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Hoshino, K.

Publications and source records attributed to Hoshino, K..

10 recordsLinked to original sources

Emergent Tissue Rheology in a 3D Mechanically Adaptive Viscoelastic Cell Network Model

We introduce a 3D mechanically adaptive viscoelastic cell-network model that links single-cell interactions to emergent tissue rheology. Unlike existing continuum or cell-based models, viscoelasticity is embedded within discrete, mechanically adaptive intercellular connections, allowing tissue-scale rheology and phenomena such as swirling and jamming to arise from single-cell behaviors and connection remodeling. The framework is motivated by recent advances in three-dimensional imaging and structural analysis that resolve single-cell behaviors within aggregates. It is validated against two gold-standard bulk assays performed on spherical aggregates: micropipette aspiration and Hertzian plate compression. Under aspiration, the model demonstrates a transition from elastic deformation to viscous creep governed by localized packing and emergent jamming at the aspirated neck, accompanied by increased mechanically adaptive remodeling. Under compression, core rheology determines deformation mode: liquid-like aggregates exhibit enhanced swirling, consistent with experimental observations, whereas solid-like aggregates exhibit affine, Poisson-like deformation. These results bridge cell-scale dynamics and quantifiable tissue rheology including elastic modulus and vicosity, providing a framework to interpret emerging 3D measurements of multicellular mechanics.

biophysics↗

Colorectum and Embedded Networks of Nerve Fibers Present Auxetic Responses During Uniaxial Circumferential Extension

Understanding the multiscale mechanics of the colorectum is essential for uncovering the mechanotransductive pathways underlying visceral nociception. Intraluminal distension of the large intestine reliably evokes pain in disorders of gut-brain interaction (DGBIs), yet the tissue-level and nerve fiber-level responses to mechanical loading remain poorly defined. Here, we present results from a novel biomechanical testing framework that integrates uniaxial circumferential extension with high-resolution optical imaging to quantify deformation in both bulk colorectal tissue and embedded sensory nerve fibers. We tested intact, cylindrical colorectal segments from mice using a custom 3-D-printed chamber with intraluminal stainless-steel rods to apply circumferential stretch while maintaining a planar imaging field. We measured bulk-tissue deformation via Digital Image Correlation (DIC), while we assessed stretch in nerve fibers through fluorescence imaging of VGLUT2-labeled afferents analyzed using a custom fiber-network analyses. Across specimens, we observed a consistent auxetic response-characterized by positive axial strain during circumferential extension-at both the macroscale and microscale. Five out of six colorectal specimens exhibited positive axial Green-Lagrange strain (Exx), with an average median Exx of 0.0177, during circumferential extension generating an average median Eyy of 0.1273. Nerve fiber analysis across nine specimens revealed an average median stretch ratio of 1.0631, indicating 6.31% elongation, with substantial heterogeneity driven by fiber orientation. These findings demonstrate that the colorectum and its embedded network of nerve fibers exhibit auxetic behavior, a property that may amplify mechanical signaling and influence nociceptive signaling. Our methods and results provide foundational insight into structure-function relationships of colorectum and inform design of bioinspired auxetic materials.

bioengineering↗

5-axis CNC micro-milling machine for three-dimensional microfluidics

The gold standard of microfluidic fabrication techniques, SU-8 patterning, requires photolithography equipment and facilities and is not suitable for 3D microfluidics. A 3D printer is more convenient and may achieve high resolutions comparable to conventional photolithography, but only with select materials. Alternatively, 5-axis CNC micro-milling machines can efficiently prototype structures with high resolutions, high aspect ratios, and non-planar geometries from a variety of materials. These machines, however, have not been catered for laboratory-based, small-batch microfluidics development and are largely inaccessible to researchers. In this paper, we present a new 5-axis CNC micro-milling machine specifically designed for prototyping 3D microfluidic channels, made affordable for research and laboratories. The machine is assembled from commercially available products and custom-build parts, occupying 0.72 cubic meters, and operating entirely from computer aided design (CAD) and manufacturing (CAM) software. The 5-axis CNC micro-milling machine achieves sub-{micro}m bidirectional repeatability ([&le;]0.23 {micro}m), machinable features <20 {micro}m, and a work volume of 50 x 50 x 68 mm. The tool compatibility and milling parameters were designed to enable fabrication of virtually any mill-able material including metals like aluminum, brass, stainless steel, and titanium alloys. To demonstrate milling high resolution and high aspect ratios, we milled a thin wall from 360 brass with a width of 18.1 {micro}m and an aspect ratio of [~]50:1. We also demonstrated fabricating molds from 360 brass with non-planar geometries to create PDMS microfluidic channels. These included a channel on a 90{degrees} edge and a channel on a rounded edge with a 250-{micro}m radius of curvature. Our 5-axis CNC micro-milling machine offers the most versatility in prototyping microfluidics by enabling high resolutions, geometric complexity, a large work volume, and broad material compatibility, all within a user-friendly benchtop system.

bioengineering↗

Lightsheet microscopy integrates single-cell optical visco-elastography and fluorescence cytometry of 3D live tissues

Most common cytometry methods, including flow cytometry, observe suspended or fixed cells and cannot evaluate their structural roles in 3D tissues. However, cellular physical interactions are critical in physiological, developmental, and pathological processes. Here, we present a novel optical visco-elastography that characterizes single-cellular physical interactions by applying in-situ micro-mechanical perturbation to live microtissues under 3D lightsheet microscopy. The 4D digital image correlation (DIC) analysis of [~]20,000 nodes tracked the compressive deformation of 3D tissues containing [~]500 cells. The computational 3D image segmentation allowed cell-by-cell qualitative observation and statistical analysis, directly correlating multi-channel fluorescence and viscoelasticity. To represent epithelia-stroma interactions, we used a 3D organoid model of maternal-fetal interface and visualized solid-like, well-aligned displacement and liquid-like random motion between individual cells. The statistical analysis through our unique cytometry confirmed that endometrial stromal fibroblasts stiffen in response to decidualization. Moreover, we demonstrated in the 3D model that interaction with placental extravillous trophoblasts partially reverses the attained stiffness, which was supported by the gene expression analysis. Placentation shares critical cellular and molecular significance with various fundamental biological events such as cancer metastasis, wound healing, and gastrulation. Our analysis confirmed existing beliefs and discovered new insights, proving the broad applicability of our method.

bioengineering↗

A stress sensor IRE1α is required for bacterial exotoxin-induced inflammasome activation in tissue-resident macrophages

Cholera toxin (CT), a bacterial exotoxin composed of one A subunit (CTA) and five B subunits (CTB), functions as an immune adjuvant. CTB can induce production of interleukin-1{beta} (IL-1{beta}), a proinflammatory cytokine, in synergy with a lipopolysaccharide (LPS), from resident peritoneal macrophages (RPMs) through the pyrin and NLRP3 inflammasomes. However, how CTB or CT activates these inflammasomes in the macrophages has been unclear. Here, we clarified the roles of IRE1, an endoplasmic reticulum (ER) stress sensor, in CT-induced IL-1{beta} production from RPMs. In RPMs, CTB is incorporated into ER and induced ER stress responses, depending on GM1, a cell membrane ganglioside. IRE1-deficient RPMs showed a significant impairment of CT- or CTB-induced IL-1{beta} production, indicating that IRE1 was required for CT- or CTB-induced IL-1{beta} production from RPMs. This study first demonstrates the critical roles of IRE1 in activation of both NLRP3 and pyrin inflammasomes in tissue-resident macrophages. One sentence summaryIRE1 is required for NLRP3 and pyrin-mediated IL-1{beta} production

immunology↗

Microbiome ssRNA as an environmental cue to activate TLR13-dependent tissue-protective programs in CD5Lhi hepatic macrophages

Hepatic macrophages maintain liver homeostasis, but little is known about the signals that activate the hepatoprotective programs within macrophages. Here, we show that toll-like receptor 13 (TLR13), a sensor of bacterial 23S ribosomal RNA (rRNA), senses microbiome RNAs to drive tissue-protective responses in CD5Lhi hepatic macrophages. Splenomegaly and hepatomegaly developed in the absence of the endosomal RNase, RNaseT2, via TLR13-dependent macrophage proliferation. Furthermore, TLR13 in hepatic Ly6Clo macrophages activated the transcription factors LXR and MafB, leading to expression of tissue-clearance molecules, such as CD5L, C1qb, and Axl. Consequently, Rnaset2-/- mice developed resistance to acute liver injury caused by challenges with acetaminophen and lipopolysaccharide + D-galactosamine. TLR13 responses in Rnaset2-/- mice were impaired by antibiotics, suggesting that TLR13 were activated by microbiome rRNAs, which was detected in the sera and hepatic macrophages. Repeated administration of wild-type mice with the TLR13 ligand, rather than other TLR ligands, selectively increased the number of Kupffer cells, which expressed immunoregulatory and tissue-clearance genes as hepatic macrophages in Rnaset2-/- mice did. Our results suggest that microbiome ssRNA serves as an environmental cue for initiating tissue-protective TLR13 responses in hepatic macrophages. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=192 SRC="FIGDIR/small/540294v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@69614eorg.highwire.dtl.DTLVardef@737c69org.highwire.dtl.DTLVardef@1ecd9eforg.highwire.dtl.DTLVardef@d7e10d_HPS_FORMAT_FIGEXP M_FIG In the absence of an endosomal RNase, RNase T2, microbiome RNAs circulating in the vasculature activate TLR13 in hepatic macrophages to drive hepatoprotective responses through expression of immunoregulatory and tissue-clearance molecules. Consequently, mice lacking RNase T2 are resistant against acute liver injuries caused by acetaminophen and LPS + D-galactosamine. C_FIG

immunology↗

Latent taste diversity revealed by a vertebrate-wide catalogue of T1R receptors

Taste is a vital chemical sense for feeding behavior. In mammals, the umami and sweet taste receptors are composed of three members of the taste receptor type 1 (T1R/TAS1R) family: T1R1, T1R2, and T1R3. Because their functional homologs exist in teleosts, only three TAS1R genes generated by gene duplication are believed to have been inherited from the common ancestor of bony vertebrates. Here, we report five previously uncharacterized TAS1R members in vertebrates, named TAS1R4, 5, 6, 7, and TAS1Rcf, through a genome-wide survey of diverse taxa. For TAS1R2 and TAS1R3, mammalian and teleost fish genes were found to be paralogous. Phylogenetic analysis suggests that the bony vertebrate ancestor had nine TAS1Rs due to multiple gene duplications, and some TAS1Rs were lost independently in each lineage; ultimately, mammals and teleosts have retained only three TAS1Rs, whereas other lineages have retained more TAS1Rs. Functional assays and expression analysis in non-teleost fishes suggest that the novel T1Rs form heterodimers in taste receptor cells and contribute to the recognition of a broad range of ligands such as essential amino acids, including branched-chain amino acids, which were not previously considered as T1R ligands. These results highlight an unexpected diversity of taste sensations in both modern and the ancestors of vertebrates. The complex evolution of the taste receptor family might have enabled vertebrates to adapt to diverse habitats on Earth.

evolutionary biology↗

Imbalance of circuit plasticity and consolidation in autism model marmosets is adjusted by oxytocin administration

Alterations in the experience-dependent and autonomous elaboration of neural circuits are assumed to underlie autism spectrum disorder (ASD), though it is unclear what synaptic traits are responsible. Here, we used a valproic acid-induced ASD marmoset model, which shares common molecular features with idiopathic ASD, to investigate the structural dynamics of tuft dendrites of upper-layer pyramidal neurons and adjacent axons in the dorsomedial prefrontal cortex using two-photon microscopy. In model marmosets, dendritic spine turnover was upregulated, and spines were actively generated in clusters and subsequently survived more often than in control marmosets. Presynaptic boutons in local axons but not in commissural long-range axons showed hyperdynamic turnover in model marmosets, suggesting alterations in projection-specific plasticity. Intriguingly, nasal administration of oxytocin reduced the clustered spine emergence. Enhanced clustered spine generation, possibly unique to certain presynaptic partners, may be associated with ASD and may be a potential therapeutic target.

neuroscience↗

FT-GO: a multiplex fluorescent tyramide signal amplification system for histochemical analysis

Tyramide signal amplification (TSA) is a highly sensitive method for histochemical analysis. Previously, we reported a TSA system, BT-GO, for bright-filed imaging. Here, we develop FT-GO (Fluorochromized Tyramide-Glucose Oxidase) as a multiplex fluorescent TSA system. FT-GO involves peroxidase-catalyzed deposition of FT with hydrogen peroxide produced in enzymatic reaction between glucose and glucose oxidase. We showed that FT-GO enhanced immunofluorescence signals while maintaining low background signals. Compared with indirect immunofluorescence detections, FT-GO demonstrated a more widespread distribution of monoaminergic projection systems in mouse and marmoset brains. For multiplex labeling with FT-GO, we quenched Ab-conjugated peroxidase using sodium azide. We applied FT-GO to multiplex fluorescent in situ hybridization, and succeeded in labeling neocortical interneuron subtypes by coupling with immunofluorescence. FT-GO immunofluorescence further increased the detectability of an adeno-associated virus tracer. Given its simplicity and a staining with a high signal-to-noise ratio, FT-GO would provide a versatile platform for histochemical analysis.

neuroscience↗

Distinct synaptic and related transcriptional abnormalities in neonatal, childhood and mature autism model of primate: implications for early-age therapeutic intervention

Autism spectrum disorder (ASD) is a synapse-related disorder that is diagnosed at around 3 years of age. Earlier intervention is desirable for better ASD prognosis; however, there is limited biological literature regarding early-age ASD. This study aimed to assess altered cortical synapses and gene expression in the ASD model marmoset. There were distinct phenotypes in the model animals across the neonate, childhood, and mature stages in the dorsomedial prefrontal cortex (Brodmann area 8b/9). At the neonate stage, synapses were underdeveloped and modulated genes were enriched with synaptogenesis- and ASD-related genes. At the childhood stage, synaptic features and gene expressions associated with experience-dependent circuit remodeling were altered in model animals. At the mature stage, there were synapse overdevelopment and altered gene expression similar to those in human ASD. These early synaptic phenotypes and altered gene expressions could be novel targets of efficient therapy from a young age.

neuroscience↗