One cannot overstate that both vaccine and antiviral therapeutics are required to control viral infection. The caveat in the initial response to COVID-19 was that the severity of COVID-19 varied much: some patients have no symptoms, but others die on respirators. While only large randomized studies can give insight into whether the "drugs" help patients, clinicians and researchers were fooled into thinking that those who recovered early were helped by the test drug. Currently, there are only few to name in the list of efficacious therapeutics; however, we have already encountered the emergence of drug-resistant SASRS-CoV-2 variants and flaring-up upon conclusion of current chemotherapy. In my presentation, I will discuss the development of orally available therapeutics for COVID-19 employing the knowledge and skills evolved in the development of therapeutics for HIV/AIDS and hepatitis B as well as the prospect for the future.

Bioactive small molecules that show remarkable activities on living organisms always have specific target molecules in the cell. The identification of such target molecules has provided deep insight into drug discovery. We have been aiming to elucidate the mechanism of action of small-molecule compounds by chemical genetics, a new method to discover the interaction between compounds and their intracellular targets, by replacing mutations in genetics with compounds. As a result, we have identified histone deacetylase HDAC, which regulates epigenetics, CRM1, a receptor for protein nuclear export signals, and SF3b, a spliceosome component, all of which are now considered important targets for new anticancer drugs. This approach should be useful not only for the discovery of anticancer targets but also for therapeutic targets for other diseases, such as genetic diseases and intractable rare diseases. In this talk, I will report on the identification of glycolytic enzyme phosphofructokinase and BGLT3, a long non-coding RNA, as the potential targets for the treatment of mitochondrial diseases and sickle cell disease, respectively, based on the latest results of our chemical genetics research.

In tumor microenvironment (TME), active inflammation occurs with immunosuppression. The former promotes tumor growth and the latter facilitates evasion of tumor cells from immune surveillance. Given that active inflammation generally induces acquired immunity, how immunosuppression is elicited in actively-inflamed TME remains an enigma. Immune cells infiltrating the tumor, stromal cells activated in TME and tumor cells themselves produce and secrete various mediators, which are supposed to trigger inflammation and elicit immunosuppression. We have examined the role of prostaglandin E2 (PGE2) in this process bidirectionally by both translational and reverse translational research. As a translational research, we have used mouse syngeneic tumor models, and interfered with PGE2 signaling with EP2 and EP4 antagonists. As a reverse translation research, we have obtained surgical specimen of human tumors, dissociated them and sorted EP4-positive immune cells in TME. In both researches, we have employed single cell RNA sequencing technology, which allows us to identify the immune landscape, phenotypic changes and cell-cell communications dependent on these EP receptors in an unbiased way. The findings obtained by these researches are presented and the validity of this approach is discussed.

Elevated intracellular Ca²⁺ concentration plays a very broad role as an intracellular signal, which is formed via Ca²⁺ influx from outside the cell via Ca²⁺ channels in the plasma membrane and via two types of Ca²⁺ release channels (IP₃ receptors and ryanodine receptors) from intracellular stores (ER). Ca²⁺ signaling regulates rapid intracellular responses (contraction, neurotransmitter release, etc.) associated with action potentials in excitatory cells. On the other hand, time-lapse Ca²⁺ imaging of prolonged responses such as immune responses and blood pressure control show repeated rise and fall of Ca²⁺ concentrations (Ca²⁺ oscillations). Such responses are a mechanism to avoid persistent increases in Ca²⁺ concentration and efficiently produce a signal. It may be no exaggeration to say that Ca²⁺ signaling regulates cellular functions in all cell types. This indicates that Ca²⁺ signaling can be used as a starting point to obtain clues for understanding unknown cellular functions. Various physiological functions have been analyzed by applying this approach and visualization techniques, and its application to pharmacology is also expected. In this talk, I would like to introduce these efforts.

In recent years, many seeds of innovative new drugs have been created by academia and venture companies. These are co-developed, manufactured and launched in the world under the collaboration with pharmaceutical companies. The development of COVID-19 vaccines is an example. On the other hand, in Japan, there are various challenges such as the cultivation of entrepreneurs, the investment by venture capitals, and bridging the gap between pharmaceutical and venture companies. As a result, there is concern that the drug discovery capabilities in Japan will decline.

Last year, the Japanese government released the Japanese Policy Vision 2021 for the Pharmaceutical Industry, which shows the vision and direction of the pharmaceutical industry policy. In addition to focusing on human resources, science technology and innovation, startups, and digital transformation (DX) as priority focus areas, the government declares that it will strengthen Japan's drug discovery capabilities.

In order for Japan to continue to be a country that creates new drugs, and to achieve "the Extension of Healthy Life Expectancy of the People", "Economic Growth", and "Ensuring security", industry, academia, and government will work together to build an ecosystem that promotes organic collaboration among various players in it.

The stress response is one of the most fundamental biological phenomena of cells, and its disruption is a pathogenic factor in a wide variety of diseases, including cancer, neurodegenerative diseases, immune diseases, and metabolic diseases. This talk will focus mainly on our latest findings on cellular stress responses, especially osmotic responses.Cells are constantly exposed to stresses that force a change in volume due to the difference in osmotic pressure between the inside and outside of the cell (osmotic stress), and they maintain a constant cell volume by sensing and responding appropriately to osmotic pressure changes. Until now, most studies have been based on the idea that osmotic changes without physical substance are sensed via changes in the cell membrane in contact with the extracellular environment. Using the ASK3 protein as a research model, we have demonstrated that cells sense osmotic stress inside the cell, triggered by the physical phenomenon of liquid-liquid phase separation, using biochemical methods and computer simulations. I hope to introduce some aspects of stress signaling through this basic research on osmotic stress response.

Cancer Genomic Medicine (CGM) optimizes therapeutic intervention based on the cancer genomic profiling (CGP) tests. To discuss a necessary platform to actualize CGM under the national health insurance system in Japan, The Ministry of Health, Labour and Welfare (MHLW) defined the network of CGM hospitals, and also set a central datacenter, Center for Cancer Genomics and Advanced Therapeutics (C-CAT), to aggregate genomic as well as clinical information for the cancer patients. CGM officially started in 2019 with two CGP tests, and, as of July 2022, Japan has a total of 233 CGM hospitals, and C-CAT has already collected the genomic/clinical information of over 38,000 patients. Also, from 2021, Japan has started a large-scale whole genome sequencing (WGS) research project for cancer. About ten thousands of cancer specimens are expected to be analyzed with WGS/RNA-sequencing every year, and Japan is seeking an adequate way to bring such WGS results to the patients. I would like to overview how CGM has been constructed in Japan and where it heads.

Electrophiles have long been understood as bad guys that cause carcinogenesis and tissue damage. For example, acetaminophen undergoes metabolic activation, resulting in formation of highly reactive metabolites that covalently bind to cellular protein, thereby causing a toxic effect. This is a typical example of the recognized mechanism of toxicity seen in overdose of acetaminophen. Glutathione conjugation is known as a system for detoxifying electrophiles, but another strategy for inactivation of electrophiles was not understood. Furthermore, toxicology-oriented researchers were interested in the unfavorable intracellular events of exogenous electrophiles, and had no way of knowing the defense mechanism occurring outside the cell. In this lecture, I introduce 1) adaptive response through modulation of cellular redox signaling pathways (activation at low dose, disruption at high dose), 2) capture and inactivation through sulfur adduct formation by reactive sulfur molecules containing sulfane sulfur atoms, 3) trapping by cysteine excreted extracellularly during electrophilic stress.

The decline and stagnation of Japan's scientific and technological capabilities continue unabated. The number of Top 10% papers in the world was recently published, and Japan has been in a long-term stagnant trend, being overtaken by two countries this year, moving from 10th to 12th place. Surprisingly, Japan was overtaken by Spain, which had fallen behind among European countries, and its neighbor in Asia, South Korea. The cause is the Ministry of Finance (MOF) and the Ministry of Education, Culture, Sports, Science and Technology (MEXT), which have been suppressing the nation's science and technology research expenditures. Since the incorporation of national universities, MOF and MEXT have been reducing the subsidies for national university management fees by 1% annually since 2004, and the amount has now been reduced by more than 10%. The Ministry of Health, Labour and Welfare(MHLW) has also continued to bash basic medical research. This rejection of academia is an outrage reminiscent of the Cultural Revolution of China. Thanks to these policies, Japan's research capability has declined markedly. A good example of this is the recent outbreak of COVID-19.　The development of both vaccines and therapeutics has fallen far behind Europe and the United States. Unless these policies to suppress academism, especially scientific and technological research, are immediately reversed, Japan's scientific and technological capabilities may indeed fall to the ground, and I am deeply concerned about this.

Although we cannot normalize their chromosomes and genes with chemical drugs, we may be able to manipulate the amounts and patterns of mRNAs transcribed from patients DNAs with small chemicals. Based on this simple idea, we have looked for chemical compounds which can be applicable for human diseases targeting kinase families of CDKs, CLKs and DYRKs which are involved in the regulation of gene expression, and eventually succeeded to find FIT039, TG003, and ALGERNON as potential therapeutic drugs to cure diseases such as viral infections, Duchenne muscular dystrophy, and Down syndrome, respectively. In addition, we established splicing reporter assay of pathogenic genes, and found splicing modulators which can rectify the aberrant mRNA splicing in patient cells of familial dysautonomia, cardiac Fabry diseas, and type V cystic fibrosis. With the original drug discovery methods, we have found potential drugs available for wide ranges of diseases, and some of them already entered into the stages of clinical trials.

Penicillin was discovered by Alexander Fleming (U. K.) in 1928. The method of the mass production of penicillin was established by the special project for stable supply of penicillin in United States in 1943, and it relieved many injury soldiers from an infectious disease in World War II. In Japan, Penicillin Committee was organized at the beginning of 1944 and the research and development of penicillin were started. The committee obtained pure penicillin about nine months after starting the research. Some institutions also tried the development of penicillin uniquely. In Chiba Army Hospital, Mr. Ogawa (pharmacist, second lieutenant) and Dr. Tanigawa (School of Medicine, Chiba University, military physician, first lieutenant) carried out penicillin production. In this lecture, I would like to introduce the research and development of penicillin in Japan and Chiba Army Hospital under World War II.

Pharmacology education mainly teaches the mechanisms of action of medical drugs used to treat various diseases. Everyone wants to live a long and healthy life, and students are interested in what they learn in university classes. Ultimately, however, it is a difficult task to have them remember many generic names of drugs. The two things I recommend to students to memorize are 1) to say it out loud and 2) to know the origin of the name. Just like each of us has a name, all medicines have a godfather, and even the dry, katakana-filled generic names have meaning. In addition, medicines were born through the wisdom and efforts of our predecessors. And above all, remembering the name of a drug with memorable episodes can create a memory that is hard to forget and easy to recall. In this lecture, I would like to introduce practical examples that I have been doing in my university classes in order to motivate students to learn about pharmacology.

Glutamate neurotransmission is mediated via ionotropic and metabotropic glutamatereceptors (mGlu). By acting at alternate non-conserved sites at the mGlu5subtype, allosteric modulators offer promise to treat a range ofneurodegenerative and psychiatric disorders. Allosteric modulators fine-tunereceptor activity with spatio-temporal control, greater subtype selectivity andcan bias mGlu5 activity to preference different cellular responses. Our centralhypothesis is previously unappreciated biased activation and modulation of mGlu5underpins translational failures of diverse allosteric modulators.

To build a more complete molecular fingerprint we assess multiple measures ofmGlu5 activity using a combination of recombinant cells expressing human or ratmGlu5 as well as primary brain cell cultures. Rigorous analytical methods allowquantification of allosteric modulator cooperativity and affinity from kineticbinding assays, as well as second messenger and compartmentalised kinasebiosensor assays. We found structurally diverse mGlu5 allosteric modulators havedistinct kinetic profiles and differentially influence mGlu5 activity in aspatio/temporal fashion. Probe dependence was evident for modulating glutamateversus quisqualate. This has implications for translating profiles in primarybrain cell cultures to in vivo effects.

By linking molecular pharmacological properties to known preclinical and clinicaleffects, we seek to provide an enriched understanding of the drivers of efficacyas well as failures. We imagine these molecular fingerprints of mGlu5 allostericmodulators can be employed to triage undesirable compounds and streamline futuredrug discovery efforts.

Attitude control is associated with coordinated limb, body, head, and ocular movements through vestibular interoception. During straight walking, walking speed for velocities ranging from 1.2–1.8 m/s. Over this range of walking velocities, there is both translation and rotation of the head in the sagittal plane, reaching translational frequencies close to 2 Hz, peak vertical linear accelerations of 0.3–0.5 g, and peak pitch velocities of 15–22°/s. The magnitude and frequency of the pitch angular and vertical translational head movements are sufficient to activate both the angular and linear vestibulo-ocular (aVOR and lVOR) and vestibulo-collic (aVCR and lVCR) reflexes, which may play important roles in directing gaze and in stabilizing gait. In support of this, unilateral vestibular disease is associated with instability of gait, and astronauts, whose vestibular function has been adapted to microgravity, also experience difficulty when walking a curved path after flight. The purpose of this study was to infer a possible role for the vestibular interoception in producing head and eye movements in three dimensions as the body moves in space.

Head and body movements were measured with a video-based motion analysis system and horizontal, vertical, and torsional eye movements with video-oculography. During straight walking, the head pointed along the forward motion of the body during straight walking. When turning corners, yaw head deviations moved smoothly through the turn, anticipating the shift in lateral body trajectory by as much as 25°. The trunk did not anticipate the change in trajectory. Gaze was stable in space during the slow phases and jumped forward in saccades along the trajectory, leading it by larger angles when the angular velocity of turning was greater. The anticipatory roll head movements during turning are likely to be utilized to overcome inertial forces that would destabilize balance during turning. The data show that compensatory mechanisms stabilize gaze, while orienting mechanisms direct the eyes, head, and body to tilts of the gravito-inertial acceleration in space through vestibular interocetpion.

Epithelium is the interface between the body and world, and thereby the forefront of sensing and fighting with foreign substances. There are epithelial cells that are responsive to chemical substances and communicate with afferent nerves to evoke biological reactions. However, transduction and neurotransmission mechanisms of these sensory epithelial cells seem diverse and are poorly understood. We previously identified an unprecedented chemical synapse in taste bud cells which are a type of sensory epithelial cells that mediate gustation. Remarkably, taste bud cells employ an ion channel pore as the conduit for neurotransmitter release. As chemical neurotransmission was supposed to be mediated solely by exocytosis, we termed this unique chemical neurotransmission machinery "channel synapse". Where else does the synapse exist and function outside the tongue? Here, we generated a reporter mouse for Calhm1 and 3, core components of the channel synapse, screened over 40 organs for reporter expression, and revealed extra-oral distribution of cells expressing Calhm1 and 3. In one of those CALHM1/3⁺ tissues, we genetically, anatomically, and functionally identified the presence of channel synapses and its physiological roles. The discovery, structure and function of the CALHM channel synapse will be discussed.

The afferent vagus nerve transmits ascending information regarding internal physiological states of the visceral organs, so-called interoception, to the brain. Recent studies have suggested that vagal interoceptive signals exert prominent impacts on emotional states such as anxiety and depression. While the significance of vagal-brain communications has been realized, basic research issues remain regarding whether and to what extent vagal afferent signals underpin brain neurophysiological activity that affects emotion. To address these issues, we recently developed a method to record spiking patterns from the cervical vagus nerve using a cuff–shaped electrode while simultaneously monitoring local field potential (LFP) signals from the medial prefrontal cortex (PFC) and the amygdala of mice. After identifying the relationship between vagus nerve activity and PFC-AMY LFP patterns at specific frequency bands, we examined how these vagal-brain interactions are altered by chronic stress loads. In addition, we tested whether these pathophysiological brain states can be restored by VNS that replicates VN sustained spike patterns identified from non-pathological states. These observations provide new insight for uncovered issues regarding the physiological dynamics of the vagus nerve.

Pancreatic β-cells adaptively proliferate in insulin-resistant states to increase insulin production and release. The proliferation is a compensatory mechanism aimed at maintaining glucose homeostasis. We previously discovered an inter-organ neuronal relay system, consisting of the afferent splanchnic nerve, central nervous system and efferent vagus, which is involved in adaptive β-cell proliferation. Interoceptive signals from the liver appear to function as the trigger for stimulating this inter-organ neuronal network system. We further elucidated the underlying molecular mechanisms governing this system which involve neurotransmitters from the vagus and activation of the β-cell FoxM1 pathway. However, whether activation of efferent vagal nerves in vivo alone is sufficient to promote meaningful β-cell proliferation was unclear. To address this issue, we newly developed an optogenetic vagal nerve stimulation (oVNS) system and examined the effects of vagal nerve stimulation on β-cells. Employing this system, we demonstrated that selective oVNS in the pancreas dramatically promoted β-cell proliferation. In addition, oVNS suppressed the development of hyperglycemia in insulin-deficient model mice. Thus, vagal nerve signals are not only necessary but also sufficient to induce β-cell proliferation, thereby increasing functional β-cell mass. These results enhance our understanding of the adaptation systems of organs/tissues as well as providing novel clues for developing tissue regeneration strategies based on endogenous biological systems.

Heart failure is an increasingly serious public health issue, affecting more than 37.7 million individuals worldwide. The prognosis of patients with heart failure is still poor, with 5-year survival rates of 45.5%, regardless of advanced medical therapy. Dilated cardiomyopathy (DCM) is a major cause of end-stage heart failure requiring heart transplantation. Identifying a novel causative gene for DCM and elucidating its molecular mechanisms could lead to new insight into the pathogenesis of heart failure. Using the combination approach of whole-exome sequencing and transcriptome analysis of failing hearts, we identified the BAG cochaperone 5 (BAG5) as a novel causative gene for juvenile-onset DCM requiring heart transplantation (Hakui et al. Science Translational Medicine. 2022). All the BAG5 homozygous truncating mutations disrupted the C-terminal functional BAG domain and disabled the protein folding activity of a molecular chaperone heat shock cognate 71 kDa protein. Immunocytochemical analysis revealed that BAG5 localized to the junctional membrane complex (JMC), a critical microdomain for calcium-handling in the heart. Moreover, cardiomyocytes isolated from BAG5 mutant knock-in mice showed specifically decreased JMC protein levels under cardiac stress, disrupted JMC structure, and calcium-handling abnormalities. Our findings highlight the involvement of JMC protein homeostasis in the pathogenesis of heart failure.

Dynamin-related protein 1 (Drp1) is a mitochondrial fission-inducing protein and we previously reported that the activity of Drp1 was critical for the development of heart failure. Recently, cysteine persulfide or polysulfide on proteins [reactive sulfur species (RSS)] have been identified in organisms and cysteine residue of Drp1 is also found to be polysulfidated. However, the role of polysulfidation of Drp1 have been remained to be elusive. Here, I revealed that the change in Drp1 polysulfidation state affected prognosis of pressure overload-induced heart failure.

One of the environmental electrophiles, methylmercury (MeHg), has been known as cardiotoxic agent. Indeed, MeHg-treated mice showed vulnerability to cardiac pressure overload. Interestingly, MeHg treatment induced Drp1 activation and mitochondrial fragmentation accompanied by decreased Drp1 polysulfidation (depolysulfidation). These data suggest that depolysulfidation of Drp1 increase its activity for mitochondrial fission and induce cardiac vulnerability. In addition, sulfide donor sodium hydrogen sulfide (NaHS) treatment restored Drp1 polysulfidation, inhibiting MeHg-induced Drp1 activation and cardiac vulnerability against pressure overload. This result indicates that Drp1 polysulidation state is critical for cardiac robustness.

These findings suggest that formation of RSS can be important for the development of heart failure. Several pathways for RSS formation have been recently identified and these processes can be novel therapeutic target for heart failure.

Dysfunction of the circadian clock has been implicated in the pathogenesis of cardiovascular disease. Particularly, the CLOCK protein is a core molecular component of the circadian oscillator, so that mice with a mutated Clock gene (Clk/Clk) exhibit abnormal rhythms in numerous physiological processes. In this study, we analyzed the relationship between heart failure and Clock in 5/6 nephrectomy (5/6Nx) mice, which induce heart failure by chronic kidney disease (CKD). Surprisingly, cardiac inflammation and fibrosis were attenuated in Clock mutant (Clk/Clk) 5/6Nx mice even though they had high blood pressure and increased serum angiotensin II levels. A search for the underlying cause of the attenuation of heart disorder led to identification of the monocytic expression of G protein-coupled receptor 68 (GPR68) as a risk factor of CKD-induced inflammation and fibrosis of heart. 5/6Nx induced the expression of GPR68 in circulating monocytes via altered CLOCK activation by increasing serum levels of retinol and its binding protein (RBP4). The high-GPR68-expressing monocytes had increased potential for producing inflammatory cytokines, and their cardiac infiltration under CKD conditions exacerbated inflammation and fibrosis of heart. Our present study reveals an uncovered role of monocytic clock genes in CKD-induced heart failure.

The catalytic Na⁺,K⁺-ATPase subunits include four isoforms (α1-α4 isoforms). Volume-regulated anion channel (VRAC) plays an important role in cell death signaling pathway in addition to its fundamental role in the cell volume maintenance. Disruption of actin filaments causes the dysfunction of VRAC, which elicits resistance to cisplatin in the cancer cells. First, we introduce the cardiac glycosides-induced signaling pathway mediated by the crosstalk between Na⁺,K⁺-ATPase α1-isoform (α1NaK) and VRAC in the cancer cells. In this mechanism, sub-micromolar concentrations of cardiac glycosides bind to the receptor-type α1NaK localized in the membrane microdomain of the cells, and increase VRAC activities concomitantly with a deceleration of cancer cell proliferation. Second, we introduce the pathophysiological function of α3NaK, which is abnormally expressed in the intracellular vesicles of cancer cells. In general, cancer cells can survive even under loss of anchorage because they have the avoidance mechanism for anoikis. On cancer cell detachment, we found that intracellular α3NaK is translocated to the plasma membrane and this event contributes to survival of the cells. Interestingly, cardiac glycosides inhibited the α3NaK translocation. Our findings may open up new opportunities for development of cancer medicines.

Recent evidence suggests that the targeting of membrane transporters specifically activated in cancer stem cells (CSCs) is an important strategy for cancer therapy. The objectives of the present study were to investigate the ion channel expression profiles in digestive CSCs. Cells strongly expressing CSC markers, such as ALDH1A1 and CD44, were separated from the human esophageal squamous cell carcinoma, gastric cancer, and pancreatic cancer cell lines using fluorescence-activated cell sorting, and CSCs were identified based on tumorsphere formation. Messenger RNA levels of CSC markers were higher in CSCs than in non-CSCs. These CSCs also exhibited resistance to anticancer agents. The microarray analysis revealed that the expression of transient receptor potential vanilloid 2 (TRPV2), voltage-gated calcium channels (VGCCs), and voltage-gated potassium channels (Kv) were upregulated in esophageal, gastric, and pancreatic CSCs, respectively, compared with non-CSCs. The TRPV2 inhibitor tranilast, VGCCs inhibitors amlodipine and verapamil, and Kv inhibitor 4-aminopyridine exhibited greater cytotoxicity in CSCs compared with non-CSCs, and their inhibitory effects were also confirmed in a xenograft model in nude mice. Taking these results, phase I/II study to investigate clinical safety and efficacy of neoadjuvant combination chemotherapy of tranilast in advanced esophageal squamous cell carcinoma (TNAC study) is ongoing. These researches identified a role of ion channels in the persistence of CSCs and suggested that their inhibitors may have potential as a therapeutic agent for digestive cancers.

The unscheduled proliferation of cancer cells outside their natural niches subjects the cells to multiple insults, such as metabolic aberrations, detachment from the extracellular matrix (ECM), hypoxia, and immune cell attacks. Oxidative stress is a hallmark of cancer because these insults can all lead to the accumulation of reactive oxygen species (ROS) including H₂O₂. However, it remained largely elusive how cancer cells are able to adapt to harsh oxidative environments. In this symposium, we first provide evidence that cancer cells co-opt the neuronal ROS-sensing channel TRPA1 (Takahashi N, Nature Chem. Biol. 2011) to tolerate highly oxidative environments by activating Ca²⁺-induced anti-apoptotic programs (Takahashi N, Cancer Cell 2018). We then introduce a tumor-targeted H₂O₂ probe (called "T-AP1") that we recently developed. T-AP1 not only revealed intratumor H₂O₂ heterogeneity but also identified a novel and surprising oxidative-stress defense mechanism in cancer. Thus, our works provide a significant advance in our understanding of adaptation mechanisms to oxidative stress, which represents a substantial hurdle that impedes tumor initiation and progression.

Ca²⁺-activated K⁺ channels play a critical role in the proliferation, apoptosis, migration, adhesion, and metastasis of various types of cancer cells by controlling cell volumes and Ca²⁺ signaling. The amplification of them correlated with a high tumor stage and poor prognosis, and has potential as tumor grade‐associated markers. The hypoxic tumor microenvironment (TME) promotes the anti-cancer drug resistance and stemness of solid tumors. Three‐dimensional (3D) in vitro cancer spheroid models mimic the TME of human solid tumors, and are an efficient tool for investigating chemoresistance and stemness. We here introduce the mechanisms underlying the post‐translational modification of K_Ca1.1 and the overcome of chemo- and antiandrogen-resistance by K_Ca1.1 inhibition in 3D cancer spheroid models. Cancer-associated immunosuppressive cells such as tumor-associated macrophages also promote tumorigenesis and anti-cancer drug resistance by secreting immunosuppressive cytokines/chemokines. We introduce the possible involvement of K_Ca3.1 in escape from anti-tumor immune surveillance by inhibiting immunosuppressive IL-10 and IL-8 expression in the differentiated M₂ macrophages.

In recent years, various kinds of molecular targeted drugs, such as anti-TNFα monoclonal antibody (mAb), anti-IL-6 receptor mAb, CTLA4-Ig, and JAK inhibitor, have been used in the treatment of rheumatoid arthritis. Despite differences in the molecular targets of these drugs, they strongly inhibit bone erosion and synovitis even in patients with high-level clinical disease. Recent basic studies have revealed that these molecular targeted drugs exert direct effects on osteoclast differentiation and function, although little is known about the differences in mode of action.

We have originally established an advanced imaging system for evaluating the in vivo pharmacological actions of drugs in living mice using intravital multiphoton microscopy. By means of this system, we revealed that different molecular targeted drugs acted at specific therapeutic points during osteoclastic bone destruction with different efficacies. These results enable us to grasp the real modes of action of drugs, optimizing the usage of drug regimens. We are now establishing a novel imaging system for analyzing the pathogenesis of fibrotic diseases, which could serve as the basis for developing novel anti-fibrotic therapies.

In this symposium, we show the latest data, and also discuss the further application of intravital imaging techniques.

The skin is the largest organ that separates our body from the outside world and is constantly exposed to pathogens and antigens. Therefore, various immune cells are present in the skin, and the interaction of these cells induces dermatitis in response to foreign antigens. For example, inflammation is induced by Th1 cells in viral infection and contact dermatitis, Th2 cells in atopic dermatitis, and Th17 cells in psoriasis. Antigen-presenting cells (APCs) act as a bridge between innate and adaptive immunity and play an important role in driving T cell-mediated cutaneous responses. Currently, the heterogeneous human cutaneous APC population is incompletely characterized, and its contribution to these diseases remains unclear. Therefore, we performed single-cell RNA sequencing of inflammatory skin disease to identify the all-APC subsets, including the several novel APC fractions. LAMP3+ activated dendritic cells (DCs) were increased in atopic dermatitis and psoriasis and produced IL-15. DC3 were increased only in psoriasis and produced IL-1B and IL-23A, essential for psoriasis development. TREM2-positive macrophages were increased in granulomatous diseases. Single-cell RNA sequencing allows for a detailed classification of APCs, which will help elucidate the pathogenesis at the single-cell level.

In this work, we demonstrated that PGE2-EP2/EP4 signaling promoted activeinflammation through NF-κB-mediated upregulation of target proinflammatory andangiogenesis genes in myeloid cells and simultaneously induced immunosuppressionthrough mregDC-mediated Ccl22 and Ccl17 production to facilitate Tregrecruitment and activation in the tumor. We found that EP2/EP4 inhibitionreduced NF-κB dependent gene expression, decreased Tregs infiltration andactivation, and suppressed LLC1 tumor growth in mouse model. Moreover, weanalyzed TCGA database and found that expression of PTGER2 andPTGER4 (encoding EP2 and EP4) together correlated with poorprognosis in several cancers. Thus, PGE₂ -EP2/EP4 signaling inducesimmunosuppression in proinflammatory tumor microenvironment, which is amenableto EP2 and EP4 inhibitor.

Immune responses are regulated by gut environmental factors, including diet and microbiota. Here, we show our recent findings of the emerging roles of w3 and w6 essential fatty acid metabolites in the regulation of immunity, allergy and inflammation, and their involvement with intestinal microbes. We found that dietary linseed oil which is high in w3 a-linolenic acid ameliorated allergic and inflammatory symptoms through conversion to potent anti-allergic and anti-inflammatory lipid metabolites, including 17,18-epoxyeicosatetraenoic acid and 12-hydroxyeicosapentaenoic acid. Further, we recently found that 10-oxo-cis-12-cis-15-octadecadienoic acid (aKetoA) was produced by intestinal microbes, and acted as a novel postbiotic derived from a-linolenic acid for the control of contact hypersensitivity and diabetic adipose tissue inflammation. We also found that w6 fatty acid metabolism is a key factor for the establishment of oral vaccine through mediating innate immune signal from intestinal microbes. These results indicate that the metabolism of essential fatty acid plays crucial roles in the regulation of immunity, allergy and inflammatory diseases.

Mie University School of Medicine has adapted problem-based learning (PBL)-tutorial education to students in the 3rd and 4th grades. The PBL program has 10 units. Each unit focuses on specific disease areas. For example, unit 1 focuses on infectious diseases, whereas unit 2 is designed for cardiovascular and hematological diseases. Each unit consists of 2 or 3 cases with the diseases focused on the unit. In each case, students are provided with a document that contains information about the patient. Each student makes a portfolio based on the information within a few days. They then discuss the case in a small group consisting of 7 or 8 students. After the group discussion, additional information is provided to students. Each student again makes the portfolio based on the information within a few days and then discusses the case in the same group. During the unit, lectures from the standpoints of basic and clinical medicine are given to help students deepen their knowledge about the diseases. Lectures from pharmacological standpoints are also incorporated into the PBL program. In this symposium, I would like to discuss the role of pharmacology in the PBL program, focusing on the horizontal and vertical integration in medical education.

The Japan Accreditation Council for Medical Education has strengthened to promote horizontal and vertical integration of medical education, assuring the quality of medical education in Japan from an international standpoint. Pharmacology plays an important role as a central hub to connect basic medical education with clinical medical education. As part of promoting horizontal integration of medical education, Tokushima University has started a joint practice with four basic medical departments with Biochemistry, Physiology, Cell Biology, and Pharmacology for 2^nd grade medical students in 2019. Each department is in charge of 2 or 3 items of practice, and total 10 of items are performed for 2 weeks in integrated practice every year. This joint practice has become an official subject in 2022. In this symposium, we would like to introduce our experiences of the unique practice based on advantage and limitation.

Osaka Metropolitan University received a time-limited accreditation decision in the first medical education programs evaluation review in 2017. Based on the advice for improvement, the university resubmitted an improvement version for evaluation and underwent an additional review in 2020, as a result of which the improvement was evaluated and the review was approved. However, one of the issues that still required improvement after the additional review was the structure, organization, and duration of the educational program. First, it was desirable to devise a curriculum that would further promote horizontal and vertical integration of basic and clinical medicine, integrate lecture schedules, and reconsider the balance between the various fields of study. It was also desirable to further promote horizontal integration of related scientific and academic disciplines and issues, as well as seamless vertical integration of basic medicine, behavioral science, and social medicine with clinical medicine. This presentation will introduce the efforts, including its current and challenges, by Osaka Metropolitan University.

" To Err Is Human: Building a Safer Health System" from the Institute of Medicine was issued in 1999. This report has led to an increase in social needs for quality assurance and improvement of medical care. Clinical education throughout the continuum of undergraduate, graduate, and continuing education for medical training must be reconstructed and developed to meet social needs of medical care. Medical institutions must explain to society what medical graduates can do for patients as an outcome of medical education. The quality of medical education can be guaranteed by proving it. In 2010, ECFMG noticed that " Only those who have graduated from a medical school certified with international standards will be eligible to apply for becoming a doctor in the United States after 2023". In order to realize the quality assurance of medical education, medical education in Japan also must change to outcome-based education (OBE) from the traditional process-based education. OBE is included in the evaluation standards (international standards) of WFME, which is an international certification organization responsible for quality assurance of medical education, and OBE has become a global standard that guarantees quality assurance of medical education. Japan Accreditation Council for Medical Education (JACME), which complies with WFME, has also adopted international standards based on OBE, and OBE has become the standard for medical education in Japan.

Successful maturation of the brain relies on complex interactions between various neurotransmitter signaling. Glutamate, a major excitatory neurotransmitter in mammalian central nervous system, and an ionotropic glutamate receptor subtype, N-methyl-D-aspartate (NMDA) receptor, play essential roles in brain development. It has been reported that animals treated with an NMDA receptor antagonist during neonatal period show various behavioral abnormalities relevant to neurodevelopmental disorders in later life. We previously found that NMDA receptor blockade during neonatal period, but not adulthood, caused significant cognitive impairment in rats. Thus, the adverse effects of NMDA receptor blockade are dependent on the time when the treatment is administered. We further investigated the precise timing that NMDA receptors are involved in the development of cognitive functions, and the mechanism underlying the vulnerability of the immature brain to NMDA receptor blockade. In this symposium, we discuss the importance of the second postnatal week on the development of hippocampus-dependent learning in rats. We also discuss the involvement of NR2A-containing NMDA receptors in the formation of schizophrenia-related behavioral changes induced by neonatal NMDA receptor blockade.

Autism spectrum disorder (ASD) is a range of neurodevelopmental conditions generally characterized by impaired social communication and intense interests, and these symptoms are observed from early childhood in ASD. Although ASD has a strong genetic basis and numerous candidate genes have been located, only small effects seem to be attributed to any particular gene. Therefore, the involvement of environmental (non-genetic) factors in the development or exacerbation of ASD cannot be overlooked. Recently, the gut microbiota has attracted attention as an environmental (non-genetic) factor that can cause or exacerbate ASD, and many analyses of the gut microbiota of ASD children have been performed. However, the only consistent finding from these studies is that the gut microbiota of ASD children is clearly different from that of typically developing children, and the details of the relationship between gut microbiota and ASD are not yet clear. In this presentation, we introduce our studies investigating ASD-like behaviors, the gut microbiota, gene expression in the brain, and their relationship in mice treated with antibiotics in early life. We would like to discuss the impact of antibiotic use in early life as a risk factor that disrupts the gut microbiota, and how it affects the neurodevelopment.

Early social experience is critical for development of social and emotional functions, and deprivation of early social experience induces social and emotional dysfunctions in rodents and human. Recently, the orbitofrontal cortex (OFC) and amygdala have been highlighted as key brain strictures for social and emotional functions. Because prefrontal-amygdala synaptic function develops during adolescence, adolescent social deprivation may cause social and emotional abnormalities though OFC-amygdala disruption. In this study, we examined effects of adolescent social isolation on the OFC-basolateral amygdala (BLA) pathway in mice. First, we examined synaptic transmissions to BLA from medial or lateral subregions of the OFC (mOFC or lOFC) by optogenetic and patch-clamp methods. Interestingly, AMPA/NMDA ratio in the mOFC-BLA synapse was decreased by social isolation, while the ratio was increased in the lOFC-BLA synapse. Furthermore, optogenetic manipulation in behaving mice clarified that the mOFC-BLA and lOFC-BLA pathways regulated social and passive-coping behaviors, respectively. Our results suggested that adolescent social isolation induced distinct changes in the mOFC-BLA and lOFC-BLA synapses, and these changes separately contributed to social and emotional abnormalities.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by asynchronous development in several areas, such as communication, social behaviors, cognitive capabilities, and sensory responsiveness. The opioid system is well known to relieve pain and underpin the rewarding properties of most drugs of abuse. Additionally, accumulating evidence suggests that mu-opioid receptors (MORs) play an important role in modulating social behavior in humans and animals. We have investigated the effects of MOR agonists on social behavioral deficits in a mouse model of ASD and found that low to moderate MOR activation without analgesic efficacy ameliorated social impairments. Low doses of MOR agonists activated neurons in the medial prefrontal cortex and nucleus accumbens, while high doses caused a further increase in neural activity in the periaqueductal gray matter, a main site of the opioidergic analgesia. These results suggests that low-dose MOR agonists improve social behavioral deficits through activation of specific brain regions and might be useful for treating ASD symptoms. In this symposium, we would like to discuss about new treatment perspectives in ASD.

In a context of drug development, natural medicines are ordinally focused as chemical sources. If extracts showed some pharmacological activities, active ingredients would be identified to serve drug seeds. However, extracts themselves are able to be developed as botanical drugs or functional foods. Especially, crude drugs classified as Non-drug in "Fundamental policies of ingredients (raw materials) in the food and drug classification in Japan" have an advantage of clinical study doable comparably due to anticipated safety. Based on our basic studies, clinical studies can be seamlessly performed aiming to develop products.

Today, I introduce two lines of our studies. C. tubulosa extract improved motor function in spinal cord injured mice despite of intractable chronic phase and sarcopenia model mice. The molecular mechanism of acteoside, an active constituent in the extract, was partially revealed. RCT clinical study showed that C. tubulosa extract improved walking ability in locomotive syndrome. Now, another RCT of the extract for cervical spondylosis myelopathy is ongoing.

Diosgenin showed a potent anti-dementia activity, and realized accurate axon pathfinding in the Alzheimer's disease (AD) model mice. Detail molecular mechanism of diosgenin has clarified. RCT of diosgenin-rich Dioscorea batatas extract enhanced cognitive function in healthy adults. Now, another RCT of the extract for mild AD and MCI patients is ongoing. Our research is underway to get these two extracts on the drug approval track.

Capsaicin is a constituent of chili pepper that induces the burning sensation on the tongue. The site of action of capsaicin was discovered to be the transient receptor potential vanilloid receptor subtype 1 (TRPV1) that resides on the membranes of pain- and heat-sensing primary afferent sensory nerves. Immunohistochemical study of the stomach revealed that nerve fibers expressing TRPV1 exist along gastric glands in the mucosa, around blood vessels in the submucosa, in the myenteric plexus, and in the smooth muscle layers. Appropriate capsaicin protects gastric mucosa, but excessive amounts cause gastric damage. Numerous TRPV1 axons were also observed in esophagus, colon and rectum. Capsaicin is not only felt on the tongue, but throughout the digestive tract. It is good for our health if we consume appropriate spices. In this presentation, menthol receptor TRPM8 in gut is also introduced.

Visceral sensory hypersensitivity is induced during gastrointestinal inflammation. The increased TRPV1-expressing nerve fibers in the gut mucosa are involved in the visceral hypersensitivity in colitis model animals. Abnormalities of primary afferent nerve fibers are strongly associated with the visceral hypersensitivity in gastrointestinal disease. Therefore, when the gastrointestinal tract is upset, consuming a lot of spices is not good for the integrity of the digestive tract.

Tight junctions (TJ) are intercellular barriers between epithelial cells that separate the internal and external environments of cellular sheets, and control the invasion of foreign substances and the diffusion of solutes and water across the epithelium. Biologics with high molecular weight and hydrophilicity are unable to diffuse through the lipid bilayer of the cell membrane. Control of TJ opening by attenuating the barrier function of TJ has proved to be attractive because it could allow safe and controllable transmucosal/transdermal administration of biologics. However, TJ prevent foreign substances from entering the body and are essential for maintaining homeostasis in the body, sustained opening of TJ is risky. Therefore, we have focused on the chemicals that induce reversible opening of TJ, i.e., chemicals that temporarily open the TJ and restore the barrier function of TJ after a few hours.

Here, we show our investigations on reversible TJ openers identified from food ingredients and natural products. Capsaicin is a famous TRPV1 agonist, however we found this compound opens TJ reversibly via non-TRPV1-mediated mechanism. MA026 is a natural product targeting claudin-1, a most important TJ components, and we found this chemical enhances transdermal penetration of large hydrophilic material. Our results not only reveal the new targets of TJ regulators with novel mechanisms but also might be useful for transmucosal/transdermal administration of large hydrophilic biologics.

Vitamin B1 (thiamine) deficiency (TD) has been known to induce cognitive dysfunction including deficits in memory formation known as Wernicke-Korsakoff's syndrome in humans. However, mechanisms by which TD leads to deficits in learning and memory still remain unclear. In this study, to understand them, we examined the effects of pyrithiamine-induced thiamine deficiency (PTD) on learning and memory in mice. PTD-treated mice showed chronic impairments in the formation of hippocampus-dependent memories. Importantly, anatomical analyses indicated that PTD-treated mice displayed significant decreases in sizes of hippocampus and spine density of hippocampal neurons, suggesting the degeneration of hippocampal neurons by PTD-treatment. We next performed RNA-seq analyses of the hippocampus using next-generation sequencing and found that PTD mice showed increases in expressions of inflammation-related genes in the hippocampus and significant decreases in mRNA expressions of transcription factor CREB in the hippocampus, suggesting that PTD showed impaired CREB signaling pathways in the hippocampus. We finally examined the effects of PTD on transgenic mice increasing the CREB activity by expressing a constitutively active CREB mutant in the forebrain (DIEDML mice, Suzuki et al 2011) and found that activation of CREB rescued impairments in hippocampal degeneration and hippocampus-dependent memory by PTD. Taken together, our findings suggest that PTD causes strong inflammation, thereby leading to hippocampal degeneration and subsequent impairments in CREB signaling pathways that play essential roles in memory formation.

Basophils play critical roles in the development of delayed-onset skin allergic inflammation in mice (IgE-CAI model). Importantly, they also contribute to the resolution of allergic inflammation by promoting the generation of M2 macrophages. However, it remains unclear how M2 macrophages suppress excess inflammation. To address this, we conducted single-cell RNA-seq (scRNA-seq) analysis of the IgE-CAI skin lesion. scRNA-seq analysis identified two distinct M2 macrophage populations, namely early and late M2 macrophages, in IgE-CAI skin lesion. The former population was preferentially observed at the peak of inflammation (3 days after allergen challenge), whereas the latter one at the termination phase of inflammation (5 days). Gene ontology analysis revealed that genes associated with phagocytosis were enriched in late M2 macrophages. In particular, late M2 macrophages displayed upregulated expression of Gas6 and Mertk, key genes responsible for phagocytic clearance of apoptotic cells. Of note, MERTK inhibitor significantly aggravated ear swelling and accumulation of inflammatory cells in the skin lesion. Taken together, scRNA-seq identified M2 macrophages that display high capacity of dead cell clearance and contribute to the resolution of IgE-CAI.

Mast cells are highly reactive and release a variety of mediators that cause allergic and inflammatory reactions. The most well-known mechanism of mast cell activation is antigen-induced aggregation of IgE-binding FcεRI complexes on the cell surface. The IgE-dependent mast cell activation is regulated by various humoral factors that lower the threshold for antigen-mediated activation, exacerbating allergic reactions. Recently, we found that extracellular ATP is an important factor in enhancing mast cell response to weak signals elicited by IgE-dependent as well as -independent mechanisms. Mast cells express many functional P2 receptors, but ATP-induced synergistic mast cell activation to antigens and G protein-coupled receptor agonists, such as PGE₂, adenosine and compound 48/80 were exclusively mediated by ionotropic P2X4 receptors. In addition, genetic and pharmacological inhibition of P2X4 receptor improved the IgE-dependent and -independent anaphylactic responses in vivo. Since ATP is a ubiquitous intercellular mediator that coexists with other chemical mediators, P2X4 receptor signal should play an important role in mast cell-dependent allergic reaction in vivo. In this symposium, we will introduce the unique effects of P2X4 receptor signals on various mast cell activation mechanisms found in our laboratory.

Mast cells play a central role in IgE-dependent allergic responses. Engagement of antigen-specific IgE-bound FceRI with the same antigen induces mast cell degranulation, leading to the immediate hypersensitivity reaction. On the other hand, stimulation with cationic drugs (e.g., compound 48/80) induces IgE-independent degranulation of connective tissue mast cells via Mrgprb2, the murine homolog of MRGPRX2, leading to pseudo-allergic reaction. However, an inhibitory receptor CD300f down-regulates the excessive activation of mast cells in vivo. In fact, both FceRI-mediated anaphylactic responses and Mrgprb2-mediated pseudo-allergic responses are enhanced in CD300f-deficient mice compared to wild-type mice. We have previously identified ceramide as a ligand for CD300f. Consistently, administration of ceramide liposomes, prepared by using an extruder, inhibits both anaphylactic and pseudo-allergic responses in mice. In addition, we recently developed a new method to generate stable ceramide liposomes and demonstrated that intranasal administration of newly-generated ceramide liposomes inhibits ragweed pollen-induced allergic rhinitis in murine models. Thus, intranasal administration of ceramide liposomes will be a useful therapeutic strategy against allergic rhinitis.

Mast cells are strategically distributed as sentinels, which alert the immune system upon infiltration of foreign materials and pathogens. Mast cells trigger inflammatory responses by releasing their pro-inflammatory mediators. Some materials are recognized by IgE and cross-link the FceRI and others directly activate surface membrane receptors expressed in mast cells. Although it long remained to be clarified how mast cells are activated in the latter cases, a series of recent studies have revealed that Mas-related G protein-coupled receptors (Mrgprs) should play critical roles in IgE-independent degranulation of mast cells. On the other hand, large-scale ligand screenings suggested that an orphan G protein-coupled receptor (GPCR), GPR35, should be the candidate for the target molecules of mast cell stabilizers, such as disodium cromoglycate. Here I present our recent progress in the investigation of the roles of various Mrgpr family receptors and GPR35 expressed in murine mast cells. Development of the antagonists of Mrgprs and the agonists of GPR35 might open up novel therapeutic approaches for inflammatory diseases, in which tissue mast cells play a primary role.

Because drug therapy typically involves multiple concurrent treatments, there is a need for a framework that can systematically predict drug interactions (DIs). For this reason, we focused on pharmacokinetic DIs, collecting all available information on DIs involving 5 CYP molecular species and treating in vitro and in vivo observations equally to construct a framework for comprehensive and quantitative prediction of drug exposure by using MCMC method. The change in drug exposure (AUC change rate; AUCR) and in vitro observations of 67 substrates and 30 inhibitors for five CYP molecular species were collected for model building. Regarding the drug combinations for which clinical trials (in vivo) have been conducted, the AUCR prediction accuracy was within the 1/2- fold to 2-fold confidence interval. As in vitro parameters could help to estimate the contribution of CYP molecular species, indeed, the AUCR accuracy improved depending on the amount of in vitro information. The estimation of 2010 AUCRs, including unknown combinations, suggested that a considerable number of combinations are overlooked by the current FDA and PMDA classification based solely on in vivo AUCRs. In the future, the lack of in vivo information can be compensated for by increasing in vitro information and using it appropriately for DI management.

In patients with chronic heart failure (CHF), exercise therapy is generally recommended in addition to pharmacotherapy such as ACE inhibitors and beta-blockers. However, our previous model-based meta-analysis showed that the reduction in mortality with pharmacotherapy requires a reduction in cardiac load prior to an improvement in cardiac function; thus increased workload caused by exercise therapy may be conflicting depending on patients. In the present study, using individual patient data from the HF-ACTION trial, we explored the influence of pharmacotherapy on the effect of exercise therapy with a Cox proportional hazards model focusing on interactions. The results showed that the exercise effect on all-cause mortality varied greatly depending on the pharmacotherapy at randomization, with exercise therapy significantly decreasing the number of deaths only in patients on a beta-blocker. In addition, various other factors were also identified as influencing the exercise effect, and clinical scores generated using these factors were useful in discriminating patients whose prognosis was improved or worsened by exercise. These results could compel a review of the original primary analysis of the HF-ACTION study, which found that exercise therapy had little effect on the prognosis of patients with CHF.

Covid-19 is firstly reported in Dec 2019 and has spread to countries around the world. Variants represented by alpha, beta, gamma, delta, and omicron strains have been reported as of Jul 2022 and the pandemic has not yet ended.

It is reported that the number of Covid-19 cases and deaths differ among regions and countries, and the virus mutation, measures to prevent the spread of infection such as lockdown, social distance strategy, therapeutic drugs and vaccination, or other factors such as population or economic activities can cause the difference. However, it is difficult to quantitatively evaluate the effect of each factor on increase or decrease of the cases and deaths when the data from a country is analyzed since various factors are complicatedly related and change with time.

In this study, we described the dynamics of infectious diseases using a mathematical model based on SIR model, performed population analysis on the number of Covid-19 cases, confirmed deaths and excess deaths from over 150 countries using MCMC method, and examined the factors which can explain the difference of the cases and deaths by regions and countries. The effect of lockdown could be described with the model in which the potential of lockdown decreases with time, and the difference of transmissibility among variants could be estimated successfully.

Ceramide is the central lipid of sphingolipids and is metabolized by various metabolic enzymes. Sphingolipids play important roles as a constituent of biological membranes and exert multiple physiological functions. Thus, understanding the physiological functions of ceramide metabolism enzymes will lead to elucidation of various diseases and drug discovery. There are three therapeutic agents targeting ceramide-related metabolism enzyme or receptor. Recently, we and other groups have found that ceramide metabolism enzymes may be therapeutic targets for Niemann-Pick disease type C (NPC). NPC is a lipid storage disorder caused by mutations in NPC1 or NPC2 genes. While cholesterol is well known to be accumulated in NPC, multiple species of sphingolipids accumulate as well. We found that ceramide-1-phosphate (C1P), a phosphorylated ceramide produced by ceramide kinase (CerK), levels were increased in NPC1^−/− cells, NPC1 mutant cells, NPC1^−/− mouse brain, and the plasma from the patients with NPC. CerK inhibition decreased free cholesterol accumulation in NPC1^−/− cells, NPC1 mutant cells, and patient-derived induced pluripotent stem cell neurons. C1P accumulation in NPC1^−/− cells negatively regulated the transport of LDL-derived free cholesterol to the endoplasmic reticulum. Genetic deletion of CerK in NPC1^−/− mice attenuated cholesterol accumulation in the cerebellum, improved Purkinje cell survival, and prolonged lifespan. These results suggest that CerK is a novel therapeutic target for NPC.