As we all know, the brain is the collection of human intelligence and the most complex organ. With nearly 100 billion neurons and 100 trillion connections, the human brain is the most difficult to build organoid models due to its unique complexity. Since the official launch of the "China Brain Project" in 2021, brain organoid technology, as the world's cutting-edge technology, has provided important support for the basic research and clinical application of a variety of brain diseases in China.
Recently, Huante biological brainThe organ model has been successfully constructed, and the brain organoids based on embryonic stem cells (ESCS) or human induced pluripotent stem cells (HIPSCs) are artificially cultured and differentiated, and their functional tissue structure is similar to that of the brain, which can partially reproduce the process of human brain development and disease occurrenceIt is used to simulate human brain development and the occurrence of Parkinson's, Alzheimer's, stroke, depression and other diseases, as well as the study of the mechanism of nervous system diseases and drug screening models, to help a new era of brain science research!
BrainsResearch directions of organs.
At present, with the development of human induced pluripotent stem cell (iPSCs) technology, brain organoid research is hot in the field of neuroscience. As an emerging research tool, brain organoids play an increasingly important role in the field of scientific research, and are used for brain development, neurogenesis research, degenerative diseases, tumors and other brain diseases, etc., bringing hope for understanding the human brain and analyzing a variety of biological and medical problems, showing great application potential. His research interests mainly include the following aspects:
Construct models of neurological diseases.
By constructing brain organoid models, radioglial cells, intermediate precursor cells, deep and superficial neurons can be observed in brain-like tissues, which is a unique and excellent tool for simulating the physiological characteristics of the human brain. Therefore, the construction of brain organoid neurological disease models, such as autism, mental disorder, Alzheimer's disease, ALS, etc., is helpful to study the pathogenesis of diseases by simulating the pathological process of brain diseases, and provides strong support for drug screening and methods.
Drug Screening & Personalization**.
Brain organoids can be used as a drug screening platform, based on the high-throughput screening system and classified phenotypic fingerprints, to construct a compound library with unknown targets, test potential drug compounds, and evaluate the efficacy of drug candidates for neurological diseases and can also be combined with gene editing technology to construct brain organoids with specific gene mutations, identify gene switches, and study personalized protocols.
Research on brain development and neurogenesis.
Brain organoids can simulate the process of brain development, obtain complex neural structures by fusing different exogenous brain-like tissues, explore the early development of the brain, and use them for epigenetic research of brain development processes and neurogenesis, neuronal differentiation, synapse formation and other processes, so as to help to understand the molecular mechanisms and signaling pathways of brain development, study the impact of epigenetic signaling molecules on neurodevelopment in the embryonic stage, and provide theoretical support for the prevention and development of neurological diseases.
Research on the mechanism of nerve regeneration and repair.
Brain organoids can also be used to study the mechanism of nerve regeneration and repair, establish phenotypic defects in neural mechanisms such as neurogenesis, nerve survival, axon outgrowth and calcium homeostasis, and help to discover the key factors and signaling pathways that promote nerve regeneration and repair by simulating the repair process after nerve injury, and provide new ideas and methods for the development of nervous system injury.
BrainsorgansHow to cultivate?
Currently, two types of stem cells can be used to obtain organoids: pluripotent stem cells (PSCs) and tissue stem cells (TSCS). Recently, Huante Biotech has successfully constructed a brain organoid model, which differentiates into a three-dimensional tissue similar to the human brain through human-derived induced pluripotent stem cells (iPSCs)** in a culture medium that simulates the brain development environment, providing a new research model for the study of human brain development and function, disease occurrence, drug discovery, etc.
Huante Biotech relies on more than 10 years of experience in gene editing, organoids and zebrafish technical servicesLiveBrain organoid-related reagents, andWe are committed to carrying out IPSCS brain organoid construction and identification for customers, forebrain organoid injury model construction and other technologiestechnical servicesto make brain science research more effective with half the effort. So, how are brain organoids cultured?
iPSCs** Brain Organoid Construction Method.
Based on human induced pluripotent stem cells (iPSCs), after the iPSCs are cultured in 3D to form embryoid bodies, EBs are induced to differentiate to form neural progenitor cells with self-renewal ability, and then the 3D culture stage is further extended to form a more complex hierarchical structure, similar to the developing cerebral cortex.
Specifically, neural progenitor cells can self-organize to form a continuous organization of neuroepithelial cells, and as these brain regionalized structures develop, neurons produced by neural progenitor cells migrate from the germinal zone to the basal region. This cell stratification and neural cell migration is very similar to that of the developing human brain. Thus, iPSCs-induced brain organoids are aggregates of 3D cells that can self-organize to reconstruct some endogenous tissues and exhibit similar physiological characteristics to the human brain. Brain organoid construction by iPSCs**,It can deliver constructed organoids (fixed organoids), organoid brightfield microscopy identification, and organoid marker identificationWait. The schematic diagram is as follows:
Figure 1Typical brightfield diagrams of different stages of brain organoid culture.
Figure 2Typical diagram of neural stem cells, forebrain markers, and neuronal markers.
Methods for constructing a model of injury to forebrain organoids.
Based on the normal forebrain organoid strain of human induced pluripotent stem cells (iPSCs)**, an alcohol-induced brain organoid injury model and an FBS-induced brain neurological injury model were constructed.
In normal brains, due to the presence of the blood-brain barrier (BBB), brain tissue cannot directly contact related substances in the blood. Under certain injury conditions, the permeability of the blood-brain barrier of brain tissue is changed, resulting in the leakage of substances in the blood into the brain tissue, which causes an inflammatory response in the brain tissue and causes brain damage. Therefore, FBS can be used to expose brain organoids in vitro to simulate this damage process and find relevant methods.
SOX2 is a protein that characterizes neurostemness, and in the process of brain development, SOX2 should be distributed in a rosette structure, and under the condition of injury, the development of brain organs will be disturbed and affect neurostemness, so the expression of SOX2 can reflect the damage of brain organoids.
In apoptosis, chromosomal DNA double-strand breaks or single-strand breaks produce a large amount of stickiness3'-OH-terminus, which labels deoxyribonucleotides and derivatives formed by fluorescein, peroxidase, alkaline phosphatase, or biotin to DNA in the presence of deoxyribonucleotide terminal transferases (TDTs)3'-terminal, which allows for the detection of apoptotic cells, and this method is called terminal-deoxynucleotidyl transferase mediated nick end labeling (tunel). Since normal or proliferating cells have little to no DNA breakage, there is none3'-OH is formed and is rarely able to be stained. Thus, TUNEL staining can be used to reflect apoptosis.
Through the construction of the forebrain organoid injury model, the fluorescence staining of brain organoids SOX2 and the TUNEL staining of brain organoids were evaluated, and the damage of forebrain organoids and the mechanism of occurrence were evaluated**and**. The schematic diagram is as follows:
Figure 1Typical image of SOX2 fluorescence staining of brain organoids treated with alcohol and FBS.
Figure 2Typical image of TUNEL staining of brain organoids treated with alcohol and FBS.
BrainsCutting-edge application cases of organs.
The brain is a complex and sophisticated network of cells. At present, with the continuous improvement of brain organoid models, many innovative breakthrough studies have emerged in the modeling and research of complex brain diseases such as autism and ALS, the research of nerve regeneration and repair, and the study of brain development and neurogenesis mechanisms, which provide new opportunities for the development of brain science and neuroscience, and are expected to bring revolutionary breakthroughs to the development of neurological diseases and drug development. The progress of the international frontier application of brain organoids is as follows
Disease modeling and research applications.
In terms of disease modeling, brain organoids are widely used to simulate neurological diseases, such as autism, ALS, RTT syndrome, Parkinson's disease, and Alzheimer's disease. By constructing disease-related brain organoid models, researchers can gain a deeper understanding of the pathogenesis of disease, providing a powerful tool for drug discovery and new drug screening.
Autism:In October 2023, scientists from Austria and Switzerland published a report in Nature (Impact Factor=64.).8) Publish the latest research**, which pioneered the integration of human brain organoids, single-cell gene sequencing and gene editing technology, so as to achieve high-throughput, high-precision, and high-robust comprehensive testing of gene mutations and cell types that form autism developmental defects at the single-cell level of human brain organoids, bringing new hope for the study of the most complex brain diseases.
ALS:The damage of motor neurons can cause muscles to contract normally, affecting the body's ability to exercise, and "ALS" is one of the representatives. For the first time, a Stanford research team has successfully generated a three-dimensional model of the human neural circuits responsible for voluntary movement. They used iPSC technology to generate three types of organs—the cerebral cortex, spinal cord, and skeletal muscle—and "assembled" them on their own in a petri dish, opening up a new perspective on ALS**. 
The figure shows a PSC-derived human cerebral cortex-motor organoid assembly.
RTT Syndrome:RTT syndrome is a disorder that severely affects children's psychomotor development, and its ** is a mutation in the MECP2 gene on the X chromosome. Due to the lack of effective methods and the inability of traditional 2D and 3D cultured cells to characterize diseases, researchers used brain organoid models to conduct research. By culturing brain organoids from different regions of the brain separately and combining these organoids for detection with high-resolution MEA, it will help to better understand the pathogenesis of RTT syndrome and provide clues for future **.
Zika virus:Researchers used brain organoids to reveal the pathogenic mechanism of congenital cranial defects (microcephaly) caused by Zika virus, found that human neural progenitor cells are the direct targets of Zika virus, and used brain organoid models to conduct drug screening, and found a small molecule inhibitor with the most potential. This provides a new drug candidate for Zika virus.
Application in drug screening and personalization**.
Since the birth of brain organoid technology, human brain organoids differentiated from induced pluripotent stem cells (iPSCs) from patients** have broad prospects in drug screening, preclinical testing, and personalization as an excellent model for studying the mechanism of human endemic brain diseases.
A 2021 study showed that human brain organoids with Down syndrome had a defect in cortical development, which could be rescued by interfering with DSCAM gene expression and inhibiting the downstream molecule PAK1. In this way, in vitro-induced human brain organoids can not only be used for diseases, but also become a good tool for disease program screening, providing a humanized model for researchers studying neurological diseases.
Recently, Pascal, a neuroscientist at Stanford University, led his team to publish a new research article on brain organoids in the top international journal Nature. In this study, the researchers induced differentiation of human pluripotent stem cells into cerebral cortical organoids and transplanted them in situ into the somatosensory cortex of neonatal athymic rats to construct a human-mouse hybrid brain organoid, T-HCO. This organoid can not only grow normally in rats and exhibit normal brain physiology, but also participate in the brain's neural circuits that control behavior. This research provides a new strategy for the research of neurodegenerative diseases of the brain and the development of new drugs.
In addition, it has been shown that brain organoids respond to established antiprism protein compounds, and they have great potential as drug screening models.
Applications in the study of brain development.
On January 8, 2024, researchers at the Princess Máxima Centre for Pediatric Oncology in the Netherlands, among others, have opened up a completely new approach by developing brain organoids directly from the brain tissue of human fetuses, providing a valuable means of studying the development and ** of diseases related to brain development, including brain tumors. The study was published in the journal Cell under the title Human Fetal Brain Self-Organizes Into Long-Term Expanding Organoids.
In this study, the researchers found that healthy human fetal brain tissue self-organizes into organoids (febos) in vitro, exhibiting similar heterogeneity and complex tissues as cells in vivo. The growth of Febos is required to maintain the integrity of the tissue, which guarantees the generation of the tissue extracellular matrix (ECM) niche, which ultimately gives Febos the ability to expand. Using CRISPR-Cas9 gene editing technology, the researchers also demonstrated the generation of syngeneically mutant Febos cell lines for brain cancer research.
*:Application of human fetal brain self-organizes into long-term expanding organoids in the study of nerve regeneration and repair.
Brain organoids also play an important role in the study of neural regeneration and repair. Researchers use brain organoid models to study the differentiation, migration, and synapse formation of neural stem cells, providing new ideas and methods for neural regenerative medicine.
In November 2023, the Florent Ginhoux team from the National University of Singapore published a report in Nature (Impact Factor: IF=64.).8) Publish the latest research results to reveal the role of microglia in human brain development through brain organoids. In this study, macrophages of pluripotent stem cells** were co-cultured with brain organoids to mimic the characteristics of embryonic microglia, which can synthesize cholesterol and store it in lipid droplets, which can be taken up by neuronal precursor cells, affecting neuronal precursor cell maturation and differentiation. Brain organoids provide a powerful model for future neuroscience research and neurological diseases.
*:IPS-cell-derived microglia promote brain organoid maturation via cholesterol transferIn recent years, with the continuous development of organoid technology, it has provided new possibilities for disease**, new drug research and development, and mechanism research. Relying on the 4 major technology platforms of zebrafish + mammals + organoids + gene editing, based on the continuous technological innovation practice of the past 10 years, and with professional and cutting-edge technical service solutions, Huante Bio helps researchers make more breakthroughs in the application of organoid technology and scientific research, jointly explore more unknowns, and create a new era of brain science research!