Thèses sur le sujet « DNA extracellulare »
Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres
Consultez les 50 meilleures thèses pour votre recherche sur le sujet « DNA extracellulare ».
À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.
Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.
Parcourez les thèses sur diverses disciplines et organisez correctement votre bibliographie.
Shields, Robert Colquhoun. « Extracellular DNA in head and neck biofilms ». Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/2498.
Texte intégralFisher, Mark. « Intra and extracellular responses to DNA damage ». Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/214106/1/Mark_Fisher_Thesis.pdf.
Texte intégralDos, Santos Goncalves Marina. « Rôle des exopolysaccharides et de l'ADN extracellulaire dans le développement du biofilm par Klebsiella pneumoniae ». Thesis, Clermont-Ferrand 1, 2014. http://www.theses.fr/2014CLF1PP02.
Texte intégralBiofilms are defined as microbial communities adhering to biotic or abiotic surfaces and embedded in a self-produced extracellular matrix. Natural biofilms are composed of several microbial species and their interactions, synergistic or antagonistic, play important roles in development, composition and functioning of the consortia. Furthermore, the relationships often involve the production of antagonist molecules that impair competitors' growth or adhesion. The composition and evolution of the extracellular matrix plays also an important role in the biofilms' robustness. In this work, study of the interactions within biofilms formed by K. pneumoniae and S. epidermidis led to the isolation of a polysaccharide produced by K. pneumoniae able to inhibit the adherence to abiotic surfaces of several Gram-negative and Gram-positive bacterial species. The physico-chemical characterization of this high molecular weight molecule showed it was composed of galactose, glucose, rhamnose and glucuronic acid. This data, together with the analysis of extracts from capsule-deficient mutants, indicated that the capsule of K. pneumoniae was responsible for the biofilm inhibition phenotype, probably by inhibiting the initial interactions between bacteria and surface. By monitoring the formation of monospecies biofilm by K. pneumoniae with the Biofilm Ring Test® technique, we were able to detect an original phenotype. Indeed, detection of bacterial aggregates still occurred after a few hours of incubation but in a different way, probably related to changes of the biofilm robustness towards magnetic forces. The presence of extracellular DNA in the matrix of the biofilm is likely to play a role in the occurrence of this phenotype, as indicated by the assays performed in presence of the enzyme DNase I. At the same time, observations of biofilm formed by K. pneumoniae in kinetic experimental models showed massive detachment events during biofilm maturation, which could be correlated to changes in internal strength of the matrix. All these dtat contribute to a better characterization of the intimate interactions occuring within biofilms formed by K. pneumoniae and will ultimately lead to the development of efficient anti-biofilm strategies
Carrera, Samantha. « Influence of extracellular factors on p53-mediated DNA damage responses ». Thesis, University of Leicester, 2013. http://hdl.handle.net/2381/27796.
Texte intégralTursi, Sarah Anne. « Curli-Extracellular DNA Complexes : Pathogenicity and Role in Enteric Biofilms ». Diss., Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/511656.
Texte intégralPh.D.
The first recorded observation of bacterial biofilms dates back to the 17th century by Antoine Van Leeuwenhoek. Today, biofilms are known as bacteria encapsulated within a self-produced extracellular matrix adherent to biotic or abiotic surfaces. Since the initial discovery of biofilms, research has explored the structure and function of biofilms. Only until recently has the role of biofilms within the medical setting become apparent. Here, we investigate the role of curli-extracellular DNA (eDNA) complexes in disease pathogenicity and explore the ability to target bacterial amyloid curli as a novel anti-biofilm therapeutic target. Biofilms of enteric bacteria, such as Escherichia coli and Salmonella enterica serovar Typhimurium, are composed of various components that act in consortium to fortify the extracellular matrix. One of the main components of enteric biofilms is amyloid curli. Curli, one of the best characterized bacterial amyloids, is a protein with a conserved cross beta sheet structure that forms basket like structures encapsulating the bacteria. Within the biofilm, curli serves to fortify the extracellular matrix, aids in bacterial attachment and protects bacteria from harsh environmental conditions. Extracellular DNA (eDNA) is another integral component of enteric biofilms. Recent reports from our lab has suggested that curli forms irreversible complexes with eDNA. Even with exposure to DNases, co-localized curli and eDNA can be observed. Other components of enteric biofilms include cellulose and Biofilm Associated Protein A. Biofilms of S. Typhimurium have been associated with significant disease pathologies. In addition to identifying the existence of curli-eDNA complexes within S. Typhimurium biofilms, our lab has also reported that curli-eDNA complexes of S. Typhimurium potentiate the autoimmune disease Systemic Lupus Erythematosus (SLE). SLE is an autoimmune disease characterized by the production of type I interferons and autoantibodies, although the etiology remains unknown. Systemically, curli binds to and activates the Toll like Receptor (TLR)1/2 complex leading to a pro-inflammatory response. In these studies we aimed to identify the innate immune mechanisms leading to the autoimmune phenotype following stimulation with curli-eDNA complexes. As TLR9 is activated by unmethylated bacterial DNA CpG DNA sequences leading to the production of type I interferons we hypothesized a potential role for TLR9 in recognizing eDNA of the curli-eDNA complex leading to the generation of the hallmarks of SLE. To investigate this hypothesis, we stimulated wild-type, TLR2 knockout, TLR9 knockout and TLR2-9 double knockout immortalized macrophages with curli-eDNA complexes purified from S. Typhimurium biofilms. We observed a significant reduction in the transcript level of type I interferons (IFN), Ifnβ, Isg15 and Cxcl10, upon stimulation of TLR2 knockout, TLR9 knockout and TLR2-9 double knockout immortalized macrophages implicating a role in TLR9 recognition of the curli-eDNA complex. As there was a significant reduction of type I interferon levels upon stimulation of TLR2 knockout macrophages, we hypothesized that TLR2 may serve as a carrier to bring the curli-eDNA complex into the endosome containing TLR9. To inhibit phagocytosis, we pretreated cells with endocytosis inhibitors and stimulated wild-type macrophages with curli-eDNA complexes. We observed a reduction in the transcript level of Ifnβ suggesting that curli-eDNA complexes gain access to endosomal TLR9 via TLR2 engagement. Finally, to explore the role of TLR2 and TLR9 in the production of autoantibodies, curli-eDNA complexes were intraperitoneal injected twice weekly for six weeks into C57BL/6 wild-type, TLR2 knockout, TLR9 mutant and TLR2 knockout-TLR9 mutant mice. We observed a robust generation of anti-double stranded autoantibodies within the first three weeks, however the production of autoantibodies was significantly decreased and delayed in the TLR2 knockout, TLR9 mutant and TLR2 knockout-TLR9 mutant mice. Overall, these data suggest that curli acts as a carrier for DNA to elicit an autoimmune response via TLR2 and TLR9. Within biofilms of S. Typhimurium, curli is the main proteinaceous component. Biofilms lacking curli destabilize and fail to form mature biofilms. Recent research has shown that in response to the production of host amyloids, the body will generate anti-amyloid antibodies in the serum. Monoclonal antibodies (mAb) generated from serum antibodies have been shown to have pan anti-amyloid properties in vitro and in vivo due to the β-sheet conformational epitope. As amyloids from both human and bacterial origin share a β-sheet conformational structure, we hypothesized as to if the anti-amyloid mAbs can eradicate S. Typhimurium biofilms by targeting curli. We incubated S. Typhimurium biofilms in the presence of various mAbs (ALZ.4A6, ALZ.4GI, ALZ.2C10 and ALZ.3H3) and observed a significant reduction of biofilm thickness and curli content within the biofilm. We deduced that ALZ.3H3 conferred the greatest anti-biofilm response. When we visualized the three-dimensional architecture of biofilms incubated with ALZ.3H3, we observed that ALZ.3H3 induced the formation of a loose architecture compared to untreated biofilms that were dense and compact. The resulting loose biofilm architecture induced by incubation with ALZ.3H3 enhanced the susceptibility of the biofilms to antibiotic exposure and macrophage clearance. We also observed enhanced biofilm eradication in vivo when catheters precoated with S. Typhimurium biofilms were inserted into the back flanks of mice that were percutaneously injected with ALZ.3H3. Both in vitro and in vivo, combination therapy of ALZ.3H3 and antibiotic enhanced biofilm clearance. In summary, we propose a novel anti-biofilm strategy by targeting the amyloid component of the biofilm, thus satisfying an unmet need in the art of biofilm prevention. Overall, these data in summation significantly broadens our understanding of disease pathogenicity and the role of curli-eDNA complexes in S. Typhimurium biofilms. As amyloid-eDNA complexes may be found in other biofilms, these results may extend beyond enteric bacteria proving novel insight into host-microbe interactions and the generation of novel anti-biofilm therapeutics.
Temple University--Theses
Bußkamp, Holger [Verfasser]. « From New DNA Conjugation Approaches to 3D DNA Networks for an Artificial Extracellular Matrix / Holger Bußkamp ». Konstanz : Bibliothek der Universität Konstanz, 2015. http://d-nb.info/1112745408/34.
Texte intégralSusevski, Vanessa. « Development of DNA Aptamers Targeting Breast Cancer Derived Extracellular Vesicles for Biomarker Discovery ». Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41035.
Texte intégralRapsinski, Glenn James. « Immune Recognition of S. Typhimurium Biofilms via Amyloids and Extracellular DNA ». Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/273605.
Texte intégralPh.D.
Salmonella enterica serovar Typhimurium is an important cause of gastroenteritis in the United States and the developing world. Biofilm growth is an significant mechanism, which S. Typhimurium utilizes to contaminate food products and survive in the environment. Biofilms are also an important part of the infectious process for many pathogenic bacteria. As part of the biofilm, S. Typhimurium produces an extracellular matrix consisting of cellulose, extracellular DNA, and most importantly, the amyloid protein curli. Similar to amyloids associated with human diseases, curli is recognized by the innate immune system through Toll-Like Receptors (TLRs). Here, we studied the immune receptors recognizing curli as well as interactions between eDNA and curli during biofilm development in order to glean a better understanding of these complex bacterial communities and the immune response to them. Recently, our lab demonstrated that curli fibers are recognized by the TLR2/TLR1 complex. CD14 has been shown to be a common adaptor protein for TLR2/TLR1 complex in response to one of its ligands, tri-acylated lipopeptide, Pam3CSK4. In order to study the role of CD14 in the immune receptor complex recognizing curli, we utilized HeLa 57A cells, a human cervical cancer cell line that has a stably transfected luciferase reporter for Nf-κB activation. When these cells were transiently transfected with TLR2 and TLR1 together or with the addition of membrane-bound CD14, NfκB activation was enhanced by the presence of CD14 in response to purified curli, GST-tagged curli subunit (GST-CsgA), and the control lipopeptide Pam3CSK4. Soluble CD14 also increased NfκB activation in response to purified curli. Bone marrow derived macrophages (BMDM) from wild type (C57BL/6) mice produced more IL-6 and nitric oxide in response to stimulation with purified curli, GST-CsgA, and Pam3CSK4, than BMDMs deficient in CD14. Binding assays demonstrated direct binding of curli to all members of this hypothesized trimolecular complex, TLR2, TLR1, and CD14. Utilizing synthetic peptides corresponding to the fourth and fifth repeat of the CsgA monomer, CsgA R4-5, and its modified version, CsgA R4-5N122A deficient in forming amyloid fibers, we also showed that binding to CD14, and CD14 enhancement of IL-6 production required the fibrillar amyloid structure of curli. To study interactions between curli and eDNA in biofilms and the resulting immune response generated to composites formed by these ECM components, we analyzed biofilms of GFP expressing S. Typhimurium using confocal laser scanning microscopy (CLSM). Staining for amyloids with Congo Red revealed the presence of curli in the biofilms and staining with propidium iodide demonstrated the presence of extracellular DNA in the biofilms. Co-staining with TOTO-1, a nucleic acid stain, and Congo Red showed co-localization of the fluorescent signal for these molecules within the biofilms. DNase I treatment of the biofilms produced no significant change in biofilm thickness by confocal microscopy signifying that the biofilm, possibly eDNA, was resistant to DNase treatment. This was further confirmed by the presence of DNA in purified curli fibers, which were treated twice with DNase and RNase. Polymerization assays showed acceleration of amyloid polymerization in the presence of DNA from both bacteria and salmon sperm. CLSM of bone marrow derived dendritic cells demonstrated that DCs are able to sample antigens from biofilms. BMDCs also produced robust quantities of proinflammatory cytokines in response to wild type, msbB, and ΔfliCfljB S. Typhimurium biofilms and purified amyloid/DNA composites as measured by ELISA. Using BMDCs deficient in TLR2 and TLR9, we found that this cytokine production was partially dependent on TLR2, but did not require TLR9. Together, these findings significantly broaden our understanding of S. Typhimurium biofilms and the immune response to ECM components present in its biofilms. We now understand that a trimolecular complex of TLR2/TLR1/CD14 is required for full response to curli by innate immune cells. We also discerned that interactions between biofilm components aid biofilm development and create composites that are highly immunogenic. This new information enhances the need to explore the interaction between composite ligands and the immune system rather than only studying ligands individually.
Temple University--Theses
Apel, Falko. « Recognition of Neutrophil Extracellular Traps by the Cytosolic DNA Sensor cGAS ». Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/19727.
Texte intégralThe first line of cellular defense of the immune system are neutrophils. They are the most abundant white blood cell, which exert an array of antimicrobial effector functions. Neutrophils release neutrophil extracellular traps (NETs), a composite of chromatin and antimicrobial molecules, into the extracellular space during a form of regulated cell death called NETosis. Their net-like structure prevent further dissemination of the invader and establishes a high local concentration of toxic molecules that mediate pathogen killing. NETs provide a platform for undesired immune activation and contribute to the production of autoantibodies and pro-inflammatory cytokines. NETs are implicated in a growing list of inflammatory and autoimmune diseases, but the exact mechanism how NETs are recognized by the immune system is not fully understood. In this study, I demonstrate that the cytosolic DNA sensor cyclic GMP-AMP synthase (cGAS) senses NETs and induces the production of type I interferons (TIIFN). I first showed that NETs are recognized by recombinant cGAS and that cells treated with isolated NETs produce TIIFN in a cGAS dependent mechanism. Secondly, I demonstrate that neutrophils undergoing NETosis are taken up by neighboring immune cells and induce cGAS-dependent TIIFN expression. Lastly, I confirmed our in vitro results in a mouse model of systemic NET induction. Wildtype mice injected with Concanavalin A significantly upregulate the expression of interferon stimulated genes, while cGAS-/- mice and Cybb-/- mice, which are incapable of producing NETs, fail to induce this response.
Lawler, Danielle Suzanne. « The role of respiratory viral infection and extracellular DNA in allergic sensitisation ». Thesis, Lawler, Danielle Suzanne (2018) The role of respiratory viral infection and extracellular DNA in allergic sensitisation. Honours thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/43144/.
Texte intégralChambard, Marie. « Analyse génomique de l'ADN extracellulaire du Root Extracellular Trap (RET) et caractérisations omiques des "root Associated Cap-Devrived Cells" (AC-DC) chez le soja Glycine max (L.) Merr.1917 ». Thesis, Normandie, 2020. http://www.theses.fr/2020NORMR020.
Texte intégralSoybean, a crop of Normand and world agronomic interest, is threatened by numerous phytopathogens like the oomycete Phytophthora sojae Kaufm. & Gerd., wich generate high levels of economical losses. The RET (root extracellular trap) is located at the root apex and is composed of border cells or AC-DC (root associated cap-derived cells) and their mucilage. This mucilage is made up of glycomolecules, proteins or also extracellular DNA (exDNA). The RET play a role in root protection against biotic stresses. In order to better understand the role of the RET in root protection, a transcriptomic and a proteomic analysis where done on AC-DC and roots in controle condition and in elicited condition with PEP-13 (an elicitor from Phytophthora sp.). The results show a specificity of AC-DC compared to the root, and an answer to PEP-13 wich seems to be different between these two tissues. An other experiment was to sequence RET exDNA in controle and elicited conditions, in order to define the origin of this exDNA. We show that the coverage of mitochondrial and plastidial DNA where much better than the coverage of chromosomic DNA. It could mean that chromosomic DNA isn’t conserved as well as organelles DNA, or exDNA could originate from organelles. Furthermore, results seems to show no differences between the sequences of elicited or control exDNA
Finke, Alexander [Verfasser]. « Development of DNA-Based Materials as Mimicry of the Extracellular Matrix / Alexander Finke ». Konstanz : KOPS Universität Konstanz, 2019. http://d-nb.info/1183573391/34.
Texte intégralWen, Fushi. « Root Border Cell Development and Functions of Extracellular Proteins and DNA in Fungal Resistance at the Root Tip ». Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195136.
Texte intégralPeters, Dimetrie Leslie. « Evaluation of eukaryotic cultured cells as a model to study extracellular DNA / D.L. Peters ». Thesis, North-West University, 2011. http://hdl.handle.net/10394/6929.
Texte intégralThesis (M.Sc. (Biochemistry))--North-West University, Potchefstroom Campus, 2011.
Moulière, Florent. « Etude de la structure et de l'origine des ADN circulants : application à la mise au point d'un test de détection des mutations KRAS et BRAF dans le cancer colorectal ». Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20245/document.
Texte intégralCell-free circulating DNA (cfDNA) are considered as potentials non invasive biomarkers of tumor progression. They present the advantage to exhibit the genetic alterations from their tumor of origin. Knowledge on the forms, mechanism of release, and biological effect of cfDNA are however still less characterized. We have hypothesized that focalizing on the study of cfDNA structure and origin will open new perspectives of application in personalized genomic. Our works demonstrated, with an animal model, that cfDNA from colorectal cancer tumor are highly fragmented at size lower than 145 bp. This observation was confirmed on human plasma with AFM by realizing the first direct picture of tumor-derived cfDNA. We have determined that cfDNA proportion highly varied in bloodstream, but more than a third of individual exhibit proportions larger than 25 % of blood total cfDNA.These discoveries let us participate to the development of a specific analysis method of plasma cfDNA owing to determinate by Q-PCR the cfDNA concentration, its fragmentation and the presence of KRAS and BRAF mutation. This method has been clinically validated on 79 samples of metastatic colorectal cancer patients by comparing it, with a concordance of 96 %, with the technique of reference using DNA from tumoral tissue.cfDNA could be used as « liquid biospy » and could be a central biomarker in the personalized genomic for the future years, and this thesis work participate to the development of this new approach
Silva, Eliane Pereira da. « Influência da temperatura, de enzimas degradantes de DNA e do sobrenadante de cultura de estafilococos na formação de biofilme por Listeria monocytogenes em superfície abiótica ». Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/60/60135/tde-19122013-103644/.
Texte intégralListeriosis is a rare and serious mainly food-borne infection. It is caused by the bacterium Listeria monocytogenes that primarily affects pregnant women and immunologically compromised individuals. This pathogen is recognized as a problem for the food industry due to its ability to form biofilms. Biofilms are microbial communities adhered to biotic or abiotic surfaces embebed by self produced extracellular polymers. These structures are resistant to cleaning and disinfection procedures, allowing the survival and persistence of L. monocytogenes in food processing environments. Thus, several strategies have been adopted to prevent and control the formation of biofilms on food contact surfaces. The present study investigated biofilm formation by L. monocytogenes on abiotic surface at different temperatures, in the presence of DNA degrading enzymes (DNAses) and in the presence of culture supernatant with and without staphylococcal thermonuclease activity. For this purpose, we used culture techniques and microscopy. The results showed that L. monocytogenes was able to adhere on stainless steel surface on average 105-106 CFU per cm2. The different incubation temperatures affected the adhesion of L. monocytogenes on stainless steel surface, although other factors in combination were also involved, such as the bacterial strain and the type of system used for assay. By fluorescence microscopy, we noticed the formation of mature biofilms by L. monocytogenes, with channels likely involved in flow of nutrients and holes typical of cell dispersion. Furthermore, we found a predominance of metabolically active cells surrounded by extracellular matrix polymer containing extracellular DNA (eDNA) stained with acridin orange. By laser confocal microscopy, we observed the formation of microcolonies containing eDNA and homogeneous thin layer of viable cells stained with SYTO 9 and DDAO. The eDNA was also observed in locations with absence of cells characteristics of cell dispersion. The culture supernatant of S. aureus with thermonuclease activity was able to inhibit L. monocytogenes free on culture medium and interfered with the formation of biofilm by the pathogen for up to 24h at 37°C. The commercial DNAses did not affect biofilm formation by L. monocytogenes, possibly excluding the action of thermonuclease of S. aureus on the inhibition of planktonic or sessile forms of L. monocytogenes. It has been found a production of a thermostable protein by S. aureus and it was able to inhibit L. monocytogenes in agar antagonism assays but further studies are needed to characterize such inhibitory substance.
Cioccoloni, Andrea. « Pro-inflammatory effect of extracellular vesicles released by senescent-like C2C12 ». Doctoral thesis, Urbino, 2021. http://hdl.handle.net/11576/2688889.
Texte intégralBrundin, Malin. « Stability of bacterial DNA in relation to microbial detection in teeth ». Doctoral thesis, Umeå universitet, Institutionen för odontologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-82735.
Texte intégralMavropalias, Georgios. « Muscle damage and adaptations induced by eccentric cycling in relation to extracellular matrix ». Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2020. https://ro.ecu.edu.au/theses/2336.
Texte intégralLiu, Yang. « Transcriptioal [sic] and post-transcriptional regulation of extracellular enzyme production in Erwinia carotovora subsp. Carotovora / ». free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9999305.
Texte intégralTanos, Rita. « Développement de tests diagnostiques par détection d'ADN extracellulaire ». Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTT054.
Texte intégralAfter its discovery in 1948, circulating DNA (cirDNA) was studied in various fields. It has become an emerging biomarker, particularly in oncology, and several studies have recently sought to investigate its interest in cancer screening and early detection. The first part of my thesis was devoted to the study of the quantitative and structural characteristics of cirDNA, taking into account its origin (nuclear and mitochondrial cirDNA) and its structure (fragmentation and size profile), for the screening and early detection of cancer. Two cirDNA parameters, the Ref A 67 (total nuclear cirDNA concentration) and the MNR (Mitochondrial to Nuclear Ratio), were quantified by q-PCR in a mouse model and further validated in cell culture media to assess their potential to discriminate between a healthy and a cancerous state. These two variables were evaluated by taking into account other quantitative and structural parameters of cirDNA, after age adjustment, in the plasma of 289 healthy individuals, 99 individuals at risk of colorectal cancer (CRC) and 983 patients with CRC (n = 791), breast cancer (n = 169) and other cancers (hepatocellular, pancreatic, ovarian and lymphoma) (n = 23). Through a machine learning approach, we combined these different parameters into a prediction model using decision trees for the classification of healthy and cancer patients. We have obtained very encouraging results, especially for early-stage cancers. This method seems promising for early and non-invasive cancer detection. The addition of other biomarkers such as the size profile of the cirDNA or the detection of methylation markers could further increase its potential.The second part of my thesis was devoted to the study of the relationship between the quantity of extracellular DNA of nuclear and mitochondrial origin in the embryo culture medium, and the quality of these embryos during in vitro fertilization (IVF). It has been shown that an embryo releases extracellular DNA into the culture medium during IVF, and that this DNA could be a predictive biomarker of embryo quality and thus be used as a non-invasive preimplantation genetic test (PGT). We detected, as well, the SRY gene in the culture medium to determine the sex of the embryo, which is an important information in the case of gender-related genetic disorders. We also tried to detect the presence of the Delta F508 mutation of the CFTR gene responsible for cystic fibrosis, by analyzing extracellular DNA from high-risk embryos to assess its potential as a non-invasive PGT
Strachan, Sarah [Verfasser], et Dirk [Akademischer Betreuer] Reinhardt. « Investigating the biomarker potential of extracellular vesicle nucleic acids in cancer, and the role of extracellular vesicle DNA in cell-to-cell communication / Sarah Strachan ; Betreuer : Dirk Reinhardt ». Duisburg, 2021. http://d-nb.info/1228270414/34.
Texte intégralGRISTINA, Valerio. « Circulating cell-free DNA (cfDNA) and extracellular vesicles (EVs) as prognostic and predictive biomarkers in patients with advanced Non-Small Cell Lung Cancer (NSCLC) : the LEXOVE prospective study ». Doctoral thesis, Università degli Studi di Palermo, 2022. https://hdl.handle.net/10447/571952.
Texte intégralMuthukrishnan, Uma. « The release of histone proteins from cells via extracellular vesicles ». Licentiate thesis, Umeå universitet, Umeå centrum för molekylär medicin (UCMM), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-147409.
Texte intégralEhrens, Alexandra [Verfasser]. « Eosinophil Extracellular DNA Trap Cell Death (EETosis) occurs as a life-cycle stage-specific response to filariae / Alexandra Ehrens ». Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1239729839/34.
Texte intégralDubash, Adi Dara Burridge Keith. « Regulation of RhoA GTPase signaling by guanine nucleotide exchange factors in response to extracellular matrix adhesion and DNA damage ». Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2009. http://dc.lib.unc.edu/u?/etd,2407.
Texte intégralTitle from electronic title page (viewed Sep. 3, 2009). "... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Cell and Developmental Biology within the School of Medicine." Discipline: Cell and Developmental Biology; Department/School: Medicine.
Apel, Falko [Verfasser], Arturo [Gutachter] Zychlinsky, Klaus [Gutachter] Osterrieder et Benedikt [Gutachter] Beckmann. « Recognition of Neutrophil Extracellular Traps by the Cytosolic DNA Sensor cGAS / Falko Apel ; Gutachter : Arturo Zychlinsky, Klaus Osterrieder, Benedikt Beckmann ». Berlin : Humboldt-Universität zu Berlin, 2019. http://d-nb.info/1182541429/34.
Texte intégralVan, Andre P. « Characterisation of chromatin extracellular traps in rainbow trout (Oncorhynchus mykiss) ». Thesis, University of Stirling, 2018. http://hdl.handle.net/1893/27930.
Texte intégralSusin, Michelle Fernanda. « Análise funcional das proteínas HrcA, GroES/GroEL e DnaK/DnaJ em Caulobacter crescentus ». Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-14062016-171416/.
Texte intégralIn Caulobacter crescentus, the groESL operon presents a dual type of control. Heat shock induction of the operon is dependent on the heat shock sigma factor σ-32. At physiological temperatures, groESL expression is cell cycle regulated and the control involves the repressor protein HrcA and the element CIRCE (controlling inverted repeat of chaperonin ~xpression). To study the activity of HrcA in vitro, we produced and purified from E. coli a histidine-tagged version of the protein, and specific binding to the CIRCE element was analyzed in electrophoretic mobility shift assays (EMSA). The amount of retarded DNA increased significantly in the presence of GroES/GroEL, suggesting that these proteins modulate HrcA activity. Further evidence of this modulation was obtained using lacZ transcription fusions with the groESL regulatory region in C. crescentus cells producing different amounts of GroES/GroEL. The mutants proteins HrcA Pro81Ala and HrcA Arg87Ala, that contain amino acid substitutions in the putative DNA-bindíng domain of the protein, were found to be deficient in binding to CIRCE in vitro and in vivo. Furthermore, HrcA Ser56Ala expressed together with the wild type protein within the same cell, produced a dominant-negative phenotype, indicating that C. crescentus HrcA binds to CIRCE in an oligomeric form, most likely as a dimer. Attempts to obtain null mutants for groESL or dnaKJ were unsuccessful indicating the importance of GroES/GroEL and DnaK/lDnaJ to the survival of C. crescentus cells. Conditional mutants were then constructed in our laboratory in which groESL and dnaKJ expression is under the control ofaxylose inducible promoter (PxyIX) , giving rise to strains SG300 and SG400, respectively. These strains were characterized in regard to their morphology under permissive and restrictive conditions, as well as their viability under different types of environmental stresses. SG300 cells depleted of GroES/GroEL are resistant to heat shock at 42°C and can acquire some thermotolerance, but they are sensitive to oxidative, saline and osmotic stresses. SG400 cells depleted of DnaKlJ are quite sensitive to heat shock, ethanol and freezing, and are unable of acquiring thermotolerance. Cells depleted of either GroES/EL or DnaKlJ also present morphological problems. SG300 cells depleted of GroES/EL form long and pinched filaments. SG400 cells depleted of DnaKlJ are only somewhat more elongated than wild-type predivisional cells and most cells do not present septum. These observations indicate a cell division arrest, which should occur at different stages in each strain.
Shi, Chongxu [Verfasser], et Hans-Joachim [Akademischer Betreuer] Anders. « Extracellular DNA contributes to cholesterol crystal embolism-induced clot formation, acute kidney injury, and tissue infarction / Chongxu Shi ; Betreuer : Hans-Joachim Anders ». München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2021. http://d-nb.info/1233600680/34.
Texte intégralSun, Wenchao. « DNA Nanoparticles for Non-viral Gene Therapy : Mechanistic Studies and Targeting ». Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1327614453.
Texte intégralCui, Kui, Christopher Ardell, Nataly Podolnikova et Valentin Yakubenko. « The prevention of αDβ2-mediated macrophage adhesion to inflamed extracellular matrix thwarts macrophage retention during chronic inflammation ». Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/210.
Texte intégralBinnenkade, Lucas [Verfasser], et Kai [Akademischer Betreuer] Thormann. « Molecular Control of Extracellular DNA Release and Degradation in Shewanella oneidensis MR-1 Biofilms : The Role of Phages and Nucleases / Lucas Binnenkade. Betreuer : Kai Thormann ». Marburg : Philipps-Universität Marburg, 2015. http://d-nb.info/1080299068/34.
Texte intégralSchuster, Anna-Kathrin [Verfasser], Ulrich [Akademischer Betreuer] Szewzyk, Ulrich [Gutachter] Szewzyk et Isolde [Gutachter] Röske. « Production of extracellular DNA (eDNA) of the γ-Proteobacterium Rheinheimera sp. F8 in biofilms / Anna-Kathrin Schuster ; Gutachter : Ulrich Szewzyk, Isolde Röske ; Betreuer : Ulrich Szewzyk ». Berlin : Technische Universität Berlin, 2017. http://d-nb.info/1156184126/34.
Texte intégralKoenig, Michael J. « LKB1 Loss in Lung Adenocarcinoma ». The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555503848137523.
Texte intégralKeup, Corinna [Verfasser], et Sabine [Akademischer Betreuer] Kasimir-Bauer. « Comprehensive molecular characterization of circulating tumor cells, extracellular vesicles and cell-free DNA as matched multi-parametric liquid biopsy for therapy management in metastatic breast cancer patients / Corinna Keup ; Betreuer : Sabine Kasimir-Bauer ». Duisburg, 2020. http://d-nb.info/1221960350/34.
Texte intégralVaubourg, Camille. « Développement de nouvelles approches thérapeutiques pour la dystrophie musculaire de Duchenne, basées sur l'utilisation de vésicules extracellulaires Minimal Consequences of CMAH and DBA/2J Background on a FKRP Deficient Model ». Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL012.
Texte intégralDuchenne muscular dystrophy is a rare genetic disease caused by mutations in the DMD gene, coding for dystrophin, affecting skeletal, cardiac and respiratory muscles. Patients show a dystrophic phenotype reducing their mobility and life span. Today, no cure is available for all patients. This thesis work aimed to develop new therapeutic approaches based on the use of extracellular vesicles (EVs), particles of 40-500 nm of diameter secreted by the majority of cell types and playing a role in intercellular communication by transferring biomolecules. The EVs are more and more studied as new non-viral delivery system of therapeutic molecules as they present a number of advantages: biocompatibility, low immunogenicity, ability to modulate some signalling pathways, the possibility to load them with different kind of molecules and to target them to tissues of interest. In this work, we were interested in the vectorization, by mesenchymal stem cells (MSCs)-derived EVs, of two molecules acting on main pathways of the dystrophic process (Smad7 and siRNA against NF-kB) as well as the nuclease of the CRISPR/Cas9 system for acting on dystrophin expression. Before the development of Smad7 vectorization by EVs, its therapeutic potential have been evaluated by AAV gene transfer. An increase of the muscle mass without any reduction of the fibrosis level has been observed. In parallel, EVs production, isolation and characterization protocols have been set up and validated. The effect of MSCs-derived EVs on dystrophic process have been assessed and showed an impact on regulatory elements as microRNA. Also, the loading of siRNA in EVs have been initiated and the one of the spCas9 have been validated. The in vitro transfer of the last one have also been validated, but its functionality has to be confirmed
Malmlöf, Maria. « Mdm2 phosphorylations : characterization and applications / ». Stockholm : Karolinska institutet, 2007. http://diss.kib.ki.se/2007/978-91-7357-265-1/.
Texte intégralAl-Maalouf, Samar Wadih. « Exploration of a mammary epithelial cell model for the study of epithelial inflammation and mechanisms of anti-inflammatory activity in medicinal plants ». Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1166806742.
Texte intégralBustos, Silvina Odete. « Resposta celular associada à expressão de galectina-3 em linhagens de melanoma expostas a irradiação ». Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/5/5155/tde-21052014-110608/.
Texte intégralSkin cancer is the most common cancer among humans, melanoma being the least common type but very important due to its aggressive behavior. A major etiologic agent of this type of tumor is ultraviolet radiation from the sunlight. The ultraviolet B rays (UVB) cause DNA damage and induce alterations over the skin cells after prolonged exposition without protection. The UVB response in melanocytes and melanoma cells is different. This shows the importance of the cellular profile. The genotoxic effect of UVB light can alter the expression of molecules such as galectine-3 and MAPKs and also triggers multiple responses UVB-dependent. Galectin-3 is a lectin that recognizes beta-galactosides. It is involved in the regulation of many cellular processes that modify cellular viability and proliferation and presents specific behavior depending on its subcellular localization. In the present study we showed that galectine-3 distribution in melanoma cells and melanocytes is large, lying both in the nucleus and in the cytoplasm. After UVB irradiation this distribution could be modified or even galactine-3 secreted itself into the extracellular space. Moreover, we observed that UVB light activates the mitogen-activated protein kinase pathway (MAPK) involved in growth, survival, differentiation and stress-response in melanocytes and in melanoma cells just a few minutes after exposure. An increased activity of p38 and ERK was observed in melanomas, while in melanocytes just p38 pathway was highly active, supporting the notion that the cellular response to UVB light differs between melanocytes and melanoma cells. The molecules p38 and JNK are stress-activated protein kinases (SAPK). The JNK pathway is not responsive in some melanoma cells, but the activation of this molecule appears to be involved in cell survival and mitochondrial translocation after being exposed to UVB. Inhibition of JNK leads to increased cell death in irradiated and non-irradiated melanocytic lineage, but in melanoma cells induces cell death and increased autophagy only after irradiation. This molecule seems to interact with galectin-3 in mouse models but not in human melanomas, whereas ERK physically interacts with galectin-3 in human melanocytes and melanoma cells, regardless of UVB exposure. Through the knockdown of galectin-3 by siRNA, we showed increased activation of the ERK and its downstream pathway after irradiation, thus inducing cell proliferation. In melanocytes seems to be a negative regulation of the ERK pathway by galectin-3 accompanied by a decrease in cell viability after its knockdown regardless of UVB exposure. These results show that galectin-3 is an important regulatory molecule of events associated with cell death and survival in melanoma, which has different behavior depending on the cell type
PIETRAMELLARA, GIACOMO. « Fenomeni di scambio genetico nel suolo : Interazioni tra DNA batterico extracellulare e minerali argillosi ». Doctoral thesis, 1996. http://hdl.handle.net/2158/676453.
Texte intégralMantilla, Calderon David. « Antibiotic resistance genes and antibiotic resistant bacteria as emerging contaminants in wastewater : fate and persistence in engineered and natural environments ». Diss., 2018. http://hdl.handle.net/10754/631716.
Texte intégralBeauchemin, Karine. « Dissection moléculaire de l’interaction de la DNA topoisomérase I avec la matrice extracellulaire et les fibroblastes ». Thèse, 2009. http://hdl.handle.net/1866/3202.
Texte intégralSystemic sclerosis is an autoimmune disease in which one of the major complications is fibrosis. DNA topoisomerase I (topo) is a major autoantigen associated with this disease. However, no link has yet been established between the presence of anti-topo and the development of fibrosis. Previous work of the host laboratory showed a direct interaction of the topo with the surface of fibroblasts and extracellular matrix. We wanted to characterize these interactions at the molecular level. Topo was expressed in 5 fragments, determined from its main structural domains and its major epitopes, in E. coli. The purified fragments were analyzed for their interaction with heparin, representing heparan sulfates on the surface of fibroblasts, and with purified proteins of the extracellular matrix. We have shown that the topo-N fragment is responsible for interaction with heparin, suggesting hence, potential involvement of this domain in the interaction of topo with the surface of fibroblasts. The topo-DIDII fragment is responsible for the interaction with most proteins of the extracellular matrix studied, whereas the topo-H15 fragment only binds to vitronectin. No interaction of fragments topo-DIII and topo-C was found. These results can now be used to better understand the potential role of topo and circulating anti-topo autoantibodies in the fibrosis present in patients with systemic sclerosis in helping to identify the target of topo on fibroblasts.
LIOU, HENG-YU, et 劉姮妤. « The RNA Contents Of Extracellular Vesicles In HeLa Cells Treated With Polyethyleneimine-DNA Complexes ». Thesis, 2017. http://ndltd.ncl.edu.tw/handle/s4q68g.
Texte intégral嘉南藥理大學
藥學系
105
Poly(ethylenimine) (PEI) is one of the most intensively used cationic polymers in non-viral nucleic acid delivery. Despite of great potentials of the applications in gene delivery systems, PEI has been shown to influence the regulations of gene expression in vitro and in vivo. Previous studies on PEI-induced gene regulation have primarily been based on encoding mRNAs that are translated into proteins. However, recent studies have demonstrated that non-coding RNAs are closely related to complex cellular development systems and various human diseases. Among these non-coding RNAs, microRNAs (miRNAs) are approximately 22 nucleotides long and primarily play important roles in the post-transcriptional regulation of gene expression, making them potential targets for therapeutic applications. Therefore, we explored the regulated miRNAs and identified their target genes in PEI-treated mouse embryonic fibroblast cells. The pathway analysis of target genes was performed using DIANA miRPath v.3.0, which is based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Our study may provide a deeper insight into the molecular pathways in cells caused by PEI.
Madeira, Catarina Alexandra Catanas. « Activity of the major autolysin of Staphylococcus aureus Atl in the presence of extracellular DNA ». Master's thesis, 2018. http://hdl.handle.net/10362/53142.
Texte intégral« Discovery of an extracellular stress sensory protein in Beauveria bassiana and identification of photolyase encoding phr-1 sequences in five entomopathogenic fungi ». Thesis, 2013. http://hdl.handle.net/10388/ETD-2013-08-1210.
Texte intégralMedapati, Manoj Reddy. « Extracellular S100A4 induces human thyroid cancer cell migration ». 2013. http://hdl.handle.net/1993/22120.
Texte intégralHsu, Chi Yu, et 徐啟育. « Vancomycin Promotes the Bacterial Autolysis, Release of Extracellular DNA, and Biofilm Formation in Vancomycin-non-Susceptible Staphylococcus aureus ». Thesis, 2012. http://ndltd.ncl.edu.tw/handle/16108511334120609795.
Texte intégral長庚大學
醫學生物技術暨檢驗學系
100
Staphylococcus aureus, an important human pathogen, is particularly adept at producing biofilms on implanted medical devices. Although antibiotic treatment of non-susceptible bacteria will not kill these strains, the consequences should be studied. The present study focuses on investigating the effect of vancomycin on biofilm formation by vancomycin-non-susceptible S. aureus. Biofilm adherence assays and scanning electron microscopy demonstrated that biofilm formation was significantly enhanced following vancomycin treatment. Bacterial autolysis of some subpopulations was observed and was confirmed by the live/dead staining and confocal laser scanning microscopy (CLSM). A significant increase in polysaccharide intercellular adhesin (PIA) production was observed by measuring icaA transcript levels and in a semi-quantitative PIA assay in one resistant strain. We show that the release of extracellular DNA (eDNA) via cidA-mediated autolysis is a major contributor to vancomycin-enhanced biofilm formation. The addition of xenogeneic DNA could also significantly enhance biofilm formation by a PIA-overproducing S. aureus strain. The magnitude of the development of the biofilm depends on the balance between the amounts of eDNA and PIA. In conclusion, sublethal doses of cell wall-active antibiotics like vancomycin induce biofilm formation through an autolysis-dependent mechanism in vancomycin-non-susceptible S. aureus.
Sanchez, Torres Viviana. « Escherichia coli Enhanced Hydrogen Production, Genome-wide Screening for Extracellular DNA, and Influence of GGDEF Proteins on Early Biofilm Formation ». Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8889.
Texte intégralBeckett, Emma Louise. « Folate and vitamin D : the role of nutritional status and nutrigenetics in predicting levels of extracellular microRNA and circulating DNA methylation status ». Thesis, 2016. http://hdl.handle.net/1959.13/1316824.
Texte intégralmicroRNA (miRNA) in systemic circulation are proposed as potential biomarkers for disease diagnosis and prognosis. However, miRNA profiles may also be modulated by other exposures such as nutritional status, and this may have consequences for use of miRNA as biomarkers, particularly in diseases for which diet is a modifiable determinant. Furthermore, little is known about the interactions that exist between these relationships and underlying variance in genes related to the processing of nutrients that may influence these relationships, or how these miRNA interact with other modifiers of gene expression, such as DNA methylation. This thesis focuses on folate and vitamin D, two key micronutrients known to have the potential to influence gene expression. The data presented here investigates the relationships between these micronutrients and related nutrigenetics in predicting levels of extracellular miRNA and circulating DNA methylation status. The studies presented here were designed to capitalise on the availability of two well-characterised human cohorts; a case-control cohort of adenomatous polyp patients and healthy controls (n=263), and an elderly cross-sectional cohort (n=649). These are appropriate cohorts in which to investigate these relationships, as systemic circulating miRNA have been proposed as biomarkers for adenomatous polyps and colorectal cancer (CRC), diseases with known dietary modifiers of risk (including folate and vitamin D) which accumulate over a lifetime of exposures. Four candidate miRNA (let-7a, miR-15a, miR-21 and miR-155) were selected due to a combination of factors; each has known oncogenic or tumour-suppressor properties and each had existing evidence to suggest potential regulation by nutritional factors. The first results chapter (Chapter 2) presents novel observations on the levels of systemic circulating levels of let-7a, miR-15a and miR-155 in adenomatous polyp cases relative to controls. Furthermore, by adding a sex specific level of analysis, it adds to the body of knowledge surrounding these miRNA and miR-21, which is currently proposed as a biomarker for adenomatous polyps. Novel data on the correlations between blood levels of folate and related micronutrients and the candidate miRNA are presented, with key findings including a positive correlation between red blood cell folate levels and all candidate miRNA, regardless of their tumour-suppressor or oncogenic properties. Stepwise regression analyses investigating the correlations between systemic circulating miRNA levels and multiple dietary intakes, including vitamin D, are also presented. Chapter 3 builds upon these results by incorporating common folate and vitamin D related genetic polymorphisms into the analyses. The relationships between these polymorphisms, systemic circulating miRNA levels, and risk for adenomatous polyps were assessed, as well as interactions with nutrient status. Statistically significant relationships were identified between multiple polymorphisms and risk for adenomatous polyps, and miRNA levels, as well as potential interactions between folate status and genotype in predicting miRNA levels. These are the first reported observations of the potential relationships and interactions between miRNA profiles and nutrigenetic variance. As the human cohorts used can only demonstrate correlation and not causation, Chapter 4 contains data obtained from cell culture models. Three CRC cell lines were used to demonstrate that miRNA are differentially expressed intracellularly and extracellularly under folate excess or deficient conditions, and following stimulation with the active vitamin D metabolite. Treatment with a DNA demethylating agent was also used to demonstrate that some of these processes are dependent on DNA methylation. The relationships between vitamin D and DNA methylation were further investigated in Chapter 5. A sub-cohort was used to conduct a pilot study investigating the relationships between vitamin D status, methyl donor-related micronutrients and DNA methylation in genes of vitamin D metabolism. The relationship between methylation status in this pathway and the systemic circulating levels of the candidate miRNA were also assessed, and provides new information demonstrating the potential complexity of the complementary pathways for the regulation of cellular processes and pathways. Together, the data in this thesis constitute a significant contribution to the body of knowledge surrounding the extracellular levels of miRNA, and how this may relate to vitamin D and folate status, related polymorphisms, DNA methylation, and intracellular miRNA expression levels. Relationships were identified between folate status, nutrient intake and systemic circulating levels of multiple candidate miRNA. Relationships identified between polymorphisms in related genes and systemic circulating miRNA levels support these observations, and these observations may link dietary factors to modified risk for disease. This thesis expands our understanding of how nutrition and nutrigenetics can interact to modify nutrigenomics and disease risk. The data presented here for the candidate miRNA and two key nutrients, provides an impetus to investigate these relationships for other nutrients and miRNA, particularly those known to modify disease risk. These results have implications for the use of systemic circulating miRNA as biomarkers, and may also have implications for the future of personalised nutrition and personalised medicine.