Drug discovery research takes many years and tons of effort, and the success rate is extremely low. In order to overcome this situation, pharmaceutical companies struggle to improve the probability of success drug research and development with multiple approaches. Recently, it is important to predict the clinical effects of the candidates as early as possible in drug discovery stage, to stratify patients with diseases, and to provide appropriate readouts for evaluation of pharmacological efficacy for increasing the success rate. In this environment, the importance of non-clinical research that actively utilizes human-derived samples including patient-derived samples is increasing. In this article, author describes the use of human-derived samples in non-clinical research, especially focusing on the utilization of induced pluripotent stem cells. Human-derived samples are valuable experimental materials that have, at least in part, human-specific characteristics that experimental animals do not possess. In particular, patient-derived samples are thought to have the genetic predisposition and at least some disease characteristics that cause the disease, and are useful from the perspective of elucidating the pathogenesis, disease modeling, and predictability of clinical effects. This is also valuable for drug discovery research in diseases that are difficult to reproduce in experimental animals such as mice. Whereas, human-derived samples have some limitations, and we need ethical procedures and consideration when researchers use them. Author will provide an overview of the use of human-derived samples in non-clinical research based on the perspectives as described above and introduce our research group cases, and future research prospects using them.

Prediction of intestinal drug absorption and drug-induced intestinal toxicity is critical for the development of orally-administered drugs. However, it is difficult to accurately predict these events because of large species differences and a lack of appropriate in vitro assay. Then, we proposed the use of human crypt-derived intestinal cells for the prediction of intestinal absorption and the risk of intestinal toxicity. 3D human intestinal spheroids were established from fresh surgical specimens of proximal jejunum and terminal ileum using the conditioned media containing Wnt3a, R-spondin 3, and noggin. To generate 2D monolayer, spheroids were enzymatically dissociated into single cells and plated onto Matrigel-precoated culture plates/inserts. We have confirmed the activities of typical drug-metabolizing enzymes and uptake/efflux transporters in human jejunal spheroid-derived differentiated cells. Intestinal availability (Fg) estimated from the apical-to-basal permeation clearance across the jejunal monolayer showed a good correlation with in vivo human Fg values for five CYP3A substrate drugs. As for the prediction of intestinal toxicity, we found that the degree of ATP decreases in intestinal spheroids incubated with different EGFR-TKIs varied greatly depending on the drugs and the rank order of the extent of ATP decrease corresponded with that of frequency of clinically-observed diarrhea. We also constructed enterochromaffin (EC) cell-rich spheroids and quantified serotonin release from EC cells upon exposure to drugs for the prediction of drug-induced nausea and vomiting. As a result, we found that the serotonin release was related to the high/low risk of nausea and vomiting of each ALK/ROS1 kinase inhibitors.

An issue in drug discovery research at pharmaceutical companies is the decline in the probability of market launch, and there is a need to improve the proof-of-concept (POC) acquisition rate by further improving clinical predictability. For this purpose, we need to deepen our understanding of human pathophysiology, and to make efficient of drug discovery research by utilizing human samples and data due to the change in mindset from “animals” to “humans” at the drug discovery research stage. In particular, with the aim of improving the efficiency of drug discovery research by utilizing human samples/data, we have established a human sample utilization support capability, then we are supporting the acquisition of appropriate human samples/data to meet each drug research need with collecting information on organizations that can provide various human samples and accumulating know-how on obtaining human samples/data. In addition, we have built a one-stop support system for surveying human samples/data, negotiating, and contracting with the organizations, obtaining ethical committee approvals, importing samples, and dealing with customs clearance. As results, our researchers can obtain high-quality human samples/data to meet their research needs rapidly/easily. By establishing this capability, the number of the research projects that implement target validation, pharmacological evaluation, BM identification, and patient stratification, etc. using human samples/data from the early stage of drug discovery, has increased, and then, the evidence obtained by using human samples/data contribute to create drug candidates with high probability of clinical effect. We will introduce our activities while showing the support flow that was actually constructed.

Recently, bottom-up technologies, in particular the utilization of self-assembly of functional polymers to form nanostructures in solutions have been collecting attention. These technologies are being explored for various applications, especially for usage in therapeutics. One of the goals of such studies is to develop a drug delivery system (DDS) that delivers bioactive substances to specific targets within our body, eliciting the desired functionality. The authors have been developing “nanomachines” using biocompatible polymers to safely and efficiently deliver drugs mainly to tumors. The aim of this study is to utilize our expertise in designing a nanomachine to develop a cutting-edge nanomachine that can efficiently penetrate the blood-brain barrier (BBB) and deliver drugs to the brain parenchyma. Furthermore, leveraging this “nanomachine” technology, the authors are advancing the “Hayabusa Nanomachine,” which can non-invasively collect and detect brain molecules, correlating them with various biological processes, ultimately leading to a better understanding of brain function and diseases. This paper also introduces the concept and ongoing efforts to the development of “Hayabusa Nanomachines,” which have the potential to revolutionize existing approaches in this field.

Because of absence of the objective biomarker for major depressive disorder (MDD) or depressive state, psychiatrists depend on subjective examinations in order to properly diagnose their patients. We recently identified the candidates of the objective biomarker of depressive state of late-onset MDD by profiling gene expressions in white blood cells of patients and model mice. We also investigated whether gene expression profiling of white blood cells was useful to elucidate the biological alterations in the brain. Furthermore, we newly developed transgenic mice which will be useful for elucidating the neurological mechanisms of emotional abnormalities in psychiatric disorder. In this review, I introduce our recent research to help for understanding of translational approaches to develop the biomarker of depression.

The central extended amygdala, including the central nucleus of the amygdala (CeA) and the lateral division of the bed nucleus of the stria terminalis (BNSTL), is a pivotal brain region involved in the threat processing responsible for emotional states such as fear and anxiety. These brain regions alter their circuit activities and exhibit necessary functions to adapt to environmental changes. When faced with excessive threats or stress, it is thought that these neural circuit functions are disrupted and cause various stress-related psychiatric disorders. The CeA and BNSTL were suggested to be the same nuclei separated during development because of their dense neural connections, and the similarities in cellular composition and connectivity patterns with other brain regions. On the other side, some recent studies suggested functional differences between these two regions in controlling emotional behaviors. However, functional segregation at the subnuclei level was insufficient since the two regions have complex circuit structures composed of multiple subnuclei. In this review, we introduce the similarities and differences between the CeA and BNSTL that have been clarified from our recent comparative studies of gene expression profiles and circuit functions at the subnuclei level. Additionally, we also discuss how it can contribute to understanding the molecular pathogenesis of neuropsychiatric disorders, including stress-related psychiatric disorders.

In recent years, various trace bioanalysis methods have been developed, including single-cell transcriptome analysis methods. As the sample volume and amount of biomolecules contained therein are extremely limited, development of new single-cell analysis methods require extremely high-level techniques. It is necessary to design an appropriate analysis system that integrates a highly sensitive detection system and a pretreatment protocol for minimizing sample loss, where separation method is especially important for analyzing diverse mixtures of biomolecules. Among them, capillary electrophoresis (CE) can separate biomolecules in nanoliter-scale solutions with high resolution, making it highly compatible with trace samples such as single cells. By combining with highly sensitive nano-electrospray ionization-mass spectrometry (MS), it is possible to detect nanomolar to sub-nanomolar biomolecules, which can be further improved by using online sample preconcentration methods. These highly sensitive analytical techniques have made it possible to analyze trace amounts of metabolites, proteins, lipids, etc. This review paper summarizes the research on CE-MS trace bioanalysis that has been reported to date, with a focus on single-cell analysis.

New approaches for elucidating mechanisms of diseases including environmental diseases, cancer, metabolic diseases, infectious diseases are challenging. After the presentation on elucidating the mechanism of cancer and infectious diseases, lectures by Dr. Tae-Young Kim (Korea) on metabolic deuterium oxide labeling in environmental diseases, Dr. Rosalia Rodriguez-Rodriguez (Spain) on targeting the hypothalamus with nanomedicines to treat metabolic diseases, Dr. Chang-Beom Park (Korea) on methodological approach for evaluation of the environmental diseases were presented. The deeper understanding of the global research approaches on diseases will be expected based on the fruitful discussion at the international symposium.

Antimicrobial resistance is currently recognized as an urgent concern against public health in worldwide. Carbapenem-resistant (CR) Gram-negative bacteria, such as Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii are listed as critical pathogens which are widely spread and can cause severe and often deadly infections in WHO guidance. Cefiderocol (Fetroja^®), a novel and first siderophore cephalosporin, was approved for the infections caused by these problematic CR Gram-negative bacteria in Japan on November 30, 2023. Cefiderocol has unique mechanisms to be incorporated into bacterial cells using bacterial iron transportation system and to be highly stable against most β-lactamases, which lead to promising antibacterial activity against these Gram-negative bacteria including CR strains in vitro. In CREDIBLE-CR Ph3 trial, cefiderocol showed the good efficacy and safety for patients with CR Gram-negative bacteria. In APEKS-cUTI and APEKS-NP trials, cefiderocol showed non-inferiority and suggested superiority to imipenem/cilastatin in complicated urinary tract infection (cUTI) patients, and non-inferiority to high dose of meropemen in pneumonia patients, respectively. Cefiderocol is expected to be an optimal treatment for CR Gram-negative infections with limited treatment options and would be an important drug to combat the threat of CR bacteria.