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1.
Nat Commun ; 11(1): 4363, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868797

RESUMO

A specialized neurogenic niche along the ventricles accumulates millions of progenitor cells in the developing brain. After mitosis, fate-committed daughter cells delaminate from this germinative zone. Considering the high number of cell divisions and delaminations taking place during embryonic development, brain malformations caused by ectopic proliferation of misplaced progenitor cells are relatively rare. Here, we report that a process we term developmental anoikis distinguishes the pathological detachment of progenitor cells from the normal delamination of daughter neuroblasts in the developing mouse neocortex. We identify the endocannabinoid-metabolizing enzyme abhydrolase domain containing 4 (ABHD4) as an essential mediator for the elimination of pathologically detached cells. Consequently, rapid ABHD4 downregulation is necessary for delaminated daughter neuroblasts to escape from anoikis. Moreover, ABHD4 is required for fetal alcohol-induced apoptosis, but not for the well-established form of developmentally controlled programmed cell death. These results suggest that ABHD4-mediated developmental anoikis specifically protects the embryonic brain from the consequences of sporadic delamination errors and teratogenic insults.


Assuntos
Anoikis , Lisofosfolipase , Neocórtex/embriologia , Animais , Encéfalo/citologia , Encéfalo/embriologia , Diferenciação Celular , Transtornos do Espectro Alcoólico Fetal/etiologia , Transtornos do Espectro Alcoólico Fetal/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Lisofosfolipase/genética , Lisofosfolipase/metabolismo , Camundongos , Neocórtex/citologia , Células-Tronco Neurais , Filogenia
2.
Ecotoxicol Environ Saf ; 203: 110934, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888599

RESUMO

Pharmaceuticals and personal care products are emerging contaminants that are increasingly detected in the environment worldwide. Certain classes of pharmaceuticals, such as selective serotonin reuptake inhibitors (SSRIs), are a major environmental concern due to their widespread use and the fact that these compounds are designed to have biological effects at low doses. A complication in predicting toxic effects of SSRIs in nontarget organisms is that their mechanism of action is not fully understood. To better understand the potential toxic effects of SSRIs, we employed an ultra-low input RNA-sequencing method to identify potential pathways that are affected by early exposure to two SSRIs (fluoxetine and paroxetine). We exposed wildtype zebrafish (Danio rerio) embryos to 100 µg/L of either fluoxetine or paroxetine for 6 days before extracting and sequencing mRNA from individual larval brains. Differential gene expression analysis identified 1550 genes that were significantly affected by SSRI exposure with a core set of 138 genes altered by both SSRIs. Weighted gene co-expression network analysis identified 7 modules of genes whose expression patterns were significantly correlated with SSRI exposure. Functional enrichment analysis of differentially expressed genes as well as network module genes repeatedly identified various terms associated with mitochondrial and neuronal structures, mitochondrial respiration, and neurodevelopmental processes. The enrichment of these terms indicates that toxic effects of SSRI exposure are likely caused by mitochondrial dysfunction and subsequent neurodevelopmental effects. To our knowledge, this is the first effort to study the tissue-specific transcriptomic effects of SSRIs in developing zebrafish, providing specific, high resolution molecular data regarding the sublethal effects of SSRI exposure.


Assuntos
Encéfalo/efeitos dos fármacos , Larva/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Inibidores de Captação de Serotonina/toxicidade , Transcriptoma/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Encéfalo/embriologia , Biologia Computacional , Embrião não Mamífero/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Humanos , Larva/genética , Análise de Sequência de RNA , Peixe-Zebra/genética
4.
Proc Natl Acad Sci U S A ; 117(32): 19544-19555, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32747566

RESUMO

Corresponding attributes of neural development and function suggest arthropod and vertebrate brains may have an evolutionarily conserved organization. However, the underlying mechanisms have remained elusive. Here, we identify a gene regulatory and character identity network defining the deutocerebral-tritocerebral boundary (DTB) in Drosophila This network comprises genes homologous to those directing midbrain-hindbrain boundary (MHB) formation in vertebrates and their closest chordate relatives. Genetic tracing reveals that the embryonic DTB gives rise to adult midbrain circuits that in flies control auditory and vestibular information processing and motor coordination, as do MHB-derived circuits in vertebrates. DTB-specific gene expression and function are directed by cis-regulatory elements of developmental control genes that include homologs of mammalian Zinc finger of the cerebellum and Purkinje cell protein 4 Drosophila DTB-specific cis-regulatory elements correspond to regulatory sequences of human ENGRAILED-2, PAX-2, and DACHSHUND-1 that direct MHB-specific expression in the embryonic mouse brain. We show that cis-regulatory elements and the gene networks they regulate direct the formation and function of midbrain circuits for balance and motor coordination in insects and mammals. Regulatory mechanisms mediating the genetic specification of cephalic neural circuits in arthropods correspond to those in chordates, thereby implying their origin before the divergence of deuterostomes and ecdysozoans.


Assuntos
Evolução Molecular , Redes Reguladoras de Genes , Mesencéfalo/fisiologia , Animais , Comportamento Animal , Encéfalo/embriologia , Encéfalo/metabolismo , Encéfalo/fisiologia , Drosophila , Fator 8 de Crescimento de Fibroblasto/genética , Fator 8 de Crescimento de Fibroblasto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Mesencéfalo/embriologia , Mesencéfalo/metabolismo , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Sequências Reguladoras de Ácido Nucleico , Rombencéfalo/embriologia , Rombencéfalo/metabolismo , Rombencéfalo/fisiologia , Transdução de Sinais
5.
Nat Commun ; 11(1): 4060, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32792512

RESUMO

Chromatin modifiers affect spatiotemporal gene expression programs that underlie organismal development. The Polycomb repressive complex 2 (PRC2) is a crucial chromatin modifier in executing neurodevelopmental programs. Here, we find that PRC2 interacts with the nucleic acid-binding protein Ybx1. In the mouse embryo in vivo, Ybx1 is required for forebrain specification and restricting mid-hindbrain growth. In neural progenitor cells (NPCs), Ybx1 controls self-renewal and neuronal differentiation. Mechanistically, Ybx1 highly overlaps PRC2 binding genome-wide, controls PRC2 distribution, and inhibits H3K27me3 levels. These functions are consistent with Ybx1-mediated promotion of genes involved in forebrain specification, cell proliferation, or neuronal differentiation. In Ybx1-knockout NPCs, H3K27me3 reduction by PRC2 enzymatic inhibitor or genetic depletion partially rescues gene expression and NPC functions. Our findings suggest that Ybx1 fine-tunes PRC2 activities to regulate spatiotemporal gene expression in embryonic neural development and uncover a crucial epigenetic mechanism balancing forebrain-hindbrain lineages and self-renewal-differentiation choices in NPCs.


Assuntos
Encéfalo/embriologia , Encéfalo/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Fatores de Transcrição/metabolismo , Animais , Western Blotting , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Células Cultivadas , Imunoprecipitação da Cromatina , Drosophila , Epigênese Genética/genética , Citometria de Fluxo , Imunofluorescência , Histona-Lisina N-Metiltransferase/genética , Imunoprecipitação , Camundongos , Camundongos Knockout , Processamento de Proteína Pós-Traducional/genética , Processamento de Proteína Pós-Traducional/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética
6.
Science ; 369(6503): 530-537, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32732419

RESUMO

Microglia, immune cells of the central nervous system (CNS), are important for tissue development and maintenance and are implicated in CNS disease, but we lack understanding of human fetal microglia development. Single-cell gene expression and bulk chromatin profiles of microglia at 9 to 18 gestational weeks (GWs) of human fetal development were generated. Microglia were heterogeneous at all studied GWs. Microglia start to mature during this developmental period and increasingly resemble adult microglia with CNS-surveilling properties. Chromatin accessibility increases during development with associated transcriptional networks reflective of adult microglia. Thus, during early fetal development, microglia progress toward a more mature, immune-sensing competent phenotype, and this might render the developing human CNS vulnerable to environmental perturbations during early pregnancy.


Assuntos
Encéfalo/embriologia , Desenvolvimento Embrionário/imunologia , Feto/imunologia , Microglia/imunologia , Fagocitose/imunologia , Encéfalo/citologia , Separação Celular , Células Cultivadas , Desenvolvimento Embrionário/genética , Redes Reguladoras de Genes , Humanos , Fagocitose/genética , Transcriptoma
7.
PLoS One ; 15(8): e0237773, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822378

RESUMO

Microglial cells play a key role in brain homeostasis from development to adulthood. Here we show the involvement of a site-specific phosphorylation of Presenilin 1 (PS1) in microglial development. Profiles of microglia-specific transcripts in different temporal stages of development, combined with multiple systematic transcriptomic analysis and quantitative determination of microglia progenitors, indicate that the phosphorylation of PS1 at serine 367 is involved in the temporal dynamics of microglial development, specifically in the developing brain rudiment during embryonic microgliogenesis. We constructed a developing brain-specific microglial network to identify transcription factors linked to PS1 during development. Our data showed that PS1 functional connections appear through interaction hubs at Pu.1, Irf8 and Rela-p65 transcription factors. Finally, we showed that the total number of microglia progenitors was markedly reduced in the developing brain rudiment of embryos lacking PS1 phosphorylation compared to WT. Our work identifies a novel role for PS1 in microglial development.


Assuntos
Redes Reguladoras de Genes , Microglia/fisiologia , Presenilina-1/metabolismo , Células-Tronco/metabolismo , Animais , Encéfalo/embriologia , Encéfalo/metabolismo , Feminino , Masculino , Camundongos Endogâmicos C57BL , Fosforilação , Presenilina-1/genética , Células-Tronco/citologia , Transcriptoma
8.
Pediatrics ; 146(2)2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32661188

RESUMO

Cannabinoids, the psychoactive compounds in marijuana, are one of the most commonly used substances in the United States. In this review, we summarize the impact of marijuana on child and adolescent health and discuss the implications of marijuana use for pediatric practice. We review the changing epidemiology of cannabis use and provide an update on medical use, routes of administration, synthetic marijuana and other novel products, the effect of cannabis on the developing brain, other health and social consequences of use, and issues related to marijuana legalization.


Assuntos
Cannabis , Uso da Maconha , Adolescente , Comportamento do Adolescente/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Canabidiol/farmacologia , Canabidiol/uso terapêutico , Canabinoides/efeitos adversos , Canabinoides/síntese química , Canabinoides/farmacologia , Cannabis/efeitos adversos , Cannabis/química , Cannabis/envenenamento , Criança , Comportamento Infantil/efeitos dos fármacos , Interações Medicamentosas , Endocanabinoides/fisiologia , Feminino , Feto/efeitos dos fármacos , Humanos , Drogas Ilícitas/efeitos adversos , Masculino , Abuso de Maconha/epidemiologia , Abuso de Maconha/terapia , Uso da Maconha/efeitos adversos , Uso da Maconha/epidemiologia , Uso da Maconha/legislação & jurisprudência , Uso da Maconha/psicologia , Meios de Comunicação de Massa , Maconha Medicinal/efeitos adversos , Maconha Medicinal/uso terapêutico , Leite Humano/química , Transtornos Neurocognitivos/induzido quimicamente , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Receptores de Canabinoides/efeitos dos fármacos , Receptores de Canabinoides/fisiologia , Uso de Tabaco/epidemiologia
9.
Proc Natl Acad Sci U S A ; 117(32): 19578-19589, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32727894

RESUMO

The CreER/LoxP system is widely accepted to track neural lineages and study gene functions upon tamoxifen (TAM) administration. We have observed that prenatal TAM treatment caused high rates of delayed delivery and fetal mortality. This substance could produce undesired results, leading to data misinterpretation. Here, we report that administration of TAM during early stages of cortical neurogenesis promoted precocious neural differentiation, while it inhibited neural progenitor cell (NPC) proliferation. The TAM-induced inhibition of NPC proliferation led to deficits in cortical neurogenesis, dendritic morphogenesis, synaptic formation, and cortical patterning in neonatal and postnatal offspring. Mechanistically, by employing single-cell RNA-sequencing (scRNA-seq) analysis combined with in vivo and in vitro assays, we show TAM could exert these drastic effects mainly through dysregulating the Wnt-Dmrta2 signaling pathway. In adult mice, administration of TAM significantly attenuated NPC proliferation in both the subventricular zone and the dentate gyrus. This study revealed the cellular and molecular mechanisms for the adverse effects of TAM on corticogenesis, suggesting that care must be taken when using the TAM-induced CreER/LoxP system for neural lineage tracing and genetic manipulation studies in both embryonic and adult brains.


Assuntos
Encéfalo/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/patologia , Tamoxifeno/efeitos adversos , Animais , Encéfalo/embriologia , Encéfalo/patologia , Diferenciação Celular , Proliferação de Células , Giro Denteado/efeitos dos fármacos , Giro Denteado/patologia , Feminino , Ventrículos Laterais/efeitos dos fármacos , Ventrículos Laterais/patologia , Camundongos , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/patologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , RNA-Seq , Análise de Célula Única , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos
10.
Nat Commun ; 11(1): 3406, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641768

RESUMO

Cancer stem cells are critical for cancer initiation, development, and treatment resistance. Our understanding of these processes, and how they relate to glioblastoma heterogeneity, is limited. To overcome these limitations, we performed single-cell RNA sequencing on 53586 adult glioblastoma cells and 22637 normal human fetal brain cells, and compared the lineage hierarchy of the developing human brain to the transcriptome of cancer cells. We find a conserved neural tri-lineage cancer hierarchy centered around glial progenitor-like cells. We also find that this progenitor population contains the majority of the cancer's cycling cells, and, using RNA velocity, is often the originator of the other cell types. Finally, we show that this hierarchal map can be used to identify therapeutic targets specific to progenitor cancer stem cells. Our analyses show that normal brain development reconciles glioblastoma development, suggests a possible origin for glioblastoma hierarchy, and helps to identify cancer stem cell-specific targets.


Assuntos
Neoplasias Encefálicas/genética , Encéfalo/metabolismo , Glioblastoma/genética , Células-Tronco Neoplásicas/metabolismo , Análise de Sequência de RNA/métodos , Transcriptoma/genética , Adulto , Animais , Antineoplásicos Alquilantes/farmacologia , Encéfalo/embriologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/terapia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Feminino , Feto , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Camundongos Endogâmicos NOD , Camundongos SCID , Células-Tronco Neoplásicas/efeitos dos fármacos , Análise de Célula Única/métodos , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
11.
J Environ Sci Health B ; 55(9): 803-812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32602772

RESUMO

Organophosphorus pesticides induce gender-specific developmental neurotoxicity after birth, especially in adolescents and adults. However, whether and when the selectivity occurs in fetus remains unclear. In this study, we analyzed chlorpyrifos (CPF)-induced neurotoxicity in the early fetal brains of male and female mice. The gestational dams were administered 0, 1, 3, and 5 mg/(kg.d) CPF during gestational days (GD)7-11, and brains from the fetuses were isolated and analyzed on GD12. Fetal gender was identified by PCR technique based on male-specific Sry gene and Myog control gene. The body weight and head weight, the activity of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and the content of malondialdehyde (MDA), as well as the oxidative stress-related gene expression were examined. Our results showed that CPF pretreatment induced AChE inhibition in GD12 fetal brain. CPF treatment activated SOD and GPX but not CAT and MDA. For oxidative stress-related gene expression, CPF pretreatment increased mRNA expression of Sod1, Cat, Gpx1, and Gpx2 in the fetal brain on GD12. The statistical analysis did not show gender-selective CPF-induced toxicity. Moreover, our results showed that although the gestational exposure to CPF could elicit abnormalities in the early fetal brain, the toxicity observed was not gender-specific.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Clorpirifos/toxicidade , Inseticidas/toxicidade , Acetilcolinesterase/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/metabolismo , Catalase/genética , Catalase/metabolismo , Inibidores da Colinesterase/toxicidade , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Camundongos Endogâmicos ICR , Síndromes Neurotóxicas/etiologia , Tamanho do Órgão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Fatores Sexuais , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Testes de Toxicidade/métodos
12.
PLoS One ; 15(7): e0236826, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32730314

RESUMO

Down syndrome (DS), is the most common cause of intellectual disability, and is characterized by defective neurogenesis during perinatal development. To identify metabolic aberrations in early neurogenesis, we profiled neurospheres derived from the embryonic brain of Ts1Cje, a mouse model of Down syndrome. High-throughput phenotypic microarray revealed a significant decrease in utilisation of 17 out of 367 substrates and significantly higher utilisation of 6 substrates in the Ts1Cje neurospheres compared to controls. Specifically, Ts1Cje neurospheres were less efficient in the utilisation of glucose-6-phosphate suggesting a dysregulation in the energy-producing pathway. T Cje neurospheres were significantly smaller in diameter than the controls. Subsequent preliminary study on supplementation with 6-phosphogluconic acid, an intermediate of glucose-6-phosphate metabolism, was able to rescue the Ts1Cje neurosphere size. This study confirmed the perturbed pentose phosphate pathway, contributing to defects observed in Ts1Cje neurospheres. We show for the first time that this comprehensive energetic assay platform facilitates the metabolic characterisation of Ts1Cje cells and confirmed their distinguishable metabolic profiles compared to the controls.


Assuntos
Encéfalo/patologia , Síndrome de Down/patologia , Neurogênese , Neurônios/metabolismo , Neurônios/patologia , Animais , Encéfalo/embriologia , Encéfalo/metabolismo , Síndrome de Down/metabolismo , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Análise em Microsséries , Fenótipo
13.
PLoS One ; 15(6): e0232493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32511256

RESUMO

Preterm birth (PTB) is the leading cause of neonatal morbidity and mortality and spontaneous PTB is a major contributor. The preceding inflammation/infection contributes not only to spontaneous PTB but is associated with neonatal morbidities including impaired brain development. Therefore, control of exaggerated immune response during pregnancy is an attractive strategy. A potential candidate is synthetic PreImplantation Factor (sPIF) as sPIF prevents inflammatory induced fetal loss and has neuroprotective properties. Here, we tested maternal sPIF prophylaxis in pregnant mice subjected to a lipopolysaccharides (LPS) insult, which results in PTB. Additionally, we evaluated sPIF effects in placental and microglial cell lines. Maternal sPIF application reduced the LPS induced PTB rate significantly. Consequently, sPIF reduced microglial activation (Iba-1 positive cells) and preserved neuronal migration (Cux-2 positive cells) in fetal brains. In fetal brain lysates sPIF decreased IL-6 and INFγ concentrations. In-vitro, sPIF reduced Iba1 and TNFα expression in microglial cells and reduced the expression of pro-apoptotic (Bad and Bax) and inflammatory (IL-6 and NLRP4) genes in placental cell lines. Together, maternal sPIF prophylaxis prevents PTB in part by controlling exaggerated immune response. Given the sPIF`FDA Fast Track approval in non-pregnant subjects, we envision sPIF therapy in pregnancy.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inflamação/terapia , Peptídeos/farmacologia , Complicações na Gravidez/tratamento farmacológico , Nascimento Prematuro/prevenção & controle , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/imunologia , Linhagem Celular , Modelos Animais de Doenças , Feminino , Inflamação/imunologia , Lipopolissacarídeos , Camundongos , Microglia/efeitos dos fármacos , Microglia/imunologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Gravidez , Complicações na Gravidez/imunologia , Nascimento Prematuro/imunologia
14.
Nat Commun ; 11(1): 3038, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546755

RESUMO

It is of considerable scientific, medical, and societal interest to understand the developmental origins of differences between male and female brains. Here we report the use of advances in MR imaging and analysis to accurately measure global, lobe and millimetre scale growth trajectory patterns over 18 gestational weeks in normal pregnancies with repeated measures. Statistical modelling of absolute growth trajectories revealed underlying differences in many measures, potentially reflecting overall body size differences. However, models of relative growth accounting for global measures revealed a complex temporal form, with strikingly similar cortical development in males and females at lobe scales. In contrast, local cortical growth patterns and larger scale white matter volume and surface measures differed significantly between male and female. Many proportional differences were maintained during neurogenesis and over 18 weeks of growth. These indicate sex related sculpting of neuroanatomy begins early in development, before cortical folding, potentially influencing postnatal development.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/embriologia , Imagem por Ressonância Magnética/métodos , Adulto , Feminino , Idade Gestacional , Humanos , Imageamento Tridimensional , Masculino , Neurogênese , Gravidez
15.
PLoS Comput Biol ; 16(6): e1007417, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32579554

RESUMO

During embryogenesis, morphogens form a concentration gradient in responsive tissue, which is then translated into a spatial cellular pattern. The mechanisms by which morphogens spread through a tissue to establish such a morphogenetic field remain elusive. Here, we investigate by mutually complementary simulations and in vivo experiments how Wnt morphogen transport by cytonemes differs from typically assumed diffusion-based transport for patterning of highly dynamic tissue such as the neural plate in zebrafish. Stochasticity strongly influences fate acquisition at the single cell level and results in fluctuating boundaries between pattern regions. Stable patterning can be achieved by sorting through concentration dependent cell migration and apoptosis, independent of the morphogen transport mechanism. We show that Wnt transport by cytonemes achieves distinct Wnt thresholds for the brain primordia earlier compared with diffusion-based transport. We conclude that a cytoneme-mediated morphogen transport together with directed cell sorting is a potentially favored mechanism to establish morphogen gradients in rapidly expanding developmental systems.


Assuntos
Padronização Corporal/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Vertebrados/embriologia , Proteínas Wnt/fisiologia , Animais , Apoptose , Encéfalo/embriologia , Linhagem da Célula , Movimento Celular , Biologia Computacional , Simulação por Computador , Desenvolvimento Embrionário , Crista Neural/embriologia , Placa Neural/embriologia , Transporte Proteico , Transdução de Sinais , Software , Processos Estocásticos , Peixe-Zebra/embriologia , beta Catenina/fisiologia
16.
Nat Commun ; 11(1): 2772, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32487986

RESUMO

Vestigial structures are key indicators of evolutionary descent, but the mechanisms underlying their development are poorly understood. This study examines vestigial eye formation in the teleost Astyanax mexicanus, which consists of a sighted surface-dwelling morph and multiple populations of blind cave morphs. Cavefish embryos initially develop eyes, but they subsequently degenerate and become vestigial structures embedded in the head. The mutated genes involved in cavefish vestigial eye formation have not been characterized. Here we identify cystathionine ß-synthase a (cbsa), which encodes the key enzyme of the transsulfuration pathway, as one of the mutated genes responsible for eye degeneration in multiple cavefish populations. The inactivation of cbsa affects eye development by increasing the transsulfuration intermediate homocysteine and inducing defects in optic vasculature, which result in aneurysms and eye hemorrhages. Our findings suggest that localized modifications in the circulatory system may have contributed to the evolution of vestigial eyes in cavefish.


Assuntos
Cistationina beta-Sintase/genética , Cistationina/metabolismo , Olho/embriologia , Olho/metabolismo , Peixes/fisiologia , Animais , Apoptose , Evolução Biológica , Encéfalo/embriologia , Sistema Cardiovascular , Cistationina beta-Sintase/metabolismo , Biologia do Desenvolvimento , Olho/citologia , Olho/crescimento & desenvolvimento , Feminino , Peixes/embriologia , Peixes/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Técnicas de Silenciamento de Genes , Cabeça , Cristalino/citologia , Cristalino/metabolismo , Masculino , Modelos Animais
17.
PLoS Biol ; 18(5): e3000746, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32453802

RESUMO

Members of the Tre2-Bub2-Cdc16 (TBC) family often function to regulate membrane trafficking and to control signaling transductions pathways. As a member of the TBC family, TBC1D23 is critical for endosome-to-Golgi cargo trafficking by serving as a bridge between Golgi-bound golgin-97/245 and the WASH/FAM21 complex on endosomal vesicles. However, the exact mechanisms by which TBC1D23 regulates cargo transport are poorly understood. Here, we present the crystal structure of the N-terminus of TBC1D23 (D23N), which consists of both the TBC and rhodanese domains. We show that the rhodanese domain is unlikely to be an active sulfurtransferase or phosphatase, despite containing a putative catalytic site. Instead, it packs against the TBC domain and forms part of the platform to interact with golgin-97/245. Using the zebrafish model, we show that impacting golgin-97/245-binding, but not the putative catalytic site, impairs neuronal growth and brain development. Altogether, our studies provide structural and functional insights into an essential protein that is required for organelle-specific trafficking and brain development.


Assuntos
Autoantígenos/metabolismo , Encéfalo/embriologia , Proteínas Ativadoras de GTPase/metabolismo , Proteínas da Matriz do Complexo de Golgi/metabolismo , Tiossulfato Sulfurtransferase/metabolismo , Fatores de Ribosilação do ADP/metabolismo , Animais , Escherichia coli , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/isolamento & purificação , Células HEK293 , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Conformação Proteica , Domínios Proteicos , Peixe-Zebra
18.
PLoS Genet ; 16(4): e1008729, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32352975

RESUMO

Evolutionarily conserved circadian clocks generate 24-hour rhythms in physiology and behaviour that adapt organisms to their daily and seasonal environments. In mammals, the suprachiasmatic nucleus (SCN) of the hypothalamus is the principal co-ordinator of the cell-autonomous clocks distributed across all major tissues. The importance of robust daily rhythms is highlighted by experimental and epidemiological associations between circadian disruption and human diseases. BMAL1 (a bHLH-PAS domain-containing transcription factor) is the master positive regulator within the transcriptional-translational feedback loops (TTFLs) that cell-autonomously define circadian time. It drives transcription of the negative regulators Period and Cryptochrome alongside numerous clock output genes, and thereby powers circadian time-keeping. Because deletion of Bmal1 alone is sufficient to eliminate circadian rhythms in cells and the whole animal it has been widely used as a model for molecular disruption of circadian rhythms, revealing essential, tissue-specific roles of BMAL1 in, for example, the brain, liver and the musculoskeletal system. Moreover, BMAL1 has clock-independent functions that influence ageing and protein translation. Despite the essential role of BMAL1 in circadian time-keeping, direct measures of its intra-cellular behaviour are still lacking. To fill this knowledge-gap, we used CRISPR Cas9 to generate a mouse expressing a knock-in fluorescent fusion of endogenous BMAL1 protein (Venus::BMAL1) for quantitative live imaging in physiological settings. The Bmal1Venus mouse model enabled us to visualise and quantify the daily behaviour of this core clock factor in central (SCN) and peripheral clocks, with single-cell resolution that revealed its circadian expression, anti-phasic to negative regulators, nuclear-cytoplasmic mobility and molecular abundance.


Assuntos
Fatores de Transcrição ARNTL/genética , Envelhecimento/genética , Ritmo Circadiano , Fatores de Transcrição ARNTL/metabolismo , Envelhecimento/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Encéfalo/embriologia , Células Cultivadas , Retroalimentação Fisiológica , Fígado/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Camundongos , Microscopia de Fluorescência/métodos , Músculo Esquelético/metabolismo , Biossíntese de Proteínas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análise de Célula Única/métodos
19.
Am J Hum Genet ; 106(6): 830-845, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32442410

RESUMO

SOX6 belongs to a family of 20 SRY-related HMG-box-containing (SOX) genes that encode transcription factors controlling cell fate and differentiation in many developmental and adult processes. For SOX6, these processes include, but are not limited to, neurogenesis and skeletogenesis. Variants in half of the SOX genes have been shown to cause severe developmental and adult syndromes, referred to as SOXopathies. We here provide evidence that SOX6 variants also cause a SOXopathy. Using clinical and genetic data, we identify 19 individuals harboring various types of SOX6 alterations and exhibiting developmental delay and/or intellectual disability; the individuals are from 17 unrelated families. Additional, inconstant features include attention-deficit/hyperactivity disorder (ADHD), autism, mild facial dysmorphism, craniosynostosis, and multiple osteochondromas. All variants are heterozygous. Fourteen are de novo, one is inherited from a mosaic father, and four offspring from two families have a paternally inherited variant. Intragenic microdeletions, balanced structural rearrangements, frameshifts, and nonsense variants are predicted to inactivate the SOX6 variant allele. Four missense variants occur in residues and protein regions highly conserved evolutionarily. These variants are not detected in the gnomAD control cohort, and the amino acid substitutions are predicted to be damaging. Two of these variants are located in the HMG domain and abolish SOX6 transcriptional activity in vitro. No clear genotype-phenotype correlations are found. Taken together, these findings concur that SOX6 haploinsufficiency leads to a neurodevelopmental SOXopathy that often includes ADHD and abnormal skeletal and other features.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/genética , Craniossinostoses/genética , Transtornos do Neurodesenvolvimento/genética , Osteocondroma/genética , Fatores de Transcrição SOXD/genética , Transporte Ativo do Núcleo Celular , Adolescente , Sequência de Aminoácidos , Sequência de Bases , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Criança , Pré-Escolar , Simulação por Computador , Feminino , Variação Estrutural do Genoma/genética , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Transtornos do Neurodesenvolvimento/diagnóstico , RNA-Seq , Fatores de Transcrição SOXD/química , Fatores de Transcrição SOXD/metabolismo , Síndrome , Transcrição Genética , Transcriptoma , Translocação Genética/genética
20.
Int. j. morphol ; 38(2): 259-264, abr. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1056432

RESUMO

The family of paired box (Pax) genes encodes the transcription factors that have been emphasized for the particular importance to embryonic development of the CNS, with the evidence obtained from various animal models. Human embryos have rarely been available for the detection of the expression of Pax family members. In this study 32 human embryos of Carnegie (CS) stages 10-20 were investigated to find the differences in the expression of Pax6 and Pax7 proteins in different regions of the neural tube and the caudal spinal cord. The expression of Pax6 and Pax7, as determined by immunohistochemistry, showed a tendency to increase in the later stages of the development both in the spinal cord and the brain. Significantly weaker expression of Pax6 and Pax7 was observed at CS 10 as compared to the later stages. At CS 10-12 weak expression of Pax6 was noticed in both dorsal and ventral parts of the developing spinal cord, while the expression of Pax7 was restricted to the cells in the roof plate and the dorsal part of the spinal cord. At CS 14-20 in the developing spinal cord Pax6 and Pax7 were detected mostly in the neuroepithelial cells of the ventricular layer, while only weak expression characterized the mantle and the marginal layers. At the same stages in the developing brain Pax6 and Pax7 were expressed in the different regions of the forebrain, the midbrain and the hindbrain suggesting for their involvement in the differentiation of neurons in specific parts of the developing brain.


La familia de genes Pax del inglés (Paired box) codifica los factores de transcripción debido a la particular importancia en el desarrollo embrionario del SNC, con la evidencia obtenida de varios modelos animales. Rara vez han estado disponibles embriones humanos para la detección de la expresión de genes de la familia Pax. En este estudio, se investigaron 32 embriones humanos de Carnegie (CS) etapas 10-20 para encontrar las diferencias en la expresión de las proteínas Pax6 y Pax7 en diferentes regiones del tubo neural y la médula espinal caudal. La expresión de Pax6 y Pax7, según la inmunohistoquímica, se observó una tendencia a aumentar en las etapas posteriores del desarrollo, tanto en la médula espinal como en el cerebro. Se observó una expresión significativamente más débil de Pax6 y Pax7 en CS 10 en comparación con las etapas posteriores. En CS 10-12 se notó una expresión débil de Pax6 en las partes dorsal y ventral de la médula espinal en desarrollo, mientras que la expresión de Pax7 se limitó a células en la placa del techo y dorsal de la médula espinal. En CS 14-20 en la médula espinal en desarrollo, Pax6 y Pax7 se observó principalmente en las células neuroepiteliales de la capa ventricular, mientras que expresión débil se caracterizó en las capas marginales. En las mismas etapas en el cerebro en desarrollo, Pax6 y Pax7 se expresaron en las diferentes áreas del prosencéfalo, el mesencéfalo y el mesencéfalo, lo que sugiere su participación en la diferenciación de las neuronas en partes específicas del cerebro en desarrollo.


Assuntos
Humanos , Medula Espinal/metabolismo , Encéfalo/crescimento & desenvolvimento , Desenvolvimento Embrionário , Fator de Transcrição PAX7/metabolismo , Fator de Transcrição PAX6/metabolismo , Medula Espinal/embriologia , Encéfalo/embriologia , Imuno-Histoquímica
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