Biology subjects

Uemura, T.

Publications and source records attributed to Uemura, T..

At least 19 recordsLinked to original sources

bioRxiv2026

Differential physiological, behavioral, and medial prefrontal cortex transcriptomic responses to chronic restraint stress between BALB/c and C57BL/6J mice

Chronic stress is a major risk factor for psychiatric disorders such as depression and anxiety, yet the biological basis of individual differences in stress susceptibility and resilience remains poorly understood. Here, we examined physiological, behavioral, and medial prefrontal cortex (mPFC) transcriptomic responses to chronic restraint stress (CRS) in male BALB/c and C57BL/6J mice. After 21 days of CRS, BALB/c mice exhibited greater stress-related changes than C57BL/6J mice, including greater body weight loss, elevated serum corticosterone, reduced serum antioxidant capacity, and more pronounced depression-like behaviors. RNA sequencing showed largely strain-specific transcriptional changes in the mPFC. Strain x stress interaction analysis, followed by canonical pathway analysis using Ingenuity Pathway Analysis (IPA), identified strain-dependent molecular signatures. The most prominent differences involved extracellular matrix (ECM) organization and remodeling and neuroinflammatory signaling pathways, with greater predicted activation in BALB/c mice. IPA upstream regulator analysis further predicted multiple candidate regulators associated with these pathways, including TGF-{beta}/SMAD, C4a/C4b, and MAPK14. Among genes associated with these pathways, several ECM-related genes were preferentially upregulated in BALB/c mice, whereas activity-dependent immediate early genes were preferentially downregulated in C57BL/6J mice. These findings suggest that the strain-dependent mPFC transcriptional programs identified here may contribute to differential stress susceptibility and resilience.

neuroscience↗

bioRxiv2026

The membrane-tethered cis-ligand Belly roll elicits GPCR signaling thereby enabling adaptive avoidance behaviors

Animals adapt their behavioral responses to sensory stimuli through neuromodulatory circuits. Increasing fluid osmolality drives water-seeking behaviors via neuromodulation. However, the neural circuits and molecular mechanisms linking internal osmotic state to behavioral adaptation remain unclear. Here, we show that desiccation stress increases hemolymph osmolality and enhances avoidance of dry substrates in Drosophila larvae, enabling larvae to seek humid environments. We identify the abdominal leucokinin-producing (ABLK) neurons as a key circuit node that mediates this adaptive response. We further show that the GPI-anchored protein Belly roll (Bero), a member of the lymphocyte antigen-6/urokinase-type plasminogen activator receptor (LU) superfamily, acts as a non-canonical endogenous cis-ligand for the neuropeptide G protein-coupled receptor Allatostatin C receptor 2 (AstC-R2). Genetic, biochemical, and imaging analyses revealed that Bero activates AstC-R2 to induce phospholipase C {beta} (PLC{beta})-dependent signaling, thereby suppressing sensory transmission in ABLK neurons. Desiccation-induced increase in hemolymph osmolality activates VMA-AstC neurons to trigger Allatostatin C (AstC) release, which antagonizes Bero-mediated AstC-R2 signaling and promotes dry substrate avoidance. Together, our findings uncover a neural circuit and a molecular mechanism by which changes in internal physiological state dynamically switch GPCR signaling through the opposing actions of membrane-tethered and secreted ligands, thereby reshaping adaptive behavioral responses.

neuroscience↗

bioRxiv2026

A GPI-anchored Ly6/uPAR superfamily gene belly roll is expressed in multiple peptidergic neurons in Drosophila melanogaster larvae

The Lymphocyte antigen-6 (Ly6)/urokinase-type plasminogen activator receptor (uPAR) superfamily (LU super family) of proteins are involved in diverse biological processes. In Drosophila melanogaster, members of the LU superfamily have undergone lineage-specific gene duplication and acquired specialized functions in distinct tissues. A glycosylphosphatidylinositol (GPI)-anchored LU family protein Belly roll (Bero) has recently been shown to regulate larval escape behavior; however, its cellular expression profile and potential roles remain incompletely understood. In this study, we generated a bero-GAL4T2A transgenic line to delineate endogenous bero expression. This analysis revealed that bero is expressed in the peptidergic neurons in the central nervous system (CNS) that had not been documented in previous studies, as well as in the peripheral nervous system (PNS) and non-neuronal tissues, such as the anal pad and epidermis. Reanalysis of publicly available single-cell RNA sequencing (scRNA-seq) datasets demonstrated that bero is expressed in several peptidergic neurons. These findings suggest that Bero is specifically expressed in diverse peptidergic neurons and may play important roles in coordinating hormonal and neural regulation in D. melanogaster.

neuroscience↗

bioRxiv2025

Roles of a Drosophila ADAM 10 transmembrane metalloprotease, Kuzbanian, in tissue architecture and function of the adult adipose tissue

Various molecular mechanisms in mature adipose tissue regulate whole-body physiology. In contrast, our current understanding of the development of this tissue is limited. The adult fat body (AFB) of Drosophila melanogaster is an emerging model for investigating the regulatory mechanisms of adipose tissue morphogenesis in vivo. AFB precursor cells undergo long-range directional and collective migration, proliferation, and homotypic adhesion, leading to the formation of monolayered AFB during metamorphosis. Here, we show that a Drosophila ADAM10 transmembrane metalloprotease, Kuzbanian (Kuz), is required for the AFB morphogenesis in the precursor cells at the onset of adhesion. Histological and ultrastructural analyses revealed that the kuz knocked-down AFB cells formed multilayered structures or clumps, indicating that Kuz is essential for forming a single-cell-thick tissue sheet. Furthermore, adults with the morphologically altered AFB were supersensitive to starvation stress. Finally, we tested the hypothesis that Notch (N), a well-characterized substrate for Kuz or ADAM10, participates in AFB development, and found that knocking down N reduced AFB area coverage and made the adults less adaptive to starvation, similar to kuz knockdown. Altogether, our study highlights the critical role of Kuz in both the architecture and function of adult adipose tissue.

developmental biology↗

bioRxiv2025

Intrathecal administration of palmitoyl-lysophosphatidylethanolamine reduces secondary injury and improves locomotor recovery following spinal cord injury

Spinal cord injury (SCI) triggers secondary pathophysiological cascades, including glutamate excitotoxicity, that result in neuronal loss and impair functional recovery. We have previously shown that lysophosphatidylethanolamine (LPE), a lysophospholipid, promotes neurite outgrowth and protects against glutamate excitotoxicity in cultured cortical neurons. However, whether these effects extend to spinal cord neurons and occur in vivo has remained unclear. In this study, we compared the effects of different LPE species: myristoyl-LPE (14:0 LPE), palmitoyl-LPE (16:0 LPE), stearoyl-LPE (18:0 LPE), and oleoyl-LPE (18:1 LPE) in cultured spinal commissural neurons, and evaluated their effects in vivo using a mouse model of SCI. In cultured neurons, all LPE species promoted neurite outgrowth. Although several species demonstrated a tendency toward neuroprotection, only 16:0 LPE exhibited a statistically significant protective effect against glutamate-induced excitotoxic cell death. Intrathecal administration of 16:0 LPE after SCI reduced TUNEL-positive cells in the acute phase and attenuated lesion expansion at 8 weeks post-injury. Moreover, 5-HT fluorescence intensity was increased in 16:0 LPE-treated mice, suggesting enhanced serotonergic innervation. Furthermore, administration of 16:0 LPE after SCI significantly improved hind-limb motor performance compared with vehicle controls, as assessed by the Basso Mouse Scale. Collectively, these findings suggest that intrathecal administration of 16:0 LPE reduces secondary injury and promotes functional recovery following SCI. Our findings highlight its potential as a therapeutic candidate for SCI.

neuroscience↗

bioRxiv2025

Differential Effects of Inducible Cerebellar Granule Cell and Purkinje Cell Ablation on Motor Coordination and Motor Learning in Adult Mice

The cerebellum regulates motor coordination and motor learning through highly organized circuits composed mainly of granule cells (GCs) and Purkinje cells (PCs). To investigate their distinct roles, we generated two lines of inducible transgenic mice in which either GCs or PCs could be selectively ablated in adulthood by administration of the progesterone receptor antagonist RU-486. This system combined a Cre recombinase-progesterone receptor fusion, in which Cre activity is induced in an RU-486-dependent manner, with a Cre-dependent diphtheria toxin A expression to achieve cell-type-specific ablation. High-dose RU-486 induced nearly complete loss of either GCs or PCs and resulted in severe ataxia. When partial ablation was induced by low-dose RU-486, different phenotypes emerged. Mice retaining about 20% of PCs were still able to improve motor coordination in the rotarod test and maintained performance in the balance beam test comparable to that of controls. In contrast, mice with about 30% of GCs remaining showed marked deficits, failing to improve across rotarod trials and exhibiting reduced latency to fall in the balance beam test. These results suggest that while both GCs and PCs are indispensable for motor coordination, a sufficient number of GCs is required for both motor coordination and motor learning. This inducible ablation model highlights the differential contributions of cerebellar neurons and provides a valuable tool to dissect circuit-specific functions in the adult brain.

neuroscience↗

bioRxiv2025

The chicken retrovirus-like gene ENS-1/ERNI and its LTR Soprano are involved in primordial germ cell development.

Cultured chicken primordial germ cells (PGCs) are attractive tools for reproductive biology and for preserving and modifying genetic resources. However, it remains difficult to establish cell lines from some breeds or females. In the present study, we performed transcriptome analyses of cultured PGCs from different breeds and found that the expression of the Galliformes-specific endogenous retrovirus-like gene ENS-1/ERNI correlated with the establishment efficiency of PGC lines. CRISPRi targeting the ENS-1/ERNI long terminal repeat (LTR) sequence (Soprano) broadly reduced homeostasis-related genes including ribosome, endoplasmic reticulum, and oxidative phosphorylation. These PGCs exhibited abnormal cell cycle arrest under DNA-damaged conditions, suggesting involvement in the quality control mechanisms of chicken PGCs. Furthermore, when transplanted into blastoderms, these PGCs showed a reduction in colonization of the genital ridges. These results indicate the involvement of Soprano LTR and ENS-1/ERNI in the development of chicken PGCs and their adaptation to the in vitro environment.

cell biology↗

bioRxiv2024

A microendovascular system can record precise neural signals from cortical and deep vessels with minimal invasiveness

Minimally invasive intravascular electroencephalography (ivEEG) signals are a promising tool for developing clinically feasible brain-computer interfaces (BCIs) that restore communication and motor functions in paralyzed patients. However, current ivEEG techniques can only record signals from the superior sagittal sinus (SSS), making it challenging to record motor responses related to hand and mouth movements from brain regions distant from the SSS, despite their critical role in BCIs. Here, using micro intravascular electrodes, ivEEGs recorded from the cortical or deep veins of eight pigs could measure cortical activities with greater signal power and better spatial resolution than those recording in the SSS, thus allowing mapping of the sensorimotor and visual functional areas. Additionally, electrical stimulation in the cortical vein between the micro intravascular electrodes induced muscle contractions contralateral to the stimulated area in five anesthetized pigs. These results demonstrate that ivEEG using micro intravascular electrodes is a promising tool for developing BCIs.

neuroscience↗

bioRxiv2024

Loss of SPNS1, a lysosomal transporter, in the nervous system causes dysmyelination and white matter dysplasia

Protein spinster homolog 1 (SPNS1) is a lysosomal transporter of lysophospholipids and sphingosine, which has recently been identified to be mutated in patients with neurodegeneration. However, its physiological role, especially in the nervous system, remains largely unknown. In this study, we generated, for the first time, nervous system-specific Spns1 knockout mice, Spns1flox/flox;nestin-Cre, and found that the mutant mice develop neurological symptoms, such as epilepsy, and growth retardation, and die by 5 weeks of age. The mutant mice exhibited dysmyelination and oligodendrocyte shedding, while maintaining the neurons. Mutant mouse brains showed accumulation of lysophospholipids, predominantly in regions, such as the olfactory bulb and hippocampus. Furthermore, whereas sphingosine accumulated in the mutant mouse brain, the levels of ceramide and sphingoglycolipids, which are the main myelin components, were decreased. Our findings imply that abnormal sphingosine metabolism causes dysmyelination and white matter dysplasia in brain-specific Spns1-knockout mice, and indicate a possible role of SPNS1 mutation in the pathogenesis of congenital cerebral white matter dysplasia in humans.

cell biology↗

bioRxiv2024

Combinatorial expression of neurexin genes regulates glomerular targeting by olfactory sensory neurons

Precise connectivity between specific neurons is essential for the formation of the complex neural circuitry necessary for executing intricate motor behaviors and higher cognitive functions. While trans-interactions between synaptic membrane proteins have emerged as crucial elements in orchestrating the assembly of these neural circuits, the synaptic surface proteins involved in neuronal wiring remain largely unknown. Here, using unbiased single-cell transcriptomic and mouse genetic approaches, we uncover that the neurexin family of genes enables olfactory sensory neuron (OSNs) axons to form appropriate synaptic connections with their mitral and tufted (M/T) cell synaptic partners, within the mammalian olfactory system. Neurexin isoforms are differentially expressed within distinct populations of OSNs, resulting in unique pattern of neurexin expression that is specific to each OSN type, and synergistically cooperate to regulate axonal innervation, guiding OSN axons to their designated glomeruli. This process is facilitated through the interactions of neurexins with their postsynaptic partners, including neuroligins, which have distinct expression patterns in M/T cells. Our findings suggest a novel mechanism underpinning the precise assembly of olfactory neural circuits, driven by the trans-interaction between neurexins and their ligands.

developmental biology↗

bioRxiv2023

Refinement of a technique for collecting and evaluating the osmolality of haemolymph from Drosophila larvae

ex vivo physiological experiments using small insect models such as Drosophila larvae have become increasingly useful to address fundamental biological questions. To perform such experiments, various artificial saline solutions have been developed, but their osmolality varies significantly from one to the next. Such a variation of osmolality stems, in part, from the difficulty of determining the true value of haemolymph osmolality in Drosophila larvae. Thus, there is a pressing need to refine protocols for collecting and measuring the osmolality of the larval haemolymph. Two major obstacles are thought to impede the accurate analysis of haemolymph collected from small insects: melanin formation and gut-derived contamination. Here, we greatly refined existing haemolymph collecting methods, evaluated the purity of the collected haemolymph under melanin-free conditions, and concluded that the true value of haemolymph osmolality is close to 306.0 mOsm kg-1 in Drosophila larvae.

physiology↗

bioRxiv2023

Rapid Vacuolar Sorting of the Borate Transporter BOR1 Requires the Adaptor Protein Complex AP-4 in Arabidopsis

Plants maintain nutrient homeostasis by controlling the activities and abundance of nutrient transporters. In Arabidopsis thaliana, the borate (B) transporter BOR1 plays a role in the efficient translocation of B under low-B conditions. BOR1 undergoes polyubiquitination in the presence of sufficient B and is then transported to the vacuole via multivesicular bodies (MVBs) to prevent B accumulation in tissues at a toxic level. A previous study indicated that BOR1 physically interacts with subunits of adaptor protein complexes AP-3 and AP-4, both involved in vacuolar sorting pathways. In this study, we investigated the roles of AP-3 and AP-4 subunits in BOR1 trafficking in Arabidopsis. The lack of AP-3 subunits did not affect either vacuolar sorting or polar localization of BOR1-GFP, whereas the absence of AP-4 subunits resulted in a delay in high-B-induced vacuolar sorting without affecting polar localization. Super-resolution microscopy revealed a rapid sorting of BOR1-GFP into AP-4-positive spots in the trans-Golgi network (TGN) upon high-B supply. These results indicate that AP-4 is involved in sequestration of ubiquitinated BOR1 into a TGN-specific subdomain "vacuolar-trafficking zone," and is required for efficient sorting to MVB and vacuole. Our findings elucidate the rapid vacuolar sorting process facilitated by AP-4 in plant nutrient transporters. Subject areas(7) Membrane and transport

plant biology↗

bioRxiv2023

ER-to-Golgi trafficking via a dynamic intermediate cis-Golgi tubular network in Arabidopsis

Endoplasmic Reticulum (ER)-to-Golgi trafficking is a central process of the secretory system of eukaryotic cells that ensures proper spatiotemporal sorting of proteins and lipids1-5. However, the nature of the ER-Golgi Intermediate Compartments (ERGIC) and the molecular mechanisms mediating the transition between the ERGIC and the Golgi, as well as the universality of these processes amongst Eukaryotes, remain undiscovered. Here, we took advantage of the plant cell system in which the Golgi is highly dynamic and in close vicinity to the ER6-9. We discovered that the ERGIC is composed from at least two distinct subpopulations of cis-Golgi. A subpopulation is a reticulated tubulo-vesicular network mostly independent from the Golgi, highly dynamic at the ER-Golgi interface and crossed by ER-induced release of luminal cargos at early stage. Another subpopulation is more stable, cisterna-like and mostly associated to the Golgi. Our results identified that the generation and dynamics of the ER-Golgi intermediate tubulo-vesicular network is regulated by the acyl-chain length of sphingolipids as well as the contacts it establishes with existing Golgi cisternae. Our study is a major twist in the understanding of the Golgi by identifying that the ERGIC in plants is a Golgi-independent highly dynamic tubular network from which arise more stable cisternae-like Golgi structures. This novel model presents a mechanism for early secretory trafficking adapted to respond to developmental and environmental stimuli, including susceptibility or resistance to diseases, autophagy or cell-reprograming.

cell biology↗

bioRxiv2023

Identification of Core Yeast Species and Microbe-Microbe Interactions Impacting Larval Growth of Drosophila in the Wild

Microbiota consisting of various fungi and bacteria have a significant impact on the physiological functions of the host. However, it is unclear which species are essential to this impact and how they affect the host. This study analyzed and isolated microbes from natural food sources of Drosophila larvae, and investigated their functions. Hanseniaspora uvarum is the predominant yeast responsible for larval growth in the earlier stage of fermentation. As fermentation progresses, Acetobacter orientalis emerges as the key bacterium responsible for larval growth, although yeasts and lactic acid bacteria must coexist along with the bacterium to stabilize this host-bacterial association. By providing nutrients to the larvae in an accessible form, the microbiota contributes to the upregulation of various genes that function in larval cell growth and metabolism. Thus, this study elucidates the key microbial species that support animal growth under microbial transition.

developmental biology↗

bioRxiv2022

The GPI-anchored Ly6 protein Belly roll regulates Drosophila melanogaster escape behaviors by modulating the excitability of nociceptive peptidergic interneurons

Appropriate modulation of escape behaviors in response to potentially damaging stimuli is essential for survival. Although nociceptive circuitry has been studied, it is poorly understood how genetic contexts affect the relevant escape responses. Using an unbiased genome-wide association analysis, we identified a Ly6/-neurotoxin family protein, Belly roll (Bero), which negatively regulates Drosophila nociceptive escape behavior. We show that Bero is expressed in abdominal leucokinin-producing neurons (ABLK neurons) and bero knockdown in ABLK neurons resulted in enhanced escape behavior. Furthermore, we demonstrated that ABLK neurons responded to the activation of nociceptors and initiated the behavior. Notably, bero knockdown reduced the persistent neuronal activity and increased the evoked nociceptive responses in ABLK neurons. Our findings reveal that Bero modulates an escape response by regulating distinct neuronal activities in ABLK neurons.

neuroscience↗

bioRxiv2022

Inter-organ Wingless/Ror/Akt signaling regulates nutrient-dependent hyperarborization of somatosensory neurons

Nutrition in early life has profound effects on an organism, altering processes such as organogenesis. However, little is known about how specific nutrients affect neuronal development. Dendrites of class IV neurons in Drosophila larvae become more complex when the larvae are reared on a low-yeast diet compared to a high-yeast diet. Our systematic search for key nutrients revealed that the neurons increase their dendrite densities in response to a combined deficiency in vitamins, metal ions, and cholesterol. These nutrients affect dendrite branching through the Wingless/Ror/Akt pathway between the neuron and closely located muscles, and this short range-pathway is regulated by a systemic Upd2-Stat92E pathway between the fat body and muscles. Additionally, the low-yeast diet blunts neuronal light responsiveness and light avoidance behavior, which may help larvae optimize their survival strategies under low-nutritional conditions. Together, our studies illustrate how the availability of specific nutrients affects neuronal development through inter-organ signaling.

developmental biology↗

bioRxiv2022

Dynamic de novo adipose tissue development during metamorphosis in Drosophila melanogaster

Adipose tissue is a central organ for controlling systemic metabolism both in invertebrates and vertebrates. Here, we have investigated the cellular mechanisms of the adult-type fat body (AFB) development in Drosophila. We have established genetic tools that allow visualization and genetic manipulations of cells in the AFB lineage from early in metamorphosis. We identified precursor cells that give rise to the AFB and delineated dynamic cellular mechanisms underlying AFB formation. These precursor cells displayed polarized cell shapes and oriented motility, with emigration from the thorax and subsequent dispersal to the abdomen and head. After the migration period, these cells adhered to each other, assembling into the AFB with a sheet-like architecture. Continuous cell proliferation occurred during and after the large-scale migration to achieve appropriate fat tissue mass. Homotypic cell fusion after the sheet formation contributed to the establishment of multinucleated cells in the AFB. We also examined candidate gene functions, and our results argue that Rac1, ecdysone signaling, and the transcription factor Serpent support adult fat body organogenesis. Brief Summary StatementDrosophila adult fat body precursor cells form adult adipose tissue during metamorphosis by directional migration, continuous cell proliferation, and homotypic cell fusion.

developmental biology↗

bioRxiv2022

Cryo-EM structures of human zinc transporter ZnT7 reveal the mechanism of Zn2+ uptake into the Golgi apparatus

Zinc ions (Zn2+) are vital to most cells, with the intracellular concentrations of Zn2+ being tightly regulated by multiple zinc transporters located at the plasma and organelle membranes. We herein present the 2.8-2.9 [A]-resolution cryo-EM structures of a Golgi-localized human Zn2+/H+ antiporter ZnT7 (hZnT7) in its outward- and inward-facing forms. Cryo-EM analyses showed that hZnT7 exists as a homodimer via tight interactions in both the cytosolic and transmembrane (TM) regions of two protomers, each of which contains a single Zn2+-binding site in its TM domain. hZnT7 undergoes a TM-helix rearrangement to create a negatively charged cytosolic cavity for Zn2+ entry in the inward-facing form and a widened luminal cavity for Zn2+ release in the outward-facing form. An exceptionally long cytosolic histidine-rich loop characteristic of hZnT7 can bind at least two Zn2+ ions, likely facilitating Zn2+ recruitment from the cytosol. Unique mechanisms of hZnT7-mediated Zn2+ uptake into the Golgi are proposed.

molecular biology↗