Aspects of airway epithelia cell physiology

Airway epithelial cells are continuously exposed to significant external stresses as a consequence of inhaling atmospheric air, which is full of pollutants and micro-organisms. More than just a physical barrier, these epithelial cells dynamically respond to these insults and have a large number of mechanisms to protect against damage from inhaled foreign material. My research program investigates various aspects of the multitude of ways airway epithelial cells are able to mount to defend themselves. Recently, as part of this research program into host defence, we have begun to investigate two previously unappreciated proteins which play key roles in this area, and have discovered novel and exciting roles for these proteins in airways biology. This proposal is divided into two overall objectives focused on these two proteins, in order to contribute significantly to our understanding of how these factors affect and impact host defence of the airways. Specifically, the short term objectives of this proposal are to investigate a large number of different questions pertaining to the biological and physiological roles of psoriasin and IL-22 in model airway epithelial cells. The work outlined in this proposal fits into my long-term global research program which aims to understand how these epithelial cells are able to defend themselves so well against insult from foreign material. Furthermore, it complements other, more clinical, aspects of my research by providing a fundamental biological basis for understanding these questions of epithelial defence, with the goal of integrating this understanding into innovative technologies and therapeutic approaches. This proposal will use a variety of different methodologies and model cell lines presently available in my laboratory to investigate a wide-ranging series of questions concerning the biological role of these proteins. The use of cell culture models has a number of benefits for these studies; cells derived from different parts of the airways can be used to model a variety of physiologically relevant situations; they are relatively cheap and easy to maintain; and they can be genetically manipulated to definitively investigate the role of one particular protein in isolation. The methodologies employed will range from molecular biology and protein detection techniques, wound healing and proliferation assays, cell viability and apoptosis measurements, measurements of oxidative stress and measurements of epithelial barrier function. Building on our knowledge and previous findings in the area of airway epithelial host defence, we will investigate a number of essential questions concerning these two proteins, and what their exact roles might be in protecting the lungs against the insults it receives. This work will increase our fundamental knowledge of the biology of this system, ascribe novel biological roles for these agents in essential cellular processes, and further our knowledge in this area. In all cases, the research questions outlined are merely initial starting points for our investigations, and will provide important preliminary findings to be investigated more fully over the full course of the Discovery grant.