1
|
Zhao Q, Hu Q, Meng S, Zhang Q, Wang T, Liu C, Liu D, Jiang Z, Hong X. Metabolic profiling of patients with different idiopathic inflammatory myopathy subtypes reveals potential biomarkers in plasma. Clin Exp Med 2023; 23:3417-3429. [PMID: 37103652 PMCID: PMC10618316 DOI: 10.1007/s10238-023-01073-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/07/2023] [Indexed: 04/28/2023]
Abstract
Idiopathic inflammatory myopathy (IIM) are heterogeneous autoimmune diseases that primarily affect the proximal muscles. IIM subtypes include dermatomyositis (DM), polymyositis (PM), and anti-synthetase syndrome (ASS). Metabolic disturbances may cause irreversible structural damage to muscle fibers in patients with IIM. However, the metabolite profile of patients with different IIM subtypes remains elusive. To investigate metabolic alterations and identify patients with different IIM subtypes, we comprehensively profiled plasma metabolomics of 46 DM, 13 PM, 12 ASS patients, and 30 healthy controls (HCs) using UHPLC-Q Exactive HF mass spectrometer. Multiple statistical analyses and random forest were used to discover differential metabolites and potential biomarkers. We found that tryptophan metabolism, phenylalanine and tyrosine metabolism, fatty acid biosynthesis, beta-oxidation of very long chain fatty acids, alpha-linolenic acid and linoleic acid metabolism, steroidogenesis, bile acid biosynthesis, purine metabolism, and caffeine metabolism are all enriched in the DM, PM, and ASS groups. We also found that different subtypes of IIM have their unique metabolic pathways. We constructed three models (five metabolites) to identify DM, PM, ASS from HC in the discovery and validation sets. Five to seven metabolites can distinguish DM from PM, DM from ASS, and PM from ASS. A panel of seven metabolites can identify anti-melanoma differentiation-associated gene 5 positive (MDA5 +) DM with high accuracy in the discovery and validation sets. Our results provide potential biomarkers for diagnosing different subtypes of IIM and a better understanding of the underlying mechanisms of IIM.
Collapse
Affiliation(s)
- Qianqian Zhao
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China
| | - Qiu Hu
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Shuhui Meng
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Qinguo Zhang
- The Office of Healthcare Committee of Shenzhen Municipal, Shenzhen, 518020, China
| | - Tingting Wang
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China
| | - Cuilian Liu
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
| | - Dongzhou Liu
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China
- Shenzhen People's Hospital, The Frist Affiliated Hospital of Southern University of Science and Technology, Shenzhen, 518020, China
| | - Zhenyou Jiang
- Department of Microbiology and Immunology, College of Basic Medicine and Public Hygiene, Jinan University, Guangzhou, 510632, China.
| | - Xiaoping Hong
- Department of Rheumatology and Immunology, The Second Clinical Medical College, Jinan University (Shenzhen People's Hospital), Shenzhen, 518020, China.
- Integrated Chinese and Western Medicine Postdoctoral Research Station, Jinan University, Guangzhou, 510632, China.
- Shenzhen People's Hospital, The Frist Affiliated Hospital of Southern University of Science and Technology, Shenzhen, 518020, China.
| |
Collapse
|
2
|
Pu Q, Wang M, Jiang N, Luo Y, Li X, Hu C, Du D. Novel Isotope-Labeled Derivatization Strategy for the Simultaneous Analysis of Fatty Acids and Fatty Alcohols and Its Application in Idiopathic Inflammatory Myopathies and Pancreatic Cancer. Anal Chem 2023; 95:8197-8205. [PMID: 37191225 DOI: 10.1021/acs.analchem.2c05558] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Fatty acids (FAs) and fatty alcohols (FOHs) are essential compounds for maintaining life. Due to the inherent poor ionization efficiency, low abundance, and complex matrix effect, such metabolites are challenging to precisely quantify and explore deeply. In this study, a pair of novel isotope derivatization reagents known as d0/d5-1-(2-oxo-2-(piperazin-1-yl) ethyl) pyridine-1-ium (d0/d5-OPEPI) were designed and synthesized, and an in-depth screening strategy for FAs and FOHs was established based on d0/d5-OPEPI coupled with liquid chromatography-tandem high-resolution mass spectrometry (LC-HRMS/MS). Using this approach, a total of 332 metabolites were identified and annotated (some of the FAs and FOHs were reconfirmed by standards). Our results demonstrated that OPEPI labeling could significantly enhance the MS response of FAs and FOHs via the introduction of permanently charged tags. The detection sensitivities of FAs were increased by 200-2345-fold compared with the nonderivatization method. At the same time, for FOHs, due to the absence of ionizable functional groups, sensitive detection was achieved utilizing OPEPI derivatization. One-to-one internal standards were provided by using d5-OPEPI labeling to minimize the errors in quantitation. Moreover, the method validation results showed that the method was stable and reliable. Finally, the established method was successfully applied to the study of the FA and FOH profiles of two heterogeneous severe clinical disease tissues. This study would improve our understanding of the pathological and metabolic mechanisms of FAs and FOHs for inflammatory myopathies and pancreatic cancer and also prove the generality and accuracy of the developed analytical method for complex samples.
Collapse
Affiliation(s)
- Qianlun Pu
- Advanced Mass Spectrometry Center, Research Core Facility, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital/West China Medical School, Sichuan University, Chengdu 610041, China
| | - Manjiangcuo Wang
- Advanced Mass Spectrometry Center, Research Core Facility, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital/West China Medical School, Sichuan University, Chengdu 610041, China
| | - Na Jiang
- Advanced Mass Spectrometry Center, Research Core Facility, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital/West China Medical School, Sichuan University, Chengdu 610041, China
| | - Yubin Luo
- Laboratory of Rheumatology & Immunology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Xia Li
- Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Chenggong Hu
- Department of Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dan Du
- Advanced Mass Spectrometry Center, Research Core Facility, Frontiers Science Center for Disease-Related Molecular Network, West China Hospital/West China Medical School, Sichuan University, Chengdu 610041, China
| |
Collapse
|
3
|
Alexandropoulou I, Grammatikopoulou MG, Gkouskou KK, Pritsa AA, Vassilakou T, Rigopoulou E, Lindqvist HM, Bogdanos DP. Ceramides in Autoimmune Rheumatic Diseases: Existing Evidence and Therapeutic Considerations for Diet as an Anticeramide Treatment. Nutrients 2023; 15:nu15010229. [PMID: 36615886 PMCID: PMC9824311 DOI: 10.3390/nu15010229] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/03/2023] Open
Abstract
Autoimmune rheumatic diseases (AIRDs) constitute a set of connective tissue disorders and dysfunctions with akin clinical manifestations and autoantibody responses. AIRD treatment is based on a comprehensive approach, with the primary aim being achieving and attaining disease remission, through the control of inflammation. AIRD therapies have a low target specificity, and this usually propels metabolic disturbances, dyslipidemias and increased cardiovascular risk. Ceramides are implicated in inflammation through several different pathways, many of which sometimes intersect. They serve as signaling molecules for apoptosis, altering immune response and driving endothelial dysfunction and as regulators in the production of other molecules, including sphingosine 1-phosphate (S1P) and ceramide 1-phosphate (C1P). With lipid metabolism being severely altered in AIRD pathology, several studies show that the concentration and variety of ceramides in human tissues is altered in patients with rheumatic diseases compared to controls. As a result, many in vitro and some in vivo (animal) studies research the potential use of ceramides as therapeutic targets in rheumatoid arthritis (RA), ankylosing spondylitis, systemic lupus erythematosus, fibromyalgia syndrome, primary Sjögren's syndrome, systemic sclerosis, myositis, systemic vasculitis and psoriatic arthritis. Furthermore, the majority of ceramide synthesis is diet-centric and, as a result, dietary interventions may alter ceramide concentrations in the blood and affect health. Subsequently, more recently several clinical trials evaluated the possibility of distinct dietary patterns and nutrients to act as anti-ceramide regimes in humans. With nutrition being an important component of AIRD-related complications, the present review details the evidence regarding ceramide levels in patients with AIRDs, the results of anti-ceramide treatments and discusses the possibility of using medical nutritional therapy as a complementary anti-ceramide treatment in rheumatic disease.
Collapse
Affiliation(s)
- Ioanna Alexandropoulou
- Department of Nutritional Sciences & Dietetics, Faculty of Health Sciences, International Hellenic University, Alexander Campus, GR-57400 Thessaloniki, Greece
| | - Maria G. Grammatikopoulou
- Department of Rheumatology and Clinical Immunology, University General Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, GR-41110 Larissa, Greece
| | - Kalliopi K. Gkouskou
- Laboratory of Biology, School of Medicine, National and Kapodistrian University of Athens, GR-11527 Athens, Greece
| | - Agathi A. Pritsa
- Department of Nutritional Sciences & Dietetics, Faculty of Health Sciences, International Hellenic University, Alexander Campus, GR-57400 Thessaloniki, Greece
| | - Tonia Vassilakou
- Department of Public Health Policy, School of Public Health, University of West Attica, GR-11521 Athens, Greece
| | - Eirini Rigopoulou
- Department of Medicine and Research Laboratory of Internal Medicine, University Hospital of Larissa, Biopolis, GR-41222 Larissa, Greece
| | - Helen M. Lindqvist
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, P.O. Box 115, 40530 Gothenburg, Sweden
| | - Dimitrios P. Bogdanos
- Department of Rheumatology and Clinical Immunology, University General Hospital of Larissa, Faculty of Medicine, School of Health Sciences, University of Thessaly, Biopolis, GR-41110 Larissa, Greece
- Correspondence:
| |
Collapse
|
4
|
Li H, Cai HR. The relationship between immunosuppressive therapy and clinical isolates for patients diagnosed with dermatomyositis-related interstitial lung diseases. Int Immunopharmacol 2022; 113:109351. [DOI: 10.1016/j.intimp.2022.109351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/05/2022] [Accepted: 10/11/2022] [Indexed: 11/05/2022]
|
5
|
Del Rio Oliva M, Kirk CJ, Groettrup M, Basler M. Effective therapy of polymyositis in mice via selective inhibition of the immunoproteasome. Eur J Immunol 2022; 52:1510-1522. [PMID: 35733374 DOI: 10.1002/eji.202249851] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/16/2022] [Accepted: 06/20/2022] [Indexed: 11/08/2022]
Abstract
Polymyositis (PM) is a chronic autoimmune inflammatory myopathy resulting in muscle weakness. The limited approved therapies and their poor efficacy contribute to its comorbidity. We investigated the therapeutic use of ONX 0914 and KZR-616, selective inhibitors of the immunoproteasome, in C protein-induced myositis (CIM), a mouse model of PM that closely resembles the human disease. Diseased mice (day 13 post-immunization) were treated with 10 mg/kg ONX 0914 or KZR-616 or vehicle on alternate days until day 28. Endpoints included muscle strength assessed by a grip strength meter, serum creatine kinase activity, histology, and immunohistochemistry analysis. Treatment with ONX 0914 or KZR-616 prevented the loss of grip strength in mice after CIM induction, while vehicle-treated animals displayed progressive muscle weakness. Immunoproteasome inhibition lowered PM-associated leukocyte infiltration of the muscle and prevented increased serum creatine kinase levels. LMP7-deficient mice were resistant to CIM induction as they depicted no alteration in the grip strength, creatine kinase (CK) levels, nor showed muscular alterations. In conclusion, selective inhibition of the immunoproteasome displays therapeutic efficacy in a pre-clinical mouse model of PM with suppression of muscle inflammation and preservation of muscle strength. Positive results from this study support the rationale for using KZR-616 in clinical studies. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Marta Del Rio Oliva
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany
| | | | - Marcus Groettrup
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany.,Biotechnology Institute Thurgau at the University of Konstanz, Kreuzlingen, Switzerland
| | - Michael Basler
- Division of Immunology, Department of Biology, University of Konstanz, Konstanz, Germany.,Biotechnology Institute Thurgau at the University of Konstanz, Kreuzlingen, Switzerland
| |
Collapse
|
6
|
Chen W, Wang Q, Zhou B, Zhang L, Zhu H. Lipid Metabolism Profiles in Rheumatic Diseases. Front Pharmacol 2021; 12:643520. [PMID: 33897433 PMCID: PMC8064727 DOI: 10.3389/fphar.2021.643520] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/18/2021] [Indexed: 12/25/2022] Open
Abstract
Rheumatic diseases are a group of chronic autoimmune disorders that involve multiple organs or systems and have high mortality. The mechanisms of these diseases are still ill-defined, and targeted therapeutic strategies are still challenging for physicians. Recent research indicates that cell metabolism plays important roles in the pathogenesis of rheumatic diseases. In this review, we mainly focus on lipid metabolism profiles (dyslipidaemia, fatty acid metabolism) and mechanisms in rheumatic diseases and discuss potential clinical applications based on lipid metabolism profiles.
Collapse
Affiliation(s)
- Weilin Chen
- Department of Rheumatology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.,Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Changsha, China
| | - Qi Wang
- Department of Radiology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Bin Zhou
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Lihua Zhang
- Department of Rheumatology, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, China
| | - Honglin Zhu
- Department of Rheumatology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, China.,Provincial Clinical Research Center for Rheumatic and Immunologic Diseases, Xiangya Hospital, Changsha, China
| |
Collapse
|
7
|
Vernerová L, Horváthová V, Kropáčková T, Vokurková M, Klein M, Tomčík M, Oreská S, Špiritović M, Štorkánová H, Heřmánková B, Kubínová K, Kryštůfková O, Mann H, Ukropec J, Ukropcová B, Vencovský J. Alterations in activin A-myostatin-follistatin system associate with disease activity in inflammatory myopathies. Rheumatology (Oxford) 2021; 59:2491-2501. [PMID: 31990347 DOI: 10.1093/rheumatology/kez651] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/22/2019] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVES The aim of this study was to investigate the systemic and skeletal muscle levels of atrophy-associated myokines in patients with idiopathic inflammatory myopathies (IIM) and their association with clinical characteristics of myositis. METHODS A total of 94 IIM patients and 162 healthy controls were recruited. Of those, 20 IIM patients and 28 healthy controls underwent a muscle biopsy. Circulating concentrations of myostatin, follistatin, activin A and TGF-β1 were assessed by ELISA. The expression of myokines and associated genes involved in the myostatin signalling pathway in muscle tissue was determined by real-time PCR. RESULTS We report decreased levels of circulating myostatin (median 1817 vs 2659 pg/ml; P = 0.003) and increased follistatin (1319 vs 1055 pg/ml; P = 0.028) in IIM compared with healthy controls. Activin A levels were also higher in IIM (414 vs 309 pg/ml; P = 0.0005) compared with controls. Myostatin was negatively correlated to muscle disease activity assessed by physician on visual analogue scale (MDA) (r = -0.289, P = 0.015) and positively to manual muscle testing of eight muscles (r = 0.366, P = 0.002). On the other hand, follistatin correlated positively with MDA (r = 0.235, P = 0.047). Gene expression analysis showed higher follistatin (P = 0.003) and myostatin inhibitor follistatin-like 3 protein (FSTL3) (P = 0.008) and lower expression of activin receptor type 1B (ALK4) (P = 0.034), signal transducer SMAD3 (P = 0.023) and atrophy marker atrogin-1 (P = 0.0009) in IIM muscle tissue compared with controls. CONCLUSION This study shows lower myostatin and higher follistatin levels in circulation and attenuated expression of myostatin pathway signalling components in skeletal muscle of patients with myositis, a newly emerging pattern of the activin A-myostatin-follistatin system in muscle wasting diseases.
Collapse
Affiliation(s)
- Lucia Vernerová
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague
| | - Veronika Horváthová
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Tereza Kropáčková
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Martina Vokurková
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague
| | - Martin Klein
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Michal Tomčík
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Sabína Oreská
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Maja Špiritović
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic
| | - Hana Štorkánová
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Barbora Heřmánková
- Department of Physiotherapy, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic
| | - Kateřina Kubínová
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Olga Kryštůfková
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Heřman Mann
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| | - Jozef Ukropec
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava
| | - Barbara Ukropcová
- Institute of Experimental Endocrinology, Biomedical Research Center, Slovak Academy of Sciences, Bratislava.,Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Jiří Vencovský
- Division of Experimental Rheumatology, Institute of Rheumatology, Prague.,Department of Rheumatology, First Faculty of Medicine
| |
Collapse
|
8
|
Bampi GB, Rauscher R, Kirchner S, Oliver KE, Bijvelds MJC, Santos LA, Wagner J, Frizzell RA, de Jonge HR, Sorscher EJ, Ignatova Z. Global assessment of the integrated stress response in CF patient-derived airway and intestinal tissues. J Cyst Fibros 2020; 19:1021-1026. [PMID: 32451204 PMCID: PMC7932027 DOI: 10.1016/j.jcf.2020.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/19/2020] [Accepted: 04/17/2020] [Indexed: 12/20/2022]
Abstract
BACKGROUND Chronic inflammation is a hallmark among patients with cystic fibrosis (CF). We explored whether mutation-induced (F508del) misfolding of the cystic fibrosis transmembrane conductance regulator (CFTR), and/or secondary colonization with opportunistic pathogens, activate tissue remodeling and innate immune response drivers. METHODS Using RNA-seq to interrogate global gene expression profiles, we analyzed stress response signaling cascades in primary human bronchial epithelia (HBE) and intestinal organoids. RESULTS Primary HBE acquired from CF patients with advanced disease and prolonged exposure to pathogenic microorganisms display a clear molecular signature of activated tissue remodeling pathways, unfolded protein response (UPR), and chronic inflammation. Furthermore, CFTR misfolding induces inflammatory signaling cascades in F508del patient-derived organoids from both the distal small intestine and colon. CONCLUSION Despite the small patient cohort size, this proof-of-principle study supports the use of RNA-seq as a means to both identify CF-specific signaling profiles in various tissues and evaluate disease heterogeneity. Our global transcriptomic data is a useful resource for the CF research community for analyzing other gene expression sets influencing CF disease signature but also transcriptionally contributing to CF heterogeneity.
Collapse
Affiliation(s)
- Giovana B Bampi
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Robert Rauscher
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Sebastian Kirchner
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany; University of Potsdam, Potsdam, Germany
| | - Kathryn E Oliver
- Emory University School of Medicine, Atlanta, GA, USA; Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Marcel J C Bijvelds
- Gastroenterology and Hepatology Erasmus MC University Medical Center, Rotterdam, USA
| | - Leonardo A Santos
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Johannes Wagner
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | - Raymond A Frizzell
- Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Hugo R de Jonge
- Gastroenterology and Hepatology Erasmus MC University Medical Center, Rotterdam, USA
| | - Eric J Sorscher
- Emory University School of Medicine, Atlanta, GA, USA; Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Zoya Ignatova
- Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany.
| |
Collapse
|
9
|
Liu D, Zuo X, Luo H, Zhu H. The altered metabolism profile in pathogenesis of idiopathic inflammatory myopathies. Semin Arthritis Rheum 2020; 50:627-635. [PMID: 32502727 DOI: 10.1016/j.semarthrit.2020.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/28/2020] [Accepted: 05/11/2020] [Indexed: 11/29/2022]
Abstract
Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases characterized by muscle weakness, muscle inflammation and extramuscular manifestations. Despite extensive efforts, the mechanisms of IIMs remain largely unknown, and treatment is still a challenge for physicians. Metabolism changes have emerged as a crucial player in autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). However, little is known about metabolism changes in IIMs. In this review, we focus on the alteration of metabolism profile in IIMs, and the relationships with clinical information. We highlight the potential roles of metabolism in the pathogenesis of IIMs and discuss future perspectives for metabolic checkpoint-based therapeutic interventions.
Collapse
Affiliation(s)
- Di Liu
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Xiaoxia Zuo
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Hui Luo
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China
| | - Honglin Zhu
- Department of Rheumatology, Xiangya Hospital, Central South University, 87 Xiangya Road, Changsha, Hunan 410008, People's Republic of China.
| |
Collapse
|
10
|
Honma F, Fujigaki Y, Nemoto Y, Kikuchi H, Nagura M, Arai S, Ishizawa K, Yamazaki O, Tamura Y, Kondo F, Ohashi R, Uchida S, Shibata S. A Case of Rheumatoid Arthritis Presenting with Renal Thrombotic Microangiopathy Probably due to a Combination of Chronic Tacrolimus Arteriolopathy and Severe Hypertension. Case Rep Nephrol 2019; 2019:3923190. [PMID: 30963011 PMCID: PMC6431373 DOI: 10.1155/2019/3923190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 02/18/2019] [Indexed: 11/24/2022] Open
Abstract
A 51-year-old woman with rheumatoid arthritis presented with mild hypertension 20 months after tacrolimus treatment and developing proteinuria 24 months after the treatment. Tacrolimus was discontinued 27 months after the treatment, followed by heavy proteinuria, accelerated hypertension, and deteriorating renal function without ocular fundus lesions as a clinical sign of malignant hypertension. Renal biopsy revealed malignant nephrosclerosis characterized by subacute and chronic thrombotic microangiopathy (TMA), involving small arteries, arterioles, and glomeruli. Focal segmental glomerulosclerosis, probably secondary to chronic TMA, was identified as a cause of heavy proteinuria. The zonal tubulointerstitial injury caused by subacute TMA may have mainly contributed to deteriorating renal function. The presence of nodular hyalinosis in arteriolar walls was indicative of tacrolimus-associated nephrotoxicity. Together with other antihypertensive drugs, administration of aliskiren stabilized renal function with reducing proteinuria. Owing to the preexisting proteinuria prior to severe hypertension and the complex renal histopathology, we postulated that chronic TMA, which was initially triggered by tacrolimus, was aggravated by severe hypertension, resulting in overt renal TMA.
Collapse
Affiliation(s)
- Fumika Honma
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Yoshihide Fujigaki
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Yoshikazu Nemoto
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Hirotoshi Kikuchi
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Michito Nagura
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Shigeyuki Arai
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Kenichi Ishizawa
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Osamu Yamazaki
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Yoshifuru Tamura
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Fukuo Kondo
- Department of Pathology, Teikyo University Hospital, Itabashi-ku, Tokyo, Japan
| | - Ryuji Ohashi
- Department of Diagnostic Pathology, Nippon Medical School Musashikosugi Hospital, Kawasaki, Kanagawa, Japan
| | - Shunya Uchida
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| | - Shigeru Shibata
- Department of Internal Medicine, Teikyo University School of Medicine, Itabashi-ku, Tokyo, Japan
| |
Collapse
|
11
|
Abstract
PURPOSE OF REVIEW To review the novel development of standardized clinical outcome measures used in adult patients with idiopathic inflammatory myopathies (IIMs). A further aim was to determine what aspects of IIM are covered by these outcome measures according to the International Classification of Functioning, Disability and Health (ICF). RECENT FINDINGS The sporadic inclusion body myositis functional assessment (sIFA) is the first diagnosis-specific patient-driven patient-reported outcome measure. The adult myositis assessment tool (AMAT) is a new outcome measure assessing physical performance. Also, new criteria to assess response to treatment have been presented for both adults and children with IIM. The ICF provides a standardized frame and structure to report outcome, including functional disability. Using this framework, it is evident that there is a lack of validated patient-reported outcome measures to assess disease aspects important to patient, and that no studies have evaluated life-style factors such as physical activity in these patients. SUMMARY The sIFA will ensure patient-relevant patient-reported assessment of activity limitations in patients with inclusion body myositis. The AMAT is a partly validated tool that needs to be used in clinical trials for further validation. The response criteria will enhance assessment of individual response to different treatments.
Collapse
|
12
|
Raouf J, Idborg H, Englund P, Alexanderson H, Dastmalchi M, Jakobsson PJ, Lundberg IE, Korotkova M. Targeted lipidomics analysis identified altered serum lipid profiles in patients with polymyositis and dermatomyositis. Arthritis Res Ther 2018; 20:83. [PMID: 29720222 PMCID: PMC5932839 DOI: 10.1186/s13075-018-1579-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 03/27/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Polymyositis (PM) and dermatomyositis (DM) are severe chronic autoimmune diseases, characterized by muscle fatigue and low muscle endurance. Conventional treatment includes high doses of glucocorticoids and immunosuppressive drugs; however, few patients recover full muscle function. One explanation of the persistent muscle weakness could be altered lipid metabolism in PM/DM muscle tissue as we previously reported. Using a targeted lipidomic approach we aimed to characterize serum lipid profiles in patients with PM/DM compared to healthy individuals (HI) in a cross-sectional study. Also, in the longitudinal study we compared serum lipid profiles in patients newly diagnosed with PM/DM before and after immunosuppressive treatment. METHODS Lipidomic profiles were analyzed in serum samples from 13 patients with PM/DM, 12 HI and 8 patients newly diagnosed with PM/DM before and after conventional immunosuppressive treatment using liquid chromatography tandem mass spectrometry (LC-MS/MS) and a gas-chromatography flame ionization detector (GC-FID). Functional Index (FI), as a test of muscle performance and serum levels of creatine kinase (s-CK) as a proxy for disease activity were analyzed. RESULTS The fatty acid (FA) composition of total serum lipids was altered in patients with PM/DM compared to HI; the levels of palmitic (16:0) acid were significantly higher while the levels of arachidonic (20:4, n-6) acid were significantly lower in patients with PM/DM. The profiles of serum phosphatidylcholine and triacylglycerol species were changed in patients with PM/DM compared to HI, suggesting disproportionate levels of saturated and polyunsaturated FAs that might have negative effects on muscle performance. After immunosuppressive treatment the total serum lipid levels of eicosadienoic (20:2, n-6) and eicosapentaenoic (20:5, n-3) acids were increased and serum phospholipid profiles were altered in patients with PM/DM. The correlation between FI or s-CK and levels of several lipid species indicate the important role of lipid changes in muscle performance and inflammation. CONCLUSIONS Serum lipids profiles are significantly altered in patients with PM/DM compared to HI. Moreover, immunosuppressive treatment in patients newly diagnosed with PM/DM significantly affected serum lipid profiles. These findings provide new evidence of the dysregulated lipid metabolism in patients with PM/DM that could possibly contribute to low muscle performance.
Collapse
Affiliation(s)
- Joan Raouf
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Helena Idborg
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Petter Englund
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden
| | - Helene Alexanderson
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Maryam Dastmalchi
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Per-Johan Jakobsson
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Ingrid E Lundberg
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden
| | - Marina Korotkova
- Division of Rheumatology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Center for Molecular Medicine, Stockholm, Sweden.
| |
Collapse
|
13
|
Pérez-Baos S, Prieto-Potin I, Román-Blas JA, Sánchez-Pernaute O, Largo R, Herrero-Beaumont G. Mediators and Patterns of Muscle Loss in Chronic Systemic Inflammation. Front Physiol 2018; 9:409. [PMID: 29740336 PMCID: PMC5928215 DOI: 10.3389/fphys.2018.00409] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/04/2018] [Indexed: 12/25/2022] Open
Abstract
Besides its primary function in locomotion, skeletal muscle (SKM), which represents up to half of human's weight, also plays a fundamental homeostatic role. Through the secretion of soluble peptides, or myokines, SKM interacts with major organs involved in metabolic processes. In turn, metabolic cues from these organs are received by muscle cells, which adapt their response accordingly. This is done through an intricate intracellular signaling network characterized by the cross-talking between anabolic and catabolic pathways. A fine regulation of the network is required to protect the organism from an excessive energy expenditure. Systemic inflammation evokes a catabolic reaction in SKM known as sarcopenia. In turn this response comprises several mechanisms, which vary depending on the nature of the insult and its magnitude. In this regard, aging, chronic inflammatory systemic diseases, osteoarthritis and idiopathic inflammatory myopathies can lead to muscle loss. Interestingly, sarcopenia may persist despite remission of chronic inflammation, an issue which warrants further research. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) system stands as a major participant in muscle loss during systemic inflammation, while it is also a well-recognized orchestrator of muscle cell turnover. Herein we summarize current knowledge about models of sarcopenia, their triggers and major mediators and their effect on both protein and cell growth yields. Also, the dual action of the JAK/STAT pathway in muscle mass changes is discussed. We highlight the need to unravel the precise contribution of this system to sarcopenia in order to design targeted therapeutic strategies.
Collapse
Affiliation(s)
- Sandra Pérez-Baos
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| | - Iván Prieto-Potin
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| | - Jorge A Román-Blas
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| | - Olga Sánchez-Pernaute
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| | - Raquel Largo
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| | - Gabriel Herrero-Beaumont
- Bone and Joint Research Unit, Service of Rheumatology, IIS-Fundación Jiménez Díaz, Autonomous University of Madrid, Madrid, Spain
| |
Collapse
|
14
|
Schneidereit D, Nübler S, Prölß G, Reischl B, Schürmann S, Müller OJ, Friedrich O. Optical prediction of single muscle fiber force production using a combined biomechatronics and second harmonic generation imaging approach. LIGHT, SCIENCE & APPLICATIONS 2018; 7:79. [PMID: 30374401 PMCID: PMC6199289 DOI: 10.1038/s41377-018-0080-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/19/2018] [Accepted: 09/24/2018] [Indexed: 05/22/2023]
Abstract
Skeletal muscle is an archetypal organ whose structure is tuned to match function. The magnitude of order in muscle fibers and myofibrils containing motor protein polymers determines the directed force output of the summed force vectors and, therefore, the muscle's power performance on the structural level. Structure and function can change dramatically during disease states involving chronic remodeling. Cellular remodeling of the cytoarchitecture has been pursued using noninvasive and label-free multiphoton second harmonic generation (SHG) microscopy. Hereby, structure parameters can be extracted as a measure of myofibrillar order and thus are suggestive of the force output that a remodeled structure can still achieve. However, to date, the parameters have only been an indirect measure, and a precise calibration of optical SHG assessment for an exerted force has been elusive as no technology in existence correlates these factors. We engineered a novel, automated, high-precision biomechatronics system into a multiphoton microscope allows simultaneous isometric Ca2+-graded force or passive viscoelasticity measurements and SHG recordings. Using this MechaMorph system, we studied force and SHG in single EDL muscle fibers from wt and mdx mice; the latter serves as a model for compromised force and abnormal myofibrillar structure. We present Ca2+-graded isometric force, pCa-force curves, passive viscoelastic parameters and 3D structure in the same fiber for the first time. Furthermore, we provide a direct calibration of isometric force to morphology, which allows noninvasive prediction of the force output of single fibers from only multiphoton images, suggesting a potential application in the diagnosis of myopathies.
Collapse
Affiliation(s)
- Dominik Schneidereit
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), FAU Erlangen-Nürnberg, Paul-Gordan-Str. 7, 91052 Erlangen, Germany
| | - Stefanie Nübler
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), FAU Erlangen-Nürnberg, Paul-Gordan-Str. 7, 91052 Erlangen, Germany
| | - Gerhard Prölß
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
| | - Barbara Reischl
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
| | - Sebastian Schürmann
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), FAU Erlangen-Nürnberg, Paul-Gordan-Str. 7, 91052 Erlangen, Germany
- Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Oliver J Müller
- Department of Internal Medicine III, University of Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site Hamburg/Kiel/Lübeck, Kiel, Germany
| | - Oliver Friedrich
- Institute of Medical Biotechnology, Friedrich-Alexander-University (FAU) Erlangen-Nürnberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany
- Erlangen Graduate School in Advanced Optical Technologies (SAOT), FAU Erlangen-Nürnberg, Paul-Gordan-Str. 7, 91052 Erlangen, Germany
- Muscle Research Center Erlangen (MURCE), Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
15
|
IFN-β-induced reactive oxygen species and mitochondrial damage contribute to muscle impairment and inflammation maintenance in dermatomyositis. Acta Neuropathol 2017. [PMID: 28623559 DOI: 10.1007/s00401-017-1731-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dermatomyositis (DM) is an autoimmune disease associated with enhanced type I interferon (IFN) signalling in skeletal muscle, but the mechanisms underlying muscle dysfunction and inflammation perpetuation remain unknown. Transcriptomic analysis of early untreated DM muscles revealed that the main cluster of down-regulated genes was mitochondria-related. Histochemical, electron microscopy, and in situ oxygraphy analysis showed mitochondrial abnormalities, including increased reactive oxygen species (ROS) production and decreased respiration, which was correlated with low exercise capacities and a type I IFN signature. Moreover, IFN-β induced ROS production in human myotubes was found to contribute to mitochondrial malfunctions. Importantly, the ROS scavenger N-acetyl cysteine (NAC) prevented mitochondrial dysfunctions, type I IFN-stimulated transcript levels, inflammatory cell infiltrate, and muscle weakness in an experimental autoimmune myositis mouse model. Thus, these data highlight a central role of mitochondria and ROS in DM. Mitochondrial dysfunctions, mediated by IFN-β induced-ROS, contribute to poor exercise capacity. In addition, mitochondrial dysfunctions increase ROS production that drive type I IFN-inducible gene expression and muscle inflammation, and may thus self-sustain the disease. Given that current DM treatments only induce partial recovery and expose to serious adverse events (including muscular toxicity), protecting mitochondria from dysfunctions may open new therapeutic avenues for DM.
Collapse
|
16
|
Wakiguchi H. Liposteroid therapy for juvenile and adult dermatomyositis: efficacy and side effects. ANNALS OF TRANSLATIONAL MEDICINE 2017; 5:110. [PMID: 28361075 DOI: 10.21037/atm.2017.01.36] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Hiroyuki Wakiguchi
- Department of Pediatrics, Yamaguchi University Graduate School of Medicine, Ube, Japan
| |
Collapse
|
17
|
|
18
|
The immunoproteasomes are key to regulate myokines and MHC class I expression in idiopathic inflammatory myopathies. J Autoimmun 2016; 75:118-129. [PMID: 27522114 DOI: 10.1016/j.jaut.2016.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/26/2016] [Accepted: 08/03/2016] [Indexed: 12/18/2022]
Abstract
Idiopathic inflammatory myopathies (IIMs) are diseases with muscle weakness, morphologically characterized by inflammatory infiltration and increased expression of MHC class I molecule on myofibers. Immunoproteasome, as a proteolytic complex that shapes the repertoire of antigenic peptides, has been previously demonstrated to be over-expressed in IIMs at mRNA level. In this study, we investigated the expression and the function of the immunoproteasome in IIMs in more detail. As shown by immunofluorescence staining, expression of relevant players of the immunoproteasome was detectable in the inflamed skeletal muscle tissue from IIM patients. In fact, two subunits of the immunoproteasome, β1i or β5i were upregulated in sporadic inclusion body myositis, immune-mediated necrotizing myopathies and dermatomyositis muscle biopsies and co-localized with the MHC class I expressing myofibers. Double immunofluorescence revealed that both myofibers and muscle infiltrating cells, including CD8+ T-cells and CD68 + macrophages in IIMs expressed β1i or β5i. In addition, we have also investigated the role of the immunoproteasome in myoblasts during in vitro inflammatory conditions. Using human primary myoblasts cultures we found that pro-inflammatory cytokines, TNF-α or IFN-γ upregulate β1i or β5i. Selective inhibition or depletion of β5i amplified the TNF-α or IFN-γ mediated expression of cytokines/chemokines (myokines) in myoblasts. Furthermore, we demonstrated that specific inhibitors of β1i or β5i reduced the cell surface expression of MHC class I in myoblasts induced by IFN-γ. Taken together, our data suggest that the immunoproteasome is involved in pathologic MHC class I expression and maintenance of myokine production in IIMs. Thus, induction of the immunoproteasome was identified as a pathomechanism underlying inflammation in IIMs.
Collapse
|