Biology subjects

Yamaguchi, Y.

Publications and source records attributed to Yamaguchi, Y..

At least 19 recordsLinked to original sources

bioRxiv2026

A thermoregulatory design principle for transitions into hypometabolism

Mammals entering torpor or hibernation undergo an abrupt transition from normothermia to hypothermia, yet how thermoregulation enables this switch remains poorly understood. Here, we identify dynamical signatures that precede these transitions and a mathematical principle that can generate them. In fasting-induced torpor in mice, body-temperature fluctuations increased before torpor onset, providing an early-warning signal that tracked proximity to the transition better than temperature decline alone. A heat-balance model showed that reducing how strongly the effective heat-loss coefficient depends on body temperature reorganizes thermoregulatory stability, allowing a low-temperature equilibrium to emerge while the normothermic state remains stable. This organization is consistent with a symmetry-broken pitchfork involving a saddle-node. Similar increases in temperature fluctuations preceded hibernation onset in hamsters. These findings link pre-transition temperature dynamics to changes in the underlying thermoregulatory landscape and provide a framework for detecting and understanding transitions from normothermia to hypothermia.

systems biology↗

bioRxiv2026

A single-nucleus and spatial transcriptomic atlas of the Syrian hamster preoptic area across hibernation states

Hibernation is an extreme physiological state in certain mammals that is characterized by a reversible reduction in metabolic and thermogenic demands. Although the preoptic area has been implicated in the regulation of hibernation, comprehensive molecular and spatial resources for this brain region in hibernating mammals remain limited. Here, we present an integrated transcriptomic resource of the preoptic area generated using single-nucleus RNA sequencing (snRNA-seq) and Xenium-based spatial transcriptomics in a mammalian hibernator, Syrian hamster. The resource includes cross-species transcriptomic annotations relative to mouse preoptic area datasets, seasonal snRNA-seq datasets obtained under non-hibernating and hibernating conditions, and spatially resolved cell-type annotations generated from Xenium profiling. Together, these datasets provide a reference framework for identifying neuronal populations, examining molecular conservation across species and conditions, and integrating transcriptomic identity with spatial organization.

neuroscience↗

bioRxiv2026

Radioligand therapy in combination with CAR T cells overcomes the heterogeneous immunosuppressive prostate tumor microenvironment

177Lu-PSMA-617 (PluvictoTM, Lu-177 RLT) is an FDA-approved targeted radioligand therapy (RLT) for metastatic castration-resistant prostate cancer (mCRPC), but its durability of response to this singular approach poses a challenge to the field. Chimeric antigen receptor (CAR) T cell therapy has revolutionized clinical practice for hematological malignancies, but its clinical development for solid tumors, including mCRPC, has been encumbered by antigen heterogeneity and the immunosuppressive tumor microenvironment (TME). Here, we evaluate the therapeutic combination of Lu-177 RLT and PSCA-CAR T cells to overcome these barriers. In human xenograft and mouse syngeneic prostate cancer models with homogeneous or heterogeneous antigen expression, the sequential administration of Lu-177 RLT, cyclophosphamide (Cy), and PSCA-CAR T cells improves tumor control and prolongs survival compared to monotherapies. Mechanistically, Lu-177 RLT alone or with Cy remodels the TME by promoting pro-inflammatory myeloid responses and activating endogenous T cells, while enhancing CAR T cell activation and effector function. We additionally evaluated 225Ac-PSMA-617 RLT as an emerging approach in combination with CAR T cells and observed anti-tumor responses, supporting its potential as an alternative RLT partner. These findings support RLT as an immune priming strategy to enhance CAR T cell therapy and provide a rationale for clinical translation of this combination in mCRPC. One Sentence SummaryCombining 177Lu-PSMA-617 radioligand therapy with PSCA-CAR T cells improves tumor control and survival in prostate cancer models by overcoming the antigen heterogeneity and reshaping the immunosuppressive tumor microenvironment.

cancer biology↗

bioRxiv2026

Focal radiotherapy improves CAR T cell therapy targeting prostate cancer

Chimeric antigen receptor (CAR) T cell therapy has limited efficacy against solid tumors such as prostate cancer due to the immunosuppressive tumor microenvironment (TME). Combining CAR T cells with existing therapies that remodel the TME and promote endogenous immune responses, such as radiation therapy and chemotherapies, may strengthen antitumor responses. Here, we assessed the potency of combining focal radiotherapy (RT), cyclophosphamide (Cy) preconditioning, and prostate stem cell antigen (PSCA)-CAR T cells against syngeneic prostate cancer models. Focal RT alone increased T cell and dendritic cell infiltration and activation in the irradiated tumor. Furthermore, the combination of all three therapies was critical for enhanced antitumor responses and survival across multiple subcutaneous, bone-metastatic, and multifocal disease models. This combination, in the irradiated TME and tumor-draining lymph nodes (tdLN), led to greater antigen presentation by myeloid cells and endogenous T cell activation and cytotoxicity. Our study demonstrates the potency of combining focal RT with PSCA-CAR T cells, significantly improving therapeutic responses in the irradiated tumor and contributing to a more robust systemic immune response against metastatic burden in prostate cancer.

Cancer Biology↗

bioRxiv2026

Visualization of neuronal morphology of the suprachiasmatic nucleus vasopressin neurons by Cre/FLPe-based genetic two-step sparse labelling - GT-SPARCL

Resolving the morphology of individual neurons in densely packed brain regions remains challenging. Sparse labeling is essential for delineating cellular architecture, yet achieving reproducible low-density labeling e.g. < 1% has been a persistent technical hurdle/problem. We present a genetically encoded two-step strategy, GT-SPARCL (Genetic Two-Step Sparse Cre/FLPe Combination Labeling), which leverages two independent stochastic recombination events to deliver stable, tunable low-density labeling in mice. As a proof of concept, we applied this method to visualizing arginine vasopressin (AVP) neurons in the suprachiasmatic nucleus (SCN), the master circadian pacemaker composed of [~]10,000 neurons per side in mice. Using two-photon imaging of whole-mount SCN blocks, we reconstructed individual AVP neurons and uncovered previously under-resolved morphological heterogeneity. Based on axonal trajectories, we distinguished five structural types, including subclasses with commissural projections to the contralateral SCN and others extending projections beyond the nucleus. The majority ([~]70%) exhibited projections both within and outside the ipsilateral SCN, whereas the second most dominant subset ([~]20%) projected exclusively outside the SCN, representing an output-biased type. In contrast, neurons projecting exclusively within the ipsilateral SCN were exceptionally rare, suggesting that "dedicated" local-circuit AVP neurons do not form a major structural subtype. Collectively, our data indicate that AVP neurons are not structurally uniform but instead comprise diverse projection-defined subtypes, implying subtype-depen-dent contributions to intra-SCN communication, bilateral coupling, and circadian output. Beyond the SCN, our GT-SPARCL method may be applicable for achieving low-density labelling of neurons that can be defined by other specific Cre mouse lines.

neuroscience↗

bioRxiv2026

A preoptic circuit triggers rewarming from torpor

Torpor is an adaptive hypometabolic state that enables homeotherm to survive periods of energetic challenge. This strategy ranges from short bouts of daily torpor to prolonged hibernation. During torpor, animals markedly suppress metabolic rate, body temperature, heart rate, and respiration, while retaining the ability to rewarm. Torpor therefore comprises two critical transitions -entry into a hypometabolic state and active rewarming-both essential for organismal viability. Although neural mechanisms controlling torpor entry have begun to emerge, the circuits that initiate active rewarming and restore euthermia remain poorly defined. Here we identify corticotropin-releasing hormone (Crh)-expressing neurons in the anterodorsal preoptic area (ADP) as a key population for rewarming from fasting-induced torpor in mice. These neurons become active around natural rewarming and are selectively required to limit the depth and duration of torpor. Unlike pathways mediating acute cold defence, stress hyperthermia, or LPS-induced fever, this circuit is dedicated to promoting timely recovery to euthermia. Closed-loop optogenetic activation of ADPCrh neurons during torpor entry rapidly initiates rewarming, and thermographic recordings show that brown adipose tissue (BAT) thermogenesis precedes locomotor arousal. ADPCrh neurons are predominantly GABAergic and project monosynaptically to the lateral preoptic area, whose terminal activation is sufficient to increase body temperature and locomotor activity. Finally, we find robust activation of ADPCrh neurons during rewarming in a hibernator, suggesting conserved logic for exiting deep torpor. Together, our results define a discrete preoptic circuit that drives recovery from torpor and provide a framework for understanding and potentially controlling timely rewarming from profound hypothermia.

neuroscience↗

bioRxiv2026

IL12-engineered human PSMA-CAR T cells for the treatment of advanced prostate cancer

Adoptive cell therapies used to treat advanced prostate cancer are being developed to target several tumor-associated antigens, including prostate-specific membrane antigen (PSMA). Chimeric antigen receptor (CAR) T cell therapy using the single chain variable fragment (scFv) derived from the humanized murine mAb clone, J591, as the antigen-binding domain has shown promising anti-tumor activity. However, it has also been associated with macrophage activation syndrome and other unwanted toxicities, highlighting the need for more specific and human-derived antigen-binders with optimized construct designs for improved safety and efficacy. Here, we optimize a human scFv-based PSMA-targeted CAR (hPSMA-CAR) with highly selective PSMA targeting. We further introduce a membrane-bound IL-12 (mbIL12) molecule, which enhances potency with increased T cell expansion, IFNy production and anti-tumor cell activity in vitro. Using two clinically-relevant bone-metastatic prostate cancer models, we show that mbIL12-engineered hPSMA-CAR T cells drive potent in vivo anti-tumor responses. In summary, we have developed a promising therapeutic that has potential to promote safe and effective treatment of advanced PSMA+ prostate cancer.

bioengineering↗

bioRxiv2025

TMEM2 maintains hyaluronan turnover and cartilage homeostasis during early osteoarthritis progression

Osteoarthritis (OA) is a degenerative joint disease characterized by progressive disruption of the cartilage extracellular matrix (ECM), yet the molecular mechanisms governing ECM turnover during disease initiation remain incompletely defined. Hyaluronan (HA) is a major structural component of articular cartilage, and its regulated turnover is essential for maintaining tissue integrity. Transmembrane protein 2 (TMEM2) is a cell-surface hyaluronidase capable of degrading high-molecular weight HA under physiological conditions, but its role in joint tissues has remained unclear. Here, we examine the spatiotemporal expression and functional contribution of TMEM2 in articular cartilage using single-cell transcriptomic analysis, histological approaches, and a chondrocyte-specific conditional knockout mouse model. Under physiological conditions, Tmem2 was predominantly expressed in non-calcified articular chondrocytes. Following joint destabilization, Tmem2 expression was transiently increased during early osteoarthritis, coinciding with reduced cartilage HA content, consistent with altered HA turnover. Importantly, genetic ablation of Tmem2 in chondrocytes markedly exacerbated osteoarthritis progression, resulting in accelerated cartilage delamination, increased chondrocyte apoptosis, reduced proliferative activity, and enhanced hypertrophic differentiation. These changes occurred without detectable abnormalities in the synovium, subchondral bone, or osteophyte formation, indicating a cartilage-intrinsic phenotype. Collectively, these findings identify TMEM2 as an important regulator of hyaluronan homeostasis within the cartilage ECM and provide in vivo genetic evidence that TMEM2- dependent HA turnover contributes to the maintenance of articular cartilage integrity during osteoarthritis progression.

molecular biology↗

bioRxiv2025

Genome-wide and gene expression analyses of the hagfish olfactory receptors illuminate lineage-specific diversification of olfaction in basal vertebrates

Olfactory receptors (ORs) of vertebrates have undergone remarkable diversification, but the ancestral repertoire remains incompletely understood. Here, we present a comprehensive genome-wide survey and gene expression analyses of OR genes in hagfish, a cyclostome group that typically inhabits the deep sea with a well-developed olfactory system. We identified 48 main olfactory receptors (mORs), two vomeronasal type 1 receptors (V1Rs), 135 typical vomeronasal type 2 receptors (V2Rs), and no trace amine-associated receptors (TAARs) in the inshore hagfish (Eptatretus burgeri). Notably, V2Rs were highly clustered on a single scaffold, suggesting tandem gene duplications as the main mechanism of diversification. Transcriptome analysis confirmed that most of these OR genes are expressed predominantly in the olfactory organ. Using in situ hybridization, we further confirmed that at least some of these genes are expressed in olfactory receptor cells. These gene expression analyses support the role of these genes as functional ORs. Our findings challenge the prevailing view that typical olfactory V2Rs originated in gnathostomes and instead suggest that they were present in the common ancestor of all vertebrates but were lost in lampreys. The extensive diversification of V2Rs in hagfish likely reflects adaptations to life in low-light and chemically complex environments. This study highlights the evolution of vertebrate sensory systems in a mosaic manner, underscoring the importance of hagfish as a key animal for reconstructing the evolutionary history of early vertebrates. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/666228v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@ba336borg.highwire.dtl.DTLVardef@85b62corg.highwire.dtl.DTLVardef@7b23ccorg.highwire.dtl.DTLVardef@6b2b74_HPS_FORMAT_FIGEXP M_FIG C_FIG Highlights- Genomic and expression analyses reveal hagfish olfactory receptor repertoire. - V2Rs are extensively diversified in hagfish. - The olfactory function of V2Rs is traced back to the common ancestor of vertebrates. - The olfactory receptor repertoires of basal vertebrates underwent mosaic evolution.

evolutionary biology↗

bioRxiv2025

Cold-induced suppression of myogenesis in skeletal muscle stem cells contributes to delayed muscle regeneration during hibernation

Mammalian hibernators experience profound cold stress and prolonged physical inactivity during torpor periods; however, it is unclear how skeletal muscle stem cells (satellite cells; SCs) respond to these challenges. In this study, we demonstrate that SCs from a mammalian hibernator, Syrian hamster exhibit remarkable resistance to cold-induced cell death, which is associated with intrinsically higher expression of the antioxidant enzyme GPX4, which likely contributes to the suppression of ferroptosis. RNA-seq analysis revealed widespread downregulation of myogenesis-related genes following cold exposure, which suggests suppression of the myogenic program. Consistently, SCs exposed to cold stress exhibited reduced activation and differentiation capacities upon subsequent rewarming, with an increased number of quiescent Pax7-positive/MyoD-negative cells. Muscle regeneration was markedly delayed during hibernation, accompanied by decreased SC activation and macrophage infiltration, suggesting that cold-induced suppression of SC function underlies limited regenerative capacity in hibernating hamsters. Our results provide insight into the unique physiology of mammalian hibernators: SC viability is preserved, whereas regenerative activity is selectively suppressed during hibernation.

physiology↗

bioRxiv2025

Proteinase 3 is involved in presepsin production through neutrophil extracellular trap phagocytosis by macrophages

Presepsin (P-SEP), a soluble subtype of CD14, has been widely reported as a useful biomarker for sepsis in clinical studies. However, the cytological mechanism underlying its production remains poorly understood. Previous research has demonstrated that P-SEP is generated when M1 macrophages (M1 M{Phi}s) phagocytose neutrophil extracellular traps (NETs) and degrade internalized CD14. In this study, we demonstrated that M1 M{Phi}s phagocytose NETs and that proteinase 3 (PR3) within M1 M{Phi}s degrades NET-derived CD14, resulting in the production of P-SEP. Furthermore, we observed a strong correlation between the amount of NETs and P-SEP levels, indicating that NET phagocytosis is a key process in P-SEP generation. Our findings also suggest that PR3 released extracellularly along with NETs may degrade CD14 in plasma, contributing to elevated P-SEP levels. This mechanism may contribute to increased P-SEP concentrations observed in autoimmune diseases associated with NET accumulation, proposing P-SEP as a potential biomarker of disease activity beyond sepsis.

cell biology↗

bioRxiv2025

Chronic social defeat causes dysregulation of systemic glucose metabolism via the cerebellar fastigial nucleus

Chronic psychological stress leads to hyperglycemia through the endocrine and sympathetic nervous systems, which contributes to the development of type II diabetes mellitus (T2DM). Higher plasma corticosteroids after stress is one well-established driver of insulin resistance in peripheral tissues. However, previous studies have indicated that only a fraction of patients with depression and post-traumatic disorder (PTSD) who develop T2DM exhibit hypocortisolism, so corticosteroids do not fully explain psychological stress-induced T2DM. Here, we find that chronic social defeat stress (CSDS) in mice enhances gluconeogenesis, which is accompanied by a decrease in plasma insulin, an increase in plasma catecholamines, and a drop in plasma corticosterone levels. We further reveal that these metabolic and endocrinological changes are mediated by the activation of neurons projecting from the cerebellar fastigial nucleus (FN) to the medullary parasolitary nucleus (PSol). These neurons are crucial in shifting the bodys primary energy source from glucose to lipids. Additionally, data from patients with depression reveal correlations between the presence of cerebellar abnormalities and both worsening depressive symptoms and elevated HbA1c levels. These findings highlight a previously unappreciated role of the cerebellum in metabolic regulation and its importance as a potential therapeutic target in depression, PTSD, and similar psychological disorders.

neuroscience↗

bioRxiv2024

Tools of Hibernation Measurement and Interpretation (TOHMIN) for quantifying various values from body temperature fluctuation during hibernation

Hibernation is a fascinating physiological phenomenon that dramatically reduces basal metabolism and thermogenesis, resulting in a large deviation in body temperature (Tb) from homeothermic ranges in mammals. Although high-resolution long-term Tb recording in wild or laboratory animals has become possible through data loggers, few standardized methods to analyze details of hibernation patterns are available, making it difficult to reproduce and compare the results across different studies and species. To facilitate the analysis of hibernation patterns and accelerate hibernation research, we developed an open-source program, tools of hibernation measurement and interpretation (TOHMIN). As a proof of concept, we analyzed a dataset from two pilot studies on (1) the effects of distinct diets on hibernation patterns and (2) differences in hibernation patterns between males and females in a mammalian hibernator, Syrian hamster (Mesocricetus auratus), and found previously undetectable fine-scale differences in hibernation patterns. First, different types of diets affected the duration of periodic arousal. Second, females maintained higher body temperatures during periodic arousal than males. Third, the duration of the pre-hibernation period was negatively correlated with the hibernation period for this species. Thus, TOHMIN accelerates studies to assess the effects of various experimental manipulations on hibernation phenotypes in mammals.

physiology↗

bioRxiv2024

Engineered coagulation factor VIII with enhanced secretion and coagulation potential for hemophilia A gene therapy

The major challenges of gene therapy for hemophilia A using adeno-associated virus (AAV) vectors are reducing vector doses and the long-term maintenance of stable factor VIII (FVIII). Here, we developed engineered human B-domain-deleted FVIIIs (FVIIISQs) with enhanced secretion and coagulation potential. Intracellular accumulation was markedly reduced in some engineered FVIIISQs, resulting in reduced unfolded protein responses. The administration of AAV vectors carrying engineered FVIIISQ to hemophilia A mice resulted in approximately eight-fold higher FVIII activity and four-fold higher FVIII antigen levels compared with wild-type FVIIISQ administration. The specific FVIII activity of the engineered FVIIISQ was 3.6 times higher than that of the wild-type FVIIISQ, and its binding to activated coagulation factor IX was significantly enhanced, which is supported by the structural analysis. In macaques, the administration of AAV5 vector carrying the engineered FVIIISQ without CpG sequences resulted in a supra-physiological increase in plasma FVIII activity at a dose one-thirtieth that of valoctocogene roxaparvovec (2 x 1012 vg/kg). The engineered FVIIISQ may thus provide stable, long-term therapeutic efficacy in AAV-mediated hemophilia A gene therapy even at low doses.

bioengineering↗

bioRxiv2024

Key role of P230 in the hinge region on the IgG architecture and function

Immunoglobulin G (IgG) is a molecule that plays an important role in biological defense; IgG molecules have been applied as drugs due to their high specificity for antigens and their ability to activate immunity via effector molecules on immune cells. On the other hand, the flexibility of the hinge region makes it difficult to apply conventional structural biology approaches due to its dynamic conformational changes, and the mechanism of action of the molecule as a whole has not been elucidated. Here, we introduced a deletion amino acid mutation in the hinge region to elucidate the role of the hinge region and its effect on the structure and function of the IgG molecule. Deletion of Pro230 resulted in the formation of a half-molecular in which the interaction between heavy chains was lost. We elucidated the mechanism of half-IgG formation by structural analysis using nuclear magnetic resonance (NMR) measurements and by disulfide quantification using peptide mapping using LC-MS/MS. For this purpose, a new NMR stable isotope labeling method was introduced. Finally, cell assay revealed that the IgG half-molecules have specific Fc{gamma}RI-mediated activity. This report provides new insights into the higher-order structure formation of IgG molecules and is expected to contribute to the elucidation of the molecular basis of the Fc{gamma} receptor-mediated activation mechanism of the immune system.

biophysics↗

bioRxiv2023

Identification of genes supporting cold resistance of mammalian cells: lessons from a hibernator

Susceptibility of human cells to cold stress restricts the use of therapeutic hypothermia and long-term preservation of organs at low temperatures. In contrast, cells of mammalian hibernators possess remarkable cold resistance, but little is known about the molecular mechanisms underlying this phenomenon. In this study, we conducted a gain-of-function screening of genes that confer cold resistance to cold-vulnerable human cells using a cDNA library constructed from the Syrian hamster, a mammalian hibernator, and identified Gpx4 as a potent suppressor of cold-induced cell death. Additionally, genetic or pharmacological inhibition of Gpx4 in a hamster cell line under prolonged cold culture led to cell death, which resembles ferroptosis characterized by accumulation of lipid peroxide and ferrous iron dependency. Genetic disruption of other ferroptosis-suppressing pathways, namely biopterin synthesis and mitochondrial or plasma membrane CoQ reduction pathways, accelerated cold-induced cell death under Gpx4 dysfunction. Collectively, ferroptosis-suppressing pathways protect the cells of a mammalian hibernator from cold-induced cell death and the augmentation of these pathways renders cold resistance to cells of non-hibernators, including humans.

cell biology↗

bioRxiv2023

Membrane mechanics dictate axonal morphology and function

Axons are thought to be ultrathin membrane cables of a relatively uniform diameter, designed to conduct electrical signals, or action potentials. Here, we demonstrate that unmyelinated axons are not simple cylindrical tubes. Rather, axons have nanoscopic boutons repeatedly along their length interspersed with a thin cable with a diameter of [~]60 nm like pearls-on-a-string. These boutons are only [~]200 nm in diameter and do not have synaptic contacts or a cluster of synaptic vesicles, hence non-synaptic. Our in silico modeling suggests that axon pearling can be explained by the mechanical properties of the membrane including the bending modulus and tension. Consistent with modeling predictions, treatments that disrupt these parameters like hyper- or hypo-tonic solutions, cholesterol removal, and non-muscle myosin II inhibition all alter the degree of axon pearling, suggesting that axon morphology is indeed determined by the membrane mechanics. Intriguingly, neuronal activity modulates the cholesterol level of plasma membrane, leading to shrinkage of axon pearls. Consequently, the conduction velocity of action potentials becomes slower. These data reveal that biophysical forces dictate axon morphology and function and that modulation of membrane mechanics likely underlies plasticity of unmyelinated axons.

neuroscience↗

bioRxiv2023

DNA methylation signature in NSD2 loss-of-function variants appeared similar to that in Wolf-Hirschhorn syndrome

PurposeWolf-Hirschhorn syndrome (WHS), a contiguous gene syndrome caused by the hemizygous deletion of the distal short arm of chromosome 4 where NSD2 is, reportedly exhibits specific DNA methylation signatures in peripheral blood cells. However, responsible genomic loci for signatures are unreported. The objective of the study is to define the loci of WHS-related DNA methylation signatures and to explore the role of NSD2 for the signatures. MethodsWe conducted genome-wide methylation analysis of individuals with WHS or NSD2 variants using array. We studied genome-edited knock in mice or induced pluripotent stem cells to explore the function of NSD2 variants which are observed in congenital anomaly cases. ResultsThree undiagnosed cases with NSD2 variants showed WHS-related DNA methylation signatures. These variants were validated to be NSD2 loss-of-function in induced pluripotent stem cells or genome-edited knock-in mice. p.Pro905Leu variant decreased Nsd2 protein levels, and changed Histone H3-Lysine 36 demethylation levels in similar way in the same genomic regions as Nsd2 knock out mice regulated. Nsd2 knock out mice exhibited common DNA methylation changes. ConclusionThese results revealed that WHS-related DNA methylation signatures are dependent on NSD2 dysfunction and are useful in diagnosing NSD2 variants of unknown significance.

genetics↗