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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Μοριακοί μηχανισμοί που ενέχονται στην παθογένεια των νεοπλασμάτων των ωοθηκών

Γιοπάνου, Ιωάννα 09 July 2013 (has links)
Ο καρκίνος εκ του επιθηλίου επιφανείας των ωοθηκών είναι η 5η πιο κοινή αιτία θανάτου σε γυναίκες στο Δυτικό κόσμο και είναι υπεύθυνος για τους περισσότερους θανάτους από ότι όλες οι γυναικολογικές κακοήθειες μαζί. Τόσο ο μηχανισμός του νεοπλαστικού μετασχηματισμού όσο και τα μοριακά μονοπάτια που οδηγούν στο ωοθηκικό επιθηλιακό καρκίνωμα δεν έχουν εξακριβωθεί πλήρως. Ένα πρόσφατα αναγνωρισμένο γονίδιο, η μετατχερίνη (MTDH), γνωστή και ως AEG-1 ή LYRIC ενοχοποιείται ως πιθανός σημαντικός διαμεσολαβητής κατά την καρκινογένεση, την μετάσταση και την αντίσταση στις χημειοθεραπείες. Ωστόσο, η κλινική σημασία και ο βιολογικός ρόλος της μετατχερίνης (MTDH), στο επιθηλιακό καρκίνωμα των ωοθηκών δεν έχουν γίνει αποσαφηνισθεί πλήρως. Η υπερέκφραση της MTDH/AEG-1 μπορεί να ενεργοποιήσει πολλά σηματοδοτικά μονοπάτια, όπως για παράδειγμα το NF-κΒ σηματοδοτικό μονοπάτι σε διάφορους καρκινικούς τύπους. Ο NF-κΒ έχει πρόσφατα συσχετισθεί με την ανάπτυξη και την εξέλιξη των όγκων και επιπλέον τα διμερή του NF-κΒ ενισχύουν την έκφραση ποικίλων γονιδίων που αφορούν την κυτταρική αύξηση, τη διαφοροποίηση, τις φλεγμονώδεις αντιδράσεις και τη ρύθμιση της απόπτωσης. Η παρούσα μελέτη σχεδιάστηκε προκειμένου να διερευνηθεί η έκφραση των πρωτεϊνών MTDH και NF-kB (p65/p50) σε επιθηλιακά ωοθηκικά καρκινώματα (καλοήθεις, οριακής κακοήθειας και διηθητικά καρκινώματα). Για το σκοπό αυτό μελετήθηκαν τμήματα επιθηλιακών νεοπλασμάτων ωοθηκών από 76 ασθενείς (15/46 οριακής κακοήθειας όγκοι, 30/46 διηθητικά αδενοκαρκινώματα και 31/76 κυσταδενώματα), μονιμοποιημένα σε ουδέτερη φορμόλη και εγκλεισμένα σε παραφίνη με τη μέθοδο της ανοσοϊστοχημείας για την έκφραση των πρωτεϊνών MTDH και NF-κB (p50/p65). Επίσης εκτιμήθηκε η σχέση της MTDH/AEG-1 με τον NF-κB και με κλινικοπαθολογοανατομικές παραμέτρους όπως ο βαθμός κακοήθειας του όγκου, το στάδιο, η μέγιστη διάμετρος του όγκου και η ηλικία της ασθενούς. Τα αποτελέσματα της ανοσοϊστοχημείας αναλύθηκαν με τη χρήση του στατιστικού πακέτου SPSS. Ο φυσιολογικός ωοθηκικός ιστός και τα κυσταδενώματα ήταν κυρίως αρνητικά για τις πρωτεΐνες MTDH/AEG-1 και NF-κB (p50, p65). Η έκφραση των MTDH/AEG-1 και NF-kappa B/ p50, πρωτεϊνών ήταν σημαντικά αυξημένες στα αδενοκαρκινώματα σε σχέση με τους οριακής κακοήθειας όγκους. Σε αντίθεση η έκφραση της NF-kappa B/ p65 πρωτεΐνης δεν έδειξε σημαντικές διαφορές μεταξύ των οριακής κακοήθειας όγκων και των αδενοκαρκινωμάτων. Σημαντική στατιστική συσχέτιση παρατηρήθηκε στην έκφραση των πρωτεϊνών MTDH/AEG-1, NF-kappa B/p50 και NF-kappaB/p65 στα αδενοκαρκινώματα. Καμία στατιστική συσχέτιση δεν παρατηρήθηκε στην έκφραση μεταξύ του NF-κB, της MTDH πρωτεΐνης και κλινικοπαθολογοανατομικών παραμέτρων. Συμπερασματικά, τα αποτελέσματα μας υποδεικνύουν ότι η MTDH/AEG-1 ίσως παίζει ένα σημαντικό ρόλο στην παθογένεια του ανθρώπινου ωοθηκικού καρκίνου, πιθανώς μέσω της ενεργοποίησης του σηματοδοτικού μονοπατιού του πυρηνικού μεταγραφικού παράγοντα NF-κB. Επειδή η MTDH συσχετίζεται σημαντικά με την αντίσταση στη χημειοθεραπεία, θα μπορούσε ενδεχομένως να αποτελέσει σημαντικό στόχο για θεραπεία, ενισχύοντας την αποτελεσματικότητα της χημειοθεραπείας στον επιθηλιακό ωοθηκικό καρκίνο. / Epithelial ovarian cancer is the fifth most common cause of cancer death in women in the Western world and the leading cause of death from gynaecological malignancies. Little is known about the mechanism of neoplastic transformation and the molecular events leading to epithelial ovarian cancer are poorly understood. A recently discovered gene, metadherin (MTDH, also known as AEG-1 or LYRIC) has emerged as a potentially crucial mediator of tumor progression, metastasis, and resistance to chemotherapies. The clinical significance and biological role of metadherin (MTDH), in epithelial ovarian carcinoma however, remains unclear. Overexpression of MTDH/AEG-1 can activate several downstream pathways, including the NFκB pathway in various types of cancer cells. Recently, NF-kB has been related to cancer development and progression and NF-kB dimers (p50/p65) could induce the expression of various genes regarding cell growth, differentiation, inflammatory responses and the regulation of apoptosis. This study was designed in order to determine the expression of the MTDH and NF-kB (p65/p50) proteins in epithelial ovarian tumors (benign, borderline and malignant). Formalin-fixed and paraffin embedded tissue blocks from 76 patients with epithelial ovarian neoplasms (15/46 borderline tumors, 30/46 invasive adenocarcinomas and 31/76 cystadenomas) were studied. Expressions of MTDH/AEG-1, NF-κB (p50, p65) were investigated immunohistochemically. The relationship of MTDH/AEG-1 with NF-κB and clinicopathological parameters such as tumor grade, stage, tumor maximal diameter and patient age were evaluated. The results of immunohistochemistry were analyzed with the SPSS statistic analyze protocol. Normal ovarian tissue and benign ovarian cystadenomas were mostly MTDH/AEG-1, NF-κB (p50, p65) negative. The expression of MTDH/AEG-1 and NF-kappaB p50, proteins were significantly higher in adenocarcinoma tissue in comparison with borderline tumors. In contast NF-kappaB p65 expession shows no significant differences between borderline tumors and adenocarcinomas. A statistical significant correlation was observed between MTDH/AEG-1 and NF-kappaB p50, p65 protein expression in adenocarcinomas. No statistical correlation was observed between the NF-Kb and MTDH protein expression and clinicopathological parameters. In conclusion our data indicate that the upregulation of MTDH/AEG-1 may play an important role in the pathogenesis of human ovarian cancer possibly through activation of Nuclear factor-κB signalling pathway. Since MTDH has also a significant correlation with chemoresistance could be an important therapeutic target enhancing chemotherapy efficacy in ovarian epithelial cancer.
22

Expressão do fator de transcrição nuclear kB (NF-kB) em neurônios ocitocinérgicos de ratos submetidos à sobrecarga salina : influência da dexametasona / Expression of nuclear transcription factor kB (NF-kB) in rat ocxytocinergic neurons submitted to salt loading : the influence of dexamethasone

Santos, Patricia Rabelo dos 27 January 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The hypothalamic-neurohypophysial system is the main system through which the brain maintains homeostasis of bodily fluids. Specifically, the supraoptic (SON) and paraventricular (PVN) hypothalamic nuclei are directly involved with hydroelectrolytic equilibrium and are specialized in the synthesis and secretion of vasopressin and oxytocin (OT). Changes in the milieu intérieur are conceived as stressors by the central nervous system (CNS) and are modulated by the hypothalamic-pituitary-adrenal axis (HPA). Nuclear transcription factor kappa B (NF-κB) mediates immunosuppressant and anti-inflammatory of glucocorticoids. Thus, the aim of this study was to verify the expression profile of component p65 of the NF-κB classical pathway in SON and PVN oxytocinergic neurons in response to dehydration, glucocorticoid treatment, and in normal conditions. Methods: Wistar rats (250-300g) were maintained in controlled environment with temperature (23 ± 2ºC), light/dark cycle of 12 hours and water and food specific for rodents ad labitum until the beginning of experimental period. All procedures were approved by Ethical Comitee of Research with Animals from UFS (Protocol # 60/2012). Animals were grouped into Control (water ad libitum for 4 days, n = 6-7); Control + Dexa (water ad libitum and treated with dexamethasone, n = 6-7); SL4 (salt overloading ad libitum, 1.8% NaCl for 4 days, n = 6-7); SL4 + Dexa (salt overloading ad libitum, 1.8% NaCl for 4 days and dexamethasone, n = 6-7). Dexamethasone (10 mg/kg i.p.) was administered 12 and 2 hours before perfusion and removal of brains for OT/p65 immunofluorescence, or before sacrifice for blood sampling and angiotensin II (ANGII) dosage. We applied two-way ANOVA and Bonferroni posthoc test to analyze behavioral and hormonal dosage data. Results obtained from imunohistochemestry for evaluation of oxytocin and/or p65 neuronal activity, were subjected to qualitative evaluation. We verified SL4 animals ingested more fluid than control, on second (p<0.01), third (p<0.01) and forth (p<0.001) experimental day. SL4 also increased plasmatic concentration of ANGII (p<0.01). Qualitative analysis of double labeling OT/p65 on PVN and SON revealed a weak immunoreactivity for oxytocin on SL4 and SL4 + Dexa groups, when compared to control and Control + Dexa groups. Was observed expression of p65 subunit of NF-κB in all hypothalamic studied areas, with predominant cytoplasmic imunoreactivity in all groups. These data demonstrate that p65 subunit of NF-κB are present in oxytocinergic neurons from the most important hypothalamic areas that integrates the stress axis (HPA) and hidroelectrolyte balance (SHNH). More studies are necessary to clarify the real participation of NF-κB intracellular pathway evoked by intracellular dehydration on endocrines and behavioral hidroelectrolyte adjustments. / O sistema hipotálamo neuro-hipofisário (SHNH) é o principal sistema pelo qual o cérebro mantém a homeostase dos líquidos corporais. Especificamente, os núcleos supra-óptico (SON) e paraventricular (PVN) do hipotálamo estão diretamente envolvidos com o controle do balanço hidroeletrolítico e são especializados na síntese e secreção de vasopressina (AVP) e ocitocina (OT). Alterações no milieu intérieur são vistas como estressoras pelo sistema nervoso central (SNC) e moduladas pelo eixo hipotálamo-hipófise-adrenal (HHA). O fator de transcrição nuclear kappa B (NF-κB) é conhecido por mediar os efeitos imunossupressores e anti-inflamatórios dos glicocorticoides. Sendo assim, o objetivo do presente estudo foi verificar o perfil de expressão do componente p65 da via clássica do NF-κB em neurônios ocitocinérgicos do PVN e SON, em resposta à desidratação crônica, associada, ou não, ao tratamento com glicocorticoides. Métodos: Ratos wistar (250-300 g) foram mantidos em ambiente com temperatura (23 ± 2ºC) e luminosidade, ciclo claro-escuro de 12 horas (luz das 6 às 18 horas), controladas, com água e ração específica para roedores (Labina®- Purina) ad libitum até o início dos experimentos. Todos os procedimentos foram aprovados pelo Comitê de Ética em Pesquisa com Animais da UFS (Protocolo # 60/2012). Os animais foram divididos de modo a constituir os grupos Controle (ratos com acesso à água ad libitum, durante quatro dias, n = 6 - 7); Controle + Dexa (ratos com acesso à água ad libitum, durante quatro dias, e tratados com dexametasona, n = 6 - 7); SL4 (ratos com acesso à sobrecarga salina ad libitum, solução de NaCl 1,8%, durante quatro dias, n = 6 - 7); SL4 + Dexa (ratos com acesso à sobrecarga salina ad libitum, NaCl 1,8%, durante quatro dias e tratados com dexametasona, n = 6 - 7). A dexametasona (10 mg / kg, i.p.) foi administrada apenas no 4º dia, 12h e 2 h antes da perfusão para coleta do cérebro e realização da dupla imunofluorescência OT/p65 ou eutanásia para coleta de sangue do tronco e posterior dosagem de angiotensina II (ANGII). Os dados comportamentais e de dosagem hormonal obtidos foram submetidos ao teste ANOVA de duas vias e pós-teste Bonferroni. Os resultados obtidos da imuno-histoquímica, para a marcação de neurônios expressando ocitocina e/ou p65, foram submetidos à avaliação qualitativa. Verificou-se que os animais SL4 ingeriram mais fluido que seus controles, no segundo (p < 0,01), terceiro (p < 0,001) e quarto (p < 0,001) dia experimental. A SL4 elevou a concentração plasmática de ANGII (p < 0,01). A análise qualitativa da dupla imunofluorescência OT/p65 no PVN e SON revelou uma fraca imunorreatividade à ocitocina nos grupos SL4 e SL4 + Dexa, quando comparados aos grupos Controle e Controle + Dexa. Observou-se expressão da subunidade p65 do NF-κB em todas áreas hipotalâmicas estudadas, com imunorreatividade predominantemente citoplasmática em todos os grupos. Estes dados mostram que a subunidade p65 do NF-κB está presente em neurônios ocitocinérgicos das principais áreas hipotalâmicas que integram os eixos do estresse (HHA) e do equilíbrio hidroeletrolítico (SHNH). Mais estudos são necessários a fim de esclarecer sobre a real participação da via intracelular do NF-κB evocada pela desidratação intracelular, nos ajustes hidroeletrolíticos endócrinos e comportamentais.
23

Death-Associated Protein Kinase Regulates Vascular Smooth Muscle Cell Signaling and Migration

Blue, Emily Keller 16 March 2011 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Cardiovascular disease is the number one cause of death for Americans. New treatments are needed for serious conditions like atherosclerosis, as it can lead to stroke and heart attack. Many types of cells contribute to the progression of cardiovascular disease, including smooth muscle cells that comprise the middle layers of arteries. Inappropriate growth and migration of smooth muscle cells into the lumen of arteries has been implicated in vascular diseases. Death associated protein kinase (DAPK) is a protein that has been found to regulate the survival and migration of cancer cells, but has not been well characterized in vascular cells. The objective of this work was to determine the signaling pathways that DAPK regulates in smooth muscle cells. These studies have focused on smooth muscle cells isolated from human coronary arteries (HCASM cells). We have determined that HCASM cells depleted of DAPK exhibit more rapid migration, showing that DAPK negatively regulates migration of vascular cells. Results from a focused RT-PCR array identified matrix metalloproteinase 9 (MMP9) as a gene that is increased in cells depleted of DAPK. MMP9 is an important enzyme that degrades collagen, a component of the extracellular matrix through which smooth muscle cells migrate during atherosclerosis. We found that DAPK regulates phosphorylation of the NF-kappa B transcription factor p65 at serine 536, a modification previously found to correlate with increased nuclear levels and activity of p65. In DAPK-depleted HCASM cells, there was more phosphorylation of p65, which causes increased MMP9 promoter activity. Additional experiments were conducted using transgenic mice in which the DAPK gene has been deleted. By studying these mice, we have determined that under some circumstances DAPK augments maximal MMP9 levels in mouse carotid arteries which have been injured by ligation surgery via other signaling pathways. MMP9 has been previously implicated as a protein that promotes vascular diseases such as atherosclerosis. Our research in identifying DAPK as a regulator of MMP9 expression identifies a new target for treatment of vascular diseases like atherosclerosis.
24

The Role of ApoE and Liver X Receptors in Alzheimer's Disease

Jiang, Qingguang 23 June 2008 (has links)
No description available.
25

The effect of androstenediol on gene expression and NF-κB activation in vitro

Farrow, Michael John 30 August 2007 (has links)
No description available.
26

The nuclear pore complex and its transporters : from virus-host interactors to subverting the innate antiviral immunity

Gagné, Bridget 05 1900 (has links)
Les virus ont besoin d’interagir avec des facteurs cellulaires pour se répliquer et se propager dans les cellules d’hôtes. Une étude de l'interactome des protéines du virus d'hépatite C (VHC) par Germain et al. (2014) a permis d'élucider de nouvelles interactions virus-hôte. L'étude a également démontré que la majorité des facteurs de l'hôte n'avaient pas d'effet sur la réplication du virus. Ces travaux suggèrent que la majorité des protéines ont un rôle dans d'autres processus cellulaires tel que la réponse innée antivirale et ciblées pas le virus dans des mécanismes d'évasion immune. Pour tester cette hypothèse, 132 interactant virus-hôtes ont été sélectionnés et évalués par silençage génique dans un criblage d'ARNi sur la production interferon-beta (IFNB1). Nous avons ainsi observé que les réductions de l'expression de 53 interactants virus-hôte modulent la réponse antivirale innée. Une étude dans les termes de gène d'ontologie (GO) démontre un enrichissement de ces protéines au transport nucléocytoplasmique et au complexe du pore nucléaire. De plus, les gènes associés avec ces termes (CSE1L, KPNB1, RAN, TNPO1 et XPO1) ont été caractérisé comme des interactant de la protéine NS3/4A par Germain et al. (2014), et comme des régulateurs positives de la réponse innée antivirale. Comme le VHC se réplique dans le cytoplasme, nous proposons que ces interactions à des protéines associées avec le noyau confèrent un avantage de réplication et bénéficient au virus en interférant avec des processus cellulaire tel que la réponse innée. Cette réponse innée antivirale requiert la translocation nucléaire des facteurs transcriptionnelles IRF3 et NF-κB p65 pour la production des IFNs de type I. Un essai de microscopie a été développé afin d'évaluer l’effet du silençage de 60 gènes exprimant des protéines associés au complexe du pore nucléaire et au transport nucléocytoplasmique sur la translocation d’IRF3 et NF-κB p65 par un criblage ARNi lors d’une cinétique d'infection virale. En conclusion, l’étude démontre qu’il y a plusieurs protéines qui sont impliqués dans le transport de ces facteurs transcriptionnelles pendant une infection virale et peut affecter la production IFNB1 à différents niveaux de la réponse d'immunité antivirale. L'étude aussi suggère que l'effet de ces facteurs de transport sur la réponse innée est peut être un mécanisme d'évasion par des virus comme VHC. / Viruses interact with cellular factors in order to successfully replicate and propagate in host cells. Germain et al. (2014) performed a proteomics analysis to elucidate viral-host interactors of hepatitis C virus (HCV). They found that the majority of host factors did not have an effect on viral replication, suggesting that these host proteins may be beneficial to the virus by affecting other cellular processes such as evading the innate antiviral immunity. To test that hypothesis, 132 virus-host interactors were selected and silenced by RNAi for their effect on inteferon-beta (IFNB1) production as a readout of the innate antiviral response. 53 were found to modulate the response with enrichment in the gene ontology (GO) terms related to nucleocytoplasmic transport and the nuclear pore complex. An interesting point is that the genes associated with these terms (CSE1L, KPNB1, RAN, TNPO1, and XPO1) were previously elucidated as HCV NS3/4A interactors by Germain et al. (2014), as well as positive regulators of the innate antiviral response. Although it is surprising that a cytoplasmic-replicating virus like HCV would interact with proteins associated with the nucleus, we proposed that viruses interact with these proteins for their benefit to interfere with the innate immune response. The innate antiviral response requires the nuclear translocation of IRF3 and NF-κB p65 for the production of type I interferons. As it is unclear which transporters or nucleoporins are involved, 60 genes associated with the nuclear pore complex and nucleocytoplasmic transport were studied for their effect on the nuclear translocation of IRF3 and NF-κB p65 via a microscopy-based RNAi screen during a 10-hour viral infection time course. Overall, the study revealed that many of these proteins are involved in the trafficking of these transcription factors during a viral infection, and can affect the production of IFNB1 at different levels of the innate antiviral response. The study also suggests that the effect of these transport factors on the immune response may be an evasion mechanism for viruses such as HCV.
27

Mecanismes de regulació en l'activitat biològica del factor de transcripció Snail

Domínguez Solà, David 03 April 2003 (has links)
Els factors de transcripció de la família Snail són fonamentals en la "transició epiteli-mesènquima", procés morfogènic essencial en el desenvolupament embrionari i en els fenòmens metastàsics tumorals.En els mamífers l'activitat d'Snail és modulada per dos mecanismes. (i) En el promotor humà es troben regions definides de resposta a factors repressors, predominants en les cèl·lules epitelials, i elements diferenciats de resposta a inductors de la "transició epiteli-mesènquima". (ii) L'activitat d'Snail és condicionada també per la seva localització subcel·lular, modulada per mecanismes no transcripcionals: la fosforilació d'Snail determina si és o no exclós del nucli. Al citosol no pot actuar com a repressor transcripcional però pot interaccionar amb la xarxa microtubular, que estabilitza i en condiciona el dinamisme. Això coincideix amb l'activació de la GTPasa RhoA i la reorientació dels filaments de vimentina, fets associats a l'adquisició de capacitat migratòria. L'efecte com a repressor transcripcional i la modulació del dinamisme microtubular són possiblement esdeveniments coordinats necessaris per al rol biològic d'Snail en mamífers. / Snail family of transcription factors is fundamental to the "epithelial-mesenchymal transition", morphogenic process essential to embryonic development and metastatic phenomena in tumors.Snail's activity is modulated in two ways in mammals. (i) The human promoter harbors definite regions that respond to repressor factors, which prevail in epithelial cells; and differentiated elements that respond to known inducers of the "epithelial-mesenchymal transition". (ii) Snail's activity is also conditioned by its subcellular localization, mechanism not dependent on its transcriptional control: Snail phosphorylation determines whether Snail is excluded or not from the nucleus. When in the cytosol, Snail is unable to act as a transcriptional repressor, but however binds to the microtubular meshwork, which becomes stabilized and whose dynamism is conditioned as a result. This fact coincides with the activation of the RhoA GTPase and reorientation of vimentin filaments, both phenomena being related to the acquisition of cell motility. The transcriptional repressor and the microtubule dynamics effects are probably two coordinated events necessary to Snail's biological role in mammals.

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