Your browser does not allow saving data (e.g. private mode): bookmarks will be lost when the tab closes.
Search PubMed
Keywords, author, journal, years — results from PubMed, abstracts with Russian translation, bookmarks in your browser.
Found: 5 447
Page 29 of 545-
Expanding the neuroimmune research toolkit with in vivo brain organoid technologies.
Human pluripotent stem cell-derived microglia-like cells (MLCs) and brain organoid systems have revolutionized the study of neuroimmune interactions, providing new opportunities to model human-specific brain development and disease. Over the past decade, advances in protocol design have improved the fidelity, reproducibility and scalability of MLC and brain organoid generation. Co-culturing of MLCs and brain organoids have enabled direct investigations of human microglial interactions in vitro, although opportunities remain to improve microglial maturation and long-term survival. To address these limitations, innovative xenotransplantation approaches have introduced MLCs, organoids or neuroimmune organoids into the rodent brain, providing a vascularized environment that supports prolonged development and potential behavioral readouts. These expanding in vitro and in vivo toolkits offer complementary strategies to study neuroimmune interactions in health and disease. In this Perspective, we discuss the strengths, limitations and synergies of these models, highlighting important considerations for their future applications.
-
Brain Organoid Research in a Post-Dobbs World.
The creation and study of brain organoids may hold significant promise for understanding brain functions, disorders, and diseases. This research may also raise novel considerations and ethical concerns, but it has significant public and professional support when thoughtfully undertaken. Current legislative and judicial restrictions on abortion and pronouncements about fetal personhood could, however, have a surprisingly broad and unintended reach, even conceivably restricting the development and use of brain organoids and other biomedical and bioengineered research tools. Brain organoid research thus may constitute a cautionary tale about the risks of performative policy-making.
-
In depth characterization of midbrain organoids derived from wild type iPSC lines.
The ability to model human neurological tissues in vitro has been a major hurdle to effective drug development for neurological disorders. iPSC-derived brain organoids have emerged as a compelling solution to this problem as they have the potential to relevantly model the protein expression pattern and physiology of specific brain regions. Although many protocols now exist for the production of brain organoids, few attempts have been made to do an in-depth kinetic evaluation of expression of mature regiospecific markers of brain organoids. To address this, we differentiated midbrain-specific brain organoids from iPSC-lines derived from three apparently healthy individuals using a matrix-free, bioreactor method. We monitored the expression of midbrain-specific neuronal markers from 7 to 90-days using immunofluorescence and immunohistology. The organoids were further characterized using electron microscopy and RNA-seq. In addition to serving as a potential benchmark for the future evaluation of other differentiation protocols, the markers observed in this study can be useful as control parameters to identify and evaluate the disease phenotypes in midbrain organoid derived from patient iPSC-lines with genetic neurological disorders.
-
Stretchable Microelectrode Arrays with Microneedles for Reliable Electrophysiological Recording of Human Heart and Brain Organoids.
Real-time, non-destructive monitoring of electrophysiological dynamics of 3D organoids is imperative for advancing disease modeling and high-throughput drug screening. However, obtaining continuous, reliable signals remains difficult due to the destructive nature of penetrating probes and the unreliable contact issue prone to surface recordings. Here, we present a stretchable 3D microelectrode array with microneedles (3D MN-sMEA) fabricated via a scalable wafer-level stud-bump bonding process for minimally destructive and stable monitoring. We achieve high-fidelity, reliable electrophysiological recordings of both human iPSC-derived heart and cerebral models. Compared with 2D and 3D planar microelectrodes, 3D microelectrodes with microneedles achieve a higher signal-to-noise ratio and greater long-term recording stability. Furthermore, quantitative pharmacological profiling validates its ability to enable precise drug screening. By combining scalable manufacturing with flexible, tissue-compliant interfaces, our approach enables stable, minimally invasive, and long-term electrophysiological monitoring of 3D organoids for scalable disease modeling and drug discovery.
-
Human brain organoid-on-a-chip to model prenatal nicotine exposure.
Nicotine has been recognized to trigger various neuronal disabilities in the fetal brain and long-lasting behavioral deficits in offspring. However, further understanding of fetal brain development under nicotine exposure is challenging due to the limitations of existing animal models. Here, we create a new brain organoid-on-a-chip system derived from human induced pluripotent stem cells (hiPSCs) that allows us to model neurodevelopmental disorders under prenatal nicotine exposure (PNE) at early stages. The brain organoid-on-a-chip system facilitates 3D culture, in situ neural differentiation, and self-organization of brain organoids under continuous perfused cultures in a controlled manner. The generated brain organoids displayed well-defined neural differentiation, regionalization, and cortical organization, which recapitulates the key features of the early stages of human brain development. The brain organoids exposed to nicotine exhibited premature neuronal differentiation with enhanced expression of the neuron marker TUJ1. Brain regionalization and cortical development were disrupted in the nicotine-treated organoids identified by the expressions of forebrain (PAX6 and FOXG1), hindbrain (PAX2 and KROX20) and cortical neural layer (preplate TBR1 and deep-layer CTIP2) markers. Moreover, the neurite outgrowth showed abnormal neuronal differentiation and migration in nicotine-treated brain organoids. These results suggest that nicotine exposure elicits impaired neurogenesis in early fetal brain development during gestation. The established brain organoid-on-a-chip system provides a promising platform to model neurodevelopmental disorders under environmental exposure, which can be extended for applications in brain disease studies and drug testing.
-
An On-Chip Method for Long-Term Growth and Real-Time Imaging of Brain Organoids.
Brain organoids are an emerging technique for studying human neurodevelopment in vitro, with biomedical implications. However, three-dimensional tissue culture poses several challenges, including lack of nutrient exchange at the organoid core and limited imaging accessibility of whole organoids. Here we present a method for culturing organoids in a micro-fabricated device that enables in situ real-time imaging over weeks with efficient nutrient exchange by diffusion. Our on-chip approach offers a means for studying the dynamics of organoid development, cell differentiation, cell cycle, and motion. © 2018 by John Wiley & Sons, Inc.
-
The uses of transcriptomics and lipidomics indicated that direct contact with graphene oxide altered lipid homeostasis through ER stress in 3D human brain organoids.
The potential uses of graphene-based nanomaterials (NMs) in various fields lead to the concern about their neurotoxicity, considering that graphene-based NMs are capable to cross blood brain barrier (BBB) and enter central nervous system (CNS). Although previous studies reported the possibility of graphene-based NM exposure to alter lipid homeostasis in animals or cultured neurons, recent studies suggested the need to use 3D human brain organoids for mechanism-based toxicological studies as this model might better recapitulate the complex human brains. Herein, we used multi-omics techniques to investigate the mechanisms of graphene oxide (GO) on lipid homeostasis in a novel 3D brain organoid model. We found that 50 μg/mL GO induced cytotoxicity but not superoxide. RNA-sequencing data showed that 50 μg/mL GO significantly up-regulated and down-regulated 80 and 121 genes, respectively. Furthermore, we found that GO exposure altered biological molecule metabolism pathways including lipid metabolism. Consistently, lipidomics data supported dose-dependent alteration of lipid profiles by GO in 3D brain organoids. Interestingly, co-exposure to GO and endoplasmic reticulum (ER) stress inhibitor 4-phenylbutyric acid (4-PBA) decreased most of the lipid classes compared with the exposure of GO only. We further verified that exposure to GO promoted ER stress marker GRP78 proteins, which in turn activated IRE1α/XBP-1 axis, and these changes were partially or completely inhibited by 4-PBA. These results proved that direct contact with GO disrupted lipid homeostasis through the activation of ER stress. As 3D brain organoids resemble human brains, these data might be better extrapolated to humans.
-
A microglia-containing cerebral organoid model to study early life immune challenges.
Prenatal infections and activation of the maternal immune system have been proposed to contribute to causing neurodevelopmental disorders (NDDs), chronic conditions often linked to brain abnormalities. Microglia are the resident immune cells of the brain and play a key role in neurodevelopment. Disruption of microglial functions can lead to brain abnormalities and increase the risk of developing NDDs. How the maternal as well as the fetal immune system affect human neurodevelopment and contribute to NDDs remains unclear. An important reason for this knowledge gap is the fact that the impact of exposure to prenatal risk factors has been challenging to study in the human context. Here, we characterized a model of cerebral organoids (CO) with integrated microglia (COiMg). These organoids express typical microglial markers and respond to inflammatory stimuli. The presence of microglia influences cerebral organoid development, including cell density and neural differentiation, and regulates the expression of several ciliated and mesenchymal cell markers. Moreover, COiMg and organoids without microglia show similar but also distinct responses to inflammatory stimuli. Additionally, IFN-γ induced significant transcriptional and structural changes in the cerebral organoids, that appear to be regulated by the presence of microglia. Specifically, interferon-gamma (IFN-γ) was found to alter the expression of genes linked to autism. This model provides a valuable tool to study how inflammatory perturbations and microglial presence affect neurodevelopmental processes.
-
A Murine Model of Glioblastoma Initiating Cells and Human Brain Organoid Xenograft for Photodynamic Therapy Testing.
Glioblastoma (GB) is one of the most aggressive brain tumors, characterized by high infiltrative capacity that enables tumor cells to invade healthy brain tissue and evade complete surgical resection. This invasiveness contributes to resistance against conventional therapies and a high recurrence rate. Strategies capable of eliminating residual tumor cells are urgently needed. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA), an FDA- and EMA-approved compound, induces selective accumulation of the photosensitizer protoporphyrin IX (PpIX) in metabolically active tumor cells, enabling targeted cytotoxicity through light activation. A major limitation to its clinical application is the unclear variation in the cytotoxic effect of PDT according to individual tumoral differences. In this study, we propose and validate an in vivo model of patient-derived GB initiating cells (GICs) and brain organoids to test the effects of PDT. First, patient-derived GICs were molecularly characterized by flow cytometry and copy number variation profiling using OncoScan CNV Assays, then co-cultured with human brain organoids to generate a hybrid model recapitulating key aspects of the tumor microenvironment. 5-ALA photodynamic therapy (PDT) efficacy was assessed in vitro by GFP-based viability measurements, LDH release assays, and TUNEL staining. Then, a murine model was generated to study PDT in vivo, based on a heterotopic (renal subcapsular engraftment) xenograft of the GICs-human brain organoid co-culture. PDT was tested in the model; in each subject, one kidney tumoral engraftment was treated and the contralateral served as a control. Immunofluorescence analysis was used to study the cell composition of the brain organoid-tumoral engraftment after PDT, and the effects on non-GIC cells. The antitumoral effect was determined by the degree of cell death analysis with the TUNEL technique. The GICs-brain organoid co-culture resulted in tumoral growth and infiltration both in vitro and in vivo. The pattern of growth and infiltration varied according to the tumoral genetic profile. 5-ALA PDT resulted in a reduction in the number of GICs and an increase in apoptotic cells in all four lines tested in vitro. A correlation was found between the induced phototoxicity in vivo with the molecular typification of GICs cell lines in vitro. There were no changes in the number or distribution of neuronal cells after the application of PDT, while a reduction in active astrocytes was observed. 5-ALA PDT could be effective in eradicating GICs with a heterogeneous molecular profile. The hybrid human-murine model presented here could be useful in investigating adjuvant therapies in GB, under the concept of personalized medicine.
-
Modeling pediatric low-grade glioma heterogeneity using human forebrain organoids.
Pediatric low-grade gliomas (pLGGs) are the most common type of brain tumors in children, characterized by their typically slow growth and oncogene-induced senescence. Preclinical models provide the opportunity to investigate the effects of various treatments in a controlled setting before they are tested in human patients; however, reliable models for pLGGs are limited. Here we developed two organoid models for pLGGs, which, after engraftment into mice, exhibited low-grade features. Furthermore, the genome-wide DNA methylation and RNA profiles of the organoids demonstrated closer similarity to low-grade glioma entities compared to high-grade counterparts. Additionally, pLGG organoid-derived cells align with oligodendrocyte-like, astrocyte-like and MAPK signature clusters seen in patient tumors, indicating that the organoids generate a heterogeneous population of cancer cells, where cellular diversity may influence disease progression and treatment response.