Biology subjects

Tamada, K.

Publications and source records attributed to Tamada, K..

5 recordsLinked to original sources

bioRxiv2026

Neonatal social communication and single genes predict the variability of post-pubertal social behavior in a mouse model of paternal 15q11-13 duplication

Mental illnesses associated with high-risk copy number variations (CNVs) are characterized by incomplete penetrance and variable severity, with their underlying mechanisms remaining inadequately understood. We hypothesized that such phenotypic variability is evident from the neonatal stage and is, at least in part, attributable to individual differences in the expression levels of CNV-encoded genes in the brain. We conducted an analysis of the quantitative and functional structure of neonatal social communication, assessed post-pubertal social interaction, and evaluated the brain expression levels of genes within the same cohort of a mouse model of paternal human 15q11-13 duplication, a high-risk factor variably associated with neurodevelopmental disorders. Subsequently, computational methods were utilized to identify predictive variables for the variability of post-pubertal social interaction. Mice harboring the 15q11-13 duplication exhibited distinctive call sequences characterized by diverse connections, which lacked the incentive value necessary for effective social communication with mother mice. The neonatal call sequences and the expression levels of Magel2, along with, to a lesser extent, Herc2 and Ndn, in the prefrontal cortex of the 15q11-13 duplication model were predictive of post-pubertal social interaction. Our findings demonstrate that variability in post-pubertal social interaction--a dimensional characteristic of neurodevelopmental disorders--can be predicted by the variability of neonatal social communication and is influenced by the expression levels of specific CNV-encoded genes in the prefrontal cortex. This computational approach has the potential to predict the developmental trajectories of various dimensions of mental illness among CNV carriers in humans and to identify CNV-encoded driver genes in preclinical models, thereby providing potential mechanistic bases for the development of gene-based therapeutic strategies.

neuroscience↗

bioRxiv2025

Efficient gene disruption with CRISPR-Cas3 in human T cells

The CRISPR-Cas9 system has been widely adopted as a genome editing tool due to its high efficiency and versatility, contributing to the development of various therapeutic strategies. However, its clinical application remains limited by safety concerns, including off-target effects and large-scale chromosomal rearrangements such as translocations and inversions. Recently, the CRISPR-Cas3 system, a Class 1 CRISPR effector complex with unidirectional DNA degradation activity, has gained attention as a potential alternative, offering reduced off-target activity. In this study, we applied the CRISPR-Cas3 system to human T cells and successfully disrupted two clinically relevant genes, T cell receptor alpha constant (TRAC) and beta-2 microglobulin (B2M). These gene deletions were associated with a reduction in both graft-versus-host disease (GVHD) risk and host immune rejection. Importantly, no off-target mutations were detected in CRISPR-Cas3-edited cells, in contrast to the off-target effects observed with CRISPR-Cas9. Furthermore, CAR-T cells generated by deleting TRAC or B2M using CRISPR-Cas3 maintained their antigen-specific cytotoxicity against tumor cells, while exhibiting reduced alloreactivity. These results suggest that CRISPR-Cas3 provides a safer and promising platform for genome editing in T cell engineering, with potential applications in the development of next-generation allogeneic T cell therapies.

cancer biology↗

bioRxiv2025

TRPV4 activation enhances LPS-induced IL10 production to suppress excessive microglial activation

Microglia are resident immune cells in the brain. Under pathological conditions, activated microglia trigger neurodegeneration by secreting pro-inflammatory molecules such as NO, TNF, IL6 and IL1{beta}. In contrast, microglia also possess a negative feedback mechanism to prevent the excessive inflammation by secreting anti-inflammatory cytokines such as IL10. It is reported that activation of transient receptor potential vanilloid 4 (TRPV4), one of the non-selective cation channels, suppresses the lipopolysaccharide (LPS)-induced microglial activation. However, the effects of TRPV4 activation on the microglial anti-inflammatory responses remain unknown. In this study, we investigated whether TRPV4 contributes microglial anti-inflammatory responses using primary cultured murine microglia. We found that application of a selective TRPV4 agonist, GSK1016790A, enhanced LPS-induced IL10 release in the microglia, which was fully suppressed by co-application of a selective TRPV4 antagonist, GSK2193874, or absent in cultured microglia derived from TRPV4-knockout (TRPV4-KO) mice. Furthermore, neutralization of extracellular IL10 significantly reversed suppressive effects of GSK1016790A on LPS-induced release of TNF, IL6 and IL1{beta}. Expression pattern of microglial activation markers implied that GSK1016790A shifted microglial activation status to an immunoregulatory phenotype. Taken together, these results indicate that microglial TRPV4 plays an important role in promoting the production of LPS-induced IL10, which results in suppressing excessive inflammation in an autocrine or paracrine fashion.

pharmacology and toxicology↗

bioRxiv2025

Editing strigolactone biosynthesis genes in tomato reveals novel phenotypic effects and highlights D27 as a key target for parasitic weed resistance

Parasitic weed infestations pose an increasing threat to agriculture worldwide, especially in the Mediterranean region. Phelipanche ramosa and P. aegyptiaca (broomrapes) cause severe damage to field-grown tomato (Solanum lycopersicum L.). Strigolactones (SLs), apocarotenoid phytohormones, play a critical role in plant physiology and development, and are also the primary signals that trigger the germination of parasitic weed seeds. We generated CRISPR/Cas9 tomato knock-out lines for the SlD27 gene, as well as three other key genes involved in SL biosynthesis (SlCCD7, SlCCD8, SlMAX1), all within the same genetic background. The edited lines exhibited a marked reduction in SL content in root exudates, along with impaired broomrape seed germination. A comprehensive analysis of morphological, reproductive, and fruit-related traits revealed gene-specific effects on plant phenotype, including vegetative traits, fruit set, fruit development, and volatilome. Specifically, the knock-out of two CCDs and the MAX1 had a specific impact not only on plant development but also on the production of volatile organic compounds during fruit ripening. In contrast, the Sld27 lines, produced for the first time in this study, displayed a phenotype similar to the control non-edited plants, suggesting that the D27 gene holds promise as a breeding target for enhancing resistance to parasitic weeds in tomato. HighlightThe characterization of tomato CRISPR/Cas9-edited lines for the four core genes involved in strigolactone biosynthesis revealed gene-specific effects on plant phenotype, with D27 emerging as a potential target for resistance to parasitic weeds.

genetics↗

bioRxiv2020

Comprehensive Topographical Map of the Serotonergic Fibers in the Mouse Brain

It is well established that serotonergic fibers distribute throughout the brain. Abnormal densities or patterns of serotonergic fibers have been implicated in neuropsychiatric disorders. Although many classical studies have examined the distribution pattern of serotonergic fibers, most of them were either limited to specific brain areas or had limitations in demonstrating the fine axonal morphology. In this study, we utilize transgenic mice expressing GFP under the SERT promoter to map the topography of serotonergic fibers across the rostro-caudal extent of each brain area. We demonstrate previously unreported regional density and fine-grained anatomy of serotonergic fibers. Our findings include: 1) SERT fibers distribute abundantly in the thalamic nuclei close to the midline and dorsolateral areas, in most of the hypothalamic nuclei with few exceptions such as the median eminence and arcuate nuclei, and within the basal amygdaloid complex and lateral septal nuclei, 2) the source fibers of innervation of the hippocampus traverse through the septal nuclei before reaching its destination, 3) unique, filamentous type of straight terminal fibers within the nucleus accumbens, 4) laminar pattern of innervation in the hippocampus, olfactory bulb and cortex with heterogenicity in innervation density among the layers, 5) cortical labelling density gradually decreases rostro-caudally, 6) fibers traverse and distribute mostly within the gray matter, leaving the white fiber bundles uninnervated, and 7) most of the highly labelled nuclei and cortical areas have predominant anatomical connection to limbic structures. In conclusion, we provide novel, regionally specific insights on the distribution map of serotonergic fibers using transgenic mouse.

neuroscience↗