Neural Progenitor Cells Research Articles

Increased spontaneous activity and progressive suppression of adult neurogenesis in the hippocampus of rat offspring after maternal exposure to imidacloprid

Imidacloprid (IMI) is a widely used neonicotinoid insecticide that poses risks for developmental neurotoxicity in mammals. The present study investigated the effects of maternal exposure to IMI on behaviors and adult neurogenesis in the hippocampal dentate gyrus (DG) of rat offspring. Dams were exposed to IMI via diet (83, 250, or 750 ppm in diet) from gestational day 6 until day 21 post-delivery on weaning, and offspring were maintained until adulthood on postnatal day 77. In the neurogenic niche, 750-ppm IMI decreased numbers of late-stage neural progenitor cells (NPCs) and post-mitotic immature granule cells by suppressing NPC proliferation and ERK1/2–FOS-mediated synaptic plasticity of granule cells on weaning. Suppressed reelin signaling might be responsible for the observed reductions of neurogenesis and synaptic plasticity. In adulthood, IMI at ≥ 250 ppm decreased neural stem cells by suppressing their proliferation and increasing apoptosis, and mature granule cells were reduced due to suppressed NPC differentiation. Behavioral tests revealed increased spontaneous activity in adulthood at 750 ppm. IMI decreased hippocampal acetylcholinesterase activity and Chrnb2 transcript levels in the DG on weaning and in adulthood. IMI increased numbers of astrocytes and M1-type microglia in the DG hilus, and upregulated neuroinflammation and oxidative stress-related genes on weaning. In adulthood, IMI increased malondialdehyde level and number of M1-type microglia, and downregulated neuroinflammation and oxidative stress-related genes. These results suggest that IMI persistently affected cholinergic signaling, induced neuroinflammation and oxidative stress during exposure, and increased sensitivity to oxidative stress after exposure in the hippocampus, causing hyperactivity and progressive suppression of neurogenesis in adulthood. The no-observed-adverse-effect level of IMI for offspring behaviors and hippocampal neurogenesis was determined to be 83 ppm (5.5–14.1 mg/kg body weight/day).

Cell-type-specific loops linked to RNA polymerase II elongation in human neural differentiation

DNA is folded into higher-order structures that shape and are shaped by genome function. The role of long-range loops in the establishment of new gene expression patterns during cell fate transitions remains poorly understood. Here, we investigate the link between cell-specific loops and RNA polymerase II (RNA Pol II) during neural lineage commitment. We find thousands of loops decommissioned or gained de novo upon differentiation of human induced pluripotent stem cells (hiPSCs) to neural progenitor cells (NPCs) and post-mitotic neurons. During hiPSC-to-NPC and NPC-to-neuron transitions, genes changing from RNA Pol II initiation to elongation are >4-fold more likely to anchor cell-specific loops than repressed genes. Elongated genes exhibit significant mRNA upregulation when connected in cell-specific promoter-enhancer loops but not invariant promoter-enhancer loops or promoter-promoter loops or when unlooped. Genes transitioning from repression to RNA Pol II initiation exhibit a slight mRNA increase independent of loop status. Our data link cell-specific loops and robust RNA Pol II-mediated elongation during neural cell fate transitions.

Comprehensive characterization of the neurogenic and neuroprotective action of a novel TrkB agonist using mouse and human stem cell models of Alzheimer’s disease

BackgroundNeural stem cell (NSC) proliferation and differentiation in the mammalian brain decreases to minimal levels postnatally. Nevertheless, neurogenic niches persist in the adult cortex and hippocampus in rodents, primates and humans, with adult NSC differentiation sharing key regulatory mechanisms with development. Adult neurogenesis impairments have been linked to Alzheimer’s disease (AD) pathology. Addressing these impairments by using neurotrophic factors is a promising new avenue for therapeutic intervention based on neurogenesis. However, this possibility has been hindered by technical difficulties of using in-vivo models to conduct screens, including working with scarce NSCs in the adult brain and differences between human and mouse models or ethical limitations.MethodsHere, we use a combination of mouse and human stem cell models for comprehensive in-vitro characterization of a novel neurogenic compound, focusing on the brain-derived neurotrophic factor (BDNF) pathway. The ability of ENT-A011, a steroidal dehydroepiandrosterone derivative, to activate the tyrosine receptor kinase B (TrkB) receptor was tested through western blotting in NIH-3T3 cells and its neurogenic and neuroprotective action were assessed through proliferation, cell death and Amyloid-β (Aβ) toxicity assays in mouse primary adult hippocampal NSCs, mouse embryonic cortical NSCs and neural progenitor cells (NPCs) differentiated from three human induced pluripotent stem cell lines from healthy and AD donors. RNA-seq profiling was used to assess if the compound acts through the same gene network as BDNF in human NPCs.ResultsENT-A011 was able to increase proliferation of mouse primary adult hippocampal NSCs and embryonic cortical NSCs, in the absence of EGF/FGF, while reducing Aβ-induced cell death, acting selectively through TrkB activation. The compound was able to increase astrocytic gene markers involved in NSC maintenance, protect hippocampal neurons from Αβ toxicity and prevent synapse loss after Aβ treatment. ENT-A011 successfully induces proliferation and prevents cell death after Aβ toxicity in human NPCs, acting through a core gene network shared with BDNF as shown through RNA-seq.ConclusionsOur work characterizes a novel BDNF mimetic with preferable pharmacological properties and neurogenic and neuroprotective actions in Alzheimer’s disease via stem cell-based screening, demonstrating the promise of stem cell systems for short-listing competitive candidates for further testing.

Co-Transplantation-Based Human-Mouse Chimeric Brain Models to Study Human Glial-Glial and Glial-Neuronal Interactions.

Human-mouse chimeric brain models, generated by transplanting human induced pluripotent stem cell (hiPSC)-derived neural cells, are valuable for studying the development and function of human neural cells in vivo. Understanding glial-glial and glial-neuronal interactions is essential for unraveling the complexities of brain function and developing treatments for neurological disorders. To explore these interactions between human neural cells within an intact brain environment, we employe a co-transplantation strategy involving the engraftment of hiPSC-derived neural progenitor cells along with primitive macrophage progenitors into the neonatal mouse brain. This approach creates human-mouse chimeric brains containing human microglia, macroglia (astroglia and oligodendroglia), and neurons. Using super-resolution imaging and 3D reconstruction techniques, we examine the dynamics between human neurons and glia, unveiling human microglia engulfing immature human neurons, microglia pruning synapses of human neurons, and significant interactions between human oligodendrocytes and neurons. Single-cell RNA sequencing analysis of the chimeric brain uncovers a close recapitulation of the human glial progenitor cell population, along with a dynamic stage in astroglial development that mirrors the processes found in the human brain. Furthermore, cell-cell communication analysis highlights significant neuronal-glial and glial-glial interactions, especially the interaction between adhesion molecules neurexins and neuroligins. This innovative co-transplantation model opens up new avenues for exploring the complex pathophysiological mechanisms underlying human neurological diseases. It holds particular promise for studying disorders where glial-neuronal interactions and non-cell-autonomous effects play crucial roles.

Neural progenitor-derived Apelin controls tip cell behavior and vascular patterning.

During angiogenesis, vascular tip cells guide nascent vascular sprouts to form a vascular network. Apelin, an agonist of the G protein-coupled receptor Aplnr, is enriched in vascular tip cells, and it is hypothesized that vascular-derived Apelin regulates sprouting angiogenesis. We identify an apelin-expressing neural progenitor cell population in the dorsal neural tube. Vascular tip cells exhibit directed elongation and migration toward and along the apelin-expressing neural progenitor cells. Notably, restoration of neural but not vascular apelin expression in apelin mutants remedies the angiogenic defects of mutants. By functional analyses, we show the requirement of Apelin signaling for tip cell behaviors, like filopodia formation and cell elongation. Through genetic interaction studies and analysis of transgenic activity reporters, we identify Apelin signaling as a modulator of phosphoinositide 3-kinase and extracellular signal-regulated kinase signaling in tip cells in vivo. Our results suggest a previously unidentified neurovascular cross-talk mediated by Apelin signaling that is important for tip cell function during sprouting angiogenesis.

TSC2 loss in neural progenitor cells suppresses translation of ASD/NDD-associated transcripts in an mTORC1- and MNK1/2-reversible fashion.

Tuberous sclerosis complex (TSC) is an inherited neurodevelopmental disorder (NDD) with frequent manifestations of epilepsy and autism spectrum disorder (ASD). TSC is caused by inactivating mutations in TSC1 or TSC2 tumor suppressor genes, with encoded proteins hamartin (TSC1) and tuberin (TSC2) forming a functional complex inhibiting mechanistic target of rapamycin complex 1 (mTORC1) signaling. This has led to treatment with allosteric mTORC1 inhibitor rapamycin analogs ("rapalogs") for TSC tumors; however, rapalogs are ineffective for treating neurodevelopmental manifestations. mTORC1 signaling controls protein synthesis by regulating formation of the eIF4F complex, with further modulation by MNK1/2 kinases via phosphorylation of the eIF4F subunit eIF4E. While both these pathways modulate translation, comparing their impact on transcriptome-wide mRNA translation, as well as effects of inhibiting these pathways in TSC has not been explored. Here, employing CRISPR-modified, isogenic TSC2 patient-derived neural progenitor cells (NPCs), we have examined transcriptome-wide changes in mRNA translation upon TSC2 loss. Our results reveal dysregulated translation in TSC2 -Null NPCs, which significantly overlaps with the translatome from TSC1 -Null NPCs. Interestingly, numerous non-monogenic ASD-, NDD-and epilepsy-associated genes identified in patients harboring putative loss-of-function mutations, were translationally suppressed in TSC2 -Null NPCs. Importantly, translation of these ASD- and NDD-associated genes was reversed upon inhibition of either mTORC1 or MNK1/2 signaling using RMC-6272 or eFT-508, respectively. This study establishes the importance of mTORC1-eIF4F- and MNK-eIF4E-sensitive mRNA translation in TSC, ASD and other neurodevelopmental disorders laying the groundwork for evaluating drugs in clinical development that target these pathways as a treatment strategy for these disorders.

SRSF10 regulates migration of neural progenitor cells and granule cells and affects the formation of dentate gyrus during the development of mouse hippocampus

Hippocampus is a critical component of the central nervous system. SRSF10 is expressed in central nervous system and plays important roles in maintaining normal brain functions. However, its role in hippocampus development is unknown. In this study, using SRSF10 conditional knock-out mice in neural progenitor cells (NPCs), we found that dysfunction of SRSF10 leads to developmental defects in the dentate gyrus of hippocampus, which manifests as the reduced length and wider suprapyramidal blade and infrapyramidal blade.Furthermore, we proved that loss of SRSF10 in NPCs caused inhibition of the differentiation activity and the abnormal migration of NPCs and granule cells, resulting in reduced granule cells and more ectopic granule cells dispersed in the molecular layer and hilus. Finally, we found that the abnormal migration may be caused by the radial glia scaffold and the reduced DISC1 expression in NPCs. Together, our results indicate that SRSF10 is required for the cell migration and formation of dentate gyrus during the development of hippocampus.

GDF-15 Attenuates the Epithelium-Mesenchymal Transition and Alleviates TGFβ2-Induced Lens Opacity.

We sought to evaluate the efficacy of growth differentiation factor (GDF)-15 treatment for suppressing epithelial-mesenchymal transition (EMT) and alleviating transforming growth factor β2 (TGFβ2)-induced lens opacity. To test whether GDF-15 is a molecule that prevents EMT, we pretreated the culture with GDF-15 in neural progenitor cells, retinal pigment epithelial cells, and lens epithelial cells and then treated with factors that promote EMT, GDF-11, and TGFβ2, respectively. To further investigate the efficacy of GDF-15 on alleviating lens opacity, we used mouse lens explant culture to mimic secondary cataracts. We pretreated the lens culture with GDF-15 and then added TGFβ2 to develop lens opacity (n = 3 for each group). Western blot and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to measure EMT protein and gene expression, respectively. In cell culture, GDF-15 pretreatment significantly attenuated EMT marker expression in cultured cells induced by treatment with GDF-11 or TGFβ2. In the lens explant culture, GDF-15 pretreatment also reduced mouse lens opacity induced by exposure to TGFβ2. Our results indicate that GDF-15 could alleviate TGFβ2-induced EMT and is a potential therapeutic agent to slow or prevent posterior capsular opacification (PCO) progression after cataract surgery. Cataracts are the leading cause of blindness worldwide, with the only current treatment involving surgical removal of the lens and replacement with an artificial lens. However, PCO, also known as secondary cataract, is a common complication after cataract surgery. The development of an adjuvant that slows the progression of PCO will be beneficial to the field of anterior complications.

Indirect neurogenesis in space and time.

During central nervous system (CNS) development, neural progenitor cells (NPCs) generate neurons and glia in two different ways. In direct neurogenesis, daughter cells differentiate directly into neurons or glia, whereas in indirect neurogenesis, neurons or glia are generated after one or more daughter cell divisions. Intriguingly, indirect neurogenesis is not stochastically deployed and plays instructive roles during CNS development: increased generation of cells from specific lineages; increased generation of early or late-born cell types within a lineage; and increased cell diversification. Increased indirect neurogenesis might contribute to the anterior CNS expansion evident throughout the Bilateria and help tomodify brain-region size without requiring increased NPC numbers or extended neurogenesis. Increased indirect neurogenesis could be an evolutionary driver of the gyrencephalic (that is, folded) cortex that emerged during mammalian evolution and might even have increased during hominid evolution. Thus, selection of indirect versus direct neurogenesis provides a powerful developmental and evolutionary instrument that drives not only the evolution of CNS complexity but also brain expansion and modulation of brain-region size, and thereby the evolution of increasingly advanced cognitive abilities. This Review describes indirect neurogenesis in several model species and humans, and highlights some of the molecular genetic mechanisms that control this important process.

The Effect of Bone Marrow Mesenchymal Stem Cells on Nestin and Sox-2 Gene Expression and Spatial Learning (Percent Alternation Y-Maze Test) against AlCl3-Induced Alzheimer's-like Pathology in a Rat Model.

Alzheimer's disease (AD) is a neurodegenerative condition characterized by gradual cognitive impairment, including loss of synapses and nerve cells involved in learning, memory, and habit formation processes. Bone Marrow Mesenchymal Stem Cells (BM-MSCs) are multipotent cells. Because of their self-renewable, differentiation, and immunomodulatory capabilities, they are commonly used to treat many disorders. Hence, the current study intends to examine the effect of BM-MSCs transplantation on Aluminum chloride (AlCl3)-induced cognitive problems, an experimental model resembling AD's hallmarks in rats. The study was conducted in 2022 at The Biomedical Laboratory Faculty of Medicine, Andalas University, Indonesia. Adult male Wistar rats (three groups: negative control; no intervention+treatment with PBS; positive control: AlCl3+treatment with aqua dest; AlCl3+BM-MSCs: AlCl3+treatment with BM-MSCs, n=5 each) were treated daily with AlCl3 orally for five days. Stem cells were intraperitoneally injected into rats at a dose of 1x106 cells/rat. The same quantity of phosphate-buffered saline was given to the control group. One month after stem cell injection, the rat brain tissue was removed and placed in the film bottles that had been created. The expression of neural progenitor cell markers, including nestin and sex-determining Y-box 2 (SOX-2), was analyzed using real-time polymerase chain reaction (RT-PCR). Rats' cognitive and functional memory were examined using Y-maze. Data were analyzed using SPSS software (version 26.0) with a one-way analysis of variance (ANOVA) test. The gene expression of nestin (29.74±0.42), SOX-2 (31.44±0.67), and percent alternation of Y-maze (67.04±2.28) increased in the AlCl3+BM-MSCs group compared to that in the positive control group. RT-PCR analysis indicated that nestin (P<0.001) and SOX-2 (P<0.001) were significantly enhanced in the AlCl3+BM-MSCs group compared to the positive control group. This group also indicated an increased percent alternation of Y-maze (P<0.001) in the AlCl3+BM-MSCs group compared to the positive control group. Due to its potential effects on cell therapy, BM-MSCs were found effective in a rat model of AD on the impairment of the rats' behavior and increased expression of neural progenitor cell markers.

Epistatic interactions between NMD and TRP53 control progenitor cell maintenance and brain size.

Mutations in human nonsense-mediated mRNA decay (NMD) factors are enriched in neurodevelopmental disorders. We show that deletion of key NMD factor Upf2 in mouse embryonic neural progenitor cells causes perinatal microcephaly but deletion in immature neurons does not, indicating NMD's critical roles in progenitors. Upf2 knockout (KO) prolongs the cell cycle of radial glia progenitor cells, promotes their transition into intermediate progenitors, and leads to reduced upper-layer neurons. CRISPRi screening identified Trp53 knockdown rescuing Upf2KO progenitors without globally reversing NMD inhibition, implying marginal contributionsof most NMD targets to the cell cycle defect. Integrated functional genomics shows that NMD degrades selective TRP53 downstream targets, including Cdkn1a, which, without NMD suppression, slow the cell cycle. Trp53KO restores the progenitor cell pool and rescues the microcephaly of Upf2KO mice. Therefore, one physiological role of NMD in the developing brain is to degrade selective TRP53 targets to control progenitor cell cycle and brain size.

STAMBP is Required for Long-Term Maintenance of Neural Progenitor Cells Derived from hESCs.

Mutations in STAMBP have been well-established to cause congenital human microcephaly-capillary malformation (MIC-CAP) syndrome, a rare genetic disorder characterized by global developmental delay, severe microcephaly, capillary malformations, etc. Previous biochemical investigations and loss-of-function studies in mice have provided insights into the mechanism of STAMBP, however, it remains controversial how STAMBP deficiency leads to malformation of those affected tissues in patients. In this study, we investigated the function and underlying mechanism of STAMBP during neural differentiation of human embryonic stem cells (hESCs). We found that STAMBP is dispensable for the pluripotency maintenance or neural differentiation of hESCs. However, neural progenitor cells (NPCs) derived from STAMBP-deficient hESCs fail to be long-term maintained/expanded in vitro. We identified the anti-apoptotic protein CFLAR is down-regulated in those affected NPCs and ectopic expression of CFLAR rescues NPC defects induced by STAMBP-deficiency. Our study not only provides novel insight into the mechanism of neural defects in STAMBP mutant patients, it also indicates that the death receptor mediated apoptosis is an obstacle for long-term maintenance/expansion of NPCs in vitro thus counteracting this cell death pathway could be beneficial to the generation of NPCs in vitro.

Brain Chimeroids reveal individual susceptibility to neurotoxic triggers.

Interindividual genetic variation affects the susceptibility to and progression of many diseases1,2. However, efforts to study how individual human brains differ in normal development and disease phenotypes are limited by the paucity of faithful cellular human models, and the difficulty of scaling current systems to represent multiple people. Here we present human brain Chimeroids, a highly reproducible, multidonor human brain cortical organoid model generated by the co-development of cells from a panel of individual donors in a single organoid. By reaggregating cells from multiple single-donor organoids at the neural stem cell or neural progenitor cell stage, we generate Chimeroids in which each donor produces all cell lineages of the cerebral cortex, even when using pluripotent stem cell lines with notable growth biases. We used Chimeroids to investigate interindividual variation in the susceptibility to neurotoxic triggers that exhibit high clinical phenotypic variability: ethanol and the antiepileptic drug valproic acid. Individual donors varied in both the penetrance of the effect on target cell types, and the molecular phenotype within each affected cell type. Our results suggest that human genetic background may be an important mediator of neurotoxin susceptibility and introduce Chimeroids as a scalable system for high-throughput investigation of interindividual variation in processes of brain development and disease.

Deciphering the dynamical chromosome structural reorganizations in human neural development

Understanding the mechanisms of cell-fate determination in neural development is pivotal for advancing regenerative medicine and addressing neurodegenerative diseases. Cell-fate determination is controlled by the underlying gene expression networks, which are further regulated by the three-dimensional chromosome structures. During neural development, chromosomes progressively adapt their structures to accommodate the requisite gene expressions. However, elucidating the pathways of chromosome structural dynamics during these transitions remains a grand challenge. In this study, we employed the data-driven coarse-grained molecular dynamics simulations, coupled with the nonequilibrium landscape-switching model, to quantify the chromosome structural dynamics during human neural development. We focused on a simplified human neural developmental system, comprising of cell differentiation, reprogramming, and transdifferentiation among the neural progenitor cell (NPC), the glia cell, and the neuron cell. We identified significant large-scale chromosome structural reorganizations during cell-state transitions. From the chromosome structural perspective, the transdifferentiation processes between the glia and neuron cells exhibited nonmonotonic behaviors characterized by an initial increase followed by a subsequent decrease in cell stemness. The transdifferentiation appeared to share the same routes of differentiation after passing through the NPC. Additionally, our findings revealed that the chromosome structural dynamical pathways at the scale of topologically associating domains exhibited little overlap, in contrast to the ones at the long-range regions. This suggests that the active, ATP-driven molecular processes play dominant roles in modulating topologically associating domain (TAD) structures, while the compartmental segregation in chromosomes is primarily governed by the passive phase separation. Our study offers a theoretical exploration of neural cell-fate determination from the chromosome structural perspective, paving a way for potential applications in neuroregeneration. Published by the American Physical Society 2024

Transplantation of Neural Progenitor Cells Derived from Stem Cells from Apical Papilla Through Small-Molecule Induction in a Rat Model of Sciatic Nerve Injury

Background:Stem cell-based transplantation therapy holds promise for peripheral nerve injury treatment, but adult availability is limited. A cell culture protocol utilizing a small-molecule cocktail effectively reprogrammed stem cells from apical papilla (SCAPs) into neural progenitor cells, subsequently differentiating into neuron-like cells. This study aims to evaluate neural-induced SCAPs, with and without small-molecule cocktail, for sciatic nerve repair potential.Methods:A scaffold-free cell sheet technique was used to construct a three-dimensional cell sheet. Subsequently, this cell sheet was carefully rolled into a tube and seamlessly inserted into a collagen conduit, which was then transplanted into a 5 mm sciatic nerve injury rat model. Functional sciatic nerve regeneration was evaluated via toe spread test, walking track analysis and gastrocnemius muscle weight. Additionally, degree of sciatic nerve regeneration was determined based on total amount of myelinated fibers.Results:Small-molecule cocktail induced SCAPs enhanced motor function recovery, evident in improved sciatic function index and gastrocnemius muscle retention. We also observed better host myelinated fiber retention than undifferentiated SCAPs or neural-induced SCAPs without small-molecule cocktail. However, clusters of neuron-like cell bodies (surrounded by sparse myelinated fibers) were found in all cell sheet-implanted groups in the implantation region. This suggests that while the implanted cells likely survived transplantation, integration was poor and would likely hinder long-term recovery by occupying the space needed for host nerve fibers to project through.Conclusion:Neural-induced SCAPs with small-molecule cocktail demonstrated promising benefits for nerve repair; further research is needed to improve its integration and optimize its potential for long-term recovery.

Expansion and differentiation of human neural stem cells on synthesized integrin binding peptide surfaces

The extracellular matrix plays a crucial role in the growth of human neural stem cells (hNSCs) by forming a stem cell niche, both in vitro and in vivo. The demand for defined synthetic substrates has been increasing recently in stem cell research, reflecting the requirements for precise functions and safety concerns in potential clinical approaches. In this study, we tested the adhesion and expansion of one of the most representative hNSC lines, the ReNcell VM Human Neural Progenitor Cell Line, in a pure-synthesized short peptide-based in vitro niche using a previously established integrin-binding peptide array. Spontaneous cell differentiation was then induced using two different in vitro approaches to further confirm the multipotent features of cells treated with the peptides. Twelve different integrin-binding peptides were capable of supporting hNSC adhesion and expansion at varied proliferation rates. In the ReNcell medium-based differentiation approach, cells detached in almost all peptide-based groups, except integrin α5β1 binding peptide. In an altered differentiation process induced by retinoic acid containing neural differentiation medium, cell adhesion was retained in all 12 peptide groups. These peptides also appeared to have varied effects on the differentiation potential of hNSCs towards neurons and astrocytes. Our findings provide abundant options for the development of in vitro neural stem cell niches and will help develop promising tools for disease modeling and future stem cell therapies for neurological diseases.

Integration of Functional Human Auditory Neural Circuits Based on a 3D Carbon Nanotube System.

The physiological interactions between the peripheral and central auditory systems are crucial for auditory information transmission and perception, while reliable models for auditory neural circuits are currently lacking. To address this issue, mouse and human neural pathways are generated by utilizing a carbon nanotube nanofiber system. The super-aligned pattern of the scaffold renders the axons of the bipolar and multipolar neurons extending in a parallel direction. In addition, the electrical conductivity of the scaffold maintains the electrophysiological activity of the primary mouse auditory neurons. The mouse and human primary neurons from peripheral and central auditory units in the system are then co-cultured and showed that the two kinds of neurons form synaptic connections. Moreover, neural progenitor cells of the cochlea and auditory cortex are derived from human embryos to generate region-specific organoids and these organoids are assembled in the nanofiber-combined 3D system. Using optogenetic stimulation, calcium imaging, and electrophysiological recording, it is revealed that functional synaptic connections are formed between peripheral neurons and central neurons, as evidenced by calcium spiking and postsynaptic currents. The auditory circuit model will enable the study of the auditory neural pathway and advance the search for treatment strategies for disorders of neuronal connectivity in sensorineural hearing loss.

Neural Progenitor Cell-Mediated Magnetic Nanoparticles for Magnetic Resonance Imaging and Photothermal Therapy of Glioma.

Glioma is the most common primary malignant tumor in the brain. The diagnostic accuracy and treatment efficiency of glioma are facing great challenges due to the presence of the blood-brain barrier (BBB) and the high infiltration of glioma. There is an urgent need to explore the combination of diagnostic and therapeutic approaches to achieve a more accurate diagnosis, as well as guidance before and after surgery. In this work, we induced human induction of pluripotent stem cell into neural progenitor cells (NPCs) and synthesized nanoprobes labeled with enhanced green fluorescent protein (EGFP, abbreviated as MFe3O4-labeled EGFP-NPCs) for photothermal therapy. Nanoprobes carried by NPCs can effectively penetrate the BBB and target glioma for the purpose of magnetic resonance imaging and guiding surgery. More importantly, MFe3O4-labeled EGFP-NPCs can effectively induce local photothermal therapy, conduct preoperative tumor therapy, and inhibit the recurrence of postoperative glioma. This work shows that MFe3O4-labeled EGFP-NPCs is a promising nanoplatform for glioma diagnosis, accurate imaging-guided surgery, and effective photothermal therapy.

Haloperidol, Olanzapine, and Risperidone Induce Morphological Changes in an In Vitro Model of Human Hippocampal Neurogenesis.

Induced pluripotent stem cell (iPSC) based neuronal differentiation is valuable for studying neuropsychiatric disorders and pharmacological mechanisms at the cellular level. We aimed to examine the effects of typical and atypical antipsychotics on human iPSC-derived neural progenitor cells (NPCs). Proliferation and neurite outgrowth were measured by live cell imaging, and gene expression levels related to neuronal identity were analyzed by RT-QPCR and immunocytochemistry during differentiation into hippocampal dentate gyrus granule cells following treatment of low- and high-dose antipsychotics (haloperidol, olanzapine, and risperidone). Antipsychotics did not modify the growth properties of NPCs after 3 days of treatment. However, the characteristics of neurite outgrowth changed significantly in response to haloperidol and olanzapine. After three weeks of differentiation, mRNA expression levels of the selected neuronal markers increased (except for MAP2), while antipsychotics caused only subtle changes. Additionally, we found no changes in MAP2 or GFAP protein expression levels as a result of antipsychotic treatment. Altogether, antipsychotic medications promoted neurogenesis in vitro by influencing neurite outgrowth rather than changing cell survival or gene expression. This study provides insights into the effects of antipsychotics on neuronal differentiation and highlights the importance of considering neurite outgrowth as a potential target of action.

Early transcriptional similarities between two distinct neural lineages during ascidian embryogenesis

In chordates, the central nervous system arises from precursors that have distinct developmental and transcriptional trajectories. Anterior nervous systems are ontogenically associated with ectodermal lineages while posterior nervous systems are associated with mesoderm. Taking advantage of the well-documented cell lineage of ascidian embryos, we asked to what extent the transcriptional states of the different neural lineages become similar during the course of progressive lineage restriction. We performed single-cell RNA sequencing (scRNA-seq) analyses on hand-dissected neural precursor cells of the two distinct lineages, together with those of their sister cell lineages, with a high temporal resolution covering five successive cell cycles from the 16-cell to neural plate stages. A transcription factor binding site enrichment analysis of neural specific genes at the neural plate stage revealed limited evidence for shared transcriptional control between the two neural lineages, consistent with their different ontogenies. Nevertheless, PCA analysis and hierarchical clustering showed that, by neural plate stages, the two neural lineages cluster together. Consistent with this, we identified a set of genes enriched in both neural lineages at the neural plate stage, including miR-124, Celf3.a, Zic.r-b, and Ets1/2. Altogether, the current study has revealed genome-wide transcriptional dynamics of neural progenitor cells of two distinct developmental origins. Our scRNA-seq dataset is unique and provides a valuable resource for future analyses, enabling a precise temporal resolution of cell types not previously described from dissociated embryos.