title: Microtubules modulate the stiffness of cardiomyocytes against shear stress.
abstract: Although microtubules are involved in various pathological conditions of the heart including hypertrophy and congestive heart failure, the mechanical role of microtubules in cardiomyocytes under such conditions is not well understood. In the present study, we measured multiple aspects of the mechanical properties of single cardiomyocytes, including tensile stiffness, transverse (indentation) stiffness, and shear stiffness in both transverse and longitudinal planes using carbon fiber-based systems and compared these parameters under control, microtubule depolymerized (colchicine treated), and microtubule hyperpolymerized (paclitaxel treated) conditions. From all of these measurements, we found that only the stiffness against shear in the longitudinal plane was modulated by the microtubule cytoskeleton. A simulation model of the myocyte in which microtubules serve as compression-resistant elements successfully reproduced the experimental results. In the complex strain field that living myocytes experience in the body, observed changes in shear stiffness may have a significant influence on the diastolic property of the diseased heart.
authors.affiliation: Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishimura
authors.forename: Shinya
authors.initials: S
authors.lastname: Nagai
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Katoh
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamashita
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Saeki
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Okada
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hisada
authors.forename: Ryozo
authors.initials: R
authors.lastname: Nagai
authors.forename: Seiryo
authors.initials: S
authors.lastname: Sugiura
mesh_terms: D000818:Animals; D006332:Cardiomegaly / Q000503:physiopathology; D003078:Colchicine / Q000494:pharmacology; D006224:Cricetinae; D003599:Cytoskeleton / Q000502:physiology; D005260:Female; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D008297:Male; D008647:Mesocricetus; D008870:Microtubules / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D033081:Shear Strength; D013314:Stress, Mechanical
chemical_list: D003078:Colchicine