Development of a Novel Microphysiological System for Peripheral Neurotoxicity Prediction Using Human iPSC-Derived Neurons with Morphological Deep Learning.

A microphysiological system (MPS) is an in vitro culture technology that reproduces the physiological microenvironment and functionality of humans and is expected to be applied for drug screening. In this study, we developed an MPS for the structured culture of human iPSC-derived sensory neurons and then predicted drug-induced neurotoxicity by morphological deep learning. Using human iPSC-derived sensory neurons, after the administration of representative anti-cancer drugs, the toxic effects on soma and axons were evaluated by an AI model with neurite images.

Development of an evaluation method for addictive compounds based on electrical activity of human iPS cell-derived dopaminergic neurons using microelectrode array.

Addiction is known to occur through the consumption of substances such as pharmaceuticals, illicit drugs, food, alcohol and tobacco. These addictions can be viewed as drug addiction, resulting from the ingestion of chemical substances contained in them. Multiple neural networks, including the reward system, anti-reward/stress system and central immune system in the brain, are believed to be involved in the onset of drug addiction.

Induced pluripotent stem cell-derived neural stem cells promote bone formation in mice with calvarial defects.

Nerve-derived factors have attracted attention in bone regeneration therapy due to their ability to promote bone regeneration and nerve innervation. Mesenchymal stem cells transported to target sites promote osteogenesis. However, there are few reports on the effects of neural stem cells on bone regeneration.

An In Vitro Assessment Method for Chemotherapy-Induced Peripheral Neurotoxicity Caused by Anti-Cancer Drugs Based on Electrical Measurement of Impedance Value and Spontaneous Activity.

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major adverse event of anti-cancer drugs, which still lack standardized measurement and treatment methods. In the present study, we attempted to evaluate neuronal dysfunctions in cultured rodent primary peripheral neurons using a microelectrode array system. After exposure to typical anti-cancer drugs (i.

Development of an In Vitro Assessment Method for Chemotherapy-Induced Peripheral Neuropathy (CIPN) by Integrating a Microphysiological System (MPS) with Morphological Deep Learning of Soma and Axonal Images.

Several anticancer drugs used in cancer therapy induce chemotherapy-induced peripheral neuropathy (CIPN), leading to dose reduction or therapy cessation. Consequently, there is a demand for an in vitro assessment method to predict CIPN and mechanisms of action (MoA) in drug candidate compounds. In this study, a method assessing the toxic effects of anticancer drugs on soma and axons using deep learning image analysis is developed, culturing primary rat dorsal root ganglion neurons with a microphysiological system (MPS) that separates soma from neural processes and training two artificial intelligence (AI) models on soma and axonal area images.

Evaluation of neurotoxicity for pesticide-related compounds in human iPS cell-derived neurons using microelectrode array.

In vivo evaluations of chemicals in neurotoxicity have certain limitations due to the considerable time and cost required, necessity of extrapolation from rodents to humans, and limited information on toxicity mechanisms. To address this issue, the development of in vitro test methods using new approach methodologies (NAMs) is important to evaluate the chemicals in neurotoxicity. Microelectrode array (MEA) allows the assessment of changes in neural network activity caused by compound administration.

Neuroprotective Potential of L-Glutamate Transporters in Human Induced Pluripotent Stem Cell-Derived Neural Cells against Excitotoxicity.

Human induced pluripotent stem cell (hiPSC)-derived neural cells have started to be used in safety/toxicity tests at the preclinical stage of drug development. As previously reported, hiPSC-derived neurons exhibit greater tolerance to excitotoxicity than those of primary cultures of rodent neurons; however, the underlying mechanisms remain unknown. We here investigated the functions of L-glutamate (L-Glu) transporters, the most important machinery to maintain low extracellular L-Glu concentrations, in hiPSC-derived neural cells.

Large-Area Field Potential Imaging Having Single Neuron Resolution Using 236 880 Electrodes CMOS-MEA Technology.

The electrophysiological technology having a high spatiotemporal resolution at the single-cell level and noninvasive measurements of large areas provide insights on underlying neuronal function. Here, a complementary metal-oxide semiconductor (CMOS)-microelectrode array (MEA) is used that uses 236 880 electrodes each with an electrode size of 11.22 × 11.

Detection of astrocytic slow oscillatory activity and response to seizurogenic compounds using planar microelectrode array.

Since the development of the planar microelectrode array (MEA), it has become popular to evaluate compounds based on the electrical activity of rodent and human induced pluripotent stem cell (iPSC)-derived neurons. However, there are no reports recording spontaneous human astrocyte activity from astrocyte-only culture sample by MEA. It is becoming clear that astrocytes play an important role in various neurological diseases, and astrocytes are expected to be excellent candidates for targeted therapeutics for the treatment of neurological diseases.

A functional neuron maturation device provides convenient application on microelectrode array for neural network measurement.

Background: Microelectrode array (MEA) systems are valuable for in vitro assessment of neurotoxicity and drug efficiency. However, several difficulties such as protracted functional maturation and high experimental costs hinder the use of MEA analysis requiring human induced pluripotent stem cells (hiPSCs). Neural network functional parameters are also needed for in vitro to in vivo extrapolation.

Responses to antibiotics in human iPSC-derived neurons based on the clinical antibiotic-associated encephalopathy classification.

Antibiotic-associated encephalopathy (AAE) is a central nervous system disorder caused by antibiotics administration and classified into three types based on clinical symptoms. Type 1 AAE causes seizures and myoclonus, type 2 causes psychiatric symptoms, and type 3 is characterized by cerebellar ataxia. In this study, we investigated whether the electrical activity of in vitro human iPSC-derived neurons to antibiotics could be classified based on the 3 types of AAEs classified by clinical symptoms.

Histograms of Frequency-Intensity Distribution Deep Learning to Predict the Seizure Liability of Drugs in Electroencephalography.

Detection of seizures as well as that of seizure auras is effective in improving the predictive accuracy of seizure liability of drugs. Whereas electroencephalography has been known to be effective for the detection of seizure liability, no established methods are available for the detection of seizure auras. We developed a method for detecting seizure auras through machine learning using frequency-characteristic images of electroencephalograms.

Can We Panelize Seizure?

Seizure liability remains a significant cause of attrition in drug discovery and development, leading to loss of competitiveness, delays, and increased costs. Current detection methods rely on observations made in in vivo studies intended to support clinical trials, such as tremors or other abnormal movements. These signs could be missed or misinterpreted; thus, definitive confirmation of drug-induced seizure requires a follow-up electroencephalogram study.

Versatile live-cell activity analysis platform for characterization of neuronal dynamics at single-cell and network level.

Chronic imaging of neuronal networks in vitro has provided fundamental insights into mechanisms underlying neuronal function. Current labeling and optical imaging methods, however, cannot be used for continuous and long-term recordings of the dynamics and evolution of neuronal networks, as fluorescent indicators can cause phototoxicity. Here, we introduce a versatile platform for label-free, comprehensive and detailed electrophysiological live-cell imaging of various neurogenic cells and tissues over extended time scales.

[Approach to drug efficacy and safety assessment based on functions of a human iPSC-derived neuronal network].

Development of an in vitro drug efficacy and safety assessment based on the function of the neural network is required in preclinical studies. A microelectrode array (MEA), which can simultaneously measure the electrical activity of a human induced pluripotent stem cell-derived neural network at multiple points, is an effective assay system. In this study, we focused on seizure liability and clarified the responsiveness to seizure-positive compounds depending on the excitatory and inhibitory balance (E/I balance) of each evaluation sample.

[Evaluation methods for drug-induced seizure by microelectrode array recording using human iPS cell-derived neurons].

In the drug development in pharmaceuticals, development of drugs may be discontinued due to the toxicity and clinical side effect, therefore, safety assessment is one of the important factors in drug development. Consortium for Safety Assessment using Human Cells (CSAHi) has been launched for developing and standardizing a toxicity evaluation system for development of drug using human iPS cell differentiated cells. CSAHi focuses on hepato-, cardio-, and neuro-toxicities as important toxicity organs which are attributed to the causes of discontinuation of drug development.

Approach to Neurotoxicity using Human iPSC Neurons: Consortium for Safety Assessment using Human iPS Cells.

Neurotoxicity, as well as cardiotoxicity and hepatotoxicity, resulting from administration of a test article is considered a major adverse effect both pre-clinically and clinically. Among the different types of neurotoxicity occurring during the drug development process, seizure is one of the most serious one. Seizure occurrence is usually assessed using in vivo animal models, the Functional Observational Battery, the Irwin test or electroencephalograms.

Impact of Sleep-Wake-Associated Neuromodulators and Repetitive Low-Frequency Stimulation on Human iPSC-Derived Neurons.

The cross-regional neurons in the brainstem, hypothalamus, and thalamus regulate the central nervous system, including the cerebral cortex, in a sleep-wake cycle-dependent manner. A characteristic brain wave, called slow wave, of about 1 Hz is observed during non-REM sleep, and the sleep homeostasis hypothesis proposes that the synaptic connection of a neural network is weakened during sleep. In the present study, human induced pluripotent stem cell (iPSC)-derived neurons, we investigated the responses to the neuromodulator known to be involved in sleep-wake regulation.

Synchronous spike patterns in differently mixed cultures of human iPSC-derived glutamatergic and GABAergic neurons.

Human induced-pluripotent stem cell (hiPSC)-derived neurons develop organized neuronal networks under in vitro cultivation conditions. Here, using a multielectrode array system, we examined whether the spike patterns of hiPSC-derived neuronal populations differed in a manner that depended on the proportions of glutamatergic and gamma-aminobutyric acid (GABA)ergic neurons in the cultures. Synchronous burst firing events spanning multiple electrodes became more frequent as the number of days in culture increased.

Temporally coordinated spiking activity of human induced pluripotent stem cell-derived neurons co-cultured with astrocytes.

In culture conditions, human induced-pluripotent stem cells (hiPSC)-derived neurons form synaptic connections with other cells and establish neuronal networks, which are expected to be an in vitro model system for drug discovery screening and toxicity testing. While early studies demonstrated effects of co-culture of hiPSC-derived neurons with astroglial cells on survival and maturation of hiPSC-derived neurons, the population spiking patterns of such hiPSC-derived neurons have not been fully characterized. In this study, we analyzed temporal spiking patterns of hiPSC-derived neurons recorded by a multi-electrode array system.

Near-Infrared-Responsive Peptide that Targets Collagen Fibrils to Induce Cytotoxicity.

A novel conjugate, PHG10 dye, was synthesized using a collagen peptide and a near-infrared (NIR)-responsive dye to achieve targeted cytotoxicity. The collagen peptide motif, -(Pro-Hyp-Gly)10 - (PHG10), was incorporated for targeting collagen fibrils that are excessively produced by activated fibroblasts around tumor cells. PHG10 dye was purified by HPLC and identified by MALDI-MS.

Carbon nanotube multi-electrode array chips for noninvasive real-time measurement of dopamine, action potentials, and postsynaptic potentials.

Multi-electrode arrays (MEAs) can be used for noninvasive, real-time, and long-term recording of electrophysiological activity and changes in the extracellular chemical microenvironment. Neural network organization, neuronal excitability, synaptic and phenotypic plasticity, and drug responses may be monitored by MEAs, but it is still difficult to measure presynaptic activity, such as neurotransmitter release, from the presynaptic bouton. In this study, we describe the development of planar carbon nanotube (CNT)-MEA chips that can measure both the release of the neurotransmitter dopamine as well as electrophysiological responses such as field postsynaptic potentials (fPSPs) and action potentials (APs).

Control of neural network patterning using collagen gel photothermal etching.

Two-dimensional (2D) micropatterning techniques have been developed to guide dissociated neurons into predefined distributions on solid substrates, such as glass and plastic. Micropatterning methods using three-dimensional (3D) substrates or scaffolds that reproduce aspects of the in vivo microenvironment could facilitate the engineering of functional tissues for transplantation or more robust experimental models. We developed a 3D collagen gel photothermal etching method using an infrared laser that precisely controls the area of cell adhesion and neurite projection by etching a small targeted section of the collage gel.