Intracellular Reaction of Skeletal Muscle in Myasthenia Gravis

2015 Fiscal Year Final Research Report

• Project/Area Number: 25461273
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Neurology
• Research Institution: Kanazawa University
• Principal Investigator: Iwasa Kazuo 金沢大学, 医学系, 准教授 (10345613)
• Co-Investigator(Renkei-kenkyūsha): YOSHIKAWA Hiroaki 金沢大学, 保健管理センター, 教授 (10272981)
• Research Collaborator: FURUKAWA Yutaka ; MOTOZAKI Yuko
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 重症筋無力症 / 抗アセチルコリン受容体抗体 / 骨格筋 / 神経筋接合部 / 小胞体ストレス応答 / カベオリン3 / 骨格筋再生機能 / 骨格筋免疫応答

Outline of Final Research Achievements

In myasthenia gravis (MG), intracellular reaction of muscle was important for pathology and medication. We evaluated GRP78 (ER stress protein) upregulation in muscle with MG. ER stress in muscle is important for repair after injury. Upregulation of GRP78 in MG muscle plays an important role in muscle repair and improvement. An increase of GRP78 also plays immunoregulatory roles in MG, such as serving as a defense mechanism against immunological attack and modulating the immune system itself. Some MG muscles showed patchy/scarce caveolin-3 distribution. Partial loss of caveolin-3 expression was relatively common in MG. Caveolin-3 levels were higher in MG vs. non-myogenic patient. Caveolin-3 upregulation may be required for restoring MG muscle.
In summary, MG might have damage not only in the neuromuscular junction, but also in muscle intracellular areas. Our findings may help to understand the muscle response in MG. However, more studies are needed for elucidating the mechanisms.

Free Research Field

神経内科