scholarly journals Interpolated twitches in fatiguing single mouse muscle fibres: implications for the assessment of central fatigue

2008 ◽  
Vol 586 (11) ◽  
pp. 2799-2805 ◽  
Author(s):  
Nicolas Place ◽  
Takashi Yamada ◽  
Joseph D. Bruton ◽  
Håkan Westerblad
1990 ◽  
Vol 240 (1297) ◽  
pp. 197-210 ◽  

Immunolabelling with a 5 nm gold probe was used to localize dystrophin at the ultrastructural level in human muscle. The primary antibody was monoclonal, raised against a segment (amino acids 1181-1388) from the rod domain of dystrophin. The antibody (Dy4/6D3) is specific for dystrophin and shows no immunoreactivity with any protein from mdx mouse muscle or from patients with a gene deletion spanning part of the molecule recognized by the antibody (Nicholson et al . 1989 a ; England et al . 1990). Using this antibody, labelling was almost entirely confined to a narrow 75 nm rim at the periphery of the muscle fibres. Histograms of the distance from the gold probe to the cytoplasmic face of the plasma membrane and of the distance between gold probes (nearest neighbour in a plane parallel with the plasma membrane) displayed modes at approximately 15 nm and 120 nm, respectively. The distribution of the probe was the same in longitudinal and transverse sections of the muscle. These observations suggest that the rod portion of the dystrophin mole­cule is normally arranged close to the cytoplasmic face of the plasma membrane and that the molecules form an interconnecting network. Labelling was not associated with the transverse tubular system.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Jacob A. Ross ◽  
Hichem Tasfaout ◽  
Yotam Levy ◽  
Jennifer Morgan ◽  
Belinda S. Cowling ◽  
...  

Abstract X-linked myotubular myopathy (XLMTM) is a life-threatening skeletal muscle disease caused by mutations in the MTM1 gene. XLMTM fibres display a population of nuclei mispositioned in the centre. In the present study, we aimed to explore whether positioning and overall distribution of nuclei affects cellular organization and contractile function, thereby contributing to muscle weakness in this disease. We also assessed whether gene therapy alters nuclear arrangement and function. We used tissue from human patients and animal models, including XLMTM dogs that had received increasing doses of recombinant AAV8 vector restoring MTM1 expression (rAAV8-cMTM1). We then used single isolated muscle fibres to analyze nuclear organization and contractile function. In addition to the expected mislocalization of nuclei in the centre of muscle fibres, a novel form of nuclear mispositioning was observed: irregular spacing between those located at the fibre periphery, and an overall increased number of nuclei, leading to dramatically smaller and inconsistent myonuclear domains. Nuclear mislocalization was associated with decreases in global nuclear synthetic activity, contractile protein content and intrinsic myofilament force production. A contractile deficit originating at the myofilaments, rather than mechanical interference by centrally positioned nuclei, was supported by experiments in regenerated mouse muscle. Systemic administration of rAAV8-cMTM1 at doses higher than 2.5 × 1013 vg kg−1 allowed a full rescue of all these cellular defects in XLMTM dogs. Altogether, these findings identify previously unrecognized pathological mechanisms in human and animal XLMTM, associated with myonuclear defects and contractile filament function. These defects can be reversed by gene therapy restoring MTM1 expression in dogs with XLMTM.


2019 ◽  
Vol 597 (7) ◽  
pp. 1993-2006 ◽  
Author(s):  
Laura Gerwin ◽  
Corinna Haupt ◽  
Katherine A. Wilkinson ◽  
Stephan Kröger

2014 ◽  
Vol 592 (9) ◽  
pp. 2003-2012 ◽  
Author(s):  
Joachim Nielsen ◽  
Arthur J. Cheng ◽  
Niels Ørtenblad ◽  
Håkan Westerblad

2013 ◽  
Vol 591 (15) ◽  
pp. 3739-3748 ◽  
Author(s):  
Arthur J. Cheng ◽  
Nicolas Place ◽  
Joseph D. Bruton ◽  
Hans-Christer Holmberg ◽  
Håkan Westerblad

2006 ◽  
Vol 91 (4) ◽  
pp. 781-789 ◽  
Author(s):  
Erik P. Rader ◽  
Wook Song ◽  
Holly Van Remmen ◽  
Arlan Richardson ◽  
John A. Faulkner
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document