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La culture cellulaire in vitro a toujours motivé les scientifiques pour découvrir de nouveaux médicaments, explorer de nouvelles thérapies et pour mieux comprendre la biologie cellulaire. Cependant, la culture cellulaire requiert un environnement très bien contrôlé, d'où l'émergence des incubateurs cellulaires commerciaux. Ceci dit, la recherche scientifique requiert l'observation en continu du développement cellulaire dans un environnement contrôlé. Bien que plusieurs approches soient disponibles afin de miniaturiser des instruments pour les intégrer dans un incubateur, peu d'approches ont été abordées avec succès pour miniaturiser un micro-incubateur et l'intégrer dans des systèmes de contrôle. Ainsi, le parallélisme présent dans un système à base de FPGA ajouté à la puissance de calcul des processeurs motive l'intégration d'un système de contrôle de micro-incubateur sur une même puce. La volonté de miniaturiser et d'intégrer plusieurs sous-systèmes de contrôle dans un même système embarqué motive d'autant plus l'utilisation d'une architecture Zynq UltraScale+. Ces travaux de recherche permettent d'intégrer le contrôle d'un micro-incubateur sur une architecture Zynq UltraScale+, de développer une interface graphique conviviale permettant l'observation et le contrôle d'un système de micro-incubateur et, finalement, de tester et valider le fonctionnement de l'implémentation des différents sous-systèmes de contrôle du micro-incubateur. Le développement des éléments de contrôle du micro-incubateur s'effectue à l'aide des outils de Xilinx. Ceux-ci permettent de développer le code VHDL, le code des processeurs temps réels et de compiler un système d'exploitation Linux personnalisé. L'interface graphique est développée avec l'outil QtCreator et intégrée sur le système d'exploitation Linux. Une carte de développement Ultra96 et des cartes électroniques connexes permettent de valider le fonctionnement de l'implémentation du contrôle du micro-incubateur. Toutes les composantes du contrôle du micro-incubateur sont validées en simulation VHDL, intégrées sur la carte Ultra96 et testées. L'interface graphique développée sur le système d'exploitation Linux communique de manière efficace avec les processeurs temps réels afin de permettre le contrôle et l'observation des différents sous-systèmes. / The in vitro cell culture has always motivated scientists to discover new drugs, explore new therapies or for a better understanding of cell biology. However, cell culture requires a very well controlled environment, hence the emergence of commercial cell incubators. Thus, research in this field requires the continuous observation of cell development in a controlled environment, among others. Although several approaches were available to miniaturize tools used in biological research to be integrated into an incubator, few approaches have been successfully addressed to miniaturize a micro-incubator to be integrated into a biological sensor. Thus, the parallelism of an FPGA-based system in addition to the computing performances were key elements for the integration of a micro-incubator control system on the same FPGA. In addition, the miniaturization and integration of several control subsystems in a single on-board systems were a key element to use a Zynq UltraScale + architecture. In this research work we aim to integrate the control system of a micro-incubator on a Zynq UltraScale + architecture and to develop a user-friendly graphical interface to observe and to control of a micro-incubator system. Finally, we aim to test and validate our implementations of the various micro-incubator control subsystems. The development of the micro-incubator's control elements is carried out using Xilinx tools. These allow to develop the VHDL code, the code for real-time processors and to compile a custom Linux operating system. The graphical interface was developed with the QtCreator tool and integrated into the Linux operating system. An Ultra96 development board and related electronic boards were used to validate the operation of the micro-incubator control implementation. All the micro-incubator control components were validated in VHDL simulation, integrated in the Ultra96 card and tested. The graphical interface developed on the Linux operating system communicates with the real-time processors in order to control and to observe various subsystems' behavior.

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In this study, we show that removal of a quorum sensing subtype of stromal macrophage expands the support capacity of ex vivo bone marrow culture. Notably, this system maintains much of the remaining paracrine signaling of the organ, unlike traditional macrophage ablation or cytokine supplemented media and does not place undue stress on the HSPC itself. Recent studies have independently identified alternatively activated macrophages that suppress hematopoiesis in in vitro culture. We have identified for the first time, a small molecule capable of preferentially killing those cells, thus providing a method to both culture unaltered HSPC ex vivo for long periods of time and significantly expand transient progenitor cells to assist transplantation efficiency. Our culture system in unique in its ability to maintain cultured HSPC in the physiological micro-environment of the bone marrow We found the small molecule “999” capable of expanding hematopoietic capacity of stroma culture by selectively eliminating an MHCII-Hi subpopulation of stromal macrophages that suppress HSPC growth. Removal of these macrophages enables long-term HSC ex vivo stability and massive expansion of the MPP and its progeny. Cultures expanded in this manner have increased engraftment potential and behave physiologically normal upon transplantation. This investigation has also helped to uncover the role of TGFB in bone marrow quiescence signaling. The MHCII-HI target cells express TGFB and through it, signal quiescence to the HSPC, likely as a form of quorum sensing. Targeted acute elimination of that signal leads to unabashed expansion of MPP. Furthermore, macrophage polarization in the tumor microenvironment has also been show to promote tumor formation and often leads to poor prognosis. Molecular tools such as 999 that have the ability to alter macrophage polarization ratios may prove to be valuable synergistic tools for oncologists in conjunction with current therapies.

Fong Shu Pan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 147-167). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.i / LIST OF PUBLICATIONS --- p.ii / ABSTRACT --- p.iii / ABSTRACT [IN CHINESE] --- p.vii / TABLE OF CONTENT --- p.ix / LISTS OF FIGURES --- p.xv / LIST OF TABLES --- p.xxi / LIST OF ABBREVATIONS --- p.xxii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Embryonic stem (ES) cells --- p.1 / Chapter 1.2 --- Stem cell plasticity --- p.5 / Chapter 1.2.1 --- Differentiation and trans-differentiation of lineage-restricted stem cells --- p.5 / Chapter 1.2.1.1 --- Multilineage differentiation in-vitro --- p.5 / Chapter 1.2.1.2 --- Trans-differentiation --- p.6 / Chapter 1.2.2 --- Prospective applications of stem cells --- p.7 / Chapter 1.2.2.1 --- Basic research on development --- p.7 / Chapter 1.2.2.2 --- Study of human disease --- p.7 / Chapter 1.2.2.3 --- Cancer research --- p.7 / Chapter 1.2.2.4 --- Drug screening --- p.8 / Chapter 1.2.2.5 --- Cell therapy --- p.8 / Chapter 1.3 --- Neuro-degenerative diseases and cell therapy --- p.9 / Chapter 1.3.1 --- Neuro-degenerative diseases --- p.9 / Chapter 1.3.2 --- Neuro-regeneration --- p.10 / Chapter 1.3.3 --- Cell sources for neuro-regenerative therapy --- p.11 / Chapter 1.3.3.1 --- Comparison of stem cells --- p.11 / Chapter 1.3.3.2 --- Stem cells in neuro-regenerative therapy --- p.12 / Chapter 1.4 --- In-vitro derivation into neural lineage --- p.17 / Chapter 1.4.1 --- In-vitro induction strategies available --- p.17 / Chapter 1.4.1.1 --- Chemical agents --- p.18 / Chapter 1.4.1.1.1 --- Retinoic acid (RA) --- p.18 / Chapter 1.4.1.1.2 --- Ascorbic acid --- p.19 / Chapter 1.4.1.2 --- Growth factors/cytokines --- p.19 / Chapter 1.4.1.2.1 --- Neurotrophins --- p.20 / Chapter 1.4.1.2.2 --- Stimulants --- p.20 / Chapter 1.4.1.2.3 --- Signalling molecules --- p.21 / Chapter 1.4.1.3 --- Culture Selection --- p.23 / Chapter 1.4.1.3.1 --- Conditions --- p.23 / Chapter 1.4.1.3.2 --- Medium --- p.23 / Chapter 1.4.1.4 --- Transfection of regulator genes using viral vector --- p.24 / Chapter 1.4.1.5 --- Stromal cell-derived inducing activity (SDIA) --- p.26 / Chapter Chapter 2 --- Aims --- p.28 / Chapter 2.1 --- Hypothesis and study objectives --- p.28 / Chapter 2.1.1 --- Soliciting an optimal method for ES cell propagation --- p.28 / Chapter 2.1.2 --- Pursuing alternative SDIA --- p.29 / Chapter Chapter 3 --- Materials and Methods --- p.33 / Chapter 3.1 --- Chemicals and Reagents --- p.33 / Chapter 3.1.1 --- Cell Culture --- p.33 / Chapter 3.1.2 --- Immunohistochemistry and staining --- p.35 / Chapter 3.1.3 --- Molecular Biology --- p.36 / Chapter 3.2 --- Consumable --- p.37 / Chapter 3.3 --- Cell lines --- p.39 / Chapter 3.3.1 --- Feeder cells --- p.39 / Chapter 3.3.1.1 --- Primary mouse embryonic fibroblasts --- p.39 / Chapter 3.3.1.2 --- STO --- p.39 / Chapter 3.3.1.3 --- L Cells --- p.40 / Chapter 3.3.1.4 --- L-Wnt-3A Cells --- p.40 / Chapter 3.3.1.5 --- C17.2 --- p.40 / Chapter 3.3.2 --- ES cells --- p.41 / Chapter 3.3.2.1 --- ES-D3 --- p.41 / Chapter 3.3.2.2 --- ES-E14TG2a --- p.41 / Chapter 3.4 --- In-house prepared solutions --- p.42 / Chapter 3.4.1 --- "Stock solution of Insulin, Transferrin, Selentine (ITS) Supplement" --- p.42 / Chapter 3.4.2 --- Enriched Knock-Out Dulbecco's Modified Eagle's Medium (KO DMEM) --- p.42 / Chapter 3.4.3 --- Mitomycin C solution --- p.42 / Chapter 3.4.4 --- Gelatin solution 0.1% --- p.42 / Chapter 3.4.5 --- p-mercaptoethanol solution --- p.43 / Chapter 3.4.5.1 --- (3-mercaptoethanol solution 0.1M --- p.43 / Chapter 3.4.5.2 --- P-mercaptoethanol solution 0.1M --- p.43 / Chapter 3.4.5.3 --- p-mercaptoethanol solution 0.1M for preparation of culture medium --- p.43 / Chapter 3.4.6 --- ALL-trans retinoic acid --- p.43 / Chapter 3.4.6.1 --- ALL-trans retinoic acid stock solution 0.01M --- p.43 / Chapter 3.4.6.2 --- ALL-trans retinoic acid working solution lμM --- p.43 / Chapter 3.4.7 --- Paraformaldehyde solution 4% (PFA) --- p.44 / Chapter 3.4.8 --- TritoxX-100 solution --- p.44 / Chapter 3.4.8.1 --- Tritox X-100 solution 3% --- p.44 / Chapter 3.4.8.2 --- Tritox X-100 solution 0.3% --- p.44 / Chapter 3.4.9 --- Popidium iodide solution lug/mL (PI) --- p.44 / Chapter 3.4.10 --- Geneticin solution --- p.45 / Chapter 3.4.10.1 --- Geneticin solution 50mg/mL --- p.45 / Chapter 3.4.10.2 --- Geneticin solution 5mg/mL --- p.45 / Chapter 3.4.11 --- Poly-L-ornithine solution --- p.45 / Chapter 3.4.12 --- Laminin solution --- p.45 / Chapter 3.4.13 --- Maintenance medium for cell feeders --- p.46 / Chapter 3.4.14 --- Mitomycin C inactivation medium --- p.46 / Chapter 3.4.15 --- Freezing medium --- p.46 / Chapter 3.4.16 --- Propagation medium for ES cells --- p.47 / Chapter 3.4.16.1 --- Serum-based propagation medium for ES cells --- p.47 / Chapter 3.4.16.2 --- Serum-free propagation medium for ES cells --- p.47 / Chapter 3.4.16.3 --- Serum-free induction medium for ES cells --- p.48 / Chapter 3.4.16.3.1 --- Serum-free induction medium 1 --- p.48 / Chapter 3.4.16.3.2 --- Serum-free induction medium II --- p.48 / Chapter 3.4.16.3.3 --- Serum-free induction medium III --- p.48 / Chapter 3.5 --- Equipments --- p.49 / Chapter 3.6 --- Methods --- p.50 / Chapter 3.6.1 --- Cell Culture --- p.50 / Chapter 3.6.1.1 --- Preparation of round cover-slips --- p.50 / Chapter 3.6.1.2 --- Gelatinization of tissue culture wares --- p.51 / Chapter 3.6.1.3 --- Poly-L-ornithine and laminin coating --- p.51 / Chapter 3.6.1.4 --- Thawing frozen cells --- p.51 / Chapter 3.6.1.5 --- Passage of adherent culture --- p.52 / Chapter 3.6.1.6 --- Cell count --- p.52 / Chapter 3.6.1.7 --- Cytospin --- p.53 / Chapter 3.6.1.8 --- Cell viability test --- p.53 / Chapter 3.6.1.9 --- Cryopreservation --- p.53 / Chapter 3.6.1.10 --- Preparation of primary mouse embryonic fibroblast (PMEF) --- p.54 / Chapter 3.6.1.11 --- Mitomycin C inactivation of feeder cells --- p.55 / Chapter 3.6.1.12 --- Gamma irradiation of various feeders --- p.55 / Chapter 3.6.1.13 --- Preparation of CM from feeder cells --- p.56 / Chapter 3.6.1.14 --- Propagation of ES cells in serum-based medium --- p.56 / Chapter 3.6.1.15 --- Propagation of ES cell in serum-free medium --- p.56 / Chapter 3.6.1.16 --- Neural differentiation using all-trans retinoic acid --- p.57 / Chapter 3.6.1.17 --- Stromal cells-derived inducing activity --- p.58 / Chapter 3.6.1.18 --- BrdU labeling of the cell products --- p.59 / Chapter 3.6.2 --- Molecular analysis --- p.60 / Chapter 3.6.2.1 --- RNA extraction --- p.60 / Chapter 3.6.2.2 --- RNA quantitation --- p.60 / Chapter 3.6.2.3 --- Reverse Transcription of the First Strand complementary DNA --- p.61 / Chapter 3.6.2.4 --- Polymerase chain reaction --- p.61 / Chapter 3.6.2.5 --- RNA Integrity Check --- p.66 / Chapter 3.6.2.6 --- Electrophoresis and visualization of gene products --- p.66 / Chapter 3.6.3 --- Immunofluoresent staining --- p.66 / Chapter 3.6.4 --- In-vivo studies --- p.69 / Chapter 3.6.4.1 --- Induction of cerebral ischaemia in mice --- p.69 / Chapter 3.6.4.2 --- Transplantation --- p.69 / Chapter 3.6.4.3 --- Assessment of learning ability and memory --- p.70 / Chapter 3.6.5 --- Histological analysis --- p.70 / Chapter 3.6.5.1 --- Animal sacrifice for brain harvest --- p.70 / Chapter 3.6.5.2 --- Cryosectioning --- p.71 / Chapter 3.6.5.3 --- Paraffin sectioning --- p.71 / Chapter 3.6.5.4 --- Haematoxylin and eosin staining --- p.72 / Chapter 3.7 --- Data analysis --- p.73 / Chapter Chapter 4 --- Results --- p.74 / Chapter 4.1 --- ES cell maintenance --- p.74 / Chapter 4.1.1 --- Serum effect --- p.74 / Chapter 4.1.2 --- Feeder effect --- p.79 / Chapter 4.1.3 --- Serum-free and feeder-free condition --- p.86 / Chapter 4.1.4 --- Overall effect --- p.89 / Chapter 4.2 --- ES cell Induction --- p.91 / Chapter 4.2.1 --- Retinoic acid --- p.91 / Chapter 4.2.2 --- Stromal cell-derived inducing activity --- p.96 / Chapter 4.2.2.1 --- Molecular characterization of candidate stromal cells --- p.96 / Chapter 4.2.2.2 --- Direct contact co-culture --- p.98 / Chapter 4.2.2.3 --- Non-contact co-culture --- p.100 / Chapter 4.2.2.4 --- Cultures in CM --- p.109 / Chapter 4.3. --- ES cell Differentiation --- p.115 / Chapter 4.4 --- In vivo study of ES cell-derived cell products --- p.117 / Chapter 4.4.1 --- Animal preparation --- p.117 / Chapter 4.4.2 --- Cell preparation --- p.117 / Chapter 4.4.3 --- Cell implantation --- p.117 / Chapter 4.4.4 --- Behaviour Monitoring --- p.121 / Chapter 4.4.5 --- Histology of cell-implanted brain --- p.125 / Chapter Chapter 5 --- Discussion --- p.129 / Chapter Chapter 6 --- Conclusion --- p.144 / References --- p.147

Ce travail cherche à définir plus précisément la culture de l‘information notamment de manière conceptuelle. L‘examen généalogique et archéologique du concept montre une diversité des représentations. Nous cherchons à montrer que la culture de l‘information repose sur divers héritages qui font d‘elle une culture technique au sens de Simondon, c'est-à-dire une culture qui ne repose pas sur le seul usage mais sur la compréhension de l‘objet technique. Ce positionnement que Simondon qualifie de majeur face à la technique est proche de du statut de majorité de l‘entendement tel que le définit Kant dans son texte sur les Lumières. Nous examinons également les proximités avec lrinformation literacy dont la culture de l‘information constitue une des traductions possibles. Les évolutions des usages notamment liés au numérique font apparaître une convergence médiatique, bien mise en avant par Henry Jenkins, et qui sont le sujet d‘étude de nombreuses littératies et notamment de la translittératie. La nécessité d‘une formation commune et plus rationnelle apparaît face à la diversité des enjeux numériques, informationnels et institutionnels. La culture de l‘information devient de plus en plus une culture de la communication ou des hypomnemata selon la définition de Stiegler. La diversité des enjeux institutionnels et obstacles informationnels et médiatiques qui s‘avèrent souvent des déformations obligent à penser la reformation de la culture de l‘information notamment dans l‘optique d‘une transmission intergénérationnelle.

L'activité cellulaire répond à la stimulation électrique (SE). Le but de cette thèse était le développement d'un composite multifonctionnel et l'étude de la réponse des ostéoblastes à la SE transmise par un tel composite. Les objectifs spécifiques étaient les suivants: a) synthèse des particules de haute conductivité en polypyrroles (PPy) avec des rendements élevés en contrôlant la taille et la régularité moléculaire; b) bioactivation des particules PPy par dopage à l'héparine (HE); c) préparation de composites multifonctionnels électriquement stables et présentant une haute affinité biologique; d) étude de la prolifération et de la minéralisation des ostéoblastes sur un échafaudage conducteur sous SE. Le chapitre I résume les phénomènes bioélectriques chez l'humain à différents niveaux, les mécanismes possibles de l'action de l'électricité sur les cellules, et l'étude de la SE en génie tissulaire osseux. Ce chapitre propose également une revue critique des différentes techniques et des différentes méthodologies de SE utilisées pour des études environnementales, scientifiques et pour les soins cliniques. Les hypothèses et les objectifs de la thèse sont présentés. Le chapitre II décrit la synthèse des nanoparticules en PPy par polymérisation en emulsion en utilisant le réactif de Fenton comme oxydant. Ces nanoparticules présentent une morphologie polygonale creuse, avec une épaisseur approximative de 50 nm et un diamètre de 400-500 nm. Les caractéristiques cristallines de ces nanoparticules ont été démontrées. Un mécanisme plausible de synthèse est proposé. Le chapitre III rapporte la bioactivation des particules en PPy en utilisant F héparine (HE) comme dopant, la préparation d'une membrane conductrice biodégradable, et la culture de fibroblastes sur ces membranes. Le dopage avec HE améliore la stabilité électrique de la membrane conductrice et augmente l'adhésion et la prolifération de cellules. Le chapitre IV démontre que la SE induite par la membrane conductrice peut moduler l'activité des ostéoblastes et accélérer la formation osseuse. Un champ électrique optimal de 200 mV/mm avec une durée de stimulation entre 2 et 8 h a favorisé la prolifération des ostéoblastes et augmenté l'expression et la production de ses marqueurs spécifiques de maturation (ALP) et de minéralisation (CO). Le chapitre V présente une discussion générale, le sommaire des conclusions et les perspectives de recherche pour le futur. L'implication de ces travaux en génie tissulaire et en santé humaine est également abordée.

In recent years, three dimensional (3D)-culture technique has emerged as a very popular approach to reconstruct tissue architectures and develop experimental models for studying epithelial cancers. However, 3D culture models of prostate epithelial cells to mimic prostate cancer development are relatively rare, making it highly desirable to develop and characterize novel 3D culture models suitable for studying prostate cancer. Recently, epithelial-mesenchymal transition (EMT) has emerged as an important mechanism for cancer cell invasion. The zinc finger transcriptional factor Snail as a key regulator of EMT has been found to contribute to aggressive progression in many types of neoplasms. Even though several studies corroborated that EMT is implicated in prostate cancer, the expression patterns of Snail in normal prostate and prostate cancer, and the functional role of Snail in prostate cancer as well as its relation with EMT are still unknown. Based on this background, my major efforts were to establish a 3D culture model of human prostatic epithelial cells with structural and functional relevance to prostate gland and to employ this model to study the functional role of Snail in the prostate cancer. / When embedded in Matrigel for 3D culture, BPH-1 cells developed into growth-arrested acinar structures with a hollow lumen. Ultrastructural examination of BPH-1 spheroids by electricon microscopy indicated that BPH-1 spheroids displayed a polarized differentiation phenotype. Immunoflurescence analysis of polarized epithelial markers further confirmed that BPH-1 spheroids were polarized. In contrast, tumorigenic BPH-1CAFTD cells exhibited disorganized and continuously proliferating structures in Matrigel, with polarized epithelial markers randomly diffused or completely lost. In addition, BPH-1 CAFTD cells displayed significantly higher invasive capacity in comparison to BPH-1 cells by transwell invasion assay. Moreover, LY294002 treatment of BPH-1CAFTD1 and BPH-1CAFTD3 cells in 3D cultures resulted in impaired cell proliferation as evidenced by reduced colony size and decreased Ki-67 index, and western blot analysis showed that cyclin D1 protein levels were significantly decreased, while p21 protein levels were slightly up-regulated in LY294002-treated 3D cultures. Additionally, LY94002 significantly decreased the invasive capacity of BPH-1CAFTD1 and BPH-1CAFTD3 cells. Interestingly, LY294002 treatment completely reverted the disorganized non-polar 3D structures of BPH-1CAFTD1 cells to well-organized polarized spheroid structures in Matrigel, but failed to restore the polarized differentiation in 3D cultures of BPH-1CAFTD3 cells, which still formed compact aggregates as shown by confocal immunofluorescence analysis. Snail protein was barely detected in the epithelial cells of human benign prostatic tissue but significantly elevated as nuclear protein in primary prostate cancer and bone metastatic specimens by immunohistochemical analysis. Snail transcript levels were weakly expressed in a majority of nonmalignant prostatic epithelial cell lines, while markedly increased in almost all tested cancer cell lines. Snail expression induced a morphological switch to more scattered and spindle-shaped appearance in BPH-1 and BPH-1CAFTD1 cells in 2D culture, and immunofluorescence analysis of several EMT specific markers indicated that Snail-expressing cells underwent EMT. In 3D contexts, Snail-expressing cells developed into more disorganized structures with many cords or protrusions, with a concurrent EMT change as evidenced by reduced E-cadherin and increased vimentin expression. In addition, Snail expression augmented the invasive capacities in both BPH-1 cells and BPH-lCAFTD1 cells, but did not significantly affect the migratory capacities. Snail expression enhanced the MMP2 activity in BPH-1 cells and promoted both MMP-2 and MMP-9 activities in BPH-1CAFTD1 cells. Moreover, Snail expression enhanced anchorage-independent growth capability in BPH-1 cells, but failed to initiate tumor formation in nude-mice. Lastly, Snail expression induced a dramatic increase in FoxC2 and SPARC transcripts but a marked decrease in claudin-1 and p63 transcripts. / Chu, Jianhong. / Adviser: Franky Chan Leung. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3448. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 143-166). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Dans un contexte où les problématiques urbaines, les formes de l'action publique et les systèmes d'acteurs ont bouleversé ces dernières décennies les façons de fabriquer la ville, il s'agit de saisir les logiques d'action qui participent de la dynamique de transformation des espaces et des territoires contemporains. Elaboré sous l'angle de la sociologie urbaine, le modèle d'analyse repose sur trois grands processus interactifs. Un processus de cadrage dont le référentiel donne la mesure en termes de socle de représentations partagées. Un processus d'organisation complexe de ressources et d'hommes dont il faut coordonner et réguler les actions et les interventions au sein de dispositifs techniques , réglementaires et organisationnels spécifiques.Un processus de traduction spatiale, matérielle et formelle visant à la réalisation concrète sur des territoires privilégiés d'opérations, combinant sur la base des intentions initiales et dans le cadre d'un espace d'activités spécifique, autant d'objectifs économiques, sociaux, politiques et symboliques. La notion de projet urbain traduit le chaînage de ces trois processus qui à partir d'un enjeu défini en commun à l'échelle de la ville ou de l'agglomération génère en continuum sur une donnée donnée une activité collective, mobilisant et enrôlant à chaque étape et niveaux de responsabilité, une pluralité d'acteurs autour d'une série d'opérations urbaines et architecturales. Le cas de l'agglomération bordelaise et de ses transformations sur la période 1995-2007 sert de terrain de référence. / In a context where urban problems forms of public action and systems of actors drastically change the ways to build the city these last decades, we must understand the logics of action that influence the dynamics of spatial and territorial changes. The analysis model is developed from the point of view of the urban sociology and is based on three important intercative processes. A strategic framing process whose reference system gives the standart in terms of a base of shared representations. A complicated organizational process (networking), involving ressources and persons whose actions and interventions need to be coordonated and controlled within a specifical technical, legal and organisatinal system (urban contracting owner). A process, of a precise, material and spatial translation aiming the concrete realization, on privileged territories of operations which on the basis of the initial intentions and within the framework of a space of specific activities, combine economic, political and symbolic objectives. The concept of urban project is the expression of the chaining of these three processes. Starting from a jointly defined issue on the scale of the city of agglomeration, it generates during a given time period a collective activity, mobilizes and recruits in each stage of all levels of responsabilities a plurality of actors around a serie of urban and architectural operations. The agglomeration of Bordeaux and its transformation over the period 1995-2006 is used as reference base.