Center for Rheumatology and Spine Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark; Department of Pathology, Department of Clinical Research, University of Southern Denmark, Odense University Hospital, Denmark.
Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.
Neuromuscul Disord. 2022 Jun;32(6):493-502. doi: 10.1016/j.nmd.2022.04.006. Epub 2022 Apr 26.
Sporadic inclusion body myositis (sIBM) is characterised by skeletal muscle inflammation, progressive muscle loss and weakness, which is largely refractory to immunosuppressive treatment. Low-load blood-flow restricted (BFR) training has been shown to evoke gains in myofibre cross sectional area (mCSA) in healthy adults. This could partially be due to the activation and integration of muscle satellite cells (SC) resulting in myonuclei addition. Consequently, this study investigated the effect of 12-weeks lower limb low-load BFR resistance training in sIBM patients on SC and myonuclei content, myofibre size and capillarization. Muscle biopsies from sIBM patients randomised to 12-weeks of low-load BFR resistance training (n = 11) or non-exercising controls (CON) (n = 9) were analysed for SC and myonuclei content, myofibre size and capillarization using three-colour immunofluorescence microscopy and computerised quantification procedures. No between-group differences (time-by-group interactions) or within-groups changes were observed for resident SCs (Pax7/Six1), proliferating SCs (Pax7/ Ki67), myonuclei (Six1), type 1 mCSA or capillary number (CD31). However, a time-by-group interaction for type 2 mCSA was observed (p = 0.04). Satellite cell content, myonuclei number, mCSA and capillary density remained unaffected following 12-weeks low-load BFR resistance training, indicating limited myogenic capacity and satellite cell plasticity in long-term sIBM patients.
散发性包涵体肌炎（sIBM）的特征是骨骼肌炎症、进行性肌肉损失和无力，这在很大程度上对免疫抑制治疗有抗性。低负荷血流限制（BFR）训练已被证明可以在健康成年人中引起肌纤维横截面积（mCSA）的增加。这可能部分是由于肌肉卫星细胞（SC）的激活和整合，导致肌核的增加。因此，本研究调查了 12 周下肢低负荷 BFR 抗阻训练对 sIBM 患者 SC 和肌核含量、肌纤维大小和毛细血管化的影响。将随机分为 12 周低负荷 BFR 抗阻训练（n=11）或不运动对照组（CON）（n=9）的 sIBM 患者的肌肉活检进行分析，使用三色免疫荧光显微镜和计算机化定量程序分析 SC 和肌核含量、肌纤维大小和毛细血管化。未观察到组间差异（时间-组相互作用）或组内变化在驻留的 SC（Pax7/Six1）、增殖的 SC（Pax7/Ki67）、肌核（Six1）、1 型 mCSA 或毛细血管数（CD31）中。然而，观察到 2 型 mCSA 的时间-组交互作用（p=0.04）。12 周低负荷 BFR 抗阻训练后，卫星细胞含量、肌核数、mCSA 和毛细血管密度均无变化，表明长期 sIBM 患者的肌生成能力和卫星细胞可塑性有限。
