Biology subjects

Sugishita, H.

Publications and source records attributed to Sugishita, H..

8 recordsLinked to original sources

bioRxiv2026

Polycomb establishes TAD-scale H3K27me3 mega-domains to safeguard neuronal identity

During development, pluripotent stem cells generate diverse cell types through gene regulatory networks orchestrated by combinations of transcription factors (TFs). Following terminal differentiation, however, cellular identities become remarkably stable and resistant to TF-mediated perturbation, yet the mechanisms underlying this stability remain poorly understood. Here, we identify Polycomb repressive complexes (PRCs) as key regulators of neuronal identity maintenance. Although PRCs are well known for repressing the promoters of developmental genes during early cell fate specification, we unexpectedly find that PRC-mediated H3K27me3 expands into megabase-scale domains during neuronal maturation that align with topologically associating domains (TADs). These H3K27me3 "mega-domains" selectively encompass genes associated with alternative neural and non-neural lineages. While depletion of H3K27me3 in mature neurons has only modest effects on basal gene expression, it significantly increases neuronal activity-dependent c-FOS binding and induction of lineage-inappropriate genes within these mega-domains. Our findings reveal a previously unrecognized role for PRCs in establishing TAD-scale repressive chromatin domains during neuronal maturation, thereby safeguarding neuronal identity from external stimuli through broad silencing of alternative cell fate programs.

developmental biology↗

bioRxiv2026

Type I IFN dynamics define an early checkpoint for survival and orchestrate systemic neutrophil heterogeneity in lethal viral infection

The early host response is critical for protection against viral infections, yet the systemic events that dictate individual differences in outcomes remain poorly defined. Here, we leveraged variability in survival following intranasal vesicular stomatitis virus (VSV) challenge in genetically identical mice to retrospectively profile systemic immune responses associated with survival or lethality. Survival was strongly associated with a robust systemic type I interferon (IFN) surge within 24 hours of infection, and blockade of type I IFN signaling during this narrow early window markedly reduced survival, establishing early IFN induction as a key determinant of outcome. This protective IFN surge rapidly remodeled the systemic immune landscape. Single-cell profiling revealed a transcriptionally and functionally distinct ICAM1 neutrophil subset as the strongest early correlate of survival, primed within the bone marrow. ICAM1 neutrophils exhibited a pro-inflammatory signature and enhanced phagocytic activity compared with ICAM1- neutrophils, which predominated in lethal outcomes. Together, these findings define a type I IFN-driven early checkpoint that governs survival in lethal viral infection and identify ICAM1 neutrophils as a blood-accessible biomarker of protective immunity, highlighting the critical role of early innate immune dynamics in shaping disease trajectories and providing a framework for early prognostic markers and host-directed therapies.

immunology↗

bioRxiv2025

Local niche-derived immunosuppressive CXCR2+ cells impair antiviral immunity

Symptom severity after viral infection varies among individuals, yet its mechanism remains poorly understood. We categorized mice into recovering and non-recovering groups based on body weight after infection of the same titer of vesicular stomatitis virus (VSV). We revealed that in the olfactory bulb (OB) where VSV initially expands, non-recovering mice exhibited an anti-inflammatory environment, suggesting its detrimental effect. Importantly, CXCR2+ cells resembling immunosuppressive myeloid-derived suppressor cells (MDSCs) were more abundant in the OB of non-recovering mice than in that of recovering mice after VSV infection. Depleting CXCR2+ MDSC-like cells from the brain increased inflammatory responses and the animals survival after infection. Furthermore, site-specific labeling indicated that a significant fraction of these cells in the OB originate from the skull-bone marrow (skull-BM) as well as circulation. This study reveals the lethal effects of CXCR2+ MDSC-like cells on local immune responses to viral infection, highlighting their therapeutic potential for antiviral defense.

immunology↗

bioRxiv2023

A centrifugation-based method for high-throughput biomaterial separation using magnetic microbeads

Magnetic microbeads are small iron oxide nanoparticles coated with a bioaffinity material that selectively binds to specific biomolecules of interest, enabling their capture and isolation from complex biological samples. Magnetic microbeads are widely used for purification of specific biomolecules in various experiments in molecular biology. However, current methods of manual pipetting to separate supernatants from magnetic microbeads are often inefficient- time-consuming, labor intensive and inaccurate. Furthermore, the use of pipetting robots and liquid handlers specifically designed for multi-well plates can be a cost-prohibitive approach due to the high cost of equipment and disposable supplies. Here, we developed a centrifugation-based method for high-throughput separation of supernatant from magnetic microbeads. To facilitate the centrifugal separation process, we used the 384 transfer plate (Watson, Japan) and a magnetic stand equipped with a 384-well magnetic stand, allowing easy handling of several hundred samples and rapid separation of supernatant from magnetic microbeads. The centrifugal force was used to drive the separation of target molecules from the magnetic microbeads, and sample were successfully separated with relatively high recovery rates. Thus, this technology provides a simple, rapid, and cost- and labor-effective biomolecule separation method with potential applications in various fields, including molecular biology, clinical diagnostics, and biotechnology, and is a valuable addition to the existing toolbox of biomolecule separation methods.

molecular biology↗

bioRxiv2021

Three-dimensional chromatin architecture of early-stage mouse embryos reconstructed via recurrence plots

The chromatin conformation capture-related methods such as Hi-C have improved our understanding of nuclear architecture and organization in recent years. However, reconstruction of nuclear architecture from single-cell Hi-C (scHi-C) data is challenging due to limited information of DNA contacts obtained from a single cell. We have previously developed the Recurrence Plot-Based Reconstruction (RPR) method for reconstructing three dimensional (3D) genomic structure from Hi-C data of single haploid cells (1) and diploid cells (2). This algorithm is based on a recurrence plot, a tool of nonlinear time-series analysis for visualizing patterns within a time series (3, 4), and enables the reconstruction of a unique 3D chromosome architecture even from low-coverage DNA contact information. Here we used the RPR method to analyzing published scHi-C data of diploid cells derived from early-stage F1 hybrid embryos (5) as a proof-of-concept for understanding of global developmental changes in chromosomal architecture of early stage embryos. We found that paternal and maternal chromosomes become gradually intermingled from 1 cell to 64 cell stage, and that discrete chromosome territories are largely established between 8 cell and 64 cell stages. We also observed Rabl-like polarization of chromosomes from the 2-to 8-cell stages, but this polarization becomes mostly dissolved by the 64-cell stage. Rabl-like chromosome polarization precedes rod-like extension and parallel alignment of chromosomes, implicating the role of Rabl-like polarization in effective mixing of chromosomes before establishing chromosome territories. We also found cell-to-cell variability in chromatin configuration. A combination of scHi-C and RPR analyses can depict features of the 3D chromatin architecture of individual cells at different developmental stages during early embryogenesis.

developmental biology↗

bioRxiv2021

Preparation of "stress-free" concanavalin A-conjugated Dynabeads magnetic beads for CUT&Tag

Epigenome research has employed various methods to identify genomic location of proteins of interest, such as transcription factors and histone modifications. A recently established method called CUT&Tag uses a Protein-A Tn5 transposase fusion protein, which cuts the genome and inserts adapter sequences nearby the target protein. Throughout most of the CUT&Tag procedure, cells are held on concanavalin A (con A)-conjugated magnetic beads. Proper holding of cells would be decisive for the accessibility of Tn5 to the chromatin, and efficacy of the procedure of washing cells. However, BioMag(R)Plus ConA magnetic beads, used in the original CUT&Tag protocol, often exhibit poor suspendability and severe aggregation. Here, we compared the BioMag beads and Dynabeads(R) magnetic particles of which conjugation of con A was done by our hands, and examined the performance of these magnetic beads in CUT&Tag. Among tested, one of the Dynabeads, MyOne-T1, kept excessive suspendability in a buffer even after overnight incubation. Furthermore, the MyOne-T1 beads notably improved the sensitivity in CUT&Tag assay for H3K4me3. In conclusion, the arrangement and the selection of MyOne-T1 refine the suspendability of beads, which improves the association of chromatin with Tn5, which enhances the sensitivity in CUT&Tag assay.

bioinformatics↗

bioRxiv2020

In silico integration of thousands of epigenetic datasets into 707 cell type regulatory annotations improves the trans-ethnic portability of polygenic risk scores

Poor trans-ethnic portability of polygenic risk score (PRS) models is a critical issue that may be partially due to limited knowledge of causal variants shared among populations. Hence, leveraging noncoding regulatory annotations that capture genetic variation across populations has the potential to enhance the trans-ethnic portability of PRS. To this end, we constructed a unique resource of 707 cell-type-specific IMPACT regulatory annotations by aggregating 5,345 public epigenetic datasets to predict binding patterns of 142 cell-type-regulating transcription factors across 245 cell types. With this resource, we partitioned the common SNP heritability of diverse polygenic traits and diseases from 111 GWAS summary statistics of European (EUR, average N=180K) and East Asian (EAS, average N=157K) origin. For 95 traits, we were able to identify a single IMPACT annotation most strongly enriched for trait heritability. Across traits, these annotations captured an average of 43.3% of heritability (se = 13.8%) with the top 5% of SNPs. Strikingly, we observed highly concordant polygenic trait regulation between populations: the same regulatory annotations captured statistically indistinguishable SNP heritability (fitted slope = 0.98, se = 0.04). Since IMPACT annotations capture both large and consistent proportions of heritability across populations, prioritizing variants in IMPACT regulatory elements may improve the trans-ethnic portability of PRS. Indeed, we observed that EUR PRS models more accurately predicted 21 tested phenotypes of EAS individuals when variants were prioritized by key IMPACT tracks (49.9% mean relative increase in R2). Notably, the improvement afforded by IMPACT was greater in the trans-ethnic EUR-to-EAS PRS application than in the EAS-to-EAS application (47.3% vs 20.9%, P < 1.7e-4). Overall, our study identifies a crucial role for functional annotations such as IMPACT to improve the trans-ethnic portability of genetic data, and this has important implications for future risk prediction models that work across populations.

genetics↗

bioRxiv2019

Large scale genome-wide association study in a Japanese population identified 45 novel susceptibility loci for 22 diseases

INTRODUCTORY PARAGRAPHThe overwhelming majority of participants in current genetic studies are of European ancestry1-3, limiting our genetic understanding of complex disease in non-European populations. To address this, we aimed to elucidate polygenic disease biology in the East Asian population by conducting a genome-wide association study (GWAS) with 212,453 Japanese individuals across 42 diseases. We detected 383 independent signals in 331 loci for 30 diseases, among which 45 loci were novel (P < 5 x 10-8). Compared with known variants, novel variants have lower frequency in European populations but comparable frequency in East Asian populations, suggesting the advantage of this study in discovering these novel variants. Three novel signals were in linkage disequilibrium (r2 > 0.6) with missense variants which are monomorphic in European populations (1000 Genomes Project) including rs11235604(p.R220W of ATG16L2, a autophagy-related gene) associated with coronary artery disease. We further investigated enrichment of heritability within 2,868 annotations of genome-wide transcription factor occupancy, andidentified 378 significant enrichments across nine diseases (FDR < 0.05) (e.g. NF-{kappa}B for immune-related diseases). This large-scale GWAS in a Japanese population provides insights into the etiology of common complex diseases and highlights the importance of performing GWAS in non-European populations.

genetics↗