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 21 of 545-
Human brain development and its in vitro recapitulation.
Humans have a large and gyrencephalic brain. The higher intellectual ability of humans is dependent on the proper development of the brain. Brain malformation is often associated with cognitive dysfunction. It is thus important to know how our brain grows during development. Several animal species have been used as models to understand the mechanisms of brain development, and have provided us with basic information in this regard. It has been revealed that mammalian brain development basically proceeds through a similar process by common mechanisms, including neural stem cell proliferation and neurogenesis. However, humans also display species-specific features in these processes. These differences seem to be important for building the proper human brain structure. Analysis of these human-specific features requires human brain samples, which are difficult to obtain due to both ethical and practical reasons. Nevertheless, brain organoids derived from human pluripotent stem cells can be used as models to study human brain development and pathology because such organoids can partly recapitulate human fetal developmental processes. In this review, we will review some human-specific features during brain development and discuss brain organoid technology as a model system. We will especially focusing on neocortical development.
-
In situ generation of human brain organoids on a micropillar array.
Brain organoids derived from human induced pluripotent stem cells can recapitulate the early stages of brain development, representing a powerful in vitro system for modeling brain development and diseases. However, the existing methods for brain organoid formation often require time-consuming procedures, including the initial formation of embryoid bodies (EBs) from hiPSCs, and subsequent neural induction and differentiation companied by multi-steps of cell transfer and encapsulation in a 3D matrix. Herein, we propose a simple strategy to enable in situ formation of massive brain organoids from hiPSCs on a micropillar array without tedious manual procedures. The optimized micropillar configurations allow for controlled EB formation, neural induction and differentiation, and generation of functional human brain organoids in 3D culture on a single device. The generated brain organoids were examined to imitate brain organogenesis in vivo at early stages of gestation with specific features of neuronal differentiation, brain regionalization, and cortical organization. By combining microfabrication techniques with stem cells and developmental biology principles, the proposed method can greatly simplify brain organoid formation protocols as compared to conventional methods, overcoming the potential limitations of cell contamination, lower throughput and variance of organoid morphology. It can also provide a useful platform for the engineering of stem cell organoids with improved functions and extending their applications in developmental biology, drug testing and disease modeling.
-
Navigating Brain Organoid Maturation: From Benchmarking Frameworks to Multimodal Bioengineering Strategies.
Brain organoid technology has revolutionized in vitro modeling of human neurodevelopment and disease, providing unprecedented insights into cortical patterning, neural circuit assembly, and pathogenic mechanisms of neurological disorders. Critically, human brain organoids uniquely recapitulate human-specific developmental processes-such as the expansion of outer radial glia and neuromelanin-that are absent in rodent models, making them indispensable for studying human brain evolution and dysfunction. However, a major bottleneck persists: Extended culture periods (≥6 months) are empirically required to achieve late-stage maturation markers like synaptic refinement, functional network plasticity, and gliogenesis. Yet prolonged conventional 3D culture exacerbates metabolic stress, hypoxia-induced necrosis, and microenvironmental instability, leading to asynchronous tissue maturation-electrophysiologically active superficial layers juxtaposed with degenerating cores. This immaturity/heterogeneity severely limits their utility in modeling adult-onset disorders (e.g., Alzheimer's disease) and high-fidelity drug screening, as organoids fail to recapitulate postnatal transcriptional signatures or neurovascular interactions without bioengineering interventions. We summarize emerging strategies to decouple maturation milestones from rigid temporal frameworks, emphasizing the synergistic integration of chronological optimization (e.g., vascularized co-cultures) and active bioengineering accelerators (e.g., electrical stimulation and microfluidics). By bridging biological timelines with scalable engineering, this review charts a roadmap to generate translationally relevant, functionally mature brain organoids.
-
Single cell RNA sequencing and emerging transcriptomic technologies in Alzheimer's disease cerebral organoids: a mini review.
Alzheimer's disease (AD), the most common cause of dementia worldwide, presents a formidable challenge due to its complex, multifactorial etiology, and limited translational success of existing models. Recent advances in stem cell biology have enabled the generation of three-dimensional human cerebral organoids which exhibit multicellular complexity and self-organisation, recapitulating key aspects of fetal brain development in vitro. This mini review highlights the landscape of AD modelling in human cerebral organoids. While studies using single cell RNA sequencing (scRNA-seq) form the core of this review, we also discuss single-nucleus RNA sequencing, computational deconvolution, and spatial approaches as translationally relevant extensions. We categorise current organoid research into distinct model types: (1) familial AD models driven by APP, PSEN1, and PSEN2 mutations; (2) sporadic AD models incorporating genetic APOE variants and environmental risk factors (serum exposure, pollutants, and viral reactivation); (3) tauopathy models highlighting astrocyte-driven metabolic disruption; (4) models featuring glial-immune interactions; and (5) emerging models of mitochondrial dysfunction as an early disease initiator. Across these categories, single cell technologies reveal critical alterations in lipid metabolism, synaptic programs, and glial-immune crosstalk. Finally, we review methodological innovations-drawing on non-AD developmental organoid studies such as region-specific patterning, morphodynamic control, and enhanced cellular diversity, which offer a roadmap for improving the physiological fidelity of next-generation AD organoid models. Ultimately, integrating these advanced cerebral organoid platforms with single cell technologies offer a powerful toolkit to dissect early disease mechanisms and accelerate the development of personalised therapeutics.
-
A review on current brain organoid technologies from a biomedical engineering perspective.
Brain organoids are 3D cytoarchitectures resembling the embryonic human brain. This review focuses on current advancements in biomedical engineering methods to develop organoids such as pluripotent stem cells assemblies, quickly aggregated floating culture, hydrogel suspension, microfluidic systems (both photolithography and 3D printing), and brain organoids-on-a-chip. These methods have the potential to create a large impact on neurological disorder studies by creating a model of the human brain investigating pathogenesis and drug screening for individual patients. 3D brain organoid cultures mimic not only features of patients' unknown drug reactions, but also early human brain development at cellular, structural, and functional levels. The challenge of current brain organoids lies in the formation of distinct cortical neuron layers, gyrification, and the establishment of complex neuronal circuitry, as they are critically specialized, developmental aspects. Furthermore, recent advances such as vascularization and genome engineering are in development to overcome the barrier of neuronal complexity. Future technology of brain organoids is needed to improve tissue cross-communication, body axis simulation, cell patterning signals, and spatial-temporal control of differentiation, as engineering methods discussed in this review are rapidly evolving.
-
Effects of Sevoflurane Exposure on Fetal Brain Development Using Cerebral Organoids.
Sevoflurane is a safe and well-known inhaled anesthetic. Given that sevoflurane can be delivered to developing fetuses through the mother, it is critical to determine whether this agent affects fetal neurodevelopment. Recent research has sought to determine whether sevoflurane affects fetal brain development when the mother is exposed during the second to third trimester of pregnancy, considered to be the crucial period for the development of nervous system. However, even though the first trimester is a critical period for fetal organogenesis and the most susceptible time to teratogen exposure, research regarding the effects of sevoflurane on organogenesis, especially on brain development, is insufficient. In the present study, human embryonic stem cells (hESC)-derived cerebral organoids were exposed to sevoflurane during the time corresponding to the first trimester to investigate the effect of early sevoflurane exposure on fetal brain development, specifically the processes of neuronal differentiation and maturation. Organoid size exposed to the intermediate concentration of sevoflurane did not differ from control, immunofluorescence demonstrated that sevoflurane temporarily decreased the size of SOX2 + /N-cad + ventricular zone structures only during the mid-time point, and upregulated expression of TUJ1 and MAP2 only during the early time point. However, all markers returned to normal levels, and organoids formed normal cortical structures at the late time point. Our results suggest that maternal sevoflurane exposure during the first trimester of pregnancy can cause abnormal neuronal differentiation in the fetal brain. However, considering the recovery observed in later periods, sevoflurane exposure might not have lasting impacts on fetal brain development.
-
A large and diverse brain organoid dataset of 1,400 cross-laboratory images of 64 trackable brain organoids.
Brain organoids represent a useful tool for modeling of neurodevelopmental disorders and can recapitulate brain volume alterations such as microcephaly. To monitor organoid growth, brightfield microscopy images are frequently used and evaluated manually which is time-consuming and prone to observer-bias. Recent software applications for organoid evaluation address this issue using classical or AI-based methods. These pipelines have distinct strengths and weaknesses that are not evident to external observers. We provide a dataset of more than 1,400 images of 64 trackable brain organoids from four clones differentiated from healthy and diseased patients. This dataset is especially powerful to test and compare organoid analysis pipelines because of (1) trackable organoids (2) frequent imaging during development (3) clone diversity (4) distinct clone development (5) cross sample imaging by two different labs (6) common imaging distractors, and (6) pixel-level ground truth organoid annotations. Therefore, this dataset allows to perform differentiated analyses to delineate strengths, weaknesses, and generalizability of automated organoid analysis pipelines as well as analysis of clone diversity and similarity.
-
Modelling host- Trypanosoma brucei gambiense interactions in vitro using human induced pluripotent stem cell-derived cortical brain organoids.
Background: Sleeping sickness is caused by the extracellular parasite Trypanosoma brucei and is associated with neuroinflammation and neuropsychiatric disorders, including disruption of sleep/wake patterns, and is now recognised as a circadian disorder. Sleeping sickness is traditionally studied using murine models of infection due to the lack of alternative in vitro systems that fully recapitulate the cellular diversity and functionality of the human brain. The aim of this study is to develop a much-needed in vitro system that reduces and replaces live animals for the study of infections in the central nervous system, using sleeping sickness as a model infection. Methods: We developed a co-culture system using induced pluripotent stem cell (iPSC)-derived cortical human brain organoids and the human pathogen T. b. gambiense to model host-pathogen interactions in vitro. Upon co-culture, we analysed the transcriptional responses of the brain organoids to T. b. gambiense over two time points. Results: We detected broad transcriptional changes in brain organoids exposed to T. b. gambiense, mainly associated with innate immune responses, chemotaxis, and blood vessel differentiation compared to untreated organoids. Conclusions: Our co-culture system provides novel, more ethical avenues to study host-pathogen interactions in the brain as alternative models to experimental infections in mice. Although our data support the use of brain organoids to model host-pathogen interactions during T. brucei infection as an alternative to in vivo models, future work is required to increase the complexity of the organoids ( e.g., addition of microglia and vasculature). We envision that the adoption of organoid systems is beneficial to researchers studying mechanisms of brain infection by protozoan parasites. Furthermore, organoid systems have the potential to be used to study other parasites that affect the brain significantly reducing the number of animals undergoing moderate and/or severe protocols associated with the study of neuroinflammation and brain infections.
-
Application of Flow Cytometric Analysis for Measuring Multiple Mitochondrial Parameters in 3D Brain Organoids.
Mitochondrial dysfunction is a common primary or secondary contributor to many types of neurodegeneration, and changes in mitochondrial mass, mitochondrial respiratory chain (MRC) complexes, and mitochondrial DNA (mtDNA) copy number often feature in these processes. Human brain organoids derived from human induced pluripotent stem cells (iPSCs) recapitulate the brain's three-dimensional (3D) cytoarchitectural arrangement and offer the possibility to study disease mechanisms and screen new therapeutics in a complex human system. Here, we report a unique flow cytometry-based approach to measure multiple mitochondrial parameters in iPSC-derived cortical organoids. This report details a protocol for generating cortical brain organoids from iPSCs, single-cell dissociation of generated organoids, fixation, staining, and subsequent flow cytometric analysis to assess multiple mitochondrial parameters. Double staining with antibodies against the MRC complex subunit NADH: Ubiquinone Oxidoreductase Subunit B10 (NDUFB10) or mitochondrial transcription factor A (TFAM) together with voltage-dependent anion-selective channel 1 (VDAC 1) permits assessment of the amount of these proteins per mitochondrion. Since the quantity of TFAM corresponds to the amount of mtDNA, it provides an indirect estimation of the number of mtDNA copies per mitochondrial content. This entire procedure can be completed within a span of 2-3 h. Crucially, it allows for the concurrent quantification of multiple mitochondrial parameters, including both total and specific levels relative to the mitochondrial mass.
-
Systematic time-dependent visualization and quantitation of the neurogenic rate in brain organoids.
Organoids mimicking the formation of the brain cortex have been demonstrated to be powerful tools for developmental studies as well as pathological investigations of brain malformations. Here, we report an integrated approach for the quantification of temporal neural production (neurogenic rate) in organoids derived from embryonic brains. Spherical tissue fragments with polarized cytoarchitectures were incubated in multiple cavities arranged in a polymethylmethacrylate chip. The time-dependent neurogenic rate in the organoids was monitored by the level of EGFP under the promoter of Tbr2, a transcription factor that is transiently expressed in neural fate-committed progenitors during corticogenesis. Importantly, our monitoring system exhibited a quick response to DAPT, a drug that promotes neural differentiation. Furthermore, we successfully quantified the temporal neurogenic rate in a large number of organoids by applying image processing that semi-automatically recognized the positions of organoids and measured their signal intensities from sequential images. Taken together, we provide a strategy to quantitate the neurogenic rate in brain organoids in a time-dependent manner, which will also be a potent method for monitoring organoid formation and drug activity in other tissue types.