Coordinated linear and rotational movements of endothelial cells compartmentalized by VE-cadherin drive angiogenic sprouting.

Angiogenesis is a sequential process to extend new blood vessels from preexisting ones by sprouting and branching. During angiogenesis, endothelial cells (ECs) exhibit inhomogeneous multicellular behaviors referred to as "cell mixing," in which ECs repetitively exchange their relative positions, but the underlying mechanism remains elusive. Here we identified the coordinated linear and rotational movements potentiated by cell-cell contact as drivers of sprouting angiogenesis using and approaches.

Persistent homological cell tracking technology.

In this paper, we develop a cell tracking method based on persistent homological figure detection technology. We apply our tracking method to 9 different time-series cell images and extract several kinds of cell movements. Being able to analyze various images with a single method allows researchers to systematically understand and compare different tracking data.

PERK-Mediated Suppression of microRNAs by Sildenafil Improves Mitochondrial Dysfunction in Heart Failure.

Oxidative/nitrosative stress is a major trigger of cardiac dysfunction, involving the unfolded protein response and mitochondrial dysfunction. Activation of nitric oxide-cyclic guanosine monophosphate-protein kinase G signaling by sildenafil improves cardiac mal-remodeling during pressure-overload-induced heart failure. Transcriptome analysis was conducted in failing hearts with or without sildenafil treatment.

Cohesive and anisotropic vascular endothelial cell motility driving angiogenic morphogenesis.

Vascular endothelial cells (ECs) in angiogenesis exhibit inhomogeneous collective migration called "cell mixing", in which cells change their relative positions by overtaking each other. However, how such complex EC dynamics lead to the formation of highly ordered branching structures remains largely unknown. To uncover hidden laws of integration driving angiogenic morphogenesis, we analyzed EC behaviors in an in vitro angiogenic sprouting assay using mouse aortic explants in combination with mathematical modeling.

In vivo myosin step-size from zebrafish skeletal muscle.

Muscle myosins transduce ATP free energy into actin displacement to power contraction. In vivo, myosin side chains are modified post-translationally under native conditions, potentially impacting function. Single myosin detection provides the 'bottom-up' myosin characterization probing basic mechanisms without ambiguities inherent to ensemble observation.

In vivo orientation of single myosin lever arms in zebrafish skeletal muscle.

Cardiac and skeletal myosin assembled in the muscle lattice power contraction by transducing ATP free energy into the mechanical work of moving actin. Myosin catalytic/lever-arm domains comprise the transduction/mechanical coupling machinery that move actin by lever-arm rotation. In vivo, myosin is crowded and constrained by the fiber lattice as side chains are mutated and otherwise modified under normal, diseased, or aging conditions that collectively define the native myosin environment.

Nonlinear photocurrent with a threshold of excitation density induced by the long-range electron-electron interaction in the charge-ordered molecular conductor (BEDT-TTF)3(ClO4)2.

We investigated a photoexcited state in the molecular conductor (BEDT-TTF)3(ClO4)2 (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) with charge localization due to the electron-electron Coulomb interaction. Photocurrent induced by intramolecular excitation was observed in a charge-ordered insulating state. As a result, nonlinear photocurrent with a threshold of excitation light density was experimentally obtained.

Lattice distortion stabilizes the photoinduced metallic phase in the charge-ordered organic salts (BEDT-TTF)3X2 (X=ReO4, ClO4).

Photoinduced effects caused by intramolecular excitation were investigated by simultaneous optical and transport measurement in two charge-ordered organic salts, (BEDT-TTF)3X2 (X=ReO4, ClO4) [BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene]. Although the two salts have the same molecular (average) charge and arrangement, they showed different photoinduced effects. A photoinduced insulator-to-metal phase transition with a metastable charge order-melting state was observed in the ReO4 salt where the charge ordered state is associated with the lattice distortion.

Nonuniversal nature of dynamic critical anomaly in polymer solutions.

Critical anomaly of viscosity has been studied for ideal polymer solutions, focusing on its dependence on the molecular weight of polymer M(w). According to the conventional understanding that polymer solutions should belong to the same dynamic universal class as classical fluids, the critical exponent of viscosity y(c) should be a universal constant (approximately 0.04).