Differentiation Of Neural Progenitor Cells Research Articles

RING1 missense variants reveal sensitivity of DNA damage repair to H2A monoubiquitination dosage during neurogenesis

Polycomb repressive complex 1 (PRC1) modifies chromatin through catalysis of histone H2A lysine 119 monoubiquitination (H2AK119ub1). RING1 and RNF2 interchangeably serve as the catalytic subunit within PRC1. Pathogenic missense variants in PRC1 core components reveal functions of these proteins that are obscured in knockout models. While Ring1a knockout models remain healthy, the microcephaly and neuropsychiatric phenotypes associated with a pathogenic RING1 missense variant implicate unappreciated functions. Using an in vitro model of neurodevelopment, we observe that RING1 contributes to the broad placement of H2AK119ub1, and that its targets overlap with those of RNF2. PRC1 complexes harboring hypomorphic RING1 bind target loci but do not catalyze H2AK119ub1, reducing H2AK119ub1 by preventing catalytically active complexes from accessing the locus. This results in delayed DNA damage repair and cell cycle progression in neural progenitor cells (NPCs). Conversely, reduced H2AK119ub1 due to hypomorphic RING1 does not generate differential expression that impacts NPC differentiation. In contrast, hypomorphic RNF2 generates a greater reduction in H2AK119ub1 that results in both delayed DNA repair and widespread transcriptional changes. These findings suggest that the DNA damage response is more sensitive to H2AK119ub1 dosage change than is regulation of gene expression.

Cross-linking manipulation of waterborne biodegradable polyurethane for constructing mechanically adaptable tissue engineering scaffolds

Abstract Mechanical adaptation of tissue engineering scaffolds is critically important since natural tissue regeneration is highly regulated by mechanical signals. Herein, we report a facile and convenient strategy to tune the modulus of waterborne biodegradable polyurethanes (WBPU) via cross-linking manipulation of phase separation and water infiltration for constructing mechanically adaptable tissue engineering scaffolds. Amorphous aliphatic polycarbonate and trifunctional trimethylolpropane were introduced to polycaprolactone-based WBPUs to interrupt interchain hydrogen bonds in the polymer segments and suppress microphase separation, inhibiting the crystallization process and enhancing covalent cross-linking. Intriguingly, as the crosslinking density of WBPU increases and the extent of microphase separation decreases, the material exhibits a surprisingly soft modulus and enhanced water infiltration. Based on this strategy, we constructed WBPU scaffolds with a tunable modulus to adapt various cells for tissue regeneration and regulate the immune response. As a representative application of brain tissue regeneration model in vivo, it was demonstrated that the mechanically adaptable WBPU scaffolds can guide the migration and differentiation of endogenous neural progenitor cells into mature neurons and neuronal neurites and regulate immunostimulation with low inflammation. Therefore, the proposed strategy of tuning the modulus of WBPU can inspire the development of novel mechanically adaptable biomaterials, which has very broad application value.

Differentiation of Neural Progenitor Cells into Neurons

Differentiation of Neural Progenitor Cells into Neurons

Differentiation of Neural Progenitor Cells into Neurons

Differentiation of Neural Progenitor Cells into Neurons

Differentiation of Spinal Cord Neural Progenitor Cells into Motor Neurons

Differentiation of Spinal Cord Neural Progenitor Cells into Motor Neurons

Differentiation of Spinal Cord Neural Progenitor Cells into Motor Neurons

Differentiation of Spinal Cord Neural Progenitor Cells into Motor Neurons

BaTiO3 nanocrystals with tunable exposed {001} polar facets: A high-performance piezocatalyst and piezoelectric regenerative medicine

Piezocatalysis triggered by ultrasonic vibration has emerged as an effective strategy to address the widespread environmental challenges and human health concerns. Nevertheless, the pursuit of high-performance piezoelectrics that can simultaneously realize catalysis and biotherapy still poses a significant challenge. Herein, we report a notable enhancement in piezocatalytic performance of BaTiO3 nanoplates featuring highly exposed {001} facets. By controlling the exposure of polar facets, BaTiO3 with highly {001} facets (I{001}/I{110} = 4.17) exhibits an impressive 1500 % improvement in degradation efficiency compared to BaTiO3 with less-exposed {001} facets (I{001}/I{110} = 0.76). Through in vitro ultrasonic stimulation, BaTiO3 also demonstrates a remarkable ability to regenerate neurons, facilitating the rapid differentiation of neural progenitor cells into mature neurons. The mechanism of how polar facets enhance the piezocatalytic activity is systematically investigated by finite element method (FEM) simulation and density functional theory (DFT) calculations, revealing that the enhancement stems from the abundant active sites and strong charge transfer ability. This study thus offers a comprehensive understanding of the relationship between polar facets and piezocatalytic performance, also providing inspiration for the development of high-performance piezoelectric medicine for nerve repair.

Electrical Stimulation-Induced Differentiation of Neural Stem and Progenitor Cells

Electrical Stimulation-Induced Differentiation of Neural Stem and Progenitor Cells

A comprehensive protocol for efficient differentiation of human NPCs into electrically competent neurons

BackgroundThe study of neurons is fundamental to unraveling the complexities of the nervous system. Primary neuronal cultures from rodents have long been a cornerstone of experimental studies, yet limitations related to their non-human nature and ethical concerns have prompted the development of alternatives. In recent years, the derivation of neurons from human-induced pluripotent stem cells (hiPSCs) has emerged as a powerful option, offering a scalable source of cells for diverse applications. Neural progenitor cells (NPCs) derived from hiPSCs can be efficiently differentiated into functional neurons, providing a platform to study human neural physiology and pathology in vitro. However, challenges persist in achieving consistent and reproducible outcomes across experimental settings. Comparison with existing methodsOur aim is to provide a step-by-step methodological protocol, augmenting existing procedures with additional instructions and parameters, to guide researchers in achieving reproducible results. Methods and resultsWe outline procedures for the differentiation of hiPSC-derived NPCs into electrically competent neurons, encompassing initial cell density, morphology, maintenance, and differentiation. We also describe the analysis of specific markers for assessing neuronal phenotype, along with electrophysiological analysis to evaluate biophysical properties of neuronal excitability. Additionally, we conduct a comparative analysis of three different chemical methods—KCl, N-methyl-D-aspartate (NMDA), and bicuculline—to induce neuronal depolarization and assess their effects on the induction of both fast and slow post-translational, transcriptional, and post-transcriptional responses. ConclusionOur protocol provides clear instructions for generating reliable human neuronal cultures with defined electrophysiological properties to investigate neuronal differentiation and model diseases in vitro.

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).

The Gap Junction Inhibitor Octanol Decreases Proliferation and Increases Glial Differentiation of Postnatal Neural Progenitor Cells.

Neural precursor cells (NPCs) that persist in the postnatal/adult subventricular zone (SVZ) express connexins that form hemichannels and gap junctions. Gap junctional communication plays a role in NPC proliferation and differentiation during development, but its relevance on postnatal age remains to be elucidated. In this work we aimed to evaluate the effect of the blockade of gap junctional communication on proliferation and cell fate of NPCs obtained from the SVZ of postnatal rats. NPCs were isolated and expanded in culture as neurospheres. Electron microscopy revealed the existence of gap junctions among neurosphere cells. Treatment of cultures with octanol, a broad-spectrum gap junction blocker, or with Gap27, a specific blocker for gap junctions formed by connexin43, produced a significant decrease in bromodeoxyuridine incorporation. Octanol treatment also exerted a dose-dependent antiproliferative effect on glioblastoma cells. To analyze possible actions on NPC fate, cells were seeded in the absence of mitogens. Treatment with octanol led to an increase in the percentage of astrocytes and oligodendrocyte precursors, whereas the percentage of neurons remained unchanged. Gap27 treatment, in contrast, did not modify the differentiation pattern of SVZ NPCs. Our results indicate that general blockade of gap junctions with octanol induces significant effects on the behavior of postnatal SVZ NPCs, by reducing proliferation and promoting glial differentiation.

YAP and TAZ differentially regulate postnatal cortical progenitor proliferation and astrocyte differentiation.

WW domain-containing transcription regulator 1 (WWTR1, referred to here as TAZ) and Yes-associated protein (YAP, also known as YAP1) are transcriptional co-activators traditionally studied together as a part of the Hippo pathway, and are best known for their roles in stem cell proliferation and differentiation. Despite their similarities, TAZ and YAP can exert divergent cellular effects by differentially interacting with other signaling pathways that regulate stem cell maintenance or differentiation. In this study, we show in mouse neural stem and progenitor cells (NPCs) that TAZ regulates astrocytic differentiation and maturation, and that TAZ mediates some, but not all, of the effects of bone morphogenetic protein (BMP) signaling on astrocytic development. By contrast, both TAZ and YAP mediate the effects on NPC fate of β1-integrin (ITGB1) and integrin-linked kinase signaling, and these effects are dependent on extracellular matrix cues. These findings demonstrate that TAZ and YAP perform divergent functions in the regulation of astrocyte differentiation, where YAP regulates cell cycle states of astrocytic progenitors and TAZ regulates differentiation and maturation from astrocytic progenitors into astrocytes.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

SERS-based long-term mitochondrial pH monitoring during differentiation of human induced pluripotent stem cells to neural progenitor cells

As one of the important organelles in the process of cell differentiation, mitochondria regulate the whole process of differentiation by participating in energy supply and information transmission. Mitochondrial pH value is a key indicator of mitochondrial function. Therefore, real-time monitoring of mitochondrial pH value during cell differentiation is of great significance for understanding cell biochemical processes and exploring differentiation mechanisms. In this study, Surface-enhanced Raman scattering (SERS) technology was used to achieve the real-time monitoring of mitochondrial pH during induced pluripotent stem cells (iPSCs) differentiation into neural progenitor cells (NPCs). The results showed that the variation trend of mitochondrial pH in normal and abnormal differentiated batches was different. The mitochondrial pH value of normal differentiated cells continued to decline from iPSCs to embryoid bodies (EB) day 4, and continued to rise from EB day 4 to the NPCs stage, and the mitochondrial microenvironment of iPSCs to NPCs differentiation became acidic. In contrast, the mitochondrial pH value of abnormally differentiated cells declined continuously during differentiation. This study improves the information on acid-base balance during cell differentiation and may provide a basis for further understanding of the changes and regulatory mechanisms of mitochondrial metabolism during cell differentiation. This also helps to improve more accurate and useful differentiation protocols based on the microenvironment within the mitochondria, improving the efficiency of cell differentiation.

Harnessing developmental dynamics of spinal cord extracellular matrix improves regenerative potential of spinal cord organoids

Neonatal spinal cord tissues exhibit remarkable regenerative capabilities as compared to adult spinal cord tissues after injury, but the role of extracellular matrix (ECM) in this process has remained elusive. Here, we found that early developmental spinal cord had higher levels of ECM proteins associated with neural development and axon growth, but fewer inhibitory proteoglycans, compared to those of adult spinal cord. Decellularized spinal cord ECM from neonatal (DNSCM) and adult (DASCM) rabbits preserved these differences. DNSCM promoted proliferation, migration, and neuronal differentiation of neural progenitor cells (NPCs) and facilitated axonal outgrowth and regeneration of spinal cord organoids more effectively than DASCM. Pleiotrophin (PTN) and Tenascin (TNC) in DNSCM were identified as contributors to these abilities. Furthermore, DNSCM demonstrated superior performance as a delivery vehicle for NPCs and organoids in spinal cord injury (SCI) models. This suggests that ECM cues from early development stages might significantly contribute to the prominent regeneration ability in spinal cord.

Reduced mTORC1-signaling in progenitor cells leads to retinal lamination deficits.

Neuronal lamination is a hallmark of the mammalian central nervous system (CNS) and underlies connectivity and function. Initial formation of this tissue architecture involves the integration of various signaling pathways that regulate the differentiation and migration of neural progenitor cells. Here, we demonstrate that mTORC1 mediates critical roles during neuronal lamination using the mouse retina as a model system. Down-regulation of mTORC1-signaling in retinal progenitor cells by conditional deletion of Rptor led to decreases in proliferation and increased apoptosis during embryogenesis. These developmental deficits preceded aberrant lamination in adult animals which was best exemplified by the fusion of the outer and inner nuclear layer and the absence of an outer plexiform layer. Moreover, ganglion cell axons originating from each Rptor-ablated retina appeared to segregate to an equal degree at the optic chiasm with both contralateral and ipsilateral projections displaying overlapping termination topographies within several retinorecipient nuclei. In combination, these visual pathway defects led to visually mediated behavioral deficits. This study establishes a critical role for mTORC1-signaling during retinal lamination and demonstrates that this pathway regulates diverse developmental mechanisms involved in driving the stratified arrangement of neurons during CNS development.

DMRTA2 supports glioma stem-cell mediated neovascularization in glioblastoma

Glioblastoma (GBM) is the most common and lethal brain tumor in adults. Due to its fast proliferation, diffusive growth and therapy resistance survival times are less than two years for patients with IDH-wildtype GBM. GBM is noted for the considerable cellular heterogeneity, high stemness indices and abundance of the glioma stem-like cells known to support tumor progression, therapeutic resistance and recurrence. Doublesex- and mab-3–related transcription factor a2 (DMRTA2) is involved in maintaining neural progenitor cells (NPC) in the cell cycle and its overexpression suppresses NPC differentiation. Despite the reports showing that primary GBM originates from transformed neural stem/progenitors cells, the role of DMRTA2 in gliomagenesis has not been elucidated so far. Here we show the upregulation of DMRTA2 expression in malignant gliomas. Immunohistochemical staining showed the protein concentrated in small cells with high proliferative potential and cells localized around blood vessels, where it colocalizes with pericyte-specific markers. Knock-down of DMRTA2 in human glioma cells impairs proliferation but not viability of the cells, and affects the formation of the tumor spheres, as evidenced by strong decrease in the number and size of spheres in in vitro cultures. Moreover, the knockdown of DMRTA2 in glioma spheres affects the stabilization of the glioma stem-like cell-dependent tube formation in an in vitro angiogenesis assay. We conclude that DMRTA2 is a new player in gliomagenesis and tumor neovascularization and due to its high expression in malignant gliomas could be a biomarker and potential target for new therapeutic strategies in glioblastoma.

Substrate-bound and soluble domains of tenascin-C regulate differentiation, proliferation and migration of neural stem and progenitor cells.

The lack of regenerative capacity of the central nervous system is one of the major challenges nowadays. The knowledge of guidance cues that trigger differentiation, proliferation, and migration of neural stem and progenitor cells is one key element in regenerative medicine. The extracellular matrix protein tenascin-C (Tnc) is a promising candidate to regulate cell fate due to its expression in the developing central nervous system and in the adult neural stem cell niches. Of special interest are the alternatively spliced fibronectin type III (FnIII) domains of Tnc whose combinatorial diversity could theoretically generate up to 64 isoforms in the mouse. A total of 27 isoforms have already been discovered in the developing brain, among others the domain combinations A1D, CD, and A124BCD. In the present study, these domains as well as the combination of the constitutively expressed FnIII domains 7 and 8 (78) were expressed in Chinese hamster ovary cells as pseudo-antibodies fused to the Fc-fragment of a human immunoglobulin G antibody. The fusion proteins were presented to primary mouse neural stem/progenitor cells (NSPCs) grown as neurospheres, either as coated culture substrates or as soluble additives in vitro. The influence of the domains on the differentiation, proliferation and migration of NSPCs was analyzed. We observed that the domain combination A124BCD promoted the differentiation of neurons and oligodendrocytes, whereas the domain A1D supported astrocyte differentiation. The constitutively expressed domain 78 had a proliferation and migration stimulating impact. Moreover, most effects were seen only in one of the presentation modes but not in both, suggesting different effects of the Tnc domains in two- and three-dimensional cultures. This knowledge about the different effect of the Tnc domains might be used to create artificial three-dimensional environments for cell transplantation. Hydrogels spiked with Tnc-domains might represent a promising tool in regenerative medicine.

CUL4B mutations impair human cortical neurogenesis through PP2A-dependent inhibition of AKT and ERK

Mutation in CUL4B gene is one of the most common causes for X-linked intellectual disability (XLID). CUL4B is the scaffold protein in CUL4B-RING ubiquitin ligase (CRL4B) complex. While the roles of CUL4B in cancer progression and some developmental processes like adipogenesis, osteogenesis, and spermatogenesis have been studied, the mechanisms underlying the neurological disorders in patients with CUL4B mutations are poorly understood. Here, using 2D neuronal culture and cerebral organoids generated from the patient-derived induced pluripotent stem cells and their isogenic controls, we demonstrate that CUL4B is required to prevent premature cell cycle exit and precocious neuronal differentiation of neural progenitor cells. Moreover, loss-of-function mutations of CUL4B lead to increased synapse formation and enhanced neuronal excitability. Mechanistically, CRL4B complex represses transcription of PPP2R2B and PPP2R2C genes, which encode two isoforms of the regulatory subunit of protein phosphatase 2 A (PP2A) complex, through catalyzing monoubiquitination of H2AK119 in their promoter regions. CUL4B mutations result in upregulated PP2A activity, which causes inhibition of AKT and ERK, leading to premature cell cycle exit. Activation of AKT and ERK or inhibition of PP2A activity in CUL4B mutant organoids rescues the neurogenesis defect. Our work unveils an essential role of CUL4B in human cortical development.

Ischemic and hemorrhagic stroke lesion environments differentially alter the glia repair potential of neural progenitor cell and immature astrocyte grafts

Using cell grafting to direct glia-based repair mechanisms in adult CNS injuries represents a potential therapeutic strategy for supporting functional neural parenchymal repair. However, glia repair directed by neural progenitor cell (NPC) grafts is dramatically altered by increasing lesion size, severity, and mode of injury. To address this, we studied the interplay between astrocyte differentiation and cell proliferation of NPC in vitro to generate proliferating immature astrocytes (ImA) using hysteretic conditioning. ImA maintain proliferation rates at comparable levels to NPC but showed robust immature astrocyte marker expression including Gfap and Vimentin. ImA demonstrated enhanced resistance to myofibroblast-like phenotypic transformations upon exposure to serum enriched environments in vitro compared to NPC and were more effective at scratch wound closure in vitro compared to quiescent astrocytes. Glia repair directed by ImA at acute ischemic striatal stroke lesions was equivalent to NPC but better than quiescent astrocyte grafts. While ischemic injury environments supported enhanced survival of grafts compared to healthy striatum, hemorrhagic lesions were hostile towards both NPC and ImA grafts leading to poor survival and ineffective modulation of natural wound repair processes. Our findings demonstrate that lesion environments, rather than transcriptional pre-graft states, determine the survival, cell-fate, and glia repair competency of cell grafts applied to acute CNS injuries.