Mechanotransduction Mechanisms for Intraventricular Diastolic Vortex Forcesand Myocardial Deformations: Part 2

摘要

Epigenetic mechanisms are fundamental in cardiac adaptations, remodeling, reverse remodeling, and disease. A primary goal of translational cardiovascular research is recognizing whether disease related changes in phenotype can be averted by eliminating or reducing the effects of environmental epigenetic risks. There may be significant medical benefits in using gene-by-environment interaction knowledge to prevent or reverse organ abnormalities and disease. This survey proposes that “environmental” forces associated with diastolic RV/LV rotatory flows exert important, albeit still unappreciated, epigenetic actions influencing functional and morphological cardiac adaptations. Mechanisms analogous to Murray's law of hydrodynamic shear-induced endothelial cell modulation of vascular geometry are likely to link diastolic vortex-associated shear, torque and “squeeze” forces to RV/LV adaptations. The time has come to explore a new paradigm in which such forces play a fundamental epigenetic role, and to work out how heart cells react to them. Findings are considered from various disciplines, imaging modalities, computational fluid dynamics, molecular cell biology and cytomechanics. Examined are, among others, structural dynamics of myocardial cells (endocardium, cardiomyocytes, and fibroblasts), cytoskeleton, nucleoskeleton, and extracellular matrix, mechanotransduction and signaling, and mechanical epigeneticinfluences on genetic expression. To help integrate and focus relevant pluridisciplinaryresearch, rotatory RV/LV filling flow is placed within a working context that has acytomechanics perspective. This new frontier in contemporary cardiac research shoulduncover versatile mechanistic insights linking filling vortex patterns and attendantforces to variable expressions of gene regulation in RV/LV myocardium. In due course, itshould reveal intrinsic homeostatic arrangements that support ventricular myocardialfunction and adaptability.