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1.
Cell Mol Life Sci ; 80(1): 29, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36607431

RESUMO

Technological advancements have facilitated the implementation of realistic, terrestrial-based complex 33-beam galactic cosmic radiation simulations (GCR Sim) to now probe central nervous system functionality. This work expands considerably on prior, simplified GCR simulations, yielding new insights into responses of male and female mice exposed to 40-50 cGy acute or chronic radiations relevant to deep space travel. Results of the object in updated location task suggested that exposure to acute or chronic GCR Sim induced persistent impairments in hippocampus-dependent memory formation and reconsolidation in female mice that did not manifest robustly in irradiated male mice. Interestingly, irradiated male mice, but not females, were impaired in novel object recognition and chronically irradiated males exhibited increased aggressive behavior on the tube dominance test. Electrophysiology studies used to evaluate synaptic plasticity in the hippocampal CA1 region revealed significant reductions in long-term potentiation after each irradiation paradigm in both sexes. Interestingly, network-level disruptions did not translate to altered intrinsic electrophysiological properties of CA1 pyramidal cells, whereas acute exposures caused modest drops in excitatory synaptic signaling in males. Ultrastructural analyses of CA1 synapses found smaller postsynaptic densities in larger spines of chronically exposed mice compared to controls and acutely exposed mice. Myelination was also affected by GCR Sim with acutely exposed mice exhibiting an increase in the percent of myelinated axons; however, the myelin sheathes on small calibur (< 0.3 mm) and larger (> 0.5 mm) axons were thinner when compared to controls. Present findings might have been predicted based on previous studies using single and mixed beam exposures and provide further evidence that space-relevant radiation exposures disrupt critical cognitive processes and underlying neuronal network-level plasticity, albeit not to the extent that might have been previously predicted.


Assuntos
Hipocampo , Exposição à Radiação , Feminino , Camundongos , Masculino , Animais , Sinapses , Potenciação de Longa Duração , Plasticidade Neuronal
2.
Proc Natl Acad Sci U S A ; 118(42)2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34593624

RESUMO

The coronaviruses responsible for severe acute respiratory syndrome (SARS-CoV), COVID-19 (SARS-CoV-2), Middle East respiratory syndrome-CoV, and other coronavirus infections express a nucleocapsid protein (N) that is essential for viral replication, transcription, and virion assembly. Phosphorylation of N from SARS-CoV by glycogen synthase kinase 3 (GSK-3) is required for its function and inhibition of GSK-3 with lithium impairs N phosphorylation, viral transcription, and replication. Here we report that the SARS-CoV-2 N protein contains GSK-3 consensus sequences and that this motif is conserved in diverse coronaviruses, raising the possibility that SARS-CoV-2 may be sensitive to GSK-3 inhibitors, including lithium. We conducted a retrospective analysis of lithium use in patients from three major health systems who were PCR-tested for SARS-CoV-2. We found that patients taking lithium have a significantly reduced risk of COVID-19 (odds ratio = 0.51 [0.35-0.74], P = 0.005). We also show that the SARS-CoV-2 N protein is phosphorylated by GSK-3. Knockout of GSK3A and GSK3B demonstrates that GSK-3 is essential for N phosphorylation. Alternative GSK-3 inhibitors block N phosphorylation and impair replication in SARS-CoV-2 infected lung epithelial cells in a cell-type-dependent manner. Targeting GSK-3 may therefore provide an approach to treat COVID-19 and future coronavirus outbreaks.


Assuntos
COVID-19/prevenção & controle , Proteínas do Nucleocapsídeo de Coronavírus/metabolismo , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Compostos de Lítio/uso terapêutico , Adulto , Idoso , Feminino , Quinase 3 da Glicogênio Sintase/metabolismo , Células HEK293 , Humanos , Compostos de Lítio/farmacologia , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Estudos Retrospectivos
3.
Development ; 146(8)2019 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-30910828

RESUMO

In most species, early germline development occurs in the absence of transcription with germline determinants subject to complex translational and post-translational regulations. Here, we report for the first time that early germline development is influenced by dynamic regulation of the proteasome system, previously thought to be ubiquitously expressed and to serve 'housekeeping' roles in controlling protein homeostasis. We show that proteasomes are present in a gradient with the highest levels in the animal hemisphere and extending into the vegetal hemisphere of Xenopus oocytes. This distribution changes dramatically during the oocyte-to-embryo transition, with proteasomes becoming enriched in and restricted to the animal hemisphere and therefore separated from vegetally localized germline determinants. We identify Dead-end1 (Dnd1), a master regulator of vertebrate germline development, as a novel substrate of the ubiquitin-independent proteasomes. In the oocyte, ubiquitin-independent proteasomal degradation acts together with translational repression to prevent premature accumulation of Dnd1 protein. In the embryo, artificially increasing ubiquitin-independent proteasomal degradation in the vegetal pole interferes with germline development. Our work thus reveals novel inhibitory functions and spatial regulation of the ubiquitin-independent proteasome during vertebrate germline development.


Assuntos
Células Germinativas/metabolismo , Ubiquitina/metabolismo , Animais , Citoplasma/metabolismo , Células Germinativas/citologia , Oócitos/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas de Ligação a RNA/metabolismo , Ubiquitina/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis
4.
Dev Biol ; 462(1): 20-35, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32119833

RESUMO

As development proceeds, inductive cues are interpreted by competent tissues in a spatially and temporally restricted manner. While key inductive signaling pathways within competent cells are well-described at a molecular level, the mechanisms by which tissues lose responsiveness to inductive signals are not well understood. Localized activation of Wnt signaling before zygotic gene activation in Xenopus laevis leads to dorsal development, but competence to induce dorsal genes in response to Wnts is lost by the late blastula stage. We hypothesize that loss of competence is mediated by changes in histone modifications leading to a loss of chromatin accessibility at the promoters of Wnt target genes. We use ATAC-seq to evaluate genome-wide changes in chromatin accessibility across several developmental stages. Based on overlap with p300 binding, we identify thousands of putative cis-regulatory elements at the gastrula stage, including sites that lose accessibility by the end of gastrulation and are enriched for pluripotency factor binding motifs. Dorsal Wnt target gene promoters are not accessible after the loss of competence in the early gastrula while genes involved in mesoderm and neural crest development maintain accessibility at their promoters. Inhibition of histone deacetylases increases acetylation at the promoters of dorsal Wnt target genes and extends competence for dorsal gene induction by Wnt signaling. Histone deacetylase inhibition, however, is not sufficient to extend competence for mesoderm or neural crest induction. These data suggest that chromatin state regulates the loss of competence to inductive signals in a context-dependent manner.


Assuntos
Cromatina/metabolismo , Indução Embrionária/genética , Histonas/metabolismo , Acetilação , Animais , Blástula/metabolismo , Cromatina/genética , Gástrula/metabolismo , Gastrulação/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Histonas/genética , Mesoderma/metabolismo , Crista Neural/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Proteínas Wnt/metabolismo , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia , Proteínas de Xenopus/metabolismo , Xenopus laevis/embriologia , Xenopus laevis/metabolismo
5.
Neurobiol Dis ; 151: 105252, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33418069

RESUMO

Galactic cosmic radiation (GCR), composed of highly energetic and fully ionized atomic nuclei, produces diverse deleterious effects on the body. In researching the neurological risks of GCR exposures, including during human spaceflight, various ground-based single-ion GCR irradiation paradigms induce differential disruptions of cellular activity and overall behavior. However, it remains less clear how irradiation comprising a mix of multiple ions, more accurately recapitulating the space GCR environment, impacts the central nervous system. We therefore examined how mixed-ion GCR irradiation (two similar 5-6 beam combinations of protons, helium, oxygen, silicon and iron ions) influenced neuronal connectivity, functional generation of activity within neural circuits and cognitive behavior in mice. In electrophysiological recordings we find that space-relevant doses of mixed-ion GCR preferentially alter hippocampal inhibitory neurotransmission and produce related disruptions in the local field potentials of hippocampal oscillations. Such underlying perturbation in hippocampal network activity correspond with perturbed learning, memory and anxiety behavior.


Assuntos
Radiação Cósmica/efeitos adversos , Hipocampo/efeitos da radiação , Transmissão Sináptica/efeitos da radiação , Animais , Comportamento Animal/efeitos da radiação , Disfunção Cognitiva/etiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
6.
Int J Mol Sci ; 22(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34445726

RESUMO

A recognized risk of long-duration space travel arises from the elevated exposure astronauts face from galactic cosmic radiation (GCR), which is composed of a diverse array of energetic particles. There is now abundant evidence that exposures to many different charged particle GCR components within acute time frames are sufficient to induce central nervous system deficits that span from the molecular to the whole animal behavioral scale. Enhanced spacecraft shielding can lessen exposures to charged particle GCR components, but may conversely elevate neutron radiation levels. We previously observed that space-relevant neutron radiation doses, chronically delivered at dose-rates expected during planned human exploratory missions, can disrupt hippocampal neuronal excitability, perturb network long-term potentiation and negatively impact cognitive behavior. We have now determined that acute exposures to similar low doses (18 cGy) of neutron radiation can also lead to suppressed hippocampal synaptic signaling, as well as decreased learning and memory performance in male mice. Our results demonstrate that similar nervous system hazards arise from neutron irradiation regardless of the exposure time course. While not always in an identical manner, neutron irradiation disrupts many of the same central nervous system elements as acute charged particle GCR exposures. The risks arising from neutron irradiation are therefore important to consider when determining the overall hazards astronauts will face from the space radiation environment.


Assuntos
Radiação Cósmica/efeitos adversos , Hipocampo/efeitos da radiação , Nêutrons/efeitos adversos , Animais , Comportamento Animal/efeitos da radiação , Masculino , Memória/efeitos da radiação , Camundongos , Plasticidade Neuronal/efeitos da radiação
7.
J Neurosci ; 38(5): 1232-1248, 2018 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-29273603

RESUMO

Maintenance of a low intracellular Cl- concentration ([Cl-]i) is critical for enabling inhibitory neuronal responses to GABAA receptor-mediated signaling. Cl- transporters, including KCC2, and extracellular impermeant anions ([A]o) of the extracellular matrix are both proposed to be important regulators of [Cl-]i Neurons of the reticular thalamic (RT) nucleus express reduced levels of KCC2, indicating that GABAergic signaling may produce excitation in RT neurons. However, by performing perforated patch recordings and calcium imaging experiments in rats (male and female), we find that [Cl-]i remains relatively low in RT neurons. Although we identify a small contribution of [A]o to a low [Cl-]i in RT neurons, our results also demonstrate that reduced levels of KCC2 remain sufficient to maintain low levels of Cl- Reduced KCC2 levels, however, restrict the capacity of RT neurons to rapidly extrude Cl- following periods of elevated GABAergic signaling. In a computational model of a local RT network featuring slow Cl- extrusion kinetics, similar to those we found experimentally, model RT neurons are predisposed to an activity-dependent switch from GABA-mediated inhibition to excitation. By decreasing the activity threshold required to produce excitatory GABAergic signaling, weaker stimuli are able to propagate activity within the model RT nucleus. Our results indicate the importance of even diminished levels of KCC2 in maintaining inhibitory signaling within the RT nucleus and suggest how this important activity choke point may be easily overcome in disorders such as epilepsy.SIGNIFICANCE STATEMENT Precise regulation of intracellular Cl- levels ([Cl-]i) preserves appropriate, often inhibitory, GABAergic signaling within the brain. However, there is disagreement over the relative contribution of various mechanisms that maintain low [Cl-]i We found that the Cl- transporter KCC2 is an important Cl- extruder in the reticular thalamic (RT) nucleus, despite this nucleus having remarkably low KCC2 immunoreactivity relative to other regions of the adult brain. We also identified a smaller contribution of fixed, impermeant anions ([A]o) to lowering [Cl-]i in RT neurons. Inhibitory signaling among RT neurons is important for preventing excessive activation of RT neurons, which can be responsible for generating seizures. Our work suggests that KCC2 critically restricts the spread of activity within the RT nucleus.


Assuntos
Neurônios GABAérgicos/fisiologia , Formação Reticular/fisiologia , Transdução de Sinais/fisiologia , Tálamo/fisiologia , Animais , Cloretos/metabolismo , Cloretos/farmacologia , Simulação por Computador , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Patch-Clamp , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/genética , Receptores de GABA-A/fisiologia , Simportadores/genética , Simportadores/fisiologia , Cotransportadores de K e Cl-
8.
Anal Chem ; 91(14): 8891-8899, 2019 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-31194517

RESUMO

Techniques that allow single cell analysis are gaining widespread attention, and most of these studies utilize genomics-based approaches. While nanofluidic technologies have enabled mass spectrometric analysis of single cells, these measurements have been limited to metabolomics and lipidomic studies. Single cell proteomics has the potential to improve our understanding of intercellular heterogeneity. However, this approach has faced challenges including limited sample availability, as well as a requirement of highly sensitive methods for sample collection, cleanup, and detection. We present a technique to overcome these limitations by combining a micropipette (pulled glass capillary) based sample collection strategy with offline sample preparation and nanoLC-MS/MS to analyze proteins through a bottom-up proteomic strategy. This study explores two types of proteomics data acquisition strategies namely data-dependent (DDA) and data-independent acquisition (DIA). Results from the study indicate DIA to be more sensitive enabling analysis of >1600 proteins from ∼130 µm Xenopus laevis embryonic cells containing <6 nL of cytoplasm. The method was found to be robust in obtaining reproducible protein quantifications from single cells spanning the 1-128-cell stages of development. Furthermore, we used micropipette sampling to study intercellular heterogeneity within cells in a single embryo and investigated embryonic asymmetry along both animal-vegetal and dorsal-ventral axes during early stages of development. Investigation of the animal-vegetal axis led to discovery of various asymmetrically distributed proteins along the animal-vegetal axis. We have further compared the hits found from our proteomic data sets with other studies and validated a few hits using an orthogonal imaging technique. This study forms the first report of vegetal enrichment of the germ plasm associated protein DDX4/VASA in Xenopus embyos. Overall, the method and data presented here holds promise to enable important leads in developmental biology.


Assuntos
Embrião não Mamífero/citologia , Proteômica/métodos , Análise de Célula Única/métodos , Proteínas de Xenopus/análise , Xenopus laevis/embriologia , Animais , Embrião não Mamífero/química , Espectrometria de Massas em Tandem/métodos
9.
J Surg Res ; 243: 14-22, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31146086

RESUMO

BACKGROUND: The objective of this study was to investigate the long-term outcome of incisional hernias treated with the Erlangen Inlay Onlay Mesh (EIOM) repair technique, taking into account recurrence, complications, and patient satisfaction. METHODS: A total of 163 patients treated in the surgical department of Erlangen university hospital with the EIOM repair between the years 1996 and 2009 were evaluated retrospectively. RESULTS: The collected data revealed a mean follow-up period of 70 (18-190) months. Incisional hernia recurrence after EIOM repair was observed in 6 (3.7%) patients after a mean observation period of 70 mo (18-190) postoperatively. The recurrence rate increased significantly when the body mass index (BMI) was higher than 32 kg/m2. Here, a recurrence rate of 10.5% for BMI> 32 versus 1.7% with BMI ≤32 was reported. There were no significant differences in hernia recurrence if haven been operated by an assistant under supervision or by a consultant. In regard to patient satisfaction, 91% of patients included in this study were satisfied with the surgical outcome. CONCLUSIONS: The EIOM procedure is a safe surgical technique that can be used for the treatment of all, also for giant incisional abdominal wall hernias regardless of the size, BMI, or position of the incisional hernia.


Assuntos
Herniorrafia/métodos , Hérnia Incisional/cirurgia , Telas Cirúrgicas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Seguimentos , Herniorrafia/instrumentação , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Recidiva , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
10.
J Biol Chem ; 292(44): 18240-18255, 2017 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-28916722

RESUMO

Glycogen synthase kinase-3 (GSK-3) is a constitutively active, ubiquitously expressed protein kinase that regulates multiple signaling pathways. In vitro kinase assays and genetic and pharmacological manipulations of GSK-3 have identified more than 100 putative GSK-3 substrates in diverse cell types. Many more have been predicted on the basis of a recurrent GSK-3 consensus motif ((pS/pT)XXX(S/T)), but this prediction has not been tested by analyzing the GSK-3 phosphoproteome. Using stable isotope labeling of amino acids in culture (SILAC) and MS techniques to analyze the repertoire of GSK-3-dependent phosphorylation in mouse embryonic stem cells (ESCs), we found that ∼2.4% of (pS/pT)XXX(S/T) sites are phosphorylated in a GSK-3-dependent manner. A comparison of WT and Gsk3a;Gsk3b knock-out (Gsk3 DKO) ESCs revealed prominent GSK-3-dependent phosphorylation of multiple splicing factors and regulators of RNA biosynthesis as well as proteins that regulate transcription, translation, and cell division. Gsk3 DKO reduced phosphorylation of the splicing factors RBM8A, SRSF9, and PSF as well as the nucleolar proteins NPM1 and PHF6, and recombinant GSK-3ß phosphorylated these proteins in vitro RNA-Seq of WT and Gsk3 DKO ESCs identified ∼190 genes that are alternatively spliced in a GSK-3-dependent manner, supporting a broad role for GSK-3 in regulating alternative splicing. The MS data also identified posttranscriptional regulation of protein abundance by GSK-3, with ∼47 proteins (1.4%) whose levels increased and ∼78 (2.4%) whose levels decreased in the absence of GSK-3. This study provides the first unbiased analysis of the GSK-3 phosphoproteome and strong evidence that GSK-3 broadly regulates alternative splicing.


Assuntos
Glicogênio Sintase Quinase 3 beta/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Proteínas de Homeodomínio/metabolismo , Proteínas Nucleares/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas de Ligação a RNA/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Processamento Alternativo , Animais , Isótopos de Carbono , Linhagem Celular , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Células-Tronco Embrionárias/enzimologia , Células-Tronco Embrionárias/metabolismo , Técnicas de Inativação de Genes , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta/genética , Proteínas de Homeodomínio/química , Camundongos , Isótopos de Nitrogênio , Proteínas Nucleares/química , Nucleofosmina , Mapeamento de Peptídeos , Fosforilação , Estabilidade Proteica , Proteômica/métodos , Proteínas de Ligação a RNA/química , Proteínas Recombinantes/metabolismo , Proteínas Repressoras , Fatores de Processamento de Serina-Arginina/química , Especificidade por Substrato
11.
Thorac Cardiovasc Surg ; 65(7): 560-566, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26962969

RESUMO

Background Pulmonary metastasectomy is a commonly performed surgery in patients with controlled metastatic colorectal cancer (CRC). We reviewed our long-term single institution experience with lung resections for colorectal metastases to assess the factors influencing patient survival. Materials and Methods A cohort of 220 patients (138 men and 82 women; median age, 59 years) who underwent complete pulmonary metastasectomy for CRC with curative intent between 1972 and 2014 was retrospectively analyzed. The impact of factors related to primary tumor, metastases, and associated therapy on patient survival was assessed. Results Two postoperative inhospital deaths occurred. The median interoperative interval was 26 months. The overall 5-year survival rate after pulmonary metastasectomy was 49.4%. In univariable analysis, bilateral pulmonary metastases (log rank p = 0.02), multiple metastases (log rank p = 0.005), and stage IV UICC (the International Union Against Cancer) CRC at the time of initial presentation (log rank p = 0.008) were significantly associated with poor outcome. Multivariable Cox analysis demonstrated that stage IV CRC (p = 0.02) and multiple metastases (p = 0.0019) were statistically significant predictors of survival after the pulmonary metastasectomy. There was no significant difference in survival between patients with high versus low preoperative carcinoembryonic antigen serum level (p = 0.149), high versus low preoperative carbohydrate antigen 19-9 serum level (p = 0.291), and primary tumor location in rectum versus colon (p = 0.845). Conclusion Patients with unilateral metastasis and stages I to III primary tumor benefited most from pulmonary metastasectomy for CRC.


Assuntos
Neoplasias Colorretais/patologia , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/cirurgia , Metastasectomia/métodos , Pneumonectomia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno CA-19-9/sangue , Antígeno Carcinoembrionário/sangue , Neoplasias Colorretais/sangue , Neoplasias Colorretais/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/mortalidade , Masculino , Metastasectomia/efeitos adversos , Metastasectomia/mortalidade , Pessoa de Meia-Idade , Análise Multivariada , Estadiamento de Neoplasias , Pneumonectomia/efeitos adversos , Pneumonectomia/mortalidade , Complicações Pós-Operatórias/etiologia , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
12.
Adv Exp Med Biol ; 953: 441-487, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27975277

RESUMO

Following fertilization, vertebrate embryos delay large-scale activation of the zygotic genome from several hours in fish and amphibians to several days in mammals. Externally developing embryos also undergo synchronous and extraordinarily rapid cell divisions that are accelerated by promiscuous licensing of DNA replication origins, absence of gap phases and cell cycle checkpoints, and preloading of the egg with maternal RNAs and proteins needed to drive early development. After a species-specific number of cell divisions, the cell cycle slows and becomes asynchronous, gap phases appear, checkpoint functions are acquired, and large-scale zygotic gene activation begins. These events, along with clearance of maternal RNAs and proteins, define the maternal to zygotic transition and are coordinated at a developmental milestone termed the midblastula transition (MBT). Despite the relative quiescence of the zygotic genome in vertebrate embryos, genes required for clearance of maternal RNAs and for the initial steps in mesoderm induction are robustly transcribed before MBT. The coordination and timing of the MBT depends on a mechanism that senses the ratio of nuclear to cytoplasmic content as well as mechanisms that are independent of the nuclear-cytoplasm ratio. Changes in chromatin architecture anticipate zygotic gene activation, and maternal transcription factors identified as regulators of pluripotency play critical roles in kick-starting the transition from the proliferative, pluripotent state of the early embryo to the more lineage-committed phase of development after the MBT. This chapter describes the regulation of the cell cycle and the activation of zygotic gene expression before and after the MBT in vertebrate embryos.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Desenvolvimento Embrionário/genética , Ativação Transcricional/genética , Zigoto/crescimento & desenvolvimento , Animais , Ciclo Celular/genética , Divisão Celular/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento
13.
J Physiol ; 594(20): 5851-5860, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-26845064

RESUMO

Zona glomerulosa cells (ZG) of the adrenal gland constantly integrate fluctuating ionic, hormonal and paracrine signals to control the synthesis and secretion of aldosterone. These signals modulate Ca2+ levels, which provide the critical second messenger to drive steroid hormone production. Angiotensin II is a hormone known to modulate the activity of voltage-dependent L- and T-type Ca2+ channels that are expressed on the plasma membrane of ZG cells in many species. Because the ZG cell maintains a resting membrane voltage of approximately -85 mV and has been considered electrically silent, low voltage-activated T-type Ca2+ channels are assumed to provide the primary Ca2+ signal that drives aldosterone production. However, this view has recently been challenged by human genetic studies identifying somatic gain-of-function mutations in L-type CaV 1.3 channels in aldosterone-producing adenomas of patients with primary hyperaldosteronism. We provide a review of these assumptions and challenges, and update our understanding of the state of the ZG cell in a layer in which native cellular associations are preserved. This updated view of Ca2+ signalling in ZG cells provides a unifying mechanism that explains how transiently activating CaV 3.2 channels can generate a significant and recurring Ca2+ signal, and how CaV 1.3 channels may contribute to the Ca2+ signal that drives aldosterone production.


Assuntos
Córtex Suprarrenal/metabolismo , Aldosterona/metabolismo , Canais de Cálcio/metabolismo , Zona Glomerulosa/metabolismo , Animais , Cálcio/metabolismo , Humanos
14.
Stem Cells ; 33(1): 278-88, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25284014

RESUMO

Hematopoiesis is maintained throughout life by self-renewing hematopoietic stem cells (HSCs) that differentiate to produce both myeloid and lymphoid cells. The NR4A family of orphan nuclear receptors, which regulates cell fate in many tissues, appears to play a key role in HSC proliferation and differentiation. Using a NR4A1(GFP) BAC transgenic reporter mouse we have investigated NR4A1 expression and its regulation in early hematopoiesis. We show that NR4A1 is most highly expressed in a subset of Lin(-) Sca-1(+) c-Kit(+) CD48(-) CD150(+) long-term (LT) HSCs, and its expression is tightly associated with HSC quiescence. We also show that NR4A1 expression in HSCs is induced by PGE2, a known enhancer of stem cell engraftment potential. Finally, we find that both NR4A1(GFP+) and NR4A1(GFP-) HSCs successfully engraft primary and secondary irradiated hosts; however, NR4A1(GFP+) HSCs are distinctly myeloid-biased. These results show that NR4A1 expression identifies a highly quiescent and distinct population of myeloid-biased LT-HSCs.


Assuntos
Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Animais , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Camundongos , Camundongos Endogâmicos C57BL
15.
Proc Natl Acad Sci U S A ; 110(13): 5199-204, 2013 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-23479645

RESUMO

Homeostatic plasticity is characterized by compensatory changes in synaptic strength and intrinsic membrane properties in response to chronic changes in neuronal activity. Neonatal seizures are a naturally occurring source of neuronal overactivation and can lead to long-term epilepsy and cognitive deficits. Using a rodent model of hypoxia-induced neonatal seizures that results in a persistent increase in AMPA receptor (AMPAR) function in hippocampal CA1 pyramidal neurons, we aimed to determine whether there was any evidence of an opposing endogenous homeostatic antiepileptic response. Given that this model results in long-term epilepsy, we also examined mechanisms whereby this homeostasis fails. Whole-cell patch-clamp recordings from neurons in slices removed at intervals following seizure onset revealed an initial up-regulation of AMPAR function that was followed by a transient dynamic attenuation of this enhancement by 48-72 h, although AMPAR function was still increased compared with nonseizure control baseline. This secondary down-regulation of enhanced AMPAR function was coincident with a marked transient increase in expression and function of the Polo-like kinase 2 (PLK2), which has previously been implicated in homeostatic down-regulation of neuronal excitability in cell/slice culture models. The effects were transient and at 1 wk AMPAR function once again became up-regulated, simultaneous with a decrease in PLK2 expression and function. This negative regulation was mediated by subacute postseizure increases in mammalian target of rapamycin (mTOR). Application of the mTOR inhibitor rapamycin prevented post-hypoxic seizure impairment of homeostasis, suggesting that homeostatic plasticity mechanisms may be potentially modifiable therapeutic targets in epileptogenesis.


Assuntos
Região CA1 Hipocampal/metabolismo , Plasticidade Neuronal , Proteínas Serina-Treonina Quinases/metabolismo , Células Piramidais/metabolismo , Convulsões/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Animais , Animais Recém-Nascidos , Antibacterianos/farmacologia , Região CA1 Hipocampal/patologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Microdissecção , Complexos Multiproteicos , Proteínas/antagonistas & inibidores , Proteínas/metabolismo , Células Piramidais/patologia , Ratos , Ratos Long-Evans , Receptores de AMPA/metabolismo , Convulsões/patologia , Sirolimo/farmacologia , Fatores de Tempo , Técnicas de Cultura de Tecidos
16.
Genomics ; 105(1): 31-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25451743

RESUMO

Arabidopsis nudix hydrolase 7 (AtNudt7) plays an important role in regulating redox homeostasis during stress/defense signaling and seed germination. The early responsiveness of AtNudt7 provides a useful marker especially during oxidative cell death in plants. Nuclear run-on assays demonstrate that AtNudt7 is transcriptionally regulated. AtNUDT7 promoter-GUS transgenic plants show rapid inducibility in response to ozone and pathogens. A 16-bp insertion containing a GCC-box motif was identified in the promoter of a Ws-2 ecotype and was absent in Col-0. The 16-bp sequence was identified in 5% of the Arabidopsis ecotypes used in the 1001 genome sequencing project. The kinetics of expression of Ethylene Response Factor 1 (ERF1), a GCC-box binding factor is in synchrony with expression of AtNudt7 in response to ozone stress. ERF1 protein binds to the GCC-box motif in the AtNUDT7 promoter. In silico analysis of erf1 mutant and overexpressor lines supports a role for this protein in regulating AtNUDT7 expression.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimologia , Oxidantes Fotoquímicos/farmacologia , Ozônio/farmacologia , Fatores de Terminação de Peptídeos/metabolismo , Pirofosfatases/genética , Arabidopsis/classificação , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Simulação por Computador , Ecótipo , Regulação da Expressão Gênica de Plantas , Motivos de Nucleotídeos , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas , Pirofosfatases/metabolismo , Nudix Hidrolases
17.
Langenbecks Arch Surg ; 400(1): 19-26, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25240610

RESUMO

PURPOSE: Perioperative regional anesthesia with consecutive reduction of intra- and postoperative systemic opioid requirements in order to improve oncological result after cancer surgery has only been addressed by a few reports. This hypothesis has never been proved in esophageal cancer with a long-term follow-up of more than 5 years. Therefore, we addressed the impact on short- and long-term outcomes of epidural analgesia for esophagus cancer surgery. METHODS: All available records from patients who underwent esophageal cancer surgery from 1995 to 2005 were retrospectively analyzed. Short- and long-term outcome variables including opioid requirements, duration of ICU-stay, survival, and cancer recurrence were compared between patients with and patients without epidural analgesia for abdomino-right-thoracic esophagectomy. RESULTS: Overall, the analysis included 153 patients, 118 received epidural analgesia; in 35 patients, epidural analgesia was avoided. We found significantly increased postoperative median opioid consumption (10-day intravenous morphine equivalent 187 versus 104 mg) and duration of ICU hospitalization (10.1 vs. 5.9 days, p < 0.05) in the non-epidural group compared with the epidural group. However, there were no significant differences in cancer recurrence (23 % non-epidural group, 27 % epidural group), 1-year mortality (14 vs. 11 %), or 5-year survival (29 vs. 28 %) between the two patient groups. CONCLUSIONS: The results of our study underline the well-known clinical benefits of epidural analgesia for esophagus surgery. However, we found no evidence that the further oncological outcome is determined or significantly influenced by the presence or absence of epidural analgesia.


Assuntos
Adenocarcinoma/mortalidade , Adenocarcinoma/cirurgia , Analgesia Epidural , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Neoplasias Esofágicas/mortalidade , Neoplasias Esofágicas/cirurgia , Idoso , Analgésicos Opioides/administração & dosagem , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/epidemiologia , Estudos Retrospectivos
18.
Curr Ther Res Clin Exp ; 77: 66-72, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26265958

RESUMO

BACKGROUND: Echinacea has antiviral activity against influenza viruses in vitro and has traditionally been used for treatment of colds and flu. OBJECTIVES: This randomized, double-blind, double-dummy, multicenter, controlled clinical trial compared a new echinacea formulation with the neuraminidase inhibitor oseltamivir, the gold standard treatment for influenza. METHODS: Following informed consent, 473 patients with early influenza symptoms (≤48 hours) were recruited in primary care in the Czech Republic and randomized to either 5 days of oseltamivir followed by 5 days of placebo, or 10 days of an Echinacea purpurea-based formulation called Echinaforce Hotdrink (A. Vogel Bioforce AG, Roggwil, Switzerland). The proportion of recovered patients (influenza symptoms rated as absent or mild in the evening) was analyzed for noninferiority between treatment groups using a generalized Wilcoxon test with significance level α = 0.05 (2-sided) and using a CI approach in the per-protocol sample. RESULTS: Recovery from illness was comparable in the 2 treatment groups at 1.5% versus 4.1% after 1 day, 50.2% versus 48.8% after 5 days, and 90.1% versus 84.8% after 10 days of treatment with Echinaforce Hotdrink and oseltamivir, respectively. Noninferiority was demonstrated for each day and overall (95% CI, 0.487-0.5265 by generalized Wilcoxon test). Very similar results were obtained in the group with virologically confirmed influenza virus infections and in a retrospective analysis during the peak influenza period. The incidence of complications was lower with Echinaforce Hotdrink than with oseltamivir (2.46% vs 6.45%; P = 0.076) and fewer adverse events (particularly nausea and vomiting) were observed with Echinaforce Hotdrink. CONCLUSIONS: Echinaforce Hotdrink is as effective as oseltamivir in the early treatment of clinically diagnosed and virologically confirmed influenza virus infections with a reduced risk of complications and adverse events. It appears to be an attractive treatment option, particularly suitable for self-care. Clinical trial identifier: Eudra-CT: 2010-021571-88. (Curr Ther Res Clin Exp. 2015; 77:66-72).

19.
Proc Natl Acad Sci U S A ; 108(45): E1070-9, 2011 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-22025691

RESUMO

Tuberous sclerosis complex (TSC) is a multiorgan genetic disease in which brain involvement causes epilepsy, intellectual disability, and autism. The hallmark pathological finding in TSC is the cerebral cortical tuber and its unique constituent, giant cells. However, an animal model that replicates giant cells has not yet been described. Here, we report that mosaic induction of Tsc1 loss in neural progenitor cells in Tsc1(cc) Nestin-rtTA(+) TetOp-cre(+) embryos by doxycycline leads to multiple neurological symptoms, including severe epilepsy and premature death. Strikingly, Tsc1-null neural progenitor cells develop into highly enlarged giant cells with enlarged vacuoles. We found that the vacuolated giant cells had multiple signs of organelle dysfunction, including markedly increased mitochondria, aberrant lysosomes, and elevated cellular stress. We found similar vacuolated giant cells in human tuber specimens. Postnatal rapamycin treatment completely reversed these phenotypes and rescued the mutants from epilepsy and premature death, despite prenatal onset of Tsc1 loss and mTOR complex 1 activation in the developing brain. This TSC brain model provides insights into the pathogenesis and organelle dysfunction of giant cells, as well as epilepsy control in patients with TSC.


Assuntos
Modelos Animais de Doenças , Neurônios/metabolismo , Células-Tronco/metabolismo , Esclerose Tuberosa/patologia , Proteínas Supressoras de Tumor/fisiologia , Animais , Western Blotting , Sobrevivência Celular/efeitos dos fármacos , Humanos , Camundongos , Microscopia Eletrônica , Microscopia de Fluorescência , Reação em Cadeia da Polimerase , Sirolimo/farmacologia , Esclerose Tuberosa/genética , Proteína 1 do Complexo Esclerose Tuberosa , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
20.
Dev Dyn ; 242(2): 108-21, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23184530

RESUMO

BACKGROUND: Histone deacetylases (HDACs) regulate multiple developmental processes and cellular functions. However, their roles in blood development have not been determined, and in Xenopus laevis a specific function for HDACs has yet to be identified. Here, we employed the class I selective HDAC inhibitor, valproic acid (VPA), to show that HDAC activity is required for primitive hematopoiesis. RESULTS: VPA treatment during gastrulation resulted in a complete absence of red blood cells (RBCs) in Xenopus tadpoles, but did not affect development of other mesodermal tissues, including myeloid and endothelial lineages. These effects of VPA were mimicked by Trichostatin A (TSA), a well-established pan-HDAC inhibitor, but not by valpromide, which is structurally similar to VPA but does not inhibit HDACs. VPA also caused a marked, dose-dependent loss of primitive erythroid progenitors in mouse yolk sac explants at clinically relevant concentrations. In addition, VPA treatment inhibited erythropoietic development downstream of bmp4 and gata1 in Xenopus ectodermal explants. CONCLUSIONS: These findings suggest an important role for class I HDACs in primitive hematopoiesis. Our work also demonstrates that specific developmental defects associated with exposure to VPA, a significant teratogen in humans, arise through inhibition of class I HDACs.


Assuntos
Gástrula/efeitos dos fármacos , Hematopoese/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Xenopus laevis/embriologia , Animais , Primers do DNA/genética , Células Precursoras Eritroides/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Immunoblotting , Hibridização In Situ , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Ácido Valproico/farmacologia , Saco Vitelino/citologia
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