Made available in DSpace on 2014-06-11T19:23:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-27Bitstream added on 2014-06-13T20:49:48Z : No. of bitstreams: 1 franca_tgd_me_botib.pdf: 1122114 bytes, checksum: b51b8daa83b9ac30277dedceb8466a47 (MD5) / A desnutrição diminui a eficácia da resposta imune aumentando a susceptibilidade aos agentes infecciosos. 0 principal tipo de deficiência nutricional e a desnutrição proteico-calórica (DPC). A restrição alimentar experimental e utilizada como modelo de estudo para a DPC. Neste contexto, os objetivos principais deste trabalho foram caracterizar urn modelo murino de DPC e avaliar seu efeito na susceptibilidade e na imunidade protetora ao Staphylococcus aureus. Foram testados três percentuais de restrição alimentar (10, 20 e 30%) em camundongos BALB/c e a restrição de 20% determinou as seguintes alterações as quais são condizentes com um estado de subnutrição: queda significativa de peso corporal e número de linfócitos, alteração na produção de citocinas e atrofia no timo e epitélio intestinal. A comparação do grau de susceptibilidade e da capacidade de montar uma resposta imune protetora ao S. aureus foi realizada atraves de duas metodologias: determinação do numero de unidades formadoras de colônias (UFC) em alguns órgãos e análise histopatológica do tecido pulmonar. Os resultados foram distintos dependendo da metodologia empregada. Quanto a susceptibilidade ao patógeno, a técnica de UFC indicou susceptibilidade similar nos grupos normal e subnutrido, enquanto que a análise histopatológica indicou maior quantidade de bactérias no pulmão dos animais normais. 0 processo de imunização controlou eficazmente a multiplicação bacteriana no pulmão dos animais normais, mas nao dos animais subnutridos. A análise histopatológica também mostrou perfis inflamatórios distintos nestes 2 grupos: camundongos normais apresentaram inflamação pulmonar só após infecção com S. aureus, como esperado, e a imunização prévia com antígenos de S. aureus preveniu esta inflamação. Por outro lado, camundongos subnutridos ja apresentavam inflamação pulmonar antes... / Undernutriton is one of the most relevant causes of secundary immunodeficiency. The main type of nutritional deficiency is called protein energy malnutrition (PEM). Animals submitted to different degrees of food restriction can be used as models of PEM. In this context, this work was done to establish a murine experimental model for PEM and to evaluate the effect of malnutrition on both, susceptibility and ability to mount a protective immunity against Staphylococcus aureus. BALB/c mice were therefore submitted to three distinct percentages of dietary re§triction (10, 20 and 30%). The 20% restricted diet determined the following alterations that characterize a state of malnutrition: a significant decrease in both, body weight and lymphocyte number, alteration in cytokine production and atrophy in thymus and intestinal epithelium. Two methodologies were used to compare susceptibility and ability to mount a protective immunity: determination of the number of colony forming units (CFU) in some organs and histopathological analysis of the lungs. Results varied according to the methodology. CFU indicated a similar susceptibility whereas the histopathological analysis showed a higher amount of bacterias in the lungs of normal mice. Immunization controlled bacterial growth in the lungs of normal mice but not in the ones from undernourished animals. Histopathological analysis also revealed distinct inflammatory scenarios: inflammation appeared in lungs from normal mice only after infection with S. aureus and immunization prevented lung inflammation in the animals. On the other hand, undernourished mice presented lung inflammation even before infection. In addition, the degree of this inflammatory process did not change with infection or previous immunization. Together, this data demonstrates that BALB/c mIce submitted to 20% food restriction developed... (Complete abstract click electronic access below)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste estudo investigamos as consequências da restrição protéica materna durante a lactação sobre a resposta de timócitos da prole jovem de ratos Wistar (grupo D), identificando o papel da leptina nas alterações encontradas. Observamos que, quando comparados ao grupo controle, os animais do grupo D apresentaram, aos 30 dias de vida, uma diminuição significativa tanto do peso corporal quanto do timo. Contudo, não observamos alterações no número de timócitos, no perfil de células CD4/CD8 ou na resposta proliferativa destas células. Sistemicamente, o grupo D não apresentou alterações nos níveis séricos de corticosterona ou no conteúdo nuclear do seu receptor (GR) em timócitos. Apesar dos animais D não apresentarem alterações nos níveis circulantes de leptina, a expressão do seu receptor, ObRb, estava aumentada nos timócitos. Esta alteração foi acompanhada pela amplificação da resposta de sinalização da leptina nestas células, observada por um aumento na ativação de JAK2 e STAT3 após a incubação com leptina. Os timócitos isolados do grupo D apresentaram uma diminuição significativa na taxa de apoptose espontânea quando comparados ao grupo controle. Corroborando estes resultados, demonstramos que os timócitos dos animais D apresentam um aumento na expressão da proteína antiapoptótica Bcl-2 e uma redução da expressão da proteína próapoptótica Bax, além de um maior conteúdo de Pró-caspase-3, entretanto, não encontramos alterações no conteúdo de Bad. Além disso, timócitos do grupo D apresentaram um maior conteúdo da subunidade p65 do NFĸB no núcleo, associado a uma menor expressão de IĸBα no citoplasma. Finalmente, observamos um aumento na expressão do RNAm para o gene ob (leptina) mas não para o gene db (receptor) no microambiente tímico dos animais D. Em conjunto, nossos dados mostram que a restrição protéica durante a lactação afeta a homeostase tímica, induzindo uma maior atividade de leptina, que protege os timócitos da apoptose na prole jovem, sugerindo que esses animais poderiam ser mais suscetíveis a alterações na resposta imune na vida aduta. / In this study, we investigated the consequences of maternal protein deprivation during lactation on thymocyte responses of the offspring Wistar rats (PD group) and the role of leptin in these alterations. Compared to group C, PD animals showed at 30 days of age, lower body and thymus weights, with no alteration in the thymocyte number or any difference in the profile of T cell subsets, or in their proliferative response. Similar circulating levels of corticosterone and GR nuclear contents were detected in thymic cells of PD or control groups. In contrast, despite the rats from PD group did not present alterations in leptin circulating levels, the expression of leptin receptor ObRb was enhanced in their thymocytes. This change was accompanied by an amplification in leptin signaling response of thymocytes from PD rats, which showed an increase in JAK2 and STAT3 phosphorylation after stimulation with leptin. Moreover, the thymic cells from PD rats presented a decreased rate of spontaneous apoptosis when compared to controls. Accordingly, higher expression of both the anti-apoptotic protein Bcl-2 and Procaspase-3 and lower expression of pro-apoptotic protein Bax were detected in PD thymocytes, however, the pro-apoptotic protein bad expression was similar between the groups. Thymocytes from PD group also exhibited a constitutive higher nuclear content of p65 NFkB associated to a lower IkB content in the cytoplasm. Finally, although there was no change in db genic (leptin receptor) expression in PD thymocytes, a higher expression of mRNA for ob gene (leptin) was observed in the thymic microenvironment from PD animals. Taken together, the results show that maternal protein deprivation during lactation affects thymic homeostasis, inducing leptin activity, which protect thymocytes from apoptosis in young progeny and, perhaps,may prone these animals for alterations in immune response in adult life.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-16T14:35:21Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Livia de Almeida Lira_ POSNEURO 2016.pdf: 2312565 bytes, checksum: 6dc0de86f266e98ad31d5c7c89d2219e (MD5) / Made available in DSpace on 2017-02-16T14:35:22Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese Livia de Almeida Lira_ POSNEURO 2016.pdf: 2312565 bytes, checksum: 6dc0de86f266e98ad31d5c7c89d2219e (MD5) Previous issue date: 2016-02-26 / FACEPE / O controle do comportamento alimentar é um fenômeno complexo dependente da interação entre os sinais originados na periferia do corpo e em várias regiões do sistema nervoso central, incluindo o núcleo do trato solitário (NTS). Esse núcleo regula muitos aspectos do comportamento alimentar e expressa receptores para vários peptídeos e hormônios indutores de saciedade, incluindo a serotonina. Prejuízos na via de sinalização e no conteúdo encefálico deste neurotransmissor estão associadas à hiperfagia e obesidade. Algumas regiões encefálicas responsáveis pela regulação do comportamento alimentar são alvos de ajustes permanentes promovidos por eventos que ocorrem durante os estágios iniciais do desenvolvimento. Nessa fase, a influência de estímulos ambientais, particularmente os nutricionais, podem modular os eventos ontogenéticos e promover sérias consequências na vida adulta. Nesse estudo, o objetivo foi investigar os efeitos da desnutrição proteica perinatal sobre aspectos morfofuncionais do NTS relacionados ao controle do comportamento alimentar. Ratos da linhagem Wistar, mantidos em condições padrões de biotério foram distribuídos aleatoriamente em dois grupos de acordo com a dieta ofertada para mães durante a gestação e lactação: grupo controle (C, caseína 17% / n = 10) ou grupo desnutrido (D, caseína 8% / n =10). Foram avaliados aos 35 e 180 dias de vida: a) peso corporal; b) ingestão alimentar; c) expressão da proteína FOS nas regiões rostral e medial do NTS em resposta ao estímulo alimentar; d) sequência comportamental de saciedade e os parâmetros microestruturais da alimentação e apenas aos 35 dias de vida: e) densidade de terminais e distribuição de receptores serotoninérgicos 5-HT1B nos subnúcleos ventrolateral, intermediário, medial e comissural do NTS. As áreas estudadas foram identificadas e quantificadas com auxílio do atlas estereotáxico de Paxinos e Watson (1998). Com base nessas avaliações, o presente trabalho demonstrou que a desnutrição perinatal promove: 1) redução do peso corporal (35 dias: C=129.06±0.20; D=68.10±0.35; 180 dias: C = 435.70±0.70; D = 370.30±0.70); (2) hiperfagia (35 dias: C = 6.8±0.6; D = 11.9±0.9; 180 dias C = 6.6±0.4; D = 10±0.8); (3) retardo na saciedade, (4) aumento no tamanho (C= 5,5 ±0,43; D= 7,8± 0,57) e duração (C=14,3± 1.8; D= 20,4±1,7) das refeições; (5) aumento na ativação neuronal nas porções rostral (35 dias: C = 134.5±22.23; D= 366.8±58.02/ 180 dias = 240.6±38.10; D = 444.2±57.05) e medial do NTS (35 dias: C = 172.8±26.28; D= 435.2±72.69/180 dias: C= 224.4±33.10; D= 434.0±45.31); (6) aumento na densidade de terminais serotoninérgicos no NTS (C= 34,4 ± 1,5 n= 5; D= 48± 3,6) e no subnúcleo intermediário (C= 28,3 ± 2; D= 43± 1,5) e (7) maior quantidade de neurônios 5-HT1B-IR no NTS (C= 159,6± 18,2;D= 317,1± 18,6) e nos subnúcleos ventrolateral (C= 20,1± 2,7/N=5D= 34,4± 3,5), intermediário (C= 20,9± 2,8/N=5; D= 49,3± 3) e medial (C= 45,6 ± 6/N=5; D= 95,4± 6). Estes resultados indicam que o NTS é uma estrutura particularmente vulnerável às influências da manipulação nutricional nos estágios iniciais do desenvolvimento e pode ser alvo de processos adaptativos do controle comportamento alimentar observados nesses animais na vida adulta. / The control of feeding behavior is dependent on the interactions among a variety of signals originated from periphery and several brain areas, such as the nucleus of the solitary tract (NTS) in the caudal brainstem. This nucleus regulates many aspects of feeding behavior and expressed receptors for several satiety inducing peptides and hormones including serotonin. Losses in the signaling pathway and the brain content of this neurotransmitter are associated with hyperphagia and obesity. Some brain regions responsible for the regulation of feeding behavior are targets of permanent adjustments promoted by events that occur during the early stages of development. At that stage, the influence of environmental stimuli, particularly the nutritional, may modulate ontogenetic events and promote serious consequences in adult life. In this study, the main aim was to investigate the effects of perinatal protein malnutrition on morphological and functional aspects of the NTS related to control of feeding behavior. Male Wistar rats were divided into two groups according to the diet offered to the dams during gestation and lactation: control group (C, diet containing 17% casein/ n=10) or isocaloric lowprotein group (LP, diet containing 8% casein/ n=10). We evaluated: a) body weight; b) food intake; c) c-Fos protein expression in the rostral and medial NTS; d) behavioural sequence satiety and micro-structural parameters of feeding and e) density of serotoninergic terminals and distribution of 5-HT1B receptor in the ventro-lateral, intermediate, medial and commissural subnucleus of NTS. The areas studied were identified and quantified with Stereotactic atlas of Paxinos and Watson (2005). Based on these evaluations, the present study showed that the malnutrition: (1) promotes perinatal) reduced body weight (35 days: C = 129.06 ± 0.20; D = 68.10 ± 0.35; 180 days: C = 435.70 ± 0.70; D = 370.30 ± 0.70); (2) hyperphagia (35 days: C = 6.8 ± 0.6; D = 11.9 ± 0.9; 180 days C = 6.6 ± 0.4; D = 10 ± 0.8); (3) delay in satiety, (4) increase in size (C = 5.5 ± 0.43; D = 7.8 ± 0.57) and duration (C = 14.3 ± 1.8; D = 20.4 ± 1.7) meals; (5) increase in neuronal activation in the rostral portions (35 days: C = ± 134.5 22.23; D = ± 366.8/58.02 180 days = 240.6 ± 38.10; D = ± 444.2 57.05) and medial NTS (35 days: C = 172.8 ± 26.28; D = ± 72.69/180 days 435.2: C = ± 224.4 33.10; D = ± 45.31 434.0); (6) increase in density of serotonergic terminals in the NTS (C = 34.4 ± 1.5 n = 5; D = 48 ± 3.6) and the intermediate subnucleus (C = 28.3 ± 2; D = 43 ± 1.5) and (7) increased amount of 5-HT1B-IR neurons in the NTS (C = 159.6 ± 18.2; D = 317.1 ± 18.6) and ventro-lateral (C = 20.1 ± 2.7/N = 5 d = 34.4 ± 3.5), intermediate (C = 20.9 ± 2.8/N = 5; D = 49.3 ± 3) and medial subnucleus (C = 45.6 ± 6/N = 5; D = 95.4 ± 6). These results indicate that the NTS is a particularly vulnerable structure to the influences of nutritional manipulation in the early stages of development and may be adaptive processes of control feeding behavior observed in these animals into adulthood.

A subnutrição é um quadro caracterizado por escassez proteico-calórica e sua manifestação na República de Moçambique é responsável por um terço das mortes de crianças com idade inferior a 5 anos. É a responsável pela falha no crescimento nos primeiros anos de vida e no Brasil, até 2011, era considerada um problema grave de saúde pública. O objetivo deste trabalho foi investigar possíveis repercussões no tecido nervoso periférico de ratos Wistar subnutridos, comparando-os com aqueles que receberam a dieta padrão de Moçambique (baseada em proteína vegetal) e com aqueles que receberam nutrição balanceada. Para a realização deste estudo foram utilizados 15 ratos machos da linhagem Wistar e as técnicas utilizadas foram: Microscopia Eletrônica de Transmissão e Varredura, possibilitando a aquisição de dados quantitativos e qualitativos, utilizando ainda princípios estereológicos. Os resultados demonstraram alterações morfológicas nos grupos S e M, assim como diferenças quanto ao contorno das fibras nervosas e a disposição das camadas de mielina. Em relação ao peso e a ASTn, os três grupos são diferentes estatisticamente. Ao contrário, quanto à densidade de fibras nervosas mielínicas e ao número total estimado de fibras mielínicas, não houve diferença significante entre os grupos. Em relação à ASTax do nervo isquiático, houve significância entre os três grupos, já na análise da ASTbm e da ASTfm, houve diferença apenas entre os grupos S ≠ N, M ≠ N. Foi concluído, portanto que a subnutrição promoveu alterações morfológicas na estrutura do nervo isquiático e nas fibras nervosas mielínicas que podem ser irreparáveis, e numericamente gerou um mecanismo compensatório de aumento de densidade em relação a área do nervo, ou seja, um nervo de área menor, porém com fibras nervosas mais próximas, não havendo diferença na quantidade de fibras por nervo / Undernutrition is a condition characterized by protein-calorie shortage and its manifestation in the Republic of Mozambique is responsible for a third of deaths of children under the age of 5 years. It is responsible for growth failure early in life and in Brazil until 2011, was considered a serious public health problem. The objective of this study was to investigate possible effects on peripheral nerve tissue of Wistar rats undernourished, comparing them with those who received standard diet of Mozambique (based on vegetable protein) and those who received balanced nutrition. For this study were used 15 male rats of the Wistar and techniques used were: Transmission Electron Microscopy and Scanning, enabling acquisition of quantitative and qualitative data, using stereological principles. The results showed morphological changes in S and M groups as well as differences in the contour of nerve fibers and of the layers of myelin. In terms of weight and ASTn, the three groups are statistically different. Rather, density of myelinated nerve fibers and the estimated total number of myelinated fibers, not present significant difference between groups. Regarding ASTax sciatic nerve, there was significant difference between the three groups, and in the analysis of ASTms and ASTmf, there was difference only between the groups. It was concluded therefore that malnutrition promoted morphological changes in the sciatic nerve structure and myelin nerve fibers that may be irreparable, numerically generating a compensatory mechanism of density increase in relation to nerve area, in other words, a nerve smaller area but with next nerve fibers, with no difference in the number of nerve fibers by

Fatores nutricionais e metabólicos são capazes de comprometer o desenvolvimento pleno dos tecidos dentários, especialmente quando impingidos em períodos críticos. Estudos revelam que condições derivadas da subnutrição precoce e também tardia, interferem na atividade da insulina e do sistema IGF, demonstrando possível envolvimento com algumas patologias e apontando, em sua maioria, caráter permanente em alto grau, se não imediato, prospectivo e comprometedor da performance morfológica e funcional dos tecidos. Desta maneira, o presente estudo teve o propósito de avaliar os efeitos da subnutrição proteica pré e pós-natal e da renutrição pós-natal sobre o desenvolvimento da polpa dentária e do epitélio juncional do periodonto de ratos wistar, visando encontrar possível correspondência entre as alterações metabólicas e morfofuncionais decorrentes da subnutrição proteica, previamente relacionadas em estudos relativos à ação desses hormônios. Para tanto, formou-se grupos de animais heterogênicos (n=3) que, de acordo com a ração oferecida, normoproteica ou hipoproteica, e as respectivas idades, foram divididos nos seguintes grupos experimentais: nutridos (N) e subnutridos (S) com 60 dias de vida (fase na qual o período púbere termina) e renutridos (R), recuperados a partir de 22 até alcançarem 60 dias de vida. Após a eutanásia, os espécimes foram submetidos às técnicas de microscopia de luz (coradas com Azo-Carmim, Hematoxilina-Eosina e Picro-Sirius, esta última para a avaliação do componente colágeno) e imunohistoquímica para a identificação da expressão do IGF-I, insulina e respectivos receptores. A polpa dentária apresentou-se debilitada sob subnutrição o que foi verificado através da desorganização da camada odontoblástica e da estagnação dos componentes colágenos nos animais subnutridos. A renutrição não foi capaz de promover a recuperação de nenhum dos dois parâmetros. O estudo morfométrico permitiu verificar que a porcentagem média do número de expressões ao IGF-I foi maior nos animais do grupo N e que houve diferenças estatísticas significantes entre estes e os animais dos grupos S e R. Da mesma forma, a maior expressão de seus receptores (IGF-IR) foi encontrada nos animais do grupo N com indicação de diferença estatística apenas entre este e o grupo de animais subnutridos. A maior porcentagem média das expressões de insulina ocorreu nos animais nutridos (N), mas estatisticamente não foi detectada diferença significativa entre os grupos. Já em relação ao receptor de insulina (IR), foram constatadas diferenças estatísticas significativas entre o grupo N em relação aos grupos S e R. No epitélio juncional, a subnutrição determinou modificações no padrão das células e camadas epiteliais nos animais subnutridos, além de uma maior quantidade de colágeno do tipo III no tecido conjuntivo que o sustenta, caracterizando um atraso no desenvolvimento desses tecidos. A renutrição não foi capaz de recuperar satisfatoriamente os seus componentes estruturais. Sobre as expressões imunohistoquímicas a todos os anticorpos utilizados (para IGF-I, IGF-IR, I e IR), a análise estatística demonstrou não haver diferenças significativas entre os valores encontrados nos diferentes grupos N, S e R no epitélio juncional. / Nutritional and metabolic factors can cause serious injury of the development of dental tissue, especially when occurred in critical periods. Several studies reveal that conditions derived from early and later under nutrition interfere in insulin and IGF system activities; in these studies has been demonstrated the possible involvement of some pathologies most of them pointing to permanent in high degree (if not immediate) prospective and \"possible dangerous\" morphological and functional performance of tissues. Thus, the present study aimed to evaluate the effects of the pre and post-natal protein under nutrition, and, post-natal refeeding on the development of the dental pulp and periodontal junctional ephitelium of wistar rats, in order to find possible correlation between the metabolic and morph-functional changes arising from protein under nutrition, previously associated with studies related to the effects of these hormones. For this purpose, heterogenic animal groups were formed (n=3) divided in accordance of their diets (protein or hypo protein) and their ages into the following experimental groups: nourished (N) under nourished (S) aged 60 days (final of pubescent l periods) and renourish (R), recovered from the 22nd to 60th day old. After euthanasia, the specimens were analyzed by light microscopy (stained with Azo-carmine, Hematoxylin-Eosin and Picro Sirius, the later for collagen component analysis) and immunohistochemistry examination for identification of IGF-I expression, Insulin and respective receptors. The dental pulp turned out to be impaired in the context of undernutrition. This phenomenom was seen through disorganization of the odontoblastic layer and the stagnation of collagen components in undernourished animals. The refeeding procedure was unable to promote the recovery from any of the two parameters. With the immunohistochemistry on the dental pulp, it was found that the number of IGF-I expression was higher in group N and that there were significant differences involving these animals and those from groups S and R. Similarly, the highest expression of their receptors (IGF-IR) was found in group N, demonstrating statistical difference between this one and the group of undernourished animals. The highest average percentage of the expressions of insulin occurred in nourished animals (N), but no statistically significant difference was detected among the groups. In regard to the insulin receptor (IR), statistically significant differences were found when the group N was compared to groups S and R. In the junctional ephitelium, the undernutrition determined changes in the pattern of epithelial cells in undernourished animals and the prevalence of type III collagen fibers in the connective tissue that supports it, featuring a delay in the development of these tissues. The refeeding was not able to satisfactorily recover their structural components. About immunohistochemical expressions of all antibodies used for IGF-I, IGF-IR, I e IR in the junctional ephitelium, the statistical analysis showed no significant differences among the values found in the groups N, S and R.

Le microbiote a un impact majeur sur la physiologie de son hôte, cependant notre compréhension des mécanismes régulant la relation hôte/microbiote reste limitée. Nous utilisons un hôte modèle simple, la Drosophile, afin de répondre à ces questions. Durant mon doctorat, je me suis attaché à une étape particulière du cycle de vie de la Drosophile, sa phase larvaire. Celle-ci constitue sa phase de croissance et est influencée par le contexte nutritionnel. Le microbiote influence également cette étape: l’association avec la bactérie Lactobacillus plantarum tempère les effets de la carence alimentaire en soutenant un taux de croissance élevé et une maturation rapide, en modulant chez l’hôte l’activité de l’hormone Ecdysone et de l’insuline. En retour, L.plantarum bénéficie de l’association, les larvesassurant sa persistance dans la niche (la niche étant le substrat nutritif, les larves et les bactéries associées). Pour caractériser les mécanismes mis en jeu dans ce mutualisme nous avons décrit les réponses transcriptomiques et métaboliques de la larve et avons également étudié les perturbations métaboliques de la niche. Nos résultats mettent en avant l’optimisation de l’extraction des acides aminés du substrat comme facteur clef du mutualisme. L.plantarum active l’expression des protéases intestinales de l’hôte via la voie IMD/NF-κB, et bénéficierait en retour d’une quantité d’acides aminés plus importante assurant sa persistance. Ainsi, nos travaux contribuent à l’effort de compréhension desmécanismes régulant l’interaction hôte/microbiote et pourraient conduire à de nombreuses applications thérapeutiques, notamment dans le cadre de déséquilibres nutritionnels. / Symbiotic bacterial populations (also called the “microbiota”) have a dramatic impact on their host’s physiology. However, our understanding of the mechanisms shaping host/microbes mutualism remains limited. We took advantage of Drosophila tractability to characterize the host’s and the microbial factors engaged in mutualism. During my PhD, I focused on the impact of the microbiota during the Drosophila larval phase, which constitutes its juvenile growth period. Drosophila larval phase is influenced by nutrition, but also by symbiotic microbes: specific association with the bacterium Lactobacillus plantarum buffers the deleterious effects of nutrient scarcity on the host’s juvenile growth, by sustaining greater growth rates and hastening maturation. L.plantarum mediate these effects by modulating the activity of the steroid hormone Ecdysone and the Insulin/Insulin-like Signaling pathway in its host. In return, L.plantarum benefits from Drosophila presence, as larvae ensure its long-term persistence in the niche (the niche being the nutritive substrate, the larvae and the bacteria dwelling on it). To characterize the mechanisms engaged in this mutualistic relationship, we described the host’s transcriptomic and metabolic responses to L.plantarum presence and characterized the metabolic perturbations occurring in the niche. Our results put forward the optimization of amino-acids extraction from the nutritive substrate as a cornerstone of mutualism. L.plantarum activates the expression of the host’s digestive proteases via IMD/NF-κB signaling and would benefit in return from an enhanced AA availability, which would help sustaining its long-term persistence. Altogether, our studies contribute to the understanding of the mechanisms regulating host/microbiota interaction and could lead to numerous therapeutic applications, notably aiming at counteracting the deleterious effects of nutritional imbalances.

Epidemiological studies show that offspring subjected to maternal undernutrition during early pregnancy are prone to developing obesity and other diseases in adulthood. The hypothalamic energy regulating pathway may be altered in these offspring, with epigenetic changes as a core mechanism. Therefore, this thesis aimed to determine if epigenetic changes are present in this pathway in the hypothalami from offspring subjected to maternal undernutrition. The investigations are focused on the glucocorticoid receptor (GR) as an inhibitor of the anorexigenic neuropeptide pro-opiomelanocortin (POMC), with potential modifications leading to increased food intake and the development of obesity. To achieve this, an established sheep model developed by our collaborators was used, during which maternal ewes were undernourished periconceptionally to produce a 10-15% decrease in body weight. We found that hypothalami from fetal offspring had greater epigenetic modifications when this reduction in maternal body weight was maintained from 60 days before conception until 30 days into pregnancy, with lower levels of POMC and GR promoter methylation. This was associated with increased GR mRNA expression. Other regions of the brain that also express POMC and GR, did not exhibit these epigenetic modifications. This study revealed that maternal undernutrition induces tissue specific epigenetic changes in fetal hypothalami which may contribute to disease in later life. Twins have been shown to have similar phenotypic characteristics as maternally undernourished offspring and therefore it has been suggested that they may also be programmed, but by intrauterine growth restriction. Consequently, extensive methylation and histone analysis of GR and POMC promoter regions was carried out in twin fetal hypothalami and compared to maternally undernourished groups. Interestingly, the decreased POMC and GR methylation of our amplicons in the maternally undernourished fetal hypothalami was also observed in twin fetal hypothalamic. This was concomitant with histone modifications and alterations in overall DNA methyltransferase activity. However, it was found that there were no changes in the POMC and GR mRNA expression levels in twin fetuses, but we postulate that this may occur later in life. To determine if changes in the fetal epigenetic status of hypothalamic GR and POMC impacted the adult progeny, tissues were obtained from adult offspring of maternally undernourished ewes. Epigenetic changes in the hypothalamic GR promoter observed in the fetal group persisted into adulthood, with concurrent increases in GR mRNA and GR protein expression. Of these groups the undernourished adult male offspring had decreased hypothalamic POMC expression and increased fat mass, changes that are consistent with an obese phenotype. The epigenetic and expression status of GR in the hippocampus and pituitary were modified, but in a tissue and sex specific manner. POMC epigenetic changes in the brain were complex, with various levels of epigenetic and expression changes. Overall periconceptional undernutrition induces hypothalamic specific changes in the epigenetic status of the GR gene which is known to regulate energy balance. Hypothalamic changes were persistent from the fetal stage into adulthood, with modifications in other tissues occurring after birth. These adaptations have the potential to increase the offspring’s propensity to develop obesity and altered stress regulation in later life.

Literature Review Undernutrition in the hospital setting has been shown to cause adverse outcomes. Screening for nutritional risk assists in the detection of undernutrition with subsequent early intervention to prevent further decline. While many nutrition screening tools exist, none are proven to detect undernutrition. Furthermore, many barriers exist for utilizing nurses as primarily responsible for screening patients for nutritional risk. Background A hospital reviewed the nutrition screening process and found that the form used and screening factors were insufficient to adequately detect undernutrition and appropriate referrals for dietitians. Objectives 1) Determine if nursing compliance improved when the nutrition screening form was integrated with the Interdisciplinary Care Plan form. 2) Improve the relevance of the nutrition screening risk factors used and the overall screening tool. Methods The Interdisciplinary Plan of Care form was updated to include the nutrition screening tool and used on the Medical /Surgical unit. Data was also collected on the Intensive Care Unit which continued to use the original screening tool. Results Screening completion did not improve with the implementation of the new screening process, however the quality and quantity of referrals from the new screening form did improve. Total compliance for nurses responsibility also improved with the new form. Conclusion Integrating nutrition screening factors into an interdisciplinary plan of care can improve the rate of dietitian referrals. Nutritional screening procedures must be continually reevaluated for effectiveness in detecting undernutrition in the hospitalized patient. Further studies must be conducted to evaluate the validity and specificity of all nutrition screening tools.

No description available.

Este trabalho avaliou a reparação e indicadores de desnutrição de ratos submetidos à fratura unilateral de côndilo mandibular e com desnutrição protéica (8% de proteína com suplemento de vitaminas e minerais). Foram utilizados 45 Rattus norvegicus Wistar, adultos machos, distribuídos em 3 grupos de 15 animais: grupo fraturado, submetido à fratura de côndilo, sem alteração de dieta (23% de proteínas); grupo fraturado desnutrido, submetido à dieta hipoprotéica por 30 dias e posterior fratura condilar; grupo desnutrido, com dieta hipoprotéica prévia por 30 dias e mantida até o final do experimento, sem fratura de côndilo. Foi documentada a quantidade de ingestão de ração e água, feita a avaliação do peso e obtido o coeficiente de eficácia alimentar (CEA). Os animais foram sacrificados nos períodos de 24 horas e 7, 15, 30 e 90 dias pós-operatório. Foram realizados os seguintes testes bioquímicos do sangue: proteínas totais, albumina sérica, cálcio sérico, fosfatase alcalina, ferro sérico e creatinina sérica; e o leucograma. A seguir, foram feitas mensurações cefalométicas por radiografias da maxila e da mandíbula. O estudo histológico compreendeu a avaliação do local da fratura e da articulação temporomandibular. Os valores numéricos foram submetidos a análises estatísticas. O consumo de ração e água foi maior no grupo fraturado desnutrido, na maioria dos períodos. Os valores do CEA foram baixos principalmente nos períodos iniciais, sendo mais significativos para o grupo fraturado desnutrido. Houve pouco ganho de peso nos períodos iniciais, exceto no grupo fraturado desnutrido que apresentou perdas significativas, havendo recuperação de peso nos demais períodos, significativamente menor neste grupo. Os testes de bioquímica do sangue mostraram queda, principalmente nos períodos iniciais, para os valores de proteínas totais e albumina, bem como para cálcio sérico em todos os períodos, significante para o grupo fraturado desnutrido. O leucograma mostrou aumento, principalmente nos períodos iniciais, de leucócitos, linfócitos e neutrófilos, mais significativo no grupo fraturado desnutrido. Houve desvio da linha média mandibular em relação à linha média maxilar, significante para o grupo fraturado desnutrido, bem como assimetria de maxila e mandíbula, em especial no período final do experimento. A análise histológica mostrou que a desnutrição protéica levou à atrofia da fibrocartilagem do côndilo. A fratura sob desnutrição comprometeu a formação do calo ósseo, bem como houve anquilose fibrosa. Foi concluído que a fratura de côndilo mandibular em ratos com desnutrição protéica promoveu alterações negativas nos valores de proteínas totais, albumina e cálcio sérico, leucocitose, bem como comprometeu a formação do calo ósseo e induziu atrofia da fibrocartilagem e anquilose fibrosa. / This study evaluated the healing and undernutrition indicatives of rats submitted to mandibular condyle fracture and with protein undernutrition (8% of protein with vitamin and minerals supplement). Forty-five adult male Wistar Rattus norvegicus were used and distributed in 3 groups of 15 animals: fracture group, submitted to condylar fracture with no changes in diet (23% of proteins); undernutrition fracture group, submitted to hypoproteic diet by 30 days and later to condylar fracture; undernutrition group, with previous hypoproteic diet by 30 days, kept until the end of experiment, without condylar fracture. The amounts of feed and water intake were registered, as well as body weight and food efficiency ratio (FER) were obtained. Animals were sacrificed at 24 hours and 7, 15, 30 and 90 days postoperatively. The following blood biochemical tests were made: total serum proteins, serum albumin, serum calcium, alkaline phosphatase, serum iron, and serum creatinine; and also white blood count. Subsequently, cephalometric mensurations by radiograms of the maxilla and mandible were made. Histological study comprised fracture site and temporomandibular joint evaluations. Numerical values were submitted to statistical analyses. Feed and water intake were higher in undernutrition fracture group, in most of periods. Values of FER were low, in special in the initial periods, being more significative to undernutrition fracture group. There was low gain of weight in the initial periods, but undernutrition fracture group which presented significative loss of weight, with recovering of weight in the remaining periods, significatively lower in this group. Blood biochemical tests showed decrease, mainly in the initial periods, of the values of total serum proteins and serum albumin, as well as serum calcium in all the periods, significative to undernutrition fracture group. White blood count showed increase, in special in the initial periods, of leukocytes, lymphocytes and neutrophils, more significative in undernutrition fracture group. There was deviation of the median line of the mandible relative to the median line of the maxilla, significative to undernutrition fracture group, as well as asymmetry of the maxilla and mandible, in special in the final period of experiment. Histological analysis showed that proteic undernutrition lead to atrophy of condylar fibrocartilage. Fracture in undernutrition impaired callus formation, as well as there was fibrous ankylosis. It was concluded that mandibular condyle fracture in rats with proteic undernutrition promoted negative alterations in values of total proteins, albumin and serum calcium, leukocytosis, as well as impaired callus formation, and induced atrophy of condylar fibrocartilage and fibrous ankylosis.