RESUMO
Neurodevelopmental disorders are characterized by alterations in the development of the cerebral cortex, including aberrant changes in the number and function of neural cells. Although neurogenesis is one of the most studied cellular processes in these pathologies, little evidence is known about glial development. Genetic association studies have identified several genes associated with neurodevelopmental disorders. Indeed, variations in the PTPRD gene have been associated with numerous brain disorders, including autism spectrum disorder, restless leg syndrome, and schizophrenia. We previously demonstrated that constitutive loss of PTPRD expression induces significant alterations in cortical neurogenesis, promoting an increase in intermediate progenitors and neurons in mice. However, its role in gliogenesis has not been evaluated. To assess this, we developed a conditional knockout mouse model lacking PTPRD expression in telencephalon cells. Here, we found that the lack of PTPRD in the mouse cortex reduces glial precursors, astrocytes, and oligodendrocytes. According to our results, this decrease in gliogenesis resulted from a reduced number of radial glia cells at gliogenesis onset and a lower gliogenic potential in cortical neural precursors due to less activation of the JAK/STAT pathway and reduced expression of gliogenic genes. Our study shows PTPRD as a regulator of the glial/neuronal balance during cortical neurodevelopment and highlights the importance of studying glial development to understand the etiology of neurodevelopmental diseases.
RESUMO
BACKGROUND: Stage-specific embryonic antigen-4 (SSEA-4) is a marker for the identification of multipotent embryonic cells. It is also positive in neuroepithelial cells, precursor neural cells (NPC), and human dental pulp cells. The aim of this study was to evaluate the potential morphodifferentiation and histodifferentiation to NPC of SSEA-4 positive stem cells from human exfoliated deciduous teeth (SHED). METHODS: A SHED population in culture, positive to SSEA-4, was obtained by magnetic cell separation. The cells were characterized by immunohistochemistry and flow cytometry. Subsequently, a neurosphere assay was performed in a medium supplemented with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF); afterward, cells were neurodifferenciated with a neurobasal medium. Finally, indirect immunohistochemistry was performed to identify neuronal markers. RESULTS: The morphological and histological changes in the SSEA-4 positive SHEDs were observed after induction with epidermal and fibroblast growth factors in neurobasal culture medium. At the end of induction, the markers Nestin, TuJ-1, and GFAP were identified. CONCLUSIONS: The findings show that SSEA-4 positive SHEDs have a behavior similar to neuronal precursor cells. Our findings indicate that the dental pulp of deciduous teeth is a promising source for regeneration therapies associated with neurodegenerative diseases or peripheral nerve alterations.
Assuntos
Polpa Dentária , Células-Tronco Neurais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Antígenos Embrionários Estágio-Específicos , Dente DecíduoRESUMO
PURPOSE: This study aimed to evaluate a cell therapy strategy with human neural precursor cells (hNPCs) to treat diabetic retinopathy (DR) in Wistar rats induced to diabetes by injecting streptozotocin. MATERIAL AND METHODS: The Wharton's jelly mesenchymal stem cells (WJ-MSCs) were isolated, expanded, and seeded onto a biopolymer substrate to develop neurospheres and obtain the hNPCs. The animals were divided into three groups: non-diabetic (ND) n = four, diabetic without treatment (DM) n = nine, and diabetic with cell therapy (DM + hNPCs) n = nine. After 8 weeks of diabetes induction and DR characteristics installed, intravitreal injection of hNPCs (1 × 106 cell/µL) was performed in the DM + hNPCs group. Optical Coherence Tomography (OCT) and Electroretinography (ERG) evaluations were conducted before and during diabetes and after cell therapy. Four weeks posttreatment, histopathological and immunohistochemistry analyses were performed. RESULTS: The repair of the retinal structures in the treated group (DM + hNPCs) was observed by increased thickness of neuroretinal layers, especially in the ganglion cell and photoreceptor layers, higher ERG oscillatory potentials (OPs) amplitudes, and transplanted hNPCs integration into the Retinal Pigment Epithelium. CONCLUSIONS: The results indicate that hNPCs reduced DR progression by a neuroprotective effect and promoted retinal repair, making them potential candidates for regenerating the neuroretinal tissue.
Assuntos
Diabetes Mellitus Experimental , Retinopatia Diabética , Células-Tronco Neurais , Animais , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/terapia , Retinopatia Diabética/patologia , Retinopatia Diabética/terapia , Humanos , Ratos , Ratos Wistar , Retina/patologiaRESUMO
The continuous generation of new neurons occurs in at least two well-defined niches in the adult rodent brain. One of these areas is the subgranular zone of the dentate gyrus (DG) in the hippocampus. While the DG is associated with contextual and spatial learning and memory, hippocampal neurogenesis is necessary for pattern separation. Hippocampal neurogenesis begins with the activation of neural stem cells and culminates with the maturation and functional integration of a portion of the newly generated glutamatergic neurons into the hippocampal circuits. The neurogenic process is continuously modulated by intrinsic factors, one of which is neuroinflammation. The administration of lipopolysaccharide (LPS) has been widely used as a model of neuroinflammation and has yielded a body of evidence for unveiling the detrimental impact of inflammation upon the neurogenic process. This work aims to provide a comprehensive overview of the current knowledge on the effects of the systemic and central administration of LPS upon the different stages of neurogenesis and discuss their effects at the molecular, cellular, and behavioral levels.
Assuntos
Lipopolissacarídeos , Células-Tronco Neurais , Giro Denteado , Hipocampo , NeurogêneseRESUMO
The amyloid beta-peptide (Aß) is the low-abundance product of amyloid precursor protein (APP), which is produced lifelong in the healthy brain. The functional properties of Aß40 and Aß42 peptides have not been completely elucidated to date. Although, several studies suggest that these peptides have a number of neurotrophic and neurotoxic properties, respectively. Interestingly, low concentrations of Aß40 and Aß42 regulate synaptic plasticity and improve cognitive functions, whereas the accumulation of Aß42, coupled with the effects of age, can cause dysregulation of synaptic function, as is shown in Alzheimer's disease. Additionally, several studies suggest that both peptides, Aß40 and Aß42, are involved in neurogenic processes; however, these results are still controversial. Moreover, existing data indicate a direct relationship between the physicochemical characteristics of the peptides and their effects. Herein, we evaluated the effect of Aß40 oligomers on hippocampal precursor cells isolated from the dentate gyrus of adult female C57Bl6 mice (mADGPCs). To this end, mADGPCs were treated with nanomolar and micromolar range concentrations of oligomeric forms of Aß40 for 24, 48, and 72 h to evaluate their effects on several events in the neurogenic process in vitro, including viability, proliferation, and early differentiation. The results indicate that Aß40 favors mADGPC proliferation, survival, and neuronal differentiation following a mechanism that involves activation of the Akt signaling pathway. Thus, this study provides evidence about the positive effects of Aß40 oligomers on the neurogenic process in adult mouse hippocampal precursor cells in vitro.
Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Encéfalo/metabolismo , Diferenciação Celular/fisiologia , Neurônios/metabolismo , Animais , Hipocampo/metabolismo , Camundongos Endogâmicos C57BL , Neurogênese/fisiologia , Fragmentos de Peptídeos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Neural precursor cells differentiate into several cell types that display distinct functions. However, little is known about how cell surface mechanics vary during the differentiation process. Here, by precisely measuring membrane tension and bending modulus, we map their variations and correlate them with changes in neural precursor cell morphology along their distinct differentiation fates. Both cells maintained in culture as neural precursors as well as those plated in neurobasal medium reveal a decrease in membrane tension over the first hours of culture followed by stabilization, with no change in bending modulus. During astrocyte differentiation, membrane tension initially decreases and then increases after 72 h, accompanied by consolidation of glial fibrillary acidic protein expression and striking actin reorganization, while bending modulus increases following observed alterations. For oligodendrocytes, the changes in membrane tension are less abrupt over the first hours, but their values subsequently decrease, correlating with a shift from oligodendrocyte marker O4 to myelin basic protein expressions and a remarkable actin reorganization, while bending modulus remains constant. Oligodendrocytes at later differentiation stages show membrane vesicles with similar membrane tension but higher bending modulus as compared to the cell surface. Altogether, our results display an entire spectrum of how membrane elastic properties are varying, thus contributing to a better understanding of neural differentiation from a mechanobiological perspective.
Assuntos
Diferenciação Celular , Membrana Celular/fisiologia , Elasticidade , Células-Tronco Neurais/citologia , Animais , Astrócitos/citologia , Biomarcadores/metabolismo , Fenômenos Biomecânicos , Células Cultivadas , Meios de Cultura , Citoesqueleto/metabolismo , Camundongos , Pinças ÓpticasRESUMO
Se presenta el caso de un paciente de 20 días de nacido, procedente de Cartagena (Bolívar), hospitalizado por presentar fiebre de 6 días de evolución asociado a sintomatología respiratoria con evaluación neurológica normal. La ecografía obstétrica evidenció una microcefalia con un percentil de perímetro cefálico <2, con hipoplasia del cuerpo calloso y tomografía axial computarizada de cráneo que reportó diámetros cefálicos disminuidos, finas calcificaciones residuales en región frontal-parietal y cambios atróficos cerebrales subcorticales. Se le inició terapia antibiótica por presentar sepsis neonatal, las pruebas serológicas y la PCR para Zika resultaron positivas. Se decidió dar el alta médica al 6 día por mejoría clínica y no presentar déficit neurológico aparente. Aunque no existe un tratamiento específico, el pilar del manejo de un recién nacido con microcefalia es el seguimiento y la vigilancia futura de las posibles comorbilidades, como epilepsia, parálisis cerebral o retraso cognitivo y motor.
We present the case of a 20-day-old patient from Cartagena (Bolívar), hospitalized for presenting a 6-day fever associated with respiratory symptoms with normal neurological evaluation. The obstetric ultrasound showed a microcephaly with a percentile of cephalic perimeter <2, with hypoplasia of the corpus callosum and computed tomography of the skull that reported decreased cephalic diameters, fine residual calcifications in the frontal-parietal region and atrophic subcortical cerebral changes. Antibiotic therapy was initiated due to neonatal sepsis, the serological tests and the PCR for Zika were positive. It was decided to discharge the hospital after 6 days due to clinical improvement and for not presenting apparent neurological deficit. Although there is no specific treatment, the pillar of the management of a newborn with microcephaly is the monitoring and future surveillance of possible comorbidities, such as epilepsy, cerebral palsy or cognitive and motor retardation.
Assuntos
Humanos , Masculino , Recém-Nascido , Zika virus , Microcefalia , Células-Tronco , Gravidez , Diagnóstico por Imagem , Febre , AntibacterianosRESUMO
Neurogenesis plays a significant role during adulthood, and the observation that neural stem cells reside in the central nervous system and the olfactory epithelium has attracted attention due to their importance in neuronal regeneration. In addition, soluble factors (SFs) release by neural stem cells may modulate the neurogenic process. Thus, in this study, we identified the SFs released by olfactory human neural stem/progenitor cells (hNS/PCs-OE). These cells express Ki67, nestin, and ßIII-tubulin, indicating their neural lineage. The hNS/PCs-OE also express PSD95 and tau proteins during proliferation, but increased levels are observed after differentiation. Thus, we evaluated the effects of SFs from hNS/PCs-OE on the viability, proliferation, and differentiation potential of adult murine hippocampal neural precursor cells (AHPCs). SFs from hNS/PCs-OE maintain cells in the precursor and proliferative stages and mainly promote the astrocytic differentiation of AHPCs. These effects involved the activation, as measured by phosphorylation, of several proteins (Erk1/2; Akt/PRAS40/GSK3ß and JAK/STAT) involved in key events of the neurogenic process. Moreover, according to the results from the antibody-based microarray approach, among the soluble factors, hNS/PCs-OE produce interleukin-6 (IL-6) and neurotrophin 4 (NT4). However, residual epidermal growth factor (EGF) was also detected. These proteins partially reproduced the effects of SFs from hNS/PCs-OE on AHPCs, and the mechanism underlying these effects is mediated by Src proteins, which have been implicated in EGF-induced transactivation of TrkB receptor. The results of the present study suggest the potential use of SFs from hNS/PCs-OE in controlling the differentiation potential of AHPCs. Thus, the potential clinical relevance of hNS/PCs-OE is worth pursuing.
Assuntos
Linhagem da Célula , Hipocampo/citologia , Células-Tronco Neurais/citologia , Mucosa Olfatória/citologia , Adulto , Animais , Anticorpos Neutralizantes/farmacologia , Astrócitos/citologia , Astrócitos/efeitos dos fármacos , Biomarcadores/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem da Célula/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Citocinas/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Fosforilação/efeitos dos fármacos , Receptor trkB/metabolismo , Solubilidade , Ativação Transcricional/efeitos dos fármacosRESUMO
This chapter describes a proteomic analysis of neural progenitor cells using isobaric tagging for relative and absolute quantitation (iTRAQ) mass spectrometry. A detailed procedure is described for the isolation, proliferation, and differentiation of these cells, including a comparative iTRAQ mass spectrometry analysis of the precursor and differentiated states. In total, there were changes in the levels of 55 proteins, many of which are not resolved easily by other proteomic methods. Therefore, this method should be useful for the identification of important regulatory molecules in the study of other precursor cells involved in neuronal or metabolic regulation in nutritional programming diseases.
Assuntos
Biomarcadores , Células-Tronco Neurais/metabolismo , Fenótipo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Animais , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Camundongos , Células-Tronco Neurais/citologia , Espectrometria de Massas em TandemRESUMO
The ventral mesencephalic neural precursor cells (vmNPCs) that give rise to dopaminergic (DA) neurons have been identified by the expression of distinct genes (e.g., Lmx1a, Foxa2, Msx1/2). However, the commitment of these NPCs to the mesencephalic DA neuronal fate has not been functionally determined. Evaluation of the plasticity of vmNPCs suggests that their commitment occurs after E10.5. Here we show that E9.5 vmNPCs implanted in an ectopic area of E10.5 mesencephalic explants, retained their specification marker Lmx1a and efficiently differentiated into neurons but did not express the gene encoding tyrosine hydroxylase (Th), the limiting enzyme for dopamine synthesis. A proportion of E10.5-E11.5 implanted vmNPCs behaved as committed, deriving into Th+ neurons in ectopic sites. Interestingly, implanted cells from E12.5 embryos were unable to give rise to a significant number of Th+ neurons. Concomitantly, differentiation assays in culture and in mesencephalic explants treated with Fgf2+LIF detected vmNPCs with astrogenic potential since E11.5. Despite this, a full suspension of E12.5 vmNPCs give rise to DA neurons in a similar proportion as those of E10.5 when they were transplanted into adult brain, but astrocytes were only detected with the former population. These data suggest that the subventricular postmitotic progenitors present in E12.5 ventral mesencephalon are unable to implant in embryonic explants and are the source of DA neurons in the transplanted adult brain. Based on our findings we propose that during DA differentiation committed vmNPCs emerge at E10.5 and they exhaust their neurogenic capacity with the rise of NPCs with astrogenic potential.
Assuntos
Diferenciação Celular , Neurônios Dopaminérgicos/citologia , Mesencéfalo/citologia , Células-Tronco Neurais/citologia , Neurogênese , Animais , Astrócitos/citologia , Linhagem da Célula , Proliferação de Células , Sobrevivência Celular , Neurônios Dopaminérgicos/metabolismo , Embrião de Mamíferos/citologia , Feminino , Proteínas Hedgehog/metabolismo , Proteínas com Homeodomínio LIM/metabolismo , Masculino , Camundongos Transgênicos , Modelos Biológicos , Células-Tronco Neurais/metabolismo , Ratos Wistar , Nicho de Células-Tronco , Fatores de Transcrição/metabolismoRESUMO
This chapter describes the basics of two-dimensional difference gel electrophoresis (2D-DIGE) for multiplex analysis of up to distinct proteomes. The example given describes the analysis of undifferentiated and differentiated neural precursor cells labelled with fluorescent Cy3 and Cy5 dyes in comparison to a pooled standard labelled with Cy2. After labelling, the proteomes are mixed together and electrophoresed on the same 2D gels. Scanning the gels at wavelengths specific for each dye allows direct overlay of the two different proteomes and the differences in abundance of specific protein spots can be determined through comparison to the pooled standard.
Assuntos
Proteínas do Tecido Nervoso/análise , Células-Tronco Neurais/química , Eletroforese em Gel Diferencial Bidimensional/métodos , Animais , Fracionamento Celular , Células Cultivadas , Indicadores e Reagentes , Ventrículos Laterais/citologia , Camundongos , Proteínas do Tecido Nervoso/isolamento & purificação , Esferoides Celulares , Eletroforese em Gel Diferencial Bidimensional/instrumentaçãoRESUMO
The generation of new neurons during adulthood involves local precursor cell migration and terminal differentiation in the dentate gyrus. These events are influenced by the hippocampal microenvironment. Brain-derived neurotrophic factor (BDNF) is relevant for hippocampal neuronal development and behavior. Interestingly, studies that have been performed in controlled in vitro systems that involve isolated precursor cells that were derived from the dentate gyrus (AHPCs) have shown that BDNF induces the activation of the TrkB receptor and, consequentially, might activate signaling pathways that favor survival and neuronal differentiation. Based on the fact that the cellular events of AHPCs that are induced by single factors can be studied in this controlled in vitro system, we investigated the ability of BDNF and the involvement of protein kinase C (PKC), as one of the TrkB-downstream activated signaling proteins, in the regulation of migration, here reflected by motility, of AHPCs. Precursor cells were cultured following a concentration-response curve (1-640 ng/ml) for 24 or 96 h. We found that BDNF favored cell survival without altering the viability under culture proliferative conditions of the AHPCs. Concomitantly, glial- and neuronal-differentiated precursor cells increased as a consequence of survival promoted by BDNF. Additionally, pharmacological approaches showed that BDNF (40 ng/ml)-induced migration of AHPCs was blocked with the compounds K252a and GF109203x, which prevent the activation of TrkB and PKC, respectively. The results indicate that in the in vitro migration of differentiated AHPCs it is involved the BDNF and TrkB cascade. Our results provide additional information about the mechanism by which BDNF impacts adult neurogenesis in the hippocampus.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Movimento Celular/fisiologia , Sobrevivência Celular/fisiologia , Hipocampo/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Células-Tronco Adultas/citologia , Células-Tronco Adultas/efeitos dos fármacos , Células-Tronco Adultas/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/administração & dosagem , Carbazóis/farmacologia , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Feminino , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Alcaloides Indólicos/farmacologia , Indóis/farmacologia , Maleimidas/farmacologia , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/efeitos dos fármacos , Neuroglia/citologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neurônios/citologia , Neurônios/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Receptor trkB/antagonistas & inibidores , Receptor trkB/metabolismoRESUMO
Cell therapy for neurological disorders has advanced, and neural precursor cells (NPC) may become the ideal candidates for neural transplantation in a wide range of diseases. However, additional work has to be done to determine either the ideal culture environment for NPC expansion in vitro, without altering their plasticity, or the FGF-2 and EGF mechanisms of cell signaling in neurospheres growth, survival and differentiation. In this work we evaluated mouse neurospheres cultured with and without FGF-2 and EGF containing medium and showed that those growth factors are responsible for NPC proliferation. It is also demonstrated that endogenous production of growth factors shifts from FGF-2 to IGF-1/PDGFb upon EGF and FGF-2 withdrawal. Mouse NPC cultured in suspension showed different patterns of neuronal localization (core versus shell) for both EGF and FGF-2 withdrawal and control groups. Taken together, these results show that EGF and FGF-2 removal play an important role in NPC differentiation and may contribute to a better understanding of mechanisms of NPC differentiation. Our findings suggest that depriving NPC of growth factors prior to grafting might enhance their chance to effectively integrate into the host.
As terapias celulares para doenças neurológicas têm avançado e células precursoras neurais (NPC) surgem como candidatas ideais para o transplante de células neurais em muitas doenças. No entanto, trabalhos adicionais devem ser feitos para determinar o ambiente de cultivo ideal para a expansão in vitro das NPC, sem alterar sua plasticidade, e os mecanismos de sinalização celular do fator de crescimento epidérmico (EGF) e fator de crescimento de fibroblasto 2 (FGF-2) no crescimento, sobrevivência e diferenciação da neuroesfera. Nesse trabalho avaliamosNPCcultivadas na presença e na ausência de FGF-2 e EGF e mostramos que esses fatores de crescimento são responsáveis pela proliferação das NPC. Também foi demonstrado que a produção endógena de fatores de crescimento alterna de FGF-2 a fator de crescimento de insulina 1 (IGF-1) e fator de crescimento derivado de plaquetas b (PDGFb) após remoção de EGF e FGF-2. NPC de camundongo cultivadas em suspensão mostraram padrões de localização neuronal distintos (centro versus borda) tanto no grupo controle como no grupo sem EGF e FGF-2. Juntos, esses resultados mostram que a remoção de EGF e FGF-2 exerce importante ação na diferenciação de NPC e possivelmente contribui para melhor compreensão dos mecanismos envolvidos na diferenciação. Nossos achados sugerem que, privando as NPC de fatores de crescimento antes do transplante, talvez aumente as chances de que as células efetivamente se integrem ao hospedeiro.