Biology subjects

Ishizuka, K.

Publications and source records attributed to Ishizuka, K..

17 recordsLinked to original sources

bioRxiv2026

Olfactory neuroepithelium biomarker platform: a proof from Alzheimer's disease

Unlike other diseases where target organs for biopsy are accessible, surrogate platforms are warranted for biomarkers of neuropsychiatric disorders due to the inaccessibility of the brain. We demonstrate a non-invasive platform combining a nasal soft-brush swab with single-cell Western blotting for neuron-specific protein analysis. Applied to Alzheimer's disease targeting phosphorylated tau, this demonstrated superior diagnostic capacity compared with blood-based approaches, indicating that the olfactory neuroepithelium is a sensitive biomarker platform.

biochemistry↗

bioRxiv2026

Adolescent prodromal phenotypes of psychiatric disorders: insights from a novel DISC1-perturbed monkey model

Neurodevelopmental deficits frequently lead to mild but significant adolescent social and cognitive changes, representing prodromal manifestations of adult-onset psychiatric disorders in a cross-disease manner. Although experimental medicine utilizes animal models to address the mechanisms, rodent brains lack critical structures for human higher brain functions such as the dorsolateral prefrontal cortex. To fill this translational gap, we generated monkeys with an impaired DISC1 gene locus, targeting the multifunctional protein essential for neurodevelopment and involved in transdiagnostic mental health risks. Here we analyze the F0 animals by minimizing mosaicism. At ages equivalent to human adolescence, these monkeys exhibited blunted responsiveness to social stimuli and increased internal drives, mirroring altered social behaviors in the prodromal stage in humans. Resting-state functional MRI data indicated disrupted global functional connectivity and reorganization of network topology, marked by a shift in the dominance of brain hubs from prefrontal regions to sensory areas. This primate model provides a unique platform for studying psychiatric disorders, such as schizophrenia, across the developmental trajectory.

neuroscience↗

bioRxiv2026

The anterior insular cortex mediates higher-order threat learning and memory

Learning about potential threats is indispensable for survival, and its deficits underlie numerous neuropsychiatric disorders. Human brain imaging suggests the anterior insular cortex (AIC) as a key neural correlate of threat learning, yet its mechanistic role remains unclear. Leveraging multimodal systems neuroscience approaches, we demonstrate that AIC excitatory neurons, specifically layer 5 pyramidal neurons projecting to the basolateral amygdala, are essential for higher-order threat learning/memory. They are specifically required when a predictor is temporally separated from an aversive event or when the predictive information is embedded within a diffuse context. In contrast, the AIC is dispensable for elementary, temporally contiguous threat learning. Surprisingly, while the AIC promotes memory formation, it also constrains the level of fear expression during retrieval in a context-dependent manner. This bidirectional control is mediated by the recruitment of distinct AIC neuronal ensembles. Together, we identify a novel circuit mechanism for bidirectional regulation of higher-order threat learning/memory.

neuroscience↗

bioRxiv2026

A Translational Model of MASLD-Associated HFpEF Defines Mitochondrial Dysfunction and Cardiac Plasticity During Disease Progression and Regression

Metabolic dysfunction-associated steatotic liver disease (MASLD) and its progressive form, metabolic dysfunction-associated steatohepatitis (MASH), are strongly linked to cardiac dysfunction, particularly, heart failure with preserved ejection fraction (HFpEF), yet the mechanisms underlying this association remain unclear because robust integrative preclinical models are lacking and the liver and heart are rarely studied as a coordinated system. Here we show that Alms1-/- (Foz/Foz) mice fed a Western diet develop MASH with advanced liver fibrosis accompanied by a HFpEF-like phenotype characterized by left ventricular hypertrophy, impaired cardiomyocyte contractility, reduced {beta}-adrenergic reserve, elevated BNP, and increased mortality despite ejection fraction >50%. Liver fibrosis emerged as a parameter strongly associated with the cardiac dysfunction. Remarkably, dietary reversal improved hepatic architecture, normalized cardiac function, and improved survival, revealing marked plasticity of the liver-heart axis. Analyses of left ventricular (LV) remodeling revealed mitochondrial dysfunction, altered substrate utilization, and extracellular matrix remodeling in the LV, with consistent concordance to human HFpEF transcriptomic signatures. Ultrastructural studies confirmed mitochondrial injury and sarcomeric disorganization, linking metabolic failure to impaired cardiomyocyte performance. Together, these findings identify mitochondrial dysfunction as an important feature of MASLD-associated HFpEF-like cardiac dysfunction and establish the Foz/Foz model as a powerful platform for investigating pathophysiological pathways linking metabolic liver disease to cardiac dysfunction and for testing mechanism-based therapeutic strategies. STRUCTURED ABSTRACTO_ST_ABSBackgroundC_ST_ABSMetabolic dysfunction associated steatotic liver disease (MASLD) and its advanced form, MASH, are closely linked to cardiac dysfunction, particularly heart failure with preserved ejection fraction (HFpEF). However, the mechanisms underlying MASLD-associated HFpEF and its reversibility remain poorly understood, largely due to the lack of robust preclinical models. Here, we established a translational model of MASLD-associated cardiac dysfunction that recapitulates the key features of human HFpEF. We applied functional and transcriptomic analyses of the left ventricle (LV) to define the pathways associated with cardiac dysfunction and its reversibility. MethodsAlms1-/- (Foz/Foz) mice and wild-type littermates were fed normal chow (NC) or Western diet (WD) for up to 36 weeks (wk). Reversibility was modeled by switching WD-fed Foz/Foz mice at 12wk back to NC for 12wk. Cardiac assessment included echocardiography, invasive hemodynamics with dobutamine stimulation, histopathology, electron microscopy and isolated cardiomyocyte contractility. LV transcriptomes were profiled by bulk RNA sequencing and analyzed by differential expression and pathway enrichment. ResultsFoz/Foz mice on WD for 24wk developed metabolic syndrome and MASH with advanced liver fibrosis. Cardiac phenotyping showed LV hypertrophy, impaired cardiomyocyte contractility, reduced {beta}-adrenergic reserve, elevated plasma BNP, and increased mortality while the ejection fraction was preserved (>50%), consistent with HFpEF. The progression of cardiac dysfunction was closely associated with liver fibrosis that developed during MASH. Switching WD-fed Foz/Foz mice at 12wk to normal chow diet reversed hepatic fibrosis, restored LV function, and reduced mortality, demonstrating plasticity of the liver-heart axis. LV transcriptomic analysis revealed that cardiac impairment in these mice was associated with mitochondrial dysfunction, altered substrate utilization, extracellular matrix remodeling, and metabolic stress; pathways that are similarly dysregulated in human HFpEF. Cardiac electron microscopy revealed swollen mitochondria with disrupted cristae, which improved following dietary intervention. ConclusionsMitochondrial dysfunction and fibroinflammatory remodeling are prominent features of MASLD-associated cardiac dysfunction. Reversal of hepatic and cardiac phenotypes with dietary intervention, together with elucidation of underlying pathways, establish the Foz/Foz model as a useful translational platform for studying liver-heart axis in MASLD. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/708088v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@60bd2aorg.highwire.dtl.DTLVardef@1234a09org.highwire.dtl.DTLVardef@1d1c5aborg.highwire.dtl.DTLVardef@1086089_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2025

DISC1-PML protein interaction for congenital CMV infection-induced cortical neural progenitor deficit: perturbance of host signaling via viral IE1

Congenital CMV infection is the most common perinatal infection, affecting up to 0.5% of infants. This elicits long-term disabilities that include neuropsychiatric manifestations, such as intellectual disability, microcephaly. Despite its high prevalence, the underlying mechanism of how congenitally acquired CMV infection causes brain pathology remains unknown. Here we discovered the molecular interplay of key host (DISC1 and PML) and viral (IE1) proteins within the neural progenitor cells, which underlay an attenuated neural progenitor proliferation. Abolishing the viral IE1 protein by delivering IE1-targeting CRISPR/Cas9 to fetal brain rescued this progenitor cell deficit, a key pathology in congenital CMV infection. A selective targeting to a viral-specific protein by the CRISPR/Cas9 system is minimal in off-target effects. Therefore, we believe that a pivotal role of IE1 in an attenuated neural progenitor proliferation in the developing cortex through its interfering with interaction between host DISC1 and PML proteins.

developmental biology↗

bioRxiv2025

Attenuated CaV1.2-BK channel protein interaction in bipolar disorder

Bipolar disorder (BP) is a severe mental illness featured with potential cycling of depressive and manic episodes. The recurrent cycling is known to be associated with poor prognosis. Thus, it is important to decipher the pathophysiological mechanism that may possibly underlie the cycling. In our study, by using BP patient-derived neurons, we discovered the delay of time-to-peak in depolarization-associated intracellular calcium dynamics. This cellular deficit is selectively associated with the number of manic episodes in BP patients, suggesting that this deficit may participate in the mechanism of clinical cycling. We also observed an attenuated protein interaction between the calcium and voltage-activated potassium (BK) channel and the CaV1.2 L-type VGCC in BP patients. Pharmacological and molecular interventions that target CaV1.2-BK protein interaction, directly to BK channel for the amelioration of this attenuated protein interaction rescues the disease-associated intracellular calcium deficit. To test the involvement of BK channel in cycling-associated behaviors, we generated a novel animal model.

neuroscience↗

bioRxiv2023

Frequency modulation increases the specificity of time-resolved connectivity: A resting-state fMRI study

The human brain is a highly dynamic system, and the methods we use to analyze the data gathered from this organ should account for this dynamism. One such family of methods that has attracted a lot of attention in the past decades is based on networks. The most well-known method for estimating the connection among these networks uses the sliding window Pearson correlation (SWPC) estimator. Although quite a useful tool, there are some important limitations. One such limitation is that SWPC applies a high pass filter to the activity time series. If we select a small window size (which is desirable to estimate rapid changes in functional connectivity), we will filter out important low-frequency activity information. In this work, we propose an approach based on single sideband modulation (SSB) in communication theory, which aims to solve this issue, allowing us to select smaller window sizes and capture rapid changes in the time-resolved functional connectivity. We use both simulation and real data to demonstrate the superior performance of the proposed method, SSB+SWPC, compared to classical SWPC. In addition, we compare the temporal recurring functional connectivity patterns between individuals with the first episode of psychosis (FEP) and typical controls (TC) and show that FEP stays more in FNC states that show weaker connectivity across the whole brain. A result exclusive to SSB+SWPC is that TC stays more in a state with negative connectivity between sub-cortical and cortical regions. All in all, based on both simulated data and real data, we argue that the proposed method, SSB+SWPC, is more sensitive for capturing temporal variation in functional connectivity.

neuroscience↗

bioRxiv2022

Immune-related molecular changes in the olfactory epithelium, structural alteration in the olfactory bulb, and psychosis

Smell deficits and neurobiological changes in the olfactory bulb (OB) and olfactory epithelium (OE) have been observed in schizophrenia and related disorders. The OE is the most peripheral olfactory system located outside the cranium, and is connected with the brain via direct neuronal projections to the OB. Nevertheless, it is unknown whether and how a disturbance of the OE affects the OB in schizophrenia and related disorders. Addressing this gap would be the first step in studying the impact of OE pathology in the disease pathophysiology in the brain. In this cross-species study, we observed that chronic, local OE inflammation with a set of upregulated genes in an inducible olfactory inflammation (IOI) mouse model led to a volume reduction, layer structure changes, and alterations of neuron functionality in the OB. Furthermore, IOI model also displayed behavioral deficits relevant to negative symptoms (avolition) in parallel to smell deficits. In first episode psychosis (FEP) patients, we observed a significant alteration in immune/inflammation-related molecular signatures in olfactory neuronal cells (ONCs) enriched from biopsied OE and a significant reduction in the OB volume, compared with those of healthy controls (HC). The increased expression of immune/inflammation-related molecules in ONCs was significantly correlated to the OB volume reduction in FEP patients, but no correlation was found in HCs. Moreover, the increased expression of human orthologues of the IOI genes in ONCs was significantly correlated with the OB volume reduction in FEP, but not in HCs. Together, our study implies a potential mechanism of the OE-OB pathology in patients with psychotic disorders (schizophrenia and related disorders). We hope that this mechanism may have a cross-disease implication, including COVID-19-elicited mental conditions that include smell deficits.

molecular biology↗

bioRxiv2022

Olfactory neuronal cells: biopsied surrogates for neurons in the brain

Biopsy is crucial in clinical medicine to obtain tissues and cells that directly reflect the pathological changes of each disease. However, the brain is an exception due to ethical and practical challenges. Nasal biopsy, which captures the olfactory neuronal epithelium, has been considered as an alternative method of obtaining neuronal cells from living patients. Multiple groups have enriched olfactory neuronal cells (ONCs) from biopsied nasal tissue. ONCs can be obtained from repeated biopsies in a longitudinal study, providing mechanistic insight associated with dynamic changes along the disease trajectory and treatment response. Nevertheless, molecular characterization of biopsied nasal cells/tissue has been insufficient. Taking advantage of recent advances in next-generation sequencing technologies at the single-cell resolution and related rich public databases, we aimed to define the neuronal characteristics, homogeneity, and utility of ONCs. We applied single-cell and bulk RNA sequencing for ONCs, analyzing and comparing the data with multiple public datasets. We observed that the molecular signatures of ONCs are similar to those of neurons, distinct from major glial cells. The signatures of ONCs resemble those of developing neurons and share features of excitatory neurons in the prefrontal and cingulate cortex. The high homogeneity of ONCs is advantageous in pharmacological, functional, and protein studies. Accordingly, we provide two proof-of-concept examples for functional and protein studies, solidifying the utility of ONCs in studying objective biomarkers and molecular mechanisms for brain disorders. The ONCs may also be useful in the studies for the olfactory epithelium impairment and the resultant mental dysfunction elicited by SARS-CoV-2. SIGNIFICANCE STATEMENTTo study dynamic changes and underlying mechanisms along disease trajectory and treatment response in neuropsychiatric disorders, olfactory neuronal cells (ONCs) enriched from biopsied nasal tissue may provide a crucial tool. Because ONCs can be obtained from repeated biopsies in a longitudinal study, this tool has been believed to be useful and complementary to postmortem brains and induced pluripotent stem cell-derived neurons. Nevertheless, molecular characterization of biopsied nasal cells/tissue has been insufficient, which hampers a broader use of this resource. Taking advantage of recent advances in next-generation sequencing technologies at the single-cell resolution and related rich public databases, the present study defines ONCs neuronal characteristics, homogeneity, and unique utility for the first time.

molecular biology↗

bioRxiv2022

Canonical and Replicable Multi-Scale Intrinsic Connectivity Networks in 100k+ Resting-State fMRI Datasets

Resting-state functional magnetic resonance imaging (rsfMRI) has shown considerable promise for improving our understanding of brain function and characterizing various mental and cognitive states in the healthy and disordered brain. However, the lack of accurate and precise estimations of comparable functional patterns across datasets, individuals, and ever-changing brain states in a way that captures both individual variation and inter-subject correspondence limits the clinical utility of rsfMRI and its application to single-subject analyses. We posit that using reliable network templates and advanced group-informed network estimation approaches to accurately and precisely obtain individualized (dynamic) networks that retain cross-subject correspondence while maintaining subject-specific information is one potential solution to overcome the aforementioned barrier when considering cross-study comparability, independence of subject-level estimates, the limited data available in single studies, and the low signal-to-noise ratio (SNR) of rsfMRI. Toward this goal, we first obtained a reliable and replicable network template. We combined rsfMRI data of over 100k individuals across private and public datasets and selected around 58k that meet quality control (QC) criteria. We then applied multi-model-order independent component analysis (ICA) and subsampling to obtain reliable canonical intrinsic connectivity networks (ICNs) across multiple spatial scales. The selected ICNs (i.e., network templates) were also successfully replicated by independently analyzing the data that did not pass the QC criteria, highlighting the robustness of our adaptive template to data quality. We next studied the feasibility of estimating the corresponding subject-specific ICNs using a multivariate-spatially constrained ICA as an example of group-informed network estimation approaches. The results highlight that several factors, including ICNs themselves, data length, and spatial resolution, play key roles in successfully estimating the ICNs at the subject level. Large-scale ICNs, in general, require less data to achieve a specific level of spatial similarity with their templates (as well as within- and between-subject spatial similarity). Moreover, increasing data length can reduce an ICNs subject-level specificity, suggesting longer scans might not always be desirable. We also show spatial smoothing can alter results, and the positive linear relationship we observed between data length and spatial smoothness (we posit that it is at least partially due to averaging over intrinsic dynamics or individual variation) indicates the importance of considering this factor in studies such as those focused on optimizing data length. Finally, the consistency in the spatial similarity between ICNs estimated using the full-length of data and subset of it across different data lengths may suggest that the lower within-subject spatial similarity in shorter data lengths is not necessarily only defined by lower reliability in ICN estimates; rather, it can also be an indication of brain dynamics (i.e., different subsets of data may reflect different ICN dynamics), and as we increase the data length, the result approaches the average (also known as static) ICN pattern, and therefore loses its distinctiveness.

neuroscience↗

bioRxiv2022

The nuclear GAPDH-HMGB cascade in cortical microglia regulates cognitive flexibility

We report a mechanism that underlies stress-induced cognitive inflexibility at the molecular level. In a mouse model under subacute stress in which deficits in rule shifting tasks were elicited, the nuclear glyceraldehyde dehydrogenase (N-GAPDH) cascade was activated specifically in microglia in the prelimbic cortex. The cognitive deficits were normalized with a pharmacological intervention with a compound (the RR compound) that selectively blocked the initiation of N-GAPDH cascade without affecting glycolytic activity. The normalization was also observed with a microglia-specific genetic intervention targeting the N-GAPDH cascade. Furthermore, hyperactivation of the prelimbic layer 5 excitatory neurons, which are known to be a neuronal substrate of cognitive inflexibility, was also normalized by the pharmacological and microglia-specific genetic interventions. The RR compound may offer a mechanism-driven, translational opportunity against stress-induced cognitive inflexibility. Taken together, we show a pivotal role of cortical microglia and microglia-neuron interaction in stress-induced cognitive inflexibility. We underscore the N-GAPDH cascade in microglia, which causally mediates stress-induced cognitive alteration.

molecular biology↗

bioRxiv2022

Loss of the protein disrupted in schizophrenia 1 (DISC1) impairs cardiac resistance against ischemia.

Molecular targets that contribute to post-myocardial infarction heart failure remains elusive. Here we studied the global transcriptional landscape of human inducible pluripotent stem cell-derived cardiomyocytes under simulated ischemia at the whole genome level in an unbiased manner. Unexpectedly, we identified Disrupted in Schizophrenia 1 (DISC1), which has been almost exlusively studied in neurodevelopment/neurosignaling, as a key molecule. Reduced DISC1 levels increase infarct size in mouse hearts, increases cTnT release following surgery in coronary artery bypass grafting patients and decrease the survival of human AC16 cardiomyocytes exposed to ischemic conditions by disrupting cardioprotective pathways. Mechanistically, the loss of DISC1 interaction with Glycogen Synthase Kinase 3 Beta (GSK3{beta}) heightens GSK3{beta} activity, promoting cell death. Conversely, increasing DISC1 levels enhances cardioprotective signaling by maintaining the DISC1-GSK3{beta} interaction. Although DISC1 is known to interact with many proteins as an intracellular hub, we have identified that its specific interaction with GSK3{beta} is crucial for cardioprotection. These data also indicate that a key molecule involved in brain health and disease also contributes to cardiac health and disease, supporting the idea that neuropsychiatric conditions are systemic. SummaryThrough an unbiased screening at the whole genome level, we underscore that DISC1 is a key molecule for cardiomyocyte resilience post-myocardial infarction. DISC1 has been studied almost exclusively in neuroscience, involving in multiple cellular mechanisms. In contrast, we highlight DISC1s interaction with GSK3{beta} as specific mechanism that drives cardioprotection. We also report DISC1s implication in cardiac health following coronary artery bypass grafting.

molecular biology↗

bioRxiv2021

The miR-124-AMPAR pathway connects polygenic risks with behavioral changes shared between schizophrenia and bipolar disorder

Schizophrenia (SZ) and bipolar disorder (BP) are highly heritable major psychiatric disorders that share a substantial portion of genetic risk as well as their clinical manifestations. This raises a fundamental question of whether, and how, common neurobiological pathways translate their shared polygenic risks into shared clinical manifestations. The present study shows the miR-124-AMPAR pathway as a key common neurobiological mediator that connects polygenic risks with behavioral changes shared between these two psychotic disorders. We discovered upregulation of miR-124 in biopsied neuronal cells and postmortem prefrontal cortex from both SZ and BP patients, implying its role not only as a biomarker, but also as a pathophysiological mediator. Intriguingly, the upregulation is associated with the polygenic risks shared between these two disorders. Seeking mechanistic dissection, we generated a mouse model that upregulates miR-124 in the medial prefrontal cortex, which includes brain regions homologous to sub-regions of the human prefrontal cortex. We demonstrated that upregulation of miR-124 increases GRIA2-lacking calcium permeable-AMPARs and perturbs AMPAR-mediated excitatory synaptic transmission, leading to deficits in the behavioral dimensions shared between SZ and BP.

neuroscience↗

bioRxiv2021

Volumetric alteration of olfactory bulb and immune-related molecular changes in olfactory epithelium in first episode psychosis patients

BackgroundOlfactory dysfunction has been reproducibly reported in patients with psychosis, including first episode psychosis (FEP) patients. Consistently, structural abnormalities in the olfactory bulb (OB), a key region of the peripheral olfactory system, have also been reported in psychotic disorders. Meanwhile, air pollution and viral infections in the upper respiratory tract, including those of SARS-CoV-2, are reportedly risk factors for brain dysfunction and mental disorders. These risk factors can disturb the olfactory epithelium (OE) that is located adjacent to the OB and connected via direct neuronal projections. Nevertheless, it is unknown how a disturbance of the OE possibly affects the OB in the pathophysiological context of psychotic disorders. MethodsWe examined the volume of the OB in FEP patients and healthy controls from 3 Tesla magnetic resonance imaging and molecular expression profiles of olfactory neuronal cells (ONCs) enriched from freshly biopsied OE. ResultsWe observed a reduction of the OB volume in FEP patients compared with healthy controls. We also observed a significant alteration in gene expression profiles in the ONCs from FEP patients, supporting the pathological changes in the OE. Among such molecular changes, immune-related molecules and pathways were underscored in association with the OB volume changes in FEP patients. ConclusionsOur data support the OB and OE pathologies in FEP patients. Immune-related molecular changes in the OE can biologically link adverse factors in the nasal cavity, such as air pollution and viral infection, with the OB structural change, both of which have been reported for psychotic disorders.

neuroscience↗

bioRxiv2021

Face processing of social cognition in patients with first episode psychosis: Its deficits and association with the right subcallosal anterior cingulate cortex

The clinical importance of social cognition is well acknowledged in patients with psychosis, in particular those with first episode psychosis (FEP). Nevertheless, its brain substrates and circuitries remain elusive, lacking precise analysis between multimodal brain characteristics and behavioral sub-dimensions within social cognition. In the present study, we examined face processing of social cognition in 79 FEP patients and 80 healthy controls (HCs). We looked for a possible correlation between face processing and multimodal MRI characteristics such as resting-state functional connectivity (rsFC) and brain volume. We observed worse recognition accuracy, longer recognition response time, and longer memory response time in FEP patients when compared with HCs. Of these, memory response time was selectively correlated with specific rsFCs, which included the right subcallosal sub-region of BA24 in the ACC (scACC), only in FEP patients. The volume of this region was also correlated with memory response time in FEP patients. The scACC is functionally and structurally important in FEP-associated abnormalities of face processing measures in social cognition.

neuroscience↗

bioRxiv2019

Nuclear GAPDH signaling mediates pathological cardiac hypertrophy

Here we report that stress-induced nuclear translocation of GAPDH mediates heart hypertrophy via Brahma-Related-Gene-1 (BRG1)-associated chromatin remodelling. In response to pressure overload elicited by transverse aortic constriction, we observed nuclear translocation of GAPDH in the mouse heart. We also demonstrated a robust nuclear localization of GAPDH in cardiomyocytes from patients with dilated hypertrophic cardiomyopathy, whereas negligible GAPDH in the nucleus in control subjects. This is the first demonstration of disease-associated nuclear GAPDH directly in living patients. Using immunohistochemical methods and a pharmacological way that selectively blocks GAPDH nuclear translocation (RR compound), we proved the causal involvement of GAPDH cysteine-150 modification in this translocation in Gq-induced cell model for heart hypertrophy. Accordingly, both pharmacological and genetic interventions proved that the same mechanism played a causal role for heart hypertrophy and dysfunction in vivo. We discovered that, upon nuclear translocation, GAPDH augmented the protein interaction of BRG1 and histone deacetylase 2 (HDAC2), which further facilitated the Myh7/Myh6 isoform ratio from the mature to immature status, an essential mechanism for heart hypertrophy. Beyond medical implications, we provide a novel mechanism of stress-induced reversion of a cellular phenotype from adult to fetal state, which is mediated by a "moonlighting" function of GAPDH.

molecular biology↗

bioRxiv2018

The cortico-striatal circuit regulates sensorimotor gating via Disc1/Huntingtin-mediated Bdnf transport

Sensorimotor information processing that underlies normal cognitive and behavioral traits is dysregulated across a subset of neurological and psychiatric disorders. The cross-disease deficit in sensorimotor gating poses a unique opportunity to integrate hierarchical findings at molecular, cellular, through circuitry levels to obtain an in-depth mechanistic understanding of this process that contributes to brain physiology and pathophysiology beyond categorical segmentation of brain disorders. Based on circuitry recording with wild-type mice, we demonstrated that the cortico-striatal projection mediates sensorimotor gating responses during prepulse inhibition (PPI) task. We also found that these circuitry responses were disrupted in Disc1 locus-impairment (LI) mice, a model representing neuropsychiatric conditions. Thus, we hypothesized that Disc1-mediated molecular and cellular machinery along the cortico-striatal circuit may regulate sensorimotor gating. Anatomical and biochemical analyses of Disc1-LI mice revealed attenuated Bdnf transport along the cortico-striatal circuit. Pharmacologically augmenting Bdnf transport by chronic lithium administration, in part via Ser-421 phosphorylation of Huntingtin (Htt) and its integration into the motor machinery, restored the striatal Bdnf levels and PPI deficits in Disc1-LI mice, suggesting that the Bdnf transport attenuation mechanistically underlies the circuitry and behavioral deficits. These results also shed light on a novel mechanism and utility of lithium that is currently used as a major mood stabilizer in clinical settings. Collectively, the present study illustrates integrative biological mechanisms for sensorimotor gating, underscoring the cross-disease nature of this behavioral dimension and translational utility of the findings under the era of precision medicine in brain disorders.

neuroscience↗