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1.
Sci Rep ; 11(1): 6471, 2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33742056

RESUMO

Oxytocin is a neuropeptide released by the central nervous system. A number of studies have demonstrated the role of this neuropeptide in the pathogenesis of breast cancer. In the present project, we have identified mRNA coding genes and long non-coding RNAs (lncRNAs) that are associated with this pathway through an in-silico strategy, and measured their expression in a cohort of Iranian females affected with this type of malignancy. Expression levels of OXTR, FOS, ITPR1, RCAN1, CAMK2D, CACNA2D and lnc_ZFP161 were significantly down-regulated in breast cancer tissues compared with nearby non-cancerous tissues. On the other hand, expression of lnc_MTX2 was higher in breast cancer tissues compared with controls. Expression of lnc_TNS1 and lnc_FOXF1 were not different between these two kinds of samples. Expression of CACNA2D was associated with mitotic rate and PR status (P values = 3.02E-02 and 2.53E-02, respectively). Expression of other oxytocin-related genes was not associated with clinicopathological parameters. FOS and ITPR1 had the highest AUC value among the oxytocin-related genes. Combination of expression profiles of all oxytocin-related genes increased the AUC value to 0.75. However, the combinatorial sensitivity and specificity values were lower than some individual genes. In the breast cancer tissues, the most robust correlations have been detected between lnc_ZFP161/ lnc_FOXF1, CAMK2D/ lnc_ZFP161 and CAMK2D / lnc_FOXF1 (r = 0.86, 0.71 and 0.64 respectively). In the non-cancerous tissues, the strongest correlation was detected between lnc_FOXF1/lnc_MTX2 and lnc_ZFP161/CAMK2D respectively (r = 0.78 and 0.65). Taken together, oxytocin-associated genes have been dysregulated in breast cancer tissues. Moreover, the correlation ratio between these genes is connected with the existence of cancer.


Assuntos
Neoplasias da Mama/genética , Redes Reguladoras de Genes , Ocitocina/metabolismo , RNA Longo não Codificante/genética , Adulto , Idoso , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Pessoa de Meia-Idade , Ocitocina/genética , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , RNA Longo não Codificante/metabolismo
2.
Microscopy (Oxf) ; 70(2): 201-214, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32816022

RESUMO

This study was aimed to verify the cellular interplay between vascular endothelial cells and surrounding cells in the chondro-osseous junction of murine tibiae. Many CD31-positive endothelial cells accompanied with Dolichos Biflorus Agglutinin lectin-positive septoclasts invaded into the hypertrophic zone of the tibial epiphyseal cartilage. MMP9 immunoreactive cytoplasmic processes of vascular endothelial cells extended into the transverse partitions of cartilage columns. In contrast, septoclasts included several large lysosomes which indicate the incorporation of extracellular matrices despite no immunopositivity for F4/80-a hallmark of macrophage/monocyte lineage. In addition, septoclasts were observed in c-fos-/- mice but not in Rankl-/- mice. Unlike c-fos-/- mice, Rankl-/- mice showed markedly expanded hypertrophic zone and the irregular shape of the chondro-osseous junction. Immunoreactivity of platelet-derived growth factor-bb, which involved in angiogenic roles in the bone, was detected in not only osteoclasts but also septoclasts at the chondro-osseous junction. Therefore, septoclasts appear to assist the synchronous vascular invasion of endothelial cells at the chondro-osseous junction. Vascular endothelial cells adjacent to the chondro-osseous junction possess endomucin but not EphB4, whereas those slightly distant from the chondro-osseous junction were intensely positive for both endomucin and EphB4, while being accompanied with ephrinB2-positive osteoblasts. Taken together, it is likely that vascular endothelial cells adjacent to the chondro-osseous junction would interplay with septoclasts for synchronous invasion into the epiphyseal cartilage, while those slightly distant from the chondro-osseous junction would cooperate with osteoblastic activities presumably by mediating EphB4/ephrinB2. MINI-ABSTRACT: Our original article demonstrated that vascular endothelial cells adjacent to the chondro-osseous junction would interplay with septoclasts for synchronous invasion into the epiphyseal cartilage, while those slightly distant from the chondro-osseous junction would cooperate with osteoblastic activities presumably by mediating EphB4/ephrinB2. (A figure that best represents your paper is Fig. 5c).


Assuntos
Células Endoteliais/metabolismo , Lâmina de Crescimento/crescimento & desenvolvimento , Osteogênese/fisiologia , Tíbia/citologia , Animais , Becaplermina/metabolismo , Osso e Ossos/citologia , Efrina-B2/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoclastos/citologia , Fagócitos/citologia , Lectinas de Plantas/farmacologia , Proteínas Proto-Oncogênicas c-fos/genética , Receptor EphB4/metabolismo
3.
Cerebellum ; 19(1): 68-77, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31768920

RESUMO

Early life stress increases the risk of abnormal brain development, and it is associated with psychological disorders. Maternal separation is an established animal model of early life stress that produces changes in the development of the central nervous system. The objective of this study was to evaluate the effect of maternal separation on the rat cerebellum, both behaviourally and physiologically. We used 32 rats, males (n = 8) and females (n = 7), subjected to maternal separation for 21 days and a control group (9 males and 8 females). Spatial reference memory was assessed using the Morris water maze, and brain metabolic activity and the expression of an immediate early gene were determined, respectively, using the histochemical technique of cytochrome c oxidase and the immunocytochemistry of c-Fos. Results showed that both groups successfully performed the spatial memory task. Although there were no behavioural differences, the experimental group showed lower metabolic activity in the medial nucleus of the cerebellum, as well as fewer c-Fos-positive cells in the three deep nuclei of the cerebellum. These decreases could contribute to the emotional or behavioural impairments reported in maternal separation subjects.


Assuntos
Cerebelo/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Privação Materna , Estresse Oxidativo/fisiologia , Proteínas Proto-Oncogênicas c-fos/biossíntese , Animais , Animais Recém-Nascidos , Feminino , Masculino , Aprendizagem em Labirinto/fisiologia , Proteínas Proto-Oncogênicas c-fos/genética , Distribuição Aleatória , Ratos , Ratos Wistar
4.
J Bone Miner Res ; 34(9): 1707-1720, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30998833

RESUMO

Energy metabolism and bone homeostasis share several regulatory pathways. The AP1 transcription factor ΔFosB and leptin both regulate energy metabolism and bone, yet whether their pathways intersect is not known. Transgenic mice overexpressing ΔFosB under the control of the Enolase 2 (ENO2) promoter exhibit high bone mass, high energy expenditure, low fat mass, and low circulating leptin levels. Because leptin is a regulator of bone and ΔFosB acts on leptin-responsive ventral hypothalamic (VHT) neurons to induce bone anabolism, we hypothesized that regulation of leptin may contribute to the central actions of ΔFosB in the VHT. To address this question, we used adeno-associated virus (AAV) expression of ΔFosB in the VHT of leptin-deficient ob/ob mice and genetic crossing of ENO2-ΔFosB with ob/ob mice. In both models, leptin deficiency prevented ΔFosB-triggered reduction in body weight, increase in energy expenditure, increase in glucose utilization, and reduction in pancreatic islet size. In contrast, leptin deficiency failed to prevent ΔFosB-triggered increase in bone mass. Unlike leptin deficiency, galanin deficiency blocked both the metabolic and the bone ΔFosB-induced effects. Overall, our data demonstrate that, while the catabolic energy metabolism effects of ΔFosB require intact leptin and galanin signaling, the bone mass-accruing effects of ΔFosB require galanin but are independent of leptin. © 2019 American Society for Bone and Mineral Research.


Assuntos
Osso e Ossos/anatomia & histologia , Metabolismo Energético , Galanina/metabolismo , Hipotálamo/metabolismo , Leptina/metabolismo , Proteínas Proto-Oncogênicas c-fos/genética , Animais , Peso Corporal , Deleção de Genes , Glucose/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Tamanho do Órgão , Fosfopiruvato Hidratase/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo
5.
Yakugaku Zasshi ; 138(7): 945-954, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-29962474

RESUMO

 Selective sodium glucose transporter-2 inhibitor (SGLT2i) treatment promotes urinary glucose excretion, thereby reducing blood glucose as well as body weight. However, only limited body weight reductions are achieved with SGLT2i administration. Hyperphagia is reportedly one of the causes of this limited weight loss. However, the effects of SGLT2i on systemic energy expenditure have not been fully elucidated. We investigated the acute effects of dapagliflozin, an SGLT2i, on systemic energy expenditure in mice. Eighteen hours after dapagliflozin administration, oxygen consumption and brown adipose tissue (BAT) expression of ucp1, a thermogenesis-related gene, were significantly decreased as compared with those after vehicle administration. In addition, dapagliflozin significantly suppressed norepinephrine (NE) turnover in BAT and c-fos expression in the rostral raphe pallidus nucleus (rRPa), which contains the sympathetic premotor neurons responsible for thermogenesis. These findings indicate that the dapagliflozin-mediated acute decrease in energy expenditure involves a reduction in BAT thermogenesis via decreased sympathetic nerve activity from the rRPa. Furthermore, common hepatic branch vagotomy abolished the reductions in ucp1 expression, NE contents in BAT, and c-fos expression in the rRPa. In addition, alterations in hepatic carbohydrate metabolism, such as decreases in glycogen contents and upregulation of phosphoenolpyruvate carboxykinase, occurred prior to the suppression of BAT thermogenesis, e.g., 6 h after dapagliflozin treatment. Collectively, these results suggest that SGLT2i acutely suppresses energy expenditure in BAT via regulation of an interorgan neural network consisting of the common hepatic vagal branch and sympathetic nerves.


Assuntos
Tecido Adiposo Marrom/metabolismo , Compostos Benzidrílicos/farmacologia , Metabolismo Energético/efeitos dos fármacos , Glucosídeos/farmacologia , Rede Nervosa/fisiologia , Transdução de Sinais/efeitos dos fármacos , Inibidores do Transportador 2 de Sódio-Glicose , Animais , Compostos Benzidrílicos/administração & dosagem , Expressão Gênica/efeitos dos fármacos , Glucosídeos/administração & dosagem , Humanos , Fígado/inervação , Camundongos , Núcleos da Rafe do Mesencéfalo/metabolismo , Norepinefrina/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Transportador 2 de Glucose-Sódio , Sistema Nervoso Simpático/fisiologia , Termogênese/genética , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo , Nervo Vago/fisiologia
6.
Biomed Res ; 38(2): 123-134, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28442663

RESUMO

Since osteoblastic activities are believed to be coupled with osteoclasts, we have attempted to histologically verify which of the distinct cellular circumstances, the presence of osteoclasts themselves or bone resorption by osteoclasts, is essential for coupled osteoblastic activity, by examining c-fos-/- or c-src-/- mice. Osteopetrotic c-fos deficient (c-fos-/-) mice have no osteoclasts, while c-src deficient (c-src-/-) mice, another osteopetrotic model, develop dysfunctional osteoclasts due to a lack of ruffled borders. c-fos-/- mice possessed no tartrate-resistant acid phosphatase (TRAPase)-reactive osteoclasts, and showed very weak tissue nonspecific alkaline phosphatase (TNALPase)-reactive mature osteoblasts. In contrast, c-src-/- mice had many TNALPase-positive osteoblasts and TRAPase-reactive osteoclasts. Interestingly, the parallel layers of TRAPase-reactive/osteopontin-positive cement lines were observed in the superficial region of c-src-/- bone matrix. This indicates the possibility that in c-src-/- mice, osteoblasts were activated to deposit new bone matrices on the surfaces that osteoclasts previously passed along, even without bone resorption. Transmission electron microscopy demonstrated cell-to-cell contacts between mature osteoblasts and neighboring ruffled border-less osteoclasts, and osteoid including many mineralized nodules in c-src-/- mice. Thus, it seems likely that osteoblastic activities would be maintained in the presence of osteoclasts, even if they are dysfunctional.


Assuntos
Osteoblastos/fisiologia , Osteoclastos/metabolismo , Quinases da Família src/genética , Animais , Biomarcadores , Reabsorção Óssea/genética , Reabsorção Óssea/metabolismo , Proteína Tirosina Quinase CSK , Calcificação Fisiológica , Comunicação Celular , Microambiente Celular , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Osteoblastos/ultraestrutura , Osteoclastos/ultraestrutura , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Quinases da Família src/deficiência
7.
Methods Mol Biol ; 1474: 153-70, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27515079

RESUMO

Bimolecular fluorescence complementation (BiFC) is a fluorescence imaging technique used to visualize protein-protein interactions (PPIs) in live cells and animals. One unique application of BiFC is to reveal subcellular localization of PPIs. The superior signal-to-noise ratio of BiFC in comparison with fluorescence resonance energy transfer or bioluminescence resonance energy transfer enables its wide applications. Here, we describe how confocal microscopy can be used to detect and quantify PPIs and their subcellular localization. We use basic leucine zipper transcription factor proteins as an example to provide a step-by-step BiFC protocol using a Nikon A1 confocal microscope and NIS-Elements imaging software. The protocol given below can be readily adapted for use with other confocal microscopes or imaging software.


Assuntos
Microscopia Confocal/estatística & dados numéricos , Imagem Óptica/métodos , Mapeamento de Interação de Proteínas/métodos , Fator 2 Ativador da Transcrição/genética , Fator 2 Ativador da Transcrição/metabolismo , Animais , Células COS , Chlorocebus aethiops , Transferência Ressonante de Energia de Fluorescência , Expressão Gênica , Sinais de Localização Nuclear/genética , Sinais de Localização Nuclear/metabolismo , Plasmídeos/química , Plasmídeos/metabolismo , Ligação Proteica , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Razão Sinal-Ruído , Software
8.
PLoS One ; 9(11): e112293, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25384019

RESUMO

One purpose of the EC funded project, SPIDIA, is to develop evidence-based quality guidelines for the pre-analytical handling of blood samples for RNA molecular testing. To this end, two pan-European External Quality Assessments (EQAs) were implemented. Here we report the results of the second SPIDIA-RNA EQA. This second study included modifications in the protocol related to the blood collection process, the shipping conditions and pre-analytical specimen handling for participants. Participating laboratories received two identical proficiency blood specimens collected in tubes with or without an RNA stabilizer. For pre-defined specimen storage times and temperatures, laboratories were asked to perform RNA extraction from whole blood according to their usual procedure and to return extracted RNA to the SPIDIA facility for further analysis. These RNA samples were evaluated for purity, yield, integrity, stability, presence of interfering substances, and gene expression levels for the validated markers of RNA stability: FOS, IL1B, IL8, GAPDH, FOSB and TNFRSF10c. Analysis of the gene expression results of FOS, IL8, FOSB, and TNFRSF10c, however, indicated that the levels of these transcripts were significantly affected by blood collection tube type and storage temperature. These results demonstrated that only blood collection tubes containing a cellular RNA stabilizer allowed reliable gene expression analysis within 48 h from blood collection for all the genes investigated. The results of these two EQAs have been proposed for use in the development of a Technical Specification by the European Committee for Standardization.


Assuntos
Coleta de Amostras Sanguíneas/métodos , RNA/sangue , Proteínas Ligadas por GPI/genética , Perfilação da Expressão Gênica , Humanos , Interleucina-1beta/genética , Proteínas Proto-Oncogênicas c-fos/genética , Controle de Qualidade , RNA/genética , Membro 10c de Receptores do Fator de Necrose Tumoral , Receptores Chamariz do Fator de Necrose Tumoral/genética
9.
Methods Enzymol ; 485: 25-35, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21050909

RESUMO

The angiotensin II (AngII) type 1 (AT1) receptor is a seven-transmembrane G-protein-coupled receptor that plays a regulatory role in the physiological and pathological processes of the cardiovascular system. AT1 receptor inherently shows constitutive activity even in the absence of AngII, and it is activated not only by AngII but also by AngII-independent mechanisms. Especially, mechanical stress induces cardiac hypertrophy through activation of AT1 receptor without the involvement of AngII. These AngII-independent activities of AT1 receptor can be inhibited by inverse agonists, but not by neutral antagonists. In this chapter, we describe the methods used for biochemical assessment of inverse agonism of a ligand for AT1 receptor. Their applications will improve our understanding of receptor activation and inactivation at a molecular level, and contribute to the development of AT1 receptor blockers possessing superior therapeutic efficacy in cardiovascular diseases.


Assuntos
Avaliação Pré-Clínica de Medicamentos/métodos , Agonismo Inverso de Drogas , Receptor Tipo 1 de Angiotensina/metabolismo , Animais , Western Blotting/métodos , Linhagem Celular , Técnicas Citológicas/métodos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Ligantes , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-fos/genética , Ensaio Radioligante/métodos , Estresse Mecânico , Ativação Transcricional , Transfecção/métodos
10.
Endocrinology ; 150(1): 135-43, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18772235

RESUMO

Obesity and osteoporosis are major health issues affecting millions of individuals. Transgenic mice overexpressing DeltaFosB, an activator protein-1 transcription factor, under the control of the enolase 2 (ENO2) promoter exhibit both an increase in bone density and a decrease in adipose mass. Here we demonstrate that DeltaFosB overexpression increases fatty-acid oxidation and energy expenditure, leading to a decrease in adipocyte size and adipose mass. In addition, the ENO2-DeltaFosB mice exhibit increased insulin sensitivity and glucose tolerance. Targeted overexpression of DeltaFosB in adipocytes using the adipocyte protein 2 promoter failed to induce changes in fat or in bone, showing that the effect on metabolic activity is not due to cell-autonomous effects of DeltaFosB within adipocytes. Detailed analysis of the ENO2-DeltaFosB mice demonstrated that energy expenditure was increased in muscle, independent of locomotor activity. These findings provide evidence that signaling downstream of DeltaFosB is a potential target for not only osteoporosis but also obesity and diabetes.


Assuntos
Densidade Óssea/genética , Metabolismo Energético/efeitos dos fármacos , Insulina/farmacologia , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-fos/genética , Animais , Ingestão de Energia , Ácidos Graxos/metabolismo , Camundongos , Obesidade/genética , Tamanho do Órgão/genética , Osteocalcina/metabolismo , Fosfopiruvato Hidratase/genética , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-fos/deficiência
12.
J Neural Transm (Vienna) ; 114(7): 899-908, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17318306

RESUMO

Induction of Fos protein by the potent and direct NMDA agonist (tetrazol-5-yl)glycine (TZG) was examined in mice. Effects of antipsychotic drugs were assessed on this in vivo index of NMDA receptor activation. TZG induced the expression of Fos in a neuroanatomically selective manner, with the hippocampal formation showing the most robust response. In mice genetically altered to express low levels of the NR1 subunit of the NMDA receptor, TZG-induced Fos was reduced markedly in comparison to the wild type controls. TZG-induced Fos was also blocked by the selective NMDA antagonist MK-801. Pretreatment of mice with clozapine (3 and 10 mg/kg) reduced TZG-induced Fos in the hippocampal formation but not in other brain regions. Haloperidol at a dose of 0.5 mg/kg did not antagonize TZG induced Fos in any region. Haloperidol at a dose of 1.0 mg/kg did attenuate the induction of Fos by TZG in the hippocampus but not in other brain regions. The relatively high dose (1 mg/kg) of haloperidol required to block effects of TZG suggests that this action may not be related to the D(2) dopamine receptor-blocking properties, since maximal D(2) receptor blockade was probably achieved by the 0.5 mg/kg dose of haloperidol. The antidepressant drug imipramine (10 or 20 mg/kg) did not antagonize TZG induced Fos in any brain region. The data suggest that clozapine can reduce excessive activation of NMDA receptors by TZG administration in vivo at doses relevant to the drugs' actions in rodent models of antipsychotic activity. Whether or not this action of clozapine contributes to its therapeutic properties will require further study.


Assuntos
Clozapina/farmacologia , Glicina/análogos & derivados , Haloperidol/farmacologia , N-Metilaspartato/agonistas , Proteínas Proto-Oncogênicas c-fos/biossíntese , Receptores de N-Metil-D-Aspartato/metabolismo , Tetrazóis/farmacologia , Animais , Glicina/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-fos/genética , Receptores de Glutamato Metabotrópico/deficiência , Receptores de Glutamato Metabotrópico/genética
13.
Cancer Res ; 66(4): 2385-90, 2006 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-16489045

RESUMO

Factors predicting sensitivity to epidermal growth factor receptor (EGFR) blockade are largely unknown and new strategies are being sought to individualize cancer therapy. This study evaluated the variation in the expression of the early response gene c-fos as a distal effect of EGFR inhibition and its relationship to antitumor effects. The growth-inhibitory and c-fos-modulating effects of gefitinib and erlotinib in human cancer cell lines (A431, CAL27, HN11, HuCCT1, and Hep2) were determined. Next, these cell lines were xenografted in mice and treated for 14 days with gefitinib (A431 and HuCCT1) or erlotinib (CAL27, HN11, and Hep2). Fine needle aspiration biopsy of tumors was done at baseline and after 14 days of therapy for c-fos assessment. In addition, we tested the feasibility of analyzing this marker in five paired tumor samples from a clinical trial of gefitinib in patients with solid tumors. In culture, gefitinib and erlotinib decreased c-fos mRNA levels in the susceptible cell lines A431, CAL27, and HN11; however, both drugs failed to achieve c-fos inhibition in resistant cells. Gefitinib or erlotinib abrogated the increase in c-fos expression in vivo in EGFR-sensitive A431, CAL27, and HN11 tumors but not in resistant strains. Ex vivo evaluation was feasible and predicted in vivo effects. The feasibility study in paired human tumor biopsies showed that this biomarker can be reliably measured in clinical materials. In summary, variations in c-fos expression reflect the pharmacologic actions of EGFR inhibitors in in vitro and in vivo models.


Assuntos
Biomarcadores Tumorais/análise , Receptores ErbB/antagonistas & inibidores , Genes fos/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/análise , Animais , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/genética , Linhagem Celular Tumoral , Fator de Crescimento Epidérmico/farmacologia , Cloridrato de Erlotinib , Feminino , Gefitinibe , Humanos , Camundongos , Camundongos Nus , Neoplasias/tratamento farmacológico , Neoplasias/genética , Proteínas Proto-Oncogênicas c-fos/biossíntese , Quinazolinas/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Mol Endocrinol ; 18(3): 558-73, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14673133

RESUMO

cAMP-dependent mechanisms regulate the steroidogenic acute regulatory (StAR) protein even though its promoter lacks a consensus cAMP response-element (CRE, TGACGTCA). Transcriptional regulation of the StAR gene has been demonstrated to involve combinations of DNA sequences that provide recognition motifs for sequence-specific transcription factors. We recently identified and characterized three canonical 5'-CRE half-sites within the cAMP-responsive region (-151/-1 bp) of the mouse StAR gene. Among these CRE elements, the CRE2 half-site is analogous (TGACTGA) to an activator protein-1 (AP-1) sequence [TGA(C/G)TCA]; therefore, the role of the AP-1 transcription factor was explored in StAR gene transcription. Mutation in the AP-1 element demonstrated an approximately 50% decrease in StAR reporter activity. Using EMSA, oligonucleotide probes containing an AP-1 binding site were found to specifically bind to nuclear proteins obtained from mouse MA-10 Leydig and Y-1 adrenocortical tumor cells. The integrity of the sequence-specific AP-1 element in StAR gene transcription was assessed using the AP-1 family members, Fos (c-Fos, Fra-1, Fra-2, and Fos B) and Jun (c-Jun, Jun B, and Jun D), which demonstrated the involvement of Fos and Jun in StAR gene transcription to varying degrees. Disruption of the AP-1 binding site reversed the transcriptional responses seen with Fos and Jun. EMSA studies utilizing antibodies specific to Fos and Jun demonstrated the involvement of several AP-1 family proteins. Functional assessment of Fos and Jun was further demonstrated by transfecting antisense c-Fos, Fra-1, and dominant negative forms of Fos (A-Fos) and c-Jun (TAM-67) into MA-10 cells, which significantly (P < 0.01) repressed transcription of the StAR gene. Mutation of the AP-1 site in combination with mutations in other cis-elements resulted in a further decrease of StAR promoter activity, demonstrating a functional cooperation between these factors. Mammalian two-hybrid assays revealed high-affinity protein-protein interactions between c-Fos and c-Jun with steroidogenic factor 1, GATA-4, and CCAAT/enhancer binding protein-beta. These findings demonstrate that Fos and Jun can bind to the TGACTGA element in the StAR promoter and provide novel insights into the mechanisms regulating StAR gene transcription.


Assuntos
Fosfoproteínas/genética , Fator de Transcrição AP-1/metabolismo , Transcrição Gênica , Animais , Sítios de Ligação , Proteína beta Intensificadora de Ligação a CCAAT/genética , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fator de Transcrição GATA4 , Regulação da Expressão Gênica , Humanos , Células Intersticiais do Testículo/fisiologia , Masculino , Camundongos , Mutação , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Elementos de Resposta , Fator Esteroidogênico 1 , Fator de Transcrição AP-1/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Rev Neurosci ; 5(2): 171-8, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7827709

RESUMO

Immediate early genes are rapidly and transiently induced by many stimuli and produce their transcription factors. Of the immediate early genes, the proto-oncogene c-fos and its product Fos play a role in cell proliferation, differentiation and general signal transmission as the 'third messenger' regulating the transcription of other genes. Even minute stimuli such as the attachment of electrodes, needle injection and saline administration increase the level of c-fos mRNA expression in animal brains. It is, therefore, necessary to investigate the effects of using anesthetics and solvents for drug administration on c-fos expression in order to accurately assess net c-fos induction after stimulation. Furthermore, experimental procedures might themselves affect c-fos mRNA expression in the brain after in vivo stimulation. In this review, we discuss technical pitfalls in assessing in vivo c-fos expression. Rough handling with repeated saline administration enhanced cortical c-fos mRNA expression in the rat brain after a single saline injection by increasing baseline c-fos mRNA levels. In contrast, gentle handling with repeated saline administration diminished c-fos mRNA expression after a single injection by decreasing baseline c-fos mRNA levels. These two types of handling with the repeated injection led to diametrically opposite results on c-fos mRNA expression after a single stimulation. Our results suggest that c-fos mRNA induction after a single stimulation might be affected by the types or intensities of animal handling and that effects of animal handling must be considered when estimating c-fos mRNA induction.


Assuntos
Química Encefálica/fisiologia , Expressão Gênica/fisiologia , Manobra Psicológica , Proteínas Proto-Oncogênicas c-fos/biossíntese , RNA Mensageiro/biossíntese , Animais , Química Encefálica/genética , Proteínas Proto-Oncogênicas c-fos/genética
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