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Previous issue date: 2016-03-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Funda??o de Amparo ? Pesquisa do Estado do Rio Grande do Sul - FAPERGS / The LPS mechanism of action is still not completely elucidated on vertebrates like fish, and indeed differs from higher vertebrates. In zebrafish, LPS is capable of increasing the recruitment of immune cells and the expression of genes related to the immune response. The purinergic system has a great relation to the regulation of the immune system and inflammatory responses. The nucleotide ATP is able to induce cytokine secretion, recruitment and differentiation of immune cells. ATP can be dephosphorylated sequentially generating adenosine. In the context of inflammation adenosine serves as an innate immunomodulatory molecule. The control of adenosine extracellular levels is performed by nucleoside transporters and ecto-5'-nucleotidase. The ecto-5'-nucelotidase is an ectonucleotidase with pacemaker role in the production of adenosine and is one of the focuses of this study. Considering the analysis of the input images approach to the study of inflammation context, it is known that in rodents the uptake of 18F-FDG, an analogue of glucose, is increased under inflammation, which generates a differential image. The micro Positron Emission Tomography/ Computed Tomography (?PET /CT) is used for research in small animals and take images using a radiopharmaceutical. The use of ?PET/CT contributes with information at the molecular, structural and functional level and allows too monitor the effect of drugs in physiological / pathological situations in the range of a small animal as the zebrafish. The technology ?PET/CT is relatively new and so far there are no published scientific studies applying radiopharmaceuticals in zebrafish. In this context, the aim of the project was to study the involvement of the enzyme ecto-5'-nucleotidase in the development of inflammation induced by LPS using the cytological, biochemical, molecular and image (?PET) in different tissues of adult zebrafish (Danio rerio). To induce inflammation in zebrafish, the animals were injected with a solution of LPS (10 ug/g body weight, i.p) after being subjected to anesthesia (tricaine 0.1 g/L). The animals were kept for 2 hours or 24 hours in this treatment. For confirmation of inflammation were analyzed the gene expression of specific markers (tnf-? and cox-2) in encephalon, heart, kidney and intestine and differential counts of cells of the immune system. The activity and expression of ecto-5'-nucleotidase enzyme was analyzed in the encephalon, heart, kidney and intestine of control and treated animals. To keep the animals in ?PET/CT was performed anesthetic concentration curve (tricaine - 0.1, 0.12, 0.15 g/L) and standardized an apparatus to keep the fish in the presence of water, but yet still. A curve of time after injection of 18F-FDG was performed to obtain images in ?PET/CT (0, 10, 20 and 30 min) for standardizing the radiation quantitation in a gamma counter (15, 30, 60 90 and 120 min). Exposure to the LPS was able to increase the tnf-? expression in nearly all tissues studied (heart, kidney and intestine) and cox-2 in the kidney. The number of active peripheral blood white cells was also increased, confirming the induction of the inflammatory response. Hydrolysis of AMP in animals injected with LPS was increased in the heart in 24 hpi [72% compared to control] with no change in gene expression of ecto-5'-nucleotidase. The gene expression of ecto-5'-nucleotidase was adjusted temporarily in the kidney and intestine without altering the enzyme activity. After patterning images with ?PET/ CT and quantitation radiation by gamma counter for each organ examined, 30 minutes was defined as the best time for the biodistribution of 18F-FDG. After acquiring inflamed animal ?PET images it was not identified changes in the uptake of 18F-FDG compared to the control. Tissue quantification radiation registered a decrease in bone samples in animals treated with LPS, while other tissues have not changed. These data indicate that zebrafish responds to LPS by altering gene expression of specific markers, especially in kidney, and activation of white blood cells. The inflammation appears to be accompanied by a fine adjustment tissue-specific expression and activity of ecto-5'-nucleotidase in response to the inflammatory process. Although inflammation has been confirmed, the registration images by ?PET and radiation determination in different tissues have not been able to register differences in metabolic activity in animals treated with LPS. However, standardization of these techniques provides an advance in the use of radiopharmaceuticals in small animals, such as zebrafish. / O mecanismo de a??o do LPS ainda n?o ? completamente elucidado em vertebrados como os peixes, e se diferencia dos vertebrados superiores. Em zebrafish, o LPS ? capaz de aumentar o recrutamento de c?lulas imunes e a express?o de genes relacionados com a resposta imune. O sistema purin?rgico tem uma grande rela??o com a regula??o do sistema imune e as respostas inflamat?rias. O ATP ? um nucleot?deo importante na secre??o de citocinas e no recrutamento e diferencia??o de c?lulas imunes, podendo ser sequencialmente desfosforilado gerando adenosina. No contexto da inflama??o, a adenosina atua como uma mol?cula imunomodulat?ria inata. Participam do controle dos n?veis extracelulares da adenosina, os transportadores de nucleos?deos e a ecto-5?-nucleotidase. A ecto-5?-nucleotidase ? uma enzima com papel de marcapasso na produ??o de adenosina e constitui um dos focos do presente estudo. Considerando a contribui??o da abordagem de an?lise de imagens no contexto do estudo da inflama??o, ? sabido que a capta??o do radiof?rmaco 18F-FDG, um an?logo da glicoseest? aumentada em roedores submetidos ? inflama??o, o que gera uma imagem diferenciada. O micro Tom?grafo por Emiss?o de P?sitron/Tomografia Computadorizada (?PET/CT) ? utilizado para pesquisas em animais de pequeno porte e obt?m imagens utilizando um radiof?rmaco. O uso da ?PET/CT contribui com informa??es a n?vel molecular, funcional e estrutural em tempo real e permite acompanhar o efeito de f?rmacos em situa??es fisiol?gicas/patol?gicas na escala de um animal diminuto como o zebrafish. A tecnologia do ?PET/CT ? relativamente nova e at? o momento n?o existem estudos cient?ficos publicados aplicando radiof?rmacos em zebrafish. Neste contexto, o objetivo do projeto foi estudar o envolvimento da enzima ecto-5?-nucleotidase no desenvolvimento de inflama??o induzida por LPS utilizando-se de par?metros citol?gicos, bioqu?micos, moleculares e de imagem por ?PET em diferentes tecidos de zebrafish adulto (Danio rerio). Para induzir inflama??o no zebrafish, os animais foram injetados com uma solu??o de LPS (10 ?g/g de peso corporal; i.p) ap?s terem sido submetidos ? anestesia (trica?na 0.1 g/L). Os animais permaneceram por 2 h ou 24 h neste tratamento. Para confirma??o da inflama??o foram analisadas a express?o g?nica de marcadores espec?ficos (tnf-? e cox-2) em enc?falo, cora??o, rim e intestino e contagem diferencial de c?lulas do sistema imune. A atividade e express?o da enzima ecto-5?-nucleotidase foi analisada no enc?falo, cora??o, rim e intestino dos animais controle e tratados. Para manter os animais no ?PET/CT foi realizada uma curva de concentra??o de anest?sico MS-222 (0.1, 0. 12, 0.15 g/L) e determinado um aparato para manter o peixe na presen?a de ?gua mas, ainda im?vel. Uma curva de tempo ap?s a inje??o de 18F-FDG foi realizada para a obten??o de imagens em ?PET/CT (0, 10, 20 e 30 min) e para a padroniza??o da quantifica??o de radia??o em um Gamma counter (15, 30, 60, 90 e 120 min). A exposi??o ao LPS foi capaz de aumentar a express?o de tnf-? em quase todos os tecidos estudados (cora??o, rim e intestino) e de cox-2 no rim. O n?mero de c?lulas brancas ativas do sangue perif?rico tamb?m foi aumentado, confirmando a indu??o da resposta inflamat?ria. A hidr?lise de AMP em animais injetados com LPS foi aumentada no cora??o em 24 hpi [72% em rela??o ao controle] com nenhuma altera??o na express?o g?nica da ecto-5?-nucleotidase. A express?o g?nica do ecto-5?-nucleotidase foi ajustada temporalmente no rim e intestino sem altera??o da atividade enzim?tica. Ap?s a padroniza??o de imagens com ?PET/CT e da quantifica??o de radia??o por Gamma counter para cada ?rg?o analisado, definiu-se 30 min como o melhor tempo para a biodistribui??o do 18F-FDG. Ap?s a aquisi??o de imagens em ?PET de animais inflamados n?o se identificou altera??es na capta??o do 18F-FDG comparado com o controle. A quantifica??o tecidual de radia??o registrou uma queda nas amostras de ossos nos animais tratados com LPS, embora os demais tecidos n?o tenham sido alterados. Estes dados indicam que o zebrafish responde ao LPS alterando express?o g?nica de marcadores espec?ficos, especialmente no rim e ativando c?lulas brancas do sangue. A inflama??o induzida parece estar acompanhada por um t?nue ajuste tecido-espec?fico da atividade e express?o da ecto-5?-nucleotidase em resposta ao processo inflamat?rio. Ainda que a inflama??o tenha sido confirmada, o registro de imagens por ?PET e a determina??o de radia??o nos diferentes tecidos n?o foram capazes de registrar diferen?as na atividade metab?lica em animais tratados com LPS. Entretanto, a padroniza??o destas t?cnicas oferece um avan?o no uso de radiof?rmacos em animais de pequeno porte, como o zebrafish.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/6927 |
| Date | 21 March 2016 |
| Creators | Nazario, Luiza Reali |
| Contributors | Silva, Rosane Souza da, Jeckel, Cristina Maria Moriguchi |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Biologia Celular e Molecular, PUCRS, Brasil, Faculdade de Bioci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 8198246930096637360, 600, 600, 600, 600, 600, 36528317262667714, -1634559385931244697, 2075167498588264571, -3614735573891122254 |
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