title: Breaking sarcomeres by in vitro exercise.
abstract: Eccentric exercise leads to focal disruptions in the myofibrils, referred to as "lesions". These structures are thought to contribute to the post-exercise muscle weakness, and to represent areas of mechanical damage and/or remodelling. Lesions have been investigated in human biopsies and animal samples after exercise. However, this approach does not examine the mechanisms behind lesion formation, or their behaviour during contraction. To circumvent this, we used electrical pulse stimulation (EPS) to simulate exercise in C2C12 myotubes, combined with live microscopy. EPS application led to the formation of sarcomeric lesions in the myotubes, resembling those seen in exercised mice, increasing in number with the time of application or stimulation intensity. Furthermore, transfection with an EGFP-tagged version of the lesion and Z-disc marker filamin-C allowed us to observe the formation of lesions using live cell imaging. Finally, using the same technique we studied the behaviour of these structures during contraction, and observed them to be passively stretching. This passive behaviour supports the hypothesis that lesions contribute to the post-exercise muscle weakness, protecting against further damage. We conclude that EPS can be reliably used as a model for the induction and study of sarcomeric lesions in myotubes in vitro.
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Zacharias
authors.initials: Z
authors.lastname: Orfanos
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Markus P O
authors.initials: MP
authors.lastname: Gödderz
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Soroka
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Gödderz
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Rumyantseva
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Peter F M
authors.initials: PF
authors.lastname: van der Ven
authors.affiliation: Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, L8N 3Z5, Canada.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hawke
authors.affiliation: Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
authors.forename: Dieter O
authors.initials: DO
authors.lastname: Fürst
mesh_terms: D000818:Animals; D001706:Biopsy; D006801:Humans; D051379:Mice; D009119:Muscle Contraction / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000503:physiopathology / Q000648:ultrastructure*; D010805:Physical Conditioning, Animal; D012518:Sarcomeres / Q000473:pathology / Q000502:physiology / Q000648:ultrastructure*