Epithelia are constantly turned over: constant proliferation cells at a rate that exactly matches cell loss is required for tissue maintenance. Our group has combined cell lineage analysis with statistical physics to identify quantitative rules followed by proliferating cells in homeostatic tissue, overturning the long held hypothesis that stem cell proliferation is required for epithelial homeostasis. Here we propose applying this approach to the squamous lining of the oesophagus, to define t he behaviour of oesophageal stem cells (OSC) and progenitor cells in transgenic mice. Label retaining assays will be used to identify quiescent OSC, whilst inducible genetic labelling will enable the fate of large cohorts of proliferating cells to be tracked: this data will yield a quantitative account of cellular homeostasis. Molecular profiling of murine OSC will be used identify new stem cell markers, whose expression will also be analysed in human oesophagus. Finally we will analyse how O SC and progenitor cells maintain the epithelium under the stress of retinoic acid (RA) treatment. Two treatment protocols will be used to test the predictive ability of the RA model, validating a new and widely applicable approach to study the effects of drugs on stem and progenitor cells in vivo.

The project follows three main themes: Goal (1): To investigate the importance of structural complexity (topology), chain connectivity, secondary structure content and sequence in determining folding energy landscapes. Central to our approach is to make comparisons of proteins within a structural family (e.g. simple 3-helix bundles) or between families (e.g. between different classes of Greek-key proteins). Goal (2): To investigate whether (and how) inclusion within a multidomain protein affe cts the folding landscape. We will investigate how the interface and linker between domains modulate their properties. Since the local domain concentration is high in a multidomain protein we also ask how evolution has prevented significant inter-domain misfolding. We have developed a single molecule approach to detect and analyse rare misfolding events in folding conditions. Finally, we will investigate the role of translational pausing in the efficient folding of multidomain proteins. Goal (3): To investigate the mechanism of folding upon binding of intrinsically disordered proteins. A significant proportion of proteins have large disordered segments. These fold upon binding to a target. We will use the tools developed to study globular protein folding to investigate the mechanisms of folding. We will investigate the effect of pathogenic mutations in disordered regions of spectrin.

Aims: This interdisciplinary project seeks to understand the human and system factors involved in the safe, effective and timely use of injectable end-of- life symptom control medications for adults dying at home. It will advance an inclusive design research methodology and identify with stakeholders where and how systems for using injectable medications can be improved. Methods: Drawing on engineering, patient safety and social science disciplines, I will use innovative systems-driven inclusive design methods to examine the human and system factors involved in the use of injectable end-of-life medications; where and how this complex adaptive system can be improved will be investigated through three sequential stages. Stage 1. Mixed-methods analysis of reported patient safety incidents occurring in England and Wales using the National Reporting and Learning System (NRLS) database. Stage 2. Longitudinal patient-centred case studies exploring the views, experiences and interactions of patients prescribed medications, their family caregivers and clinicians. Stage 3. Stakeholder focus groups with patients, family caregivers and healthcare teams exploring key issues, generating further knowledge of systems for using medications and how these can be improved. Outputs: Findings will be disseminated via scientific publications, conferences and targeted online briefings and videos for researcher, clinician and policy maker communities.