An exploration of the role of lymphatic vessels and its mechanism in promoting the recovery of muscle damage following effective stretching stimulation

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K11156
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Oita University
• Principal Investigator: Ji Rui-Cheng 大分大学, 福祉健康科学部, 准教授 (60305034)
• Co-Investigator(Kenkyū-buntansha): 河上 敬介 大分大学, 福祉健康科学部, 教授 (60195047)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 筋損傷 / リンパ管新生 / 内皮細胞増殖因子（VEGF-C/-D） / 免疫組織化学 / 分子生物学 / 伸張刺激

Outline of Final Research Achievements

A muscle injury model was created by lengthening contraction of the ankle dorsiflexor muscles in male C57BL/6J mice. The histological and biochemical changes of the injured tissues, especially intramuscular lymphatic vessels were investigated during the healing process. The number, density, and area fraction of lymphatic vessels increased in four days after injury compared to other groups, and the mRNA expression levels of VEGF-C/-D and their receptor VEGFR-3 increased. The macrophage-related inflammatory factors, e.g., TNF-α, IL-1β, Fizzl and Ym1 were also highly expressed. The muscle function represented by maximal ankle dorsiflexion torque in seven days after injury tended to recover as muscle fibers regenerated. These findings suggested that the intramuscular lymphatic responses like lymphangiogenesis may play an important role in promoting recovery from muscle injury.

Free Research Field

リハビリテーション科学・福祉工学 / 小区分59010:リハビリテーション科学関連

Academic Significance and Societal Importance of the Research Achievements

リンパ管系は、筋損傷後に集積される炎症性細胞などにより分解された筋線維のタンパク質や過剰な筋間質液の還流のために、可塑的な変化を引き起こすと考える。本研究では、筋損傷組織における筋内毛細リンパ管分布の変化、内皮細胞増殖因子VEGF-C/-Dや炎症性サイトカインなどを解析した結果から、筋内リンパ管系の応答が筋損傷の回復過程に密接な関係性を持っており、筋組織内の恒常性を維持する重要な機構であることを明らかにした。従って、筋内リンパ管内皮細胞の機能制御メカニズムを解明することにより、炎症性筋疾患に有効な治療薬の開発に繋がる可能性が期待される。