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Wei Y, Guo J, Meng T, Gao T, Mai Y, Zuo W, Yang J. The potential application of complement inhibitors-loaded nanosystem for autoimmune diseases via regulation immune balance. J Drug Target 2024; 32:485-498. [PMID: 38491993 DOI: 10.1080/1061186x.2024.2332730] [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: 12/20/2023] [Accepted: 03/14/2024] [Indexed: 03/18/2024]
Abstract
The complement is an important arm of the innate immune system, once activated, the complement system rapidly generates large quantities of protein fragments that are potent mediators of inflammation. Recent studies have shown that over-activated complement is the main proinflammatory system of autoimmune diseases (ADs). In addition, activated complements interact with autoantibodies, immune cells exacerbate inflammation, further worsening ADs. With the increasing threat of ADs to human health, complement-based immunotherapy has attracted wide attention. Nevertheless, efficient and targeted delivery of complement inhibitors remains a significant challenge owing to their inherent poor targeting, degradability, and low bioavailability. Nanosystems offer innovative solutions to surmount these obstacles and amplify the potency of complement inhibitors. This prime aim to present the current knowledge of complement in ADs, analyse the function of complement in the pathogenesis and treatment of ADs, we underscore the current situation of nanosystems assisting complement inhibitors in the treatment of ADs. Considering technological, physiological, and clinical validation challenges, we critically appraise the challenges for successfully translating the findings of preclinical studies of these nanosystem assisted-complement inhibitors into the clinic, and future perspectives were also summarised. (The graphical abstract is by BioRender.).
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Affiliation(s)
- Yaya Wei
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Jueshuo Guo
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Tingting Meng
- Department of Pharmaceutical Preparation, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Ting Gao
- Department of Pharmaceutical Preparation, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Yaping Mai
- School of Science and Technology Centers, Ningxia Medical University, Yinchuan, China
| | - Wenbao Zuo
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, China
| | - Jianhong Yang
- Department of Pharmaceutics, School of Pharmacy, Ningxia Medical University, Yinchuan, China
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2
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Kuboi Y, Suzuki Y, Motoi S, Matsui C, Toritsuka N, Nakatani T, Tahara K, Takahashi Y, Ida Y, Tomimatsu A, Soejima M, Imai T. Identification of potent siRNA targeting complement C5 and its robust activity in pre-clinical models of myasthenia gravis and collagen-induced arthritis. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 31:339-351. [PMID: 36789273 PMCID: PMC9900455 DOI: 10.1016/j.omtn.2023.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 01/10/2023] [Indexed: 01/15/2023]
Abstract
Complement component 5 (C5), an important molecule in the complement cascade, blockade by antibodies shows clinical efficacy in treating complement-mediated disorders. However, insufficient blockading induced by single-nucleotide polymorphisms in the C5 protein or frequent development of "breakthrough" intravascular hemolysis in patients with paroxysmal nocturnal hemoglobinuria treated with eculizumab have been reported. Herein, we developed a lipid nanoparticle (LNP)-formulated siRNA targeting C5 that was efficiently delivered to the liver and silenced C5 expression. We identified a potent C5-siRNA with an in vitro IC50 of 420 pM and in vivo ED50 of 0.017 mg/kg following a single administration. Single or repeated administrations of the LNP-formulated C5-siRNA allowed robust and durable suppression of liver C5 expression in mice. Complement C5 silencing ameliorated C5b-dependent anti-acetylcholine receptor antibody-induced myasthenia gravis and C5a-dependent collagen-induced arthritis symptoms. Similarly, in nonhuman primates, a single administration of C5-siRNA/LNP-induced dose-dependent plasma C5 suppression and concomitantly inhibited serum complement activity; complement activity recovered to the pre-treatment levels at 65 days post administration, thus indicating that the complement activity can be controlled for a specific period. Our findings provide the foundation for further developing C5-siRNA delivered via LNPs as a potential therapeutic for complement-mediated diseases.
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Affiliation(s)
- Yoshikazu Kuboi
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Corresponding author: Yoshikazu Kuboi, MS, KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Kobe, Hyogo 650-0047, Japan.
| | - Yuta Suzuki
- Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Sotaro Motoi
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Chiyuki Matsui
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Naoki Toritsuka
- Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Tomoya Nakatani
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Kazuhiro Tahara
- Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Yoshinori Takahashi
- Tsukuba Research Laboratories, Eisai Co., Ltd., 5-1-3 Tokodai, Tsukuba, Ibaraki 300-2635, Japan
| | - Yoko Ida
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Ayaka Tomimatsu
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Motohiro Soejima
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Toshio Imai
- KAN Research Institute, Inc., 6-8-2 Minatojima minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
- Advanced Therapeutic Target Discovery, Kobe University Graduate School of Medicine, 1-5-6 Minatojima-minamimachi, Chuo-ku, Kobe 650-0047, Japan
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3
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Schubert M, Pelz A, Trautmann G, Block K, Furlan S, Gutsmann M, Kohler S, Volpe P, Blottner D, Meisel A, Salanova M. Opposite Regulation of Homer Signal at the NMJ Postsynaptic Micro Domain between Slow- and Fast-Twitch Muscles in an Experimentally Induced Autoimmune Myasthenia Gravis (EAMG) Mouse Model. Int J Mol Sci 2022; 23:ijms232315052. [PMID: 36499379 PMCID: PMC9738765 DOI: 10.3390/ijms232315052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/17/2022] [Accepted: 11/26/2022] [Indexed: 12/03/2022] Open
Abstract
Accelerated postsynaptic remodelling and disturbance of neuromuscular transmission are common features of autoimmune neurodegenerative diseases. Homer protein isoform expression, crosslinking activity and neuromuscular subcellular localisation are studied in mouse hind limb muscles of an experimentally induced autoimmune model of Myasthenia Gravis (EAMG) and correlated to motor end plate integrity. Soleus (SOL), extensor digitorum longus (EDL) and gastrocnemius (GAS) skeletal muscles are investigated. nAChR membrane clusters were studied to monitor neuromuscular junction (NMJ) integrity. Fibre-type cross-sectional area (CSA) analysis is carried out in order to determine the extent of muscle atrophy. Our findings clearly showed that crosslinking activity of Homer long forms (Homer 1b/c and Homer2a/b) are decreased in slow-twitch and increased in fast-twitch muscle of EAMG whereas the short form of Homer that disrupts Homer crosslinking (Homer1a) is upregulated in slow-twitch muscle only. Densitometry analysis showed a 125% increase in Homer protein expression in EDL, and a 45% decrease in SOL of EAMG mice. In contrast, nAChR fluorescence pixel intensity decreased in endplates of EAMG mice, more distinct in type-I dominant SOL muscle. Morphometric CSA of EAMG vs. control (CTR) revealed a significant reduction in EDL but not in GAS and SOL. Taken together, these results indicate that postsynaptic Homer signalling is impaired in slow-twitch SOL muscle from EAMG mice and provide compelling evidence suggesting a functional coupling between Homer and nAChR, underscoring the key role of Homer in skeletal muscle neurophysiology.
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Affiliation(s)
- Martin Schubert
- Institute of Integrative Neuroanatomy, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10115 Berlin, Germany
| | - Andreas Pelz
- Department of Experimental Neurology, Charité—Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Gabor Trautmann
- Institute of Integrative Neuroanatomy, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10115 Berlin, Germany
| | - Katharina Block
- Center of Space Medicine Berlin, Neuromuscular Signaling and System, 10115 Berlin, Germany
| | - Sandra Furlan
- C.N.R. Institute of Neuroscience, 35131 Padova, Italy
| | - Martina Gutsmann
- Institute of Integrative Neuroanatomy, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10115 Berlin, Germany
| | - Siegfried Kohler
- Department of Experimental Neurology, Charité—Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Pompeo Volpe
- Department of Biomedical Sciences, University of Padova, 35122 Padova, Italy
| | - Dieter Blottner
- Institute of Integrative Neuroanatomy, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10115 Berlin, Germany
- Center of Space Medicine Berlin, Neuromuscular Signaling and System, 10115 Berlin, Germany
| | - Andreas Meisel
- Department of Experimental Neurology, Charité—Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Michele Salanova
- Institute of Integrative Neuroanatomy, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, 10115 Berlin, Germany
- Center of Space Medicine Berlin, Neuromuscular Signaling and System, 10115 Berlin, Germany
- Correspondence: ; Tel.: +49-30-450528-354
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4
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Rose N, Holdermann S, Callegari I, Kim H, Fruh I, Kappos L, Kuhle J, Müller M, Sanderson NSR, Derfuss T. Receptor clustering and pathogenic complement activation in myasthenia gravis depend on synergy between antibodies with multiple subunit specificities. Acta Neuropathol 2022; 144:1005-1025. [PMID: 36074148 PMCID: PMC9547806 DOI: 10.1007/s00401-022-02493-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/17/2022] [Accepted: 09/02/2022] [Indexed: 01/26/2023]
Abstract
Myasthenia gravis is an autoimmune disorder defined by muscle weakness and fatigability associated with antibodies against proteins of the neuromuscular junction (NMJ). The most common autoantibody target is the acetylcholine receptor (AChR). Three mechanisms have been postulated by which autoantibodies might interfere with neurotransmission: direct antagonism of the receptor, complement-mediated destruction of the postsynaptic membrane, and enhanced internalization of the receptor. It is very likely that more than one of these mechanisms act in parallel. Dissecting the mechanisms of autoantibody-mediated pathology requires patient-derived, monoclonal antibodies. Using membrane antigen capture activated cell sorting (MACACS), we isolated AChR-specific B cells from patients with myasthenia gravis, and produced six recombinant antibodies. All AChR-specific antibodies were hypermutated, including isotypes IgG1, IgG3, and IgG4, and recognized different subunits of the AChR. Despite clear binding, none of the individual antibodies showed significant antagonism of the AChR measured in an in vitro neuromuscular synapse model, or AChR-dependent complement activation, and they did not induce myasthenic signs in vivo. However, combinations of antibodies induced strong complement activation in vitro, and severe weakness in a passive transfer myasthenia gravis rat model, associated with NMJ destruction and complement activation in muscle. The strongest complement activation was mediated by combinations of antibodies targeting disparate subunits of the AChR, and such combinations also induced the formation of large clusters of AChR on the surface of live cells in vitro. We propose that synergy between antibodies of different epitope specificities is a fundamental feature of this disease, and possibly a general feature of complement-mediated autoimmune diseases. The importance of synergistic interaction between antibodies targeting different subunits of the receptor can explain the well-known discrepancy between serum anti-AChR titers and clinical severity, and has implications for therapeutic strategies currently under investigation.
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Affiliation(s)
- Natalie Rose
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Sebastian Holdermann
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Ilaria Callegari
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Hyein Kim
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Isabelle Fruh
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Ludwig Kappos
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
| | - Jens Kuhle
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Matthias Müller
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002, Basel, Switzerland
| | - Nicholas S R Sanderson
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland.
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland.
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland.
| | - Tobias Derfuss
- Department of Biomedicine, University Hospital Basel and University of Basel, Basel, Switzerland
- Neurologic Clinic and Policlinic and MS Center, University Hospital Basel, University of Basel, Basel, Switzerland
- Research Center for Clinical Neuroimmunology and Neuroscience (RC2NB), University Hospital and University of Basel, Basel, Switzerland
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5
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Fanella G, Baiata C, Candeloro E, Toscano G, Colnaghi S, Mauri M, Cariddi LP, Rebecchi V, Solazzo F, Banfi P, Piatti M, Ferrarese C, Versino M. New-onset myasthenia gravis after mRNA SARS-CoV-2 vaccination: a case series. Neurol Sci 2022; 43:5799-5802. [PMID: 35870026 PMCID: PMC9308404 DOI: 10.1007/s10072-022-06284-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 07/18/2022] [Indexed: 11/26/2022]
Abstract
Background Myasthenia gravis (MG) is an autoimmune disease that targets acetylcholine receptor (AChR) of the neuromuscular junction. New-onset MG after SARS-CoV-2 vaccination has rarely been reported. Case presentation We report about three patients who presented new-onset myasthenia gravis after receiving mRNA SARS-CoV-2 vaccination. The patients were all males and older than 55 years. All the patients presented with ocular and bulbar symptoms. The interval between vaccine administration and MG onset ranged from 3 days after the first dose to 10 days after the second dose. All the patients had elevated serum AChR antibodies and responded to pyridostigmine. Two out of three patients were successfully treated with IVIG or plasma exchange and with long-term immunosuppression. Conclusions MG is a rare disease; clinicians should be aware of possible new-onset MG after SARS-CoV-2 vaccination, especially with the current recommendation of booster doses. The hyperstimulation of the innate immune system or the exacerbation of a subclinical pre-existing MG could be possible explanations.
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Affiliation(s)
- Gaia Fanella
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy.
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.
| | - Claudio Baiata
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Elisa Candeloro
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Gianpaolo Toscano
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Silvia Colnaghi
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Marco Mauri
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
- DMC, University of Insubria, Varese, Italy
| | - Lucia Princiotta Cariddi
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
- Clinical and Experimental Medicine and Medical Humanities, Center of Research in Medical Pharmacology, University of Insubria, Varese, Italy
| | - Valentina Rebecchi
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Francesca Solazzo
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Paola Banfi
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
| | - Marialuisa Piatti
- Department of Neurology, San Gerardo Hospital, ASST Monza, Monza, Italy
| | - Carlo Ferrarese
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
- Department of Neurology, San Gerardo Hospital, ASST Monza, Monza, Italy
| | - Maurizio Versino
- Neurology and Stroke Unit, Circolo Hospital ASST Sette Laghi, Varese, Italy
- DMC, University of Insubria, Varese, Italy
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Song J, Zhao R, Yan C, Luo S, Xi J, Ding P, Li L, Hu W, Zhao C. A Targeted Complement Inhibitor CRIg/FH Protects Against Experimental Autoimmune Myasthenia Gravis in Rats via Immune Modulation. Front Immunol 2022; 13:746068. [PMID: 35154091 PMCID: PMC8825366 DOI: 10.3389/fimmu.2022.746068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 01/04/2022] [Indexed: 11/13/2022] Open
Abstract
Antibody-induced complement activation may cause injury of the neuromuscular junction (NMJ) and is thus considered as a primary pathogenic factor in human myasthenia gravis (MG) and animal models of experimental autoimmune myasthenia gravis (EAMG). In this study, we tested whether CRIg/FH, a targeted complement inhibitor, could attenuate NMJ injury in rat MG models. We first demonstrated that CRIg/FH could inhibit complement-dependent cytotoxicity on human rhabdomyosarcoma TE671 cells induced by MG patient-derived IgG in vitro. Furthermore, we investigated the therapeutic effect of CRIg/FH in a passive and an active EAMG rodent model. In both models, administration of CRIg/FH could significantly reduce the complement-mediated end-plate damage and suppress the development of EAMG. In the active EAMG model, we also found that CRIg/FH treatment remarkably reduced the serum concentration of autoantibodies and of the cytokines including IFN-γ, IL-2, IL-6, and IL-17, and upregulated the percentage of Treg cells in the spleen, which was further verified in vitro. Therefore, our findings indicate that CRIg/FH may hold the potential for the treatment of MG via immune modulation.
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Affiliation(s)
- Jie Song
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Rui Zhao
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Chong Yan
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
| | - Peipei Ding
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Ling Li
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Weiguo Hu
- Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China.,Key Laboratory of Breast Cancer in Shanghai, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital Fudan University, Shanghai, China.,National Center for Neurological Disorders, Shanghai, China
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7
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The Neuromuscular Junction: Roles in Aging and Neuromuscular Disease. Int J Mol Sci 2021; 22:ijms22158058. [PMID: 34360831 PMCID: PMC8347593 DOI: 10.3390/ijms22158058] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized synapse that bridges the motor neuron and the skeletal muscle fiber and is crucial for conversion of electrical impulses originating in the motor neuron to action potentials in the muscle fiber. The consideration of contributing factors to skeletal muscle injury, muscular dystrophy and sarcopenia cannot be restricted only to processes intrinsic to the muscle, as data show that these conditions incur denervation-like findings, such as fragmented NMJ morphology and corresponding functional changes in neuromuscular transmission. Primary defects in the NMJ also influence functional loss in motor neuron disease, congenital myasthenic syndromes and myasthenia gravis, resulting in skeletal muscle weakness and heightened fatigue. Such findings underscore the role that the NMJ plays in neuromuscular performance. Regardless of cause or effect, functional denervation is now an accepted consequence of sarcopenia and muscle disease. In this short review, we provide an overview of the pathologic etiology, symptoms, and therapeutic strategies related to the NMJ. In particular, we examine the role of the NMJ as a disease modifier and a potential therapeutic target in neuromuscular injury and disease.
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8
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High mobility group box 1 is involved in the pathogenesis of passive transfer myasthenia gravis model. Neuroreport 2021; 32:803-807. [PMID: 33994526 DOI: 10.1097/wnr.0000000000001665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Myasthenia gravis (MG) is an autoimmune disease with autoantibodies against the mainly nicotinic acetylcholine receptor (AChR). High mobility group box1 (HMGB1) acts as a danger signal and drives the pathogenesis of autoimmune-mediated diseases. However, the role of HMGB1 in the pathogenesis of MG is not fully understood. Therefore, in this study, we analyzed serum levels of HMGB1 and immunohistochemical HMGB1 staining of muscle tissues in the passive transfer MG model to investigate the role of HMGB1 in MG. As a result, serum HMGB1 levels tended to be higher and the quantitative score of muscle pathology showed greater HMGB1 deposition (P = 0.02) along with sparser AChR staining and more severe inflammation in the passive transfer MG rats (n = 6) than those in control rats (n = 6). These findings indicate that HMGB1 is an important mediator and biomarker for inflammation in the pathogenesis of MG and can be a therapeutic target in MG.
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9
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Albazli K, Kaminski HJ, Howard JF. Complement Inhibitor Therapy for Myasthenia Gravis. Front Immunol 2020; 11:917. [PMID: 32582144 PMCID: PMC7283905 DOI: 10.3389/fimmu.2020.00917] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Accepted: 04/20/2020] [Indexed: 01/01/2023] Open
Abstract
Complement activation as a driver of pathology in myasthenia gravis (MG) has been appreciated for decades. The terminal complement component [membrane attack complex (MAC)] is found at the neuromuscular junctions of patients with MG. Animals with experimental autoimmune MG are dependent predominantly on an active complement system to develop weakness. Mice deficient in intrinsic complement regulatory proteins demonstrate a significant increase in the destruction of the neuromuscular junction. As subtypes of MG have been better defined, it has been appreciated that acetylcholine receptor antibody-positive disease is driven by complement activation. Preclinical assessments have confirmed that complement inhibition would be a viable therapeutic approach. Eculizumab, an antibody directed toward the C5 component of complement, was demonstrated to be effective in a Phase 3 trial with subsequent approval by the Federal Drug Administration of the United States and other worldwide regulatory agencies for its use in acetylcholine receptor antibody-positive MG. Second- and third-generation complement inhibitors are in development and approaching pivotal efficacy evaluations. This review will summarize the history and present the state of knowledge of this new therapeutic modality.
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Affiliation(s)
- Khaled Albazli
- Department of Neurology, George Washington University, Washington, DC, United States
| | - Henry J. Kaminski
- Department of Neurology, George Washington University, Washington, DC, United States
| | - James F. Howard
- Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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10
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Vanhaesebrouck AE, Webster R, Maxwell S, Rodriguez Cruz PM, Cossins J, Wickens J, Liu WW, Cetin H, Cheung J, Ramjattan H, Palace J, Beeson D. β2-Adrenergic receptor agonists ameliorate the adverse effect of long-term pyridostigmine on neuromuscular junction structure. Brain 2020; 142:3713-3727. [PMID: 31633155 PMCID: PMC6892641 DOI: 10.1093/brain/awz322] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/04/2019] [Accepted: 08/26/2019] [Indexed: 01/07/2023] Open
Abstract
Acetylcholine receptor deficiency is the most common form of the congenital myasthenic syndromes, a heterogeneous collection of genetic disorders of neuromuscular transmission characterized by fatiguable muscle weakness. Most patients with acetylcholine receptor deficiency respond well to acetylcholinesterase inhibitors; however, in some cases the efficacy of acetylcholinesterase inhibitors diminishes over time. Patients with acetylcholine receptor deficiency can also benefit from the addition of a β2-adrenergic receptor agonist to their medication. The working mechanism of β2-adrenergic agonists in myasthenic patients is not fully understood. Here, we report the long-term follow-up for the addition of β2-adrenergic agonists for a cohort of patients with acetylcholine receptor deficiency on anticholinesterase medication that demonstrates a sustained quantitative improvement. Coincidently we used a disease model to mirror the treatment of acetylcholine receptor deficiency, and demonstrate improved muscle fatigue, improved neuromuscular transmission and improved synaptic structure resulting from the addition of the β2-adrenergic agonist salbutamol to the anticholinesterase medication pyridostigmine. Following an initial improvement in muscle fatiguability, a gradual decline in the effect of pyridostigmine was observed in mice treated with pyridostigmine alone (P < 0.001). Combination therapy with pyridostigmine and salbutamol counteracted this decline (P < 0.001). Studies of compound muscle action potential decrement at high nerve stimulation frequencies (P < 0.05) and miniature end-plate potential amplitude analysis (P < 0.01) showed an improvement in mice following combination therapy, compared to pyridostigmine monotherapy. Pyridostigmine alone reduced postsynaptic areas (P < 0.001) and postsynaptic folding (P < 0.01). Combination therapy increased postsynaptic area (P < 0.001) and promoted the formation of postsynaptic junctional folds (P < 0.001), in particular in fast-twitch muscles. In conclusion, we demonstrate for the first time how the improvement seen in patients from adding salbutamol to their medication can be explained in an experimental model of acetylcholine receptor deficiency, the most common form of congenital myasthenic syndrome. Salbutamol enhances neuromuscular junction synaptic structure by counteracting the detrimental effects of long-term acetylcholinesterase inhibitors on the postsynaptic neuromuscular junction. The results have implications for both autoimmune and genetic myasthenias where anticholinesterase medication is a standard treatment.
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Affiliation(s)
- An E Vanhaesebrouck
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Richard Webster
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Susan Maxwell
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Pedro M Rodriguez Cruz
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK.,Department of Clinical Neurology, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Judith Cossins
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - James Wickens
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | - Wei-Wei Liu
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Hakan Cetin
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Jonathan Cheung
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
| | - Hayley Ramjattan
- Paediatric Neurology, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Jacqueline Palace
- Department of Clinical Neurology, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - David Beeson
- Neurosciences Group, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DS, UK
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11
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Huda R. New Approaches to Targeting B Cells for Myasthenia Gravis Therapy. Front Immunol 2020; 11:240. [PMID: 32153573 PMCID: PMC7047318 DOI: 10.3389/fimmu.2020.00240] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 01/29/2020] [Indexed: 01/06/2023] Open
Abstract
Current therapies for myasthenia gravis (MG) are limited, and many investigations have recently focused on target-specific therapies. B cell-targeting monoclonal antibody (mAb) therapies for MG are increasingly attractive due to their specificity and efficacy. The targeted B cell biomarkers are mainly the cluster of differentiation (CD) proteins that mediate maturation, differentiation, or survival of pathogenic B cells. Additional B cell-directed therapies include non-specific peptide inhibitors that preferentially target specific B cell subsets. The primary goals of such therapies are to intercept autoantibodies and prevent the generation of an inflammatory response that contributes to the pathogenesis of MG. Treatment of patients with MG using B cell-directed mAbs, antibody fragments, or selective inhibitors have exhibited moderate to high efficacy in early studies, and some of these therapies appear to be highly promising for further drug development. Numerous other biologics targeting various B cell surface molecules have been approved for the treatment of other conditions or are either in clinical trials or preclinical development stages. These approaches remain to be tested in patients with MG or animal models of the disease. This review article provides an overview of B cell-targeted treatments for MG, including those already available and those still in preclinical and clinical development. We also discuss the potential benefits as well as the shortcomings of these approaches to development of new therapies for MG and future directions in the field.
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Affiliation(s)
- Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
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12
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Giannoccaro MP, Wright SK, Vincent A. In vivo Mechanisms of Antibody-Mediated Neurological Disorders: Animal Models and Potential Implications. Front Neurol 2020; 10:1394. [PMID: 32116982 PMCID: PMC7013005 DOI: 10.3389/fneur.2019.01394] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/19/2019] [Indexed: 12/25/2022] Open
Abstract
Over the last two decades, the discovery of antibodies directed against neuronal surface antigens (NSA-Abs) in patients with different forms of encephalitis has provided a basis for immunotherapies in previously undefined disorders. Nevertheless, despite the circumstantial clinical evidence of the pathogenic role of these antibodies in classical autoimmune encephalitis, specific criteria need to be applied in order to establish the autoimmune nature of a disease. A growing number of studies have begun to provide proof of the pathogenicity of NSA-Abs and insights into their pathogenic mechanisms through passive transfer or, more rarely, through active immunization animal models. Moreover, the increasing evidence that NSA-Abs in the maternal circulation can reach the fetal brain parenchyma during gestation, causing long-term effects, has led to models of antibody-induced neurodevelopmental disorders. This review summarizes different methodological approaches and the results of the animal models of N-methyl-d-aspartate receptor (NMDAR), leucine-rich glioma-inactivated 1 (LGI1), contactin-associated protein 2 (CASPR2), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antibody-mediated disorders and discuss the results and the limitations. We also summarize recent experiments that demonstrate that maternal antibodies to NMDAR and CASPR2 can alter development in the offspring with potential lifelong susceptibility to neurological or psychiatric disorders.
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Affiliation(s)
- Maria Pia Giannoccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna and IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Sukhvir K. Wright
- School of Life and Health Sciences & Aston Neuroscience Institute, Aston University, Birmingham, United Kingdom
- Department of Neurology, Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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13
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Chamberlain JL, Huda S, Whittam DH, Matiello M, Morgan BP, Jacob A. Role of complement and potential of complement inhibitors in myasthenia gravis and neuromyelitis optica spectrum disorders: a brief review. J Neurol 2019; 268:1643-1664. [PMID: 31482201 DOI: 10.1007/s00415-019-09498-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 02/08/2023]
Abstract
The complement system is a powerful member of the innate immune system. It is highly adept at protecting against pathogens, but exists in a delicate balance between its protective functions and overactivity, which can result in autoimmune disease. A cascade of complement proteins that requires sequential activation, and numerous complement regulators, exists to regulate a proportionate response to pathogens. In spite of these mechanisms there is significant evidence for involvement of the complement system in driving the pathogenesis of variety of diseases including neuromyelitis optica spectrum disorders (NMOSD) and myasthenia gravis (MG). As an amplification cascade, there are an abundance of molecular targets that could be utilized for therapeutic intervention. Clinical trials assessing complement pathway inhibition in both these conditions have recently been completed and include the first randomized placebo-controlled trial in NMOSD showing positive results. This review aims to review and update the reader on the complement system and the evolution of complement-based therapeutics in these two disorders.
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Affiliation(s)
| | - Saif Huda
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK
| | - Daniel H Whittam
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK
| | - Marcelo Matiello
- Department of Neurology, Massachusetts General Hospital, 55 Fruit Street, Boston, MA, 02114, USA
| | - B Paul Morgan
- School of Medicine, Henry Wellcome Building for Biomedical Research, University Hospital of Wales, Heath Park, Cardiff, CF14 4XN, UK
| | - Anu Jacob
- Department of Neurology, The Walton Centre, Lower Lane, Liverpool, L9 7LJ, UK.,University of Liverpool, Liverpool, UK
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14
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Kusner LL, Yucius K, Sengupta M, Sprague AG, Desai D, Nguyen T, Charisse K, Kuchimanchi S, Kallanthottathil R, Fitzgerald K, Kaminski HJ, Borodovsky A. Investigational RNAi Therapeutic Targeting C5 Is Efficacious in Pre-clinical Models of Myasthenia Gravis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:484-492. [PMID: 31193726 PMCID: PMC6539425 DOI: 10.1016/j.omtm.2019.04.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 04/26/2019] [Indexed: 10/26/2022]
Abstract
Complement-mediated damage to the neuromuscular junction (NMJ) is a key mechanism of pathology in myasthenia gravis (MG), and therapeutics inhibiting complement have shown evidence of efficacy in the treatment of MG. In this study, we describe the development of a subcutaneously administered N-acetylgalactosamine (GalNAc)-conjugated small interfering RNA (siRNA) targeting the C5 component of complement that silences C5 expression in the liver (ALN-CC5). Treatment of wild-type rodents with ALN-CC5 resulted in robust and durable suppression of liver C5 expression. Dose-dependent serum C5 suppression was observed in non-human primates, with a lowering of serum C5 of up to 97.5% and the concomitant inhibition of serum complement activity. C5 silencing was efficacious in ameliorating disease symptoms in two standard rat models of MG, demonstrating the key role of circulating C5 in pathology at the NMJ. Improvement in disease activity scores and NMJ pathology was observed at intermediate levels of complement activity inhibition, suggesting that complete ablation of complement activity may not be required for efficacy in MG. The pre-clinical studies of ALN-CC5 and efficacy of C5 silencing in rat models of MG support further clinical development of ALN-CC5 as a potential therapeutic for the treatment of MG and other complement-mediated disorders.
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Affiliation(s)
- Linda L Kusner
- Department of Pharmacology and Physiology, George Washington University, Washington, DC 20037, USA
| | | | - Manjistha Sengupta
- Department of Neurology, George Washington University, Washington, DC 20037, USA
| | | | - Dhruv Desai
- Alnylam Pharmaceuticals, Cambridge, MA 02142, USA
| | - Tuyen Nguyen
- Alnylam Pharmaceuticals, Cambridge, MA 02142, USA
| | | | | | | | | | - Henry J Kaminski
- Department of Neurology, George Washington University, Washington, DC 20037, USA
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15
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Zhang L, Shen H, Gong Y, Pang X, Yi M, Guo L, Li J, Arroyo S, Lu X, Ovchinnikov S, Cheng G, Liu X, Jiang X, Feng S, Deng H. Development of a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF) for targeted antibody blocking. Chem Sci 2019; 10:3271-3280. [PMID: 30996912 PMCID: PMC6429600 DOI: 10.1039/c8sc05273e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/28/2019] [Indexed: 01/12/2023] Open
Abstract
Targeted antibody blocking enables characterization of binding sites on immunoglobulin G (IgG), and can efficiently eliminate harmful antibodies from organisms. In this report, we present a novel peptide-denoted as a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF)-for targeted blocking of antibodies. Synthesis of DCAF was achieved by native chemical ligation, and the molecule consists of three functional parts: a specific antigenic peptide, a linker and the Fc-III mimetic peptide, which has a high affinity toward the Fc region of IgG molecules. We demonstrate that DCAF binds the cognate antibody with high selectivity by simultaneously binding to the Fab and Fc regions of IgG. Animal experiments revealed that DCAF molecules diminish the antibody-dependent enhancement effect in a dengue virus infection model, and rescue the acetylcholine receptor by inhibiting the complement cascade in a myasthenia gravis model. These results suggest that DCAFs could have utility in the development of new therapeutics against harmful antibodies.
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Affiliation(s)
- Lin Zhang
- MOE Key Laboratory of Bioinformatics , Center for Synthetic and Systems Biology , School of Life Sciences , Tsinghua University , Beijing , China .
| | - Hao Shen
- Institute for Protein Design , Department of Biochemistry , University of Washington , Seattle , WA , USA
| | - Yiyi Gong
- Central Research Laboratory , Peking Union Medical College Hospital , Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing , China
| | - Xiaojing Pang
- Tsinghua-Peking Center for Life Sciences , School of Medicine , Tsinghua University , Beijing , China
| | - Meiqi Yi
- MOE Key Laboratory of Bioinformatics , Center for Synthetic and Systems Biology , School of Life Sciences , Tsinghua University , Beijing , China .
| | - Lin Guo
- MOE Key Laboratory of Bioinformatics , Center for Synthetic and Systems Biology , School of Life Sciences , Tsinghua University , Beijing , China .
| | - Jin Li
- MOE Key Laboratory of Bioinformatics , Center for Synthetic and Systems Biology , School of Life Sciences , Tsinghua University , Beijing , China .
| | - Sam Arroyo
- Department of Biological Sciences , University of Notre Dame , South Bend , IN , USA
| | - Xin Lu
- Department of Biological Sciences , University of Notre Dame , South Bend , IN , USA
| | - Sergey Ovchinnikov
- Institute for Protein Design , Department of Biochemistry , University of Washington , Seattle , WA , USA
| | - Gong Cheng
- Tsinghua-Peking Center for Life Sciences , School of Medicine , Tsinghua University , Beijing , China
| | - Xudong Liu
- Central Research Laboratory , Peking Union Medical College Hospital , Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing , China
| | - Xu Jiang
- Central Research Laboratory , Peking Union Medical College Hospital , Chinese Academy of Medical Sciences and Peking Union Medical College , Beijing , China
| | - Shan Feng
- Mass Spectrometry Facility , Westlake Lake University , Hangzhou , Zhejiang Province , China .
| | - Haiteng Deng
- MOE Key Laboratory of Bioinformatics , Center for Synthetic and Systems Biology , School of Life Sciences , Tsinghua University , Beijing , China .
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16
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Heterogeneity of auto-antibodies against nAChR in myasthenic serum and their pathogenic roles in experimental autoimmune myasthenia gravis. J Neuroimmunol 2018; 320:64-75. [PMID: 29759142 DOI: 10.1016/j.jneuroim.2018.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/23/2018] [Accepted: 04/23/2018] [Indexed: 11/20/2022]
Abstract
Many myasthenia gravis (MG) patients have auto-antibodies against the nicotinic acetylcholine receptor (nAChR), and monoclonal antibodies against the main immunogenic region (MIR) of nAChR can induce experimental autoimmune MG (EAMG). We investigated whether Fab fragment of MIR antibody (Fab35) could block the pathogenicity of polyclonal antibodies. Fab35 partially inhibited nAChR downmodulation, blocked EAMG serum-induced binding of polyclonal antibodies and complement deposition in vitro. Moreover, Fab35 did not ameliorate the EAMG serum-induced EAMG phenotype in rats. These results suggested that the EAMG serum possessed several different pathogenic antibodies that might be sufficient to induce the EAMG phenotype.
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17
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Kusner LL, Sengupta M, Kaminski HJ. Acetylcholine receptor antibody-mediated animal models of myasthenia gravis and the role of complement. Ann N Y Acad Sci 2018; 1413:136-142. [PMID: 29356015 DOI: 10.1111/nyas.13555] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/23/2017] [Accepted: 10/25/2017] [Indexed: 12/22/2022]
Abstract
Because of the failure of many promising therapeutics identified in preclinical evaluation, funding sources have established guidelines for increased rigor in animal evaluations. The myasthenia gravis (MG) community of scientists has developed guidelines for preclinical assessment for potential MG treatments. Here, we provide a focused summary of these recommendations and the role of complement in disease development in experimental models of MG.
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Affiliation(s)
- Linda L Kusner
- Department of Pharmacology and Physiology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Manjistha Sengupta
- Department of Neurology, George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Henry J Kaminski
- Department of Neurology, George Washington University School of Medicine and Health Sciences, Washington, DC
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18
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Mori S, Motohashi N, Takashima R, Kishi M, Nishimune H, Shigemoto K. Immunization of mice with LRP4 induces myasthenia similar to MuSK-associated myasthenia gravis. Exp Neurol 2017; 297:158-167. [PMID: 28823823 DOI: 10.1016/j.expneurol.2017.08.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 08/11/2017] [Accepted: 08/11/2017] [Indexed: 12/21/2022]
Abstract
Since the first report of experimental animal models of myasthenia gravis (MG) with autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4), there have not been any major reports replicating the pathogenicity of anti-LRP4 antibodies (Abs). Recent clinical studies have cast doubt on the specificity and pathogenicity of anti-LRP4 antibodies for MG, highlighting the need for further research. In this study, we purified antigens corresponding to the extracellular region of human LRP4 stably expressed with chaperones in 293 cells and used these antigens to immunize female A/J mice. Immunization with LRP4 protein caused mice to develop myasthenia having similar electrophysiological and histological features as are observed in MG patients with circulating Abs against muscle-specific kinase (MuSK). Our results clearly demonstrate that active immunization of mice with LRP4 proteins causes myasthenia similar to the MG induced by anti-MuSK Abs. Further experimental and clinical studies are required to prove the pathogenicity of anti-LRP4 Abs in MG patients.
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Affiliation(s)
- Shuuichi Mori
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Norio Motohashi
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Rumi Takashima
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan
| | - Masahiko Kishi
- Department of Internal Medicine, Toho University Sakura Medical Center, Chiba, Japan
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States
| | - Kazuhiro Shigemoto
- Department of Geriatric Medicine, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
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19
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Kaminski HJ, Himuro K, Alshaikh J, Gong B, Cheng G, Kusner LL. Differential RNA Expression Profile of Skeletal Muscle Induced by Experimental Autoimmune Myasthenia Gravis in Rats. Front Physiol 2016; 7:524. [PMID: 27891095 PMCID: PMC5102901 DOI: 10.3389/fphys.2016.00524] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 10/24/2016] [Indexed: 01/14/2023] Open
Abstract
The differential susceptibility of skeletal muscle by myasthenia gravis (MG) is not well understood. We utilized RNA expression profiling of extraocular muscle (EOM), diaphragm (DIA), and extensor digitorum (EDL) of rats with experimental autoimmune MG (EAMG) to evaluate the hypothesis that muscles respond differentially to injury produced by EAMG. EAMG was induced in female Lewis rats by immunization with acetylcholine receptor purified from the electric organ of the Torpedo. Six weeks later after rats had developed weakness and serum antibodies directed against the AChR, animals underwent euthanasia and RNA profiling performed on DIA, EDL, and EOM. Profiling results were validated by qPCR. Across the three muscles between the experiment and control groups, 359 probes (1.16%) with greater than 2-fold changes in expression in 7 of 9 series pairwise comparisons from 31,090 probes were identified with approximately two-thirds being increased. The three muscles shared 16 genes with increased expression and 6 reduced expression. Functional annotation demonstrated that these common expression changes fell predominantly into categories of metabolism, stress response, and signaling. Evaluation of specific gene function indicated that EAMG led to a change to oxidative metabolism. Genes related to muscle regeneration and suppression of immune response were activated. Evidence of a differential immune response among muscles was not evident. Each muscle had a distinct RNA profile but with commonality in gene categories expressed that are focused on muscle repair, moderation of inflammation, and oxidative metabolism.
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Affiliation(s)
- Henry J Kaminski
- Department of Neurology, George Washington University Washington, DC, USA
| | - Keiichi Himuro
- Department of Neurology, Graduate School of Medicine, Chiba University Chiba, Japan
| | - Jumana Alshaikh
- Department of Neurology, George Washington University Washington, DC, USA
| | - Bendi Gong
- Department of Pediatrics, Washington University St. Louis, MO, USA
| | - Georgiana Cheng
- Department of Pathobiology, Cleveland Clinic Cleveland, OH, USA
| | - Linda L Kusner
- Pharmacology and Physiology, George Washington University Washington, DC, USA
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20
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Abstract
Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ) caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (Ig)G1 and IgG3 antibodies to the acetylcholine receptor (AChR). They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms.
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Affiliation(s)
- William D Phillips
- Physiology and Bosch Institute, University of Sydney, Anderson Stuart Bldg (F13), Sydney, 2006, Australia
| | - Angela Vincent
- Neurosciences Group, Nuffield Department of Clinical Neurosciences, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
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21
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Mantegazza R, Cordiglieri C, Consonni A, Baggi F. Animal models of myasthenia gravis: utility and limitations. Int J Gen Med 2016; 9:53-64. [PMID: 27019601 PMCID: PMC4786081 DOI: 10.2147/ijgm.s88552] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Myasthenia gravis (MG) is a chronic autoimmune disease caused by the immune attack of the neuromuscular junction. Antibodies directed against the acetylcholine receptor (AChR) induce receptor degradation, complement cascade activation, and postsynaptic membrane destruction, resulting in functional reduction in AChR availability. Besides anti-AChR antibodies, other autoantibodies are known to play pathogenic roles in MG. The experimental autoimmune MG (EAMG) models have been of great help over the years in understanding the pathophysiological role of specific autoantibodies and T helper lymphocytes and in suggesting new therapies for prevention and modulation of the ongoing disease. EAMG can be induced in mice and rats of susceptible strains that show clinical symptoms mimicking the human disease. EAMG models are helpful for studying both the muscle and the immune compartments to evaluate new treatment perspectives. In this review, we concentrate on recent findings on EAMG models, focusing on their utility and limitations.
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Affiliation(s)
- Renato Mantegazza
- Neurology IV Unit, Neuroimmunology and Neuromuscular Disorders, Foundation IRCCS Neurological Institute "Carlo Besta", Milan, Italy
| | - Chiara Cordiglieri
- Neurology IV Unit, Neuroimmunology and Neuromuscular Disorders, Foundation IRCCS Neurological Institute "Carlo Besta", Milan, Italy
| | - Alessandra Consonni
- Neurology IV Unit, Neuroimmunology and Neuromuscular Disorders, Foundation IRCCS Neurological Institute "Carlo Besta", Milan, Italy
| | - Fulvio Baggi
- Neurology IV Unit, Neuroimmunology and Neuromuscular Disorders, Foundation IRCCS Neurological Institute "Carlo Besta", Milan, Italy
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22
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Bradl M, Lassmann H. Neurologic autoimmunity: mechanisms revealed by animal models. HANDBOOK OF CLINICAL NEUROLOGY 2016; 133:121-43. [PMID: 27112675 DOI: 10.1016/b978-0-444-63432-0.00008-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Over the last decade, neurologic autoimmunity has become a major consideration in the diagnosis and management of patients with many neurologic presentations. The nature of the associated antibodies and their targets has led to appreciation of the importance of the accessibility of the target antigen to antibodies, and a partial understanding of the different mechanisms that can follow antibody binding. This chapter will first describe the basic principles of autoimmune inflammation and tissue damage in the central and peripheral nervous system, and will then demonstrate what has been learnt about neurologic autoimmunity from circumstantial clinical evidence and from passive, active, and occasionally spontaneous or genetic animal models. It will cover neurologic autoimmune diseases ranging from disorders of neuromuscular transmission, peripheral and ganglionic neuropathy, to diseases of the central nervous system, where autoantibodies are either pathogenic and cause destruction or changes in function of their targets, where they are harmless bystanders of T-cell-mediated tissue damage, or are not involved at all. Finally, this chapter will summarize the relevance of current animal models for studying the different neurologic autoimmune diseases, and it will identify aspects where future animal models need to be improved to better reflect the disease reality experienced by affected patients, e.g., the chronicity or the relapsing/remitting nature of their disease.
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Affiliation(s)
- Monika Bradl
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria.
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria
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Hu B, Simon-Keller K, Küffer S, Ströbel P, Braun T, Marx A, Porubsky S. Myf5 and Myogenin in the development of thymic myoid cells - Implications for a murine in vivo model of myasthenia gravis. Exp Neurol 2015; 277:76-85. [PMID: 26708556 DOI: 10.1016/j.expneurol.2015.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/24/2015] [Accepted: 12/15/2015] [Indexed: 01/24/2023]
Abstract
Myasthenia gravis (MG) is caused by autoantibodies against the neuromuscular junction of striated muscle. Most MG patients have autoreactive T- and B-cells directed to the acetylcholine receptor (AChR). To achieve immunologic tolerance, developing thymocytes are normally eliminated after recognition of self-antigen-derived peptides. Presentation of muscle-specific antigens is likely achieved through two pathways: on medullary thymic epithelial cells and on medullary dendritic cells cross-presenting peptides derived from a unique population of thymic myoid cells (TMC). Decades ago, it has been hypothesized that TMC play a key role in the induction of immunological tolerance towards skeletal muscle antigens. However, an experimental model to address this postulate has not been available. To generate such a model, we tested the hypothesis that the development of TMC depends on myogenic regulatory factors. To this end, we utilized Myf5-deficient mice, which lack the first wave of muscle cells but form normal skeletal muscles later during development, and Myogenin-deficient mice, which fail to form differentiated myofibers. We demonstrate for the first time that Myf5- and Myogenin-deficient mice showed a partial or complete, respectively, loss of TMC in an otherwise regularly structured thymus. To overcome early postnatal lethality of muscle-deficient, Myogenin-knockout mice we transplanted Myogenin-deficient fetal thymuses into Foxn1(nu/nu) mice that lack their own thymus anlage. We found that the transplants are functional but lack TMC. In combination with established immunization strategies (utilizing AChR or Titin), this model should enable us in the future testing the hypothesis that TMC play an indispensable role in the development of central tolerance towards striated muscle antigens.
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Affiliation(s)
- Bo Hu
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Katja Simon-Keller
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Stefan Küffer
- Institute of Pathology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Philipp Ströbel
- Institute of Pathology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | - Thomas Braun
- Cardiac Development and Remodelling, Max Planck Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany
| | - Alexander Marx
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Stefan Porubsky
- Institute of Pathology, University Medical Centre Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany.
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