Дисертації з теми "Médecine fonctionnelle de précision"
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Boilève, Alice. "La médecine de précision dans le cancer du pancréas." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASL013.
Pancreatic ductal adenocarcinoma (PDAC) is an increasingly common cancer with limited therapeutic options and a poor prognosis. Conventional chemotherapies have limited efficacy, emphasizing the need for new therapeutic approaches. Genomic precision medicine, made possible by advances in high-throughput sequencing technologies, has seen significant development in oncology over the past decade. However, the utility of molecular profiling in PDAC has not yet been established, despite improved overall survival when patients receive molecularly matched treatment. Functional precision medicine (FPM) is another promising strategy that relies on testing a panel of drugs on live tumor cells to identify the sensitivity and resistance profile of each tumor. Organoids are robust and promising tools for assessing a specific tumor's sensitivity to various drugs and identifying the best therapeutic option for each patient.Three axes were developed in this thesis. First, a translational axis evaluated the impact of organoids as tools for functional precision medicine in pancreatic cancer. The primary objective of this project was to establish a framework for integrating organoid-based drug sensitivity testing into the clinical management of PDAC patients. Organoid responses to a panel of anticancer drugs were correlated with clinical responses in patients, suggesting potential clinical benefits. Additionally, the contribution of organoids to preclinical studies was tested by assessing the efficacy of a KRASG12D inhibitor, MRTX1133, in monotherapy and in combination with other inhibitors. The combination of MRTX1133 and anti-EGFR proved to be the most promising.Secondly, a clinical axis assessed the impact of KRAS mutation in PDAC in terms of clinical and molecular characteristics, treatment response, and prognosis, particularly in cases where targeted treatment was received. Comparing non-mutated KRAS tumors to mutated KRAS tumors revealed clinical differences and better prognosis for non-mutated tumors. Furthermore, the impact of different KRAS mutated codons was studied by comparing KRASG12 mutated tumors versus other KRAS mutations. KRASG12 mutations were associated with a worse prognosis, although there was no difference in treatment sensitivity.Finally, a fundamental axis investigated the invasive phenotype of PDAC. A new "onco-morphogenetic" program was identified as a mediator of metastatic dissemination in colorectal cancers (CRC) through TSIPs (tumor spheres with reversed polarity, malignant tumor intermediates). The presence of TSIPs in pancreatic cancers was confirmed, and their transcriptional program and chemosensitivity were characterized using organoids. However, the clinical and prognostic impact of TSIP presence in pancreatic cancer appears to be minor.In conclusion, this doctoral project aimed to develop a comprehensive framework for the use of PDOs as a tool for modeling PDAC (fundamental axis), selecting personalized treatments, and conducting preclinical drug tests (translational and clinical axes). By bridging the gap between preclinical trials and clinical practice, this project aims to bring us closer to precision medicine in managing PDAC
Morice, Pierre-Marie. "Evaluation de la déficience de la recombinaison homologue et de la réponse des tumeurs ovariennes aux inhibiteurs de PARP grâce à l'utilisation de modèles de culture 3D en vue du développement d'un test prédictif Identifying eligible patients to PARP inhibitors: from NGS-based tests to promising 3D functional assays Automated scoring for assessment of RAD51-mediated homologous recombination in patient-derived tumor organoids of ovarian cancers Risk of myelodysplastic syndrome and acute myeloid leukemia related to PARP inhibitors: a combined approach using a safety meta-analysis of placebo randomized controlled trials and the World Health Organization's pharmacovigilance database The long non-coding RNA ‘UCA1’ modulates the response to chemotherapy of ovarian cancer through direct binding to miR-27a-5p and control of UBE2N levels." Thesis, Normandie, 2020. http://www.theses.fr/2020NORMC414.
Worldwide each year, more than 150 000 women die from epithelial ovarian cancer largely due to emergence of resistance to chemotherapy. Approximately half of these cancers display molecular alterations that cause deficiency of DNA repair via homologous recombination (HRD), which confer sensitivity to PARP protein inhibitors (PARPi). To date, there is no test capable of fully identifying the HRD phenotype, thus limiting access to these treatments. In this context, we are developing functional assays based on the use of tumor explant slices and then, on the use of tumor organoids derived from ovarian tumors of chemotherapy-naive or previously treated patients. The culture of explants was unsuitable for this application and we then focused our work on tumor organoids. Tumor organoids were exposed to carboplatin (first-line treatment) and two PARP inhibitors (olaparib and niraparib) used for maintenance therapy. In parallel, we collected clinical data from patients (survival, platinum-free interval, RECIST, treatments) to evaluate the predictive potential of these models. The established tumor organoids responded heterogeneously to different drugs, and our results show that the organoid-based assay is capable of identifying patients highly resistant to carboplatin, suggesting that this functional assay could have a predictive value for patients treated with carboplatin. Regarding the potential of organoids in predicting PARPi response, multiple sensitivity profiles have been identified, but the correlation with clinical response has yet to be determined by studies conducted on tumor samples from patients treated with these drugs
Folon, Lise. "Étude de l'impact des variants génétiques rares sur l'obésité monogénique." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. https://pepite-depot.univ-lille.fr/ToutIDP/EDBSL/2023/2023ULILS059.pdf.
Obesity is a complex multifactorial disease with a strong genetic component. Unlike common obesity, which is a polygenic disease, monogenic forms of obesity are caused by a single rare genetic variant with a strong and deleterious effect. These monogenic forms are rare, early-onset and generally very severe, affecting around 5% of individuals with obesity. Most rare mutations associated with monogenic obesity are found in genes within the leptin-melanocortin pathway, which is crucial for the regulation of food intake. Identifying these genes is crucial for understanding the pathophysiology of obesity and developing new treatments.I initially studied rare heterozygous variants of the PCSK1 gene, which encodes the prohormone convertase 1 (PC1/3) enzyme. PC1/3 is involved in the leptin-melanocortin pathway. Biallelic mutations in PCSK1 cause early-onset obesity with severe endocrinopathy. Patients with PCSK1 deficiency (heterozygous or homozygous) can now be treated with setmelanotide injections to promote weight loss. However, the impact of rare heterozygous variants of PCSK1 on obesity and their relevance in precision medicine are still not well-defined. In the RaDiO study, which included 9,320 participants, 65 rare heterozygous variants of PCSK1 were identified and assessed in vitro. These variants were classified into five groups based on the severity of their impact on the enzymatic activity of PC1/3. Association analysis results revealed that rare variants inducing a complete loss of function significantly increased the risk of obesity and body mass index (BMI), whereas variants in other groups with partial or neutral effects on PC1/3 activity had no impact on adiposity. We observed that in silico prediction tools were unreliable in detecting mutations leading to a complete loss of function.Subsequently, I focused on rare variants of the DYRK1B gene. Although this gene is not directly involved in the leptin-melanocortin pathway, pathogenic variants of DYRK1B have been described in several patients with central obesity, type 2 diabetes (T2D), and coronary artery disease. However, the impact of rare DYRK1B variants has not been assessed on a large scale. In the RaDiO study, which included 9,353 participants, 65 rare variants in DYRK1B were detected. Following in vitro analysis of each variant, we identified 20 pathogenic or likely pathogenic variants (P/LP) according to the criteria of the American College of Medical Genetics and Genomics. Among these P/LP variants, six showed an effect leading to a complete loss of function of DYRK1B (P/LP-full). Association analyses showed that P/LP-full variants of DYRK1B were strongly associated with increased BMI and fasting glucose levels, as well as a heightened risk of obesity and T2D, whereas P/LP variants had only a modest effect on adiposity and no impact on glucose homeostasis.In conclusion, the use of functional genetics has demonstrated that only heterozygous variants of PCSK1 and DYRK1B with a complete loss of function cause monogenic obesity. For DYRK1B, obesity is additionally associated with T2D. These results underscore the critical significance of assessing the functional impact of mutations in vitro for genetic diagnosis and the potential selection of appropriate treatments. We have demonstrated that in silico prediction tests are currently not precise enough
Commo, Frederic. "Analyse génomique en médecine de précision : Optimisations et outils de visualisation." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS132/document.
In oncology, a new paradigm tries to impose itself ; analyzing patient’s tumors, and identifying molecular alterations matching with targeted therapies to guide a personalized therapeutic orientation. Here, We discuss the molecular alterations possibly relevant for a therapeutic orientation, as well as the methods used for their identification : among the alterations of interest, copy number variations are widely used, and we more specifically focus on comparative genomic hybridization (aCGH). We show, using well characterized cell lines, that identification of CNV is not trivial. In particular, the choice for centralizing profiles can be critical, and different strategies for adjusting profiles on a theoretical 2n baseline can lead to erroneous interpretations. Next, we show, using tumor samples, that a major consequence is to include, or miss, targetable alterations within the decision procedure. This work lead us to develop a comprehensive workflow, dedicated to aCGH analysis. This workflow supports the major aCGH platforms, ensure a full traceability of the entire process and provides interactive visualization tools to assist the interpretation. This workflow, called rCGH, has been implemented as a R package, and is available on Bioconductor. The interactive visualization tools are available on line, and are ready to be installed on any institutional server
Le, Collen Lauriane. "Médecine de précision du diabète de type 2 et des obésités génétiques." Electronic Thesis or Diss., Université de Lille (2022-....), 2023. http://www.theses.fr/2023ULILS042.
This scientific thesis delves deeply into critical health issues, specifically diabetes, obesity, and rare familial lipodystrophies. These health concerns hold immense importance due to their substantial medical and financial implications, impacting individuals, healthcare systems, and national economies. The central aim of this research was to harness the capabilities of next-generation sequencing (NGS), such as exome sequencing, to detect genetic mutations within genes already associated with these conditions in diagnostically challenging patients. It is now established that up to 2% of cases of type 2 diabetes can be attributed to pathogenic variants in genes related to Maturity-Onset Diabetes of the Young (MODY). This study sought to enhance the diagnostic process and optimize therapeutic management for these complex conditions while demonstrating the effectiveness of the sequencing approach in comprehensive disease management.In a first case, we showcased the significance of this approach by examining a patient with an atypical syndromic form of diabetes. Through in-depth genetic analysis using NGS, we identified a pathogenic heterozygous variant in the WFS1 gene inherited from the diabetic father. This discovery had a profound impact on the patient's treatment, highlighting the effectiveness of GLP1 analog therapy in optimizing diabetes management. Furthermore, our study investigated the impact of a de novo deletion in 16q24.2, which had the potential to affect the regulation of a neighboring gene, FOXC2, implicated in lymphedema-distichiasis syndrome. This case also raised questions about neurodevelopmental disorders, potentially linked to this deletion and a variant located in USP9X inherited from the patient's mother. These results underscore the critical importance of precise diagnosis in selecting appropriate treatments.In a second article, our research focused on the PDX1 gene, responsible for MODY 4, by analyzing heterozygous carriers of pathogenic variants. Our investigations revealed complete penetrance of diabetes, an increase in body mass index, and an elevated risk of pancreatic insufficiency in these individuals. Once again, the judicious use of GLP1 analogs proved beneficial in optimizing glycemic control.Next, we explored the case of a patient suffering from morbid obesity, presenting with combined pituitary deficiency and composite heterozygosity in POMC. This observation challenged the previous notion that heterozygosity in POMC could cause monogenic obesity. This reconsideration raises crucial questions about the effectiveness of targeted treatment with MC4R agonists in POMC heterozygotes, posing significant financial challenges for its use in this indication.Finally, we studied a large family with a severe metabolic syndrome associated with partial lipodystrophy. Genetic analysis revealed a variant in the ZMPSTE24 gene, previously identified in the same geographic region, raising the question of a founder variant. However, the contribution of this heterozygous variant to partial lipodystrophy remains to be confirmed, necessitating further studies to definitively establish its role.In conclusion, this thesis has highlighted the remarkable efficacy of next-generation sequencing in elucidating complex cases of atypical diabetes and obesity, shedding light on monogenic forms of these conditions. Moreover, this research expanded its investigations to the broader population through comprehensive literature reviews and analysis of various databases, including the Human Gene Mutation Database, RaDIO, and UK Biobank. We hope that these compelling results will encourage wider adoption of genetic sequencing, paving the way for increased customization of treatments based on patients' genotypes in the near future
El, Bacha Taib. "Apport des techniques de prototypage rapide pour la validation fonctionnelle des assemblages de précision." Mémoire, Université de Sherbrooke, 2004. http://savoirs.usherbrooke.ca/handle/11143/1226.
Aldrin, Katell. "Analyse biophysique des vésicules extracellulaires pour le diagnostic et la médecine de précision." Electronic Thesis or Diss., Université Grenoble Alpes, 2023. http://www.theses.fr/2023GRALY102.
Over the past few years, nanoparticles have sparked a great interest in the biomedical field. Examples include lipid nanoparticles as drug delivery systems for targeted therapy or biological nanoparticles such as extracellular vesicles, which are released by all human cells. Extracellular vesicles have been shown to be involved in many physiological and pathological mechanisms, demonstrating their strong potential as new biomarkers for the early detection of a number of diseases using liquid biopsy. Precise characterization of such particles is of utmost importance, to ensure quality control of samples dedicated to clinical use, or simply to characterize their biophysical properties (size, density, stiffness, etc.). However, due to their nanometric size and their potential heterogeneity, standard methods are usually not sufficient to characterize properly such particles. Over the past few years, MEMS technologies such as Suspended Microchannel Resonators (SMR) have already proven their potential to characterize precisely microparticles, at a single cell level. Such sensors are composed of a hollow microcantilever beam containing a buried nanofluidic channel, suspended in a vacuum cavity. This configuration allows the fluid to be confined inside the resonator, thus maintaining its mechanical properties and low damping in its environment. As an individual nanoparticle flows through the channel, it induces a transient shift in resonance frequency, which is directly proportional to its buoyant mass. Using fabrication methods derived from microelectronics, microscale dimensions of SMR sensors allows them to weigh single cells or bacteria with a resolution of 1 fg (10^-15 g).The aim of this work is to use a miniaturized version of this technology, called SNR (Suspended Nanochannel Resonators), and to implement it to characterize lipid nanoparticles. Due to the reduced dimensions, it becomes possible to weigh single particles at the attogram scale (10^-18 g), such as 10-15 nm diameter gold nanoparticles. First, a test bench has been developed to conduct gold nanoparticle characterizations using this type of sensors. Then, this method has been challenged to weigh nanoparticles of biological origin, for which an efficient and robust passivation strategy is crucial to prevent non-specific adsorption of the sample to the channel walls. On the other hand, a new type of microfluidic architecture has been explored, containing two cantilevers connected in series, to measure the density of nanoparticles. Lastly, the test bench has been adapted to integrate and characterize miniaturized sensors, showing signs of enhanced sensitivity and a reduced limit of detection. In the future, the building blocks developed during this work could lead to a label-free, multiparametric characterization platform (mass, size, density, stiffness), using this unique technology to perform quality control measurements for bioproduction applications, to provide diagnostic or prognostic information, or to better understand physiological and pathological processes involving extracellular vesicles
Salem, Joe-Élie. "Pharmacologie de précision : approches pour l'évaluation pharmacodynamique et pharmacogénétique de médicaments cardiovasculaires." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066491/document.
Drugs are chemical substances leading to pharmacodynamic responses through interactions with biological systems of variable complexity. For each individual, this response, whether desired or not, is variable and modulated by many parameters including the pharmacokinetic properties of the drug and pathophysiological, genetic and environmental factors. In this thesis, personalized medicine work were conducted to identify sources of variability in individual response to several cardiovascular drugs.In the first part, it is shown that parameters currently used in echocardiography (including E/e') to estimate non-invasively left ventricular filling pressures in patients with decompensated systolic heart failure, in order to guide depletion or filling therapeutics, are not reliable in case of concomitant use of inotropes.The second part details the pharmacodynamics modeling work that identified sources of variability altering the effect of amiodarone on heart rate control in the treatment of supra-ventricular arrhythmias in unstable patients admitted in Intensive Care. Co-administration of magnesium and fluid repletion improved the effectiveness of amiodarone to slow heart rate while the use of dobutamine had an opposite effect.The last part reported the results of a study where 1000 individuals were challenged by a same dose of sotalol in order to perform a genome-wide association study aiming at identifying genetic sources of variability of sotalol induced IKr block ventricular repolarization abnormalities in healthy subjects. Another study evaluating the impact of sex hormones on ventricular repolarization is also detailed
Bertrand, Julien. "Pathologie fonctionnelle en médecine générale : signification et approche relationnelle." Montpellier 1, 2001. http://www.theses.fr/2001MON11002.
Lefort, Sylvain. "Caractérisation fonctionnelle de la protéine K-bZIP de l'herpèsvirus humain 8." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26066/26066.pdf.
Poulin, Jean-François. "Les enképhalines et la réponse au stress:Caractérisation neuroanatomique et fonctionnelle." Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27944/27944.pdf.
Geffard, Estelle. "Développement d’outils de médecine de précision pour accompagner la prise de décision médicale en transplantation." Thesis, Nantes, 2020. http://www.theses.fr/2020NANT1035.
Precision medicine can be defined as a system of care adapted to an individual using population-based data. The aim of this new medicine’s approach is to optimize an individual's medical care by supporting clinicians in their decision-making process using digital applications for example. This work focuses on 2 applications of precision medicine for transplantation to improve patient care. In this context, we built the Easy-HLA web suite to simplify the analysis of HLA genotypes, essential molecules of the immune response. The core of Easy-HLA's algorithms is a database of more than 600,000 HLA haplotypes and their frequencies. We also created KiTapp, an application that improves patient follow-up after kidney transplantation. KiTapp is designed as a decision support tool for clinicians. This tool exploits data from the DIVAT cohort using contextualization algorithms. Easy-HLA and KiTapp allow the systematic representation, comparison and analysis of individual information compared to a similar population. Tomorrow's medicine is moving towards a precision medicine based on realtime analysis of multiparametric data with the patient as the starting point while relying on computational tools that have become essential nowadays
Vikova, Veronika. "Analyses génomiques et épigénomiques pour le développement d’une médecine de précision dans le myélome multiple." Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTT031.
Multiple myeloma (MM) is the second most common hematological malignancy after lymphoma. Recent advances in treatment have led to an overall survival of intensively-treated patients of 6-7 years. However, patients invariably relapse after multiple lines of treatment, with shortened intervals between relapses, and finally become resistant to all treatments, resulting in loss of clinical control over the disease in association with drug resistance. Treatment improvements will come from a better comprehension of tumorigenesis and detailed molecular analyses to develop individualized therapies taking into account the molecular heterogeneity and subclonal evolution. In this purpose, we analyzed the exome, transcriptome and epigenome of primary MM cells from patients and human MM cell lines. Our results have highlighted new mechanisms involved in the pathophysiology of MM as well as potential new therapeutic targets, prognostic signatures and theranostic biomarkers. The data and results of our studies represent an important resource to understand the mechanisms of tumor progression and drug resistance and develop new ways to diagnose and treat patients
Pirotte, Benoît. "Intégration de l'imagerie fonctionnelle dans la neurochirurgie guidée par l'image." Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210818.
Guérette, Dominique. "Analyse phylogénétique et fonctionnelle du domaine HR de la transitine." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24172/24172.pdf.
Merzougui, Aziza. "Étude fonctionnelle de la protéine MRP2." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25917/25917.pdf.
Hébert, Sébastien. "Analyse structurale et fonctionnelle de la préséniline-I humaine : implications dans la maladie d'Alzheimer." Thesis, Université Laval, 2003. http://www.theses.ulaval.ca/2003/21411/21411.pdf.
Potvin, Éric. "Génomique fonctionnelle de Pseudomonas aeruginosa et analyse moléculaire fine d'un facteur sigma-anti-sigma." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24237/24237.pdf.
Pseudomonas aeruginosa is an opportunistic pathogen that can cause pulmonary infections in cystic fibrosis patients (CF). To overcome innate self defense, P. aeruginosa possesses a wide arsenal of virulence factors. These include degradation enzymes such as proteases, lipases and phospholipases and the production of three specific toxins: exotoxin A and exoenzymes S and T. Sequencing of the complete P. aeruginosa chromosome (strain PAO1) of 6.3 Mb revealed a highly regulated and complex genomic organization. In order to better understand host-pathogen molecular interactions, we developped a new signature-tagged mutagenesis (STM) approach based on PCR screening. The PCR-based STM technology lead to the identification of 214 mutants deficient in their ability to maintain a chronic pulmonary infection in the rat lung. In that pool of STM mutants, STM2895, which contains a transposon insertion in functional PA2895, was the most frequently drafted during the whole mutant library screening. Phenotypic analyses of the STM2895 strain allowed us to identify an exoprotease production defect as compared with wild type strain PAO1. The biochemical characterization of that proteolytic default using specific degradation assays combined with western blotting revealed that at least two (LasA and LasB) of the four major exoproteases from P. aeruginosa STM2895 strain are inactive. In fact, LasA and LasB elastases were shown to be present in the STM2895 culture supernatant, correctly processed but inactive due to a probable misfolding of proteins. The PA2895 gene (unknown function) encodes a protein with a predicted transmembrane domain. Basic genomic context analyses strongly suggest a cotranscription unit with the downstream gene PA2896, a putative sigma 70 factor from ECF (extracytoplasmic function) type. Microarray experiments on the STM2895 strain and an insertional mutant of the PA2896 gene were performed to establish a link between the putative PA2895-PA2896 operon and the metabolism of iron. Transcriptome analysis also demonstrated a repressive action of PA2895 on the transcription of PA2896 putative sigma factor. Finally, in vivo studies in the rat lung chronic infection model clearly showed a ten-fold decrease in survival capacity of the mutant strain when compared to the PAO1 wild-type strain.
Ferte, Charles. "Modèles prédictifs utilisant des données moléculaires de haute dimension pour une médecine de précision en oncologie." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA11T101.
The mediocre level of the rates of answers and the improvements of survival when conventional strategies are applied underlines the necessity of developing successful, strong and applicable predictive tools in private hospital. The democratization of the technologies of analyses with top-debit(-flow) is the substratum of the medicine of precision allowing the development of predictive models capable of directing the therapeutic strategies and the definition of a new taxonomy of cancers by the integration of molecular data of high dimension(size).Through this thesis(theory), we analyzed at first public data of genic expression of bronchial cancer not in small cells(units) with the aim of predicting the probability of survival in three years. The strong predictive power of the only TNM and
Bellemare, Véronique. "Caractérisation fonctionnelle de l'enzyme 17 beta-hydroxystéroïde déshydrogénase de type 12." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26543/26543.pdf.
Richard, Karine. "Génomique fonctionnelle in vivo de l'oxydoréductase PA3498 chez Pseudomonas aeruginosa." Thesis, Université Laval, 2005. http://www.theses.ulaval.ca/2005/22856/22856.pdf.
Pseudomonas aeruginosa is a Gram negative bacteria causing chronic pulmonary infections in cystic fibrosis patients. Virulence factors of this pathogen facilitate the colonization of the pulmonary tract and lungs of cystic fibrosis patients. Our team has developed a PCR-based signature-tagged mutagenesis technique permitting the screening of a collection of 7968 mutants. A total of 214 mutants, representing transposition events into 148 open reading frames, were shown to be attenuated in lung infection and were retained for further analysis. Of these genes, we chose PA3498 for its characterization. We have concluded that this gene is coding for an oxydoreductase sharing homology with a familly of oxydoreductases including PDR protein of Burkholderia cepacia. Finally, PA3498 protein is needed to initiate or/and to maintain the pathogen in vivo and this protein plays a role in the maturation and processing of the P. aeruginosa exoproteases.
Berrigan, Félix. "Obésité et stabilité posturale : impact sur la relation vitesse-précision d'un mouvement de pointage." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25082/25082.pdf.
Bergeron, Marc. "Caractérisation fonctionnelle et moléculaire des cotransporteurs K-Cl." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24647/24647.pdf.
Wittamer, Valérie. "Caractérisation fonctionnelle du récepteur orphelin Chem23, spécifiquement exprimé par les cellules présentatrices d'antigènes." Doctoral thesis, Universite Libre de Bruxelles, 2004. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211082.
Perinet, Simone. "Génomique fonctionnelle d'un gène modA essentiel à l'infection pulmonaire chronique chez Pseudomonas aeruginosa." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30603/30603.pdf.
Pseudomonas aeruginosa is the main pathogen causing chronic lung infections in cystic fibrosis patients. The genome of the laboratory reference strain PAO1 was sequenced revealing its highly complex virulence regulatory network and a large part of genes of unknown function. A PCR-based signature tagged mutagenesis (STM) allowed the identification of 148 genes essential for chronic lung infection in a rat model. The PAO1-derivated strain STM_modA was obtained using this technique and is thus unable to persist in the rat lug in competition with a pool of strains. This strain carries an insertional mutation interrupting the open reading frame of the modA gene. This gene codes with the co-transcribed modB and modC genes for an ATP-binding cassette transporter (ModABC) responsible for the internalization of molybdate from the periplasmic space. Molybdate is the environmental molybdenum-containing ion, which is essential for the activity of the molybdoenzymes, a group of enzymes involved in a wide range of metabolic functions. The present work demonstrates that the ModABC transporter activity is essential for chronic lung infection in a rat model, for biofilm formation, for resistance to predation by the amoeba Dictyostelium discoideum as well as for denitrification and subsequent anaerobic growth. Whole transcriptome shotgun sequencing demonstrated major changes in the gene transcription levels of STM_modA in comparison with wild-type PAO1 in anaerobic conditions. This work highlights the ModABC transporter as a potential target for the inhibitors development, a new strategy for antimicrobial research.
Maltais, Annie. "Analyse structurale et fonctionnelle du récepteur nucléaire orphelin NOR-1 et inactivation du gène chez la souris." Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23444/23444.pdf.
NOR-1 is a member of the nuclear receptor superfamily which comprises a great diversity of transcription factors. The steroid, thyroid, retinoid, and vitamin D receptors represent some widely-know members of this superfamily. The nuclear receptors induce a vast number of biologic responses by the regulation of target genes. They are involved in the control of different cell functions like growth, differentiation, metabolism and apoptosis. They also play roles in tumorigenesis. NOR-1, NGFI-B and NURR1 form a subfamily of orphan nuclear receptors. They are associated to the central nervous system development and homeostasy. These proteins are coded by immediate-early genes which are rapidly induced by growth factors in different cell types. NOR-1 and NGFI-B have an important function in T-cell receptor (TCR)-mediated apoptosis. NOR-1, NGFI-B and NURR1 could be involved in neuroendocrine control at the level of the hypothalamic/pituitary/adrenal axis. A NURR1 knock-out mouse has been created and shows the essential role of this nuclear receptor in the development of mesencephalic dopamine neurons. The NGFI-B knock-out mouse shows no significant phenotype both at the level of thymocyte apoptosis and on the regulation of the adrenocortical function. The EWS and NOR-1 gene fusion was discovered in extraskeletal myxoid chondrosarcoma bones tumors. This chromosom translocation is at the origin of a hybrid protein composed of the N-terminal of EWS fused to the full length nuclear receptor NOR-1. It is presumed that the EWS/NOR-1 fusion protein plays a central role in the tumoral process. Threes other NOR-1 fusion partners were discovered in extraskeletal myxoid chondrosarcomas. TAF2N, TCF12 and TFG are fused to the nuclear receptor by a similar pattern. We have compared the NOR-1 and EWS/NOR-1 transcriptional activity in different chondrocyte cell lines. The AF2 domain of NOR-1 is essential for the transcriptional activity of the EWS/NOR-1 fusion protein. This result suggests that some NOR-1 specific co-activators participate to the tumorigenic process involved in the development of extraskeletal myxoid chondrosarcomas development. In order to better understand the orphan nuclear receptor NOR-1, we have created a NOR-1 knock-out mouse. Analysis of this mouse indicate an absence of significant phenotype. These observations suggest functional redundancy between NGFI-B or NURR1 (or both) and NOR-1.
Boaventura, Bomfim Daniela. "Mettre en place la médecine de précision au travers d’un essai clinique : le cas du projet pilote en cancérologie du plan France médecine génomique 2025." Electronic Thesis or Diss., Bordeaux, 2023. http://www.theses.fr/2023BORD0472.
This doctoral research in the field of sociology aimed to follow the deployment of the France Genomic Medicine Plan 2025 (PFMG 2025) based on the study of one of its pilot project in oncology, the VERYSARC clinical trial. In the context of precision medicine, these types of trials aim to test the integration of high-throughput genome sequencing (NGS) into routine care. Drawing on a qualitative methodology (interviews and participant observation) informed by the sociology of science and health, the investigation questions the boundaries between care and research. The incorporation of the trial into the Plan was done through a process of transformation of the initial objectives of the trial. As part of this transformation, the essay is mobilized in various technoscientific rhetorics aimed at different audiences (patients, researchers, political actors). That said, the promises are not detached from the concrete reality of the trial which remains for the majority of players in the hospital world a major research instrument defined by great organizational complexity. At the CLCC level, the implementation of the trial highlights organizational dysfunctions. Despite a long socio-history of links between care and research, CLCCs remain a social world governed by and for care. The observations thus made it possible to identify situations of asynchrony, despite the existence of an organizational framework dedicated to coordination, which once again raise the question of the boundaries between care and research. This complexity is also visible in the relationships maintained by the patients included in the trial. We have identified phenomena of ignorance, information deficit and therapeutic illusion. We conclude that all these explanations ultimately refer to a situation of non-demarcation of boundaries which is characterized by a spatio-temporal blur between care and research
Germain, Robitaille Mathieu. "Effets des contraintes de précision et de la nature d'un pointage sur la coordination entre la tête et la main." Thesis, Université Laval, 2012. http://www.theses.ulaval.ca/2012/29520/29520.pdf.
Visually corrected movements involving head and hand movements require a temporal coordination between both effectors. The present work observes this coordination during discrete and reciprocal pointings with various accuracy requirements (ID). The kinematics of the two segments and the coordination between them was examined. Results show a modification of head movements in function of the accuracy requirements (ID) during reciprocal pointings which was not the case during discrete pointings. Since hand movements followed Fitts’ law during both types of pointings, the coordination pattern adapted to both the accuracy constraints and the nature of the executed movement. These results suggest observations made during discrete pointings should not be transferred de facto to reciprocal movements.
Detournay, Olivier. "Caractérisation phénotypique et fonctionnelle de cellules dendritiques différenciées, in vitro, en présence d'Interféron-B." Doctoral thesis, Universite Libre de Bruxelles, 2005. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210917.
Vanderheyde, Nathalie. "Les cellules dendritiques humaines: inhibition fonctionnelle par les glucocorticoïdes et propriétés anti-tumorales intrinsèques." Doctoral thesis, Universite Libre de Bruxelles, 2003. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211310.
Bruelle, Céline. "Étude fonctionnelle de la phosphorylation mitotique de P54nrb." Thesis, Université Laval, 2011. http://www.theses.ulaval.ca/2011/27967/27967.pdf.
Massinga, Loembé Marguerite. "Caractérisation phénotypique et fonctionnelle des lymphocytes B dans la lymphocytose polyclonale chronique B." Thesis, Université Laval, 2004. http://www.theses.ulaval.ca/2004/22193/22193.pdf.
Persistent polyclonal B cell lymphocytosis (PPBL) is an unusual haematological disorder, mainly detected in adult female smokers, that shares features of both benignity (polyclonal expansion, polyconal IgM secretion, lack of clinical symptoms, stable and mostly uneventful course); and features of malignancy (atypical binucleated cells, multiple bcl-2/Ig translocations, chromosome 3 anomalies, bone marrow involvement). Still, these morphological and clonal genetic anomalies have not been restricted to a distinctive B cell subset, and the apparent heterogeneity of the involved cellular population has long impeded further characterization of the syndrome. The aim of our research was to formally identify the population involved in the lymphocytosis, to gain some insight into the mechanisms at play in its development and to evaluate the risk for subsequent transformation in patients. Over the recent years, technical inputs from the molecular field have largely contributed to a better discrimination of the various B cells subsets and, by extension, of B cell lymphoid disorders. Thus, detailed immunophenotypic studies conducted in numerous PPBL patients allowed us to definitely circumscribe the disorder to IgD+IgM+CD27+ B lymphocytes, whereas exhaustive molecular analysis of immunoglobulin genes’ variable regions has corroborated the memory status of these cells. Yet, molecular signature of the antigenic selection process, the characteristic of a T-dependent immune response, was not detected. Sequencing of the CD40 and AID genes, key regulators in the diversification and affinity maturation of the immunoglobulin receptor, was additionally carried out and expression of both molecules was assessed. No anomaly was evidenced for either gene. In light of those observations, we conclude that a differentiation block in PPBL B lymphocytes is unlikely. Rather, we propose that defects in the affinity maturation process, namely impairment of the antigenic selection mechanism, allows the survival of low affinity IgD+IgM+CD27+ memory B lymphocytes in PPBL patients. Conversely, these cells could be related to the as yet scantily characterized IgD+IgM+CD27+ memory B cell subset from the splenic MZ, also found in the blood, and presumably derived from a germinal centre independent diversification pathway. Altogether, our results contributed to the elaboration of an accurate clinical definition for PPBL, and delineated avenues for future investigations regarding both the pathological aspects of the disorder and its purely fundamental biologic ramifications.
Bransi, Ali. "Caractérisation fonctionnelle et structurale d'un homologue phagique de la protéine humaine RAD52." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26338/26338.pdf.
Fausther, Bovendo Michel. "Caractérisation fonctionnelle des NTPDASE1, NTPDASE2, NTPDASE8 et de l'ECTO-5'NUCLÉOTIDASE HÉPATIQUES." Thesis, Université Laval, 2009. http://www.theses.ulaval.ca/2009/26773/26773.pdf.
Lévesque, Martin. "Organisation anatomo-fonctionnelle du striatum et de ses projections efférentes." Thesis, Université Laval, 2006. http://www.theses.ulaval.ca/2006/23778/23778.pdf.
Kukavica-Ibrulj, Iréna. "Génomique fonctionnelle du régulateur transcriptionnel PYCR de Pseudomonas aeruginosa essentiel in vivo et comparaison des cinétiques d'infection pulmonaire chronique." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24735/24735.pdf.
The opportunistic pathogen Pseudomonas aeruginosa is highly resistant to most classes of antibiotics and causes a wide variety of infections in compromised hosts. In addition, it represents the major cause of morbidity and mortality in cystic fibrosis (CF) patients. The principal goal of the present research project was to identify and to characterise P. aeruginosa genes essential for causing a chronic lung infection. Using a PCR-based signature-tagged mutagenesis, we identified a P. aeruginosa STM5437 mutant having an insertion into the PA5437 gene; its inactivation causes attenuation of virulence in vivo. The PA5437 gene, now called pycR, regulates the adjacent operon encoding the pyruvate carboxylase subunits (pyruvate carboxylase regulator). PycR has the signature of a putative transcriptional regulator with a predicted helix-turn-helix motif binding to a typical LysR DNA-binding motif identified in the PA5436 (pycA)-PA5437 (pycA) intercistronic region. Transcriptional start sites of pycA and pycR were identified by primer extension and the DNA binding capacity of PycR was confirmed by a DNA mobility gel shift assay. Genome-wide transcriptional profiling indicated that the genes whose control were differentially expressed by PycR implicated genes responsible for lipid metabolism, lipolytic activity, anaerobic respiration, biofilm formation and a number of quorum sensing regulated genes. This study defines PycR as a major regulator in virulence and where mutations in pycR have pleiotropic effects on the expression of multiple virulence factors such as lipase, esterase and biofilm formation. The expressions of several of these genes are associated with chronic lung persistence. In the second part of the study, P. aeruginosa prototype strains PAO1 and PA14 were compared with the CF isolate LESB58 in the rat model of chronic lung infection. This comparative study identified major differences for LESB58; in vivo in bacterial localisation in the rat lung and in vitro for motility and biofilm production. Functional genomics of P. aeruginosa will provide new insights for the development of novel therapeutic targets. Genomic biodiversity may explain the variation in severity of the P. aeruginosa infections in CF disease.
Leroy, Karelle. "La glycogène synthase kinase-3B: rôle dans l'étiopathogénie et dans la régulation fonctionnelle du cytosquelette microtubulaire." Doctoral thesis, Universite Libre de Bruxelles, 2003. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211247.
Schiffmann, Serge N. "Implications de l'adénosine, la cholecystokinine et leurs récepteurs dans l'organisation fonctionnelle des ganglions de la base." Doctoral thesis, Universite Libre de Bruxelles, 1992. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212970.
Seitlinger, Joseph. "Optimisation d’un modèle d’organoïde de cancer du poumon vascularisé dérivé de patient à des fins de médecine de précision." Electronic Thesis or Diss., Strasbourg, 2022. http://www.theses.fr/2022STRAJ022.
Despite numerous recent advances, lung cancer is the leading cause of cancer mortality worldwide. Every year, new therapeutic drugs are developed to fight this disease whose prognosis remains poor. The development of precision medicine should make it possible to improve its effectiveness. In this perspective, we have optimized an organoid model derived from lung cancer patients. In this work, we were able to show that our model is reproducible and that it mimics the patient's tumor. Finally, the formation of a vascular network at the level of the organoid is possible : it can infiltrate the formed organoid but can also grow from the organoid to infiltrate the microenvironment. The model that we put forward thus meets the specifications of a patient Avatar model. The tests of therapeutic drugs or irradiation that we are currently carrying out will allow us to define if this model is compatible with a future use in clinical practice to improve the management of patients diagnosed with lung cancer
Desjardins, Patrick. "Évaluation de la capacité fonctionnelle chez des patients atteints de la dystrophie myotonique de type 1." Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/30290/30290.pdf.
Tremblay, Cédric. "Analyse fonctionnelle de l'interaction du complexe Fanconi avec l'effecteur HES1 : inter-relation des voies signalétiques de l'anémie de Fanconi et de NOTCH1." Thesis, Université Laval, 2008. http://www.theses.ulaval.ca/2008/25385/25385.pdf.
Seigneur, Josée. "Impacts des rythmes du sommeil sur la connectivité fonctionnelle et effets des changements ioniques sur la synchronisation neuronale et la connectivité fonctionnelle." Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29935/29935.pdf.
The neuronal synchronisation is an intrinsic phenomenon in the brain that allows neurons to be connected to the network to communicate. Oscillations inherent of the states of vigilance such as the slow-wave sleep, the REM sleep, and waking state or pathological conditions such as epilepsy emerge from the network synchronisation of a group of neurons. Several interactions influence the synchronization: the chemical or electrical transmission, the ionic variations, and the ephaptic interactions. At cellular level, the synaptic plasticity also influences the functional connectivity of neurons. In this thesis, I aim to explain the impact of sleep rhythms on the functional connectivity and the effects of ionic variations on the neuronal synchrony and the functional connectivity. States of vigilance implicated in the memory consolidation. We demonstrated that the presence of slow oscillations and the spiking pattern during slow-wave sleep favours the long-term synaptic facilitation, which could be a key element for the sleep-dependent reinforcement of synaptic efficacy contributing to memory consolidation. By contrast synaptic activities generated during waking state in a conditions of increased level acetylcholine favour short-term facilitation. Sleep allows also the brain to disrupt partially the communication with the environment. The accepted model is that the thalamus provides gating of sensory information during sleep, but the exact mechanisms of that gating are unknown. We demonstrated that the failure rate to a lemniscal stimulation is increased during the thalamic Ca2+ spike bursts and the generation of those Ca2+ spikes cause a depletion of the extracellular calcium which is sufficient to reduce the synaptic efficacy. Bursts of action potential occur preferentially during slow-wave sleep, but also in the pathological form of paroxysmal depolarization shift during the generation of cortical epileptic seizures. During seizures, the paroxysmal neuronal activity causes a decrease of extracellular Ca2+ and an increase of extracellular potassium. We demonstrated that those ionic variations affect the synaptic transmission by increasing the failure rate of unitary responses at a synapse and by blocking the axonal transmission of action potentials, which disrupts the neuronal communication between neurons, facilitating seizure termination.
Tomoiu, Andru. "Caractérisation fonctionnelle de la protéine précoce-immédiate 2 de l'herpèsvirus humain 6." Thesis, Université Laval, 2007. http://www.theses.ulaval.ca/2007/24149/24149.pdf.
Human herpesvirus 6 (HHV-6) is an opportunistic pathogen whose infection or reactivation are associated with diseases such as roseola, central nervous system disorders and organ transplant anomalies. Sequencing of the viral genome has exposed the existence of two HHV-6 variants (A and B), with diverging sequences in specific regions, and different biological characteristics. Our work focused on the characterization of HHV-6A immediate-early IE2 protein. Its prompt expression following infection and its transactivating ability suggest that IE2 constitutes a key protein for the establishment of a productive infection, owing to its control over the viral gene expression cascade. Moreover, the IE2 coding transcript is located in the most variable region between HHV-6A and -6B, suggesting that the biology of this protein could help explain the clinical differences between the two viral variants. In order to identify cellular proteins recruited by IE2 during the establishment of infection, we have screened a T-cell library for interaction partners. We have isolated Ubiquitin conjugating enzyme 9 (Ubc9), a protein involved in the small ubiquitin-related modifier (SUMO) conjugation pathway. This interaction has a functional relevance for IE2, with Ubc9 significantly repressing promoter activation by the viral protein. Protein domains essential for IE2 function had never been characterized. We have determined that the N- and C-terminal domains are both required for optimal transactivation, and that the deletion of the C-terminal tail of IE2 significantly alters transactivation and the intranuclear localization of the protein. Moreover, we have determined that the R3 domain of the immediate-early HHV-6A promoter represents an IE2 responsive element. Overall, this work provides a more precise image of the role of IE2 during the initiation of HHV-6 infection and a better comprehension of the biology of this complex virus.
Wirotius, Jean-Michel. "Approche sémiotique des pratiques professionnelles en médecine physique et de réadaptation : la question du sens en rééducation fonctionnelle." Limoges, 2006. http://www.theses.fr/2006LIMO2010.
Voisin, Aurore. "LES ENKÉPHALINES ET LA NEUROBIOLOGIE DU SEL Caractérisation électrophysiologique, neuroanatomique et fonctionnelle." Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29978/29978.pdf.
In rats, extracellular sodium (Na+) variations are detected by neurons in the median preoptic nucleus (MNPO) due to the presence of NaX channels. First, we wanted to determine the electrical properties of MnPO Na+ sensor neurons using electrophysiological recordings. We demonstrate an increase in the excitability of Na+ sensors, probably due to a decrease in ionic channels responsible for spike frequency adaptation and an increase in the ionic channels sustaining time-dependent membrane rectification. Since our laboratory demonstrated a modulation of Na+ sensors excitability by enkephalins (ENK) and mu-opioid receptors (mu-OR) system for an acute sodium deficit, so we wanted to demonstrate an enhancement in this neuronal excitability during repeated sodium depletion. Our results demonstrate that repeated sodium depletion induced desensitization of Na+ sensors and NaX channels expression. However, Na+ sensors show a hyperexcitability in response to three Na+ deficits that appears to be mitigated by the overexpression of functional mu-OR. Then, we wanted to determine the brain regions releasing ENK within the MNPO by injecting a fluorescent retrograde tracer. Our data report the parabrachial nucleus and the nucleus of solitary tract as the main ENK sources to MNPO; the bed nucleus of stria terminalis and the paraventricular nucleus as moderate ENK projections. This ENK release could initiate salt appetite in response to sodium deficit. Since salt appetite is a motivated behavior and some studies reported an enhanced salt appetite named salt sensitization, so we wanted to correlate ENK and/or mu-OR expression in reward circuit and salt sensitization. We show that salt sensitization is not a universal phenomenon in rats and that it is correlated with a decreased mu-OR expression in the ventral pallidum (VP). In addition, mu-OR expression in the VP is a fundamental requisite to the development of salt sensitization.
Jannot, Guillaume. "Caractérisation fonctionnelle de la voie des microARNs chez le nématode caenorhabditis elegans." Thesis, Université Laval, 2013. http://www.theses.ulaval.ca/2013/29403/29403.pdf.
Paille, Philippe. "Transferts logiques et technologiques en suppléance fonctionnelle." Bordeaux 2, 1993. http://www.theses.fr/1993BOR2M205.
Lay, Guillaume. "Caractérisation morphologique et fonctionnelle du granulome mycobactérien." Toulouse 3, 2006. http://www.theses.fr/2006TOU30275.
In Escherichia coli, the ATP-dependent DNA translocase FtsK transports DNA across the site of cell division and activates recombination by the XerCD recombinases at a specific site on the E. Coli chromosome, dif, to ensure the equal distribution of the genetic material and the topological integrity of daughter chromosomes during the last stages of chromosome segregation. We showed that DNA mobilization and Xer recombination activation, two functions required to resolve dimers, are genetically separable. We have also shown that DNA transport by FtsK is oriented by 8 bp asymmetric sequences (“KOPS”) displaying a biased orientation and distribution on the E. Coli chromosome and that KOPS promote FtsK loading on DNA and that translocation is oriented at this step
Sircoulomb, Fabrice. "Génomique fonctionnelle des cancers du sein." Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX20726.
High Troughput technologies dissect several aspects of cancer. Transcriptomic analyses have defined five breast cancer molecular subtypes. During my phD I analysed two molecular subtypes associated with agressive phénotype and bad prognosis : ERBB2 and Luminal B subtypes. Firstly, I caracterized genomic heterogenity of ERBB2 amplified tumors which is related to estrogen receptor (ER) expression. Integrated genomictranscriptomic analyses identified PVT1 and TRSP1 as candidate oncogenes in ER positive ERBB2 amplified tumors. On the contrary, RE négative tumors express Wnt/ß-catenin related genes, an other interesting therapeutic strategy. Secondly, genomic analyses of Luminal B tumors point 8p12 amplification as the major genomic évents. This amplification target several known putative oncogenes (RCP, ZNF703, PPAPDC1B…). ZNF703 overexpression induced cancer stem cells increase in MCF7 cell line. ZNF703 co-localise with SMRT and PHB-2 in the nucleus. Finally, ZNF703 overexpression reduce RE transcriptionnal activity. These results are concordant with others showing that ZNF703 as un HDAC dependant transcriptionnal répression activity. Thus, HDAC inhibitors could be a interesting therapeutic strategy for luminal B tumors. Together, these studies show importance of combination of several aspect to define potential therapeutic strategy associated with breast cancer molecular subtypes
Lafargue, Audrey. "Étude mécanistique & fonctionnelle de la sénescence radio-induite des cellules endothéliales microvasculaires." Nantes, 2014. http://archive.bu.univ-nantes.fr/pollux/show.action?id=920fc9d7-fa70-4586-9662-a4f810b303d0.
The benefits of radiation therapy depend on the balance between the impact on tumoral tissues and on healthy peripheral tissues. Sphingosine-1-Phosphate (S1P) treatment allows to limit acute radiation toxicity through prevention of Ceramide-dependent microvascular endothelial cell death. However, numerous physiopathological observations indicate that endothelial cells also play an essential role in late radiation toxicity, possibly owing to premature senescence. S1P treatment, by protecting endothelial cells, could stabilize DNA damages and/or downstream signalization, and thereby promote senescence. The objectives of this thesis aimed at understanding the molecular mechanisms involved in in vitro development of radiation-induced microvascular endothelial cell senescence, and evaluate the impact of S1P treatment. We have observed that induction of senescence is associated with an activated phenotype, and with an increase in endothelial cell monolayer permeability. Regarding the mechanisms, our results indicate that, interestingly, endothelial cell senescence is independent of the persistence of DNA damage signalization. Instead, we show that it depends on chronic mitochondrial oxidative stress and p53 upregulation. These original findings suggest as perspectives the combination between S1P and an endothelial cell senescence inhibitor, so as to limit both acute and late toxicity