In order to deeply understand the principle of organisms, it is necessary to unravel the information of each cell existing in the organism. For many years, many cell types, such as nerves and macrophages, that make up living organisms have been thought to be homogeneous cell populations. However, it has become clear that in many cases, heterogeneity exists within each cell population, and that it is composed of cells with different states and functions. Recent advances in research technology have dramatically improved the sensitivity and accuracy of cell information analysis, enabling high-throughput analysis at the single-cell level, which makes it possible to conduct research targeting rare cells that may originally perform crucial functions, and to discover important changes that could not be known by analysis based on the classical assumption of a homogeneous cell population. In this symposium, I will discuss current knowledge about the characteristics of CNS macrophages that have recently been uncovered by single-cell analysis.

Patients with neurodegenerative diseases (NDDs) are rapidly increasing worldwide. Alzheimer’s disease (AD), frontotemporal lobar degeneration (FTLD), Huntington’s disease (HD), and other several diseases are classified as NDDs; however, no therapeutic drugs have been developed yet.

In NDDs, protein oligomers and aggregates are formed in neuronal and glial cells and they trigger neuronal cell death and axonal degeneration. We discovered several chemicals and proteins can reverse these phenomena. In this symposium, we show phorbol 12-myristate 13-acetate (PMA) and a certain saccharide significantly inhibits aggregate formation and promotes neurite regeneration in cell culture model of FTLD and AD.

We expressed R406W mutant tau protein found in FTLD patients in SH-SY5Y human neuronal cells as FTLD cell culture model. FTLD neuronal cells showed intracellular aggregate formation and impaired neurite growth. Addition of PMA showed 60% decrease of aggregates. PMA also recovered neurite growth to the normal level. We cultured SH-SY5Y cells in the medium containing b-amyloid (1-42) as AD cell culture model. In these cells, neurite growth was deceased to less than 50% of controls, but addition of PMA dramatically recovered neurite extension in AD culture model cells. The other, a certain saccharide showed the almost same effects as PMA. These results suggest PMA and a certain saccharide have unexpected potentials for the drug development against NDDs (we will talk what is ‘a certain saccharide’ in symposium but please forgive that we do not open the name in abstract).

Aging is associated with decline in various brain functions, having a significant impact on individual's quality of life. Synaptic plasticity is cellular basis for higher brain functions, including learning and memory and cognition. Although there are various reports on the age-dependent decline in higher brain functions, profile and molecular mechanism of age-dependent changes in cerebellar synaptic plasticity are not fully understood.

Cerebellar synapses of mouse are excellent models for the studies on age-dependent changes in synaptic plasticity, because the cerebellar neuronal circuit is simple and various types of synaptic plasticity, including long-term depression (LTD) and long-term potentiation (LTP) at parallel fiber (PF)-to-Purkinje cell (PC) synapse (PF synapse), are identified. However, profile and molecular mechanism of age-dependent changes in cerebellar synaptic plasticity have yet to be examined.

In this symposium, I will introduce our recent studies indicating that involvements of ROS-related signaling in inhibition of LTP at PF synapse (PF-LTP) in the aged cerebellum. ROS impairs PF-LTP and nitric oxide-induced Ca²⁺ release, which is essential for the induction of PF-LTP, through the inhibition of S-nitrosylation of intracellular Ca²⁺ release channel. Surprisingly, ROS is also indicated to be involved in cerebellar-dependent motor learning as well as PF-LTD in young-adult cerebellum. Taken together, these observations suggest dual functions of ROS in physiological and pathophysiological events in brain systems in young and aged mouse, respectively.

Alz­heimer’s dis­ease (AD) is the most common neuro­degenerative dis­ease characterized by cognitive decline and irreversible memory loss. Excessive amount of ammonia has been detected in the brain and serum of AD patients, and the toxicity of ammonia has been thought as a factor which con­tri­butes to the pro­gression of AD. In the central nervous system, astro­cytes play a key role in ammonia meta­bolism by ex­pressing the enzyme called glutamine synthetase, which catalyzes the synthesis of glutamine from glu­tam­ate and ammonia, and supply glutamine to neu­rons for the pro­duction of neuro­trans­mitters. Here we report that pro­longed NH₄Cl treat­ment accumulates amyloid pre­cursor pro­tein (APP) in astro­cytes. Enhanced APP levels was detected in both the plasma mem­branes and in­tra­cellular com­partments. Immuno­cyto­chemistry revealed that NH₄Cl induces the accu­mulation of APP in the endo­plasmic reticulum and cleaved to become amyloid beta. In addition, NH₄Cl treat­ment induced astrocyte senescence, which inhibits cell proliferation. To­gether, our data sug­gests that ammonia induces the pro­duction and accu­mulation of APP and Aβ in astro­cytes as well as astrocyte senescence, and possibly exacerbate AD patho­logy.

Ca²⁺/ calmodulin-dependent protein kinases (CaMKs) are widely distributed in neuron and glial cells such as astrocyte or microglia of the mammalian brain and play a critical role in cortical functions including cognition, attention, and memory.CaMKs family is mainly comprised of calcium/calmodulin-dependent protein kinase I, Ca²⁺/ calmodulin-dependent protein kinase II（CaMKII）, and Ca²⁺/ calmodulin-dependent protein kinase IV (CaMKIV). CaMKII is predominantlyexpressed in the dendritic spine of excitatory pyramidal neurons and CaMKIV is predominantly localized in the nucleus of neurons. We previously reported that downregulation of CaMKII and CaMKIV activities is critical for cognitive decline and depressive-like behaviors in pathological animal model. Especially, inhibition of ATP-sensitive K⁺ (K_ATP) channels increased intracellular Ca²⁺ concentration and CaMKII autophosphorylation and improved cognitive decline in AD model mice. By contrast, CaMKIV null mouse reveals increased hippocampal adult neurogenesis which is correlated with drug-resistant depression. In this symposium, we focus the age-related cognitive/mental disorders via calcium signal pathways.

Cardiomyocytes derived from pluripotent stem cells hold promise for applying cardiac pharmacology studies and regeneration therapy. One of the most significant issues for their biomedical applications is the immaturity of pluripotent stem cell-derived cardiomyocytes. Cardiomyocytes derived from pluripotent stem cells tend to halt their maturation and maintain an embryonic state during in vitro cultivation. Thus far, our efforts have been focused on inducing the maturation of the cardiomyocytes. Using the reporter iPSCs of cardiomyocyte maturation, we conducted a high throughput screening and identified an ERRγ agonist that induced upregulation of TNNI3, a marker for mature cardiomyocytes.

Furthermore, the ERRγ agonist induced comprehensive maturation of iPSC-derived cardiomyocytes, including electrophysiological properties, mitochondria functions, sarcomere structures, and T tubule formation. We also confirmed that this compound-based maturation can be applied to generate 3D mature engineered heart tissue by combining mechanical stimulation. The mature engineered heart tissue can be used for toxicology studies to assess the cardiotoxicity of anticancer drugs and model cardiac diseases to investigate the disease mechanism.

Collectively, the generation of mature cardiac tissues will help efficiently establish models for cardiac pharmacology studies.

Cardiac dysfunction is a major side effect caused by anticancer drug treatment. Doxorubicin, an anthracycline-derivative anticancer drug, exhibits dose-dependent cardiotoxicity, which limits its clinical use. Cardiotoxicity ranges from decreased ejection fraction, arrhythmias, to highly symptomatic congestive heart failure, which are all associated with high mortality. Cardiomyocytes require energy to beat and therefore retain an abundance of mitochondria. We established quantitative measurements of mitochondrial length and respiratory activities, and contractile functions using cardiomyocytes. We found that exposure of human iPS cell-derived cardiomyocytes to anticancer agents suppressed myocardial contraction and enhanced mitochondrial hyperfission. The oxygen consumption rate was significantly reduced. Knockdown of dynamin-related protein 1 (Drp1), mitochondrial fission-accelerating GTP-binding protein, suppressed mitochondrial hyperfission and cytotoxicity caused by anticancer agents. This indicates that visualizing mitochondrial functions in human iPS cell-derived cardiomyocytes will be helpful to assess the risk of cardiotoxicity caused by anticancer agents, and that the maintenance of mitochondrial quality will become a new strategy to reduce anti-cancer drug-induced cardiotoxicity.

In drug discovery, it is very important to correctly assess cardiotoxicity in safety pharmacological evaluations. In particular, the ability to correctly evaluate the cardiotoxicity as to QT prolongation, likely to lead to fatal arrhythmias such as Torsade de Pointes, is considered to be of paramount importance. So far, in vitro and in vivo assessments of cardiotoxicity have been mainly performed, and myocardial cells and tissues with average electrophysiological properties are often employed in order to evaluate whether the average pharmacological effect is cardiotoxic or not. However, there is a paradox that drug-induced QT prolongation in real-world clinical practice often occurs only under special circumstances, such as transient diarrhea, hypothermia, and concomitant medications. In silico models of myocardial cells and tissues can arbitrarily change such input parameters, and might be a useful approach to view safety cardiotoxicity assessment not only as an average property but also as a zone of safety. In this talk, I would like to outline the desirable application of such in silico myocardial models in cardiotoxicity assessment.

Recently, new approaches and methodologies (NAMs) are expected to use human relevant models for drug development to predict the effects of drugs in humans more accurately. In vitro, in silico, and machine learning are considered as NAMs in terms of 3Rs principles. It is expected that cutting-edge innovations would be considered in drug screening and efficacy/safety assessment.

We have developed a new platform to detect cardiotoxicities, such as contractility dysfunction and cell damage, using iPSC-cardiomyocytes and performed an international validation study with international agencies.

Here we would like to share our international collaboration using iPSC-cardiomyocytes and discuss future perspectives.

[Introduction] Sepsis is a pathological condition in which organ dysfunction progresses due to infection. The international definition of sepsis was changed in 2016, and it is managed as Sepsis-3. Infectious diseases exacerbate organ dysfunction and immunodeficiency as a second attack in cancer, stroke, acute myocardial infarction, diabetes and mental disorders. On the other side, septic shock is a condition in which sepsis is accompanied by cardiovascular disorders, and is classified as a severe condition in sepsis. The management and drug discovery against sepsis and septic shock is required in an area of intensive care medicine and pharmacology. In this symposium, we will discuss and review the current definition and scientific approaches, and the pathophysiological characteristics of sepsis and septic shock, We will discuss the drug discovery science against sepsis/septic shock from a pharmacological perspective.

[Contents] 1. Current definition of sepsis and the World Health Organization activity, 2. Molecular pharmacological approach on septic shock: Pathophysiology of septic heart injury, 3. Accelerated cell death in sepsis, 4. Molecular pharmacological involvement in drug discovery against sepsis/septic shock.

[Conclusion] In the pathophysiological approach to sepsis, various transcription factors are activated and related with the catabolism of proteins and lipids and accelerated cell death. We will discuss the possibility of new drug discovery against sepsis and septic shock.

Recent studies highlight the central role of skeletal muscle in sepsis-related inflammation and metabolic problems. ICU-acquired weakness, a condition prevalent in 50-75% of sepsis survivors, is associated with persistent muscle weakness that complicates recovery and reduces long-term survival. The pathogenesis of this weakness is complex, likely resulting from factors such as hyperglycemia, immobility, and drug use during ICU care, which exacerbate conditions such as hypercytokine and hyperoxidative states. The underlying mechanisms remain unclear. Males are more susceptible to septic death, which has been linked to enigmatic molecular causes. Skeletal muscle inflammatory responses contribute significantly to sepsis, and emerging evidence suggests that these responses underlie sex differences in septic mortality. Our investigation of four core genotype (FCG) mice with distinct gonadal and chromosomal patterns highlights the remarkable resistance of female XX mice to septic death. Our analysis of septic FCG muscle tissue reveals differential inflammatory pathway activity and specific overexpression of four inflammation-related genes in XX females. In vitro analysis shows that estradiol, but not testosterone, enhances gene expression. Our study highlights the interplay between gonadal and chromosomal differences, sheds light on sex-specific variations in sepsis, and identifies candidate genes that influence these differences.

Angiotensin-converting enzyme 2 (ACE2) is the carboxypeptidase that degrades angiotensin II (Ang II) and improves the pathologies of cardiovascular disease and acute respiratory distress syndrome (ARDS)/acute lung injury. B38-CAP, a carboxypeptidase derived from Paenibacillus sp. B38, is an ACE2-like enzyme to decrease angiotensin II levels in mice and ameliorates hypertension and heart failure (Nat Commun. 2020). Here we show the therapeutic effects of B38-CAP on acute lung injury induced by abdominal sepsis, acid aspiration, or SARS_CoV2 infection. ACE2 expression was downregulated in the lungs of hamsters with SARS-CoV2 infection, or the lungs of mice with cecal ligation puncture (CLP)-induced sepsis or acid-induced lung injury thereby leading to upregulation of Ang II levels. Intraperitoneal injection of B38-CAP decreased Ang II levels and suppressed the pathologies of lung inflammation, improved lung dysfunction, and downregulated elevated cytokine mRNA levels in acute lung injury in these animal models. Thus, systemic treatment with an ACE2-like enzyme might be a potential therapeutic strategy for patients with severe sepsis or ARDS (Nat Commun. 2021; PLoS One. 2022).

A cardiac potassium channel, the I_Ks channels composed of the alpha subunit KCNQ1 and beta subunit KCNE1, contributes to the repolarization phase of the cardiac action potential. Mutations in these genes are associated with the development of lethal arrhythmias due to congenital QT prolongation syndrome and are influenced by sympathetic nerve stimulation and sex hormones. As a molecular mechanism, we have demonstrated the involvement of a molecular complex of the KCNQ1 channel in the I_Ks regulation by intracellular Ca²⁺, cAMP , and NO. Our proteomic analysis revealed that the KCNQ1 molecular complex involves in Ca²⁺ signaling, epithelial junction signaling, mitochondrial dysfunction and so on, but the pathophysiological role has not been elucidated. Therefore, we aimed to test whether I_Ks channels activated by pathological Ca²⁺ overload may compensate for arrhythmias using genetically engineered (I_Ks-Tg) mice expressing cardiac human I_Ks channels. We employed a sepsis model (Cecal Slurry) intraperitoneal injection method) for pathological Ca²⁺ overload condition. We found that the sepsis score I_Ks-Tg male mice was significantly lower than that in wild-type mice. In this talk, I would like to discuss the molecular mechanisms of sepsis-induced cardiac dysfunction development based on patch clamp data of isolated cardiomyocytes.

Regulation of the proton concentration (pH) in the brain is important for maintaining normal brain function. In the brain of healthy individuals, intracellular pH is maintained at 6.8-7.0, while extracellular pH is maintained at 7.2-7.4. While the homeostatic importance of pH regulation has long been recognized, recent studies have shown that protons may also be directly involved in neurotransmission. This suggests an additional dimension to the relevance of pH changes to brain function under both physiological and pathological conditions. Double-barrel and concentric microelectrodes can only measure pH at a single point, limiting their utility for correlating proton changes with globalized brain activity during seizures and ischemia. In contrast, magnetic resonance imaging (MRI) can simultaneously measure the distribution of protons throughout the brain and thus detect regional variations in pH. However, to further investigate regional and neural activity-dependent proton dynamics in the brain, the development of a device with both wide area detectability and high temporal-spatial resolution is necessary. Therefore, we have developed a novel image sensor with high spatio-temporal resolution specifically designed for in vivo proton measurements. Here, we show that spatially distinct neural stimulation by visual stimulation induces distinct patterns of proton changes in the visual cortex. This result indicates that our biosensor can detect micrometer- and millisecond-scale changes in protons over a large area. To our knowledge, this is the first report showing that a CMOS-based proton image sensor with high spatial and temporal precision can be used to detect pH changes associated with biological events. In this symposium, we will also report on the application of our sensor to pathological models, the development of a multi-ion image sensor, and its miniaturization to enable ion imaging under free-moving conditions.

Quality of life gradually declined with aging due to deterioration of various bodily functions such as motor function and immune response. Glaucoma, the leading cause of blindness, is a neurodegenerative disease and the incidence increases with age. Currently, more than 180,000 people in Japan are blindness, and more than 25% of these cases are caused by retinal neurodegeneration due to glaucoma. Neuroprotection and regeneration therapies are essential for neurodegenerative diseases, such as glaucoma.

We have been investigating new therapy for glaucoma via neuroprotective and axon regenerative approaches using mouse models. We focused on TrkB molecule, a neurotrophic factor receptor, and have attempted to enhance TrkB signaling in neurons without ligand, BDNF. We found that artificially modified TrkB, which was truncated form of intracellular region and artificially attached the plasma membrane localization signal, possess the effect of neuroprotection and axon regeneration. This modified TrkB is localized to the plasma membrane, allowing for constitutive activation of intracellular signaling, such as ERK and AKT, in the absence of ligands. In addition, gene therapy with the modified TrkB in a mouse model of glaucoma maintained visual function through its neuroprotective effects. Furthermore, the modified TrkB promoted axon regeneration in an optic nerve crush mouse model. These results suggests that intracellular signal activation utilizing gene therapy is a good approach for developing neuroprotective and regenerative therapies.

Age-related macular degeneration is a neuroinflammatory disease that is the leading cause of blindness worldwide. In addition to mutations in immune-related genes, it is caused by the accumulation of environmental factors such as obesity and other inflammatory triggers with age. We have found that the past histories of obesity and infections can lead to immunological reprogramming in the innate immune system and affect the development of age-related macular degeneration in later life. This reveals a new link in the role of innate immune memory in neuroinflammatory diseases, and intervention in innate immune memory may be a new therapeutic strategy.

The ocular tissue is one of the most densely populated tissues in the body with extremely small blood vessels, and vascular lesions have been reported to be a factor in vision loss and visual field defects in many ocular diseases. Currently, vascular endothelial growth factor (VEGF)-targeted agents are the first line of treatment for intraocular vascular lesions, however, there are some cases in which they are not fully effective. Therefore, exploring pathogenesis molecules other than VEGF and identifying target molecule-selective therapies may help to solve the problem. Through experimental pathological models that mimic intraocular vascular lesions, we have been investigating factors that maintain the physiological balance of blood vessels and analyzing their functions. In this symposium, we will focus on the Bric-a-brac, Tramtrack, and Broad Complex (BTB) proteins. Using an intraocular vascular lesion model, we found that ankyrin repeat and FYVE domain containing 1 (ANKFY1) and B-cell CLL/lymphoma 6 member B protein (BCL6B) play important roles in neovascularization and hyperpermeability. Whether ANKFY1 and BCL6B may be a new therapeutic strategy to complement the disadvantages of anti-VEGF therapy will be discussed as a potential therapeutic target of BTB proteins for intraocular vascular lesions.

Approximately 80% of all the information we receive about the world comes through the visual pathways and visual function deterioration causes severe decline in QOL. Glaucoma is the leading cause of blindness in the world, in which visual field deficit deteriorates as the optic nerve degeneration progresses. Hence, the development of fundamental cure is needed.

Our research focuses on the signaling of BDNF, one neurotrophic factor reduced with aging and glaucoma patients. We generated modified TrkB receptor which can be constitutively activated in the absence of its ligand BDNF. The active site of the TrkB receptor is localized to the plasma membrane, allowing for constitutive activation of intracellular signaling. Gene therapy with the modified TrkB receptor in a mouse model of glaucoma was proven to be protective (Molecular Therapy, 2023).

In addition, our group reported that ASK1, one of the stress response factors, is related to the severity of optic neuritis and myelitis in model mice of multiple sclerosis (EMBO Mol Med, 2010). We generated four lines of cell type specific ASK1 conditional knockout mice and found that ASK1 in glia cells increased the severity of neuroinflammation while ASK1 deficiency in immune cells had no significant effects. Further, we found that ASK1 is required in microglia and astrocytes to cause and maintain neuroinflammation by a feedback loop between these two cell types. Our results suggest that ASK1 might be a promising therapeutic target for reducing neuroinflammation (PNAS, 2022).

Ultrasound, or sound at frequencies exceeding the conventional range of human hearing, is not only audible to mice, microbats, and dolphins, but also creates an auditory sensation when delivered through bone conduction in humans. Although ultrasound is utilized for brain activation and in hearing aids, the physiological mechanism of ultrasonic hearing remains unknown. In guinea pigs, we found that ultrasound above the hearing range delivered through the temporal bone evokes not only an auditory brainstem response (ABR) but also a mechano-electrical transduction current through hair cells, as shown by the local field potential called the cochlear microphonic potential (CM). The CM synchronizes with ultrasound, and like the response to audible sounds is actively and nonlinearly amplified. The results indicate that the cochlea can detect ultrasound stimuli with frequencies more than two octaves higher than the upper limit of the ordinary hearing range. If hearing thresholds in ultrasonic hearing can capture the pre-symptomatic states of diseases, they could be used for prevention, prognostic prediction, and the development of treatments.

In the quarter-century since odorant receptor (OR) genes were first identified, considerable effort has gone into understanding how each OSN chooses to express a single receptor gene. In order to make this choice possible, OSNs must first choose between two classes of OR genes, class I and class II ORs, a fundamental distinction that is critical to both the anatomical and functional organization of olfactory system. However, the mechanisms that regulate the OR class choice have remained unknown. In this paper, we identify the transcription factor Bcl11b as a critical regulator that determines the OR class to be expressed in OSNs. Both loss- and gain-of-function mutations of Bcl11b demonstrate that class I is a default class of OR to be expressed in OSNs and that Bcl11b dictates the class II OR choice by suppressing the J element, a class I OR enhancer. We further demonstrate that genetic manipulations of Bcl11b bias the OR class choice, generating mice with "class I-dominant" and "class II-dominant" noses, which display contrasting innate olfactory behaviors to two distinct aversive odorants, indicating that alternations of the OR class choice in peripheral OSNs change the odor world for mice. Overall, these findings reveal a unique transcriptional mechanism that serves as a binary switch for OR class choice that is crucial to both the anatomical and functional organization of the olfactory system.

Itching is the biggest problem for atopic dermatitis (AD) patients. The incidence of AD has been increasing, particularly among young people. Therefore, it is important to clarify the molecular mechanism of itching in AD and to provide a therapeutic agent for itching. 

It is known that type 2 inflammation is dominant in the immunological background of AD and that activation of TRP channels, a group of calcium channels, is involved in the transduction of itching as well as that of pain or temperature. It is now widely accepted that cytokines or mediators targeting GPCRs produced in the inflamed sites of AD patients bind to their receptors on sensory neurons followed by activation of TRPA1 and/or TRPV1 transducing the itching signals. 

We previously demonstrated that periostin, a matricellular protein, plays an important role in the setting of AD. However, the relationship between periostin and itching had been unclear and no appropriate inhibitor for periostin had been available. We found that mice deleting Ikk2 named FADS mouse show AD-like phenotypes together with severe itching and, moreover, that CP4715, a compound developed as an alpha_Vbeta₃ integrin inhibitor can be an inhibitor against periostin. We investigated the role of periostin on itching in AD using FADS mouse and CP4715 finding that either genetic deficiency of periostin in FADS mice or administration of CP4715 into FADS mice improves itching together with eczema. 

Taken together, the periostin/integrin pathway is a novel itching pathway in AD and integrin inhibitors would be promising therapeutic agents for itching in AD.

Amyloid beta (Aβ) protein is well known as a primary risk factor for Alzheimer disease (AD). Aβ peptide forms amyloid plaque to interact with several cell surface receptors, leading to synaptic dysfunction and cognitive impairment in AD. Lateral olfactory tract usher substance (LOTUS) was identified as an endogenous antagonist for paired immunoglobulin-like receptor-B (PirB) as well as Nogo receptor 1 (NgR1). Previous studies have shown that LOTUS plays a crucial role in synapse formation and cognitive function through the blockade of these receptor functions. Since the deletion of PirB, reported as a receptor for Aβ, improved Aβ-induced synaptic dysfunction and restored cognitive function in AD model animals. Therefore, PirB is considered to be an important molecule mediating Aβ pathology. We assessed whether LOTUS inhibits Aβ-induced synapse elimination in primary cultured hippocampal neurons. We found that LOTUS suppressed the binding of Aβ to PirB and that cultured hippocampal neurons from LOTUS-tg mice improved the Aβ-induced decrease in dendritic spine density. On the other hand, PirB is also expressed in microglia, which is known as an immune cell in the brain and involved in Aβclearance and neuroinflammation. We also found that LOTUS suppressed Aβ-induced cytokine production and promoted Aβ phagocytosis. These findings suggest that LOTUS may have a role in suppressing disease progression of AD.

Alzheimer's disease (AD) is pathologically characterized by the deposition of Aβ and tau protein. The amyloid hypothesis that Aβ accumulation is causally involved in the pathogenesis of AD is widely accepted and is a promising target for disease-modifying therapies. Since Aβ accumulation progresses decades before cognitive impairment becomes apparent, attention has recently focused on risk factors involved in the early pathogenesis of AD.

Epidemiological studies have established that diabetes is a risk factor for AD, but it is not fully understood which factors associated with diabetes contribute to the development of AD. Our research focuses on the causal relationship between diabetes and Aβ pathology using APP Tg mice that forms amyloid plaques in the brain. High-fat diet (HFD) feeding induced obesity, insulin resistance, and diabetes in APP Tg mice, resulting in a concomitant increase in brain Aβ accumulation. This exacerbation of Aβ pathology was reversible with subsequent dietary intervention, suggesting a close association between peripheral metabolic states and brain pathology. We further focused on endoplasmic reticulum stress, one of the triggers of insulin resistance, and pharmacologically showed that reducing endoplasmic reticulum stress by targeting peripheral tissues can improve brain Aβ pathology. These results underscore the importance of elucidating the pathomechanisms linking the brain and periphery.

The extracellular matrix (ECM) plays a crucial role in maintaining brain homeostasis. Specifically, ECM serves as the neurogenic niche supporting the self-renewal and differentiation of neural stem cells (NSCs)/neuronal progenitor cells (NPCs) into newborn granule cells. One of the key components of the ECM structure is chondroitin sulfate proteoglycan (CSPG), consisting of a core protein and glycosaminoglycan side chains. CSPG has been implicated in embryonic neurogenesis and brain development. We have reported the potential of CSPG to promote the differentiation and maturation of NPCs in the adult mouse hippocampus. Another study highlighted the critical involvement of ECM composition in the differentiation and maturation of NSCs in the adult brain. Additionally, we reported that CSPG and newborn granule cells in the mouse hippocampus were increased by memantine, an anti-dementia drug. The expression levels of genes related to the biosynthesis and degradation of CSPG were increased and decreased by memantine, respectively. Anxiety-related behavior was reduced by memantine, short- and long-term memory performance were improved by memantine, and depletion of CSPG in the hippocampus impaired the effects of memantine. These findings suggest that ECM may be a potential therapeutic target for anti-dementia drugs.

Dementia, characterized by cognitive and memory deficits, leads to brain atrophy, cell death, and insoluble substance accumulation. Alzheimer's disease (AD), linked to the APP gene, is the most common dementia type. Amyloid-beta's production and aggregation can forecast AD progression 20 years before onset, though the exact triggers remain unclear. Treatments focus on symptoms, with no cure available. Juvenile Alzheimer's in Down syndrome adults is prevalent and resembles isolated Alzheimer's, making it a preventive treatment target (Fortea et al., Lancet, 2020). However, its initial pathogenesis is still unknown (Flores Aguilar et al., Brain, 2020). Our study found that wild type mice transplanted with hematopoietic stem cells from Down syndrome models had impaired short-term memory, indicating bone marrow-derived cells' influence on brain memory. Analyses of hippocampal neurons also showed changed neuronal properties. We are currently examining the mechanisms behind brain function changes induced by bone marrow transplantation, and further investigation is vital for understanding dementia's pathogenesis and opening paths for therapeutic development.

The differentiation and homeostasis of small intestinal epithelium are regulated, with essential support from mesenchymal cells in the lamina propria. However, the existing in vitro small intestine models have limitations because they only consist of epithelial cells and lack mesenchymal cells, which restricts their functionality. Additionally, conventional static cell culture systems do not allow for the exposure of cells to physiological dynamic stimulations. Here, to develop small intestine tissue-on-a-chip, we integrated human iPS cells, capable of differentiating into both small intestinal epithelial and mesenchymal cells simultaneously, with a microfluidic device that mimics the mechanical stimulation in the small intestine. Under fluidic flow exposure, small intestine tissue-on-a-chip developed a 3D crypt-villus axis-like structure and expressed higher levels of mature intestinal markers compared to the static cultured chip, promoting intestinal differentiations. Further analysis revealed the pivotal role of medium flow in orienting intestinal fibroblasts and collagen fibers, contributing to the maturation of intestinal epithelial cells within the small intestine tissue-on-a-chip. Our small intestine tissue-on-a-chip offers a greater level of precision in understanding the pathophysiology of intestinal diseases.

Chemotherapy induced peripheral neuropathy is a major common adverse event associated with neurological abnormalities. Due to the multifactorial mechanisms of toxicity, there is an issue with the low predictive accuracy of toxicity observed.In this presentation, we introduce a method for predicting peripheral neuropathies and mechanism of action using the microfluidic device combined with morphological analysis.

The tumor microenvironment, including the vascular network and blood flow, influence cancer cell behaviors in a tumor. To accurately replicate this environment in vitro, we developed a tumor model with a perfusable vascular network. We incorporated tumor spheroids or colorectal cancer-derived organoids into a microfluidic device [1-2]. Angiogenic secretions from the tumor models facilitated the formation of the vascular network. After integrating with a vascular network, drugs were administered through the network, and we assessed cellular responses using immunostaining and oxygen metabolism analysis. The vascular network successfully perfused the tumor models for at least four days, promoting their proliferation and preventing cell death. We observed different drug sensitivities between static and perfusion conditions. Our electrochemical method effectively quantified the oxygen metabolism of the cancer organoids and revealed differences in drug sensitivity [2]. This innovative approach holds great promise for advancing cancer models, including selectively targeting specific subpopulations within a tumor [3].

References: [1] Y. Nashimoto et al., Biomaterials, 229, 119547 (2020). [2] Y. Nashimoto et al., Biosens. Bioelecton., 219, 114808 (2023). [3] Y. Nashimoto et al., Front. Bioeng. Biotechnol., 11, 1184325 (2023).

MPS (microphysiological systems) are attracting attention worldwide as useful tools for emerging in vitro assessments, with the aim of improving human extrapolation, replacing animal experiments, and reducing drug development costs.

We are developing a contractility assay system using 3D cardiac tissue composed of human iPS cardiomyocytes (hiPS-CMs) as an evaluation system to predict the side effects of congestive heart failure caused by anticancer drugs. Furthermore, we are exploring suitable culture conditions for co-culturing with liver cells and aiming to develop a cardiac toxicity assessment that takes into account liver metabolism by integrating the 3D cardiac tissue into a kinetic pump integrated microfluidic plate.

Thus, we are developing evaluation systems and applications in terms of cardiac MPS. However, in order to social implementation and further utilize the MPS in regulatory acceptance, it is necessary for academia, industry, and government to collaborate and discuss. To put this into practice, the Japan MPS consortium was launched. In this presentation, I also would like to introduce some of the activities of this consortium.

Various intensiometric biosensors have emerged to date, capable of monitoring concentration changes in intracellular signaling molecules as fluorescence intensity changes. However, these biosensors frequently encounter difficulties in quantitative analysis due to their inherent problem of intensity-based analysis. To overcome this limitation, fluorescence lifetime imaging microscopy (FLIM) has garnered attention as a more quantitative approach based on robust physicochemical parameters. Recently, we have developed several FLIM-based biosensors, using both genetically encoded biosensors and small chemical probes. For instance, we designed biosensors by linking GFP variants with binding domains for the target analyte through optimal peptide linkers. Consequently, we successfully generated FLIM biosensors for ATP and Ca²⁺. Notably, the Ca²⁺ sensor proved effective for endoplasmic reticulum and mitochondria with higher concentrations compared to the cytoplasm. Conversely, we also produced small chemical FLIM probes to detect intracellular temperature at organelles in thermogenic skeletal muscles. Since elements like ATP, Ca²⁺, and intracellular temperature are critical for skeletal muscle homeostasis, in this talk, we demonstrate the potential of these tools for skeletal muscle studies.

Skeletal muscle myofibers possess regenerative capacity in response to muscle injuries caused by excessive exercise. Muscle-resident stem cells, called muscle satellite cells (MuSCs), play a critical role in myofiber regeneration to maintain homeostasis in skeletal muscle. Mechanosensation and concomitant adaptation are presumed to be involved in myofber regeneration, but the molecular entity that converts the mechanical stimuli into biochemical signals for myofiber regeneration remains unknown. Here we identify PIEZO1, a Ca²⁺-permeable mechanosensitive cation channel that is activated by membrane tension, as a key determinant for muscle regeneration. Fluorometric Ca²⁺ imaging detected PIEZO1-dependent Ca²⁺ fluctuation in freshly isolated MuSCs. Myofiber regeneration after muscle injury was significantly delayed in MuSC-specific Piezo1-deficient mice, at least partly because of mitotic defects of undifferentiated MuSCs, such as the presence of chromosomal bridges and micronuclei. Moreover, pharmacological studies revealed that the cell division defects in Piezo1-deficient MuSCs could be restored by Rho activation. Collectively, PIEZO1 plays a role in muscle regeneration by controlling cell division of MuSCs in a Rho-dependent manner, suggesting that the mechanosensing machinery is central to the maintenance of muscle homeostasis. In this session, we will also present our preliminary results showing that a series of mechanosensitive ion channels could orchestrate muscle regeneration.

Skeletal muscle channelopathies are rare genetic disorders caused by mutations in voltage-gated ion channel genes regulating the excitability of the sarcomere. In SCN4A gene coding for Nav1.4, the skeletal muscle type voltage-gated sodium channel, more than one hundred heterozygous missense mutations have been identified so far, which represent broad clinical phenotype including sodium channel myotonia (SCM), paramyotonia congenita (PMC), hyperkalemic periodic paralysis (HyperPP) and hypokalemic periodic paralysis (HypoPP). In addition, recent case reports showed that hetero-compound mutations or homozygous mutations in SCN4A are associated with congenital myopathy or congenital myasthenic syndrome. Many electrophysiological analyses revealed an association between functional alteration of the mutant Nav1.4 and clinical phenotype. On the other hand, there is little progress in the discovery of the therapeutics. Recently, we have generated HEK293T-based HypoPP-model cell lines aiming to establish the in vitro platform for the high-throughput drug screen. Our HypoPP-model cells would give a new insight to develop novel therapeutics for channelopathy.

Protein activity is temperature sensitive. The temperature sensitivity is usually examined by adjusting the room or medium temperature. However, as these global heating and cooling processes are slow, biological samples can be thermally damaged at higher temperatures. This issue can be avoided by limiting volume of the heat source, so that the temperature gradient created around the small heat source is immediately dissipated by heat diffusion to the surrounding media when the power supply is terminated. We have applied an optically controlled rapid heating method based on focused infrared laser irradiation to examine the thermal sensitivity of the type 1 ryanodine receptor. Here, I will briefly introduce our results that mutants of RyR1 implicated in malignant hyperthermia are more heat-sensitive than the wild type. Detailed analysis led to the discovery of the heat-induced Ca²⁺ release (HICR) mechanism in RyR1 channels. HICR is proposed to form a positive feedback loop between thermogenesis during malignant hyperthermia and the heat-induced Ca²⁺ release through RyR1 mutants. More recently, we have extended the variation of RyR1 mutants examined, which are providing us with insights into the molecular mechanism of the heat-hypersensitivity.

Cells in our body are continuously exposed to various mechanical forces. Almost all cells sense and respond to such forces, which deeply related to development, homeostasis, and diseases. These forces are dynamic and temporally and spatially coordinated forces are significant. However, due to the limited tools for visualizing force applied to cells, it is hard to precisely measure various force signals such as magnitude, orientation, and temporally and spatially changing values like frequency and fluctuation. Therefore, the question of what type of force signals cells detect with sensitivity and respond to in each context remains elusive. Herein we present our DNA mechanotechnology to dissect mechanical force applied to cells with high sensitivity.

Skeletal muscle maintains its tissue homeostasis through the high regenerative capacity. Muscle-resident stem cells called muscle satellite cells (MuSC), which is essential for muscle regeneration, suffer from various types of mechanical forces (e.g. shear stress, substrate stiffness, and tensile strain). These physical forces are presumed to regulate MuSCs fate, but the molecular mechanism underlying the conversion of the mechanical stimuli into muscle homeostasis remains to be elucidated. Here we identify PIEZO1, a mechanosensitive ion channel that is activated by membrane tension, as a critical mechano-sensor for MuSCs. Conditional deletion of Piezo1 in MuSCs results in impaired muscle regeneration after injury, at least in part due to abnormalities in cell division such as existence of chromosomal bridges and micronuclei. Importantly, when MuSCs were cultured on dishes with a stiffer (32 kPa) substate, rigidity-dependent increase in proliferation was observed in control but not in Piezo1-deficient MuSCs. These results suggest that PIEZO1 acts as a mechano-sensor to respond to changes in the surrounding mechanical properties, which may be important for muscle homeostasis. In this session, we will present mechanistic aspects as to how PIEZO1 promotes the MuSCs functions for maintenance of functional resilience in skeletal muscle.

The heart maintains pump function by remodeling in response to changes in mechanical forces caused by heartbeats and hemodynamic loading. For example, the heart shows the compensative hypertrophy when it’s hemodynamic stress increases, such as with hypertension. This is because cardiomyocytes exhibit plasticity via mechanotransduction, and a reduction in this ability leads to heart failure. However, the mechanisms that organization of plasticity during cardiomyocyte growth are not clear. We defined "cardiac resilience" as the state in which hearts maintain plasticity in response to changes in hemodynamic load. Previously, we have shown that transient receptor potential cation channel vanilloid-family type 2 (TRPV2) is a key molecule in cardiomyocyte mechanotransduction and is crucial for the maintenance of cardiac physiology. In this symposium, we will show that TRPV2 is significantly involved in the organization of cardiomyocyte plasticity. Mice deficient in TRPV2 from juvenile age exhibited small cardiac morphology and weak contractility as adults. The cardiomyocytes of these TRPV2-deficient mice had abnormal dyadic structure and reduced Ca²⁺ handling associated with E-C coupling. In addition, TRPV2-deficient mice had an attenuated IGF-1R/Akt/mTOR pathway and did not show hypertrophy in response to IGF-1 administration. These TRPV2cKO hearts did not show an adaptive hypertrophic response to increased hemodynamic stress, resulting in heart failure. These results indicate that TRPV2 is an essential molecule for the maturation of the young heart into a heart with plasticity to hemodynamic stress.

Cell membranes are composed of diverse phospholipid molecules, whose structure and distribution are actively controlled in response to various stresses. Furthermore, the structure and distribution of phospholipid molecules influence the physicochemical properties of membranes and affect the activity of a variety of membrane proteins including ion channels and receptors. Therefore, membrane phospholipids can be considered to be the determinants of cellular resilience. We used Drosophila cells in which the phospholipid composition and regulatory mechanisms are relatively simple, to understand the molecular mechanism underlying the membrane phospholipid-mediated control of cellular resilience against temperature change and mechanical stimuli. In this presentation, I would like to introduce the flexible cellular responses mediated by the dynamic regulation of membrane phospholipids in Drosophila cells.

Humans are daily exposed to a wide variety of xenobiotic electrophiles through living environments, lifestyles, and dietary habits. Electrophiles have low electron deficiency sites in the molecule that are able to covalently bind with nucleophiles such as cysteine residues of proteins to form adducts. It has long been believed that this is the cause of the toxicity. For example, acetaminophen itself exhibits little electrophilicity, but its electrophilic metabolite produced by metabolic activation forms protein adduct associated with liver injury. On the other hand, the discoveries of endogenous electrophiles in the body and cellular redox signaling pathways activated by covalent modification of sensor proteins with reactive thiols suggested possibility of the existence of defense systems against exogenous electrophiles. We found that exposure of cells to exogenous electrophiles with different structures at low dose causes the activation of a variety of redox signaling pathways associated with an adaptive response. We also showed that exogenous electrophiles undergo capturing by reactive sulfur species, leading to formation of sulfur adducts, thereby repressing reactivity of exogenous electrophiles. In this symposium, I also introduce the importance of electrophile as priority a component in the "exposome" research.

Epigenetic regulation of gene expression determines cell fate and influences fundamental processes such as development, differentiation, and proliferation. On the other hand, epigenetic genetic information is relatively easily changed by environmental changes and its abnormalities can cause diseases such as cancer. One of the molecular bases of epigenetic regulation of gene expression is the histone lysine acyl modifications. Some of these lysine acylations, at least in part, are induced by the addition of endogenous carboxylic acids such as fatty acids to the ε-amino group of lysine residues via chemical reactions. We unintentionally take in various exogenous carboxylic acids every day into our bodies through diet or other means. Some of these carboxylic acids can add to lysine residues of histones and function as epigenetic marks. Indeed, we found that several environmentally derived carboxylic acids add to lysine residues of histones and that some of them induce gene expression changes. In this presentation, we would like to introduce the effects of adduct formation by environment-derived carboxylic acids on epigenetic gene expression and discuss the hidden functions of environment-derived carboxylic acids and their effects on the organism.

Methylmercury (MeHg) is an electrophilic environmental neurotoxicant that is biologically concentrated into seafood. High-dose MeHg exposure leads covalent modification of protein thiol groups to form S-mercuration (MeHg-S-protein). This pathological protein modification, in part, explains the neurotoxicity of MeHg. Epidemiological studies have also suggested that MeHg increases cardiac risk at a lower concentration than that associated with neurotoxicity. However, the underlying mechanism is unclear. We previously identified that aberrant mitochondrial fission induced by hypoxic stress cause cardiac vulnerability. Here we show that exposure to a low dose of MeHg increased cardiac risk induced by pressure overload in mice. MeHg exposure caused mitochondrial hyperfission in myocardium through the activation of mitochondrial fission factor Drp1. MeHg treatment promoted Drp1 activation by increasing the interaction between Drp1 and its guanine nucleotide exchange factor filamin A. Modification of cysteine residues in proteins with polysulfides play an indispensable role in redox signaling and mitochondrial homeostasis in mammalian cells. Drp1 activity was negatively regulated by polysulfidation at Cys624, a redox-sensitive residue. MeHg exposure induced the depolysulfidation of Cys624 in Drp1, which led to filamin A-dependent activation of Drp1 and mitochondrial hyperfission. Other environmental pollutant, cigarette sidestream smoke that is a significant contributor to increased cardiovascular mortality also led cardiomyocyte dysfunction through Drp1 depolysulfidation. Treatment with NaHS, which acts as a donor for reactive polysulfides, reversed MeHg-evoked Drp1 depolysulfidation and vulnerability to mechanical load in rodent and human cardiomyocytes and mouse hearts. These results suggest that depolysulfidation of Drp1 at Cys624 by environmental stress such as MeHg increases cardiac fragility to mechanical load through filamin-dependent mitochondrial hyperfission.

Environmental electrophiles are known to covalently bind to nucleophilic residues such as cysteine, serine, and histidine in proteins. Modification of protein by electrophiles is predicted to play some pivotal roles in the homeostasis and development of disorders. Previously, we demonstrated that the environmental electrophile 1,2-naphthoquinone (1,2-NQ) is a novel chemical activator of EGFR but not other EGFR family proteins. We have found that 1,2-NQ forms a covalent bond, in a reaction referred to as N-arylation, with Lys80, which is in the ligand-binding domain. This modification activates the EGFR-Akt signaling pathway, which inhibits serum deprivation-induced cell death in a human lung adenocarcinoma cell line. Subsequently, we next focused on methyl vinyl ketone (MVK) found in cigarette smoke and exhaust gas. Interestingly, MVK suppressed phosphatidylinositol-3 kinase (PI3K)–Akt signaling. We persued that MVK directly modified Cys656 in the SH2 domain of the PI3K p85 subunit and inhibited the interaction between the epidermal growth factor (EGF) receptor and PI3K in vitro and in human A549 adenocarcinoma cells. These results provide some models for future studies analyzing environmental reactive species. In this symposium, we will discuss the roles of environmental electrophiles via protein modifications.

Recently, the term of gut environment has been attracted in the relationship with health and diseases. In this background, the possibility of "microbiome-based drug or medicine" using useful bacteria are expected to have therapeutic effects on various diseases. In this talk, I will introduce the possibility of Blautia as a candidate of microbiome-based drug, which we found in a cohort study of Japanese people, which is expected to be effective against obesity and diabetes. I will also outline the regulatory research to realize the microbiome-based drug.

Gut microbiota have been shown to be associated with the development of various diseases, and also to be used as disease markers or therapeutic targets. In Japan, fecal transplantation was clinically applied for inflammatory bowel diseases, but strict management including safety should be required, and the details mechanism of action have not been elucidated. In Nature medicine in 2018, oral administration of Akkermanisia muciniphila for obesity and glucose intolerance showed weight loss and improvement of glucose metabolism. A company has been established and oral tablets are being sold. 

We have shown in clinical studies that there is a decrease in Bacteroidetes in patients with coronary artery disease (CAD) compared to patients with lifestyle-related diseases. Among them, two bacterial species, Bacteroides vulgatus and Bacteroides dorei, were found to be significantly reduced in CAD patients. Oral administration of these two Bacteroides species to arteriosclerosis model mice reduced the activity of lipopolysaccharide (LPS), a gram-negative bacilli toxin in blood and feces, and exhibited anti-inflammatory effects and suppressed arteriosclerosis. We are exploring the possibility of treatment using these two Bacteroides species. I would like to introduce research related to gut microbiota that focuses on cardiovascular and metabolic diseases, talk about the possibilities and prospects for future therapeutic targets, and discuss with everyone who attends.

Microbiome therapeutics were officially approved by regulatory authorities in Australia and the U.S. in 2022 as a new drug modality. starting with a milestone paper published in 2014 on the surprising therapeutic efficacy of fecal microbiota transplantation therapy for refractory C. difficile infection.Many biotech ventures, mainly in Europe and the U.S., have created pipelines since then. On the other hand, in Japan, although microbiome research has been conducted at a high level mainly in academia for some time and many prebiotics and other products have been produced, Japan is undeniably lagging behind the rest of the world in terms of research and development of microbiome based drug discovery as a pharmaceutical field. In Japan, the Japan Microbiome Consortium (JMBC) was established in 2017 to promote the industrial application of human microbiome research. The JMBC has been participating in national projects to achieve some of these goals. In addition, JMBC is participating in AMED's "The Next generation Drug Discovery and Development Technology on Regulating Intestinal Microbiome " and is challenging to establish an ecosystem for microbiome based drug discovery in Japan. This presentation will focus on the activities of JMBC and share international trends in microbiome based drug discovery activities.

Heart failure is the most costly medical condition among the elderly in Japan, and although there are various therapeutic agents available, the 5-year survival rate is not high and still claims the lives of many patients.

We have shown that cardiac macrophages interact with cardiomyocytes and are essential for cardiac homeostasis, and that elimination or genetic modification of macrophages to induce loss of function results in death from heart failure and fatal arrhythmias.

The most potent risk factor for heart failure is aging. The mechanism of age-related deterioration of cardiac function is currently unknown, and, of course, there is no treatment for it. In this study, we will examine how cardiac macrophages and other immune cells in the heart change with age and how they adversely affect the heart. We will examine not only the relationship between macrophages and cardiac myocytes, but also their interaction with cardiac fibroblasts and blood vessels.

In addition, the extent to which aging immune system cells within the heart are involved in cardiac aging will be examined to identify novel therapeutic targets in age-related heart failure.

Evidence indicates the pathogenic role of cellular senescence in age-related cardiovascular-metabolic disorders including heart failure, atherosclerotic diseases, obesity, and diabetes. Protein p53 is described as a “guardian of the genome”, but is also known to mediate cellular senescence. Activation of p53 was observed in aged vessels, and failing hearts, and this is recognized to promote pathogenesis in atherosclerosis or heart failure. Suppression of cellular senescence takes the risk of tumorigenesis, and more safe approach needs to be explored to suppress the accumulation of senescent cells. Recently, the senolytic approach opened a new avenue for aging research. Senolysis, the specific depletion of senescent cells, mediated through the genetic/ pharmacologic/ vaccination approach reversed aging and pathologies in age-related diseases. Specific depletion of senescent cells would become next-generation therapies for cardiovascular diseases.

Currently in Japan, around 900 patients with advanced heart failure are waiting for heart transplantation under mechanical support or continuous infusion of inotropic agents, and about 70% of them are diagnosed with dilated cardiomyopathy. Although recent advances in high-throughput sequencing technologies have revealed the genetic basis of dilated cardiomyopathy, the molecular basis underlying the rapid progression of advanced heart failure remains to be elucidated. Furthermore, while various pharmacological treatments have been established for most types of heart failure, there are no disease-specific therapy to prevent the juvenile-onset advanced heart failure caused by dilated cardiomyopathy. Our research aim is to elucidate the molecular basis of intractable cardiomyopathies and to develop medical therapy using genetic information, clinical information, human samples and disease-specific iPS cell-derived cardiomyocytes. In this symposium, I would like to present our recent research findings focusing on a female Becker muscular dystrophy carrier and a desmoglein-2-deficient cardiomyopathy patient who developed advanced heart failure and to discuss the possibility of future precision medicine.

Heart failure is a leading cause of death in developed countries. The role of mRNA regulation in the pathology of heart failure remains elusive. CCR4-NOT complex is a multi-subunit protein complex constituting exonuclease-mediated shortening of poly(A) tails of mRNA, a process called deadenylation. We had previously elucidated that CNOT3, a scaffold subunit of the CCR4-NOT complex, is a crucial regulator of heart function (Cell 2010, Science Signaling 2018). Here we show our analyses on the multiple roles of CCR4-NOT complex in mouse heart failure models, which is associated with molecular functions of each subunits. While CNOT6L deadenylase subunit regulates gene-specific mRNA regulation of fibrotic genes upon pressure overload stress, global mRNA deadenylation by the whole complex contributes to cardiac energy homeostasis. CNOT4, a temporal interactor of the complex, is protective from several cardiac pathogenic conditions other than pressure overload stress. These results suggest the significance of RNA remodeling in cardiac resilience against various heart stress, and I shall discuss CCR4-NOT-mediated deadenylation/mRNA remodeling and its connection to transcription and translation.

We are developing novel analgesics to relieve intractable pain for cancer patients. We are also working on drug repositioning study to expand the indications of present drugs. Treatment with anticancer drugs frequently causes oral stomatitis with severe pain in cancer patients. Patients can eat and get adequate nutrition energy if the pain is relieved when eating. For cancer patients, orally taking nutrients is essential for maintaining and improving activities of daily living and quality of life. Lidocaine, a local anesthetic that inhibits all sensory neuronal activities, has been used as a pain-killer. However, lidocaine causes impaired taste and texture to the patients. 

We discovered a novel analgesic Compound X based on the voice of cancer patients. With support from Japan Agency for Medical Research and Development (AMED), we developed Compound X as a novel drug for stomatitis having a long-lasting pain-relieving effect without changing texture and taste. 

On the other hand, there are patients who need urgent supportive palliative care, and such patients cannot wait for future novel drugs. In this regard, we focused on the Japanese herbal medicine hangeshashinto to relieve pain and cure oral stomatitis. We proved hangeshashinto accelerates healing of stomatitis with a pain-killer activity.

Determination of target cancer types and prediction of therapeutic efficacy are essential for the successful development of anticancer drugs. Cell lines have been used in preclinical studies to select cancer types. However, it has been pointed out that the homogenization of tumor cells during the establishment process leads to changes in genomic information and tumor characteristics, resulting in poor prediction of clinical response.

As a bioresource, patient derived-xenografted (PDX) models is recognized as an essential tool. Although it is complicated and costly to manage, it maintains tumor cells' heterogeneity, microenvironment, and tissue structure and is highly predictive of clinical response (60-80%).

The National Cancer Center has created a lot of PDX models derived from Japanese cancer patients for predicting treatment effects. It has established the J-PDX library, Japan's largest bioresource of PDX. This library has collected much information on biological characteristics such as growth behavior, pathology, genomic analysis, gene expression analysis, epigenomic analysis during PDX establishment, and donor patient's detailed clinical information.

We have been conducting preclinical studies of novel anticancer drugs using PDX models to evaluate drug responsiveness across cancer types, to make "Go or No-Go" decisions to move into Phase I clinical trials, and to select cancer types to be developed.

In this symposium, we will present the results of a Co-Clinical study comparing the clinical response of PDX models and cancer patients and the utility of tumor tissue derived from cancer patients in drug discovery research.