Ho Wing Man. / On t.p. "gamma" appears as the Greek letter. / Thesis submitted in: December 2007. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 95-106). / Abstracts in English and Chinese. / ABSTRACT --- p.I / 摘要 --- p.III / ACKNOWLEDGMENTS --- p.V / ABBREVIATIONS --- p.VI / LIST OF FIGURES --- p.IX / LIST OF TABLES --- p.X / CONTENTS --- p.XII / Chapter CHAPTER ONÉؤ --- GENERAL INTRODUCTION --- p.1 / Chapter 1.1 --- Background --- p.2 / Chapter 1.1.1 --- Thyroid cancer --- p.2 / Chapter 1.1.2 --- Apoptosis and thyroid cancer --- p.4 / Chapter 1.2 --- Estrogen receptors and apoptosis --- p.5 / Chapter 1.2.1 --- Estrogen receptor-α (ERα) and estrogen receptor-β (ERβ) --- p.5 / Chapter 1.2.2 --- Differential roles of estrogen receptor-α(ERα) and estrogen receptor-β (ERβ) in apoptosis --- p.6 / Chapter 1.2.3 --- Bcl-2 family --- p.8 / Chapter 1.3 --- Peroxisome proliferator-activated receptor-γ (PPARγ) --- p.9 / Chapter 1.3.1 --- Molecular aspects of PPAR --- p.9 / Chapter 1.3.2 --- PPAR/RXR complex --- p.13 / Chapter 1.3.3 --- PPARγ ligands --- p.16 / Chapter 1.3.4 --- PPARγ and apoptosis in thyroid cancer --- p.19 / Chapter 1.3.5 --- PPARγ ligands-mediated apoptosis pathway --- p.21 / Chapter 1.4 --- Previous results from our laboratory --- p.25 / Chapter 1.5 --- Summary of previous studies --- p.27 / Chapter 1.6 --- Perspectives --- p.28 / Chapter 1.7 --- Objectives of this project --- p.29 / Chapter CHAPTER TWÓؤ --- GENERAL MATERIALS AND METHODS --- p.30 / Chapter 2.1 --- Materials --- p.31 / Chapter 2.1.1 --- Cell lines --- p.31 / Chapter 2.1.2 --- Plasmid vectors used in this study --- p.31 / Chapter 2.1.3 --- Antibodies --- p.32 / Chapter 2.1.4 --- Culture media and transfection reagents --- p.32 / Chapter 2.1.5 --- Materials for protein manipulation --- p.33 / Chapter 2.1.6 --- Drugs for treatment --- p.34 / Chapter 2.1.7 --- Kits --- p.35 / Chapter 2.1.8 --- Instruments --- p.35 / Chapter 2.2 --- Methods --- p.36 / Chapter 2.2.1 --- Cell culture --- p.36 / Chapter 2.2.2 --- Cell viability analysis --- p.36 / Chapter 2.2.3 --- Preparation of protein extract --- p.37 / Chapter 2.2.4 --- Determination of the concentration of target protein --- p.37 / Chapter 2.2.5 --- Gel electrophoresis and protein transfer --- p.38 / Chapter 2.2.6 --- Immunoblotting --- p.39 / Chapter 2.2.7 --- Apoptosis detected by Cell Death ELISAplus --- p.41 / Chapter 2.2.8 --- PPARγ-ligand Enzyme Immunoassay --- p.45 / Chapter 2.2.8.1 --- 15d-PGJ3 Enzyme Immunoassay --- p.45 / Chapter 2.2.8.2 --- 15(S)-HETE Enzyme Immunoassay --- p.46 / Chapter 2.2.8.3 --- 13(S)-HODE Enzyme Immunoassay --- p.46 / Chapter 2.2.9 --- Transient tranfection and luciferase activity assay --- p.47 / Chapter 2.2.10 --- Statistical Analysis --- p.52 / Chapter CHAPTER THREÉؤ --- ESTROGEN RECEPTORa (ERa) AND ESTROGEN RECEPTORP(ERP) MEDIATE THE PROLIFERATION AND APOPTOSIS OF HUMAN THYROID PAPILLARY CARCINOMA CELLS --- p.53 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Materials and Methods --- p.56 / Chapter 3.2.1 --- Cell culture and treatment --- p.56 / Chapter 3.2.2 --- Western Blot --- p.56 / Chapter 3.2.3 --- Cell proliferation determined by MTT assay --- p.57 / Chapter 3.2.4 --- Apoptosis detected by Cell Death ELISAplus assay --- p.58 / Chapter 3.3 --- Results --- p.59 / Chapter 3.3.1 --- "The expression of ERα, ERβ and PPARγ in NPA, FRO, ARO and WRO thyroid cancer cell lines" --- p.59 / Chapter 3.2.2 --- Effects of PPT and DPN on cell viability --- p.61 / Chapter 3.3.3 --- Apoptotic cells quantification by Cell Death ELISAplus assay --- p.64 / Chapter 3.4 --- Discussion --- p.67 / Chapter CHAPTER FOUŔؤ --- THE RELATIONSHIP BETWEEN PPARγ AND ESTROGEN RECEPTOR AND THE REGULATION OF THE APOPTOSIS IN THYROID CANCER CELL LINES --- p.70 / Chapter 4.1 --- Introduction --- p.71 / Chapter 4.2 --- Material and Methods --- p.74 / Chapter 4.2.1 --- Transient transfection --- p.74 / Chapter 4.2.2 --- Luciferase assay --- p.74 / Chapter 4.2.3 --- 15d-PGJ2 ELISA assay --- p.75 / Chapter 4.2.4 --- 15S-HETE ELISA assay --- p.76 / Chapter 4.2.5 --- 13S-HODE ELISA assay --- p.77 / Chapter 4.3 --- Results --- p.78 / Chapter 4.3.1 --- "PPT, ERα-agonist, increased thyroid cancer cell proliferation and caused the decrease the level of PPARγ ligands" --- p.78 / Chapter 4.3.2 --- "DPN, ERβ-agonist, inhibited thyroid cancer cell proliferation, induced apoptosis and caused the increase the level of PPARγ ligands" --- p.83 / Chapter 4.3.3 --- PPT did not alter the transcriptional activity of PPARγ --- p.88 / Chapter 4.4 --- Discussion --- p.90 / Chapter CHAPTER FIVÉؤ --- CONCLUSIONS AND FUTURE PROSPECT --- p.92 / Chapter 5.1 --- Summary of results --- p.93 / Chapter 5.2 --- Conclusion --- p.94 / Chapter 5.3 --- Future prospects --- p.94 / REFERENCE LIST --- p.95

Microarrays have been widely used to study differential gene expression at the genomic level. They can also provide genome-wide co-expression information. Robust approaches are needed for integration and validation of independently-collected datasets which may contribute to a common hypothesis. Previously, attempts at meta-analysis have contributed to solutions to this problem. As an alternative, for microarray data from multiple highly similar biological experimental designs, a more direct combined approach is possible. In this thesis, a novel approach is described for microarray combined analysis, including gene-level unification into a virtual platform followed by normalization and a method for ranking candidate genes based on co-expression information - called Coex-Rank. We applied this approach to our Sppar (a PPARγ mutant) dataset, which illustrated an improvement in statistical power and a complementary advantage of the Coex-Rank method from a biological perspective. We also performed analysis to other PPARγ-related microarray datasets. From the perspective of gene sets, we observed that up-regulated genes from mice treated with the PPARγ ligand rosiglitazone were significantly down-regulated in mice with a global knock-in dominant-negative mutation of PPARγ. Integrated with publicly available PPRE (PPAR Response Element) datasets, we found that the genes which were most up-regulated by rosiglitazone treatment and which were also down-regulated by the global knock-in mutation of PPARγ were robustly enriched in PPREs near transcription start sites. In addition, we identified several potential PPARγ targets in the aorta and mesenteric artery for further experimental validation, such as Rhobtb1 and Rgs5.

Nombroses evidències mostren l'important paper dels receptors nuclears PPAR en el control de l'homeòstasi energètica a través de les seves accions reguladores sobre el metabolisme lipídic i glucídic, a més de la seva implicació en processos inflamatoris, tumorals i en la reproducció i el desenvolupament embrionari. La falta de lligands específics de PPARβ/δ fins fa relativament poc ha fet que els efectes fisiològics d'aquest subtipus hagin estat poc estudiats en relació als altres subtipus de PPAR, PPARα i PPARγ. Actualment però, la disponibilitat d'agonistes selectius de PPARβ/δ com GW501516, ha ajudat a conèixer i entendre l'important paper fisiològic que juga aquest receptor com regulador de múltiples funcions cel·lulars, especialment en la regulació del metabolisme i la resposta inflamatòria. Encara, però, resta per determinar els mecanismes moleculars responsables d'aquets efectes provocats per l'administració d'aquests fàrmacs, ja que només han estat parcialment estudiats. Els objectius d'aquesta tesi doctoral han estat:1. Establir els mecanismes responsables de l'efecte hipotrigliceremiant de l'agonista de PPARβ/δ GW501516 en ratolins alimentats amb una dieta rica en greixos (HFD).2. Establir els mecanismes responsables pels quals l'activador de PPARβ/δ GW501516 és capaç d'inhibir la resposta inflamatòria en queratinòcits humans estimulats amb TNF-α.Respecte el primer objectiu els resultats obtinguts indiquen que l'agonista PPARβ/δ GW501516 podria reduir els nivells de triglicèrids en plasma en un model animal de hipertrigliceridèmia evitant la reducció de l'AMPK i activant la via PGC1-α-Lipin 1-PPARα. D'altra banda, respecte el segon objectiu els resultats també demostren que GW501516 pot evitar la inflamació induïda per TNF-α en queratinòcits humans reduint l'activació del factor de transcripció pro-inflamatori NF-κB per l'activació de l'AMPK i SIRT1. / The effects of PPARβ/δ subtype and its role in the metabolic syndrome and the inflammatory diseases has been elucidated in the last years, in part, by the availability of PPARβ/δ agonist GW501516, althought the mechanism involved is still unkonwn. In this study we examined the effects of PPARβ/δ activator GW501516 on high-fat diet (HFD)-induced hypertriglyceridemia. Our results showed that the hipertrigliceridemia caused by the HFD was reduced by the drug treatment. Also the PPARβ/δ activation prevented the reduction in the AMPK-Lipin1-PGC-1α pathway caused by the HFD, leading to an increase in hepatic fatty acid oxidation. This effect, together with increased hepatic expression in VLDL-receptor might be responsible for the hypotriglyceridemic effect of GW501516.Moreover, the PPARβ/δ activation by GW501516 also prevented TNF-α-induced NF-κB activation in human HaCaT cells by reducing p65 acetylation through AMPK and SIRT1.

Background: Foods rich in polyunsaturated fatty acids (PUFA) are susceptible to oxidation through heating or storage. Oxidized lipids are known to act as ligands for a transcription factor (PPAR-gamma) that affects adipocyte differentiation and insulin sensitivity. Objective: The purpose of this study was to determine the amounts of oxidation products of a variety of PUFA containing foods over time, and to determine whether extracted fats from these foods act as ligands for PPAR-gamma. Method: To study the effect of room-temperature storage on oxidation, 5 foods (walnuts, sunflower seeds, ground flax, fish oil capsules, and infant formula) were purchased and stored at room temperature for 1, 2, and 3 months. To determine oxidation levels in fried foods, French fries and chicken nuggets were used. Fat was extracted from each food and the levels of oxidation products were analyzed by spectrophotometry and kits designed to measure oxidation products. Using a fluorescence polarization-based ligand screening assay kit, fat extracted from foods was analyzed for its binding affinity for PPAR-gamma. Results: Among foods stored at room temperature, the levels of oxidation products did not change significantly with time. Most foods exhibited the highest levels of oxidation at the purchase date. Infant formula and ground flax demonstrated higher levels of oxidation products than did other foods. In preliminary ligand binding assays, extracted fat from French fries showed the greatest binding affinity for PPAR-gamma; a select few other oils showed slight affinity. Discussion: Surprisingly, storage time did not affect oxidation levels. The greatest amount of oxidation may occur during pre-purchase storage conditions. The processing of formula and ground flax may be the cause of the relatively higher oxidation levels in those foods. The binding affinity for PPAR-gamma demonstrated by French fries needs further investigation. Conclusion: Certain oxidized lipids from foods may act as ligands for PPAR-gamma. Further research is required not only to determine which component of these PUFA-containing foods activates PPAR-gamma but also to determine whether that component acts as an agonist or antagonist for PPAR-gamma.

1,1-Bis(3'-indolyl)-1-(p-substitutedphenyl)methanes containing ptrifluoromethyl (DIM-C-pPhCF3), p-t-butyl (DIM-C-pPhtBu), and phenyl (DIM-CpPhC6H5) substituents have been identified as a new class of peroxisome proliferatoractivated receptor γ (PPARγ) agonists that exhibit antitumorigenic activity. In this study, the PPARγ-active compounds decreased HT-29, HCT-15, RKO, HCT116 and SW480 colon cancer cell survival and KU7 and 253JB-V33 bladder cancer cell survival. In HT- 29, HCT-15, SW480 and KU7 cells, the PPARγ agonists induced caveolin-1 expression and this induction was significantly downregulated after cotreatment with the PPARγ antagonist GW9662. Since overexpression of caveolin-1 is known to suppress cancer cell and tumor growth, the growth inhibitory effects of the DIM compounds in these cell lines are associated with PPARγ-dependent induction of caveolins. These PPARγ-active compounds did not induce caveolin-1 in HCT-116 cells. However, these compounds induced NSAID-activated gene-1 (NAG-1) and apoptosis in this cell line. This represents a novel receptor-independent pathway for C-DIM-induced growth inhibition and apoptosis in colon cancer cells. In SW480 colon cancer cells 2.5-7.5 μM C-DIMs induced caveolin-1 whereas high concentrations (10 μM) induced pro-apoptotic NAG-1 expression. In athymic nude mice bearing SW480 cell xenografts DIM-C-pPhC6H5 inhibited tumor growth and immunohistochemical staining of the tumors show induction of apoptosis and NAG-1 expression. Thus, the PPARγ-active compounds induce both receptor-dependent and-independent responses in SW480 cells which are separable over a narrow range of concentrations and this dual mechanism of action enhances their antiproliferative and anticancer activities. Similar results were obtained for another structural class of PPARγ agonists namely 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid (CDDO) and the corresponding methyl (CDDO-Me) and imidazole (CDDO-Im) esters. Structure-activity studies show that 1,1-bis(3'-indolyl)-1-(psubstitutedphenyl) methanes containing p-trifluoromethyl (DIM-C-pPhCF3), hydrogen (DIM-C-pPh) and p-methoxy (DIM-C-pPhOCH3) substituents activate Nur77 and induce apoptosis in pancreatic, prostate, and breast cancer cell lines. Nur77 agonists activate the nuclear receptor, and downstream responses include decreased cell survival, induction of cell death pathways including tumor necrosis factor related apoptosis-inducing ligand (TRAIL) and PARP cleavage. Nur77 agonists also inhibit tumor growth in vivo in athymic nude mice bearing Panc-28 cell xenografts.

The liver maintains energy substrate homeostasis by synchronizing circadian or diurnal expression of metabolic genes with the feeding/fasting state. The activities of hepatic de novo lipogenic gene products peak during feeding, converting carbohydrates into fats that provide vital energy sources for peripheral tissues. Conversely, deregulated hepatic lipid synthesis leads to systemic metabolic dysfunction, establishing the importance of temporal regulation of fat synthesis/usage in metabolic homeostasis. Pharmacological activation of peroxisome proliferator-activated receptor \(\delta / \beta (PPAR \delta / \beta)\)improves glucose handling and systemic insulin sensitivity. However, the mechanisms of hepatic \(PPAR\delta\) actions and the molecular pathways through which it is able to modulate global metabolic homeostasis remain unclear. Here we show that hepatic \(PPAR\delta\) controls the diurnal expression of lipogenic genes in the dark/feeding cycle. Adenovirus mediated liver restricted activation of \(PPAR\delta\) promotes glucose utilization in the liver and fat utilization in the muscle. Liver specific deletion of either \(PPAR\delta\) or the \(PPAR\delta\)-regulated lipogenic gene acetyl-CoA carboxylase 1 (ACC1) reduces muscle fatty acid uptake. Unbiased metabolite profiling identifies 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) as a serum lipid derived from the hepatic \(PPAR\delta\)-ACC1 activity that reduces postprandial lipid levels and increases muscle fatty acid uptake. These findings reveal a regulatory mechanism that coordinates lipid synthesis and utilization in the liver-muscle axis, providing mechanistic insights into the hepatic regulation of systemic energy substrates homeostasis.

The aim of this thesis was to verify the hypothesis implying that n-3 polyunsaturated fatty acids inhibit the development of mild chronic inflammation. The experiment was conducted on rats with different diets (control, with the addition of safflower oils, fish oils and oils from algae Schizochytrium). For processing the results of the collected tissues was used determination of expression of selected genes by qRT-PCR, detection of proteins and in the cytosol and nuclear fractions by Western blot and the quantification of cytokines by ELISA. Feeding oil from algae Schizochytrium has led to lowering the final weight and blood glucose, further to enhance expression of PPAR-gama and increasing the production of anti-inflammatory cytokines IL-10 and TGF-beta1. In kontrast, no difference was observed in the expression of GPR120 and adiponectin receptors or proteins in an amount of NF-kappaB and PPAR-gama between diets. Elevated plasma levels of adiponectin were found. The results of the experiment shows that it is possible to recommend oil from algae Schizochytrium as a useful supplement of human diet as prevention of chronic degenerative diseases.

Made available in DSpace on 2016-05-11T13:01:08Z (GMT). No. of bitstreams: 2 rafael_torres_ioc_dout_2015.pdf: 4727913 bytes, checksum: 39b1968a4427b96bd96b03ae25ef6316 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015 / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil / O Diabetes mellitus é uma das principais doenças crônicas que afetam a população mundial. Além de hiperglicemia, os pacientes diabéticos exibem uma marcante hiperatividade do eixo hipotálamo-hipófise-adrenal (HPA) evidenciada pelo aumento dos níveis de glicocorticoides (GCs) circulantes. Este hipercortisolismo é importante em várias complicações diabéticas. No entanto, há poucas evidências da participação dos GCs em outras morbidades do diabetes, como na atrofia muscular, compartilhadas por pacientes com o diabetes e pessoas com Cushing, uma doença caracterizada pela hiperatividade deste eixo HPA. A redução na expressão do receptor nuclear PPAR-\03B3 tem sido demonstrada em órgãos de animais diabéticos acometidos por complicações da doença, e a ativação de PPAR-\03B3 é capaz de restaurar a funcionalidade desses órgãos. Além disso, o tratamento de pacientes com a doença de Cushing com ligantes de PPAR-\03B3 reduz os níveis de GCs circulantes. Desse modo, o nosso objetivo foi investigar o papel do PPAR-\03B3 na atividade do eixo HPA em animais diabéticos. O diabetes foi induzido por injeção intravenosa de aloxana em ratos em jejum. O agonista de PPAR-\03B3 rosiglitazona (rosi), o antagonista do receptor de GCs RU486 ou inibidor de PI3K wortmannin foram administrados diariamente durante 18 dias consecutivos, começando três dias após a injeção de aloxana. Observamos que a condição diabética induzida por administração de aloxana em ratos é caracterizada por hiperatividade do eixo HPA com redução na expressão de receptores de GCs na hipófise, hipertrofia adrenal e aumento dos níveis de GCs circulantes O papel destes hormônios esteroides sobre a atrofia muscular em animais diabéticos foi evidenciado pela melhoria no parâmetro microvascular funcional do músculo grácil, e aumento da massa do músculo gastrocnêmio observada em animais diabéticos tratados com RU486. Em paralelo com a hiperatividade do eixo HPA, observamos uma redução da expressão de PPAR-\03B3 nas adrenais e hipófise, bem como uma diminuição no ligante de PPAR-\03B3 15-d-PGJ2 no plasma dos animais diabéticos. O tratamento destes animais com rosi foi capaz de reduzir os níveis de GCs, em associação com a diminuição da hipertrofia adrenal e expressão de MC2-R. Em paralelo, a rosi restaurou os níveis de ACTH no plasma, em associação com a redução no número de células corticotróficas e expressão de POMC na hipófise dos ratos diabéticos, mesmo não restabelecendo o mecanismo de controle por retroalimentação da produção de GCs na hipófise através dos receptores de mineralocorticoides e GCs, respectivamente, MR e GR. Além disso, o tratamento com rosi aumentou a expressão de PPAR-\03B3 nas glândulas adrenais e hipófise dos ratos diabéticos, e o bloqueio de PPAR-\03B3 com GW9662 inibiu a capacidade da droga de reduzir os níveis plasmáticos de GCs. Os ratos diabéticos também apresentaram redução na expressão de PI3K na hipófise, e a rosi aumentou a expressão desta cinase nas glândulas adrenais e na hipófise. Além disso, o pré-tratamento de ratos diabéticos com wortmannin foi capaz de reduzir parcialmente a capacidade da rosi em reduzir os níveis de GCs no plasma. Assim, sugerimos que a hiperatividade do eixo HPA em animais diabéticos está diretamente relacionada com a atrofia muscular Além disso, a ativação de PPAR-\03B3 restaura a reatividade eixo HPA em ratos diabéticos através de um mecanismo dependente da ativação de PI3K, surgindo como um possível alvo no controle das complicações da doença / Diabetes mellitu s is one of the major chronic diseases that affect the world population . Beyond of hyperglycemia, diabetic patients exhi bit a marked hyperactivity of the hypothalam us - pituitary - adrenal (HPA) axis evidenced by increased levels of circulating glucocorticoids (GCs) . This hypercortisolism is important in several diabetic complications. However, there are few evidence s of the pa rticipation of GCs in other diabetic morbidities , including muscle atr o phy, that are shared by patients with diabet es and individuals with Cushing , a disease characterized by hyperactivity of HPA axis. The reduction in the expression of the nuclear recepto r PPAR - γ has been demonstrated in diabetic animal organs affected by complications of disease, and the PPAR - γ activation is able to restore the functionality of these organs. Furthermore, treatment of patients w ith Cushing’s disease with PPAR - γ ligands reduc es the levels of circulating GC s. Thereby, our aim was to investigate the role of PPAR - γ on HPA axis activity in diabetic animals. Diabetes was induced by the intravenous injection of alloxan into fasted rats. The PPAR -  agonist rosiglitazone (rosi) , GCs r eceptor antagonist RU486 or PI3K inhibitor wortmannin were administered daily for 18 consecutive days, starting three days after alloxan injection . We observed that the diabetic condition induced by alloxan administration in rats is characterized by a hype ractivity of the HPA axis with reduction in GCs receptor expression in the pituitary, adrenal hypertrophy and increase in circulating levels of GC s. The role of these steroid hormones on muscular atrophy in the diabetic animals was evidenced by improvement in the microvascular functional parameter of gracilis muscle, and increase of the mass of the gastrocnemius muscle observed in diabetic animals treated with RU486. In parallel with the hyperactivity of the HPA axis, we observed a reduction of PPAR - γ expre ssion in the adrenal and pituitary as well as a decreased on plasma PPAR - γ ligand 15 - d - PGJ 2 in the diabetic animals . Trea tment of these animals with rosi was able to reduce the GCs levels , in association with decrease of adrenal hypertrophy and MC2R expres sion. In parallel, rosi restore d plasma ACT H levels , in association with reduction of corticotrophic cells and POMC expressio n in pituitary of diabetic rats, despite of not restoring the feedback control of GCs production in the pituitary through mineraloc orticoid and GCs receptors, respectively MR and GR . Furthermore, treatment with rosi increase s the expression of PPAR - γ in both adrenal and pituitary glands in diabetic rats , and the blocka g e of PPAR - γ with GW9662 inhibited the capacity of the drug to reduce plasma GCs levels . Diabetic rats also presented reduction of PI3K expression in pituitary, and r osi increased the expression of this kinase in both adrenal and pituitary glands. In addition, pre - treatment of diabetic rats with wortmannin was able to partially reduce the ability of rosi to reduce plasma GCs levels . Thus, we suggest that the HPA axis h yperactivity in diabetic animals is directly related with muscle atrophy. Moreover, the activation of PPAR - γ restored HPA axis reactivity in diabetic rats via a mechanism dependent on PI3K activation , emerging as a possible target in the control of the disease complications / 2016-11-28

Made available in DSpace on 2014-06-12T15:54:39Z (GMT). No. of bitstreams: 2 arquivo69_1.pdf: 1795837 bytes, checksum: ba87379a6491423f781892ab0ffd0aa3 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / O processo inflamatório tem sido uma importante causa de morbidade e mortalidade humana, tornando-se objeto de estudos experimentais que procuram avaliar o papel dos diversos mediadores envolvidos na resposta inflamatória. Nesse contexto, a busca por novas moléculas revelou o potencial antiinflamatório dos derivados tiazolidínicos, grupo de moléculas estruturalmente relacionadas caracterizados pelo anel tiazolidínico. Tais moléculas têm o receptor ativado por proliferadores de peroxissomos gama (PPARγ) como principal alvo biológico. Neste trabalho foram descritos a síntese e as características físico-químicas de novos derivados tiazolidinônicos-3,5-dissubstituídos da série química LPSF/GQ: o LPSF/GQ-138 (3-(3-flúor-benzil)-5-(4-metóxi-benzilideno)-tiazolidina-2,4-diona) e o LPSF/GQ-140 (3-(3-flúor-benzil)-5-(4-metil-benzilideno)-tiazolidina-2,4-diona) obtidos a partir da reação de adição de Michael entre a 3-(3-flúor-benzil)-tiazolidina-2,4-diona (LPSF/GQ-56) com derivados 3-fenil-2-ciano-acrilatos de etila substituídos (LPSF/IP-6 e LPSF/IP-15). Ambos os compostos sintetizados tiveram suas estruturas químicas elucidadas por espectroscopia de infravermelho (IV) e ressonância magnética nuclear de hidrogênio (RMN1N). Em seguida foi investigada a atividade antiinflamatória dos compostos sintetizados no ensaio da peritonite induzida por carragenina 1% onde foram escolhidas as doses 0,37; 1,11; 3,33 e 10 μmol/kg e o fármaco de referência indometacina na dose de 28 μmol/kg, apresentando inibição da migração celular num percentual variando de 45,7 a 71,0% para os compostos e 54,3% para a indometacina. Foi realizada ainda a avaliação da atividade antinociceptiva através do teste de contorções abdominais induzidas por ácido acético 1% e do teste da formalina utilizando-se a melhor dose encontrada no ensaio da peritonite (10 μmol/kg). No teste de contorções abdominais os compostos LPSF/GQ-138 e LPSF/GQ-140 apresentaram percentuais de inibição de 32,2 % e 20,8 % respectivamente, em comparação com a dipirona na dose de 450 μmol/kg (50,2%). No teste da formalina, foram obtidos percentuais de inibição para o LPSF/GQ-138 na 1ª e 2ª fases do teste de 33,3 % e 59,5 % respectivamente e para o LPSF/GQ-140 na 1ª e 2ª fases do teste de 24,0 % e 42,4 % respectivamente, em comparação com a dipirona na dose de 450 μmol/kg (42,9% e 83,4%, respectivamente)

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