Force transmission by retrograde actin flow-induced dynamic molecular stretching of Talin.

Force transmission at integrin-based adhesions is important for cell migration and mechanosensing. Talin is an essential focal adhesion (FA) protein that links F-actin to integrins. F-actin constantly moves on FAs, yet how Talin simultaneously maintains the connection to F-actin and transmits forces to integrins remains unclear.

KUS121, a VCP modulator, has an ameliorating effect on acute and chronic heart failure without calcium loading via maintenance of intracellular ATP levels.

Aims: As heart failure (HF) progresses, ATP levels in myocardial cells decrease, and myocardial contractility also decreases. Inotropic drugs improve myocardial contractility but increase ATP consumption, leading to poor prognosis. Kyoto University Substance 121 (KUS121) is known to selectively inhibit the ATPase activity of valosin-containing protein, maintain cellular ATP levels, and manifest cytoprotective effects in several pathological conditions.

Force transmission by retrograde actin flow-induced dynamic molecular stretching of Talin.

Force transmission at integrin-based adhesions is important for cell migration and mechanosensing. Talin is an essential focal adhesion (FA) protein that links F-actin to integrins. F-actin constantly moves on FAs, yet how Talin simultaneously maintains the connection to F-actin and transmits forces to integrins remains unclear.

Protocol to generate fast-dissociating recombinant antibody fragments for multiplexed super-resolution microscopy.

Multiplexed high-density label super-resolution microscopy image reconstruction by integrating exchangeable single-molecule localization (IRIS) enables elucidating fine structures and molecular distribution in cells and tissues. However, fast-dissociating binders are required for individual targets. Here, we present a protocol for generating antibody-based IRIS probes from existing antibody sequences.

Scale Space Calibrates Present and Subsequent Spatial Learning in Barnes Maze in Mice.

Animals are capable of representing different scale spaces from smaller to larger ones. However, most laboratory animals live their life in a narrow range of scale spaces like homecages and experimental setups, making it hard to extrapolate the spatial representation and learning process in large scale spaces from those in conventional scale spaces. Here, we developed a 3-m diameter Barnes maze (BM3), then explored whether spatial learning in the Barnes maze (BM) is calibrated by scale spaces.

Microglia-triggered hypoexcitability plasticity of pyramidal neurons in the rat medial prefrontal cortex.

Lipopolysaccharide (LPS), an outer component of Gram-negative bacteria, induces a strong response of innate immunity via microglia, which triggers a modulation of the intrinsic excitability of neurons. However, it is unclear whether the modulation of neurophysiological properties is similar among neurons. Here, we found the hypoexcitability of layer 5 (L5) pyramidal neurons after exposure to LPS in the medial prefrontal cortex (mPFC) of juvenile rats.

Tuberous Sclerosis Complex (TSC) Inactivation Increases Neuronal Network Activity by Enhancing Ca Influx via L-Type Ca Channels.

Tuberous sclerosis complex (TSC) is a multisystem developmental disorder characterized by hamartomas in various organs, such as the brain, lungs, and kidneys. Epilepsy, along with autism and intellectual disability, is one of the neurologic impairments associated with TSC that has an intimate relationship with developmental outcomes and quality of life. Sustained activation of the mammalian target of rapamycin (mTOR) via or mutations is known to be involved in the onset of epilepsy in TSC.

Oscillatory expression of Ascl1 in oligodendrogenesis.

The proneural gene Ascl1 promotes formation of both neurons and oligodendrocytes from neural stem cells (NSCs), but it remains to be analyzed how its different functions are coordinated. It was previously shown that Ascl1 enhances proliferation of NSCs when its expression oscillates but induces differentiation into transit-amplifying precursor cells and neurons when its expression is up-regulated and sustained. By time-lapse imaging and immunohistological analyses, we found that Ascl1 expression oscillated in proliferating oligodendrocyte precursor cells (OPCs) at lower levels than in transit-amplifying precursor cells and was repressed when OPCs differentiated into mature oligodendrocytes.

Paradoxical activation of c-Src as a drug-resistant mechanism.

ATP-competitive inhibitors have been developed as promising anti-cancer agents. However, drug-resistance frequently occurs, and the underlying mechanisms are not fully understood. Here, we show that the activation of c-Src and its downstream phosphorylation cascade can be paradoxically induced by Src-targeted and RTK-targeted kinase inhibitors.

Hop flower extracts mitigate retinal ganglion cell degeneration in a glaucoma mouse model.

In glaucoma, retinal ganglion cells degenerate progressively, leading to visual field loss and blindness. Presently, the only treatment strategy for glaucoma is lowering the intraocular pressure. However, there are cases in which patients develop progressive visual field loss even though their intraocular pressures are within normal ranges.

The significance of gene expression dynamics in neural stem cell regulation.

Neural stem cells (NSCs) actively proliferate and generate neurons and glial cells (active state) in the embryonic brain, whereas they are mostly dormant (quiescent state) in the adult brain. The expression dynamics of Hes1 are different between active and quiescent NSCs. In active NSCs, Hes1 expression oscillates and periodically represses the expression of proneural genes such as Ascl1, thereby driving their oscillations.

Effect of VCP modulators on gene expression profiles of retinal ganglion cells in an acute injury mouse model.

In glaucoma, retinal ganglion cells are damaged, leading to the progressive constriction of the visual field. We have previously shown that the valosin-containing protein (VCP) modulators, Kyoto University Substance (KUS)121 and KUS187, prevent the death of retinal ganglion cells in animal models of glaucoma, including the one generated by N-methyl-D-aspartate (NMDA)-induced neurotoxicity. KUSs appeared to avert endoplasmic reticulum (ER) stress by maintaining ATP levels, resulting in the protection of ganglion cells from cell death.

Safety and effectiveness of a novel neuroprotectant, KUS121, in patients with non-arteritic central retinal artery occlusion: An open-label, non-randomized, first-in-humans, phase 1/2 trial.

Kyoto University Substance (KUS) 121, an ATPase inhibitor of valosin-containing protein, is a novel neuroprotectant. We tested the safety and effectiveness of KUS121 in patients with acute central retinal artery occlusion (CRAO). We conducted an investigator-initiated, first-in-humans, phase 1/2 clinical trial.

C-Type Natriuretic Peptide Restores Growth Impairment Under Enzyme Replacement in Mice With Mucopolysaccharidosis VII.

Growth impairment in mucopolysaccharidoses (MPSs) is an unresolved issue as it is resistant to enzyme replacement therapy (ERT) and growth hormone therapy. C-type natriuretic peptide (CNP) is a promising agent that has growth-promoting effects. Here we investigate the effects of CNP on growth impairment of MPSs using Gusbmps-2J mice, a model for MPS type VII, with combination therapy of CNP and ERT by hydrodynamic gene delivery.

mDia1/3-dependent actin polymerization spatiotemporally controls LAT phosphorylation by Zap70 at the immune synapse.

The mechanism by which the cytosolic protein Zap70 physically interacts with and phosphorylates its substrate, the transmembrane protein LAT, upon T cell receptor (TCR) stimulation remains largely obscure. In this study, we found that the pharmacological inhibition of formins, a major class of actin nucleators, suppressed LAT phosphorylation by Zap70, despite TCR stimulation-dependent phosphorylation of Zap70 remaining intact. High-resolution imaging and three-dimensional image reconstruction revealed that localization of phosphorylated Zap70 to the immune synapse (IS) and subsequent LAT phosphorylation are critically dependent on formin-mediated actin polymerization.

Real-time Bioluminescence Imaging of Notch Signaling Dynamics during Murine Neurogenesis.

Notch signaling regulates the maintenance of neural stem/progenitor cells by cell-cell interactions. The components of Notch signaling exhibit dynamic expression. Notch signaling effector Hes1 and the Notch ligand Delta-like1 (Dll1) are expressed in an oscillatory manner in neural stem/progenitor cells.

Cardioprotective Effects of VCP Modulator KUS121 in Murine and Porcine Models of Myocardial Infarction.

No effective treatment is yet available to reduce infarct size and improve clinical outcomes after acute myocardial infarction by enhancing early reperfusion therapy using primary percutaneous coronary intervention. The study showed that Kyoto University Substance 121 (KUS121) reduced endoplasmic reticulum stress, maintained adenosine triphosphate levels, and ameliorated the infarct size in a murine cardiac ischemia and reperfusion injury model. The study confirmed the cardioprotective effect of KUS121 in a porcine ischemia and reperfusion injury model.

Lamellipodium tip actin barbed ends serve as a force sensor.

Cells change direction of migration by sensing rigidity of environment and traction force, yet its underlying mechanism is unclear. Here, we show that tip actin barbed ends serve as an active "force sensor" at the leading edge. We established a method to visualize intracellular single-molecule fluorescent actin through an elastic culture substrate.

Regulation of active and quiescent somatic stem cells by Notch signaling.

Somatic stem/progenitor cells actively proliferate and give rise to different types of mature cells (active state) in embryonic tissues while they are mostly dormant (quiescent state) in many adult tissues. Notch signaling is known to regulate both active and quiescent states of somatic stem cells, but how it regulates these different states is unknown. Recent studies revealed that the Notch effector Hes1 is expressed differently during the active and quiescent states during neurogenesis and myogenesis: high in the quiescent state and oscillatory in the active state.

RECK in Neural Precursor Cells Plays a Critical Role in Mouse Forebrain Angiogenesis.

RECK in neural precursor cells (NPCs) was previously found to support Notch-dependent neurogenesis in mice. On the other hand, recent studies implicate RECK in endothelial cells (ECs) in WNT7-triggered canonical WNT signaling essential for brain angiogenesis. Here we report that RECK in NPCs is also critical for brain angiogenesis.

KUS121, a valosin-containing protein modulator, attenuates ischemic stroke via preventing ATP depletion.

Reduced adenosine triphosphate (ATP) levels in ischemic stroke constitute an upstream contributor to neuronal cell death. We have recently created a small chemical, named Kyoto University Substance 121 (KUS121), which can reduce cellular ATP consumption. In this study, we examined whether KUS121 has neuroprotective effects in rodent cerebral ischemia models.