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1.
Nat Commun ; 15(1): 5489, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38942786

RESUMO

Lipid droplets (LDs) are dynamic lipid storage organelles. They are tightly linked to metabolism and can exert protective functions, making them important players in health and disease. Most LD studies in vivo rely on staining methods, providing only a snapshot. We therefore developed a LD-reporter mouse by labelling the endogenous LD coat protein perilipin 2 (PLIN2) with tdTomato, enabling staining-free fluorescent LD visualisation in living and fixed tissues and cells. Here we validate this model under standard and high-fat diet conditions and demonstrate that LDs are highly abundant in various cell types in the healthy brain, including neurons, astrocytes, ependymal cells, neural stem/progenitor cells and microglia. Furthermore, we also show that LDs are abundant during brain development and can be visualized using live imaging of embryonic slices. Taken together, our tdTom-Plin2 mouse serves as a novel tool to study LDs and their dynamics under both physiological and diseased conditions in all tissues expressing Plin2.


Assuntos
Encéfalo , Gotículas Lipídicas , Perilipina-2 , Animais , Perilipina-2/metabolismo , Perilipina-2/genética , Gotículas Lipídicas/metabolismo , Encéfalo/metabolismo , Camundongos , Neurônios/metabolismo , Técnicas de Introdução de Genes , Camundongos Transgênicos , Feminino , Proteínas Luminescentes/metabolismo , Proteínas Luminescentes/genética , Masculino , Astrócitos/metabolismo , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/citologia , Microglia/metabolismo
2.
Sci Rep ; 12(1): 6022, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35411060

RESUMO

Neocortical excitatory neurons belong to diverse cell types, which can be distinguished by their dates of birth, laminar location, connectivity, and molecular identities. During embryogenesis, apical progenitors (APs) located in the ventricular zone first give birth to deep-layer neurons, and next to superficial-layer neurons. While the overall sequential construction of neocortical layers is well-established, whether APs produce multiple neuron types at single time points of corticogenesis is unknown. To address this question, here we used FlashTag to fate-map simultaneously-born (i.e. isochronic) cohorts of AP daughter neurons at successive stages of corticogenesis. We reveal that early in corticogenesis, isochronic neurons differentiate into heterogeneous laminar, hodological and molecular cell types. Later on, instead, simultaneously-born neurons have more homogeneous fates. Using single-cell gene expression analyses, we identify an early postmitotic surge in the molecular heterogeneity of nascent neurons during which some early-born neurons initiate and partially execute late-born neuron transcriptional programs. Together, these findings suggest that as corticogenesis unfolds, mechanisms allowing increased homogeneity in neuronal output are progressively implemented, resulting in progressively more predictable neuronal identities.


Assuntos
Neurogênese , Neurônios , Córtex Cerebral/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Análise de Célula Única
3.
Elife ; 112022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35262486

RESUMO

In the neocortex, functionally distinct areas process specific types of information. Area identity is established by morphogens and transcriptional master regulators, but downstream mechanisms driving area-specific neuronal specification remain unclear. Here, we reveal a role for RNA-binding proteins in defining area-specific cytoarchitecture. Mice lacking Pum2 or overexpressing human TDP-43 show apparent 'motorization' of layers IV and V of primary somatosensory cortex (S1), characterized by dramatic expansion of cells co-expressing Sox5 and Bcl11b/Ctip2, a hallmark of subcerebral projection neurons, at the expense of cells expressing the layer IV neuronal marker Rorß. Moreover, retrograde labeling experiments with cholera toxin B in Pum2; Emx1-Cre and TDP43A315T mice revealed a corresponding increase in subcerebral connectivity of these neurons in S1. Intriguingly, other key features of somatosensory area identity are largely preserved, suggesting that Pum2 and TDP-43 may function in a downstream program, rather than controlling area identity per se. Transfection of primary neurons and in utero electroporation (IUE) suggest cell-autonomous and post-mitotic modulation of Sox5, Bcl11b/Ctip2, and Rorß levels. Mechanistically, we find that Pum2 and TDP-43 directly interact with and affect the translation of mRNAs encoding Sox5, Bcl11b/Ctip2, and Rorß. In contrast, effects on the levels of these mRNAs were not detectable in qRT-PCR or single-molecule fluorescent in situ hybridization assays, and we also did not detect effects on their splicing or polyadenylation patterns. Our results support the notion that post-transcriptional regulatory programs involving translational regulation and mediated by Pum2 and TDP-43 contribute to elaboration of area-specific neuronal identity and connectivity in the neocortex.


Assuntos
Neocórtex , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Hibridização in Situ Fluorescente , Camundongos , Neocórtex/metabolismo , Membro 2 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo
4.
Mol Psychiatry ; 27(4): 2080-2094, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35022531

RESUMO

Mutations in the SHANK3 gene have been recognized as a genetic risk factor for Autism Spectrum Disorder (ASD), a neurodevelopmental disease characterized by social deficits and repetitive behaviors. While heterozygous SHANK3 mutations are usually the types of mutations associated with idiopathic autism in patients, heterozygous deletion of Shank3 gene in mice does not commonly induce ASD-related behavioral deficit. Here, we used in-vivo and ex-vivo approaches to demonstrate that region-specific neonatal downregulation of Shank3 in the Nucleus Accumbens promotes D1R-medium spiny neurons (D1R-MSNs) hyperexcitability and upregulates Transient Receptor Potential Vanilloid 4 (Trpv4) to impair social behavior. Interestingly, genetically vulnerable Shank3+/- mice, when challenged with Lipopolysaccharide to induce an acute inflammatory response, showed similar circuit and behavioral alterations that were rescued by acute Trpv4 inhibition. Altogether our data demonstrate shared molecular and circuit mechanisms between ASD-relevant genetic alterations and environmental insults, which ultimately lead to sociability dysfunctions.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Animais , Transtorno do Espectro Autista/genética , Transtorno Autístico/genética , Modelos Animais de Doenças , Humanos , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Comportamento Social , Canais de Cátion TRPV/genética
5.
Int J Mol Sci ; 21(20)2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-33050604

RESUMO

The complexity of brain structure and function is rooted in the precise spatial and temporal regulation of selective developmental events. During neurogenesis, both vertebrates and invertebrates generate a wide variety of specialized cell types through the expansion and specification of a restricted set of neuronal progenitors. Temporal patterning of neural progenitors rests on fine regulation between cell-intrinsic and cell-extrinsic mechanisms. The rapid emergence of high-throughput single-cell technologies combined with elaborate computational analysis has started to provide us with unprecedented biological insights related to temporal patterning in the developing central nervous system (CNS). Here, we present an overview of recent advances in Drosophila and vertebrates, focusing both on cell-intrinsic mechanisms and environmental influences. We then describe the various multi-omics approaches that have strongly contributed to our current understanding and discuss perspectives on the various -omics approaches that hold great potential for the future of temporal patterning research.


Assuntos
Padronização Corporal/genética , Genômica , Metabolômica , Neurogênese/genética , Proteômica , Análise de Célula Única , Lobo Temporal/embriologia , Lobo Temporal/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Genômica/métodos , Proteômica/métodos , Análise de Célula Única/métodos
6.
Cereb Cortex ; 30(11): 5667-5685, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32572460

RESUMO

The formation of functional cortical maps in the cerebral cortex results from a timely regulated interaction between intrinsic genetic mechanisms and electrical activity. To understand how transcriptional regulation influences network activity and neuronal excitability within the neocortex, we used mice deficient for Nr2f1 (also known as COUP-TFI), a key determinant of primary somatosensory (S1) area specification during development. We found that the cortical loss of Nr2f1 impacts on spontaneous network activity and synchronization of S1 cortex at perinatal stages. In addition, we observed alterations in the intrinsic excitability and morphological features of layer V pyramidal neurons. Accordingly, we identified distinct voltage-gated ion channels regulated by Nr2f1 that might directly influence intrinsic bioelectrical properties during critical time windows of S1 cortex specification. Altogether, our data suggest a tight link between Nr2f1 and neuronal excitability in the developmental sequence that ultimately sculpts the emergence of cortical network activity within the immature neocortex.


Assuntos
Fator I de Transcrição COUP/metabolismo , Neurogênese/fisiologia , Células Piramidais/metabolismo , Córtex Somatossensorial/embriologia , Córtex Somatossensorial/crescimento & desenvolvimento , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Córtex Somatossensorial/metabolismo
7.
Elife ; 5: e09531, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26814051

RESUMO

During cortical development, the identity of major classes of long-distance projection neurons is established by the expression of molecular determinants, which become gradually restricted and mutually exclusive. However, the mechanisms by which projection neurons acquire their final properties during postnatal stages are still poorly understood. In this study, we show that the number of neurons co-expressing Ctip2 and Satb2, respectively involved in the early specification of subcerebral and callosal projection neurons, progressively increases after birth in the somatosensory cortex. Ctip2/Satb2 postnatal co-localization defines two distinct neuronal subclasses projecting either to the contralateral cortex or to the brainstem suggesting that Ctip2/Satb2 co-expression may refine their properties rather than determine their identity. Gain- and loss-of-function approaches reveal that the transcriptional adaptor Lmo4 drives this maturation program through modulation of epigenetic mechanisms in a time- and area-specific manner, thereby indicating that a previously unknown genetic program postnatally promotes the acquisition of final subtype-specific features.


Assuntos
Epigênese Genética , Neurônios/fisiologia , Córtex Somatossensorial/embriologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Regulação da Expressão Gênica no Desenvolvimento , Proteínas com Domínio LIM/metabolismo , Proteínas de Ligação à Região de Interação com a Matriz/análise , Camundongos , Proteínas Repressoras/análise , Fatores de Transcrição/análise , Proteínas Supressoras de Tumor/análise
8.
Cell Mol Life Sci ; 71(1): 43-62, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23525662

RESUMO

Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are nuclear receptors belonging to the superfamily of the steroid/thyroid hormone receptors. Members of this family are internalized to the nucleus both in a ligand-dependent or -independent manner and act as strong transcriptional regulators by binding to the DNA of their target genes. COUP-TFs are defined as orphan receptors, since ligands regulating their activity have not so far been identified. From the very beginning of metazoan evolution, these molecules have been involved in various key events during embryonic development and organogenesis. In this review, we will mainly focus on their function during development and maturation of the central nervous system, which has been well characterized in various animal classes ranging from ctenophores to mammals. We will start by introducing the current knowledge on COUP-TF mechanisms of action and then focus our discussion on the crucial processes underlying forebrain ontogenesis, with special emphasis on mammalian development. Finally, the conserved roles of COUP-TFs along phylogenesis will be highlighted, and some hypotheses, worth exploring in future years to gain more insight into the mechanisms controlled by these factors, will be proposed.


Assuntos
Fatores de Transcrição COUP/metabolismo , Prosencéfalo/metabolismo , Animais , Fatores de Transcrição COUP/química , Fatores de Transcrição COUP/classificação , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Humanos , Neurogênese , Prosencéfalo/crescimento & desenvolvimento
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