Hattab, Danah S. Al-, Safi, Hamza A., Nagalingam, Raghu S., Bagchi, Rushita A., Stecy, Matthew T., and Czubryt, Michael P.
American Journal of Physiology (Consolidated). Sept, 2018, Vol. 315 Issue 3, H658, 11 p.
Cell differentiation -- Research, Biological control systems -- Research, and Transcription factors -- Research
Numerous physiological and pathological events, from organ development to cancer and fibrosis, are characterized by an epithelial-to-mesenchymal transition (EMT), whereby adherent epithelial cells convert to migratory mesenchymal cells. During cardiac development, proepicardial organ epithelial cells undergo EMT to generate fibroblasts. Subsequent stress or damage induces further phenotype conversion of fibroblasts to myofibroblasts, causing fibrosis via synthesis of an excessive extracellular matrix. We have previously shown that the transcription factor scleraxis is both sufficient and necessary for the conversion of cardiac fibroblasts to myofibroblasts and found that scleraxis knockout reduced cardiac fibroblast numbers by 50%, possibly via EMT attenuation. Scleraxis induced expression of the EMT transcriptional regulators Twistl and Snai 1 via an unknown mechanism. Here, we report that scleraxis binds to E-box consensus sequences within the Twistl and Snail promoters to transactivate these genes directly. Scleraxis upregulates expression of both genes in A549 epithelial cells and in cardiac myofibroblasts. Transforming growth factor-[beta] induces EMT, fibrosis, and scleraxis expression, and we found that transforming growth factor-[beta]-mediated upregulation of Twistl and Snail completely depends on the presence of scleraxis. Snail knockdown upregulated the epithelial marker E-cadherin; however, this effect was lost after scleraxis overexpression, suggesting that scleraxis may repress E-cadherin expression. Together, these results indicate that scleraxis can regulate EMT via direct transactivation of the Twist 1 and Snail genes. Given the role of scleraxis in also driving the myofibroblast phenotype, scleraxis appears to be a critical controller of fibroblast genesis and fate in the myocardium and thus may play key roles in wound healing and fibrosis. NEW & NOTEWORTHY The molecular mechanism by which the transcription factor scleraxis mediates Twist1 and Snai1 gene expression was determined. These results reveal a novel means of transcriptional regulation of epithelial-to-mesenchymal transition and demonstrate that transforming growth factor-[beta]-mediated epithelial-to-mesenchymal transition is dependent on scleraxis. providing a potential target for controlling this process. epithelial-to-mesenchymal transition; epithelial cells; fibroblasts; gene regulation; transcription doi: 10.1152/ajpheart.00092.2018.
Al-Qallaf, Danah A. A. A. Q., Tomlinson, Darren, Bell, Sandra, and McPherson, Michael
Biomarkers are molecules present in the patients' samples. They are used to detect the presence of a disease or an infection. An array of laboratory tools is used to monitor changes in the biomarker levels for diagnostic and prognostic purposes. Affimers are relatively new tools, which can be used in similar ways to commonly used antibodies with many advantages over the later. The work described in this PhD thesis has focused on a number of methodologies for the generation of Affimers against purified proteins and cell-surface molecules, with the intention of using these to detect biomarkers in cancer. To ensure the development of functional Affimer reagents against different membrane target molecules, EGFR, HER2, and HER3 were used as models to optimise the process of Affimers isolation and selection using phage display technology. In vitro production of Affimers using bacterial cells was assessed and optimised. Following optimisation, a range of Affimers that bound to EGFR, HER2, and HER3 were generated and partially characterised by different molecular applications, including immunofluorescence, immunohistochemistry, and pull-down assay. Upon characterisation, the developed reagents were not only able to identify their targets on cells and to precipitate them down from cell lysates, but also exhibited a complete inhibition of the downstream signalling activation of both EGFR and HER3. In addition, this thesis provides clear evidence of the potential of Affimers in biomarker discovery studies. After multiple rounds on non-tumourigenic (HB2) and cancerous (MDA-MB-453) breast-cell lines, eight novel anti-breast-cancer Affimers were successfully isolated and characterised. Following pull-down assay and mass spectrometry analysis, the target proteins to which these Affimers were found to bind was identified as CK18 and 19. Upon identification, the specificity of Affimers was further validated on a panel of breast cells, tissues, and on multiple breast-tissue microarrays (TMAs). There is a need to develop the knowledge to utilise this new Affimers-based technology to encourage adoption of this useful tool. With the aid of such technology, several novel detection reagents were generated, partially validated and proved to be promising tools for biomarker detection in different conventional assays.
Childhood obesity has reached epidemic proportions globally, and poses a considerable burden on a child’s short- and long-term health. Most obesity presents in the early (preschool) years, and once established tracks into later life. Therefore, identification of risk factors in the preschool period is considered critical for prevention of long-term obesity. In the United Arab Emirate (UAE), the rising prevalence of childhood obesity is of great public health concern. However, no previous study has explored risk factors for obesity in preschool children. This PhD aimed to: (i) identify risk factors for preschool obesity in the UAE (Study 1); (ii) describe dietary intake and patterns of preschool children, and explore their associations with risk of obesity (Study 2); and (iii) in a randomised controlled trial investigate the effectiveness of the ‘Eat Right Emirates’ (ERE) tool, a simple leaflet intervention designed to encourage a healthy lifestyle and prevent preschool obesity (Study 3). Study 1 showed that a longer duration of breastfeeding, and later introduction of complementary foods were associated with lower BMI z-score. Study 2 found that, compared with UK dietary guidelines, preschool children in the UAE exceeded intakes of protein, but did not meet recommended intakes for fibre. A high carbohydrate intake as a percentage of energy was associated with lower BMI z-score, whereas a high fat intake was associated with higher BMI z-score. A priori derived diet score found diets of preschool children were suboptimal, and principal component analysis identified three dietary patterns (‘traditional/health-conscious’, ‘processed/western’ and ‘convenience/snack’), which were not associated with BMI z-score. Study 3 found that the ERE tool was effective in reducing obesity risk compared to controls at 6-month follow-up. These findings, and the high compliance rate, suggest that the simple intervention is a promising approach for prevention of obesity in the UAE.
This research considers the possibility of a locally-centric design education curricula in Amman, Jordan by investigating the philosophies, theories, practices and models of curriculum and pedagogy most appropriate for design education. It describes perceptions of design and examines the possibilities for shifting these perceptions to move towards transforming design education. Jordan is a neopatriarchal society, and education re-enacts the dominant structures of the state within curriculum and pedagogy centred on the authority of the educator. This thesis argues for a decolonised design education based on a student-centred pedagogy drawn from the process and praxis curriculum models - a design education and design otherwise. Working with a range of designers, students and educators, it investigates the potential of these actors to contribute to the development of a pedagogy for design education in Jordan that is relevant to the milieu and locality. It poses the following questions: What philosophies, theories, practices, models of curriculum, and pedagogy are appropriate?; What potential shifts could this require and create?; How do we shift perceptions? This qualitative research uses interviews, focus groups, and design charrettes for data collection. Through participation and engagement with people that have most at stake in design education - designers, design educators and design students - I argue for an emancipatory design education that reflects on design beyond its traditional service-provider definition. Drawing on scholarship from design and education studies, and literature from fields such as history, decolonial studies, architecture and urbanism, political science, economics and philosophy, I argue for a curriculum model and student-centred pedagogy that considers design's role in society. Literature on Arab higher education is preoccupied with reforms to help the Arab region build a knowledge-society without considering the role of curriculum models and pedagogy nor addressing power structures. In addition, within design, little literature exists on the Arab region or Jordan, leaving its design culture(s) largely undocumented. My thesis investigates design education in higher education in Jordan by concentrating on models of pedagogy and curriculum and provides an overview of Jordan's contemporary design culture.