Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-06-21T15:37:43Z No. of bitstreams: 1 daniellegomesmarconato.pdf: 2747967 bytes, checksum: 9b5932356e36c2997fb2e0f9fb1227b9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T19:11:05Z (GMT) No. of bitstreams: 1 daniellegomesmarconato.pdf: 2747967 bytes, checksum: 9b5932356e36c2997fb2e0f9fb1227b9 (MD5) / Made available in DSpace on 2017-08-07T19:11:05Z (GMT). No. of bitstreams: 1 daniellegomesmarconato.pdf: 2747967 bytes, checksum: 9b5932356e36c2997fb2e0f9fb1227b9 (MD5) Previous issue date: 2016-03-04 / Nucleotídeos e nucleosídeos extracelulares podem funcionar como moléculas de sinalização dos processos inflamatórios e da resposta imune. Nesse contexto, as NTPDases representam uma importante família de enzimas capazes de hidrolisar nucleosídeos di e tri-fosfatados, responsáveis por regular a sinalização purinérgica na maioria dos seres vivos. A homologia entre diferentes enzimas dessa família estimula investigações das interações dos anticorpos direcionados contra as isoformas destas enzimas presentes em parasitos e sua conexão com as isoformas expressas em seus hospedeiros mamíferos. As isoformas de NTPDases do helminto Schistosoma mansoni, denominadas SmATPDases 1 e 2 são antigênicas e exibem uma homologia significativa com as isoformas de NTPDases presentes em células de mamíferos. O objetivo do trabalho foi verificar se anticorpos anti-SmATPDase 1 presentes no soro de animal infectado com S. mansoni podem ter imunorreatividade cruzada com isoforma NTPDase 1 das células do sistema imune de mamíferos. Essa imunorreatividade pode afetar a proliferação e sinalização celular, justificando uma modulação direta da sinalização purinérgica desenvolvida durante a progressão da esquistossomose. Na primeira etapa, foi detectado que os anticorpos contra a isoforma de SmATPDase 1 presente no “pool” de soros de animais infectados foram capazes de reconhecer a isoforma NTPDase 1 em preparações de macrófagos e esplenócitos, resultando na visualização de bandas nítidas com peso molecular de aproximadamente 53 e 58 kDa. A isoforma NTPDase 1 também foi identificada na superfície destas células por imunofluorescência. A reatividade entre preparações de células e anticorpos anti-IgG presentes no soro de animais com esquistossomosse (diluições 1:50 e 1:100) também sugeriu a existência de proteínas homólogas entre o parasito e as células imunes, podendo estar relacionadas às NTPDases. Estes anticorpos utilizados foram capazes de reduzir a atividade fosfohidrolítica nas preparações de macrófagos (22%) e esplenócitos (58%), assim como os anticorpos anti-CD39 promoveram decréscimo nessa atividade em 40% e 83%, respectivamente. Em ensaios de proliferação celular, houve redução na proliferação de macrófagos em 24 h (14%), 48 h (14%) e 72 h (11%) em células incubadas com “pool” soros de animais infectados e com anti-CD39 29%, 12% e 90%, respectivamente. A atividade proliferativa de esplenócitos incubadas com anti-CD39 aumentou nos tempos de 48h (45%) e 72h (70%) e nas células mantidas com soro imune de animal infectado não foi observada nenhuma diferença significativa. Em ensaio de proliferação de linfócitos por citometria de fluxo houve um aumento significativo do número de linfócitos T nos grupos incubados com soro imune (36%) e anti-CD39 (>100%). Por sua vez, houve um decréscimo de 44% na proliferação de linfócitos B tratados previamente com soro de animal infectado e de 34% no grupo tratado com anti-CD39. Com esses resultados sugerimos que a inibição da NTPDase 1 de células imunes por anticorpos produzidos contra a isoforma da enzima do S. mansoni pode ser responsável pela modulação da resposta imune que ocorre na esquistossomose, contribuindo para um perfil Th2. Porém, outros testes são necessários para corroborar essa hipótese. A inibição das NTPDases pode contribuir para o estudo dos mecanismos envolvidos em diversas disfunções relacionadas a defeitos na sinalização purinérgica. / Extracellular nucleotides and nucleosides may act as signaling molecules that control inflammation and immune response. In this context, NTPDases represent an important family of enzymes capable of hydrolyzing di- and tri-phosphate nucleosides which regulate purinergic signaling in most living beings. The homology between different enzymes from the NTPDase family supports new investigations about the interactions of antibodies directed against isoforms of these enzymes in parasites and the connection to their isoforms expressed in mammalian hosts. The NTPDase isoforms in Schistosoma mansoni, called SmATPDases 1 and 2 are antigenic and display a significant homology with the NTPDases isoforms found in mammalian cells. The aim of this work was to verify if anti-SmATPDase 1 antibodies from serum of animals infected with S. mansoni show cross-immunoreactivity with the NTPDase 1 isoform from immune system cells of mammalians. This cross-immunoreactivity could affect cell proliferation and cell signalization, justifying a direct modulation of the purinergic signaling developed during the progression of schistosomiasis. Through western blotting technique we verified that antibodies against SmATPDase isoforms from serum of infected animals were able to recognize NTPDase isoform 1 from homogenized splenocytes and macrophages, resulting in clear display of bands with molecular weights of approximately 53 and 58 kDa. Additionally, NTPDase 1 was identified and localized in these cells by immunofluorescence. The reactivity between preparations of cells and anti-IgG antibodies present in the serum of animals with schistosomiasis (dilutions 1:50 and 1: 100) also suggested the existence of homologous proteins between the parasite and the immune cells that could be related to NTPDases. Antibodies were also able to reduce activity enzyme in preparations of macrophages (22%) and splenocytes (58%). Anti-CD39 promoted decrease in this activity by 40% and 83%, respectively. In cell proliferation assays, there was a reduction in the proliferation of macrophages in 24 h (14%), 48 h (14%) and 72 h (11%) in cells incubated with pool infected animal sera and with anti-CD39 29%, 12% and 90%, respectively. When the splenocytes culture was incubated with anti-CD39, proliferative activity increased in 48h (45%) and 72 h (70%) and in cells maintained with immune serum of the infected animal, it observed no significant difference. The lymphocyte proliferation assay by flow cytometry there is a significant increase in the number of T lymphocytes incubated with immune serum (36%) and anti-CD39 (> 100%). In turn, there was a 44% decrease in proliferation of B cells previously treated with infected animal serum and 34% in the group treated with anti-CD39. These results suggest that inhibition of NTPDase 1 of immune cells by antibodies produced against the isoforms of the S. mansoni could be responsible for modulation of the immune response during the schistosomiasis, conducting to a Th2 response. However, more tests should be carried out to confirm this hypothesis. The NTPDases inhibition may contribute for studies of the mechanisms involved in various disorders related to defects in purinergic signaling.

Quimioreceptores centrais (QC) e periféricos (QP) são células especializadas em detectar alterações de CO2, O2 e H+, e promover ajustes na ventilação e pressão arterial via sistema nervoso central. Avaliamos aqui a ação da sinalização purinérgica em áreas que apresentam essa propriedade (RTN, C1, NTScom e RPa) durante as respostas cardiorrespiratórias promovidas pela ativação dos quimiorreceptores, e a possível participação de astrócitos. Encontramos evidências que receptores P2 modulam a resposta de QC no RTN, enquanto que receptores P2Y1 e receptores glutamatérgicos, modulam a resposta de QP no C1, e que a sinalização purinérgica na região do NTScom ou na região RPa não contribui para resposta de QC. A manipulação farmacológica de astrócitos do RTN com fluorocitrato, mas não da região do NTScom e RPa, produz alterações respiratórias via receptores P2. Nossos achados evidenciam a importância e contribuem para descriminação dos mecanismos de ação da sinalização purinérgica na região bulbo ventrolateral rostral durante a ativação QC e QP. / Central (CC) and peripherals (PC) chemoreceptors are specialized cells to detect changes in CO2, O2 and H+, and produce adjustments in ventilation and blood pressure via the central nervous system. Here we evaluate the action of purinergic signaling in areas with this property (RTN, C1, commNTS, RPA) during the cardiorespiratory responses elicited by activation of chemoreceptors, and a possible role of astrocytes. We found evidence that P2 receptors modulate CC responses in RTN, while P2Y1 and glutamate receptors modulate PC responses in C1, and that the purinergic signaling in the RPa and commNTS region does not contribute to CC responses. The pharmacological manipulation of the RTN astrocytes, but not commNTS or RPa, with fluorocitrate produces respiratory changes via P2 receptors. Our findings show the importance and contribute to discrimination of the mechanisms of purinergic signaling in the rostral ventrolateral medulla during CC and PC activation.

Hepatitis C is an infectious disease caused by Hepatitis C virus (HCV) and characterized by development of inflammation as well as fibrosis. On the other hand, the extracellular nucleotides and adenine nucleosides are important signaling molecules that can modulate inflammatory responses in platelets and lymphocytes. This study sought to determine the activities of ectoenzymes [ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5 -nucleotidase (E-5 -NT) and ecto-adenosine deaminase (E-ADA)] that metabolize nucleotides in platelets and lymphocytes and to evaluate cytokine levels of patients with HCV. Twenty five HCV patients and fifty healthy subjects (control group) were selected for this study. In lymphocytes, was observed a lower ATP hydrolysis (P<0.001), and higher ADP hydrolysis (P<0.001) and E- ADA activity (P<0.001) in HCV patients when compared to the control group. In addition, the results revealed a higher ATP and ADP hydrolysis by E-NTPDase and higher E-ADA activity in platelets of HCV patients when compared with the control group. Also, IL-4 and IL-10 were significantly (P<0.05) increased while IL-6 was decreased (P<0.05) in HCV patients. In conclusion, the results showed that the activities of E-NTPDase and E-ADA were altered in both lymphocytes and platelets of HCV patients. These alterations in enzymes activities may be possible regulatory mechanisms in an attempt to manage liver damage and ongoing inflammatory process. Furthermore, decreased IL-6 as well as increased IL-4 and IL-10 in HCV patients may suggest an antiinflammatory process and possible compensatory mechanisms in minimizing liver injury. / Hepatitis C is an infectious disease caused by Hepatitis C virus (HCV) and characterized by development of inflammation as well as fibrosis. On the other hand, the extracellular nucleotides and adenine nucleosides are important signaling molecules that can modulate inflammatory responses in platelets and lymphocytes. This study sought to determine the activities of ectoenzymes [ectonucleoside triphosphate diphosphohydrolase (E-NTPDase), ecto-5 -nucleotidase (E-5 -NT) and ecto-adenosine deaminase (E-ADA)] that metabolize nucleotides in platelets and lymphocytes and to evaluate cytokine levels of patients with HCV. Twenty five HCV patients and fifty healthy subjects (control group) were selected for this study. In lymphocytes, was observed a lower ATP hydrolysis (P<0.001), and higher ADP hydrolysis (P<0.001) and E- ADA activity (P<0.001) in HCV patients when compared to the control group. In addition, the results revealed a higher ATP and ADP hydrolysis by E-NTPDase and higher E-ADA activity in platelets of HCV patients when compared with the control group. Also, IL-4 and IL-10 were significantly (P<0.05) increased while IL-6 was decreased (P<0.05) in HCV patients. In conclusion, the results showed that the activities of E-NTPDase and E-ADA were altered in both lymphocytes and platelets of HCV patients. These alterations in enzymes activities may be possible regulatory mechanisms in an attempt to manage liver damage and ongoing inflammatory process. Furthermore, decreased IL-6 as well as increased IL-4 and IL-10 in HCV patients may suggest an antiinflammatory process and possible compensatory mechanisms in minimizing liver injury.

Quimioreceptores centrais (QC) e periféricos (QP) são células especializadas em detectar alterações de CO2, O2 e H+, e promover ajustes na ventilação e pressão arterial via sistema nervoso central. Avaliamos aqui a ação da sinalização purinérgica em áreas que apresentam essa propriedade (RTN, C1, NTScom e RPa) durante as respostas cardiorrespiratórias promovidas pela ativação dos quimiorreceptores, e a possível participação de astrócitos. Encontramos evidências que receptores P2 modulam a resposta de QC no RTN, enquanto que receptores P2Y1 e receptores glutamatérgicos, modulam a resposta de QP no C1, e que a sinalização purinérgica na região do NTScom ou na região RPa não contribui para resposta de QC. A manipulação farmacológica de astrócitos do RTN com fluorocitrato, mas não da região do NTScom e RPa, produz alterações respiratórias via receptores P2. Nossos achados evidenciam a importância e contribuem para descriminação dos mecanismos de ação da sinalização purinérgica na região bulbo ventrolateral rostral durante a ativação QC e QP. / Central (CC) and peripherals (PC) chemoreceptors are specialized cells to detect changes in CO2, O2 and H+, and produce adjustments in ventilation and blood pressure via the central nervous system. Here we evaluate the action of purinergic signaling in areas with this property (RTN, C1, commNTS, RPA) during the cardiorespiratory responses elicited by activation of chemoreceptors, and a possible role of astrocytes. We found evidence that P2 receptors modulate CC responses in RTN, while P2Y1 and glutamate receptors modulate PC responses in C1, and that the purinergic signaling in the RPa and commNTS region does not contribute to CC responses. The pharmacological manipulation of the RTN astrocytes, but not commNTS or RPa, with fluorocitrate produces respiratory changes via P2 receptors. Our findings show the importance and contribute to discrimination of the mechanisms of purinergic signaling in the rostral ventrolateral medulla during CC and PC activation.