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Watanabe, M.

Publications and source records attributed to Watanabe, M..

At least 37 records · Page 2Linked to original sources

Cytoplasmic and nuclear protein interaction networks of the synapto-nuclear messenger CRTC1 in neurons reveal cooperative chromatin binding between CREB1 and CRTC1, MEF2C and RFX3

Glutamatergic stimulation of excitatory neurons triggers the synapto-nuclear translocation of the cAMP response element (CRE) binding protein (CREB) regulated transcription coactivator 1 (CRTC1), resulting in the transcription of CREB1 target genes. Whether and how CRTC1 and CREB1 interact with other transcription factors to regulate activity-dependent transcription, and what the role of CRTC1 is in neurons beyond the activation of CREB1 regulated transcription, remains unknown. To address these questions in an unbiased manner, we used proximity labeling to identify CRTC1-proximal proteins in cytoplasmic and nuclear compartments of rodent forebrain neurons. The cytoplasmic CRTC1 proxisome included a variety of signaling pathways and downstream cellular processes involved in synaptic plasticity. In contrast, the nuclear CRTC1 proxisome included transcription factors that mediate activity-dependent transcription, chromatin factors, and splicing factors. Our data revealed that CRTC1 and CREB1 interact with MEF2C and RFX3 transcription factors in an activity-dependent manner. Thus, in chromatin immunoprecipitation-sequencing experiments, CREB1 was prebound to chromatin regions containing bZIP motifs in a manner that was unchanged by neuronal activity, while glutamatergic stimulation triggered the recruitment of CRTC1 and CREB1 to activity-dependent enhancers enriched in motifs for MEF2C and RFX3. Collectively, these results not only enhance our understanding of the role of cytoplasmic and nuclear CRTC1 in neurons, but also reveal a role for CRTC1 in promoting cooperativity of CREB1 with other transcription factors in response to synaptic activity.

neuroscience↗

Genomic characterization of sub-populations in human pluripotent stem cell-derived retinal progenitor cells that drive retinal layer structure

The mechanism underlying retinal spheroid layer formation was investigated using Rax::GFP-positive retinal progenitor cells from human embryonic stem cell-derived retinal organoids. Single-cell RNA sequencing revealed that well-layered spheroids transiently activated canonical WNT2B-FZD7 signaling followed by temporary expression of non-canonical WNT5A. Despite structural differences in vitro, non- layered and well-layered retinal spheroids on differentiation Day 60 successfully developed into cone and rod subtypes of photoreceptors and established synaptic connections with host bipolar cells after transplantation in a retinal degeneration rat model, resulting in light-evoked functional recovery. Additionally, part of the presumable Rax::GFP-positive retinal progenitor cells differentiated into non- retinal lineages, including ciliary marginal zone-like, retinal pigment epithelium, and spinal cord-like tissues in vitro, reflecting the developmental plasticity of RAX-positive cells. These findings suggest that canonical and non-canonical WNT signaling pathways sequentially orchestrate early retinal morphogenesis, whereas environmental factors within the host retina strongly drive the alignment and functional integration of graft photoreceptors.

cell biology↗

Cold-induced suppression of myogenesis in skeletal muscle stem cells contributes to delayed muscle regeneration during hibernation

Mammalian hibernators experience profound cold stress and prolonged physical inactivity during torpor periods; however, it is unclear how skeletal muscle stem cells (satellite cells; SCs) respond to these challenges. In this study, we demonstrate that SCs from a mammalian hibernator, Syrian hamster exhibit remarkable resistance to cold-induced cell death, which is associated with intrinsically higher expression of the antioxidant enzyme GPX4, which likely contributes to the suppression of ferroptosis. RNA-seq analysis revealed widespread downregulation of myogenesis-related genes following cold exposure, which suggests suppression of the myogenic program. Consistently, SCs exposed to cold stress exhibited reduced activation and differentiation capacities upon subsequent rewarming, with an increased number of quiescent Pax7-positive/MyoD-negative cells. Muscle regeneration was markedly delayed during hibernation, accompanied by decreased SC activation and macrophage infiltration, suggesting that cold-induced suppression of SC function underlies limited regenerative capacity in hibernating hamsters. Our results provide insight into the unique physiology of mammalian hibernators: SC viability is preserved, whereas regenerative activity is selectively suppressed during hibernation.

physiology↗

Glucosylation of Endogenous Haustorium-inducing factors Underpins Kin Avoidance in Parasitic Plants

Parasitic plants rarely attack themselves, suggesting the activity of a kin-avoidance mechanism. In the root parasitic plant Phtheirospermum japonicum, prehaustorium formation is triggered by host-secreted haustorium-inducing factors (HIFs), but it is unresponsive to its own root exudates. Here we report the identification of the spontaneous prehaustorium 1 (spoh1) mutant, which forms prehaustoria without external HIFs. spoh1 harbors a point mutation in the gene encoding UDP-glycosyltransferase GT72B1, an enzyme that glucosylates and thereby inactivates phenolic HIFs. Notably, PjGT72B1 possesses a different substrate specificity from its ortholog of the host Arabidopsis. Introduction of PjGT72B1 in Arabidopsis reduced HIF activity, indicating that HIF glucosylation regulates haustorium induction by hosts. Our findings suggest that parasitic plants have evolved kin-avoidance mechanisms through the glucosylation of endogenous HIFs.

plant biology↗

Visualization of stochastic expression of clustered protocadherin β isoforms in vivo

The stochastic expression of clustered protocadherin (cPcdh) establishes a single-cell identity fundamental to cellular self/non-self-discrimination. However, it has been challenging to reveal the spatiotemporal patterning of the stochastic cPcdh expression in vivo. We developed XFP (tdTomato or GFP) knock-in mice using a new strategy to enhance XFP expression, which allows us to visualize cPcdh{beta}3 or 19-positive cells throughout the brain. These mouse lines demonstrate the cell-type selectivity, spatial biases, inter-individual differences, left-right asymmetry, developmental regulation, alteration in pathological or aging brain, and monoallelic expression of stochastic cPcdh{beta} expression in vivo. Our findings further demonstrate that the cPcdh{beta}3 expression undergoes significant changes in the mature brain over time. These results demonstrate the potential of these reporter mice to advance our understanding of cPcdh cellular barcode in vivo.\n\nOne Sentence SummaryNovel established cPcdh{beta} reporter mouse lines reveal stochastic expression of cPcdh{beta} isoforms in vivo.

neuroscience↗

Volitional stopping is preceded by a transient beta oscillation

Human motor cortex EEG beta (15-30 Hz) oscillations undergo transient power modulations (bursts) during volitional control of movements. They are a potential control signal for brain-machine interfaces and are a therapeutic target in Parkinsons disease. The prevailing view is that EEG beta bursts increase during stopping and immobility, but do not precede stopping. In contrast to prior work in humans and animals that used a latent and unobservable stopping time in the stop-signal task, we developed a translational animal model to align EEG with overt action stopping. We recorded 32-electrode EEG along with the angular velocity of a treadmill while head-fixed rats stopped in-progress running on a freely-rotating, non-motorized treadmill. Contrasting prior work, motor cortex beta bursts increased before stopping and not during stopping or immobility. Using information theoretic measures, we show that beta power was informative about treadmill velocity 200 msec in the future, but only during planning to stop. By introducing artificial temporal jitter to mimic the estimation of stopping time used in prior work, we show that this predictive brain-action relationship fails with even small jitter. Finally, we use a variety of machine learning methods to show that, despite EEG beta oscillations being a clear neural correlate preceding stopping, it has limited utility for real-time action decoding. Our work suggests a new conceptual model for neural control of action stopping.

neuroscience↗

Afadin-deficient retinas exhibit severe neuronal lamination defects but preserve visual functions

Neural lamination is a common feature of the central nervous system (CNS), with several subcellular structures, such as adherens junctions (AJs), playing a role in this process. The retina is also heavily laminated, but it remains unclear how laminar formation impacts retinal cell morphology, synapse integrity, and overall retinal function. In this study, we demonstrate that the loss of afadin, a key component of AJs, in mice leads to significant pathological changes. These include the disruption of outer retinal lamination and a notable decrease as well as mislocalization of photoreceptors, their outer segments, and photoreceptor synapses. Interestingly, despite these severe impairments, we recorded small local field potentials, including the a- and b-waves. We also classified retinal ganglion cells (RGCs) into ON, ON-OFF, and OFF types based on their firing patterns in response to light stimuli. Additionally, we successfully characterized the receptive fields of certain RGCs. Overall, these findings provide evidence that retinal circuit function can be partially preserved even when there are significant disruptions in both retinal lamination and photoreceptor synapses. Our results indicate that retinas with severely altered morphology still retain some capacity to process light stimuli.

neuroscience↗

Large MAF Transcription Factors Reawaken Evolutionarily Dormant Fast-Glycolytic Type IIb Myofibers in Human Skeletal Muscle

Small mammals rely on type IIb myofibers, expressing the fastest myosin IIb (encoded by MYH4), for rapid muscle contraction. In contrast, larger mammals, including humans, show reduced or absent MYH4 expression and type IIb myofibers, favoring slower-contracting myofibers. The evolutionary mechanisms underlying this shift remain unclear. Here, we identify large MAF transcription factors (MAFA, MAFB, MAF) as key regulators of MYH4 expression in large mammals, including human and bovine. Overexpression of large MAFs induces MYH4 expression and enhances glycolytic capacity in human myotubes, supported by RNA-seq and metabolic flux analyses. RNA-seq of human muscle biopsies reveals a positive correlation between MAFA, MAF, and MYH4 expression, with these genes elevated in power-trained individuals. These findings reveal a conserved mechanism across mammals, showing that large MAFs can induce type IIb myofibers even in humans, with potential applications for enhancing athletic performance and addressing age-related muscle weakness associated with the loss of fast-twitch myofibers.

cell biology↗

Spatial confinement induces reciprocating migration of epidermal keratinocytes and forms triphasic epithelia

Epithelial cells undergo epithelial-mesenchymal transition (EMT) during migration and regain their epithelial phenotype in the post-migration phase (mesenchymal-epithelial transition; MET). We established an experimental system that reproduces a three-compartment epithelial structure comprising the original epithelium, its EMT state, and its MET state. Keratinocytes (KCs), skin epithelial cells, placed on a microporous membrane migrated through 3.0-{micro}m or larger micropores. The 3.0-{micro}m-pored membrane induced an epithelial structure with three distinct states: stratified KCs above the membrane, KCs showing EMT within the micropores, and a new stratified epithelium under the membrane. The membrane with larger micropores failed to maintain the three-compartment epithelial structure. Live imaging revealed that KCs moved in an oscillatory manner, with actin-rich filopodia-like structures extending into and out of the 3.0-{micro}m micropores, while the cells migrated unidirectionally into larger micropores. Piezo1 and keratin 6 were identified as negative modulators of KC entry into and exit from the 3.0-{micro}m micropores. These results demonstrate that non-cancerous epithelial cells migrate through confined spaces in an oscillatory manner, which might contribute to the formation of a three-compartment epithelial structure that recapitulates key aspects of wound healing.

cell biology↗

Aberrant prefrontal activity and arousal level correlate with action initiation and response vigor

Orchestrating learned Stimulus-Response (S-R) mappings has been suggested as one of the central functions of the prefrontal cortex (PFC). While S-R selective activity has been demonstrated, it remains unclear whether the strength of such activity is related to the vigor of the subsequent response. Here, we trained male rats to perform a Go/NoGo response task while head-fixed on a treadmill. This allowed us to record PFC (cingulate, area 24) single unit spiking, as well as running speed as a proxy for response vigor. We show that aberrant activation of the "wrong" S-R mapping is correlated with initiation of the incorrect response. The vigor of the incorrect response was directly related to the strength of the aberrant stimulus-evoked activity. A similar relationship was observed for pre-trial arousal state and response vigor. Our findings confirm the long-standing concept, established in psychology and cognitive neuroscience, that S-R mappings are directly related to response vigor. Moreover, we provide evidence for the often suggested but rarely tested relationship between arousal and response vigor and a potential underlying neuronal mechanism involving neuromodulation of S-R mapping activity. Significance statementThe concept of stimulus-response (S-R) mappings is fundamental in psychology and has been widely documented as a key function of the prefrontal cortex. Here, the authors directly link prefrontal single neuron mapping-selective activity to the vigor of responses. Moreover, they link a physiological measure of arousal to response vigor and suggest that neuromodulatory systems invigorate responses by potentially modulating PFC S-R mapping-selective activity.

neuroscience↗

Tumor suppressor p53 controls thymic NKT17 development

The tumor suppressor p53 antagonizes tumorigenesis, notably including the suppression of T cell lymphomas while its role on physiological T cell biology including thymic T cell development has not been fully understood. Invariant natural killer T (iNKT) cells develop in the thymus as innate-like {beta}-T cells which consist of NKT1, NKT2 and NKT17 subsets. We found that the tumor suppressor p53 regulates specifically thymic NKT17 development. p53 is highly expressed in NKT17 relative to other T cell populations. Loss of p53 in the T cell lineage resulted in increased thymic NKT17 cell number with retention of lineage specific cytokine production, while development of NKT1, NKT2 and conventional T cells was not affected. Of interest, {gamma}H2AX expression was higher in NKT17 than NKT1 and NKT2 at steady state, and it was further increased in p53-deficient NKT17, suggesting that NKT17 development involves selectively greater DNA damage or genomic instability and that p53 expression might be in response to these damage signals. Taken together, our results indicated that the tumor suppressor p53 is active in selectively controlling thymic NKT17 development, with absence of p53 leading to an increase in thymic NKT17 cells expressing high levels of DNA damage response.

immunology↗

MitoNEET reduces the mitochondrial oxidative phosphorylation during epithelial-mesenchymal transition

Mitochondrial functions range from catabolic to anabolic, which are tightly coordinated to meet cellular demands for proliferation and motility. MitoNEET is a mitochondrial outer membrane protein with a CDGSH domain and is involved in mitochondrial function. Epithelial-to-mesenchymal transition (EMT) is the process in which cells lose their epithelial characteristics and acquire mesenchymal traits, such as motility, which is a vital step for organism development and wound-healing. Cellular motility is associated with high ATP consumption owing to lamellipodia formation, which is supported by upregulated oxidative phosphorylation (OXPHOS) capacity. However, how mitoNEET is involved in the regulation of OXPHOS capacity and subsequent cellular motility remains unclear. Here we show that loss of mitoNEET regulation during EMT impairs both OXPHOS enhancement and cell motility in non-transformed NMuMG mouse mammary gland epithelial cells. We found that mitoNEET is downregulated during EMT, and that the aberrant expression of mitoNEET abolishes the upregulation of OXPHOS, leading to the inhibition of cell motility. Furthermore, we found that mitoNEET topology may be crucial for the regulation of the mitochondrial electron transfer chain, suggesting an additional regulatory pathway for OXPHOS capacity. Our results demonstrate that mitochondrial OXPHOS capacity during EMT is partly regulated by the dynamics of the outer membrane protein. We believe that our findings are the first step towards understanding the mechanisms by which mitochondrial outer membrane protein topology affects organelle functions.

cell biology↗

Distinct roles of two thalamostriatal systems in learning processes of visual discrimination in common marmosets

The thalamostriatal projections arising from the intralaminar thalamic nuclei (ILN) constitute the principal source of input information to specified subregions of the striatum, a key structure of the cortico-basal ganglia circuitry. However, the roles of primate ILN in cortico-basal ganglia circuit functions remain unclear. Here, we performed immunotoxin-induced selective targeting of two representative structures of the ILN, the parafascicular nucleus (Pf) and centre median nucleus (CM) projecting to the caudate nucleus (Cd) and putamen (Pu), respectively, in common marmosets. Elimination of Pf-Cd neurons resulted in impaired reversal learning of a two-choice visual discrimination task, whereas removal of CM-Pu neurons disturbed the task acquisition. No marked impact of such manipulations was observed on either motor skill learning or spontaneous locomotor activity. Our findings reveal that the two thalamostriatal systems play distinct roles in the learning processes of external cue-dependent decision-making in nonhuman primates.

neuroscience↗

Distinct release properties of glutamate/GABA co-transmission serve as a frequency-dependent filtering of supramammillary inputs

Glutamate and GABA co-transmitting neurons exist in several brain regions; however, the mechanism by which these two neurotransmitters are co-released from the same synaptic terminals remains unclear. Here, we show that the supramammillary nucleus (SuM) to dentate granule cell synapses, which co-release glutamate and GABA, exhibit differences between glutamate and GABA release properties in paired-pulse ratio, Ca2+-sensitivity, presynaptic receptor modulation, and Ca2+ channel-vesicle coupling configuration. Moreover, uniquantal synaptic responses show independent glutamatergic and GABAergic responses. Morphological analysis reveals that most SuM terminals form distinct glutamatergic and GABAergic synapses in proximity, each characterized by GluN1 and GABAA1 labeling, respectively. Notably, glutamate/GABA co-transmission exhibits distinct short-term plasticities, with frequency-dependent depression of glutamate and frequency-independent stable depression of GABA. Our findings suggest that glutamate and GABA are co-released from different synaptic vesicles within the SuM terminals, and reveal that distinct transmission modes of glutamate/GABA co-release serve as frequency-dependent filters of SuM inputs.

neuroscience↗

Bidirectional emotional regulation through prefrontal innervation of the locus coeruleus

Traumatic experiences produce powerful emotional memories which can subsequently be enhanced or reduced through cognitive control mechanisms. Noradrenaline from the brainstem locus coeruleus (LC) is activated during aversive emotion-inducing experiences and upregulated in individuals suffering from anxiety and trauma related disorders. The medial prefrontal cortex (mPFC) participates in cognitive and emotional control processes such as production of learned defensive responses and suppression of aversive memories through extinction. However, it is unclear whether or how distinct mPFC regions influence the LC to regulate learned emotional responding. Using viral based anatomical tracing techniques, we found that the LC receives topographically organized projections from the prelimbic (PL) and infralimbic (IL) subregions of mPFC. Furthermore, optogenetic approaches revealed that PL and IL inputs to LC are required to inhibit or facilitate, respectively, the extinction of aversive memories. Moreover, LC-projecting neurons in PL and IL exhibited distinct activity patterns during extinction learning, with IL-to-LC neurons displaying sustained, sensory cue-evoked activation, while activity in PL-to-LC inputs is elevated during periods of externally and internally generated aversive emotional responding. Together, these results demonstrate that mPFC subregions bidirectionally regulate extinction of emotional memories through differential modulation of the LC-noradrenaline system.

neuroscience↗

Functional Modification of Cyanobacterial Phycobiliprotein and Phycobilisomes through Bilin Metabolism Control

The light-harvesting antenna complexes in cyanobacteria are known as phycobilisomes (PBSs), and they can adapt to a diverse range of light environments owing to the deployment of different phycobiliproteins within the PBS structures. Freshwater cyanobacteria such as Synechococcus elongatus PCC 7942 thrive under red light due to phycocyanin (PC), along with phycocyanobilin (PCB), in PBS. Conversely, cyanobacteria in shorter-wavelength light environments, such as green light, employ phycoerythrin paired with phycoerythrobilin (PEB) alongside PC in PBS. Synthetic biology studies have shown that PEB production can be enhanced by additional expression of the heterologous PEB synthases, namely 15,16-dihydrobiliverdin:ferredoxin oxidoreductase and PEB:ferredoxin oxidoreductase (PebAB), leading to cellular browning due to PEB accumulation. This approach is genetically unstable, and the properties of the resulting PEB-bound PBS complexes remain uncharacterized. Herein, we engineered a novel strain of Synechococcus 7942 PEB1, with finely tuned control of PEB metabolism. PEB1 exhibited a remarkable and reversible color shift from green to brown and pink, based on the PebAB induction levels. High induction led to a complete PCB-to-PEB substitution, causing the disassembly of the PBS rod complex. In contrast, low PebAB levels resulted in the formation of a stable chimeric PBS complex with partial PCB-to-PEB substitution. This adaptation enabled efficient light harvesting in the green spectrum and energy transfer to the photosynthetic reaction center. These findings, which improve our understanding of PBS and highlight the structural importance of the bilin composition, lay the foundation for future PBS adaptation studies in bioengineering, synthetic biology, and renewable energy.

synthetic biology↗

Neurofeedback of prefrontal unit activity during working memory in the macaque

Techniques utilizing neurofeedback, a form of biofeedback using neural signals from the brain, have been applied lately to higher association areas such as the lateral prefrontal cortex (LPFC); however, it remains unexplored how well neurofeedback using unit activity in the LPFC modulates its working memory-related activity and performance. To address this issue, we provided neurofeedback of LPFC unit activity during a delay period to two monkeys while they performed a delayed matching-to-paired-sample task. In the task, neurofeedback allowed the animals to shorten the delay length by increasing delay activity and make an earlier choice. Neurofeedback significantly increased delay activity in two-thirds of task-related neurons. Notably, in 16% of these neurons, a preference for delay activity and performance dependent on the stimulus emerged. Although neurofeedback decreased performance primarily due to choice errors, the disassociation of neurofeedback linkage rescued performance. Further, the neuronal activity of simultaneously recorded neurons without neurofeedback linkage suggests that neurofeedback reconfigured the net activity of the LPFC to adapt to new situations. These findings indicate that LPFC neurons can dynamically multiplex different types of information to adapt to environmental changes. Thus, we demonstrated the significant potential of neurofeedback using unit activity to investigate information processing in the brain.

neuroscience↗

Piezo1 Mutant Zebrafish as a Model of Idiopathic Scoliosis

Scoliosis is a condition where the spine curves sideways, unique to humans due to their upright posture. However, the cause of this disease is not well understood because its challenging to find a model for experimentation. This study aimed to create a model for human idiopathic scoliosis by manipulating the function of mechanosensitive channels called Piezo channels in zebrafish. Zebrafish were chosen because they experience similar biomechanical forces to humans, particularly in relation to the role of mechanical force in scoliosis progression. Here we describe piezo1 and piezo2a are involved in bone formation, with a double knockout resulting in congenital systemic malformations. However, an in-frame mutation of piezo1 led to fully penetrant juvenile-onset scoliosis, bone asymmetry, reduced tissue mineral density, and abnormal intervertebral discs-resembling non-congenital scoliosis symptoms in humans. These findings suggest that functional Piezo channels responding to mechanical forces are crucial for bone formation and maintaining spine integrity, providing insights into skeletal disorders.

developmental biology↗