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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Epidemiologia genética em leishmaniose visceral: Estudo de associação com a população de Bauru - SP / Genetic epidemiology in visceral leishmaniasis: Association study with population of Bauru-SP.

Valezi, Keren Bastos 01 November 2017 (has links)
Submitted by KEREN BASTOS VALEZI null (keren.valezi@hotmail.com) on 2017-12-18T18:47:58Z No. of bitstreams: 1 Dissertação de Mestrado Keren Valezi.pdf: 1447594 bytes, checksum: 988c2b1fc1fbd371daf1230457df1fa9 (MD5) / Approved for entry into archive by Luciana Pizzani null (luciana@btu.unesp.br) on 2017-12-19T14:03:37Z (GMT) No. of bitstreams: 1 valezi_kb_me-int.pdf: 1447594 bytes, checksum: 988c2b1fc1fbd371daf1230457df1fa9 (MD5) / Made available in DSpace on 2017-12-19T14:03:37Z (GMT). No. of bitstreams: 1 valezi_kb_me-int.pdf: 1447594 bytes, checksum: 988c2b1fc1fbd371daf1230457df1fa9 (MD5) Previous issue date: 2017-11-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A leishmaniose é uma doença antropozoonótica causada pelo protozoário do gênero Leishmania. Ele apresenta três formas clínicas, conhecidas como leishmaniose visceral, leishmaniose cutânea e leishmaniose mucocutânea. A leishmaniose visceral afeta dois milhões de indivíduos anualmente no mundo. Os fato res genéticos envolvidos na interação hospedeiro - parasita foram associados ao desfecho clínico da doença. Este estudo investigou pela primeira vez a associação de polimorfismos nos genes candidatos IL10, NOD2 e TLR1 com leishmaniose visceral na população b rasileira. Para isso, escolhemos três marcadores anteriormente associados a infecções causadas por parasitas intracelulares na população brasileira. Nós genotipificamos 135 pacientes e 380 controles saudáveis. A presença do alelo G do rs4833095 no gene TLR 1 foi fortemente associada à susceptibilidade a esta doença: análise do alelo G (OR 2.04; IC 1.22 - 3.39; p - value 0.0061); Análise do genótipo GG (OR 3,87; 95 %IC 1,85 - 8,08, p - valor 0,0003); Análise de portadores de G (OR 2,5; 95 %IC 1,33 - 5,00; valor p 0,0047) . Para o gene NOD2, também encontramos uma associação para o genótipo AA (OR 2.07 95 %IC 1.05 - 4.05, p - value 0.0335) do polimorfismo rs8057341. Finalmente, poderíamos confirmar a associação do marcador rs1800871 na região promotora do gene IL10 com susceptib ilidade à leishmaniose visceral, para o genótipo TT (OR 2,34; CI 95 %IC 1,11 - 4,94 p - value 0,0245). Conclusão. Nossos dados demonstram pela primeira vez a associação desses genes candidatos com leishmaniose visceral na população brasileira, colocando esses ma rcadores como candidatos fortes na composição de futuros painéis genéticos para prever o risco de infecções na população brasileira e para estudos de meta - análise em visceral leishmaniose / 193614-1
2

Einfluss der Src-kinase-Inhibitoren auf die TLR-4-induzierte IL-10 bzw. IL-12 Produktion in Tumor-assoziierten Makrophagen / Impact of src-kinase-inhibitors on the TLR-4 induced IL-10 and IL-12 production in tumor-associated macrophages

Hölldorfer, Constanze Lotte-Marie January 2020 (has links) (PDF)
Die Tumormikroumgebung (TME) spielt eine wichtige Rolle in Bezug auf das Ansprechen von Therapien, Tumorwachstum und die Bildung von Metastasen. In den letzten Jahren konnte belegt werden, dass Tyrosinkinaseinhibitoren (TKIs) Einfluss auf Zellen des TME haben und vor allem die dort vorherrschenden Zellen, Tumor-assoziierte Makrophagen (TAM), durch die TKIs moduliert werden können. Sie entsprechen meist dem M2-Phänotyp, sezernieren antiinflammatorische Zytokine und sind protumoral, indem sie u.a. die Metastasierung und das Tumorwachstum unterstützen. Zentrale Targets für die Reprogrammierung von Makrophagen stellen sowohl der NF-κB als auch die Inhibition des CSF1-Rezeptors dar. An diesen beiden Schlüsselstellen wirken u.a. TKIs. In den durchgeführten Versuchen wurden drei TKIs verwendet – Dasatinib, Src-Kinase-Inhibitor-I, Bosutinib – um die Ergebnisse von Vorarbeiten zu verifizieren und um zu untersuchen, ob ein Klasseneffekt in Bezug auf eine gesteigerte IL-12-Produktion vorliegen könnte. Ein wichtiger Ansatzpunkt in der Bekämpfung von Tumoren ist die Aktivierung von Immunzellen gegen Tumorzellen, in unserem Fall eine Modulation von TAM in Richtung M1-Makrophagen. Eine signifikante Änderung des Phänotyps konnte nicht festgestellt werden. Allerdings wurde eine gesteigerte IL-12-Produktion aller Makrophagensubtypen durch die Inkubation mit Dasatinib- bzw. Src-kinase-inhibitor-I oder Bosutinib gezeigt. IL-12 ist ein wichtiges proinflammatorisches Schlüsselzytokin des Immunsystems, indem es u.a. NK-Zellen und T-Zellen aktiviert. Die funktionellen Auswirkungen der verstärkten IL-12-Produktion in Hinblick auf NK-Zellen haben wir untersucht. Eine deutlich verstärkte Aktivierung anhand Aktvierungsmarker von NK-Zellen konnten wir nicht beweisen. Allerdings wurde eine erhöhte Zytotoxizität durch Ko-Kultivierung der NK-Zellen mit den unterschiedlichen Makrophagensubtypen und gleichzeitiger Inkubation mit Dasatinib demonstriert. Die erhöhte IL-12-Produktion von APCs sowie verringerte IL-10-Produktion und der Einfluss auf andere Immunzellen, hier am Beispiel der NK-Zellen, zeigen u.a. das therapeutische Potential der TKIs als antineoplastisch wirksame Substanz. Als alleinige Therapie ist deren Wirkungsbereich nach den hier vorliegenden Ergebnissen jedoch noch zu gering. In Kombination mit anderen Therapieoptionen stellen die TKIs allerdings ein mögliches Therapieregime dar. Der genaue Wirkmechanismus und die dadurch entstehenden Veränderungen sind noch genauer zu untersuchen. Ein weiteres Ziel ist in vitro etablierte Ergebnisse auch in die klinische Anwendung einfließen zu lassen. Der zweite Teil der Arbeit befasste sich mit einem proinflammatorischen Zytokin IL-32γ und dessen Wirkung auf Makrophagen. Wie bereits auch bei den TKIs wurde der Einfluss des Interleukins auf das Tumormikromilieu und die entsprechenden Auswirkungen untersucht. IL-32γ wirkt nicht nur selbst als proinflammatorisches Zytokin, sondern reguliert eine Vielzahl an weiteren Zytokinen. Der Einfluss von IL-32 auf das Tumormikromilieu und dessen Zellen stellt einen der zentralen Interessenspunkte dar. In unseren Versuchen konnte unter IL-32γ eine effektivere Antigenpräsentation der Makrophagen – gemessen an einer verstärkten Expression von CD80 und CD86 – gezeigt werden. Auf der anderen Seite wurde das antiinflammatorische Zytokin, IL-10, von IL-32γ-stimulierten Makrophagen ebenfalls verstärkt sezerniert. Eine Ko-Kultivierung von Makrophagen und NK-Zellen und gleichzeitige Inkubation mit IL-32γ führte bei NK-Zellen zu einer verstärkten Aktivierung sowie zu einer erhöhten Zytotoxizität. Die Auswirkungen auf NK-Zellen deuten eine antitumorale Wirkung von IL-32γ an. Das breite Wirkspektrum des Interleukins ist vielversprechend und könnte neue Therapiestrategien eröffnen, wofür allerdings weitere Versuche sowohl in vitro als auch in vivo notwendig sind, um das Interleukin und seine Wirkungen genauestens zu verstehen. / Tumor microenviroment (TME) plays an important role in therapies, tumor development and metastasis formation. In recent years it could be proven that tyrosinekinaseinhibitors (TKIs) have an influence on cells of the TME and that especially the main cells located there, tumor-associated macrophages (TAM), can be modulated by the TKIs. They usually are of the M2 phenotype, secrete anti-inflammatory cytokines and are protumoral in respect to fostering metastasis and tumor development. The NF-κB as well as the inhibition of the CSF1 receptor are central targets for the reprogramming of macrophages. TKIs, amonst others, impact on those two central points. Three TKIs were used in the experiments – Dasatinib, Src Kinase Inhibitor-I, Bosutinib – to verify the results of previous work and to examine whether a class effect can be measured in terms of increased IL-12 production. An important starting point in fighting tumors is the activation of immune cells against tumor cells, in our case a modulation of TAM in the direction of M1 macrophages. A significant change of the phenotype could not be determined. It could be shown, however, that the incubation with Dasatinib, Src-kinase-inhibitor I or Bosutinib resulted in increased IL-12 production of all macrophage subtypes. IL-12 is an important pro-inflammatory key cytokine of the immune system, activating NK cells and T cells, amongst others. We examined the functional impact of the increased IL-12 production in respect to NK cells. A significantly increased activation using activation markers of NK cells could not be proven. However, an increased cytotoxicity was demonstrated by co-culturing the NK cells with the different macrophage subtypes and simultaneous incubation with Dasatinib. The increased IL-12 production of APCs as well as the reduced IL-10 production and the influence on other immune cells, here using the example of NK cells, show, among other things, the therapeutic potential of TKIs as an antineoplastic substance. However, according to the results available here, its impact is still too small as an independent therapy. In combination with other therapy options, however, the TKIs represent a possible therapy regimen. The specific mechanism of action and the resulting changes remain to be further examined. Another goal is to incorporate the results established in vitro into clinical application. The second part of the thesis dealt with a pro-inflammatory cytokine IL-32γ and its effect on macrophages. As with the TKIs, the influence of interleukin on the tumor microenvironment and the corresponding effects were investigated. IL-32γ not only acts as a pro-inflammatory cytokine itself, but also regulates a large number of other cytokines. The influence of IL-32 on the tumor microenvironment as well as its cells is one of the main points of interest. Our experiments showed a more effective antigen presentation of the macrophages under IL-32γ – measured with an increased expression of CD80 and CD86. On the other hand, IL-32γ-stimulated macrophages also secreted more of the anti-inflammatory cytokine IL-10. The co-cultivation of macrophages and NK cells and simultaneous incubation with IL-32γ lead to an increased activation of NK cells as well as an increased cytotoxicity. The impact on NK cells indicate an anti-tumor effect of IL-32γ. The broad spectrum of action of interleukin is promising and could open up new therapeutic strategies, for which, however, further experiments in vitro and in vivo are required in order to understand the interleukin and its effects in enough detail.
3

Cellular and Molecular Mechanisms of Immunoregulation In Vivo

McBerry, Cortez January 2012 (has links)
No description available.
4

Expression et fonction du récepteur antigénique B membranaire sur les plasmocytes médullaires producteurs d'IgM / Antigen sensing by long-lived bone marrow IgM-expressing plasma cells

Blanc, Pascal 26 February 2015 (has links)
Le plasmocyte (PC), stade terminal de la différenciation du lymphocyte B induite par l'antigène, est la cellule effectrice de l'immunité humorale responsable de la production des anticorps. La population plasmocytaire se divise en deux grands sous-types différant par leur durée de vie et par leur localisation anatomique. On distingue ainsi les PC à durée de vie courte ou PC effecteurs (dans les tissus lymphoïdes secondaires) et les PC à longue durée de vi (LLPC ou PC à mémoire) localisés principalement dans la moelle osseuse. Ces derniers contribuent à la mémoire humorale en continuant à sécréter des anticorps protecteurs après résolution de l'infection. Nos résultats expérimentaux montrent que les Ags thymo-dépendants (TD) et les Ag thymo-indépendants (TI) induisent des PC médullaires exprimant des caractéristiques phénotypiques et fonctionnelles différentes. Ainsi, l'expression d'une forme membranaire fonctionnelle du récepteur antigénique (BCR) persiste sur les LLPC TI alors qu'elle est perdue sur les LLPC TD. Cette fonctionnalité nouvelle portée par les PC médullaires TI n'est pas dépendante de la sous population lymphocytaire B recrutée ni de la nature de l'Ag, mais de l'isotype IgM. Nos résultats montrent également que cette population de PC médullaires a les caractéristiques des LLPC : ces PC sont quiescents, ils demeurent dans la moelle osseuse jusqu'à 180 jours et sont phénotypiquement semblables aux LLPC. Nos travaux ont permis de montrer que les LLPC à IgM sont capables de reconnaître l'Ag et que l'engagement de leur BCR par l'Ag conduit à la production d'IL10 / Plasma cells (PC) represent the terminal differentiation stage of B lymphocytes. Their canonical function is to secrete antibodies (Abs). PC differentiation is driven by remodeling of the B cell transcriptional program, highlighted by the induction of the transcriptional repressor Blimp-1 and repression of Pax5, considered as the guardian of B cell identity. The dogma holds that PC, as opposed to B cells, have lost the Ag recognition capacity because they have switched from expression of a membrane-bound Ag receptor (mBCR) to production of the secreted form of the BCR (Abs). Here, we have compared the phenotypical and functional attributes of memory PC generated by the T cell-dependent (TD) and T-cell independent (TI) forms of the hapten NP. Our data show that TI NP-specific bone marrow (BM) PC generated by NP-dextran retain an Ag-binding capacity comparable to that of B cells long after immunization while TD NP-specific BM PC do not. We found that this difference is not imputable to the structure of the immunogen but is a specific feature of IgM-expressing PC, which are prominent in response to TI Ag. Upon Ag recognition in vitro, the mBCR of IgM+ BM PC promotes: i) Ca++ mobilization, ii) phosphorylation of Syk and Blnk, iii) Ag internalization and phosphorylation of the late endosomal kinase Erk. Finally, we demonstrate that Ag recall in vivo induces significant changes in the gene expression profile of NP-specific IgM+ BM PC with evidence for activation of a cytokine production program characterized in particular by up-regulation of the CCL5 and IL10 transcripts. In conclusion, our data show that IgM-expressing BM PC can sense Ag and may be driven to express a regulatory function upon Ag recall
5

Avaliação da influência do exercício físico regular na modulação do sistema imunológico de camundongos infectados com Toxoplasma Gondii

Bortolini, Miguel Junior Sordi 26 June 2014 (has links)
Physical exercise has been implicated in several immunophysiological improvements especially during the aging process when an immunocompromised status could be established. Toxoplasma gondii is a protozoan parasite that causes a widespread opportunistic infection, which may present severe consequences, particularly to the fetus and immunocompromised patients. It is estimated that one-third of the human population worldwide has been infected by this parasite, being the reactivation during immunesenescence an unexplored public health issue. The present study was designed to assess the immunophysiological differences between exercised versus sedentary C57BL/6 male mice that have been infected by T. gondii. Before the two key set of experiments, several other sets were carried out to the prospection of the main found data of this study. There were two main sets of experiments: in the first set, the animals were infected after exercising and three groups were formed: experimental groups - infected sedentary (IS, n=6); infected exercised (IEx, n=6) and control group - non-infected sedentary (NIS, n=6). When splenocytes were stimulated by T. gondii-soluble tachyzoite antigens, it was found an significant increasing (P<0.0001) in interferon-gamma (IFN-&#61543;) production concomitant with any changes in IL-10, allowing a greater IFN-&#61543;/IL-10 ratios, produced by the cells from exercised group compared to sedentary one. However, there was no difference concerning quantification of T. gondii genomic DNA by qPCR and immunohistochemistry analysis in brain cysts (P>0.05). In order to further investigate the consequences of these data for the host, a second set of experiments was performed, when the animals were infected before exercising and four groups of animals were established for comparison purpose, as follows: experimental groups - infected sedentary (IS, n=7); infected exercised (IEx, n=6) and control groups - non-infected sedentary (NIS, n=6) and non-infected exercised (NIEx, n=6). It was found that exercised group survived longer (P<0.05) than sedentary one. In both sets of experiments, mice have been submitted to moderate exercises: running (14m/min; 3x/week) and strength (60-80% of one-repetition maximum; 2x/week). In summary, moderated aerobic and strength exercises are able to modulate immune responses against T. gondii infection, being these immunological features beneficial to the host. / A prática regular de exercício físico tem sido relacionado com melhoras imunopatológicas, especialmente durante o processo de envelhecimento quando pode haver um estado de imunocomprometimento. O Toxoplasma gondii é um parasito protozoário que causa infecção oportunista de forma global, podendo apresentar consequências severas, particularmente ao feto e pacientes imunocomprometimentos. É estimado que um terço da população mundial esteja atualmente infectado por este parasito, sendo a reativação durante a imunossenescência um tópico em saúde pública não explorado. O presente estudo foi projetado para avaliar parâmetros de diferenças imunológicas entre camundongos machos C57BL/6 exercitados e sedentários que tenham sido infectados por T. gondii. Antes dos experimentos chaves vários outros conjuntos de experimentos foram realizados para prospecção dos principais achados desta tese. Houve dois conjuntos de experimentos principais: no primeiro conjunto de experimentos, os animais foram infectados após o início dos exercícios formando-se três grupos: um grupo controle - sedentário não infectado (NIS, IS, n=4); dois grupos infectados - um sedentário (IS, n=4) e um exercitado (IEx, n=6). Quando esplenócitos foram estimuladas com antígeno de taquizoíto solúvel de T gondii (STAg), encontrou-se uma maior produção de IFN-&#61543;, concomitante à uma manutenção das taxas de IL-10, que permitiu uma maior razão de IFN-&#61543;/IL10 (P<0,0001) para o grupo exercitado comparado com o sedentário. No entanto, não houve diferenças no que diz repeito a quantificação de DNA genômico de T. gondii pelas análises de qPCR e imunohistoquímica de cistos cerebrais (P>0,05). Com objetivo de se pesquisar posteriormente as consequências destes dados para o hospedeiro, um segundo conjunto de experimentos foram realizados, quando os animais foram infectados antes do início dos exercícios, e quatro grupos foram estabelecidos para comparação deste propósito, como se segue: dois grupos controles não infectados - sedentário (NIS, n=6) e exercitado (NIEx, n=6), e dois grupos infectados - sedentário (IS, n=7) e exercitado (IEx, n=6). Encontrou-se que o grupo infectado exercitado teve sua longevidade aumentada (P<0,05) comparado com o infectado sedentário. Em ambos os conjuntos de experimentos, os camundongos foram submetidos à exercícios moderados: de corrida (14 m/min; 3 x/semana) e resistido (60-80% de uma repetição máxima; 2x/semana). Em síntese, exercícios físicos aeróbicos e resistidos moderados são capazes de modular a resposta do sistema imune no combate da infecção por T. gondii sendo estas características imunológicas benéficas para o hospedeiro. / Doutor em Imunologia e Parasitologia Aplicadas
6

Use of IFNγ/IL10 Ratio for Stratification of Hydrocortisone Therapy in Patients With Septic Shock

König, Rainer, Kolte, Amol, Ahlers, Olaf, Oswald, Marcus, Krauss, Veiko, Roell, Daniela, Sommerfeld, Oliver, Dimopoulos, George, Tsangaris, Iraklis, Antoniadou, Eleni, Jaishankar, Neeraja, Bogatsch, Holger, Löffler, Markus, Rödel, Markus, Garcia-Moreno, Marina, Tuchscherr, Lorena, Sprung, Charles L., Singer, Mervyn, Brunkhorst, Frank, Oppert, Michael, Gerlach, Herwig, Claus, Ralf A., Coldewey, Sina M., Briegel, Josef, Giamarellos-Bourboulis, Evangelos J., Keh, Didier, Bauer, Michael 24 March 2023 (has links)
Large clinical trials testing hydrocortisone therapy in septic shock have produced conflicting results. Subgroups may benefit of hydrocortisone treatment depending on their individual immune response. We performed an exploratory analysis of the database from the international randomized controlled clinical trial Corticosteroid Therapy of Septic Shock (CORTICUS) employing machine learning to a panel of 137 variables collected from the Berlin subcohort comprising 83 patients including demographic and clinical measures, organ failure scores, leukocyte counts and levels of circulating cytokines. The identified theranostic marker was validated against data from a cohort of the Hellenic Sepsis Study Group (HSSG) (n = 246), patients enrolled in the clinical trial of Sodium Selenite and Procalcitonin Guided Antimicrobial Therapy in Severe Sepsis (SISPCT, n = 118), and another, smaller clinical trial (Crossover study, n = 20). In addition, in vitro blood culture experiments and in vivo experiments in mouse models were performed to assess biological plausibility. A low serum IFNg/IL10 ratio predicted increased survival in the hydrocortisone group whereas a high ratio predicted better survival in the placebo group. Using this marker for a decision rule, we applied it to three validation sets and observed the same trend. Experimental studies in vitro revealed that IFNg/IL10 was negatively associated with the load of (heat inactivated) pathogens in spiked human blood and in septic mouse models. Accordingly, an in silico analysis of published IFNg and IL10 values in bacteremic and non-bacteremic patients with the Systemic Inflammatory Response Syndrome supported this association between the ratio and pathogen burden. We propose IFNg/IL10 as a molecular marker supporting the decision to administer hydrocortisone to patients in septic shock. Prospective clinical studies are necessary and standard operating procedures need to be implemented, particularly to define a generic threshold. If confirmed, IFNg/IL10 may become a suitable theranostic marker for an urging clinical need.
7

Base moléculaire des effets de l'huile d'argan sur le métabolisme mitochondrial et peroxysomal des acides gras et sur l'inflammation / Molecular basis of the effects of argan oil on mitochondrial and peroxisomal metabolism of the fatty acids and inflammation

El Kebbaj, Riad 17 December 2012 (has links)
L’objectif des travaux de cette thèse a été d’explorer les bases moléculaires de l’effet de l’huile d’Argan (HA) sur le métabolisme lipidique au niveau mitochondriale et peroxysomale ainsi qu’élucider son potentiel anti-inflammatoire. Nous avons donc montré, dans un premier temps, que les méthodes artisanales préservaient les propriétés antioxydantes d’HA empêchant l’oxydation de l’acide férulique contrairement à l’HA d’origines commerciale. Ensuite, le traitement par l‘HA ou par les lipopolysaccharides (LPS) de fibroblastes humains, un modèle cellulaire de la pseudo-adrénoleucodystrophie néonatale (P-NALD), révèle pour l’HA une prolifération des peroxysomes indépendante de l’activation du récepteur nucléaire PPARα et de son coactivateur PGC-1α. Par contre, l’induction de la prolifération de peroxysomes par les LPS est accompagnée d’une activation de PPAR et de PGC-1Parallèlement, une étude a été réalisée au niveau hépatique chez des souris traitées par l‘HA ou par les LPS. Nous avons montré pour la première fois l’activité antioxydante de l’huile d’Argan in vivo au niveau hépatique par l’induction de l’activité enzymatique de la catalase peroxysomale et une activité hypolipémiante par la stimulation des activités déshydrogénases (ACADs) de la -oxydations mitochondriale des acides gars. De plus, l’HA induit la transcription des gènes PPECK et G6PH de la voie de la néoglucogenèse. Nous avons montré également pour la première fois un effet préventif de l’HA contre la répression des activités déshydrogénases des voies de -oxydations mitochondriale et peroxysomale, ainsi que celle la voie de la néoglucogenèse. Nos travaux démontrent que l’HA possède un potentiel anti-inflammatoire, induit par le LPS, élucidé par la répression de cytokines pro-inflammatoires IL-6 et TNFα et par l’induction de cytokines anti-inflammatoires IL10 et IL-4. L’ensemble de nos résultats indiquerait que l’huile d’Argan, du fait de sa composition riche en acide gras mono et polyinsaturés et en antioxydants, a des effets hypolipémiants et anti-inflammatoires au niveau hépatique qui se traduisent par une régulation de l’expression à la fois de récepteurs nucléaires et de leur gènes cibles ainsi que de certaines cytokines / The objective of this thesis work was to explore the molecular basis of Argan Oil (AO) effects on the mitochondrial and peroxisomal lipid metabolism and to elucidate its anti-inflammatory potential. We thus showed, initially, that the artisanal method preparation preserved the antioxidant properties of AO preventing the oxidation of the ferulic acid, by contrast to AO of commercial origin. Then, the treatment by the AO or lipopolysaccharides (LPS) of human fibroblasts, the cellular model of pseudo-neonatal adrenoleukodystrophy (P-NALD), revealed for the AO that peroxisomes proliferation is independent from the activation of the nuclear receptor PPARα and the co-activator PGC-1α. On the other side, the induction of the proliferation of peroxisomes by LPS is accompanied by an activation of both PPARα and PGC-1α. At the same time, mice treatments by AO or by the LPS showed, for the first time, the hepatic antioxidant activity of AO through the induction of the activity of the peroxisomal catalase. In addition, we showed a hypolipidemic activity of AO, by the stimulation of dehydrogenase activities (ACADs) of the mitochondrial fatty acid b-oxidation. Moreover, the AO induces the transcription of genes involved in gluconeogenesis pathway (i.e. PEPCK and G6PH). We also revealed, for the first time, the preventive effect of AO against LPS repressions of mitochondrial and peroxisomal fatty acid degradation as well as on the gluconeogenic pathway. Furthermore, the AO anti-inflammatory potential has been shown, in mice treated by LPS, through the repression of the pro-inflammatory cytokines IL-6 and TNFα and by the induction of the anti-inflammatory cytokines IL10 and IL-4. All together, our results may indicate that the Argan oil, because of its composition rich in mono and polyunsaturated fatty acids and in antioxidants as well, has a hypolipidemic and an anti-inflammatory effects, which are revealed by the regulation of the expressions of nuclear receptors and their target genes including several cytokines
8

Base moléculaire des effets de l'huile d'argan sur le métabolisme mitochondrial et peroxysomal des acides gras et sur l'inflammation

El Kebbaj, Riad 17 December 2012 (has links) (PDF)
L'objectif des travaux de cette thèse a été d'explorer les bases moléculaires de l'effet de l'huile d'Argan (HA) sur le métabolisme lipidique au niveau mitochondriale et peroxysomale ainsi qu'élucider son potentiel anti-inflammatoire. Nous avons donc montré, dans un premier temps, que les méthodes artisanales préservaient les propriétés antioxydantes d'HA empêchant l'oxydation de l'acide férulique contrairement à l'HA d'origines commerciale. Ensuite, le traitement par l'HA ou par les lipopolysaccharides (LPS) de fibroblastes humains, un modèle cellulaire de la pseudo-adrénoleucodystrophie néonatale (P-NALD), révèle pour l'HA une prolifération des peroxysomes indépendante de l'activation du récepteur nucléaire PPARα et de son coactivateur PGC-1α. Par contre, l'induction de la prolifération de peroxysomes par les LPS est accompagnée d'une activation de PPAR et de PGC-1Parallèlement, une étude a été réalisée au niveau hépatique chez des souris traitées par l'HA ou par les LPS. Nous avons montré pour la première fois l'activité antioxydante de l'huile d'Argan in vivo au niveau hépatique par l'induction de l'activité enzymatique de la catalase peroxysomale et une activité hypolipémiante par la stimulation des activités déshydrogénases (ACADs) de la -oxydations mitochondriale des acides gars. De plus, l'HA induit la transcription des gènes PPECK et G6PH de la voie de la néoglucogenèse. Nous avons montré également pour la première fois un effet préventif de l'HA contre la répression des activités déshydrogénases des voies de -oxydations mitochondriale et peroxysomale, ainsi que celle la voie de la néoglucogenèse. Nos travaux démontrent que l'HA possède un potentiel anti-inflammatoire, induit par le LPS, élucidé par la répression de cytokines pro-inflammatoires IL-6 et TNFα et par l'induction de cytokines anti-inflammatoires IL10 et IL-4. L'ensemble de nos résultats indiquerait que l'huile d'Argan, du fait de sa composition riche en acide gras mono et polyinsaturés et en antioxydants, a des effets hypolipémiants et anti-inflammatoires au niveau hépatique qui se traduisent par une régulation de l'expression à la fois de récepteurs nucléaires et de leur gènes cibles ainsi que de certaines cytokines

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