Biology subjects

Enomoto, M.

Publications and source records attributed to Enomoto, M..

8 recordsLinked to original sources

bioRxiv2026

Iro-C/IRX creates anti-cancerized epithelial field against IL-6-dependent malignant tumorigenesis

Some epithelial regions appear intrinsically resistant to malignancy, yet how such anti-cancerized fields are established remains elusive. Here, we show in Drosophila that Iroquois Complex (Iro-C), a group of transcriptional repressors specifically expressed in the notum region of the wing imaginal epithelium, creates anti-cancerized field against malignant tumorigenesis. Clones of cells with Ras activation and cell polarity defect (RasV12/scrib-/-) develop into malignant tumors in the pouch and hinge regions of the wing disc, yet they failed to overgrow in the notum. Mechanistically, intrinsic Iro-C expression in the notum represses upd/IL-6 transcription, thereby preventing JAK-STAT activation essential for driving malignant growth. Forced expression of Upd/IL-6 converted the notum into tumor-prone field, whereas forced expression of Iro-C in the pouch and hinge abolished their RasV12/scrib-/- tumorigenesis. Our findings provide a mechanistic explanation for how some epithelial regions, such as distal segments of the kidney, where Iro-C/IRX1 is specifically expressed, exhibit resistance to cancer development, and offer a novel therapeutic strategy against IL-6-dependent cancers.

cancer biology↗

bioRxiv2025

Microbiome-host interactions drive a trade-off between sleep quality and lifespan in Drosophila

Understanding the interactions between various aging processes and the resulting heterogeneity in aging is crucial for promoting healthy aging. Here, we provide evidence that heterogeneity in microbiome and host interactions contributes to diversifying aging phenotypes in sleep, gut integrity, and longevity in Drosophila. Aged flies exhibiting sleep fragmentation preserve gut integrity, accompanied by a shift in microbiota composition, particularly an increase in Acinetobacter junii. A. junii induces sleep fragmentation via its metabolite, urocanic acid, through serotonin receptor-dependent dopamine upregulation. In parallel, A. junii exploits the host response to promote its growth, leading to lifespan extension, which is recapitulated by genetically modified Escherichia coli, suggesting a trade-off between sleep quality and lifespan. Our study demonstrates a systematic mechanism underlying aging heterogeneity, suggesting interventions through bacterial supplements.

animal behavior and cognition↗

bioRxiv2025

Oligo DNA-based quantum dot (QD) single-particle tracking for multicolor single-molecule imaging

Quantum dot single-particle tracking (QD-SPT), a powerful tool for analyzing membrane domains that are critical to various cellular processes, is widely used in membrane molecular dynamics research. QDs, which possess both a broad excitation range and a narrow emission bandwidth, are inherently suited for multicolor imaging at various wavelengths. However, applying multicolor QD-SPT with multiple biomolecular targets has been challenging due to the limited methods for specifically conjugating QDs to biomolecules. Here, we propose a DNA hybridization-based QD labeling method that generates several specific interactions based on sequence. QD fused with 20-mer oligo DNA specifically labeled membrane lipid 1,2-dipalmitoyl-sn-glycero-3-phosphatidylethanolamine (DPPE) covalently bound to complementary oligo DNA, forming a stable label that is suitable for SPT. The combination of polyA-polyT sequence as the linker oligo caused more QDs to fuse to DPPE compared with a random sequence linker. Oligo DNA-based QD-SPT accurately reflected the diffusion dynamics of DPPE measured using the single-fluorescence tracking technique and was compatible with conventional QD-SPT utilizing secondary antibody Fab. Using different pairs of oligo DNA sequences, we successfully achieved multicolor QD-SPT that distinguishes the lateral diffusion of DPPE and a membrane protein, GABAA receptor (GABAAR), within the same cell. The oligo DNA-based QD labeling method developed in this study is anticipated to substantially advance simultaneous multicolor QD-SPT of different living cell membrane molecules specific to DNA sequences.

biophysics↗

bioRxiv2025

CD33 and Clusterin Interact Biophysically and Genetically to Modulate Alzheimer Risk

We report the results of structural, functional and genetic studies on the CD33 sialic acid- binding receptor that reveal how non-coding variants in CD33 alter risk for Alzheimers disease (AD). The full-length CD33M isoform, whose expression is upregulated by non-coding AD-risk alleles, preferentially forms dimers at the cell surface, where they interact with AD-related proteins (clusterin and A{beta}). This interaction induces CD33M inhibitory signalling and downregulates protective microglial functions including phagocytic removal of amyloid plaques. Human brain expression quantitative trait loci (eQTL) and causal mediation analyses confirm that quantitative interactions between CLU and CD33 genotypes modulate AD phenotypes and suggest that genotypes at these loci might be used to personalise future therapeutic approaches. Our work also highlights several other unexpected aspects of CD33 biology, including a soluble shed extracellular fragment of CD33M and a similar soluble secreted product arising from a truncating mutation in the CD33 extracellular domain (CD33M{Delta}4bp).

neuroscience↗

bioRxiv2024

Lewy-MSA hybrid fold drives distinct neuronal a-synuclein pathology

The ordered assembly of -synuclein protein into filaments encoded by SNCA characterizes neurodegenerative diseases called synucleinopathies. Lewy body disease (LBD) shows predominantly neuronal -synuclein pathology and multiple system atrophy (MSA) predominantly oligodendrocytic -synuclein pathology affecting subcortical brain structures. Based on cryo-electron microscopy, it was reported that structures of -synuclein filaments from LBD differ from MSA and juvenile onset synucleinopathy (JOS) caused by a 21-nucleotide duplication in the second exon of one allele of SNCA gene 1-3. Importantly, a rare subtype of MSA, called atypical MSA4 shows abundant neuronal argyrophilic -synuclein inclusions in the limbic system. Current concepts indicate that disease entities are characterized by unique protofilament folds. Here we demonstrate that in addition to the MSA fold, -synuclein can form a new Lewy-MSA hybrid fold in the same brain region, leading to the atypical histopathological form of MSA. Distinct biochemical characteristics of -synuclein, as demonstrated by protease-sensitivity digestion assay, seed amplification assays (SAAs) and conformational stability assay (CSA), are also linked to cytopathological differences (e.g. neuronal or oligodendroglial). We expand the current structure-based classification of -synucleinopathies and propose that cell-specific protein pathologies can be associated with distinct filament folds.

pathology↗

bioRxiv2021

Liquid-liquid phase separation of florigen activation complex induces flowering

Floral transition, regulated by the systemic action of the mobile florigen protein FLOWERING LOCUS T (FT), is essential for successful plant reproduction1. How FT controls downstream gene expression remains incompletely understood, although it relies on the florigen activation complex (FAC), a core component of FT function2-4. The FAC is a nucleus-localized transcriptional activator of genes encoding MADS-box transcription factors critical to reproductive development and consists of florigen FT; a scaffold 14-3-3 protein that is a key component for complex assembly; and FD, a basic leucine-zipper protein that recruits the FAC to DNA. Here we report that the FAC exhibits phase separation. In rice shoot apical meristem cells, rice florigen Heading date 3a (Hd3a) fused to the green fluorescent protein formed speckles in the nucleus. The FAC speckle is formed in a FAC-dependent manner in tobacco cells. Recombinant Hd3a, but not OsFD1, phase-separated in vitro, and this effect was enhanced in the presence of 14-3-3 protein. Furthermore, mutations affecting functionally important residues in the pocket region or C-terminal disordered region of Hd3a affected FAC phase separation, providing a biochemical framework for the proteins effect on flowering. The ability to form condensates via phase transition represents a previously unknown mechanism for gene activation by the FAC.

plant biology↗

bioRxiv2020

Wild-type sTREM2 blocks Aβ aggregation and neurotoxicity, while the Alzheimer's R47H mutant does the opposite

Missense mutations (e.g. R47H) of the microglial receptor TREM2 increase risk of Alzheimers disease (AD), and the soluble ectodomain of wild-type TREM2 (sTREM2) appears to protect in vivo, but the underlying mechanisms are unclear. We show that A{beta} oligomers bind to TREM2, inducing shedding of sTREM2. Wild-type sTREM2 inhibits A{beta} oligomerization, fibrillization and neurotoxicity, and disaggregates preformed A{beta} oligomers and protofibrils. In contrast, the R47H AD-risk variant of sTREM2 is less able to bind and disaggregate oligomeric A{beta}, but rather promotes A{beta} protofibril formation and neurotoxicity. Thus, in addition to mediating phagocytosis, wild-type TREM2 may protect against amyloid pathology by A{beta}-induced release of sTREM2 that blocks A{beta} aggregation and neurotoxicity; while R47H sTREM2 promotes A{beta} aggregation into neurotoxic forms, which may explain why the R47H variant gene increases AD risk several fold.

biochemistry↗

bioRxiv2018

Plasma redox imbalance caused by albumin oxidation promotes lung-predominant NETosis and pulmonary cancer metastasis

Neutrophil extracellular traps (NETs) entrap circulating tumor cells (CTCs) and promote metastasis within distant organs in preclinical models1,2. In these models, NETosis is triggered by exogenous massive inflammatory stimuli, and thus it remains unknown whether cancer hosts under physiologic inflammation-free conditions experience NETosis and consequent cancer metastasis. Here we show that plasma redox imbalance caused by albumin oxidation promotes inflammation-independent NETosis and cancer metastasis specifically in the lungs. Albumin is the major source of free thiol that maintains redox balance in vitro and in vivo. Oxidation of albumin-derived free thiol is sufficient to trigger NETosis via accumulation of reactive oxygen species within neutrophils. The resultant NETs are found predominantly within lungs where they contribute to the colonization of CTCs leading to pulmonary metastases in mouse models. These effects are abrogated by pharmacologic inhibition of NET formation. Moreover, albumin oxidation and the resultant decline of plasma free thiol are associated with pulmonary metastasis in a cohort of head and neck cancer patients. These results implicate plasma redox balance as an endogenous and physiologic regulator of NETosis and pulmonary cancer metastasis, providing new therapeutic and diagnostic opportunities for combatting cancer progression.

cancer biology↗