RESUMO
Multiple Sclerosis (MS) is an autoimmune condition targeting the central nervous system (CNS) characterized by focal demyelination with inflammation, causing neurodegeneration and gliosis. This is accompanied by a refractory period in relapsing MS or chronic progression in primary progressive MS. Current MS treatments target disease relapses and aim to reduce further demyelination and disability. These include the treatment of acute exacerbations through global immunomodulation upon corticosteroid administration, which are accompanied by adverse reactions. Disease modifying therapies (DMTs) which provide targeted immunosuppression of T and B cells, and sequestration of leukocytes out of CNS, have led to further improvements in demyelination prevention and disease burden reduction. Despite their efficacy, DMTs are ineffective in remyelination, pathology reversal and have minimal effects in progressive MS. The advent of modern biomedical engineering approaches in combination with a better understanding of MS pathology, has led to the development of novel, regenerative approaches to treatment. Such treatments utilize neural stem cells (NSCs) and can reduce disease relapses and reverse damage caused by the disease through localized tissue regeneration. While at initial stages, pre-clinical and clinical studies utilizing NSCs and immune modulation have shown promising outcomes in tissue regeneration, creating a potential new era in MS therapy.
Assuntos
Esclerose Múltipla , Humanos , Esclerose Múltipla/terapia , Animais , Engenharia Biomédica/métodos , Células-Tronco Neurais/transplanteRESUMO
BACKGROUND: SETBP1 Haploinsufficiency Disorder (SETBP1-HD) is characterised by mild to moderate intellectual disability, speech and language impairment, mild motor developmental delay, behavioural issues, hypotonia, mild facial dysmorphisms, and vision impairment. Despite a clear link between SETBP1 mutations and neurodevelopmental disorders the precise role of SETBP1 in neural development remains elusive. We investigate the functional effects of three SETBP1 genetic variants including two pathogenic mutations p.Glu545Ter and SETBP1 p.Tyr1066Ter, resulting in removal of SKI and/or SET domains, and a point mutation p.Thr1387Met in the SET domain. METHODS: Genetic variants were introduced into induced pluripotent stem cells (iPSCs) and subsequently differentiated into neurons to model the disease. We measured changes in cellular differentiation, SETBP1 protein localisation, and gene expression changes. RESULTS: The data indicated a change in the WNT pathway, RNA polymerase II pathway and identified GATA2 as a central transcription factor in disease perturbation. In addition, the genetic variants altered the expression of gene sets related to neural forebrain development matching characteristics typical of the SETBP1-HD phenotype. LIMITATIONS: The study investigates changes in cellular function in differentiation of iPSC to neural progenitor cells as a human model of SETBP1 HD disorder. Future studies may provide additional information relevant to disease on further neural cell specification, to derive mature neurons, neural forebrain cells, or brain organoids. CONCLUSIONS: We developed a human SETBP1-HD model and identified perturbations to the WNT and POL2RA pathway, genes regulated by GATA2. Strikingly neural cells for both the SETBP1 truncation mutations and the single nucleotide variant displayed a SETBP1-HD-like phenotype.
Assuntos
Proteínas de Transporte , Diferenciação Celular , Haploinsuficiência , Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Humanos , Proteínas de Transporte/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Mutação , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA2/metabolismo , Neurônios/metabolismo , Células-Tronco Neurais/metabolismo , Via de Sinalização Wnt/genética , Deficiência Intelectual/genética , FenótipoRESUMO
The Zika virus (ZIKV) epidemic declared in Brazil between 2015 and 2016 was associated with an increased prevalence of severe congenital malformations, including microcephaly. The distribution of microcephaly cases was not uniform across the country, with a disproportionately higher incidence in the Northeast region (NE). Our previous work demonstrated that saxitoxin (STX), a toxin present in the drinking water reservoirs of the NE, exacerbated the damaging effects of ZIKV on the developing brain. We hypothesized that the impact of STX might vary among different neural cell types. While ZIKV infection caused severe damages on astrocytes and neural stem cells (NSCs), the addition of STX did not exacerbate these effects. We observed that neurons subjected to STX exposure were more prone to apoptosis and displayed higher ZIKV infection rate. These findings suggest that STX exacerbates the harmful effects of ZIKV on neurons, thereby providing a plausible explanation for the heightened severity of ZIKV-induced congenital malformations observed in Brazil's NE. This study highlights the importance of understanding the interactive effects of environmental toxins and infectious pathogens on neural development, with potential implications for public health policies.
Assuntos
Astrócitos , Células-Tronco Neurais , Neurônios , Saxitoxina , Infecção por Zika virus , Zika virus , Células-Tronco Neurais/virologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Humanos , Zika virus/fisiologia , Astrócitos/virologia , Astrócitos/efeitos dos fármacos , Astrócitos/metabolismo , Neurônios/virologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Infecção por Zika virus/virologia , Infecção por Zika virus/patologia , Saxitoxina/toxicidade , Apoptose/efeitos dos fármacos , Microcefalia/virologia , Morte Celular/efeitos dos fármacos , Brasil , Células CultivadasRESUMO
BACKGROUND: Stem cell-based therapy is a promising strategy for treating Parkinson's disease (PD) characterized by the loss of dopaminergic neurons. Recently, induced neural stem cell-derived dopaminergic precursor cells (iNSC-DAPs) have been emerged as a promising candidate for PD cell therapy because of a lower tumor-formation ability. Designer receptors exclusively activated by designer drugs (DREADDs) are useful tools for examining functional synaptic connections with host neurons. METHODS: DREADD knock-in human iNSCs to express excitatory hM3Dq and inhibitory hM4Di receptors were engineered by CRISPR. The knock-in iNSCs were differentiated into midbrain dopaminergic precursor cells (DAPs) and transplanted into PD mice. The various behavior test such as the Apomorphine-induced rotation test, Cylinder test, Rotarod test, and Open field test were assessed at 4, 8, or 12 weeks post-transplantation with or without the administration of CNO. Electrophysiology were performed to assess the integrated condition and modulatory function to host neurons. RESULTS: DREADD expressing iNSCs were constructed with normal neural stem cells characteristics, proliferation ability, and differentiation potential into dopaminergic neuorns. DAPs derived from DREADD expressing iNSC showed matched function upon administration of clozapine N-oxide (CNO) in vitro. The results of electrophysiology and behavioral tests of transplanted PD mouse models revealed that the grafts established synaptic connections with downstream host neurons and exhibited excitatory or inhibitory modulation in response to CNO in vivo. CONCLUSION: iNSC-DAPs are a promising candidate for cell replacement therapy for Parkinson's disease. Remote DREADD-dependent activation of iNSC-DAP neurons significantly enhanced the beneficial effects on transplanted mice with Parkinson's disease.
Assuntos
Diferenciação Celular , Modelos Animais de Doenças , Neurônios Dopaminérgicos , Células-Tronco Neurais , Doença de Parkinson , Animais , Neurônios Dopaminérgicos/metabolismo , Camundongos , Humanos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/transplante , Células-Tronco Neurais/citologia , Doença de Parkinson/terapia , Clozapina/análogos & derivados , Clozapina/farmacologiaRESUMO
Accumulating evidence has shown that some hallucinogens, such as LSD, have fast and persistent effects on anxiety and depression. According to a proposed mechanism, LSD activates the TrkB and HTR2A signaling pathways, which enhance the density of neuronal dendritic spines and synaptic function, and thus promote brain function. Moreover, TrkB signaling is also known to be crucial for neural stem cell (NSC)-mediated neuroregeneration to repair dysfunctional neurons. However, the impact of LSD on neural stem cells remains to be elucidated. In this study, we observed that LSD and BDNF activated the TrkB pathway in human NSCs similarly to neurons. However, unlike BDNF, LSD did not promote NSC proliferation. These results suggest that LSD may activate an alternative mechanism to counteract the effects of BDNF-TrkB signaling on NSCs. Our findings shed light on the previously unrecognized cell type-specificity of LSD. This could be crucial for deepening our understanding of the mechanisms underlying the effects of LSD.
Assuntos
Fator Neurotrófico Derivado do Encéfalo , Alucinógenos , Dietilamida do Ácido Lisérgico , Células-Tronco Neurais , Receptor trkB , Transdução de Sinais , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Humanos , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Alucinógenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Receptor trkB/metabolismo , Dietilamida do Ácido Lisérgico/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/citologia , Glicoproteínas de MembranaRESUMO
The peripheral nervous system consists of ganglia, nerve trunks, plexuses, and nerve endings, that transmit afferent and efferent information. Regeneration after a peripheral nerve damage is sluggish and imperfect. Peripheral nerve injury frequently causes partial or complete loss of motor and sensory function, physical impairment, and neuropathic pain, all of which have a negative impact on patients' quality of life. Because the mechanism of peripheral nerve injury and healing is still unclear, the therapeutic efficacy is limited. As peripheral nerve injury research has processed, an increasing number of studies have revealed that biological scaffolds work in tandem with progenitor cells to repair peripheral nerve injury. Here, we fabricated collagen chitosan nerve conduit bioscaffolds together with collagen and then filled neuroepithelial stem cells (NESCs). Scanning electron microscopy showed that the NESCs grew well on the scaffold surface. Compared to the control group, the NESCs group contained more cells with bigger diameters and myelinated structures around the axons. Our findings indicated that a combination of chitosan-collagen bioscaffold and neural stem cell transplantation can facilitate the functional restoration of peripheral nerve tissue, with promising future applications and research implications.
Assuntos
Quitosana , Colágeno , Regeneração Nervosa , Traumatismos dos Nervos Periféricos , Alicerces Teciduais , Quitosana/química , Regeneração Nervosa/fisiologia , Colágeno/química , Animais , Alicerces Teciduais/química , Traumatismos dos Nervos Periféricos/terapia , Ratos , Células Neuroepiteliais/citologia , Células-Tronco Neurais/citologia , Nervos Periféricos/fisiologia , Nervo Isquiático/fisiologiaRESUMO
The complex interplay between vascular signaling and neurogenesis in the adult brain remains a subject of intense research. By exploiting the unique advantages of the zebrafish model, in particular the persistent activity of neural stem cells (NSCs) and the remarkable ability to repair brain lesions, we investigated the links between NSCs and cerebral blood vessels. In this study, we first examined the gene expression profiles of vascular endothelial growth factors aa and bb (vegfaa and vegfbb), under physiological and regenerative conditions. Employing fluorescence in situ hybridization combined with immunostaining and histology techniques, we demonstrated the widespread expression of vegfaa and vegfbb across the brain, and showed their presence in neurons, microglia/immune cells, endothelial cells and NSCs. At 1 day post-lesion (dpl), both vegfaa and vegfbb were up-regulated in neurons and microglia/peripheral immune cells (macrophages). Analysis of vegf receptors (vegfr) revealed high expression throughout the brain under homeostatic conditions, with vegfr predominantly expressed in neurons and NSCs and to a lower extent in microglia/immune cells and endothelial cells. These findings were further validated by Vegfr3 and Vegfr4 immunostainings, which showed significant expression in neurogenic radial glial cells.Following brain lesion (1 dpl), while vegfr gene expression remained stable, vegfr transcripts were detected in proliferative cells within the injured parenchyma. Collectively, our results provide a first overview of Vegf/Vegfr signaling in the brain and suggest important roles for Vegf in neurogenesis and regenerative processes.
Assuntos
Encéfalo , Neurogênese , Fator A de Crescimento do Endotélio Vascular , Proteínas de Peixe-Zebra , Peixe-Zebra , Animais , Neurogênese/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Encéfalo/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Células-Tronco Neurais/metabolismo , Fator B de Crescimento do Endotélio Vascular/metabolismo , Fator B de Crescimento do Endotélio Vascular/genética , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptores de Fatores de Crescimento do Endotélio Vascular/genética , Regeneração Nervosa/fisiologiaRESUMO
BACKGROUND: The established association between Alzheimer's disease (AD) and compromised neural regeneration is well-documented. In addition to the mitigation of apoptosis in neural stem cells (NSCs), the induction of neurogenesis has been proposed as a promising therapeutic strategy for AD. Our previous research has demonstrated the effective inhibition of NSC injury induced by microglial activation through the repression of oxidative stress and mitochondrial dysfunction by Sirtuin 3 (SIRT3). Nonetheless, the precise role of SIRT3 in neurogenesis remains incompletely understood. METHODS: In vivo, SIRT3 overexpression adenovirus was firstly injected by brain stereotaxic localization to affect the hippocampal SIRT3 expression in APP/PS1 mice, and then behavioral experiments were performed to investigate the cognitive improvement of SIRT3 in APP/PS1 mice, as well as neurogenic changes in hippocampal region by immunohistochemistry and immunofluorescence. In vitro, under the transwell co-culture condition of microglia and neural stem cells, the mechanism of SIRT3 improving neurogenesis of neural stem cells through DVL/GSK3/ISL1 axis was investigated by immunoblotting, immunofluorescence and other experimental methods. RESULTS: Our findings indicate that the overexpression of SIRT3 in APP/PS1 mice led to enhanced cognitive function and increased neurogenesis. Additionally, SIRT3 was observed to promote the differentiation of NSCs into neurons during retinoic acid (RA)-induced NSC differentiation in vitro, suggesting a potential role in neurogenesis. Furthermore, we observed the activation of the Wnt/ß-catenin signaling pathway during this process, with Glycogen Synthase Kinase-3a (GSK3a) primarily governing NSC proliferation and GSK3ß predominantly regulating NSC differentiation. Moreover, the outcomes of our study demonstrate that SIRT3 exerts a protective effect against microglia-induced apoptosis in neural stem cells through its interaction with DVLs. CONCLUSIONS: Our results show that SIRT3 overexpressing APP/PS1 mice have improved cognition and neurogenesis, as well as improved neurogenesis of NSC in microglia and NSC transwell co-culture conditions through the DVL/GSK3/ISL1 axis.
Assuntos
Doença de Alzheimer , Células-Tronco Neurais , Neurogênese , Transdução de Sinais , Sirtuína 3 , Animais , Sirtuína 3/metabolismo , Sirtuína 3/genética , Camundongos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/terapia , Doença de Alzheimer/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas Desgrenhadas/metabolismo , Proteínas Desgrenhadas/genética , Camundongos Transgênicos , Microglia/metabolismo , Diferenciação Celular , Hipocampo/metabolismoRESUMO
The neocortex varies in size and complexity among mammals due to the tremendous variability in the number and diversity of neuronal subtypes across species. The increased cellular diversity is paralleled by the expansion of the pool of neocortical progenitors and the emergence of indirect neurogenesis during brain evolution. The molecular pathways that control these biological processes and are disrupted in neurological disorders remain largely unknown. Here we show that the transcription factors BRN1 and BRN2 have an evolutionary conserved function in neocortical progenitors to control their proliferative capacity and the switch from direct to indirect neurogenesis. Functional studies in mice and ferrets show that BRN1/2 act in concert with NOTCH and primary microcephaly genes to regulate progenitor behavior. Analysis of transcriptomics data from genetically modified macaques provides evidence that these molecular pathways are conserved in non-human primates. Our findings thus demonstrate that BRN1/2 are central regulators of gene expression programs in neocortical progenitors critical to determine brain size during evolution.
Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Neocórtex , Células-Tronco Neurais , Neurogênese , Fatores do Domínio POU , Animais , Feminino , Masculino , Camundongos , Proliferação de Células , Furões , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Macaca , Neocórtex/metabolismo , Neocórtex/embriologia , Neocórtex/citologia , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Neurogênese/genética , Fatores do Domínio POU/metabolismo , Fatores do Domínio POU/genética , Receptores Notch/metabolismo , Receptores Notch/genéticaRESUMO
Cholinergic neurons in the basal forebrain play a crucial role in regulating adult hippocampal neurogenesis (AHN). However, the circuit and molecular mechanisms underlying cholinergic modulation of AHN, especially the initial stages of this process related to the generation of newborn progeny from quiescent radial neural stem cells (rNSCs), remain unclear. Here, we report that stimulation of the cholinergic circuits projected from the diagonal band of Broca (DB) to the dentate gyrus (DG) neurogenic niche promotes proliferation and morphological development of rNSCs, resulting in increased neural stem/progenitor pool and rNSCs with longer radial processes and larger busy heads. Interestingly, DG granule cells (GCs) are required for DB-DG cholinergic circuit-dependent modulation of proliferation and morphogenesis of rNSCs. Furthermore, single-nucleus RNA sequencing of DG reveals cell type-specific transcriptional changes in response to cholinergic circuit stimulation, with GCs (among all the DG niche cells) exhibiting the most extensive transcriptional changes. Our findings shed light on how the DB-DG cholinergic circuits orchestrate the key niche components to support neurogenic function and morphogenesis of rNSCs at the circuit and molecular levels.
Assuntos
Neurônios Colinérgicos , Giro Denteado , Células-Tronco Neurais , Neurogênese , Animais , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Giro Denteado/metabolismo , Giro Denteado/citologia , Neurogênese/fisiologia , Neurônios Colinérgicos/metabolismo , Neurônios Colinérgicos/fisiologia , Camundongos , Proliferação de Células , Células-Tronco Adultas/metabolismo , Células-Tronco Adultas/fisiologia , Células-Tronco Adultas/citologia , Morfogênese , Nicho de Células-Tronco/fisiologia , MasculinoRESUMO
Neural stem cells (NSCs) in the subventricular zone (SVZ) located along the lateral ventricles (LVs) of the mammalian brain continue to self-renew to produce new neurons after birth and into adulthood. Quiescent LV cells, which are situated close to the ependymal cells lining the LVs, are activated by choline acetyltransferase-positive (ChAT+) neurons within the subependymal (subep) region of the SVZ when these neurons are stimulated by projections from the anterior cingulate cortex (ACC). Here, we uncovered a signaling pathway activated by the ACC-subep-ChAT+ circuit responsible for the activation and proliferation of quiescent LV NSCs specifically in the ventral area of the SVZ. This circuit activated muscarinic M3 receptors on quiescent LV NSCs, which subsequently induced signaling mediated by the inositol 1,4,5-trisphosphate receptor type 1 (IP3R1). Downstream of IP3R1 activation, which would be expected to increase intracellular Ca2+, Ca2+-/calmodulin-dependent protein kinase II δ and the MAPK10 signaling pathway were stimulated and required for the proliferation of quiescent LV NSCs in the SVZ. These findings reveal the mechanisms that regulate quiescent LV NSCs and underscore the critical role of projections from the ACC in promoting their proliferative activity within the ventral SVZ.
Assuntos
Receptores de Inositol 1,4,5-Trifosfato , Ventrículos Laterais , Células-Tronco Neurais , Transdução de Sinais , Animais , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Ventrículos Laterais/metabolismo , Ventrículos Laterais/citologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Camundongos , Colina O-Acetiltransferase/metabolismo , Colina O-Acetiltransferase/genética , Proliferação de Células , Receptor Muscarínico M3/metabolismo , Receptor Muscarínico M3/genética , Giro do Cíngulo/metabolismo , Giro do Cíngulo/citologia , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismoRESUMO
Stem cell niche is critical for regulating the behavior of stem cells. Drosophila neural stem cells (Neuroblasts, NBs) are encased by glial niche cells closely, but it still remains unclear whether glial niche cells can regulate the self-renewal and differentiation of NBs. Here, we show that ferritin produced by glia, cooperates with Zip13 to transport iron into NBs for the energy production, which is essential to the self-renewal and proliferation of NBs. The knockdown of glial ferritin encoding genes causes energy shortage in NBs via downregulating aconitase activity and NAD+ level, which leads to the low proliferation and premature differentiation of NBs mediated by Prospero entering nuclei. More importantly, ferritin is a potential target for tumor suppression. In addition, the level of glial ferritin production is affected by the status of NBs, establishing a bicellular iron homeostasis. In this study, we demonstrate that glial cells are indispensable to maintain the self-renewal of NBs, unveiling a novel role of the NB glial niche during brain development.
Iron is an essential nutrient for almost all living organisms. For example, iron contributes to the replication of DNA, the generation of energy inside cells, and the transport of oxygen around the body. Iron deficiency is the most common of all nutrient deficiencies, affecting over 40% of children worldwide. This can lead to anemia and also impair how the brain and nervous system develop, potentially resulting in long-lasting cognitive damage, even after the deficiency has been treated. It is poorly understood how iron contributes to the development of the brain and nervous system. In particular, whether and how it supports nerve stem cells (or NSCs for short) which give rise to the various neural types in the mature brain. To investigate, Ma et al. experimentally reduced the levels of ferritin (a protein which stores iron) in the developing brains of fruit fly larvae. This reduction in ferritin led to lower numbers of NSCs and a smaller brain. Unexpectedly, this effect was largest when ferritin levels were reduced in glial cells which support and send signals to NSCs, rather than in the stem cells themselves. Ma et al. then used fluorescence microscopy to confirm that glial cells make and contain a lot of ferritin which can be transported to NSCs. Adding iron supplements to the diet of flies lacking ferritin did not lead to normal numbers of stem cells in the brains of the developing fruit flies, whereas adding compounds that reduce the amount of iron led to lower numbers of stem cells. Together, this suggests that ferritin transports iron from glial cells to the NSCs. Without ferritin and iron, the NSCs could not produce enough energy to divide and make new stem cells. This caused the NSCs to lose the characteristics of stem cells and prematurely turn into other types of neurons or glial cells. Together, these findings show that when iron cannot move from glial cells to NSCs this leads to defects in brain development. Future experiments will have to test whether a similar transport of iron from supporting cells to NSCs also occurs in the developing brains of mammals, and whether this mechanism applies to stem cells in other parts of the body.
Assuntos
Proteínas de Drosophila , Ferritinas , Ferro , Células-Tronco Neurais , Neuroglia , Animais , Células-Tronco Neurais/metabolismo , Neuroglia/metabolismo , Ferro/metabolismo , Ferritinas/metabolismo , Ferritinas/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Drosophila/metabolismo , Proliferação de Células , Diferenciação Celular , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Autorrenovação CelularRESUMO
The spalt (Sal) gene family has four members (Sall1-4) in vertebrates, all of which play pivotal roles in various biological processes and diseases. However, the expression and function of SALL2 in development are still less clear. Here, we first charted SALL2 protein expression pattern during mouse embryo development by immunofluorescence, which revealed its dominant expression in the developing nervous system. With the establishment of Sall2 deficient mouse embryonic stem cells (ESCs), the in vitro neural differentiation system was leveraged to interrogate the function of SALL2, which showed impaired neural differentiation of Sall2 knockout (KO) ESCs. Furthermore, neural stem cells (NSCs) could not be derived from Sall2 KO ESCs and the generation of neural tube organoids (NTOs) was greatly inhibited in the absence of SALL2. Meanwhile, transgenic expression of E1 isoform of SALL2 restored the defects of neural differentiation in Sall2 KO ESCs. By chromatin immunoprecipitation sequencing (ChIP-seq), Tuba1a was identified as downstream target of SALL2, whose function in neural differentiation was confirmed by rescuing neural phenotypes of Sall2 KO ESCs when overexpressed. In sum, by elucidating SALL2 expression dynamics during early mouse development and mechanistically characterizing its indispensable role in neural differentiation, this study offers insights into SALL2's function in human nervous system development, associated pathologies stemming from its mutations and relevant therapeutic strategy.
Assuntos
Diferenciação Celular , Células-Tronco Embrionárias Murinas , Fatores de Transcrição , Animais , Camundongos , Células-Tronco Embrionárias Murinas/metabolismo , Células-Tronco Embrionárias Murinas/citologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Neurogênese , Camundongos Knockout , Regulação da Expressão Gênica no DesenvolvimentoRESUMO
The number of neural stem cells reflects the total number of neurons in the mature brain. As neural stem cells arise from neuroepithelial cells, the neuroepithelial cell population must be expanded to secure a sufficient number of neural stem cells. However, molecular mechanisms that regulate timely differentiation from neuroepithelial to neural stem cells are largely unclear. Here, we show that TCF4/Daughterless is a key factor that determines the timing of the differentiation in Drosophila. The neuroepithelial cells initiated but never completed the differentiation in the absence of TCF4/Daughterless. We also found that TCF4/Daughterless binds to the Notch locus, suggesting that Notch is one of its downstream candidate genes. Consistently, Notch expression was ectopically induced in the absence of TCF4/Daughterless. Furthermore, ectopic activation of Notch signaling phenocopied loss of TCF4/Daughterless. Our findings demonstrate that TCF4/Daughterless directly inactivates Notch signaling pathway, resulting in completion of the differentiation from neuroepithelial cells into neural stem cells with optimal timing. Thus, the present results suggest that TCF4/Daughterless is essential for determining whether to move to the next state or stay in the current state in differentiating neuroepithelial cells.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Diferenciação Celular , Proteínas de Drosophila , Células-Tronco Neurais , Células Neuroepiteliais , Receptores Notch , Transdução de Sinais , Animais , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Receptores Notch/metabolismo , Receptores Notch/genética , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/genética , Células Neuroepiteliais/metabolismo , Células Neuroepiteliais/citologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Diferenciação Celular/genética , Regulação da Expressão Gênica no Desenvolvimento , Drosophila melanogaster/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/citologia , Fatores de Tempo , Drosophila/metabolismoRESUMO
Astrocytes are essential for the formation and maintenance of neural networks. However, a major technical challenge for investigating astrocyte function and disease-related pathophysiology has been the limited ability to obtain functional human astrocytes. Despite recent advances in human pluripotent stem cell (hPSC) techniques, primary rodent astrocytes remain the gold standard in coculture with human neurons. We demonstrate that a combination of leukemia inhibitory factor (LIF) and bone morphogenetic protein-4 (BMP4) directs hPSC-derived neural precursor cells to a highly pure population of astroglia in 28â d. Using single-cell RNA sequencing, we confirm the astroglial identity of these cells and highlight profound transcriptional adaptations in cocultured hPSC-derived astrocytes and neurons, consistent with their further maturation. In coculture with human neurons, multielectrode array recordings revealed robust network activity of human neurons in a coculture with hPSC-derived or rat astrocytes [3.63 ± 0.44â min-1 (hPSC-derived), 2.86 ± 0.64â min-1 (rat); p = 0.19]. In comparison, we found increased spike frequency within network bursts of human neurons cocultured with hPSC-derived astrocytes [56.31 ± 8.56â Hz (hPSC-derived), 24.77 ± 4.04â Hz (rat); p < 0.01], and whole-cell patch-clamp recordings revealed an increase of postsynaptic currents [2.76 ± 0.39â Hz (hPSC-derived), 1.07 ± 0.14â Hz (rat); p < 0.001], consistent with a corresponding increase in synapse density [14.90 ± 1.27/100â µm2 (hPSC-derived), 8.39 ± 0.63/100â µm2 (rat); p < 0.001]. Taken together, we show that hPSC-derived astrocytes compare favorably with rat astrocytes in supporting human neural network activity and maturation, providing a fully human platform for investigating astrocyte function and neuronal-glial interactions.
Assuntos
Astrócitos , Técnicas de Cocultura , Neurônios , Células-Tronco Pluripotentes , Astrócitos/fisiologia , Humanos , Animais , Células-Tronco Pluripotentes/fisiologia , Ratos , Neurônios/fisiologia , Células Cultivadas , Células-Tronco Neurais/fisiologia , Diferenciação Celular/fisiologiaRESUMO
Inhalation anesthesia stands as a pivotal modality within clinical anesthesia practices. Beyond its primary anesthetic effects, inhaled anesthetics have non-anesthetic effects, exerting bidirectional influences on the physiological state of the body and disease progression. These effects encompass impaired cognitive function, inhibition of embryonic development, influence on tumor progression, and so forth. For many years, inhaled anesthetics were viewed as inhibitors of stem cell fate regulation. However, there is now a growing appreciation that inhaled anesthetics promote stem cell biological functions and thus are now regarded as a double-edged sword affecting stem cell fate. In this review, the effects of inhaled anesthetics on self-renewal and differentiation of neural stem cells (NSCs), embryonic stem cells (ESCs), and cancer stem cells (CSCs) were summarized. The mechanisms of inhaled anesthetics involving cell cycle, metabolism, stemness, and niche of stem cells were also discussed. A comprehensive understanding of these effects will enhance our comprehension of how inhaled anesthetics impact the human body, thus promising breakthroughs in the development of novel strategies for innovative stem cell therapy approaches.
Assuntos
Anestésicos Inalatórios , Diferenciação Celular , Células-Tronco Neurais , Humanos , Diferenciação Celular/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Animais , Células-Tronco Embrionárias/efeitos dos fármacos , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Autorrenovação Celular/efeitos dos fármacosRESUMO
Mitochondrial activity directs neuronal differentiation dynamics during brain development. In this context, the long-established metabolic coupling of mitochondria and the eukaryotic host falls short of a satisfactory mechanistic explanation, hinting at an undisclosed facet of mitochondrial function. Here, we reveal an RNA-based inter-organellar communication mode that complements metabolic coupling of host-mitochondria and underpins neuronal differentiation. We show that within minutes of exposure to differentiation cues and activation of the electron transport chain, the mitochondrial outer membrane transiently fuses with the nuclear membrane of neural progenitors, leading to efflux of nuclear-encoded RNAs (neRNA) into the positively charged mitochondrial intermembrane space. Subsequent degradation of mitochondrial neRNAs by Polynucleotide phosphorylase 1 (PNPase) located in the intermembrane space curbs the transcriptomic memory of progenitor cells. Further, acquisition of neRNA by mitochondria leads to a collapse of proton motive force, suppression of ATP production, and a resultant amplification of autophagic flux that attenuates proteomic memory. Collectively, these events force the progenitor cells towards a "tipping point" characterised by emergence of a competing neuronal differentiation program. It appears that neuronal differentiation is a consequence of reprogrammed coupling of metabolomic and transcriptomic landscapes of progenitor cells, with mitochondria emerging as key "reprogrammers" that operate by acquiring and metabolising neRNAs. However, the documented role of mitochondria as "reprogrammers" of differentiation remains to be validated in other neuronal lineages and in vivo.
Assuntos
Diferenciação Celular , Mitocôndrias , Neurônios , RNA Nuclear , Mitocôndrias/metabolismo , Neurônios/metabolismo , Neurônios/citologia , Animais , RNA Nuclear/metabolismo , RNA Nuclear/genética , Humanos , Camundongos , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Neurogênese/genéticaRESUMO
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.
Assuntos
Reparo do DNA , Histonas , Mutação de Sentido Incorreto , Neurogênese , Complexo Repressor Polycomb 1 , Ubiquitinação , Animais , Humanos , Camundongos , Cromatina/metabolismo , Dano ao DNA , Histonas/metabolismo , Histonas/genética , Microcefalia/genética , Microcefalia/metabolismo , Células-Tronco Neurais/metabolismo , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 1/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genéticaRESUMO
A gallium nitride (GaN) semiconductor is one of the most promising materials integrated into biomedical devices to play the roles of connecting, monitoring, and manipulating the activity of biological components, due to its excellent photoelectric properties, chemical stability, and biocompatibility. In this work, it was found that the photogenerated free charge carriers of the GaN substrate, as an exogenous stimulus, served to promote neural stem cells (NSCs) to differentiate into neurons. This was observed through the systematic investigation of the effect of the persistent photoconductivity (PPC) of GaN on the differentiation of primary NSCs from the embryonic rat cerebral cortex. NSCs were directly cultured on the GaN surface with and without ultraviolet (UV) irradiation, with a control sample consisting of tissue culture polystyrene (TCPS) in the presence of fetal bovine serum (FBS) medium. Through optical microscopy, the morphology showed a greater number of neurons with the branching structures of axons and dendrites on GaN with UV irradiation. The immunocytochemical results demonstrated that GaN with UV irradiation could promote the NSCs to differentiate into neurons. Western blot analysis showed that GaN with UV irradiation significantly upregulated the expression of two neuron-related markers, ßIII-tubulin (Tuj-1) and microtubule-associated protein 2 (MAP-2), suggesting that neurite formation and the proliferation of NSCs during differentiation were enhanced by GaN with UV irradiation. Finally, the results of the Kelvin probe force microscope (KPFM) experiments showed that the NSCs cultured on GaN with UV irradiation displayed about 50 mV higher potential than those cultured on GaN without irradiation. The increase in cell membrane potential may have been due to the larger number of photogenerated free charges on the GaN surface with UV irradiation. These results could benefit topical research and the application of GaN as a biomedical material integrated into neural interface systems or other bioelectronic devices.
Assuntos
Diferenciação Celular , Gálio , Células-Tronco Neurais , Semicondutores , Raios Ultravioleta , Gálio/química , Gálio/farmacologia , Animais , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos da radiação , Células-Tronco Neurais/metabolismo , Diferenciação Celular/efeitos da radiação , Ratos , Células Cultivadas , Proliferação de Células , Neurônios/citologia , Neurônios/efeitos da radiação , Neurônios/metabolismoRESUMO
Aging and various neurodegenerative diseases cause significant reduction in adult neurogenesis and simultaneous increase in quiescent neural stem cells (NSCs), which impact the brain's regenerative capabilities. To deal with this challenging issue, current treatments involve stem cell transplants or prevention of neurodegeneration; however, the efficacy or success of this process remains limited. Therefore, extensive and focused investigation is highly demanding to overcome this challenging task. Here, we have designed an efficient peptide-based EphA4 receptor-targeted ligand through an in silico approach. Further, this strategy involves chemical conjugation of the peptide with adipose tissue stem cell-derived EV (Exo-pep-11). Interestingly, our newly designed engineered EV, Exo-pep-11, targets NSC through EphA4 receptors, which offers promising therapeutic advantages by stimulating NSC proliferation and subsequent differentiation. Our result demonstrates that NSC successfully internalized Exo-pep-11 in both in vitro culture conditions as well as in the in vivo aging rats. We found that the uptake of Exo-pep-11 decreased by â¼2.3-fold when NSC was treated with EphA4 antibody before Exo-pep-11 incubation, which confirms the receptor-specific uptake of Exo-pep-11. Exo-pep-11 treatment also increases NSC proliferation by â¼1.9-fold and also shows â¼1.6- and â¼2.4-fold increase in expressions of Nestin and ID1, respectively. Exo-pep-11 also has the potential to increase neurogenesis in aging rats, which is confirmed by â¼1.6- and â¼1.5-fold increases in expressions of TH and Tuj1, respectively, in rat olfactory bulb. Overall, our findings highlight the potential role of Exo-pep-11 for prospective applications in combating age-related declines in NSC activity and neurogenesis.