Adenosine A2B receptor activation regulates the balance between T helper 17 cells and regulatory T cells, and inhibits regulatory T cells exhaustion in experimental autoimmune myositis.
Idiopathic inflammatory myopathy (IIM) is a systemic autoimmune disease characterized by skeletal muscle involvement. This study aimed to investigate the role of adenosine receptor signalling pathways in the development of experimental autoimmune myositis (EAM).
An ecto-5'-nucleotidase (CD73) inhibitor, adenosine receptor agonists, a hypoxia-inducible factor-1α (HIF-1α) inhibitor or a vehicle were administered to control and EAM mice. Murine splenic CD4+ or regulatory T cells (Tregs) were isolated using magnetic beads and subsequently stimulated with an adenosine A2B receptor agonist, a HIF-1α inhibitor, or vehicle in vitro. In cross-sectional studies, we collected 64 serum samples (69% female, 49 ± 9 years), 63 peripheral blood samples (70% female, 50 ± 11 years), and 34 skeletal muscle samples (71% female, 63 ± 6 years) from patients with IIM. Additionally, 35 serum samples and 30 peripheral blood samples were obtained from age- and sex-matched healthy controls, and six quadriceps muscle samples were collected from patients with osteoarthritis to serve as the normal group.
Patients with IIM exhibited increased CD73 [dermatomyositis (DM), polymyositis (PM): P < 0.01; immune-mediated necrotizing myopathy (IMNM): P < 0.0001] and adenosine deaminase (ADA) expression (DM: P < 0.001; PM, IMNM: P < 0.0001) in the skeletal muscles, and serum ADA levels [56.7 (95% CI: 53.7, 58.7) vs. 198.8 (95% CI: 186.2, 237.3) ng/μL, P < 0.0001]. Intervention with a CD73 inhibitor exacerbated (P = 0.0461), whereas adenosine receptor agonists (A1: P = 0.0009; A2B: P < 0.0001; A3: P = 0.0001) and the HIF-1α inhibitor (P = 0.0044) alleviated skeletal muscle injury in EAM mice. Elevated expression of programmed cell death protein-1 (PD1: P = 0.0023) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3: P < 0.0001) in skeletal muscles of patients with IIM were correlated with creatine kinase levels (PD1, r = 0.7072, P < 0.0001; TIM3, r = 0.4808, P = 0.0046). PD1+CD4+ (r = 0.3243, P = 0.0115) and PD1+CD8+ (r = 0.3959, P = 0.0017) T cells were correlated with Myositis Disease Activity Assessment Visual Analogue Scale scores (muscle) in IIM. The exhausted Tregs were identified in the skeletal muscles of patients with IIM. Activation of the A2B adenosine receptor downregulated HIF-1α (protein or mRNA level, P < 0.01), resulting in decreased T helper cell 17 (Th17) (13.58% vs. 5.43%, P = 0.0201) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3)+ Th17 (16.32% vs. 6.73%, P = 0.0029), decreased exhausted Tregs (PD1+ Tregs: 53.55% vs. 40.28%, P = 0.0005; TIM3+ Tregs: 3.93% vs. 3.11%, P = 0.0029), and increased Tregs (0.45% vs. 2.89%, P = 0.0006) in EAM mice.
The exhausted T cells may be pathogenic in IIM, and the activation of adenosine A2B receptor signalling pathway can regulate Th17/Treg balance and inhibit Tregs exhaustion, thereby slowing EAM disease progression.
Zhou Y
，Kang L
，Yin G
，Yang L
，Chen B
，Liu B
，Zhu X
，Xie Q
... -
《-》
Metabolic profiling of patients with different idiopathic inflammatory myopathy subtypes reveals potential biomarkers in plasma.
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.
Zhao Q
，Hu Q
，Meng S
，Zhang Q
，Wang T
，Liu C
，Liu D
，Jiang Z
，Hong X
... -
《-》
Interleukin-35 in idiopathic inflammatory myopathies.
Interleukin-35 (IL-35) is a recently described heterodimeric cytokine that belongs to the IL-12 family and consists of p35 (IL-12a) and EBI3 (IL-27b) subunits. The expression of IL-35 in humans is inducible in response to inflammatory stimuli. Increased IL-35 levels were documented in several autoimmune inflammatory diseases, suggesting a possible immunomodulatory role in their pathogenesis.
The aim of this study was to explore a potential role of IL-35 in the pathogenesis of idiopathic inflammatory myopathies (IIM) by studying the expression of IL-35 subunits in muscle biopsy samples and by evaluating serum levels of IL-35 and their association with disease activity in IIM patients.
The expression of IL-35 subunits was studied in serial sections of 9 muscle biopsy samples [4 polymyositis (PM), 5 dermatomyositis (DM)] and in 7 non-inflammatory control muscle biopsies. Serum levels of IL-35 were measured in 23 PM, 28 DM and 15 cancer associated myositis (CAM) patients as well as in 40 healthy controls. Disease activity was evaluated using the Myositis Disease Activity Assessment Tool (MDAAT) and by serum muscle enzymes.
Expression of both IL-35 subunits was evident in the inflammatory infiltrates in IIM muscle biopsies, while no IL-35 expression was observed in control muscle samples. IL-35 serum levels were increased in all IIM patients compared to healthy controls [median 119.5 (range 32.1-1074.5) vs 36.2 (range 1.5-86.5) pg/ml, P < 0.001]. There were no differences in IL-35 serum levels between myositis subgroups (DM, PM or CAM). Serum IL-35 levels correlated significantly with physician's assessment of global (r = 0.29, p = 0.021), muscle (r = 0.30, p = 0.017) and extramuscular (r = 0.30, p = 0.016) disease activity as well as creatine kinase (r = 0.26, p = 0.044) and lactate dehydrogenase (r = 0.40, p = 0.003) levels. There was a significant correlation with pulmonary activity in patients with interstitial lung disease (r = 0.39, p = 0.037). Serum IL-35 correlated negatively with duration of treatment (r = -34, p = 0.009).
IL-35 is overexpressed in inflammatory infiltrates in muscle tissue and serum in IIM patients and there is correlation with several disease activity parameters. These data suggest potential role of locally produced IL-35 in the pathogenesis of inflammatory myopathies.
Mann H
，Kryštůfková O
，Zámečník J
，Háček J
，Hulejová H
，Filková M
，Vencovský J
，Šenolt L
... -
《-》
Characterised intron retention profiles in muscle tissue of idiopathic inflammatory myopathy subtypes.
Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases. Intron retention (IR) serves as an important post-transcriptional and translational regulatory mechanism. This study aims to identify changes in IR profiles in IIM subtypes, investigating their influence on proteins and their correlations with clinical features.
RNA sequencing and liquid chromatography-tandem mass spectrometry were performed on muscle tissues obtained from 174 patients with IIM and 19 controls, following QC procedures. GTFtools and iREAD software were used for IR identification. An analysis of differentially expressed IRs (DEIs), exons and proteins was carried out using edgeR or DEP. Functional analysis was performed with clusterProfiler, and SPIRON was used to assess splicing factors.
A total of 6783 IRs located in 3111 unique genes were identified in all IIM subtypes compared with controls. IIM subtype-specific DEIs were associated with the pathogenesis of respective IIM subtypes. Splicing factors YBX1 and HSPA2 exhibited the most changes in dermatomyositis and immune-mediated necrotising myopathy. Increased IR was associated with reduced protein expression. Some of the IIM-specific DEIs were correlated with clinical parameters (skin rash, MMT-8 scores and muscle enzymes) and muscle histopathological features (myofiber necrosis, regeneration and inflammation). IRs in IFIH1 and TRIM21 were strongly correlated with anti-MDA5+ antibody, while IRs in SRP14 were associated with anti-SRP+ antibody.
This study revealed distinct IRs and specific splicing factors associated with IIM subtypes, which might be contributing to the pathogenesis of IIM. We also emphasised the potential impact of IR on protein expression in IIM muscles.
Xiao Y
，Xie S
，Li HD
，Liu Y
，Zhang H
，Zuo X
，Zhu H
，Li Y
，Luo H
... -
《-》
ResearchGate
(全网免费下载)
钛学术
(全网免费下载)
