Biology subjects

Takano, K.

Publications and source records attributed to Takano, K..

7 recordsLinked to original sources

bioRxiv2026

A bistable UV-sensitive opsin from a reef building coral showing a switchable and tunable regulation of Gs-signaling by different wavelengths of light

Cnidarians possess large number of opsins in their genomes for their various photoreceptive functions. In particular, they uniquely possess Gs-coupled opsins that induce intracellular cAMP accumulation in a light-dependent manner. These Gs-coupled opsins, cnidopsins, are powerful optogenetic tools manipulating cAMP-dependent cellular responses. In this study, we characterized a cnidopsin, named as AtCnidop3a, from the coral Acropora tenuis as a Gs-coupled and UV-sensitive bistable pigment. This cnidopsin showed a large spectral shift upon activation from absorption maxima from 395 nm to 560 nm, and the resting and activated states are interconvertible by illumination with UV (or violet) and orange light. The activated state efficiently activated Gs proteins and elevated intracellular cAMP levels in mammalian cultured cells. To engineer the opsin mutant that can be turned on and off upon long wavelength light illumination by utilizing the large spectral separation, negatively charged amino acids were introduced near the retinal Schiff base region. Among tested opsin mutants, the Y1133.28E mutant is capable of being activated by green light unlike the wild-type while retaining the property of being inactivated by orange light like the wild-type, indicating successful conversion of the opsin to a visible light sensitive bistable pigment. The visible light-induced cAMP regulation of the Y1133.28E mutant was enhanced by an additional L942.61G substitution. Our characterization and engineering of the cnidopsin revealed functional diversity of cnidarian opsins and its potential utility as optogenetic tools regulating Gs-dependent physiological responses.

biochemistry↗

bioRxiv2025

Dietary soy shapes murine microbiota to consolidate the mucosal IgA response through T follicular helper cells

The commensal microbiota plays a crucial role in shaping mucosal immunity, particularly in the induction of T follicular helper (Tfh) cells and IgA production. Here, we demonstrate that dietary soy elicits a robust Tfh cell and IgA response in Peyers patches of weaning mice. Soy feeding promotes the expansion of two principal commensal bacterial species, Limosilactobacillus reuteri and Muribaculum intestinale. Mechanistically, L. reuteri provides cognate antigens for Tfh cell activation, while M. intestinale functions as an adjuvant by promoting IL-1{beta} production from myeloid cells. The resulting IgA exhibits polyreactivity and enhances protection against Salmonella infection. These findings highlight the specific interplay among dietary components, intestinal microbiota, and mucosal immunity, thereby establishing a diet-microbe-immune axis that shapes host defense in early life. This axis represents a promising therapeutic target for developing novel strategies to enhance resistance to enteric pathogens. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=170 HEIGHT=200 SRC="FIGDIR/small/669459v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1ae8277org.highwire.dtl.DTLVardef@1f787ceorg.highwire.dtl.DTLVardef@1f51fd6org.highwire.dtl.DTLVardef@1fd3439_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIDietary soy promotes T follicular helper (Tfh) cell and IgA responses in the Peyers patches of weaning mice. C_LIO_LISoy enhances the colonization of two key commensals, Limosilactobacillus reuteri and Muribaculum intestinale, in the small intestine. C_LIO_LIThese two bacteria synergize to drive mucosal immunity: L. reuteri provides cognate antigens, while M. intestinale provides an adjuvant signal by promoting IL-1{beta} production from myeloid cells. C_LIO_LISoy-induced IgA is polyreactive and protects against Salmonella infection. C_LI

immunology↗

bioRxiv2024

Deep Learning-Based Inference of Uterine Contractions from Maternal ECG

BackgroundPreterm birth and stillbirth have multifaceted causes, many of which remain unknown. Factors such as maternal age, sexually transmitted infections, and genetic abnormalities are notably implicated. Globally, there has been minimal improvement in preterm birth rates, leading to substantial economic losses and underscoring the need for innovative approaches. ObjectiveThis study aims to analyze and detect uterine contractions by applying deep learning techniques to physiological data derived from maternal electrocardiograms (ECGs). Leveraging ECGs, which are easily obtainable from wearable devices, allows for effective and convenient monitoring of uterine contractions outside clinical settings. Since uterine contractions are a critical indicator for assessing the risk of preterm birth, our algorithm has the potential to facilitate early identification of high-risk individuals, thereby contributing to timely interventions and improved maternal-fetal outcomes. MethodsParticipants meeting all inclusion criteria and none of the exclusion criteria were recruited from patients admitted to or attending outpatient services at Saintpaulia Misao Ladies Hospital in Gifu, Japan, between December 6, 2023, and July 31, 2024. Our deep learning model was developed using maternal ECG data, uterine contraction waveforms obtained from cardiotocograms (CTGs). The collected data were divided into training and evaluation datasets. The AI-generated uterine contraction waveforms from the developed model were compared with ground truth labels obtained from the fetal monitoring devices. This study was reviewed and approved by the Ethics Committee of the Graduate School of Medicine at Gifu University and was conducted as a collaborative research effort with nonat Inc. (the lead research institution) and Saintpaulia Misao Ladies Hospital (joint research institution). ResultsFinally, 73 participants took part in this study, and 57 datasets were used for algorithm development and evaluation. Multiple measurements were taken on the same subjects on different days only with their consent. Our analysis demonstrated a strong correlation between the uterine contraction waveforms estimated by the developed model and the ground truth waveforms from CTGs, achieving an average correlation across all evaluation data (Pearson correlation coefficient = 0.53). ConclusionThis is the worlds first trial to detect uterine contractions from maternal ECGs using deep learning algorithms. In this study, we successfully developed a deep learning algorithm capable of accurately inferring uterine contraction waveforms from maternal ECGs. Given that ECGs can be easily obtained using wearable devices, this approach may provide healthcare professionals with objective and precise information on uterine contractions--a crucial indicator of preterm labor--even in resource-limited settings outside hospital environments.

physiology↗

bioRxiv2023

Identification of novel sex determination loci in Japanese weedy melon

Sex expression contributes to fruit quality and yield in the Cucurbitaceae. In melon, orchestrated regulation by sex determination genes explains the mechanism of sex expression, resulting in a great variety of sexual morphologies. In this study, we examined the Japanese weedy melon UT1, which does not follow the reported model of sex expression. We conducted QTL analysis using F2 plants for flower sex on the main stem and the lateral branch and mapped a "femaleness" locus on Chr. 3 (Fem3.1) and a "type of flower femaleness" (female or bisexual) locus on Chr. 8 (tff8.1). Fem3.1 included the known sex determination gene CmACS11. Sequence comparison of CmACS11 between parental lines revealed three nonsynonymous SNPs. A CAPS marker developed from one of the SNPs was closely linked to femaleness in two F2 populations with different genetic backgrounds. The femaleness allele was dominant in F1 lines from crosses between UT1 and diverse cultivars and breeding lines. This study suggests that the identity of tff8.1 is CmCPR5, a recently reported bisexual flower control gene. We found that the Japanese weedy melon UT1 does not follow the conventional sex expression model because of the interaction of the loci Fem3.1 and tff8.1 with the previously reported sex determination genes. The results of this study provide new insights into the molecular mechanisms of sex determination in melons and considerations for the application of femaleness in melon breeding. Key messageJapanese weedy melon exhibits unique sex expression with interactions between previously reported sex determination genes and two novel loci.

plant biology↗

bioRxiv2022

Quantitative analysis of calcium oxalate monohydrate and dihydrate for elucidating the formation mechanism of calcium oxalate kidney stones

We aimed to identify and quantitatively analyze calcium oxalate (CaOx) kidney stones on the order of micrometers, with a focus on the quantitative identification of calcium oxalate monohydrate (COM) and dihydrate (COD). Fourier Transform Infrared (FTIR) spectroscopy, powder X-ray diffraction (PXRD), and microfocus X-ray CT measurements (micro-CT) were performed, and the results were compared. The extended analysis method of the FTIR spectrum, focusing on the 780 cm-1 peak, made it possible to achieve a reliable analysis of the COM/COD ratio. We succeeded in the quantitative analysis of COM/COD in the region of 50 x 50 m by microscopic FTIR for thin sections of kidney stones, and by the micro-CT for bulk samples. The extended analysis method of the FTIR spectrum focusing on the 780 cm-1 peak was introduced to analyze the COM/COD ratio. The analysis results based on PXRD measurement with micro sampling, microscopic FTIR analysis of a thin section, and micro-CT observation of a bulk sample of a kidney stone showed roughly consistent results, indicating that all methods can be used complementarily. This quantitative analysis method evaluates the detailed CaOx composition on the preserved stone surface and provides information on the stone formation processes and interactions with organic molecules.

biophysics↗

bioRxiv2021

Prefrontal-amygdalar oscillations related to social interaction behavior in mice

The medial prefrontal cortex and amygdala are involved in the regulation of social behavior and associated with psychiatric diseases but their detailed neurophysiological mechanisms at a network level remain unclear. We recorded local field potentials (LFPs) from the dorsal medial PFC (dmPFC) and basolateral amygdala (BLA) while mice engaged on social behavior. We found that in wild-type mice, both the dmPFC and BLA increased 4-7 Hz oscillation power and decreased 30-60 Hz power when they needed to attend to another target mouse. In mouse models with reduced social interactions, dmPFC 4-7 Hz power further increased especially when they exhibited social avoidance behavior. In contrast, dmPFC and BLA decreased 4-7 Hz power when wild-type mice socially approached a target mouse. Frequency-specific optogenetic manipulations of replicating social approach-related LFP patterns restored social interaction behavior in socially deficient mice. These results demonstrate a neurophysiological substrate of the prefrontal cortex and amygdala related to social behavior and provide a unified pathophysiological understanding of neuronal population dynamics underlying social behavioral deficits.

neuroscience↗

bioRxiv2021

Dynamic product-precursor relationships underlie cuticular lipid accumulation on maize silks

The hydrophobic cuticle is the first line of defense between aerial portions of a plant and the external environment. On maize silks, the cuticular cutin matrix is infused with cuticular lipids, consisting of a homologous series of very-long-chain fatty acids (VLCFAs), aldehydes, and hydrocarbons that serve as precursors, intermediates, and end-products of the elongation, reduction, and decarbonylation reactions of the hydrocarbon-producing pathway. To deconvolute the potentially confounding impacts of the silk microenvironment and silk development on the hydrocarbon-producing pathway, spatio-temporal cuticular lipid profiling was conducted on the agronomically important inbreds B73 and Mo17, and their reciprocal hybrids. Statistical interrogation via multivariate analyses of the metabolite abundances of the hydrocarbon-producing pathway demonstrate that the cellular VLCFA pool is positively correlated with the cuticular lipid metabolome, and this metabolome is primarily affected by the silk microenvironment and the plant genotype. Moreover, genotype has a major effect on the pathway, with increased cuticular hydrocarbon and concomitant reduction of cuticular VLCFA accumulation on B73 silks, suggesting that conversion of VLCFAs to hydrocarbons is more effective in B73 than Mo17. Statistical modeling of the ratios between cuticular hydrocarbons and cuticular VLCFAs reveals the complexity of the product-precursor ratio relationship, demonstrating a significant role of precursor chain length. Longer-chain VLCFAs are preferentially utilized as precursors for hydrocarbon biosynthesis. Collectively, these findings demonstrate maize silks as an effective and novel system for dissection of the complex dynamics of cuticular lipid accumulation in plants. One-sentence SummaryThe product-precursor ratios in the cuticular hydrocarbon-producing pathway are impacted by fatty acid precursor chain length, plant genotype and the spatio-temporal dynamic gradients of maize silks.

plant biology↗