumar R. Neurological and Neuropsychiatric Manifestations of Antiphospholipid-Antibody Syndrome (APS). Cureus 2022; 14:e26022. [PMID: 35865415 PMCID: PMC9293251 DOI: 10.7759/cureus.26022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2022] [Indexed: 02/01/2023] Open
Abstract
Antiphospholipid antibody syndrome (APS) is an autoimmune disorder mediated by the presence of a group of autoantibodies, specifically the anticardiolipin antibody (aCL), the beta-2 glycoprotein I (β2GPI), and the lupus anticoagulant (LA). Patients diagnosed with antiphospholipid antibody syndrome (APS) present with many symptoms, the most common being the consequence of thrombotic events that can be catastrophic and lead to mild to severe residual disabilities over a significant amount of time and can impair the quality of life. These events are often present in the younger population. Many times, these thrombotic events are heralded by a spectrum of psychiatric symptoms, which when worked up in the right direction may hint toward an oncoming thrombotic event and may potentially prevent those events by prompting primary prophylaxis treatment by the treating physician. In this review, we aim to comprehensively put forth the many neurological and neuropsychiatric manifestations of APS, their pathology, and management.
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Grossi C, Artusi C, Meroni P, Borghi MO, Neglia L, Lonati PA, Oggioni M, Tedesco F, De Simoni MG, Fumagalli S. β2 glycoprotein I participates in phagocytosis of apoptotic neurons and in vascular injury in experimental brain stroke. J Cereb Blood Flow Metab 2021; 41:2038-2053. [PMID: 33444093 PMCID: PMC8323337 DOI: 10.1177/0271678x20984551] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Beta-2 Glycoprotein I (β2-GPI) is the main target of anti-phospholipid antibodies (aPL) in the autoimmune anti-phospholipid syndrome, characterized by increased risk of stroke. We here investigated the antibody independent role of β2-GPI after ischemia/reperfusion, modeled in vivo by transient middle cerebral artery occlusion (tMCAo) in male C57Bl/6J mice; in vitro by subjecting immortalized human brain microvascular endothelial cells (ihBMEC) to 16 h hypoxia and 4 h re-oxygenation. ApoH (coding for β2-GPI) was upregulated selectively in the liver at 48 h after tMCAo. At the same time β2-GPI circulating levels increased. β2-GPI was detectable in brain parenchyma and endothelium at all time points after tMCAo. Parenchymal β2-GPI recognized apoptotic neurons (positive for annexin V, C3 and TUNEL) cleared by CD68+ brain macrophages. Hypoxic ihBMEC showed increased release of IL-6, over-expression of thrombomodulin and IL-1α after re-oxygenation with β2-GPI alone. β2-GPI interacted with mannose-binding lectin in mouse plasma and ihBMEC medium, potentially involved in formation of thrombi. We show for the first time that brain ischemia triggers the hepatic production of β2-GPI. β2-GPI is present in the ischemic endothelium, enhancing vascular inflammation, and extravasates binding stressed neurons before their clearance by phagocytosis. Thus β2-GPI may be a new mediator of brain injury following ischemic stroke.
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Affiliation(s)
- Claudia Grossi
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Carolina Artusi
- Rheumatology Department, ASST Gaetano Pini-CTO, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - PierLuigi Meroni
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Maria Orietta Borghi
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy.,Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Laura Neglia
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Neuroscience, Milan, Italy
| | - Paola Adele Lonati
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Marco Oggioni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Neuroscience, Milan, Italy
| | - Francesco Tedesco
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Maria-Grazia De Simoni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Neuroscience, Milan, Italy
| | - Stefano Fumagalli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Department of Neuroscience, Milan, Italy
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8
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Kumar S, Chinnaraj M, Planer W, Zuo X, Macor P, Tedesco F, Pozzi N. An allosteric redox switch in domain V of β 2-glycoprotein I controls membrane binding and anti-domain I autoantibody recognition. J Biol Chem 2021; 297:100890. [PMID: 34197876 PMCID: PMC8326733 DOI: 10.1016/j.jbc.2021.100890] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/09/2021] [Accepted: 06/16/2021] [Indexed: 01/27/2023] Open
Abstract
β2-glycoprotein I (β2GPI) is an abundant multidomain plasma protein that plays various roles in the clotting and complement cascades. It is also the main target of antiphospholipid antibodies (aPL) in the acquired coagulopathy known as antiphospholipid syndrome (APS). Previous studies have shown that β2GPI adopts two interconvertible biochemical conformations, oxidized and reduced, depending on the integrity of the disulfide bonds. However, the precise contribution of the disulfide bonds to β2GPI structure and function is unknown. Here, we substituted cysteine residues with serine to investigate how the disulfide bonds C32-C60 in domain I (DI) and C288-C326 in domain V (DV) regulate β2GPI's structure and function. Results of our biophysical and biochemical studies support the hypothesis that the C32-C60 disulfide bond plays a structural role, whereas the disulfide bond C288-C326 is allosteric. We demonstrate that absence of the C288-C326 bond, unlike absence of the C32-C60 bond, diminishes membrane binding without affecting the thermodynamic stability and overall structure of the protein, which remains elongated in solution. We also document that, while absence of the C32-C60 bond directly impairs recognition of β2GPI by pathogenic anti-DI antibodies, absence of the C288-C326 disulfide bond is sufficient to abolish complex formation in the presence of anionic phospholipids. We conclude that the disulfide bond C288-C326 operates as a molecular switch capable of regulating β2GPI's physiological functions in a redox-dependent manner. We propose that in APS patients with anti-DI antibodies, selective rupture of the C288-C326 disulfide bond may be a valid strategy to lower the pathogenic potential of aPL.
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Affiliation(s)
- Suresh Kumar
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Mathivanan Chinnaraj
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - William Planer
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, Lemont, Illinois, USA
| | - Paolo Macor
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Francesco Tedesco
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Nicola Pozzi
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, Missouri, USA.
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Krilis M, Qi M, Ioannou Y, Zhang JY, Ahmadi Z, Wong JWH, Vlachoyiannopoulos PG, Moutsopoulos HM, Koike T, Sturgess AD, Chong BH, Krilis SA, Giannakopoulos B. Clinical relevance of nitrated beta 2-glycoprotein I in antiphospholipid syndrome: Implications for thrombosis risk. J Autoimmun 2021; 122:102675. [PMID: 34098405 DOI: 10.1016/j.jaut.2021.102675] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 05/26/2021] [Accepted: 05/29/2021] [Indexed: 02/03/2023]
Abstract
Β2-Glycoprotein I (β2GPI) is an important anti-thrombotic protein and is the major auto-antigen in the antiphospholipid syndrome (APS). The clinical relevance of nitrosative stress in post translational modification of β2GPI was examined.The effects of nitrated (n)β2GPI on its anti-thrombotic properties and its plasma levels in primary and secondary APS were determined with appropriate clinical control groups. β2-glycoprotein I was nitrated at tyrosines 218, 275 and 309. β2-glycoprotein I binds to lipid peroxidation modified products through Domains IV and V. Nitrated β2GPI loses this binding (p < 0.05) and had diminished activity in inhibiting platelet adhesion to vWF under high shear flow (p < 0.01). Levels of nβ2GPI were increased in patients with primary APS compared to patients with either secondary APS (p < 0.05), autoimmune disease without APS (p < 0.05) or non-autoimmune patients with arterial thrombosis (p < 0.01) and healthy individuals (p < 0.05).In conclusion tyrosine nitration of plasma β2GPI is demonstrated and has important implications with regards to the pathophysiology of platelet mediated thrombosis in APS. Elevated plasma levels of nβ2GPI in primary APS may be a risk factor for thrombosis warranting further investigation.
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Affiliation(s)
- M Krilis
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia.
| | - M Qi
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia.
| | - Y Ioannou
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia; Division of Medicine, Centre for Rheumatology Research, University College London, London, UK.
| | - J Y Zhang
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia.
| | - Z Ahmadi
- Haematology Research Unit, St George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
| | - J W H Wong
- Prince of Wales Clinical School and Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia.
| | - P G Vlachoyiannopoulos
- Department of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
| | - H M Moutsopoulos
- Department of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
| | - T Koike
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University School of Medicine, Sapporo, Japan.
| | - A D Sturgess
- Department of Rheumatology, St George Hospital, University of New South Wales, Sydney, NSW, Australia.
| | - B H Chong
- Haematology Research Unit, St George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.
| | - S A Krilis
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia.
| | - B Giannakopoulos
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital and Department of Medicine, St George and Sutherland Clinical School, University of New South Wales, Sydney, NSW, Australia; Department of Rheumatology, St George Hospital, University of New South Wales, Sydney, NSW, Australia.
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10
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Tang KT, Wu TY, Chen HH, Lin CC, Hsu YHH. Cardiolipin interacts with beta-2-glycoprotein I and forms an open conformation-Mechanisms analyzed using hydrogen/deuterium exchange. Protein Sci 2021; 30:927-939. [PMID: 33641242 PMCID: PMC8040858 DOI: 10.1002/pro.4054] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 12/25/2022]
Abstract
Beta‐2‐glycoprotein I (β2GPI) is the major antigen for the antiphospholipid antibodies in the antiphospholipid syndrome. The exposed epitope in domain I of β2GPI can be recognized by the anti‐β2GPI antibody. Here, we prepared the anionic di‐oleoyl‐phosphatidylserine (DOPS) and cardiolipin (CL) liposomes to interact with the β2GPI. The conformational changes of β2GPI upon binding with the liposomes were analyzed using hydrogen/deuterium exchange mass spectrometry. The exchange level of sequences 21–27 significantly increased after β2GPI had interacted with DOPS. This change indicated a reduced interaction between domain I and domain V, inferring to a protrusion of the sequences 21–27 from the ring conformation. After β2GPI had interacted with CL for 30 min, the exchange levels in 4 of the 5 domains increased significantly. The deuteration levels of sequences 1–20, 21–27, 196–205, 273–279 and 297–306 increased, suggesting that these regions had become more exposed, and the domain I was no longer in contact with domain V. The increasing deuteration levels in sequences 70–86, 153–162, 191–198, 196–205 and 273–279 indicated β2GPI undergoing conformational changes to expose these inner regions, suggesting a structural transition. Overall, DOPS and CL induced minor conformational changes of β2GPI at sequences 21–27 and forms an intermediate conformation after 10 min of interaction. After a complete protein–lipid interaction, high negatively charged CL membrane induced a major conformation transition of β2GPI.
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Affiliation(s)
- Kuo-Tung Tang
- Division of Allergy, Immunology and Rheumatology, Taichung Veterans General Hospital, Taichung, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Ph.D. Program in Translational Medicine and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Ting-Yuan Wu
- Department of Chemistry, Tunghai University, Taichung, Taiwan
| | - Hsin-Hua Chen
- Division of Allergy, Immunology and Rheumatology, Taichung Veterans General Hospital, Taichung, Taiwan.,Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.,Department of Medical Research, Taichung Veterans General Hospital, Taichung, Taiwan.,Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Chi-Chien Lin
- Institute of Biomedical Science and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, Taiwan.,Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
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11
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Buchholz I, McDonnell T, Nestler P, Tharad S, Kulke M, Radziszewska A, Ripoll VM, Schmidt F, Hammer E, Toca-Herrera JL, Rahman A, Delcea M. Specific domain V reduction of beta-2-glycoprotein I induces protein flexibility and alters pathogenic antibody binding. Sci Rep 2021; 11:4542. [PMID: 33633190 PMCID: PMC7907366 DOI: 10.1038/s41598-021-84021-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 02/10/2021] [Indexed: 01/31/2023] Open
Abstract
Beta-2-glycoprotein I (β2GPI) is a blood protein and the major antigen in the autoimmune disorder antiphospholipid syndrome (APS). β2GPI exists mainly in closed or open conformations and comprises of 11 disulfides distributed across five domains. The terminal Cys288/Cys326 disulfide bond at domain V has been associated with different cysteine redox states. The role of this disulfide bond in conformational dynamics of this protein has not been investigated so far. Here, we report on the enzymatic driven reduction by thioredoxin-1 (recycled by Tris(2-carboxyethyl)phosphine; TCEP) of β2GPI. Specific reduction was demonstrated by Western blot and mass spectrometry analyses confirming majority targeting to the fifth domain of β2GPI. Atomic force microscopy images suggested that reduced β2GPI shows a slightly higher proportion of open conformation and is more flexible compared to the untreated protein as confirmed by modelling studies. We have determined a strong increase in the binding of pathogenic APS autoantibodies to reduced β2GPI as demonstrated by ELISA. Our study is relevant for understanding the effect of β2GPI reduction on the protein structure and its implications for antibody binding in APS patients.
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Affiliation(s)
- Ina Buchholz
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
- ZIK HIKE, University of Greifswald, Greifswald, Germany
| | - Thomas McDonnell
- Division of Biochemical Engineering, Bernard Katz Institute, University College London, London, UK
| | - Peter Nestler
- Institute of Physics, University of Greifswald, Greifswald, Germany
| | - Sudarat Tharad
- Institute for Biophysics, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Martin Kulke
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Anna Radziszewska
- Centre for Adolescent Rheumatology Versus Arthritis at UCL, UCLH, GOSH, London, UK
- Division of Medicine, Centre for Rheumatology, University College London, London, UK
| | - Vera M Ripoll
- Division of Medicine, Centre for Rheumatology, University College London, London, UK
| | - Frank Schmidt
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
- Proteomics Core, Weill Cornell Medicine-Qatar, Doha, Qatar
| | - Elke Hammer
- Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany
| | - Jose L Toca-Herrera
- Institute for Biophysics, University of Natural Resources and Life Sciences Vienna, Vienna, Austria
| | - Anisur Rahman
- Division of Medicine, Centre for Rheumatology, University College London, London, UK.
| | - Mihaela Delcea
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany.
- ZIK HIKE, University of Greifswald, Greifswald, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, Greifswald, Germany.
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12
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Misasi R, Longo A, Recalchi S, Caissutti D, Riitano G, Manganelli V, Garofalo T, Sorice M, Capozzi A. Molecular Mechanisms of "Antiphospholipid Antibodies" and Their Paradoxical Role in the Pathogenesis of "Seronegative APS". Int J Mol Sci 2020; 21:ijms21218411. [PMID: 33182499 PMCID: PMC7665122 DOI: 10.3390/ijms21218411] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/30/2020] [Accepted: 11/06/2020] [Indexed: 02/06/2023] Open
Abstract
Antiphospholipid Syndrome (APS) is an autoimmune disease characterized by arterial and/or venous thrombosis and/or pregnancy morbidity, associated with circulating antiphospholipid antibodies (aPL). In some cases, patients with a clinical profile indicative of APS (thrombosis, recurrent miscarriages or fetal loss), who are persistently negative for conventional laboratory diagnostic criteria, are classified as "seronegative" APS patients (SN-APS). Several findings suggest that aPL, which target phospholipids and/or phospholipid binding proteins, mainly β-glycoprotein I (β-GPI), may contribute to thrombotic diathesis by interfering with hemostasis. Despite the strong association between aPL and thrombosis, the exact pathogenic mechanisms underlying thrombotic events and pregnancy morbidity in APS have not yet been fully elucidated and multiple mechanisms may be involved. Furthermore, in many SN-APS patients, it is possible to demonstrate the presence of unconventional aPL ("non-criteria" aPL) or to detect aPL with alternative laboratory methods. These findings allowed the scientists to study the pathogenic mechanism of SN-APS. This review is focused on the evidence showing that these antibodies may play a functional role in the signal transduction pathway(s) leading to thrombosis and pregnancy morbidity in SN-APS. A better comprehension of the molecular mechanisms triggered by aPL may drive development of potential therapeutic strategies in APS patients.
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13
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Weaver JC, Ullah I, Qi M, Giannakopoulos B, Rye KA, Kockx M, Kritharides L, Krilis SA. Free Thiol β2-GPI (β-2-Glycoprotein-I) Provides a Link Between Inflammation and Oxidative Stress in Atherosclerotic Coronary Artery Disease. Arterioscler Thromb Vasc Biol 2020; 40:2794-2804. [DOI: 10.1161/atvbaha.120.315156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective:
Atherosclerotic coronary artery disease is well recognised as an inflammatory disorder that is also influenced by oxidative stress. β2-GPI (β-2-glycoprotein-I) is a circulating plasma protein that undergoes post-translational modification and exists in free thiol as well as oxidized forms. The aim of this study was to assess the association between these 2 post-translational redox forms of β2-GPI and atherosclerotic coronary artery disease.
Approach and Results:
Stable patients presenting for elective coronary angiography or CT coronary angiography were prospectively recruited. A separate group of patients after reperfused ST-segment–elevation myocardial infarction formed an acute coronary syndrome subgroup. All patients had collection of fasting serum and plasma for quantification of total and free thiol β2-GPI. Coronary artery disease extent was quantified by the Syntax and Gensini scores. A total of 552 patients with stable disease and 44 with acute coronary syndrome were recruited. While total β2-GPI was not associated with stable coronary artery disease, a higher free thiol β2-GPI was associated with its presence and extent. This finding remained significant after correcting for confounding variables, and free thiol β2-GPI was a better predictor of stable coronary artery disease than hs-CRP (high-sensitivity C-reactive protein). Paradoxically, there were lower levels of free thiol β2-GPI after ST-segment–elevation myocardial infarction.
Conclusions:
Free thiol β2-GPI is a predictor of coronary artery disease presence and extent in stable patients. Free thiol β2-GPI was a better predictor than high-sensitivity C-reactive protein.
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Affiliation(s)
- James C. Weaver
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
- Department of Cardiology, Royal Prince Alfred Hospital, Camperdown, Sydney, Australia (J.C.W.)
| | - Inaam Ullah
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
- Department of Cardiology, St George Hospital, Kogarah, Sydney, Australia (I.U.)
| | - Miao Qi
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital, Kogarah, Sydney, Australia (M.Q., B.G., S.A.K.)
| | - Bill Giannakopoulos
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital, Kogarah, Sydney, Australia (M.Q., B.G., S.A.K.)
- Department of Rheumatology, St George Hospital, Kogarah, Sydney, Australia (B.G.)
| | - Kerry Anne Rye
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
| | - Maaike Kockx
- ANZAC Research Institute, University of Sydney, Concord, Australia (M.K., L.K.)
| | - Leonard Kritharides
- ANZAC Research Institute, University of Sydney, Concord, Australia (M.K., L.K.)
- Department of Cardiology, Concord Hospital, Sydney, Australia (L.K.)
| | - Steven A. Krilis
- University of NSW, Sydney, Australia (J.C.W., I.U., M.Q., B.G., K.A.R., S.A.K.)
- Department of Infectious Disease, Immunology and Sexual Health, St George Hospital, Kogarah, Sydney, Australia (M.Q., B.G., S.A.K.)
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14
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Ruben E, Planer W, Chinnaraj M, Chen Z, Zuo X, Pengo V, De Filippis V, Alluri RK, McCrae KR, Macor P, Tedesco F, Pozzi N. The J-elongated conformation of β 2-glycoprotein I predominates in solution: implications for our understanding of antiphospholipid syndrome. J Biol Chem 2020; 295:10794-10806. [PMID: 32518155 PMCID: PMC7397106 DOI: 10.1074/jbc.ra120.013939] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/06/2020] [Indexed: 01/07/2023] Open
Abstract
β2-Glycoprotein I (β2GPI) is an abundant plasma protein displaying phospholipid-binding properties. Because it binds phospholipids, it is a target of antiphospholipid antibodies (aPLs) in antiphospholipid syndrome (APS), a life-threatening autoimmune thrombotic disease. Indeed, aPLs prefer membrane-bound β2GPI to that in solution. β2GPI exists in two almost equally populated redox states: oxidized, in which all the disulfide bonds are formed, and reduced, in which one or more disulfide bonds are broken. Furthermore, β2GPI can adopt multiple conformations (i.e. J-elongated, S-twisted, and O-circular). While strong evidence indicates that the J-form is the structure bound to aPLs, which conformation exists and predominates in solution remains controversial, and so is the conformational pathway leading to the bound state. Here, we report that human recombinant β2GPI purified under native conditions is oxidized. Moreover, under physiological pH and salt concentrations, this oxidized form adopts a J-elongated, flexible conformation, not circular or twisted, in which the N-terminal domain I (DI) and the C-terminal domain V (DV) are exposed to the solvent. Consistent with this model, binding kinetics and mutagenesis experiments revealed that in solution the J-form interacts with negatively charged liposomes and with MBB2, a monoclonal anti-DI antibody that recapitulates most of the features of pathogenic aPLs. We conclude that the preferential binding of aPLs to phospholipid-bound β2GPI arises from the ability of its preexisting J-form to accumulate on the membranes, thereby offering an ideal environment for aPL binding. We propose that targeting the J-form of β2GPI provides a strategy to block pathogenic aPLs in APS.
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Affiliation(s)
- Eliza Ruben
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - William Planer
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Mathivanan Chinnaraj
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Zhiwei Chen
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Xiaobing Zuo
- X-Ray Science Division, Argonne National Laboratory, Argonne, Illinois, USA
| | - Vittorio Pengo
- Thrombosis Research Laboratory, Department of Cardiac Thoracic and Vascular Sciences, and Public Health, University of Padova, Padova, Italy,Arianna Foundation on Anticoagulation, Bologna, Italy
| | - Vincenzo De Filippis
- Department of Pharmaceutical & Pharmacological Sciences, University of Padua, Padua, Italy
| | - Ravi K. Alluri
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Keith R. McCrae
- Department of Cellular and Molecular Medicine, Cleveland Clinic, Cleveland, Ohio, USA
| | - Paolo Macor
- Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Francesco Tedesco
- Istituto Auxologico Italiano, IRCCS, Laboratory of Immuno-Rheumatology, Milan, Italy
| | - Nicola Pozzi
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA,For correspondence: Nicola Pozzi,
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15
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Hell L, Lurger K, Mauracher LM, Grilz E, Reumiller CM, Schmidt GJ, Ercan H, Koder S, Assinger A, Basilio J, Gebhart J, Ay C, Pabinger I, Zellner M. Altered platelet proteome in lupus anticoagulant (LA)-positive patients-protein disulfide isomerase and NETosis as new players in LA-related thrombosis. Exp Mol Med 2020; 52:66-78. [PMID: 31956273 PMCID: PMC7000701 DOI: 10.1038/s12276-019-0358-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/06/2019] [Accepted: 09/25/2019] [Indexed: 01/22/2023] Open
Abstract
Patients with antiphospholipid syndrome (APS) are at high risk of developing venous and arterial thromboembolism (TE). The role of platelets in the pathogenesis of these prothrombotic conditions is not yet fully understood. The aim of this study was to gain mechanistic insights into the role of platelets in APS by comparing the platelet proteome between lupus anticoagulant (LA)-positive patients with (LA+ TE+) and without a history of TE (LA+ TE-) and healthy controls. The platelet proteome of 47 patients with LA, 31 with a history of TE and 16 without thrombotic history, and 47 healthy controls was analyzed by two-dimensional differential in-gel electrophoresis and mass spectrometry to identify disease-related proteins. Afterward, selected LA-related platelet proteins were validated by western blot and ELISA. Alterations of 25 proteins were observed between the study groups. STRING pathway analysis showed that LA-related protein profiles were involved in platelet activation, aggregation, and degranulation. For example, protein disulfide isomerase family members, enzymes that promote thrombosis, were upregulated in platelets and plasma of LA+ TE+ patients. Leukocyte elastase inhibitor (SERPINB1), an antagonist of neutrophil extracellular trap (NET) formation, was decreased in platelets of LA+ TE+ patients compared to healthy controls. Additionally, citrullinated histone H3, a NET-specific marker, was increased in plasma of LA+ TE+ patients. These findings suggest that decreased platelet SERPINB1 levels favor prothrombotic NETosis, especially in LA+ TE+ patients. Our findings reveal protein abundance changes connected to altered platelet function in LA-positive patients, thus suggesting a pathogenic role of platelets in thrombotic complications in APS.
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Affiliation(s)
- Lena Hell
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Kristina Lurger
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Lisa-Marie Mauracher
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Ella Grilz
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Christina Maria Reumiller
- 0000 0000 9259 8492grid.22937.3dCenter for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Georg Johannes Schmidt
- 0000 0000 9259 8492grid.22937.3dDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Huriye Ercan
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Silvia Koder
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Alice Assinger
- 0000 0000 9259 8492grid.22937.3dCenter for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - José Basilio
- 0000 0000 9259 8492grid.22937.3dCenter for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Johanna Gebhart
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Cihan Ay
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Ingrid Pabinger
- 0000 0000 9259 8492grid.22937.3dClinical Division of Haematology and Haemostaseology, Department of Medicine I, Medical University of Vienna, Vienna, Austria
| | - Maria Zellner
- 0000 0000 9259 8492grid.22937.3dCenter for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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16
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Oxidative stress in endothelial cells induced by the serum of women with different clinical manifestations of the antiphospholipid syndrome. ACTA ACUST UNITED AC 2019; 39:673-688. [PMID: 31860179 PMCID: PMC7363350 DOI: 10.7705/biomedica.4701] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Indexed: 12/27/2022]
Abstract
Introducción. El síndrome antifosfolípido se caracteriza por la presencia persistente de anticuerpos antifosfolípidos y manifestaciones clínicas de trombosis o morbilidad gestacional, las cuales se asocian con estrés oxidativo y disfunción endotelial. Objetivo. Evaluar los marcadores de estrés oxidativo en células endoteliales, inducidos por el suero de mujeres con diferentes manifestaciones clínicas del síndrome antifosfolípido y analizar la capacidad antioxidante de los sueros. Materiales y métodos. Se incluyeron 48 mujeres que fueron clasificadas así: presencia de anticuerpos antifosfolípidos y criterios clínicos de morbilidad gestacional, trombosis vascular o ambas. Como grupos control se incluyeron mujeres negativas para anticuerpos antifosfolípidos. En un modelo in vitro de células endoteliales estimuladas con los sueros de las mujeres del estudio, se determinaron algunos marcadores de estrés oxidativo por citometría de flujo. También, se analizó la capacidad antioxidante de los sueros incluidos. Resultados. Los sueros de los grupos de mujeres con síndrome antifosfolípido que presentaban trombosis, con morbilidad gestacional o sin ella, generaron un incremento significativo (p<0,05 y p<0,001) en los marcadores de estrés oxidativo endotelial, en contraste con el control de suero humano normal. No se observaron diferencias en el efecto de los sueros de los diferentes grupos de estudio sobre la lipoperoxidación endotelial. Tampoco se encontró diferencia en la actividad antioxidante de los sueros. Conclusión. El estrés oxidativo mitocondrial en el endotelio se asocia con la presencia de trombosis. Sin embargo, cuando esta se asocia con morbilidad gestacional, también se genera estrés oxidativo intracelular.
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17
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Abstract
Angiotensinogen mediates an important role in the pathophysiology of preeclampsia, a disorder of pregnancy characterized by hypertension and proteinuria usually after 20 weeks of gestation. Angiotensinogen is found in two distinct posttranslational forms in the plasma, an oxidized and a reduced (free thiol) form. Higher levels of the oxidized form are associated with an increased risk of preeclampsia. We have developed novel ELISA assays to quantitate the levels of total and free thiol angiotensinogen allowing for calculation of the amount of oxidized angiotensinogen species. We describe the methodology for performing these assays.
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18
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Wirestam L, Arve S, Linge P, Bengtsson AA. Neutrophils-Important Communicators in Systemic Lupus Erythematosus and Antiphospholipid Syndrome. Front Immunol 2019; 10:2734. [PMID: 31824510 PMCID: PMC6882868 DOI: 10.3389/fimmu.2019.02734] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 11/07/2019] [Indexed: 12/15/2022] Open
Abstract
Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are two autoimmune diseases that can occur together or separately. Insights into the pathogenesis have revealed similarities, such as development of autoantibodies targeting subcellular antigens as well as a shared increased risk of cardiovascular morbidity, potentially due to mutual pathologic mechanisms. In this review, we will address the evidence implicating neutrophils in the pathogenesis of these conditions, highlighting their shared features. The neutrophil is the most abundant leukocyte, recognized for its role in infectious and inflammatory diseases, but dysregulation of neutrophil effector functions, including phagocytosis, oxidative burst and formation of neutrophil extracellular traps (NETs) may also contribute to an autoimmune process. The phenotype of neutrophils in SLE and APS differs from neutrophils of healthy individuals, where neutrophils in SLE and APS are activated and prone to aggregate. A specific subset of low-density neutrophils with different function compared to normal-density neutrophils can also be found within the peripheral blood mononuclear cell (PBMC) fraction after density gradient centrifugation of whole blood. Neutrophil phagocytosis is required for regular clearance of cell remnants and nuclear material. Reactive oxygen species (ROS) released by neutrophils during oxidative burst are important for immune suppression and impairment of ROS production is seen in SLE. NETs mediate pathology in both SLE and APS via several mechanisms, including exposure of autoantigens, priming of T-cells and activation of autoreactive B-cells. NETs are also involved in cardiovascular events by forming a pro-thrombotic scaffolding surface. Lastly, neutrophils communicate with other cells by producing cytokines, such as Interferon (IFN) -α, and via direct cell-cell contact. Physiological neutrophil effector functions are necessary to prevent autoimmunity, but in SLE and APS these are altered.
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Affiliation(s)
- Lina Wirestam
- Section of Rheumatology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Sabine Arve
- Section of Rheumatology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Petrus Linge
- Section of Rheumatology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Anders A Bengtsson
- Section of Rheumatology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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19
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Buttari B, Profumo E, Capozzi A, Saso L, Sorice M, Riganò R. Post-translational modifications of proteins in antiphospholipid antibody syndrome. Crit Rev Clin Lab Sci 2019; 56:511-525. [DOI: 10.1080/10408363.2019.1650714] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Brigitta Buttari
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Aging, Istituto Superiore di Sanità, Rome, Italy
| | - Elisabetta Profumo
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Aging, Istituto Superiore di Sanità, Rome, Italy
| | - Antonella Capozzi
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Luciano Saso
- Department of Physiology and Pharmacology, “Vittorio Erspamer”, Sapienza University of Rome, Rome, Italy
| | - Maurizio Sorice
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Rachele Riganò
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Aging, Istituto Superiore di Sanità, Rome, Italy
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20
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Obstetric and vascular antiphospholipid syndrome: same antibodies but different diseases? Nat Rev Rheumatol 2019; 14:433-440. [PMID: 29891914 DOI: 10.1038/s41584-018-0032-6] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recurrent thrombosis and miscarriages are the main clinical manifestations of antiphospholipid syndrome (APS). Although most patients display both clinical signs, some patients can have isolated vascular or obstetric variants. Emerging data raise the question of whether obstetric and vascular APS are the same or different diseases. An important difference between the two conditions is that a thrombophilic state is a common feature in vascular APS, whereas clot occlusions of the decidual spiral arteries are seldom observed in obstetric APS, and infarctions are found in only one-third of APS placentae. Conversely, inflammation, which is undetectable in vascular APS, is frequently observed in the placentae of patients with obstetric APS and has been documented in the placentae of pregnant mice with fetal loss mediated by antiphospholipid antibodies. Attempts to identify different antibodies or epitopes responsible for the two clinical manifestations of APS have so far been unsuccessful. Possible mechanisms exist that might explain the development of the two clinical presentations, including the tissue distribution and expression level of the main target antigen of antiphospholipid antibodies, β2 glycoprotein I (β2GPI). The identification of the factors that promote the onset of either obstetric or vascular APS has important diagnostic and therapeutic implications.
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21
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Baerenfaenger M, Meyer B. Simultaneous characterization of SNPs and N-glycans from multiple glycosylation sites of intact β-2-glycoprotein-1 (B2GP1) by ESI-qTOF-MS. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2019; 1867:556-564. [DOI: 10.1016/j.bbapap.2019.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/21/2019] [Accepted: 03/19/2019] [Indexed: 12/16/2022]
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A novel de novo MTOR gain-of-function variant in a patient with Smith-Kingsmore syndrome and Antiphospholipid syndrome. Eur J Hum Genet 2019; 27:1369-1378. [PMID: 31053780 DOI: 10.1038/s41431-019-0418-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/21/2019] [Accepted: 04/16/2019] [Indexed: 01/22/2023] Open
Abstract
We report the clinical, biochemical and genetic findings from a Spanish girl of Caucasian origin who presented with macrocephaly, dysmorphic facial features, developmental delay, hypotonia, combined oxidative phosphorylation (OxPhos) deficiency, epilepsy and anti-phospholipid antibodies (aPL). Whole-exome sequencing (WES) uncovered a heterozygous variant in the MTOR gene (NM_004958.3: c.7235A>T: p.(Asp2412Val)) that encodes for the Serine/threonine-protein kinase mTOR. The substrates phosphorylation experiments demonstrated that this variant exerts its effect by gain-of-function (GOF) and autosomal dominant mechanism. GOF variants in this protein have been associated with Smith-Kingsmore syndrome (SKS), a rare autosomal dominant disorder characterized by intellectual disability, macrocephaly, seizure, developmental delay and dysmorphic facial features. Furthermore, the mTOR pathway has been demonstrated previously to be involved in many types of endothelium injuries including the antiphospholipid syndrome (APS), a systemic autoimmune disease characterized by the production of aPL with recurrent vascular thrombosis. Therefore, our patient is the first one with an mTOR variant and diagnosed with SKS and APS. In conclusion, our data expand both the genetic and phenotypic spectrum associated with MTOR gene variants.
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23
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Carubbi F, Alunno A, Cipriani P, Bistoni O, Scipioni R, Liakouli V, Ruscitti P, Berardicurti O, Di Bartolomeo S, Gerli R, Giacomelli R. Laboratory Assessment of Patients with Suspected Rheumatic Musculoskeletal Diseases: Challenges and Pitfalls. Curr Rheumatol Rev 2019; 15:27-43. [PMID: 29557752 DOI: 10.2174/1573397114666180320113603] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 03/14/2018] [Accepted: 03/15/2018] [Indexed: 11/22/2022]
Abstract
Current patient care in rheumatology relies primarily on a combination of traditional clinical assessment and standard laboratory tests. Investigators seek to discover new biomarkers and novel technologies to boost the research in this field. Mechanistic biomarkers such as cytokines, cell types, antibodies, signaling molecules, are rooted in the mechanism underlying the disease and can guide the clinical management of the disease. Conversely, descriptive biomarkers are byproducts of the disease process, depict the state of a disease but are not involved in its pathogenesis. In this article, we reviewed the field of common laboratory biomarkers in rheumatology, highlighting both their descriptive or mechanistic value as well as their role in clinical practice.
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Affiliation(s)
- Francesco Carubbi
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy.,Department of Medicine, ASL1 Avezzano-Sulmona-L'Aquila, L'Aquila, AQ, Italy
| | - Alessia Alunno
- Rheumatology Unit, Department of Medicine, University of Perugia, Perugia, PG, Italy
| | - Paola Cipriani
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
| | - Onelia Bistoni
- Rheumatology Unit, Department of Medicine, University of Perugia, Perugia, PG, Italy
| | - Rosa Scipioni
- Department of Medicine, ASL1 Avezzano-Sulmona-L'Aquila, L'Aquila, AQ, Italy
| | - Valiki Liakouli
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
| | - Piero Ruscitti
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
| | - Onorina Berardicurti
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
| | - Salvatore Di Bartolomeo
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
| | - Roberto Gerli
- Rheumatology Unit, Department of Medicine, University of Perugia, Perugia, PG, Italy
| | - Roberto Giacomelli
- Rheumatology Unit, Department of Biotechnological and Applied Clinical Science, School of Medicine, University of L'Aquila, L'Aquila, AQ, Italy
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24
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Qi M, Weaver JC, Krilis SA, Giannakopoulos B. Quantitation of Total and Free Thiol β 2-Glycoprotein I Levels for Diagnostic and Prognostic Purposes in the Antiphospholipid Syndrome. Methods Mol Biol 2019; 1967:275-283. [PMID: 31069777 DOI: 10.1007/978-1-4939-9187-7_17] [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] [Indexed: 06/09/2023]
Abstract
β2-Glycoprotein I is the major autoantigen in the antiphospholipid syndrome (APS), a prothrombotic disorder characterized by the occurrence of either venous or arterial thrombosis. In women it is also associated with an increased risk of obstetric complications such as recurrent miscarriages. We have identified that the plasma protein β2-glycoprotein I in healthy individuals exists in an optimal ratio between two distinct forms, an oxidized and free thiol, reduced form. This ratio is disrupted in pathophysiological conditions associated with increased oxidative stress such as the APS, but also in the setting of age-related macular degeneration and gram-negative sepsis. We have developed assays that quantify plasma/serum levels of total and free thiol β2-glycoprotein I which can potentially be used for risk stratification and prognostic purposes in the early stages of the aforementioned conditions.
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Affiliation(s)
- M Qi
- Department of Infectious Diseases, Immunology and Sexual Health, St George Public Hospital, Sydney, NSW, Australia
- Faculty of Medicine, St George and Sutherland Clinical School, St George Public Hospital, University of New South Wales, Sydney, NSW, Australia
| | - James C Weaver
- Faculty of Medicine, St George and Sutherland Clinical School, St George Public Hospital, University of New South Wales, Sydney, NSW, Australia
- Department of Cardiology, St George Public Hospital, Sydney, NSW, Australia
| | - S A Krilis
- Department of Infectious Diseases, Immunology and Sexual Health, St George Public Hospital, Sydney, NSW, Australia.
- Faculty of Medicine, St George and Sutherland Clinical School, St George Public Hospital, University of New South Wales, Sydney, NSW, Australia.
| | - B Giannakopoulos
- Department of Infectious Diseases, Immunology and Sexual Health, St George Public Hospital, Sydney, NSW, Australia.
- Faculty of Medicine, St George and Sutherland Clinical School, St George Public Hospital, University of New South Wales, Sydney, NSW, Australia.
- Department of Rheumatology, St George Public Hospital, Sydney, NSW, Australia.
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25
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Velásquez M, Rojas M, Abrahams VM, Escudero C, Cadavid ÁP. Mechanisms of Endothelial Dysfunction in Antiphospholipid Syndrome: Association With Clinical Manifestations. Front Physiol 2018; 9:1840. [PMID: 30627104 PMCID: PMC6309735 DOI: 10.3389/fphys.2018.01840] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 12/06/2018] [Indexed: 12/13/2022] Open
Abstract
The endothelium is a monolayer of cells that covers the inner surface of blood vessels and its integrity is essential for the maintenance of vascular health. Endothelial dysfunction is a key pathological component of antiphospholipid syndrome (APS). Its systemic complications include thrombotic endocarditis, valvular dysfunction, cerebrovascular occlusions, proliferative nephritis, deep vein thrombosis, and pulmonary embolism. In women, APS is also associated with pregnancy complications (obstetric APS). The conventional treatment regimens for APS are ineffective when the clinical symptoms are severe. Therefore, a better understanding of alterations in the endothelium caused by antiphospholipid antibodies (aPL) may lead to more effective therapies in patients with elevated aPL titers and severe clinical symptoms. Currently, while in vivo analyses of endothelial dysfunction in patients with APS have been reported, most research has been performed using in vitro models with endothelial cells exposed to either patient serum/plasma, monoclonal aPL, or IgGs isolated from patients with APS. These studies have described a reduction in endothelial cell nitric oxide synthesis, the induction of inflammatory and procoagulant phenotypes, an increase in endothelial proliferation, and impairments in vascular remodeling and angiogenesis. Despite these lines of evidence, further research is required to better understand the pathophysiology of endothelial dysfunction in patients with APS. In this review, we have compared the current understanding about the mechanisms of endothelial dysfunction induced by patient-derived aPL under the two main clinical manifestations of APS: thrombosis and gestational complications, either alone or in combination. We also discuss gaps in our current knowledge regarding aPL-induced endothelial dysfunction.
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Affiliation(s)
- Manuela Velásquez
- Grupo Reproducción, Departamento de Microbiología y Parasitología, Escuela de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Mauricio Rojas
- Grupo de Inmunología Celular e Inmunogenética, Facultad de Medicina, Coordinador Unidad de Citometría de Flujo, Sede de Investigación Universitaria, Universidad de Antioquia, Medellín, Colombia
| | - Vikki M Abrahams
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT, United States
| | - Carlos Escudero
- Vascular Physiology Laboratory, Group of Investigation in Tumor Angiogenesis (GIANT), Department of Basic Sciences, Universidad del Bío-Bío, Chillán, Chile.,Group of Research and Innovation in Vascular Health (GRIVAS Health), Chillan, Chile.,Red Iberoamericana de Alteraciones Vasculares Asociadas a Transtornos del Embarazo, Chillan, Chile
| | - Ángela P Cadavid
- Grupo Reproducción, Departamento de Microbiología y Parasitología, Escuela de Medicina, Universidad de Antioquia, Medellín, Colombia.,Red Iberoamericana de Alteraciones Vasculares Asociadas a Transtornos del Embarazo, Chillan, Chile
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26
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Rauch J, Salem D, Subang R, Kuwana M, Levine JS. β2-Glycoprotein I-Reactive T Cells in Autoimmune Disease. Front Immunol 2018; 9:2836. [PMID: 30619248 PMCID: PMC6295551 DOI: 10.3389/fimmu.2018.02836] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 11/16/2018] [Indexed: 01/15/2023] Open
Abstract
Anti-phospholipid syndrome (APS) and systemic lupus erythematosus (SLE) are autoimmune diseases characterized by autoantibody production and autoantibody-related pathology. Anti-phospholipid antibodies (aPL) are found in all patients with APS and in 20-30% of individuals with SLE. aPL recognize a number of autoantigens, but the primary target in both APS and SLE is β2-glycoprotein I (β2GPI). The production of IgG aPL in APS and SLE, as well as the association of aPL with certain MHC class II molecules, has led to investigation of the role of β2GPI-reactive T helper (Th). β2GPI-reactive CD4 Th cells have been associated with the presence of aPL and/or APS in both primary APS and secondary APS associated with SLE, as well as in SLE patients and healthy controls lacking aPL. CD4 T cells reactive with β2GPI have also been associated with atherosclerosis and found within atherosclerotic plaques. In most cases, the epitopes targeted by autoreactive β2GPI-reactive CD4 T cells in APS and SLE appear to arise as a consequence of antigenic processing of β2GPI that is structurally different from the soluble native form. This may arise from molecular interactions (e.g., with phospholipids), post-translational modification (e.g., oxidation or glycation), genetic alteration (e.g., β2GPI variants), or molecular mimicry (e.g., microbiota). A number of T cell epitopes have been characterized, particularly in Domain V, the lipid-binding domain of β2GPI. Possible sources of negatively charged lipid that bind β2GPI include oxidized LDL, activated platelets, microbiota (e.g., gut commensals), and dying (e.g., apoptotic) cells. Apoptotic cells not only bind β2GPI, but also express multiple other cellular autoantigens targeted in both APS and SLE. Dying cells that have bound β2GPI thus provide a rich source of autoantigens that can be recognized by B cells across a wide range of autoantigen specificities. β2GPI-reactive T cells could potentially provide T cell help to autoantigen-specific B cells that have taken up and processed apoptotic (or other dying) cells, and subsequently present β2GPI on their surface in the context of major histocompatibility complex (MHC) class II molecules. Here, we review the literature on β2GPI-reactive T cells, and highlight findings supporting the hypothesis that these T cells drive autoantibody production in both APS and SLE.
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Affiliation(s)
- Joyce Rauch
- Division of Rheumatology, Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - David Salem
- Division of Rheumatology, Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Rebecca Subang
- Division of Rheumatology, Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Masataka Kuwana
- Department of Allergy and Rheumatology, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
| | - Jerrold S Levine
- Section of Nephrology, Department of Medicine, University of Illinois at Chicago and Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States
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27
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Krilis M, Qi M, Qi J, Wong JWH, Guymer R, Liew G, Hunyor AP, Madigan M, McCluskey P, Weaver J, Krilis SA, Giannakopoulos B. Dual roles of different redox forms of complement factor H in protecting against age related macular degeneration. Free Radic Biol Med 2018; 129:237-246. [PMID: 30253188 DOI: 10.1016/j.freeradbiomed.2018.09.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 09/19/2018] [Accepted: 09/21/2018] [Indexed: 11/22/2022]
Abstract
Complement Factor H (CFH) is an important inhibitor of the alternate complement pathway in Bruch's membrane (BM), located between the choriocapillaris and the retinal pigment epithelium. Furthermore dysfunction of its activity as occurs with certain polymorphisms is associated with an increased risk of age related macular degeneration (AMD). The retina is a site of high generation of reactive oxygen species (ROS) and dysfunction of redox homeostasis in this milieu also contributes to AMD pathogenesis. In this study we wanted to explore if CFH exists in distinct redox forms and whether these species have unique protective biological functions. CFH can be reduced by the naturally occurring thioredoxin - 1 in CFH domains 1-4, 17-20. We found a duality of function between the oxidised and reduced forms of CFH. The oxidised form was more efficient in binding to C3b and lipid peroxidation by-products that are known to accumulate in the retinae and activate the alternate complement pathway. Oxidised CFH enhances Factor I mediated cleavage of C3 and C3b whereas the reduced form loses this activity. In the setting of oxidative stress (hydrogen peroxide)-mediated death of human retinal pigment epithelial cells as can occur in AMD, the free thiol form of CFH offers a protective function compared to the oxidised form. We found for the first time using a novel ELISA system we have developed for free thiol CFH, that both redox forms of CFH are found in the human plasma. Furthermore there is a distinct ratio of these redox forms in plasma depending if an individual has early or late AMD, with individuals with early AMD having higher levels of the free thiol form compared to late AMD.
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Affiliation(s)
- Matthew Krilis
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - Miao Qi
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Jian Qi
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Jason W H Wong
- Prince of Wales Clinical School and Lowy Cancer Research Centre, University of New South Wales, Sydney, NSW, Australia
| | - Robyn Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne, 32 Gisborne Street, East Melbourne, Victoria, Australia
| | - Gerald Liew
- Westmead Institute for Medical Research University of Sydney, NSW, Australia
| | - Alex P Hunyor
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - Michele Madigan
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia; School of Optometry and Visual Science, University of New South Wales, Sydney, NSW, Australia
| | - Peter McCluskey
- Save Sight Institute, University of Sydney and Sydney Eye Hospital, 8 Macquarie Street, Sydney, NSW, Australia
| | - James Weaver
- Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia; Department of Cardiology, St George Hospital, Sydney, New South Wales, Australia
| | - Steven A Krilis
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia
| | - Bill Giannakopoulos
- Department of Infectious Diseases, Immunology and Sexual Health St George Hospital 2, South Street, Kogarah, Sydney, NSW, Australia; Faculty of Medicine, St George and Sutherland Clinical School, University of New South Wales, St George Hospital, Sydney, NSW, Australia; Department of Rheumatology, St George Hospital, Belgrave Street, Kogarah, Sydney, NSW, Australia.
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28
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Fleetwood T, Cantello R, Comi C. Antiphospholipid Syndrome and the Neurologist: From Pathogenesis to Therapy. Front Neurol 2018; 9:1001. [PMID: 30534110 PMCID: PMC6275383 DOI: 10.3389/fneur.2018.01001] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 11/06/2018] [Indexed: 12/16/2022] Open
Abstract
Antiphospholipid syndrome (APS) is an autoimmune antibody-mediated condition characterized by thrombotic events and/or pregnancy morbidity in association with persistent positivity to antiphospholipid antibodies (aPL). The nervous system is frequently affected, as intracranial vessels are the most frequent site of arterial pathology. Over the course of years, many other neurological conditions not included in the diagnostic criteria, have been associated with APS. The pathogenic mechanisms behind the syndrome are complex and not fully elucidated. aPL enhance thrombosis, interfering with different pathways. Nevertheless, ischemic injury is not always sufficient to explain clinical features of the syndrome and immune-mediated damage has been advocated. This may be particularly relevant in the context of neurological complications. The reason why only a subgroup of patients develop non-criteria nervous system disorders and what determines the clinical phenotype are questions that remain open. The double nature, thrombotic and immunologic, of APS is also reflected by therapeutic strategies. In this review we summarize known neurological manifestations of APS, revisiting pathogenesis and current treatment options.
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Affiliation(s)
- Thomas Fleetwood
- Section of Neurology, Department of Translational Medicine University of Eastern Piedmont, Novara, Italy
| | - Roberto Cantello
- Section of Neurology, Department of Translational Medicine University of Eastern Piedmont, Novara, Italy
| | - Cristoforo Comi
- Section of Neurology, Department of Translational Medicine University of Eastern Piedmont, Novara, Italy.,Interdisciplinary Research Centre of Autoimmune Diseases University of Eastern Piedmont, Novara, Italy
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29
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Buchholz I, Nestler P, Köppen S, Delcea M. Lysine residues control the conformational dynamics of beta 2-glycoprotein I. Phys Chem Chem Phys 2018; 20:26819-26829. [PMID: 30176030 DOI: 10.1039/c8cp03234c] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
One of the major problems in the study of the dynamics of proteins is the visualization of changing conformations that are important for processes ranging from enzyme catalysis to signaling. A protein exhibiting conformational dynamics is the soluble blood protein beta 2-glycoprotein I (beta2GPI), which exists in two conformations: the closed (circular) form and the open (linear) form. It is hypothesized that an increased proportion of the open conformation leads to the autoimmune disease antiphospholipid syndrome (APS). A characteristic feature of beta2GPI is the high content of lysine residues. However, the potential role of lysine in the conformational dynamics of beta2GPI has been poorly investigated. Here, we report on a strategy to permanently open up the closed protein conformation by chemical acetylation of lysine residues using acetic acid N-hydroxysuccinimide ester (NHS-Ac). Specific and complete acetylation was demonstrated by the quantification of primary amino groups with fluoraldehyde o-phthalaldehyde (OPA) reagent, as well as western blot analysis with an anti-acetylated lysine antibody. Our results demonstrate that acetylated beta2GPI preserves its secondary and tertiary structures, as shown by circular dichroism spectroscopy. We found that after lysine acetylation, the majority of proteins are in the open conformation as revealed by atomic force microscopy high-resolution images. Using this strategy, we proved that the electrostatic interaction of lysine residues plays a major role in stabilizing the beta2GPI closed conformation, as confirmed by lysine charge distribution calculations. We foresee that our approach will be applied to other lysine-rich proteins (e.g. histones) undergoing conformational transitions. For instance, conformational dynamics can be triggered by environmental conditions (e.g. pH, ion concentration, post-translational modifications, and binding of ligands). Therefore, our study may be relevant for investigating the equilibrium of protein conformations causing diseases.
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Affiliation(s)
- Ina Buchholz
- Institute of Biochemistry, Ernst-Moritz-Arndt University Greifswald, 17489 Greifswald, Germany.
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30
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Weaver JC, Krilis SA, Giannakopoulos B. Oxidative post-translational modification of βeta 2-glycoprotein I in the pathophysiology of the anti-phospholipid syndrome. Free Radic Biol Med 2018; 125:98-103. [PMID: 29604397 DOI: 10.1016/j.freeradbiomed.2018.03.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 03/23/2018] [Accepted: 03/28/2018] [Indexed: 12/13/2022]
Abstract
The anti-phospholipid syndrome (APS) is a prothrombotic autoimmune disorder characterized by either thrombosis or pregnancy complications in the setting of persistent anti-phospholipid antibodies (aPL). βeta 2-glycoprotein I (β2-GPI) is the major autoantigen in APS that binds anionic phospholipids as well as specific receptors on platelets and endothelial cells resulting in activation of prothrombotic pathways. β2-GPI consists of 5 Domains that exist in a circular or linear form, with the latter occurring after binding to anionic phospholipids. β2-GPI also undergoes dynamic posttranslational modification between oxidized and free thiol forms. The relationship between posttranslational modification and structural conformation is yet to be definitively clarified. Compared with controls, patients with the APS have higher levels of total β2-GPI and lower levels of free thiol β2-GPI. This raises the possibility of using quantification of β2-GPI posttranslational modification as a redox biomarker in the management and diagnosis of the APS.
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Affiliation(s)
- James C Weaver
- Department of Cardiology, St George Hospital, Sydney, Australia; Department of Medicine, University of NSW, Sydney, Australia
| | - Steven A Krilis
- Department of Medicine, University of NSW, Sydney, Australia; Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, Australia
| | - Bill Giannakopoulos
- Department of Medicine, University of NSW, Sydney, Australia; Department of Infectious Diseases, Immunology and Sexual Health, St George Hospital, Sydney, Australia; Department of Rheumatology, St George Hospital, Sydney, Australia.
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31
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Radic M, Pattanaik D. Cellular and Molecular Mechanisms of Anti-Phospholipid Syndrome. Front Immunol 2018; 9:969. [PMID: 29867951 PMCID: PMC5949565 DOI: 10.3389/fimmu.2018.00969] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 04/18/2018] [Indexed: 01/10/2023] Open
Abstract
The primary anti-phospholipid syndrome (APS) is characterized by the production of antibodies that bind the phospholipid-binding protein β2 glycoprotein I (β2GPI) or that directly recognize negatively charged membrane phospholipids in a manner that may contribute to arterial or venous thrombosis. Clinically, the binding of antibodies to β2GPI could contribute to pathogenesis by formation of immune complexes or modification of coagulation steps that operate along cell surfaces. However, additional events are likely to play a role in pathogenesis, including platelet and endothelial cell activation. Recent studies focus on neutrophil release of chromatin in the form of neutrophil extracellular traps as an important disease contributor. Jointly, the participation of both the innate and adaptive arms of the immune system in aspects of the APS make the complete understanding of crucial steps in pathogenesis extremely difficult. Only coordinated and comprehensive analyses, carried out in different clinical and research settings, are likely to advance the understanding of this complex disease condition.
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Affiliation(s)
- Marko Radic
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Debendra Pattanaik
- Division of Rheumatology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
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32
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Perl A. Review: Metabolic Control of Immune System Activation in Rheumatic Diseases. Arthritis Rheumatol 2017; 69:2259-2270. [PMID: 28841779 PMCID: PMC5711528 DOI: 10.1002/art.40223] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 07/25/2017] [Indexed: 02/06/2023]
Abstract
Metabolic pathways mediate lineage specification within the immune system through the regulation of glucose utilization, a process that generates energy in the form of ATP and synthesis of amino acids, nucleotides, and lipids to enable cell growth, proliferation, and survival. CD4+ T cells, a proinflammatory cell subset, preferentially produce ATP through glycolysis, whereas cells with an antiinflammatory lineage, such as memory and regulatory T cells, favor mitochondrial ATP generation. In conditions of metabolic stress or a shortage of nutrients, cells rely on autophagy to secure amino acids and other substrates, while survival depends on the sparing of mitochondria and maintenance of a reducing environment. The pentose phosphate pathway acts as a key gatekeeper of inflammation by supplying ribose‐5‐phosphate for cell proliferation and NADPH for antioxidant defenses. Increased lysosomal catabolism, accumulation of branched amino acids, glutamine, kynurenine, and histidine, and depletion of glutathione and cysteine activate the mechanistic target of rapamycin (mTOR), an arbiter of lineage development within the innate and adaptive immune systems. Mapping the impact of susceptibility genes to metabolic pathways allows for better understanding and therapeutic targeting of disease‐specific expansion of proinflammatory cells. Therapeutic approaches aimed at glutathione depletion and mTOR pathway activation appear to be safe and effective for treating lupus, while an opposing intervention may be of benefit in rheumatoid arthritis. Environmental sources of origin for metabolites within immune cells may include microbiota and plants. Thus, a better understanding of the pathways of immunometabolism could provide new insights into the pathogenesis and treatment of the rheumatic diseases.
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Affiliation(s)
- Andras Perl
- State University of New York, Upstate Medical University, Syracuse
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Raimondo MG, Pericleous C, Radziszewska A, Borghi MO, Pierangeli S, Meroni PL, Giles I, Rahman A, Ioannou Y. Oxidation of β2-glycoprotein I associates with IgG antibodies to domain I in patients with antiphospholipid syndrome. PLoS One 2017; 12:e0186513. [PMID: 29049363 PMCID: PMC5648189 DOI: 10.1371/journal.pone.0186513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 10/03/2017] [Indexed: 11/18/2022] Open
Abstract
Domain I (DI) of beta-2-glycoprotein I (β2GPI) contains the immunodominant epitope for pathogenic antiphospholipid antibodies (aPL). DI is exposed in the linear form of the molecule but not in the circular form that comprises 90% of serum β2GPI. The majority of circulating β2GPI is biochemically reduced with two free thiols in Domain V. However, increased levels of oxidised β2GPI are found in patients with antiphospholipid syndrome (APS). It is not known whether oxidation of β2GPI favours the linear form of the molecule and thus promotes development of anti-DI antibodies. We investigated whether the proportion of oxidised β2GPI associates with the presence of anti-DI in APS patients. Serum samples from 44 APS patients were screened for IgG, IgM and IgA anti-DI, anti-β2GPI, anti-cardiolipin (anti-CL) and biochemically reduced β2GPI. A negative correlation was found between the proportion of β2GPI in the biochemically reduced form and IgG anti-DI levels (r = -0.54, p = 0.0002), but not with IgM or IgA anti-DI. Moreover, the proportion of β2GPI in the reduced form was lower in IgG anti-DI positive than anti-DI negative APS patients (p = 0.02). The relative amount of reduced β2GPI was no different between patients who were positive or negative for IgG, IgM and IgA anti-β2GPI or anti-CL. This study demonstrates that oxidised β2GPI lacking free cysteine-thiol groups most closely associates with IgG anti-DI positivity compared to IgG anti-CL and anti-β2GPI. Future studies are required to ascertain the directionality of this association to define causation.
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Affiliation(s)
- Maria Gabriella Raimondo
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- * E-mail:
| | - Charis Pericleous
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
| | - Anna Radziszewska
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
- Arthritis Research UK Centre for Adolescent Rheumatology, UCL Division of Medicine, London, United Kingdom
| | - Maria Orietta Borghi
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Silvia Pierangeli
- Division of Rheumatology, Department of Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Pier Luigi Meroni
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
- IRCCS Istituto Auxologico Italiano, Milan, Italy
| | - Ian Giles
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
| | - Anisur Rahman
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
| | - Yiannis Ioannou
- Centre for Rheumatology Research, UCL Division of Medicine, London, United Kingdom
- Arthritis Research UK Centre for Adolescent Rheumatology, UCL Division of Medicine, London, United Kingdom
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Βeta 2-glycoprotein I protects mice against gram-negative septicaemia in a sexually dimorphic manner. Sci Rep 2017; 7:8201. [PMID: 28811580 PMCID: PMC5557990 DOI: 10.1038/s41598-017-07945-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/05/2017] [Indexed: 12/29/2022] Open
Abstract
The immune responses of males and females to bacterial infections display differences. The mechanisms that underlie this sexual dimorphism are multifactorial. Lipopolysaccharide (LPS) contributes to the pathogenesis of endotoxaemia. We have previously demonstrated that the plasma protein beta-2 glycoprotein-1 (β2GPI) reduces LPS-induced inflammation in male mice. In the present study using a more robust infection model of septicaemia the role of β2GPI is examined in both male and female wild type (WT) and β2GPI deficient (β2GPI-/-) mice challenged with Escherichia coli (E. coli) intravenously. β2GPI deficiency led to an increase of E. coli colony forming units (CFU) in the circulation of both male and female mice. In male β2GPI-/- mice this was associated with a worse clinical severity score. This difference was not observed between female β2GPI-/- and female WT mice. Male WT mice had decreased levels of total and increased levels of free thiol β2GPI following administration of LPS or E. coli. This pattern of sexual dimorphic response was also observed in our cohort of humans with sepsis. These findings support a role for β2GPI in modulating the sex-specific susceptibility to gram-negative septicaemia.
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Chaturvedi S, McCrae KR. Diagnosis and management of the antiphospholipid syndrome. Blood Rev 2017; 31:406-417. [PMID: 28784423 DOI: 10.1016/j.blre.2017.07.006] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 06/22/2017] [Accepted: 07/28/2017] [Indexed: 12/14/2022]
Abstract
Antiphospholipid syndrome (APS) is characterized by thrombosis and/or pregnancy complications in the presence of persistent antiphospholipid antibodies (APLA). Laboratory diagnosis of APLA depends upon the detection of a lupus anticoagulant, which prolongs phospholipid-dependent anticoagulation tests, and/or anticardiolipin (aCL) and anti-β2-glycoprotein-1 (β2GPI) antibodies. APLA are primarily directed toward phospholipid binding proteins. Pathophysiologic mechanisms underlying thrombosis and pregnancy loss in APS include APLA induced cellular activation, inhibition of natural anticoagulant and fibrinolytic systems, and complement activation, among others. There is a high rate of recurrent thrombosis in APS, especially in triple positive patients (patients with lupus anticoagulant, aCL and anti-β2GPI antibodies), and indefinite anticoagulation with a vitamin K antagonist is the standard of care for thrombotic APS. There is currently insufficient evidence to recommend the routine use of direct oral anticoagulants (DOAC) in thrombotic APS. Aspirin with low molecular weight or unfractionated heparin may reduce the incidence of pregnancy loss in obstetric APS. Recent insights into the pathogenesis of APS have led to the identification of new potential therapeutic interventions, including anti-inflammatory and immunomodulatory therapies. Additional research is needed to better understand the effects of APLA on activation of signaling pathways in vascular cells, to identify more predictive biomarkers that define patients at greatest risk for a first or recurrent APLA-related clinical event, and to determine the safety and efficacy of DOACs and novel anti-inflammatory and immune-modulatory therapies for refractory APS.
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Affiliation(s)
- Shruti Chaturvedi
- Division of Hematology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Keith R McCrae
- Department of Hematology and Solid Tumor Oncology, Cleveland Clinic, Cleveland, OH 44195, USA.
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Arachchillage DRJ, Laffan M. Pathogenesis and management of antiphospholipid syndrome. Br J Haematol 2017; 178:181-195. [PMID: 28339096 DOI: 10.1111/bjh.14632] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Antiphospholipid antibodies are a heterogeneous group of autoantibodies that have clear associations with thrombosis and pregnancy morbidity, and which together constitute the 'antiphospholipid syndrome' (APS). However, the pathophysiology of these complications is not well understood and their heterogeneity suggests that more than one pathogenic process may be involved. Diagnosis remains a combination of laboratory analysis and clinical observation but there have been significant advances in identifying specific pathogenic features, such as domain I-specific anti-β2-glycoprotein-I antibodies. This in turn has pointed to endothelial and complement activation as important factors in the pathogenesis of APS. Consequently, although anticoagulation remains the standard treatment for thrombotic APS and during pregnancy, the realisation that these additional pathways are involved in the pathogenesis of APS has significant implications for treatment: agents acting outside the coagulation system, such as hydroxychloroquine for pregnancy complications and sirolimus as an inhibitor of the mammalian target of rapamycin (mTOR) pathway, are now under evaluation and represent a radical change in thinking for haematologists. Conventional anticoagulation is also under challenge from new, direct acting anticoagulants. This review will provide a comprehensive overview of the evolving understanding of APS pathogenesis and how this and novel therapeutics will alter diagnosis and management.
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Affiliation(s)
- Deepa R J Arachchillage
- Department of Haematology, Imperial College Healthcare NHS Trust and Imperial College London, Hammersmith Hospital, London, UK
| | - Mike Laffan
- Department of Haematology, Imperial College Healthcare NHS Trust and Imperial College London, Hammersmith Hospital, London, UK
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Redox Status of β2GPI in Different Stages of Diabetic Angiopathy. DISEASE MARKERS 2016; 2016:8246839. [PMID: 27818568 PMCID: PMC5081428 DOI: 10.1155/2016/8246839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 08/09/2016] [Indexed: 12/16/2022]
Abstract
We explored the redox status of beta 2 glycoprotein I (β2GPI) in different stages of diabetic angiopathy. Type 2 diabetes mellitus (T2DM) had a significantly lower proportion of reduced β2GPI as compared to healthy controls (p < 0.05). There was a trend that the mild coronal atherosclerosis heart disease (CAD) had higher proportion of reduced β2GPI than non-CAD and severe-CAD groups, however without significances (p > 0.05). The mild-A-stenosis group and mild-diabetic retinopathy (DR) groups had higher proportion of reduced β2GPI than their severely affected counterparts. The mild-slow nerve conduction velocity (NCVS) group had higher proportion of reduced β2GPI than normal nerve conduction velocity (NCVN group) and severe-NCVS groups. The proportion of reduced β2GPI was in positive correlation with 24 h urine microalbumin and total urine protein, and the proportion of reduced β2GPI was in negative correlation with serum and skin advanced glycation end products (AGEs). Taken together, our data implicate that the proportion of reduced β2GPI increased in the early stage of angiopathy and decreased with the aggravation of angiopathy.
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Oaks Z, Winans T, Caza T, Fernandez D, Liu Y, Landas SK, Banki K, Perl A. Mitochondrial Dysfunction in the Liver and Antiphospholipid Antibody Production Precede Disease Onset and Respond to Rapamycin in Lupus-Prone Mice. Arthritis Rheumatol 2016; 68:2728-2739. [PMID: 27332042 PMCID: PMC5083168 DOI: 10.1002/art.39791] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 06/09/2016] [Indexed: 01/17/2023]
Abstract
OBJECTIVE Antiphospholipid antibodies (aPL) constitute a diagnostic criterion of systemic lupus erythematosus (SLE), and aPL have been functionally linked to liver disease in patients with SLE. Since the mechanistic target of rapamycin (mTOR) is a regulator of oxidative stress, a pathophysiologic process that contributes to the development of aPL, this study was undertaken in a mouse model of SLE to examine the involvement of liver mitochondria in lupus pathogenesis. METHODS Mitochondria were isolated from lupus-prone MRL/lpr, C57BL/6.lpr, and MRL mice, age-matched autoimmunity-resistant C57BL/6 mice as negative controls, and transaldolase-deficient mice, a strain that exhibits oxidative stress in the liver. Electron transport chain (ETC) activity was assessed using measurements of oxygen consumption. ETC proteins, which are regulators of mitochondrial homeostasis, and the mTOR complexes mTORC1 and mTORC2 were examined by Western blotting. Anticardiolipin (aCL) and anti-β2 -glycoprotein I (anti-β2 GPI) autoantibodies were measured by enzyme-linked immunosorbent assay in mice treated with rapamycin or mice treated with a solvent control. RESULTS Mitochondrial oxygen consumption was increased in the livers of 4-week-old, disease-free MRL/lpr mice relative to age-matched controls. Levels of the mitophagy initiator dynamin-related protein 1 (Drp1) were depleted while the activity of mTORC1 was increased in MRL/lpr mice. In turn, mTORC2 activity was decreased in MRL and MRL/lpr mice. In addition, levels of aCL and anti-β2 GPI were elevated preceding the development of nephritis in 4-week-old MRL, C57BL/6.lpr, and MRL/lpr mice. Transaldolase-deficient mice showed increased oxygen consumption, depletion of Drp1, activation of mTORC1, and elevated expression of NADH:ubiquinone oxidoreductase core subunit S3 (NDUFS3), a pro-oxidant subunit of ETC complex I, as well as increased production of aCL and anti-β2 GPI autoantibodies. Treatment with rapamycin selectively blocked mTORC1 activation, NDUFS3 expression, and aPL production both in transaldolase-deficient mice and in lupus-prone mice. CONCLUSION In lupus-prone mice, mTORC1-dependent mitochondrial dysfunction contributes to the generation of aPL, suggesting that such mechanisms may represent a treatment target in patients with SLE.
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MESH Headings
- Animals
- Antibodies, Anticardiolipin/biosynthesis
- Antibodies, Anticardiolipin/drug effects
- Antibodies, Anticardiolipin/immunology
- Antibodies, Antiphospholipid/biosynthesis
- Antibodies, Antiphospholipid/drug effects
- Antibodies, Antiphospholipid/immunology
- Antibody Formation/drug effects
- Antibody Formation/immunology
- Blotting, Western
- Disease Models, Animal
- Dynamins/metabolism
- Electron Transport Chain Complex Proteins/drug effects
- Electron Transport Chain Complex Proteins/metabolism
- Enzyme-Linked Immunosorbent Assay
- Female
- Immunosuppressive Agents/pharmacology
- Lupus Erythematosus, Systemic/chemically induced
- Lupus Erythematosus, Systemic/immunology
- Lupus Erythematosus, Systemic/metabolism
- Mechanistic Target of Rapamycin Complex 1
- Mechanistic Target of Rapamycin Complex 2
- Mice
- Mice, Inbred C57BL
- Mice, Inbred MRL lpr
- Mice, Knockout
- Mitochondria, Liver/drug effects
- Mitochondria, Liver/metabolism
- Multiprotein Complexes/metabolism
- Oxidative Stress/drug effects
- Oxidative Stress/immunology
- Oxygen Consumption/drug effects
- Oxygen Consumption/immunology
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases/metabolism
- Transaldolase/genetics
- beta 2-Glycoprotein I/immunology
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Affiliation(s)
- Zachary Oaks
- State University of New York, Upstate Medical University, Syracuse
| | - Thomas Winans
- State University of New York, Upstate Medical University, Syracuse
| | - Tiffany Caza
- State University of New York, Upstate Medical University, Syracuse
| | - David Fernandez
- State University of New York, Upstate Medical University, Syracuse
| | - Yuxin Liu
- State University of New York, Upstate Medical University, Syracuse
| | - Steve K Landas
- State University of New York, Upstate Medical University, Syracuse
| | - Katalin Banki
- State University of New York, Upstate Medical University, Syracuse
| | - Andras Perl
- State University of New York, Upstate Medical University, Syracuse.
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Clinical implications of the detection of antibodies directed against domain 1 of β2-glycoprotein 1 in thrombotic antiphospholipid syndrome. Thromb Res 2016; 148:32-37. [PMID: 27770664 DOI: 10.1016/j.thromres.2016.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 09/08/2016] [Accepted: 10/02/2016] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Antibodies directed against domain 1 of β2 glycoprotein 1 (aβ2GP1-Dm1) have been involved in the immunopathogenesis of antiphospholipid syndrome (APS). However, the clinical relevance of aβ2GP1-Dm1 in thrombotic APS has not yet been fully explored. OBJECTIVES To determine the frequency of aβ2GP1-Dm1 in a cohort of patients with thrombotic APS, and to evaluate whether testing for aβ2GP1-Dm1 could have a clinical impact upon the risk assessment of the disease. METHODS Patients were tested for aβ2GP1-Dm1 antibodies by chemiluminescence (BioFlash/AcuStar®, ES). The presence of aβ2GP1-Dm1 was evaluated in different clinical presentations of the disease. RESULTS Eight-four patients with a history of venous or arterial thrombosis were included. Forty-five (54%) patients had aβ2GP1 antibodies and 40% of them were positive for aβ2GP1-Dm1. Levels of aβ2GP1-Dm1 were higher in patients with systemic autoimmune disease (AUC=0.665; 95% CI=0.544-0.786; P=0.01), positive antinuclear antibody (AUC=0.654; 95% CI=0.535-0.772; P=0.01), triple antiphospholipid antibody (aPL) positivity (AUC=0.680; 95% CI=0.534-0.825; P=0.02) and positive lupus anticoagulant (AUC=0.639; 95% CI=0.502-0.776; P=0.07). In this cohort, aβ2GP1-Dm1 antibodies were not associated with the site of the first thrombosis (OR=0,62, 95% CI=0.20-1.94, P=0.42), thrombosis recurrence (OR=1.0, 95% CI=0.37-2.71, P=1.0) or pregnancy morbidity (OR=1.5, 95% CI=0.33-7.34, P=0.58). In multivariate analysis, positivity for aβ2GP1-Dm1 antibodies was associated with the diagnosis of systemic autoimmune disease (OR=4.01, 95% CI=1.14-14.2; P=0.03) and triple aPL positivity (OR=3.59, 95% CI=0.87-14.85; P=0.07). CONCLUSIONS In the present cohort of thrombotic-APS patients, aβ2GP1-Dm1 antibodies were related to the diagnosis of systemic autoimmunity and complex serological profile of the disease, as triple aPL positivity and positive antinuclear antibody. Thus, our results suggest that testing for aβ2GP1-Dm1 antibodies may be useful for improving APS risk assessment.
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El-Assaad F, Krilis SA, Giannakopoulos B. Posttranslational forms of beta 2-glycoprotein I in the pathogenesis of the antiphospholipid syndrome. Thromb J 2016; 14:20. [PMID: 27766046 PMCID: PMC5056467 DOI: 10.1186/s12959-016-0115-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The antiphospholipid syndrome (APS) is an autoimmune disease characterised by a procoagulant state that predisposes to recurrent thrombosis and miscarriages. Two major discoveries have advanced our understanding of the underlying complex pathogenesis of the APS. The first was the discovery that beta-2 glycoprotein-1 (β2GPI) is the major auto antigen in APS. The second was the discovery in more recent years that β2GPI contains allosteric disulphide bonds susceptible to posttranslational modification that may be involved in the development of autoantibodies in APS. The main allosteric disulphide bond in the fifth domain of β2GPI can exist in two redox states: free thiol or oxidised. It is the conformational transformation of β2GPI from its free thiol form to its more immunogenic oxidised form that exposes neo-epitopes on the first and fifth domains. The purpose of this review is to highlight the recent findings on the posttranslational forms of β2GPI in the pathogenesis of APS. We suggest that novel assays quantitating the different redox forms of β2GPI in plasma or serum may be used to supplement existing clinical and laboratory assays to more accurately stratify risk of thrombosis or miscarriage in APS patients.
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Affiliation(s)
- Fatima El-Assaad
- Department of Infectious Diseases, Immunology, and Sexual Health, St. George Hospital, Level 1, 2 South Street, Kogarah, NSW 2217 Australia ; St. George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales Australia, Research and Education Centre, Level 3, 4 - 10 South St, Kogarah, NSW 2217 Australia
| | - Steven A Krilis
- Department of Infectious Diseases, Immunology, and Sexual Health, St. George Hospital, Level 1, 2 South Street, Kogarah, NSW 2217 Australia ; St. George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales Australia, Research and Education Centre, Level 3, 4 - 10 South St, Kogarah, NSW 2217 Australia
| | - Bill Giannakopoulos
- Department of Infectious Diseases, Immunology, and Sexual Health, St. George Hospital, Level 1, 2 South Street, Kogarah, NSW 2217 Australia ; St. George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales Australia, Research and Education Centre, Level 3, 4 - 10 South St, Kogarah, NSW 2217 Australia
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Gram Negative Bacterial Inflammation Ameliorated by the Plasma Protein Beta 2-Glycoprotein I. Sci Rep 2016; 6:33656. [PMID: 27670000 PMCID: PMC5037396 DOI: 10.1038/srep33656] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/31/2016] [Indexed: 01/12/2023] Open
Abstract
Lipopolysaccharide (LPS) is a major component of the outer wall of gram negative bacteria. In high doses LPS contributes to the inflammation in gram negative sepsis, and in low doses contributes to the low grade inflammation characteristic of the metabolic syndrome. We wanted to assess the role of beta2-glycoprotein I (β2GPI) a highly conserved plasma protein and its different biochemical forms in a mouse model of LPS systemic inflammation. Normal and β2GPI deficient mice were administered LPS through their veins and assessed for a range of inflammation markers in their blood and liver. Different biochemical forms of β2GPI were measured in normal mice given either saline or LPS. We show that β2GPI has a significant role in inhibiting LPS induced inflammation. In this study we provide some evidence that β2GPI serves a protective role in a mouse model of LPS inflammation. This resolves the controversy of previous studies which used LPS and β2GPI in test tube based models of LPS induced activation of white cells. We also highlight the potential relevance of a newly discovered biochemical form of β2GPI in LPS mediated inflammation and we speculate that this form has a protective role against LPS induced pathology.
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López-Pedrera C, Barbarroja N, Jimenez-Gomez Y, Collantes-Estevez E, Aguirre MA, Cuadrado MJ. Oxidative stress in the pathogenesis of atherothrombosis associated with anti-phospholipid syndrome and systemic lupus erythematosus: new therapeutic approaches. Rheumatology (Oxford) 2016; 55:2096-2108. [PMID: 27018059 DOI: 10.1093/rheumatology/kew054] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 02/18/2016] [Indexed: 12/25/2022] Open
Abstract
Atherothrombosis is a recurrent complication in APS and SLE patients. Oxidative stress has been suggested as a key player underlying this process. Autoantibodies have been pointed to as the main contributors to abnormality in the oxidative status observed in APS and SLE patients, promoting the increased production of oxidant species and the reduction of antioxidant molecules. This imbalance causes vascular damage through the activation of immune cells, including monocytes, lymphocytes and neutrophils, causing the expression of pro-inflammatory and procoagulant molecules, the formation of neutrophil extracellular traps and the adhesion of these cells to the endothelium; the induction of cellular apoptosis and impaired cell clearance, which in turn enhances autoantibody neogeneration; and cytotoxicity of endothelial cells. This review describes the mechanisms underlying the role of oxidative stress in the pathogenesis of atherothrombosis associated with APS and SLE, focused on the effect of autoantibodies, the different cell types involved and the diverse effectors, including cytokines, procoagulant proteins and their main modulators, such as oxidant/antioxidant species and intracellular pathways in each pathology. We further discuss new therapies aimed at restoring the oxidative stress balance and subsequently to tackle atherothrombosis in APS and SLE.
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Affiliation(s)
- Chary López-Pedrera
- Maimonides Institute for Research in Biomedicine of Cordoba, Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain
| | - Nuria Barbarroja
- Maimonides Institute for Research in Biomedicine of Cordoba, Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain
| | - Yolanda Jimenez-Gomez
- Maimonides Institute for Research in Biomedicine of Cordoba, Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain
| | - Eduardo Collantes-Estevez
- Maimonides Institute for Research in Biomedicine of Cordoba, Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain
| | - Ma Angeles Aguirre
- Maimonides Institute for Research in Biomedicine of Cordoba, Reina Sofia University Hospital, University of Cordoba, Cordoba, Spain
| | - Ma Jose Cuadrado
- Rheumatology Service, St Thomas Hospital, Lupus Research Unit, London, UK
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Otomo K, Amengual O, Fujieda Y, Nakagawa H, Kato M, Oku K, Horita T, Yasuda S, Matsumoto M, Nakayama KI, Hatakeyama S, Koike T, Atsumi T. Role of apolipoprotein B100 and oxidized low-density lipoprotein in the monocyte tissue factor induction mediated by anti-β2 glycoprotein I antibodies. Lupus 2016; 25:1288-98. [PMID: 26964561 DOI: 10.1177/0961203316638165] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/12/2016] [Indexed: 01/23/2023]
Abstract
OBJECTIVE The objective of this paper is to elucidate the not yet known plasma molecule candidates involved in the induction of tissue factor (TF) expression mediated by β2GPI-dependent anticardiolipin antibody (aCL/β2GPI) on monocytes. METHODS Human serum incubated with FLAG-β2GPI was applied for affinity chromatography with anti- FLAG antibody. Immunopurified proteins were analyzed by a liquid chromatography coupled with mass spectrometry (LC-MS). TF mRNA induced by the identified molecules on monocytes was also analyzed. RESULTS Apolipoprotein B100 (APOB) was the only identified serum molecule in the MS search. Oxidized LDL, containing APOB as well as ox-Lig1 (a known ligand of β2GPI), was revealed as a β2GPI-binding molecule in the immunoprecipitation assay. TF mRNA was markedly induced by oxidized LDL/β2GPI complexes with either WBCAL-1 (monoclonal aCL/β2GPI) or purified IgG from APS patients. The activities of lipoprotein-associated phospholipase A2, one of the component molecules of oxidized LDL, were significantly higher in serum from APS patients than in those from controls. CONCLUSION APOB (or oxidized LDL) was detected as a major β2GPI binding serum molecule by LC-MS search. Oxidized LDL/aCL/β2GPI complexes significantly induced TF expressions on monocytes. These data suggest that complexes of oxidized LDL and aCL/β2GPI may have a crucial role in the pathophysiology of APS.
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Affiliation(s)
- K Otomo
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - O Amengual
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Y Fujieda
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - H Nakagawa
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - M Kato
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - K Oku
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - T Horita
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - S Yasuda
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - M Matsumoto
- Division of Proteomics, Multi-scale Research Center for Prevention of Medical Science, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - K I Nakayama
- Division of Proteomics, Multi-scale Research Center for Prevention of Medical Science, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - S Hatakeyama
- Department of Biochemistry, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - T Koike
- Sapporo Medical Center NTT EC, Sapporo, Japan
| | - T Atsumi
- Division of Rheumatology, Endocrinology and Nephrology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Broder A, Mowrey WB, Kim M, Murakhovskaya I, Billett H, Neugarten J, Costenbader KH, Putterman C. Association between antiphospholipid antibodies and all-cause mortality among end-stage renal disease patients with and without SLE: a retrospective cohort study. Rheumatology (Oxford) 2015; 55:817-25. [PMID: 26705328 DOI: 10.1093/rheumatology/kev423] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To investigate the association between the presence of aPL and/or LA and all-cause mortality among end-stage renal disease (ESRD) patients with and without SLE. METHODS We included ESRD patients >18 years old followed at an urban tertiary care centre between 1 January 2006 and 31 January 2014 who had aPL measured at least once after initiating haemodialysis. All SLE patients met ACR/SLICC criteria. APL/LA+ was defined as aCL IgG or IgM >40 IU, anti-β2glycoprotein1 IgG or IgM >40 IU or LA+. Deaths as at 31 January 2014 were captured in the linked National Death Index data. Time to death was defined from the first aPL measurement. RESULTS We included 34 SLE ESRD and 64 non-SLE ESRD patients; 30 patients died during the study period. SLE ESRD patients were younger [40.4 (12.5) vs 51.9 (18.1) years, P = 0.001] and more were women (88.2% vs 54.7%, P < 0.001) vs non-SLE ESRD patients. The frequency of aPL/LA+ was 24% in SLE and 13% in non-SLE ESRD (P = 0.16). Median (inter-quartile range) follow-up time was 1.6 (0.3-3.5) years in SLE and 1.4 (0.4-3.2) years in non-SLE, P = 0.74. The adjusted hazard ratio (HR) for all-cause mortality for SLE patients who were aPL/LA+ vs aPL/LA- was 9.93 (95% CI 1.33, 74.19); the adjusted HR for non-SLE aPL/LA+ vs aPL/LA- was 0.77 (95% CI 0.14, 4.29). CONCLUSION SLE ESRD patients with aPL/LA+ had higher all-cause mortality risk than SLE ESRD patients without these antibodies, while the effects of aPL/LA on mortality were comparable among non-SLE ESRD patients.
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Affiliation(s)
- Anna Broder
- Division of Rheumatology, Department of Medicine,
| | - Wenzhu B Mowrey
- Division of Biostatistics, Department of Epidemiology and Population Health
| | - Mimi Kim
- Division of Biostatistics, Department of Epidemiology and Population Health
| | | | | | - Joel Neugarten
- Division of Nephrology, Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY and
| | - Karen H Costenbader
- Division of Rheumatology, Immunology and Allergy, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Boston, MA, USA
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van den Hoogen LL, van Roon JAG, Radstake TRDJ, Fritsch-Stork RDE, Derksen RHWM. Delineating the deranged immune system in the antiphospholipid syndrome. Autoimmun Rev 2015; 15:50-60. [PMID: 26318678 DOI: 10.1016/j.autrev.2015.08.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 08/24/2015] [Indexed: 12/16/2022]
Abstract
The antiphospholipid syndrome (APS) is a systemic autoimmune disease that is characterized serologically by the presence of antiphospholipid antibodies (aPL) and clinically by vascular thrombosis and obstetric complications. The protein β2 glycoprotein I (β2GPI) is identified as the most important autoantigen in this syndrome. Activation of endothelial cells, thrombocytes and placental tissue by anti-β2GPI antibodies relates to the clinical manifestations of APS. This review describes genetic and environmental factors in relation to APS and summarizes the current knowledge on abnormalities in components of both the innate and adaptive immune system in APS. The role of dendritic cells, T-cells, B-cells, monocytes, neutrophils and NK-cells as well as the complement system in APS are discussed. Several gaps in our knowledge on the pathophysiology of APS are identified and a plea is made for future extensive immune cell profiling by a systems medicine approach in order to better unravel the pathogenesis of APS, to gain more insight in the role of the immune system in APS as well as having the potential to reveal biomarkers or novel therapeutic targets.
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Affiliation(s)
- Lucas L van den Hoogen
- Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; Laboratory of Translational Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Joël A G van Roon
- Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; Laboratory of Translational Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Timothy R D J Radstake
- Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands; Laboratory of Translational Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Ruth D E Fritsch-Stork
- Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Ronald H W M Derksen
- Department of Rheumatology and Clinical Immunology, University Medical Centre Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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Rahgozar S, Amirian T, Qi M, Shahshahan Z, Entezar-E-Ghaem M, Ghasemi Tehrani H, Miroliaei M, Krilis SA, Giannakopoulos B. Improved Assay for Quantifying a Redox Form of Angiotensinogen as a Biomarker for Pre-Eclampsia: A Case-Control Study. PLoS One 2015; 10:e0135905. [PMID: 26312482 PMCID: PMC4552422 DOI: 10.1371/journal.pone.0135905] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/28/2015] [Indexed: 01/13/2023] Open
Abstract
Objective Angiotensinogen exists in two distinct redox forms in plasma, the oxidized sulfhydryl-bridge form and the reduced, unbridged, free thiol form. The oxidized form of angiotensinogen compared to the free thiol form preferentially interacts with renin resulting in increased generation of angiotensin. The predictive potential of the ratio of free-thiol to oxidized angiotensinogen in the plasma for pre-eclampsia was first suggested by the Read group in ref 10. We propose an improved method for determining the ratio and validate the method in a larger cohort of pregnant women. Methods Plasma samples from 115 individuals with pre-eclampsia and from 55 healthy pregnant control subjects were collected sequentially over a 2 year period. Using two distinct enzyme-linked immunosorbent assays (ELISAs) the plasma levels of total and free thiol angiotensinogen were quantified. The oxidized angiotensinogen plasma level is derived by subtracting the level of free thiol, reduced angiotensinogen from the total angiotensinogen levels in the plasma. Results The relative proportion of free thiol angiotensinogen, expressed as a percentage of that observed with an in-house standard, is significantly decreased in pre-eclamptic patients (70.85% ± 29.49%) (mean ± SD) as compared to healthy pregnant controls (92.98 ± 24.93%) (mean ± SD) p ≤ 0.0001. The levels of total angiotensinogen did not differ between the two groups. Conclusion Patients with pre-eclampsia had substantially lower levels of free thiol angiotensinogen compared to healthy pregnant controls, whilst maintaining similar total angiotensinogen levels in the plasma. Hence, elevated levels of plasma oxidized angiotensinogen may be a contributing factor to hypertension in the setting of pre-eclampsia.
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Affiliation(s)
- Soheila Rahgozar
- Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran
| | - Tayebeh Amirian
- Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran
| | - Miao Qi
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, Australia
| | - Zahra Shahshahan
- Department of Obstetrics and Gynaecology, Shahid Beheshti Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | | | - Hatav Ghasemi Tehrani
- Department of Obstetrics and Gynaecology, Shahid Beheshti Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mehran Miroliaei
- Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran
| | - Steven A. Krilis
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, Australia
| | - Bill Giannakopoulos
- Department of Infectious Diseases, Immunology and Sexual Health and Department of Medicine, St George Hospital, University of New South Wales, Sydney, Australia
- * E-mail:
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47
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Patsouras MD, Sikara MP, Grika EP, Moutsopoulos HM, Tzioufas AG, Vlachoyiannopoulos PG. Elevated expression of platelet-derived chemokines in patients with antiphospholipid syndrome. J Autoimmun 2015; 65:30-7. [PMID: 26283469 DOI: 10.1016/j.jaut.2015.08.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/31/2015] [Accepted: 08/05/2015] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Platelet factor 4 tetramers (CXCL4 chemokine) form complexes with β2glycoprotein I (β2GPI), recognized by anti-β2GPI antibodies leading to platelet activation in antiphospholipid syndrome (APS), either primary (PAPS) or secondary (SAPS). Increased plasma levels of CXCL4 may favor this process; therefore we measured plasma levels of CXCL4, a CXCL4 variant (CXCL4L1) and as controls, platelet-derived chemokines CXCL7 (NAP-2) and CCL5 (RANTES), in APS, and disease controls such as patients with systemic lupus erythematosus (SLE) coronary artery disease (CAD) and healthy donors (HDs). METHODS Plasma samples and platelets were isolated from patients with APS (n = 87), SLE (n = 29), CAD (n = 14) and 54 HDs. Plasma levels of CXCL4, CXCL4L1, CXCL7 and CCL5 as well as intracellular platelet CXCL4 and CXCL4L1 were measured using ELISA. Platelet CXCL4 and CXCL4L1 RNA levels were determined by RT-PCR. RESULTS CXCL4, CXCL7 (NAP-2) and CCL5 (RANTES) plasma levels were significantly higher in patients with APS compared to both control groups (SLE, CAD) and HDs. CXCL4L1 plasma levels were also significantly higher in APS than in SLE and HDs, but lower from that of CAD patients. Statistically significant concordance was detected between CXCL4 and CXCL7 (p < 0.0001) or CCL5 (p < 0.0001) plasma levels in patients with APS, either PAPS or SAPS. CXCL4L1 plasma levels were inversely correlated with CXCL4 (P = 0.0027), CXCL7 (p = 0.012) and CCL5 (p = 0.023) in PAPS and positively with CXCL4 (p = 0.0191), CCL5 (p < 0.0001) and CXCL7 (P < 0.0001), in SAPS. Levels of CXCL4, CXCL4L1, CXCL7 and CCL5 were divided in "high" (exceeding a level defined as the mean of HDs and 3 SD) and "low" (below this level); The "CXCL4L1 high" group was characterized by increased IgG aCL, (p = 0.0215), double antibody positivity (either aCL or anti-β2GPI plus LA), (p = 0.0277), triple antibody positivity (aCL plus anti-β2GPI plus LA), (p = 0.0073) and thrombocytopenia (p = 0.0061), as well as with at least 1 thrombotic event or the last 5 years (p = 0.0001), or more than 3 thrombotic events ever (p = 0.0151). CONCLUSIONS Chemokines associated with platelet activation and immune cell chemotaxis were found to be elevated in APS patients' plasma and may contribute to the pathogenesis of the syndrome. High CXCL4L1 plasma levels are associated with the clinical expression of APS and should be prospectively evaluated as a biomarker.
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Affiliation(s)
- Markos D Patsouras
- Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
| | - Marina P Sikara
- Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
| | - Eleftheria P Grika
- Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
| | | | - Athanasios G Tzioufas
- Department of Pathophysiology, School of Medicine, National University of Athens, Athens, Greece
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Lopez-Pedrera C, Aguirre MA, Ruiz-Limon P, Pérez-Sánchez C, Jimenez-Gomez Y, Barbarroja N, Cuadrado MJ. Immunotherapy in antiphospholipid syndrome. Int Immunopharmacol 2015; 27:200-8. [PMID: 26086363 DOI: 10.1016/j.intimp.2015.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 04/20/2015] [Accepted: 06/03/2015] [Indexed: 10/23/2022]
Abstract
Antiphospholipid syndrome (APS) is a disorder characterized by the association of arterial or venous thrombosis and/or pregnancy morbidity with the presence of antiphospholipid antibodies (anticardiolipin antibodies, lupus anticoagulant antibodies, and/or anti-β2-glycoprotein I antibodies). Thrombosis is the major manifestation in patients with aPLs, but the spectrum of symptoms and signs associated with aPLs has broadened considerably, and other manifestations, such as thrombocytopenia, non-thrombotic neurological syndromes, psychiatric manifestations, livedo reticularis, skin ulcers, hemolytic anemia, pulmonary hypertension, cardiac valve abnormality, and atherosclerosis, have also been related to the presence of those antibodies. Several studies have contributed to uncovering the basis of antiphospholipid antibody pathogenicity, including the targeted cellular components, affected systems, involved receptors, intracellular pathways used, and the effector molecules that are altered in the process. Therapy for thrombosis traditionally has been based on long-term oral anticoagulation; however, bleeding complications and recurrence despite high-intensity anticoagulation can occur. The currently accepted first-line treatment for obstetric APS (OAPS) is low-dose aspirin plus prophylactic unfractionated or low-molecular-weight heparin (LMWH). However, in approximately 20% of OAPS cases, the final endpoint, i.e. a live birth, cannot be achieved. Based on all the data obtained in different research studies, new potential therapeutic approaches have been proposed, including the use of new oral anticoagulants, statins, hydroxychloroquine, coenzyme Q10, B-cell depletion, platelet and TF inhibitors, peptide therapy or complement inhibition among others. Current best practice in use of these treatments is discussed.
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Affiliation(s)
- Ch Lopez-Pedrera
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain.
| | - M A Aguirre
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - P Ruiz-Limon
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - C Pérez-Sánchez
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - Y Jimenez-Gomez
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - N Barbarroja
- Maimonides Institute for Research in Biomedicine of Cordoba (IMIBIC), Reina Sofia University Hospital, University of Cordoba, Córdoba, Spain
| | - M J Cuadrado
- Lupus Research Unit, St. Thomas Hospital, London, UK
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Lai ZW, Marchena-Mendez I, Perl A. Oxidative stress and Treg depletion in lupus patients with anti-phospholipid syndrome. Clin Immunol 2015; 158:148-52. [PMID: 25862984 DOI: 10.1016/j.clim.2015.03.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 03/26/2015] [Indexed: 01/08/2023]
Abstract
Anti-phospholipid antibodies (APLA) represent a diagnostic criterion of systemic lupus erythematosus (SLE) and cause morbidity, termed anti-phospholipid syndrome (APS). Activation of the mechanistic target of rapamycin (mTOR) has been recently associated with APS. mTOR is a sensor of oxidative stress. Therefore, we examined mitochondrial mass, superoxide production, mTOR activity and FoxP3 expression in 72 SLE patients, twelve of whom also had APS, and 54 healthy controls by flow cytometry. Mitochondrial mass was increased in CD4(-)CD8(-) double-negative (DN) T cells of SLE patients with APS (2.7-fold) in comparison to those without APS (1.7-fold; p = 0.014). Superoxide production was increased in all lymphocyte subsets of APS patients. FoxP3(+) cells were depleted within CD4(+)CD25(+) Tregs in patients with APS (28.4%) relative to those without APS (46.3%, p = 0.008). mTOR activity was similar between SLE patients with and without APS. Thus, oxidative stress and Treg depletion rather than mTOR activation underlie APS in patients with SLE.
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Affiliation(s)
- Zhi-wei Lai
- Division of Rheumatology, Department of Medicine, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA; Department of Microbiology and Immunology, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA
| | - Ivan Marchena-Mendez
- Division of Rheumatology, Department of Medicine, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA; Department of Microbiology and Immunology, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA
| | - Andras Perl
- Division of Rheumatology, Department of Medicine, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA; Department of Microbiology and Immunology, State University of New York Upstate Medical University, College of Medicine, Syracuse, NY 13210, USA.
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50
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Wang T, Chen SS, Chen R, Yu DM, Yu P. Reduced beta 2 glycoprotein I improves diabetic nephropathy via inhibiting TGF-β1-p38 MAPK pathway. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:2321-2333. [PMID: 26045739 PMCID: PMC4440048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/28/2015] [Indexed: 06/04/2023]
Abstract
PURPOSE Beta 2 glycoprotein I (β2GPI) has been shown the positive effect on diabetic atherosclerosis and retinal neovascularization. β2GPI can be reduced by thioredoxin-1, resulting in the reduced state of β2GPI. The possible protective effects of β2GPI and reduced β2GPI on diabetic nephropathy (DN) are not fully elucidated. The purpose of this study was to test a hypothesis that β2GPI and reduced β2GPI would improve DN in streptozotocin (STZ) induced diabetic mice and high-glucose (HG) exposed rat mesangial cell (RMC). METHODS The STZ-induced Balb/c mice and HG exposed RMCs were administrated with β2-GPI and reduced β2-GPI at different time and concentrations gradient respectively. The changes of glomerular structure and expression of collagen IV, TGF-β1, p38 MAPK and phospho-p38 MAPK in renal cortical and mesangial cells were observed by immunohistochemical techniques, quantitative real-time PCR and western blot with or without the treatment of β2-GPI and reduced β2-GPI. RESULTS β2GPI and reduced β2GPI improved early clinical and pathological changes of DN in STZ-diabetic mice. Treatment with β2GPI and reduced β2GPI in the STZ-diabetic mice and HG exposed RMCs resulted in decrease expression levels of TGF-β1 and collagen IV, with concomitant decrease in phospho-p38 MAPK expression. CONCLUSIONS β2GPI and reduced β2GPI improved renal structural damage and kidney function. The renoprotective and antifibrosis effects of β2GPI and reduced β2GPI on DN were closely associated with suppressing the activation of the TGF-β1-p38 MAPK pathway.
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Affiliation(s)
- Tong Wang
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University Tianjin 300070, China
| | - Si-Si Chen
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University Tianjin 300070, China
| | - Rui Chen
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University Tianjin 300070, China
| | - De-Min Yu
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University Tianjin 300070, China
| | - Pei Yu
- 2011 Collaborative Innovation Center of Tianjin for Medical Epigenetics, The Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University Tianjin 300070, China
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