title: Morphological adaptation and protein modulation of myotendinous junction following moderate aerobic training.
abstract: Myotendinous junction is the muscle-tendon interface through which the contractile force can be transferred from myofibrils to the tendon extracellular matrix. At the ultrastructural level, aerobic training can modify the distal myotendinous junction of rat gastrocnemius, increasing the contact area between tissues. The aim of this work is to investigate the correlation between morphological changes and protein modulation of the myotendinous junction following moderate training. For this reason, talin, vinculin and type IV collagen amount and spatial distribution were investigated by immunohistochemistry and confocal microscopy. The images were then digitally analyzed by evaluating fluorescence intensity. Morphometric analysis revealed a significant increased thickening of muscle basal lamina in the trained group (53.1 ± 0.4 nm) with respect to the control group (43.9 ± 0.3 nm), and morphological observation showed the presence of an electron-dense area in the exercised muscles, close to the myotendinous junction. Protein concentrations appeared significantly increased in the trained group (talin +22.2%; vinculin +22.8% and type IV collagen +11.8%) with respect to the control group. Therefore, our findings suggest that moderate aerobic training induces/causes morphological changes at the myotendinous junction, correlated to the synthesis of structural proteins of the muscular basal lamina and of the cytoskeleton.
authors.affiliation: University of Urbino, Department of Earth, Life and Environmental Sciences, Urbino, Italy. davide.curzi@uniurb.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Curzi
authors.affiliation: University of Urbino, Department of Earth, Life and Environmental Sciences, Urbino, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Baldassarri
authors.affiliation: University of Urbino, Department of Biomolecular Sciences, Urbino, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: De Matteis
authors.affiliation: Laboratory of Pre-clinic and Surgical Studies, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Salamanna
authors.affiliation: University of Bologna, Department of Experimental, Diagnostic, and Specialty Medicine, Bologna, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bolotta
authors.affiliation: University of Padova, Department of Rehabilitation Medicine, Padova, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Frizziero
authors.affiliation: Laboratory of Pre-clinic and Surgical Studies, Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.affiliation: University of Bologna, Department of Experimental, Diagnostic, and Specialty Medicine, Bologna, and Center of Sports Medicine, Don Gnocchi Foundation, IRCCS, Milano, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Marini
authors.affiliation: University of Urbino, Department of Earth, Life and Environmental Sciences, Urbino, and CNR, Molecular Genetics Institute and Rizzoli Orthopaedic Institute, Bologna, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Falcieri
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D024141:Collagen Type IV / Q000096:biosynthesis; D003599:Cytoskeleton / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D016608:Talin / Q000096:biosynthesis; D013710:Tendons / Q000378:metabolism*; D016596:Vinculin / Q000096:biosynthesis
chemical_list: D024141:Collagen Type IV; D016608:Talin; D016596:Vinculin