La polyarthrite rhumatoïde (PR) est une maladie auto-immunitaire touchant environ 1% de la population mondiale. Elle représente l'une des formes d'arthrite les plus sévères parmi plus de cent formes diagnostiquées à ce jour. Malheureusement, l'étiologie de cette maladie n'est pas encore connue et il n'existe aucun traitement curatif. Cette pathologie dégénérative est caractérisée par l'inflammation et l'hypertrophie de la membrane synoviale causant des dommages irréversibles à plusieurs articulations tels que la destruction du cartilage et l'érosion des os. Plusieurs molécules participent au développement de cette affection, notamment des facteurs de croissance, des métalloprotéinases ainsi que des cytokines. De celles-ci, le TNF[alpha] est l'une des plus importantes. En effet, il a été démontré que cette cytokine pro-inflammatoire puissante est essentielle dans la pathogenèse de la PR. Pour ce faire, le TNF[alpha] transmembranaire doit être clivé par la TACE pour générer sa forme soluble et active. Donc, la TACE, via son action protéolytique sur le TNF[alpha], est impliquée dans la progression de la PR. De plus, il a été démontré que cette protéase transmembranaire est induite au niveau des articulations arthritiques et que l'inhibition de cette enzyme diminue les symptômes chez les rats atteints d'arthrite. Ceci en fait donc une cible thérapeutique intéressante, d'où l'importance de comprendre sa régulation et son mode d'action. Afin d'étudier la régulation de la TACE en conditions inflammatoires, nous avons choisi deux agents importants dans le développement de la PR. On sait depuis longtemps que l'hypoxie, soit le manque d'oxygène, est une condition souvent présente au niveau des articulations arthritiques et que ces dernières sont caractérisées par des concentrations élevées de TNF[alpha]. Nous avons donc testé l'influence de ces deux stimuli sur la modulation de l'ARN messager de la TACE chez les deux principaux types cellulaires composant la membrane synoviale, soit les macrophages (synoviocytes de type A) et les synoviocytes de type B. Nous avons démontré, par RT-PCR, que l'hypoxie et le TNF[alpha] induisent l'accumulation de l'ARN messager de la TACE et que ces inductions sont dépendantes de la synthèse de l'ARN. De plus, nous avons établi que ces inductions au niveau de l'ARN messager corrèlent avec l'accumulation de la protéine TACE et l'augmentation de son activité protéolytique chez les synoviocytes de type B stimulés par le TNF[alpha] et en condition hypoxique. Nous avons ensuite cloné le promoteur de la TACE dans le vecteur d'expression pGL2 dans le but d'effectuer des essais luciférase afin d'étudier les mécanismes transcriptionnels régissant la régulation de la TACE. Nous avons démontré, grâce à cette technique, que l'hypoxie augmente l'activité du promoteur de la TACE via l'induction de la liaison du facteur de transcription HIF-1 à deux sites HRE contenus dans ce promoteur. D'un autre côté, même si l'induction régie par le TNF[alpha] requiert en partie la présence du HIF-1, elle est principalement dépendante du facteur de transcription NF-[kappa]B. Finalement, nous avons vérifié l'effet de l'anti-inflammatoire dexaméthasone, souvent utilisé pour traiter la PR, au niveau de la régulation de la TACE et nous avons découvert que ce glucocorticoïde a un effet inhibiteur sur l'activité du promoteur de la TACE. Ces résultats indiquent que l'hypoxie et le TNF[alpha], deux conditions présentes chez les articulations arthritiques, sont impliqués dans la régulation à la hausse de la TACE et, par conséquent, augmentent la disponibilité du TNF[alpha] soluble, une cytokine pro-inflammatoire importante dans l'amplification de la réponse inflammatoire.

L'athérosclérose est la principale cause de mortalité dans les pays industrialisés. Les lipoprotéines de haute densité (HDL) ont pour rôle de contrebalancer les effets néfastes de part leurs propriétés antiathérogènes.L'effet bénéfique des HDL est dû à leur rôle dans le transport inverse du cholestérol (TIC), ainsi qu'à leurs activités antioxydante et anti-inflammatoire.L'efflux du cholestérol, une étape importante dans le TIC, peut être moduler par les différents processus du vieillissement. Le rôle de la PON1 dans l'activité antioxydante des HDL a été largement étudié, contrairement à l'implication de la PON1 dans l'activité anti-inflammatoire des HDL qui est moins bien établit. Une activité enzymatique de PON1, soit"phospholipase-A2 like" (PL-A2 like), est à l'origine d'une controverse sur le rôle de PON1 dans les processus anti-inflammatoires. D'autres parts, il est bien connu que le vieillissement constitue un facteur de risque important dans le processus d'athérosclérose et que ce phénomène se répercute sur plusieurs facteurs. Ainsi, nos principaux objectifs sont: (1) Déterminer l'impact du vieillissement sur la capacité des HDL à promouvoir le transport inverse du cholestérol (2) Déterminer le mécanisme d'action à l'origine de rôle athéro-protecteur de la PON1 et l'implication de son activité PL-A2 like dans les propriétés anti-inflammatoire des HDL. Nos résultats montrent une réduction dans la capacité des HDL à assurer l'efflux de cholestérol au cours du vieillissement (HDL-Jeune 49.0 « 2.2% vs. HDL-Âgé 41.7 « 1.4%, p=0.013). Cette diminution semble être attribuable aux modifications oxydatives qui semble intervenir au cours du vieillissement affectant l'intégrité d'apoA-I. Nos résultats montrent que la PON1 inhibe la formation de la Lyso-PC dans les HDL oxydées (HDL oxydées 8.25 « 0.54 [mu]g vs HDL oxydées + PON1 40 U/ml 3.68 « 1.32 [mu]g) mais contribue à la formation de Lyso-Pc dans les LDL oxydées (LDL oxydés 18.46 « 2.45 [mu]g vs LDL oxydés + PON1 40 U/ml 32.88 « 4.04 [mu]g).L'utilisation des HDL reconstituées a permis de mettre en évidence des interactions possibles entre PON1 avec la LCAT dans les HDL. En conclusions, nos résultats ont permis de démontré l'importance de l'intégrité d'apo-AI et du rôle de PON1 dans les activités anti-athérogènes des HDL.

Les prostaglandines (PGs) sont des médiateurs lipidiques impliqués dans une multitude de processus physiologiques, tels que le sommeil et l'équilibre osseux, mais également dans des phénomènes pathologiques comme l'inflammation chronique et le cancer. Les PGs sont produites à partir de l'acide arachidonique par l'action des cyclooxygénases (COXs) et des PGs synthétases. La régulation de ces dernières est très mal comprise par la communauté scientifique. La L-PGDS est la principale synthétase qui produit la PGD 2 , une PG impliquée entre autres dans la nociception, l'asthme, l'athérosclérose et les allergies. Un criblage par double hybride effectué avec l'arrestine-3 (Arr3) a permis d'identifier la L-PGDS comme partenaire d'interaction. Les arrestines non visuelles sont connues pour leurs rôles dans la désensibilisation et l'endocytose des récepteurs couplés aux protéines G (RCPGs). Cependant, au fil des ans, plusieurs partenaires d'interaction de ces protéines ont été identifiés et ont permis de leur découvrir de nouvelles fonctions. Nous en sommes donc venus à penser que ces protéines multifonctionnelles pourraient réguler la L-PGDS en interagissant avec celle-ci. L'interaction a été confirmée par des essais GST-Pulldown, et de co-immunoprécipitation, dans des systèmes transfecté et endogène dans la lignée ostéoblastique MG-63. La microscopie confocale suggère que la modulation de l'activité enzymatique de la L-PGDS semble modifier la localisation cellulaire des protéines Arr3 et L-PGDS. Des dosages de PGD 2 indiquent que la présence d'Arr3 dans des essais de production de PGD2 in vitro augmente la production de PGD2 , tandis que les fibroblastes embryonnaires de souris (MEFs) déficientes pour les arrestines produisent moins de PGD 2 que les MEFs de type sauvage suite à une stimulation à la PGH2 , ainsi qu'avec l'IL-1?. Cette diminution de production est renversée par la transfection d'arrestines. Un peptide comprenant la région en acides aminés 86 à 100 sur l'Arr3 est suffisant pour augmenter les niveaux de PGD 2 observés in vitro et in cellulo dans les MG-63. Dès lors, nos études identifient pour la première fois un partenaire d'interaction pour la L-PGDS, l'Arr3, qui régule la production de PGD2 . De plus, un peptide comprenant la région d'interaction de l'Arr3 sur la L-PGDS est suffisant pour augmenter la production de PGD2 . Cette nouvelle approche pourrait être utilisée afin de synthétiser des peptides mimétiques spécifiques à la PGD2 dans un traitement anti-inflammatoire alternatif aux inhibiteurs des COXs

Gata4 est un facteur de transcription exprimé par les entérocytes. Nos études ont démontré que Gata4 pouvait réguler l'expression de Pap1 chez le rat. Ce gène encode pour une protéine sécrétoire de type lectine impliquée dans le contrôle de la prolifération bactérienne. Puisqu'il a été démontré que des lectines antibactériennes de la famille Pap sont sécrétées dans la lumière intestinale en réponse à des stimuli inflammatoires, le but de cette étude était de définir l'implication transcriptionnelle de Gata4 dans la réponse inflammatoire des cellules épithéliales intestinales. Afin de caractériser l'effet de Gata4 sur la régulation transcriptionnelle de Pap1 dans les cellules Caco-2/15, nous avons utilisé des essais luciférase et généré différents mutants de la protéine Gata4 et du promoteur Pap1 . Nous avons également utilisé des immunobuvardages et des analyses de gel de rétention afin de mesurer la quantité et l'affinité de Gata4 pour l'ADN dans les cellules IEC-6/Cdx2. Les essais luciférase ont démontré que Gata4, en combinaison avec Cdx2, amène un effet synergique important sur l'activité du promoteur de Pap1 de l'ordre d'environ 8 fois. Différents mutants de la protéine Gata4 ont montré une abolition du potentiel transcriptionnel, démontrant que l'effet observé est spécifique. Cependant, la cotransfection d'un mutant du domaine en doigt de zinc (Zn) localisé en N-terminal, en combinaison avec Cdx2, augmente radicalement l'activation du promoteur de 18 fois. Des résultats préliminaires ont également démontré que la surexpression de ce mutant dans les cellules IEC-6/Cdx2 augmente fortement l'expression endogène du gène Pap1 . Cet effet pourrait être médié par des interactions avec les cofacteurs Fog. En effet, la cotransfection de Fog1 réprime l'effet synergique observé avec Gata4 de type sauvage mais non avec le mutant du domaine en doigt de Zn en N-terminal. Les mutants générés du promoteur Pap1 ont permis d'identifier le site Cdx2 et le site Gata le plus proximal du site d'initiation de la transcription comme nécessaire à l'effet transcriptionnel de Gata4 et Cdx2. En utilisant comme modèle les cellules IEC-6/Cdx2, nous avons montré qu'une induction avec des LPS n'a pas d'effet significatif sur la quantité totale de la protéine Gata4 mais des résultats préliminaires montrent une modulation de la phosphorylation de Gata4 sur la sérine 105. Par gel de rétention, nous avons montré que GATA4 a une affinité pour plusieurs sites sur le promoteur du gène Pap1 et qu'elle est augmentée en condition de stress cellulaire induit par les LPS. Cette étude nous permet de mieux comprendre l'implication de Gata4 dans la réponse inflammatoire de la cellule épithéliale intestinale.

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Nanotechnologies are the fastest growing industry sector ever recorded. The US budget for nanotechnology is predicted to reach the 1 trillion dollar threshold in 2015, meaning that nanotechnologies will indeed be larger than all other technologies combined. High aspect ratio nanomaterials (HARN) become increasingly important in the nanotechnology industries, and show great promise, offering many advantages and improvements to a significant range of products. The main feature of HARN is the ratio of the width of a nanomaterial to its height which can be up to 1000, making the material fibre or platelet- shaped. However, this feature leads to comparison between HARN and other high aspect ratio materials including fibre shaped materials, such as asbestos fibres. Due to the structural similarities between fibrous HARN and asbestos the question arises- do HARN pose the same risk as asbestos? This project aimed to assess the potential of a range of HARN to cause similar pathological effects as asbestos fibres. In order to address this aim a panel of HARN was tested against the fibre pathogenicity paradigm in vivo by examining the pulmonary and pleural responses as well as in vitro to reveal the mechanism of cell/HARN interaction. The first part of the study focused on fibre-shaped HARN, including a panel of distinct length classes of silver nanowires (AgNW) which were injected directly into the pleural space, a target tissue for asbestos related diseases. Injection of high aspect ratio AgNW into the pleural space of mice revealed a length dependent inflammatory response in line with the fibre pathogenicity paradigm which explains fibre pathogenicity. AgNW from 5 μm in length and above led to a significant increase in granulocytes in the pleural space which is similar to that seen after treatment with long amosite asbestos. The use of additional HARN with different compositions allowed us to identify a threshold length for fibre-induced pleural inflammation, which is 5 μm. Frustrated phagocytosis has been stated as an important factor in the initiation of an inflammatory response after fibre exposure. A novel technique, backscatter scanning electron microscopy (BSEM), was used to study frustrated phagocytosis since it provides high-contrast detection of nanowires, allowing clear discrimination between the nanofibres and other cellular features. Using this technique we showed that the onset of inflammation does not correlate with the onset of frustrated phagocytosis, with a fibre length of ≥5 μm and ≥10 μm, respectively, leading to the conclusion that intermediate length fibres fully enclosed within macrophages as well as frustrated phagocytosis are associated with a proinflammatory state in the pleural space. We further showed that fibres compartmentalise in the mesothelial cells at the parietal pleura as well as in inflammatory cells in the pleural space. To investigate the mechanism of the lengthdependent inflammation caused by AgNW, the NALP3 inflammasome activation pathway was studied in vitro, however no clear correlation could be identified. We further aimed to investigate the threshold length of fibre-induced inflammation in the lung and the effect of fibre length on macrophage locomotion in an in vitro macrophage migration assay. Pharyngeal aspiration of AgNW resulted in a length dependent inflammatory response in the lungs with threshold at a fibre length of 14 μm. Shorter fibres including 3, 5 and 10 μm elicited no significant inflammation. This identified threshold length differs from that in the pleural space which may be explained by differences in clearance mechanism of deposited fibres from the airspaces compared to the pleural space. Particle clearance from the lung is partly performed by migration of particle-laden macrophages to the mucociliary escalator. We investigated if uptake of longer fibres leads to restricted mobility and showed that exposure to AgNW in the length of ≥ 5 μm resulted in impaired motility of macrophages in the wound closure assay. The second part of the study focused on HARN in the form of nanoplatelet-shaped particles since nanoplatelets may pose an unusual risk to the lungs and the pleural space because of their aerodynamic properties. We first derived the respirability of graphene nanoplatelets (GP) from the basic principles of the aerodynamic behaviour of plate-shaped particles which allowed us to calculate their aerodynamic diameter. This showed that the nanoplatelets, which were up to 25 μm in diameter, were respirable and so would deposit beyond the ciliated airways following inhalation. We therefore utilized models of pharyngeal aspiration and direct intrapleural installation of GP, as well as an in vitro model, to assess their inflammatory potential. These large but respirable GP were inflammogenic in both the lung and the pleural space at an acute timepoint although they decreased in their inflammatory potential over a 6 weeks period. Oxidation of GP in the lung tissue was investigated in order to identify if GP degraded over the 6 week period in the lung tissue and therefore showed reduced inflammogenicity. Raman spectroscopy was used to measure the oxidation state and revealed that no change occurred over the observed timeframe. The mechanism underlying acute GP inflammation was studied in THP-1 macrophages exposed to GP. These investigations showed that GP exposure led to significant expression of IL-1β, which could be blocked via a number of inhibitors related to the NALP3 inflammasome activation. This study highlights the importance of shape/length of HARN as a driver for in vivo and in vitro inflammogenicity by virtue of their respirable aerodynamic diameter, despite a considerable 2-dimensional size which leads to an inflammatory response when deposited in the distal lungs and the pleural space. The identification of the threshold length for nanofibre-induced pathogenicity in the pleura and the lung has important implications for the understanding of the structure–toxicity relationship for asbestos-induced mesothelioma. It also contributes to risk assessment by offering a template for production of safer synthetic nanofibres by the adoption of a benign-bydesign approach. The results of this work highlight the importance of testing new HARN to protect workers in nanotechnology industries and the public.

Single Nucleotide Polymorphisms (SNPs) in the intracellular pattern recognition receptor gene NLRP3 are associated with susceptibility to Crohn’s disease, a form of inflammatory bowel disease (IBD). Following cell damage or infection, NLRP3 triggers the formation of inflammasomes, a multimolecular protein complex containing NLRP3, ASC and caspase-1, which mediate secretion of IL-1β and IL-18. NLRP3 inflammasome activation in macrophages has been implicated in protection against several pathogens, but whether NLRP3 activation in tissue cells contributes to protective immunity against bacterial pathogens is unknown. We show that upon infection with the attaching/effacing (A/E) intestinal pathogen Citrobacter rodentium, Nlrp3-/- and Asc-/- mice displayed higher bacterial colonization, more weight loss and exacerbated intestinal inflammation. We further show that Nlrp3 inflammasome activation in intestinal epithelial cells (IECs) acts rapidly after infection to limit bacterial replication and penetration, and inhibits the development of inflammatory pathology in the gut. We also show that epithelial Nlrp3-mediated protection is independent of the classical inflammasome cytokines IL-1β and IL-18. Thus an Nlrp3-Asc circuit in IECs regulates early defense against a mucosal pathogen and limits inflammation in the intestine. Nlrp3 inflammasome activation has also been implicated in protection in acute models of experimental colitis, but its role in chronic models of colitis is unknown. We found that Asc signaling is necessary for the development of innate chronic intestinal inflammation driven by Helicobacter hepaticus. Thus while deficient inflammasome signaling in tissue cells increases susceptibility towards enteric pathogens, excessive inflammasome activation can drive chronic intestinal inflammation.

Apoptosis is a physiological form of cell death. It is a highly evolutionarily conserved process that is non-inflammatory or anti-inflammatory in nature. This anti-inflammatory nature of apoptosis is evident by the fact that neutrophils are histologically absent from sites where homeostatic apoptosis rates are high. The rapid phagocytosis of apoptotic cells as a means to prevent the release of noxious inflammatory compounds also accounts for the anti-inflammatory environment of such sites. However, the mechanisms that enable mononuclear phagocytes to migrate to sites where homeostatic apoptosis rates are high, and not granulocytes, the professional phagocytes that accumulate at sites of inflammation, have not been determined yet. Using Burkitt’s lymphoma (BL) as a model of apoptosis, the aim of this thesis was to identify the regulatory mechanisms or factors underlying the non-phlogistic features of sites where homeostatic apoptosis rates are high and in particular, those preventing the recruitment of neutrophils - a major granulocyte subclass to these sites. BL is a highly aggressive B cell lymphoma that is mainly characterised by a high rate of apoptosis. By carrying out a series of in vitro chemotaxis assays and biochemical approaches, it was found in this thesis that BL cells actively inhibit neutrophil migration by releasing factors that were identified to be lactoferrin, a 80 kDa iron-binding glycoprotein with anti-bacterial and anti-inflammatory properties. It was further demonstrated that lactoferrin selectively inhibited migration of granulocytes (both neutrophils and eosinophils) but not mononuclear phagocytes and this effect was irrespective of its iron saturation status and the chemoattractant used. Also, lactoferrin potently inhibited neutrophil migration, as assessed by thioglycollate-induced in vivo model of mouse peritonitis. This anti-inflammatory function of lactoferrin was attributed to its effect on granulocyte signalling pathways that regulate cell adhesion and motility. Finally, it was demonstrated that in cell types of diverse lineages, induction of apoptosis results in de novo synthesis and secretion of lactoferrin. In subsequent proliferation assays determining the in vitro growth of a number of BL cell types, it was demonstrated that lactoferrin is an essential component of BL cells and promotes their proliferation, as its antibody-mediated neutralisation or shRNA-mediated expression knockdown, reduced BL cell growth. Together, the results of this thesis identified lactoferrin as one of the few characterised antiinflammatory components of the apoptosis milieu that negatively regulate granulocyte migration. This effect may provide opportunities for broad therapeutic interventions concerning the use of lactoferrin in chronic inflammatory conditions characterised by aberrant neutrophil influx as well as atopic allergic disorders, such as asthma. Moreover, based on the tumour-supporting role of lactoferrin described in this study, targeting its expression in tumours could lead to tumour regression and thus, be a promising therapeutic molecule in tumour immunotherapy.

The normal physiological response to bacterial infection or wounding with threat of infection, termed inflammation, has been shown to be dysregulated in certain human diseases including (but not limited to): idiopathic pulmonary fibrosis, acute lung injury, arthritis and glomerulonephritis. The earliest arriving and most abundant cell responding to an inflammatory stimulus is the neutrophil granulocyte. It has been shown that under inflammatory conditions neutrophil granulocytes have extended longevity, enhanced responsiveness and upregulated activation parameters. In the setting of non-infective, or prolonged, ineffectuallycleared infective disease where resolution of inflammation does not occur then neutrophil granulocytes may cause tissue damage which is mediated by excessive, misdirected exocytosis of toxic granule contents or by spillage of the same products from necrotic or netotic cell carcasses that have lost membrane integrity. A key process in the resolution of inflammation is the induction of apoptosis in recruited neutrophils following a successful response to an inflammatory stimulus. Cellular signalling from apoptotic cells and from professional phagocytes that have ingested apoptotic cells has been shown to favour resolution of inflammation and restoration of tissue homeostasis. Additionally, the removal of key inflammatory cells in a highly regulated, non-phlogistic fashion robustly assists the resolution process. Cyclin-dependent kinase (CDK) inhibitor drugs are being developed as anti-cancer agents as it is hypothesized that they should interfere with the enhanced cellcycling ability (increased proliferative capacity and extended longevity) which is such a key feature of cancer cell biology. The CDKs that drive the cell cycle are CDKs 1, 2, 4 and 6 and consequently agents were designed to have enhanced specificity for these targets. CDK inhibitor drugs target the ATP-binding domain of CDKs and as a result usually have activity against more than one CDK. The CDK inhibitor drug, R-roscovitine which targets CDKs 2, 5, 7 and 9 was shown to promote neutrophil apoptosis and consequently resolution of inflammation. This thesis aims to investigate the mechanism by which apoptosis is induced in neutrophil granulocytes by CDK inhibitor drugs. The first experimental chapter of this thesis explores in detail the time-course and active concentration range of CDK inhibitor drugs in comparison to known promoters and inhibitors of neutrophil apoptosis. It then dissects the apoptotic machinery which is responsible for the effects of CDK inhibitor drugs before investigating their capacity to promote apoptosis even in the presence of survival mediators relevant to the context of inflammatory disease. Flow-cytometry, light and confocal microscopy as well as western blotting for caspases, mitochondrial dissipation assay, fluorometric caspase assay and the detection of DNA laddering demonstrate that CDK inhibitor drugs promote classical neutrophil apoptosis by the intrinsic pathway and show similar kinetics of apoptosis induction to drugs that inhibit transcription. The second experimental chapter investigates the key neutrophil survival protein and bcl-2 homologue Mcl-1. By flow cytometry, western blotting and RT-PCR it is demonstrated that Mcl-1 is down-regulated at the level of transcription and that this occurs even in the presence of inflammatory mediators that would normally promote neutrophil survival. Additionally, it is shown that pro-apoptotic bcl-2 homologues are affected to a lesser degree suggesting an imbalance of bcl-2 proteins is caused by effects at a transcriptional level mediated by CDK inhibitor drugs. The third experimental chapter identifies CDKs and their binding partner cyclins in neutrophil granulocytes and investigates the impact of CDK inhibitor drugs on CDK protein levels and cellular distribution by differential lysis and western blotting as well as by confocal microscopy. The key transcriptional enzyme RNA polymerase II is also identified and the effect of CDK inhibitor drugs on phosphorylation of this enzyme is documented. Western blotting and confocal microscopy demonstrate the presence of key CDKs 2, 5, 7, 9 and cyclin binding partners of CDKs 7 and 9. It is shown that the phosphorylation of RNA polymerase II mediated by CDKs 7 and 9 is inhibited by CDK inhibitor drugs. This suggests that a key mechanism by which neutrophil apoptosis is induced by CDK inhibitor drugs is the inhibition of transcription of key proteins and suggests that neutrophils require survival proteins for functional longevity. The fourth experimental chapter addresses the production and use of HIV-tat dominant negative CDK 7 and 9 proteins to knockdown CDKs 7 and 9 in neutrophil granulocytes in vitro to provide a molecular biology surrogate for the pharmacological data already presented. The cloning, production, purification and use of HIV-tat dominant negative CDK proteins are described. The final chapter describes the use of a more specific pharmacological inhibitor of CDKs 7 and 9, DRB, in the mouse bleomycin lung injury model. Resolution of inflammation by a compound specifically targeting CDKs 7 and 9 is described. This thesis identifies CDKs 7 and 9 as key targets of CDK inhibitor drugs in neutrophilic inflammation. It shows these drugs acting at the level of transcription to drive neutrophil apoptosis by exploiting the unique dependency of neutrophils on the short-lived survival protein Mcl-1. In so doing the presence of functional and essential transcriptional machinery is identified in neutrophils and the transcriptional profile of resting, stimulated and inhibited neutrophils is delineated. These findings suggest novel approaches to the pharmacological promotion of resolution of inflammation and indicate key new targets for rational drug design. In future, it will be important to further characterize the effects of CDK inhibitor drugs on other cell-types including epithelial cells, fibroblasts and mononuclear cells. This information should prove important to the continued investigation of CDK inhibitor drugs in resolution of inflammation and also to the ongoing experimental trial of these drugs in idiopathic pulmonary fibrosis.

Blood pressure has previously been associated with decline in memory over time, though the exact mechanism behind this effect is uncertain. Infections, which can lead to systemic inflammation have also been linked to some cardiovascular damage to the brain, known as microbleeds, which have themselves been linked to greater declines in cognition in old age. The present study investigates whether blood pressure, a self-reported history of infection, and an indirect measure of inflammation known as the erythrocyte sedimentation rate have any association with on episodic and semantic memory and visuospatial skills in the Betula study, a Swedish longitudinal population study. The effect of elevated blood pressure (over 140 mm Hg systolic and/or 90 mm Hg diastolic), high blood sedimentation (top 33% against bottom 33% of participants), and self-reported infection were all found to not have any significant effect on episodic memory, semantic memory or visuospatial skills. Some of the possible explanations are elaborated in the discussion. / Högt blodtryck har associerats med minnesnedsättning men den exakta mekanismen hur ett samband kan förstås är dock oklar. Infektioner har visat sig ge systematiska inflammationer och har också satts i samband med vissa kardiovaskulära förändringar i hjärnan, så kallade mikroblödningar, vilka i sig har associerats med ökad risk för kognitive nedsättning i hög ålder. Denna uppsats syftar till att undersöka om blodtryck och infektion (självrapporterad infektion samt infektion indirekt mätt genom sänkereaktion) kan relateras till episodiskt och semantisk minne samt visuospatial förmåga i Betula studien, som är en svensk longitudinell populationsbaserad studie. Resultatet visade att varken högt blodtryck (över 140 mm Hg systoliskt eller 90 mm Hg diastoliskt), hög sänkereaktion (de 33 % med högst värde jämfört med de 33 % med lägst värde) eller självrapporterad infektion hade någon signifikant effekt för episodiskt minne, semantiskt minne eller visuospatial förmåga. Några möjliga förklaringar till detta resultat utvecklas i diskussionen. / The Betula Study