AUTHOR=Ma Xue , Gao Hua-Jie , Zhang Qing , Yang Meng-Ge , Bi Zhua-Jin , Ji Su-Qiong , Li Yue , Xu Li , Bu Bi-Tao 

TITLE=Endoplasmic Reticulum Stress Is Involved in Muscular Pathogenesis in Idiopathic Inflammatory Myopathies

JOURNAL=Frontiers in Cell and Developmental Biology

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/cell-and-developmental-biology/articles/10.3389/fcell.2022.791986

DOI=10.3389/fcell.2022.791986

ISSN=2296-634X

ABSTRACT=<p><bold>Objectives:</bold> Endoplasmic reticulum (ER) stress plays pivotal roles in the regulation of skeletal muscle damage and dysfunction in multiple disease conditions. We postulate the activation of ER stress in idiopathic inflammatory myopathies (IIM).</p><p><bold>Methods:</bold> Thirty-seven patients with immune-mediated necrotizing myopathy (IMNM), 21 patients with dermatomyositis (DM), 6 patients with anti-synthetase syndrome (ASS), and 10 controls were enrolled. The expression of ER stress-induced autophagy pathway was detected using histological sections, Western blot, and real-time quantitative Polymerase Chain Reaction.</p><p><bold>Results:</bold> ER stress-induced autophagy pathway was activated in biopsied muscle of patients with IMNM, DM, and ASS. The ER chaperone protein, glucose-regulated protein 78 (GRP78)/BiP expression in skeletal muscle correlated with autophagy, myofiber atrophy, myonecrosis, myoregeneration, and disease activity in IMNM.</p><p><bold>Conclusion:</bold> ER stress was involved in patients with IIM and correlates with disease activity in IMNM. ER stress response may be responsible for skeletal muscle damage and repair in IIM.</p>