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Matsuzaki, T.

Publications and source records attributed to Matsuzaki, T..

15 recordsLinked to original sources

Interactome-based deep learning and path-level decomposition reveal TGFβ-IFNα competition in MASH

Dysregulated signaling drives Metabolic Dysfunction-Associated Steatohepatitis (MASH) through a complex crosstalk between pro- and anti-fibrotic cues. We previously observed potential competition between IFN-mediated JAK-STAT signaling and TGF{beta} in modulating MASH fibrosis, but the precise mechanism of that competition, and whether it can act directly on hepatocytes, is yet unknown. We used DT-LEMBAS, an interactome-based deep learning framework, training an ensemble of 50 models on drug-induced transcriptomics from primary human hepatocytes. The ensemble captured transcriptional changes induced by simulated receptor knockouts and aligned predicted profiles with known TGF{beta}- and IFN-induced phenotypes. Systematic simulations demonstrate their competitive modulation of MASH phenotype scores benchmarked against human cohorts. To extract mechanistic insights, we developed a gradient-based approach, where we computed the Jacobian of the used recurrent signaling network and applied chain rule decomposition to identify a four-node module of SMAD3, TP63, STAT2, and STAT3. Mechanistic hypotheses involving these canonical and non-canonical TF mediators were experimentally validated in primary hepatocyte spheroids. This work establishes a generalizable and scalable approach to decode large signaling neural networks into interpretable biological subnetworks.

systems biology↗

A bivalent Lassa virus mRNA vaccine protects guinea pigs from lethal infection with Lassa virus

Lassa virus (LASV), the causative agent of the life-threatening febrile disease, Lassa fever, remains a major public health concern in West Africa, where hundreds of thousands of infections occur annually. However, no licensed vaccine is currently available, highlighting the urgent need for effective preventive measures. We previously demonstrated that an mRNA-lipid nanoparticle (LNP) vaccine expressing LASV glycoprotein precursor (GPC; LASgpc-mRNA-LNP) conferred protection against lethal infection with a recombinant lymphocytic choriomeningitis virus expressing LASV GPC in mice. In this study, we extended our previous work with the aim of evaluating the efficacy of an mRNA-LNP vaccine expressing LASV nucleoprotein (NP; LASnp-mRNA-LNP) and a bivalent vaccine combining LASgpc-mRNA-LNP and LASnp-mRNA-LNP. Using a lethal CBA/N mouse model of infection with ML29, an LASV live-attenuated vaccine candidate encoding LASV GPC and NP, we found that LASgpc-mRNA-LNP and LASnp-mRNA-LNP each conferred protection in the absence of detectable neutralizing antibody responses. We identified LASV GPC- and NP-derived CD4 and CD8 T-cell epitope peptides in CBA/N mice and demonstrated that vaccination induced robust antigen-specific T-cell responses. Importantly, the bivalent vaccine provided complete protection against lethal challenge with doses at which monovalent vaccines failed to protect all mice, suggesting a potential dose-sparing benefit of the bivalent formulation. Furthermore, the bivalent vaccine fully protected guinea pigs against lethal challenge with authentic LASV. Together, these findings establish LASV NP, in addition to GPC, as a protective antigen in the mRNA vaccine platform and provide a rationale for developing bivalent mRNA-LNP vaccines to improve protection against Lassa fever.

microbiology↗

Developmental emergence of spatiotemporal coordination in cerebellar Purkinje cell populations

Coordinated activity across neuronal populations is fundamental to brain function, yet how such network-level organization emerges during development remains incompletely understood. Here, we performed whole-cerebellar calcium imaging at cellular scale in zebrafish larvae to examine the developmental maturation of Purkinje cell population dynamics. Visual stimulation recruited large, spatially organized populations of Purkinje cells whose responses depended on inferior olive input and were associated with optokinetic behavior. Notably, in the absence of stimuli, Purkinje cells formed transient assemblies exhibiting distance-dependent coordination. During development, long-range coordination progressively emerged, extending initially local correlations into distributed population-wide coordination. Early enucleation, but not dark rearing, disrupted the developmental refinement of long-range coordination and induced aberrant population clustering, suggesting that early retina-dependent signals contribute to cerebellar network development. Together, these findings reveal key organizational features underlying the developmental emergence of coordinated cerebellar population dynamics and suggest that early retina-dependent signals shape population-level organization.

neuroscience↗

Rapid in vitro platform for functional analysis of maternal effect genes during mouse oocyte growth

Understanding the functions of maternal effect genes during oocyte growth is essential for elucidating the mechanisms of oogenesis and early embryonic development. However, conventional gene knockout and conditional knockout approaches require extensive breeding and are time-consuming. Here, we present a rapid in vitro gene functional analysis system that combines microinjection of mRNA, siRNA and plasmid DNA into mouse secondary follicles with a two-step oocyte growth culture system. Mouse secondary follicles were subjected to microinjection of mCherry mRNA and subsequently cultured for 15 days to produce fully grown oocytes. mCherry fluorescence persisted throughout the oocyte growth period but declined rapidly after fertilization. Despite minor cellular damage occasionally caused by microinjection, injected follicles developed normally and retained developmental competence. To evaluate the efficiency of gene suppression, we introduced siRNA targeting Dnmt3l, which is abundantly expressed during oocyte growth phase. Although Dnmt3l deficiency is known not to affect oocyte growth, we observed that oocyte growth was maintained normally despite a marked reduction in endogenous Dnmt3l mRNA levels in our knockdown model. These results demonstrate that this method enables efficient manipulation of gene expression specifically during oocyte growth while preserving developmental competence, providing a versatile platform for rapid functional screening of maternal effect genes in vitro.

developmental biology↗

Pathological Angiogenesis Precedes the Onset of Aortic Dissection

Aortic dissection (AD) is a severe, life-threatening disease that occurs abruptly1. Although remodeling and inherent vulnerability of the aortic media, as observed in heritable connective tissue disorders such as Marfan syndrome, have been implicated in the onset of AD, the precise pathological mechanisms underlying the non-heritable form, which accounts for most cases, remains largely unknown2. Here, using hyperacute AD patient-derived samples, we show that pathological angiogenesis within the aortic media precedes the onset of dissection. Integrating single-cell transcriptomic analysis of aortic medial endothelial cells with high-resolution imaging revealed temporal changes preceding dissection. Hypoxic alterations in the media triggered osteochondrogenic changes in smooth muscle cells, promoted hydroxyapatite deposition, and induced angiogenesis via VEGF secretion from AD-specific CD14+CD68+CD163+MRC1(CD206)neg-low macrophages. Atomic force microscopy revealed that these processes culminated in the formation of a soft capillary layer, potentially concentrating stress on this region and contributing to AD onset. H&E staining of archived specimens revealed that non-heritable AD can be classified into angiogenic or non-angiogenic subtypes, with more than half exhibiting the former. In contrast, acute AD cases associated with Marfan syndrome typically exhibit a non-angiogenic pattern, suggesting distinct underlying mechanisms. This study reports angiogenesis as a key pathological driver in non-heritable AD and highlight potential targets for early diagnosis, prevention, and treatment.

pathology↗

Cortical excitatory and inhibitory neuron deficits may underlie the cognitive and social impairments in a mouse model of schizophrenia with exonic Reln deletion

Reelin is an essential extracellular matrix glycoprotein involved in the formation of cortical layers and has been associated with several neuropsychiatric conditions, such as schizophrenia (SCZ). To explore its role in brain function and its potential involvement in SCZ, we developed a Reln heterozygous deletion (Relndel/+) mouse model that mimics a genetic deletion observed in a Japanese patient with SCZ. In previous studies, we demonstrated that Relndel/+ mice exhibit cognitive impairments in a visual discrimination test. Here, we found that Relndel/+ mice displayed impairments in social novelty recognition, while social preference remained intact. Immunohistochemical analyses revealed a significant decrease in the numbers of calcium/calmodulin-dependent protein kinase II (CaMKII)-positive glutamatergic pyramidal neurons, gamma-aminobutyric acid (GABA)-ergic interneurons, and parvalbumin (PV)-positive interneurons in the medial prefrontal cortex (mPFC) of Relndel/+ mice. Furthermore, Relndel/+ mice exhibited significant deficits in excitatory spine density and morphology, as well as a decrease number of PV boutons in the mPFC compared to wild-type (WT) mice. Finally, we demonstrated that injection of AAV-R36-Myc virus into the mPFC can improve social novelty impairments in Relndel/+ mice, but no effects on WT control. These findings indicate that Relndel/+ mice could be a valuable model for exploring the neurobiological mechanisms underlying cognitive and social impairments in SCZ. Futhermore, our results with AAV-R36-Myc also suggest the therapeutic potential of Reelin replacement, warranting further investigation as a possible treatment strategy for SCZ. HighlightsO_LIReelin deficiency disrupts social novelty, but not social preference, in Relndel/+ mice C_LIO_LIRelndel/+ mice serve as a novel model to investigate impairments of neuronal mechanisms on schizophrenia C_LIO_LIAAV-R36-myc injection rescues social novelty deficits in Relndel/+ mice C_LIO_LIReelin replacement therapy is a potential treatment for schizophrenia C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=143 HEIGHT=200 SRC="FIGDIR/small/666057v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@1f4921aorg.highwire.dtl.DTLVardef@1a41b33org.highwire.dtl.DTLVardef@f5f2bcorg.highwire.dtl.DTLVardef@1134d8d_HPS_FORMAT_FIGEXP M_FIG C_FIG

animal behavior and cognition↗

Twinfilin-1 phosphorylation in reelin signaling regulates actin dynamics and spine development

Reelin is an extracellular glycoprotein essential for neuronal migration, spine development, and synaptic plasticity. Impaired reelin signaling is linked to neurological disorders, including schizophrenia and autism. While reelin mutant (reeler) mice exhibit behavioral deficits associated with impaired spine formation, the underlying molecular mechanisms remain unclear. We identified Twinfilin-1 (Twf1) as a downstream effector of reelin signaling via phosphoproteomic analysis, based on its reduced tyrosine phosphorylation in reeler mice. We found that Src regulated Twf1 phosphorylation at tyrosine 309, and reelin stimulation increased Twf1 phosphorylation in neurons, an effect blocked by the Src inhibitor PP2. A phospho-resistant Twf1 mutant (Twf1 Y309F) showed reduced capping protein binding and a lower F/G-actin ratio. Twf1Y309F mice exhibited cognitive deficits, reduced spine density, smaller spine head size, and a decreased F/G-actin ratio in synaptosomes. These findings highlight Twf1 phosphorylation as a key component of reelin signaling involved in actin remodeling and spine development.

neuroscience↗

Antipsychotic-like effects of the selective Rho-kinase 2 inhibitor KD025 in genetic and pharmacological mouse models of schizophrenia

1Copy number variations in the ARHGAP10 gene encoding Rho GTPase-activating protein 10 are significantly associated with schizophrenia. ARHGAP10 negatively regulates RhoA/Rho-kinase (ROCK) signaling. We previously demonstrated that fasudil, a non-selective ROCK inhibitor, exhibited antipsychotic-like effects in several mouse models of schizophrenia. ROCK has two subtypes, ROCK1 and ROCK2. ROCK1 is mainly expressed in the thymus and blood, while ROCK2 is predominantly expressed in the brain. Therefore, it is expected that like fasudil, selective ROCK2 inhibitors will exhibit antipsychotic-like effects, accompanied by a lower incidence of adverse effects due to ROCK1 inhibition. Here, we used genetic and pharmacological models of schizophrenia to investigate whether the selective ROCK2 inhibitor KD025 would show antipsychotic-like effects with a favorable adverse effect profile. Oral administration of KD025 suppressed the abnormal increase in the phosphorylation level of myosin phosphatase-targeting subunit 1, a substrate of ROCK, and ameliorated the decreased spine density of layer 2/3 pyramidal neurons in the medial prefrontal cortex of Arhgap10 S490P/NHEJ mice. Furthermore, KD025 mitigated the methamphetamine-induced impairment of visual discrimination (VD) in Arhgap10 S490P/NHEJ and wild-type mice. KD025 also reduced MK-801-induced impairments of VD, novel object recognition, and hyperlocomotion. Regarding side effects that are commonly seen with typical antipsychotics, KD025 did not affect systolic blood pressure and did not induce extrapyramidal symptoms, hyperprolactinemia, or hyperglycemia at the effective dosage in naive wild-type mice. Taken together, KD025 shows antipsychotic-like effects with a favorable adverse effect profile in genetic and pharmacological mouse models of schizophrenia.

pharmacology and toxicology↗

A simple immunohistochemical method for perinatal mammalian ovaries revealed different kinetics of oocyte apoptosis caused by DNA damage and asynapsis.

Oocytes having meiotic defects are assumed to be eliminated by apoptosis in perinatal period. However, the oocyte apoptosis caused by meiotic defects has not been well analyzed, partly due to the great technical demands for tissue sectioning of perinatal ovaries. In the present study, we applied a squash method for immunohistochemical analysis of perinatal mouse ovaries as a substitute for tissue sectioning. As a result, we could show different kinetics of apoptosis caused by DMC1- and SPO11-deficiencies, indicating that DNA damage-induced apoptosis precedes asynapsis-induced apoptosis in mouse oocytes. Double mutant analysis revealed that only asynapsis-induced apoptosis was significantly dependent on HORMAD2. The present method is simple, easy, and able to analyze a sufficient number of oocytes for detecting infrequent events in a single specimen, accelerating detailed immunohistochemical analyses of mammalian ovaries during the fetal and perinatal periods.

developmental biology↗

Transcriptional drift in aging cells: A global de-controller

As cells age, they undergo a remarkable global change: In transcriptional drift, hundreds of genes become overexpressed while hundreds of others become underexpressed. Using archetype modeling and Gene Ontology analysis on data from aging Caenorhabditis elegans worms, we find that the upregulated genes code for sensory proteins upstream of stress responses and downregulated genes are growth- and metabolism-related. We propose a simple mechanistic model for how such global coordination of multi-protein expression levels may be achieved by the binding of a single ligand that concentrates with age. A key implication is that a cells own responses are part of its aging process, so unlike for wear-and-tear processes, intervention might be able to modulate these effects.

biophysics↗

Engineered Active Zymogen of Microbial Transglutaminase

Microbial transglutaminase (MTG) has shown to be a powerful biocatalytic glue for site-specific crosslinking of a range of biomolecules and synthetic molecules, those handled with an MTG-reactive moiety. The preparation of active recombinant MTG requires the posttranslational proteolytic digestion of propeptide working as an intramolecular chaperon to assist the correct folding of MTG zymogen (MTGz) in the biosynthesis. Herein, we propose an engineered active zymogen of MTG (EzMTG) that is expressed as soluble form in the host E. coli cytosol and exhibits the cross-linking activity without limited proteolysis. Based on the 3D structure of MTGz and serendipitous findings, saturated mutagenesis of K10 or Y12 in propeptide domain leads to generate several active MTGz mutants. In particular, K10D/Y12G mutant exhibited the catalytic activity comparable with a mature form. However, the expression level was low possibly due to the reduction of chaperone activity and/or the promiscuous substrate specificity of MTG, which is potentially harmful to the host cells. By contrast, soluble K10R/Y12A mutant is expressed in the cytosol of host E. coli and exhibited unique substrate-dependent reactivity toward peptidyl substrates. The quantitative analysis of the binding affinity of mutated propeptide to the active site suggested the trade-off relationship of EzMTGs between the binding affinity and the catalytic activity. Our proof-of-concept study provides insights into the design of a new biocatalyst by using the zymogen as a scaffold and will convey a potential route to the high-throughput screening of MTG mutants for bioconjugation applications.

biochemistry↗

A novel plasmid-based experimental system in Saccharomyces cerevisiae that enables the introduction of 10 different plasmids into cells

The budding yeast Saccharomyces cerevisiae is commonly used as an expression platform to produce valuable compounds. Yeast-based genetics research can uniquely utilize use auxotrophy in transformant selection: auxotrophic complementation by an auxotrophic marker gene on exogenous DNA (such as plasmids). However, the number of auxotrophic nutrients required restricts the number of plasmids maintained by the cells. We therefore developed novel {Delta}10 strains that are auxotrophic for 10 different nutrients, and new plasmids with two multicloning sites and auxotrophic markers for use in {Delta}10 strains. We confirmed that {Delta}10 strains could maintain 10 types of these plasmids. Because each plasmid can express two different genes, this {Delta}10 strain-based expression system has the potential to co-express a maximum of 20 different proteins.

bioengineering↗

Robust capability of renal tubule fatty acid uptake from apical and basolateral membranes in physiology and disease

Excess lipid accumulation is associated with obesity-related chronic kidney disease, but the mechanisms of fatty acid (FA) uptake have been poorly understood. To this end, we investigated how FAs are taken up by tubular epithelial cells (TECs) in mice by using in vivo FA tracing and histological methods. Immunohistochemistry showed that CD36, which is a well-known FA transporter, was abundantly expressed on the basolateral side of proximal TECs (PTECs). The uptake of 125I-BMIPP (a radiolabeled FA tracer) was significantly reduced in CD36-knockout kidneys at 1 min after injection. In vivo imaging with multiphoton microscopy revealed that BODIPY-C12 (a fluorescence-labeled FA tracer) accumulated on both the basolateral and apical sides of PTECs. Numerous lipid droplets accumulated in PTECs after accelerated lipolysis. Furthermore, PTEC-specific injury via diphtheria toxin (DT) injection in transgenic mice expressing the DT receptor resulted in a compensatory increase in lipid accumulation in downstream TECs. Importantly, urinary FAs were undetectable, even in mice and humans with remarkable albuminuria. Our data demonstrate that renal TECs take up FAs from blood (CD36-dependent) and primary urine (CD36-independent) and can store excess FAs as neutral lipids. The results further show that renal tubules have hitherto largely unappreciated mechanisms by which the excretion of FAs into the urine is avoided.

biochemistry↗

A machine learning model that emulates experts decision making in vancomycin initial dose planning

Vancomycin is a glycopeptide antibiotic that has been used primarily in the treatment of methicillin-resistant Staphylococcus aureus infections. To enhance its clinical effectiveness and prevent nephrotoxicity, therapeutic drug monitoring (TDM) of trough concentrations is recommended. Initial vancomycin dosing regimens are determined based on patient characteristics such as age, body weight, and renal function, and dosing strategies to achieve therapeutic concentration windows at initial TDM have been extensively studied. Although numerous dosing nomograms for specific populations have been developed, no comprehensive strategy exists for individually tailoring initial dosing regimens; therefore, decision making regarding initial dosing largely depends on each clinicians experience and expertise. In this study, we applied a machine-learning (ML) approach to integrate clinician knowledge into a predictive model for initial vancomycin dosing. A dataset of vancomycin initial dose plans defined by pharmacists experienced in vancomycin TDM (i.e., experts) was used to build the ML model. The target trough concentration was attained at comparable rates with the model- and expert-recommended dosing regimens, suggesting that the ML model successfully incorporated the experts knowledge. The predictive model developed here will contribute to improved decision making for initial vancomycin dosing and early attainment of therapeutic windows.

pharmacology and toxicology↗

Micromanipulation of amyloplasts with optical tweezers in Arabidopsis stems

Intracellular sedimentation of highly dense, starch-filled amyloplasts toward the gravity vector is likely a key initial step for gravity sensing in plants. However, recent live-cell imaging technology revealed that most amyloplasts continuously exhibit dynamic, saltatory movements in the endodermal cells of Arabidopsis stems. These complicated movements led to questions about what type of amyloplast movement triggers gravity sensing. Here we show that a confocal microscope equipped with optical tweezers can be a powerful tool to trap and manipulate amyloplasts noninvasively, while simultaneously observing cellular responses such as vacuolar dynamics in living cells. A near-infrared ({lambda} = 1064 nm) laser that was focused into the endodermal cells at 1 mW of laser power attracted and captured amyloplasts at the laser focus. The optical force exerted on the amyloplasts was theoretically estimated to be up to 1 pN. Interestingly, endosomes and trans-Golgi networks were trapped at 30 mW but not at 1 mW, which is probably due to lower refractive indices of these organelles than that of the amyloplasts. Because amyloplasts are in close proximity to vacuolar membranes in endodermal cells, their physical interaction could be visualized in real time. The vacuolar membranes drastically stretched and deformed in response to the manipulated movements of amyloplasts by optical tweezers. Our new method provides deep insights into the biophysical properties of plant organelles in vivo and opens a new avenue for studying gravity-sensing mechanisms in plants.

plant biology↗