O presente trabalho refere-se ao estudo do papel dos microRNAs no controle pós-transcricional das células T de camundongos Non Obese Diabetic (NOD) modelo que reproduz o diabetes mellitus do tipo 1 (DM-1). Durante o desenvolvimento do trabalho, procurou-se esclarecer a hipótese de que os microRNAs controlam os níveis de determinados RNAs mensageiros (mRNAs) das células T durante a indução ou perda de tolerância imunológica. Portanto, a expressão alterada dos microRNAs estaria contribuindo com o processo da autoimunidade. Sendo assim, o objetivo do estudo foi identificar os perfis de expressão e as redes de interação entre um conjunto de microRNAs e seus respectivos mRNAs alvos nos timócitos e nos linfócitos T CD3+ periféricos durante o desenvolvimento do diabetes mellitus do tipo 1 (DM-1) em camundongos NOD. Para avaliar a expressão de genes codificadores de mRNAs, sendo estes possíveis alvos de microRNAs, utilizou-se a tecnologia de microarrays. O uso de programas de análise e para a construção das redes foi imprescindível. Acreditase que fenômenos complexos como a regulação pós-transcricional de células T e seu envolvimento no processo de tolerância imunológica, bem como o surgimento de doenças autoimunes, podem ser melhor compreendidos por meio da genômica funcional. Os resultados encontrados evidenciam uma expressão diferenciada de mRNAs e microRNAs em timócitos e linfócitos T CD3+ periféricos durante o desenvolvimento do diabetes mellitus do tipo 1 (DM-1). As diferenças nos perfis transcricionais encontradas envolvem expressão de genes (mRNAs) relacionados diretamente ao sistema imune, a diferenciação e ativação de linfócitos T e a apoptose, bem como a outros processos relacionados a resposta imune. Além disso, as redes de interação microRNA-mRNA encontradas no presente trabalho evidenciam interações já conhecidas e apresentam novas interações, mostrando a participação de um grupo de microRNAs que estão atuando no controle pós-transcricional do diabetes do tipo 1 em camundongos NOD, contribuindo com a melhor compreensão do controle genético-molecular das doenças autoimunes, principalmente do diabetes do tipo 1. / This study refers to the role played by microRNAs in the post-transcriptional control of T cells from non obese diabetic (NOD) mice model which reproduces the type 1 diabetes (T1D). During the study, it was tried to clarify the hypothesis that microRNAs control certain messenger RNAs (mRNAs) levels of the T cells during the induction or loss of immunological tolerance. Therefore, the altered expression of microRNAs might be contributing to the process of autoimmunity. Thus, the study aim was to identify the expression profiles and interaction networks between a set of microRNAs and their mRNA targets in thymocytes and peripheral CD3+ T lymphocytes during the development of type 1diabetes (T1D) in NOD mice. The microarray technology was used to evaluate the expression of mRNAs as possible targets of microRNAs involved in this process. The use of bioinformatics software to reconstruct the networks was essential. It was realized that complex phenomena as post-transcriptional regulation in T cells and their involvement in the immune tolerance process, as well as the emergence of autoimmune diseases can be better understood only by means of functional genomics. The results show differential expression of mRNAs and microRNAs in thymocytes and peripheral CD3+ T lymphocytes during the development of type 1 diabetes (T1D). The differences found in the transcriptional profiles involve mRNAs related to the immune system, differentiation and activation of T lymphocytes and apoptosis as well as other processes related to immune response. In addition, the microRNA-mRNA interaction networks obtained in this study evidence the predicted interactions as well as new ones, showing the participation of a group of microRNAs that may be acting in post-transcriptional control of type 1 diabetes in NOD mice contributing to a better understanding of the molecular genetic control of autoimmune diseases in specially type 1 diabetes.

O adequado manejo do DM Tipo 1 tem se tornado um desafio, principalmente para as próprias crianças, em virtude da presença de comportamentos, habilidades e conhecimentos inadequados que colaboram para a não adesão ao tratamento e para aumento de complicações em longo prazo. Estudos têm demonstrado que compreender as experiências de vida das crianças nos seus diversos espaços, valorizando-as e buscando maior aproximação com as mesmas, pode contribuir para a partilha do conhecimento sobre o manejo do diabetes e para o maior envolvimento da criança no cuidado. O objetivo deste trabalho foi compreender, na perspectiva de crianças com DM Tipo 1, os fatores que interferem no manejo da doença. Trata-se de uma pesquisa qualitativa, de natureza exploratória. Participaram do estudo 19 crianças. Utilizamos a entrevista semiestruturada e, como recurso facilitador da comunicação com a criança, os fantoches. Esses brinquedos foram confeccionados pelas próprias crianças e criou-se, também, um cenário que ilustrou e complementou a utilização dos fantoches no dia da entrevista. A análise dos dados empíricos foi feita por meio da análise de conteúdo. Os resultados evidenciaram a compreensão do que é ser criança com diabetes e dos fatores relacionados à sua existência, como seus sentimentos e percepções. A compreensão da interação da criança com os conhecimentos que possui sobre a sua doença, sua inserção no processo do autocuidado, as habilidades desenvolvidas e os recursos disponíveis para lidar com as demandas da doença constituem fatores que interferem de forma positiva ou negativa no manejo da doença e merecem ser foco de atenção dos profissionais de saúde. Todos esses elementos atuam dinamicamente nos espaços do cotidiano da criança, tais como o familiar, o escolar, o de amizades, o de lazer e o dos serviços de saúde, atuando como fatores que fragilizam ou potencializam o manejo da doença. O apoio de familiares, amigos, professores e profissionais de saúde que compartilham as experiências de ser uma criança com diabetes mostrou-se essencial para o alcance do adequado manejo. Além disso, o conhecimento adquirido por estes atores e pela própria criança interfere diretamente no manejo do DM Tipo 1. Os resultados deste estudo evidenciam ações que visam a fortalecer o trabalho da equipe multidisciplinar no cuidado da criança com diabetes e apontam cenários de atuação que podem ser incrementados pelos profissionais de saúde. O enfermeiro ocupa posição privilegiada para identificar e operacionalizar ações apropriadas ao estágio de desenvolvimento da criança e às suas necessidades, em todos os espaços em que vive, atuando, assim, em consonância com todos os envolvidos em prol do sucesso do manejo da doença. / The adequate handling of Type 1 DM has become a challenge, mainly for the children themselves, due to the presence of inadequate behaviors, skills and knowledge that contribute to non-adherence to treatment and increased complications in the long term. Research has demonstrated that understanding children\'s life experiences in their different spaces, valuing them and seeking greater approximation, can contribute to knowledge sharing on diabetes management and to the children\'s greater involvement in care. This research aimed to understand, from the perspective of children with Type 1 DM, the factors that interfere in the management of this disease. This is a qualitative and exploratory research. Study participants were 19 children. Semi-structured interviews were used and, to facilitate communication with the child, puppets, which the children made themselves. A scenario was also created to illustrate and complement the use of puppets on the day of the interview. Content analysis was used for empirical data analysis. Results evidenced the understanding of what it means to be a child with diabetes and the factors related to his/her existence, such as feelings and perceptions. Understanding of these children\'s interaction with their knowledge about their disease, their insertion in the self-care process, developed skills and resources available to deal with the demands of the disease constitute factors that interfere positively or negatively in disease management and deserve further attention from health professionals. All of these elements act dynamically in the child\'s daily spaces, such as the family, school, friendships, leisure and health services, as factors that weaken or strengthen disease management. Support from relatives, friends, teachers and health professionals who share the experiences of being a child with diabetes showed to be essential to achieve adequate management. Moreover, the knowledge these actors and the children themselves acquire interferes directly in Type 1 DM management. These study results evidence actions aimed at strengthening the work of the multidisciplinary team in care delivery to children with diabetes and indicate activity scenarios which health professionals can build upon. Nurses play a privileged role to identify and put in practice actions that are appropriate for the children\'s development stage and needs, in all spaces they live in. Thus, they act in line with all parties involved with a view to successful disease management.

Physical activity (PA) provides many benefits to adolescents with Type 1 Diabetes (T1D); however, adolescents with T1D tend to have lower fitness and PA levels. One reason adolescents with T1D engage in less PA is due to a fear of hypoglycemia. Most studies examining PA in relation to glycemic control measure PA through self-report, thus introducing bias. The purpose of this study was to objectively monitor PA and glucose in adolescents with T1D to examine the temporal associations between moderate and vigorous intensity physical activity (MVPA) and hypoglycemia. Twenty participants (14 to 19 yr, n=10 females and 10 males) with a T1D diagnosis for at least 1 year were recruited. Participant fitness was evaluated via indirect calorimetry during a maximal treadmill exercise test, and body composition was measured using air displacement plethysmography. An accelerometer (GENEActiv, Activinsights Ltd, Kimbolton, UK) was worn on the wrist continuously for 7 days and the waveform data used to estimate MVPA in min/d. Blood glucose values were simultaneously tracked using continuous glucose monitoring (DexCom SEVEN PLUS, San Diego, CA). After controlling for gender, % body fat (%BF), and fitness, the likelihood of hypoglycemia (¡Ü 70 mg/dl) at nighttime or the next day due to MVPA was examined using logistic regression. Participants were of avg fitness (females: 43.9 ml/kg/min; males: 49.8 ml/kg/min) and fatness (females: 26.2%; males: 19.2%), and 63.2% of participants met the US federal guidelines of accumulating 60 min/d of MVPA. Hypoglycemia was 22% more likely in those who had 30 min/d more MVPA than those with less (95% CI: 1.03, 1.45; p =0.022). The results indicate that participating in MVPA increases the risk of hypoglycemia during the night time and the following day. The relationship is independent of gender, %BF and fitness. While promoting PA as a healthy behavior, it is important to educate adolescents with T1D on prevention of hypoglycemia following PA.

Poor metabolic control is a major health concern for children and adolescents with type 1 diabetes, particularly for African American youth. The aims of this study were to test the mediating relationship between two variables consistently related to metabolic control, depressive symptoms and adherence, as well as to attempt to explain racial disparities in metabolic control. The study sample consisted of 53 European American youth and 33 African American youth ages 5 to 20 (M = 13.59, SD = 3.49) with type 1 diabetes. Information on depressive symptoms, adherence, and HbA1c was collected during routine outpatient clinic visits. Significant associations were found between depressive symptoms and metabolic control, depressive symptoms and adherence, and adherence and metabolic control. When included together in a regression model, adherence mediated the relationship between depressive symptoms and metabolic control. This mediation pathway did not significantly differ between African American youth and European American youth; however, African American youth had significantly higher HbA1c levels. These findings indicate the importance of considering depressive symptoms during treatment for type 1 diabetes. This study also supports previous research findings of racial disparities in metabolic control among youth with type 1 diabetes. Future studies should further examine mechanisms by which these racial disparities emerge. / acase@tulane.edu

In this dissertation, the posterior probability of linkage (PPL) framework is extended to the analysis of case-control (CC) data and three new linkage disequilibrium (LD) statistics are introduced. These statistics measure the evidence for or against LD, rather than testing the null hypothesis of no LD, and they therefore avoid the need for multiple testing corrections. They are suitable not only for CC designs but also can be used in application to family data, ranging from trios to complex pedigrees, all under the same statistical framework, allowing for the unified analysis of these disparate data structures. They also provide the other core advantages of the PPL framework, including the use of sequential updating to accumulate LD evidence across potentially heterogeneous sets of subsets of data; parameterization in terms of a very general trait likelihood, which simultaneously considers dominant, recessive, and additive models; and a straightforward mechanism for modeling two-locus epistasis. Finally, being implemented within the PPL framework, the new statistics readily allow linkage information obtained from distinct data, to be incorporated into LD analyses in the form of a prior probability distribution. Performance of the proposed LD statistics is examined using simulated data. In addition, the effects of key modeling violations on performance are assessed. These statistics are also applied to a previously published type 1 diabetes (T1D) family dataset with a few candidate genes with previously reported weak associations, and another T1D CC dataset also previously published as a genome-wide association (GWA) study with some strong associations reported. The new LD statistics under the PPLD framework confirm most of the findings in the published work and also find some new SNPs suspected of being associated with T1D. Sequential updating between the family dataset and the CC dataset dramatically increased the association signal strength for a CTLA4 SNP genotyped in both studies. Linkage information gleaned from the family dataset is also combined into the LD analysis of the CC dataset to demonstrate the utility of this unique feature of the PPL framework, and specifically for the new LD statistics.

<p> Syftet med detta arbete är att undersöka om det föreligger någon skillnad mellan hur personer med diabetes typ 1 med MDI- respektive IP-behandling skattar sin hälsorelaterade livskvalitet, behandlingstillfredsställelse och uppfattning av behandlingsformens påverkan på livskvaliteten. Vidare är syftet att undersöka om det föreligger någon skillnad mellan män och kvinnor, samt mellan kvinnor respektive män i MDI- respektive IP-gruppen, avseende hälsorelaterade livskvalitet, behandlingstillfredsställelse och uppfattning av behandlingsformens påverkan på livskvaliteten. Som instrument användes enkäten SF-36 samt en egenkonstruerad enkät med bakgrundsfrågor rörande skattning av behandlingstillfredsställelse och uppfattning av behandlingsformens påverkan på livskvaliteten. I MDI-gruppen deltog 40 deltagare och i IP-gruppen 37 deltagare. Studien har en deskriptiv jämförande design. Resultatet visade att det inte finns någon signifikant skillnad mellan MDI- och IP-gruppens skattning av hälsorelaterad livskvalitet. Skillnader kunde påvisas mellan behandlingsformerna gällande behandlingstillfredsställelse och uppfattningen av behandlingsformens påverkan på livskvalitet. IP-gruppen har en signifikant högre behandlingstillfredsställelse samt anser att behandlingsformen påverkar deras livskvalitet mer än MDI-gruppen. Kvinnor i MDI-gruppen skattade sin hälsorelaterade livskvalitet signifikant lägre än män i MDI-gruppen, ingen skillnad kunde dock påvisas mellan männen och kvinnorna i IP-gruppen. Männen i MDI-gruppen skattar sin hälsorelaterade livskvalitet signifikant högre än männen i IP-gruppen. Ingen skillnad kunde påvisas mellan männen i de båda grupperna gällande behandlingsstillfredsställelse eller uppfattningen av behandlingsformens påverkan på livskvaliteten. Kvinnorna i IP-gruppen skattade signifikant högre gällande behandlingsstillfredsställelse och uppfattningen av behandlingsformens påverkan på livskvaliteten än kvinnorna i MDI-gruppen.</p><p><p><p>Kvinnorna i IP-gruppen har likartad hälsorelaterad livskvalitetsskattning som männen i samma grupp och har även en högre behandlingstillfredsställelse än kvinnor i MDI-gruppen. Slutsatsen kan vara att IP är en lämplig behandling för kvinnor</p></p></p>

<p>Enterovirus (EV) infections have been associated with the pathogenesis of Type 1 Diabetes (T1D). However, the pathway(s) by which EV may induce or accelerate diabetes is not well understood. The purpose of this thesis was to obtain new information on the mechanism by which EV infections, with different strains of EV, could cause damage to the insulin-producing β-cells in isolated human islets and in a rat insulin-producing cell line (RINm5F). </p><p>Infection with EV strains isolated from T1D patients revealed replication/cell destruction in human islets and EV-like particles in the cytoplasm of the β-cell and infection with the isolates affected the release of insulin in response to glucose stimulation as early as three days post infection, before any decrease in cell viability was observed. A decrease in the induction/secretion of the chemokine RANTES in human islets during EV infection was also detected. When islets were cultured with nicotinamide (NA) the secretion of RANTES was increased irrespectively if the islets were infected or not. In addition, the degree of virus-induced cytolysis of human islets was reduced by NA, suggesting an antiviral effect of NA. Infection with EV strains revealed permissiveness to islet-derived cells. </p><p>All EV strains used for infection were able to replicate in the RIN cell clusters (RCC) but not in the RIN cells that were cultured as a monolayer. This might be due to the differences in expression of the Coxsackie-adenovirus receptor (CAR), which only could be detected on the RCC. Infection of RCC with a CBV-4 strain did not affect cell viability and did not induce nitric oxide (NO) production alone or with the addition of IFN-γ. This was in contrast to the results obtained with synthetic dsRNA, poly(IC), which induced NO, suggesting that synthetic dsRNA does not mimic enteroviral intermediate dsRNA.</p><p>During analyses performed with the samples from a family where the mother and one son where diagnosed with T1D on the same day, the results showed that the whole family had a proven EV infection at the time diagnosis.</p><p>To conclude, the ability of EV strains to replicate in RIN cells is dependent on the growth pattern of the cells and this may be due to the upregulation and/or changed expression pattern of CAR in these cells. In the RIN cells, contrary to artificial dsRNA, viral dsRNA does not induce NO. The isolated EV virus strains used were able to infect and affect human pancreatic islets in vitro. The chemokine RANTES is reduced during an EV infection of human pancreatic islets and NA causes upregulation of RANTES in infected and uninfected islets. </p>

Type 1 diabetes (T1D) is a chronic autoimmune disease in which the insulin producing β-cells in the pancreatic islets of Langerhans are selectively attacked by the immune system. The β-cells are destroyed resulting in a reduced or eliminated insulin production, which in turn lead to a high blood glucose level. The non-obese diabetic (NOD) mouse is the most commonly used animal model for human T1D. NOD mice develop diabetes spontaneously through a process that closely resembles the human pathogenesis. In both humans and the NOD mouse, disease is caused by a combination of genetic and environmental factors. In the NOD mouse, more than 30 insulin-dependent diabetes (Idd) loci on 15 chromosomes have been linked to disease susceptibility, however, most of the Idd-regions lack identification of a disease associated gene. B cells are required for T1D development, although the underlying mechanisms are not fully revealed. The aim of this thesis was to dissect B cell-related immune deviations in the NOD mouse, including the underlying genetics of these traits. The TACI receptor binds two ligands, i.e. the cytokines BAFF and APRIL.TACI ligation by APRIL mediates class switch, drives plasma cell differentiation and increases immunoglobulin production. In Paper I, a novel NOD-specific B cell-related trait was identified, i.e. the increased percentage of TACIhigh-expressing splenic B cells, by comparing NOD mice with non-autoimmune disease prone C57BL/6 mice. To investigate if the described TACI trait was controlled by genes linked to any Idd-region, an Idd-focused linkage analysis was performed. The TACI-trait mapped to regions on chromosome 1 and 8, more specifically to the vicinity of the Idd5.4 and Idd22. Interestingly, the linkage to Idd22 was explained by mice ≥61 days of age, suggesting a temporal genetic regulation of TACI expression possibly influenced by the ongoing autoimmune process. In Paper II, the linkage of the TACI trait to chromosome 1 and 8 was confirmed by analyzing the percentage of TACIhigh-expressing B cells in congenic NOD.C1/Idd22 mice. Moreover, the functional consequence of TACI upregulation was investigated, with the focus on plasma cell development and immunoglobulin production. NOD splenic B cells stimulated with APRIL displayed increased numbers of plasma cells and produced higher amounts of IgG and IgA compared to B cells from C57BL/6 mice. Thus, the TACI upregulation on NOD B cells possibly contribute to a B cell compartment which is more disposed to plasma cell differentiation and isotype switch. NOD mice display enhanced and prolonged immune response towards several antigens, including non-self immunoglobulins. In Paper III, the genetic factor(s) controlling the altered immune response against a BALB/c derived monoclonal antibody were dissected. Significant linkage to the Idd1/Idd24, Idd12, and Idd18.1 regions as well as to a proximal region on chromosome 2 (33.5 Mb) was detected. The linkage to Idd1/24 was verified by analyzing a set of H2-congenic NOD and C57BL/6 mice, and the linked region was narrowed down to ~8 Mb. Candidate gene analysis revealed a significant difference in the transcription of the H2-O/DO molecule. This suggests that multiple mechanisms contribute to the loss of immune response control, including an altered MHC class II peptide loading on NOD B cells. In Paper IV, a novel B cell intrinsic receptor for IgM and IgG was revealed. The receptor appeared to be more abundant in NOD mice compared to C57BL/6 mice, as the level of extramembranous IgG monomers and IgM pentamers on peripheral blood B cells from NOD mice was significantly higher compared to C57BL/6 mice. In addition, analysis of immune complex binding using IgG- or IgM-opsonized bacterial particles revealed a higher degree of binding in NOD mice compared with C57BL/6 mice. The enhanced capture of immunoglobulins and immune complexes could thus contribute to the development of T1D by altering normal B cell functions such as activation and immune complex transportation.

This thesis focuses on enteroviral effects on human pancreatic islets. Most knowledge of viral effects on host cells relies on studies of immortalized cell lines or animal models. The islets represent a fundamentally different and less well studied cellular host. Also, enterovirus has been implicated in the etiology of type 1 diabetes (T1D). We show that when enterovirus replicates in human islets it activates innate immunity genes and induces secretion of the chemokines MCP-1 and IP-10. An important difference in activation of innate immunity by replicating EV and synthetic dsRNA is suggested, since the chemokine secretion induced by EV infection but not by dsRNA is reduced by female sex hormone. We also demonstrate a direct antiviral effect of nicotinamide, and even though this substance failed to prevent T1D in a large-scale study, this finding could have implications for the treatment/prevention of virus- and/or immune-mediated disease. We also had access to human pancreata from two organ donors with recent onset T1D and several donors with T1D-related autoantibodies, which gave us the opportunity to study ongoing pathogenic processes at and before the onset of T1D. Despite this, we could neither confirm nor reject the hypothesis that EV is involved in T1D development. Several observations, such as ultrastructural remodeling of the beta cell, activation of innate immunity, and immunopositivity to EV capsid protein 1, supported an ongoing virus infection, but direct evidence is still lacking. An interesting finding in the donors with recent onset T1D was that the islets were positively stained for insulin, but did not secrete insulin in response to glucose-stimulation. A similar effect was observed in EV-infected islets in vitro; EV destroyed islet function and insulin gene expression, but the islets still stained positive for insulin. This may be indicative of that a functional block in addition to beta cell destruction is involved in T1D pathogenesis. In conclusion, these studies of EV in isolated human islets in vitro support that this virus can cause T1D in vivo, but future studies will have to show if and how frequently this happens.

Enterovirus (EV) infections have been associated with the pathogenesis of Type 1 Diabetes (T1D). However, the pathway(s) by which EV may induce or accelerate diabetes is not well understood. The purpose of this thesis was to obtain new information on the mechanism by which EV infections, with different strains of EV, could cause damage to the insulin-producing β-cells in isolated human islets and in a rat insulin-producing cell line (RINm5F). Infection with EV strains isolated from T1D patients revealed replication/cell destruction in human islets and EV-like particles in the cytoplasm of the β-cell and infection with the isolates affected the release of insulin in response to glucose stimulation as early as three days post infection, before any decrease in cell viability was observed. A decrease in the induction/secretion of the chemokine RANTES in human islets during EV infection was also detected. When islets were cultured with nicotinamide (NA) the secretion of RANTES was increased irrespectively if the islets were infected or not. In addition, the degree of virus-induced cytolysis of human islets was reduced by NA, suggesting an antiviral effect of NA. Infection with EV strains revealed permissiveness to islet-derived cells. All EV strains used for infection were able to replicate in the RIN cell clusters (RCC) but not in the RIN cells that were cultured as a monolayer. This might be due to the differences in expression of the Coxsackie-adenovirus receptor (CAR), which only could be detected on the RCC. Infection of RCC with a CBV-4 strain did not affect cell viability and did not induce nitric oxide (NO) production alone or with the addition of IFN-γ. This was in contrast to the results obtained with synthetic dsRNA, poly(IC), which induced NO, suggesting that synthetic dsRNA does not mimic enteroviral intermediate dsRNA. During analyses performed with the samples from a family where the mother and one son where diagnosed with T1D on the same day, the results showed that the whole family had a proven EV infection at the time diagnosis. To conclude, the ability of EV strains to replicate in RIN cells is dependent on the growth pattern of the cells and this may be due to the upregulation and/or changed expression pattern of CAR in these cells. In the RIN cells, contrary to artificial dsRNA, viral dsRNA does not induce NO. The isolated EV virus strains used were able to infect and affect human pancreatic islets in vitro. The chemokine RANTES is reduced during an EV infection of human pancreatic islets and NA causes upregulation of RANTES in infected and uninfected islets.