iPSC-based disease modeling and drug discovery in cardinal neurodegenerative disorders

Large-scale manufacturing of human gallbladder epithelial cell products and derived hepatocytes via a chemically defined approach

Manufacturing sufficient quantities of high-quality hepatocytes holds significant promise for the treatment of liver diseases and drug screening. Here, we developed a chemically defined, animal-free method for the large-scale production of human gallbladder epithelial cells (hGBECs) under good manufacturing practice conditions, enabling their clinical application. The cell products were characterized for growth ability, phenotype, freeze-thaw viability, genetic stability, biological contamination, tumorigenicity, and acute toxicity to ensure quality control and biological safety. We also provide a protocol for generating functional hepatocytes from hGBECs. The derived hepatocytes demonstrated typical liver functions, including albumin secretion, urea production, and drug metabolism. In addition, these cells were used in drug toxicity testing. We conducted further functional experiments on Cu2+ transport and alcohol metabolism. Transplantation of these cells in vivo was able to rescue mice from liver failure. This large-scale, convenient strategy for manufacturing hGBECs serves as a biobank for clinical applications and provides a valuable model for studying liver diseases.

Revisiting the Pathogenesis of X-Linked Adrenoleukodystrophy

BACKGROUND

X-ALD is a white matter (WM) disease caused by mutations in the ABCD1 gene encoding the transporter of very-long-chain fatty acids (VLCFAs) into peroxisomes. Strikingly, the same ABCD1 mutation causes either devastating brain inflammatory demyelination during childhood or, more often, progressive spinal cord axonopathy starting in middle-aged adults. The accumulation of undegraded VLCFA in glial cell membranes and myelin has long been thought to be the central mechanism of X-ALD.

METHODS

This review discusses studies in mouse and drosophila models that have modified our views of X-ALD pathogenesis.

RESULTS

In the Abcd1 knockout (KO) mouse that mimics the spinal cord disease, the late manifestations of axonopathy are rapidly reversed by ABCD1 gene transfer into spinal cord oligodendrocytes (OLs). In a peroxin-5 KO mouse model, the selective impairment of peroxisomal biogenesis in OLs achieves an almost perfect phenocopy of cerebral ALD. A drosophila knockout model revealed that VLCFA accumulation in glial myelinating cells causes the production of a toxic lipid able to poison axons and activate inflammatory cells. Other mouse models showed the critical role of OLs in providing energy substrates to axons. In addition, studies on microglial changing substates have improved our understanding of neuroinflammation.

CONCLUSIONS

Animal models supporting a primary role of OLs and axonal pathology and a secondary role of microglia allow us to revisit of X-ALD mechanisms. Beyond ABCD1 mutations, pathogenesis depends on unidentified contributors, such as genetic background, cell-specific epigenomics, potential environmental triggers, and stochasticity of crosstalk between multiple cell types among billions of glial cells and neurons.

Alzheimer's disease patient brain extracts induce multiple pathologies in novel vascularized neuroimmune organoids for disease modeling and drug discovery

Alzheimer's Disease (AD) is the most common cause of dementia, afflicting 55 million individuals worldwide, with limited treatment available. Current AD models mainly focus on familial AD (fAD), which is due to genetic mutations. However, models for studying sporadic AD (sAD), which represents over 95% of AD cases without specific genetic mutations, are severely limited. Moreover, the fundamental species differences between humans and animals might significantly contribute to clinical failures for AD therapeutics that have shown success in animal models, highlighting the urgency to develop more translational human models for studying AD, particularly sAD. In this study, we developed a complex human pluripotent stem cell (hPSC)-based vascularized neuroimmune organoid model, which contains multiple cell types affected in human AD brains, including human neurons, microglia, astrocytes, and blood vessels. Importantly, we demonstrated that brain extracts from individuals with sAD can effectively induce multiple AD pathologies in organoids four weeks post-exposure, including amyloid beta (Aβ) plaque-like aggregates, tau tangle-like aggregates, neuroinflammation, elevated microglial synaptic pruning, synapse/neuronal loss, and impaired neural network activity. Proteomics analysis also revealed disrupted AD-related pathways in our vascularized AD neuroimmune organoids. Furthermore, after treatment with Lecanemab, an FDA-approved antibody drug targeting Aβ, AD brain extracts exposed organoids showed a significant reduction of amyloid burden, along with an elevated vascular inflammation response. Thus, the vascularized neuroimmune organoid model provides a unique opportunity to study AD, particularly sAD, under a pathophysiological relevant three-dimensional (3D) human cell environment. It also holds great promise to facilitate AD drug development, particularly for immunotherapies.

Vascular models of Alzheimer's disease: An overview of recent in vitro models of the blood-brain barrier

Alzheimer's disease (AD) remains an overwhelming epidemiologic and economic burden on our healthcare systems, affecting an estimate of 11 % of individuals aged 65 years and older. Increasing evidence of the role of the blood-brain barrier (BBB) in AD pathology lends support to the vascular hypothesis of AD, which posits that damage to cerebral vasculature and impairments to cerebral blood flow are major contributors to neurodegeneration in AD. While the question remains whether the dysfunction of the BBB is the cause or consequence of the disease, understanding of the relationship between vascular pathology and AD is growing increasingly complex, warranting the need for better tools to study vasculature in AD. This review provides an overview of AD models in the context of studying vascular impairments and their relevance in pathology. Specifically, we summarize opportunities in in vitro models, cell sources, and phenotypic observations in sporadic and familial forms of AD. Further, we describe recent advances in generating models which recapitulate in vivo characteristics of the BBB in AD through the use of microfluidics, induced pluripotent stem cells (iPSC), and organoid technologies. Finally, we provide a searchable database of reported cell-based models of pathogenic AD gene variants.

The subventricular zone structure, function and implications for neurological disease

The subventricular zone (SVZ) is a region surrounding the lateral ventricles that contains neural stem cells and neural progenitor cells, which can proliferate and differentiate into various neural and glial cells. SVZ cells play important roles in neurological diseases like neurodegeneration, neural injury, and glioblastoma multiforme. Investigating the anatomy, structure, composition, physiology, disease associations, and related mechanisms of SVZ is significant for neural stem cell therapy and treatment/prevention of neurological disorders. However, challenges remain regarding the mechanisms regulating SVZ cell proliferation, differentiation, and migration, delivering cells to damaged areas, and immune responses. In-depth studies of SVZ functions and related therapeutic developments may provide new insights and approaches for treating brain injuries and degenerative diseases, as well as a scientific basis for neural stem cell therapy. This review summarizes research findings on SVZ and neurological diseases to provide references for relevant therapies.

Current Applications of Human Pluripotent Stem Cells in Neuroscience Research and Cell Transplantation Therapy for Neurological Disorders

Many neurological diseases involving tissue damage cannot be treated with drug-based approaches, and the inaccessibility of human brain samples further hampers the study of these diseases. Human pluripotent stem cells (PSCs), including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), provide an excellent model for studying neural development and function. PSCs can be differentiated into various neural cell types, providing a renewal source of functional human brain cells. Therefore, PSC-derived neural cells are increasingly used for multiple applications, including neurodevelopmental and neurotoxicological studies, neurological disease modeling, drug screening, and regenerative medicine. In addition, the neural cells generated from patient iPSCs can be used to study patient-specific disease signatures and progression. With the recent advances in genome editing technologies, it is possible to remove the disease-related mutations in the patient iPSCs to generate corrected iPSCs. The corrected iPSCs can differentiate into neural cells with normal physiological functions, which can be used for autologous transplantation. This review highlights the current progress in using PSCs to understand the fundamental principles of human neurodevelopment and dissect the molecular mechanisms of neurological diseases. This knowledge can be applied to develop better drugs and explore cell therapy options. We also discuss the basic requirements for developing cell transplantation therapies for neurological disorders and the current status of the ongoing clinical trials.

Selenium promotes neural development through the regulation of GPX4 and SEPP1 in an iPSC-derived neuronal model

Selenium (Se) is incorporated into selenoproteins in the form of selenocysteine, which has biological functions associated with neural development. Unfortunately, the specific roles and mechanisms of selenoproteins at different stages of neuronal development are still unclear. Therefore, in this study, we successfully established a neuronal model derived from induced pluripotent stem cells (iPSC-iNeuron) and used Se nanoparticles (SeNPs@LNT) with high bioavailability to intervene at different stages of neural development in iPSC-iNeuron model. Interestingly, our results showed that SeNPs@LNT could not only accelerate the proliferation of neural progenitor cells (NPCs) by upregulating glutathione peroxidase 4 (GPX4) during the NPC stage, but also can promote neuronal differentiation by increasing selenoprotein P (SEPP1) during the neuronal stage, resulting in efficient and rapid neural development. In addition, further mechanistic studies showed that SeNPs@LNT can regulate selenoproteins by activating the PI3K/Akt/Nrf2 signaling pathway, thereby affecting neuronal development. Notably, Further analysis of ASD patients in National Center for Biotechnology Information single-cell RNA-seq datasets also revealed significantly lower GPX4 expression within NRGN-expressing neurons in ASD patients, and GO enrichment analysis of genes in NRGN-expressing neurons from ASD patients showed that the downregulation of selenoproteins due to aberrant selenoprotein synthesis may be closely associated with decreased ATP synthesis resulting from abnormal mitochondrial and respiratory chain signaling pathways. Taken together, this study provides evidence that SeNPs@LNT exerts a beneficial effect on early neural development through the regulation of selenoproteins.

Tau aggregation induces cell death in iPSC-derived neurons

Abnormal accumulation of tau proteins in the brain is a hallmark of neurodegenerative diseases such as Alzheimer's disease and is closely linked with neuronal cell death. Tau accumulation is a prominent therapeutic target for Alzheimer's disease, since tau accumulation correlates well with the disease progression, and tau-targeting drugs hold potentials to halt the disease progression. Given the differential response of human and mouse neuronal cells, there is a critical need for a human cellular platform to quickly screen for tau-related neurodegenerative disease therapeutics. However, inducing rapid, tau-dependent neuronal cell death in human models remains challenging. In this study, we established a human cellular model capable of inducing tau aggregation-dependent neuronal cell death within two weeks via tau overexpression. Additionally, we demonstrated the neuroprotective efficacy of known tau-targeting compounds within this system. These findings suggest that our cellular model recapitulates the molecular pathogenesis of tau-induced neurodegeneration and could serve as a valuable platform for drug screening in tauopathies.

Induced Pluripotent Stem Cell-Derived Exosomes Promote Peripheral Nerve Regeneration in a Rat Sciatic Nerve Crush Injury Model: A Safety and Efficacy Study

Peripheral nerve injury (PNI) remains a significant clinical challenge, often leading to long-term functional impairment. Despite advances in therapies, current repair strategies offer unsatisfactory clinical outcomes. Exosomes derived from induced pluripotent stem cells (iPSC-Exos) have emerged as a promising therapeutic approach in regenerative medicine. This study assesses the efficacy and safety of iPSC-Exos in a rat model of sciatic nerve crush injury. Briefly, iPSCs were generated from peripheral blood mononuclear cells (PBMCs) of healthy donors using Sendai virus vectors and validated for pluripotency. iPSC-Exos were characterized and injected at the injury site. Functional recovery was assessed through gait analysis, grip strength, and pain response. Histological and molecular analyses were used to examine axonal regeneration, myelination, Schwann cell (SC) activation, angiogenesis, and changes in gene expression. iPSC-Exos were efficiently internalized by SC, promoting their proliferation. No adverse effects were observed between groups on body weight, organ histology, or hematological parameters. iPSC-Exos injection significantly enhanced nerve regeneration, muscle preservation, and vascularization, with RNA sequencing revealing activation of PI3K-AKT and focal adhesion pathways. These findings support iPSC-Exos as a safe and effective non-cell-based therapy for PNIs, highlighting their potential for clinical applications in regenerative medicine.

Isogenic induced pluripotent stem cell line ICGi036-A-1 from a patient with familial hypercholesterolaemia, derived by correcting a pathogenic variant of the gene LDLR c.530C>T

Familial hypercholesterolaemia is a common monogenic disorder characterized by high plasma cholesterol levels leading to chronic cardiovascular disease with high risk and often early manifestation due to atherosclerotic lesions of the blood vessels. The atherosclerotic lesions in familial hypercholesterolaemia are mainly caused by pathogenic variants of the low-density lipoprotein receptor (LDLR) gene, which plays an important role in cholesterol metabolism. Normally, cholesterol-laden low-density lipoproteins bind to the LDLR receptor on the surface of liver cells to be removed from the bloodstream by internalisation with hepatocytes. In familial hypercholesterolaemia, the function of the receptor is impaired and the uptake of low-density lipoproteins is significantly reduced. As a result, cholesterol accumulates in the subendothelial space on the inner wall of blood vessels, triggering atherogenesis, the formation of atherosclerotic plaques. At present, there are no effective and universal approaches to the diagnosis and treatment of familial hypercholesterolaemia. A relevant approach to study the molecular genetic mechanisms of the disease and to obtain systems for screening chemical compounds as potential drugs is the generation of cellular models based on patient-specific induced pluripotent stem cells. The aim of our work was to derive an isogenic genetically modified induced pluripotent stem cell line by correcting the pathogenic allelic variant c.530C of the LDLR gene in the original iPSC previously obtained from a compound heterozygote patient with familial hypercholesterolaemia. The resulting isogenic iPSC line differs from the original by only one corrected nucleotide substitution, allowing us to study the direct effect of this pathogenic genetic variant on physiological changes in relevant differentiated cells. CRISPR/Cas-mediated base editing was used to correct the single nucleotide substitution. The resulting genetically modified iPSC line has pluripotency traits, a normal karyotype, a set of short tandem repeats identical to that in the original line and can be used to obtain differentiated derivatives necessary for the elaboration of relevant cell models.

The roles of intrinsically disordered proteins in neurodegeneration

Neurodegenerative diseases such as Amyotrophic Lateral Sclerosis, Alzheimer's disease, Parkinson's disease, and Huntington's disease share a common pathological hallmark: the accumulation of misfolded proteins, particularly involving intrinsically disordered proteins (IDPs) like TDP-43, FUS, Tau, α-synuclein, and Huntingtin. These proteins undergo pathological aggregation, forming toxic inclusions that disrupt cellular function. The dysregulation of proteostasis mechanisms, including the ubiquitin-proteasome system (UPS), ubiquitin-independent proteasome system (UIPS), autophagy, and molecular chaperones, exacerbates these proteinopathies by failing to clear misfolded proteins effectively. Emerging therapeutic strategies aim to restore proteostasis through proteasome activators, autophagy enhancers, and chaperone-based interventions to prevent the toxic accumulation of IDPs. Additionally, understanding liquid-liquid phase separation (LLPS) and its role in stress granule dynamics offers novel insights into how aberrant phase transitions contribute to neurodegeneration. By targeting the molecular pathways involved in IDP aggregation and proteostasis regulation, and better understanding the specificity of each component, research in this area will pave the way for innovative therapeutic approaches to combat these neurodegenerative diseases. This review discusses the molecular mechanisms underpinning IDP pathology, highlights recent advancements in drug discovery, and explores the potential of targeting proteostasis machinery to develop effective therapies.

Pluripotent Stem Cells: Recent Advances and Emerging Trends

The field of induced pluripotent stem cells (iPSCs) continues to evolve, offering unprecedented potential for regenerative medicine, disease modeling, and therapeutic applications [...].

Inducible pluripotent stem cell models to study bone marrow failure and MDS predisposition syndromes

Induced pluripotent stem cells (iPSCs) have emerged as powerful tools for in vitro modeling of bone marrow failure (BMF) syndromes and hereditary conditions predisposing to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). This review synthesizes recent advances in iPSC-based disease modeling for various inherited BMF/MDS disorders, including Fanconi anemia, dyskeratosis congenita, Diamond Blackfan anemia syndrome, Shwachman-Diamond syndrome, and severe congenital neutropenia as well as GATA2, RUNX1, ETV6, ANKRD26, SAMD9, SAMD9L, and ADH5/ALDH2 syndromes. Although the majority of these iPSC lines are derived from patient cells, some are generated by introducing patient-specific mutations into healthy iPSC backgrounds, offering complementary approaches to disease modeling. The review highlights the ability of iPSCs to recapitulate key disease phenotypes, such as impaired hematopoietic differentiation, telomere dysfunction, and defects in DNA repair or ribosome biogenesis. We discuss how these models have enhanced our understanding of disease pathomechanisms, hematopoietic defects, and potential therapeutic approaches. Challenges in generating and maintaining disease-specific iPSCs are examined, particularly for disorders involving DNA repair. We emphasize the necessity of creating isogenic controls to elucidate genotype-phenotype relationships. Furthermore, we address limitations of current iPSC models, including genetic variability among iPSC clones derived from the same patient, and difficulties in achieving robust engraftment of iPSC-derived hematopoietic progenitor cells in mouse transplantation models. The review also explores future directions, including the potential of iPSC models for drug discovery and personalized medicine approaches. This review underscores the significance of iPSC technology in advancing our understanding of inherited hematopoietic disorders and its potential to inform novel therapeutic strategies.

Advanced nano delivery system for stem cell therapy for Alzheimer's disease

Alzheimer's Disease (AD) represents one of the most significant neurodegenerative challenges of our time, with its increasing prevalence and the lack of curative treatments underscoring an urgent need for innovative therapeutic strategies. Stem cells (SCs) therapy emerges as a promising frontier, offering potential mechanisms for neuroregeneration, neuroprotection, and disease modification in AD. This article provides a comprehensive overview of the current landscape and future directions of stem cell therapy in AD treatment, addressing key aspects such as stem cell migration, differentiation, paracrine effects, and mitochondrial translocation. Despite the promising therapeutic mechanisms of SCs, translating these findings into clinical applications faces substantial hurdles, including production scalability, quality control, ethical concerns, immunogenicity, and regulatory challenges. Furthermore, we delve into emerging trends in stem cell modification and application, highlighting the roles of genetic engineering, biomaterials, and advanced delivery systems. Potential solutions to overcome translational barriers are discussed, emphasizing the importance of interdisciplinary collaboration, regulatory harmonization, and adaptive clinical trial designs. The article concludes with reflections on the future of stem cell therapy in AD, balancing optimism with a pragmatic recognition of the challenges ahead. As we navigate these complexities, the ultimate goal remains to translate stem cell research into safe, effective, and accessible treatments for AD, heralding a new era in the fight against this devastating disease.

Long-Term Engraftment of Cryopreserved Human Neurons for In Vivo Disease Modeling in Neurodegenerative Disease

The transplantation of human neurons into the central nervous system (CNS) offers transformative opportunities for modeling neurodegenerative diseases in vivo. This study evaluated the survival, integration, and functional properties of cryopreserved forebrain GABAergic neurons (iGABAs) derived from human induced pluripotent stem cells (iPSCs) across three species used in translational research. iGABAs were stereotactically injected into the striatum of Sprague-Dawley rats, immunodeficient RNU rats, R6/2 Huntington's disease (HD) mice, wild-type controls, and Cynomolgus monkeys. Post-transplantation, long-term assessments revealed robust neuronal survival, extensive neurite outgrowth, and integration with host CNS environments. In immunodeficient rats, iGABAs innervated the neuraxis, extending from the prefrontal cortex to the midbrain, while maintaining mature neuronal phenotypes without uncontrolled proliferation. Similarly, grafts in nonhuman primates showed localized survival and stable phenotype at one month. In the neurodegenerative milieu of HD mice, iGABAs survived up to six months, projecting into the host striatum and white matter, with evidence of mutant huntingtin aggregates localized within the graft, indicating pathological protein transfer. These findings underscore the utility of cryopreserved iGABAs as a reproducible, scalable model for disease-specific CNS investigations and mechanistic studies of proteinopathic propagation. This work establishes a critical platform for studying neurodegenerative diseases and developing therapeutic interventions.

iPSC-based cell replacement therapy: from basic research to clinical application

The advancement of induced pluripotent stem cell (iPSC) technology has revolutionized regenerative medicine, enabling breakthroughs in disease modeling, drug discovery, and cell replacement therapies. This review examines the progression of iPSC-based regenerative medicine, focusing on cell replacement therapy and mechanisms like the Replacement Effect, which is crucial for long-term tissue regeneration. Using Parkinson's disease as a key example, it discusses the induction of midbrain dopaminergic neurons from iPSCs and the importance of precise signaling for safety and efficacy. By demonstrating the integration and safety of these cells, animal studies have paved the way for clinical trials. This review highlights the need for strategic collaboration among stakeholders-regulatory authorities, research and medical staff, and industry-to ensure successful clinical applications. iPSC technology's ongoing evolution holds significant promise for broader therapeutic applications and improved patient outcomes.

Human Induced Pluripotent Stem Cells: Directed Differentiation Methods and Applications in Brain Diseases

Human induced pluripotent stem cells (hiPSCs), similar to embryonic stem cells, are a class of pluripotent stem cells with the potential to differentiate into various kinds of cells. Because the application of hiPSCs obtained by reprogramming patients' somatic cells in the treatment of brain diseases bypasses the ethical constraints on the use of embryonic stem cells and mitigates immune rejection, hiPSCs have profound clinical application prospects. In this review, we first summarized the differentiation methods of hiPSCs into different kinds of neurons, and secondly discussed the application of hiPSCs in several brain disease models, so as to provide a reference for the future application of hiPSCs in the studies and treatment of brain diseases.

Swift induction of human spinal lower motor neurons and robust ALS cell screening via single-cell imaging

This study introduces a novel method for rapidly and efficiently inducing human spinal lower motor neurons (LMNs) from induced pluripotent stem cells (iPSCs) to eventually elucidate the pathomechanisms of amyotrophic lateral sclerosis (ALS) and facilitate drug screening. Previous methods were limited by low induction efficiency, poor LMN purity, or labor-intensive induction and evaluation processes. Our protocol overcomes these challenges, achieving around 80% induction efficiency within just two weeks by combining a small molecule-based approach with transcription factor transduction. Moreover, to exclude non-LMN cells from the analysis, we utilized time-lapse microscopy and machine learning to analyze the morphology and viability of iPSC-derived LMNs on a single-cell basis, establishing an effective pathophysiological evaluation system. This rapid, efficient, and streamlined protocol, along with our single-cell-based evaluation method, enables large-scale analysis and drug screening using iPSC-derived motor neurons.

Neuroligin-3 R451C induces gain-of-function gene expression in astroglia in an astroglia-enriched brain organoid model

Astroglia are integral to brain development and the emergence of neurodevelopmental disorders. However, studying the pathophysiology of human astroglia using brain organoid models has been hindered by inefficient astrogliogenesis. In this study, we introduce a robust method for generating astroglia-enriched organoids through BMP4 treatment during the neural differentiation phase of organoid development. Our RNA sequencing analysis reveals that astroglia developed within these organoids exhibit advanced developmental characteristics and enhanced synaptic functions compared to those grown under traditional two-dimensional conditions, particularly highlighted by increased neurexin (NRXN)-neuroligin (NLGN) signaling. Cell adhesion molecules, such as NRXN and NLGN, are essential in regulating interactions between astroglia and neurons. We further discovered that brain organoids derived from human embryonic stem cells (hESCs) harboring the autism-associated NLGN3 R451C mutation exhibit increased astrogliogenesis. Notably, the NLGN3 R451C astroglia demonstrate enhanced branching, indicating a more intricate morphology. Interestingly, our RNA sequencing data suggest that these mutant astroglia significantly upregulate pathways that support neural functions when compared to isogenic wild-type astroglia. Our findings establish a novel astroglia-enriched organoid model, offering a valuable platform for probing the roles of human astroglia in brain development and related disorders.

Advances in physiological and clinical relevance of hiPSC-derived brain models for precision medicine pipelines

Precision, or personalized, medicine aims to stratify patients based on variable pathogenic signatures to optimize the effectiveness of disease prevention and treatment. This approach is favorable in the context of brain disorders, which are often heterogeneous in their pathophysiological features, patterns of disease progression and treatment response, resulting in limited therapeutic standard-of-care. Here we highlight the transformative role that human induced pluripotent stem cell (hiPSC)-derived neural models are poised to play in advancing precision medicine for brain disorders, particularly emerging innovations that improve the relevance of hiPSC models to human physiology. hiPSCs derived from accessible patient somatic cells can produce various neural cell types and tissues; current efforts to increase the complexity of these models, incorporating region-specific neural tissues and non-neural cell types of the brain microenvironment, are providing increasingly relevant insights into human-specific neurobiology. Continued advances in tissue engineering combined with innovations in genomics, high-throughput screening and imaging strengthen the physiological relevance of hiPSC models and thus their ability to uncover disease mechanisms, therapeutic vulnerabilities, and tissue and fluid-based biomarkers that will have real impact on neurological disease treatment. True physiological understanding, however, necessitates integration of hiPSC-neural models with patient biophysical data, including quantitative neuroimaging representations. We discuss recent innovations in cellular neuroscience that can provide these direct connections through generative AI modeling. Our focus is to highlight the great potential of synergy between these emerging innovations to pave the way for personalized medicine becoming a viable option for patients suffering from neuropathologies, particularly rare epileptic and neurodegenerative disorders.

Are oligodendrocytes bystanders or drivers of Parkinson's disease pathology?

The major pathological feature of Parkinson 's disease (PD), the second most common neurodegenerative disease and most common movement disorder, is the predominant degeneration of dopaminergic neurons in the substantia nigra, a part of the midbrain. Despite decades of research, the molecular mechanisms of the origin of the disease remain unknown. While the disease was initially viewed as a purely neuronal disorder, results from single-cell transcriptomics have suggested that oligodendrocytes may play an important role in the early stages of Parkinson's. Although these findings are of high relevance, particularly to the search for effective disease-modifying therapies, the actual functional role of oligodendrocytes in Parkinson's disease remains highly speculative and requires a concerted scientific effort to be better understood. This Unsolved Mystery discusses the limited understanding of oligodendrocytes in PD, highlighting unresolved questions regarding functional changes in oligodendroglia, the role of myelin in nigral dopaminergic neurons, the impact of the toxic environment, and the aggregation of alpha-synuclein within oligodendrocytes.

A longevity-specific bank of induced pluripotent stem cells from centenarians and their offspring

Centenarians provide a unique lens through which to study longevity, healthy aging, and resiliency. Moreover, models of human aging and resilience to disease that allow for the testing of potential interventions are virtually non-existent. We obtained and characterized over 96 centenarian and offspring peripheral blood samples including those connected to functional independence data highlighting resistance to disability and cognitive impairment. Targeted methylation arrays were used in molecular aging clocks to compare and contrast differences between biological and chronological age in these specialized subjects. Isolated peripheral blood mononuclear cells (PBMCs) from 20 of these subjects were then successfully reprogrammed into high-quality induced pluripotent stem cell (iPSC) lines which were functionally characterized for pluripotency, genomic stability, and the ability to undergo directed differentiation. The result of this work is a one-of-a-kind resource for studies of human longevity and resilience that can fuel the discovery and validation of novel therapeutics for aging-related disease.

Siglecs-mediated immune regulation in neurological disorders

The surfaces of various immune cells are rich in glycan chains, including the sialic-acid-binding immunoglobulin-like lectins (Siglecs) family. As an emerging glyco-immune checkpoint, Siglecs have the ability to bind and interact with various glycoproteins, thereby eliciting a series of downstream reactions to modulate the immune response. The impact of Siglecs has been extensively studied in tumor immunotherapy. However, research in neurological disorders and neurological diseases is very limited, and therapeutic options involving Siglecs need further exploration. Siglecs play a crucial role in the development, homeostasis, and repair processes of the nervous system, especially in degenerative diseases. This review summarizes studies on the immunomodulatory role mediated by Siglecs expressed on different immune cells in various neurological disorders, elucidates how dysregulated sialic acid contributes to several psychiatric disorders, and discusses the progress and limitations of research on the treatment of neurological disorders.

n-Butylidenephthalide recovered calcium homeostasis to ameliorate neurodegeneration of motor neurons derived from amyotrophic lateral sclerosis iPSCs

Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease that causes muscle atrophy and primarily targets motor neurons (MNs). Approximately 20% of familial ALS cases are caused by gain-of-function mutations in superoxide dismutase 1 (SOD1), leading to MN degeneration and ion channel dysfunction. Previous studies have shown that n-Butylidenephthalide (BP) delays disease progression and prolongs survival in animal models of ALS. However, no studies have been conducted on models from human sources. Herein, we examined the protective efficacy of BP on MNs derived from induced pluripotent stem cells (iPSCs) of an ALS patient harboring the SOD1G85R mutation as well as on those derived from genetically corrected iPSCs (SOD1G85G). Our results demonstrated that the motor neurons differentiated from iPSC with SOD1G85R mutation exhibited characteristics of neuron degeneration (as indicated by the reduction of neurofilament expression) and ion channel dysfunction (in response to potassium chloride (KCl) and L-glutamate stimulation), in contrast to those derived from the gene corrected iPSC (SOD1G85G). Meanwhile, BP treatment effectively restored calcium ion channel function by reducing the expression of glutamate receptors including glutamate ionotropic receptor AMPA type subunit 3 (GluR3) and glutamate ionotropic receptor NMDA type subunit 1 (NMDAR1). Additionally, BP treatment activated autophagic pathway to attenuate neuron degeneration. Overall, this study supports the therapeutic effects of BP on ALS patient-derived neuron cells, and suggests that BP may be a promising candidate for future drug development.

Targeting Protein Aggregation in ALS

Proteinopathies involve the abnormal accumulation of specific proteins. Maintaining the balance of the proteome is a finely regulated process managed by a complex network of cellular machinery responsible for protein synthesis, folding, and degradation. However, stress and ageing can disrupt this balance, leading to widespread protein aggregation. Currently, several therapies targeting protein aggregation are in clinical trials for ALS. These approaches mainly focus on two strategies: addressing proteins that are prone to aggregation due to mutations and targeting the cellular mechanisms that maintain protein homeostasis to prevent aggregation. This review will cover these emerging drugs. Advances in ALS research not only offer hope for better outcomes for ALS patients but also provide valuable insights and methodologies that can benefit the broader field of neurodegenerative disease drug discovery.

Reporter Alleles in hiPSCs: Visual Cues on Development and Disease

Reporter alleles are essential for advancing research with human induced pluripotent stem cells (hiPSCs), notably in developmental biology and disease modeling. This study investigates the state-of-the-art gene-editing techniques tailored for generating reporter alleles in hiPSCs, emphasizing their effectiveness in investigating cellular dynamics and disease mechanisms. Various methodologies, including the application of CRISPR/Cas9 technology, are discussed for accurately integrating reporter genes into the specific genomic loci. The synthesis of findings from the studies utilizing these reporter alleles reveals insights into developmental processes, genetic disorder modeling, and therapeutic screening, consolidating the existing knowledge. These hiPSC-derived models demonstrate remarkable versatility in replicating human diseases and evaluating drug efficacy, thereby accelerating translational research. Furthermore, this review addresses challenges and future directions in refining the reporter allele design and application to bolster their reliability and relevance in biomedical research. Overall, this investigation offers a comprehensive perspective on the methodologies, applications, and implications of reporter alleles in hiPSC-based studies, underscoring their essential role in advancing both fundamental scientific understanding and clinical practice.

Role of NF-κB signaling pathway in H2O2-induced oxidative stress of hiPSCs

The balance between oxidation and antioxidation is crucial for the development of embryo. It is harmful to the early embryonic development if embryonic stem cells (ESCs) encounter the serious oxidative stress in vivo. Induced pluripotent stem cells (iPSCs) are very similar to ESCs and are the important cell source to replace ESCs for research and therapy. Studies show that iPSCs have better resistant ability to oxidative stress, but the involved mechanism remains unclear. In this study, we predicted that the NF-κB pathway might be involved in H2O2-induced developmental damage by network toxicology analysis. Then, the oxidative stress model was established with different concentrations of H2O2 to investigate the mechanism of NF-κB pathway in oxidative stress of human induced pluripotent stem cells (hiPSCs). The results showed as follows: With the increase of H2O2 concentration, the ROS level gradually went up leading to an increasing damage degree of hiPSCs; however, the MDA content was obviously high only in the 400 μM H2O2 group; the activities of some antioxidant indexes such as SOD2 and T-AOC were significantly upregulated in the 100 μM group, while most of antioxidant indexes showed downregulated tendency to different degrees with the increase of H2O2 concentration. The expression levels of P65, P50, IκB, SOD2, and FHC mRNA were upregulated in most H2O2-treated groups, showing a dose-dependent relationship. In subsequent experiments, the inhibitor of IκB-α phosphorylation, Bay11-7082, reversed the upregulation of P65, IκB, and FHC mRNA expression induced by 400 μM H2O2. The protein levels of P65, p-P65, P50, p-P50, IκB, p-IκB, SOD2, and FHC were upregulated in most H2O2-treated groups. However, the upregulation induced by 400 μM H2O2 could be reversed by BAY 11-7082, except for IκB and SOD2. In conclusion, H2O2 could promote the expressions and phosphorylations of NF-κB that could upregulate the expressions of its downstream antioxidant genes to minimize the damage of hiPSCs caused by oxidative stress. These results contribute to a fundamental understanding of the antioxidant mechanism of iPSCs and will further facilitate the application of iPSCs, as well as provide a reference for controlling the oxidative stress encountered in the early development stage of embryo.

Clinical, mechanistic, biomarker, and therapeutic advances in GBA1-associated Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease. The development of PD is closely linked to genetic and environmental factors, with GBA1 variants being the most common genetic risk. Mutations in the GBA1 gene lead to reduced activity of the coded enzyme, glucocerebrosidase, which mediates the development of PD by affecting lipid metabolism (especially sphingolipids), lysosomal autophagy, endoplasmic reticulum, as well as mitochondrial and other cellular functions. Clinically, PD with GBA1 mutations (GBA1-PD) is characterized by particular features regarding the progression of symptom severity. On the therapeutic side, the discovery of the relationship between GBA1 variants and PD offers an opportunity for targeted therapeutic interventions. In this review, we explore the genotypic and phenotypic correlations, etiologic mechanisms, biomarkers, and therapeutic approaches of GBA1-PD and summarize the current state of research and its challenges.

Emerging Human Pluripotent Stem Cell-Based Human-Animal Brain Chimeras for Advancing Disease Modeling and Cell Therapy for Neurological Disorders

Human pluripotent stem cell (hPSC) models provide unprecedented opportunities to study human neurological disorders by recapitulating human-specific disease mechanisms. In particular, hPSC-based human-animal brain chimeras enable the study of human cell pathophysiology in vivo. In chimeric brains, human neural and immune cells can maintain human-specific features, undergo maturation, and functionally integrate into host brains, allowing scientists to study how human cells impact neural circuits and animal behaviors. The emerging human-animal brain chimeras hold promise for modeling human brain cells and their interactions in health and disease, elucidating the disease mechanism from molecular and cellular to circuit and behavioral levels, and testing the efficacy of cell therapy interventions. Here, we discuss recent advances in the generation and applications of using human-animal chimeric brain models for the study of neurological disorders, including disease modeling and cell therapy.

Human-mouse chimeric brain models constructed from iPSC-derived brain cells: Applications and challenges

The establishment of reliable human brain models is pivotal for elucidating specific disease mechanisms and facilitating the discovery of novel therapeutic strategies for human brain disorders. Human induced pluripotent stem cell (iPSC) exhibit remarkable self-renewal capabilities and can differentiate into specialized cell types. This makes them a valuable cell source for xenogeneic or allogeneic transplantation. Human-mouse chimeric brain models constructed from iPSC-derived brain cells have emerged as valuable tools for modeling human brain diseases and exploring potential therapeutic strategies for brain disorders. Moreover, the integration and functionality of grafted stem cells has been effectively assessed using these models. Therefore, this review provides a comprehensive overview of recent progress in differentiating human iPSC into various highly specialized types of brain cells. This review evaluates the characteristics and functions of the human-mouse chimeric brain model. We highlight its potential roles in brain function and its ability to reconstruct neural circuitry in vivo. Additionally, we elucidate factors that influence the integration and differentiation of human iPSC-derived brain cells in vivo. This review further sought to provide suitable research models for cell transplantation therapy. These research models provide new insights into neuropsychiatric disorders, infectious diseases, and brain injuries, thereby advancing related clinical and academic research.

A comprehensive review of electrophysiological techniques in amyotrophic lateral sclerosis research

Amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, is characterized by progressive motor neuron degeneration, leading to widespread weakness and respiratory failure. While a variety of mechanisms have been proposed as causes of this disease, a full understanding remains elusive. Electrophysiological alterations, including increased motor axon excitability, likely play an important role in disease progression. There remains a critical need for non-animal disease models that can integrate electrophysiological tools to better understand underlying mechanisms, track disease progression, and evaluate potential therapeutic interventions. This review explores the integration of electrophysiological technologies with ALS disease models. It covers cellular and clinical electrophysiological tools and their applications in ALS research. Additionally, we examine conventional animal models and highlight advancements in humanized models and 3D organoid technologies. By bridging the gap between these models, we aim to enhance our understanding of ALS pathogenesis and facilitate the development of new therapeutic strategies.

Establishment of a novel amyotrophic lateral sclerosis patient (TARDBP N345K/+)-derived brain microvascular endothelial cell model reveals defective Wnt/β-catenin signaling: investigating diffusion barrier dysfunction and immune cell interaction

Amyotrophic lateral sclerosis (ALS) is a major neurodegenerative disease for which there is currently no curative treatment. The blood-brain barrier (BBB), multiple physiological functions formed by mainly specialized brain microvascular endothelial cells (BMECs), serves as a gatekeeper to protect the central nervous system (CNS) from harmful molecules in the blood and aberrant immune cell infiltration. The accumulation of evidence indicating that alterations in the peripheral milieu can contribute to neurodegeneration within the CNS suggests that the BBB may be a previously overlooked factor in the pathogenesis of ALS. Animal models suggest BBB breakdown may precede neurodegeneration and link BBB alteration to the disease progression or even onset. However, the lack of a useful patient-derived model hampers understanding the pathomechanisms of BBB dysfunction and the development of BBB-targeted therapies. In this study, we differentiated BMEC-like cells from human induced pluripotent stem cells (hiPSCs) derived from ALS patients to investigate BMEC functions in ALS patients. TARDBP N345K/+ carrying patient-derived BMEC-like cells exhibited increased permeability to small molecules due to loss of tight junction in the absence of neurodegeneration or neuroinflammation, highlighting that BMEC abnormalities in ALS are not merely secondary consequences of disease progression. Furthermore, they exhibited increased expression of cell surface adhesion molecules like ICAM-1 and VCAM-1, leading to enhanced immune cell adhesion. BMEC-like cells derived from hiPSCs with other types of TARDBP gene mutations (TARDBP K263E/K263E and TARDBP G295S/G295S) introduced by genome editing technology did not show such BMEC dysfunction compared to the isogenic control. Interestingly, transactive response DNA-binding protein 43 (TDP-43) was mislocalized to cytoplasm in TARDBP N345K/+ carrying model. Wnt/β-catenin signaling was downregulated in the ALS patient (TARDBP N345K/+)-derived BMEC-like cells and its activation rescued the leaky barrier phenotype and settled down VCAM-1 expressions. These results indicate that TARDBP N345K/+ carrying model recapitulated BMEC abnormalities reported in brain samples of ALS patients. This novel patient-derived BMEC-like cell is useful for the further analysis of the involvement of vascular barrier dysfunctions in the pathogenesis of ALS and for promoting therapeutic drug discovery targeting BMEC.

Zika virus vertical transmission induces neuroinflammation and synapse impairment in brain cells derived from children born with Congenital Zika Syndrome

Zika virus (ZIKV) infection was first reported in 2015 in Brazil as causing microcephaly and other developmental abnormalities in newborns, leading to the identification of Congenital Zika Syndrome (CZS). Viral infections have been considered an environmental risk factor for neurodevelopmental disorders outcome, such as Autism Spectrum Disorder (ASD). Moreover, not only the infection per se, but maternal immune system activation during pregnancy, has been linked to fetal neurodevelopmental disorders. To understand the impact of ZIKV vertical infection on brain development, we derived induced pluripotent stem cells (iPSC) from Brazilian children born with CZS, some of the patients also being diagnosed with ASD. Comparing iPSC-derived neurons from CZS with a control group, we found lower levels of pre- and postsynaptic proteins and reduced functional synapses by puncta co-localization. Furthermore, neurons and astrocytes derived from the CZS group showed decreased glutamate levels. Additionally, the CZS group exhibited elevated levels of cytokine production, one of which being IL-6, already associated with the ASD phenotype. These preliminary findings suggest that ZIKV vertical infection may cause long-lasting disruptions in brain development during fetal stages, even in the absence of the virus after birth. These disruptions could contribute to neurodevelopmental disorders manifestations such as ASD. Our study contributes with novel knowledge of the CZS outcomes and paves the way for clinical validation and the development of potential interventions to mitigate the impact of ZIKV vertical infection on neurodevelopment.

The application potential of iMSCs and iMSC-EVs in diseases

The immune system, functioning as the body's "defense army", plays a role in surveillance, defense. Any disruptions in immune system can lead to the development of immune-related diseases. Extensive researches have demonstrated the crucial immunoregulatory role of mesenchymal stem cells (MSCs) in these diseases. Of particular interest is the ability to induce somatic cells under specific conditions, generating a new cell type with stem cell characteristics known as induced pluripotent stem cell (iPSC). The differentiation of iPSCs into MSCs, specifically induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), hold promise as a potential solution to the challenges of MSCs, potentially serving as an alternative to traditional drug therapies. Moreover, the products of iMSCs, termed induced pluripotent stem cell-derived mesenchymal stem cell-derived extracellular vesicles (iMSC-EVs), may exhibit functions similar to iMSCs. With the biological advantages of EVs, they have become the focus of "cell-free therapy". Here, we provided a comprehensive summary of the biological impact of iMSCs on immune cells, explored the applications of iMSCs and iMSC-EVs in diseases, and briefly discussed the fundamental characteristics of EVs. Finally, we overviewed the current advantages and challenges associated with iMSCs and iMSC-EVs. It is our hope that this review related to iMSCs and iMSC-EVs will contribute to the development of new approaches for the treatment of diseases.

Proteomic insights into extracellular vesicles in ALS for therapeutic potential of Ropinirole and biomarker discovery

BACKGROUND

Extracellular vesicles (EVs) hold the potential for elucidating the pathogenesis of amyotrophic lateral sclerosis (ALS) and serve as biomarkers. Notably, the comparative and longitudinal alterations in the protein profiles of EVs in serum (sEVs) and cerebrospinal fluid (CSF; cEVs) of sporadic ALS (SALS) patients remain uncharted. Ropinirole hydrochloride (ROPI; dopamine D2 receptor [D2R] agonist), a new anti-ALS drug candidate identified through induced pluripotent stem cell (iPSC)-based drug discovery, has been suggested to inhibit ALS disease progression in the Ropinirole Hydrochloride Remedy for Amyotrophic Lateral Sclerosis (ROPALS) trial, but its mechanism of action is not well understood. Therefore, we tried to reveal longitudinal changes with disease progression and the effects of ROPI on protein profiles of EVs.

METHODS

We collected serum and CSF at fixed intervals from ten controls and from 20 SALS patients participating in the ROPALS trial. Comprehensive proteomic analysis of EVs, extracted from these samples, was conducted using liquid chromatography/mass spectrometer (LC/MS). Furthermore, we generated iPSC-derived astrocytes (iPasts) and performed RNA sequencing on astrocytes with or without ROPI treatment.

RESULTS

The findings revealed notable disparities yet high congruity in sEVs and cEVs protein profiles concerning disease status, time and ROPI administration. In SALS, both sEVs and cEVs presented elevated levels of inflammation-related proteins but reduced levels associated with unfolded protein response (UPR). These results mirrored the longitudinal changes after disease onset and correlated with the revised ALS Functional Rating Scale (ALSFRS-R) at sampling time, suggesting a link to the onset and progression of SALS. ROPI appeared to counteract these changes, attenuating inflammation-related protein levels and boosting those tied to UPR in SALS, proposing an anti-ALS impact on EV protein profiles. Reverse translational research using iPasts indicated that these changes may partly reflect the DRD2-dependent neuroinflammatory inhibitory effects of ROPI. We have also identified biomarkers that predict diagnosis and disease progression by machine learning-driven biomarker search.

CONCLUSIONS

Despite the limited sample size, this study pioneers in reporting time-series proteomic alterations in serum and CSF EVs from SALS patients, offering comprehensive insights into SALS pathogenesis, ROPI-induced changes, and potential prognostic and diagnostic biomarkers.

Induced pluripotent stem cells derived renal tubular cells from a patient with pseudohypoparathyroidism and its response to parathyroid hormone stimulation

INTRODUCTION

Creating induced pluripotent stem cells (iPSCs) from somatic cells of patients with genetic diseases offers a pathway to generate disease-specific iPSCs carrying genetic markers. Differentiating these iPSCs into renal tubular cells can aid in understanding the pathophysiology of rare inherited renal tubular diseases through cellular experiments.

MATERIALS AND METHODS

Two Japanese patients with Pseudohypoparathyroidism (PHP), a 49-year-old woman and a 71-year-old man, were studied. iPSC-derived tubular cells were established from their peripheral blood mononuclear cells (PBMCs). We examined changes in intracellular and extracellular cyclic adenosine monophosphate (cAMP) levels in these cells in response to parathyroid hormone (PTH) stimulation.

RESULTS

Renal tubular cells, differentiated from iPSCs of a healthy control (648A1), showed a PTH-dependent increase in both intracellular and extracellular cAMP levels. However, the renal tubular cells derived from the PHP patients' iPSCs showed inconsistent changes in cAMP levels upon PTH exposure.

CONCLUSION

We successfully created disease-specific iPSCs from PHP patients' PBMCs, differentiated them into tubular cells, and replicated the distinctive response of the disease to PTH in vitro. This approach could enhance our understanding of the pathophysiology of inherited renal tubular diseases and contribute to developing effective treatments.

Co-transplantation of autologous treg cells: A groundbreaking cell therapy for brain diseases

Cell therapy and regenerative medicine have made remarkable progress in treating neurodegenerative disorders. Induced pluripotent stem cells (iPSCs) offer a promising source for cell replacement therapies, but their practical application faces challenges due to poor survival and integration after transplantation. Park et al. propose a novel therapeutic strategy involving the co-transplantation of regulatory T cells (Tregs) and iPSC-derived dopamine neurons. This combined approach enhances the survival of transplanted cells and protects against neuroinflammation-induced damage. In PD animal models, the co-transplantation approach significantly suppressed the host immune response, resulting in improved behavioral recovery. Additionally, Tregs demonstrate acute neuroprotection and contribute to delayed neuro-restoration in ischemic stroke. This combined approach of cell therapy with immunomodulation offers a promising avenue for advancing our understanding of neurological diseases and promoting the development of novel treatments.

Tackling neurodegeneration in vitro with omics: a path towards new targets and drugs

Drug discovery is a generally inefficient and capital-intensive process. For neurodegenerative diseases (NDDs), the development of novel therapeutics is particularly urgent considering the long list of late-stage drug candidate failures. Although our knowledge on the pathogenic mechanisms driving neurodegeneration is growing, additional efforts are required to achieve a better and ultimately complete understanding of the pathophysiological underpinnings of NDDs. Beyond the etiology of NDDs being heterogeneous and multifactorial, this process is further complicated by the fact that current experimental models only partially recapitulate the major phenotypes observed in humans. In such a scenario, multi-omic approaches have the potential to accelerate the identification of new or repurposed drugs against a multitude of the underlying mechanisms driving NDDs. One major advantage for the implementation of multi-omic approaches in the drug discovery process is that these overarching tools are able to disentangle disease states and model perturbations through the comprehensive characterization of distinct molecular layers (i.e., genome, transcriptome, proteome) up to a single-cell resolution. Because of recent advances increasing their affordability and scalability, the use of omics technologies to drive drug discovery is nascent, but rapidly expanding in the neuroscience field. Combined with increasingly advanced in vitro models, which particularly benefited from the introduction of human iPSCs, multi-omics are shaping a new paradigm in drug discovery for NDDs, from disease characterization to therapeutics prediction and experimental screening. In this review, we discuss examples, main advantages and open challenges in the use of multi-omic approaches for the in vitro discovery of targets and therapies against NDDs.

Generation of iPSCs from a Patient with the M694V Mutation in the MEFV Gene Associated with Familial Mediterranean Fever and Their Differentiation into Macrophages

Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder caused by inherited mutations in the MEFV (Mediterranean FeVer) gene, located on chromosome 16 (16p13.3) and encoding the pyrin protein. Despite the existing data on MEFV mutations, the exact mechanism of their effect on the development of the pathological processes leading to the spontaneous and recurrent autoinflammatory attacks observed in FMF, remains unclear. Induced pluripotent stem cells (iPSCs) are considered an important tool to study the molecular genetic mechanisms of various diseases due to their ability to differentiate into any cell type, including macrophages, which contribute to the development of FMF. In this study, we developed iPSCs from an Armenian patient with FMF carrying the M694V, p.(Met694Val) (c.2080A>G, rs61752717) pathogenic mutation in exon 10 of the MEFV gene. As a result of direct differentiation, macrophages expressing CD14 and CD45 surface markers were obtained. We found that the morphology of macrophages derived from iPSCs of a patient with the MEFV mutation significantly differed from that of macrophages derived from iPSCs of a healthy donor carrying the wild-type MEFV gene.

Aberrant CHCHD2-associated mitochondriopathy in Kii ALS/PDC astrocytes

Amyotrophic Lateral Sclerosis/Parkinsonism-Dementia Complex (ALS/PDC), a rare and complex neurological disorder, is predominantly observed in the Western Pacific islands, including regions of Japan, Guam, and Papua. This enigmatic condition continues to capture medical attention due to affected patients displaying symptoms that parallel those seen in either classical amyotrophic lateral sclerosis (ALS) or Parkinson's disease (PD). Distinctly, postmortem examinations of the brains of affected individuals have shown the presence of α-synuclein aggregates and TDP-43, which are hallmarks of PD and classical ALS, respectively. These observations are further complicated by the detection of phosphorylated tau, accentuating the multifaceted proteinopathic nature of ALS/PDC. The etiological foundations of this disease remain undetermined, and genetic investigations have yet to provide conclusive answers. However, emerging evidence has implicated the contribution of astrocytes, pivotal cells for maintaining brain health, to neurodegenerative onset, and likely to play a significant role in the pathogenesis of ALS/PDC. Leveraging advanced induced pluripotent stem cell technology, our team cultivated multiple astrocyte lines to further investigate the Japanese variant of ALS/PDC (Kii ALS/PDC). CHCHD2 emerged as a significantly dysregulated gene when disease astrocytes were compared to healthy controls. Our analyses also revealed imbalances in the activation of specific pathways: those associated with astrocytic cilium dysfunction, known to be involved in neurodegeneration, and those related to major neurological disorders, including classical ALS and PD. Further in-depth examinations revealed abnormalities in the mitochondrial morphology and metabolic processes of the affected astrocytes. A particularly striking observation was the reduced expression of CHCHD2 in the spinal cord, motor cortex, and oculomotor nuclei of patients with Kii ALS/PDC. In summary, our findings suggest a potential reduction in the support Kii ALS/PDC astrocytes provide to neurons, emphasizing the need to explore the role of CHCHD2 in maintaining mitochondrial health and its implications for the disease.

Chimeric Cell Therapies as a Novel Approach for Duchenne Muscular Dystrophy (DMD) and Muscle Regeneration

Chimerism-based strategies represent a pioneering concept which has led to groundbreaking advancements in regenerative medicine and transplantation. This new approach offers therapeutic potential for the treatment of various diseases, including inherited disorders. The ongoing studies on chimeric cells prompted the development of Dystrophin-Expressing Chimeric (DEC) cells which were introduced as a potential therapy for Duchenne Muscular Dystrophy (DMD). DMD is a genetic condition that leads to premature death in adolescent boys and remains incurable with current methods. DEC therapy, created via the fusion of human myoblasts derived from normal and DMD-affected donors, has proven to be safe and efficacious when tested in experimental models of DMD after systemic-intraosseous administration. These studies confirmed increased dystrophin expression, which correlated with functional and morphological improvements in DMD-affected muscles, including cardiac, respiratory, and skeletal muscles. Furthermore, the application of DEC therapy in a clinical study confirmed its long-term safety and efficacy in DMD patients. This review summarizes the development of chimeric cell technology tested in preclinical models and clinical studies, highlighting the potential of DEC therapy in muscle regeneration and repair, and introduces chimeric cell-based therapies as a promising, novel approach for muscle regeneration and the treatment of DMD and other neuromuscular disorders.

Construction of functional neural network tissue combining CBD-NT3-modified linear-ordered collagen scaffold and TrkC-modified iPSC-derived neural stem cells for spinal cord injury repair

Induced pluripotent stem cells (iPSCs) can be personalized and differentiated into neural stem cells (NSCs), thereby effectively providing a source of transplanted cells for spinal cord injury (SCI). To further improve the repair efficiency of SCI, we designed a functional neural network tissue based on TrkC-modified iPSC-derived NSCs and a CBD-NT3-modified linear-ordered collagen scaffold (LOCS). We confirmed that transplantation of this tissue regenerated neurons and synapses, improved the microenvironment of the injured area, enhanced remodeling of the extracellular matrix, and promoted functional recovery of the hind limbs in a rat SCI model with complete transection. RNA sequencing and metabolomic analyses also confirmed the repair effect of this tissue from multiple perspectives and revealed its potential mechanism for treating SCI. Together, we constructed a functional neural network tissue using human iPSCs-derived NSCs as seed cells based on the interaction of receptors and ligands for the first time. This tissue can effectively improve the therapeutic effect of SCI, thus confirming the feasibility of human iPSCs-derived NSCs and LOCS for SCI repair and providing a valuable direction for SCI research.

Induced pluripotent stem cells (iPSCs): molecular mechanisms of induction and applications

The induced pluripotent stem cell (iPSC) technology has transformed in vitro research and holds great promise to advance regenerative medicine. iPSCs have the capacity for an almost unlimited expansion, are amenable to genetic engineering, and can be differentiated into most somatic cell types. iPSCs have been widely applied to model human development and diseases, perform drug screening, and develop cell therapies. In this review, we outline key developments in the iPSC field and highlight the immense versatility of the iPSC technology for in vitro modeling and therapeutic applications. We begin by discussing the pivotal discoveries that revealed the potential of a somatic cell nucleus for reprogramming and led to successful generation of iPSCs. We consider the molecular mechanisms and dynamics of somatic cell reprogramming as well as the numerous methods available to induce pluripotency. Subsequently, we discuss various iPSC-based cellular models, from mono-cultures of a single cell type to complex three-dimensional organoids, and how these models can be applied to elucidate the mechanisms of human development and diseases. We use examples of neurological disorders, coronavirus disease 2019 (COVID-19), and cancer to highlight the diversity of disease-specific phenotypes that can be modeled using iPSC-derived cells. We also consider how iPSC-derived cellular models can be used in high-throughput drug screening and drug toxicity studies. Finally, we discuss the process of developing autologous and allogeneic iPSC-based cell therapies and their potential to alleviate human diseases.

Induced Pluripotent Stem Cells and Organoids in Advancing Neuropathology Research and Therapies

This review delves into the groundbreaking impact of induced pluripotent stem cells (iPSCs) and three-dimensional organoid models in propelling forward neuropathology research. With a focus on neurodegenerative diseases, neuromotor disorders, and related conditions, iPSCs provide a platform for personalized disease modeling, holding significant potential for regenerative therapy and drug discovery. The adaptability of iPSCs, along with associated methodologies, enables the generation of various types of neural cell differentiations and their integration into three-dimensional organoid models, effectively replicating complex tissue structures in vitro. Key advancements in organoid and iPSC generation protocols, alongside the careful selection of donor cell types, are emphasized as critical steps in harnessing these technologies to mitigate tumorigenic risks and other hurdles. Encouragingly, iPSCs show promising outcomes in regenerative therapies, as evidenced by their successful application in animal models.

Research progress of autoimmune diseases based on induced pluripotent stem cells

Autoimmune diseases can damage specific or multiple organs and tissues, influence the quality of life, and even cause disability and death. A 'disease in a dish' can be developed based on patients-derived induced pluripotent stem cells (iPSCs) and iPSCs-derived disease-relevant cell types to provide a platform for pathogenesis research, phenotypical assays, cell therapy, and drug discovery. With rapid progress in molecular biology research methods including genome-sequencing technology, epigenetic analysis, '-omics' analysis and organoid technology, large amount of data represents an opportunity to help in gaining an in-depth understanding of pathological mechanisms and developing novel therapeutic strategies for these diseases. This paper aimed to review the iPSCs-based research on phenotype confirmation, mechanism exploration, drug discovery, and cell therapy for autoimmune diseases, especially multiple sclerosis, inflammatory bowel disease, and type 1 diabetes using iPSCs and iPSCs-derived cells.

The Role of Human Pluripotent Stem Cells in Amyotrophic Lateral Sclerosis: From Biological Mechanism to Practical Implications

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder, characterized by progressive loss of both upper and lower motor neurons, resulting in clinical features such as muscle weakness, paralysis, and ultimately, respiratory failure. Nowadays, there is not effective treatment to reverse the progression of the disease, that leads to death within 3-5 years after the onset. Nevertheless, the induced pluripotent stem cells (iPS) technology could be the answer, providing disease modelling, drug testing, and cell-based therapies for this pathology. The aim of this work was to conduct a literature review of the past 5 years about the role of iPS in ALS, to better define the neurobiological mechanisms involved in the pathogenesis and the potential future therapies. The review also deals with advanced and currently available technologies used to reprogram cell lines and generate human motor neurons in vitro, which represent the source to study the pathological processes, the relationship between phenotype and genotype, the disease progression and the potential therapeutic targets of these group of disorders. Specific treatment options with stem cells involve Advance Gene Editing Technology, neuroprotective agents, and cells or exosomes transplantation, aimed to replace dead or damaged nerve cells. In summary, this review comprehensively addresses the role of human pluripotent stem cells (hPSCs) in motor neuron diseases (MND), with a focus on physiopathology, diagnostic and prognostic implications, specific and potential future treatment options. Understanding the biological mechanisms and practical implications of hPSCs in MND is crucial for advancing therapeutic strategies and improving outcomes for patients affected by these devastating diseases.

A longevity-specific bank of induced pluripotent stem cells from centenarians and their offspring

Centenarians provide a unique lens through which to study longevity, healthy aging, and resiliency. Moreover, models of human aging and resilience to disease that allow for the testing of potential interventions are virtually non-existent. We obtained and characterized over 50 centenarian and offspring peripheral blood samples including those connected to functional independence data highlighting resistance to disability and cognitive impairment. Targeted methylation arrays were used in molecular aging clocks to compare and contrast differences between biological and chronological age in these specialized subjects. Isolated peripheral blood mononuclear cells (PBMCs) were then successfully reprogrammed into high-quality induced pluripotent stem cell (iPSC) lines which were functionally characterized for pluripotency, genomic stability, and the ability to undergo directed differentiation. The result of this work is a one-of-a-kind resource for studies of human longevity and resilience that can fuel the discovery and validation of novel therapeutics for aging-related disease.

Chronic and acute exposure to rotenone reveals distinct Parkinson's disease-related phenotypes in human iPSC-derived peripheral neurons

Peripheral autonomic nervous system (P-ANS) dysfunction is a critical non-motor phenotype of Parkinson's disease (PD). The majority of PD cases are sporadic and lack identified PD-associated genes involved. Epidemiological and animal model studies suggest an association with pesticides and other environmental toxins. However, the cellular mechanisms underlying toxin induced P-ANS dysfunctions remain unclear. Here, we mapped the global transcriptome changes in human induced pluripotent stem cell (iPSC) derived P-ANS sympathetic neurons during inhibition of the mitochondrial respiratory chain by the PD-related pesticide, rotenone. We revealed distinct transcriptome profiles between acute and chronic exposure to rotenone. In the acute stage, there was a down regulation of specific cation channel genes, known to mediate electrophysiological activity, while in the chronic stage, the human P-ANS neurons exhibited dysregulation of anti-apoptotic and Golgi apparatus-related pathways. Moreover, we identified the sodium voltage-gated channel subunit SCN3A/Nav1.3 as a potential biomarker in human P-ANS neurons associated with PD. Our analysis of the rotenone-altered coding and non-coding transcriptome of human P-ANS neurons may thus provide insight into the pathological signaling events in the sympathetic neurons during PD progression.

Estradiol enhanced neuronal plasticity and ameliorated astrogliosis in human iPSC-derived neural models

Introduction

17β-Estradiol (E2) is a sex hormone that has been previously demonstrated to have neurotherapeutic effects on animal models of Alzheimer's disease (AD). However, clinical trials on E2 replacement therapy for preventing AD onset yielded inconsistent results. Therefore, it is imperative to clarify the therapeutic effects of E2 on human cells. In this study, we utilized induced pluripotent stem cells (iPSCs) derived from multiple AD donors to explore the therapeutic effects of E2 on the in vitro model of human cells.

Methods

We conducted a systematic review and meta-analysis using a random-effects model of the previously reported AD clinical trials to summarize the effects of E2 replacement therapy on AD prevention. Subsequently, we induced iPSCs from the donors of the healthy control (1210B2 line (female) and 201B7 line (female)), the familial AD (APP V717L line (female) and APP KM670/671NL line (female)), and the sporadic AD (UCSD-SAD3.7 line (APOE ε3/ε3) (male), UCSD-SAD7D line (APOE ε3/ε4) (male), and TMGH-1 line (APOE ε3/ε3) (female)), then differentiated to neurons. In addition to the mono-culture model of the neurons, we also examined the effects of E2 on the co-culture model of neurons and astrocytes.

Results

The meta-analysis of the clinical trials concluded that E2 replacement therapy reduced the risk of AD onset (OR, 0.69; 95 % confidence interval [CI], 0.53-0.91; I2 = 82 %). Neural models from the iPSCs of AD donors showed an increase in secreted amyloid-beta (Aβ) levels in the mono-culture model and an astrogliosis-like phenotype in the co-culture model. E2 treatment to the neuronal models derived from the iPSCs enhanced neuronal activity and increased neurite complexity. Furthermore, E2 treatment of the co-culture model ameliorated the astrogliosis-like phenotype. However, in contrast to the previous reports using mouse models, E2 treatment did not change AD pathogenesis, including Aβ secretion and phosphorylated tau (pTau) accumulation.

Conclusion

E2 treatment of the human cellular model did not impact Aβ secretion and pTau accumulation, but promoted neuronal plasticity and alleviated the astrogliosis-like phenotype. The limited effects of E2 may give a clue for the mixed results of E2 clinical trials.

Mutual interaction of neurons and astrocytes derived from iPSCs with APP V717L mutation developed the astrocytic phenotypes of Alzheimer's disease

BACKGROUND

The development of induced pluripotent stem cells (iPSCs) technology has enabled human cellular disease modeling for inaccessible cell types, such as neural cells in the brain. However, many of the iPSC-derived disease models established to date typically involve only a single cell type. These monoculture models are inadequate for accurately simulating the brain environment, where multiple cell types interact. The limited cell type diversity in monoculture models hinders the accurate recapitulation of disease phenotypes resulting from interactions between different cell types. Therefore, our goal was to create cell models that include multiple interacting cell types to better recapitulate disease phenotypes.

METHODS

To establish a co-culture model of neurons and astrocytes, we individually induced neurons and astrocytes from the same iPSCs using our novel differentiation methods, and then co-cultured them. We evaluated the effects of co-culture on neurons and astrocytes using immunocytochemistry, immuno-electron microscopy, and Ca2+ imaging. We also developed a co-culture model using iPSCs from a patient with familial Alzheimer's disease (AD) patient (APP V717L mutation) to investigate whether this model would manifest disease phenotypes not seen in the monoculture models.

RESULTS

The co-culture of the neurons and astrocytes increased the branching of astrocyte processes, the number of GFAP-positive cells, neuronal activities, the number of synapses, and the density of presynaptic vesicles. In addition, immuno-electron microscopy confirmed the formation of a tripartite synaptic structure in the co-culture model, and inhibition of glutamate transporters increased neuronal activity. Compared to the co-culture model of the control iPSCs, the co-culture model of familial AD developed astrogliosis-like phenotype, which was not observed in the monoculture model of astrocytes.

CONCLUSIONS

Co-culture of iPSC-derived neurons and astrocytes enhanced the morphological changes mimicking the in vivo condition of both cell types. The formation of the functional tripartite synaptic structures in the co-culture model suggested the mutual interaction between the cells. Furthermore, the co-culture model with the APP V717L mutation expressed in neurons exhibited an astrocytic phenotype reminiscent of AD brain pathology. These results suggest that our co-culture model is a valuable tool for disease modeling of neurodegenerative diseases.