Biology subjects

Matsumoto, Y.

Publications and source records attributed to Matsumoto, Y..

45 records · Page 3Linked to original sources

bioRxiv2020

A possible stimulus to induce SPAWNING in Ezo abalone Haliotis discus hannai during a stormy condition: Fenton reaction induces spawning behavior

Synchronous spawning is an important behavior to increase fertilization success of invertebrates with external fertilization. Previous work has shown that it is possible to induce spawning behavior using free radicals in tank experiments, but the stimulus for spawning in the wild is not fully understood. Ezo abalone Haliotis discus hannai mainly spawn during stormy weather. Rainwater contains H2O2 and iron (II) ions (Fe2+). We propose that during stormy weather water layers in the ocean are mixed and the surface layer containing H2O2 and Fe2+ interacts with the ocean bottom; this leads to conditions suitable for the Fenton reaction to occur. Hydroxyl radicals ({middle dot}OH) are generated during the oxidization of Fe2+ by H2O2 and we hypothesized these induce spawning behavior of abalone in the wild. This study observed that H. discus hannai released eggs after salinity decreased due to the rainfall during stormy conditions. In addition, our tank experiment demonstrated that {middle dot}OH generated by the Fenton reaction induced synchronous spawning behavior between the sexes. This study provides a new hypothesis about control of synchronous spawning in H. discus hannai and the results could be applicable to other invertebrates.

zoology↗

bioRxiv2020

SARS-CoV-2 Spike Protein Interacts with Multiple Innate Immune Receptors

The spike (S) glycoprotein in the envelope of SARS-CoV-2 is densely glycosylated but the functions of its glycosylation are unknown. Here we demonstrate that S is recognized in a glycan-dependent manner by multiple innate immune receptors including the mannose receptor MR/CD206, DC-SIGN/CD209, L-SIGN/CD209L, and MGL/CLEC10A/CD301. Single-cell RNA sequencing analyses indicate that such receptors are highly expressed in innate immune cells in tissues susceptible to SARS-CoV-2 infection. Binding of the above receptors to S is characterized by affinities in the picomolar range and consistent with S glycosylation analysis demonstrating a variety of N- and O-glycans as receptor ligands. These results indicate multiple routes for SARS-CoV-2 to interact with human cells and suggest alternative strategies for therapeutic intervention.

biochemistry↗

bioRxiv2020

Reduced intra- and inter-individual diversity of semantic representations in the brains of schizophrenia patients

Schizophrenia patients often manifest semantic processing deficits. It has been proposed that these deficits stem from disorganized semantic representations in the brain. However, no study has yet examined the neural correlates of semantic disorganization by directly evaluating semantic representations in the brain. We used voxelwise modeling on functional magnetic resonance imaging signals to evaluate the semantic representations associated with several thousand words in individual patient brains. We then compared the structural properties of semantic representations to those in healthy controls. The variability of semantic representations was smaller both within individual patients and across patients compared to controls. Surrogate data analysis suggests that the observed reduction in representational variability is associated with disorganization of categorical information. To our knowledge, these findings provide the first evidence for sematic disorganization in schizophrenia at the level of brain representations.

neuroscience↗

bioRxiv2020

AnAms1.0: A high-quality chromosome-scale assembly of a domestic cat Felis catus of American Shorthair breed

The domestic cat (Felis catus) is one of the most popular companion animals in the world. Comprehensive genomic resources will aid the development and application of veterinary medicine including to improve feline health, in particular, to enable precision medicine which is promising in human application. However, currently available cat genome assemblies were mostly built based on the Abyssinian cat breed which is highly inbred and has limited power in representing the vast diversity of the cat population. Moreover, the current reference assembly remains fragmented with sequences contained in thousands of scaffolds. We constructed a reference-grade chromosome-scale genome assembly of a domestic cat, Felis catus genome of American Shorthair breed, Anicom American shorthair 1.0 (AnAms1.0) with high contiguity (scaffold N50 > 120 Mb), by combining multiple advanced genomic technologies, including PacBio long-read sequencing as well as sequence scaffolding by long-range genomic information obtained from Hi-C and optical mapping data. Homology-based and ab initio gene annotation was performed with the Iso-Seq data. Analyzed data is be publicly accessible on Cats genome informatics (Cats-I, https://cat.annotation.jp/), a cat genome database established as a platform to facilitate the accumulation and sharing of genomic resources to improve veterinary care.

genomics↗

bioRxiv2020

Genetic characterization of Streptococcus pyogenes emm 89 strains isolated in Japan from 2011 to 2019

Streptococcal toxic shock syndrome (STSS) caused by Streptococcus pyogenes emm89 strains has been increasing in several countries and reported to be linked with a recently emerged clade of emm89 strains, designated clade 3. In Japan, epidemiological and genetic information for emm89 strains remains elusive. In this study, we utilized emm89 strains isolated from both STSS (89 isolates) and non-STSS (72 isolates) infections in Japan from 2011 to 2019, and conducted whole-genome sequencing and comparative analysis, which resulted in classification of a large majority into clade 3 regardless of disease severity. In addition, STSS-associated genes and SNPs were found in clade 3 strains, including mutations of streptokinase (Ska), control of virulence sensor (CovS), serum opacity factor (SOF), sortase (SrtB), and fibronectin-binding protein F1 (PrtF1), and absence of the hylP1 gene encoding hyaluronidase. These findings provide insights into notable genetic features of emm89 strains.

microbiology↗

bioRxiv2019

Uncovering Staphylococcus aureus genes with roles in pathogenicity by silkworm infection model

The regulatory network of virulence factors production by Staphylococcus aureus, an opportunistic pathogen, is incompletely understood, and the functions of many uncharacterized genes in its genome remain to be uncovered. We screened 380 function unassigned genes disrupted mutants of the community-acquired methicillin-resistant S. aureus USA300 for pathogenicity using silkworms and identified 11 strains with reduced silkworm killing ability. Nine out of the 11 strains displayed reduced virulence in the mouse model as evidenced by reduced colony-forming units in organs of the infected mice. Three of the identified gene-disrupted mutants had reduced hemolytic activity, one among the three also had reduced proteolytic activity and pigment production. These results suggest that silkworm model could identify the genes required for virulence in the mouse model. The newly identified genes involved in virulence in this study facilitates the further understanding of the pathogenicity of S. aureus.\n\nImportanceWe performed a large scale screening of mutants of Staphylococcus aureus with disruption in function unassigned genes using silkworm infection model and identified eleven genes required for full virulence in silkworm. Nine of the eleven genes were involved in virulence in mice and were previously not known to aggravate virulence of S. aureus. The results suggest that silkworm model is suitable for quantitative measurement of virulence, which is shared between silkworms and mammals.

microbiology↗

bioRxiv2019

Estrogen induces mammary ductal dysplasia.

Mammary ductal dysplasia is a phenotype observed in precancerous lesions and early-stage breast cancer. However, the mechanism of dysplasia formation remains elusive. Here we show, by establishing a novel dysplasia model system, that estrogen, a female hormone, has the potential to cause mammary ductal dysplasia. We injected estradiol (E2), the most active form of estrogen, daily into scid mice with a defect in nonhomologous end joining repair and observed dysplasia formation with cell proliferation at day 30. Moreover, we found that isoflavones inhibited E2-induced dysplasia formation. Our dysplasia model system provides insight into the mechanistic understanding of breast tumorigenesis, and the development of breast cancer prevention.

cancer biology↗

bioRxiv2018

Functionalized mesoporous silica nanoparticles for innovative boron-neutron capture therapy of resistant cancers

Treatment resistance, relapse and metastasis remain critical issues in some challenging cancers, such as chondrosarcomas. Boron-neutron Capture Therapy (BNCT) is a targeted radiation therapy modality that relies on the ability of boron atoms to capture low energy neutrons, yielding high linear energy transfer alpha particles. We have developed an innovative boron-delivery system for BNCT, composed of multifunctional fluorescent mesoporous silica nanoparticles (B-MSNs), grafted with an activatable cell penetrating peptide (ACPP) for improved penetration in tumors and with Gadolinium for magnetic resonance imaging (MRI) in vivo. Chondrosarcoma cells were exposed in vitro to an epithermal neutron beam after B-MSNs administration. BNCT beam exposure successfully induced DNA damage and cell death, including in radio-resistant ALDH+ cancer stem cells (CSCs), suggesting that BNCT using this system might be a suitable treatment modality for chondrosarcoma or other hard-to-treat cancers.

cancer biology↗

bioRxiv2018

Overlapping but asymmetrical relationships between schizophrenia and autism revealed by brain connectivity

(Abstract included 248 words)Although the relationship between schizophrenia spectrum disorder (SSD) and autism spectrum disorder (ASD) has long been debated, it has not yet been fully elucidated. To address this issue, we took advantage of dual (ASD and SSD) classifiers that discriminate patients from their controls based on resting state brain functional connectivity. An SSD classifier using sophisticated machine-learning algorithms that automatically selected SSD- specific functional connections was applied to Japanese datasets including adult patients with SSD in a chronic stage. We demonstrated good performance of the SSD classification for independent validation cohorts. The generalizability was tested by USA and European cohorts in a chronic stage, and one USA cohort including first episode schizophrenia. The specificity was tested by two adult Japanese cohorts of ASD and major depressive disorder, and one European cohort of attention-deficit hyperactivity disorder. The weighted linear summation of the classifiers functional connections constituted the biological dimensions representing neural liability to the disorders. Our previously developed robust ASD classifier constituted the ASD dimension. Distributions of individuals with SSD, ASD and healthy controls were examined on the SSD and ASD biological dimensions. The SSD and ASD populations exhibited overlapping but asymmetrical patterns on the two biological dimensions. That is, the SSD population showed increased liability on the ASD dimension, but not vice versa. Furthermore, the two dimensions were correlated within the ASD population but not the SSD population. Using the two biological dimensions based on resting-state functional connectivity enabled us to quantify and visualize the relationships between SSD and ASD.

neuroscience↗