Para compreensão da biologia dos tumores adrenocorticais são utilizados marcadores moleculares que em geral são genes reguladores do ciclo celular. AP-1 é um fator dimérico composto principalmente pelas proteínas JUN (JUN, JUNB e JUND) e FOS. Nesse projeto tivemos como hipótese que as proteínas da família JUN, se correlacionam com proteínas reguladoras do ciclo celular em tumores adrenocorticais, e poderiam ser utilizados no diagnóstico e prognóstico desse tipo de tumor. O objetivo foi analisar o padrão de expressão gênica e proteica (PCR e Immunobloting). A análise por PCR Array em culturas de células de tumores adrenais, mostrou que os genes da família JUN e o gene FOS estão pouco expressos nessas culturas, o que foi confirmado em ensaios de qPCR. Não foi possível determinar um padrão de expressão que diferenciasse os tipos de culturas celulares estudados, ou mesmo tumores adultos e pediátricos. Os tratamentos com ACTH aumentam a expressão da proteina JUN e JUNB, e podem ter certa importância em tumores responsivos à esse hormônio, que merecem análises futuras. / In order to have a better comprehension of adrenocortical tumor biology, molecular markers are utillized because they are in general cell cycle regulators. AP-1 is a dimeric factor, compound mainly by JUN (JUN, JUNB, JUND) and FOS proteins. In the present study, our hypothesis is that JUN proteins are correlated with others cell cycle regulatory proteins and could be utilized as a prognose and diagnostic predictor for adrenocortical tumors. To confirm our hypothesi the aim was genic and protein profile analyzes (PCR and Immunobloting). The PCR Array analysis showed that JUN and FOS gene expression were down regulated in these adrenocortical tumors cells which were confirmed through qPCR analysis. The genes expression analysis wasn´t able to stablish a standard of expression between the studied cell cultures or even between adults and pediatric tumors. The ACTH treatments increased JUN and JUNB proteins that may have some significance in responsive tumors to this hormone, and deserve further analysis.

No description available.

HTLV-1, un rétrovirus endémique des Antilles-Guyane qui infecte plus de 10 millions de personnes dans le monde, est l’agent étiologique de l’ATL, une leucémie agressive des lymphocytes T CD4+ résistante aux traitements conventionnels actuels. Le rôle émergent des miARN dans la leucémogénèse et la résistance aux chimiothérapies a soulevé des interrogations quant à leurs rôles dans le développement de l’ATL. Les miARN sont de petits ARN non codant qui régulent l’expression génique. Récemment leur altération durant le cycle de vie du HTLV-1 a été mise en lumière. Une des caractéristiques de l’émergence de l’ATL est la perte d’expression des protéines virales codées par le promoteur en amont du génome proviral (LTR5’), à l’exception d’hbz dont l’expression est initiée dans le promoteur en aval du génome proviral (LTR3’). Dans une première étude, nous démontrons, dans un modèle mimant la cellule ATL, qu’HBZ module sa propre transcription à travers une boucle de rétrocontrôle qui implique une coopération avec le facteur de transcription de la famille AP-1 JunD. Nous montrons que l’expression d’HBZ induit des caractéristiques phénotypiques de fibroblastes transformés. Nous avons, ensuite, analysé l’effet d’HBZ sur les miARN dans les cellules ATL et montré qu’il induit une diminution des miARN cellulaires via l’inhibition d’un acteur clé de la maturation, Dicer. En accord avec notre première étude, nous montrons que l’induction d’HBZ dans les CD4+ de patients ATL corrèle avec une augmentation de la charge provirale (CPV) et donc l’évolution de l’ATL. Le traitement de ces cellules au VPA inhibe l’expression d’hbz, restaure celle de dicer et inverse la CPV et donc la prolifération des cellules malignes ex vivo. / HTLV-1, a retrovirus endemic of Antilles-Guyana that infects more than 10 million people worldwide, is the etiological agent of ATL, an aggressive leukemia of CD4+ T lymphocytes resistant in currents treatments. The emerging role of miRNA in leukemogenesis and chemoresistance has risen questioning about their role in ATL development. MiRNAs are a class of non-coding RNAs that regulate gene expression. Involvement of their alteration in the HTLV-1 life cycle has recently come to light. One of the hallmarks of progression toward ATL is the emergence of LTR5’-deficient provirus and thereby eliminating the expression of all viral proteins on the sense strands in these cells, with the exception of the hbz gene regulated by an independent promoter in the 3’LTR. In a first study, using a provirus with the 5’LTR deleted, we found that HBZ modulates its own expression through a positive-feedback loop that involves cooperation with AP-1 transcription factor JunD. We also found that hbz-expressing fibroblasts displayed of a transformed phenotype. Then, we analyzed the effect of HBZ on miRNA expression in ATL patients and report that hbz reduce significantly expression of cellular miRNAs via inhibition of an enzyme essential for maturation, Dicer1. In agreement with our previous study, we show that hbz expression in ATL samples correlates with HTLV-1–provirus load (CPV) and consequently progression of the pathology. VPA treatment of these cells inhibits hbz expression, restores Dicer expression, and inverts the proviral charge thereby reducing cellular proliferation of malignant cells.

Para compreensão da biologia dos tumores adrenocorticais são utilizados marcadores moleculares que em geral são genes reguladores do ciclo celular. AP-1 é um fator dimérico composto principalmente pelas proteínas JUN (JUN, JUNB e JUND) e FOS. Nesse projeto tivemos como hipótese que as proteínas da família JUN, se correlacionam com proteínas reguladoras do ciclo celular em tumores adrenocorticais, e poderiam ser utilizados no diagnóstico e prognóstico desse tipo de tumor. O objetivo foi analisar o padrão de expressão gênica e proteica (PCR e Immunobloting). A análise por PCR Array em culturas de células de tumores adrenais, mostrou que os genes da família JUN e o gene FOS estão pouco expressos nessas culturas, o que foi confirmado em ensaios de qPCR. Não foi possível determinar um padrão de expressão que diferenciasse os tipos de culturas celulares estudados, ou mesmo tumores adultos e pediátricos. Os tratamentos com ACTH aumentam a expressão da proteina JUN e JUNB, e podem ter certa importância em tumores responsivos à esse hormônio, que merecem análises futuras. / In order to have a better comprehension of adrenocortical tumor biology, molecular markers are utillized because they are in general cell cycle regulators. AP-1 is a dimeric factor, compound mainly by JUN (JUN, JUNB, JUND) and FOS proteins. In the present study, our hypothesis is that JUN proteins are correlated with others cell cycle regulatory proteins and could be utilized as a prognose and diagnostic predictor for adrenocortical tumors. To confirm our hypothesi the aim was genic and protein profile analyzes (PCR and Immunobloting). The PCR Array analysis showed that JUN and FOS gene expression were down regulated in these adrenocortical tumors cells which were confirmed through qPCR analysis. The genes expression analysis wasn´t able to stablish a standard of expression between the studied cell cultures or even between adults and pediatric tumors. The ACTH treatments increased JUN and JUNB proteins that may have some significance in responsive tumors to this hormone, and deserve further analysis.

Fra-1 appartient à la famille des facteurs de transcription AP-1. Son expression est particulièrement élevée dans les cellules de cancer du sein qui n'expriment pas le récepteur aux œstrogènes (RE-), c'est-à-dire les cellules les plus agressives. L'inhibition de Fra-1 dans ces cellules entraîne une diminution de la motilité, de l'invasion et de la prolifération, mais elle entraîne aussi de profonds changements de morphologie. Les cellules RE-, qui présentent un phénotype mésenchymateux s'arrondissent et établissent un plus grand nombre de contacts cellule-cellule après l'inhibition de Fra-1. Dans les cellules RE-, la β-caténine est localisée au noyau ou dans le cytoplasme, ce qui est un marqueur de mauvais pronostic. Au cours de cette thèse, j'ai montré que Fra-1 régule la localisation nucléaire de la β-caténine et ainsi régule son activité transcriptionelle en agissant très tardivement sur la voie Wnt. J'ai également mis en évidence une interaction physique directe entre Fra-1 et la β-caténine qui pourrait être responsable de cet effet. De plus, l'analyse de microarrays par RT-QPCR a révélé la régulation d'autres gènes comme la mœsine, la fibronectine et l'extracellular matrix protein 1, qui pourraient également jouer un rôle dans la régulation de l'agressivité tumorale par Fra-1. Par ailleurs, Fra-1 est une protéine instable et nous avons montré qu'elle est phosphorylée et stabilisée par PKCθ. Fra-1 est d'ailleurs nécessaire à l'effet de la kinase sur la motilité cellulaire. / Fra-1 is a member of the AP-1 transcription factor family. It is aberrantly expressed in breast cancer cells lacking Estrogen Receptor (ER-) expression, which are the most aggressive ones. Fra-1 inhibition in these cells leads to a decreased in motility, invasion and proliferation, but also to deep morphologic changes. ER- cells, which present a mesenchymal phenotype, become rounder and establish a greater number of cell-cell contacts after Fra-1 inhibition. In ER- cells, β-catenin is nuclear or cytoplasmic, which is considering as a poor prognosis marker. During this PhD, I demonstrate that Fra-1, which acts very downstream in the Wnt/β-catenin signaling pathway, regulates the nuclear localization of β-catenin leading to up-regulation transcriptional activity of β-catenin. I also found that Fra-1 directly interacts with β-catenin. In addition, RT-QPCR microarrays analysis has revealed the regulation of other genes such as mœsin, fibronectin and extracellular matrix protein 1, which might also take part in the tumoral aggressiveness regulated by Fra-1. Moreover, we show that Fra-1, which is an unstable protein, is phosphorylated and stabilized by PKCθ. Furthermore, Fra-1 is necessary to mediate the kinase effect on cell motility.

La leucémie T de l’adulte (ATL) est une pathologie lympho-proliférative aiguë associée à l’infection par le virus HTLV-1 (human T-cell leukemia virus type 1). La réactivation de la télomérase observée lors de la phase tardive du développement de l’ATL est un évènement crucial dans la progression tumorale. Elle est induite au niveau transcriptionnel par la protéine HBZ (HTLV-1 bZIP factor) et est dépendante du facteur de transcription JunD. Ce dernier est normalement associé en complexe avec le produit du gène suppresseur de tumeur MEN-1, la ménine, dont l’interaction avec JunD réprime la transcription JunD-dépendante et convertit JunD en inhibiteur de croissance.Mes résultats démontrent que la protéine virale HBZ inhibe la fonction suppresseur de tumeur de la ménine, induisant l’activité transcriptionnelle de JunD et donc l’activation de la transcription de son gène cible : la transcriptase inverse télomérase humaine (hTERT). J’ai démontré que HBZ, JunD et la ménine peuvent coexister dans un même complexe protéique et que HBZ et la ménine ont des effets opposés sur l’activité transcriptionnelle de JunD. En effet la ménine inhibe l’activation du promoteur proximal d’hTERT par JunD, alors que HBZ est capable de contre balancer cet effet. Finalement, je propose qu’en recrutant l’histone acétyltransférase p300, HBZ réverse la déacétylation des histones induite par le recrutement des HDACs par la ménine et par conséquent active le promoteur d’hTERT. L’ensemble de ces résultats a permis d’identifier les mécanismes moléculaires aboutissant à l’inhibition fonctionnelle de la protéine suppresseur de tumeur ménine, résultant en la dérégulation de la voie AP-1 dans les cellules infectées par HTLV-1. Finalement, ce travail apporte de nouvelles précisions sur le mécanisme de la surexpression transcriptionnelle de la télomérase lors de l’infection par HTLV-1, une étape importante de la mise en place et du développement de la leucémie T de l’adulte vers des stades plus agressifs. / Adult T-cell leukemia (ATL) is an aggressive lymphoproliferative disorder associated with human T-cell leukemia virus type 1 (HTLV-1) infection. Reactivation of telomerase, a critical event in tumor progression observed in late phases of ATL development, has been shown to be caused by HBZ (HTLV-1 bZIP factor), a regulatory protein encoded by the negative strand of the HTLV-1 genome. The HBZ-mediated up-regulation of the telomerase catalytic subunit is dependent on JunD, which in the cellular context occurs in the complex with menin, the product of the MEN-1 tumor suppressor gene. Interaction with menin represses JunD-dependent transcription and converts JunD into a growth suppressor, whereas it acts as a growth promoter in the absence of menin. My results demonstrate that the viral protein HBZ abrogates tumor suppressor function of menin, resulting in the activation of JunD transcriptional activity and finally in the up-regulation of its target gene, the human telomerase reverse transcriptase (hTERT). I showed that HBZ, JunD and menin can coexist in the same protein complex and that HBZ and menin exert opposite effects on JunD transcriptional activity. Moreover menin inhibits the JunD-mediated activation of the hTERT proximal promoter and HBZ is able to counteract this effect. Finally, I proposed that HBZ, by recruiting p300 histone acetyltransferase, reverses the histone deacetylation conducted by menin-recruited HDACs and therefore up-regulates the expression of the hTERT gene. Altogether, my work led to the identification of the molecular mechanism leading to the functional impairment of the menin tumor suppressor, which results in the deregulation of AP-1 signaling in HTLV-1 infected cells. Finally this work gave new insights into the mechanism of the transcriptional up-regulation of the hTERT gene upon HTLV-1 infection, being a key event during the development of Adult T-cell leukemia and a necessary step towards the progression into more aggressive courses.

As células Y-1 pertencem a uma linhagem clonal de células funcionais de córtex adrenal de camundongo, que respondem a ACTH. Em células Y-1, ACTH promove a esteroidogênese (função) e tem efeitos regulatórios complexos na transição G0→G1→S do ciclo celular. ACTH promove a transição G0→G1, mas inibe a transição G1→S. É possível que a regulação do ciclo celular por ACTH seja mediada pelo controle da expressão dos proto-oncogenes das famílias fos, jun e myc. Nosso laboratório mostrou, anteriormente, que ACTH induz a expressão dos genes fos e jun, mas inibe c-myc. O objetivo deste trabalho foi identificar pontos de controle na expressão dos genes fos, jun e myc e na atividade dos fatores de transcrição AP-1 (dímeros da proteínas Fos e Jun) por ACTH, derivados de cAMP (ativadores de PKA), PMA (ativador de PKC) e FCS (soro fetal bovino). ACTH, PMA e dcAMP aumentam a atividade de ligação de AP-1 a DNA, independentemente de síntese protéica. Ensaios de elongação de cadeia nascente de RNA (run off transcription) mostram que ACTH, PMA e FCS são fortes indutores de c-fos, c-jun e junB, enquanto dcAMP induz apenas c-fos e junB. Hibridizações Northern permitiram estimar a meia-vida dos mRNAs de c-fos e c-jun em 30 min, independentemente do tratamento com ACTH ou PMA. Diferentemente de c-fos, o mRNA de fosB é superinduzido por ActinomicinaD em células Y-1 tratadas com ACTH e PMA. / The Y-1 cells belong to a clonal lineage of functional mouse adrenocortical cells, which are responsive to ACTH. In Y-1 cells, ACTH promotes esteroidogenesis (function) and has complex effects on the G0→G1→S transition of the Y-1 cell cycle. ACTH induces the G0→G1 transition but inhibits the G1+S transition. Probably, the cell cycle regulation by ACTH is mediated by the expression control of the proto-oncogenes from the fos, jun and myc families. Our laboratory has previously shown that ACTH induces the fos and jun genes expression, but inhibits c-myc expression. The target of this work was to identify control points in the fos, jun and myc genes expression and in the AP-1 transcription factors (Fos and Jun proteins dimers) by ACTH, cAMP derivatives (PKA activators), PMA (PKC activator) and FCS (Fetal Calf Serum). ACTH, PMA and dcAMP raise the AP-1 DNA binding activity, independently of protein synthesis. Run off transcription assays show that ACTH, PMA and FCS are strong c-fos, c-jun and junB inducers, while dcAMP induces only c-fos and junB. Northern hybridisations allowed us to estimate the half life of the fos and jun mRNAs in about 30 min, independently of ACTH or PMA treatment. Differently of c-fos, fosB mRNA is superinduced by ActinomicinD treatment in Y-1 cells treated with ACTH or PMA.

Aktivator Protein-1 (AP-1) ist ein kollektiver Terminus für dimerische Transkriptionsfaktoren, die sich aus Fos- und Jun- Proteinen zusammensetzen. Diese Untereinheiten binden an eine gemeinsame, spezifische DNA-Sequenz, die AP-1 Bindungsstelle. Zusätzlich zu der gut dokumentierten Rolle des c-Fos Proteins in der Tumorgenese, wo dieses Gen als ein Aktivator beschrieben ist, übt AP-1 einen Einfluss auf mesenchymale Stromazellen und Immunzellen aus. Mesenchymale Knochenmarkszellen sind die Vorläuferzellen für Adipozyten, Osteoblasten, Chondrozyten, Myozyten und Fibroblasten. Die molekularen Mechanismen, welche die Differenzierungen regeln, sind noch weitgehend unerforscht. Der heterodimere Transkriptionsfaktor AP-1 übt eine wichtige Rolle in der Kontrolle der Zelldifferenzierung aus. Verschieden genetisch veränderte Mausmodelle untermauerten dies. Mäuse, welche das Fos-related antigen-1 (Fra1) oder eine kürzere Protein-Isoform von FosB (deltaFosB) überexpremieren, entwickelten, durch eine beschleunigte Differenzierung der Osteoblasten, eine Osteosklerose. Interessanterweise konnte gezeigt werden, dass die transgenen deltaFosB Mäuse weniger Fett haben. Die Stabilität und Aktivität von Fos Proteinen kann durch post-transkriptionale Modifizierungen geregelt werden. Basierend auf knockout Mausmodellen, wurde eine tragende Rolle für das wachstumsregulierende Enzym Rsk2 postuliert. Rsk2 spielt eine mögliche Rolle bei der Ausdifferenzierung von mesenchymalen Vorläuferzellen zu Osteoblasten und Adipozyten. Das Ziel dieser Arbeit war es molekulare Mechanismen zu finden, welche die unterschiedlichen Phänotypen (wild typ, fra1-tg, rsk2-defizient und fra1-tg/rsk2-defizient) charakterisieren. Die Knochenuntersuchungen der verschiedenen Genotypen zeigten, dass Fra1 und Rsk2, unabhängig voneinander, tragende Rollen im Knochenmetabolismus spielen. Quantitative Analysen von Adipozytenmarker, wie PPARgamma und C/EBPalpha zeigten, dass das Protein Fra1 die Adipozytenreifung in vivo und in vitro reguliert. Zusätzlich entwickelten die „doppel-mutierten“ fra1-tg/rsk2-/y Mäuse einen Lipodystrophy. Ein milderer Phänotyp wurde in den fra1-tg Tieren beobachtet, jedoch nicht in den Rsk2-knockout Mäusen. Zusätzlich wurde beobachtet, dass mesenchymale Zellen, welche Fra1 überexprimieren, gegen Glucocorticoid-induzierte Wachstumshemmung resistent waren. Diese Wirkung kann am wahrscheinlichsten durch die Fra1-vermittelte Suppression des Glucocorticoidrezeptors erklärt werden. Außerdem beeinflusste die Überexpression von Fra1 die Milzentwicklung. Leber und Herzanalysen zeigten, dass Fra1 kollagenhaltiges Gewebe induziert. Krankheiten wie Cholangitis und Fibrosen waren die Folge. / AP-1 transcription factor is a general name for multiple dimers formed by the association of Fos (or ATF) and Jun proteins. AP-1 acts as a sensor of changes in the cellular environment and thus, it is implicated in the modulation of cell proliferation, differentiation, transformation and cell death. Besides the well-documented role of c-Fos protein in oncogenesis, where this gene can function as a tumor promoter, AP-1 proteins are being recognized as regulators for mesenchymal stromal cell development and as regulators of immune cells. The mesenchymal stromal cells are the common progenitors for various mesenchymal lineages such as adipocytes, osteoblasts, chondrocytes, myocytes and fibroblasts. AP-1 seems to play a key role in the control of mesenchymal cell fate decision and differentiation. This is suggested by phenotypes of mice with a genetic modifications in either the Jun or the Fos component of AP-1. In particular, mice overexpressing the Fos-related antigen-1 (Fra1) or the short isoform of FosB (deltaFosB) have been found to develop osteosclerosis due to an accelerated differentiation of osteoblasts. Interestingly, mice overexpressing deltaFosB also developed less fat tissue. The activity of Fos proteins can be regulated by post-transcriptional modification. Based on knockout mouse model, a role for the growth factor regulated kinase Rsk2 was proposed in the differentiation of mesenchymal stromal cells to osteoblasts as well as in fat tissue development. Goal in this study was to identify the molecular mechanisms explaining the differences between the wild type, fra1-tg, rsk2-deficient and fra1-tg/rsk2-deficient phenotypes. The comparison of the bones of the different mice genotypes revealed, that Fra1 and Rsk2 were independently regulating bone metabolism. Quantitative analysis of adipocyte markers expressions, like PPARgamma and C/EBPalpha revealed, that Fra1 overexpression was blocking adipocyte maturation in vivo and in vitro. Moreover, the in vivo results show that the fra1-tg/rsk2-/y mice develop a severe lipodystrophy. A milder phenotype was observed in the parental fra1-tg strain but not in the Rsk2 knockout strain. Additionally, it was been observed, that mesenchymal cells overexpressing Fra1 were resistant to glucocorticoid-induced growth inhibition. This effect can most likely be explained by Fra1-mediated downregulation of the glucocorticoid receptor. Furthermore, Fra1 overexpression influenced spleen development. Liver and heart analyses showed that Fra1 overexpression induced collagen tissue. Diseases like cholangitis and fibrosis were the outcome.

A dor neuropática pode ser causada por lesões e/ou disfunções no sistema somatossensorial. Nestes tipos de dores, alterações plásticas ao longo de todo o sistema sensorial nociceptivo estão associadas à cronificação do processo doloroso. A plasticidade observada pode ser resultante da indução e/ou repressão de genes, os quais geralmente são modulados por fatores de transcrição. Um dos principais fatores de transcrição até então conhecido é a proteína ativadora-1 (AP-1), que pode ser estruturalmente formado principalmente por proteínas das famílias Jun e Fos. Entretanto, na dor neuropática, a participação e o papel do AP-1 não estão bem elucidados. Dessa forma, a hipótese deste trabalho é que a ativação do AP-1 contribua para a indução e/ou manutenção da dor neuropática, através da ativação de células gliais e de proteinocinases ativadas por mitógenos (MAPK) e por indução da produção e liberação de mediadores pró-inflamatórios, bem como de metaloproteinases da matriz extracelular (MMP) na medula espinal. Esses fatores contribuem para sensibilização central causada pela SNI, facilitando a transmissão dolorosa. Assim, a inibição do AP-1 seria uma potencial estratégia terapêutica no tratamento da dor neuropática. Foi utilizado o modelo experimental de dor neuropática de lesão limitada do nervo isquiático (SNI, Spared Nerve Injury) em camundongos, os quais receberam injeção intratecal (i.t.) do inibidor de AP-1, SR11302, ou seu veículo (DMSO, tween® 20 e salina). O tratamento com o inibidor de AP-1 reduziu a hipernocicepção mecânica causada pela SNI, e o perfil de redução sugeriu que esse fator de transcrição esteja relacionado com a manutenção da dor neuropática. No sétimo dia após a SNI, observou-se na medula espinal dos camundongos, ativação da microglia, dos astrócitos e das MAPK, além de aumento na expressão de TNF-, interleucina (IL)-6, IL-1, IL-17A, quimiocina derivada de queratinócito (KC), proteína quimiotáxica de monócitos (MCP-1), óxido nítrico (NO), NO sintase induzível e das MMP-2 e -9. Todos esses eventos estão associados à sensibilização central, portanto, contribuem para a facilitação da transmissão nociceptiva. O tratamento com o inibidor de AP-1 SR11302 impediu, pelo menos parcialmente, a ativação das células gliais e das MAPK e bloqueou o aumento na expressão de todos esses mediadores pró-inflamatórios e das MMPs na medula espinal. Assim, o fator de transcrição AP-1 e, consequentemente, suas vias a jusante (downstream) são potenciais alvos farmacológicos no tratamento da dor neuropática. / Neuropathic pain results from nerve damage or dysfunction, which is associated to the painful process of chronification. This process may include participation of the inducible genes, which may be modulated by transcription factors, including the activator protein-1 (AP-1), which can structurally be formed by proteins from Jun and Fos families. However, the participation and the role of AP-1 neuropathic pain remain unclear. Our hypothesis is that the activation of AP-1 would contribute for the induction and/or maintenance of neuropathic pain, by inducing the glial cells activation and mitogen-activated protein kinases, and by inducing the production/release of pro-inflammatory mediators and extracellular matrix metalloproteinase (MMP) in mices spinal cord. All these factors are contributing to SNI-evoked central sensitization, facilitating pain transmission. Thus, inhibition of AP-1 would be a potential drug target in the treatment of neuropathic pain. The animals received inhalatory anesthesia (2% isoflurane) and were submitted to an experimental model of neuropathic pain Spared Nerve Injury (SNI). The animals were treated intrathecally (i.t.) with AP-1 inhibitor SR11302 or vehicle (DMSO, tween®20 and saline). Treatment with AP-1 inhibitor reduced the SNI-induced mechanical hypernociception, suggesting that this transcription factor is related to the maintenance of neuropathic pain. On the seventh day after SNI, there was in the spinal cord of mice microglia, astrocytes and MAPK activation, increased of expression of TNF-, interleukin (IL)-6, IL-1, IL-17A, keratinocyte-derived chemokine (KC), monocyte chemoattractant protein-1 (MCP-1), nitric oxide (NO) and inducible NO synthase, and increased the expression of MMP-2 and -9. All of these effects are related with central sensitization, thus facilitating nociceptive transmission. However, treatment with SR11302 prevented, at least partially, activation of MAPK and glial cells, as well as prevented the increase in expression of all these pro-inflammatory mediators and MMPs in the spinal cord. Thus, inhibition of AP-1 and hence its way downstream is a potential pharmacological target in the treatment of neuropathic pain.

Existem evidências que o hormônio adrenocorticotrópico (ACTH) tem um papel importante no equilíbrio entre proliferação e morte celular na glândula supra-renal. As proteínas dos genes de resposta primária, proteínas da família Fos e Jun são componentes do fator de transcrição AP1, que dependendo de sua composição, pode estar relacionado com proliferação, diferenciação ou morte celular. Nesse trabalho utilizamos culturas de células primárias de adrenal de ratos para avaliar por imunocitoquímica e por imunoblotting, os efeitos do ACTH e do FGF2, na expressão das proteínas c-Fos, FosB, Fra1, Fra2, c-Jun, JunB e JunD. Os resultados mostram que tratamentos com ACTH e FGF2 modificam o padrão de expressão dessas proteínas. O ACTH induz aumento consistente da expressão de JunB, o que sugere uma composição de AP1 formada por JunB/c-Fos ou FosB. Tratamentos com FGF2, indicam a formação de um complexo c-Jun/c-Fos, FosB e Fra2. Esses resultados estão de acordo com os efeitos biológicos observados da ação do ACTH e do FGF2, como, inibição e proliferação celular nessas células. / There are evidences that in vivo the adrenocorticotropic hormone (ACTH) displays an important role in the balance of proliferation and cellular death in the adrenal gland. The early response gene proteins, Fos and Jun family, are components of the transcription factor AP-1 that, depending on its composition, could be related with proliferation, differentiation or cellular death. In this work we have been used adrenocortex cells of rat primary cultures, to evaluate, by immunocytochemistry and immunoblotting, the effects of ACTH and FGF2, in the expression of c-Fos, FosB, Fra1, Fra2, c-Jun, JunB and JunD proteins, and in such wise as to predict the composition of AP1 complex. The results showed that ACTH and FGF2 treatments modify the expression pattern of these proteins, inducing consistent and expressive increase of JunB expression in the ACTH-treated cells, suggesting an AP1 composition with JunB/c-Fos or FosB. FGF2 treatments indicate the composition of c-Jun/c-Fos or FosB or Fra-2 complexes. These results are in agreement with the biological effects observed in rat adrenal primary culture treated with ACTH and FGF2, with inhibition and cellular proliferation.