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Noda, T.

Publications and source records attributed to Noda, T..

At least 37 records · Page 2Linked to original sources

Coatomer complex I is required for the transport of SARS-CoV-2 progeny virions from the endoplasmic reticulum-Golgi intermediate compartment

SARS-CoV-2 undergoes budding within the lumen of the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) and delivers progeny virions to the cell surface by employing vesicular transport. However, the molecular mechanisms remain poorly understood. Using three-dimensional electron microscopic analysis, such as array tomography and electron tomography, we found that virion-transporting vesicles possessed a coated protein on their membrane and demonstrated that the coated protein was coatomer complex I (COPI). During the later stages of SARS-CoV-2 infection, we observed a notable alteration in the distribution of COPI and ERGIC throughout the cytoplasm. Depletion of COPB2, a key component of COPI, led to the confinement of SARS-CoV-2 structural proteins in the perinuclear region, where progeny virions were accumulated within the ERGIC. While the expression levels of viral proteins within cells were comparable, this depletion significantly reduced the efficiency of virion release, leading to the significant inhibition of viral replication. Hence, our findings suggest COPI as a critical player in facilitating the transport of SARS-CoV-2 progeny virions from the ERGIC. Thus, COPI could be a promising target for the development of antivirals against SARS-CoV-2.

microbiology↗

Structural basis of Ebola virus nucleocapsid assembly and functions

The Ebola virus, a member of the Filoviridae family, causes severe hemorrhagic fever in humans. Filamentous virions contain a helical nucleocapsid responsible for genome transcription, replication, and packaging into progeny virions. The nucleocapsid consists of a helical nucleoprotein (NP)-viral genomic RNA complex forming the core structure, to which VP24 and VP35 bind externally. Two NPs, each paired with a VP24 molecule, constitute a repeating unit. However, the detailed nucleocapsid structure remains unclear. Here, we determined the nucleocapsid-like structure within virus-like particles at 4.6 [A] resolution using single-particle cryo-electron microscopy. Mutational analysis identified specific interactions between the two NPs and two VP24s and demonstrated that each of the two VP24s in different orientations distinctively regulates nucleocapsid assembly, viral RNA synthesis, and intracellular transport of the nucleocapsid. Our findings highlight the sophisticated mechanisms underlying the assembly and functional regulation of the nucleocapsid and provide insights into antiviral development.

microbiology↗

Immediate impact of the 2021 harmful algal bloom in southeast Hokkaido on the rocky intertidal community and its spatial variation

There has been a limited number of studies on the effects of harmful algal blooms (HABs) on natural rocky intertidal ecosystems. From mid-September to early November 2021, an unprecedented HAB caused by Karenia selliformis hit the Pacific coast of southeast Hokkaido, Japan, for the first time, causing massive mortalities among marine organisms. To clarify the immediate impacts of the HAB on abundance of 10 rocky intertidal species in four functional groups (macroalgae, sessile invertebrates, molluscan grazers, and molluscan carnivores), we focused on two questions. 1) How did the HAB affect the abundance of each species differently at the regional scale? 2) How did the impacts of the HAB on the abundance of each functional groups vary spatially, and was the spatial variation of the HAB impacts related to the spatial distribution of cell density of HAB species? To study these issues, we compared census data for 17 years before the HAB and within one month after it for five shores on the southeast coast of Hokkaido. Results showed that two macroalgae species and all three molluscan grazer species declined significantly after the HAB. Moreover, the decrease of molluscan grazers was significantly correlated with cell density. These results suggest that the impacts of the HAB in southeast Hokkaido on abundance of rocky intertidal organisms are highly variable depending on species and locality, presumably because of differences in species-specific tolerances to HAB toxins and spatial variation in the density of the HAB organisms.

ecology↗

Isogenic iPSC-derived proximal and distal lung-on-chip models: Tissue- and virus-specific immune responses in human lungs

Micro-physiological systems (MPS) are set to play a vital role in preclinical studies, particularly in the context of future viral pandemics. Nonetheless, the development of MPS is often impeded by the scarcity of reliable cell sources, especially when seeking various organs or tissues from a single patient for comparative analysis of the host immune response. Herein, we developed human airway-on-chip and alveolus-on-chip models using induced pluripotent stem cell (iPSC)-derived isogenic lung progenitor cells. Both models demonstrated the replication of two different respiratory viruses, namely SARS-CoV-2 and Influenza, as well as related cellular damage and innate immune responses-on-chip. Our findings reveal distinct immune responses to SARS-CoV-2 in the proximal and distal lung-on-chip models. The airway chips exhibited a robust interferon (IFN)-dependent immune response, whereas the alveolus chips exhibited dysregulated IFN activation but a significantly upregulated chemokine pathway. In contrast, Influenza virus infection induced a more pronounced immune response and cellular damage in both chip models compared to SARS-CoV-2. Thus, iPSC-derived lung-on-chip models may aid in quickly gaining insights into viral pathology and screening potential drugs for future pandemics.

bioengineering↗

Homeostasis of a representational map in the neocortex

Cortical function in general and the processing of sensory stimuli in particular are remarkably robust against the continuous loss of neurons during aging, and even the accelerated loss during prodromal stages of neurodegeneration1,2. Population activity of neurons in sensory cortices represents the environment in form of a map, which is structured in an informative way for guiding behavior. Here, we used the mouse auditory cortex as a model and tested in how far the structure of the representational map is protected by homeostatic network mechanisms against the removal of neurons. We combined longitudinal two-photon calcium imaging of population responses evoked by a diverse set of sound stimuli with a targeted microablation of functionally characterized neurons. Unilateral microablation of 30 - 40 selected highly sound-responsive neurons in layer 2/3 led to a temporary disturbance of the representational map in the spared population that, however, recovered in subsequent days. At the level of individual neurons, we observed that the recovery of the spared network was predominantly driven by neurons unresponsive to the sounds before microablation which strengthened the correlation structure of the local network after gaining responsiveness. In contrast, selective microablation of inhibitory neurons induced a prolonged disturbance of the representational map that was primarily characterized by a destabilization of sound responses across trials. Together, our findings provide a link between the tuning and plasticity of individual neurons and the structure of a representational map at the population level which reveals homeostatic network mechanisms safeguarding sensory processing in neocortical circuits.

neuroscience↗

Genome-scale CRISPR-Cas9 screen identifies novel host factors as potential therapeutic targets for SARS-CoV-2 infection.

Although many host factors important for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, the mechanisms by which the virus interacts with host cells remain elusive. Here, we identified tripartite motif containing (TRIM) 28, TRIM33, euchromatic histone lysine methyltransferase (EHMT) 1, and EHMT2 as novel proviral factors involved in SARS-CoV-2 infection by CRISPR-Cas9 screening. We demonstrated that TRIM28 plays a role(s) in viral particle formation and that TRIM33, EHMT1, and EHMT2 are involved in viral transcription and replication using cells with suppressed gene expression. UNC0642, a compound that specifically inhibits the methyltransferase activity of EHMT1/2, strikingly suppressed SARS-CoV-2 growth in cultured cells and reduced disease severity in a hamster infection model. This study suggests that EHMT1/2 may be a novel therapeutic target for SARS-CoV-2 infection.

microbiology↗

Trim41 is essential for preventing X chromosome chaotic synapsis in male mice

Meiosis is a hallmark event in germ cell development that accompanies sequential chromosome events executed by numerous molecules. Therefore, characterization of these factors is one of the best strategies to clarify the mechanism of meiosis. Here, we report tripartite motif-containing 41 (TRIM41), a ubiquitin ligase E3, as an essential factor for proper meiotic progression and fertility in male mice. Trim41 KO spermatocytes exhibited synaptonemal complex protein 3 (SYCP3) overloading, especially on the X chromosome, showing extensive self-synapsis of X chromosome and non-homologous synapsis between the X chromosome and autosomes. Furthermore, the mutant mice lacking the RING domain of TRIM41, required for the ubiquitin ligase E3 activity, phenocopied Trim41 KO mice. We then examined the behavior of mutant TRIM41 ({Delta}RING-TRIM41) and found that {Delta}RING-TRIM41 accumulated on the chromosome axes with overloaded SYCP3. This result showed that TRIM41 exerts the function on the chromosome axes. In summary, our study revealed that Trim41 is essential for preventing SYCP3 overloading and chaotic synapsis of the X chromosome, suggesting a TRIM41-mediated mechanism for regulating unsyapsed axes during male meiotic progression. Summary statementTrim41-disruption caused abnormal synapsis configuration of the X chromosome and complete infertility in male mice. Thus, TRIM41 prevents the sex chromosome from chaotic synapsis.

developmental biology↗

Switching of OAS1 splicing isoforms mitigates SARS-CoV-2 infection

BackgroundThe rapidly accumulating disease susceptibility information collected from coronavirus disease (COVID-19) patient genomes must be urgently utilized to develop therapeutic interventions for SARS-CoV-2 infection. Chromosome 12q24.13, which encodes the 2-5-oligoadenylate synthetase (OAS) family of proteins that sense viral genomic RNAs and trigger an antiviral response, is identified as one of the genomic regions that contains SNPs associated with COVID-19 severity. A high-risk SNP identified at the splice acceptor site of OAS1 exon 6 is known to change the proportions of the various splicing isoforms and the activity of the enzyme. MethodsWe employed in-silico motif search and RNA pull-down assay to define a factor responsible for the OAS1 splicing. Next, we rationally selected a candidate for slicing modulator to modulate this splicing. ResultsWe found that inhibition of CDC-like kinase with a small chemical compound induces switching of OAS1 splice isoforms in human lung cells. In this condition, increased resistance to SARS-CoV-2 infection, enhanced RNA degradation, and transcriptional activation of interferon {beta}1, were also observed. ConclusionsThe results indicate the possibility of using chemical splicing modifiers aided by genome-based precision medicine to boost the innate immune response against SARS-CoV-2 infection.

genomics↗

Antiviral face mask functionalized with solidified hand soap: low-cost infection prevention clothing against enveloped viruses such as SARS-CoV-2

Infection prevention clothing is becoming an essential protective tool in the current pandemic, especially because now we know that SARS-CoV-2 can easily infect humans in poorly ventilated indoor spaces. However, commercial infection prevention clothing is made of fabrics that are not capable of inactivating the virus. Therefore, viral infections of symptomatic and asymptomatic individuals wearing protective clothing such as masks can occur through aerosol transmission or by contact with the contaminated surfaces of the masks, which are suspected as an increasing source of highly infectious biological waste. Herein, we report an easy fabrication method of a novel antiviral non-woven fabric containing polymer filaments that were coated with solidified hand soap. This extra protective fabric is capable of inactivating enveloped viruses such as SARS-CoV-2 and phi 6 in one minute of contact. In this study, this antiviral fabric was used to fabricate an antiviral face mask and did not show any cytotoxic effect in human keratinocyte HaCaT cells. Furthermore, this antiviral non-woven fabric could be used for the fabrication of other infection prevention clothing such as caps, scrubs, shirts, trousers, disposable gowns, overalls, hoods, aprons, and shoe covers. Therefore, this low-cost technology could provide a wide range of infection protective tools to combat COVID-19 and future pandemics in developed and underdeveloped countries.

bioengineering↗

Next generation infection prevention clothing: Non-woven Fabrics Coated with Cranberry Extracts Capable of Inactivating Enveloped Viruses such as SARS-CoV-2 and Multidrug-resistant Bacteria

The Coronavirus Disease (COVID-19) pandemic is demanding rapid action of the authorities and scientific community in order to find new antimicrobial solutions that could inactivate the pathogen SARS-CoV-2 that causes this disease. Gram-positive bacteria contribute to severe pneumonia associated with COVID-19, and their resistance to antibiotics is increasing at an alarming rate. In this regard, non-woven fabrics are currently used for the fabrication of infection prevention clothing such as face masks, caps, scrubs, shirts, trousers, disposable gowns, overalls, hoods, aprons and shoe covers as protective tools against viral and bacterial infections. However, these non-woven fabrics are made of materials that do not possess antimicrobial activity. Thus, we have developed here non-woven fabrics with antimicrobial coatings of cranberry extracts capable of inactivating enveloped viruses such as SARS-CoV-2 and the phage phi 6, and two multidrug-resistant bacteria: the methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. The non-toxicity of these advanced technology was ensured using a Caenorhabditis elegans in vivo model. These results open up a new prevention path using natural and biodegradable compounds for the fabrication of infection prevention clothing in the current COVID-19 and future pandemics.

bioengineering↗

Structural insight into Marburg virus nucleoprotein-RNA complex formation

The nucleoprotein (NP) of Marburg virus (MARV), a close relative of Ebola virus (EBOV), encapsidates the single-stranded, negative-sense viral genomic RNA (vRNA) to form the helical NP-RNA complex. The NP-RNA complex serves as a scaffold for the assembly of the nucleocapsid that is responsible for viral RNA synthesis. Although appropriate interactions among NPs and RNA are required for the formation of nucleocapsid, the structural basis of the helical assembly remains largely elusive. Here, we show the structure of the MARV NP-RNA complex determined using cryo-electron microscopy at a resolution of 3.1 [A]. The structures of the asymmetric unit, a complex of an NP and six RNA nucleotides, was very similar to that of EBOV, suggesting that both viruses share common mechanisms for the nucleocapsid formation. Structure-based mutational analysis of both MARV and EBOV NPs identified key residues for the viral RNA synthesis as well as the helical assembly. Importantly, most of the residues identified were conserved in both viruses. These findings provide a structural basis for understanding the nucleocapsid formation and contribute to the development of novel antivirals against MARV and EBOV.

microbiology↗

LRRC23 is a conserved component of the radial spoke that is necessary for sperm motility and male fertility in mice

Cilia and flagella are ancient structures that achieve controlled motor functions through the coordinated interaction of structures including dynein arms, radial spokes (RSs), microtubules, and the dynein regulatory complex (DRC). RSs facilitate the beating motion of these organelles by mediating signal transduction between dyneins and a central pair (CP) of singlet microtubules. RS complex isolation from Chlamydomonas axonemes enabled the detection of 23 different proteins (RSP1-23), with the roles of RSP13, RSP15, RSP18, RSP19, and RSP21 remained poorly understood. Herein, we show that Lrrc23 is an evolutionarily conserved testis-enriched gene encoding an RSP15 homolog in mice. Through immunoelectron microscopy, we demonstrate that LRRC23 localizes to the RS complex within murine sperm flagella. We further found that LRRC23 was able to interact with RSHP9 and RSPH3A/B. The knockout of Lrrc23 resulted in RS disorganization and impaired motility in murine spermatozoa, whereas the ciliary beating was unaffected by the loss of this protein. Spermatozoa lacking LRRC23 were unable to efficiently pass through the uterotubal junction and exhibited defective zona penetration. Together these data indicate that LRRC23 is a key regulator underpinning the integrity of RS complex within the flagella of mammalian spermatozoa, whereas it is dispensable in cilia. Author summary

cell biology↗

Sperm membrane proteins DCST1 and DCST2 are required for the sperm-egg fusion process in mice and fish

The process of sperm-egg fusion is critical for successful fertilization, yet the underlying mechanisms that regulate these steps have remained unclear in vertebrates. Here, we show that both mouse and zebrafish DCST1 and DCST2 are necessary in sperm to fertilize the egg, similar to their orthologs SPE-42 and SPE-49 in C. elegans and Sneaky in D. melanogaster. Mouse Dcst1 and Dcst2 single knockout (KO) spermatozoa are able to undergo the acrosome reaction and show normal relocalization of IZUMO1, an essential factor for sperm-egg fusion, to the equatorial segment. While both single KO spermatozoa can bind to the oolemma, they rarely fuse with oocytes, resulting in male sterility. Similar to mice, zebrafish dcst1 KO males are subfertile and dcst2 and dcst1/2 double KO males are sterile. Zebrafish dcst1/2 KO spermatozoa are motile and can approach the egg, but rarely bind to the oolemma. These data demonstrate that DCST1/2 are essential for male fertility in two vertebrate species, highlighting their crucial role as conserved factors in fertilization.

developmental biology↗

Influenza virus ribonucleoprotein complex formation occurs in the nucleolus

Influenza A virus double-helical ribonucleoprotein complex (vRNP) performs transcription and replication of viral genomic RNA (vRNA). Unlike most RNA viruses, vRNP formation accompanied by vRNA replication is carried out in the nucleus of virus-infected cell. However, the precise subnuclear site remains unknown. Here, we report the subnuclear site of vRNP formation in influenza virus. We found that all vRNP components were colocalized in the nucleolus of virus-infected cells at early stage of infection. Mutational analysis showed that nucleolar localization of viral nucleoprotein, a major vRNP component, is critical for functional double-helical vRNP formation. Furthermore, nucleolar disruption of virus-infected cells inhibited vRNP component assembly into double-helical vRNPs, resulting in decreased vRNA transcription and replication. Collectively, our findings demonstrate that the vRNA replication-coupled vRNP formation occurs in the nucleolus, demonstrating the importance of the nucleolus for influenza virus life cycle.

microbiology↗

Modeling SARS-CoV-2 infection and its individual differences with ACE2-expressing human iPS cells

Genetic differences are a primary reason for differences in the susceptibility and severity of coronavirus disease 2019 (COVID-19). Because induced pluripotent stem (iPS) cells maintain the genetic information of the donor, they can be used to model individual differences in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in vitro. Notably, undifferentiated human iPS cells themselves cannot be infected bySARS-CoV-2. Using adenovirus vectors, here we found that human iPS cells expressing the SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE2) (ACE2-iPS cells) can be infected with SARS-CoV-2. In infected ACE2-iPS cells, the expression of SARS-CoV-2 nucleocapsid protein, the budding of viral particles, the production of progeny virus, double membrane spherules, and double-membrane vesicles were confirmed. We also evaluated COVID-19 therapeutic drugs in ACE2-iPS cells and confirmed the strong antiviral effects of Remdesivir, EIDD-2801, and interferon-beta. In addition, we performed SARS-CoV-2 infection experiments on ACE2-iPS/ES cells from 8 individuals. Male iPS/ES cells were more capable of producing the virus as compared with female iPS/ES cells. These findings suggest that ACE2-iPS cells can not only reproduce individual differences in SARS-CoV-2 infection in vitro, but they are also a useful resource to clarify the causes of individual differences in COVID-19 due to genetic differences. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/432218v1_ufig1.gif" ALT="Figure 1"> View larger version (112K): org.highwire.dtl.DTLVardef@165ec06org.highwire.dtl.DTLVardef@6a9d67org.highwire.dtl.DTLVardef@1840dd3org.highwire.dtl.DTLVardef@a7a4bb_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Protective face mask filter capable of inactivating SARS-CoV-2, and methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis

Face masks have globally been accepted to be an effective protective tool to prevent bacterial and viral transmission, especially against indoor aerosol transmission. However, commercial face masks contain filters that are made of materials that are not capable of inactivating neither SARS-CoV-2 nor multidrug-resistant bacteria. Therefore, symptomatic and asymptomatic individuals can infect other people even if they wear them because some viable viral or bacterial loads can escape from the masks. Furthermore, viral or bacterial contact transmission can occur after touching the mask, which constitutes an increasing source of contaminated biological waste. Additionally, bacterial pathogens contribute to the SARS-CoV-2 mediated pneumonia disease complex and their resistance to antibiotics in pneumonia treatment is increasing at an alarming rate. In this regard, herein, we report the development of a novel protective non-woven face mask filter fabricated with a biofunctional coating of benzalkonium chloride that is capable of inactivating SARS-CoV-2 in one minute of contact, and the life-threatening methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis. Nonetheless, despite the results obtained, further studies are needed to ensure the safety and correct use of this technology for the mass production and commercialization of this broad-spectrum antimicrobial face mask filter. Our novel protective non-woven face mask filter would be useful for many health care workers and researchers working in this urgent and challenging field.

bioengineering↗

Cooperation-based sperm clusters mediate sperm oviduct entry and fertilization

Sperm cooperation has been observed in multiple species, yet its existence and benefit for reproductive success in mammals remains underexplored. Here, combining tissue-clearing with deep three-dimensional imaging, we demonstrate that postcopulatory mouse sperm congregate into unidirectional sperm cooperative clusters at the utero-tubal junction (UTJ), a key physical barrier for passage into the oviduct. Reducing sperm number in male mice by unilateral vasoligation or busulfan-treatment impairs sperm cluster formation and oviduct entry. Interestingly, sperm derived from Tex101-/- mouse has normal number, motility and morphology, yet they cannot form sperm cluster and fail to pass through the UTJ, which is at least in part due to the altered tail beating pattern of the Tex101-/- sperm. Moreover, Tex101-/- sperms defect in oviduct entry cannot be rescued by the presence of wild-type (WT) sperm in the same uteri by sequential mating, suggesting sperm cooperative cluster as an essential behavior contributing to male fertility, which could be related to human infertility or subfertility.

developmental biology↗

vRNA-vRNA interactions in influenza A virus HA vRNA packaging

The genome of the influenza A virus is composed of eight single-stranded negative-sense RNA segments (vRNAs). The eight different vRNAs are selectively packaged into progeny virions. This process likely involves specific interactions among vRNAs via segment-specific packaging signals located in the 3 and 5 terminal coding regions of vRNAs. To identify vRNA(s) that interact with hemagglutinin (HA) vRNA during genome packaging, we generated a mutant virus, HA 5m2, which possessed five silent mutations in the 5 packaging signal region of HA vRNA. The HA 5m2 virus had a specific defect in HA vRNA incorporation, which reduced the viral replication efficiency. After serial passaging in cells, the virus acquired additional mutations in the 5 terminal packaging signal regions of both HA and PB2 vRNAs. These mutations contributed to recovery of viral growth and packaging efficiency of HA vRNA. A direct RNA-RNA interaction between the 5 ends of HA and PB2 vRNAs was confirmed in vitro. Our results indicate that direct interactions of HA vRNA with PB2 vRNA via their packaging signal regions are important for selective genome packaging and enhance our knowledge on the emergence of pandemic influenza viruses through genetic reassortment.

microbiology↗