Дисертації з теми "Cellules souches humaines induites à la pluripotence"
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Jung, Laura. "Optimisation de protocoles de reprogrammation de cellules somatiques humaines en cellules souches à pluripotence induite (hiPSC)." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAJ066.
In 2006 and 2007, Yamanaka and Thomson teams achieved the reprogramming of mouse and human somatic cells into pluripotent stem cells through the transfection of two cocktails of genes: OCT4, SOX2, KLF4, cMYC (OSKM) and OCT4, NANOG, SOX2, LIN28 (ONSL). The generated cells, called induced Pluripotent Stem Cells (iPSC) share the same fundamental properties of ESC : self-renewing, pluripotency maintenance and capacity of differentiation into the three germ layers and suggest the same application potential in basic research (developmental and epigenetic biology) as well as in therapy (regenerative medicine, disease modeling for drug development). One of the major advantages of iPSC lies in their non-embryonic origin. Indeed, the use of iPSC resolves the ethical constraints and offers the possibility to work with extensive cell types directly from the patient to treat. Stéphane Viville’s research team aims to develop a hiPSC bank from patient suffering from genetic or other diseases which will be available for the scientific community. We are experienced in human primary fibroblasts reprogramming especially with the use of two polycistronic cassettes: ONSL encoding Thomson’s cocktail and OSKM encoding Yamanaka’s cocktail separated with 2A peptides. Thanks to the combination of RV-ONSL and RV-OSKM retroviral vectors (developed with Vectalys) we are yielding more than 2% of reprogramming efficiency in a highly reproducible way. Indeed, we demonstrated the reprogramming synergy of ONSL and OSKM combination. We are now focusing our effort on non-integrative strategies (ie mRNA) which are more appropriate for clinical usage
Hoarau, Priscilla. "Obtention de cellules souches humaines induites à la pluripotence à partir de cellules d'urine et leur différenciation neuronale." Master's thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27912.
Human Induced Pluripotent Stem Cells (hiPSCs) were conceived for the first time in 2007 in Japan, by Doctor Yamanaka’s team. These are somatic cells reprogrammed thanks to a retrovirus allowing, for example, neuronal differentiation for the purpose of neurodevelopmental disorders studies such as Schizophrenia. Today, the removal of somatic cells is mainly made by enough invasive methods, including skin and blood biopsies. This can represent a brake in their use predominantly children, mainly sick children. The preferred neuronal differentiation is the dopaminergic (DA) way because it's the mostly cell type affected in schizophrenics. That's why we prioritize the use of urine cells for this project, reprogrammed via a non integrative virus, the Sendai virus (SeV). The neuronal differentiation enables us to get functional DA neurons characterized by electrophysiology. Experimentations show a huge efficiency of urine cells reprogramming as well as a great potential of neuronal differentiation despite some distinctions between the two lines. Thanks to this project, the achievement of a cellular model for Schizophrenia could be established. The differences noticed between the two lines during the differentiation open up a new way to make cellular and molecular studies of this disease deeper.
Hafner, Anne-Laure. "Étude des progéniteurs adipeux dérivés des cellules souches pluripotentes induites humaines." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4062.
In mammals, two types of adipose tissue coexist: the white (WAT) wich is involved in energy storage and the brown (BAT) which is specialized in energy expenditure. Beige adipocytes have recently been described as brown –like adipocytes and represent a third type of adipocytes that are recruited in WAT. The molecular mechanisms involved in the generation of these different types of adipocytes remains unknow in humans, mainly because of the lack of appropriate in vitro cellular models. The human induced Pluripotent Stem (hips) cells are a good model to study the earliest steps of human adipogenesis. We have shown that the generation of white and brown adipocytes progenitors (AP) is regulated by acid retinoic signaling pathway during hips cells differentiation. Functional experiments indicated that the transcription factor Pax3 is a molecular mediator of the brown phenotype. During this study, we could see that AP derived from hips cells display a low adipogenic capacity as compared to progenitors derived from adult adipose tissue. We show in this work that treatment with TGFβ pathway inhibitor SB431542 together with ascorbic acid, hydrocortisone and EGF promoted differentiation of non- genetically modified hiPSCs-BAPs at a high rate. During preliminary results, we have analyzed the role of the transcription factor Hoxc8 on PA differentiation. The surexpression of this factor lead to distinct answers on the phenotype and differentiation between hiPSCs-AP and adult-derived AP
Hafner, Anne-Laure. "Étude des progéniteurs adipeux dérivés des cellules souches pluripotentes induites humaines." Electronic Thesis or Diss., Nice, 2015. http://www.theses.fr/2015NICE4062.
In mammals, two types of adipose tissue coexist: the white (WAT) wich is involved in energy storage and the brown (BAT) which is specialized in energy expenditure. Beige adipocytes have recently been described as brown –like adipocytes and represent a third type of adipocytes that are recruited in WAT. The molecular mechanisms involved in the generation of these different types of adipocytes remains unknow in humans, mainly because of the lack of appropriate in vitro cellular models. The human induced Pluripotent Stem (hips) cells are a good model to study the earliest steps of human adipogenesis. We have shown that the generation of white and brown adipocytes progenitors (AP) is regulated by acid retinoic signaling pathway during hips cells differentiation. Functional experiments indicated that the transcription factor Pax3 is a molecular mediator of the brown phenotype. During this study, we could see that AP derived from hips cells display a low adipogenic capacity as compared to progenitors derived from adult adipose tissue. We show in this work that treatment with TGFβ pathway inhibitor SB431542 together with ascorbic acid, hydrocortisone and EGF promoted differentiation of non- genetically modified hiPSCs-BAPs at a high rate. During preliminary results, we have analyzed the role of the transcription factor Hoxc8 on PA differentiation. The surexpression of this factor lead to distinct answers on the phenotype and differentiation between hiPSCs-AP and adult-derived AP
Martineau, Sabrina. "Etude des mécanismes moléculaires de l'épidermolyse bulleuse simple à partir de cellules souches humaines induites à la pluripotence." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASQ020.
Epidermolysis bullosa simplex (EBS) is a skin disorder caused mainly by dominant mutations in genes coding for keratin 5 (KRT5) or 14 (KRT14) genes. It is characterized by the presence of blisters caused by epidermal detachment, and by other complications such as cutaneous inflammation. From a genetic point of view, the mutations will alter the assembly of the keratin intermediate filament network in basal keratinocytes of the epidermis, leading to cell cytolysis and the formation of intra-epidermal blisters. Currently no effective therapeutic approach it is available. Understanding of the disease and the development of therapies have been hampered by the lack and limitations of relevant human cell and mouse models.So, the general aim of my thesis was to exploit the properties of human induced pluripotent stem cells (hiPSc) to modelling EBS. For this purpose, we generate hiPSc-derived keratinocytes from EBS patients carrying KRT5 mutations (Ker-EBS), and from healthy patients (Ker-WT). Comparison of Ker-EBS and Ker-WT enabled to show that Ker-EBS recapitulates the main phenotypes associated with EBS, namely decreased cell proliferation, increased cell migration, altered signalling pathways (ERK and JNK), as well as aggregates of intermediate keratin filaments in the cytoplasm, as observed in primary EBS keratinocytes. These results demonstrate that our hiPSc-derived cell model is relevant for study EBS.In order to identify new molecular mechanisms, a trancriptomic analysis comparing Ker-EBS with Ker-WT revealed 138 deregulated genes, revealing an enrichment in processes linked to the extracellular matrix, DNA packaging and the inflammatory response. As the inflammatory component in EBS has been poorly described, my next step was to study the pro-inflammatory cytokine phenotype. Thus, we were able to demonstrate increased expression of IL-1α, IL-1β, IL-6, IL-8 (CXCL8), CXCL5, CXCL10, CXCL11, CCL5 in Ker-EBS, at RNA level under basal or IFNy-stimulated conditions to mimic a pro-inflammatory context. Only the chemokines CXCL10 and CXCL11 are secreted at high concentrations in the culture supernatants of stimulated and unstimulated Ker-EBS, demonstrating the involvement of these cytokines in EBS.In parallel, in order to avoid biases due to genetic background, gender, patient age and epigenetics, we generated an isogenic Ker-EBS line (corrected Ker-EBS) using the CRISPR-Cas9 technique. We were thus able to demonstrate that the corrected Ker-EBS line showed a restoration of the expression level of the pro-inflammatory cytokines mentioned above, to a level close to that of Ker-WT, confirming a direct link between mutations in the KRT5 gene and the pro-inflammatory signature.In conclusion, our new cellular model enabled us to reproduce the pathological phenotypes known in the literature, and to demonstrate deregulation of pro-inflammatory cytokine expression in EBS, notably CXCL10 and CXCL11. Taken together, these results make this model a relevant tool to allow a better understanding of the molecular mechanisms associated with the pathology, particularly the inflammatory component, paving the way for new therapeutic approaches
Lemonnier, Thomas. "Modélisation de maladies neurodégénératives à l’aide de cellules souches pluripotentes induites humaines." Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05T074/document.
Reprogramming technology of somatic cells in induced pluripotent stem cells (iPS) now offers the opportunity to model neurodegenerative diseases and to study patient’s neurons. We used this technology for generating two models of neurodegenerative diseases: the muccopolysaccharidosis type IIIB (MPSIIIB) and the ALS2 form of amyotrophic lateral sclerosis (ALS). In the MPSIIIB model, we have shown that iPS and neurons of patients had characteristic defects of the disease such as the accumulation of storage vesicles. Alterations of the Golgi apparatus in these cells were also highlighted. Transcriptome analysis of MPSIIIB neural precursors showed transcriptional changes involving particularly genes implicated in cell-extracellular matrix interactions. Thus, in a subsequent study, alterations of migration and orientation of MPSIIIB mutant mouse cells and MPSIIIB patients’ cells have been demonstrated. These alterations may be responsible for the disruption of neurogenesis and neuritogenesis in sick children. In the ALS2 model, we have shown that patients’ neurons had defects including decreased endosomes’ surface and abnormal neurite outgrowth. As there was previously no relevant cellular model reproducing the disease, this model will now allow the study of physiopathological processes involved in the disease. In conclusion, the generation of iPS cells allows to model neurodegenerative diseases and to study associated physiopathological processes on cultured human neurons. These cell models could allow in the near future the screening of molecules of potential therapeutical interest
Lemonnier, Thomas. "Modélisation de maladies neurodégénératives à l'aide de cellules souches pluripotentes induites humaines." Phd thesis, Université René Descartes - Paris V, 2012. http://tel.archives-ouvertes.fr/tel-00806699.
Lay, Russo Nadège. "Différenciation des cellules souches embryonnaires murines et des cellules souches pluripotentes induites humaines en cellules dendritiques : cellules d'intérêt pour les tests de toxicologie." Nice, 2012. http://www.theses.fr/2012NICE4077.
The seventh amendment in the European cosmetic directive imposes an abandonment of the tests on animals to measure the allergenic or irritant effects of some compounds used in cosmetic. The allergenic response in animals ‘models includes five aspects but in the in vitro test each aspect is studied separately. Among the in vitro tests of toxicity which are envisaged, dendritic cells, which are antigen presenting cells, were revealed as cells of choice for study one of these aspects. However today it is difficult to obtain a reliable and strong source of dendritic cells allowing working out a reglementary test. The aim of my thesis project was to propose an alternative model in these tests on animals. For it we set up the conditions allowing generating dendritic cells derived of stern cells. For it we have two sources of stem cells (hiPS) which having all the characteristics of the embryonic stem cells without raise ethical problems. These two types of cells allowed having an inexhaustible and plentiful source of dendritic cells. We set up one protocol allowing generating and purifying a population of dendritic cells from mouse embryonic stem cells. Cells were characterized by gene expression like CD45, CD86. Furthermore we realized as functional test that consists to measure the dextran-FICT endocytosis and the answer of this cellular population to allergenic reference molecules such as MCI/MI or TNBS. We also tried to generate “dendritic-like” cells from human iPS based to expression of specifics markers as CD45, CD34, CD1a, CD14, CD209, CD207, CD86 and HLA-DR. Several protocols were envisaged. However dendritic-like cells obtained represent a low percentage of differentiated cells and the protocol is in the course of optimization. Increasingly tests use keratinocytes cells for evaluate another aspect of allergenic response. So we were interesting also to these cells and we will present first steps differentiation of hiPS that will allow generating keratinocytes
Denis, Jérôme Alexandre. "Applications médicales et pharmaceutiques des cellules souches pluripotentes : vers un changement de paradigme ?" Phd thesis, Université René Descartes - Paris V, 2011. http://tel.archives-ouvertes.fr/tel-00637075.
Mohsen-Kanson, Tala. "Cellules souches induites à la pluripotence : modèle d'étude des étapes précoces du développement adipocytaire humain." Nice, 2012. http://www.theses.fr/2012NICE4023.
The terminal steps of adipocyte differentiation are well established ; however the earliest steps controlling brown and white adipogenic lineage specification remain unknown in humans. We have investigated the human induced Pluripotent Stem cells (hips) as a model to study the early steps of brown and white adipogenesis. We will present the generation of hips cells from human multipotent adipose derived stem cells (hMADS). We have also used iPS cells reprogrammed from human neural stem cells generated using the PiggyBac technology. We provide an efficient protocol to differentiate iPS-hMADS and iPS-hNSC cells into adipocytes. Interestingly, our data show that hips cells are able to differentiate both into white and brown adipocytes. We show that Retinoic Acid (RA) pathway activation at an early phase of hips development dramatically enhanced generation of white adipocytes and inhibited generation of Brown adipocytes. In contrast, the use of SB431542, a selective inhibitor of TGFβ/Activin pathway, indicated that this pathway was required for the generation of brown adipocytes. Altogether, these data support a model in which brown and white adipocytes progenitors diverge early during human embryonic development. RA and TGFβ/Activin pathways regulate the generation of white APs and brown APs respectively
Merien, Antoine. "Étude de la fonction des protéines MBNL au cours du développement à l’aide de cellules souches humaines induites à la pluripotence." Thesis, université Paris-Saclay, 2021. https://www.biblio.univ-evry.fr/theses/2021/interne/2021UPASQ015.pdf.
Alternative splicing has emerged as a fundamental mechanism not only for the diversification of protein isoforms but also for the spatiotemporal control of development. Therefore, a better understanding of how this mechanism is regulated has the potential not only to elucidate fundamental biological principles, but also to decipher pathological mechanisms involved in diseases where normal splicing networks are mis-regulated. As part of this thesis, we took advantage of human pluripotent stem cells to decipher during human myogenesis the role of MBNL proteins, a family of tissue-specific splicing regulators whose loss of function is associated with Myotonic Dystrophy type 1 (DM1), an inherited neuromuscular disease. Thanks to the CRISPR/Cas9 technology, we generated human-induced pluripotent stem cells (hiPSCs) depleted in MBNL proteins and evaluated the molecular and functional consequences of this loss on the generation of skeletal muscle cells. Our results indicated that MBNL proteins are specifically required for the late myogenic maturation but not for early myogenic commitment. By a transcriptomic analysis, we were able to highlight the molecular pathways regulated by these proteins during myogenesis, as well as the compensatory effects between MBNL paralogs. This study also allowed us to identify a new alternative splicing defect in DM1, regulated by MBNL proteins, which leads to structural abnormalities of the muscular post-synaptic compartment. Together, our results reveal the temporal requirement of MBNL proteins in human myogenesis and allow the identification of new molecular pathways regulated by these proteins that could be involved in the development of DM1. In the longer term, the tools developed in this study should also facilitate the identification of new therapeutic strategies capable to cope with the loss of function of these proteins
Abed, Soumeya. "Développement et évaluation du potentiel hématopoïétique de cellules souches induites à la pluripotence chez le primate humain et non humain." Paris 7, 2014. http://www.theses.fr/2014PA077112.
Induced pluripotent stem cells (iPSC) technology is a cellular model full of challenge for fundamental research and important for cellular and gene therapy applications. Before clinical application, capacity and safety of iPSC-hematopoietic derivates must be scrupulously tested in animal model close enough to humans. VVe generated Cynomolgus iPSC and carried out a kinetic analysis of hematopoietic ceil development during EB and co-culture differentiation in order to explore their capacity to engraft efficientely after autologus transplantation. We demonstrated improved hematopoietic differentiation, as evidenced by significant levels of CD34+CD45+ progenitors and CFU activity. However, achieving hematopoietic engraftment in immunodeficient mice using Cy-iPS-derived hematopoietic cells remain challenging. In the second study, we combined the iPS cells properties and the therapeutic potency of gene transfert for beta-thalassemia/HBE treatment. We have generated iPSC from the beta thalassemia/HBE patient's somatic cells and corrected them with a lentiviral vector (LV) carrying beta-globin therapeutic gene. We demonstrate their production of hematopoietic cells, in vitro, showing high expression of the transferred globin gene, differentiation into multiple blood cell types in immunocompromises mice, and endogenous globin switching in vivo. LV integration occured in regions of low and high genotoxicity and common integration sites (CIS) were identified across thal-iPSC and cells retrieved from isogenic and non isogenic gene therapy patients; suggesting that CIS observed in absence of tumorigenesis result from nonrandom LV integration rather than oncogenic in vivo selection
Annab, Karima. "Etude de l’expression génique de différents syndromes progéroïdes en utilisant le modèle des cellules souches à pluripotence induite." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0101.
Progeroid syndromes are a group of pathologies characterized by accelerated and early aging. One of the most studied of these diseases is HGPS, with an estimated incidence of 1 in 8 millions birth making it an extremely rare disease. We focused our attention on three different progeroid syndromes including classic HGPS, a HGPS-like and an atypical progeroid syndrome. These pathologies share many symptoms, including osteolysis, lipodystrophy, and cardiovascular alterations. These 3 syndromes are caused by 3 different mutations in the LMNA gene that encodes A- and C-type lamins, inducing production of a truncated Lamin A in HGPS and HGPS-like and production of a mutated Lamin with a p.T528M substitution in APS. We produced hiPSCs to create a model of these different diseases and investigate in vitro the physiopathology of these syndromes by comparing them to control cells. Cells derived from mesenchymal stem cells being the most impaired type of tissue, we established in vitro models in order to study the differentiation of hiPSCs into MSCs. In addition given the massive cardiovascular defects in these patients, we also investigated differentiation toward the VSMCs. Cell phenotypes were carefully characterized and we compared the transcripttomic profile of the different cell types. We identified dysregulation in genes involved in oxidative stress response and in DNA repair in progeroid cells. In addition, pathways essential for cell survival and proliferation are also modified when comparing progeroid and controls cells. Altogether, these results might explain some of the symptoms observed in progeroid patients but also reveal pathways involved in ageing
Hiriart, Emilye. "Modélisation cellulaire des étapes précoces de la valvulogenèse à partir d'un modèle de cellules souches embryonnaires humaines, et étude de l'implication d'Oct4 dans le phénomène de transition endothélio-mésenchymateuse lors de la formation des coussins endocardiques." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLE011.
Heart disease is the leading cause of death worldwide, nearly 30% of deaths each year are attributable to such diseases; this incidence has also greatly increased in the last century (WHO).Heart disease can be classified into several subgroups of cardiovascular disease based on the tissue affected by the pathology. It thus differs diseases affecting vessels, cardiac muscle, rhythm (fabric pacemaker and conduction) and heart valve disease. Heart valve disease can be caused by defects of innate and acquired or valves represent about 30-40% of heart defects identified. The percentage of patients with valvular heart disease patients increases with age of the patient, in addition, valvular heart disease is the leading cause of morbidity in adults and children in developed countries.These defects may be of genetic origin, congenital, toxicological, with ischemic influence of various risk factors both genetic and environmental, in some cases they can even be caused by medications, if the Benfluorex (Mediator®) are probably the most known. The defects in the valves can have serious consequences on the functioning of the heart. In 2008, the United States, it was necessary to proceed with the replacement of nearly 82,000 heart valves in adult patients.If the replacement heart valves remains a major advance for patients with valvular heart disease, the use of prostheses and transplants valves nevertheless have limitations, including: no growth prostheses, the occurrence of thrombosis and releases in cases of allo-transplantation of gene valves taken from brain dead donors. Thus, it is necessary to study the mechanisms involved early embryonic development, mechanisms that could have a deleterious effect more or less long term leading the development of valvular disease in children or young adults in the old person. For this the use of an in vitro cell model used is a remarkable achievement. This model would both elucidate a number of biological mechanisms during development or pathology, but also hope the development of a protocol for the clinical use of autologous cells reprogrammed to the therapy of patients with valvular tissue or even a therapy including an endogenous repair
Ahmed, Engi. "Modélisation de l'épithélium bronchique par les cellules souches pluripotentes induites humaines dans la Bronchopathie Pulmonaire Chronique Obstructive (BPCO)." Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTT070.
COPD (Chronic Obstructive Pulmonary Disease) is a major public health problem and will be the 3rd leading cause of death in the world in 2030. Age, smoking, and air pollution through the exposure to particulate matter but also domestic pollution - mostly represented by domestic biomass combustion - are well-identified risk factors for the development of COPD. To date, there is no cure that can interfere with the natural history of the disease.Pluripotent stem cells, including induced pluripotent human stem cells (hiPSCs), are defined by two fundamental properties: self-renewal and the ability to differentiate into all cell types in our body. They offer an unprecedented opportunity to model the normal and pathological human development of the respiratory system.This research project aimed to model in vitro the trajectories of COPD, related to a developmental origin (pediatric roots) and / or susceptibility to tobacco. In order to elucidate the underlying mechanisms of COPD and tobacco susceptibility, we established two extreme groups: i) 4 patients with a severe form of COPD, the "highly susceptible" group, ii) 4 patients who are free of COPD or other tobacco-related comorbidity despite heavy smoking, called as "highly resistant" to tobacco.We have used two different but complementary in vitro cell culture models: hiPSCs and human bronchial primary epithelial cell cultures (HBECs) grown in ALI condition (Air Liquid Interface).First of all, we generate hiPSCs cell lines by reprogramming cells from peripheral blood of a healthy subject (control), and three highly characterized severe COPD patients. In a second step, the directed differentiation of hiPSCs allowed to recapitulate the early pulmonary development (NKX2.1 generation of bronchial progenitors) by the development of a robust and reproducible directed differentiation protocol of several hiPSCs lines. The maturation of these bronchial progenitors in 2D or 3D culture allows the generation of epithelial structures expressing markers of KRT5 + basal cells , CSSP + Club cells and FOXJ1 + ciliated cells. In a second step, these epithelia will be exposed to tobacco (CSE-cigarette smoke extract) in order to induce a "COPD-like" phenotype. Finally, ALI culture of HBECs of severe COPD patients was performed in unexposed and exposed condition (CSE). Transepithelial resistance, ciliary motility, secretory profile, and RNA diversity were collected.This work allowed to put in place the necessary tools to reproduce the in vitro trajectories of COPD and to clarify the origins of this pathology. The high throughput sequencing tools (transcriptomic in our study), will allow the discovery of new candidates, that represent potential targets for future pharmacological screening
Terray, Angélique. "Développement de modèles in vitro de rétinites pigmentaires à partir de cellules souches pluripotentes humaines." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066614/document.
Retinitis pigmentosa (RP) is an inherited retinal diseases characterized by a loss of photoreceptors. We focused specific forms of autosomal dominant RP with mutations in the rod visual pigment RHODOPSIN, the ubiquitous splicing factor PRPF31 and the transcription factor involved in the development of photoreceptors NR2E3. Fibroblasts from skin biopsies of patients were reprogrammed into iPS cells by a non-integrative approach. After stabilization of iPS cell lines, we verified their pluripotency property and the absence of karyotype abnormalities. Based on the retinal differentiation protocol, iPS cells carrying a mutation in the RHODOPSIN gene have been differentiated in the photoreceptor lineage. Our results showed that the photoreceptors expressing the mutated form of RHODOPSIN summarizing the process of degeneration observed in RP patients. We show that retinal pigment epithelium (RPE) cells derived from iPS cells carrying a mutation in the PRPF31 gene lack basal membranes and have cell adhesion disorders. Consequently, their phagocytic activity is disturbed, suggesting that a malfunction of the RPE could be the primary step of the development of RP caused by mutation Cys294X in the PRPF31 gene. The models developed from specific-patient iPS cells have enabled us to better understand the processes underlying the pathogenesis of some RP. These models associated with screening protocols could be used to evaluate the efficacy and toxicity of new pharmacologic compounds but also used to validate new gene therapy approaches
Rabesandratana, Oriane. "Les cellules ganglionnaires rétiniennes dérivées de cellules souches pluripotentes humaines : de la caractérisation à la transplantation." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS322.
Among the different treatments for optic neuropathies, cell therapy using transplantation of retinal ganglion cells (RGCs) derived from human induced pluripotent stem cells (hiPSC) is one of the most promising strategy. In this project, we validated the optimized production of RGCs from retinal organoids derived from four different hiPSC lines. Our methodology included a double selection process, comprising the culture of retinal dissociated cell in adherent conditions and a magnetic sorting protocol, based on the expression of surface antigen CD90/THY1. We identified enriched RGCs resulting from this double protocol, according morphological, molecular and functional properties. These results were validated for all four hiPSC lines, including a ubiquitous fluorescent reporter cell line, using Crispr/Cas9 strategy. Intravitreal injection of reporter hiPSC line-derived RGCs into an optic nerve crush mouse model led to a partial integration of surviving cells into the host retina establishing the possibility to performed RGC transplantation. This work will be continued in order to explore the capacity of hiPSC-derived RGCs to reconnect with both retinal partners and with the different targets in the brain
Lahlou, Hanae. "Génération de progéniteurs otiques dérivés de cellules souches pluripotentes induites humaines (hiPSC) : application à la thérapie cellulaire dans l'oreille interne." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0245/document.
Neurosensory hearing loss is associated to inner ear disorders and degeneration of hair cells (HCs). Unfortunately, this process is irreversible in mammals. Currently, no curative treatment allows these cells to regenerate. For this reason, the development of cell therapy arose new hopes for the treatment of neurosensory hearing loss. Stem cells, either of embryonic or adult origin, seem able to differentiate in vitro into otic progenitors and to partially restore auditory functions in vivo. However, current protocols for in vitro differentiation of stem cells into HCs are unsatisfactory, and the signals that control this phenomenon remain poorly understood. Thus, the objective of this thesis was to study in vitro HC differentiation from human induced pluripotent stem cells (hiPSCs). We were particularly interested in two major signaling pathways involved in vivo in inner ear development, the Notch and Wnt signaling pathways.In a first part, we demonstrated that Notch inhibition during late otic differentiation enhances hiPSC differentiation into hair cell-like cells. In a second part, we studied the role of the Wnt signaling pathway during otic induction and HC specification. Our results indicate that Wnt inhibition during early otic induction promotes the expression of otic placode markers and initiate HC specification. The work presented here thus propose improved protocols to obtain HCs from hiPSCs, and suggest that this cell type is perfectly adapted for the treatment of neurosensory hearing loss
Roudaut, Méryl. "Les cellules souches pluripotentes induites humaines : un modèle innovant pour la découverte d’une nouvelle fonction de PCSK9 et la mise en place d’organoïdes de foie." Thesis, Nantes, 2020. http://www.theses.fr/2020NANT1023.
Human induced pluripotent stem cell (hiPSC) offer an attractive alternative to study novel functions linked to diseases and to setup innovative models. In this context, we studied a key player of the hepatic cholesterol metabolism regulation, PCSK9. Upon hiPSC differentiation into hepatocyte-like cells, we found an unexpected role of PCSK9 in undifferentiated cells. Using tools such as overexpression, CRISPR/Cas9-mediated gene invalidation, and hiPSC derived from a patient carrying PCSK9 loss of functions mutations, we found a regulatory effect of PCSK9 on the TGFß pathway. This effect is mediated by DACT2, a negative regulator of the TGFßR subunit R1. Through DACT2 modulation by PCSK9, the SMAD2 phosphorylation is impacted, thus hiPSC proliferation. In parallel, to enhance hepatic cells functions generated from hiPSC, we setup a new simplified procedure to obtain liver organoïdes. hiPSC are cultured in a modified hydroscaffold, BIOMIMESYS®, produced by HCS Pharma in a 96-well format suitable for molecular screening. Our procedure, recapitulating key steps of liver development, allowed us to generate liver organoids including not only hepatocytes but also, biliary-, stellate- and endothelial-cells. Functional characterizations showed enhanced cytochrome activities compared to HLC and excellent pharmacological responses with lipid accumulation upon amiodarone or ethanol treatments and LDL-bodipy uptake upon statin treatments. As our model can be personalized and automatized, if offers a new perspective for high content molecular screening
Dianat, Noushin. "Cellules souches pluripotentes humaines et modélisation de maladies hépatiques : l'hypercholestérolémie familiale et les cholangiopathies." Thesis, Paris 11, 2014. http://www.theses.fr/2014PA114810.
Cell therapy can be an alternative to liver transplantation in some cases such as severe metabolic diseases. However, the shortage of organ donors implies the need to find new sources of liver cells such as hepatocytes derived from pluripotent stem cells that can be amplified and differentiated extensively into any cell type. Human embryonic stem cells (hESC) and human induced pluripotent stem cells (hiPSC) generated from somatic cells of patients and then differentiated into hepatocytes represent a potential source of transplantable hepatocytes. These cells now make it possible to consider the transplantation of genetically modified autologous hepatocytes as an alternative to liver transplantation for the treatment of genetic diseases of the liver.Familial hypercholesterolemia (FH) is an autosomal dominant disorder caused by mutations in the gene encoding the receptor for Low Density Lipoproteins (LDLR), which is the cause of high blood cholesterol in these patients. Homozygous patients should purify their serum LDL-apheresis on average twice a month starting at a young age to avoid fatal myocardial infarction occurring in childhood.Human hepatocytes differentiated from patient’s induced pluripotent stem cells (iPSCs) allow assessing the feasibility to transplant genetically modified autologous hepatocytes as treatment of familial hypercholesterolemia.During the liver development, hepatocytes and cholangiocytes, the two types of hepatic epithelial cells, derive from bipotent hepatic progenitors (hepatoblasts). Although cholangiocytes, forming intrahepatic bile ducts, represent a small fraction of the total liver cell population (3%), they actively regulate bile composition by secretion and reabsorption of bile acids, a process that is important in cholestatic liver diseases. In the first part of this study we developed an approach to differentiate pluripotent stem cells (hESC and hiPSC) into functional cholangiocytes. These cells could be used for the modeling of genetic biliary diseases. In the second part, we generated FH patient specific iPSCs (HF-iPSC), differentiated them into hepatocytes and tried to correct the disease phenotype by lentiviral introduction of LDLR cDNA cassette in HF-iPSC
Bourguignon, Chloé. "Modélisation de l’effet de la pollution atmosphérique sur l’épithélium bronchique : les cellules souches pluripotentes induites humaines, une nouvelle voie d’étude de l’exposome ?" Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTT018.
ABSTRACTAir pollution is one of the largest environmental cause of disease and every year, 7 millions of premature deaths are attributable to air pollution worldwide. Ambient fine particulate matter plays a major role in the development of chronic respiratory diseases such as chronic obstructive pulmonary disease (COPD) or asthma. Recently, several studies have highlighted pediatric roots in the trajectories of these diseases. However, only few preclinical models are available to study these early developmental stages yet critical in respiratory health. Human induced pluripotent stem cells (hiPSC) are able to differentiate into all cell types of human body. Thus, they offer a great opportunity to recapitulate lung development in vitro, especially bronchial airway development.Thanks to our differentiation protocol of hiPSC into functional airway epithelium, we can mimic in vitro key bronchial development steps: definitive endoderm, anterior foregut endoderm, lung progenitors towards functional epithelial cells such as ciliated cells, goblet cells, basal cells, club cells and neuroendocrine cells. PM2.5 exposure performed at different steps of the protocol showed high doses related cytotoxicity, oxidative stress and inflammatory responses. An effect on differentiation process was also observed with a decrease of anterior foregut endoderm and lung progenitors markers along with a modification in differentiated cells proportion.These results open new possibilities to study air pollution impact on lung development. Thanks to hiPSC self-renewal property, high scale exposure studies of environmental factors impact on lung development could emerge by adding new cell types to this model, developing new exposure systems and modifying genetic background of hiPSC
Mery-Bories, Julie. "Utilisation des cellules souches pluripotentes humaines pour avancer dans la compréhension des atteintes neuromusculaires associées à la Dystrophie Myotonique de type 1 Building neuromuscular junctions invitro." Thesis, université Paris-Saclay, 2021. https://www.biblio.univ-evry.fr/theses/2021/interne/2021UPASL012.pdf.
Myotonic Dystrophy type I (DM1) is a rare neuromuscular disease that is mainly characterized by myotonia, progressive muscle weakness and wasting. DM1 is an autosomal dominant disorder caused by an expanded CTG repeat in the 3' UTR of DMPK gene. This abnormal expansion leads to a toxic gain-of-function of the mutated mRNAs which aggregate within the nucleus in association with different RNA binding proteins such as the MBNL family proteins. Several studies suggest the involvement of motoneurons and the neuromuscular junction in the muscular defects observed in DM1 patients. However, the mechanisms by which this intercellular system might be affected in DM1 is still poorly understood. The aim of this project was to decipher the direct and indirect consequences of the DMPK mutation and the impact of MBNL sequestration in the pre-synaptic compartment and determine the pathological contribution of motorneurons in DM1 physiopathology. Thanks to the recent development by the team of a protocol allowing the efficient conversion of human pluripotent stem cells (hiPSCs), our results demonstrated that DM1 hiPSC-derived motoneurons exhibit a defective neuritic arborization that can be mimicked by the depletion of MBNL proteins. To further evaluate the functional consequences of these findings, we developed a humanized cellular model based on the coculture of hiPSC-derived motoneurons and micropatterned human primary skeletal muscle cells. Our results demonstrated that expression of DM1 mutation only in the pre-synaptic compartment led to functional defects at the post-synaptic level. Interestingly, similar results were obtained with the specific depletion of MBNL proteins in the pre-synaptic compartment.Thanks to a transcriptomic approach, we identified a panel of deregulated genes involved in synaptic plasticity which may affect function or stability of the neuromuscular junction. Altogether, these findings hold several new implications for DM pathogenesis
Bizy, Alexandra. "Sélection des myocytes atriaux et ventriculaires dérivés des cellules souches pluripotentes humaines induites basée sur l’expression des isoformes de chaînes légères de myosine." Paris 6, 2013. http://www.theses.fr/2013PA066590.
Les protocoles de différentiation des cellules souches pluripotentes induites (CSPi) humaines en cardiomyocytes (CMs) aboutissent à la présence concomitante de cellules atriales, ventriculaires et nodales, ce qui limite leur utilisation. Pour surmonter cette limitation, nous avons construit des adénovirus avec le gène de la GFP sous le contrôle des promoteurs des chaînes légères de myosine atriale et ventriculaire MLC-2a et MLC-2v. Nous montrons que ce système de marquage à la GFP associé à la technique de cytometry en flux est efficace pour la purification de CMs présentant les caractéristiques structurales et fonctionnelles de cellules atriales et ventriculaires humaines. Cependant, si MLC-2v est un marqueur robuste pour purifier les cellules ventriculaires, promouvoir la maturation des CMs dérivés des CSPi renforcerait la spécificité du promoteur MLC-2a pour les cellules atriales. Une autre barrière à l’utilisation des CMs différenciés est leur phénotype immature. Plusieurs études ont démontré l’importance de la matrice extracellulaire dans la maturation des cellules. Nous avons donc testé l’influence de différents types de matrices sur la maturation des CMs dérivés CSPi et avons identifié des matrices extracellulaires en 2 et 3 dimensions favorisant le développement des CMs vers un phénotype adulte. Purification et maturation des CMs dérivés des CPSi constituent des avancées importantes pour leur utilisation en recherche fondamentale et clinique
Raïs, Célia. "Analyse histologique et fonctionnelle du développement de précurseurs neuraux dérivés de cellules souches pluripotentes induites humaines greffés dans le cortex de la souris." Thesis, Sorbonne université, 2019. https://accesdistant.sorbonne-universite.fr/login?url=http://theses-intra.upmc.fr/modules/resources/download/theses/2019SORUS333.pdf.
Neurodevelopmental abnormalities underlie psychiatric diseases such as schizophrenia or autism, among others. However, the genetic heterogeneity of human beings makes it difficult to establish a link between a given genome and development programs that can lead to a disease. To address this problem, induced pluripotent stem cells (iPSCs) are an ethical and effective tool. They are able to develop and differentiate into functional neurons, using a mechanism similar to in vivo development. I studied a model enabling the integration and migration of neural precursors from human iPSCs into the mouse cortex. By labelling the cells grafted by immunofluorescence, I was able to show that they differentiate mainly into upper layer cortical neurons. I have studied the relationship between host and grafted cells , and show that mouse cells participate in the development of the graft, providing vascularization, and myelinating developing human neurons. Finally, I followed the functional development of human neurons using a cell line expressing a calcium indicator, GCaMP6f, and chronically observing injected mice under a 2-photon microscope. This activity changes over time, and reflects a prenatal human brain. This model offers new possibilities for in vivo modelling of human cortical development, particularly in the study of the impact of genetic alterations in the context of psychiatric diseases
Roux, Clémence. "Activité immunosuppressive des cellules stromales mésenchymateuses dérivées de cellules souches pluripotentes induites humaines : induction de lymphocytes T régulateurs in vitro et in vivo et expression de PD-L1." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4226/document.
The mesenchymal stromal cells (MSCs) present many features that render attractive as therapeutic cells. Their phenotype, multipotency and immunosuppressive properties are well described. Nevertheless, major restriction for their clinical use is due to the limited in vitro expansion and low quantity of cells that can be collected from adult tissues. The originality of my project consisted in the generation of mesenchymal stromal cells (MSCs) from human induced pluripotent stem cells (iPS). These huiPS-MSCs could fulfill some of the specification required to improve MSCs use in therapeutic approaches: welldefined and unlimited number of cells with reproducible functional characteristics. In a first approach, I characterized the huiPS-MSCs generated in the laboratory. My results highlight the immunosuppressive activity in vitro of the huiPS-MSCs on T-cell stimulation that induces a switch in T-cell cytokine polarization toward the generation of Treg cells. Secondly, in a more therapy-oriented approach, I analyzed in vivo immunosuppressive activity of huiPS-MSCs in a xenogeneic graft versus host model (NSG immunodeficient mice injected with human T lymphocytes). My data showed significantly reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines (IFNγ and TNFα). By contrast, T cells producing IL-10 and FoxP3+ Treg cells, absent in nontreated animals, were detected in huiPS-MSCs treated mice, confirming the in vitro results of a tolerizing process. The end of my work was to characterize the molecular regulation of the expression of PDL1, an immunoregulatory molecule expressed by the MSCs. Comparing bone marrow MSCs (BM-MSCs) from healthy donors and our huiPS-MSCs, I showed that the huiPSMSCs have a constitutive expression of PD-L1, which is absent on BM-MSCs. Analysing microRNAs that could limit the expression of PD-L1, I could identify several microRNAs which expression is inverse to the expression of PD-L1. For the first time, my results highlight the immunosuppressive activity of huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo and characterize the regulation of PD-L1 expression, an immunosuppressive molecule expressed by the MSCs. They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance
Roux, Clémence. "Activité immunosuppressive des cellules stromales mésenchymateuses dérivées de cellules souches pluripotentes induites humaines : induction de lymphocytes T régulateurs in vitro et in vivo et expression de PD-L1." Electronic Thesis or Diss., Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4226.
The mesenchymal stromal cells (MSCs) present many features that render attractive as therapeutic cells. Their phenotype, multipotency and immunosuppressive properties are well described. Nevertheless, major restriction for their clinical use is due to the limited in vitro expansion and low quantity of cells that can be collected from adult tissues. The originality of my project consisted in the generation of mesenchymal stromal cells (MSCs) from human induced pluripotent stem cells (iPS). These huiPS-MSCs could fulfill some of the specification required to improve MSCs use in therapeutic approaches: welldefined and unlimited number of cells with reproducible functional characteristics. In a first approach, I characterized the huiPS-MSCs generated in the laboratory. My results highlight the immunosuppressive activity in vitro of the huiPS-MSCs on T-cell stimulation that induces a switch in T-cell cytokine polarization toward the generation of Treg cells. Secondly, in a more therapy-oriented approach, I analyzed in vivo immunosuppressive activity of huiPS-MSCs in a xenogeneic graft versus host model (NSG immunodeficient mice injected with human T lymphocytes). My data showed significantly reduced percentages of human-differentiated T cells producing Th1 inflammatory cytokines (IFNγ and TNFα). By contrast, T cells producing IL-10 and FoxP3+ Treg cells, absent in nontreated animals, were detected in huiPS-MSCs treated mice, confirming the in vitro results of a tolerizing process. The end of my work was to characterize the molecular regulation of the expression of PDL1, an immunoregulatory molecule expressed by the MSCs. Comparing bone marrow MSCs (BM-MSCs) from healthy donors and our huiPS-MSCs, I showed that the huiPSMSCs have a constitutive expression of PD-L1, which is absent on BM-MSCs. Analysing microRNAs that could limit the expression of PD-L1, I could identify several microRNAs which expression is inverse to the expression of PD-L1. For the first time, my results highlight the immunosuppressive activity of huiPS-MSCs on human T-cell stimulation with a concomitant generation of human Treg cells in vivo and characterize the regulation of PD-L1 expression, an immunosuppressive molecule expressed by the MSCs. They may favor the development of new tools and strategies based on the use of huiPS cells and their derivatives for the induction of immune tolerance
Badja, Cherif. "Optimisation de la différenciation neuronale et musculaire de cellules pluripotentes induites humaines pour la modélisation des maladies rares : exemple du syndrome de DiGeorge." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM5027/document.
The DiGeorge syndrome also known as 22q11.2 microdeletion syndrome, is the most common deletion in humans. This deletion is linked to a non-allelic homologous recombination that occurs during meiosis and involves sequences called LCRs for "Low Copy Repeats". Depending on the LCRs involved, different deletions are observed, inducing the loss of approximately 40 genes. The absence of genotype/phenotype correlation in patients and the phenotypical differences regardless of the size of the microdeletion suggests the involvement of additional parameter. The hypothesis of epigenetic changes associated with the onset or variability of symptoms has been suggested but never investigated. In order to tackle this question, we decided to focus our attention of the role of the HIRA histone chaperone encoded by a gene located in the 22q11.2-deleted region. HIRA is involved in the deposition of the H3.3 histone variant, one of the main histone in the brain. In order to determine whether HIRA is implicated in the neurological manifestations in DiGeorge patients and particularly in schizophrenia, we developed and optimized a new protocol for the direct differentiation of human induced pluripotent stem cell (hiPSCs) into neural progenitors, cortical and dopaminergic neurons. In parallel, we developed a new protocol for hiPSCs differentiation toward the skeletal muscle lineage and the production of multinucleated muscle fibers. Altogether, these results open new perspectives for the modeling of a large number of pathologies, and in the context of our laboratory, the exploration of epigenetic mechanisms associated with phenotypic variability in different genetic diseases
Khedher, Ahmed. "Utilisation de technologies d'édition du génome afin de générer des cardiomyocytes matures à partir de cellules souches pluripotentes humaines induites CtIP Fusion to Cas9 Enhances Transgene Integration by Homology-Dependent Repair." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASL002.
Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a very promising model for several scientific and therapeutic applications ranging from disease modeling to drug discovery, and from predictive toxicology to regenerative medicine. Despite numerous efforts, current protocols do not yet lead to a maturation phenotype equivalent to adult human myocardium. Indeed, key features of hiPSC-CMs remaining closer to fetal stages of development, such as gene expression, electrophysiology and function. Transcriptome analysis performed at Sanofi have confirmed these findings at the genome-wide level. Indeed, KCNJ2 and CASQ2 which are implicated in the two major physiological characteristics of cardiac cells, their electrophysiological behavior and calcium handling, respectively, were expressed at very low levels in hiPSC-CMs in comparison with adult cardiomyocytes. This thesis aimed to improve the maturation of hiPSC-CMs by using genome editing technologies. We generated stable hiPSC-CMs with inducible expression of KCNJ2, or CASQ2 or both genes (KCNJ2-CASQ2 hiPSC-CMs) and studied their functional and electrophysiological phenotype by several complementary methods. Upon doxycycline induction of KCNJ2 and CASQ2, KCNJ2-CASQ2 hiPSC-CMs displayed phenotypic benefits expected from previous studies of each maturation gene, including a drastic reduction of spontaneous beating, hyperpolarized resting membrane potential, shortened action potential duration and enhanced calcium transients. In addition, co-expression of the two genes enhanced Na+ spike slope of extracellular field potential and Ca2+ handling. We tested four reference drugs and observed signatures of known cardiac effects in KCNJ2-CASQ2 hiPSC-CMs, including arrhythmias induced by QT prolonging drug (E-4031), which were more easily detected than in control hiPSC-CMs. Therefore, KCNJ2-CASQ2 hiPSC-CMs exhibited a more mature phenotype than hiPSC-CMs and such genetically engineered hiPSC-CMs could be useful for testing cardiac toxicity of novel candidate drugs
Corbineau, Sébastien. "Génération de progéniteurs hépatiques dérivés de cellules souches : application à l’hypercholestérolémie familiale." Thesis, Paris 11, 2011. http://www.theses.fr/2011PA114821/document.
Hepatocyte transplantation represents an alternative to liver for the treatment of metabolic diseases including familial hypercholesterolaemia. Embryonic stem cells (ES) and induced pluripotent stem cells (iPS) represent new sources of hepatic cells. We have developed an approach to differentiate human stem cells into hepatic cells and thus we have generated hepatic cells derived from iPS of familial hypercholesterolaemia patients
Mianné, Joffrey. "Thérapie génique par CRISPR/Cas9 pour corriger des épithéliums bronchiques dérivés de cellules souches pluripotentes induites (iPSCs) de patients atteints de dyskinésie ciliaire primitive (DCP) : une preuve de concept." Thesis, Montpellier, 2020. http://www.theses.fr/2020MONTT045.
Primary Ciliary dyskinesia (PCD) is a rare and heterogeneous genetic disorder affecting the structure and function of motile cilia. In the airway epithelium, impaired ciliary motion results in chronic airway infections responsible for progressive and definitive decline of lung functions. There is currently no effective treatment for PCD, and research is limited by the lack of convenient models to study this disease and investigate innovative therapies.In this context, the main goals of this thesis are: 1) to develop a new in vitro PCD model based on the directed differentiation of patient-derived or genetically-engineered induced pluripotent stem cells (iPSC) into multiciliated airway epithelium, and 2) to use this model to investigate the potential of an innovative CRISPR/Cas9 gene therapy approach.To this aim, we have derived two iPSC lines, one from an healthy individual and a second from a PCD patient harbouring compound heterozygous mutations in the CCDC40 gene. Using the “healthy” iPSC line and the CRISPR/Cas9 technology we have generated isogenic knock-out controls for three PCD genes including CCDC40, DNAH5 and MCIDAS. In parallel, using the CRISPR/Cas9 technology and the homology directed repair approach, we have corrected the patient-derived iPSC line. By applying our optimized differentiation protocol to these cell lines, we are efficiently generating functional multiciliated airway epithelium recapitulating the ciliary phenotypes in function of the genotype. Furthermore, this new model has allowed us to investigate the potential of a CRISPR/Cas9-mediated reframing gene therapy approach to rescue ciliary phenotype in the patient line.In conclusion, the new model developed in this work could represent a major tool for in vitro PCD modelling. This model will be of particular interest for investigating the feasibility and efficacy of personalized therapies directly on the relevant human tissue. Our pipeline could therefore accelerate the development and translation of new therapeutics for PCD and other lung diseases
Paiva, Solenne. "Facteurs environnementaux et épigénétiques impliqués dans la différenciation cardiaque de cellules souches humaines pluripotentes induites MiRroring the Multiple Potentials of MicroRNAs in Acute Myocardial Infarction Acellular therapeutic approach for heart failure: in vitro production of extracellular vesicles from human cardiovascular progenitors." Thesis, Sorbonne université, 2019. http://www.theses.fr/2019SORUS457.
The objective of this thesis was to evaluate some physical and epigenetic parameters involved during cardiac differentiation of human induced pluripotent stem cells. Environmentally, an often undervalued physical parameter remains, the stiffness defined by the Young’s modulus. Commonly stem cells are cultured and adapted to in vitro rigidities ranging between 1-10 GPa very far from physiological values, for instance 10-15 kPa for the heart. The impact of soft culture substrates with 3 kPa, 12 kPa and 25 kPa was studied on the initial stem cells. Globally, results indicated that rigidities lower than 25 kPa were not suited for total pluripotency maintenance after 6 passages. Also, cellular colonies started to grow in 3D suggesting that softness drove them to build their own microenvironment. Epigenetically, the exact role of one of the first discovered microRNAs, the let-7 family has not yet been fully elucidated. Throughout differentiation its expression was characterized by an early transient peak at the time of mesoderm formation, after which their expression extinguished to only gradually re-increase later in the course of cardiomyocytes maturation. Modulation experiments involving mimics or inhibitors of the let-7 family on different cellular contexts suggested that initially let-7 acted on future cardiac specification but later, this family had to be repressed in order for cardiac progenitors to emerge. Oppositely, the cardiac specific miR-1 always contributed to their progression into cardiomyocytes. Together these researches contribute to fundamental research on human heart development and to applied research on human engineered cardiac tissues
Secardin, Lise. "Modélisation des néoplasmes myéloprolifératifs grâce aux cellules souches induites à la pluripotence (IPSC)." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC313/document.
Myeloproliferative neoplasms (NMP) are hematological malignancies that lead to an ovrproduction of one or more myeloid lineages. They are driving by mutations in MPLl/jak2 signaling pathway, mainly JAK2V617F, MPL, and more recently calreticulin (CARL), with two main mutations being calrdel52 and calrins5. These signaling mutations are sometimes associated with epigenetic mutations, the major one being in tet2. The objective of my thesis was to study the role of TET2 and CALRdel52 in MPN thanks to an induced pluripotent stem cells (IPSC) model. In the first part i demonstrated the role of TET2 in reprogramming process, probably independently of the catalytic domain. In the second part i demonstrated that CALRdel52 induced a TPO hypersensitivity and a TPO indenpendant growth of the megakaryocytic progenitors as well as a hyperproliferation of the megakaryocytes. This phenotype is associated with a constitutive activation of stat3 and ERK. A G-CSF independent growth of the granulocyte was also demonstrated. In conclusion this work underline the role of an epegenetic factor, TET2, in the reprogramming process and demonstrate the role of CALRdel52in MPN with an endogenous expression model
Sansac, Caroline. "Modélisation de l'épithélium bronchique humain par la technologie des cellules souches pluripotentes induites (iPS)." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT014/document.
Pluripotent stem cells (PSC) include embryonic stem cells (ES) and induced pluripotent stem cells (iPS). They are defined by two fundamental properties: self-renewal and the capacity to differentiate into all cell types. ES cells are derived from the inner cell mass of embryos. They arouse the interest of the scientific community in particular for their ability to generate all tissues. They provide major therapeutic and pharmacological applications, including regenerative medicine, in vitro modelling of human diseases and molecular screening. However, the use of human blastocysts to generate ES cells raises many ethical problems. iPS circumvent these ethical issues as they can be derived from differentiated somatic tissues. Indeed, S. Yamanaka, Nobel Prize in 2012, discovered in 2006 a simple technique of cellular reprogramming. The transient expression of four genes (OCT4, SOX2, c-MYC and KLF4) is sufficient to reprogram mouse fibroblasts into iPS. These iPS cells have the same morphology and the same properties than ES cells. The following year, S. Yamanaka applied successfully his cocktail to human fibroblasts to produce human iPS (hiPS). hiPS may also overcome immunological problems raised by the use of ES cell for cellular therapy, as hiPS can be derived from the patient to be treated. In addition, it is easier to model genetic diseases from hiPS than ES, because it is possible to choose the donor cells to reprogram according to its genotype. Finally, from a pharmacological point of view, hiPS can provide a broad platform of molecular screening to treat various diseases. The aim of my research project is to use the hiPS technology to model the development of bronchial epithelium. First, in vivo, teratomas were formed by the injection of hiPS into immunodeficient mice. Teratomas highlight the ability of differentiation of our hiPS into bronchial epithelium. Second, in vitro, reproducing embryonic and foetal bronchial development provides a way to model bronchial epithelium in a dish.These techniques open the door to many potential research avenues from screening small molecules to engineering stem cells to repair bronchial epithelium, and will in fine promote new pharmacologic or cell-based treatments for respiratory diseases
Barbet, Romain. "Cellules souches embryonnaires humaines : rôle central des contrôles de la pluripotence par la superfamille des TGF-ßs." Paris 11, 2008. http://www.theses.fr/2008PA11T095.
Carbonell, Bornay Antoine. "Modèles in-vitro de la dystrophie myotonique de Steinert : les cellules souches induites à la pluripotence." Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30770/30770.pdf.
Steinert disease is the most common adult muscular dystrophy. Unfortunately, the molecular mechanisms of that disease still misunderstood. To increase the knowledge’s, it is essential to have some cellular models available with a good proliferation capacity. It is also important to be able to establish in vitro models of heart and brain, which are also affected by the disease. Since 2007, it is possible to turn somatic cells into pluripotent stem cells. My project was to differentiate human fibroblasts of patients into induced pluripotent stem cells. We were able to reach that goal. A preliminary characterization was done to show the pluripotency of those cells. We were also able to differentiate those cells into neurons precursors expressing MAP2 and TAU proteins. Those results allow us to think that the original goal of establish induced pluripotent stem cells from Steinert patients is reach.
Tapponnier, Yann. "Cellules souches pluripotentes induites de lapin : caractérisation moléculaire et fonctionnelle des états naïf et amorcé." Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10029/document.
Pluripotent stem cells (PSCs) can self-renew at two distinct states, the naive and primed states. Many differences exist between these two states, the most striking is the unique ability of PSCs naïve to colonize the preimplantation embryo and form chimeras. The purpose of my doctoral project was to study pluripotency in rabbits. In this context, I initially manufactured and characterized induced pluripotent stem cells (RbiPSCs) and then evaluated their ability to colonize the embryo and form chimeras. Three RbiPSCs lines were obtained by rabbit fibroblasts reprogramming. Their molecular characterization revealed mixed characteristics, naïve and primed. However, functionally, they are unable to colonize the rabbit embryo, a feature of primed pluripotency. The second part of my doctoral project was to reprogram RbiPSCs to the naïve state. To this end, I have overexpressed Klf2 and Klf4, two genes belonging to the naïve pluripotency network and the mouse PSCs culture conditions. These new cell lines have a gene expression profile closer to that of the rabbit ICM, particularly due to the reactivation of specific markers of naïve pluripotency. Finally, the reverted cells have an increased capacity of colonization of the preimplantation embryo rabbit. My work represents the first example of pluripotent stem cells reprogramming toward the naive state in rabbits. The cells thus produced pave the way for the production of somatic and germline chimeras
Blondel, Sophie. "Utilisation des cellules souches induites à la pluripotence pour la modélisation pathologique du syndrome de Hutchinson Gilford." Thesis, Evry-Val d'Essonne, 2013. http://www.theses.fr/2013EVRY0014/document.
Progeria is a rare genetic disease characterized by a global, premature and accelerated aging, leading to patient death at average 13 years old. The understanding of the molecular mechanism of this syndrome has recently opened the possibility to start two clinical trials, with one common objective: slow down the disease progression blocking the maturation of the mutated protein. However, the identification of new therapeutic pathway is still a challenge to rise for this pathology. The objective of this PhD thesis has consisted to use the unique potential of induced pluripotent stem cells (iPSCs) to explore cellular and molecular mechanisms of this syndrome, identify new therapautical target and propose innovative trails of treatment. The first step of this thesis was focused on the derivation and the characterization of the iPSCs lines from patient's cells affected by this syndrome. In a surprising manner, this study has highlighted a preservation of neurons generated from progeria patients. The study of the molecular mechanisms led to the identification of the microRNA miR-9 involvement. This latter regulates progerin expression, protecting neurons from accelerated aging. The second part of this work has endeavored to explore the potential of progeria iPSCs to study the efficiency of chemical compounds proposed to patients in the different clinical trials realized these last years. Although the set of tested molecules significantly improved nuclear architecture, differences in proliferation or in osteogenic differentiation or in metabolic energetic have been detected. Finally, on the basis of this pathological modeling work, the last part of this thesis praject was to develop and realize a high content screening of more than twenty thousand small molecules to select drugs which block the maturation process of prelamin A. Eleven molecules with a high therapeutical potential have been identified, with three belonging to the same chemical family, the mono-aminopyrimidins, opening new therapeutical perspectives in progeria
Mouiseddine, Moubarak. "Utilisation des cellules souches mésenchymateuses humaines dans le traitement des atteintes tissulaires radio-induites." Versailles-St Quentin en Yvelines, 2008. http://www.theses.fr/2008VERS0038.
Ionising radiation can induce toxic effects on body. They provoke physiological modifications of tissues and organs which can be lethal. Total body irradiation or local abdominal irradiation can induce serious complications. Intestine is the first tissue concerned by these side effects. Radiation induces malabsorption of the intestine and lost of it integrity. Radio-induced physiopatological effects on intestine could lead to distant effects on other tissues and organs such as liver. The actual treatments have a limited efficiency or are not adapted to gastro-intestinal damages. Indeed, in this type of lesions, the heterogeneous systems which are concerned and the gravity of lesions complicate the medical care. Our purpose is to show that cell therapy using human mesenchymal stem cells (MSC) constitutes resolution in this type of illness. Our works show that MSC are multipotent and have heterogeneous expression of molecules. These cells are able to establish its selves in many organs and tissues after injection into irradiated mouse model. Thus we have shown that MSC can prevent the small intestine from radio-induced damages. Indeed we demonstrate that through their action on gut, MSC can indirectly restore hepatic integrity
Gouder, Laura. "Etude de l'effet de mutations du gène SHANK3 dans les TSA à partir de neurones corticaux humains dérivés de cellules souches pluripotentes induites." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCB089/document.
Autism Spectrum Disorders (ASD) is a neurodevelopmental disorder affecting 1% of population ; characterised by impairments in social interaction and reciprocal communication as well as repetitive and stereotyped behaviors. The work of the laboratory lead to the identification of several genes associated with ASD, among which genes of the synaptic pathway such as SHANK. The SHANK proteins are scaffolding proteins of the post-synaptic density (PSD) of glutamatergic neurons and interact with several partners. In my thesis project, we were particularly interested in SHANK3 mutations. First, Shank3 mutations represent up to 2.12% of ASD cases with moderate to high ID. A SHANK3 deficit leads to the alteration of the synaptic functioning. Indeed, studies of mice KO for SHANK3 gene showed a decrease of the dendritic spines density, of the PSD size and of the expression of SHANK3 partners. My principal model of analysis consisted in the reprogrammation of fibroblasts into induced pluripotent stem cells (iPSCs). Then, the iPSCs were selectively derived into cortical neurons. Our studies were focus on the analysis of functional consequences of SHANK3 de novo mutations found within 4 patients. These mutations are heterozygous and within the exon 21. They result in a premature stop codon. In parallel, we obtained cells from 4 healthy individuals. The work was about the morphological and functional aspects. We analysed the mutations effects on the maturation and morphological caracteristics of the dendritic spines. We finalized a protocol that enabled a detailed analysis of the spine dendritic 3D morphology and their maturation follow-up. A important result was the observation of a decrease of the spine density on pyramidal neurons dendrites from patients compared to those from controls. Moreover, spines maturation was not fully accomplished but was not much different in its evolution between individuals (controls vs patients). Then, we used two functional skills : calcium imaging and electrophysiological experiments. The electrophysiological data are in progress. To conclude, we succeeded in the obtention of glutamatergic cortical neurons and to maintain them in culture during 40 days in order to realize some analysis at a sufficient maturation stage to observe morphological and functional phenotypes. We mainly observed a decrease of the dendritic spines density and maturation for the neurons from patients, with alterations of the spontaneous calcium oscillations
Luce, Eléanor. "Hépatocytes différenciés à partir de cellules souches pluripotentes induites : modèle pour la thérapie cellulaire et génique autologue de l'hémophilie B et modèle préclinique chez le primate." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS520/document.
This PhD project aims to model and to bring a proof of concept for autologous cell/gene therapy of inherited liver diseases by transplanting hepatocytes differentiated from patient-specific induced pluripotent stem cells (iPSCs), after correction of the genetic defect. Hemophilia B (HB) is an inherited disease caused by a mutation in the F9 gene encoding clotting factor IX (FIX), synthesized in the liver by hepatocytes. Fibroblasts of a patient with the "royal mutation" were reprogrammed in iPSCs then differentiated into hepatocytes. The study of the F9 mRNA by high-throughput sequencing confirmed the presence of an abnormal splice site leading to a truncated protein explaining hemophilia. Other iPSCs were obtained and characterized from the cells of a second HB patient expressing an inactive FIX. By targeting in these iPSCs the insertion of a therapeutic cassette encoding FIX into a safe harbor site using artificial endonucleases (CRISPR/Cas9), we differentiated the corrected and non-corrected iPSC into hepatocytes. Quantitative analyzes confirmed a higher expression of F9 mRNA and FIX protein in the corrected clones. In contrast, we did not detect transgenic FIX activity due to a lack of post-translational modifications necessary for FIX activity. We then developed a protocol of differentiation in spheroids quantitatively more efficient to produce FIX. Detection of FIX activity will validate our in vitro approach before validation in vivo by transplanting the corrected hepatocytes in a F9KO mouse model. Finally, the last part of this work consisted in the development of a differentiation protocol of nonhuman primate iPSCs into hepatocytes for autologous transplantation into the liver of the donor animal in order to validate the feasibility and the safety of such an approach in the large animal
Laaref, Abdelhamid Mahdi. "Contribution of U2AF1, NCBP1 and eIF4A3 to the control of pluripotency maintenance and cell fate determination." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT146.
Contribution of U2AF1, NCBP1 and eIF4A3 to the control of pluripotency maintenance and cell fate determination.Alternative pathways for processing the primary transcript can profoundly affect the diversity and function of the protein products that are generated from a single gene to set up complex programs involved in pluripotency and/or differentiation of human Embryonic Stem Cells (hESCs). While transcriptional networks regulating pluripotency and differentiation has been intensively studied, the role of Alternative Splicing (AS) in this process is not yet completely understood and clear examples of concerted switching of multiple genes from one isoform to another have not been demonstrated. Our goal is to identify Core Spliceosomal Factors (CSF), involved in the control of pluripotency maintenance, early differentiation into the three germ layers, and to explore their role in these processes. By RNA-Seq data analysis, we have identified several splicing factors that are differentially expressed between pluripotent stem cells and the three of the germ layers. Among these identified candidates, we focused on the factors that are more highly expressed in pluripotent stem cells, thereby they play a specific role in pluripotency maintenance. The selected candidates, U2AF1, NCBP1 and eIF4A3 were depleted in pluripotent stem cells using inducible shRNA system and RNA-Seq analyzes have been performed to understand transcriptomic changes induced by these depletions. U2AF1 depletion causes a major switch of developmental genes expression, while NCBP1 and eIF4A3 depletions regulate the expression of genes involved in metabolism, chromatin remodeling and development. Further analysis highlighted a transcriptional and post-transcriptional regulation of differentially expressed genes. Alternative Splicing (AS) were shown to be affected by both depletions. A tissue specific AS program was associated to each of the candidates and the consequences of these changes on mRNA quality control and protein synthesis will be described.Our results build a new idea regarding the role of Core Spliceosomal Factors in cell fate control trough the modulation of AS. This knowledge adds a new layer of gene expression control and will allow a better understanding of early development mechanisms and tissue diversity
Kilens, Stéphanie. "Direct reprogramming of somatic cells into human induced naive pluripotent stem cells, a novel model of preimplantation epiblast cells." Thesis, Nantes, 2017. http://www.theses.fr/2017NANT1024/document.
Induced pluripotent stem cells (iPSCs) have considerably impacted human developmental biology and regenerative medicine, notably because they circumvent the use of cells from embryonic origin and offer the potential to generate patient-specific pluripotent stem cells. However, conventional reprogramming protocols produce developmentally advanced, or primed, human iPSCs (hiPSCs), restricting their use to post-implantation human development modelling. Hence, there is a need for hiPSCs resembling preimplantation naive epiblast. Here, we developed a method to generate naive hiPSCs directly from somatic cells using OKMS overexpression and specific culture conditions without transitioning through a primed pluripotent state. Besides, this protocol enables parallel generation of isogenic lines bearing different potencies among which the primed state as it is a major control line. To evaluate the generated naive hiPSCs, we benchmarked them against human preimplantation epiblast and reveal a remarkable concordance in their transcriptome, dependency on mitochondrial respiration, DNA methylation and X chromosome status. Collectively, these results are essential for the understanding of pluripotency regulation throughout preimplantation development and will generate new opportunities for disease modeling and regenerative medicine
Corbineau, Sébastien. "Génération de progéniteurs hépatiques dérivés de cellules souches : application à l'hypercholestérolémie familiale." Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00684386.
Julita, Emeline. "Modélisation de la dysfonction des neurones dopaminergiques associée à la maladie de Lesch-Nyhan à l'aide des cellules souches induites à la pluripotence." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLE047.
Lesch-Nyhan disease (LND) is a rare genetic disease with a prevalence estimated to 1:380,000. LND is a metabolic Xchromosome linked disorder that essentially affects boys and involves HGPRT gene (hypoxanthine-guanine phosphoribosyltransferase). Mutations in this gene result in a deficit of enzyme activity that plays a central role in the metabolism of purines. This activity deficiency induces a dysfunction on purine recycling pathway and promotes accumulation of uric acid in the joints (gout) and kidneys (stones) controlled using allopurinol. Next to these metabolic symptoms are neurological disorders which are not understood and efficiently controlled. These involve abnormal movements (dystonia) and low tonus (axial hypotonia). A unique feature of LND is the occurrence of self-injurious behaviors known as SIB (biting of lips and fingers). Brain imaging studies have revealed in LND patient a decrease of cerebral dopamine concentration but no study has yet been able to clearly link dopamine defect and HGPRT loss of activity, making it difficult to develop effective therapies. The aim of my study was to take advantage of the self-renewal and pluripotency properties of human induced pluripotent stem cells (iPSC) to produce dopaminergic neurons (nDA), then to use them to determine in which extend HGPRT is essential to the development and homeostasis of nDA. To that purpose, we selected fibroblasts obtained from skin biopsies of LND children that we have reprogrammed into iPSC. These iPSC were characterized and in particular, protein expression and enzymatic activity of HGPRT was assessed to validate our pathological model. We developed a protocol to differentiate dopaminergic neurons from iPSC to allow the study of different stages of nDA development. It provides mature precursors of nDA, expressing the typical marker of ventral midbrain (VM), while respecting the different key stages of nDA development. Upon terminal differentiation, these precursors produce at least 20% of nDA that express the two main enzymes of the dopamine synthesis pathway, namely TH and AADC. These different stages of nDA development were analyzed comparing LND and control IPSC. Neurodevelopmental abnormality occurring at an early stage of nDA formation was identified. At the final stage of differentiation, the proportion of MV precursors able to exit the cell cycle and differentiate as mature neurons is lower in LND culture compared to controls. This study provided evidences that it is possible to model a metabolic disease with iPSC and that they are essential tools to study neurodevelopmental disorders. This approach provides a better understanding of mechanisms responsible for the disease, and new research directions for therapeutic approaches
Saliba, Joseph. "Modélisation des néoplasmes myéloprolifératifs sporadiques et familiaux avec les cellules de patients induites à la pluripotence." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA11T061.
Myeloproliferative neoplasms (MPN) are clonal hematologic diseases which lead to an overproduction of blood cells. The affected myeloid lineage depends on the type of MPN. JAK2V617F is the most predominant mutation in MPN and can be associated with various sporadic and familial cases.One main issue to address in MPN is to understand how a single mutation JAK2V617F can give rise to several diseases. Our hypothesis is that this phenotypic heterogeneity might be due to the JAK2V617F gene dosage. Another goal is to identify the genetic cause of familial MPN.For these reasons, we modeled sporadic and familial MPN cases with iPS technology. This approach allowed us i) to compare the impact of heterozygous and homozygous JAK2V617F mutation on hematopoiesis and ii) to get insight into the effects of a 5 genes duplication that we identified as a susceptibility locus uncovered by a genetic approach in 2 families.In the first part of the work concerning sporadic MPN modeling, we showed that JAK2V617F increases iPS myeloid potential. Furthermore, we showed a marked difference in the TPO and EPO hypersensitivity between heterozygous and homozygous JAK2V617F iPS cell lines that could be linked to the difference between PV and ET. In the second part of the work, we demonstrated a specific phenotype due to the sole duplication. This model will allow us to identify the gene(s) responsible of the phenotype. This study brings the proof of concept that iPS can be used for sporadic and familial MPN modeling and drug screening
Zhou, YI-Ping. "Lignées de cellules souches pluripotentes humaines : contribution à l'étude des contrôles de la balance pluripotence / différenciation par la super-famille des TGF-ßs." Paris 11, 2009. http://www.theses.fr/2009PA11T041.
Muller, Quentin Philippe Sylvain. "Développement par génie tissulaire d’un modèle de peau humaine innervée, vascularisée et immunocompétente pour l’étude des réactions inflammatoires cutanées." Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ061.
Immune reactions in the skin are initiated by the cutaneous dendritic cells (DCs). The potential sensitizing effect of a compound can be predicted in vitro using human monocytes differentiated into DCs (Mono-DCs). However, these simplistic models remain inaccurate because the activation of cutaneous DCs by sensitizers may be triggered or modulated by microenvironmental interactions with multiple types of non-immune cells. Our goal is to develop an immunocompetent human tissue-engineered skin that will combine DCs with all structural and functional element of the skin, i.e. an epidermal barrier laid upon a dermis containing a pseudo-vascularization and nociceptive neurons. Collagen matrix was seeded with fibroblasts and endothelial cells, then with precursors of nerve fibers derived from either human iPSC or murine embryonic DRG. Finally, we introduced Mono-DCs and keratinocytes. We observed that in situ differentiated neurons grow axons towards the epidermis as usually observed in normal human skin. What's more, the neurons derive from iPSC, express neuropeptides and calcium channel as normal nociceptive fibers. Moreover, Mono-DCs settled as expected beneath the epidermis and remained sessile to stimulation for several weeks. The model will be used to predict the irritant potential of chemical compounds, and the impact of nerves on DC activation
Bouckenheimer, Julien. "Rôle fonctionnel des longs ARN non codants dans l'adaptation et la pluripotence des cellules souches en culture." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONT3505.
The actual and future applications of human pluripotent stem cells (PSC) in the biomedical field are highly promising. Their use for the discovery of new therapeutic drugs through the development of high-throughput screening tests, cytotoxicity tests and in vitro disease modeling has been added to their tremendous interests in regenerative medicine and cellular therapy. As a source of biological material that can be used to restore partially or totally the lost functions of a damaged organ or tissue, or as a source of normal cells to study human development or test putative new drugs, their genomic integrity has to be thoroughly assessed. Therefore, an effective optimization of their culture conditions has to be considered, in order to control the absence of genomic instability and prevent their potential emergence. Any genetic or epigenetic alteration resulting from cell culturing must be detected in order to define and characterize acceptance criteria for scientific and medical purposes.PSC are particularly sensitive to stress resulting from unappropriated passaging techniques, which cause rapid genetic drift. Indeed, our team observed that many genomic abnormalities arise from aggressive single cell, enzymatic based, passaging methods, and that substantial phenotypical changes such as increased survival after cell dissociation and variation in cell shape can then occur.In order to understand the mechanisms governing the emergence of those adverse alterations, the team focused on the consequences resulting from the adaptation of PSC to single-cell dissociation. By using new generation sequencing techniques as RNA-Seq, we compared transcriptomics of PSC passaged by standard techniques (such as mechanical passaging) versus single-cell enzymatic dissociation (such as TRyPLE-based single-cell passaging). This comparison showed that the most striking difference in the gene expression pattern between adapted and non adapted cells concerned the dramatic overexpression of RNAs from a recently discovered class: long non-coding RNAs (lncRNAs).The aim of this thesis work was to determine to which extent some of these lncRNAs were functionally linked to adaptation of PSC. In order to address this matter, we first investigated in silico which lncRNAs were upregulated by single-cell dissociation, and after experimental validation of lncRNA candidates by molecular biology, we performed functional in vitro analysis (notably by siRNA-mediated loss of function) and sought their cellular localization in order to decipher their role in the cellular machinery and their level of implication. Beside this main project, other auxiliary projects were grafted. The observation of major changes in cell phenotype and behavior led to the investigation of the global mechanisms governing these modifications, underlining the potential role of epithelial-to-mesenchymal transition provoked by single-cell dissociation. Finally, the global attractiveness of lncRNAs and the emergence of exponential documentation concerning non-coding RNAs prompted the writing of an extensive review and meta-analysis concerning the implications of lncRNAs during embryo development and in pluripotent stem cells
Ferratge, Ségolène. "Immaturité, sénescence et hiérarchie fonctionnelle des progéniteurs endothéliaux humains." Thesis, Sorbonne Paris Cité, 2016. http://www.theses.fr/2016USPCC221/document.
ECFCs (endothelial colony forming cells) are derived from endothelial progenitor cells in vitro. Angiogenic capacity of these cells confers a therapeutic benefit for treating ischemic injuries resulting from cardiovascular pathologies. ECFC isolated from peripheral blood adult (AB-ECFC) are less functional and lose their ability to form long lasting blood vessels in contrast to umbilical cord blood ECFC (CB-ECFC). A better understanding of mechanisms involved in this dysfunction is required to understand and prevent alteration of AB-ECFC during aging for autologous strategy. Similarly, the use of CB-ECFC in heterologous cell therapy is conditioned by further functional characterization of this source of angiogenic cells.This thesis has established a specific profile of ECFC yield from adult and cord blood. No correlation with donor age has been demonstrated. The CB-ECFC are particularly heterogeneous, generating from 0 to more than 100 colonies. Samples generating less than 10 colonies have a similar dysfunction than AB-ECFC, associated with loss of their immature features. The most clonogenic CB-ECFC are also the most angiogenic. The initial clonogenicity of ECFC therefore appears to be the earliest marker available during their culture to predict their future functionality. It could be a relevant criterion for classifying and selecting the most effective CB-ECFC cell therapy
Nassor, Férid. "Etude de mécanismes de type prion impliqués dans la maladie d’Alzheimer sur un modèle de mini-cerveaux humains avec exploration par microscopie 3D." Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS105.
Human neurodegenerative diseases, which are all based on prion-like mechanisms (self-propagation of pathogenic protein aggregates), represent a major societal risk with the increase of their prevalence directly correlated to the increasing longevity of the world population. There is to date neither any cure nor any pertinent experimental model for their study.The objective of this work was to use the potential of human mini-brains, a self-assembled three-dimensional in vitro model able to restitute the complexity of the cerebral cortex. This model will allow us to study prion-like mechanism by developing a validation methodology based on 3D microscopy. These novel 3D structures can be obtained from reprogrammed adult cells into induced pluripotent stem cells (iPSCs) and offer unique possibilities to access, observe and disrupt biological processes in the human brain without bias nor complications as in animal models and ex vivo human brain samples. This model makes it possible to observe the development of aggregates of Aβ and hyper-phosphorylated Tau, two proteins that accumulate and propagate from cell to cell during Alzheimer’s disease.We have been to able to adapt the cerebral organoid model for a future screening approach by modifying the differentiation methodology to enhance its production ratio. We also have been able to test different modalities for disease modeling for Alzheimer’s disease, Parkinson’s disease, Fronto-Temporal Dementia and Creutzfeldt-Jakob disease: with chemical induction, with patient specific cells, through genetic modification and through contact with infectious material. These different approaches allowed us to validate that the cerebral organoid can indeed reproduce key aspects found during pathological development within patients. To compensate for the heterogeneity of the cerebral organoid, we performed an in toto analysis through microscopy, meaning in its totality without prior slicing. The chosen method of acquisition is fluorescence light-sheet microscopy used after staining and optical clearing of cerebral organoids. To do so, we have evaluated and established different strategies in order to obtain a high content screening platform for our cerebral organoid model.This platform centered around the cerebral organoid model, underpinned by 3D microscopy analysis, was developed during the “Investissements d’Avenir” project 3DNeuroSecure. This project has for ambition to bring high performance computing to the biological sciences, notably with the possibility to deal with large scale data, also called “exascale”, like the ones obtained with 3D microscopy. The development of this aspect would allow us to establish the basis for a therapeutic screening tool based on cerebral organoids for neurodegenerative diseases. We have demonstrated that prion-like mechanisms can be studied in a human mini-brain model and multiple research avenues are now opened for both fundamental and applied research. This platform could in turn become the basis for any kind of organoids derived from patients to model the whole human body and become a biological companion for personalized medicine