title: Structure of the cortical cytoskeleton in fibers of postural muscles and cardiomyocytes of mice after 30-day 2-g centrifugation.
abstract: Altered external mechanical loading during spaceflights causes negative effects on muscular and cardiovascular systems. The aim of the study was estimation of the cortical cytoskeleton statement of the skeletal muscle cells and cardiomyocytes. The state of the cortical cytoskeleton in C57BL6J mice soleus, tibialis anterior muscle fibers, and left ventricle cardiomyocytes was investigated after 30-day 2-g centrifugation ("2-g" group) and within 12 h after its completion ("2-g + 12-h" group). We used atomic force microscopy for estimating cell's transverse stiffness, Western blotting for measuring protein content, and RT-PCR for estimating their expression level. The transverse stiffness significantly decreased in cardiomyocytes (by 16%) and increased in skeletal muscles fibers (by 35% for soleus and by 29% for tibialis anterior muscle fibers) in animals of the 2-g group (compared with the control group). For cardiomyocytes, we found that, in the 2-g + 12-h group, α-actinin-1 content decreased in the membranous fraction (by 27%) and increased in cytoplasmic fraction (by 28%) of proteins (compared with the levels in the 2-g group). But for skeletal muscle fibers, similar changes were noted for α-actinin-4, but not for α-actinin-1. In conclusion, we showed that the different isoforms of α-actinins dissociate from cortical cytoskeleton under increased/decreased of mechanical load.
authors.affiliation: Department of Molecular and Cell Biomedicine, State Scientific Center of Russian Federation Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia; I. M. Sechenov First Moscow State Medical University, Moscow, Russia; iogneva@yandex.ru.
authors.forename: Irina V
authors.identifier: http://orcid.org/0000-0003-0125-5876
authors.initials: IV
authors.lastname: Ogneva
authors.affiliation: INSERM U1059 Lab Biologie Intégrée du Tissu Osseux, Université de Lyon, St. Etienne, France; and.
authors.forename: V
authors.initials: V
authors.lastname: Gnyubkin
authors.affiliation: INSERM U1059 Lab Biologie Intégrée du Tissu Osseux, Université de Lyon, St. Etienne, France; and.
authors.forename: N
authors.initials: N
authors.lastname: Laroche
authors.affiliation: Department of Molecular and Cell Biomedicine, State Scientific Center of Russian Federation Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia; Moscow Institute of Physics and Technology (State University), Moscow, Russia.
authors.forename: M V
authors.initials: MV
authors.lastname: Maximova
authors.affiliation: Department of Molecular and Cell Biomedicine, State Scientific Center of Russian Federation Institute of Biomedical Problems of the Russian Academy of Sciences, Moscow, Russia;
authors.forename: I M
authors.initials: IM
authors.lastname: Larina
authors.affiliation: INSERM U1059 Lab Biologie Intégrée du Tissu Osseux, Université de Lyon, St. Etienne, France; and.
authors.forename: L
authors.initials: L
authors.lastname: Vico
mesh_terms: D000185:Actinin / Q000378:metabolism; D000818:Animals; D002498:Centrifugation / Q000379:methods; D003593:Cytoplasm / Q000378:metabolism / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism / Q000502:physiology*; D006352:Heart Ventricles / Q000378:metabolism / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D018485:Muscle Fibers, Skeletal / Q000378:metabolism / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000502:physiology*; D013026:Space Flight / Q000379:methods
chemical_list: D000185:Actinin
keywords: actin-binding proteins; cell stiffness; hypergravity conditions; mechanoreception; nonmuscle actin