Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Neurosci ; 44(11)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38286627

RESUMO

Dopamine neurons play crucial roles in pleasure, reward, memory, learning, and fine motor skills and their dysfunction is associated with various neuropsychiatric diseases. Dopamine receptors are the main target of treatment for neurologic and psychiatric disorders. Antipsychotics that antagonize the dopamine D2 receptor (DRD2) are used to alleviate the symptoms of these disorders but may also sometimes cause disabling side effects such as parkinsonism (catalepsy in rodents). Here we show that GPR143, a G-protein-coupled receptor for L-3,4-dihydroxyphenylalanine (L-DOPA), expressed in striatal cholinergic interneurons enhances the DRD2-mediated side effects of haloperidol, an antipsychotic agent. Haloperidol-induced catalepsy was attenuated in male Gpr143 gene-deficient (Gpr143-/y ) mice compared with wild-type (Wt) mice. Reducing the endogenous release of L-DOPA and preventing interactions between GPR143 and DRD2 suppressed the haloperidol-induced catalepsy in Wt mice but not Gpr143-/y mice. The phenotypic defect in Gpr143-/y mice was mimicked in cholinergic interneuron-specific Gpr143-/y (Chat-cre;Gpr143flox/y ) mice. Administration of haloperidol increased the phosphorylation of ribosomal protein S6 at Ser240/244 in the dorsolateral striatum of Wt mice but not Chat-cre;Gpr143flox/y mice. In Chinese hamster ovary cells stably expressing DRD2, co-expression of GPR143 increased cell surface expression level of DRD2, and L-DOPA application further enhanced the DRD2 surface expression. Shorter pauses in cholinergic interneuron firing activity were observed after intrastriatal stimulation in striatal slice preparations from Chat-cre;Gpr143flox/y mice compared with those from Wt mice. Together, these findings provide evidence that GPR143 regulates DRD2 function in cholinergic interneurons and may be involved in parkinsonism induced by antipsychotic drugs.


Assuntos
Antipsicóticos , Transtornos Parkinsonianos , Receptores de Neurotransmissores , Humanos , Camundongos , Masculino , Animais , Cricetinae , Haloperidol/farmacologia , Levodopa/efeitos adversos , Catalepsia/induzido quimicamente , Células CHO , Cricetulus , Antipsicóticos/efeitos adversos , Interneurônios/metabolismo , Colinérgicos/farmacologia , Proteínas do Olho/metabolismo , Glicoproteínas de Membrana/metabolismo
3.
Cell ; 177(5): 1346-1360.e24, 2019 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-31080068

RESUMO

To decipher dynamic brain information processing, current genetically encoded calcium indicators (GECIs) are limited in single action potential (AP) detection speed, combinatorial spectral compatibility, and two-photon imaging depth. To address this, here, we rationally engineered a next-generation quadricolor GECI suite, XCaMPs. Single AP detection was achieved within 3-10 ms of spike onset, enabling measurements of fast-spike trains in parvalbumin (PV)-positive interneurons in the barrel cortex in vivo and recording three distinct (two inhibitory and one excitatory) ensembles during pre-motion activity in freely moving mice. In vivo paired recording of pre- and postsynaptic firing revealed spatiotemporal constraints of dendritic inhibition in layer 1 in vivo, between axons of somatostatin (SST)-positive interneurons and apical tufts dendrites of excitatory pyramidal neurons. Finally, non-invasive, subcortical imaging using red XCaMP-R uncovered somatosensation-evoked persistent activity in hippocampal CA1 neurons. Thus, the XCaMPs offer a critical enhancement of solution space in studies of complex neuronal circuit dynamics. VIDEO ABSTRACT.


Assuntos
Potenciais de Ação/fisiologia , Axônios/metabolismo , Córtex Cerebral/metabolismo , Hipocampo/metabolismo , Interneurônios/metabolismo , Células Piramidais/metabolismo , Animais , Córtex Cerebral/citologia , Feminino , Hipocampo/citologia , Interneurônios/citologia , Camundongos , Camundongos Transgênicos , Células Piramidais/citologia , Ratos , Ratos Sprague-Dawley
4.
Am J Reprod Immunol ; 79(2)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29205625

RESUMO

PROBLEM: Vitamin D deficiency increases the risk of developing pregnancy-related complications, including preeclampsia and small-for-gestational-age infants. Vitamin D was demonstrated to promote the invasiveness of human extravillous trophoblasts (EVTs). However, whether vitamin D induces the epithelial-mesenchymal transition (EMT) of EVTs remains unclear. Therefore, we investigated whether vitamin D promotes EMT and the related signaling pathways. METHOD OF STUDY: In this study, we performed EMT experiments using JAR cells based on the expression of the mesenchymal markers and vitamin D receptor. JAR cells were treated with calcitriol, the active form of vitamin D. Western blotting was performed to evaluate EMT markers and key molecules of signaling pathways. Invasion assays were conducted. Expression and secretion of MMPs were analyzed by real-time PCR and zymography. RESULTS: Calcitriol significantly enhanced EMT and the invasive capability of JAR cells, along with increased expression and secretion of MMP-2 and MMP-9. Moreover, ERK signaling pathway was activated by calcitriol. The effects of calcitriol were neutralized by ERK signaling blocker. CONCLUSION: Calcitriol facilitated EMT induction and expression of MMPs via ERK signaling pathway, which promoted the invasive capability of EVTs. Further studies are warranted to elucidate the potential application of vitamin D in the prevention of pregnancy complications.


Assuntos
Calcitriol/farmacologia , Transição Epitelial-Mesenquimal , Placenta/patologia , Complicações na Gravidez/prevenção & controle , Gravidez , Trofoblastos/fisiologia , Vitamina D/metabolismo , Linhagem Celular , Movimento Celular , Feminino , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz , Transdução de Sinais
5.
Nat Commun ; 8: 15977, 2017 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-28731029

RESUMO

Odour information induces various innate responses that are critical to the survival of the individual and for the species. An axon guidance molecule, Neuropilin 2 (Nrp2), is known to mediate targeting of olfactory sensory neurons (primary neurons), to the posteroventral main olfactory bulb (PV MOB) in mice. Here we report that Nrp2-positive (Nrp2+) mitral cells (MCs, second-order neurons) play crucial roles in transmitting attractive social signals from the PV MOB to the anterior part of medial amygdala (MeA). Semaphorin 3F, a repulsive ligand to Nrp2, regulates both migration of Nrp2+ MCs to the PV MOB and their axonal projection to the anterior MeA. In the MC-specific Nrp2 knockout mice, circuit formation of Nrp2+ MCs and odour-induced attractive social responses are impaired. In utero, electroporation demonstrates that activation of the Nrp2 gene in MCs is sufficient to instruct their circuit formation from the PV MOB to the anterior MeA.


Assuntos
Tonsila do Cerebelo/metabolismo , Orientação de Axônios/genética , Movimento Celular/genética , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuropilina-2/genética , Bulbo Olfatório/metabolismo , Neurônios Receptores Olfatórios/metabolismo , Tonsila do Cerebelo/citologia , Animais , Eletroporação , Camundongos , Camundongos Knockout , Vias Neurais , Odorantes , Bulbo Olfatório/citologia , Neurônios Receptores Olfatórios/citologia , Comportamento Social
6.
Am J Reprod Immunol ; 78(2)2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28328096

RESUMO

Decidual stromal cells (DSCs) are known to regulate trophoblast invasion via unveiled mechanism yet. And nucleotide-binding oligomerization domain-containing protein 1 (NOD1) may influence on this DSC-trophoblast interaction. We investigated the mechanism underlying the DSC-mediated regulation of trophoblast invasion and the effect of NOD1 on their cross talk. Using human primary DSCs, BeWo cell invasion was measured. Cytokine secretion and MAP kinase signaling were examined in DSCs following treatment with NOD1 agonist, Tri-DAP. DSCs secreted IL-8 and increased trophoblast invasion. Tri-DAP further increased IL-8 secretion from DSCs via JNK pathway and facilitated both MMP-2 production and trophoblast invasion compared with control. Upon cotreatment of IL-8 and anti-IL-8 antibody to BeWo cells, the number of invading trophoblasts and MMP-2 production decreased significantly. These results suggest that IL-8 from DSCs may play a role to increase the invasiveness of trophoblast cells into the decidua via NOD1/JNK pathway.


Assuntos
Decídua/metabolismo , Interleucina-8/metabolismo , Trofoblastos/fisiologia , Linhagem Celular Tumoral , Movimento Celular , Células Cultivadas , Decídua/citologia , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Gravidez , Primeiro Trimestre da Gravidez , Transdução de Sinais , Células Estromais/metabolismo
7.
Eur J Med Chem ; 125: 807-815, 2017 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-27750198

RESUMO

The anti-tubercular activity of 6-chloro-2-ethyl-N-(4-(4-(4-(trifluoromethoxy)phenyl)piperidin-1-yl)benzyl)imidazo [1,2-a]pyridine-3-carboxamide (Q203) is modified by varying its side chain. In this study, we synthesized Q203 analogues with different side chains and studied their effects on anti-tubercular activity. Many analogues showed good potency against M. tuberculosis replicating in liquid broth culture medium (extracellular activity) regardless of chain length and conformational changes. However, a polar character in the side chain region was unfavorable for anti-tubercular activity. The analogues, 25, 28, 35, and 36, displayed excellent activity against M. tuberculosis replicating inside macrophages (intracellular activity) and promising pharmacokinetic (PK) properties with high drug exposure level and long half-life.


Assuntos
Imidazóis/farmacologia , Piperidinas/farmacologia , Piridinas/farmacologia , Animais , Antituberculosos/química , Antituberculosos/farmacocinética , Antituberculosos/farmacologia , Células Cultivadas , Meia-Vida , Humanos , Imidazóis/síntese química , Imidazóis/química , Imidazóis/farmacocinética , Macrófagos/microbiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Piperidinas/síntese química , Piperidinas/química , Piperidinas/farmacocinética , Piridinas/síntese química , Piridinas/química , Piridinas/farmacocinética , Relação Estrutura-Atividade
8.
Kidney Res Clin Pract ; 35(3): 169-75, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27668161

RESUMO

BACKGROUND: Prealbumin, a sensitive marker for protein-energy status, is also known as an independent risk factor for mortality in hemodialysis patients. We investigated the impact of prealbumin on survival in incident peritoneal dialysis (PD) patients. METHODS: In total, 136 incident PD patients (mean age, 53.0 ± 15.8 years) between 2002 and 2007 were enrolled in the study. Laboratory data, dialysis adequacy, and nutritional parameters were assessed 3 months after PD initiation. Patients were classified into 2 groups according to prealbumin level: high prealbumin (≥ 40 mg/dL) and low prealbumin (< 40 mg/dL). RESULTS: The patients in the low-prealbumin group were older and had more comorbidities such as diabetes and cardiovascular diseases compared with the patients in the high-prealbumin group. Mean subjective global assessment scores were lower, and the high-sensitivity C-reactive protein levels were higher in the low-prealbumin group. Serum creatinine, albumin, and transferrin levels; percent lean body mass; and normalized protein catabolic rate were positively associated, whereas subjective global assessment scores and high-sensitivity C-reactive protein levels were negatively associated with prealbumin concentration. During the median follow-up of 49 months, patients in the lower prealbumin group had a higher mortality rate. Multivariate analysis revealed that prealbumin < 40 mg/dL (hazard ratio, 2.30; 95% confidence interval, 1.14-4.64) was an independent risk factor for mortality. In receiver operating characteristic curves, the area under the curve of prealbumin for mortality was the largest among the parameters. CONCLUSION: Prealbumin levels were an independent and sensitive predictor for mortality in incident PD patients, showing a good correlation with nutritional and inflammatory markers.

9.
Korean J Fam Med ; 37(3): 156-63, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27274386

RESUMO

BACKGROUND: Colonoscopy is a very effective and essential examination to diagnose colorectal cancer; however, many patients experience discomfort due to post-examination abdominal pain, which reduces colonoscopy compliance. This study was conducted to determine methods for reducing post-colonoscopic abdominal pain. METHODS: We conducted a randomized controlled study of 405 male and female adults who visited Hana General Hospital in Cheongju. We surveyed general characteristics, history of colonoscopy, and other related factors, then categorized examinees into 5 groups (0-5) according to the site of scope reinsertion. Pain was measured using a numeric rating scale (NRS). RESULTS: The mean age of examinees in this study was 47.8 years, and 210 participants had prior experience of colonoscopy. No significant difference was observed between variables, with the exception of reinsertion duration (P=0.005). Pain scores were different between performing physicians (P=0.006), and were higher when the subjective level of procedure difficulty was low (P=0.026) in univariate analysis. Pain scores decreased as the reinsertion site became closer to the proximal colon (P<0.001), but there was no significant difference between groups 3 and 4. The results of multiple logistic regression analysis, including univariate analysis, showed that group 1 had 0.48 times, group 2 had 0.38 times, group 3 had 0.09 times, and group 4 had 0.03 times odds ratio (moderate-to-severe pain, NRS ≥4) than control group 0. CONCLUSION: Air decompression by scope reinsertion is an effective way to reduce abdominal pain after colonoscopy. Removing air when the reinserted scope approaches the hepatic flexure seems to be the most effective method to reduce post-colonoscopic pain.

10.
Clin Vaccine Immunol ; 22(4): 381-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25651919

RESUMO

In developing countries, Shigella is a primary cause of diarrhea in infants and young children. Although antibiotic therapy is an effective treatment for shigellosis, therapeutic options are narrowing due to the emergence of antibiotic resistance. Thus, preventive vaccination could become the most efficacious approach for controlling shigellosis. We have identified several conserved protein antigens that are shared by multiple Shigella serotypes and species. Among these, one antigen induced cross-protection against experimental shigellosis, and we have named it pan-Shigella surface protein 1 (PSSP-1). PSSP-1-induced protection requires a mucosal administration route and coadministration of an adjuvant. When PSSP-1 was administered intranasally, it induced cross-protection against Shigella flexneri serotypes 2a, 5a, and 6, Shigella boydii, Shigella sonnei, and Shigella dysenteriae serotype 1. Intradermally administered PSSP-1 induced strong serum antibody responses but failed to induce protection in the mouse lung pneumonia model. In contrast, intranasal administration elicited efficient local and systemic antibody responses and production of interleukin 17A and gamma interferon. Interestingly, blood samples from patients with recent-onset shigellosis showed variable but significant mucosal antibody responses to other conserved Shigella protein antigens but not to PSSP-1. We suggest that PSSP-1 is a promising antigen for a broadly protective vaccine against Shigella.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Proteção Cruzada , Disenteria Bacilar/prevenção & controle , Imunidade Heteróloga , Vacinas contra Shigella/administração & dosagem , Vacinas contra Shigella/imunologia , Shigella/imunologia , Administração Intranasal , Animais , Anticorpos Antibacterianos/sangue , Pré-Escolar , Disenteria Bacilar/imunologia , Feminino , Humanos , Lactente , Injeções Intradérmicas , Interferon gama/metabolismo , Interleucina-17/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Pneumonia Bacteriana/imunologia , Pneumonia Bacteriana/prevenção & controle
11.
Neuron ; 84(1): 92-106, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25277455

RESUMO

CREB is a pivotal mediator of activity-regulated gene transcription that underlies memory formation and allocation. The contribution of a key CREB cofactor, CREB-regulated transcription coactivator 1 (CRTC1), has, however, remained elusive. Here we show that several constitutive kinase pathways and an activity-regulated phosphatase, calcineurin, converge to determine the nucleocytoplasmic shuttling of CRTC1. This, in turn, triggered an activity-dependent association of CRTC1 with CREB-dependent regulatory elements found on IEG promoters. Forced expression of nuclear CRTC1 in hippocampal neurons activated CREB-dependent transcription, and was sufficient to enhance contextual fear memory. Surprisingly, during contextual fear conditioning, we found evidence of nuclear recruitment of endogenous CRTC1 only in the basolateral amygdala, and not in the hippocampus. Consistently, CRTC1 knockdown in the amygdala, but not in the hippocampus, significantly attenuated fear memory. Thus, CRTC1 has a wide impact on CREB-dependent memory processes, but fine-tunes CREB output in a region-specific manner.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Medo/fisiologia , Hipocampo/metabolismo , Memória/fisiologia , Transdução de Sinais/fisiologia , Fatores de Transcrição/metabolismo , Animais , Animais Recém-Nascidos , Células Cultivadas , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Neurônios/metabolismo , Ratos
12.
Enzyme Microb Technol ; 66: 35-41, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25248697

RESUMO

Enzymatic biofuel cells have many great features as a small power source for medical, environmental and military applications. Both glucose oxidase (GOx) and laccase (LAC) are widely used anode and cathode enzymes for enzymatic biofuel cells, respectively. In this paper, we employed three different approaches to immobilize GOx and LAC on polyaniline nanofibers (PANFs): enzyme adsorption (EA), enzyme adsorption and crosslinking (EAC) and enzyme adsorption, precipitation and crosslinking (EAPC) approaches. The activity of EAPC-LAC was 32 and 25 times higher than that of EA-LAC and EAC-LAC, respectively. The half-life of EAPC-LAC was 53 days, while those of EA-LAC and EAC-LAC were 6 and 21 days, respectively. Similar to LAC, EAPC-GOx also showed higher activity and stability than EA-GOx and EAC-GOx. For the biofuel cell application, EAPC-GOx and EAPC-LAC were applied over the carbon papers to form enzyme anode and cathode, respectively. In order to improve the power density output of enzymatic biofuel cell, 1,4-benzoquinone (BQ) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) were introduced as the electron transfer mediators on the enzyme anode and enzyme cathode, respectively. BQ- and ABTS-mediated enzymatic biofuel cells fabricated by EAPC-GOx and EAPC-LAC showed the maximum power density output of 37.4 µW/cm(2), while the power density output of 3.1 µW/cm(2) was shown without mediators. Under room temperature and 4°C for 28 days, enzymatic biofuel cells maintained 54 and 70% of its initial power density, respectively.


Assuntos
Fontes de Energia Bioelétrica , Glucose Oxidase , Lacase , Adsorção , Compostos de Anilina , Bioengenharia , Precipitação Química , Reagentes de Ligações Cruzadas , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Enzimas Imobilizadas/ultraestrutura , Glucose Oxidase/metabolismo , Glucose Oxidase/ultraestrutura , Lacase/metabolismo , Lacase/ultraestrutura , Microscopia Eletrônica de Varredura , Nanofibras/química , Nanofibras/ultraestrutura
13.
Neurobiol Learn Mem ; 115: 21-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25173698

RESUMO

In the field of molecular and cellular neuroscience, it is not a trivial task to see the forest for the trees, where numerous, and seemingly independent, molecules often work in concert to control critical steps of synaptic plasticity and signalling. Here, we will first summarize our current knowledge on essential activity-dependent transcription factors (TFs) such as CREB, MEF2, Npas4 and SRF, then examine how various transcription cofactors (TcoFs) also contribute to defining the transcriptional outputs during learning and memory. This review finally attempts a provisory synthesis that sheds new light on some of the emerging principles of neuronal circuit dynamics driven by activity-regulated gene transcription to help better understand the intricate relationship between activity-dependent gene expression and cognitive behavior.


Assuntos
Cognição/fisiologia , Regulação da Expressão Gênica/fisiologia , Fatores de Transcrição/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Proteína de Ligação a CREB/fisiologia , Humanos , Proteínas Interatuantes com Canais de Kv/fisiologia , Aprendizagem/fisiologia , Fatores de Transcrição MEF2/fisiologia , Memória/fisiologia , Proteína 2 de Ligação a Metil-CpG/fisiologia , Proteínas Repressoras/fisiologia
14.
J Med Chem ; 57(12): 5293-305, 2014 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-24870926

RESUMO

A critical unmet clinical need to combat the global tuberculosis epidemic is the development of potent agents capable of reducing the time of multi-drug-resistant (MDR) and extensively-drug-resistant (XDR) tuberculosis therapy. In this paper, we report on the optimization of imidazo[1,2-a]pyridine amide (IPA) lead compound 1, which led to the design and synthesis of Q203 (50). We found that the amide linker with IPA core is very important for activity against Mycobacterium tuberculosis H37Rv. Linearity and lipophilicity of the amine part in the IPA series play a critical role in improving in vitro and in vivo efficacy and pharmacokinetic profile. The optimized IPAs 49 and 50 showed not only excellent oral bioavailability (80.2% and 90.7%, respectively) with high exposure of the area under curve (AUC) but also displayed significant colony-forming unit (CFU) reduction (1.52 and 3.13 log10 reduction at 10 mg/kg dosing level, respectively) in mouse lung.


Assuntos
Antituberculosos/química , Imidazóis/química , Piridinas/química , Animais , Antituberculosos/síntese química , Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla , Humanos , Imidazóis/síntese química , Imidazóis/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/microbiologia , Camundongos , Microssomos Hepáticos/metabolismo , Mycobacterium tuberculosis/efeitos dos fármacos , Piridinas/síntese química , Piridinas/farmacologia , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico
15.
Hippocampus ; 24(7): 784-93, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24599753

RESUMO

Adult hippocampal neurogenesis has been suggested to play modulatory roles in learning and memory. Importantly, previous studies have shown that newborn neurons in the adult hippocampus are integrated into the dentate gyrus circuit and are recruited more efficiently into the hippocampal memory trace of mice when they become 3 weeks old. Interestingly, a single high-dose treatment with the N-methyl-d-aspartate receptor antagonist memantine (MEM) has been shown to increase hippocampal neurogenesis dramatically by promoting cell proliferation. In the present study, to understand the impact of increased adult neurogenesis on memory performance, we examined the effects of a single treatment of MEM on hippocampus-dependent memory in mice. Interestingly, mice treated with MEM showed an improvement of hippocampus-dependent spatial and social recognition memories when they were trained and tested at 3-6 weeks, but not at 3 days or 4 months, after treatment with MEM. Importantly, we observed a significant positive correlation between the scores for spatial memory (probe trial in the Morris water maze task) and the number of young mature neurons (3 weeks old) in MEM-treated mice, but not saline-treated mice. We also observed that the young mature neurons generated by treatment with MEM were recruited into the trace of spatial memory similarly to those generated through endogenous neurogenesis. Taken together, our observations suggest that treatment with MEM temporally improves hippocampus-dependent memory formation and that the newborn neurons increased by treatment with MEM contribute to this improvement when they become 3 weeks old.


Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Memantina/farmacologia , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Memória Espacial/efeitos dos fármacos , Células-Tronco Adultas/citologia , Animais , Divisão Celular/efeitos dos fármacos , Senescência Celular , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Neurogênese/fisiologia , Neurônios/fisiologia , Reconhecimento Psicológico/fisiologia , Comportamento Social , Memória Espacial/fisiologia
16.
Philos Trans R Soc Lond B Biol Sci ; 369(1633): 20130150, 2014 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-24298152

RESUMO

During learning and memory, it has been suggested that the coordinated electrical activity of hippocampal neurons translates information about the external environment into internal neuronal representations, which then are stored initially within the hippocampus and subsequently into other areas of the brain. A widely held hypothesis posits that synaptic plasticity is a key feature that critically modulates the triggering and the maintenance of such representations, some of which are thought to persist over time as traces or tags. However, the molecular and cell biological basis for these traces and tags has remained elusive. Here, we review recent findings that help clarify some of the molecular and cellular mechanisms critical for these events, by untangling a two-way signalling crosstalk route between the synapses and the neuronal soma. In particular, a detailed interrogation of the soma-to-synapse delivery of immediate early gene product Arc/Arg3.1, whose induction is triggered by heightened synaptic activity in many brain areas, teases apart an unsuspected 'inverse' synaptic tagging mechanism that likely contributes to maintaining the contrast of synaptic weight between strengthened and weak synapses within an active ensemble.


Assuntos
Núcleo Celular/fisiologia , Aprendizagem/fisiologia , Memória/fisiologia , Modelos Neurológicos , Plasticidade Neuronal/fisiologia , Transdução de Sinais/fisiologia , Sinapses/fisiologia , Cálcio/metabolismo , Humanos , Receptor Cross-Talk/fisiologia
17.
Osong Public Health Res Perspect ; 3(2): 68-73, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24159493

RESUMO

OBJECTIVES: Bacillus Calmette-Guérin (BCG) vaccination has proven to be efficient in immunologically naïve infants; however, it has not been investigated that maternal natural exposure to Mycobacterium and/or BCG vaccine could influence the characteristics of immune responses to BCG in newborns. In this study, we analyzed whether the maternal immune status to M tuberculosis (M tb) can affect neonatal immunity to BCG using a mouse model. METHODS: Neonates were obtained from mice that were previously exposed to live BCG, to live M avium, or to heat-killed M tb H37Rv, and from naïve control mothers. One week after birth, the neonates were divided into two subgroups: one group immunized with live BCG via the subcutaneous route and the other group of neonates sham-treated. Interferon-gamma (IFNγ) secretion in response to in vitro stimulation with heat-killed BCG or purified protein derivative (PPD) was examined. Protection against M tb infection was evaluated by challenging mice nasally with live M tb H37Rv followed by counting colonies from spleen and lung homogenates. RESULTS: BCG-immunized neonates showed increased IFNγ secretion in response to heat-killed BCG or PPD. All mice in BCG-immunized neonates subgroups showed reduced bacterial burden (colony forming unit) in the lungs when compared with control naive neonate mice. However, no statistically significant difference was observed when comparing BCG-immunized mice born from mothers previously exposed to M avium or immunized with either heat-killed H37Rv or live BCG and mice born from naïve mothers. CONCLUSION: The maternal immune status to M tb does not appear to impact on the immunogenicity of BCG vaccine in their progeny in our experimental conditions.

18.
Commun Integr Biol ; 5(5): 496-8, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23739267

RESUMO

Neurons express new gene transcripts and proteins upon receiving synaptic inputs, and these events are essential for achieving proper neuronal wiring, adequate synaptic plasticity, and updatable memory. However, the biological impact of new gene expression on input-specific synaptic potentiation remains largely elusive, in part because the cell biological and biochemical mechanisms for synaptic targeting of newly synthesized proteins has remained obscure. A new study investigating the targeting of the memory related protein Arc from the soma to the synapses teases apart a novel "inverse" synaptic tagging mechanism that enables Arc to specifically target the un-potentiated synapses, thereby helping to maintain the contrast of synaptic weight between strengthened and weak synapses.

19.
Mol Brain ; 4: 9, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21314917

RESUMO

BACKGROUND: Memory retrieval is not a passive process. Recent studies have shown that reactivated memory is destabilized and then restabilized through gene expression-dependent reconsolidation. Molecular studies on the regulation of memory stability after retrieval have focused almost exclusively on fear memory, especially on the restabilization process of the reactivated fear memory. We previously showed that, similarly with fear memories, reactivated spatial memory undergoes reconsolidation in the Morris water maze. However, the underlying molecular mechanisms by which reactivated spatial memory is destabilized and restabilized remain poorly understood. In this study, we investigated the molecular mechanism that regulates the stability of the reactivated spatial memory. RESULTS: We first showed that pharmacological inactivation of the N-methyl-D-aspartate glutamate receptor (NMDAR) in the hippocampus or genetic inhibition of cAMP-responsible element binding protein (CREB)-mediated transcription disrupted reactivated spatial memory. Finally, we showed that pharmacological inhibition of cannabinoid receptor 1 (CB1) and L-type voltage gated calcium channels (LVGCCs) in the hippocampus blocked the disruption of the reactivated spatial memory by the inhibition of protein synthesis. CONCLUSIONS: Our findings indicated that the reactivated spatial memory is destabilized through the activation of CB1 and LVGCCs and then restabilized through the activation of NMDAR- and CREB-mediated transcription. We also suggest that the reactivated spatial memory undergoes destabilization and restabilization in the hippocampus, through similar molecular processes as those for reactivated contextual fear memories, which require CB1 and LVGCCs for destabilization and NMDAR and CREB for restabilization.


Assuntos
Expressão Gênica , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Percepção Espacial/fisiologia , Animais , Anisomicina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Antagonistas de Receptores de Canabinoides , Condicionamento Clássico , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Medo/fisiologia , Hipocampo/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Piperidinas/farmacologia , Biossíntese de Proteínas , Inibidores da Síntese de Proteínas/farmacologia , Pirazóis/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Rimonabanto , Percepção Espacial/efeitos dos fármacos , Verapamil/farmacologia
20.
Mol Cell Biol ; 27(18): 6497-505, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17620412

RESUMO

Grb10 is a pleckstrin homology and Src homology 2 domain-containing protein that interacts with a number of phosphorylated receptor tyrosine kinases, including the insulin receptor. In mice, Grb10 gene expression is imprinted with maternal expression in all tissues except the brain. While the interaction between Grb10 and the insulin receptor has been extensively investigated in cultured cells, whether this adaptor protein plays a positive or negative role in insulin signaling and action remains controversial. In order to investigate the in vivo role of Grb10 in insulin signaling and action in the periphery, we generated Grb10 knockout mice by the gene trap technique and analyzed mice with maternal inheritance of the knockout allele. Disruption of Grb10 gene expression in peripheral tissues had no significant effect on fasting glucose and insulin levels. On the other hand, peripheral-tissue-specific knockout of Grb10 led to significant overgrowth of the mice, consistent with a role for endogenous Grb10 as a growth suppressor. Loss of Grb10 expression in insulin target tissues, such as skeletal muscle and fat, resulted in enhanced insulin-stimulated Akt and mitogen-activated protein kinase phosphorylation. Hyperinsulinemic-euglycemic clamp studies revealed that disruption of Grb10 gene expression in peripheral tissues led to increased insulin sensitivity. Taken together, our results provide strong evidence that Grb10 is a negative regulator of insulin signaling and action in vivo.


Assuntos
Proteína Adaptadora GRB10/genética , Proteína Adaptadora GRB10/metabolismo , Insulina/metabolismo , Transdução de Sinais , Animais , Glicemia/análise , Tamanho Corporal/genética , Peso Corporal/genética , Cruzamentos Genéticos , Células-Tronco Embrionárias/citologia , Jejum , Feminino , Proteína Adaptadora GRB10/deficiência , Insulina/sangue , Insulina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Camundongos Knockout , Microinjeções , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Técnicas de Patch-Clamp , Fosforilação/efeitos dos fármacos , Gravidez , Proteínas Proto-Oncogênicas c-akt/metabolismo , Sensibilidade e Especificidade , Trofoblastos/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...