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Cytotoxicity of Metal Based Anticancer Active Complexes and their Targeted Delivery using NanoparticlesPramanik, Anup Kumar January 2016 (has links) (PDF)
Use of metal based anticancer medication began with the clinical approval of cisplatin in 1978. Research led to the development of six platinum based drug candidates which are in use around the world. However there is a great need to develop better treatment strategies. The present work entitled “Cytotoxicity of Metal Based Anticancer Active Complexes and Their Targeted Delivery
Using Nanoparticles” is an effort to prepare cytotoxic metal complexes based on platinum(IV) and copper(II) and deliver them selectively to cancer cells using a targeting ligand, biotin, with two different delivery vehicles, viz. PEGylated polyamidoamine dendrimer (PAMAM) and gold nanoparticles (AuNPs).
Chapter 1 provides a brief introduction to cancer and its characteristic features, followed by a short description about different treatment modalities in clinical practice. An account of the development of anticancer drugs starting from purely organic drugs to the field of metal based anticancer drugs is discussed. An overview of the available targeting strategies are discussed with specific examples. The section ends with the scope of the present work.
Platinum based anticancer drugs currently in use contain platinum in the +2 oxidation state. These drugs showed side effects and are often ineffective against resistant cells, especially in the latter stages of treatment. A recent focus of metal based anticancer drug research is the development of platinum(IV) systems which shows promise to have greater activity in cancer cells in a reducing environment. Reported platinum(IV) dual drugs contain the components of “cisplatin” or an analogue along with an active organic drug. But there are no known dual drugs based on platinum(IV) that would generate a cytotoxic metal complex along with cisplatin. In Chapter 2, a bimetallic dual drug (M4) (Figure 1), the first of its kind, with components of cisplatin and copper bis(thiosemicarbazone) has been prepared (Figure 1). The components and the bimetallic complex were characterized using several spectroscopic techniques. The dual drug M4 was found to be highly cytotoxic (IC50 1.3 M) against HeLa cells and was better than cisplatin (IC50 6.8 M). The bimetallic complex turned out to be better than the mixture (IC50 7.2 M) of individual drugs which indicated possible synergism of the released cisplatin and the copper bis(thiosemicarbazone) from the dual drug.
Figure 1: Structure of the platinum(IV) and copper bis(thiosemicarbazone) complexes.
A novel approach towards conjugation of platinum(IV) drugs to a carrier has been developed using
a malonate moiety (Figure 2). The bis(butyric acid) complex, Pt(NH3)2(OCOC3H7)2Cl2 (M1), was taken as model complex to demonstrate the conjugation strategy. The complex M4 was also conjugated to the partially PEGylated 5th generation PAMAM dendrimers.
Figure 2: Schematic representation of the platinum(IV) drug conjugated PAMAM dendrimer.
The cytotoxicity of M4 was reduced to a small extent on conjugation to the dendrimer. In the presence of 5 mM sodium ascorbate as a reducing agent, sustained release (40 %) of the drug was shown to occur over a period of 48 h by the drug release study. The reduction in cytotoxicity of the dendrimer conjugates could be due to incomplete release of the active drug. Unfortunately, no enhanced activity was observed with the additional targeting ligand, biotin. The drug uptake study revealed that the dendrimer conjugates were successful in entering cancer cells. There was no preferential uptake with biotin conjugated dendrimers which explained the similar cytotoxicity of dendrimer conjugates with and without biotin.
Different delivery vehicles showed varied efficiency in delivering the pay load (drugs) to the cancer site. In this connection, PEGylated gold nanoparticles have shown good promise as a drug delivery vehicle. In Chapter 3, M1 and M4 are both conjugated to malonate functionalized PEGylated gold nanoparticles (30 nm). Biotin was also attached to the AuNPs for targeting HeLa cells.
Figure 3: Schematic representation of the platinum(IV) drug and biotin conjugated AuNPs.
The AuNPs were highly stable in water without agglomeration. There was no shift in the Surface Plasmon Resonance (SPR) band after conjugation of the drug molecules and targeting ligands. TEM images and DLS measurements showed there was no change in particle size. Drug conjugated AuNPs were also very stable in high salt concentrations as well as over a large range of pH. AuNPs with M1 were found to be less cytotoxic than the parent drug. Biotinylated AuNPs with M1 were more potent than non-biotinylated nanoparticles and increased cytotoxicity (35 %) was observed with biotin conjugation. Surprisingly, the enhanced activity of biotinylated AuNPs could not be correlated to the drug uptake study. The cytotoxicity of the bimetallic dual drug containing AuNPs were about 10-fold less and no increased activity was observed with the biotinylated conjugates. The reduced activity of AuNPs with the bimetallic drug was due to incomplete release from the AuNPs (20 % release after 48 h). But the release kinetics was very slow and sustained which might increase in vivo activity. The unexpected lower activity of biotinylated conjugates with copper bis(thiosemicarbazone) was suggestive of interference between bis(thiosemicarbazone) complex and the biotin receptor resulting in reduced drug uptake.
Copper bis(thiosemicarbazone) complexes hold very good promise as a class of non-platinum anticancer drug candidates. However, they lack selectivity towards malignant cells. Recently, CuATSM has shown hypoxia selectivity and very good cytotoxicity resulting in 64CuATSM being used in advanced stages of clinical trials for imaging hypoxic cells. In Chapter 4, a copper bis(thiosemicarbazone) complex analogous to Cu(ATSM) with a redox active cleavable disulfide linker and a terminal carboxylic acid group (CuATSM-SS-COOH) was synthesised and characterised spectroscopically. The complex was highly cytotoxic and has an IC50 value (6.9 M) similar to that of cisplatin against HeLa cells. The complex was conjugated to PEGylated gold nanoparticles by amide coupling between the acid group from the drug molecule and the amine on the AuNPs (20 nm) for smart drug delivery. The gold nanoparticles were decorated with biotin for targeted delivery to the HeLa cells.
Figure 4: Schematic representation of the CuATSM-SS-COOH and biotin decorated AuNPs.
The CuATSM-SS-COOH was insoluble in water but conjugation to PEGylated gold nanoparticles made it water soluble. The drug molecules and biotin conjugated AuNPs were highly stable which was confirmed by TEM and DLS measurements. Similar to the study described in the previous chapter, these AuNPs were also stable in a wide range of pH and salt concentrations. In vitro glutathione (GSH) triggered release study demonstrated substantial release of the cytotoxic agent from the AuNPs (60 %) over a period of 48 h. In vitro cell viability study with HeLa cells showed reduced cytotoxicity (IC50 15 M) of AuNPs with and without biotin containing drug conjugates relative to the parent copper complex (IC50 6.9 M). The reduction of the cytotoxicity correlated well with the released amount of the active drug from the nanoconjugates over the same time period. In vivo studies demonstrated the effectiveness of these nanoparticle carriers as suitable vehicles as they exhibited nearly four-fold reduction of tumor volume without significant loss in body weight. Moreover, the biotin targeted nanoparticle showed significant (p < 0.5) reduction in tumor volume compared to the non-targeted gold nanoparticles. Thus, this smart linking strategy Can be extended to other cytotoxic complexes that suffer from non-specificity, low aqueous solubility and toxicity.
Multinuclear anticancer active complexes do not act in the same way as that of their corresponding mononuclear analogues. In the case of multinuclear platinum complexes, the activity not only depends on the active moiety but also on the spacer length between the moieties. In Chapter 5, a series of multinuclear copper bis(thiosemicarbazone) complexes were prepared and characterised using different techniques.
Figure 5: General structures of binuclear copper bis(thiosemicarbazone) complexes.
All the complexes showed redox activity and have a very high negative reduction potential, i.e. these compounds would not be easily reduced in the biological medium and would remain as copper(II) species. As the concentration of the reducing agents are more within cancer cells, once these complexes are inside cells they would be reduced to Cu(I). These compounds were shown to be highly lipophilic from the large log P values. Unfortunately, these binuclear complexes were less active than similar mononuclear complexes. One possible reason for the reduced cytotoxicity of these complexes could be adherence of the complexes to the cell membrane due to the high lipophilicity of these complexes. Out of five different methylene spacers between two bis(thiosemicrarbazone) moieties, the complex with a three carbon spacer was shown to be the most active against HeLa cells. The complexes with five and six methylene spacers turn out to be noncytotoxic. Further experiments are necessary to reveal the mechanism of action in these complexes.
In summary, bimetallic complexes can be very active and may be a way of overcoming drug resistance in platinum based therapy. A dual drug can be delivered using a malonate moiety and a disulfide linker. Gold nanoparticles are good delivery vehicles for these dual drugs and show great potential for improvement and translation to the next stage. (For figures pl refer the abstract pdf file)
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Analysis of the roles of Interleukin 15 and CD4+ T cells specific of a dietary antigen in a mouse model of celiac-like enteropathy / Analyse des rôles de l’Interleukine 15 et cellules T CD4+ spécifiques d’un antigène alimentaire dans un modèle murin de l’entéropathie céliaqueKorneychuk, Natalia 09 July 2014 (has links)
Dans les conditions physiologiques des robustes mécanismes immunologiques empêchent le développement des réponses exagérées aux antigènes alimentaires. En revanche, dans le cas de maladie céliaque, qui affecte environ 1% de la population occidentale, l’exposition au gluten alimentaire d’individus génétiquement prédisposés HLA-DQ2.5/DQ8 provoque l’entéropathie chronique de l’intestin grêle. Les études précédentes chez l’homme ont établi le rôle crucial de la réponse cellulaire T CD4+ restreinte par HLA-DQ2.5/DQ8 et spécifique du gluten. La réponse T CD4+ est nécessaire mais cependant insuffisante pour induire des lésions tissulaires. D’autres études ont suggéré le rôle de l’interleukine 15 (IL-15). Ainsi, l’IL-15 surexprimée dans la muqueuse des patients céliaques peut interférer avec les mécanismes d’immunorégulation et stimuler l’activation des lymphocytes intraépithéliaux T CD8+ cytotoxiques probablement induisant des lésions épithéliales. Comment les cellules T CD4+ spécifiques du gluten et l’IL-15 interagissent pour activer les lymphocytes intraépithéliaux T CD8+ et induisent des lésions n’a pas été toutefois établi. Pour répondre à cette question, nous avons créé un modèle murin basé en croisant des souris OTII possédant des cellules T CD4+ spécifiques de l’antigène modèle, ovalbumine, avec les souris transgéniques hétérozygotes surexprimant une forme secrétée de l’IL-15 humaine dans l’épithélium intestinale (souris hIL-15Tge). Les souris obtenues OTII+/- B6 and OTII+/- hIL-15Tge+/- ont été mises au régime riche en ovalbumine depuis la période prénatale jusqu’à l’âge de 3 mois. Les souris OTII+/- hIL-15Tge+/-, contrairement aux souris OTII+/- B6, exposées de façon chronique à l’ovalbumine ont développé un retard de croissance et une atrophie villositaire associée à l’expansion des cellules intestinales T CD8+ cytotoxiques, comme dans la maladie céliaque. En outre, nous avons démontré que l’IL-15 altérait l’immunorégulation par les cellules T FoxpP3+ et coopérait avec l’IL-2, produite par les cellules T CD4+ activées par l’OVA, pour l’expansion des cellules T CD8+ non-spécifiques de l’OVA. Nous suggérons que le scénario similaire pourrait opérer dans la maladie céliaque. Au cours de cette étude, j’ai observé que la surexpression chronique de l’IL-15 était associée avec l’expansion de cellules dendritiques CD103+CD11c+CD11b-. Dans la partie de résultats supplémentaires, j’ai démontré que cet effet dépend de la production de la cytokine GM-CSF secrétée par les cellules Natural Killer (NK) activées par l’IL-15 et que ces cellules dendritiques étaient enrichies en cellules CD103+ ayant une capacité accrue de cross-présentation in vitro. Ces derniers résultats illustrent comment l’IL-15 peut moduler les réponses immunes adaptatives en orchestrant la coopération entre les cellules NK et les phagocytes mononucléaires. / In physiological conditions, robust immunological mechanisms avoid adverse responses to food antigens. In contrast, in celiac disease that affects about 1% of Western populations, exposure to dietary gluten of genetically predisposed HLA-DQ2.5/ DQ8 individuals triggers a chronic small intestinal enteropathy. Previous studies in humans have established the crucial role of HLA-DQ2/DQ8 restricted gluten-specific intestinal CD4 T cell response. This CD4 T cell response is necessary but is however not sufficient to induce tissue damage. Other studies have pointed to the role of interleukin 15 (IL-15). Thus, IL-15 over-expressed in the mucosa of celiac patients can interfere with immunoregulatory mechanisms and stimulate the activation of cytotoxic CD8 T intraepithelial lymphocytes, thought to induce epithelial lesions. Whether and how gluten-specific CD4 T cells and IL-15 interact to activate CD8 T intraepithelial lymphocytes and to drive intestinal tissue damage has not been however established. To address this question, we have set up a mouse model based on the breeding of OTII mice possessing CD4 T cells specific of a model antigen, ovalbumin, with heterozygous transgenic mice overexpressing a secreted form of human IL-15 in intestinal epithelium (hIL-15Tge mice). Resulting OTII+/- B6 and OTII+/- hIL-15Tge+/- mice were exposed to dietary ovalbumin from the prenatal period until 3 months of age. Upon chronic exposure to ovalbumin, OTII+/- hIL-15Tge+ mice, contrary to their OTII+/- B6 littermates, developed growth retardation, and villous atrophy associated with expansion of intestinal cytotoxic CD8 T cells, as in celiac disease. Moreover, we showed that IL-15 impaired immunoregulation by FoxP3+ T cells and cooperated with IL-2 produced by OVA-activated CD4 T cells to stimulate the expansion of non-cognate cytotoxic CD8 T cells. We suggest that a comparable scenario can operate in celiac disease. During this study, I observed that chronic overexpression of IL-15 was associated with an expansion of CD103+CD11c+CD11b- mononuclear cells. In the Supplementary results, I have shown that this effect depends on the production of GM-CSF secreted by IL-15-activated NK cells and that CD11c+ DCs differentiated in mice overexpressing IL-15 were enriched in CD103+ cells and displayed enhanced cross-presentation abilities in vitro. The latter results illustrate how IL-15, by orchestrating a crosstalk between NK cells and mononuclear phagocytes, can modulate adaptive immune responses.
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Biološka aktivnost i hemijski sastav ekstrakata odabranih autohtonih makrogljiva / Biological activity and chemical caracteristics of selected extracts of autochtonous macrofungiJanjušević Ljiljana 18 September 2017 (has links)
<p>Prema postavljenim ciljevima u ovoj doktorskoj disertaciji sakupljeno je i <br />determinisano ukupno sedam vrsta autohtonih gljiva sa područja Fruške gore, Tare i Vršačkog brega, pet lignikolnih ‐ <em>Bjerkandera adusta</em>, <em>Pleurocybella porrigens</em>, St<em>ereum hirsutum, Stereum subtomentosum</em> i Trametes versicolor, i <br />dve terikolne ‐ <em>Amanita strobiliformis</em> i Hydnum repandum. Utvrđena je njihova biološka aktivnost (antiradikalska, antioksidativna, antimikrobna, anti‐acetilholinesterazna i citotokisčna) spram hemijskog sastava njihovih vodenih <br />(H<sub>2</sub>O), etanolnih (EtOH), metanolnih (MeOH) i polisaharidnih (PSH) ekstrakata. <br />Analiza hemijskog sastava odabranih vrsta uključila je određivanje hemijske <br />karakterizacije PSH ekstrakata ‐ FTIR analizom, određivanje fenolnog profila ‐ <br />HPMC/MS‐MS, sadržaja organskih kiselina ‐ HPLC, sadržaja masnih kiselina ‐ <br />GC‐FID i sadržaja biogenih elemenata ‐ AAS. Spektrofotometrijskim metodama<br />određen je ukupan sadržaj proteina i ukupan sadržaj fenola i flavonoida. <br />Prema antiradikalskoj aktivnosti OH<sup>• , </sup>O2<sup>•‐</sup>, OH<sup>•</sup>, Asc<sup>•</sup>, DPPH<sup>• </sup> i ABTS<sup>•+</sup> izdvojili <br />su se ekstrakti lignikolnih vrsta: MeOH ekstrakt vrste <em>P. porrigens</em>, H<sub>2</sub>O ekstrakt <em>P. porrigens</em>, MeOH ekstrakt <em>T. versicolor</em>, H<sub>2</sub>O ekstrakt <em>S. hirsutum, </em>MeOH ekstrakt <em>S. subtomentosum</em> i H<sub>2</sub>O ekstrakt <em>B. adusta</em>, navedenim redom. <br />Najjaču antioksidativnu aktivnost dobijenu FRAP i polarografskom HPMC <br />metodom ispoljili su PSH i H<sub>2</sub>O ekstrakti terikolne vrste <em>A. strobiliformis</em>. <br />Antimikrobna aktivnost analiziranih ekstrakata određena je ispitivanjem <br />antibakterijskog, antifungalnog i antiviralnog potencijala, pri čemu se izdvojila <br />vrsta <em> H. repandum</em> ispoljavajući najbolji efekat na Gram‐pozitivne i Gram‐<br />negativne bakterije i na sve analizirane fitopatogene izolate <em>(Fusarium </em>i <br />Alternaria) i<em> T. versicolor</em> na analizirani bakteriofag. Anti‐acetilholinesterazna <br />aktivnost određena je testovima in solid i in liquid, a najbolji procenat <br />inhibicije AChE ispoljili su EtOH ekstrakti vrsta <em>S. hirsutum</em>, <em>B. adusta</em>, <em>S</em>. <br /><em>subtomentosum</em> i <em>T. versicolor</em>. Citotoksična aktivnost ekstrakata određena je <br />MTT testom, a prema najboljoj ispoljenoj aktivnosti izdvojili su se MeOH <br />ekstrakt<em> P. porrigens </em>i ekstrakti<em> B. adusta</em>, H<sub>2</sub>O i EtOH. Citotoksična aktivnost <br />ovih lignikolnih vrsta naročito je izražena nakon 72 h. Na osnovu dobijenih <br />rezultata, gde su se istakle različite vrste i njihovi različiti ekstrakti u <br />primenjenim testovima, jasno je da biološka aktivnost i hemijski sastav zavise <br />od porekla, vrste i tipa ekstrakta analiziranih gljiva. Na osnovu tipa rastvarača <br />odnosno ekstrakata vrsta, koje su pokazale najbolju aktivnost spram pomenutih testova i na osnovu dobijenih korelacija kao i na osnovu detektovanih jedinjenja, pretpostavljamo da su za ispoljene aktivnosti u najvećoj meri odgovorna fenolna jedinjenja i polisaharidi. <br /> <br />Ispoljeni biopotencijal analiziranih vrsta gljiva upućuje na njihovu potencijalnu <br />upotrebu kao funkcionalne hrane i nutraceutika, kao i u biokontroli <br />fitopatogena.</p> / <p>According to the set aims of the presented PhD thesis, seven autochthonous fungal species from the region of Fruska Gora, Tara and Vršac Mountains were collected and determined: five lignicolous ‐ <em>Bjerkandera adusta, Pleurocybella porrigens, Stereum hirsutum, Stereum subtomentosum and Trametes versicolor</em>, and two terricolous ‐ <em>Amanita strobiliformis </em>and <em>Hydnum repandum</em>. Biological activity of these species (antiradical, antioxidant, antimicrobial, anti‐ acetylcholinesterase and cytotoxic) was determined in relation to the chemical composition of the extracts, aqueous (H<sub>2</sub>O), ethanolic (EtOH), methanolic (MeOH) and polysaccharide (PSH). Analysis of the chemical content of analyzed species included chemical characterization of PSH extracts – by FTIR analysis, determination of phenolic profile ‐ by HPMC/MS‐MS, content of organic acids ‐ by HPLC, fatty acid content ‐ by GC‐FID and content of biogenic elements ‐ by AAS. Spectrophotometric methods were applied for determination of the content of total proteins, polyphenols and flavonoids. According to the antiradical activity obtained towards OH<sup>•</sup>, О2<sup>•‐</sup>, OH<sup>•</sup>, Asc<sup>•</sup>, DPPH<sup>•</sup> and ABTS<sup>•+</sup> extracts of lignicolous species were singled out: <em>P. porrigens </em> (MeOH extract), <em> P. porrigens</em> (H<sub>2</sub>O extract), <em>T. versicolor</em> (MeOH extract),<em> S. hirsutum </em>(H<sub>2</sub>O extract), <em>S. subtomentosum</em> (MeOH extract) and <em>B. austa</em> (H<sub>2</sub>O extract), respectively. The highest antioxidant activity obtained by FRAP and the polarographic HPMC method was exhibited for PSH and H<sub>2</sub>O extracts of the terricolous species <em>A. strobiliformis</em>. The intimicrobial activity of analyzed extracts was determined by examination of antibacterial, antifungal and antiviral potentials, whereby the species <em>H. repandum </em>was separated by exhibiting the best effect on Gram‐positive and Gram‐negative bacteria, and all the analyzed hytopathogenic isolates (<em>Fusarium, Alternaria</em>) and <em>T. versicolor</em> against analyzed bacteriophage. Anti‐cetylcholinesterase activity was determined by tests in solid and in liquid, while the best percent of AChE inhibition was showed by EtOH extracts of the species <em>S. hirsutum, B. adusta, S. subtomentosum </em>and <em>T. versicolor</em>.bThe cytotoxic activity of extracts was determined by MTT assay, and according to the best activity, the MeOH extract of <em>P. porrigens</em>, and H<sub>2</sub>O and EtOH extracts of <em>B. adusta</em> were distinguished particularly after 72 h. Based on the results obtained, favoring different species and their different extracts in the applied tests, it is clear that the biological activity and chemical composition depend on the origin, species and type of extract of the analyzed fungi. Based on the type of solvent or extract of the species that showed the best activity in relation to the above tests and on the basis of the obtained correlations as well as on the basis of the detected compounds, we assume that the phenol compounds and polysaccharides are responsible for the activities performed.<br />Demonstrated bio‐potential of analyzed fungal species indicates their potential use as functional foods and nutraceutics, as well as in the biocontrol of phytopathogens.</p>
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Les interactions entre l’interleukine-15, l’haplotype HLA-DQ8 et le gluten conduisent au développement de la maladie cœliaque chez la sourisLejeune, Thomas Bastien 09 1900 (has links)
La maladie cœliaque est une entéropathie inflammatoire chronique se développant chez des individus génétiquement prédisposés par l’expression des haplotypes HLA-DQ2 ou HLA-DQ8 et survenant suite à la consommation de gluten. Elle se caractérise par le développement d’une atrophie des villosités de la muqueuse intestinale débouchant sur un syndrome de malabsorption alimentaire. La seule thérapie actuelle est le suivi d’une diète sans gluten mais cette éviction totale du gluten n’est pas toujours efficace et est lourde en concessions. Il est par conséquent urgent de développer des thérapies alternatives mais ce domaine constitue un pipeline évoluant lentement, notamment suite à l’absence d’un modèle animal pertinent et complet sur le plan physiologique. L’objectif de cette thèse doctorale est de répondre à ce besoin crucial en développant un modèle murin capable de récapituler les caractéristiques de la maladie.
Le chapitre 1 dresse le portrait de la maladie en quatre parties amenant progressivement le lecteur dans les détails de sa pathogenèse. Cette introduction débute par un rappel sur la physiologie et l’immunité intestinale puis elle définit la face clinique de la maladie. Ensuite, le lecteur évolue dans une partie plus détaillée de la pathogenèse aidant au discernement de ses acteurs cellulaires et moléculaires. Finalement, elle se termine par une revue de la littérature sur les actuels modèles animaux. Le chapitre 2 brossent les objectifs de la thèse sur base de données clés de la littérature, notamment, les patients présentent au minimum une copie de l’halplotype HLA-DQ2 ou HLA-DQ8 et plus des deux-tiers sur-expriment la cytokine pro-inflammatoire interleukine-15 au niveau de leur muqueuse intestinale. Il est donc raisonnable de penser qu’ensemble, le gluten, l’haplotype HLA et l’interleukine-15 contribuent activement à la pathogenèse. Bien que soupçonnés, leurs rôles et interactions nécessitent l’apport de preuves tangibles in vivo. Le chapitre 3 détaille ainsi ces interactions démontrées à l’aide du développement de notre nouveau modèle murin. Ce dernier est caractérisé par la surexpression de l’interleukine-15 dans l’épithélium et dans la lamina propria intestinale et par l’expression de l’haplotype HLA-DQ8. Ce travail démontre que l’exposition de cette souris au gluten s’accompagne d’une atrophie villositaire et de la signature complète de la maladie, tant sur le plan sérologique, cellulaire que transcriptionnel. Nous démontrons que la surexpression simultanée de l’interleukine-15 dans les deux compartiments de la muqueuse intestinale que sont la lamina propria et l’épithélium est une condition sine qua non au développement de l’atrophie. Aussi, cette étude permet de mettre en lumière la nécessité des cellules T CD4+ et de l’interféron-gamma dans l’activation des lymphocytes intraépithéliaux et le développement de l’atrophie. Finalement, cette recherche établit le rôle central joué par l’haplotype HLA-DQ8 et par l’enzyme transglutaminase II tissulaire dans la survenue de ces lésions. De manière générale, les résultats issus de ce modèle et présentés au chapitre 3 reflètent toute la complexité des interactions entre le gluten, la génétique et l’IL-15 dans le développement de la maladie cœliaque. Enfin, le chapitre 4 apporte une conclusion à ce travail et le chapitre 5 discute des futures directions envisagées pour ce modèle préclinique. Ce dernier va sans doute contribuer à une meilleure compréhension de la maladie cœliaque et permettre l’identification de potentielles cibles thérapeutiques. / Coeliac disease is a chronic inflammatory enteropathy characterized by autoimmune features. This disease occurs in genetically predisposed individuals expressing HLA-DQ2 or HLA-DQ8 haplotypes and is triggered following gluten consumption. The disease is characterized by the development of intestinal villous atrophy leading to malabsorption. The only current therapy is the adherence to a gluten-free diet, but the diet is not always effective and is heavy in concessions. Therefore, the development of alternative therapies is urgent but is a slowly evolving pipeline, mainly due to the absence of a physiologically relevant animal model. The aim of this thesis is to answer this unmet need by developing an animal model capable of recapitulating the main characteristics of the disease. Chapter 1 depicts a portrait of the disease in four points, gradually leading the reader into the details of its pathogenesis. This introduction begins with a review of the physiology and intestinal immunity and then draws a clinical portrait of the disease. Third, the reader evolves in a more detailed part of the pathogenesis helping him to discern its cellular and molecular actors. Finally, the introduction ends with a review of the literature on current animal models. Chapter 2 outlines the thesis objectives based on key data from the literature, in particular, patients present at least one copy of the HLA-DQ2 or HLA-DQ8 haplotype and more than two-thirds over-express the proinflammatory cytokine interleukin-15 at the level of their intestinal mucosa. It is therefore reasonable to hypothesize that gluten, HLA haplotype and interleukin-15 together contribute to the pathogenesis. Although suspected, their roles and interactions still require the provision of tangible evidence in vivo. Chapter 3 details these interactions based on the proposed new mouse model. This model is characterized by the overexpression of interleukin-15 in the intestinal epithelium and lamina propria and by the expression of the HLA-DQ8 haplotype. This work demonstrates that the exposure of this mouse to gluten is accompanied by villous atrophy and the complete serological, cellular and transcriptional signature of the disease. We also demonstrate that simultaneous overexpression of interleukin-15 in both mucosal compartments is a prerequisite for the development of atrophy. This study also highlights the need for CD4+ T cells and interferon-gamma in the activation of intraepithelial lymphocytes and the development of villous atrophy. Finally, this research establishes the central role played by the HLA-DQ8 haplotype and the enzyme tissue transglutaminase II in the occurrence of these lesions. In general, the results from this model presented in Chapter 3 reflects the complexity of the interactions between gluten, genetics and IL-15 in the development of coeliac disease. Finally, chapter 4 concludes this work and chapter 5 discusses future directions for this powerful preclinical model that will undoubtedly contribute to a better understanding of coeliac disease and will allow the identification of new potential therapeutic targets.
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Enantiodivergentna totalna sinteza odabranih stiril laktona i preliminarno ispitivanje njihove citotoksičnosti / Enantiodivergent total synthesis of selected styryl lactones and preliminary evaluation of their cytotoxicityBenedeković Goran 11 October 2012 (has links)
<p>U radu je ostvarena enantiodivergentna totalna sinteza oba enantiomera goniofufurona, 7-epi-goniofufurona i krasalaktona C polazeći iz D-glukoze. Ključne faze u sintezi 7-epi-(+)-goniofufurona bile su stereoselektivna adicija fenilmagnezijum bromida na aldehidnu grupu pogodno zaštićene dialdoze, i stereospecifično formiranje furano-laktonskog prstena ciklokondenzacijom odabranog hemiacetalnog derivata sa Meldrum-ovom kiselinom. Sinteza (+)-goniofufurona i (+)-krasalaktona C zahtevala je inverziju konfiguracije na C-5<br />u zajedničkom intermedijeru, koja je efikasno ostvarena u uslovima Mitsunobu-ove reakcije, ili alternativno oksidacijom benzilne hidroksilne grupe u prohiralni keton, uz naknadnu stereoselektivnu redukcijom sa borohidridom. Sličan pristup je zatim primenjen za sintezu neprirodnih (−)-enantiomera goniofufurona, 7-epi-goniofufurona i krasalaktona C, dva nova konformaciono ograničena analoga (+)- i (−)-goniofufurona (oksetani 36 i ent-36), kao i odgovarajućih 7-deoksigenovanih derivata (31 i ent-31). Takodje je razvijena i prva totalna sinteza prirodnog (+)-krasalaktona B (3) i alternativna sinteza (+)-krasalaktona C (4) polazeći iz D-glukoze. Selektivni pristup molekulima 3, odnosno 4 omogućen je promenom uslova za TBDPS deprotekciju u finalnom intermedijeru 53. Osnovna karakteristika pomenutih pristupa je njihova generalnost i fleksibilnost. Na taj način je omogućena sinteza serije analoga i derivata (+)-goniofufurona, ili 7-epi-goniofufurona, uključujući i do sada nepoznate 7-epi-(+)-krasalaktone B (6) i C (7), 5,7-di-O-cinamoil derivate 8 i 9, 5,7-di-O-izopropilidenske derivate 5 i 10, kao i više lipofilnih derivata (jedinjenja 26, 30, 33, 65, ent-30 i ent-33). Konačno, u drugom delu rada, ispitan je uticaj sintetizovanih stiril-laktona na rast odabranih tumorskih ćelijskih linija in vitro.</p> / <p> Enantiodivergent total syntheses of both (+)- and (−)-enantiomers of goniofufurone, 7-epi-goniofufurone and crassalactone C have been accomplished starting from D-glucose. The key steps of the synthe-sis of 7-epi-(+)-goniofufurone were a stereo-selective addition of <br /> phenyl magnesium bromide to a protected dialdose, followed by a stereospecific furano-lactone ring formation by condensation of a partially protected lactole with Meldrum’s acid. The synthesis of (+)-goniofufurone and (+)-crassalactone C required a configurational inversion at C-5 in the common intermediate that was efficiently achieved under the standard Mitsunobu conditions, or alternatively through a sequential oxidation of the benzylic hydroxyl group followed by a stereo-selective reduction with borohydride. A similar approach was applied to the synthesis of the unnatural enantiomers of goniofufurone, 7-epi-goniofufurone and crassalactone C, two novel, conformationally constrained analogues of both (+)- and (−)-goniofufurone (oxetanes 34 and ent-34). as well as the corresponding 7-deoxygenated derivatives (31 and ent-31). We have also developed the first total synthesis of (+)-crassalactone B (2) and an alternative synthesis of (+)-crassalactone C (3) starting from D-glucose. Finally, the synthesized styryl-lactones were evaluated for their antiproliferative activity against a panel of human tumor cell lines.</p>
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Effect of Moderate Exercise on Proliferative Responses of Peripheral Blood Mononuclear CellsSmith, J, Chi, D, Salazar, S, Krish, G., Berk, S., Reynolds, S., Cambron, G. 01 June 1993 (has links)
We studied the effects of 30 minutes of exercise on T lymphocyte counts and proliferative responses of peripheral blood mononuclear cells (PBMC) in 25 runners. Exercise resulted in a T lymphocytosis in the immediate post-exercise period in all subjects (p < 0.001), and reduced CD4+/CD8+ ratios in 22/25 subjects (p = 0.001). The change was due primarily to a 2.2-fold increase in CD8+ cells (p < 0.001). Exercise also reduced PBMC mitogenic responses to phytohemagglutinin (PHA) in 13/14 subjects (p = 0.049), and to pokeweed mitogen (PWM) in 11/14 subjects (p = 0.022), but not to concanavalin A. Postrun sera from 5 of 6 subjects inhibited PHA but not PWM responses of resting autologous PBMC with normal CD4+/CD8+ ratios (p < or = 0.05): indomethacin and monocyte depletion blocked the serum inhibition (p = 0.003, p = 0.0006, respectively). We conclude that post-exercise suppression of mitogenic responses to PHA is due to the release of a serum factor(s) capable of inducing prostaglandin synthesis by circulating monocytes, whereas exercise-induced suppression of PWM responses depends primarily on the reversal of CD4+/CD8+ ratios.
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Proteins bind Neutrophil extracellular traps in specific patternsWinkler, Jonay Moritz Julius 24 June 2024 (has links)
Neutrophile sind die häufigsten weißen Blutkörperchen im menschlichen Blut. Sie bilden die
erste Verteidigungslinie und töten eindringende Krankheitserreger ab. Neutrophile
extrazelluläre Fallen (NETs) sind netzartige Strukturen, die aus dekondensiertem Chromatin
bestehen und mit zytotoxischen Proteinen dekoriert sind. NETs können Mikroben in vitro
und in vivo einfangen und abtöten, sind aber auch für verschiedene Krankheiten
verantwortlich. Frühere Studien haben eine spezifische Gruppe von 20-50
Neutrophilenproteinen identifiziert, die an NETs gebunden sind und von denen einige eine
mikrobizide Wirkung haben. Wie diese Proteine an die NETs binden, wie sie interagieren
und wie die Bindung ihre antimikrobielle Aktivität beeinflusst, ist noch nicht bekannt.
In dieser Dissertation habe ich die Verteilung von acht neutrophilen Proteinen und
Nukleosomen auf NETs mit Hilfe der Superauflösungsmikroskopie untersucht. Es wurden
drei unabhängige Techniken mit Auflösungen von mehr als 90 nm verwendet. Die
Nukleosomen bildeten auf den NETs periodische Cluster mit deutlich größeren Abständen
im Vergleich zum kondensierten Chromatin. Drei NET-Proteine waren ebenfalls in
periodischen Clustern auf den NETs lokalisiert und zwei von ihnen waren stark mit
Nukleosomen kolokalisiert. Alle anderen analysierten Proteine zeigten keine Muster der
Bindung an NETs. Zusammengenommen zeigen diese Ergebnisse, dass die Bindung von
Proteinen an NETs zumindest teilweise spezifisch ist und teilweise durch Wechselwirkungen
mit Nukleosomen vermittelt wird.
Die erfolgreiche Einführung der superauflösenden Mikroskopie für schwierige NET-Proben
in Kombination mit einem vorgeschlagenen rekonstituierten NET-System eröffnet neue
Möglichkeiten für das Verständnis der molekularen Mechanismen der NET-Bildung und der
Protein-Protein-Interaktion bei der NET-vermittelten Abtötung. / Neutrophils are the most abundant human white blood cell in circulation. They are the first
line of defense and kill invading pathogens. Neutrophil Extracellular Traps (NETs) are weblike
structures composed of decondensed chromatin decorated with cytotoxic proteins. NETs
can trap and kill microbes in vitro and in vivo, but also mediate several diseases. Previous
studies identified a specific set of 20-50 neutrophil proteins bound to NETs, several with
microbicidal activity. It remains unknown how these proteins bind to NETs, how they interact
and how binding influences their anti-microbial activity.
In this dissertation, I studied the distribution of eight neutrophil proteins and nucleosomes
on NETs using super-resolution microscopy. Three independent techniques with resolutions
larger than 90nm were used. Nucleosomes formed periodic clusters on NETs, with
significantly larger spacing compared to condensed chromatin. Three NET proteins also
localized in periodic clusters on NETs and two of them strongly co-localized with
nucleosomes. All other proteins analyzed showed no patterns binding to NETs. Taken
together, these findings demonstrate that, at least some, protein binding to NETs is specific
and in part mediated by interactions with nucleosomes.
The successful introduction of super-resolution microscopy to the challenging NET samples
in combination with a proposed reconstituted NET system opens new possibilities to
understand the molecular mechanisms behind NET formation and protein-protein
interaction in NET mediated killing.
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Fitohemijski skrining i biološka aktivnost ekstrakata i tradicionalnih proizvoda od plodova divljih ruža (Rosa L.;Rosaceae) / Phytochemical screening and biological activity ofextracts and traditional preserves of rose hips (Rosa L., Rosaceae)Nađpal Jelena 13 July 2017 (has links)
<p> Cilj ove doktorske disertacije predstavljalo je ispitivanje fitohemijskog sastava i biološke aktivnosti vodenih i metanolnih ekstrakata svežih i suvih plodova, kao i voćne kaše i džema pripremljenih po tradicionalnoj recepturi od plodova šest samoniklih vrsta <em>Rosa L.: R. canina, R. dumalis, R. dumetorum, R. tomentosa, R. arvensis, R. sempervirens. </em>Ispitivanje fitohemijskog sastava obuhvatalo je LC -MS/MS analizu 64 odabrana fenolna jedinjenja, hinske kiseline (organske kiseline) kao i tri triterpenoida. Takođe, izvršeno je spektrofotometrijsko određivanje sadržaja ukupnih fenolnih i flavonoidnih jedinjenja, kao i vitamina C. Evaluacija biološke aktivnosti obuhvatala je in vitro ispitivanja antioksidantne i antiinflamatorne aktivnosti, kao i ispitivanje uticaja ekstrakata odabranih vrsta Rosa na aktivnost enzima acetilholinesteraze i rast tumorskih i netumorskih ćelija.</p><p> Sumiranjem dobijenih rezultata može se zaključiti da sveži i suvi plodovi ispitivanih vrsta <em>Rosa</em>, kao i voćne kaše i džemovi predstavljaju značajan izvor vitamina C i fenolnih jedinjenja, sa elagnom kiselinom kao najzastupljenijom fenolnom komponentom. Takođe u pojedinim ekstraktima vrsta<em> R. dumetorum</em> i<em> R. tomentosa</em> detektovana je visoka koncentracija ursolne kiseline, dok je hinska kiselina prisutna u značajnoj koncentraciji u svim ispitivanim ekstraktima.</p><p> Ekstrakti ispitivanih vrsta, izuzev vrste<em> Rosa arvensis</em>, pokazali su visok antioksidantni potencijal koji se ogleda u njihovoj sposobnosti neutralizacije nekoliko radikalskih vrsta, redukcionom potencijalu i sposobnosti inhibicije lipidne peroksidacije. Ispitivani ekstrakti ispoljili su umerenu antiinflamatornu aktivnost u pogledu inhibicije produkcije odabranih metabolita ciklooksigenaznog (12-HHT, TXB<sub>2</sub>, PGE<sub> 2</sub>) i 12-lipooksigenaznog (12-HETE) metaboličkog puta arahidonske kiseline, posebno prostaglandina E . Takođe, in vitro ispitivanjem uticaja ekstrakata odabranih vrsta Rosa na aktivnost acetilholinesteraze pokazana je umerena aktivnost. Vodeni ekstrakti i ekstrakti voćnih kaša vrsta <em>R. canina, R. tomentosa i R. sempervirens</em> pokazali su umereni inhibitorni potencijal prema rastu HeLa ćelijske linije, dok su ekstrakti vrste <em>R. sempervirens </em>pokazali aktivnost i prema HT-29 ćelijama. Dobijeni rezultati ukazuju na značajni potencijal plodova i tradicionalnih proizvoda ispitivanih vrsta <em>Rosa</em> za upotrebu u proizvodnji nutraceutika i funkcionalne hrane.</p> / <p> The aim of presented doctoral thesis was investigation of phytochemical composition and biological activity of water and methanol extracts of fresh and air- dried rose hips, as well as purée and jam made according to traditional recipe of hips of six wild growing<em> Rosa L. species: R. canina, R. dumalis, R. dumetorum, R</em>. <em>tomentosa, R. arvensis, and R. sempervirens.</em> Examination of phytochemical composition included LC-MS/MS analysis of 64 selected phenolic compounds, quinic acid (organic acid) and three triterpenoids. Also, total phenolic and flavonoid contents, as well as vitamin C contents were determined spectrophotometrically. Biological activity evaluation of extracts of six <em>Rosa</em> species included in vitro investigation of antioxidant, anti- inflammatory, anti-acetylcholinesterase and cytotoxic activity.<br /> According to obtained results, fresh and air-dried rose hips, as well as their preserves present valuable source of vitamin C and phenolic compounds, especially ellagic acid, which was the most abundant examined phenolic compound. Furthermore, high concentration of ursolic acid was detected in some<em> Rosa </em> <em>tomentosa and R. rumetorum</em> extracts, while notable concentration of quinic acid was present in all examined extracts.<br /> Extracts of all examined species, apart from <em>Rosa arvensis</em>, showed considerable antioxidant activity in terms of radical scavenging ability, reduction potential and inhibition of lipid peroxidation. Moreover, extracts exhibited moderate anti- inflammatory activity by means of inhibition of the main arachidonic acid metabolites formed incyclooxygenase-1 (12-HHT, TXB<sub>2</sub>, PGE <sub>2</sub> ) and 12-lipoxygenase (12-HETE) pathway, especially prostaglandin E<sub>2</sub> . Also, investigation of anti- cetylcholinesterase activity revealed moderate activity of extracts of all examined species. In addition, predominantly water extracts of fresh andair-dried rose hips, as well as purée of<em> R</em>. <em>canina, R. tomentosa </em>and <em>R. sempervirens</em> showed inhibitory activity toward HeLa, while <em>R.sempervirens</em> extracts also inhibited HT-29 cell growth. Presented results indicate significant potential of examined rose hips and their preserves for use as nutraceuticals and functional food.</p>
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Etude des mécanismes anti-cancéreux induits par milieux activés par jet de plasma froid : vers une nouvelle approche thérapeutique / Study of anti-tumoral mechanisms induced by cold plasma jet activated medium : towards a new therapeutic strategyChauvin, Julie 03 December 2018 (has links)
Les thérapies anticancéreuses basées sur des principes physiques (radiofréquences, ultrasons, laser, électroporation...) ont considérablement augmenté lors de la dernière décennie. Leurs objectifs sont de détruire directement les cellules cancéreuses, de favoriser l'entrée ciblée de molécules thérapeutiques ou encore de stimuler le système immunitaire du patient afin d'éliminer la tumeur. Le plasma froid suscite l'intérêt dans le domaine de l'oncologie grâce à sa capacité à générer des espèces réactives oxygénées (ROS) et azotées (RNS) qui peuvent être génotoxiques et cytotoxiques pour les cellules cancéreuses. Deux approches d'utilisation du plasma sont étudiées : soit l'exposition directe de cellules au jet plasma, soit l'exposition indirecte via l'utilisation d'un Milieu Activé par Plasma (PAM). Le PAM étant plus facile à délivrer par injection dans la tumeur, c'est cette approche qui est choisie lors de ces travaux. Le travail de thèse présenté consiste à étudier l'effet génotoxique et cytotoxique du PAM, obtenu après exposition du milieu au jet de plasma d'hélium, sur des tumeurs in vitro et in vivo. Pour les études in vitro, nous avons choisi d'utiliser un modèle 3D : le sphéroïde (MCTS - MultiCellular Tumor Spheroid). Ce modèle présente des caractéristiques proches du modèle in vivo grâce à son organisation en sphéroïde. Les MCTS présentent en effet des gradients de pénétration d'oxygène, de nutriments et de prolifération cellulaire. La première partie de la thèse concerne l'identification et la quantification des espèces générées dans le PAM. Les méthodes d'analyses utilisées sont la résonance paramagnétique électronique, la fluorimétrie, la colorimétrie, la chromatographie en phase liquide et la spectrométrie de masse. Ces analyses ont mis en évidence que la toxicité du PAM était due à plusieurs facteurs : d'un côté la génération de ROS et RNS mais aussi à la dégradation des nutriments pour les cellules contenues dans le milieu via par exemple l'oxydation et la nitrosylation des acides aminés. La deuxième partie est dédiée à l'étude des effets du PAM sur les MCTS HCT-116 (cancer du côlon).[...] / Cancer therapies based on physical principles (radiofrequency, ultrasound, laser, electroporation...) have considerably increased in the last decade. Their objectives are to directly destroy cancer cells, to favor the targeted entry of therapeutic molecules or to stimulate the patient's immune system in order to eliminate the tumor. Cold plasma still arouses interest in the field of oncology through its ability to generate reactive oxygen species (ROS) and nitrogen species (RNS) which can be genotoxic and cytotoxic for cancer cells. Two approaches to the use of plasma are studied: either direct exposure of cells to the plasma jet, or indirect exposure via the use of a Plasma Activated Medium (PAM). The PAM being easier to deliver by injection into the tumor, this approach was chosen in this work. The work presented consists in studying the genotoxic and cytotoxic effects of PAM resulting from exposure of the medium to the helium plasma jet on in vitro and in vivo tumors. For in vitro studies, we chose to use a 3D model: the spheroid (MCTS - MultiCellular Tumor Spheroid). This model has similar characteristics to the in vivo model thanks to its spheroidal organization. The spheroids have indeed gradients of oxygen penetration, nutrients and cell proliferation. The first part of the thesis concerns the identification and quantification of the species generated in PAM. The analytical methods used are paramagnetic electronic resonance, fluorimetry, colorimetry, liquid chromatography and mass spectrometry. These analyses revealed that the toxicity of PAM was due to several factors: on the one hand to the generation of ROS and RNS and on the other hand to the degradation of cell nutrients contained in the medium via, for example, the oxidation and nitrosylation of the amino acids. The second part is dedicated to the study of the effects of PAM on HCT-116 (colon cancer) spheroids[...]
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Aberrations in Cytokine Signaling in Leukemia: Variations in Phosphorylation and O-GlcNAcylationTomic, Jelena 31 August 2012 (has links)
Tumor-induced immunosuppression can occur by multiple mechanisms, each posing a significant obstacle to immunotherapy. Evidence presented in this dissertation suggests that aberrant cytokine signaling, as a result of altered metabolism of Chronic Lymphocytic Leukemia (CLL) cells, confers a selective advantage for tumor survival and growth. Cells from CLL patients with aggressive disease (as indicated by high-risk cytogenetics) were found to exhibit prolongation in Interferon (IFN)-induced STAT3 phosphorylation, and increased levels of reactive oxygen species (ROS) in these cells reflected these signaling processes. Changes in the relative balance of phospho-STAT3 and phospho-STAT1 levels, in response to combinations of IL-2 + Toll-like receptor (TLR)-7 agonist + phorbol esters, as well as IFN, were associated with the immunosuppressive and immunogenic states of CLL cells. In addition, immunosuppressive leukemic cells were found to express high levels of proteins with O-linked N-acetylglucosamine (O-GlcNAc) modifications, due to increased metabolic activity through the Hexosamine Biosynthetic Pathway (HBP), which caused impaired intracellular signaling responses and affected disease progression. A conclusion of the studies presented here is that the intrinsic immunosuppressive properties of leukemic cells may be overcome by agents such as Resveratrol that target metabolic pathways of these cells.
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