RESUMO
Neuroinflammation in the central nervous system is detrimental for learning and memory, as evident form epidemiological studies linking developmental defects and maternal exposure to harmful pathogens. Postnatal infections can also induce neuroinflammatory responses with long-term consequences. These inflammatory responses can lead to motor deficits and/or behavioral disabilities. Toll like receptors (TLRs) are a family of innate immune receptors best known as sensors of microbial-associated molecular patterns, and are the first responders to infection. TLR2 forms heterodimers with either TLR1 or TLR6, is activated in response to gram-positive bacterial infections, and is expressed in the brain during embryonic development. We hypothesized that early postnatal TLR2-mediated neuroinflammation would adversely affect cognitive behavior in the adult. Our data indicate that postnatal TLR2 activation affects learning and memory in adult mice in a heterodimer-dependent manner. TLR2/6 activation improved motor function and fear learning, while TLR2/1 activation impaired spatial learning and enhanced fear learning. Moreover, developmental TLR2 deficiency significantly impairs spatial learning and enhances fear learning, stressing the involvement of the TLR2 pathway in learning and memory. Analysis of the transcriptional effects of TLR2 activation reveals both common and unique transcriptional programs following heterodimer-specific TLR2 activation. These results imply that adult cognitive behavior could be influenced in part, by activation or alterations in the TLR2 pathway at birth.
Assuntos
Aprendizagem/fisiologia , Memória/fisiologia , Destreza Motora/fisiologia , Neurônios/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Condicionamento Psicológico/fisiologia , Comportamento Exploratório/fisiologia , Medo/fisiologia , Camundongos , Camundongos Knockout , Teste de Desempenho do Rota-Rod , Aprendizagem Espacial/fisiologia , Receptor 2 Toll-Like/genéticaRESUMO
In a breast tumor xenograft model, the MCT-1 oncogene increases the in vivo tumorgenicity of MCF7 cells by promoting angiogenesis and inhibiting apoptosis. Increases in the tumor microvascular density are accompanied by a strong reduction in the levels of the angiogenesis inhibitor thrombospondin-1 (TSP1), but the mechanisms underlying this process are unknown. We show that TSP1 expression is controlled, at least in part, by post-transcriptional events. Using RNA interference to knock down the expression of the RNA-binding protein HuR in MCF7 cells as well as HuR overexpression, we demonstrate that HuR plays an important role in translation of the TSP1 mRNA. Furthermore, employing the RIP-Chip assay yielded 595 transcripts with significantly altered binding to HuR in the more tumorigenic breast cancer clones compared with the weakly tumorigenic clones. These mRNAs clustered in several pathways implicated in the transformed phenotype, such as the RAS pathway (involved in mitogenesis), the PI3K pathway (evasion of apoptosis) and pathways mediating angiogenesis and the cellular response to hypoxia. These findings demonstrate for the first time that global changes in HuR-bound mRNAs are implicated in the evolution to a more tumorigenic phenotype in an in vivo tumor model and underscore the role of global mRNA-protein interactions toward tumor progression.
Assuntos
Antígenos de Superfície/fisiologia , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Ligação a RNA/fisiologia , Trombospondina 1/genética , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/fisiologia , Linhagem Celular Tumoral , Proteínas ELAV , Proteína Semelhante a ELAV 1 , Feminino , Humanos , Proteínas Oncogênicas/fisiologia , Fenótipo , Fosfatidilinositol 3-Quinases/fisiologia , Biossíntese de Proteínas , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Transdução de Sinais , Transcrição GênicaRESUMO
The psychostimulant effects of cocaine are thought to result from its ability to block dopamine (DA) uptake and increase DA levels in ventral striatum. In addition, cocaine causes biochemical changes in the brain areas involved in learning and memory, including hippocampus and cortex, whose role in drug reinforcement is now being actively investigated. Thus, we studied molecular events in the hippocampus and frontal cortex of rats treated with cocaine conditioned place preference (CPP) paradigm. After exposure to cocaine conditioning (cocaine paired), cocaine alone (cocaine non-paired) or saline rats were tested for place conditioning. Cocaine (10 mg/kg) caused increases in time spent in the drug-paired compartment. By using microarray analyses, we examined gene expression in the hippocampi and frontal cortices of cocaine-paired rats, cocaine non-paired and saline-treated controls. Our study revealed that 214 transcripts were differentially regulated in the hippocampi of cocaine-paired rats. These include genes that play roles in protein phosphorylation, RNA processing and protein synthesis, ubiquitin-dependent protein degradation and cytoskeleton organization. In contrast, 39 genes were differently expressed in the frontal cortex. Our data support the possibility that molecular changes in the hippocampus might participate in the formation and maintenance of memory patterns induced by cocaine in the brain. Differences in the transcriptional responses in the hippocampus and cortex suggest the primary importance of the hippocampus for recent memory processing associated with cocaine-induced CPP.
Assuntos
Córtex Cerebral/fisiologia , Cocaína/farmacologia , Hipocampo/fisiologia , Ratos Wistar/genética , Reforço Psicológico , Transcrição Gênica , Animais , Córtex Cerebral/efeitos dos fármacos , Condicionamento Psicológico/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Abrigo para Animais , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , RNA/genética , RNA/isolamento & purificação , Ratos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The molecular pathways activated in response to acute cisplatin exposure, as well as the mechanisms involved in the long-term development of cisplatin-resistant cancer cells remain unclear. Using whole genome oligonucleotide microarrays, we have examined the kinetics of gene expression changes in a cisplatin-sensitive cell line, A2780, and its cisplatin-resistant derivative, ACRP. Both sensitive and resistant cell lines exhibited a very similar response of p53-inducible genes as early as 16 h after treatment. This p53 response was further increased at the 24-h time point. These experiments identify p53 as the main pathway producing a large-scale transcriptional response after cisplatin treatment in these cells containing wild-type p53. Consistent with a role for the p53 response in cisplatin sensitivity, knockdown of the p53 protein with small interfering RNA led to a twofold decrease in cell survival in the resistant cells. In addition, our analysis also allowed the identification of several genes that are differentially expressed between sensitive and resistant cells. These genes include GJA1 (encoding connexin 43 (Cx43)) and TWIST1, which are highly upregulated in cisplatin-resistant cells. The importance of Cx43 in drug resistance was demonstrated through functional analyses, although paradoxically, inhibition of Cx43 function in high expressing cells led to an increase in drug resistance. The pathways important in cisplatin response, as well as the genes found differentially expressed between cisplatin-resistant and -sensitive cells, may represent targets for therapy aimed at reversing drug resistance.
Assuntos
Cisplatino/farmacologia , Cistadenocarcinoma Seroso/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Ovarianas/genética , Análise por Conglomerados , Conexina 43/genética , Cistadenocarcinoma Seroso/patologia , Feminino , Perfilação da Expressão Gênica , Humanos , Neoplasias Ovarianas/patologia , RNA Interferente Pequeno/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
Due to brain tissue heterogeneity, the molecular genetic profile of any neurotransmitter-specific neuronal subtype is unknown. The purpose of this study was to purify a population of dopamine neurons, construct a cDNA library, and generate an initial gene expression profile and a microarray representative of dopamine neuron transcripts. Ventral mesencephalic dopamine neurons were purified by fluorescent-activated cell sorting from embryonic day 13.5 transgenic mice harboring a 4.5-kb rat tyrosine hydroxylase promoter-lacZ fusion. Nine-hundred sixty dopamine neuron cDNA clones were sequenced and arrayed for use in studies of gene expression changes during methamphetamine neurotoxicity. A neurotoxic dose of methamphetamine produced a greater than twofold up-regulation of the mitochondrial cytochrome c oxidase polypeptide I transcript from adult mouse substantia nigra at 12 h posttreatment. This is the first work to describe a gene expression profile for a neuronal subtype and to identify gene expression changes during methamphetamine neurotoxicity.
Assuntos
Inibidores da Captação de Dopamina/toxicidade , Dopamina/análise , Complexo IV da Cadeia de Transporte de Elétrons/biossíntese , Perfilação da Expressão Gênica , Biblioteca Gênica , Metanfetamina/toxicidade , Proteínas do Tecido Nervoso/biossíntese , Neurônios/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Ácido 3,4-Di-Hidroxifenilacético/análise , Animais , DNA Complementar/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Indução Enzimática , Feminino , Genes Sintéticos , Óperon Lac , Masculino , Mesencéfalo/citologia , Mesencéfalo/embriologia , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Regiões Promotoras Genéticas , Ratos , Transcrição Gênica , Tirosina 3-Mono-Oxigenase/genéticaRESUMO
Using cDNA microarrays we have investigated gene expression patterns in brain regions of patients with schizophrenia. A cDNA neuroarray, comprised of genes related to brain function, was used to screen pools of samples from the cerebellum and prefrontal cortex from a matched set of subjects, and middle temporal gyrus, from a separate subject cohort. Samples of cerebellum and prefrontal cortex from neuroleptic naive patients were also included. Genes that passed a 3% reproducibility criterion for differential expression in independent experiments included 21 genes for drug-treated patients and 5 genes for drug-naive patients. Of these 26 genes, 10 genes were increased and 16 were decreased. Many of the differentially expressed genes were related to synaptic signaling and proteolytic functions. A smaller number of these genes were also differentially expressed in the middle temporal gyrus. The five genes that were differentially expressed in two brain regions from separate cohorts are: tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, eta polypeptide; sialyltransferase; proteasome subunit, alpha type 1; ubiquitin carboxyl-terminal esterase L1; and solute carrier family 10, member 1. Identification of patterns of changes in gene expression may lead to a better understanding of the pathophysiology of schizophrenia disorders.
Assuntos
Química Encefálica/genética , Encéfalo/metabolismo , Regulação da Expressão Gênica/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos/tendências , RNA Mensageiro/análise , Esquizofrenia/genética , Adulto , Idoso , Encéfalo/patologia , Encéfalo/fisiopatologia , Cerebelo/metabolismo , Cerebelo/patologia , Cerebelo/fisiopatologia , Feminino , Testes Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , Reprodutibilidade dos Testes , Esquizofrenia/metabolismo , Esquizofrenia/patologia , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Lobo Temporal/fisiopatologiaRESUMO
cDNA microarray technology has been increasingly used to monitor global gene expression patterns in various tissues and cell types. However, applications to mammalian development have been hampered by the lack of appropriate cDNA collections, particularly for early developmental stages. To overcome this problem, a PCR-based cDNA library construction method was used to derive 52,374 expressed sequence tags from pre- and peri-implantation embryos, embryonic day (E) 12.5 female gonad/mesonephros, and newborn ovary. From these cDNA collections, a microarray representing 15,264 unique genes (78% novel and 22% known) was assembled. In initial applications, the divergence of placental and embryonic gene expression profiles was assessed. At stage E12.5 of development, based on triplicate experiments, 720 genes (6.5%) displayed statistically significant differences in expression between placenta and embryo. Among 289 more highly expressed in placenta, 61 placenta-specific genes encoded, for example, a novel prolactin-like protein. The number of genes highly expressed (and frequently specific) for placenta has thereby been increased 5-fold over the total previously reported, illustrating the potential of the microarrays for tissue-specific gene discovery and analysis of mammalian developmental programs.
Assuntos
Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genoma , Placenta/metabolismo , Proteínas da Gravidez/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Primers do DNA , DNA Complementar , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Gravidez , Proteínas da Gravidez/química , Homologia de Sequência de AminoácidosRESUMO
An overview of infection as it applies to the oral and maxillofacial region has been provided. The following conclusions are drawn: odontogenic infections are caused by microbes found in the host's oral flora; cultures of purulent material generally will yield three to six anaerobes and one aerobe, (the aerobe is usually a Streptococcus species); Gram stains of purulent material can aid in therapeutic strategies; anaerobic as well as aerobic cultures are necessary to isolate all pathogens; pathogens found in infections of bite wounds reflect the oral flora of the aggressor; early postoperative wound infections are caused by the host's own flora, whereas later infections may be caused by hospital-acquired bacteria; and hepatitis B and herpes simplex virus are occupational hazards. Recommendations have been made for antimicrobial prophylaxis and for treatment. We recognize that some of these selections may be controversial. For instance, the value of prophylactic antibiotics in orthognathic surgery is not well defined; recommendations were made only in certain instances. However, in severe penetrating maxillofacial injuries with devitalized tissue, recommendations for antibiotics were for broad and prolonged coverage. In this instance, use of antibiotics is considered therapeutic and not prophylactic. In each instance, we tried to validate the selection. Our rationale has been to choose the antibiotics most active against the likely pathogens; additionally, consideration was given to drug toxicity and adverse reactions. We regard penicillin as the preferred agent for prophylaxis and treatment of most odontogenic infections. Alternative drugs include cephalosporins, doxycycline, and clindamycin. Erythoromycin and tetracycline are considered less effective than the former agents. Finally, we believe that successful treatment of infection depends as much on changing the microenvironment of the infected tissue by debridement and drainage as on appropriate antimicrobial therapy.
Assuntos
Antibacterianos/uso terapêutico , Infecções Bacterianas/microbiologia , Doenças Maxilomandibulares/microbiologia , Doenças da Boca/microbiologia , Actinomicose/microbiologia , Anaerobiose , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/prevenção & controle , Infecções por Bacteroides/microbiologia , Cefalosporinas/uso terapêutico , Endocardite Bacteriana/prevenção & controle , Eritromicina/uso terapêutico , Humanos , Doenças Maxilomandibulares/tratamento farmacológico , Traumatismos Maxilofaciais/tratamento farmacológico , Doenças da Boca/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Infecção da Ferida Cirúrgica/prevenção & controle , Tetraciclina/uso terapêutico , Doenças Dentárias/microbiologia , Viroses/microbiologiaAssuntos
Lúpus Eritematoso Sistêmico/induzido quimicamente , Propranolol/efeitos adversos , Humanos , Hidrazinas/uso terapêutico , Hipertensão/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Practolol/efeitos adversos , Practolol/uso terapêutico , Propranolol/uso terapêutico , Manifestações CutâneasAssuntos
Cetilpiridínio/farmacologia , Dente Molar/cirurgia , Compostos de Piridínio/farmacologia , Sepse/etiologia , Dente Impactado/cirurgia , Adolescente , Adulto , Bacteroides/isolamento & purificação , Feminino , Fusobacterium/isolamento & purificação , Humanos , Masculino , Antissépticos Bucais , Peptostreptococcus/isolamento & purificação , Cuidados Pré-Operatórios , Sepse/microbiologia , Cloreto de Sódio , Soluções , Staphylococcus/isolamento & purificação , Streptococcus/isolamento & purificação , Fatores de Tempo , Veillonella/isolamento & purificaçãoAssuntos
Anticorpos/análise , Bacteriúria/etiologia , Disrafismo Espinal/complicações , Bexiga Urinaria Neurogênica/etiologia , Infecções Urinárias/etiologia , Formação de Anticorpos , Antígenos de Bactérias/isolamento & purificação , Criança , Pré-Escolar , Escherichia coli/imunologia , Humanos , Pielonefrite/microbiologia , Disrafismo Espinal/imunologia , Bexiga Urinaria Neurogênica/imunologia , Infecções Urinárias/imunologia , Infecções Urinárias/microbiologiaRESUMO
Cell walls prepared by mechanically disrupting intact Rickettsia mooseri (R. typhi) were examined in an electron microscope and analyzed chemically. Electron micrographs of metal-shadowed and negatively stained rickettsial cell walls revealed no significant differences, except for smaller size, from bacterial cell walls prepared in a similar manner. The chemical composition was complex, and resembled that of gram-negative bacterial cell walls more closely than that of gram-positive bacterial cell walls. R. mooseri cell walls contained the sugars, glucose, galactose, and glucuronic acid, the amino sugars, glucosamine, and muramic acid, and at least 15 amino acids. Diaminopimelic acid, a compound hitherto found only in bacteria and blue-green algae, was demonstrated in rickettsiae for the first time. Teichoic acids were not detected. The compounds identified accounted for about 70% of the dry weight of the cell walls.