Direction-dependent contributions of cardiac myofilament networks to myocardial passive stiffness reveal a major disparity for titin.

ABSTRACT: Progressive myocardial dysfunction in patients with heart failure often involves alterations in myocardial passive stiffness, yet the underlying mechanisms remain incompletely understood. While passive stiffness in the longitudinal direction has been extensively characterized via uniaxial tensile stretching of cardiac specimens, transverse stiffness has received far less attention despite its equal mechanical importance. In this study, we combined atomic force microscopy nanoindentation with stretching assays on myocardial preparations to quantify the relative contributions of the three myofilament networks - actin, myosin, and titin - to passive stiffness in both transverse and longitudinal orientations. We employed a transgenic mouse model in which titin's elastic springs contain a tobac

SUBMITTER: Wagner FA 

PROVIDER: S-EPMC12325546 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature