Biology subjects

Takeda, N.

Publications and source records attributed to Takeda, N..

At least 19 recordsLinked to original sources

bioRxiv2026

REN-former prioritizes candidate regulators of kidney disease-state transitions through single-cell foundation modeling and human genetics

Background Acute kidney injury (AKI)-to-chronic kidney disease (CKD) transition is associated with dynamic changes in tubular cell state. However, conventional single-cell transcriptomic analyses primarily identify genes differentially expressed between disease states and do not directly evaluate genes associated with directional transitions between cellular states. Methods We developed REN-former by fine-tuning Geneformer using the GSE183276 single-cell RNA-sequencing dataset from 45 participants representing Normal Reference, AKI, and CKD states. In silico gene deletion and overexpression analyses were used to estimate directional transcriptomic shifts, with a focus on proximal tubular cells. Selected genes were evaluated using summary-data-based Mendelian randomization (SMR), colocalization and expression analysis in additional KPMP participants not included in GSE183276. Results REN-former achieved recall values of 0.99, 0.80, and 0.79 for Normal Reference, AKI, and CKD, respectively. In silico perturbation analyses identified distinct gene programs associated with transitions from Normal Reference to AKI, from Normal Reference to CKD, from AKI to CKD, and from CKD to Normal Reference. Conventional analysis showed metabolic suppression and increased inflammatory and stress-response activation. SMR identified IFITM3, CALR, TTR, CALM1, MUC13, and RPL13, and colocalization supported IFITM3, CALR, TTR, and CALM1. In additional KPMP data, IFITM3 was higher, whereas TTR and CALM1 were lower, in CKD proximal tubules; CALR did not differ significantly. The observed expression changes were concordant with the REN-former-predicted directions for TTR and CALM1 but discordant for IFITM3. Conclusion REN-former provides a framework for prioritizing candidate regulators of kidney disease-associated cell states by integrating predicted perturbation effects with human genetic and transcriptomic evidence.

bioinformatics↗

bioRxiv2026

The Il1r2-CreERT2 knock-in mouse enables inducible labeling of slow-cycling epidermal basal cells and genetic ablation of the IL-1 decoy receptor

The interfollicular epidermis is maintained by spatially organized basal cell populations with distinct molecular signatures and division kinetics; however, the markers that define these populations remain poorly defined. In this study, we identified Il1r2, which encodes the IL-1 decoy receptor IL-1R2, as a marker of the slow-cycling basal population in the epidermis. Single-cell RNA-seq analysis of epidermal and hair follicle basal populations in the murine tail skin revealed that Il1r2 is preferentially expressed in the slow-cycling epidermal basal population, and immunofluorescence staining confirmed its protein localization in tissues. To enable fate mapping of this population, we generated an Il1r2-CreERT2 knock-in mouse line using a CRISPR-Cas9-based PITCh method. Tamoxifen induction in Il1r2-CreERT2/Rosa-tdTomato mice exhibited selective labeling of basal cells localized to the slow-cycling interscale region of the tail epidermis. Because the CreERT2 cassette was inserted into the Il1r2 coding sequence, homozygous Il1r2-CreERT2 knock-in mice can also serve as an Il1r2 knockout model through targeted gene ablation. Thus, the Il1r2-CreERT2 mouse line provides a dual genetic tool for lineage tracing of the slow-cycling epidermal basal population and for functional modulation of IL-1 signaling in vivo.

developmental biology↗

bioRxiv2026

A single PLAT domain protein couples reproductive arrest and carotenoid pigmentation during diapause in the two-spotted spider mite, Tetranychus urticae Koch

Adult females of the two-spotted spider mite, Tetranychus urticae Koch, enter a photoperiodically induced diapause to overwinter. Diapause in T. urticae is accompanied by reproductive arrest and the orange body coloration that arises from the accumulation of astaxanthin esters. How these two traits are coordinated at the molecular level remains poorly understood. Here, we compared the proteomes of adult females reared under diapause-inducing (long-night) and non-diapause-inducing (short-night) photoperiods using liquid chromatography-tandem mass spectrometry, followed by RNA interference (RNAi) of candidate genes. The carotenoid biosynthesis enzymes phytoene desaturase (TuPDS) and lycopene cyclase/phytoene synthase (TuLCPS), both encoded by genes horizontally transferred from fungi, were more abundant in diapausing females than in non-diapausing females. RNAi of the genes encoding TuPDS and TuLCPS markedly reduced orange pigmentation as well as {beta}-carotene and astaxanthin contents, demonstrating that these enzymes are required for diapause-associated pigmentation. Our proteomic analysis further identified a single PLAT (Polycystin-1, Lipoxygenase, Alpha-toxin) domain protein, TuPLAT10, as one of the most strongly upregulated proteins in diapausing females. The PLAT domain is a lipid-binding module, suggesting a role for TuPLAT10 in lipid metabolism. In addition to the suppression of orange pigmentation, RNAi of the TuPLAT10 gene restored reproduction even under diapause-inducing conditions and selectively reduced TuPDS and TuLCPS protein levels, despite the absence of sequence similarity to their genes. We propose that TuPLAT10 acts as a lipid-allocation switch that, in response to photoperiodic information, partitions fatty acids between astaxanthin esterification and yolk lipid supply, thereby coupling reproductive arrest and carotenoid pigmentation during diapause in T. urticae.

physiology↗

bioRxiv2026

Repeated mutation of a GT92 glycosyltransferase gene confers antiviral resistance in two Caenorhabditis species

Host-pathogen interactions evolve rapidly within species, providing natural genetic resources for the identification of specific ecological interaction factors. We previously identified RNA viruses that infect the nematodes C. elegans and C. briggsae in a species-specific manner. Wild strains of both host species demonstrate ample variation in viral sensitivity. Specifically, the wild C. elegans strain MY10, despite carrying a deletion in a key immunity factor, was among the most resistant strains. Here we use recombinant inbred lines and pool-sequencing approaches to genetically map the major MY10 resistance locus, narrowing down its position by CRISPR/Cas9 mediated recombination and testing candidates by genome editing. A rare non-synonymous polymorphism in the gtnt-1 gene, encoding a putative glycosyltransferase of the GT92 family, causes resistance to viral infection in MY10. We find that viral resistance through gtnt-1 mutation occurred repeatedly in C. elegans, with diverse resistance alleles each remaining at low frequency (<1%). Furthermore, leveraging closely related C. briggsae strains differing in viral susceptibility, we demonstrate that repeated reduction-of-function alleles of the Cbr-gtnt-1 ortholog similarly impair viral infection and enhance host fitness upon infection. In conclusion, we found recurrent evolution in two host species of reduction-of-function alleles of the gtnt-1 orthologs, which repeatedly lead to viral resistance yet remain at low frequency. These repeated events provide a case of transient ecological adaptation to a pathogen through recurrent mutation of the same gene in two species. The low population frequencies of the resistant alleles point to a changing eco-evolutionary context that prevents their spread in populations, resulting in high allelic heterogeneity.

evolutionary biology↗

bioRxiv2026

The REFLEX system enables in vivo identification of perivascular angiogenic macrophages in the heart

Direct identification of physically interacting cells in vivo remains challenging because conventional interactome analyses infer signaling partners from transcriptomes and cannot reveal which cells are in direct contact. In pressure-overload induced cardiac remodeling, VEGF-A plays a central role in the maintenance of vascular integrity and cardiac function. However, the cell type which produces VEGF-A and how the VEGF-A peptide is delivered to vascular endothelial cells remains unclear. Here, we developed a genetically encoded platform that combines REFLEX mice with HUNTERuni-seq, enabling unbiased detection and transcriptional profiling of the cells that physically interact with vascular endothelial cells. The REFLEX and HUNTERuni-seq approach identified subpopulations of Vegfa positive macrophages which we named perivascular angiogenic macrophages (PVAMs). Although the amount of VEGF-A in PVAMs is small, loss of VEGF-A in PVAMs impaired angiogenesis and systolic function during pressure overload. We additionally show that direct contact between PVAMs and endothelial cells is critical for the delivery of VEGF-A to endothelial cells. Conventional interactome analysis predicted that cardiomyocytes as dominant sources of VEGF-A in the heart. However, cardiomyocyte Vegfa deletion had no effect on capillary density nor systolic function in a model of heart failure. These results suggest that VEGF-A signaling does not rely on free diffusion through the interstitium and that cellular proximity and physical contact between PVAMs and endothelial cells are the key determinants of effective signal delivery. Together, these findings establish REFLEX and HUNTERuni-seq as a versatile platform for uncovering biologically critical cell-to-cell interactions and provide new insight into intercellular communication in pathological tissue contexts.

cell biology↗

bioRxiv2026

Cell-autonomous thermogenesis of macrophage alters its antibacterial function

Dynamic temperature gradients exist across the bodies of endothermic animals, from the core to peripheral organ, resulting in the physiological cold environment in superficial regions. Consequently, macrophages distributed throughout the body must be able to adapt not only to thermoneutral conditions but also to colder environments. In fact, it is known that environmental temperature influences macrophage immune responses. However, the thermo-responsive mechanisms of macrophage have been largely unexplored. Here we show that macrophage themselves maintains intracellular temperature under physiological cold condition by increasing proton leak index (defined as mitochondrial proton leak per spare respiratory capacity). We further identified a contribution of ADP/ATP carrier (AAC) to this increase in proton leak index. This cell-autonomous thermogenesis pathway, which does not depend on neural or hormonal inputs, highlights the potential for local and organ-specific temperature regulation. Moreover, cold stress reduced mitochondrial membrane potential, which in turn suppressed the expression of the antimicrobial peptide Resistin-like molecule alpha (RETNLA) and diminished antibacterial properties. Together, these findings suggest that macrophages generate heat whereas compromising antibacterial properties, thereby increasing susceptibility to bacterial infection in physiological cold environment. This adaptation mechanism may underscore the important role of temperature homeostasis in non-adipocyte cells.

physiology↗

bioRxiv2025

Adaptation of an herbivorous arthropod to green tea plants by overcoming catechin defenses

Green tea catechins are known antioxidants that benefit human health and protect tea plants from biotic stressors. However, some herbivores can counteract catechin defenses and can use tea plants as a host. Among herbivorous mites, an extreme generalist Tetranychus urticae has not been reported as a tea pest. Instead, T. kanzawai, another generalist, has some populations that thrive on tea plants. Here, we investigated the mechanism of the adaptation of these mites to tea plants. Comparative study of the intra- and inter-specific variations in mite performances uncovered differences in their behavioral and xenobiotic responsiveness to green tea catechins. We showed that green tea catechins exert complex defensive roles. They were repellent and toxic to T. urticae and tea non-adapted T. kanzawai mites. In addition, they had an antifeedant effect on tea non-adapted T. kanzawai mites. Matching the catechin structure, we identified an intradiol ring-cleavage dioxygenase DOG15, a gene horizontally transferred from fungi, as one required for the adaptation of T. kanzawai mites to tea plants. The DOG15 gene has an enhanced inducible expression in tea-adapted T. kanzawai mites, with mRNA and protein levels up to 31.6 and 12.1 times higher than in T. urticae mites fed on tea plants. Furthermore, we identified two amino acid substitutions in DOG15 between Tetranychus species leading to the increased efficacy of the T. kanzawai encoded enzyme toward cleavage of green tea catechins. Thus, we showed that mite adaptation to tea plants occurred in a two-step process. The amino acid substitutions in DOG15 predispose T. kanzawai but not T. urticae for the adaptation to tea plants. Further increased expression of modified DOG15 enables T. kanzawai mites to efficiently detoxify green tea catechins, leading to intra- and inter-specific differences in mites ability to use tea plants as a host. Our findings reveal how a horizontally transferred gene can be co-opted through structural and regulatory changes to overcome plant chemical defenses, with implications for herbivore host adaptation and tea pest management.

evolutionary biology↗

bioRxiv2025

Rhizobial infection-specific accumulation ofphosphatidylinositol 4,5-bisphosphate inhibits the excessive infection of rhizobia in Lotus japonicus

O_LIDuring the symbiosis of legume with nitrogen-fixing bacteria, collectively called rhizobia, suppression of excessive rhizobial infection by host plants is important to maximize the benefits of symbiotic nitrogen fixation. However, it remains relatively poorly understood the molecular mechanism involved in the suppression. C_LIO_LIWe performed LC-MS and RNA-seq analysis using rhizobia-infected Lotus japonicus roots and investigated the role of phosphatidylinositol (PI) and phosphatidylinositol phosphates (PIPs) in the symbiosis. Phosphatidylinositol transfer protein (PITP)-like proteins 4 (PLP4), phosphatidylinositol 3-phosphate 5-kinase 4 (PIP5K4) and PIP5K6 mutants, which are involved in the vesicular transport of lipids and phosphorylation of PIPs, were used to show the involvement of the signaling of PI and PIPs. Accumulation of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] during rhizobial infection were examined by a fluorescent marker 1xTUBBY-C (TUBBY). C_LIO_LIWe found that PI signaling-related genes were upregulated, and the amount of PIP2 increased in L. japonicus roots during rhizobial infection. In the PLP4, PIP5K4 and PIP5K6 mutants, rhizobial infection increased and PIP2 accumulation was failed. Furthermore, the observation of PI(4,5)P2 in rhizobia-infected roots revealed that the ectopic accumulation was closely related to suppression of rhizobial infection. C_LIO_LIOur findings indicate that the accumulation of PI(4,5)P2, which is mediated by PLP and PIP5Ks, suppresses excessive rhizobial infection in the root epidermis and cortex, leading to the optimal number of nodules. C_LI

plant biology↗

bioRxiv2025

PAH-former: Transfer Learning for Efficient Discovery of Pulmonary Arterial Hypertension-Associated Genes

Single-cell RNA sequencing (scRNA-seq) of patient samples holds promise for understanding disease mechanisms, but faces the challenge of excessive cost and effort in acquisition, processing, and data analysis, making it essential to leverage existing data. Pulmonary artery hypertension (PAH) is a refractory disease characterized by pulmonary vascular remodeling, and access to patient specimens is limited due to difficulties in tissue collection. In this study, we employed transfer learning with Geneformer, a deep learning algorithm pre-trained with scRNA-seq datasets and fine-tuned it with public PAH lung tissue data to identify the disease-relevant genes. The resulting algorithm, which we named PAH- former, demonstrated that its prediction accuracy varied significantly depending on the dataset used for fine-tuning. PAH-former enabled us to perform in silico perturbation analysis and identified PAH related genes. Loss-of-function PAH related genes in human pulmonary artery endothelial cells increased the expression of SOX18, a signature gene of PAH. This integration of artificial intelligence and biological experiments can significantly advance our understanding of molecular mechanisms of PAH.

bioinformatics↗

bioRxiv2025

Neuronal migration induces DNA damage in developing brain

Migratory cells tend to have soft nuclei that deform and penetrate narrow spaces1,2. Extensive nuclear deformation during migration can cause nuclear envelope rupture and DNA damage in cancer cells, which may contribute to the malignant transformation during tumor progression3,4,5,6. However, the significance of DNA damage in physiological migration is less well understood. Here, we demonstrate that the migration of neurons in developing cerebral and cerebellar cortices is accompanied by massive DNA double-strand breaks (DSBs) due to mechanostress during passage through narrow interstitial spaces. Confined migration enhances the binding and cleavage of the genome by topoisomerase II{beta}, expressed in neuronal nucleus, independently of the nuclear envelope rupture. Genome sequencing revealed that DSBs tend to occur outside of protein-coding regions and transcription regulatory regions. During normal development, DSBs are rapidly repaired by the non-homologous end joining pathway. The deletion of ligase IV at the onset of neuronal migration leads to persistent DSB accumulation in cerebellar neurons with moderate transcriptional changes in genes related to synaptic function, neuronal development, and stress and immune responses. The mutant mouse develops mild motor deficits in later life, suggesting that the DNA damage generated during normal brain development poses a potential disease risk if left unrepaired.

cell biology↗

bioRxiv2025

A light-modulated clock mechanism in a hydrozoan jellyfish that synchronises evening gamete release.

For marine species that reproduce by external fertilisation, spawning is precisely coordinated within a local cohort to maximise the chances of producing offspring. Gamete release is often synchronised with respect to the daily light changes at sunrise and sunset. In the hydrozoan jellyfish Clytia hemisphaerica, morning spawning occurs when oocyte maturation and gamete release are induced by maturation-inducing hormone (MIH) neuropeptides released from opsin-expressing cells in the gonad directly upon light stimulus. Here, we characterise the distinct spawning cycle of a previously undescribed species Clytia sp. IZ-D identified on the Pacific coast of Japan, which releases gametes in the evening. Clytia sp. IZ-D jellyfish spawn 14 hours after light stimuli under a 24-hour light-dark cycle and exhibit autonomous and synchronised spawning cycles with a 20-hour interval under constant light. We found that the female spawning cycle reflects the growth and acquisition of maturation competence by oocytes, such that each day a new batch of growing oocytes becomes responsive to MIH at a time that correlates with the timing of actual spawning. We propose that the synchronised evening spawning in this species is controlled by an unusual circadian timing mechanism based on the progressive development of gamete competence to MIH and modulation of the opsin-controlled MIH signalling pathway. This mechanism may provide resilience to light cycle instability due to local climate variation and ensure reproductive isolation from other Clytia species by alternating the gamete release timing.

developmental biology↗

bioRxiv2025

Machine Learning-Assisted Decoding of Temporal Transcriptional Dynamics via Fluorescent Timer

Investigating the temporal dynamics of gene expression is crucial for understanding gene regulation across various biological processes. Using the Fluorescent Timer protein (Timer), the Timer-of-cell-kinetics-and-activity (Tocky) system enables analysis of transcriptional dynamics at the single-cell level. However, the complexity of Timer data has limited its broader application. Here, we introduce an integrative approach combining molecular biology and machine learning to elucidate Foxp3 transcriptional dynamics through flow cytometric Timer analysis. We have developed a Convolutional Neural Networks (ConvNet) approach that incorporates image conversion and Gradient-weighted Class Activation Mapping (Grad-CAM) for class-specific feature identification at the single-cell level. Biologically, we developed a novel CRISPR mutant of Foxp3-Tocky lacking the Conserved Non-coding Sequence 2 (CNS2), which has successfully elucidated CNS2-dependent Foxp3 transcription dynamics, revealing novel roles of CNS2 in regulating Foxp3 transcription frequency under specific conditions. Furthermore, generating new data from WT Foxp3 Tocky mice at various ages, the Grad-CAM methods successfully revealed distinct dynamics of Foxp3 expression from neonatal to aged mice, highlighting prominent thymus-like features of neonatal splenic Foxp3+ T cells. In conclusion, our study uncovers previously unrecognised Foxp3 transcriptional dynamics, establishing a proof-of-concept for integrating CRISPR, Tocky, and machine learning methods as advanced techniques to understand transcriptional dynamics in vivo.

immunology↗

bioRxiv2025

Salivary proteins in spider mites: dual roles in feeding and silk fiber coating

Spider mites are plant cell-sucking herbivores that spin nanoscale adhesive silk fibers released from their mouthpart appendages. Previous whole-genome sequencing predicted 17 silk genes in the two-spotted spider mite, Tetranychus urticae, while silk proteomics detected two candidates, Fibroin-1 and Fibroin-2. However, saliva proteomics also detected Fibroin-1, Fibroin-2, and sFibroin-1 (with high sequence similarity to Fibroin-1). We investigated whether these three proteins function in silk, saliva, or both. We found Fibroin-1, sFibroin-1, and Fibroin-2 genes expressed in the salivary glands but found no direct internal connection between salivary and silk glands. Our silk proteomics detected 8 silk proteins previously predicted and 66 salivary proteins, including Fibroin-1, sFibroin-1, and Fibroin-2. We detected a bead-on-a-string pattern formed by fluid (hypothesized to be saliva) on the silk fiber and a fluid patch that remains at the piercing site on the leaf surface after mite feeding. RNAi-mediated silencing of Fibroin-1 and sFibroin-1 genes reduced mite feeding duration, survival, and fecundity, and silencing of Fibroin-2 gene showed a tendency to reduce the thickness of individual silk fibers. These results suggest that Fibroin-1, sFibroin-1, and Fibroin-2 are secreted from the salivary glands and then adhere to silk fibers. Fibroin-1 and sFibroin-1 may assist mites to adhere the tip of the mouthparts to the leaf surface when sucking with their stylets, while Fibroin-2 may coat silk fibers. This study reveals the dual role of saliva in plant cell-sucking herbivorous mites, namely, stabilizing the mouthparts during feeding and coating silk fibers to provide them with adhesive properties. HighlightsThree salivary proteins of spider mites are abundantly detected in their silk fibers. Though the salivary glands and silk glands are not connected, saliva appears to adhere to silk fibers after secretion. Knockdown of two of the three salivary protein genes suppressed the feeding behavior of spider mites, resulting in reduced survival and fecundity. Knockdown of the remaining salivary protein gene showed a tendency to reduce the thickness of the silk filament.

molecular biology↗

bioRxiv2025

A bright synthetic near-infrared luciferin enhances the capabilities of deep-tissue bioluminescence imaging using firefly luciferases

Synthetic bioluminescence reactions exhibiting near-infrared (NIR)-shifted spectra have been explored to improve deep-tissue imaging through the design of firefly luciferin analogues. Although the NIR bioluminescence reactions improve the tissue penetration of bioluminescence signals from deep tissues, their photon output is markedly lower compared to the natural reaction with D-luciferin and firefly luciferase (Fluc), often by an order of magnitude or more. Consequently, in most instances, the sensitivity of NIR bioluminescence imaging (NIR-BLI) has not yet substantially surpassed that of BLI with the natural firefly reaction. Here, we present a synthetic firefly luciferin, named AkaSuke, that generates intense NIR bioluminescence ({lambda}max = 680 nm) in reaction with Fluc, greatly improving the detection sensitivity beyond that of the D-luciferin/Fluc reaction for targeting deep tissue. AkaSuke enables sensitive visualizations of ectopic hematogenesis through entire tissues of mice over time following transplantation of bone marrow stem cells labeled with Fluc. We additionally identify a Japanese firefly luciferase, DkumLuc1, that displays higher catalytic activities for bioluminescence emission of AkaSuke compared to typical Fluc, resulting in detection sensitivity comparable to that of AkaLumine/Akaluc reaction, one of the most sensitive bioluminescence systems for deep tissue imaging. We further propose the potential of the AkaSuke/DkumLuc1 reaction as an orthogonal pair with the AkaLumine/Akaluc for sensitive dual-target tracking in mice. Overall results suggest that AkaSuke enhances the capabilities of deep-tissue bioluminescence imaging using Fluc and its variant, and could serve as an emerging benchmark for the molecular design of NIR luciferin analogues.

cancer biology↗

bioRxiv2023

Morc1 re-establishes heterochromatin on activated transposons and shapes the host transcriptome in gonocytes

Following reprogramming of DNA methylation, numerous transposable elements (TEs) are transiently activated in male prenatal gonocytes. Persistent expression of such TEs to adulthood leads to arrest of germ cell development. However, how these TEs are re-silenced has been unexplored. Here, we found that DNA-binding protein Morc1 re-established H3K9me3-marked heterochromatin on activated TEs, which involved methyltransferase SetDB1. Although Morc1 also triggered DNA methylation, the types of Morc1-targeted TEs for each epigenetic modification were different, suggesting that these two mechanisms were largely independent of each other. Significant overlap between TEs targeted by Morc1 and those by Miwi2, a nuclear PIWI protein, indicated that piRNA-loaded Miwi2 conferred target specificity to Morc1. Activated TEs drove transcription of adjacent genes by acting as ectopic cis-regulatory elements. Such a disrupting effect of TEs on the transcriptome was compensated by Morc1. Thus, Morc1 ensures proper interactions of TEs with host genes through re-establishment of heterochromatin in gonocytes.

bioinformatics↗

bioRxiv2023

Cardiomyocyte transcriptomic signatures in response to Trypanosoma cruzi infection underpin Chagas cardiomyopathy progression.

Chagas disease can lead to life-threatening cardiac manifestations that occur more frequently in geographic areas more prevalent with the TcI/II circulating genetic strains. To elucidate the differential transcriptomic signatures of the cardiomyocyte resulting from infection with TcI/II or TcVI T. cruzi strains and explore their relationships with pathogenesis, HL-1 rodent cardiomyocytes were infected with TcI/II or TcVI T. cruzi trypomastigotes. RNA was isolated serially post-infection for microarray analysis. Enrichment analyses of differentially expressed genes (fold-change [≥]2 or [≤] 0.5) highlighted the over-represented biological pathways. We found that Oxidative stress-related GO terms, Hypertrophy model, Apoptosis, and MAPK signaling pathways (all with p<0.01) were upregulated. Glutathione and one-carbon metabolism pathway, and Cellular nitrogen compound metabolic process GO term (all with p <0.001) were upregulated exclusively in the cardiomyocytes infected with the TcI/II strains. Upregulation in the oxidative stress-related and hypertrophic responses are shared hallmarks with viral myocarditis, another inflammatory cardiac pathology. Nitrogen metabolism upregulation and Glutathione metabolism imbalance may implicate the relation of nitrosative stress and poor oxygen radicals scavenging in the unique pathophysiology of chagasic cardiomyopathy development. ImportanceChagas disease affects more than 6 million people worldwide. One-third of those chronically infected will develop the life-threatening condition Chagas Cardiomyopathy (CCM). Trypanosoma cruzi (T. cruzi), grouped based on their genetic variability into six discrete typing units (DTU), are associated with DTU-specific clinical phenotypes. The diverse genetic make-up of parasite virulence factors shall evoke unique host defense responses of variable magnitude, collectively affecting the phenotypic expression of CCM. To address this, we performed a transcriptome analysis of cardiomyocytes infected with three different T. cruzi strains each belonging to a different DTU. As a result, we were able to point out dysregulation in nitrogen metabolic processes, Glutathione, and one-carbon metabolism pathways as main features in the host response against cardiomyopathy-prone T. cruzi strains. Further research on these pathways could serve not only in the lookout for progression biomarkers but also in the lead toward the discovery of new therapeutic targets.

cell biology↗

bioRxiv2023

Migrating neurons adapt motility modes to brain microenvironments via a mechanosensor, PIEZO1

Migration of newborn neurons is essential for brain morphogenesis and circuit formation, yet controversy exists regarding how neurons generate the driving force against strong mechanical stresses in crowded neural tissues. We found that cerebellar granule neurons adopt differential motility modes in distinct extracellular environments. In 3-dimensional (3D) confinement, actomyosin produces contractile forces at the posterior cell membrane, in addition to the traction force in the leading process that is exclusively observed in 2D cultures. The 3D migration is initiated by activation of a mechanosensitive channel PIEZO1. PIEZO1-induced calcium influx in the soma triggers the PKC-ezrin cascade, which recruits actomyosin to the posterior plasma membrane. Thus, migrating neurons use a mechano-sensing mechanism to activate multiple driving forces to maneuver in irregular brain tissue. One-Sentence SummaryCerebellar granule neurons use a mechanosensor PIEZO1 to switch migratory modes in confined spaces.

cell biology↗

bioRxiv2022

Inverse Agonist Activity of Angiotensin II Receptor Blocker Is Crucial for Prevention of Aortic Aneurysm Formation in Marfan Syndrome

BackgroundMarfan syndrome (MFS), an inherited disorder caused by FBN1 gene mutations, causes fatal aortic aneurysm. Selective angiotensin II (Ang II) type 1 (AT1) receptor blockade is a preventive option for patients with MFS aortopathy, and recent clinical studies demonstrated that the inhibitory effect of an AT1 receptor blocker (ARB) losartan on aortic aneurysm growth is equivalent to that of {beta}-blockers. At present, several ARBs are clinically available, and they have drug-specific differences in pharmacological properties. Especially, inverse agonism of ARBs has potential benefits for cardiovascular protection, but its impact on MFS aortopathy remains poorly understood. MethodsCandesartan-7H is a candesartan derivative which lacks the carboxyl group critical for inverse agonist activity and works as a neutral antagonist for AT1 receptor. Candesartan cilexetil (1 mg/kg/day), candesartan-7H (1 mg/kg/day or 20 mg/kg/day), or vehicle was administered to Fbn1C1041G/+ mice, and aortic aneurysm formation was analyzed using echocardiography, histological staining, and in situ MMP assay. Activation of TGF-{beta} signaling and mechanosensitive signaling was studied using western blot and immunohistochemical analysis. ResultsCandesartan cilexetil (1 mg/kg/day) and candesartan-7H (20 mg/kg/day) lowered blood pressures equally in Fbn1C1041G/+ mice, but that candesartan-7H (1 mg/kg/day) did not. Aortic aneurysmal progression in association with aortic wall thickening, degeneration of elastic fibers, deposition of collagen, MMP activation, and TGF-{beta} signaling activation in Fbn1C1041G/+ mice was significantly suppressed by treatment with candesartan cilexetil (1 mg/kg/day), but not by candesartan-7H even at 20 mg/kg/day. In addition, candesartan cilexetil, but not candesartan-7H, inhibited up-regulation of mechanical stress-responsive transcriptional factor Egr-1 in ascending aorta of Fbn1C1041G/+ mice. ConclusionsOur findings support a crucial role of inverse agonist activity of ARB for prevention of mechanical stress-induced AT1 receptor activation and aortic aneurysm formation in MFS mice.

pharmacology and toxicology↗