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Transcriptomic changes during differentiation of the leukaemia cell line THP-1 and the role of chromatin modifying enzymesGaz̆ová, Iveta January 2018 (has links)
During normal cell development, many genes are activated and repressed, usually through epigenetic mechanisms. These are modifications of the DNA and protein within the nucleus that result in changes in gene expression without alteration in DNA sequence. Key proteins for epigenetic modifications are the histone proteins bound to DNA in the nucleus. The best-characterised epigenetic complexes that modify histone proteins are the polycomb group proteins (PcG), comprising polycomb repressive complexes 1 (PRC1) and 2 (PRC2). The repressive modifications generated by these complexes can be removed, and the blocked genes reactivated, by enzymes that are the subject of this project. PRC1 repressive marks are removed by deubiquitinases USP12, USP16 and BAP1, whereas PRC2 marks are removed by demethylases KDM6A, KDM6B and potentially UTY. During the development of cancer, the regulation of many genes becomes abnormal, allowing the cells to escape normal growth restrictions. In this thesis, the expression of this set of chromatin-modifying enzymes in a leukaemia cell line was investigated. The FANTOM consortium has been helping to understand patterns of gene expression for over 10 years. The FANTOM4 dataset described changes in gene expression and promoter usage during differentiation of the THP-1 acute monocytic leukaemia cell line, using CAGE (Cap Analysis of Gene Expression) technology. This human monocyte-like cancer cell line can be stimulated with phorbol esters to halt proliferation and differentiate into macrophages. However, the FANTOM4 time course did not capture detailed mechanisms of regulatory factors in macrophage differentiation due to sparse time points and low read coverage. The main aim of this project was therefore to repeat the time course with tighter time points and deeper sequencing of the transcriptome to develop a very precise picture of sequential activation of gene expression, transcription start site (TSS) usage and the activity of enhancers during the transition from proliferating monocytes to differentiated macrophage phenotype of the THP-1 leukaemia cell line, using CAGE. The focus of this research was on the chromatin-modifying enzymes, but other key cell cycle and macrophage genes have also been examined. The differentiation time course was repeated in triplicate. RNA was extracted and CAGE libraries generated for 18 time points, including the 6 originally studied in FANTOM4. Sequencing results were analysed and normalised using bioinformatics tools. It was shown that analysing 8 samples on one Illumina HiSeq 2500 lane yielded enough read coverage to detect activity from even low expression TSSs, such as those associated with enhancer activity. Clusters of genes which were up- and downregulated at different time points during the differentiation process were identified and characterised. CAGE results for key genes encoding chromatin modifying enzymes and macrophage markers were validated by qRT-PCR. There was a rapid increase of histone demethylase KDM6B mRNA once differentiation was initiated. Histone deubiquitinase USP12 mRNA was also upregulated early in the process. Histone deubiquitinase BAP1 mRNA shows an interesting cyclic regulation pattern which was not seen in the more limited samples of FANTOM4. These interesting chromatin-modifying enzymes and their close paralogues (deubiquitinases USP12, USP16 and BAP1, together with demethylases KDM6A, KDM6B and UTY) were investigated by bioinformatics and genetic tools. USP16 knockout THP-1 cell line was successfully created using CRISPR-Cas9 and its ability to differentiate into macrophages was examined using cell cycle analysis and CAGE sequencing. The USP16 knockout cell line, along with siRNA knock downs of USP12, USP16 and BAP1, was also compared to wildtype THP-1 differentiation using CAGE. Unfortunately, creating other mutant THP-1 cell lines was unsuccessful due to low THP-1 viability after single cell sorting. Investigating KDM6A, KDM6B and UTY using bioinformatics showed that UTY and KDM6A gene expression is positively correlated and this is disrupted in cancer samples. Gene expression and sequence comparison suggested that KDM6A and UTY are coregulated and may act in a similar way in histone demethylation. In summary, the results in this thesis show the transcriptomic changes as the leukaemia cell line ceases proliferation and commences differentiation. Detailed examination suggests that histone modifications are important in the transition between proliferation and differentiation and provide better understanding of regulatory factors in macrophage differentiation and leukaemia.
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The functionalisation of wool by tris(hydroxymethyl)phosphine for metal ion recoveryAddison, Simon James January 2009 (has links)
Tris(hydroxymethyl)phosphine (THP) was prepared by the addition of a stoichiometric amount of base to tetrakis(hydroxymethyl)phosphonium chloride (THPC). Freshly prepared THP was successfully immobilised onto wool through a Mannich-type condensation reaction between a hydroxymethyl group and an amine on the wool surface, forming stable gt;P-CH2-Nlt; coupling links. The immobilisation of THP to wool stabilised the THP, which resulted in the decreased oxidation of THP to tris(hydroxymethyl)phosphine oxide (THPO). The presence of immobilised phosphine groups was determined colorimetrically by reaction with Ni2+ ions, which produced a bright orange nickel-phosphine complex, as well as quantitatively, by measuring nickel uptake using ICP-MS. Immobilised THP-wool showed proportional binding for varying concentrations of metal solution. Decreasing or increasing the concentration of the metal solution resulted in a corresponding proportional response of metal binding. Following immobilisation onto wool, oxidation of the system by 6% H2O2 resulted in a reduced binding of 24% for Cu, 25% for Co, 27% for Ni, and 93% for Cd relative to unoxidised THP immobilised onto wool. Additional modification of the THP-wool systems via reaction with amino acids and other related compounds overall did not appear to enhance the metal binding capacity relative to the unmodified THP-wool system. The only modified THP-wool system that showed either retention or an increase in metal binding capacity for all metals analysed was that of 2-aminopyridine, followed by oxidation with H₂O₂.
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Regulation of macrophage subsets in homeostatic and inflammatory mucosal environmentsAlshaghdali, Khalid January 2018 (has links)
The interaction between epithelial cells and macrophages is integral to mucosal immune fate: determining the decision between tolerance and immune activation/inflammation. Endotoxin tolerisation (ET) is a circumstance where cells go through a hypo-responsive state, unable to respond to further endotoxin-LPS challenge. Mucosal macrophages (MΦs) have a dual functionality that determines tolerance to commensal organisms or immune response to entropathogens such as E. coli. In the case of mucosal inflammatory pathologies, such as Crohn’s disease, this state of tolerance is broken, resulting in destruction of gut mucosal tissue where the macrophage phenotype has been altered from a regulatory M2-like subset phenotype to an inflammatory M1-like subset phenotype, responding to both pathogenic and commensal bacteria. Chronic inflammation by bacterial pathogen related molecular patterns (PAMPs), such as LPS, is well established to induce tolerisation. The aims of this project were firstly, to characterise the control of macrophage differentiation in a mucosal setting by investigating the immunomodulatory effects of PAMPs, such as LPS in presence or absence of TNFα and to investigate ET mechanisms associated with MΦ subsets responding to the entropathogen E. coli K12-LPS. Secondly, to investigate the effect of epithelial cells on macrophage subsets behaviour upon inflammation and ET. M1- and M2-like MΦs were generated in vitro from the THP-1 monocyte cell line by differentiation with PMA and vitamin D3, respectively, whereas differentiated epithelial cells (Caco-2) were obtained by long term culturing for 21 days. A transwell co-culture system of Caco2 cells and MΦ subsets was developed to mimic the cell-to-cell cross-talk between epithelial cells and immune cells. Mono- and co-culture models were pre-treated with either LPS, TNFα or IL-1β prior to stimulation by PAMPs. TNFα, IL-1β, IL-18, IL-6 and IL-10 were qualified by ELISA. Cytokines, PRRs and endogenous negative regulatory molecules were detected by RT-PCR and WB and epithelial barrier function was measured by trans epithelial electrical resistance (TEER). ET induced by K12-LPS failed to demonstrate a differential subset-specific response in MΦ mono-culture system whereas, LPS differentially suppress LPS induced cytokine expression in MΦ co-culture system. Tolerised M1- and M2-like MΦs exhibited a significant reduction in expression and secretion of pro-inflammatory cytokines and comparable levels of anti-inflammatory cytokine, IL-10. The suppression of pro-inflammatory cytokine in these MΦs appeared to be linked to the differential TLR4 expression and up-regulation of negative regulators, such as IRAK-M and Tollip. In addition, MΦ subsets differentially responded to inflammation induced by pro-inflammatory cytokines, TNFα and IL-1β in mono- and co-culture models. In conclusion, tolerisation induced in MΦs is presented by the suppression of pro-inflammatory cytokine, which is associated with corresponding up-regulation of IL-10, TLR4 receptor and the negative regulators, in a subset-independent manner. In the case of cross-talk between epithelial cells and macrophages however, a differential sensitivities to ET was displayed. These findings allow more understanding of MΦ subsets functions and ET mechanisms, which may be beneficial for the development of in-vitro models of MΦ subsets and therapeutics targeting Crohn’s diseases.
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COPPER-CATALYZED HYDROXYCYCLOPROPANOL RING OPENING CHEMISTRY AND TOTAL SYNTHESIS OF GA18Weida Liang (12447090) 22 April 2022 (has links)
<p> </p>
<p>Tetrahydrofurans (THFs) and tetrahydropyrans (THPs) are important core scaffolds frequently found in many bioactive natural products and important drug molecules. Regardless of the recent advances, achieving high stereoselective disubstituted or polysubstituted THFs and THPs still remains a synthetic challenge especially via metal catalyzed direct intramolecular Csp<sup>3</sup>-O bond formation for the ring closure. Cyclopropanols are important and useful building blocks in synthetic chemistry, and due to the intrinsic ring strain, they are prone to undergo ring opening process under transition metal catalyst to produce homoenolates. Herein, we have developed a novel Cu(II)-catalyzed hydroxyl tethered cyclopropanol ring-opening cyclization to diastereoselective syntheses of THF and THP rings. The reaction features a broad substrate scope, scalability, and good functional-group tolerability. Further mechanism study has revealed that the 7-membered metallocycle intermediate generated by Cu and hydroxycyclopropanol plays an important role in reaction pathway. It also enabled us to complete the shortest enantioselective total synthesis of hyperione A and B.</p>
<p>The gibberellins contain a family of nearly 130 highly functionalized diterpenoids in the plant world. Gibberellic acids (GAs) are produced by plants and microorganisms to regulate the cell growth and development. We have developed a comprehensive synthesis strategy for the natural product GA<sub>18</sub> that includes the ene reaction, one-pot ozonolysis cascade aldol condensation, photocatalyzed [2+2] reaction, and Sm-induced rearrangement to build the critical tetracyclic skeleton. Additionally, efforts also have been made in functional group interconversion to finalize the end game. </p>
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PROFILING GANGLIOSIDE EXPRESSION AND CHANGE IN THP-1 MACROPHAGES UPON LPS STIMULATIONTomar, Sonia January 2021 (has links)
No description available.
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Einfluss von NAD-Metaboliten auf THP-1 ZellenPetin, Katharina 11 February 2022 (has links)
No description available.
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Inhibition of Cytokine Induced Indoleamine 2, 3-Dioxygenase Expression in a Human Monocytic Cancer Cell LineGalik, Ryan January 2018 (has links)
No description available.
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Estrategias para mitigar la toxicidad asociada a la exposición crónica al mercurio a través de la dietaRodríguez Viso, Pilar 20 April 2023 (has links)
[ES] La dieta es la principal vía de exposición a mercurio (Hg) para la mayoría de la población. Las principales formas de Hg en los alimentos son el metilmercurio (MeHg) y el Hg inorgánico divalente [Hg(II)]. Aunque el intestino es la principal puerta de entrada del tóxico en la circulación sistémica, los estudios sobre su toxicidad a nivel intestinal son escasos. El objetivo de la presente tesis ha sido evaluar la toxicidad y los mecanismos de acción del Hg(II) y el MeHg a nivel intestinal. Adicionalmente, se ha ensayado la eficacia de cepas de bacterias ácido- lácticas (BAL) como estrategia de reducción de esta toxicidad. Para los estudios in vitro se ha desarrollado un modelo celular en el que se han combinado enterocitos, células mucosecretoras y macrófagos en un sistema bicameral. Las células se han expuesto a Hg(II) y MeHg (0.1-1 mg/L) durante 10 días. Los datos han evidenciado que ambas especies generan un aumento de la respuesta inflamatoria, incrementando la liberación de la citoquina IL-8 e IL-1β, y una respuesta pro-oxidante, con un aumento de las especies reactivas de oxígeno/nitrógeno (ROS/RNS) y una sobreexpresión de proteínas de estrés (HSP70, HSP90 y MT2A). Esta respuesta ha sido más notable en macrófagos, indicando que posiblemente sean las células inmunitarias las que gobiernen la respuesta al tóxico. La situación de estrés va acompañada de una alteración de la expresión de la proteína de las uniones estrechas ZO-1 y una modificación de la morfología de la monocapa. Además, la exposición genera un aumento de la secreción de mucus y una sobreexpresión de su principal mucina, principalmente a MeHg. Los mecanismos de esta hipersecreción podrían estar relacionados con la ruta IL4/IL13/STAT6. Todos estos efectos sobre la monocapa epitelial conllevan un aumento de la permeabilidad y una reducción de la capacidad de regeneración. En los ensayos in vivo se han expuesto ratones BALB/c a Hg(II) y MeHg (1- 10 mg/L) durante 4 meses a través del agua de bebida. Los datos obtenidos han confirmado lo observado in vitro. La exposición a ambas especies (especialmente a 5 y 10 mg/L) induce un proceso inflamatorio en el colon, con un aumento de las citoquinas TNF-α e IL1-β y la presencia de infiltrados de neutrófilos. Paralelamente, la exposición genera estrés oxidativo con un incremento de las ROS/RNS y los peróxidos lipídicos. Se ha confirmado in vivo la participación en esta respuesta de algunas rutas apuntadas in vitro, en concreto p38 MAPK y JNK. Además, también se evidencian alteraciones en la expresión de proteínas de las uniones estrechas y de la mucina MUC2 en el colon, acompañada de una hiperplasia de las células mucosecretoras, especialmente en los tratamientos con MeHg. En estos animales se observa, además, un aumento de la expresión de IL13 e IL4, lo que apunta a la participación de la ruta IL4/IL13/STAT6, tal y como indicaban los ensayos in vitro. Además, estos ensayos in vivo muestran un efecto de ambas especies sobre el metabolismo de la microbiota intestinal con una reducción de los contenidos luminales de los ácidos grasos de cadena corta (SCFA), aunque los cambios detectados en la composición de la microbiota son mínimos. Finalmente, los animales tratados presentan un aumento de la permeabilidad. Todos los datos obtenidos in vitro e in vivo ponen de manifiesto que una exposición continuada a Hg(II) y MeHg genera una disrupción de la barrera intestinal. Los ensayos in vitro realizados para determinar la eficacia de las cepas de BAL de origen murino LE1 y LE2 como estrategia de protección se han realizado coexponiendo el modelo celular a Hg(II) o MeHg (1 mg/L) junto con las cepas durante 7 días. Los datos obtenidos han mostrado un efecto protector de ambas cepas, con una reducción de la respuesta inflamatoria, el estrés y los efectos sobre las uniones estrechas y la producción de mucus. Asimismo, la presencia de ambas bacterias restaura parcialmente la permeabilidad y la capacidad de regeneración de las monocapas. Teniendo en cuenta que en este estudio las BAL están inactivadas térmicamente, esta protección se asocia principalmente a su capacidad de quelación del Hg, aunque no hay que descartar que algún componente estructural de la pared bacteriana pueda ejercer otro tipo de efecto beneficioso. Los ensayos in vivo para confirmar el efecto protector de las BAL se han realizado en ratones BALB/c expuestos durante 2 meses a MeHg (5 mg/L) a través del agua de bebida. Las bacterias, en este caso viables, se han administrado por sonda gástrica diariamente. Los datos obtenidos muestran que, aunque las dos cepas reducen por igual los contenidos colónicos de MeHg, la reducción de los efectos tóxicos es mucho más notable con la cepa LE1. Se observan reducciones de los contenidos de mediadores de inflamación y estrés en el colon, hay una recuperación de la expresión de proteínas constituyentes de las uniones estrechas y del mucus. Se reestablecen los niveles luminales de los metabolitos de la microbiota y se restaura parcialmente la permeabilidad intestinal. Los resultados muestran que, además del proceso de quelación, la cepa LE1 activa la ruta de señalización Nrf2/Keap1/ARE y la producción de la citoquina anti-inflamatoria IL10. Los datos obtenidos in vitro e in vivo, apuntan a que la cepa LE1 podría ser una buena alternativa para reducir la toxicidad intestinal del Hg; reducción que puede tener también repercusiones beneficiosas a nivel sistémico. / [CA] La dieta és la principal via d'exposició a mercuri (Hg) per a la majoria de la
població. Les principals formes de Hg en els aliments són el metilmercuri (MeHg)
i el Hg inorgànic divalent [Hg(II)]. Encara que l'intestí és la principal porta
d'entrada del tòxic a la circulació sistèmica, els estudis sobre la seua toxicitat a
nivell intestinal són escassos. L'objectiu de la present tesi ha sigut avaluar la
toxicitat i els mecanismes d'acció del Hg(II) i el MeHg a nivell intestinal.
Addicionalment, s'ha assajat l'eficàcia de soques de bacteris àcid-làctics (BAL)
com a estratègia de reducció d'aquesta toxicitat.
Per als estudis in vitro s'ha desenvolupat un model cel·lular en el qual s'han
combinat enteròcits, cèl·lules mucosecretores i macròfags en un sistema
bicameral. Les cèl·lules s'han exposat des de l'inici a Hg(II) i MeHg (0.1-1 mg/L)
durant 10 dies. Les dades han evidenciat que totes dues espècies generen un
augment de la resposta inflamatòria, incrementant l'alliberament de la citocina IL-
8 i IL-1β, i una resposta pro-oxidant, amb un augment de les espècies reactives
d'oxigen/nitrogen (ROS/RNS) i una sobreexpressió de proteïnes d’estrès (HSP70,
HSP90 i MT2A). Aquesta resposta ha sigut més notable en macròfags, indicant
que possiblement són les cèl·lules immunitàries les que governen la resposta al
tòxic. La situació d’estrès va acompanyada d'una alteració de l'expressió de la
proteïna de les unions estretes ZO-1 i una modificació de la morfologia de la
monocapa. A més, l'exposició, principalment a MeHg, genera un augment de la
secreció de mucus i una sobreexpressió de la seua principal mucina. Els
mecanismes d'aquesta hipersecreció podrien estar relacionats amb la ruta
IL4/IL13/STAT6. Tots aquests efectes sobre la monocapa epitelial comporten un
augment de la permeabilitat i una reducció de la capacitat de regeneració.
En els assajos in vivo s'han exposat ratolins BALB/c a Hg(II) i MeHg (1-10
mg/L) durant 4 mesos a través de l'aigua de beguda. Les dades obtingudes han
confirmat l'observat in vitro. L'exposició a totes dues espècies (especialment a 5 i
10 mg/L) indueix un procés inflamatori en el còlon, amb un augment de les
citocines TNF-α i IL1-β i la presència d'infiltrats de neutròfils. Paral·lelament,
l'exposició genera estrès oxidatiu amb un increment de les ROS/RNS i els peròxids
lipídics. S'ha confirmat in vivo la participació en aquesta resposta d'algunes rutes
apuntades in vitro, en concret p38 MAPK i JNK. A més, també s'evidencien
alteracions en l'expressió de proteïnes de les unions i de la mucina MUC2 en el
còlon, acompanyada d'una hiperplàsia de les cèl·lules mucosecretores,
especialment en els tractaments amb MeHg. En aquests animals hi ha, a més, un
augment de l'expressió d'IL13 i IL4, la qual cosa apunta a la participació de la ruta
IL4/IL13/STAT6, tal com indicaven els assajos in vitro. A més, aquests assajos in
vivo mostren un efecte de les espècies de Hg sobre el metabolisme de la microbiota
intestinal, amb una reducció dels continguts luminals dels àcids grassos de cadena
curta (SCFA), encara que els canvis en la composició de microbiota intestinal son
minims. Finalment, els animals tractats presenten un augment de la permeabilitat.
Totes les dades obtingudes in vitro i in vivo posen de manifest que una exposició
continuada a Hg(II) i MeHg genera una disrupció de la barrera intestinal.
Els assajos in vitro realitzats per a determinar l'eficàcia de les soques de BAL
d'origen murí LE1 i LE2 com a estratègia de protecció s'han realitzat coexposant
el model cel·lular combinat a Hg(II) o MeHg (1 mg/L) juntament amb les soques
durant 7 dies. Les dades obtingudes han mostrat un efecte protector de totes dues
soques, amb una reducció de la resposta inflamatòria, l'estrès i els efectes sobre
les unions estretes i la producció de mucus. Així mateix, la presència dels bacteris
restaura parcialment la permeabilitat i la capacitat de regeneració de les
monocapes. Tenint en compte que en aquest estudi les BAL estan inactivades
tèrmicament, aquesta protecció s'associa principalment a la seua capacitat de
quelació del Hg, encara que no cal descartar que algun component estructural de
la paret bacteriana puga exercir un altre tipus d'efecte beneficiós.
Els assajos in vivo per a confirmar l'efecte protector de les BAL s'han realitzat
en ratolins BALB/c exposats durant 2 mesos a MeHg (5 mg/L) a través de l'aigua
de beguda. Els bacteris, en aquest cas viables, s'han administrat per sonda gàstrica
diàriament. Les dades obtingudes en aquest assaig mostren que, encara que els
dues soques redueixen per igual els continguts colònics de MeHg, la reducció dels
efectes tòxics és molt més notable amb la soca LE1. S'observen reduccions dels
continguts dels mediadors d'inflamació i estrès en el còlon, hi ha una recuperació
de l'expressió de proteïnes constituents de les unions estretes i el mucus. Es
restableixen els nivells luminals dels metabòlits de la microbiota i es restaura
parcialment la permeabilitat intestinal. Els resultats mostren que a més del procés
de quelació, la soca LE1 activa la ruta de senyalització Nrf2/Keap1/ARE i la
producció de la citocina anti-inflamatòria IL10. Les dades obtingudes in vitro i in
vivo apunten al fet que la soca LE1 podria ser una bona alternativa per a reduir la
toxicitat intestinal del Hg; reducció que pot tindre també repercussions
beneficioses a nivell sistèmic. / [EN] A cell model for in vitro studies in which enterocytes, mucosecretory cells and macrophages have been combined in a bicameral system has been developed. Cells have been exposed to Hg for 10 days. The data have shown that both species induce an inflammatory response and a pro-oxidant response, with an increase in reactive oxygen/nitrogen species and an overexpression of stress proteins. The situation of stress is accompanied by alterations in the expression of the tight junction protein ZO-1 and changes in the morphology of the intestinal monolayer. In addition, exposure, especially to MeHg, generates an increase in mucus secretion and an overexpression of its main mucin. The mechanisms of this hypersecretion could be related to the IL4/IL13/STAT6 pathway. All these effects on the epithelial monolayer lead to and increased permeability and a reduced regeneration capacity.
In vivo assays have been performed in BALB/c mice exposed to Hg (1-10 mg/L) for 4 months through drinking water. The data obtained have confirmed the previous results observed in vitro. Exposure to both species induces an inflammatory process in the colon and generates oxidative stress with an increase in ROS/RNS and lipid peroxides. The participation in this response of some signaling pathways targeted in vitro has been confirmed in vivo. In addition, alterations in the expression of tight junction proteins and the mucin MUC2 in the colon are also evidenced, accompanied by a hyperplasia of the mucosecretory cells, especially in MeHg treatments. In these animals, there is also an increase in the expression of IL-13 and IL-4 cytokines, which points to the participation of the IL4/IL13/STAT6 pathway. In addition, these in vivo assays show an effect of both species on the metabolism of the intestinal microbiota, with a reduction in the luminal contents of short-chain fatty acids, although changes in the intestinal microbiota composition are minimal. Finally, the treated animals showed an increase in permeability.
The in vitro studies carried out to determine the efficacy of the BAL strains of murine origin LE1 and LE2 as a strategy of protection have been performed by co-exposing the combined cell model to Hg (1 mg/L) together with the strains for 7 days. The data obtained have shown a protective effect of both strains, with a reduction in the inflammatory response, oxidative stress and the effects on tight junctions and mucus production. In the same way, the presence of both bacteria partially restores the permeability and the regenerative capacity of the monolayers. Bearing in mind that in this study the LABs are heat-inactivated, this protection is mainly associated with their ability to bind Hg, although it cannot be ruled out that some structural components of the bacterial wall may exert another type of beneficial effect.
In vivo assays carry out to confirm the protective effect of LAB have been performed in BALB/c mice exposed for 2 months to MeHg (5 mg/L) through drinking water. The strains of LAB have been administered daily by gavage. Data show that, the reduction of the toxic effects is much more pronounced when LE1 strain is administrated. Reductions in the contents of inflammatory and stress mediators in the colon are observed, together with a recovery in the expression of proteins of the tight junctions and the mucus layer. The luminal levels of microbiota metabolites are restored, and intestinal permeability is partially reestablished. The results show that in addition to the chelation process, LE1 strain activates the Nrf2/Keap1/ARE signaling pathway and the production of the anti-inflammatory cytokine IL10. The data obtained in vitro and in vivo suggest that LE1 strain could be a good strategy to reduce Hg intestinal toxicity; reduction that can also have beneficial repercussions at a systemic level. / Rodríguez Viso, P. (2023). Estrategias para mitigar la toxicidad asociada a la exposición crónica al mercurio a través de la dieta [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/192865
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Estudo dos mecanismos de virulência de cepas resistentes e sensíveis de Mycobacterium tuberculosis / Study of mechanisms of virulence of resistant and susceptible strains of Mycobacterium tuberculosisCouto, Jamile 14 November 2008 (has links)
A tuberculose continua sendo um grave problema de saúde pública mundial. O principal agente etiológico da doença é o Mycobacterium tuberculosis, infectando entre outras células, os macrófagos. A infecção pode manter-se latente por vários anos sem causar sintomas clínicos aparentes. Para esta pesquisa, foi proposto o estudo de indução de marcadores de resposta inflamatória em células THP-1 diferenciadas em macrófagos utilizando isolados micobacterianos sensíveis, uni ou multidrogas resistentes transfectados com o plasmídeo pFPCAGFP carreando o gene da proteína verde fluorescente, como marcador de infecção celular. Objetivou também avaliar a relação entre isolados clínicos de M.tuberculosis sensíveis ou com resistência a uma ou multidrogas e sua relação à virulência. Para isso, culturas da linhagem monocítica humana (THP-1) foram mantidas para posterior infecção por isolados clínicos, genotipicamente identificados pertencentes à nossa micobacterioteca. A expressão do RNAm foi quantificada e avaliada por RTPCR e posteriormente, PCR em tempo real foi realizado. Após infecção das células THP-1 diferenciadas em macrófagos, observou-se que houve um aumento na expressão das citocinas pró-inflamatórias (IL-1β, IL-6 e TNF-α) e TLRs (TLR2 e TLR4) em relação ao controle da infecção. As análises estatísticas permitiram a correlação na expressão destas citocinas e TLRs, e através desses resultados, foi possível constatar que TLR2 regula a expressão das citocinas pró-inflamatórias (IL-1β, IL-6 e TNF-α) e que os Isolados clínicos com maior resistência, sinalizam melhor a expressão das citocinas próinflamatórias e TLRs, ao passo que isolados clínicos sensíveis, possuem uma fraca sinalização. / Tuberculosis is the major causative of death and morbidity and still is a serious problem to the health in the world. Mycobacterium tuberculosis is the major causative agent of tuberculosis disease, infecting cells like macrophages. The infection can keep dormant for several years without any clinical symptoms. For this research, the study was proposed for induction of markers of inflammatory response in cells differentiated THP-1 in macrophages by clinical isolates from sensitive or multidrug resistant mycobacteria caring pFPCAGFP plasmid that contains green fluorescent protein gene, a marker of infection cell. Also objective assesses the relationship between clinical isolates of sensitive or with resistance to one or four drugs M.tuberculosis and its relationship to virulence. For this, cultures of monocitic lineage human (THP-1) were kept for subsequent infection by clinical isolates, genotypically identified belonging to our mycobacterioteca. The expression of mRNA was quantified and evaluated by RT-PCR and subsequently, real-time PCR was performed. After infection of the THP-1 differentiated cells in macrophages, it was observed that there was an increase expression of pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and TLRs (TLR2 and TLR4) compared to infection control. Statistical analyses allowed expression correlation of these cytokines and TLRs, and through those results, it was possible to see that TLR2 regulates pro-inflammatory cytokines (IL-1β , IL-6 and TNF-α) expression and those clinical isolates with four resistance have better signal of pro-inflammatory cytokines and TLRs expression, while sensitive clinical isolates, has a weak signal.
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Le modèle cellulaire THP-1 : adaptation à l'étude de modulateurs de l'activité inflammatoire précoce implicant l'inflammasomeMaugé, Loranne 04 December 2013 (has links)
L’inflammation joue un rôle clé dans de nombreuses pathologies, telles que les maladies inflammatoires chroniques, les désordres métaboliques et le cancer. L’un de ses médiateurs le plus puissant est l’interleukine-1β (IL-1β), qui est une cytokine pro-inflammatoire participant à tous les stades de l’inflammation et de l’immunité. Son activation est régulée par un complexe multi-protéique nommé inflammasome, dont la caspase-1 active en découlant est responsable du clivage et de la maturation de l’IL-1β. Huit types d’inflammasomes activant et clivant la pro-caspase-1 ont été identifiés et contiennent tous la protéine ASC (apoptosis-associated speck-like protein containing a CARD). Les inflammasomes partagent un signal intracellulaire commun et le mécanisme menant à leur assemblage et leur activation n’est pas totalement élucidé. L’utilisation de la lignée cellulaire humaine monocytaire, THP-1, différenciée en macrophages grâce à un ester de phorbol, le TPA, a permis la mise en place d’un modèle d’étude de modulateurs de l’inflammasome en conditions stériles. Ce modèle a permis l’étude des mécanismes impliqués suite à des signaux issus de l’inflammation chronique, tels que l’ATP et les espèces réactives de l’oxygène (ROS). Ce travail montre qu’il existe une synergie entre ATP et ROS, qui agissent grâce à une boucle d’activation impliquant probablement plusieurs inflammasomes, dont NLRP3. Des donneurs de NO connus (trinitrine et isosorbide dinitrate) ou nouveau (dérivé de purine) ont montré une activité anti-inflammatoire. D’autres composés ont été identifiés comme de potentiels inhibiteurs d’inflammasome (extraits de dattes et dérivé de purine portant un acide lipoïque) / Inflammation has a pivotal role in several disorders, such as chronic inflammatory diseases, metabolic disorders and cancer. Interleukin-1β (IL-1β) is one of the most powerful mediators in this mechanism. IL-1β is a pro-inflammatory cytokine which is implicated in every step of inflammation and immunity. IL-1β is regulated by a multi-protein complex named inflammasome, in which active caspase-1 is responsible for IL-1β processing and maturation. Eight inflammasomes processing and activating pro-caspase-1 has been identified and all contain the adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD). Inflammasomes share a common intracellular signal and the mechanism for their structural assembly and activation is not totally clear. The human monocytic cell line, THP-1, has been used and cells have been differentiated in macrophages by the phorbol ester, TPA. Based on this, a cellular pattern has been established for studying inflammasome modulators under sterile conditions. This pattern allowed the study of implicated mechanisms in chronic inflammatory signals, such as ATP and reactive oxygen species (ROS). This study shows that ATP and ROS synergize for activating inflammasomes and NLRP3 and act in an autocrine loop. Stimulation with others natural or synthetic compounds has been realized for characterization of their inflammatory activity. Therapeutic NO donors (trinitrin and isosorbide dinitrate) and a new NO donor (purine nitrate ester) have been characterized for their anti-inflammatory activity. Others compounds from a new category of inflammasome inhibitors have been identified (date fruit extracts and lipoic acid purine derivative)
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