TY - JOUR
T1 - Lack of muscle stem cell proliferation and myocellular hypertrophy in sIBM patients following blood-flow restricted resistance training
AU - Jensen, Kasper Yde
AU - Nielsen, Jakob Lindberg
AU - Schrøder, Henrik Daa
AU - Jacobsen, Mikkel
AU - Boyle, Eleanor
AU - Jørgensen, Anders Nørkær
AU - Bech, Rune Dueholm
AU - Frandsen, Ulrik
AU - Aagaard, Per
AU - Diederichsen, Louise Pyndt
N1 - Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.
PY - 2022/6
Y1 - 2022/6
N2 - 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.
AB - 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.
KW - Adult
KW - Cell Proliferation
KW - Exercise/physiology
KW - Homeodomain Proteins/metabolism
KW - Humans
KW - Hypertrophy/pathology
KW - Muscle, Skeletal/blood supply
KW - Myositis, Inclusion Body/metabolism
KW - Resistance Training/methods
KW - Satellite Cells, Skeletal Muscle
U2 - 10.1016/j.nmd.2022.04.006
DO - 10.1016/j.nmd.2022.04.006
M3 - Article
C2 - 35595645
SN - 0960-8966
VL - 32
SP - 493
EP - 502
JO - Neuromuscular Disorders
JF - Neuromuscular Disorders
IS - 6
ER -