Photoresponsive Adenosine Derivatives for the Optical Control of Adenosine A Receptors in Living Cells.

The use of photoresponsive ligands to optically control proteins of interest, known as photopharmacology, is a powerful technique for elucidating cellular function in living cells and animals with a high spatiotemporal resolution. The adenosine A receptor (AR) is a G protein-coupled receptor that is expressed in various tissues; its dysregulation is implicated in severe diseases such as insomnia and Parkinson's disease. A detailed elucidation of the physiological function of AR is, therefore, highly desirable.

Crystal structure reveals the binding mode and selectivity of a photoswitchable ligand for the adenosine A receptor.

Rational synthetic expansion of photoresponsive ligands is important for photopharmacological studies. Adenosine A receptor (AR) is stimulated by adenosine and related in Parkinson's disease and other diseases. Here, we report the crystal structure of the AR in complex with the novel photoresponsive ligand photoNECA (blue) at 3.

[Next-Generation Chemogenetics for Elucidating Higher Brain Functions].

To understand higher brain function, we need to understand the cellular function in a cell-type-specific manner. In recent decades, cell manipulation techniques termed chemogenetics (e.g.

Coordination chemogenetics for activation of GPCR-type glutamate receptors in brain tissue.

Direct activation of cell-surface receptors is highly desirable for elucidating their physiological roles. A potential approach for cell-type-specific activation of a receptor subtype is chemogenetics, in which both point mutagenesis of the receptors and designed ligands are used. However, ligand-binding properties are affected in most cases.

Chemogenetics of cell surface receptors: beyond genetic and pharmacological approaches.

Cell surface receptors transmit extracellular information into cells. Spatiotemporal regulation of receptor signaling is crucial for cellular functions, and dysregulation of signaling causes various diseases. Thus, it is highly desired to control receptor functions with high spatial and/or temporal resolution.

Orthogonal Activation of Metabotropic Glutamate Receptor Using Coordination Chemogenetics.

Cell-surface receptors play a pivotal role as transducers of extracellular input. Although different cell types express the same receptor, the physiological roles of the receptor are highly dependent on cell type. To understand each role, tactics for cell-specific activation of the target receptor are in high demand.

Tethering-based chemogenetic approaches for the modulation of protein function in live cells.

Proteins are the workhorse molecules performing various tasks to sustain life. To investigate the roles of a protein under physiological conditions, the rapid modulation of the protein with high specificity in a living system would be ideal, but achieving this is often challenging. To address this challenge, researchers have developed chemogenetic strategies for the rapid and selective modulation of protein function in live cells.

Ligand-directed two-step labeling to quantify neuronal glutamate receptor trafficking.

The regulation of glutamate receptor localization is critical for development and synaptic plasticity in the central nervous system. Conventional biochemical and molecular biological approaches have been widely used to analyze glutamate receptor trafficking, especially for α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate-type glutamate receptors (AMPARs). However, conflicting findings have been reported because of a lack of useful tools for analyzing endogenous AMPARs.

Selective acetylcholinesterase inhibitors derived from muscle relaxant dantrolene.

Dantrolene, the only therapeutic agent for malignant hyperthermia, is known to have not only a muscle relaxant effect, but also a neuroprotective effect and Alzheimer's disease improving effect. Recently, it has been reported that dantrolene has a weak inhibitory effect on acetylcholinesterase (AChE), which is a therapeutic drug target for Alzheimer's disease. Thus, we focused on developing of AChE inhibitors with benzylpiperidine/piperazine moieties that are based on the dantrolene skeleton.

Hybrid cell reactor system from Escherichia coli protoplast cells and arrayed lipid bilayer chamber device.

We developed a novel hybrid cell reactor system via functional fusion of single Escherichia coli protoplast cells, that are deficient in cell wall and expose plasma membrane, with arrayed lipid bilayer chambers on a device in order to incorporate the full set of cytosolic and membrane constituents into the artificial chambers. We investigated gene expression activity to represent the viability of the hybrid cell reactors: over 20% of hybrid cells showed gene expression activity from plasmid or mRNA. This suggests that the hybrid cell reactors retained fundamental activity of genetic information transduction.

Miniaturization of thiol-organosilica nanoparticles induced by an anionic surfactant.

Thiol-organosilica nanoparticles are a promising nanomaterial for biomedical applications. The enhanced permeability and retention (EPR) effect is useful for tumor targeting within the biomedical applications of nanomaterials, and nanomaterials with a size of less than 200 nm exhibit the maximum EPR effect. However, the synthesis of thiol-organosilica nanoparticles with a diameter of less than 200 nm is not efficient for the yield using the present conventional synthetic methods.

Combretastatin A4-β-Galactosyl Conjugates for Ovarian Cancer Prodrug Monotherapy.

Chemotherapy for ovarian cancer often causes severe side effects. As candidates for combretastatin A4 (CA4) prodrug for ovarian cancer prodrug monotherapy (PMT), we designed and synthesized two β-galactose-conjugated CA4s (CA4-βGals), CA4-βGal-1 and CA4-βGal-2. CA4 was liberated from CA4-βGals by β-galactosidase, an enzyme more strongly expressed in ovarian cancer cells than normal cells.

Detection of LacZ-Positive Cells in Living Tissue with Single-Cell Resolution.

The LacZ gene, which encodes Escherichia coli β-galactosidase, is widely used as a marker for cells with targeted gene expression or disruption. However, it has been difficult to detect lacZ-positive cells in living organisms or tissues at single-cell resolution, limiting the utility of existing lacZ reporters. Herein we present a newly developed fluorogenic β-galactosidase substrate suitable for labeling live cells in culture, as well as in living tissues.

PAMAM Dendron Lipid Assemblies That Undergo Structural Transition in Response to Weakly Acidic pH and Their Cytoplasmic Delivery Capability.

Dendron lipids designed to consist of amine-terminated polyamidoamine G1 dendron and two octadecyl chains were used for the preparation of pH-responsive molecular assemblies having phase structures that are changed through their dynamic molecular shape. The dendron lipid contains two primary amines and two tertiary amines in the dendron moiety, changing its charged state in the pH region between pH 10 and pH 4. The assemblies were shown to take a vesicle structure at neutral and alkaline pHs, but their structure changed to a micelle-like structure below pH 6.

Phenylboronic acid-based (19)F MRI probe for the detection and imaging of hydrogen peroxide utilizing its large chemical-shift change.

Herein, we report on a new (19)F MRI probe for the detection and imaging of H2O2. Our designed 2-fluorophenylboronic acid-based (19)F probe promptly reacted with H2O2 to produce 2-fluorophenol via boronic acid oxidation. The accompanying (19)F chemical-shift change reached 31 ppm under our experimental conditions.

An adhesive (19)F MRI chemical probe allows signal off-to-on-type molecular sensing in a biological environment.

We report a new strategy for designing a signal off-to-on-type (19)F MRI chemical probe that operates in biological environments. The present strategy is based on the control of adherence of a (19)F MRI chemical probe to certain blood proteins, accompanied by a change in transverse relaxation time of (19)F nuclei.

A platform for designing hyperpolarized magnetic resonance chemical probes.

Hyperpolarization is a highly promising technique for improving the sensitivity of magnetic resonance chemical probes. Here we report [(15)N, D(9)]trimethylphenylammonium as a platform for designing a variety of hyperpolarized magnetic resonance chemical probes. The platform structure shows a remarkably long (15)N spin-lattice relaxation value (816 s, 14.

Atom arrangement strategy for designing a turn-on 1H magnetic resonance probe: a dual activatable probe for multimodal detection of hypochlorite.

The first dual activatable hypochlorite ((-)OCl)-sensing probe was developed, based on a new proof-of-concept design involving signal-activatable (1)H chemical probes using the triple-resonance NMR technique. The probe enabled fluorescence-(1)H MR dual turn-on detection of (-)OCl in solution and in crude tissue extracts.