Zhou Yueyuan, Kang Limei, Yin Geng, Yang Leiyi, Chen Bo, Liu Binhan, Zhu Xiaoyan, Xie Qibing
Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Wuhou District, China.
Department of General Practice, General Practice Medical Center, West China Hospital, Sichuan University, Chengdu, Wuhou District, China.
J Cachexia Sarcopenia Muscle. 2024 Dec;15(6):2460-2475. doi: 10.1002/jcsm.13581. Epub 2024 Sep 16.
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). PD1CD4 (r = 0.3243, P = 0.0115) and PD1CD8 (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.
特发性炎性肌病（IIM）是一种以骨骼肌受累为特征的全身性自身免疫性疾病。本研究旨在探讨腺苷受体信号通路在实验性自身免疫性肌炎（EAM）发展中的作用。
将一种胞外5'-核苷酸酶（CD73）抑制剂、腺苷受体激动剂、一种缺氧诱导因子-1α（HIF-1α）抑制剂或赋形剂给予对照小鼠和EAM小鼠。使用磁珠分离小鼠脾脏CD4或调节性T细胞（Tregs），随后在体外用腺苷A2B受体激动剂、HIF-1α抑制剂或赋形剂进行刺激。在横断面研究中，我们收集了64份IIM患者的血清样本（69%为女性，49±9岁）、63份外周血样本（70%为女性，50±11岁）和34份骨骼肌样本（71%为女性，63±6岁）。此外，从年龄和性别匹配的健康对照中获得35份血清样本和30份外周血样本，并从骨关节炎患者中收集6份股四头肌样本作为正常组。
IIM患者骨骼肌中CD73[皮肌炎（DM）、多发性肌炎（PM）：P<0.01；免疫介导的坏死性肌病（IMNM）：P<0.0001]和腺苷脱氨酶（ADA）表达增加（DM：P<0.001；PM、IMNM：P<0.0001），血清ADA水平[56.7（95%CI：53.7，58.7）对198.8（95%CI：186.2，237.3）ng/μL，P<0.0001]。用CD73抑制剂干预会加重病情（P=0.0461），而腺苷受体激动剂（A1：P=0.0009；A2B：P<0.0001；A3：P=0.0001）和HIF-1α抑制剂（P=0.0044）可减轻EAM小鼠的骨骼肌损伤。IIM患者骨骼肌中程序性细胞死亡蛋白-1（PD1：P=0.0023）和含T细胞免疫球蛋白和粘蛋白结构域3（TIM3：P<0.0001）的表达升高与肌酸激酶水平相关（PD1，r=0.7072，P<0.0001；TIM3，r=0.4808，P=0.0046）。PD1 CD4（r=0.3243，P=0.0115）和PD1 CD8（r=0.3959，P=0.0017）T细胞与IIM患者的肌炎疾病活动评估视觉模拟量表评分（肌肉）相关。在IIM患者的骨骼肌中鉴定出耗竭的Tregs。腺苷A2B受体的激活下调了HIF-1α（蛋白或mRNA水平，P<0.01），导致EAM小鼠中辅助性T细胞17（Th17）减少（13.58%对5.43%，P=0.0201）和磷酸化信号转导和转录激活因子3（p-STAT3）Th17减少（16.32%对6.73%，P=0.0029），耗竭的Tregs减少（PD1 Tregs：53.55%对40.28%，P=0.0005；TIM3 Tregs：3.93%对3.11%），P=0.0029），Tregs增加（0.45%对2.89%，P=0.0006）。
耗竭的T细胞可能在IIM中具有致病性，腺苷A2B受体信号通路的激活可调节Th17/Treg平衡并抑制Tregs耗竭，从而减缓EAM疾病进展。
