Introduction et objectifs: L’asthme professionnel (AP) est la maladie respiratoire d’origine professionnelle la plus fréquente dans les pays industrialisés. Plus de 300 agents étiologiques de l’AP ont été recensés. Il s’agit d’agents de haut poids moléculaire tels que les enzymes, la farine, les animaux de laboratoire et d’agents de bas poids moléculaire tels que les isocyanates, les persulfates. Les conséquences socioprofessionnelles de l’AP sont graves et mal compensées par la réparation accordée au titre des maladies professionnelles. Des efforts considérables de prévention sont faits dans plusieurs pays. Le repérage rapide du sujet à risque d’AP constitue un aspect majeur de ce volet de prévention. L’inflammation des voies aériennes (IVA) est la manifestation princeps de l’AP. Plusieurs méthodes permettent d’investiguer aujourd’hui cette IVA. Il s’agit de la biopsie bronchique, de la mesure de l’hyperréactivité bronchique (HRB) spécifique, de l’hyperréactivité bronchique non spécifique à stimulus chimique. Mais ces méthodes sont invasives et difficiles à mettre en œuvre en pratique courante. Depuis peu, des méthodes non invasives sont proposées. Parmi ces méthodes figurent la mesure du monoxyde d’azote exhalé (NOE) et l’analyse du liquide de lavage nasal. L’étude MIBAP (Marqueurs d’Inflammation Bronchique dans l’Asthme Professionnel) s’inscrit dans cette ligne. Son principal objectif est d’examiner les performances d’une batterie de tests faciles à mettre en œuvre dans un cadre épidémiologique et professionnel et permettant d’évaluer de façon non invasive l’inflammation bronchique initiale susceptible d’évoluer vers l’installation d’un AP. Matériel et méthodes : Il s’agit d’une étude longitudinale prospective visant à évaluer chez 441apprentis boulangers/pâtissiers et coiffeurs le développement d’une IVA au cours de leurs deux années de formation. La version abrégée du test à la métacholine a été utilisée comme référence pour détecter l’IVA. Les autres examens dont le lien avec l’IVA a été étudié sont : le questionnaire clinique, la mesure du NOE, la spirométrie et l’impédance respiratoire, l’analyse du liquide de lavage nasal, la recherche de la sensibilisation aux allergènes communs et professionnels. Résultats : Les sujets, tous volontaires, sont âgés en moyenne de 17 ans à l’entrée de l’étude. Le nombre de perdus de vue est de 90 (20.0 %), sans lien avec l’objet de l’étude. Parmi les symptômes, seuls ceux évocateurs d’asthme augmentent significativement entre le début et la fin de l’étude. Alors que la prévalence de l’atopie est restée stable, la sensibilisation aux allergènes professionnels est passée de 6.4 % à 9.6 % (p=0.01). L’incidence de l’HRB non spécifique est de 18,2% chez l’ensemble des sujets ; à 7 mois du début de la formation, le taux d’incidence chez les boulangers et pâtissiers est statistiquement plus élevé que chez les coiffeurs (différence de 0,206 cas pour 100 personnes-années [IC à 95 % = 0,01 – 0,40]. L’augmentation du NOE depuis le début de l’apprentissage est associée à l’apparition de l’HRB à un moment donné du suivi (OR = 2,00 IC à 95 % = 1,21-3,32). Cette augmentation est plus importante chez les non atopiques (21,6 % Vs 3,8 % chez les atopiques). L’atopie chez les boulangers/pâtissiers et la sensibilisation aux persulfates alcalins chez les coiffeurs sont associés à l’apparition de l’hyperréactivité bronchique. Discussion et conclusion : Le taux d’abandon observé dans cette étude est plus faible que celui souvent rapporté dans les études de suivi d’apprentis. Ceci montre la faisabilité du protocole et l’acceptabilité des tests par les sujets. La différence dans la cinétique d’apparition de l’HRB observée selon les filières pourrait être due à la différence de mécanisme de sensibilisation mis en jeu par les deux types d’agents (haut poids et bas poids moléculaire). Les agents de haut poids moléculaire impliquent un mécanisme de type IgE alors que le mécanisme des agents de bas poids moléculaire n’est pas encore clairement élucidé. L’augmentation du monoxyde d’azote exhalé pourrait s’avérer être un moyen simple pour repérer la survenue d’une HRB. Ces résultats méritent d’être confirmés dans d’autres études avant de proposer ces outils comme moyen de dépistage des sujets à risque d’asthme professionnel. / Background and objectives: Occupational asthma (OA) is the most frequent work-related lung disease in industrialized countries. More than 300 agents, either of high molecular weight (such as flour, laboratory animal...) or of low molecular weight (isocyanates, alkalin persulfates...) have been reported to cause occupational asthma. The socio-economic consequences of OA are important and poorly compensated by the occupational diseases mitigation system. Considerable efforts of prevention are made in industrial nations. Early identification of subjects at risk of OA represents a major aspect of this prevention. Airways inflammation is the first and key expression of occupational asthma. It is investigated by means of several tests such as bronchial biopsy, assessment of bronchial hyperresponsiveness (BHR) to specific occupational agents, non specific BHR to a chemical stimulus. But these examinations are invasive, time consuming, difficult to implement away from medical facilities. Recently, non invasive tests have been proposed such as measurement of fractional exhaled nitric oxide (FENO), and cellular and molecular analysis of lavage nasal fluid. The MIBAP project (Markers of Bronchial Inflammation in Occupational Asthma) takes place in this setting. Its main objective is to examine the performance of a battery of non invasive tests likely to detect early airways inflammation that might eventually develop into OA. Material and methods: It is a prospective follow-up study of 441 bakers, pastry-makers and hairdressers apprentices in order to evaluate the airways inflammation during their 2-year apprenticeship period. The methacholine challenge test was used the “gold standard” to evaluate the airways inflammation. The other medical examinations whose association with airways inflammation have been studied are a clinical questionnaire, measurement of FENO, spirometry and measurement of respiratory impedance, count of eosinophil cells in nasal lavage fluid, and sensitization to common and occupational allergens by skin prick test. Results: Subjects, all volunteers, are 17 years old on average. Among them, 90 (20.0%) quit for several reasons, unrelated to the study outcome. Among work-related respiratory conditions, only asthma-like symptoms increased significantly since the the beginning of the study. While atopy (sensitization to commons allergens) remained stable, sensitization to occupational allergens increased from 6.4% to 9.6% (p=0.01) during the study. Incidence of BHR was 18.2% over all subjects; 7 months after the beginning of the training, the incidence rate among bakers and pastry-makers was statistically greater than among hairdressers (difference of 0,206 case per 100 person-yaers [CI = 0.01 – 0.40]). The increase of FENO levels is correlated with occurrence of BHR during the follow-up period (OR = 2.0 CI 95% = 1.21-3.32), regardless of atopy (increase of 21.6% and of 3.8% median FENO respectively for non-atopic and atopic subjects). Atopy when engaging in the training programme was associated with incidence of BHR among bakers and pastry-makers, not among hairdressers. Conversely, sensitization of hairdressers to alkaline persulfates at the end of the follow-up was related with occurrence of BHR. Discussion and conclusion: The number of subjects lost to follow-up was reasonably low (about 20%) for this kind of longitudinal study, compared with other similar works, which is in favour of the acceptability of the tests. The difference in the kinetics of BHR according to the training track might relate to differences in the mechanisms of sensitization between LMW and HMW agents. The latter involve IgE dependant processes while the mechanisms at hand with the former are yet to be elucidated. To date, no study has been published concerning the association between the increase of FENO and the occurrence of BHR. Further studies are necessary to confirm these results, before usage of FENO as a means for early detection of subjects at risk of OA be recommended.

Cancer procoagulant (EC 3.4.22.26) is an enzyme that is derived from tumour and foetal tissue, but not normal tissue. It is a direct activator of factor X and has been isolated from amnion-chorion membranes as well as from extracts and cells from human melanoma. The presence of cancer procoagulant has been associated with the malignant phenotype, as well as having a particularly high activity in metastatic cells. Cancer procoagulant activity is elevated in the serum of early stage breast cancer patients and decreased to normal in the advanced stages of the disease. In this study, cancer procoagulant was successfully isolated from amnion-chorion membranes and purified to homogeneity. The molecular weight of cancer procoagulant was determined using SDS-PAGE and was found to be 68 kDa. Cancer procoagulant was delipidated and it was shown that its activity was increased by the presence of lipids in a dose-dependent manner. Recovery of cancer procoagulant after delipidation is poor, consequently, a larger mass of sample is required to obtain sufficient amounts of delipidated material for N-terminal amino acid analysis. The optimum pH of cancer procoagulant was determined to be pH 8 and its optimal temperature was found to be 50°C. Novel synthetic substrates were designed to assay for cancer procoagulant activity. Currently, 2 potential candidates have been identified, namely, PQVR-AMC and AVSQSKP-AMC. Cancer procoagulant-induced expression of cytokines is differently modulated in the less aggressive MCF-7 cell line as compared to the metastatic and more aggressive MDA-MB-231 cell line. There are marked similarities in the inflammatory response produced by cancer procoagulant in hTERT-HDLEC and MDA-MB-231 cells, which are both associated with migratory capacity. Furthermore, cancer procoagulant-induced PDGF-β expression in hTERT-HDLEC and MDA-MB-231 cells could point to involvement of cancer procoagulant in wound healing and metastatic spread, respectively. Cancer procoagulant induced the motility of MDA-MB-231, MCF-7 and hTERT- cells in vitro in a time- and dose-dependent manner. Together, these results suggest that cancer procoagulant plays a role in the migration of breast cancer cells as well as the migration of endothelial cells.

Abstract : Multiple Sclerosis (MS) is an organ-specific autoimmune disease characterized by the presence of demyelinating plaques throughout the central nervous system (CNS) as a result of an abnormal inflammatory response. During MS, activated microglia can play the role of antigen presenting cells and can, therefore, skew T cell responses towards a pro-inflammatory phenotype. Once activated, microglia upregulate the expression of pro-inflammatory molecules. In addition to microglial responses during MS, astrocytes are also implicated in the development of MS lesions. Upon injury and nearby neuronal death, astrocytes undergo astrogliosis. To date, several molecular pathways were identified as targets for therapeutic interventions for MS such as NF-kB & Nlrs. Nlrs are regulatory proteins of the immune system capable of regulating both innate and adaptive responses. Nlrp12 is a pyrin-containing intracellular protein, largely expressed in cells of myeloid origin. Nlrp12 plays an important role in immune inflammatory responses by negatively regulating the NF-κB pathway and modulatory roles, such as dendritic cell migration. The focus of this study was to evaluate the hypothesis where Nlrp12 plays an anti-inflammatory role in Experimental Autoimmune Encephalomyelitis (EAE), a well-characterized mouse model to study MS. Over a course of 9 weeks, Nlrp12 KO mice demonstrated increased severity in disease levels compared to WT mice. In both genotypes, the disease was observed to peak around the 3rd week post immunization A significant increase in Nlrp12 mRNA was observed in diseased WT compared to healthy WT mice. A significant increase in the expression of CCR5, COX-2, and IL-1 β in Nlrp12 KO mice relative to WT mice, was observed. Interestingly, no differences in the percentage of gliosis was seen at 3 weeks post injection in both genotypes, however after 9 weeks of diseases, in Nlrp12 KO mice we observed a significant increase in the percentage of reactive gliosis compared to WT mice. A significant activation of NF-kB-dependent inflammation was seen in primary microglial cell cultures from Nlrp12 KO relative to WT following LPS stimulation. Moreover, supernatants of analysis for the level of nitrates with Griess reagent and with ELISA for TNFα and IL-6, demonstrated an increase in the pro-inflammatory phenotype from microglia from Nlrp12 KO mice compared to WT mice. These results suggest a critical role of Nlrp12 in suppressing inflammation during the development of the disease given that in its absence, we observed an increase in the inflammatory response. / La sclérose en plaques est une maladie auto-immune déclenchée par une réaction inflammatoire anormale et caractérisée par la dégradation de myéline au niveau du système nerveux central. Durant la sclérose en plaques, la microglie promeut l’expression de molécules pro-inflammatoires et joue le rôle de cellules présentatrices d’antigènes pour forcer les cellules T à adopter un phénotype pro-inflammatoire. Outre les réponses associées à la microglie, les astrocytes sont aussi impliqués dans le développement des lésions. Jusqu’à présent, plusieurs voies moléculaires ont été identifiées comme cibles pour des interventions thérapeutiques tel que les voies de NF-kB et Nlrs. Les récepteurs Nlrs sont des protéines régulatrices du système immunitaire inné et adaptatif. Nlrp12 joue un rôle important dans les réponses inflammatoires immunes en régulant négativement la voie NF-kB et la migration de cellules dendritiques. L’objectif de cette étude est d’étudier l’hypothèse dans laquelle Nlrp12 joue un rôle anti-inflammatoire dans l’encéphalopathie expérimentale autoimmune (EAE), un modèle murin de la sclérose en plaques. Durant 9 semaines, des souris n’exprimant pas Nlrp12 ont démontré un état sévère de la maladie comparativement aux souris de type sauvage (WT). Dans les deux types de génotypes, la maladie était observée à son maximum autour de la 3ème semaine après immunisation. Une augmentation significative de l’expression d’ARNm de Nlrp12 était observée dans les souris contrôles malades comparativement aux souris saines. Une augmentation significative de l’expression de Ccr5, COX-2 ainsi qu’IL-1β était détectée dans les souris Nlrp12 KO par rapport aux souris WT. De plus, aucune différence dans le pourcentage de gliose était observée dans les deux génotypes à 3 semaines post-injection. Par contre, le pourcentage de gliose activée augmentait dans les souris Nlrp12 KO après 9 semaines de maladie. Nous avons remarqué une activation prononcée de l’inflammation dépendante de NF-kB dans des cultures cellulaires primaires de microglie provenant de souris Nlrp12 KO soumise à une stimulation au LPS. Finalement, la quantification des niveaux de nitrates et des cytokines TNFα et IL-6 traduisait une signature pro-inflammatoire de la microglie des souris Nlrp12 KO comparativement aux souris WT. Ces résultats suggèrent un rôle antiinflammatoire de Nlrp12 durant le développement de la sclérose en plaques considérant la réponse inflammatoire accrue en absence de Nlrp12.

Maternal tolerance during pregnancy increases the risk of infection with certain intracellular pathogens such as Salmonella enterica serovar Typhimurium (S.Tm). Systemic S.Tm infection during pregnancy in normally resistant 129X1/SvJ mice, with a functional natural resistance-associated macrophage protein-1 (Nramp1), leads to severe placental infection followed by fetal and maternal death. We hypothesized infection-induced inflammatory trophoblast cell death contributes to adverse pregnancy outcomes. We therefore investigated the kinetics of systemic and oral S.Tm infection in wild-type and gene deficient mice with defects in specific inflammatory pathways. Systemic infection with S.Tm resulted in preferential placental replication compared to other tissues in Nramp1+/+ mice. At 24 hours, <25% of individual placentas per mouse were infected, progressively increasing to >75% by 72 hours which correlated with a steady increase in resorption rates. Moreover, placental infection was associated with increased neutrophils, macrophages and natural killer cells whereas neutrophil numbers in the spleen remained unchanged, suggesting dichotomous modulation of inflammation in the systemic compartment compared to the feto-maternal interface. Oral infection resulted in systemic dissemination of the bacteria, substantial placental colonization and fetal loss five days post-infection in C57BL/6J mice. Systemic infection in pregnant cell death deficient Rip3-/-Nramp1+/+ mice (with defective necroptosis) resulted in decreased fetal demise relative to Nramp1+/+ and Caspase-1,11-/-Nramp1+/+ mice (with defective pyroptosis) suggesting a role for necroptotic inflammation. This study provides insight into the kinetics and mechanism of inflammation and cell death during placental S.Tm infection. Such studies may assist in the rational management of foodborne pathogens contracted during pregnancy.

Objectives The aims of this thesis were to (1) investigate the association of gestational exposure to environmental phthalates with maternal and perinatal outcomes, and (2) explore phthalate-induced changes to maternal inflammatory responses as potential mediators of possible health effects. Methods A systematic review was performed to summarize existing evidence on the association of gestational exposure to phthalates with obstetrical outcomes, including pre-eclampsia (PE), pregnancy-induced hypertension (PIH), gestational diabetes mellitus (GDM), intrauterine growth restriction (IUGR), birth weight (BW), head circumference (HC), gestational age (GA), preterm birth (PB), and Apgar scores (AS). Additionally, a secondary analysis of data from the MIREC Study was conducted to evaluate the association of phthalate metabolites with clinical outcomes in the mother and infant using multiple linear and logistic regression, and with inflammatory biomarkers using multinomial logistic regression. Results The systematic review identified a total of 24 articles, and observed inconsistent evidence on BW, HC, GA, and PB, a paucity of research on IUGR, PE, GDM, and AS, and a lack of studies on PIH. However, among studies with statistically significant (p<0.05) results, most suggest an association of phthalates with decreased BW and GA, and increased HC and PB. Findings from the MIREC Study indicate a significant (p<0.01) positive association between MBP and HC among female infants; however, null results were identified for BW, GA, PB, AS, and PIH. In relation to the exposure to phthalates, general trends among suggestive associations (p<0.05) for head circumference showed consistent increases in females and decreases in males, and for gestational age displayed decreases in both stratums. Additionally, a significant positive association of MBzP and ∑DEHP was observed with high MMP-2 and low VCAM levels, respectively. Results approaching statistical significance demonstrated a positive association of ∑DEHP with low MCP1 and ICAM levels, MCPP with low GMCSF levels, MBzP with low CRP and high ICAM levels, and MEP with high MMP-7 and IL-2 levels. Conclusion From the systematic review, the effects of phthalates on maternal and perinatal health remain unclear, possibly due to sources of heterogeneity and challenges in exposure assessment. In the MIREC Study cohort, phthalate levels were associated with GA and HC in infants in a sex-specific manner. Phthalates also appear to influence the circulating inflammatory marker levels, possibly explaining the observed adverse effects. Future research is needed to validate these findings.

Le corépresseur nucléaire NCOR1 est un répresseur transcriptionnel qui régule l’expression génique en s’associant à des récepteurs nucléaires ou à des facteurs de transcription comme AP-1 et NF-B. Ce projet de recherche visait à déterminer comment NCOR1 régule la prolifération et la réponse inflammatoire dans les cellules épithéliales intestinales (CEIs). Nous avons utilisé deux modèles murins de délétion du gène Ncor1 (Ncor1ID et Ncor1Exon11) ainsi que la Cre-recombinase sous le contrôle du promoteur du gène Vil1 (12.4KbVilCre) afin d’invalider le gène Ncor1 au niveau des CEIs (Ncor1IDΔCEI et Ncor1Exon11ΔCEI). Nous avons induit une réponse inflammatoire dans les CEIs en utilisant de l’IL-1 et du LPS. Nous avons observé que l’expression de NCOR1 est augmentée dans les CEIs lors de la réponse inflammatoire. Nous avons également traité les souris invalidées pour le gène Ncor1 avec du DSS afin d’induire une colite chimique expérimentale. Nous avons observé que les animaux Ncor1IDΔCEI et Ncor1Exon11ΔCEI sont plus susceptibles que les témoins. Nous avons analysé l’expression génique chez les animaux Ncor1IDΔCEI et Ncor1Exon11ΔCEI. L’analyse des gènes modulés dans les animaux Ncor1IDΔCEI a révélé que l’expression de la Retnlb est augmentée chez ces animaux, ce qui suggère un dérèglement dans la microflore. Dans les animaux Ncor1Exon11ΔCEI, nous avons noté que l’expression du gène Ido1, un puissant immunosuppresseur, est augmentée et permettrait possiblement à ces animaux de se maintenir dans un état homéostatique en absence de stress. Lorsque nous avons diminué l’expression de NCOR1 dans les CEIs à l’aide de shARN (shNCOR1_655), nous avons observé que celles-ci arrêtent de proliférer et sont sénescentes. De plus, nous avons remarqué une induction de molécules inflammatoires associées au SASP dans ces cellules. Nous avons analysé le transcriptome des cellules shNCOR1_655. Nous avons identifié le facteur de pluripotence SOX2 comme étant induits lorsque l’expression de NCOR1 est diminuée. Finalement, nous avons utilisé la technologie SILAC et la spectrométrie de masse afin de déterminer la composition du complexe de répression de NCOR1 dans les CEIs. Nous avons identifié de nouveaux partenaires d’interaction potentiels de NCOR1.

This study provides a parallel characterization of the cytokine and chemokine response to stroke in the human and mouse brain at different stages of infarct resolution. The study goal was to address the hypothesis that chronic inflammation may contribute to stroke-related dementia. We used C57BL/6 and BALB/c mice to control for strain related differences in the mouse immune response. Our data indicate that in both mouse strains, and humans, there is increased granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), interleukin-12 p70 (IL-12p70), interferon gamma-induced protein-10 (IP-10), keratinocyte chemoattractant/interleukin-8 (KC/IL-8), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1 alpha), macrophage inflammatory protein-1 beta (MIP-1 beta), regulated on activation, normal T cell expressed and secreted (RANTES), and Tumor necrosis factor-alpha (TNF-alpha) in the infarct core during the acute time period. Nevertheless, correlation and two-way ANOVA analyses reveal that despite this substantial overlap between species, there are still significant differences, particularly in the regulation of granulocyte colony-stimulating factor (G-CSF), which is increased in mice but not in humans. In the weeks after stroke, during the stage of liquefactive necrosis, there is significant resolution of the inflammatory response to stroke within the infarct. However, CD68+ macrophages remain present, and levels of IL-6 and MCP-1 remain chronically elevated in infarcts from both mice and humans. Furthermore, there is a chronic T cell response within the infarct in both species. This response is differentially polarized towards a T helper 1 (Th1) response in C57BL/6 mice, and a T helper 2 (Th2) response in BALB/c mice, suggesting that the chronic inflammatory response to stroke may follow a different trajectory in different patients. To control for the fact that the average age of the patients used in this study was 80 years, they were of both sexes, and many had suffered from multiple strokes, we also present findings that reveal how the chronic inflammatory response to stroke is impacted by age, sex, and multiple strokes in mice. Our data indicate that the chronic cytokine and chemokine response to stroke is not substantially altered in 18-month old compared to 3-month old C57BL/6 mice, although T cell infiltration is attenuated. We found a significant correlation in the chronic cytokine response to stroke in males and females. However, the chronic cytokine response to stroke was mildly exacerbated by a recurrent stroke in both C57BL/6 and BALB/c mice.

Orientador: Patrícia de Oliveira Prada / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-26T21:26:16Z (GMT). No. of bitstreams: 1 Abboud_KahlileYoussef_M.pdf: 2486444 bytes, checksum: c7ecb857ad37f6bfbb7dd2e09bd6bfed (MD5) Previous issue date: 2014 / Resumo: A obesidade tornou-se um dos maiores problemas de saúde publica no mundo. Nas ultimas décadas, estudos têm demonstrado que a obesidade produz um estado de inflamação crônica subclínica e resistência à insulina em vários tecidos. Indivíduos obesos podem apresentar elevados níveis séricos de LPS e esta condição está associada à resistência à insulina e ao aumento na expressão de citocinas pró-inflamatórias e consequentemente na inflamação subclínica associada à obesidade. Neste contexto, a ação da glutamina tem despertado interesse por melhorar a resistência à insulina em tecidos periféricos através redução da expressão de marcadores inflamatórios nestes tecidos. Entretanto, ainda não foi bem elucidado se a suplementação oral de glutamina pode intervir nestas condições. Portanto, o objetivo do presente estudo foi de investigar se a suplementação oral com glutamina influencia o estado nutricional de indivíduos sobrepeso e obesos e também os níveis de LPS e citocinas pró-inflamatórias. No nosso estudo, a suplementação com glutamina não demonstrou reduzir significativamente os níveis séricos de LPS, no entanto, houve redução da citocina próinflamatória TNF-'alfa', dos níveis séricos de insulina de jejum, bem como da circunferência da cintura. Assim, a suplementação com GLN em indivíduos com sobrepeso e obesos pode ser benéfica para reduzir a adiposidade e melhorar a inflamação subclínica associada ao aumento do peso corpóreo. A suplementação com GLN em indivíduos com sobrepeso e obesos também melhora o quadro de resistência à insulina. Neste sentido, sua suplementação, pelo menos em curto prazo, pode ser recomendada para a melhora do metabolismo energético / Abstract: Obesity has become a major public health problem. In the last decades studies shown that it can induce low-grade chronic inflammation and insulin resistance in tissues. Obese individuals can have elevated lipopolissacharides (LPS) serum levels and this condition is associated to insulin resistance and the increased inflammatory cytokine expression. In this context, Glutamine actions has been studied for its role in insulin resistance in peripheral tissues decreasing of inflammatory markers expression. Although, it's still not clear if oral glutamine supplementation can change these conditions. Therefore, the aim of this study is to investigate whether oral glutamine supplementation can influence in the nutritional state of overweight and obese individuals and also in LPS serum levels and proinflammatory citokines In our study, glutamine doesn¿t demonstrate to significantly reduce LPS serum levels, although TNF-'alfa', fasting insulin and waist circumference was decreased after supplementation. Finally, supplementation with glutamine in overweight and obese individuals can show benefits reducing adiposity and improve low-grade chronic inflammation. It can also improve insulin resistance. Is this sense, GLN supplementation can be recommended in short term to improve energy metabolism / Mestrado / Nutrição / Mestra em Ciências da Nutrição e do Esporte e Metabolismo

Le tissu adipeux (TA) joue un rôle majeur dans les maladies métaboliques induites par l’obésité. L’activation de l’anti-oncogène p53 dans l’adipocyte a été impliquée dans le développement de la résistance à l’insuline lors de l’obésité. Cependant, les causes et les conséquences de cette activation étaient encore inconnues. Nos travaux montrent que, chez des souris obèses, le niveau d'oxydation de l'ADN est plus élevé et la longueur des télomères réduite dans le TA épididymaire. Nous observons également une augmentation des dommages à l’ADN dans les adipocytes. Ces dommages à l’ADN provoquent l’activation de la voie de réponse aux dommages à l’ADN puisque nous avons observé une activation de la voie p53 (stabilisation de la protéine et expression d’une cible p21). De manière intéressante, nous avons démontré que les dommages à l’ADN et l’activation de la voie p53 dans les adipocytes sont des événements précoces lors du développement de l’obésité qui pourraient être la conséquence d’une augmentation également précoce du stress oxydatif dans le tissu adipeux et les adipocytes. De plus, l’augmentation des dommages à l’ADN et l’activation de p53 dans les adipocytes précèdent l’inflammation du tissu adipeux et la résistance à l’insuline systémique. Nous apportons également des arguments en faveur d’un rôle causal des dommages à l’ADN et de l’activation de p53 dans l’adipocyte dans le développement de l’inflammation du tissu adipeux et la résistance à l’insuline adipocytaire. In vitro, nous montrons que la création expérimentale de dommages à l’ADN avec de la doxorubicine et l’activation pharmacologique de p53 avec l’inhibiteur de l’ubiquitine ligase Mdm2, la nutline3a, dans des adipocytes humains et murins en culture inhibent la signalisation insulinique, le transport de glucose et la translocation de Glut4 stimulés par l’insuline. Ils perturbent également l’activité sécrétoire des adipocytes. En particulier, le sécrétome de ces adipocytes possède une activité chimioattractive pour les neutrophiles et les macrophages. Des résultats préliminaires indiquent qu’il pourrait également affecter les préadipocytes en perturbant leur survie et leur différenciation en 8 adipocytes. In vivo, l’injection de doxorubicine à des souris provoque l’infiltration de neutrophiles et de macrophages dans le TA, l’inflammation du TA, et la résistance à l’insuline adipocytaire. Nous montrons également une induction précoce du locus CDKN2A dans le TA lors de l’obésité. Ce locus code pour p16INK4A, un inhibiteur des kinases dépendantes des cyclines CDK4/6, et p19ARF, un inhibiteur de Mdm2. Nous confirmons que la surexpression de p19ARF dans des adipocytes en culture permet la stabilisation de p53 et étudions actuellement l’impact de l’absence de p19ARF dans les adipocytes in vivo dans le développement des maladies métaboliques lors de l’obésité. En résumé, nos travaux démontrent que les dommages à l’ADN observés précocement dans les adipocytes lors du développement de l’obésité ont le potentiel de déclencher des signaux dépendants de p53 impliqués dans l'altération du métabolisme adipocytaire et de sa fonction sécrétoire conduisant à une inflammation du TA, un dysfonctionnement des adipocytes, et la résistance à l'insuline. / Non disponible

Objective: Physical exercise decreases disability and pain associated with chronic articular cartilage degradation. However, understanding of the pathology is lacking. In this study, the levels of 17 biomarkers of inflammation and cartilage degradation were measured in synovial fluid (SF) before and after a 30-minute run in able-bodied and previously-injured individuals. Materials & Methods: Four able-bodied recreational runners (3 men and 1 woman: 24 ± 2 years, 68 ± 7 kg, and 173 ± 9 cm) and 4 recreational runners who had undergone a unilateral anterior cruciate ligament reconstruction (ACLr) (2 men and 2 women: 23 ± 1 years, 71 ± 6 kg, and 175 ± 4 cm) were recruited to participate in this study. Using a saline-assisted method, SF was aspirated before and after both a 30-minute unloading and 30-minute exercise session. Samples were corrected for blood contamination and analyzed for 15 cytokines and 2 matrix metalloproteinases (MMPs). Mixed model analyses were used to determine the main effects of session, case/control status, pre/post aspirations, and the interactions between case/control status and pre/post aspirations. Results: Blood protein contamination was calculated and accounted for in 15 of 32 synovial fluid samples. Granulocyte colony stimulating factor (GCSF) was the only detectable cytokine of the 15 analyzed. No statistical differences were found in GCSF concentrations between pretreatment and posttreatment aspirations (p = 0.45), ACLr and able-bodied control groups (p = 0.60), or unloading and exercise sessions (p = 0.96). MMP-13 was undetectable. No statistical differences were found in MMP-3 between pretreatment and posttreatment aspirations (p = 0.15), ACLr and able-bodied control groups (p = 0.85), or unloading and exercise sessions (p = 0.14).Conclusions: Two (GCSF and MMP-3) of the 17 measured biomarkers were detectable. There were no significant differences in either GCSF or MMP-3 due to a 30-minute run or 30-minute unloading period in either the able-bodied or ACLr participants. Further, there were no significant differences between biomarker concentrations and case-control status. A novel method of controlling for blood contamination in synovial fluid samples was implemented.