Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Endocrinology ; 165(7)2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38815068

RESUMO

The growth hormone secretagogue receptor (GHSR), primarily known as the receptor for the hunger hormone ghrelin, potently controls food intake, yet the specific Ghsr-expressing cells mediating the orexigenic effects of this receptor remain incompletely characterized. Since Ghsr is expressed in gamma-aminobutyric acid (GABA)-producing neurons, we sought to investigate whether the selective expression of Ghsr in a subset of GABA neurons is sufficient to mediate GHSR's effects on feeding. First, we crossed mice that express a tamoxifen-dependent Cre recombinase in the subset of GABA neurons that express glutamic acid decarboxylase 2 (Gad2) enzyme (Gad2-CreER mice) with reporter mice, and found that ghrelin mainly targets a subset of Gad2-expressing neurons located in the hypothalamic arcuate nucleus (ARH) and that is predominantly segregated from Agouti-related protein (AgRP)-expressing neurons. Analysis of various single-cell RNA-sequencing datasets further corroborated that the primary subset of cells coexpressing Gad2 and Ghsr in the mouse brain are non-AgRP ARH neurons. Next, we crossed Gad2-CreER mice with reactivable GHSR-deficient mice to generate mice expressing Ghsr only in Gad2-expressing neurons (Gad2-GHSR mice). We found that ghrelin treatment induced the expression of the marker of transcriptional activation c-Fos in the ARH of Gad2-GHSR mice, yet failed to induce food intake. In contrast, food deprivation-induced refeeding was higher in Gad2-GHSR mice than in GHSR-deficient mice and similar to wild-type mice, suggesting that ghrelin-independent roles of GHSR in a subset of GABA neurons is sufficient for eliciting full compensatory hyperphagia in mice.


Assuntos
Núcleo Arqueado do Hipotálamo , Privação de Alimentos , Neurônios GABAérgicos , Grelina , Glutamato Descarboxilase , Hiperfagia , Receptores de Grelina , Animais , Masculino , Camundongos , Neurônios GABAérgicos/metabolismo , Receptores de Grelina/genética , Receptores de Grelina/metabolismo , Hiperfagia/metabolismo , Grelina/metabolismo , Grelina/farmacologia , Núcleo Arqueado do Hipotálamo/metabolismo , Privação de Alimentos/fisiologia , Glutamato Descarboxilase/metabolismo , Glutamato Descarboxilase/genética , Camundongos Transgênicos , Proteína Relacionada com Agouti/metabolismo , Proteína Relacionada com Agouti/genética , Camundongos Endogâmicos C57BL
2.
Development ; 147(14)2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32586977

RESUMO

Cortical interneurons (CINs) originate in the ganglionic eminences (GEs) and migrate tangentially to the cortex guided by different attractive and repulsive cues. Once inside the cortex, the cellular and molecular mechanisms determining the migration of CINs along the rostrocaudal axis are less well understood. Here, we investigated the cortical distribution of CINs originating in the medial and caudal GEs at different time points. Using molecular and genetic labeling, we showed that, in the mouse, early- and late-born CINs (E12 versus E15) are differentially distributed along the rostrocaudal axis. Specifically, late-born CINs are preferentially enriched in cortical areas closer to their respective sites of origin in the medial or caudal GE. Surprisingly, our in vitro experiments failed to show a preferential migration pattern along the rostrocaudal axis for medial- or caudal-born CINs. Moreover, in utero transplantation experiments suggested that the rostrocaudal dispersion of CINs depends on the developmental stage of the host brain and is limited by the migration time and the increasing size of the developing brain. These data suggest that the embryonic expansion of the cortex contributes to the rostrocaudal distribution of CINs.


Assuntos
Encéfalo/crescimento & desenvolvimento , Córtex Cerebral/citologia , Neurônios GABAérgicos/citologia , Animais , Encéfalo/embriologia , Encéfalo/fisiologia , Linhagem da Célula , Movimento Celular , Córtex Cerebral/embriologia , Córtex Cerebral/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Neurônios GABAérgicos/metabolismo , Camundongos , Camundongos Knockout , Tamanho do Órgão , Córtex Somatossensorial/citologia , Córtex Somatossensorial/embriologia , Córtex Somatossensorial/metabolismo , Fator Nuclear 1 de Tireoide/deficiência , Fator Nuclear 1 de Tireoide/genética , Fator Nuclear 1 de Tireoide/metabolismo , Ácido gama-Aminobutírico/metabolismo
3.
Cell Rep ; 26(5): 1157-1173.e5, 2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30699346

RESUMO

Mafb and c-Maf transcription factor (TF) expression is enriched in medial ganglionic eminence (MGE) lineages, beginning in late-secondary progenitors and continuing into mature parvalbumin (PV+) and somatostatin (SST+) interneurons. However, the functions of Maf TFs in MGE development remain to be elucidated. Herein, Mafb and c-Maf were conditionally deleted, alone and together, in the MGE and its lineages. Analyses of Maf mutant mice revealed redundant functions of Mafb and c-Maf in secondary MGE progenitors, where they repress the generation of SST+ cortical and hippocampal interneurons. By contrast, Mafb and c-Maf have distinct roles in postnatal cortical interneuron (CIN) morphological maturation, synaptogenesis, and cortical circuit integration. Thus, Mafb and c-Maf have redundant and opposing functions at different steps in CIN development.


Assuntos
Linhagem da Célula , Córtex Cerebral/metabolismo , Interneurônios/metabolismo , Fator de Transcrição MafB/metabolismo , Proteínas Proto-Oncogênicas c-maf/metabolismo , Potenciais de Ação , Animais , Animais Recém-Nascidos , Apoptose , Membrana Celular/metabolismo , Movimento Celular , Proliferação de Células , Hipocampo/metabolismo , Eminência Mediana/metabolismo , Camundongos Knockout , Neuritos/metabolismo , Neurogênese , Parvalbuminas/metabolismo , Somatostatina/metabolismo , Sinapses/metabolismo
4.
Cell ; 172(3): 491-499.e15, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29358049

RESUMO

Non-coding "ultraconserved" regions containing hundreds of consecutive bases of perfect sequence conservation across mammalian genomes can function as distant-acting enhancers. However, initial deletion studies in mice revealed that loss of such extraordinarily constrained sequences had no immediate impact on viability. Here, we show that ultraconserved enhancers are required for normal development. Focusing on some of the longest ultraconserved sites genome wide, located near the essential neuronal transcription factor Arx, we used genome editing to create an expanded series of knockout mice lacking individual or combinations of ultraconserved enhancers. Mice with single or pairwise deletions of ultraconserved enhancers were viable and fertile but in nearly all cases showed neurological or growth abnormalities, including substantial alterations of neuron populations and structural brain defects. Our results demonstrate the functional importance of ultraconserved enhancers and indicate that remarkably strong sequence conservation likely results from fitness deficits that appear subtle in a laboratory setting.


Assuntos
Sequência Conservada , Desenvolvimento Embrionário/genética , Elementos Facilitadores Genéticos , Animais , Encéfalo/anormalidades , Encéfalo/embriologia , Encéfalo/metabolismo , Feminino , Deleção de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Masculino , Camundongos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Cereb Cortex ; 28(11): 3797-3815, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29028947

RESUMO

The postnatal functions of the Dlx1&2 transcription factors in cortical interneurons (CINs) are unknown. Here, using conditional Dlx1, Dlx2, and Dlx1&2 knockouts (CKOs), we defined their roles in specific CINs. The CKOs had dendritic, synaptic, and survival defects, affecting even PV+ CINs. We provide evidence that DLX2 directly drives Gad1, Gad2, and Vgat expression, and show that mutants had reduced mIPSC amplitude. In addition, the mutants formed fewer GABAergic synapses on excitatory neurons and had reduced mIPSC frequency. Furthermore, Dlx1/2 CKO had hypoplastic dendrites, fewer excitatory synapses, and reduced excitatory input. We provide evidence that some of these phenotypes were due to reduced expression of GRIN2B (a subunit of the NMDA receptor), a high confidence Autism gene. Thus, Dlx1&2 coordinate key components of CIN postnatal development by promoting their excitability, inhibitory output, and survival.


Assuntos
Córtex Cerebral/crescimento & desenvolvimento , Neurônios GABAérgicos/fisiologia , Proteínas de Homeodomínio/fisiologia , Interneurônios/fisiologia , Sinapses/fisiologia , Fatores de Transcrição/fisiologia , Ácido gama-Aminobutírico/biossíntese , Animais , Córtex Cerebral/citologia , Feminino , Neurônios GABAérgicos/citologia , Regulação da Expressão Gênica no Desenvolvimento , Glutamato Descarboxilase/metabolismo , Proteínas de Homeodomínio/genética , Interneurônios/citologia , Masculino , Camundongos Knockout , Potenciais Pós-Sinápticos em Miniatura , Fatores de Transcrição/genética , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/metabolismo
6.
Neuron ; 84(5): 940-53, 2014 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-25467980

RESUMO

Little is known about genetic mechanisms that regulate the ratio of cortical excitatory and inhibitory neurons. We show that NPAS1 and NPAS3 transcription factors (TFs) are expressed in progenitor domains of the mouse basal ganglia (subpallium, MGE, and CGE). NPAS1(-/-) mutants had increased proliferation, ERK signaling, and expression of Arx in the MGE and CGE. NPAS1(-/-) mutants also had increased neocortical inhibition (sIPSC and mIPSC) and generated an excess of somatostatin(+) (SST) (MGE-derived) and vasoactive intestinal polypeptide(+) (VIP) (CGE-derived) neocortical interneurons, but had a normal density of parvalbumin(+) (PV) (MGE-derived) interneurons. In contrast, NPAS3(-/-) mutants showed decreased proliferation and ERK signaling in progenitors of the ganglionic eminences and had fewer SST(+) and VIP(+) interneurons. NPAS1 repressed activity of an Arx enhancer, and Arx overexpression resulted in increased proliferation of CGE progenitors. These results provide insights into genetic regulation of cortical interneuron numbers and cortical inhibitory tone.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Córtex Cerebral/citologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Interneurônios/classificação , Interneurônios/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Transtorno Autístico/genética , Transtorno Autístico/patologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proliferação de Células/genética , Células Cultivadas , Córtex Cerebral/embriologia , Córtex Cerebral/crescimento & desenvolvimento , Embrião de Mamíferos , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Glutamato Descarboxilase/genética , Glutamato Descarboxilase/metabolismo , Humanos , Proteínas com Homeodomínio LIM/genética , Proteínas com Homeodomínio LIM/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Polimorfismo de Nucleotídeo Único/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Farm Hosp ; 38(6): 454-60, 2014 Nov 03.
Artigo em Espanhol | MEDLINE | ID: mdl-25542655

RESUMO

PURPOSE: Analyze the impact of economic and social crisis in volume and funding of clinical trials (CT) and observational studies (ES) from the activity of an Research Ethics Committee (REC). METHOD: REC memories 2003-2012 were reviewed. Financing of evaluated projects, CT and OS were analyzed classifying them into four groups: 1) promoted by pharmaceutical industry, 2) by scientific societies with industry support, 3) by scientific societies with government support and 4) unfunding.Two periods were compared: pre-crisis (2003-2007) and crisis (2008-2012). RESULTS: During 10 studied years, 744 protocols were evaluated: a 71% of group 1, a 9% of group 2, a 3% of group 3 and a 17% was no funding. Regarding OS, 40%, 5,4%, 8,6% and 46% were the groups 1, 2, 3 and 4 respectively. Analyzing crisis versus pre-crisis period, statistically significant differences were observed in the decreasing of number of CT phase 2 and 3 and in the rising EO. Comparing crisis related to the pre-crisis period, the Group 4 increased statistically significantly. CONCLUSIONS: Evolution of total number of studies evaluated by REC tends to be maintained and even increased over time. REC maintains its activity and even increased at the expense of financing and unfunded OS.


Objetivos: Analizar el impacto de la crisis económico-social en volumen y financiación de los ensayos clínicos (EC) y estudios observacionales (EO) a partir de la actividad de un Comité Ético de Investigación Clínica (CEIC). Método: Se revisaron las memorias del CEIC desde 2003 hasta 2012. Se analizó la financiación de los EC y los EO clasificándolos en cuatro grupos: 1) promovidos por la industria farmacéutica, 2) por sociedades científicas con soporte de la industria, 3) por sociedades apoyadas por las administraciones públicas y 4) sin financiación. Se compararon dos períodos: precrisis (2003- 2007) y crisis (2008-2012). Resultados: Se evaluaron 744 protocolos: un 71% del grupo 1, un 9% del grupo 2, un 3% del grupo 3 y un 17% carecía de financiación. En cuanto a los EO, un 40%, un 5,4%, un 8,6% y un 46% correspondían a los grupos 1, 2, 3 y 4 respectivamente. Analizando periodo crisis versus precrisis, se observaron diferencias estadísticamente significativas en el número de los EC de fase 2 y fase 3 que disminuyeron y en los EO que aumentaron. En el periodo crisis respecto al precrisis, el Grupo 4 aumentó de manera estadísticamente significativa. Conclusiones: La evolución del número total de estudios evaluados por el CEIC tiende a mantenerse e incluso incrementarse en el tiempo. El CEIC mantiene su actividad e incluso la incrementa, a expensas de EO con y sin financiación.


Assuntos
Ensaios Clínicos como Assunto/economia , Recessão Econômica , Comitês de Ética em Pesquisa/economia , Comitês de Ética em Pesquisa/tendências , Apoio à Pesquisa como Assunto/tendências , Pesquisa Biomédica , Indústria Farmacêutica/economia , Humanos , Estudos Observacionais como Assunto/economia , Sociedades Científicas , Espanha
8.
Farm. hosp ; 38(6): 454-460, nov.-dic. 2014. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-133178

RESUMO

Objetivos: Analizar el impacto de la crisis económico-social en volumen y financiación de los ensayos clínicos (EC) y estudios observacionales (EO) a partir de la actividad de un Comité Ético de Investigación Clínica (CEIC). Método: Se revisaron las memorias del CEIC desde 2003 hasta 2012. Se analizó la financiación de los EC y los EO clasificándolos en cuatro grupos: 1) promovidos por la industria farmacéutica, 2) por sociedades científicas con soporte de la industria, 3) por sociedades apoyadas por las administraciones públicas y 4) sin financiación. Se compararon dos períodos: precrisis (2003-2007) y crisis (2008-2012). Resultados: Se evaluaron 744 protocolos: un 71% del grupo1, un 9% del grupo 2, un 3% del grupo 3 y un 17% carecía de financiación. En cuanto a los EO, un 40%, un 5,4%,un 8,6% y un 46% correspondían a los grupos 1, 2, 3 y 4respectivamente. Analizando periodo crisis versus precrisis, se observaron diferencias estadísticamente significativas en el número de los EC de fase 2 y fase 3 que disminuyeron y en los EO que aumentaron. En el periodo crisis respecto al precrisis, el Grupo 4 aumentó de manera estadísticamente significativa. Conclusiones: La evolución del número total de estudios evaluados por el CEIC tiende a mantenerse e incluso incrementarse en el tiempo. El CEIC mantiene su actividad e incluso la incrementa, a expensas de EO con y sin financiación (AU)


Purpose: Analyse the impact of economic and social crisis in volume and funding of clinical trials (CT) and observational studies(ES) from the activity of an Research Ethics Committee (REC). Method: REC memories 2003-2012 were reviewed. Financing of evaluated projects, CT and OS were analyzed classifying them into four groups: 1) promoted by pharmaceutical industry, 2) by scientific societies with industry support, 3) by scientific societies with government support and 4) unfunding. Two periods were compared: pre-crisis (2003-2007) and crisis (2008-2012). Results: During 10 studied years, 744 protocols were evaluated: a 71% of group 1, a 9% of group 2, a 3% of group 3 and a 17% was no funding. Regarding OS, 40%, 5,4%, 8,6% and 46% were the groups 1, 2, 3 and 4 respectively. Analyzing crisis versus pre-crisis period, statistically significant differences were observed in the decreasing of number of CT phase 2 and 3 and in the rising EO. Comparing crisis related to the pre-crisis period, the Group 4 increased statistically significantly. Conclusions: Evolution of total number of studies evaluated by REC tends to be maintained and even increased over time. REC maintains its activity and even increased at the expense of financing and unfunded OS (AU)


Assuntos
Humanos , Comitês de Ética em Pesquisa/organização & administração , Ensaios Clínicos como Assunto/economia , Financiamento da Pesquisa , Recessão Econômica , Pesquisa Biomédica/economia
9.
J Comp Neurol ; 521(7): 1561-84, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23042297

RESUMO

Mice lacking the Dlx1 and Dlx2 homeobox genes (Dlx1/2 mutants) have severe deficits in subpallial differentiation, including overexpression of the Gsx1 and Gsx2 homeobox genes. To investigate whether Gsx overexpression contributes to the Dlx1/2 mutant phenotypes, we made compound loss-of-function mutants. Eliminating Gsx2 function from the Dlx1/2 mutants rescued the increased expression of Ascl1 and Hes5 (Notch signaling mediators) and Olig2 (oligodendrogenesis mediator). In addition, Dlx1/2;Gsx2 mutants, like Dlx1/2;Ascl1 mutants, exacerbated the Gsx2 and Dlx1/2 patterning and differentiation phenotypes, particularly in the lateral ganglionic eminence (LGE) caudal ganglionic eminence (CGE), and septum, including loss of GAD1 expression. On the other hand, eliminating Gsx1 function from the Dlx1/2 mutants (Dlx1/2;Gsx1 mutants) did not severely exacerbate their phenotype; on the contrary, it resulted in a partial rescue of medial ganglionic eminence (MGE) properties, including interneuron migration to the cortex. Thus, despite their redundant properties, Gsx1 and -2 have distinct interactions with Dlx1 and -2. Gsx2 interaction is strongest in the LGE, CGE, and septum, whereas the Gsx1 interaction is strongest in the MGE. From these studies, and earlier studies, we present a model of the transcriptional network that regulates early steps of subcortical development.


Assuntos
Encéfalo/fisiologia , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Neurogênese/fisiologia , Fatores de Transcrição/genética , Animais , Encéfalo/embriologia , Embrião de Mamíferos , Imunofluorescência , Hibridização In Situ , Camundongos , Camundongos Mutantes , Fenótipo
10.
Neuron ; 76(2): 338-52, 2012 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-23083737

RESUMO

Neurogenesis relies on a delicate balance between progenitor maintenance and neuronal production. Progenitors divide symmetrically to increase the pool of dividing cells. Subsequently, they divide asymmetrically to self-renew and produce new neurons or, in some brain regions, intermediate progenitor cells (IPCs). Here we report that central nervous system progenitors express Robo1 and Robo2, receptors for Slit proteins that regulate axon guidance, and that absence of these receptors or their ligands leads to loss of ventricular mitoses. Conversely, production of IPCs is enhanced in Robo1/2 and Slit1/2 mutants, suggesting that Slit/Robo signaling modulates the transition between primary and intermediate progenitors. Unexpectedly, these defects do not lead to transient overproduction of neurons, probably because supernumerary IPCs fail to detach from the ventricular lining and cycle very slowly. At the molecular level, the role of Slit/Robo in progenitor cells involves transcriptional activation of the Notch effector Hes1. These findings demonstrate that Robo signaling modulates progenitor cell dynamics in the developing brain.


Assuntos
Proliferação de Células , Sistema Nervoso Central/citologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores Imunológicos/metabolismo , Transdução de Sinais/fisiologia , Células-Tronco/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Caderinas/metabolismo , Contagem de Células , Ciclo Celular/genética , Células Cultivadas , Sistema Nervoso Central/embriologia , Distribuição de Qui-Quadrado , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Homeodomínio/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Neocórtex/citologia , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Neurogênese , Neurônios/fisiologia , Receptores Imunológicos/deficiência , Transdução de Sinais/genética , Fatores de Transcrição HES-1 , Transfecção , Proteínas Roundabout
11.
J Neurosci ; 31(46): 16570-80, 2011 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-22090484

RESUMO

GABA-containing (GABAergic) interneurons comprise a very heterogeneous group of cells that are crucial for cortical function. Different classes of interneurons specialize in targeting specific subcellular domains of excitatory pyramidal cells or other interneurons, which provides cortical circuits with an enormous capability for information processing. As in other regions of the CNS, cortical interneuron diversity is thought to emerge from the genetic specification of different groups of progenitor cells within the subpallium. Most cortical interneurons originate from two main regions, the medial and the caudal ganglionic eminences (MGE and CGE, respectively). In addition, it has been shown that progenitors in the embryonic preoptic area (POA) also produce a small population of cortical GABAergic interneurons. Here, we show that the contribution of the POA to the complement of cortical GABAergic interneurons is larger than previously believed. Using genetic fate mapping and in utero transplantation experiments, we demonstrate that Dbx1-expressing progenitor cells in the POA give rise to a small but highly diverse cohort of cortical interneurons, with some neurochemical and electrophysiological characteristics that were previously attributed to MGE- or CGE-derived interneurons. There are, however, some features that seem to distinguish POA-derived interneurons from MGE- or CGE-derived cells, such as their preferential laminar location. These results indicate that the mechanisms controlling the specification of different classes of cortical interneurons might be more complex than previously expected. Together with earlier findings, our results also suggest that the POA generates nearly 10% of the GABAergic interneurons in the cerebral cortex of the mouse.


Assuntos
Interneurônios/fisiologia , Células-Tronco Neurais/fisiologia , Área Pré-Óptica/citologia , Área Pré-Óptica/embriologia , Córtex Somatossensorial/citologia , Ácido gama-Aminobutírico/metabolismo , Animais , Animais Recém-Nascidos , Proteínas de Bactérias/genética , Bromodesoxiuridina/metabolismo , Movimento Celular/genética , Estimulação Elétrica , Embrião de Mamíferos , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Homeodomínio/genética , Técnicas In Vitro , Indóis/metabolismo , Proteínas Luminescentes/genética , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/genética , Camundongos , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/metabolismo , Células-Tronco Neurais/transplante , Técnicas de Patch-Clamp , Área Pré-Óptica/metabolismo , Proteínas/genética , RNA não Traduzido , Córtex Somatossensorial/crescimento & desenvolvimento
12.
Neuron ; 69(1): 77-90, 2011 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21220100

RESUMO

The chemokine Cxcl12 binds Cxcr4 and Cxcr7 receptors to control cell migration in multiple biological contexts, including brain development, leukocyte trafficking, and tumorigenesis. Both receptors are expressed in the CNS, but how they cooperate during migration has not been elucidated. Here, we used the migration of cortical interneurons as a model to study this process. We found that Cxcr4 and Cxcr7 are coexpressed in migrating interneurons, and that Cxcr7 is essential for chemokine signaling. Intriguingly, this process does not exclusively involve Cxcr7, but most critically the modulation of Cxcr4 function. Thus, Cxcr7 is necessary to regulate Cxcr4 protein levels, thereby adapting chemokine responsiveness in migrating cells. This demonstrates that a chemokine receptor modulates the function of another chemokine receptor by controlling the amount of protein that is made available for signaling at the cell surface.


Assuntos
Movimento Celular/fisiologia , Quimiocina CXCL12/metabolismo , Interneurônios/metabolismo , Receptores CXCR4/metabolismo , Receptores CXCR/metabolismo , Transdução de Sinais/fisiologia , Animais , Células Cultivadas , Córtex Cerebral/citologia , Córtex Cerebral/crescimento & desenvolvimento , Imuno-Histoquímica , Hibridização In Situ , Interneurônios/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores CXCR/genética , Receptores CXCR4/genética
13.
Nature ; 464(7293): 1376-80, 2010 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-20393464

RESUMO

Schizophrenia is a complex disorder that interferes with the function of several brain systems required for cognition and normal social behaviour. Although the most notable clinical aspects of the disease only become apparent during late adolescence or early adulthood, many lines of evidence suggest that schizophrenia is a neurodevelopmental disorder with a strong genetic component. Several independent studies have identified neuregulin 1 (NRG1) and its receptor ERBB4 as important risk genes for schizophrenia, although their precise role in the disease process remains unknown. Here we show that Nrg1 and ErbB4 signalling controls the development of inhibitory circuitries in the mammalian cerebral cortex by cell-autonomously regulating the connectivity of specific GABA (gamma-aminobutyric acid)-containing interneurons. In contrast to the prevalent view, which supports a role for these genes in the formation and function of excitatory synapses between pyramidal cells, we found that ErbB4 expression in the mouse neocortex and hippocampus is largely confined to certain classes of interneurons. In particular, ErbB4 is expressed by many parvalbumin-expressing chandelier and basket cells, where it localizes to axon terminals and postsynaptic densities receiving glutamatergic input. Gain- and loss-of-function experiments, both in vitro and in vivo, demonstrate that ErbB4 cell-autonomously promotes the formation of axo-axonic inhibitory synapses over pyramidal cells, and that this function is probably mediated by Nrg1. In addition, ErbB4 expression in GABA-containing interneurons regulates the formation of excitatory synapses onto the dendrites of these cells. By contrast, ErbB4 is dispensable for excitatory transmission between pyramidal neurons. Altogether, our results indicate that Nrg1 and ErbB4 signalling is required for the wiring of GABA-mediated circuits in the postnatal cortex, providing a new perspective to the involvement of these genes in the aetiology of schizophrenia.


Assuntos
Córtex Cerebral/metabolismo , Receptores ErbB/metabolismo , Interneurônios/metabolismo , Vias Neurais/fisiologia , Neuregulina-1/metabolismo , Transdução de Sinais , Ácido gama-Aminobutírico/metabolismo , Animais , Diferenciação Celular , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Córtex Cerebral/crescimento & desenvolvimento , Dendritos/metabolismo , Embrião de Mamíferos , Receptores ErbB/deficiência , Receptores ErbB/genética , Potenciais Pós-Sinápticos Excitadores/genética , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Técnicas In Vitro , Camundongos , Inibição Neural/genética , Inibição Neural/fisiologia , Células Piramidais/metabolismo , Receptor ErbB-4 , Esquizofrenia/genética , Esquizofrenia/metabolismo , Sinapses/metabolismo
14.
J Neurosci ; 30(8): 2824-34, 2010 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-20181580

RESUMO

The mechanisms controlling the assembly of brain nuclei are poorly understood. In the forebrain, it is typically assumed that the formation of nuclei follows a similar sequence of events that in the cortex. In this structure, projection neurons are generated sequentially from common progenitor cells and migrate radially to reach their final destination, whereas interneurons are generated remotely and arrive to the cortex through tangential migration. Using the globus pallidus as a model to study the formation of forebrain nuclei, we found that the development of this basal ganglia structure involves the generation of several distinct classes of projection neurons from relatively distant progenitor pools, which then assemble together through tangential migration. Our results thus suggest that tangential migration in the forebrain is not limited to interneurons, as previously thought, but also involves projection neurons and reveal that the assembly of forebrain nuclei is more complex than previously anticipated.


Assuntos
Globo Pálido/embriologia , Globo Pálido/metabolismo , Neurônios/metabolismo , Prosencéfalo/embriologia , Prosencéfalo/metabolismo , Células-Tronco/metabolismo , Acetilcolina/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores/análise , Biomarcadores/metabolismo , Diferenciação Celular/fisiologia , Movimento Celular/fisiologia , Colina O-Acetiltransferase/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Globo Pálido/citologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/citologia , Vias Neurais/embriologia , Vias Neurais/metabolismo , Neurogênese/fisiologia , Neurônios/citologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Parvalbuminas/metabolismo , Prosencéfalo/citologia , Células-Tronco/citologia , Fator Nuclear 1 de Tireoide , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Ácido gama-Aminobutírico/metabolismo
15.
Drug News Perspect ; 22(6): 325-39, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19771322

RESUMO

A clinical investigation program was carried out to replace endogenous albumin of patients with mild to moderate Alzheimer's disease (AD) with 5% Human Albumin Grifols(R) through a plasma exchange (PE) schedule, in order to alter the dynamic equilibrium between albumin-bound Abeta in plasma and Abeta in cerebrospinal fluid. In a pilot proof-of-concept study, 7 patients underwent 6 PE in 3 weeks and 1 year of follow-up. Plasma Abeta determinations demonstrated a variation pattern in levels in relation with the PEs. Cognitive status scores (MMSE and ADAS-Cog) were more stable than expected. In a phase II clinical trial, 29 patients were randomized into PEtreated and control groups with 1 year follow-up. Interim results point toward the occurrence of Abeta40 mobilization in the PE-treated patients, who scored better in cognitive tests (differences at 9 months: 2.5 in MMSE and 5.5 in ADAS-cog). These results suggest that a PE program with 5% Human Albumin Grifols may have a promising role in the treatment of mild to moderate AD.


Assuntos
Doença de Alzheimer/terapia , Troca Plasmática/métodos , Albumina Sérica/administração & dosagem , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Animais , Ensaios Clínicos como Assunto , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/terapia , Sistemas de Liberação de Medicamentos , Humanos , Albumina Sérica/metabolismo
16.
Transfus Apher Sci ; 39(2): 115-21, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18710822

RESUMO

Thirty-six fresh frozen plasma (FFP) units obtained from whole blood donations were used for 12 replicate experiments. For each replicate experiment, three ABO-matched FFP units were pooled and divided into three units containing different volumes of identical plasma. One unit was used as control FFP, one unit was treated with methylene blue plus visible light and one unit was treated with amotosalen and UVA light. The overall coagulation factor levels were better maintained in untreated FFP than in photochemically treated plasma. However, treated-plasma by both photochemical methods maintained coagulation factor levels that met or exceeded the European Pharmacopeia requirements for therapeutic plasma.


Assuntos
Proteínas Sanguíneas/análise , Azul de Metileno/farmacologia , Plasma/química , Inativação de Vírus , Fatores de Coagulação Sanguínea/análise , Patógenos Transmitidos pelo Sangue/efeitos da radiação , Fibrinogênio/análise , Furocumarinas/farmacologia , Furocumarinas/efeitos da radiação , Humanos , Luz , Azul de Metileno/efeitos da radiação , Fotoquímica , Plasma/efeitos dos fármacos , Raios Ultravioleta , Fator de von Willebrand/análise
17.
Transfusion ; 48(9): 1966-70, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18564402

RESUMO

BACKGROUND: The transfusion of red cell (RBC) bags with high amounts of potassium (K(+)) causes concern about an increased risk of cardiac arrest because of transient hyperkalemia. To prevent K(+) overload, a K(+) adsorption filter (PAF) is available for use at bedside. The aim of the present study was to analyze the efficacy in reducing K(+) load in irradiated RBC bags with this PAF. STUDY DESIGN AND METHODS: Whole-blood (WB) bags were collected from volunteer donors on Day 0. RBC bags were prepared from WB bags on Day +1 and stored at 2 to 6 degrees C. RBC bags were irradiated on Day +14 and filtered with the PAF on Day +28, according to the manufacturers' instructions. The plasma electrolyte levels (Na(+), K(+), Cl(-), Ca(2+), and Mg(2+)) were measured at the different points during storage. RESULTS: Twelve RBC bags were prepared with a final volume of 274 +/- 15 mL. On Day +28, the volume of RBC bags was 257 +/- 15 mL, and the PAF was used at a flow rate of 4 +/- 0.7 mL per minute. K(+) level after RBC bag preparation was 1.28 +/- 0.59 mmol per L. The K(+) level was 60.6 +/- 2.68 mmol per L on Day +28, just before filtration with the PAF. After filtration, the level of K(+) was 3.42 +/- 2.91 mmol per L. CONCLUSION: This study has shown a high efficacy in reducing potassium load in irradiated RBC bags with the use of the PAF.


Assuntos
Transfusão de Eritrócitos/instrumentação , Transfusão de Eritrócitos/métodos , Potássio/isolamento & purificação , Adsorção , Doadores de Sangue , Filtração/instrumentação , Filtração/métodos , Humanos , Potássio/sangue , Potássio/química , Reprodutibilidade dos Testes
18.
J Neurosci ; 28(7): 1613-24, 2008 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-18272682

RESUMO

Functioning of the cerebral cortex requires the coordinated assembly of circuits involving glutamatergic projection neurons and GABAergic interneurons. Although much is known about the migration of interneurons from the subpallium to the cortex, our understanding of the mechanisms controlling their precise integration within the cortex is still limited. Here, we have investigated in detail the behavior of GABAergic interneurons as they first enter the developing cortex by using time-lapse videomicroscopy, slice culture, and in utero experimental manipulations and analysis of mouse mutants. We found that interneurons actively avoid the cortical plate for a period of approximately 48 h after reaching the pallium; during this time, interneurons disperse tangentially through the marginal and subventricular zones. Perturbation of CXCL12/CXCR4 signaling causes premature cortical plate invasion by cortical interneurons and, in the long term, disrupts their laminar and regional distribution. These results suggest that regulation of cortical plate invasion by GABAergic interneurons is a key event in cortical development, because it directly influences the coordinated formation of appropriate glutamatergic and GABAergic neuronal assemblies.


Assuntos
Movimento Celular/fisiologia , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Quimiocina CXCL12/metabolismo , Interneurônios/citologia , Interneurônios/metabolismo , Receptores CXCR4/metabolismo , Animais , Comunicação Celular , Técnicas de Cocultura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Transdução de Sinais , Ácido gama-Aminobutírico/metabolismo
19.
J Neurosci ; 27(36): 9682-95, 2007 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-17804629

RESUMO

The mammalian telencephalon is considered the most complex of all biological structures. It comprises a large number of functionally and morphologically distinct types of neurons that coordinately control most aspects of cognition and behavior. The subpallium, for example, not only gives rise to multiple neuronal types that form the basal ganglia and parts of the amygdala and septum but also is the origin of an astonishing diversity of cortical interneurons. Despite our detailed knowledge on the molecular, morphological, and physiological properties of most of these neuronal populations, the mechanisms underlying their generation are still poorly understood. Here, we comprehensively analyzed the expression patterns of several transcription factors in the ventricular zone of the developing subpallium in the mouse to generate a detailed molecular map of the different progenitor domains present in this region. Our study demonstrates that the ventricular zone of the mouse subpallium contains at least 18 domains that are uniquely defined by the combinatorial expression of several transcription factors. Furthermore, the results of microtransplantation experiments in vivo corroborate that anatomically defined regions of the mouse subpallium, such as the medial ganglionic eminence, can be subdivided into functionally distinct domains.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Células-Tronco/fisiologia , Telencéfalo/embriologia , Fatores de Transcrição/fisiologia , Animais , Transplante de Tecido Encefálico , Ventrículos Cerebrais/citologia , Ventrículos Cerebrais/embriologia , Desenvolvimento Embrionário , Genes Reporter , Proteínas de Fluorescência Verde/genética , Camundongos , Camundongos Transgênicos , Células-Tronco/citologia , Telencéfalo/citologia
20.
Transfus Apher Sci ; 36(3): 243-7, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17569593

RESUMO

We compared the data of our quality control laboratory of the blood components according to the blood component preparation method that we used. We prepared blood components from top and top whole blood (WB) bags and manual pooling of buffy coats (BCs) (method I) or from top and bottom WB bags and automated pooling of BCs with OrbiSac (method II). Pooled platelet concentrates (PC) obtained with method II had higher platelet content when compared with pooled PCs obtained with method I (3.5+/-0.7x10(11) vs. 2.6+/-0.8x10(11); p<0.001). The hemoglobin content in the RBCs obtained with method I was higher when compared with method II (55+/-7g vs. 52.5+/-6.6g; p<0.001).


Assuntos
Remoção de Componentes Sanguíneos/métodos , Sangue , Hemoglobinometria , Hemoglobinas/análise , Humanos , Métodos , Controle de Qualidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...