Pluripotent Stem Cell-derived Cerebral Organoids Research Articles

Enhanced development of human pluripotent stem cell-derived cerebral organoids via an electrical stimulation bioreactor

Human brain-like 3D cultures or brain organoids are promising models for expanding our knowledge of brain development and the mechanisms that contribute to neurological disorders. Moreover, it may address the hardware bottleneck for the fast-growing field of artificial intelligence and the development of brain-machine interfaces. Current methods for developing brain organoids are limited mainly due to insufficient differentiation and inaccurate structural organization. Here, a novel engineering approach is proposed to accelerates the development of human cerebral organoids by electrical stimulation via an electrical bioreactor. This approach not only promotes proliferation and neurogenesis but also improves function, network formation, and organization of the cortical plate into upper and deep layers in which PI3K/Akt pathway at least partially participates. These results demonstrate the impact of electrical stimulation on generation of more mature and the functional cerebral organoids and may provide new insights into the hardware of its applications.

CLN3 deficiency leads to neurological and metabolic perturbations during early development.

Juvenile neuronal ceroid lipofuscinosis (or Batten disease) is an autosomal recessive, rare neurodegenerative disorder that affects mainly children above the age of 5 yr and is most commonly caused by mutations in the highly conserved CLN3 gene. Here, we generated cln3 morphants and stable mutant lines in zebrafish. Although neither morphant nor mutant cln3 larvae showed any obvious developmental or morphological defects, behavioral phenotyping of the mutant larvae revealed hyposensitivity to abrupt light changes and hypersensitivity to pro-convulsive drugs. Importantly, in-depth metabolomics and lipidomics analyses revealed significant accumulation of several glycerophosphodiesters (GPDs) and cholesteryl esters, and a global decrease in bis(monoacylglycero)phosphate species, two of which (GPDs and bis(monoacylglycero)phosphates) were previously proposed as potential biomarkers for CLN3 disease based on independent studies in other organisms. We could also demonstrate GPD accumulation in human-induced pluripotent stem cell-derived cerebral organoids carrying a pathogenic variant for CLN3 Our models revealed that GPDs accumulate at very early stages of life in the absence of functional CLN3 and highlight glycerophosphoinositol and BMP as promising biomarker candidates for pre-symptomatic CLN3 disease.

A brain metastasis model for breast cancer using human embryonic stem cell-derived cerebral organoids

Background: Breast cancer is a common cause of brain metastasis. Although breast cancer has relatively high survival rates, its survival rate after metastasis to the brain is lower. Conventional two-dimensional cell culture models and animal models are widely used in metastatic cancer research, and these models have tremendously contributed to the understanding of this disease. However, these models have some limitations, such as different physiological features and genetic backgrounds.Methods: We established a simple metastatic breast cancer model using human pluripotent stem cell-derived cerebral organoids (COs)—in this case, breast cancer cerebral organoids (BC-COs).Results: Using the BC-CO model, we induced the metastasis of MDA-MB-231 cells into COs by co-culture of cells with COs and compared the differences between adapted cancer cells in BC-COs and non-adapted cells. Our results showed that the proliferative capacity increased in adapted cells. Additionally, the expression levels of endothelial-mesenchymal transition markers and cancer stem cells were significantly higher in adapted cancer cells.Conclusion: We conclude that metastasis promotes the metastatic capacity of breast cancer cells. Our results also showed that the BC-CO model could be a novel tool for research on brain metastasis in breast cancer.

Impaired p53-Mediated DNA Damage Response Contributes to Microcephaly in Nijmegen Breakage Syndrome Patient-Derived Cerebral Organoids.

Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive genetic disorder caused by mutations within nibrin (NBN), a DNA damage repair protein. Hallmarks of NBS include chromosomal instability and clinical manifestations such as growth retardation, immunodeficiency, and progressive microcephaly. We employed induced pluripotent stem cell-derived cerebral organoids from two NBS patients to study the etiology of microcephaly. We show that NBS organoids carrying the homozygous 657del5 NBN mutation are significantly smaller with disrupted cyto-architecture. The organoids exhibit premature differentiation, and Neuronatin (NNAT) over-expression. Furthermore, pathways related to DNA damage response and cell cycle are differentially regulated compared to controls. After exposure to bleomycin, NBS organoids undergo delayed p53-mediated DNA damage response and aberrant trans-synaptic signaling, which ultimately leads to neuronal apoptosis. Our data provide insights into how mutations within NBN alters neurogenesis in NBS patients, thus providing a proof of concept that cerebral organoids are a valuable tool for studying DNA damage-related disorders.

A Cerebral Organoid Connectivity Apparatus to Model Neuronal Tract Circuitry.

Mental disorders have high prevalence, but the efficacy of existing therapeutics is limited, in part, because the pathogenic mechanisms remain enigmatic. Current models of neural circuitry include animal models and post-mortem brain tissue, which have allowed enormous progress in understanding the pathophysiology of mental disorders. However, these models limit the ability to assess the functional alterations in short-range and long-range network connectivity between brain regions that are implicated in many mental disorders, e.g., schizophrenia and autism spectrum disorders. This work addresses these limitations by developing an in vitro model of the human brain that models the in vivo cerebral tract environment. In this study, microfabrication and stem cell differentiation techniques were combined to develop an in vitro cerebral tract model that anchors human induced pluripotent stem cell-derived cerebral organoids (COs) and provides a scaffold to promote the formation of a functional connecting neuronal tract. Two designs of a Cerebral Organoid Connectivity Apparatus (COCA) were fabricated using SU-8 photoresist. The first design contains a series of spikes which anchor the CO to the COCA (spiked design), whereas the second design contains flat supporting structures with open holes in a grid pattern to anchor the organoids (grid design); both designs allow effective media exchange. Morphological and functional analyses reveal the expression of key neuronal markers as well as functional activity and signal propagation along cerebral tracts connecting CO pairs. The reported in vitro models enable the investigation of critical neural circuitry involved in neurodevelopmental processes and has the potential to help devise personalized and targeted therapeutic strategies.

Rottlerin inhibits La Crosse virus-induced encephalitis in mice and blocks release of replicating virus from the Golgi body in neurons.

La Crosse virus (LACV) is a mosquito-borne orthobunyavirus that causes approximately 60 to 80 hospitalized pediatric encephalitis cases in the United States yearly. The primary treatment for most viral encephalitis, including LACV, is palliative care, and specific antiviral therapeutics are needed. We screened the National Center for Advancing Translational Sciences library of 3,833 FDA-approved and bioactive small molecules for the ability to inhibit LACV-induced death in SH-SY5Y neuronal cells. The top three hits from the initial screen were validated by examining their ability to inhibit virus-induced cell death in multiple neuronal cell lines. Rottlerin consistently reduced LACV-induced death by 50% in multiple human and mouse neuronal cell lines with an effective concentration of 0.16-0.69 µg ml-1 depending on cell line. Rottlerin was effective up to 12 hours post-infection in vitro and inhibited virus particle trafficking from the Golgi apparatus to trans-Golgi vesicles. In human inducible pluripotent stem cell-derived cerebral organoids, rottlerin reduced virus production by one log and cell death by 35% compared with dimethyl sulfoxide-treated controls. Administration of rottlerin in mice by intraperitoneal or intracranial routes starting at 3 days post-infection decreased disease development by 30-50%. Furthermore, rottlerin also inhibited virus replication of other pathogenic California serogroup orthobunyaviruses (Jamestown Canyon and Tahyna virus) in neuronal cell lines.

The Application of the Tissue Microarray (TMA) Technology to Analyze Cerebral Organoids.

"Multi-Omics" technologies have contributed greatly to the understanding of various diseases by enabling researchers to accurately and rapidly investigate the molecular circuitry that connects cellular systems. The tissue-engineered, three-dimensional (3D), in vitro disease model "organoid" integrates the "omics" results in a model system, elucidating the complex links between genotype and phenotype. These 3D structures have been used to model cancer, infectious disease, toxicity, and neurological disorders. Here, we describe the advantage of using the tissue microarray (TMA) technology to analyze human-induced pluripotent stem cell-derived cerebral organoids. Compared with the conventional processing of individual samples, sectioning and staining of TMA slides are faster and can be automated, decreasing labor and reagent costs. The TMA technology faithfully captures cell morphology variations and detects specific biomarkers. The use of this technology can scale up organoid research results in at least two ways: (1) in the number of specimens that can be analyzed simultaneously and (2) in the number of consecutive sections that can be produced for analysis with different probes and antibodies.

A simple method to improve the quality and yield of human pluripotent stem cell-derived cerebral organoids

The development of cerebral organoid technology has allowed the human neural tissue to be collected for studying human brain development and neurological diseases. Human pluripotent stem cell-derived cerebral organoids (hCOs) are a theoretically infinite source of fresh human brain tissue for various research purposes. However, hCOs have limitations, including core necrotic cell death. To solve this problem, we tested a simple method, which has been previously overlooked. In this study, we mechanically cut 70-day-old hCOs with a scalpel blade into 2 to 4 pieces, each depending on their original size. After culturing cut hCOs for additional 7 days, their size was less variable and smaller than uncut hCOs and there were no histological differences between uncut and cut hCOs. Note that hypoxia-inducible factor (HIF)−1α was expressed in the central area of uncut hCOs but not in cut hCOs. Uncut hCOs, therefore, showed broad core areas stained with terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL), whereas cut hCOs did not. In conclusion, this simple mechanical cutting method allowed us to acquire a larger number of hCOs without a necrotic core.

Integrated RNA Sequencing Reveals Epigenetic Impacts of Diesel Particulate Matter Exposure in Human Cerebral Organoids

Autism spectrum disorder (ASD) manifests early in childhood. While genetic variants increase risk for ASD, a growing body of literature has established that in utero chemical exposures also contribute to ASD risk. These chemicals include air-based pollutants like diesel particulate matter (DPM). A combination of single-cell and direct transcriptomics of DPM-exposed human-induced pluripotent stem cell-derived cerebral organoids revealed toxicogenomic effects of DPM exposure during fetal brain development. Direct transcriptomics, sequencing RNA bases via Nanopore, revealed that cerebral organoids contain extensive RNA modifications, with DPM-altering cytosine methylation in oxidative mitochondrial transcripts expressed in outer radial glia cells. Single-cell transcriptomics further confirmed an oxidative phosphorylation change in cell groups such as outer radial glia upon DPM exposure. This approach highlights how DPM exposure perturbs normal mitochondrial function and cellular respiration during early brain development, which may contribute to developmental disorders like ASD by altering neurodevelopment.

Chromatin Remodeler CHD8 in Autism and Brain Development.

Chromodomain Helicase DNA-binding 8 (CHD8) is a high confidence risk factor for autism spectrum disorders (ASDs) and the genetic cause of a distinct neurodevelopmental syndrome with the core symptoms of autism, macrocephaly, and facial dysmorphism. The role of CHD8 is well-characterized at the structural, biochemical, and transcriptional level. By contrast, much less is understood regarding how mutations in CHD8 underpin altered brain function and mental disease. Studies on various model organisms have been proven critical to tackle this challenge. Here, we scrutinize recent advances in this field with a focus on phenotypes in transgenic animal models and highlight key findings on neurodevelopment, neuronal connectivity, neurotransmission, synaptic and homeostatic plasticity, and habituation. Against this backdrop, we further discuss how to improve future animal studies, both in terms of technical issues and with respect to the sex-specific effects of Chd8 mutations for neuronal and higher-systems level function. We also consider outstanding questions in the field including ‘humanized’ mice models, therapeutic interventions, and how the use of pluripotent stem cell-derived cerebral organoids might help to address differences in neurodevelopment trajectories between model organisms and humans.

Human cerebral organoids establish subcortical projections in the mouse brain after transplantation

Numerous studies have used human pluripotent stem cell-derived cerebral organoids to elucidate the mystery of human brain development and model neurological diseases in vitro, but the potential for grafted organoid-based therapy in vivo remains unknown. Here, we optimized a culturing protocol capable of efficiently generating small human cerebral organoids. After transplantation into the mouse medial prefrontal cortex, the grafted human cerebral organoids survived and extended projections over 4.5 mm in length to basal brain regions within 1 month. The transplanted cerebral organoids generated human glutamatergic neurons that acquired electrophysiological maturity in the mouse brain. Importantly, the grafted human cerebral organoids functionally integrated into pre-existing neural circuits by forming bidirectional synaptic connections with the mouse host neurons. Furthermore, compared to control mice, the mice transplanted with cerebral organoids showed an increase in freezing time in response to auditory conditioned stimuli, suggesting the potentiation of the startle fear response. Our study showed that subcortical projections can be established by microtransplantation and may provide crucial insights into the therapeutic potential of human cerebral organoids for neurological diseases.

Modelling Toxoplasma gondii infection in human cerebral organoids

ABSTRACT Pluripotent stem cell-derived cerebral organoids have the potential to recapitulate the pathophysiology of in vivo human brain tissue, constituting a valuable resource for modelling brain disorders, including infectious diseases. Toxoplasma gondii, an intracellular protozoan parasite, infects most warm-blooded animals, including humans, causing toxoplasmosis. In immunodeficient patients and pregnant women, infection often results in severe central nervous system disease and fetal miscarriage. However, understanding the molecular pathophysiology of the disease has been challenging due to limited in vitro model systems. Here, we developed a new in vitro model system of T. gondii infection using human brain organoids. We observed that tachyzoites can infect human cerebral organoids and are transformed to bradyzoites and replicate in parasitophorous vacuoles to form cysts, indicating that the T. gondii asexual life cycle is efficiently simulated in the brain organoids. Transcriptomic analysis of T. gondii-infected organoids revealed the activation of the type I interferon immune response against infection. In addition, in brain organoids, T. gondii exhibited a changed transcriptome related to protozoan invasion and replication. This study shows cerebral organoids as physiologically relevant in vitro model systems useful for advancing the understanding of T. gondii infections and host interactions.

Establishing Cerebral Organoids as Models of Human-Specific Brain Evolution

Direct comparisons of human and non-human primate brains can reveal molecular pathways underlying remarkable specializations of the human brain. However, chimpanzee tissue is inaccessible during neocortical neurogenesis when differences in brain size first appear. To identify human-specific featuresof cortical development, we leveraged recent innovationsthat permit generating pluripotent stem cell-derived cerebral organoids from chimpanzee. Despite metabolic differences, organoid models preserve gene regulatory networks related to primary cell types and developmental processes. We further identified 261 differentially expressed genes in human compared to both chimpanzee organoids and macaque cortex, enriched for recent gene duplications, and including multiple regulators of PI3K-AKT-mTOR signaling. We observed increased activation of this pathway in human radial glia, dependent on two receptors upregulated specifically in human: INSR and ITGB8. Our findings establish a platform for systematic analysis of molecular changes contributing to human brain development and evolution.

25.3 OLIGODENDROCYTES MEDIATE ENERGY METABOLISM ALTERATIONS IN SCHIZOPHRENIA: A PROTEOMIC STUDY

BackgroundWhile comparing the proteomes and subproteomes of 8 post-mortem brain regions and cerebrospinal fluid from schizophrenia patients to controls, we consistently observed alterations in energy metabolism, cell growth and maintenance, synaptic function, and myelinization processes. Considering the nature of these analyses, it was not possible to reveal which particular cell types display such alterations. This is essential information given increasing evidence of glia cells as pivotal players in schizophrenia. With this in mind, we analyzed the proteomes and phosphoproteomes of cultured astrocytes, oligodendrocytes and neurons treated with MK-801, a NMDA-receptor antagonist which impairs glutamatergic transmission as postulated in schizophrenia. We also analyzed biochemical pathways modulated by typical and atypical antipsychotics in human oligodendrocytes. Results led us to employ induced pluripotent stem cell-derived cerebral organoids to deepen our understanding of the data. The central aim of this study is to depict which cell type(s) present proteome changes similarly to those we found in our earlier analysis of human brain tissue as well as identify key pathways for an effective antipsychotic response.MethodsCell line cultures (astrocytes, oligodendrocytes and neurons) were treated with MK-801 and oligodendrocytes were also treated with a range of typical and atypical antipsychotics. In addition, human embryonic stem cells reprogramed from schizophrenia patients and controls fibroblasts were cultured in mTeSR1 media on Matrigel coated surface and then differentiated into cerebral organoids. All pre-clinical models here employed were submitted to state-of-the art large-scale proteomic analyses. In silico systems biology was employed to identify key pathways in the studied processes.ResultsMK-801-treated astrocytes, and especially MK-801-treated oligodendrocytes displayed several proteins differentially expressed which overlapped with previous findings of schizophrenia human brains. On the other hand, MK801-treated neurons displayed very few differences in their proteome, an overlap with previous findings in human brain tissue below 10%. More interestingly, the dysregulation of glycolytic enzymes in MK801-treated oligodendrocytes are very similar to our observations in schizophrenia brain tissue, corroborating with recent findings about of the importance of oligodendrocytes in the energy status of the brain. In oligodendrocytes, antipsychotics displayed differences in translational machinery and eIF2 signaling. Findings on cerebral organoids also showed overlaps with previous postmortem data, mainly on synaptic proteins and specially energy metabolism-associated pathways.DiscussionThese findings hold potential for the investigation of developmental and evolutionary features of schizophrenia brains and provides targets to be drug-screened as well as leads to the schizophrenia pathobiology.

25. OLIGODENDROCYTE-BASED IMPAIRMENT OF BRAIN CONNECTIVITY AS TARGET FOR NEW TREATMENT STRATEGIES IN SCHIZOPHRENIA

Overall : This symposium has a translational approach. First, we present human post-mortem and in-vivo imaging studies on the pivotal role of oligedondrocyte loss and dysfunction with consecutive impairments of brain connectivity in schizophrenia. Natalya Uranova will show morphometric data on ultrastructural alterations of oligodendrocytes, myelin damage and degeneration and disturbed oligodendrocyte-axon interactions in post-mortem prefrontal white matter in schizophrenia. Adrienne Lahti will report diffusion tensor imaging data suggesting impaired axonal and myelin integrity. Because, MR Spectroscopy permits the non-invasive measurement of neurometabolites, such as N-acetylaspartate, a marker of neuronal integrity, and glutamate, which can be neurotoxic when overproduced, this technique provides further understanding of the relationship between white matter microstructure and neuronal function.Second, we present data from cell culture and animal models suggesting that restoration of oligodendrocyte function (in terms of energy metabolism, maturation and myelin production) is a promising target for the development of novel treatment strategies in schizophrenia. Proteomic studies in postmortem brain by Daniel Martins-de-Souza have suggested a schizophrenia-related energy metabolism dysfunction in oligodendrocytes. These findings have been followed up using oligodendroglia cell lines and induced pluripotent stem cell-derived cerebral organoids, supporting the notion that alterations in glycolysis in oligodendrocytes are pivotal to the overall energy dysfunction in schizophrenia brains. Lan Xiao′s lab has shown that oligodendrocyte dysfunction and impaired myelination in the prefrontal cortex is correlated with schizophrenia-like behavior in mice undergoing prolonged social isolation. Enhancing oligodendrocyte generation and myelin repair by FDA-approved compounds, like quetiapine (an APD) or clemastine (a histamine antagonist) successfully reversed the above phenotype.

Tranylcypromine Causes Neurotoxicity and Represses BHC110/LSD1 in Human-Induced Pluripotent Stem Cell-Derived Cerebral Organoids Model.

Recent breakthroughs in human pluripotent stem cell-derived cerebral organoids provide a valuable platform for investigating the human brain after different drugs treatments and for understanding the complex genetic background to human pathology. Here, we identified tranylcypromine, which is used to treat refractory depression, caused human-induced pluripotent stem cell-derived brain organoids neurotoxicity, leading to decreased proliferation activity and apoptosis induction. Moreover, tranylcypromine treatment affects neurons and astrocytes, which impairs cell density and arrangement. Finally, staining of histone demethylation-related genes revealed that tranylcypromine suppresses the transcriptional activity of BHC110/LSD1-targeted genes and increases the expression of histone di-methylated K4. These results show that human brain organoids can be applied as an in vitro model for CNS drug screening to evaluate structural, cellular, and molecular changes in the normal brains or brains of patients with neuropsychiatric disorders after drug treatments.