Biology subjects

Noda, T.

Publications and source records attributed to Noda, T..

42 records · Page 3Linked to original sources

bioRxiv2019

Serine-arginine protein kinase 1 regulates Ebola virus transcription

Ebola virus (EBOV) causes a severe and often fatal disease for which no approved vaccines or antivirals are currently available. EBOV transcription requires the sequential phosphorylation and dephosphorylation of the viral transcription factor VP30. While dephosphorylation is carried out by phosphatases PP2A and PP1, the VP30-specific kinase is unknown. Here, we report that serine-arginine protein kinase 1 and 2 (SRPK1 and SRPK2) phosphorylate serine-29 of VP30, which is located in an N-terminal R26xxS29 motif. Interaction with VP30 via the R26xxS29 motif recruits SRPK1 into EBOV-induced inclusion bodies, the sites of viral RNA synthesis and an inhibitor of SRPK1/SRPK2 downregulates primary viral transcription. When the SRPK1 recognition motif of VP30 was mutated in a recombinant EBOV, virus replication was severely impaired. It is presumed that the interplay between SRPK1 and PP2A in the EBOV inclusions provides a comprehensive regulatory circuit to ensure the activity of VP30 in EBOV transcription.

microbiology↗

bioRxiv2019

Microtubule-dependent transport of arenavirus matrix protein demonstrated using live-cell imaging microscopy.

Lassa virus (LASV), belonging to the family Arenaviridae, causes severe haemorrhagic manifestations and is associated with a high mortality rate in humans. Thus, it is classified as a biosafety level (BSL)-4 agent. Since counter measures for LASV diseases are yet to be developed, it is important to elucidate the molecular mechanisms underlying the life cycle of the virus, including its viral and host cellular protein interactions. These underlying molecular mechanisms may serve as the key for developing novel therapeutic options. Lymphocytic choriomeningitis virus (LCMV), a close relative of LASV, is usually asymptomatic and is categorised as a BSL-2 agent. In the present study, we visualised the transport of viral matrix Z protein in LCMV-infected cells using live-cell imaging microscopy. We demonstrated that the transport of Z protein is mediated by polymerised microtubules. Interestingly, the transport of LASV Z protein showed characteristics similar to those of Z protein in LCMV-infected cells. The live-cell imaging system using LCMV provides an attractive surrogate measure for studying arenavirus matrix protein transport in BSL-2 laboratories. In addition, it could be also utilised to analyse the interactions between viral matrix proteins and the cellular cytoskeleton, as well as to evaluate the antiviral compounds that target the transport of viral matrix proteins.

microbiology↗

bioRxiv2019

A live-cell imaging system for visualizing the transport of Marburg virus nucleocapsid-like structures

Live-cell imaging is a powerful tool for visualization of the spatio-temporal dynamics of living organisms. Although this technique is utilized to visualize nucleocapsid transport in Marburg virus (MARV)- or Ebola virus-infected cells, the experiments require biosafety level-4 (BSL-4) laboratories, which are restricted to trained and authorized individuals. To overcome this limitation, we developed a live-cell imaging system to visualize MARV nucleocapsid-like structures using fluorescence-conjugated viral proteins, which can be conducted outside BSL-4 laboratories. Our experiments revealed that nucleocapsid-like structures have similar transport characteristics to nucleocapsids observed in MARV-infected cells. This system provides a safe platform to evaluate antiviral drugs that inhibit MARV nucleocapsid transport.

molecular biology↗

bioRxiv2018

PTGER2-β-Catenin Axis Links High Salt Environments to Autoimmunity by Balancing IFNγ and IL-10 in FoxP3+ Regulatory T cells

Foxp3+ regulatory T cells (Tregs) are the central component of peripheral immune tolerance. While dysregulation of the Treg cytokine signature has been observed in autoimmune diseases such as multiple sclerosis (MS) and type 1 diabetes, the regulatory mechanisms balancing pro- and anti-inflammatory cytokine production are not known. Here, we identify imbalance between IFN{gamma} and IL-10 as a shared Treg signature, present in patients with MS and under high salt conditions. By performing RNA-seq analysis on human Treg subpopulations, we identify {beta}-catenin as a key regulator that controls the expression of IFN{gamma} and IL-10. The activated {beta}-catenin signature is enriched specifically in IFN{gamma}+Tregs in humans, and this was confirmed in vivo with Treg-specific {beta}-catenin-stabilized mice exhibiting lethal autoimmunity with a dysfunctional, IFN{gamma}-producing, Treg phenotype. Moreover, we identify PTGER2 as a major factor balancing IFN{gamma} and IL-10 production in the context of a high salt environment, with skewed activation of the {beta}-catenin/SGK1/Foxo axis in IFN{gamma}+Tregs. These findings identify a novel molecular mechanism underlying inflammatory Tregs in human autoimmune disease and reveal a new role for a PTGER2-{beta}-catenin loop in Tregs linking environmental high salt conditions to autoimmunity.

immunology↗

bioRxiv2018

National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB): Outline and Patient-Matching Technique

BackgroundThe National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) is a comprehensive database of health insurance claims data under Japans National Health Insurance system. The NDB uses two types of personal identification variables (referred to in the database as \"ID1\" and \"ID2\") to link the insurance claims of individual patients. However, the information entered against these ID variables is prone to change for several reasons, such as when claimants find or change employment, or due to variations in the spelling of their name. In the present study, we developed a new patient-matching technique that improves upon the existing system of using ID1 and ID2 variables. We also sought to validate a new personal ID variable (ID0) that we propose in order to enhance the efficiency of patient matching in the NDB database.\n\nMethodsOur study targeted data from health insurance claims filed between April 2013 and March 2016 for hospitalization, combined diagnostic procedures, outpatient treatment, and dispensing of prescription medication. We developed a new patient-matching algorithm based on the ID1 and ID2 variables, as well as variables for treatment date and clinical outcome. We then attempted to validate our algorithm by comparing the number of patients identified by patient matching with the current ID1 variable and our proposed ID0 variable against the estimated patient population as of 1 October 2015.\n\nResultsThe numbers of patients in each sex and age group that were identified with the ID0 variable were lower than those identified using the ID1 variable. By using the ID0 variable, we were able to reduce the number of duplicate records for male and female patients by 5.8% and 6.4%, respectively. The numbers of children, adults older than 75 years, and women of reproductive age identified using the ID1 patient-matching variable were all higher than their corresponding estimates. Conversely, the numbers of these patients identified with the ID0 patient-matching variable were all within their corresponding estimates.\n\nConclusionOur findings show that the proposed ID0 variable delivers more precise patient-matching results than the existing ID1 variable. The ID0 variable is currently the best available technique for patient matching in the NDB database. Future patient population estimates should therefore rely on the ID0 variable instead of the ID1 variable.

epidemiology↗

bioRxiv2017

Identifying developmentally important genes with single-cell RNA-seq from an embryo

Single-cell RNA-seq has been established as a reliable and accessible technique enabling new types of analyses, such as identifying cell types and studying spatial and temporal gene expression variation and change at single-cell resolution. Recently, single-cell RNA-seq has been applied to developing embryos, which offers great potential for finding and characterising genes controlling the course of development along with their expression patterns. In this study, we applied single-cell RNA-seq to the 16-cell stage of the Ciona embryo, a marine chordate and performed a computational search for cell-specific gene expression patterns. We recovered many known expression patterns from our single-cell RNA-seq data and despite extensive previous screens, we succeeded in finding new cell-specific patterns, which we validated by in situ and single-cell qPCR.

developmental biology↗