Techn. Universiẗat, Diss., 2005--München.

Made available in DSpace on 2014-06-11T19:27:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-21Bitstream added on 2014-06-13T18:56:30Z : No. of bitstreams: 1 gomes_ac_me_araca.pdf: 617778 bytes, checksum: dc3fa0c485a53f6482fbc321ee95103f (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi investigar os mecanismos envolvidos na migração de neutrófilos induzida pelo MTA para cavidade peritoneal de camundongos. Observouse que o MTA induziu migração de neutrófilos de maneira dose-dependente (0,5; 5; 50 e 100 mg/cavidade), alcançando o pico de migração 6 horas após a injeção do estímulo com a dose de 50 mg/cavidade. Esta migração foi parcialmente inibida pelo pré-tratamento dos animais com dexametasona (1 mg/Kg), BWA4C (50 mg/Kg) e U75302 (0,5 mg/Kg). Diferentemente, a Indometacina (5 mg/Kg) foi inefetiva neste processo. Verificou-se também que os animais estimulados com MTA (50 mg/cavidade) apresentaram uma liberação significativa de IL-1ß e MIP-2 no exsudato peritoneal. O pré-tratamento com Tioglicolato aumentou em cerca de 380% a população de macrófagos na cavidade peritoneal, potencializando a migração de neutrófilos induzida pelo MTA (p<0,05). O pré-tratamento com composto 48/80 depletou cerca de 75% a população de mastócitos, diminuindo a migração de neutrófilos (p<0,05). A injeção de MTA na bolha de ar subcutânea induziu uma migração de neutrófilos menor comparada à cavidade peritoneal. Estes resultados confirmam a participação de mastócitos e macrófagos na migração de neutrófilos induzida pelo MTA. A injeção de sobrenadante de macrófagos e mastócitos estimulados com MTA na cavidade peritoneal de camundongos causou significante migração de neutrófilos (p<0,05), que foi parcialmente inibida pelo pré-tratamento das células por dexametasona (10 æMolar), BWA4C (100 æMolar) e U75302 (10 æMolar) sugerindo a liberação por essas células de LTB4 e citocinas e/ou quimiocinas. Confirmando esses dados,... / The aim of this study was to investigate the mechanism involved in the neutrophil migration induced by MTA into peritoneal cavity in mice. It was observed that MTA induced a dose dependent neutrophil migration (0.5, 5, 50 and 100 mg/cavity), achieving the peak 6 hours after the stimulation with 50 mg/cavity. Neutrophil migration was inhibited by the pre-treatment with dexamethasone (1 mg/Kg), BWA4C (50 mg/Kg) and U75302 (0,5 mg/Kg). Differently indometacin (5 mg/Kg) was ineffective in this process. It was seen that the animals stimulated with MTA (50 mg/cavity) showed a significative amount of IL-1ß and MIP-2 released to the peritoneal exudate. The pretreatment with Thioglycolate 3% increased 380% the macropahge population into the peritoneal cavity, increasing the MTA-induced neutrophil migration (p<0.05). The pretreatment with 48/80 compound decreased 75% the mast cell population in the peritoneal cavity and decreased the MTAinduced neutrophil migration (p<0.05). The injection of MTA in the air-pouch cavity induced a neutrophil migration, however, the recruitment was shorter than that induced into the peritoneal cavity. These data confirm the participation of the mast cell and macrophages in the MTA-induced neutrophil migration. The injection of MTA-stimulated macrophages and mast cells supernatants into the mice peritoneal cavity induced a significant neutrophil migration that was inhibited by the pretreatment with dexamethasone (10 æMolar), BWA4C (100 æMolar) and U75302 (10 æMolar) suggesting the release of LTB4 and cytokines and/or chemokines by these cells. Besides, macrophages and mast cells MTA-induced were able to express in vitro IL-1ß MIP-2 and 5-LO mRNA. In conclusion, the neutrophil migration into mice peritoneal cavity induced by MTA was dependent on mast cells and macrophages, which expressed IL-1ß, MIP-2 and LTB4.

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No. of bitstreams: 2 Dissertação - Camila Imai Morato - 2013.pdf: 4002125 bytes, checksum: 75c6fdada46a41f441e1dc6455c95483 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The American Tegumentary Leishmaniasis (ATL) is an infectious disease caused by parasitic protozoa of the genus Leishmania, whose most prevalent species in Brazil is L. (Viannia) braziliensis. The human macrophage infection with L. (V.) braziliensis has been poorly investigated and is not known whether leukotrienes, lipid mediators produced by macrophages, may modulate this infection. The objective of this study was to evaluate whether leukotrienes modulate infection of human macrophages with L. (V.) braziliensis IMG3, a field clinical isolate. Human monocyte-derived macrophages were infected with promastigote forms of MHOM/BR/2003/IMG (IMG3) at a ratio of ~ 10:1 (parasite:cell). Cultures were incubated for 4 h and then washed to remove excess extracellular parasites, and incubated for additional 24, 48 or 72 h. To inhibit leukotriene synthesis, the cultures were treated with MK0591 and to antagonize the LTB4 receptor, CP-105, 696. LTB4 was also added to the cultures. The measurement of LTB4 was performed on culture supernatants using enzyme immunoassay. To evaluate the involvement of reactive oxygen intermediates (ROI) and nitric oxide (NO) their respective inhibitors were used, apocynin and aminoguanidine. To assess the production of ROIs it was used nitroblue tetrazolium salt (NBT). The IMG3 infected human macrophages, being selected periods of 4 h and 48 h incubation to assess phagocytosis and microbicidal activity, respectively. Treatments with MK0591 or CP105, 696 significantly increased the infection index after 4 h or 48 h incubation (p <005). The results show that the presence of MK0591 is need during whole incubation time (48 h) but not the LTB4 antagonist, whose effect is maintained after incubation for 4 h. The addition of LTB4 to the cultures significantly decreased macrophage infection, both during the first 4 h and after 48 h of incubation (p <0.05). The parasites induced LTB4 production in macrophage cultures during the first 30 min, but this production decreased after 4 h (p <0.05). The ROI and NO inhibitors significantly increased the infection index, before (ROI and NO) or after treatment with LTB4 (ROI). Preliminary results showed that production of superoxide anion is induced by parasites and this is further increased by LTB4. In conclusion, the results suggest that human macrophages produce leukotrienes following infection with L. (V.) braziliensis, and the main of them is LTB4. The LTB4 inhibits phagocytosis and enhances the microbicidal activity of macrophages, contributing to control of the infection. Results suggest that L. (V.) braziliensis induces LTB4, NO and ROI production and, in turn, LTB4 increases the microbicidal activity of macrophages via increase of ROI. Understanding the involvement of leukotrienes in the control of human macrophage infection with L. (V.) braziliensis can lead to the development of novel therapeutic targets for ATL. / A Leishmaniose Tegumentar Americana (LTA) é uma doença infecto-parasitária causada por protozoários do gênero Leishmania, cuja espécie mais prevalente no Brasil é L. (Viannia) braziliensis.A infecção de macrófagos humanos com L. (V.) braziliensis tem sido pouco estudada e não é conhecido se os leucotrienos, mediadores lipídicos produzidos por macrófagos, podem modular a infecção destas células por este parasito. O objetivo deste trabalho foi avaliar se os leucotrienos modulam a infecção de macrófagos humanos pelo isolado L. (V.) braziliensis IMG3. Macrófagos humanos foram derivados de monócitos do sangue periférico e infectados com formas promastigotas do isolado MHOM/BR/2003/IMG (IMG3) na proporção de ~10:1 (parasitos:célula). As culturas foram incubadas por 4 h, sendo em seguida lavadas para retirar o excesso de parasitos extracelulares, e incubadas por adicionais 24, 48 ou 72 h. Para inibir a síntese dos leucotrienos, as culturas foram tratadas com MK0591 e para antagonizar o receptor de LTB4, CP-105,696. O LTB4 também foi adicionado às culturas. A dosagem de LTB4 foi realizada nos sobrenadantes das culturas, usando ensaio imunoenzimático. Para avaliar a participação de espécies intermediárias do oxigênio (ROI) e do óxido nítrico (NO), foram utilizados os seus respectivos inibidores, apocinina e aminoguanidina. Para avaliar a produção de ROIs foi utilizada a técnica do azul de tetrazólio (NBT). O isolado IMG3 infectou os macrófagos humanos, sendo selecionados os períodos de 4 h e 48 h de incubação para avaliar a fagocitose e a atividade microbicida, respectivamente. Os tratamentos com MK0591 ou CP105,696 aumentaram significantemente o índice de infecção, após 4 h ou 48 h de incubação (p < 005). Os resultados mostraram que há necessidade da presença do composto MK0591 durante todo o período de incubação (48 h), mas não a do antagonista do LTB4, cujo efeito é mantido após incubação por 4 h. A adição de LTB4 às culturas diminuiu significantemente a infecção dos macrófagos, tanto durante as primeiras 4 h quanto após 48 h de cultura (p < 0,05). Os parasitos induziram a produção de LTB4 nas culturas de macrófagos nos primeiros 30 min, caindo esta produção após 4 h (p < 0,05). Além disso, o uso de inibidores de ROI e NO aumentaram significantemente a infecção de macrófagos antes (ROI e NO) ou após a ativação com LTB4 (ROI). Os resultados preliminares mostram a produção de ânion superóxido, induzida pelos parasitos e uma tendência no aumento pelo LTB4. Em conclusão, os resultados sugerem que os macrófagos humanos produzem leucotrienos após a infecção por L. (V.) braziliensis, sendo o LTB4 o principal leucotrieno produzido. O LTB4 inibe a fagocitose e aumenta a atividade microbicida dos macrófagos, contribuindo para diminuir a infecção. Os resultados sugerem que há produção de ROI e NO após infecção com L. (V.) braziliensis e que o LTB4 aumenta a atividade microbicida dos macrófagos via aumento da produção de ROI. Entender a participação dos leucotrienos no controle da infecção de macrófagos humanos por L. (V.) braziliensis pode levar à descoberta de novos alvos terapêuticos para a LTA.

Indiana University-Purdue University Indianapolis (IUPUI) / Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe skin infections and due to antibiotic resistance there is an intrinsic need to develop new immunotherapeutic strategies. Skin immune responses to infections require the cross-talk between phagocytes and structural cells that involves the secretion of cytokines, chemokines, and lipids. Leukotriene B4 (LTB4) is a pleiotropic lipid mediator known as a chemoattractant, but is also necessary to promote antimicrobial activity through B leukotriene receptor 1 (BLT1) signaling. However, chronic LTB4 production is associated with inflammatory diseases, including diabetes. People with diabetes are more susceptible to infections. The determinants by which LTB4/BLT1 promotes protective or detrimental immune responses in homeostasis and diabetes are unknown. We hypothesize that LTB4 levels determine infection outcome; while LTB4 is necessary for infection control, excessive LTB4 levels promote overwhelming inflammation that impairs host defense. Our data show that skin macrophages were necessary for LTB4 production and that LTB4 was vital for neutrophil direction, abscess formation, IL 1β production, and MRSA clearance through reactive oxygen species production. Importantly, topical LTB4 ointment treatment enhances neutrophil direction, abscess formation, and bacterial clearance. Conversely, in the setting of diabetes, skin macrophages drove excessive LTB4 production that promoted overwhelming inflammation, uncontrolled neutrophil recruitment, poor abscess formation, and lack of bacterial control. Diabetic mice treated with a topical ointment to inhibit BLT1 dampened inflammation and restored host defense by improving abscess formation, bacterial clearance, and overall inflammatory responses in the skin. These data demonstrate the balance of LTB4-induced inflammation is critical for regulating optimal immune responses during infections. This work highlights the importance of investigating the role of inflammatory mediators in the settings of health and disease. Targeting LTB4/BLT1 has therapeutic potential to regulate inflammation during MRSA skin infection by enhancing immune responses in settings of vulnerability or decrease inflammation in diabetes.

No description available.

Lau, Ka Hoi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 139-151). / Abstracts in English and Chinese. / DECLARATION --- p.i / ACKNOWLEDGEMENT --- p.ii / ABBREVIATIONS --- p.iii / ABSTRACT IN ENGLISH --- p.iv / ABSTRACT IN CHINESE --- p.vii / TABLE OF CONTENTS --- p.x / Chapter CHAPTER I - --- INTRODUCTION / Chapter 1.1 --- Regulation of human airway surface liquid --- p.1 / Chapter 1.2 --- Cysteinyl leukotrienes in asthma --- p.2 / Chapter 1.3 --- Cysteinyl leukotriene receptor in epithelial cells --- p.5 / Chapter 1.4 --- Particular interest on CysLT1 receptor --- p.7 / Chapter 1.5 --- Cysteinyl leukotrienes receptor antagonists --- p.10 / Chapter 1.6 --- Purinergic receptors in epithelial cells --- p.11 / Chapter 1.7 --- P2Y receptors in epithelial cells --- p.13 / Chapter 1.8 --- Signalling pathways of P2Y receptors by nucleotide stimulation --- p.15 / Chapter 1.9 --- The importance of P2Y6 receptor on inflammation --- p.17 / Chapter 1.10 --- Relation between CysLT1 receptor and P2Y receptor --- p.18 / Chapter 1.11 --- The properties of 16HBE14o- cell line --- p.21 / Chapter 1.12 --- Objectives of the present project --- p.22 / Chapter CHAPTER II - --- MATERIALS AND METHODS / Chapter 2.1 --- Solutions and chemicals --- p.23 / Chapter 2.2 --- Cell culture --- p.25 / Chapter 2.3 --- Measurement of intracellular calcium concentration ([Ca2+ ]i) with fluorescent imaging / Chapter 2.3.1 --- Preparation of 16HBE14o- cells for fluorescent imaging --- p.26 / Chapter 2.3.2 --- Measurement of [Ca2+]j with fluorescent imaging --- p.28 / Chapter 2.4 --- Measurement of short-circuit current (Isc) and transepithelial resistance with Ussing chamber / Chapter 2.4.1 --- Preparation of 16HBE14o- cells for Isc and transepithelial resistance measurement --- p.31 / Chapter 2.4.2 --- Measurement of Isc and transepithelial resistance with Ussing chamber --- p.33 / Chapter 2.5 --- Immunoblot analysis for CysLT1 and P2Y6 receptors --- p.35 / Chapter 2.6 --- Measurement of protein kinase A activity --- p.36 / Chapter 2.7 --- Data analysis --- p.37 / Chapter CHAPTER III - --- RESULTS / Chapter 3.1 --- Expressions of CysLTi and P2Y6 receptor in 16HBE14o- cell monolayers --- p.38 / Chapter 3.2 --- "Differential inhibitory effects of montelukast, pranlukast and zafirlukast to UDP on Isc and [Ca2+]i in 16HBE14o- cells" / Chapter 3.2.1 --- Effect of apical or basolateral application of UDP on Isc and [Ca2+]i --- p.41 / Chapter 3.2.2 --- Effect of montelukast to the application of UDP on Isc and [Ca2+]i --- p.48 / Chapter 3.2.3 --- Effect of pranlukast to the application of UDP on Isc and [Ca2+ ]i --- p.57 / Chapter 3.2.4 --- Effect of zafirlukast to the application of UDP on Isc and [Ca2+]j --- p.63 / Chapter 3.2.5 --- "Summary of the effects of montelukast, pranlukast, zafirlukast to UDP application on Isc and [Ca2+]i" --- p.69 / Chapter 3.3 --- Cellular mechanism(s) underlying the effect of montelukast to apical UDP application on 16HBE14o-cells / Chapter 3.3.1 --- Effect of various blockers inhibiting Ca2 226}Bؤdependent pathway on UDP-induced [Ca2+]i in the presence or absence of montelukast --- p.70 / Chapter 3.3.2 --- "Effects of montelukast, pranlukast and zafirlukast to PKA or Epac on Isc induced by apical UDP" --- p.86 / Chapter 3.4 --- "Effects of montelukast, pranlukast and zafirlukast on other P2Y receptor agonists on 16HBE14o- cells" / Chapter 3.4.1 --- "Effects of montelukast, pranlukast and zafirlukast on 2-methio-ADP-induced Isc and [Ca2+]i responses on 16HBE14o- cellsl" --- p.14 / Chapter 3.4.2 --- "Effects of montelukast, pranlukast and zafirlukast on UTP-induced Isc and [Ca2+]i responses on 16HBE14o- cells" --- p.116 / Chapter CHAPTER IV - --- DISCUSSION / Chapter 4.1 --- Differential effects of CysLT1 antagonists to P2Y6 agonist on Isc and [Ca2+]i in 16HBE14o-cells --- p.120 / Chapter 4.2 --- Possible cellular mechanism(s) underlying the effects of CysLT1 antagonists on UDP-induced [Ca2+]j increase in 16HBE14o- cells --- p.125 / Chapter 4.3 --- Possible cellular mechanism(s) underlying the effects of CysLT1 antagonists on UDP-induced Isc in 16HBE14o- cells --- p.129 / Chapter 4.4 --- Effects of CysLT1antagonists on other P2Y receptor subtypes in 16HBE14o- cells --- p.132 / Chapter 4.5 --- Summary: Possible interaction between CysLT1 antagonists and P2Y6 receptor --- p.135 / Chapter 4.6 --- Clinical implications and perspectives --- p.138 / Chapter CHAPTER V - --- REFERENCES --- p.139

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Human neutrophil 5-lipoxygenase (5-LOX) oxidizes arachidonic acid (AA) to 5S-hydro(pero)xy-6E,8Z,11Z,14Z-eicosatetraenoic acid (5-H(p)ETE) and leukotriene (LT)A4, which is further converted to the chemoattractant LTB4. These cells contain also the heme enzyme myeloperoxidase (MPO) producing several potent oxidants such as hypochlorous acid (HOCl). Previously, it was shown that MPO-metabolites influence 5-LOX product formation. Here, we addressed the question, whether a simultaneous activation of MPO and 5-LOX in neutrophils results in comparable changes of 5-LOX activity. Human neutrophils were stimulated with H2O2 or phorbol 12-myristate 13-acetate (PMA) for MPO activation and subsequently treated with calcium ionophore A23187 inducing 5-LOX product formation on endogenous AA. Special attention was drawn to neutrophil vitality, formation of MPO-derived metabolites and redox status. The pre-stimulation with H2O2 resulted in a concentration-dependent increase in the ratio of 5-HETE to the sum of LTB4 + 6-trans-LTB4 in consequence of MPO activation. Thereby no impairment of cell vitality and only a slightly reduction of total glutathione level was observed. An influence of MPO on 5-LOX product formation could be suggested using an MPO inhibitor. In contrast, the pre-stimulation with PMA resulted in different changes of 5-LOX product formation leading to a reduced amount of 5-HETE unaffected by MPO inhibition. Furthermore, impaired cell vitality and diminished redox status was detected after PMA stimulation. Nevertheless, a MPO-induced diminution of LTB4 was obvious. Further work is necessary to define the type of 5-LOX modification and investigate the effect of physiological MPO activators.

Orientador: Sandra Helena Penha de Oliveira / Banca: Carlos Ferreira dos Santos / Banca: Pedro Felício Estrada Bernabé / Resumo: O objetivo deste trabalho foi investigar os mecanismos envolvidos na migração de neutrófilos induzida pelo MTA para cavidade peritoneal de camundongos. Observouse que o MTA induziu migração de neutrófilos de maneira dose-dependente (0,5; 5; 50 e 100 mg/cavidade), alcançando o pico de migração 6 horas após a injeção do estímulo com a dose de 50 mg/cavidade. Esta migração foi parcialmente inibida pelo pré-tratamento dos animais com dexametasona (1 mg/Kg), BWA4C (50 mg/Kg) e U75302 (0,5 mg/Kg). Diferentemente, a Indometacina (5 mg/Kg) foi inefetiva neste processo. Verificou-se também que os animais estimulados com MTA (50 mg/cavidade) apresentaram uma liberação significativa de IL-1ß e MIP-2 no exsudato peritoneal. O pré-tratamento com Tioglicolato aumentou em cerca de 380% a população de macrófagos na cavidade peritoneal, potencializando a migração de neutrófilos induzida pelo MTA (p<0,05). O pré-tratamento com composto 48/80 depletou cerca de 75% a população de mastócitos, diminuindo a migração de neutrófilos (p<0,05). A injeção de MTA na bolha de ar subcutânea induziu uma migração de neutrófilos menor comparada à cavidade peritoneal. Estes resultados confirmam a participação de mastócitos e macrófagos na migração de neutrófilos induzida pelo MTA. A injeção de sobrenadante de macrófagos e mastócitos estimulados com MTA na cavidade peritoneal de camundongos causou significante migração de neutrófilos (p<0,05), que foi parcialmente inibida pelo pré-tratamento das células por dexametasona (10 æMolar), BWA4C (100 æMolar) e U75302 (10 æMolar) sugerindo a liberação por essas células de LTB4 e citocinas e/ou quimiocinas. Confirmando esses dados,...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to investigate the mechanism involved in the neutrophil migration induced by MTA into peritoneal cavity in mice. It was observed that MTA induced a dose dependent neutrophil migration (0.5, 5, 50 and 100 mg/cavity), achieving the peak 6 hours after the stimulation with 50 mg/cavity. Neutrophil migration was inhibited by the pre-treatment with dexamethasone (1 mg/Kg), BWA4C (50 mg/Kg) and U75302 (0,5 mg/Kg). Differently indometacin (5 mg/Kg) was ineffective in this process. It was seen that the animals stimulated with MTA (50 mg/cavity) showed a significative amount of IL-1ß and MIP-2 released to the peritoneal exudate. The pretreatment with Thioglycolate 3% increased 380% the macropahge population into the peritoneal cavity, increasing the MTA-induced neutrophil migration (p<0.05). The pretreatment with 48/80 compound decreased 75% the mast cell population in the peritoneal cavity and decreased the MTAinduced neutrophil migration (p<0.05). The injection of MTA in the air-pouch cavity induced a neutrophil migration, however, the recruitment was shorter than that induced into the peritoneal cavity. These data confirm the participation of the mast cell and macrophages in the MTA-induced neutrophil migration. The injection of MTA-stimulated macrophages and mast cells supernatants into the mice peritoneal cavity induced a significant neutrophil migration that was inhibited by the pretreatment with dexamethasone (10 æMolar), BWA4C (100 æMolar) and U75302 (10 æMolar) suggesting the release of LTB4 and cytokines and/or chemokines by these cells. Besides, macrophages and mast cells MTA-induced were able to express in vitro IL-1ß MIP-2 and 5-LO mRNA. In conclusion, the neutrophil migration into mice peritoneal cavity induced by MTA was dependent on mast cells and macrophages, which expressed IL-1ß, MIP-2 and LTB4. / Mestre