Biology subjects

Suzuki, E.

Publications and source records attributed to Suzuki, E..

14 recordsLinked to original sources

bioRxiv2026

Dose dependent impact of global Cc2d1a reduction on cognitive, social, and metabolic phenotypes

Background Autism spectrum disorder (ASD) and Intellectual disability (ID) share an in-creased male prevalence, but the biological mechanisms underlying this male bias remain poorly understood. Mice deficient for CC2D1A, a protein scaffold mutated in ASD/ID, have shown multiple male-specific deficits both in ASD-like behaviors and in the regulation of neuronal intracellular signaling pathways. However, previous re-search relied on conditional knockout (cKO) models due to early postnatal lethality of global Cc2d1a KO strains. Thus, the ability to define the developmental impacts of CC2D1A LOF in mice has been limited. While generating a Cc2d1a knock-in strain with V5-HA epitope tags, we found that homozygous animals (Cc2d1aVH/VH) resulted in a hypomorph line that can be used to study developmental loss of CC2D1A. Methods We assessed gross morphology, behavior, and intracellular signaling in male and female Cc2d1aVH/VH animals, where only ~20% of CC2D1A is present. We then crossed this line with a null allele to obtain a more severe hypomorph (Cc2d1a-/VH) and explore phenotypic penetrance thresholds. In addition to the previous phenotypic characterization, we also assessed body composition, feeding, and molecular hall-marks of metabolic function in both sexes. Results We found that ~80% CC2D1A reduction in Cc2d1aVH/VH mice did not recapitu-late any of the behavioral or molecular disruptions seen in cKO models. In contrast, ~90% CC2D1A reduction in Cc2d1a-/VH mice resulted in ASD/ID-like behavioral phe-notypes in males, similar to those reported in cKO lines, with distinct intracellular sig-naling disruptions. Male and female Cc2d1a-/VH mice also showed subtle but signifi-cant adult weight deficits associated with distinct metabolic changes. Limitations These models still do not fully recapitulate the complete CC2D1A LOF found in patients. Due to the analysis of two independent strains over multiple metrics, these studies are not powered to compare statistical differences between sexes and data were analyzed in males and females independently. Conclusions We identified a strikingly narrow CC2D1A expression threshold for the emer-gence of ASD/ID-like behavioral deficits in males. In addition, we revealed a novel role for CC2D1A in adult weight gain. These mouse strains will be useful to better under-stand CC2D1A LOF phenotypes.

neuroscience↗

bioRxiv2025

Effect of Perinatal Ampicillin or Amoxicillin/Clavulanate Exposure on Maternal and Infant Gut Microbiome, Metabolome, and Infant Responses to the 20-valent Pneumococcal Conjugate Vaccine

Emerging studies suggest that antibiotics can disrupt the gut microbiome and alter vaccine-induced immune responses, but the specific consequences of early-life exposure on neonatal immune development remains poorly understood. Here, we examined how two antibiotics frequently used in perinatal care, broad-spectrum ampicillin (AMP) and the extended-spectrum combination amoxicillin/clavulanate (AMOX/CLAV), administered during gestation and lactation, influence neonatal gut microbiome composition, fecal metabolome profiles, and responses to the 20-valent pneumococcal conjugate vaccine (PCV20). Maternal treatment with AMOX/CLAV, but not AMP, significantly reduced PCV-specific IgG titers at 4-and 6-weeks post-prime immunization compared to untreated controls. Exclusive exposure to AMOX/CLAV also impaired neutrophil-mediated opsonophagocytic killing, indicating diminished antibody functionality. These effects were transient, with immune parameters normalizing by week 8 post-prime immunization. Metabolomic and microbiome profiling revealed that maternal AMP and AMOX/CLAV differentially perturbed specific metabolite classes including bile acids, N-acyl lipids, and indole-derivatives, as well as key commensal taxa including Bacteroidales and Coriobacteriales within the gut microbiota. Together, these findings reveal a previously underappreciated maternal-offspring route of antibiotic influence that transiently disrupts neonatal vaccine responsiveness through microbiome and metabolome alterations. These results highlight maternal antibiotic exposure as a modifiable factor shaping early-life immunity.

microbiology↗

bioRxiv2025

Influence of perinatal ampicillin exposure on maternal fecal microbial and metabolic profiles

Indirect exposure to antibiotics during early life, via maternal intrapartum antibiotic prophylaxis (IAP) or postpartum maternal antibiotic usage, is increasingly common and has been epidemiologically linked to altered growth and immune developmental trajectories in offspring. Nevertheless, the underlying mechanisms remain poorly understood. Here, we explored the effects of antepartum and postpartum maternal ampicillin administration on the dams fecal microbiome and metabolic profiles in vivo. Ampicillin caused a reproducible depletion of beneficial bacterial species belonging to the Muribaculaceae family, including Muribaculum intestinale and Duncaniella dubosii, and led to cohort-dependent enrichments of Enterococcus and Prevotella species. These microbial alterations were accompanied by substantial metabolic remodeling, characterized by elevated fecal acylcarnitines and dysregulation of the bile acids profile. Intriguingly, we identified two previously uncharacterized trihydroxylated bile acids conjugated to a hexose moiety, which appeared to be associated with antibiotic exposure across public metabolomics repositories. These alterations in the fecal maternal microbiome and metabolome coincided with increased weight gain in offspring, suggesting a possible role for maternal antibiotic exposure in shaping early developmental trajectories. Further studies are warranted to elucidate the long-term implications of these changes in infant health. IMPORTANCEPerinatal antibiotic administration is a critical intervention to reduce maternal and neonatal infections, including early-onset group B Streptococcus (GBS) disease, a major cause of neonatal mortality. Nevertheless, mounting evidence suggests that the use of broad-spectrum antibiotics during the perinatal period in mothers can affect infant gut microbiome development, with potential consequences for immune maturation and early development. Understanding how maternal antibiotic exposure affects the gut microbiome and metabolome is essential for uncovering the potential pathways by which maternal intervention may influence offspring outcomes and for guiding strategies that balance infection control with long-term infant health.

microbiology↗

bioRxiv2025

Interactome Analysis of the CC2D1A Scaffold Reveals Novel Neuronal Interactions and a Postsynaptic Role

Loss of the protein scaffold Coiled-coil and C2 domain containing 1A (CC2D1A) leads to intellectual disability (ID), autism spectrum disorder (ASD), and other neurodevelopmental presentations in humans. CC2D1A interactions have been studied in different cell lines proposing diverse roles in endolysosomal maturation and intracellular signaling, but the composition and functional mechanisms of the CC2D1A interactome remain poorly understood, especially in the brain. We performed comprehensive proteomic analyses to characterize CC2D1A binding partners, first comparing immunoprecipitations with three different anti-CC2D1A antibodies in HEK293 cells and then probing the mouse hippocampus. In HEK cells, Gene Ontology (GO) analysis revealed broad interaction networks in the nucleus, mitochondrion, and cytoplasmic vesicles sharing functions in organelle organization, vesicle mediated transport, and protein metabolism. These are unified by the best characterized CC2D1A interactor, the ESCRT III component CHMP4B, and define a pleiotropic role for CC2D1A in membrane trafficking and protein homeostasis. In the hippocampus, using stringent criteria and additional controls, including a Cc2d1a hypomorph mouse line, we identified 10 high-confidence interactors in addition to CHMP4B (TNIK, G3BP2, CEP135, MAPKAP1, SHFL, PPT1, PNKD, VAMP5, and PPP6R2) revealing roles for RNA regulation and synaptic function. The HEK studies had also pointed to CC2D1B, the only paralog of CC2D1A, as an interactor. We confirmed that not only the two proteins can bind in the brain, but also localize in different synaptic compartments, showing that CC2D1A is uniquely enriched in the post-synapse. This supports a unique function of CC2D1A in regulation of synaptic transmission that could explain the more severe cognitive deficits in humans and mice upon its loss. To our knowledge these findings provide the most comprehensive characterization of the CC2D1A interactome to date, elucidating novel, multifaceted, and dynamic cellular functions, providing potential implications for its role in neurodevelop-mental disorders.

molecular biology↗

bioRxiv2024

Glyco-phenotyping of mutants of Lacticaseibacillus paracasei by lectin microarray

We previously identified a gene cluster of Lacticaseibacillus paracasei strain Shirota (YIT 9029) for cell surface long-chain polysaccharides (LCPS-1) biosynthesis, which modulates YIT 9029 activity to induce cytokine production in immune cells, and showed that a lectin microarray can be useful for distinguishing the profile of bacterial cell-surface polysaccharide (PS) structures. Therefore, we isolated disruptive mutant strains of 51 genes predicted to be involved in cell wall PS biosynthesis in YIT 9029. Their binding profiles to lectins in conjunction with their binding abilities to YIT 9029-specific monoclonal antibody (MAb) were compared. The mutants defective in binding to the MAb all had defects within the cps1 gene cluster. Some mutants partially bound to MAb, indicating that these genes may influence the synthesis and maturation of LCPS-1. Advanced lectin microarray analyzed the cell surface glycosylation properties of YIT 9029 and its mutants. YIT 9029 bound to a rhamnose-specific lectin CSA, and three additional lectins including an O-glycan binder (rDiscoidin II) and two mannose binders (rOrysata and rBanana). Lectin binding specificity was confirmed by a gene complementation assay for the cps1C gene and a carbohydrate inhibition assay. When the binding profiles of individual cps1A through cps1J knockout mutants were compared, typical and specific binding profiles patterns were observed, in which some similarities in the functions of each gene could be predicted. In conclusion, the combined use of lectin microarray and a YIT 9029 mutant strain library is a powerful tool for identifying unknown bacterial gene functions related to cell surface glycome. IMPORTANCEPreviously, only a limited number of methods have been available for studying mutations in bacterial cell surface polysaccharide structures in relation to gene function. In this study, we focused on the lectin-binding properties of Lacticaseibacillus paracasei YIT 9029 (wild-type; WT) and investigated the lectin-binding capabilities of 51 cell wall biosynthesis gene disruption strains using lectin microarrays. The results indicated that lectin-binding properties in gene-disrupted strains varied significantly with the presence or absence of LCPS-1, ranging from similar to WT to distinctly different. The use of lectin microarrays in conjunction with the YIT 9029 mutant library has been shown to be a highly effective method for identifying the functions of unknown bacterial genes related to cell-surface glycomes. This innovative approach to glycophenotyping allows for the determination of cell wall glycomes associated with bacterial gene functions using lectin microarrays.

microbiology↗

bioRxiv2024

Glucose uptake in pigment glia suppresses tau-induced inflammation and photoreceptor degeneration in Drosophila

Brain inflammation contributes to the pathogenesis of neurodegenerative diseases such as Alzheimers disease (AD). Glucose hypometabolism and glial activation are pathological features seen in AD brains; however, the connection between the two is not fully understood. Using a Drosophila model of AD, we identified that glucose metabolism in glia plays a critical role in neuroinflammation under disease conditions. Expression of human Tau in the retinal cells, including photoreceptor neurons and pigment glia, causes photoreceptor degeneration accompanied by inclusion formation and swelling of the lamina cortex. We found that inclusions are formed by glial phagocytosis, and swelling of the laminal cortex correlates with the expression of antimicrobial peptides. Co-expression of human glucose transporter 3 (GLUT3) with Tau in the retina does not affect tau levels but suppresses these inflammatory responses and photoreceptor degeneration. We also found that expression of GLUT3, specifically in the pigment glia, is sufficient to suppress inflammatory phenotypes and mitigate photoreceptor degeneration in the tau-expressing retina. Our results suggest that glial glucose metabolism contributes to inflammatory responses and neurodegeneration in tauopathy. Summary StatementGlucose uptake into pigment glia suppresses inflammatory responses and photoreceptor degeneration in the fly model of tauopathy.

neuroscience↗

bioRxiv2024

Perinatal ampicillin administration modulates murine bile acid metabolism in vivo - an observational study

Antibiotics are an indispensable tool of modern medicine, yet their impact extends beyond eliminating harmful bacteria to perturbing the commensal bacteria constituting the gut microbiome. This collateral damage is particularly significant in early life when the gut microbiome is still developing. In humans, antibiotic administration during infancy and childhood is associated with various long-term negative health outcomes. However, existing research has predominantly focused on the direct administration of antibiotics to infants, leaving uncertainties about whether indirect antibiotic exposure produces similar effects. Here, we use mouse models to investigate how three distinct routes of exposure to the commonly prescribed broad-spectrum antibiotic ampicillin influences parent and infant metabolism. These methods simulate major modes of both direct and indirect antibiotic exposure: intravenous antibiotic administration to the mother immediately before birth mimicking intrapartum antibiotic prophylaxis, antibiotic use by the mother during lactation, and direct administration to infants mimicking empiric antibiotic treatment for neonatal sepsis. Through untargeted metabolomics of fecal samples from mouse dams and infants, we identified one class of compounds, bile acids and related cholane steroids, as particularly sensitive to ampicillin treatment. Bile acids, produced by the host and extensively modified by the gut microbiome, serve as important mediators in the cross-talk between the microbiota and the host. Here, we detail the coordinated changes in bile acid metabolism in response to a commonly prescribed antibiotic, focusing on dams treated both pre- and postpartum. Additionally, we identify unique bile acids associated with weight gain in infant mice. ImportanceAntibiotics are widely used perinatally, administered to both parents and infants before, during, and after birth. While they can play a life-saving role, antibiotics also result in collateral damage to the beneficial microbes constituting the gut microbiome. These microbes have many important functions, particularly in the metabolism of small molecules in the body. One such group of molecules, bile acids, undergo extensive modifications by bacteria and may act as a "language" through which microbes communicate with the host. This observational study investigates the impact of the commonly prescribed antibiotic ampicillin on the metabolism of these molecules during childbirth. Our results indicate that ampicillin administration pre- or post-partum significantly alters the mothers bile acid metabolism, but has a minimal influence on infant bile acid levels. However, in all cases, ampicillin administration significantly increased infant weight, even when the antibiotic was solely administered to the mother.

pharmacology and toxicology↗

bioRxiv2024

Axonal distribution of mitochondria maintains neuronal autophagy during aging via eIF2β

Neuronal aging and neurodegenerative diseases are accompanied by proteostasis collapse, while the cellular factors that trigger it have not been identified. Impaired mitochondrial transport in the axon is another feature of aging and neurodegenerative diseases. Using Drosophila, we found that genetic depletion of axonal mitochondria causes dysregulation of protein degradation. Axons with mitochondrial depletion showed abnormal protein accumulation and autophagic defects. Lowering neuronal ATP levels by blocking glycolysis did not reduce autophagy, suggesting that autophagic defects are associated with mitochondrial distribution. We found that eIF2{beta} was increased by the depletion of axonal mitochondria via proteome analysis. Phosphorylation of eIF2, another subunit of eIF2, was lowered, and global translation was suppressed. Neuronal overexpression of eIF2{beta} phenocopied the autophagic defects and neuronal dysfunctions, and lowering eIF2{beta} expression rescued those perturbations caused by depletion of axonal mitochondria. These results indicate the mitochondria-eIF2{beta} axis maintains proteostasis in the axon, of which disruption may underlie the onset and progression of age-related neurodegenerative diseases. HighlightsO_LILoss of axonal mitochondria impairs autophagy and accumulates proteins in the axon C_LIO_LILoss of axonal mitochondria increases eIF2{beta} and decreases p-eIF2 C_LIO_LINeuronal upregulation of eIF2{beta} induces autophagic defects and locomotor dysfunction C_LIO_LILowering eIF2{beta} rescues autophagic defects caused by loss of axonal mitochondria C_LI

cell biology↗

bioRxiv2023

Development of an mRNA electroporation method in immature mouse oocytes to visualize protein dynamics during early development

One of the major cause of oocyte quality deterioration along with aging, chromosome segregation abnormalities occur mainly during meiosis I. However, currently, there is a technical limitation in the introduction of mRNA into premature oocytes without impairing embryonic developmental ability. In this study, we established a low-invasive electroporation (EP) method to introduce mRNA into pre-ovulatory, germinal vesicle (GV) mouse oocytes in an easier manner than the traditional microinjection method. The EP method with an optimized impedance value resulted in the efficient introduction of mRNAs encoding enhanced green fluorescent protein (EGFP) into the GV oocytes surrounded by cumulus cells at a survival rate of 95.0%. Furthermore, the introduction of histone H2B-EGFP mRNA into the GV oocytes labeled most of the oocytes without affecting the blastocyst development rate, indicating the feasibility of the visualization of oocyte chromosomal dynamics that enable us to assay chromosomal integrity in oocyte maturation and cell count in embryonic development. The establishment of this EP method offers extensive assays to select pre-implantation embryos and enables the surveying of essential factors for mammalian oocyte quality determination. Summary blurbThis study introduces a low-invasive electroporation method with high survival rate and developmental ability, offering a potential breakthrough in preimplantation embryo treatment and assessment.

developmental biology↗

bioRxiv2023

Senescence triggers intracellular acidification and lysosomal alkalinization via ATP6AP2 attenuation in breast cancer cells

Several chemotherapy drugs induce the senescence of cancer cells; however, the mechanism underlying intracellular pH dysregulation in senescent cells remains unclear. Adenosine triphosphatase H+ transporting accessory protein 2 (ATP6AP2) plays a critical role in maintaining pH homeostasis in cellular compartments. We here report a new function of ATP6AP2 in senescent breast cancer cells induced by doxorubicin and abemaciclib treatment. ATP6AP2 expression was significantly downregulated in senescent cells, leading to aberrant pH levels that impaired lysosome function and caused immune response changes. The drugs caused cell cycle arrest and proliferation suppression through the upregulation of senescence-related genes. Additionally, senescent cells showed altered inflammatory and immune transcriptional profiles by reprogramming the senescence-associated secretory phenotype. These findings suggest that ATP6AP2-mediated pH regulation during therapy-induced senescence may be linked to immune changes in senescent cancer cells. These findings provide novel insights into understanding the cellular mechanisms underlying the response to anti-cancer drugs.

cancer biology↗

bioRxiv2023

Drosophila model to clarify the pathological significance of OPA1 in autosomal dominant optic atrophy

Autosomal dominant optic atrophy (DOA) is a progressive form of blindness caused by degeneration of retinal ganglion cells and their axons, mainly caused by mutations in the OPA1 mitochondrial dynamin like GTPase (OPA1) gene. OPA1 encodes a dynamin-like GTPase present in the mitochondrial inner membrane. When associated with OPA1 mutations, DOA can present not only ocular symptoms but also multi-organ symptoms (DOA plus). DOA plus often results from point mutations in the GTPase domain, which are assumed to have dominant negative effects. However, the presence of mutations in the GTPase domain does not always result in DOA plus. Therefore, an experimental system to distinguish between DOA and DOA plus is needed. In this study, we found that loss-of-function mutations of the dOPA1 gene in Drosophila can imitate the pathology of optic nerve degeneration observed in DOA. We successfully rescued this degeneration by expressing the human OPA1 (hOPA1) gene, indicating that hOPA1 is functionally interchangeable with dOPA1 in the fly system. However, mutations previously identified did not ameliorate the dOPA1 deficiency phenotype. By expressing both WT and DOA plus mutant hOPA1 forms in the optic nerve of dOPA1 mutants, we observed that DOA plus mutations suppressed the rescue, facilitating the distinction between loss-of-function and dominant negative mutations in hOPA1. This fly model aids in distinguishing DOA from DOA plus and guides initial hOPA1 mutation treatment strategies.

pathology↗

bioRxiv2020

Neurexins play a crucial role in cerebellar granule cell survival by organizing autocrine machinery for neurotrophins

Neurexins (NRXNs) are among the key presynaptic cell adhesion molecules that regulate synapse function and formation via trans-synaptic interaction with postsynaptic ligands. Here, we generated cerebellar granule cell (CGC)-specific Nrxn triple-knockout (TKO) mice to allow the deletion of all NRXNs. Unexpectedly, most CGCs died in these mice. The requirement of NRNXs for cell survival was reproduced in cultured CGCs. We showed that the axons of cultured Nrxn TKO CGCs that were not in contact with the postsynaptic structure had defects in the formation of presynaptic protein cluster and action potential-induced Ca2+ influx. Additionally, these cells were impaired in the secretion from axons of depolarization-induced fluorescence-tagged brain-derived neurotrophic factor (BDNF), and the cell-survival defect was rescued by the application of BDNF. Our results suggest that CGC survival is maintained by autocrine neurotrophic factors, and that NRXNs organize the presynaptic protein clusters and the autocrine neurotrophic factor secretory machinery independent of contact with postsynaptic ligands.

neuroscience↗

bioRxiv2020

Increasing glucose uptake into neurons antagonizes brain aging and promotes health and life span under dietary restriction in Drosophila

Brain neurons play a central role in organismal aging, but there is conflicting evidence about the roles of neuronal glucose availability, glucose uptake and metabolism in aging and extended lifespan. Here, we analyzed metabolic changes in the brain neurons of Drosophila during aging. Using a genetically-encoded fluorescent ATP biosensor, we found decreased ATP concentration in the neuronal somata of aged flies, which was correlated with decreased glucose content, expression of glucose transporter and glycolytic enzymes and mitochondrial quality. The age-associated reduction in ATP concentration did not occur in brain neurons with suppressed glycolysis or enhanced glucose uptake, suggesting these pathways contribute to reductions in ATP. Despite age-associated mitochondrial damage, increasing glucose uptake maintained ATP levels, suppressed age-dependent locomotor deficits and extended the life span. Increasing neuronal glucose uptake during dietary restriction resulted in the longest lifespans, suggesting an additive effect of enhancing glucose availability during a bioenergetic challenge on aging.

neuroscience↗

bioRxiv2017

Modulation of formin processivity by profilin and mechanical tension

Formins are major regulators of actin networks. They enhance actin filament dynamics by remaining processively bound to filament barbed ends. How biochemical and mechanical factors affect formin processivity are open questions. Monitoring individual actin filaments in a microfluidic flow, we report that formin mDia1 dissociates faster under higher ionic strength and when actin concentration is increased. Profilin, known to increase the elongation rate of formin-associated filaments, surprisingly decreases the formin dissociation rate, by bringing formin FH1 domains in transient contact with the barbed end. In contrast, piconewton tensile forces applied to actin filaments accelerate formin dissociation by orders of magnitude, largely overcoming profilin-mediated stabilization. We developed a model of formin conformations and its confrontation to our data indicates the existence of two different dissociation pathways, with force favoring one over the other. How cells limit formin dissociation under tension is now a key question for future studies.

biophysics↗