• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 12
  • 11
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 52
  • 12
  • 11
  • 10
  • 9
  • 8
  • 8
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 5
  • 5
  • 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.
1

Regulação da expressão gênica de FASL pela PGE2 em linfócitos T CD4+: papel do repressor transcricional ICER. / Regulation of FASL gene expression by PGE2 in CD4+ T lymphocytes: role of transcriptional repressor ICER.

Souza, Cristiane Naffah de 17 March 2014 (has links)
Os linfócitos T CD4+ orquestram a resposta imune adaptativa, auxiliando os macrófagos, os linfócitos T CD8+ e os linfócitos B na resposta mais eficiente frente a um antígeno. As etapas que caracterizam uma resposta imune adaptativa são: apresentação do antígeno, ativação e diferenciação dos linfócitos T, expansão clonal e morte celular para retorno à homeostasia via AICD. Este tipo de morte ocorre via FAS/FASL. Tendo em vista que o mecanismo pelo qual a PGE2 inibe a expressão de fasl ainda não é conhecido, o presente trabalho tem como objetivo compreender o mecanismo molecular de atuação da PGE2 sobre os linfócitos T CD4+ na inibição gênica do FASL, tendo como hipótese o envolvimento do repressor transcricional ICER. Foi verificado que PGE2 10-8 M é capaz de proteger as DO11.10 da AICD e que, nesta concentração, ela induz a expressão de icer. Este repressor apresenta uma expressão transiente e observa-se seu aumento concomitantemente à inibição da expressão de fasl. Sendo assim, sugere-se a participação de ICER na via de inibição do fasl pela PGE2. / CD4+ T lymphocytes orchestrate the adaptive immune response, helping the macrophages, CD8+ T lymphocytes and B lymphocytes to reach an efficient antigen-specific immune response. The adaptive immune response is characterized by different phases: antigen, T lymphocyte activation and differentiation, clonal expansion and, finally, clonal cell death to return to homeostasis via AICD. This cell death occurs via FAS/FASL. Since the mechanism by which PGE2 inhibits fasl expression is not known, our aim is to understand the molecular mechanism responsible for PGE2 inhibition of fasl in CD4+ lymphocytes. Our hypothesis is that the transcriptional repressor ICER, which binds to CRE sites on gene promoters, is involved in this process. We verified that PGE2 10-8 M protects DO11.10 cells from AICD, and in that concentration, PGE2 increases icer expression. This repressor has a transient expression and we observed that its expression is increased in the same time that fasl expression is inhibited. Thus, we suggest the involvement of ICER in fasl inhibition pathway by PGE2.
2

Regulação da expressão gênica de FASL pela PGE2 em linfócitos T CD4+: papel do repressor transcricional ICER. / Regulation of FASL gene expression by PGE2 in CD4+ T lymphocytes: role of transcriptional repressor ICER.

Cristiane Naffah de Souza 17 March 2014 (has links)
Os linfócitos T CD4+ orquestram a resposta imune adaptativa, auxiliando os macrófagos, os linfócitos T CD8+ e os linfócitos B na resposta mais eficiente frente a um antígeno. As etapas que caracterizam uma resposta imune adaptativa são: apresentação do antígeno, ativação e diferenciação dos linfócitos T, expansão clonal e morte celular para retorno à homeostasia via AICD. Este tipo de morte ocorre via FAS/FASL. Tendo em vista que o mecanismo pelo qual a PGE2 inibe a expressão de fasl ainda não é conhecido, o presente trabalho tem como objetivo compreender o mecanismo molecular de atuação da PGE2 sobre os linfócitos T CD4+ na inibição gênica do FASL, tendo como hipótese o envolvimento do repressor transcricional ICER. Foi verificado que PGE2 10-8 M é capaz de proteger as DO11.10 da AICD e que, nesta concentração, ela induz a expressão de icer. Este repressor apresenta uma expressão transiente e observa-se seu aumento concomitantemente à inibição da expressão de fasl. Sendo assim, sugere-se a participação de ICER na via de inibição do fasl pela PGE2. / CD4+ T lymphocytes orchestrate the adaptive immune response, helping the macrophages, CD8+ T lymphocytes and B lymphocytes to reach an efficient antigen-specific immune response. The adaptive immune response is characterized by different phases: antigen, T lymphocyte activation and differentiation, clonal expansion and, finally, clonal cell death to return to homeostasis via AICD. This cell death occurs via FAS/FASL. Since the mechanism by which PGE2 inhibits fasl expression is not known, our aim is to understand the molecular mechanism responsible for PGE2 inhibition of fasl in CD4+ lymphocytes. Our hypothesis is that the transcriptional repressor ICER, which binds to CRE sites on gene promoters, is involved in this process. We verified that PGE2 10-8 M protects DO11.10 cells from AICD, and in that concentration, PGE2 increases icer expression. This repressor has a transient expression and we observed that its expression is increased in the same time that fasl expression is inhibited. Thus, we suggest the involvement of ICER in fasl inhibition pathway by PGE2.
3

Influência da prostaglandina E2 na plasticidade de linfócitos Th17/Th1 no contexto da encefalomielite autoimune experimental /

Bazzano, Júlia Miranda Ribeiro. January 2019 (has links)
Orientador: Alexandra Ivo de Medeiros / Resumo: A prostaglandina E2 (PGE2) é um mediador lipídico que participa tanto na diferenciação como na expansão de linfócitos T helper (Th) Th1 e Th17. Esse prostanoide vem sendo descrito como um importante mediador envolvido no agravamento da Encefalomielite Autoimune Experimental (EAE). A EAE é uma doença mediada por células Th1/Th17 autorreativas, responsáveis pela intensa resposta inflamatória contra antígenos do sistema nervoso central (SNC). Alguns estudos descrevem que a inibição da síntese desse prostanoide, ou o bloqueio de seus receptores EP, reduzem os níveis de IL-17A e IFN- e atenuam drasticamente o desenvolvimento da doença. A coexistência de linfócitos Th1 e Th17 na EAE, assim como a presença de células Th17 produtoras de IFN-γ (Th1-like) no SNC sugerem uma possível plasticidade destas subpopulações de linfócitos. No entanto, até o momento, não há relatos na literatura se a presença de PGE2, presente no SNC, estaria envolvida na plasticidade de linfócitos Th17 em Th1 nessa autoimunidade. Portanto, a hipótese desse estudo é que as células Th17 migrariam para o SNC e desencadeariam o recrutamento de células inflamatórias e o aparecimento dos primeiros sinais clínicos da doença. A presença de PGE2, associado esse microambiente inflamatório, favoreceria a plasticidade das células Th17 para um padrão Th1, resultando na diferenciação de células T CD4+ patogênicas (IL17+IFN+) e células Th1-like. Os resultados obtidos demonstram que as células Th17, quando cultivadas em cond... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
4

The Role Of Pge2 Biosynthesis And Metabolism In Liver Injury And Liver Cancer

January 2015 (has links)
PGE2 plays an important role in liver inflammation and carcinogenesis. Its metabolism is regulated by a cascade of reactions catalyzed by enzymes including COX-1/2, mPGES-1/2, 15-PGDH. Among these regulators, mPGES-1 is a cytokine-inducible enzyme mainly responsible for catalyzing terminal synthesis of PGE2, 15-PGDH catalyzes the oxidation of PGE2 to 15-keto-PGE2. In this context, we exogenously expressed mPGES-1 or 15-PGDH genes in mice hepatocytes to constitute a physiological condition ideal for evaluating PGE2 and its metabolites function in liver pathogenesis. In the first part, we developed transgenic mice with targeted expression of mPGES-1 in the liver and assessed the response of the transgenic mice to Fas-induced hepatocyte apoptosis and acute liver injury. Compared to wild type mice, the mPGES-1 Tg mice showed less liver hemorrhage, lower serum alanine transaminase and aspartate transaminase levels, less hepatic necrosis/apoptosis, and lower levels of caspase activation after intraperitoneal injection of the anti-Fas antibody Jo2. Western blotting analyses revealed increased expression and activation of the serine/threonine kinase Akt and associated anti-apoptotic molecules in the liver tissues of Jo2-treated mPGES-1 Tg mice. Pretreatment with the mPGES-1 inhibitor (MF63) or the Akt inhibitor (Akt inhibitor V) restored the susceptibility of the mPGES-1 Tg mice to Fas-induced liver injury. Our findings provide novel evidence that mPGES-1 prevents Fas-induced liver injury through activation of Akt and related signaling. This finding is consistent with previous reports of the anti-apoptotic and pro-proliferative role of PGE2. Our results suggest that induction of mPGES-1 or treatment with PGE2 may represent a potential therapeutic strategy for the prevention and treatment of Fas-associated liver injuries. In the second part, we generated transgenic mice with targeted expression of 15-PGDH in the liver and the animals were subjected to LPS/GalN-induced acute liver inflammation and injury. Compared to the wild type mice, the 15-PGDH Tg mice showed lower levels of alanine aminotransferase and aspartate aminotransferase, less liver tissue damage, less hepatic apoptosis/necrosis, less macrophage activation, and lower inflammatory cytokine production. In Kupffer cell cultures, treatment with 15-keto-PGE2 or the conditioned medium (CM) from 15-PGDH Tg hepatocyes inhibited LPS-induced cytokine production. Both 15-keto-PGE2 and the CM from15-PGDH Tg hepatocyes also up-regulated the expression of PPAR-γ downstream genes in Kupffer cells. In cultured hepatocytes, 15-keto-PGE2 treatment or 15-PGDH overexpression did not influence TNF-α-induced hepatocyte apoptosis. These findings suggest that 15-PGDH protects against LPS/GalN-induced liver injury and the effect is mediated via 15-keto-PGE2, which activates PPAR-γ in Kupffer cells and thus inhibits their ability to produce inflammatory cytokines. Accordingly, we observed that the PPAR-γ antagonist, GW9662, reversed the effect of 15-keto-PGE2 in Kupffer cell in vitro and restored the susceptibility of 15-PGDH Tg mice to LPS/GalN-induced acute liver injury in vivo. Our findings not only support the pro-inflammatory role of PGE2, but also reveal a novel anti-inflammatory role of 15-keto-PGE2. The data suggest that induction of 15-PGDH expression or utilization of a 15-keto-PGE2 analog may be therapeutic for treatment of endotoxin-associated liver inflammation/injury. Consistent with a pro-carcinogenic role for PGE2, overexpression mPGES-1 enhances growth of either HCC or cholangiocarcinoma cells, while overexpression 15-PGDH inhibits tumor cell growth in vitro. In the third part, we use a pharmacological method to induce 15-PGDH in cholangiocarcinoma tumor cells to inhibit PGE2 production. Our results indicated that treatment of human cholangiocarcinoma cells (CCLP1 and TFK-1) with ω-3 PUFA (DHA) or transfection of these cells with the Fat-1 gene (encoding Caenorhabditis elegans desaturase which converts ω-6 PUFA to ω-3 PUFA) significantly increased 15-PGDH protein level in cholangiocarcinoma cell lines. Human cholangiocarcinoma cells treated with DHA or transfected with a Fat-1 expression vector showed reduction of miRNA26a and miRNA26b (both miRNAs target 15-PGDH mRNA thus inhibiting 15-PGDH translation). Consistent with these findings, we observed that overexpression of miR26a or miR26b decreased 15-PGDH protein, reversed ω-3 PUFA-induced accumulation of 15-PGDH protein, and prevented ω-3 PUFA-induced inhibition of cholangiocarcinoma cell growth. Knockdown of 15-PGDH also attenuated ω-3 PUFA-induced inhibition of tumor cell growth. We observed that ω-3 PUFA suppressed miRNA26a and miRNA26b by inhibiting c-myc, a transcription factor that co-regulates a gene cluster comprised of miR-26a/b and carboxy-terminal domain RNA polymerase II polypeptide A small phosphatases (CTDSPs). Accordingly, overexpression of c-myc enhanced the expression of miRNA26a/b and prevented ω-3 PUFA-induced inhibition of tumor cell growth. Taken together, our results support a pro-tumorigenic role for PGE2, and suggest induction of 15-PGDH as potential way for the prevention and treatment of human cholangiocarcinoma. / 1 / LU YAO
5

Effect of a single intra-articular injection of bupivacaine on synovial fluid prostaglandin E2 concentrations in normal canine stifles

Giangarra, Jenna Elizabeth 19 June 2018 (has links)
Intra-articular bupivacaine is a common analgesic used in dogs with orthopedic disease. Bupivacaine has been linked to chondrotoxicity. The mechanism for bupivacaine's chondrotoxicity is unknown, but may involve inflammation. Prostaglandin E2 (PGE2) is an inflammatory mediator and a marker of joint inflammation. The aim of this study was to compare synovial fluid PGE2 concentrations after a single intra-articular injection of bupivacaine with a saline control in normal canine stifles. We hypothesized that bupivacaine stifles would have a significantly elevated PGE2 concentration compared to controls. Stifles from eight healthy, adult Beagles were randomly selected as the treated stifle and infused with bupivacaine. The contralateral stifle was injected with saline. Synovial fluid was collected before and after injection. PGE2 was quantified using a commercial ELISA. Data were transformed and mixed model ANOVA was performed with significance set at p<0.05. There were no significant differences in PGE2 concentration between treatment groups or times. Samples acquired with one or two aspiration attempts had significantly lower PGE2 concentrations than samples with =3 aspiration attempts (p=0.001). When adjusted for number of attempts, PGE2 concentrations were significantly higher 24 (p=0.003) and 48 (p=0.041) hours after injection compared to baseline in the bupivacaine group, but not in the saline group. Intra-articular bupivacaine injection did not result in increased synovial fluid PGE2 concentrations compared to controls; however, multiple aspiration attempts did, suggesting that synovial fluid PGE2 concentration is sensitive to multiple fluid collection attempts. Future studies investigating synovial fluid inflammatory mediators should consider methods to minimize aspiration attempts. / M. S.
6

Caractérisation et régulation de la prostaglandine E synthétase dans des follicules préovulatoires bovins

Filion, France January 2002 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
7

Comprehensive Profiling of GPCR Expression in Ghrelin-producing Cells / グレリン分泌細胞におけるGPCR発現の網羅的解析

Koyama, Hiroyuki 23 May 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19887号 / 医博第4136号 / 新制||医||1016(附属図書館) / 32964 / 京都大学大学院医学研究科医学専攻 / (主査)教授 川口 義弥, 教授 横出 正之, 教授 妹尾 浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
8

Efeito da Melatonina sobre a Úlcera Gástrica Induzida por Antiinflamátorios Não-esteroidais (Piroxicam e Fenilbutazona). / Effect of melatonin on gastric ulcer induced non-steroidal anti-inflammatory drugs (piroxicam and phenylbutazone).

Buscariolo, Inês Aparecida 03 July 1997 (has links)
Os antiinflamatórios não esteroidais (AINEs) constituem um grupo de medicamentos de uso rotineiro na terapêutica clínica, principalmente no tratamento do processo inflamatório e doloroso. O efeito colateral mais comum constatado pelo seu uso é a irritação da mucosa gástrica. A atividade ulcerogênica dos AINEs tem variabilidade diária, uma vez que quando administrados à noite, são melhor tolerados que durante o dia. Tal observação chama a atenção para a possível ação do hormônio pineal, melatonina, sintetizado no período de escuro, tanto por animais de hábitos noturnos como diurnos. No presente estudo foram investigados os efeitos da administração de melatonina sobre a atividade antiinflamatória e lesão gástrica induzida pelo piroxicam e o efeito da melatonina e do piroxicam sobre a síntese de PGE2 pela mucosa gástrica, testando esse hormônio nos seguintes modelos: edema de pata de rato induzido por carragenina, lesão da mucosa gástrica induzida pelo piroxicam e determinação da síntese de PGE2 por enzima-imunoensaio (EIA). A administração intragástrica de melatonina não alterou o efeito aniinflamatório do piroxicam, mas inibiu o efeito colateral ulcerogênico. O efeito antiulcerogênico da melatonina foi observado após administração intragástrica, mas não após a administração subcutânea. As diferenças observadas entre as duas vias de de administração sugere um efeito local desse hormônio sobre a mucosa gástrica. O efeito antiulcerogênico da mealtonina intragástrica esta relacionada à prevenção da inibição da produção der PGE2 da mucosa gástrica pelo piroxicam. A pinealectomia aumentou o efeito ulcerogênico da adminstração noturna de piroxicam. Mesmo utilizando fenilbutazona, que é um AINEs ulcerogenicamente mais potente, no período da manhã, quando o efeito ulcerogênico dos AINEs parece ser acentuado, a melatonina administrada intragastricamente promoveu proteção da mucosa gástrica. Por outro lado, a melatonina administrada intragastricamente não interferiu com ulceração induzida pelo estresse, sugerindo que o efeito antiulcerogênico da melatonina está relacionado mais especificamente com fatores importantes na patogênese da lesão gástrica induzida pelos AINEs (piroxicam e fenilbutazona) em ratos, prevenindo a inibição da síntese de PGE2 da mucosa gástrica induzida pelo piroxicam, sem afetar a ação antiinflamatória. / Non-steroidal antiinflammatory drugs are, the most frequently consumed drugs worlwide. They also cause gastrointestinal adverse effects, like gastric ulceration and bleedig. Several reports indicate that, both antiinflammatory effect and the susceptibility to mucosal damage produced by NSAIDs in rats and humans show a circadian variation. Nighttime administration of NSAIDs is better tolerated than morning administration in human and rats. Melatonin, the principal hormone of the pineal gland is secreted at night both in nocturnal and diurnal animals. The purpose of this experiment was to study the effect of melatonin on the antiinflammatory action and gastric mucosal damage induced by piroxicam and the effect of melatonin and piroxicam on the gastric mucosal prostaglandin E2 (PGE2) synthesis. Intragastric administration of melatonin significantly attenuated the gastric lesions induced by piroxicam, but, did not entiinflammatory action accessed by measuring paw edema after carrageenin adminstration. Melatonin anti-ulcerogenic effect was observed after intragastric, but not subcutaneus administration. The differences observed between the two administration routes point to a local effect of the hormone on the stomach mucosa. Pinealectomy increases the ulcerogenic effect of nocturnal administred piroxicam. The anti-ulcerogenic effect of intragastric melatonin was related to prevention of the inhibition of gastric mucosal PGE2 production induced by piroxicam. Indeed, intragastric administration of melatonin protect the gastric mucosa damage induced by effect on stress-induced gastric ulceration. These data suggest that melatonin may attenuate the severity of NSAID-induced gastric mucosal lesions in rats by preventing NSAID-induced inhibition of mucosal PGE2 production whithout affecting th anti-inflamamtory action.
9

Analysis of how the production and activity of PGD2 affects glioma cell lines. / Análise de como a produção e atividade de PGD2 afetam linhagens de glioma.

Ferreira, Matthew Thomas 30 January 2015 (has links)
The World Health Organization classifies glioblastoma (GBM) as a type IV astrocytoma, making it one of the most fatal tumors that exists. Despite the advances in chemotherapy, surgery, and radiation treatments that improve a patients length of survival, the overall trajectory of the disease remains unchanged. It has been shown that GBM cells produce significant levels of prostaglandins, including prostaglandin D2 (PGD2). PGD2 possesses pro- and anti-tumorigenic properties. Hence, a more complete understanding of PGD2 activity in GBM could yield more effective treatments against GBM. Through techniques like RT-PCR, immunohistochemistry, and HPLC tandem mass spectrometry, we were able to confirm the presence of the PGD2 synthesis in GBM cell lines. We treated GBM cell lines with various concentrations of exogenous PGD2 over 72 hours and observed its effects on cell count, apoptosis, mitosis and viability. Our results suggest that PGD2 possesses contradictory functions in GBM depending on concentration (mM PGD2 vs. nM PGD2) and receptor activation. / A Organização Mundial de Saúde classifica glioblastoma (GBM) como um astrocitoma tipo IV, fazendo uns dos tumores mais fatais que existe. A pesar dos avanços em quimioterapia, cirurgia e radioterapia que melhoram a longevidade de sobrevivência, a trajetória geral da doença permanece imutável. Tem sido demonstrado que células de GBM produzem níveis significativos de prostaglandinas, incluindo prostaglandina D2 (PGD2). PGD2 possui propriedades pro- e anti-tumorigenicos. Então, um entendimento mais completo da atividade de PGD2 em GBM pode gerar tratamentos mais efetivos. Através de técnicas como RT-PCR, imunohistoquimicas e HPLC espectrometria de massa em tandem, conseguimos confirmar a presença da síntese de PGD2 em linhagens de GBM. Tratamos linhagens de GBM com concentrações variáveis de PGD2 exógeno durante 72 horas e observamos seus efeitos na contagem de células, apoptose, mitose e viabilidade. Nossos resultados sugerem que PGD2 possui funções opostas em GBM dependendo em concentração (mM PGD2 vs. nM PGD2) e ativação de receptores.
10

Analysis of how the production and activity of PGD2 affects glioma cell lines. / Análise de como a produção e atividade de PGD2 afetam linhagens de glioma.

Matthew Thomas Ferreira 30 January 2015 (has links)
The World Health Organization classifies glioblastoma (GBM) as a type IV astrocytoma, making it one of the most fatal tumors that exists. Despite the advances in chemotherapy, surgery, and radiation treatments that improve a patients length of survival, the overall trajectory of the disease remains unchanged. It has been shown that GBM cells produce significant levels of prostaglandins, including prostaglandin D2 (PGD2). PGD2 possesses pro- and anti-tumorigenic properties. Hence, a more complete understanding of PGD2 activity in GBM could yield more effective treatments against GBM. Through techniques like RT-PCR, immunohistochemistry, and HPLC tandem mass spectrometry, we were able to confirm the presence of the PGD2 synthesis in GBM cell lines. We treated GBM cell lines with various concentrations of exogenous PGD2 over 72 hours and observed its effects on cell count, apoptosis, mitosis and viability. Our results suggest that PGD2 possesses contradictory functions in GBM depending on concentration (mM PGD2 vs. nM PGD2) and receptor activation. / A Organização Mundial de Saúde classifica glioblastoma (GBM) como um astrocitoma tipo IV, fazendo uns dos tumores mais fatais que existe. A pesar dos avanços em quimioterapia, cirurgia e radioterapia que melhoram a longevidade de sobrevivência, a trajetória geral da doença permanece imutável. Tem sido demonstrado que células de GBM produzem níveis significativos de prostaglandinas, incluindo prostaglandina D2 (PGD2). PGD2 possui propriedades pro- e anti-tumorigenicos. Então, um entendimento mais completo da atividade de PGD2 em GBM pode gerar tratamentos mais efetivos. Através de técnicas como RT-PCR, imunohistoquimicas e HPLC espectrometria de massa em tandem, conseguimos confirmar a presença da síntese de PGD2 em linhagens de GBM. Tratamos linhagens de GBM com concentrações variáveis de PGD2 exógeno durante 72 horas e observamos seus efeitos na contagem de células, apoptose, mitose e viabilidade. Nossos resultados sugerem que PGD2 possui funções opostas em GBM dependendo em concentração (mM PGD2 vs. nM PGD2) e ativação de receptores.

Page generated in 0.0455 seconds