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Brandsema JF, Ginsberg M, Hoshino H, Mimaki M, Nagata S, Rao VK, Ruzhansky K, Suresh N, Tiongson E, Yamanouchi H, Frick G, Hicks E, Liao S, Howard JF. Eculizumab in Adolescent Patients With Refractory Generalized Myasthenia Gravis: A Phase 3, Open-Label, Multicenter Study. Pediatr Neurol 2024; 156:198-207. [PMID: 38810600 DOI: 10.1016/j.pediatrneurol.2024.04.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 03/10/2024] [Accepted: 04/21/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND This study evaluated the efficacy and safety of eculizumab, a terminal complement C5 inhibitor, in juvenile generalized myasthenia gravis (gMG). METHODS Adolescents aged 12 to 17 years with refractory anti-acetylcholine receptor (AChR) antibody-positive gMG received eculizumab (weekly induction [one to two doses of 600 mg or four doses of 900 mg] followed by maintenance doses [300 to 1200 mg] every two weeks for up to 26 weeks) in a phase 3, open-label multicenter study (NCT03759366). Change from baseline to week 26 in Quantitative Myasthenia Gravis (QMG) total score (primary end point) and secondary end points including Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score, Myasthenia Gravis Composite score, Myasthenia Gravis Foundation of America postintervention status, EuroQol 5-Dimensions (Youth) and Neurological Quality-of-Life Pediatric Fatigue questionnaire scores, as well as pharmacokinetics, pharmacodynamics, and safety, were recorded. RESULTS Eleven adolescents (mean ± S.D. age 14.8 ± 1.8 years) were enrolled; 10 completed the primary evaluation period. Least-squares mean changes from baseline at week 26 were -5.8 (standard error [SE] 1.2; P = 0.0004) for QMG total score and -2.3 (SE 0.6; P = 0.0017) for MG-ADL total score. Overall, the primary and all secondary efficacy end point analyses met statistical significance from the first assessment and were sustained throughout. Complete terminal complement inhibition was sustained through 26 weeks in all patients. Treatment-emergent adverse events were all mild/moderate and predominantly unrelated to eculizumab. CONCLUSIONS Eculizumab was effective in reducing disease burden and was well tolerated in adolescents with refractory AChR antibody-positive gMG.
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Affiliation(s)
- John F Brandsema
- Division of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Hideki Hoshino
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, Japan
| | - Masakazu Mimaki
- Department of Pediatrics, Teikyo University School of Medicine, Tokyo, Japan
| | - Satoru Nagata
- Department of Pediatrics, Tokyo Women's Medical University School of Medicine, Tokyo, Japan
| | - Vamshi K Rao
- Division of Neurology, Lurie Children's Hospital, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Katherine Ruzhansky
- Department of Neurology, Medical University of South Carolina, Charleston, South Carolina
| | - Niraja Suresh
- Department of Neurology, University of South Florida, Tampa, Florida
| | - Emmanuelle Tiongson
- Division of Neurology, Children's Hospital Los Angeles, Los Angeles, California
| | - Hideo Yamanouchi
- Department of Pediatrics, Comprehensive Epilepsy Center, Saitama Medical University, Saitama, Japan
| | - Glen Frick
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts.
| | - Eden Hicks
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts
| | - Serena Liao
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts
| | - James F Howard
- Department of Neurology, The University of North Carolina, Chapel Hill, North Carolina
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Vu T, Wiendl H, Katsuno M, Reddel SW, Howard JF. Ravulizumab in Myasthenia Gravis: A Review of the Current Evidence. Neuropsychiatr Dis Treat 2023; 19:2639-2655. [PMID: 38059203 PMCID: PMC10697093 DOI: 10.2147/ndt.s374694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/17/2023] [Indexed: 12/08/2023] Open
Abstract
The terminal complement C5 inhibitor ravulizumab was engineered from the humanized monoclonal antibody eculizumab to have an extended half-life and duration of action. It binds to human terminal complement protein C5, inhibiting its cleavage into C5a and C5b, thus preventing the cascade of events that lead to architectural destruction of the postsynaptic neuromuscular junction membrane by the membrane attack complex, and consequent muscle weakness in patients with anti-acetylcholine receptor (AChR) antibody-positive generalized myasthenia gravis (gMG). The 26-week randomized, placebo-controlled period (RCP) of the phase 3 CHAMPION MG study demonstrated the rapid efficacy of ravulizumab in reducing MG symptoms. Weight-based dosing of ravulizumab every 8 weeks provided sustained efficacy, in terms of patient-reported (Myasthenia Gravis-Activities of Daily Living) and clinician-reported (Quantitative Myasthenia Gravis) endpoints in patients with anti-AChR antibody-positive gMG. Pharmacokinetic and pharmacodynamic analyses showed therapeutic serum ravulizumab concentrations (>175 µg/mL) were achieved immediately after the first dose and were maintained throughout 26 weeks, irrespective of patient body weight; inhibition of serum free C5 was immediate, complete (<0.5 μg/mL), and sustained in all patients. Interim results from the open-label extension (OLE) showed that after 60 weeks, efficacy was maintained in patients continuing on ravulizumab. Rapid and sustained improvements in efficacy, similar to those seen in patients initiating ravulizumab in the RCP, were observed after initiation of ravulizumab treatment in patients who switched from placebo in the RCP to ravulizumab in the OLE. The findings from the RCP and OLE support ravulizumab's favorable safety profile. In conclusion, ravulizumab has a simple weight-based administration and long dosing interval. Its targeted mechanism of action without generalized immunosuppression is reflected in its rapid onset of symptom improvement, sustained efficacy and good safety profile in the treatment of patients with anti-AChR antibody-positive gMG.
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Affiliation(s)
- Tuan Vu
- Department of Neurology, University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | - Heinz Wiendl
- Department of Neurology with Institute of Translational Neurology, University Hospital Münster, Münster, Germany
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Stephen W Reddel
- Department of Neurology, Concord Hospital, University of Sydney, Sydney, NSW, Australia
| | - James F Howard
- Department of Neurology, The University of North Carolina, Chapel Hill, NC, USA
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Meisel A, Annane D, Vu T, Mantegazza R, Katsuno M, Aguzzi R, Frick G, Gault L, Howard JF. Long-term efficacy and safety of ravulizumab in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis: results from the phase 3 CHAMPION MG open-label extension. J Neurol 2023:10.1007/s00415-023-11699-x. [PMID: 37103755 PMCID: PMC10134722 DOI: 10.1007/s00415-023-11699-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/28/2023]
Abstract
INTRODUCTION Ravulizumab demonstrated efficacy and an acceptable safety profile versus placebo in the randomized controlled period (RCP) of the phase 3 CHAMPION MG trial in patients with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis. We report an interim analysis of the ongoing open-label extension (OLE) designed to evaluate long-term treatment effects. METHODS Following completion of the 26-week RCP, patients could enter the OLE; patients who received ravulizumab in the RCP continued the drug; patients who previously received placebo switched to ravulizumab. Patients receive body-weight-based maintenance dosing of ravulizumab every 8 weeks. Efficacy endpoints up to 60 weeks included Myasthenia Gravis-Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) scores, with least-squares (LS) mean change and 95% confidence intervals (95% CI) reported. RESULTS Long-term efficacy and safety in the OLE were analyzed in 161 and 169 patients, respectively. Improvements in all scores were maintained through 60 weeks in patients who received ravulizumab during the RCP; LS mean change from RCP baseline in MG-ADL score was - 4.0 (95% CI: - 4.8, - 3.1; p < 0.0001). Rapid (within 2 weeks) and sustained improvements occurred in patients previously receiving placebo; LS mean change in MG-ADL score from OLE baseline to Week 60 was - 1.7 (95% CI: - 2.7, - 0.8; p = 0.0007). Similar trends were seen in QMG scores. Ravulizumab treatment was associated with a decreased rate of clinical deterioration events compared with placebo. Ravulizumab was well tolerated; no meningococcal infections were reported. CONCLUSION Findings support the sustained efficacy and long-term safety of ravulizumab, administered every 8 weeks, in adults with anti-acetylcholine receptor antibody-positive generalized myasthenia gravis. CLINICALTRIALS gov identifier: NCT03920293; EudraCT: 2018-003243-39.
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Affiliation(s)
| | | | - Tuan Vu
- University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | | | | | - Rasha Aguzzi
- Alexion, AstraZeneca Rare Disease, Boston, MA, USA
| | - Glen Frick
- Alexion, AstraZeneca Rare Disease, Boston, MA, USA
| | - Laura Gault
- Alexion, AstraZeneca Rare Disease, Boston, MA, USA
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Vu T, Ortiz S, Katsuno M, Annane D, Mantegazza R, Beasley KN, Aguzzi R, Howard JF. Ravulizumab pharmacokinetics and pharmacodynamics in patients with generalized myasthenia gravis. J Neurol 2023; 270:3129-3137. [PMID: 36890354 DOI: 10.1007/s00415-023-11617-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 03/10/2023]
Abstract
INTRODUCTION The terminal complement C5 inhibitor ravulizumab has a long elimination half-life, allowing maintenance dosing every 8 weeks. In the 26-week, double-blind, randomized, placebo-controlled period (RCP) of the CHAMPION MG study, ravulizumab provided rapid and sustained efficacy and was well tolerated in adults with anti-acetylcholine receptor antibody-positive (AChR Ab+) generalized myasthenia gravis (gMG). This analysis evaluated the pharmacokinetics (PK), pharmacodynamics (PD), and potential immunogenicity of ravulizumab in adults with AChR Ab+ gMG. METHODS Data were analyzed from 86 patients who received ravulizumab in the CHAMPION MG RCP. Ravulizumab dosing was weight-based: initial loading dose of 2400/2700/3000 mg on Day 1 and maintenance doses of 3000/3300/3600 mg on Day 15 and then every 8 weeks. PK parameters were estimated from serum ravulizumab concentrations determined pre- and post-dose; PD effects of ravulizumab on serum free C5 concentrations were measured; and immunogenicity was assessed using anti-drug antibody and neutralizing-antibody assays. RESULTS Target serum ravulizumab concentrations (> 175 µg/mL) were achieved immediately after the first ravulizumab dose (within 30 min of infusion completion) and maintained throughout the 26-week treatment period irrespective of patient body weight. Following the final maintenance dose, mean Cmax was 1548 µg/mL and Ctrough 587 µg/mL; no meaningful differences were noted among body-weight categories. Inhibition of serum free C5 was immediate, complete (< 0.5 μg/mL), and sustained throughout treatment in all patients. No treatment-emergent anti-drug antibodies were observed. CONCLUSIONS PK/PD evidence supports the use of ravulizumab every 8 weeks for immediate, complete, and sustained inhibition of terminal complement C5 in adults with AChR Ab+ gMG. TRIAL REGISTRATION ClinicalTrials.gov ID: NCT03920293 (April 18, 2019).
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Affiliation(s)
- Tuan Vu
- University of South Florida Morsani College of Medicine, Tampa, FL, USA
| | | | | | - Djillali Annane
- Hôpital Raymond Poincaré, University of Versailles, Garches, France
| | | | | | - Rasha Aguzzi
- Alexion, AstraZeneca Rare Disease, Boston, MA, USA
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Yoshikawa H, Adachi Y, Nakamura Y, Kuriyama N, Murai H, Nomura Y, Sakai Y, Iwasa K, Furukawa Y, Kuwabara S, Matsui M. Nationwide survey of Lambert-Eaton myasthenic syndrome in Japan. BMJ Neurol Open 2022; 4:e000291. [PMID: 36110924 PMCID: PMC9445827 DOI: 10.1136/bmjno-2022-000291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 08/20/2022] [Indexed: 12/05/2022] Open
Abstract
Background There was no nationwide epidemiological study of Lambert-Eaton myasthenic syndrome (LEMS) in Japan; therefore, we conducted a nationwide survey. Methods For the first survey, we sent survey sheets to randomly selected medical departments (n=7545) to obtain the number of LEMS who visited medical departments between 1 January 2017 and 31 December 2017. For the second survey, we sent survey sheets to the corresponding medical departments to obtain clinical information on LEMS. Results We received 2708 responses (recovery rate: 35.9%) to the first survey. We estimated the number of LEMS as 348 (95% CI 247 to 449). The prevalence was 2.7 (95% CI 1.9 to 3.5) in 1 000 000 population. As a result of the second survey, we obtained 30 case records of 16 men and 14 women. Fourteen patients (46.7%) had a tumour, and 10 out of 14 tumours were small-cell lung carcinoma (71.4%). There was a predominance of men in the LEMS with tumour (paraneoplastic LEMS, P-LEMS) (n=11, 78.6%) and women in the LEMS without tumour (a primary autoimmune form of LEMS, AI-LEMS) (n=11, 68.8%) (p=0.0136). The onset age (mean (SD)) for the P-LEMS was 67.1 (9.0), and that for AI-LEMS was 57.8 (11.2) years old (p=0.0103). The disease duration (median) for P-LEMS was 2 years, and for AI-LEMS was 7.5 years (p=0.0134). Conclusions The prevalence of LEMS in Japan is similar to that in other countries. There are predominances of men in P-LEMS and women in AI-LEMS.
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Affiliation(s)
- Hiroaki Yoshikawa
- Health Service Center, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Yumi Adachi
- Health Service Center, Kanazawa University, Kanazawa, Ishikawa, Japan
| | | | - Nagato Kuriyama
- Department of Social Health Medicine, Shizuoka Graduate University of Public Health, Shizuoka, Japan
- Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Hiroyuki Murai
- Neurology, International University of Health and Welfare, Otawara, Tochigi, Japan
| | - Yoshiko Nomura
- Pediatric Neurology, Yoshiko Nomura Neurological Clinic for Children, Tokyo, Japan
| | - Yasunari Sakai
- Department of Pediatrics, Kyushu University, Fukuoka, Japan
| | - Kazuo Iwasa
- Health Science, Ishikawa Prefectural Nursing University, Kahoku-gun, Ishikawa, Japan
| | - Yutaka Furukawa
- Department of Neurology and Neurobiology of Aging, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Satoshi Kuwabara
- Neurology, Chiba University Graduate School of Medicine School of Medicine, Chiba, Japan
| | - Makoto Matsui
- Neurology, Kanazawa Medical University, Kahoku-gun, Ishikawa, Japan
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Rao J, Li S, Wang Q, Cheng Q, Ji Y, Fu W, Huang H, Shi L, Wu X. Comparison of Peripheral Blood Regulatory T Cells and Functional Subsets Between Ocular and Generalized Myasthenia Gravis. Front Med (Lausanne) 2022; 9:851808. [PMID: 35755064 PMCID: PMC9218215 DOI: 10.3389/fmed.2022.851808] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 04/21/2022] [Indexed: 11/29/2022] Open
Abstract
Purpose This study aims to discuss the function mechanism of regulatory T cells and its subsets in the pathogenic process of myasthenia gravis by contracting the activation levels of those cells in peripheral blood among healthy people, patients with ocular myasthenia gravis (oMG) and patients with generalized myasthenia gravis (gMG). Method Healthy people, newly diagnosed oMG patients, and gMG patients were enrolled in this study. The percentage of the CD3+CD4+CD25+ Treg cells, CD3+CD4+CD25+Foxp3+ Treg cells, CD3+CD4+CD25+Foxp3hi CD45RA–aTreg cells, CD3+CD4+CD25+Foxp3loCD45RA–n-sTreg cells, and CD3+CD4+CD25+ Foxp3loCD45RA+rTreg cells in the peripheral blood were examined by flow cytometry. And then analyzed the differences of Treg cells and its subsets among the study members. Results The percentage of the CD4+CD25+Treg cells in the peripheral blood of oMG patients and gMG patients were both lower than that of healthy people (p < 0.05), the percentage of patients with oMG had no distinct difference with that of patients with gMG (p = 0.475), however. Also, the percentage of CD3+CD4+CD25+Foxp3+Treg cells in the oMG and gMG patients’ group were both lower than that of healthy group. And the percentage of CD25+Foxp3+Treg cells in the peripheral blood of patients with oMG and healthy people were both higher than that of patients with gMG (p < 0.05). The percentage of rTreg in the CD3+CD4+CD25+Treg of the peripheral blood for both gMG and oMG patients’ group were lower than healthy group (p < 0.05), but there was no statistical significance between the oMG and gMG patients’ group (p = 0.232). The percentage of the aTreg cells in the CD3+CD4+CD25+Treg cells of the peripheral blood for the oMG patients was higher than that of gMG patients (p < 0.05), but both of them were lower than healthy group (p < 0.05). The percentage of n-sTreg cells in the peripheral blood descended among the gMG patients’ group, oMG patients’ group, and healthy group (p < 0.05). Conclusion The changes in the number and function of Treg cells and its subsets can cause the impairment of negative immune regulation, which may mediate the triggering of oMG and its progression to gMG.
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Affiliation(s)
- Jie Rao
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Siyu Li
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qiyu Wang
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Qi Cheng
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yu Ji
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Wenwen Fu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Hui Huang
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ling Shi
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiaorong Wu
- Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, China
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Vu T, Meisel A, Mantegazza R, Annane D, Katsuno M, Aguzzi R, Enayetallah A, Beasley KN, Rampal N, Howard JF. Terminal Complement Inhibitor Ravulizumab in Generalized Myasthenia Gravis. NEJM EVIDENCE 2022; 1:EVIDoa2100066. [PMID: 38319212 DOI: 10.1056/evidoa2100066] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
BACKGROUND: Generalized myasthenia gravis (gMG) is a rare, chronic, and debilitating autoimmune disease. Activation of the complement system by autoantibodies against the postsynaptic acetylcholine receptor (AChR) leads to destruction of the postsynaptic membrane and disruption of neuromuscular transmission. This trial evaluated ravulizumab, a long-acting inhibitor of terminal complement protein C5, as a treatment for gMG. METHODS: In this randomized, double-blind, placebo-controlled, multinational trial, we randomly assigned (1:1) patients with anti-AChR antibody-positive gMG to intravenous ravulizumab or placebo for 26 weeks. Patients received a loading dose on day 1, followed by maintenance doses on day 15 and every 8 weeks thereafter. The primary end point and first secondary end point (change from baseline to week 26 in patient-reported Myasthenia Gravis–Activities of Daily Living [MG-ADL] scale and clinician-reported Quantitative Myasthenia Gravis [QMG] total scores, respectively) were compared between the ravulizumab- and placebo-treated groups. RESULTS: In total, 175 patients were enrolled. Ravulizumab significantly increased the magnitude of mean changes from baseline to week 26 versus placebo in MG-ADL (−3.1 vs. −1.4; P<0.001) and QMG (−2.8 vs. −0.8; P<0.001) total scores. Improvements in both measures occurred within 1 week of ravulizumab initiation and were sustained through week 26. QMG total scores improved by 5 points or more in a significantly greater proportion of ravulizumab-treated patients than of those receiving placebo (30.0% vs. 11.3%; P=0.005). No notable differences in adverse events were observed. CONCLUSIONS: Ravulizumab demonstrated rapid and sustained improvements in both patient- and clinician-reported outcomes and had a side effect and adverse-event profile that did not limit treatment in adults with anti-AChR antibody-positive gMG. (Funded by Alexion, AstraZeneca Rare Disease; ClinicalTrials.gov number, NCT03920293; EudraCT number, 2018-003243-39.)
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Affiliation(s)
- Tuan Vu
- University of South Florida Morsani College of Medicine, Tampa
| | | | - Renato Mantegazza
- Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Istituto Neurologico Carlo Besta, Milan
| | - Djillali Annane
- Hôpital Raymond Poincaré, University of Versailles, Garches, France
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Fralish Z, Lotz EM, Chavez T, Khodabukus A, Bursac N. Neuromuscular Development and Disease: Learning From in vitro and in vivo Models. Front Cell Dev Biol 2021; 9:764732. [PMID: 34778273 PMCID: PMC8579029 DOI: 10.3389/fcell.2021.764732] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/06/2021] [Indexed: 01/02/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.
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Affiliation(s)
- Zachary Fralish
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Ethan M Lotz
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Taylor Chavez
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Alastair Khodabukus
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Nenad Bursac
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
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Mathew T, Thomas K, K John S, Venkatesh S, Nadig R, Badachi S, Souza DD, Sarma G, Parry GJ. Effective Early Treatment of AChR Antibody-Positive Myasthenia Gravis with Rituximab; the Experience from a Neuroimmunology Clinic in a Developing Country. J Cent Nerv Syst Dis 2021; 13:11795735211016080. [PMID: 34045914 PMCID: PMC8135199 DOI: 10.1177/11795735211016080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 04/16/2021] [Indexed: 12/28/2022] Open
Abstract
Background Rituximab is reserved for treating refractory myasthenia gravis (MG) patients. Here we report our experience with rituximab in AChR antibody positive generalized MG (gMG) and impending myasthenic crisis (IMC). Methods This retrospective, observational study, conducted at a tertiary care, neuroimmunology clinic, analyzed the data of patients with AChR antibody positive gMG, treated with rituximab between 1st January 2016 and 30th October 2018. Results Eleven patients with AChR antibody positive gMG received rituximab. Mean age of the cohort was 50.54 ± 18.71 years with 9 males. Seven out of 11 patients received rituximab in the early stage (<2 years from onset) and had good response to treatment. Four of the 5 patients with IMC improved with rituximab alone. In the 10 patients who regularly followed up, there was a significant difference between the QMG scores at baseline and at 1, 2, 6, 12, and 18 months (P < .0001). Conclusion Rituximab appears to be a potentially effective early treatment option for AChR antibody positive generalized MG and impending myasthenic crisis.
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Affiliation(s)
- Thomas Mathew
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Kurian Thomas
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Saji K John
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Shruthi Venkatesh
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Raghunandan Nadig
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Sagar Badachi
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Delon D Souza
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Grk Sarma
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
| | - Gareth J Parry
- Department of Neurology, St. John's Medical College Hospital, Bengaluru, Karnataka, India
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Wu Q, Zhou S, Liu J, Tong H, Sun Y, Tian W, Yu H, Huang C, Li D, Jiao P, Ma C, Cai J, Dai D. Two polymorphic mutations in promoter region of DNA polymerase β in relatively higher percentage of thymic hyperplasia patients. Thorac Cancer 2020; 12:588-592. [PMID: 33314687 PMCID: PMC7919162 DOI: 10.1111/1759-7714.13773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 11/23/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
Background DNA polymerase β is one of the key enzymes involved in the repair of DNA damage, and its high or low expression is closely related to tumorigenesis. In a previous study on lung cancer, we found three genetic mutations in the promoter region of the Polb gene could be detected in the Han Chinese population. The purpose of this study was to explore the relationship between these mutations and thymic hyperplasia. Methods Genomic DNA was extracted from 59 thymic hyperplasia patients by the salting out method and used for amplification of the promoter region of the Polb gene. The Polb gene mutation and its frequency were analyzed systematically by comparing them with the deposited wild‐type gene sequence in the NCBI database. The three typical mutated sequences in the promoter region of Polb gene, ‐196G > T, ‐168C > A and ‐188_‐187insCGCCC, were then amplified and ligated to pGL4.10 vector, so as to get the vectors used for the infection of 293T cells to explore their transcription activities by dual‐luciferase reporter system. Results Two types of mutations, ‐168C>A and‐188_‐187insCGCCC, were found in a significantly higher percentage in patients with thymic hyperplasia than in normal healthy people after sequencing analysis of 59 patients and 60 healthy controls. These results suggest that the two mutations may be closely related to thymic hyperplasia. in vitro functional experiments showed that‐168C>A could significantly increase promoter activity, whereas ‐188_‐187insCGCCC could significantly reduce promoter activity, suggesting that these two mutations may affect the expression level of the Polb gene in cells. Conclusions Two types of mutations in the promoter region of the Polb gene, ‐168C>A and‐188_‐187insCGCCC, are associated with thymic hyperplasia and may become a new risk factor for this disease. Key points Significant findings of the study Genetic mutations in the Polb gene are reported to be associated with different kinds of cancers. However, their relationship with thymic hyperplasia is still unclear. What this study adds For the first time, we report that two nucleotide mutations in the promoter region of the Polb gene are closely related with thymic hyperplasia after sequencing 59 patients and 60 healthy controls in the Han Chinese population.
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Affiliation(s)
- Qingjun Wu
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Shan Zhou
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Jian Liu
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Hongfeng Tong
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Yaoguang Sun
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Wenxin Tian
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Hanbo Yu
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Chuan Huang
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Donghang Li
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Peng Jiao
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Chao Ma
- Department of Thoracic Surgery, Beijing Hospital, National Center of Gerontology; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Jianping Cai
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
| | - Dapeng Dai
- The Key Laboratory of Geriatrics, Beijing Institute of Geriatrics, Beijing Hospital, National Center of Gerontology, National Health Commission; Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, China
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11
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Takamori M. Myasthenia Gravis: From the Viewpoint of Pathogenicity Focusing on Acetylcholine Receptor Clustering, Trans-Synaptic Homeostasis and Synaptic Stability. Front Mol Neurosci 2020; 13:86. [PMID: 32547365 PMCID: PMC7272578 DOI: 10.3389/fnmol.2020.00086] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/28/2020] [Indexed: 12/18/2022] Open
Abstract
Myasthenia gravis (MG) is a disease of the postsynaptic neuromuscular junction (NMJ) where nicotinic acetylcholine (ACh) receptors (AChRs) are targeted by autoantibodies. Search for other pathogenic antigens has detected the antibodies against muscle-specific tyrosine kinase (MuSK) and low-density lipoprotein-related protein 4 (Lrp4), both causing pre- and post-synaptic impairments. Agrin is also suspected as a fourth pathogen. In a complex NMJ organization centering on MuSK: (1) the Wnt non-canonical pathway through the Wnt-Lrp4-MuSK cysteine-rich domain (CRD)-Dishevelled (Dvl, scaffold protein) signaling acts to form AChR prepatterning with axonal guidance; (2) the neural agrin-Lrp4-MuSK (Ig1/2 domains) signaling acts to form rapsyn-anchored AChR clusters at the innervated stage of muscle; (3) adaptor protein Dok-7 acts on MuSK activation for AChR clustering from “inside” and also on cytoskeleton to stabilize AChR clusters by the downstream effector Sorbs1/2; (4) the trans-synaptic retrograde signaling contributes to the presynaptic organization via: (i) Wnt-MuSK CRD-Dvl-β catenin-Slit 2 pathway; (ii) Lrp4; and (iii) laminins. The presynaptic Ca2+ homeostasis conditioning ACh release is modified by autoreceptors such as M1-type muscarinic AChR and A2A adenosine receptors. The post-synaptic structure is stabilized by: (i) laminin-network including the muscle-derived agrin; (ii) the extracellular matrix proteins (including collagen Q/perlecan and biglycan which link to MuSK Ig1 domain and CRD); and (iii) the dystrophin-associated glycoprotein complex. The study on MuSK ectodomains (Ig1/2 domains and CRD) recognized by antibodies suggested that the MuSK antibodies were pathologically heterogeneous due to their binding to multiple functional domains. Focussing one of the matrix proteins, biglycan which functions in the manner similar to collagen Q, our antibody assay showed the negative result in MG patients. However, the synaptic stability may be impaired by antibodies against MuSK ectodomains because of the linkage of biglycan with MuSK Ig1 domain and CRD. The pathogenic diversity of MG is discussed based on NMJ signaling molecules.
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12
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Wang H, Lu CH, Ho PC. Metabolic adaptation orchestrates tissue context-dependent behavior in regulatory T cells. Immunol Rev 2020; 295:126-139. [PMID: 32147869 DOI: 10.1111/imr.12844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/19/2020] [Indexed: 02/07/2023]
Abstract
The diverse distribution and functions of regulatory T cells (Tregs) ensure tissue and immune homeostasis; however, it remains unclear which factors can guide distribution, local differentiation, and tissue context-specific behavior in Tregs. Although the emerging concept that Tregs could re-adjust their transcriptome based on their habitations is supported by recent findings, the underlying mechanisms that reprogram transcriptome in Tregs are unknown. In the past decade, metabolic machineries have been revealed as a new regulatory circuit, known as immunometabolic regulation, to orchestrate activation, differentiation, and functions in a variety of immune cells, including Tregs. Given that systemic and local alterations of nutrient availability and metabolite profile associate with perturbation of Treg abundance and functions, it highlights that immunometabolic regulation may be one of the mechanisms that orchestrate tissue context-specific regulation in Tregs. The understanding on how metabolic program instructs Tregs in peripheral tissues not only represents a critical opportunity to delineate a new avenue in Treg biology but also provides a unique window to harness Treg-targeting approaches for treating cancer and autoimmunity with minimizing side effects. This review will highlight the metabolic features on guiding Treg formation and function in a disease-oriented perspective and aim to pave the foundation for future studies.
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Affiliation(s)
- Haiping Wang
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | - Chun-Hao Lu
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
| | - Ping-Chih Ho
- Department of Fundamental Oncology, University of Lausanne, Lausanne, Switzerland.,Ludwig Institute for Cancer Research, University of Lausanne, Epalinges, Switzerland
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13
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Intravenous cyclophosphamide monthly pulses in refractory myasthenia gravis. J Neurol 2019; 267:674-678. [DOI: 10.1007/s00415-019-09622-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/19/2019] [Accepted: 11/03/2019] [Indexed: 02/04/2023]
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14
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Abstract
Myasthenia gravis (MG) is an autoimmune disorder caused by antibodies against acetylcholine receptors (AChR) or other structural proteins of the neuromuscular junction. This diminishes cholinergic transmission, thus leading to exercise-induced fatigue and sometimes manifest muscle weakness, including the bulbar and ocular musculature. Whereas ocular MG is as a rule initially symptomatically treated with acetylcholine esterase inhibitors, generalized MG requires long-term immunosuppression. The thymus plays a particular role in the pathophysiology of AChR antibody-positive MG, which can also manifest as a paraneoplastic disorder in the context of a thymoma. This article reviews the basic and advanced treatment options of the different disease subtypes including plasma exchange and immunoglobulins for treatment in a myasthenic crisis. Recently, clinical approval of eculizumab, a complement inhibitor, enriched the pharmacological armamentarium for AChR antibody-positive MG patients not appropriately responding to immunosuppression alone.
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15
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Prabhu SS, Khan SA, Doudnikoff AL, Reebye UN. Anesthetic considerations for a patient with myasthenia gravis undergoing deep sedation in an outpatient oral surgery setting. J Dent Anesth Pain Med 2019; 19:67-72. [PMID: 30859135 PMCID: PMC6405345 DOI: 10.17245/jdapm.2019.19.1.67] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/07/2019] [Accepted: 02/08/2019] [Indexed: 11/15/2022] Open
Abstract
Myasthenia gravis (MG) is a neuromuscular autoimmune disorder which clinically presents as muscular weakness and fatigue due to autoantibody formation against acetylcholine receptors (AChR), leading to their subsequent destruction. Due to the neuromuscular implications of MG, certain considerations must be taken into account when providing anesthesia to MG patients. In the following case report, we have outlined procedural considerations for the anesthetic management of a patient with MG undergoing deep sedation for an elective oral surgery in an outpatient setting, as well as a discussion of relevant literature.
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Affiliation(s)
- Shamit S Prabhu
- Triangle Implant Center, Durham, NC, USA.,Wake Forest School of Medicine, Winston-Salem, NC, USA
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16
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Heikkinen A, Härönen H, Norman O, Pihlajaniemi T. Collagen XIII and Other ECM Components in the Assembly and Disease of the Neuromuscular Junction. Anat Rec (Hoboken) 2019; 303:1653-1663. [PMID: 30768864 DOI: 10.1002/ar.24092] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/17/2018] [Accepted: 09/27/2018] [Indexed: 12/15/2022]
Abstract
Alongside playing structural roles, the extracellular matrix (ECM) acts as an interaction platform for cellular homeostasis, organ development, and maintenance. The necessity of the ECM is highlighted by the diverse, sometimes very serious diseases that stem from defects in its components. The neuromuscular junction (NMJ) is a large peripheral motor synapse differing from its central counterparts through the ECM included at the synaptic cleft. Such synaptic basal lamina (BL) is specialized to support NMJ establishment, differentiation, maturation, stabilization, and function and diverges in molecular composition from the extrasynaptic ECM. Mutations, toxins, and autoantibodies may compromise NMJ integrity and function, thereby leading to congenital myasthenic syndromes (CMSs), poisoning, and autoimmune diseases, respectively, and all these conditions may involve synaptic ECM molecules. With neurotransmission degraded or blocked, muscle function is impaired or even prevented. At worst, this can be fatal. The article reviews the synaptic BL composition required for assembly and function of the NMJ molecular machinery through the lens of studies primarily with mouse models but also with human patients. In-depth focus is given to collagen XIII, a postsynaptic-membrane-spanning but also shed ECM protein that in recent years has been revealed to be a significant component for the NMJ. Its deficiency in humans causes CMS, and autoantibodies against it have been recognized in autoimmune myasthenia gravis. Mouse models have exposed numerous details that appear to recapitulate human NMJ phenotypes relatively faithfully and thereby can be readily used to generate information necessary for understanding and ultimately treating human diseases. Anat Rec, 2019. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Anne Heikkinen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Heli Härönen
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Oula Norman
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Taina Pihlajaniemi
- Oulu Center for Cell-Matrix Research, Biocenter Oulu, Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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17
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Myasthenia Gravis. Neuromuscul Disord 2018. [DOI: 10.1007/978-981-10-5361-0_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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18
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Super-Resolution Microscopy Reveals a Nanoscale Organization of Acetylcholine Receptors for Trans-Synaptic Alignment at Neuromuscular Synapses. eNeuro 2017; 4:eN-NWR-0232-17. [PMID: 28798955 PMCID: PMC5550840 DOI: 10.1523/eneuro.0232-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/24/2017] [Accepted: 07/25/2017] [Indexed: 11/30/2022] Open
Abstract
The neuromuscular junction (NMJ) is a chemical synapse formed between motoneurons and skeletal muscle fibers. The vertebrate NMJ uses acetylcholine (ACh) as the neurotransmitter and features numerous invaginations of the postsynaptic muscle membrane termed junctional folds. ACh receptors (AChRs) are believed to be concentrated on the crest of junctional folds but their spatial organization remains to be fully understood. In this study, we utilized super-resolution microscopy to examine the nanoscale organization of AChRs at NMJ. Using Structured Illumination Microscopy, we found that AChRs appear as stripes within the pretzel-shaped mouse NMJs, which however, do not correlate with the size of the crests of junctional folds. By comparing the localization of AChRs with several pre- and postsynaptic markers of distinct compartments of NMJs, we found that AChRs are not distributed evenly across the crest of junctional folds as previously thought. Instead, AChR stripes are more closely aligned with the openings of junctional folds as well as with the presynaptic active zone. Using Stochastic Optical Reconstruction Microscopy (STORM) for increased resolution, we found that each AChR stripe contains an AChR-poor slit at the center that is equivalent to the size of the opening of junctional folds. Together, these findings indicate that AChRs are largely localized to the edges of crests surrounding the opening of folds to align with the presynaptic active zones. Such a nanoscale organization of AChRs potentially enables trans-synaptic alignment for effective synaptic transmission of NMJs.
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19
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Doyle KP, Buckwalter MS. Does B lymphocyte-mediated autoimmunity contribute to post-stroke dementia? Brain Behav Immun 2017; 64:1-8. [PMID: 27531189 PMCID: PMC5305803 DOI: 10.1016/j.bbi.2016.08.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/01/2016] [Accepted: 08/12/2016] [Indexed: 01/02/2023] Open
Abstract
Post-stroke cognitive decline and dementia pose a significant public health problem, with 30% of stroke survivors suffering from dementia. The reason for this high prevalence is not well understood. Pathogenic B cell responses to the damaged CNS are one possible contributing factor. B-lymphocytes and antibodies are present in and around the stroke core of some human subjects who die with stroke and dementia, and mice that develop delayed cognitive dysfunction after stroke have clusters of B-lymphocytes in the stroke lesion, and antibody infiltration in the stroked hemisphere. The ablation of B-lymphocytes prevents post-stroke cognitive impairment in mice. Multiple drugs that target B cells are FDA approved, and so if pathogenic B cell responses are occurring in a subset of stroke patients, this is potentially treatable. However, it has also been demonstrated that regulatory B cells can be beneficial in mouse models of stroke. Consequently, it is important to understand the relative contribution of B-lymphocytes to recovery versus pathogenicity, and if this balance is heterogeneous in different individuals. Therefore, the purpose of this review is to summarize the current state of knowledge with regard to the role of B-lymphocytes in the etiology of post-stroke dementia.
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Affiliation(s)
- Kristian P. Doyle
- Department of Immunobiology, Department of Neurology, and the Arizona Center on Aging, University of Arizona, Tucson, Arizona, USA
| | - Marion S. Buckwalter
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, USA,Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
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20
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Burbelo PD, Iadarola MJ, Alevizos I, Sapio MR. Transcriptomic Segregation of Human Autoantigens Useful for the Diagnosis of Autoimmune Diseases. Mol Diagn Ther 2017; 20:415-27. [PMID: 27259330 DOI: 10.1007/s40291-016-0211-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The measurement of autoantibodies in the clinical care of autoimmune patients allows for diagnosis, monitoring, and even disease prediction. Despite their clinical utility, the functional significance of autoantibody target proteins in many autoimmune diseases remains unclear. Here we present a comprehensive review of 52 autoantigens commonly employed for the serological diagnosis of 24 autoimmune diseases. We discuss their function, whether they have extracellular-exposed epitopes, and whether antibodies to these proteins are known to be pathogenic. Transcriptomics (RNA-Seq) datasets were mined to display messenger RNA (mRNA) expression of the autoantigens across 32 tissues and organs. This analysis revealed that autoantigens cluster into one of three groups: expression in the tissue most strongly affected in the disease (Group I), ubiquitous expression with enrichment in immune tissues (Group II), or expression in other tissues not typically associated with the clinical presentation (Group III). Clustering demonstrated that the autoantigens within Group I were often proteins containing extracellular epitopes, many of which are targets of pathogenic autoantibodies. Group II autoantigens were targets for several rheumatological diseases, including Sjögren syndrome, systemic lupus erythematosus, myositis, and systemic sclerosis, and were ubiquitously expressed with enrichment in immune-rich tissues. This raises the possibility that immune cells in Group II disorders may be the source of autoimmunization and/or targets of immune cell responses. Since tissues showing enriched autoantigen gene expression may contribute to the development of autoantibodies and subsequent autoimmunity, the emergent patterns arising from the autoantigen transcriptomic profiles may provide a new heuristic framework to deconvolute these complex disorders.
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Affiliation(s)
- Peter D Burbelo
- Dental Clinical Research Core, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bldg. 10, Rm. 5N102, Bethesda, MD, 20892, USA.
| | - Michael J Iadarola
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
| | - Ilias Alevizos
- Sjögren's Syndrome and Salivary Gland Dysfunction Unit, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Matthew R Sapio
- Department of Perioperative Medicine, Clinical Center, National Institutes of Health, Bethesda, MD, USA
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21
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Danikowski KM, Jayaraman S, Prabhakar BS. Regulatory T cells in multiple sclerosis and myasthenia gravis. J Neuroinflammation 2017; 14:117. [PMID: 28599652 PMCID: PMC5466736 DOI: 10.1186/s12974-017-0892-8] [Citation(s) in RCA: 207] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 05/29/2017] [Indexed: 01/09/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic debilitating disease of the central nervous system primarily mediated by T lymphocytes with specificity to neuronal antigens in genetically susceptible individuals. On the other hand, myasthenia gravis (MG) primarily involves destruction of the neuromuscular junction by antibodies specific to the acetylcholine receptor. Both autoimmune diseases are thought to result from loss of self-tolerance, which allows for the development and function of autoreactive lymphocytes. Although the mechanisms underlying compromised self-tolerance in these and other autoimmune diseases have not been fully elucidated, one possibility is numerical, functional, and/or migratory deficits in T regulatory cells (Tregs). Tregs are thought to play a critical role in the maintenance of peripheral immune tolerance. It is believed that Tregs function by suppressing the effector CD4+ T cell subsets that mediate autoimmune responses. Dysregulation of suppressive and migratory markers on Tregs have been linked to the pathogenesis of both MS and MG. For example, genetic abnormalities have been found in Treg suppressive markers CTLA-4 and CD25, while others have shown a decreased expression of FoxP3 and IL-10. Furthermore, elevated levels of pro-inflammatory cytokines such as IL-6, IL-17, and IFN-γ secreted by T effectors have been noted in MS and MG patients. This review provides several strategies of treatment which have been shown to be effective or are proposed as potential therapies to restore the function of various Treg subsets including Tr1, iTr35, nTregs, and iTregs. Strategies focusing on enhancing the Treg function find importance in cytokines TGF-β, IDO, interleukins 10, 27, and 35, and ligands Jagged-1 and OX40L. Likewise, strategies which affect Treg migration involve chemokines CCL17 and CXCL11. In pre-clinical animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune myasthenia gravis (EAMG), several strategies have been shown to ameliorate the disease and thus appear promising for treating patients with MS or MG.
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Affiliation(s)
- K M Danikowski
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - S Jayaraman
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - B S Prabhakar
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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22
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Bando H, Iguchi G, Okimura Y, Odake Y, Yoshida K, Matsumoto R, Suda K, Nishizawa H, Fukuoka H, Mokubo A, Tojo K, Maniwa Y, Ogawa W, Takahashi Y. A novel thymoma-associated autoimmune disease: Anti-PIT-1 antibody syndrome. Sci Rep 2017; 7:43060. [PMID: 28216655 PMCID: PMC5316939 DOI: 10.1038/srep43060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 01/17/2017] [Indexed: 12/20/2022] Open
Abstract
Anti-PIT-1 antibody syndrome has recently been reported and characterized by acquired growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) deficiencies associated with autoimmunity to a pituitary specific transcription factor PIT-1, which plays an essential role in GH-, PRL-, and TSH-producing cells. Although circulating anti-PIT-1 antibody and PIT-1-reactive cytotoxic T cells (CTLs) were detected in the patients, the pathophysiology and precise mechanisms for the autoimmunity remain unclarified. During the follow up, thymoma was diagnosed in all 3 cases with anti-PIT-1 antibody syndrome. Immunohistochemical analysis revealed that PIT-1 was strongly expressed in neoplastic cortical thymic epithelial cells. Importantly, after thymectomy, the titer of anti-PIT-1 antibody decreased and reactivity of CTLs toward PIT-1 diminished. These data strongly suggest that the aberrant expression of PIT-1 in the thymoma plays a causal role in the development of this syndrome. Thus, we define that this syndrome is a novel thymoma-associated autoimmune disease.
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Affiliation(s)
- Hironori Bando
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Genzo Iguchi
- Division of Diabetes and Endocrinology, Kobe University Hospital, Kobe, Japan
| | - Yasuhiko Okimura
- Department of Nutrition and Food Science, Kobe Women’s University Graduate School of Life Sciences, Kobe, Japan
| | - Yukiko Odake
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenichi Yoshida
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Ryusaku Matsumoto
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kentaro Suda
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Hitoshi Nishizawa
- Division of Diabetes and Endocrinology, Kobe University Hospital, Kobe, Japan
| | - Hidenori Fukuoka
- Division of Diabetes and Endocrinology, Kobe University Hospital, Kobe, Japan
| | | | - Katsuyoshi Tojo
- Division of Diabetes and Endocrinology, Department of Medicine, Jikei University School of Medicine, Tokyo, Japan
| | - Yoshimasa Maniwa
- Department of General Thoracic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Wataru Ogawa
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Yutaka Takahashi
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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Ducci RD, Lorenzoni PJ, Kay CSK, Werneck LC, Scola RH. Clinical follow-up of pregnancy in myasthenia gravis patients. Neuromuscul Disord 2017; 27:352-357. [PMID: 28256306 DOI: 10.1016/j.nmd.2017.01.021] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 01/20/2017] [Accepted: 01/27/2017] [Indexed: 02/05/2023]
Abstract
This study aimed to analyze the outcome and impact of pregnancy in women with myasthenia gravis (MG). Obstetric and clinical data were retrospectively analyzed before, during and after pregnancy. Predictors of outcome were studied. We included 35 pregnancies from 21 MG patients. In the course of MG symptoms in 30 pregnancies with live births, 50% deteriorated (mainly during the second trimester, p = 0.028), 30% improved, and 20% remained unchanged. The deterioration group had more frequent abnormal repetitive nerve stimulation (RNS) (p = 0.028) and lower myasthenia gravis composite (MGC) scores (p = 0.045) before pregnancy. The improvement group was associated with higher MGC scores (p = 0.012) before pregnancy. The no-change group was associated with longer duration of MG (p = 0.026) and normal RNS (p = 0.008) before pregnancy. The course of MG in the second pregnancy was different from that in the previous pregnancy in 65.3% of cases. Obstetric complications were reported in 20 pregnancies; the most common was preterm premature rupture of membranes (PPROM) (25.8%), and the most severe were abortion (11.4%) and fetal death (2.9%). Most of the patients delivered via caesarean section (66.7%). Spinal anesthesia was performed in 73.3%. Transient neonatal myasthenia gravis occurred in 12.9% of live-born infants, and no predictors were found. In conclusion, severity and duration of MG, RNS and treatment influence MG and pregnancy. Pregnant MG patients have greater rates of PPROM and caesarean delivery. Our data suggest that duration of MG, MGC and RNS before pregnancy may be useful in helping to predict the course of MG during pregnancy.
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Affiliation(s)
- Renata D Ducci
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Paulo J Lorenzoni
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Claudia S K Kay
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Lineu C Werneck
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Parana (UFPR), Curitiba, Brazil
| | - Rosana H Scola
- Service of Neuromuscular Disorders, Division of Neurology, Department of Internal Medicine, Hospital de Clínicas, Universidade Federal do Parana (UFPR), Curitiba, Brazil.
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Jun H, Jung CW. Immunoglobulin G4-Related Inflammatory Abdominal Aortic Aneurysm Associated With Myasthenia Gravis, With Contained Rupture. Vasc Endovascular Surg 2017; 50:571-574. [DOI: 10.1177/1538574416678557] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Immunoglobulin (Ig) G4-related disease is reportedly among the various causes of inflammatory abdominal aortic aneurysm (IAAA). Many IgG4-related diseases are closely related to allergic constitution and autoimmune disease. We report a case of a 72-year-old man with IgG4-related IAAA associated with myasthenia gravis, with contained rupture.
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Affiliation(s)
- Heungman Jun
- Department of Surgery, Korea University Anam Hospital, Seoul, Korea
| | - Cheol Woong Jung
- Department of Surgery, Korea University Anam Hospital, Seoul, Korea
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25
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Totzeck A, Mummel P, Kastrup O, Hagenacker T. Clinical Features of Neuromuscular Disorders in Patients with N-Type Voltage-Gated Calcium Channel Antibodies. Eur J Transl Myol 2016; 26:5962. [PMID: 28078065 PMCID: PMC5220212 DOI: 10.4081/ejtm.2016.5962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Neuromuscular junction disorders affect the pre- or postsynaptic nerve to muscle transmission due to autoimmune antibodies. Members of the group like myasthenia gravis and Lambert-Eaton syndrome have pathophysiologically distinct characteristics. However, in practice, distinction may be difficult. We present a series of three patients with a myasthenic syndrome, dropped-head syndrome, bulbar and respiratory muscle weakness and positive testing for anti-N-type voltage-gated calcium channel antibodies. In two cases anti-acetylcholin receptor antibodies were elevated, anti-P/Q-type voltage-gated calcium channel antibodies were negative. All patients initially responded to pyridostigmine with a non-response in the course of the disease. While one patient recovered well after treatment with intravenous immunoglobulins, 3,4-diaminopyridine, steroids and later on immunosuppression with mycophenolate mofetil, a second died after restriction of treatment due to unfavorable cancer diagnosis, the third patient declined treatment. Although new antibodies causing neuromuscular disorders were discovered, clinical distinction has not yet been made. Our patients showed features of pre- and postsynaptic myasthenic syndrome as well as severe dropped-head syndrome and bulbar and axial muscle weakness, but only anti-N-type voltage-gated calcium channel antibodies were positive. When administered, one patient benefited from 3,4-diaminopyridine. We suggest that this overlap-syndrome should be considered especially in patients with assumed seronegative myasthenia gravis and lack of improvement under standard therapy.
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Affiliation(s)
- Andreas Totzeck
- Department of Neurology, University Duisburg-Essen , Germany
| | - Petra Mummel
- Department of Neurology, University Duisburg-Essen , Germany
| | - Oliver Kastrup
- Department of Neurology, University Duisburg-Essen , Germany
| | - Tim Hagenacker
- Department of Neurology, University Duisburg-Essen , Germany
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26
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Uygun V, Daloğlu H, Öztürkmen SI, Döşemeci L, Karasu G, Hazar V, Yeşilipek A. Extracorporeal photopheresis did not prevent the development of an autoimmune disease: myasthenia gravis. Transfusion 2016; 56:3081-3085. [DOI: 10.1111/trf.13821] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/28/2016] [Accepted: 08/02/2016] [Indexed: 12/18/2022]
Affiliation(s)
- Vedat Uygun
- Pediatric Bone Marrow Transplantation Unit; Medical Park Antalya Hospital, Bahçeşehir University
| | - Hayriye Daloğlu
- Pediatric Bone Marrow Transplantation Unit; Medical Park Antalya Hospital; Antalya Turkey
| | - Seda Irmak Öztürkmen
- Pediatric Bone Marrow Transplantation Unit; Medical Park Antalya Hospital; Antalya Turkey
| | - Levent Döşemeci
- Intensive Care Unit; Istanbul Kemerburgaz University Faculty of Medicine
| | - Gülsün Karasu
- Pediatric Bone Marrow Transplantation Unit, Medical Park Göztepe Hospital; Bahçeşehir University
| | - Volkan Hazar
- Pediatric Hematology and Oncology and Bone Marrow Transplantation Unit; Medipol University Faculty of Medicine; Istanbul Turkey
| | - Akif Yeşilipek
- Pediatric Bone Marrow Transplantation Unit; Medical Park Antalya Hospital, Bahçeşehir University
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27
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Abstract
The complement system is a major component of innate immunity and a potent driver of inflammation. It has key roles in host defense against pathogens but can also contribute to pathology by driving inflammation and cell damage in diverse diseases. Complement has emerged as an important factor in the pathogenesis of numerous diseases of the CNS and PNS, including infectious, autoimmune and degenerative disorders, and is increasingly implicated in neuropsychiatric disease. Establishing the roles and relevance of complement in disease pathogenesis has become ever more important in recent years as new drugs targeting the complement system have reached the clinic, and the potential for using complement analytes as disease biomarkers has been recognized. In this brief review, the author summarizes the evidence implicating complement in these diseases and outlines ways in which this new understanding can be used to aid diagnosis and improve outcome.
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Affiliation(s)
- Bryan Paul Morgan
- a Institute of Infection and Immunity, School of Medicine, Cardiff University, Henry Wellcome Building, Heath Park, Cardiff CF144XN, UK
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28
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Vilmont V, Cadot B, Ouanounou G, Gomes ER. A system for studying mechanisms of neuromuscular junction development and maintenance. Development 2016; 143:2464-77. [PMID: 27226316 PMCID: PMC4958317 DOI: 10.1242/dev.130278] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 05/12/2016] [Indexed: 12/12/2022]
Abstract
The neuromuscular junction (NMJ), a cellular synapse between a motor neuron and a skeletal muscle fiber, enables the translation of chemical cues into physical activity. The development of this special structure has been subject to numerous investigations, but its complexity renders in vivo studies particularly difficult to perform. In vitro modeling of the neuromuscular junction represents a powerful tool to delineate fully the fine tuning of events that lead to subcellular specialization at the pre-synaptic and post-synaptic sites. Here, we describe a novel heterologous co-culture in vitro method using rat spinal cord explants with dorsal root ganglia and murine primary myoblasts to study neuromuscular junctions. This system allows the formation and long-term survival of highly differentiated myofibers, motor neurons, supporting glial cells and functional neuromuscular junctions with post-synaptic specialization. Therefore, fundamental aspects of NMJ formation and maintenance can be studied using the described system, which can be adapted to model multiple NMJ-associated disorders.
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Affiliation(s)
- Valérie Vilmont
- Myology Research Center, UM76-INSERM U974-CNRS FRE 3617 Sorbonne Universités, UPMC Université Paris 06, Paris, France
| | - Bruno Cadot
- Myology Research Center, UM76-INSERM U974-CNRS FRE 3617 Sorbonne Universités, UPMC Université Paris 06, Paris, France
| | - Gilles Ouanounou
- FRE CNRS 3693 (U.N.I.C), Unité de Neuroscience, Information et Complexité CNRS, Bât. 33, 1 Ave de la Terasse, Gif sur Yvette 91198, France
| | - Edgar R Gomes
- Myology Research Center, UM76-INSERM U974-CNRS FRE 3617 Sorbonne Universités, UPMC Université Paris 06, Paris, France Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Lisboa, Portugal
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29
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Double Roles of Macrophages in Human Neuroimmune Diseases and Their Animal Models. Mediators Inflamm 2016; 2016:8489251. [PMID: 27034594 PMCID: PMC4808549 DOI: 10.1155/2016/8489251] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 02/21/2016] [Accepted: 02/23/2016] [Indexed: 12/22/2022] Open
Abstract
Macrophages are important immune cells of the innate immune system that are involved in organ-specific homeostasis and contribute to both pathology and resolution of diseases including infections, cancer, obesity, atherosclerosis, and autoimmune disorders. Multiple lines of evidence point to macrophages as a remarkably heterogeneous cell type. Different phenotypes of macrophages exert either proinflammatory or anti-inflammatory roles depending on the cytokines and other mediators that they are exposed to in the local microenvironment. Proinflammatory macrophages secrete detrimental molecules to induce disease development, while anti-inflammatory macrophages produce beneficial mediators to promote disease recovery. The conversion of the phenotypes of macrophages can regulate the initiation, development, and recovery of autoimmune diseases. Human neuroimmune diseases majorly include multiple sclerosis (MS), neuromyelitis optica (NMO), myasthenia gravis (MG), and Guillain-Barré syndrome (GBS) and macrophages contribute to the pathogenesis of these neuroimmune diseases. In this review, we summarize the double roles of macrophage in neuroimmune diseases and their animal models to further explore the mechanisms of macrophages involved in the pathogenesis of these disorders, which may provide a potential therapeutic approach for these disorders in the future.
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30
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Hamdoon MNT, Fattouh M, El-Din AN, Elnady HM. The potential role of cell surface complement regulators and circulating CD4+ CD25+ T-cells in the development of autoimmune myasthenia gravis. Electron Physician 2016; 8:1718-26. [PMID: 26955441 PMCID: PMC4768919 DOI: 10.19082/1718] [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: 11/02/2015] [Accepted: 12/13/2015] [Indexed: 11/20/2022] Open
Abstract
INTRODUCTION CD4+CD25+ regulatory T-lymphocytes (T-regs) and regulators of complement activity (RCA) involving CD55 and CD59 play an important role in the prevention of autoimmune diseases. However, their role in the pathogenesis of human autoimmune myasthenia gravis (MG) remains unclear. This study aimed to determine the frequency of peripheral blood T-regs and CD4+ T-helper (T-helper) cells and the red blood cells (RBCs) level of expression of CD55 and CD59 in MG patients. METHODS Fourteen patients with MG in neurology outpatient clinics of Sohag University Hospital and Sohag General Hospital from March 2014 to December 2014, and 10 age-matched healthy controls participated in this case-control study. We did flowcytometric assessments of the percentage of peripheral T-regs and T-helper cells and the level of expression of CD55 and CD59 on RBCs in the peripheral blood of patients and controls. RESULTS There was a statistically significant decrease in the percentage of peripheral blood T-regs and T-regs/T-helper cell ratio in the MG patients group. Moreover, the level of expression of CD55, CD59, and dual expression of CD55/CD59 on RBCs were statistically significantly lower in MG patients than those of healthy controls. However, regression analysis indicated that there was no significant correlation between all the measured parameters and disease duration or staging. CONCLUSION Functional defects in the T-regs and RCA may play a role in the pathogenesis of autoimmune MG and their functional modulation may represent an alternative therapeutic strategy for MG treatment.
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Affiliation(s)
| | - Mona Fattouh
- Department of Microbiology and Immunology, Sohag University Hospital, Sohag, Egypt
| | - Asmaa Nasr El-Din
- Department of Microbiology and Immunology, Sohag University Hospital, Sohag, Egypt
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31
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Microbes, molecular mimicry and molecules of mood and motivation. Med Hypotheses 2015; 87:40-3. [PMID: 26826639 DOI: 10.1016/j.mehy.2015.12.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 12/15/2015] [Indexed: 12/18/2022]
Abstract
The hypothesis proposed is that functional disorders, such as irritable bowel syndrome, chronic fatigue syndrome and anorexia nervosa are caused by auto-antibodies to neuronal proteins induced by molecular mimicry with microbial antigens. The age incidence of these conditions, the marked female excess, increase with economic and technological advance, precipitation by infection, and the paucity of histological changes are all consistent with the hypothesis. It can be tested directly using human sera to search for cross reaction with brain proteins in model systems such as Drosophila melanogaster. The conditions might be amenable to treatment using pooled immunoglobulin. Identification and elimination from the microbial flora of the bacteria that express the cross reacting antigens should be possible.
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32
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Applying complement therapeutics to rare diseases. Clin Immunol 2015; 161:225-40. [PMID: 26341313 DOI: 10.1016/j.clim.2015.08.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/20/2015] [Indexed: 02/06/2023]
Abstract
Around 350 million people worldwide suffer from rare diseases. These may have a genetic, infectious, or autoimmune basis, and several include an inflammatory component. Launching of effective treatments can be very challenging when there is a low disease prevalence and limited scientific insights into the disease mechanisms. As a key trigger of inflammatory processes, complement has been associated with a variety of diseases and has become an attractive therapeutic target for conditions involving inflammation. In view of the clinical experience acquired with drugs licensed for the treatment of rare diseases such as hereditary angioedema and paroxysmal nocturnal hemoglobinuria, growing evidence supports the safety and efficacy of complement therapeutics in restoring immune balance and preventing aggravation of clinical outcomes. This review provides an overview of the candidates currently in the pharmaceutical pipeline with potential to treat orphan diseases and discusses the molecular mechanisms triggered by complement involved with the disease pathogenesis.
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33
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Neuromuscular issues in systemic disease. Curr Neurol Neurosci Rep 2015; 15:48. [PMID: 26008813 DOI: 10.1007/s11910-015-0565-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The neuromuscular system can be involved in several systemic conditions. Clinical manifestations can appear at onset or throughout the course of the disease process. New investigational methods, including imaging of peripheral nerves, new laboratory tests, and antibodies, are available. In addition to symptomatic therapies, specific treatment options, such as for familial amyloid neuropathy and Fabry's disease, are becoming increasingly available. Pathomechanisms vary depending on the underlying disease process. In addition to metabolic, hormonal, immune, and antibody-mediated mechanisms, in some generalized diseases, genetic causes need to be considered. This review focuses on different aspects of the peripheral nervous system including the nerve roots, plexuses, mononeuropathies and generalized neuropathies, neuromuscular junction disorders, muscle, and autonomic nervous system.
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34
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Huda R, Strait RT, Tüzün E, Finkelman FD, Christadoss P. IgG1 deficiency exacerbates experimental autoimmune myasthenia gravis in BALB/c mice. J Neuroimmunol 2015; 281:68-72. [PMID: 25867470 PMCID: PMC4395862 DOI: 10.1016/j.jneuroim.2015.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 03/02/2015] [Accepted: 03/04/2015] [Indexed: 10/23/2022]
Abstract
Myasthenia gravis is an autoimmune disease characterized by muscle weakness due to neuromuscular junction (NMJ) damage by anti-acetylcholine receptor (AChR) auto-antibodies and complement. In experimental autoimmune myasthenia gravis (EAMG), which is induced by immunization with Torpedo AChR in CFA, anti-AChR IgG2b and IgG1 are the predominant isotypes in the circulation. Complement activation by isotypes such as IgG2b plays a crucial role in EAMG pathogenesis; this suggested the possibility that IgG1, which does not activate complement through the classical pathway, may suppress EAMG. In this study, we show that AChR-immunized BALB/c mice genetically deficient for IgG1 produce higher levels of complement-activating isotypes of anti-AChR, especially IgG3 and IgG2a, and develop increased IgG3/IgG2a deposits at the NMJ, as compared to wild type (WT) BALB/c mice. Consistent with this, AChR-immunized IgG1(-/-) BALB/c mice lose muscle strength and muscle AChR to a greater extent than AChR-immunized WT mice. These observations demonstrate that IgG1 deficiency leads to increased severity of EAMG associated with an increase in complement activating IgG isotypes. Further studies are needed to dissect the specific role or mechanism of IgG1 in limiting EAMG and that of EAMG exacerbating role of complement activating IgG3 and IgG2a in IgG1 deficiency.
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Affiliation(s)
- Ruksana Huda
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
| | - Richard T Strait
- Division of Emergency Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA
| | - Erdem Tüzün
- Department of Neuroscience, Institute for Experimental Medical Research, University of Istanbul, Istanbul 34390, Turkey
| | - Fred D Finkelman
- Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Allergy, Immunology and Rheumatology, Department of Internal Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH 45267, USA; Department of Medicine, Cincinnati Veterans Affairs Medical Center, Cincinnati, OH 45220, USA
| | - Premkumar Christadoss
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
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