Submitted by PPG Pediatria e Sa?de da Crian?a (pediatria-pg@pucrs.br) on 2018-01-02T16:42:12Z No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-01-24T12:15:04Z (GMT) No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) / Made available in DSpace on 2018-01-24T12:17:42Z (GMT). No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) Previous issue date: 2017-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Introduction: acute bronchiolitis (AB) is an inflammatory disease of the airways considered the most common pathology of the lower respiratory tract in childhood. Responsible for a large number of hospitalizations in infants is one of the leading respiratory diseases worldwide, raising the costs of health care in infants. According to epidemiological data, between 75,000 and 125,000 children are hospitalized in the United States each year with infections caused by respiratory syncytial virus (RSV), accounting for approximately 25% of pediatric pneumonia and up to 70% of hospitalizations for acute bronchiolitis. Children with deficiencies in cell-mediated immunity can develop more severe and prolonged infections. Activation of the mTOR, STAT-3 and STAT-6 signaling pathways have been identified as key regulators in different functions of the immune system. The aim of this study was to investigate the relationship between the gene expression of mTOR, STAT-3, STAT-6 and AB severity. Methods: it is a cohort study that included a group of infants less than 12 months old with AB admitted to a tertiary hospital in Porto Alegre, Brazil. Nasopharyngeal lavage was collected from all patients and stored in Trizol solution at -80?C at the Biomedical Research Institute (IPB) of PUCRS for subsequent extraction of RNA and cDNA synthesis. Specific primers were used to verify the relative expression of mTOR, STAT-3 and STAT-6 by means of real-time PCR. The results obtained were correlated with AB severity markers such as hospitalization time and wheezing time. Results: for the analysis of expression of the mTOR signaling protein and transcription factors STAT-3 and STAT-6, 23 patients hospitalized with AB were included. A general correlation was made between clinical markers (days of hospitalization and days of wheezing) and expression of signaling pathways. Data were stratified according to severity markers and showed a trend towards decreased mTOR expression in patients with a wheezing time equal to or greater than 5 days (r = -0.702 and p = 0.024). However, the STAT-3 and STAT-6 signaling pathways were not correlated with AB severity factors when applied in this group of patients. Conclusion: transcription factors are essential for generating effective immune responses. mTOR, STAT-3 and STAT-6 participate in the expression of a variety of genes in response to cellular stimuli and may play a key role in the manifestation of the disease. Our data demonstrate the decrease in mTOR expression, with improvement in clinical markers of severity, but other studies are needed to reinforce this finding. / Introdu??o: a bronquiolite aguda (BA) ? uma doen?a inflamat?ria das vias a?reas considerada a patologia mais comum do trato respirat?rio inferior na inf?ncia. Respons?vel por um grande n?mero de hospitaliza??es em lactentes ? uma das principais doen?as respirat?rias em todo o mundo, elevando os custos de cuidados de sa?de em lactentes. Segundo dados epidemiol?gicos, entre 75.000 e 125.000 crian?as s?o hospitalizadas nos Estados Unidos anualmente com infec??es causadas pelo v?rus sincicial respirat?rio (VSR), respondendo por aproximadamente 25% das pneumonias pedi?tricas e at? 70% das interna??es por bronquiolite aguda (BA). As crian?as com defici?ncia na imunidade mediada por c?lulas podem desenvolver infec??es mais graves e prolongadas. A ativa??o das vias de sinaliza??o mTOR, STAT-3 e STAT-6 t?m sido identificadas como reguladores-chave em diferentes fun??es do sistema imune. O objetivo deste estudo foi investigar a rela??o entre a express?o g?nica de mTOR, STAT-3, STAT-6 e a gravidade da BA. M?todos: trata-se de um estudo de coorte onde foi inclu?do um grupo de lactentes de idade inferior a 12 meses, com BA, internados em um hospital terci?rio de Porto Alegre, Brasil. Foi coletado lavado nasofar?ngeo de todos os pacientes e armazenados em solu??o de Trizol ? temperatura de -80?C no Instituto de Pesquisas Biom?dicas (IPB) da PUCRS para posterior extra??o de RNA e s?ntese de cDNA. Foram utilizados os iniciadores espec?ficos para verificar a express?o relativa de mTOR, STAT-3 e STAT-6 por meio de PCR em tempo real. Os resultados obtidos foram correlacionados com marcadores de gravidade da BA como tempo de interna??o e tempo de sibil?ncia. Resultados: para a an?lise da express?o da prote?na de sinaliza??o mTOR e fatores de transcri??o STAT-3 e STAT-6, foram inclu?dos 23 pacientes hospitalizados com BA. Foi realizada uma correla??o geral entre os marcadores cl?nicos (dias de interna??o e dias de sibil?ncia) e a express?o das vias de sinaliza??o. Os dados foram estratificados de acordo com os marcadores de severidade e mostraram uma tend?ncia para a diminui??o da express?o de mTOR em pacientes com tempo de sibil?ncia igual ou superior a 5 dias (r = -0,702 e p = 0,024). No entanto, as vias de sinaliza??o STAT-3 e STAT-6 n?o foram correlacionadas com fatores de gravidade da BA quando aplicadas neste grupo de pacientes. Conclus?o: os fatores de transcri??o s?o essenciais para gerar respostas imunes eficazes. O mTOR, STAT-3 e STAT-6 participam na express?o de uma variedade de genes em resposta a est?mulos celulares e podem desempenhar um papel-chave na manifesta??o da doen?a. Nossos dados demonstram a diminui??o da express?o de mTOR, com melhora dos marcadores cl?nicos de gravidade, por?m outros estudos s?o necess?rios para refor?ar este achado.