Biology subjects

Asano, K.

Publications and source records attributed to Asano, K..

10 recordsLinked to original sources

bioRxiv2026

The epidermal stem cell-supporting matricellular protein fibulin 7 modulates skin inflammatory response in a psoriasis model

ECM composition and organization are greatly altered during inflammation but it is still elusive if ECM dynamics may protect tissue stem cells against aberrant inflammation. Fibulin 7 (encoded by Fbln7) is part of the basement membrane ECM where epidermal stem cells (EpSCs) reside. It supports the long-term potential of fast-cycling EpSCs and moderates aging-related inflammatory markers in keratinocytes. Here, we assessed fibulin 7s role during imiquimod (IMQ)-induced inflammation in 1-year-old mouse dorsal skin. We found that loss of Fbln7 aggravates epidermal inflammation, marked by increased epidermal thickness, proliferation, and phosphorylation of JNK (c-Jun N-terminal kinase). Fast-cycling EpSCs labeled with Slc1a3-creER-TdTomato demonstrated that IMQ-induced proliferation in Fbln7 KO mice is contributed by cell divisions in the suprabasal layers, a hallmark of inflammatory epidermal responses. EpSC transcriptomes further reveal IMQ-modulated genes that are more substantially affected in Fbln7 KO mice, including IL-17 pathway-related genes known in psoriasis pathogenesis. Mechanistically, fibulin 7 directly binds to IL-17A and decreases IL-17A-mediated p38 MAPK activation. In public human psoriasis datasets, FBLN7 is reduced in lesional skin compared with non-lesional or normal skin, and it is significantly correlated with common psoriasis-associated genes. Altogether, fibulin 7 is potentially beneficial to protect against skin inflammation.

cell biology↗

bioRxiv2025

Biofilm Formation by Pseudomonas aeruginosa in Medium Supplemented with Adult Bovine Serum and the Anti-Biofilm Activity of β-Lactam Antibiotics

Pseudomonas aeruginosa is a major opportunistic pathogen known for its ability to form biofilms in vivo, which contributes significantly to its resistance to antimicrobial treatment. In this study, we examined the biofilm-forming capacity of a clinical isolate cultured in medium supplemented with 30% adult bovine serum (ABS). Under these host-mimicking conditions, mature biofilms developed on microplate surfaces within 8 hours. Among the {beta}-lactam antibiotics evaluated, piperacillin and cefoperazone exhibited potent anti-biofilm activity at concentrations as low as 1/8,192 to 1/256 of their respective minimum inhibitory concentrations (MICs). In contrast, ceftazidime and meropenem required significantly higher concentrations (approximately 1/16 MIC) to produce similar effects. The anti-biofilm activity of piperacillin and cefoperazone was abolished when ABS was defatted with n-hexane or when magnesium sulfate was added to the medium, suggesting that a lipid-dependent membrane permeabilization mechanism may be involved. These findings highlight the utility of host-mimicking conditions in evaluating the activity of antibiotics against biofilms and suggest that certain {beta}-lactam agents may have previously unrecognized anti-biofilm effects mediated through serum-associated components.

microbiology↗

bioRxiv2024

A novel genetic mouse model of fatal aortic dissection reveals massive inflammatory cell infiltration in the thoracic aorta

BackgroundAortic dissection (AD) is the separation of medial layers of the aorta and is a major cause of death in patients with connective tissue disorders such as Marfan syndrome. However, molecular triggers instigating AD, its temporospatial progression, and how vascular cells in each vessel layer interact and participate in the pathological process remain incompletely understood. To unravel the underlying molecular mechanism of AD, we generated a spontaneous AD mouse model. MethodsWe incorporated a novel missense variant (p.G234D) in FBN1, the gene for fibrillin-1, identified in a non-syndromic familial AD patient into mice using CRISPR/Cas9 system. We performed histopathological analyses of the aortic lesions by histology, immunofluorescence staining, electron microscopy, synchrotron-based imaging and single-cell (sc)RNA-sequencing. Biochemical analysis was performed to examine the binding capacity of mutant human FBN1G234D protein to latent Tgf{beta} binding proteins (LTBPs), and signaling pathways in the mutant aortic wall were examined by western blot analysis. Results50% of the Fbn1G234D/G234D mutant mice died within 5 weeks of age from multiple intimomedial tears that expanded longitudinally and progressed to aortic rupture accompanied by massive immune cell infiltration. scRNA-sequencing, validated by immunostaining, revealed a significant increase in MHC class II-positive pro-inflammatory macrophages and monocytes at the site of intima tears with upregulation of MMP2/9 and marked disruption of elastic lamina. Subendothelial matrices, such as type IV collagen and laminin, expanded into the medial layer, where fibronectin expression was highly upregulated. Fbn1G234D/G234D endothelial cells exhibited altered mechanosensing with loss of parallel alignment to blood flow and upregulation of VCAM-1 and ICAM-1, all of which likely contributed to the infiltration of immune cells. Biochemically, FBN1G234D lost the ability to bind to latent TGF{beta} binding protein (LTBP)-1, -2, and -4, resulting in the downregulation of TGF{beta} signaling in the aortic wall. ConclusionsWe show that dynamic interactions involving endothelial cells (ECs) and macrophages/monocytes in the intima, where the ECM microenvironment is altered with the reduced TGF{beta} signaling, contributes to the initiation of AD. Our novel AD mouse model provides a unique opportunity to identify target molecules involved in the intimomedial tears that can be utilized for development of therapeutic strategies.

pathology↗

bioRxiv2023

Development of KASP markers for the potato virus Y resistance gene Rychc using whole-genome resequencing data

Potato virus Y is the most important potato virus worldwide, affecting tuber yield and quality. The resistance gene Rychc, derived from the potato wild relative Solanum chacoense, provides broad spectrum and durable resistance to the virus and has been used to develop resistant cultivars. Several DNA markers have been developed and have contributed to the efficient selection of resistant individuals. In this study, we developed Kompetitive Allele Specific PCR markers for Rychc using whole-genome resequencing data for a diverse set of 25 PVY susceptible cultivars and a Rychc-positive clone. Marker Ry_4099 targets two variants in the 3-UTR and was able to discriminate all five allele dosages in a tetraploid test population. Marker Ry_3331 targets two variants in Exon 4 and, although it only provides presence/absence information, it discriminates between the two known resistant alleles of Rychc. These markers will greatly contribute to efficient development of resistant cultivars.

plant biology↗

bioRxiv2023

Inosine Induces Stemness Features in CAR T cells and Enhances Potency

Adenosine (Ado) mediates immune suppression in the tumor microenvironment and exhausted CD8+ CAR T cells mediate Ado-induced immunosuppression through CD39/73-dependent Ado production. Knockout of CD39, CD73 or A2aR had modest effects on exhausted CAR T cells, whereas overexpression of Ado deaminase (ADA), which metabolizes Ado to inosine (INO), induced stemness features and potently enhanced functionality. Similarly, and to a greater extent, exposure of CAR T cells to INO augmented CAR T cell function and induced hallmark features of T cell stemness. INO induced a profound metabolic reprogramming, diminishing glycolysis and increasing oxidative phosphorylation, glutaminolysis and polyamine synthesis, and modulated the epigenome toward greater stemness. Clinical scale manufacturing using INO generated enhanced potency CAR T cell products meeting criteria for clinical dosing. These data identify INO as a potent modulator of T cell metabolism and epigenetic stemness programming and deliver a new enhanced potency platform for immune cell manufacturing. Statement of SignificanceAdenosine is well known to inhibit T cell function and substantial effort has focused on inhibiting adenosine generation and signaling. Here, we show that exhausted T cells are suppressed by adenosine, which is only modestly impacted by inhibiting adenosine generation or signaling. In contrast, metabolism of adenosine to inosine augmented T cell function and culture of T cells with inosine induced multi-level reprogramming leading to stemness and improved anti-tumor potency. We demonstrate the feasibility of introducing inosine during GMP cell manufacturing as a novel strategy to generate enhanced CAR-T cells.

immunology↗

bioRxiv2022

Zika virus spreads through infection of lymph node-resident macrophages

Zika virus (ZIKV) is an arthopod-vectored flavivirus that disseminates from the infection site into peripheral tissues, where it can elicit virus-induced pathology. To move through the body, ZIKV is thought to exploit the mobility of myeloid cells, in particular monocytes and dendritic cells. However, multiple distinct steps during viral spread culminate in peripheral tissue infection, and the timing and mechanisms underlying mobile immune cell shuttling of virus remain unclear. To understand the very early steps in ZIKV dissemination from the skin, we kinetically and spatially mapped ZIKV-infected lymph nodes (LNs), an intermediary stop en route to the blood. Contrary to dogma, migratory immune cells were not required for large quantities of virus to reach the LN or blood. Instead, ZIKV rapidly infected a subset of immobile macrophages in the LN, which shed virus through the lymphatic pathway into the blood. Importantly, infection of LN macrophages alone was sufficient to initiate viremia. Together, our studies indicate that sessile macrophages that live and die in the LN contribute to initial ZIKV spread to the blood. These data build a more complete picture of ZIKV movement through the body and identify an alternate anatomical site for potential antiviral intervention. HighlightsO_LIZIKV infects and replicates in distinct LN macrophage populations C_LIO_LILN macrophage infection results in infectious virus in the blood C_LIO_LIVirus reaches the blood in the absence of DC migration or monocyte infection C_LIO_LINodal macrophage infection does not sustain viremia or induce morbidity C_LI Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=74 HEIGHT=200 SRC="FIGDIR/small/508424v1_ufig1.gif" ALT="Figure 1"> View larger version (44K): org.highwire.dtl.DTLVardef@121bc33org.highwire.dtl.DTLVardef@1caf24borg.highwire.dtl.DTLVardef@e94a08org.highwire.dtl.DTLVardef@1fb6f62_HPS_FORMAT_FIGEXP M_FIG Caption: ZIKV infects lymph node macrophages, which shed infectious virus into the lymph and then blood. C_FIG

microbiology↗

bioRxiv2022

Enhanced Mirror Neuron Network Activity and Effective Connectivity during Live Interaction

Facial expressions are indispensable in daily human communication. Previous neuroimaging studies investigating facial expression processing have presented pre-recorded stimuli and lacked live face-to-face interaction. Our paradigm alternated between presentations of real-time model performance and pre-recorded videos of dynamic facial expressions to participants. Simultaneous functional magnetic resonance imaging (fMRI) and facial electromyography activity recordings, as well as post-scan valence and arousal ratings were acquired from 44 female participants. Live facial expressions enhanced the subjective valence and arousal ratings as well as facial muscular responses. Live performances showed greater engagement of the right posterior superior temporal sulcus (pSTS), right inferior frontal gyrus (IFG), right amygdala and right fusiform gyrus, and modulated the effective connectivity within the right mirror neuron system (IFG, pSTS, and right inferior parietal lobule). A support vector machine algorithm could classify multivoxel activation patterns in brain regions involved in dynamic facial expression processing in the mentalizing networks (anterior and posterior cingulate cortex). These results indicate that live social interaction modulates the activity and connectivity of the right mirror neuron system and enhances spontaneous mimicry, further facilitating emotional contagion. HighlightsO_LIWe alternately presented real-time and pre-recorded dynamic facial expressions. C_LIO_LILive facial expressions enhanced emotion contagion and spontaneous facial mimicry. C_LIO_LILive conditions modulated mirror neuron system activity and effective connectivity. C_LIO_LIThe mentalizing network showed distinctive multivoxel patterns in live conditions. C_LIO_LIThe results support the validity of second-person design in social neuroscience. C_LI

neuroscience↗

bioRxiv2021

Septin-microtubule association requires a MAP-like motif unique to Sept9 isoform 1 embedded into septin octamers

Septins, a family of GTP-binding proteins assembling into higher order structures, interface with the membrane, actin filaments and microtubules, which positions them as important regulators of cytoarchitecture. Septin 9 (Sept9), which is frequently overexpressed in tumors and mutated in hereditary neuralgic amyotrophy (HNA), mediates the binding of septins to microtubules, but the molecular determinants of this interaction remained uncertain. We demonstrate that a short MAP-like motif unique to Sept9 isoform 1 (Sept9_i1) drives septin octamer-microtubule interaction in cells and in vitro reconstitutions. Septin-microtubule association requires polymerizable septin octamers harboring Sept9_i1. Although outside of the MAP-like motif, HNA mutations abrogates this association, identifying a putative regulatory domain. Removal of this domain from Sept9_i1 sequesters septins on microtubules, promotes microtubule stability and alters actomyosin fiber distribution and tension. Thus, we identify key molecular determinants and potential regulatory roles of septin-microtubule interaction, paving the way to deciphering the mechanisms underlying septin associated pathologies.

cell biology↗

bioRxiv2021

Free Energy Landscape of RNA Binding Dynamics in Start Codon Recognition by Eukaryotic Ribosomal Pre-Initiation Complex

Specific interaction between the start codon, 5-AUG-3, and the anticodon, 5-CAU-3, ensures accurate initiation of translation. Recent studies show that several near-cognate start codons (e.g. GUG and CUG) can play a role in initiating translation in eukaryotes. However, the mechanism allowing initiation through mismatched base-pairs at the ribosomal decoding site is still unclear at an atomic level. In this work, we propose an extended simulation-based method to evaluate free energy profiles, through computing the distance between each base-pair of the triplet interactions (d1, d2 and d3) involved in recognition of start codons in eukaryotic translation pre-initiation complex. Our method provides not only the free energy penalty ({Delta}{Delta}G) for mismatched start codons relative to the AUG start codon, but also the preferred pathways of transitions between bound and unbound states, which has not been described by previous studies. To verify the method, the binding dynamics of cognate (AUG) and near-cognate start codons (CUG and GUG) were simulated. Evaluated free energy profiles agree with experimentally observed changes in initiation frequencies from respective codons. This work proposes for the first time how a G:U mismatch at the first position of codon (GUG)-anticodon base-pairs destabilizes the accommodation in the initiating eukaryotic ribosome and how initiation at a CUG codon is nearly as strong as, or sometimes stronger than, that at a GUG codon. Our method is expected to be applied to study the affinity changes for various mismatched base-pairs.

biophysics↗

bioRxiv2017

A portable system for metagenomic analyses using nanopore-based sequencer and laptop computers can realize rapid on-site determination of bacterial compositions

We developed a portable system for metagenomic analyses consisting of nanopore technology-based sequencer, MinION, and laptop computers, and assessed its potential ability to determine bacterial compositions rapidly. We tested our protocols using mock bacterial community that contained equimolar 16S rDNA and a pleural effusion from a patient with empyema for time effectiveness and accuracy. MinION sequencing targeting 16S rDNA detected all of 20 bacteria present in the mock bacterial community. Time course analysis indicated that sequence data obtained during the first 5-minute sequencing were enough to detect all 20 bacteria species in the mock sample and determine their compositions with sufficient accuracy. Additionally, using a clinical sample extracted from the pleural effusion of a patient with empyema, we could identify major bacteria in a pleural effusion by rapid sequencing and analysis. All of these results are comparable to or even better than the conventional 16S rDNA sequencing results using IonPGM sequencer. Our results suggest that rapid sequencing and bacterial composition determination is possible within 2 hours.Our integrative system is applicable to rapid diagnostic tests for infectious diseases in near future.

genomics↗