Toxicogenomic studies of air pollutants upon a 3D supported respiratory epithelial cell model.

The burden of respiratory disease in the UK is growing, with one in five people dying from it since 2004. It now costs the NHS £6.6 billion annually, with millions of 'bed days' taken up every year by respiratory patients. Consequently, the UK has an unenviable record compared to our EU partners. Respiratory illnesses are not all caused by smoking and there are genetic and environmental (particularly air-pollution) factors involved in many conditions. Occupational and environmental exposure to ambient particulate pollution exacerbates symptoms in persons with pre-existing lung disease and also reduces normal lung function in healthy individuals. The outcome of the latter is increased vulnerability to disease, reduction in quality of life, loss of work days and increased burden to the NHS. In Wales alone, 57 in 1000 children have long term impaired lung function due to air pollution particles and 30% of acute exacerbations of asthma are related to outdoor air pollution (HPA, 2005). Using diesel exhaust particles (DEP) as a model particulate air pollutant, (since it accounts for 80% of particles found in Welsh air pollution), an objective of this project is to investigate the gene-expression changes in lung tissue of normal patients. Toxicogenomic experiments designed to identify molecular biomarkers relating to DEP-exposure & injury will be performed and verified by qPCR. By performing differential gene expression studies and comparing the toxicological response profiles with those of well-characterised toxins, we will understand the cellular-mechanistic effects of DEP toxicity. The identification of such biomarkers for particle exposure may elucidate mechanistic pathways of lung disease. The key to conducting such biomarker research is the ability to use lung model systems which permit end-point data and both acute and chronic toxicant exposure windows. Dr. BeruBe leads Cardiff University's Lung and Particle Research Group (LPRG), and has developed such a model system. Q Chip is a Cardiff-based SME specialising in microfluidics technologies for life sciences, particularly convergent applications for biochemistry and biopolymer-engineering. Q Chip's micro-encapsulation technology enables the incorporation of biochemicals and functional reagents into uniformly sized & dosed polymer microspheres. Q Chip is currently working towards novel biopolymer encapsulant matrices containing stabilised, functional cells which express therapeutically-relevant molecules such as catecholamines. By modifying microspherical polymer matrices to contain additional extra-cellular matrix proteins such as chitosan, fibronectin & collagen, a new range of 3D growth supports will be generated to stabilise Dr. BeruBe's respiratory epithelium model. This collaborative project further aims to investigate the behaviour, growth and longevity of cells supported on microsphere surfaces. In order to further develop the 3D cell model to address chronic respiratory disease, combinations of supporting extracellular matrices and growth factors will be examined to increase the longevity and usefulness of the cell model. It is perceived that the successful attainment of the two research goals described above will enable us to approach regenerative methods for treatment of injured (by DEP) lung tissues. Successful identification of genetic biomarkers and differential gene-expression profiles will allow us to monitor and track disease progression in injured tissue samples in vitro. Successful development of biopolymer-based growth supports for the respiratory disease model will allow us to investigate therapeutic biomaterial implants which are dosed with growth or trophic factors or seeded with healthy, viable cells. Many diseases could potentially be addressed in this manner, including Parkinson's & spinal cord injury. Microsphere growth supports may also be applicable to other disease models and regenerative therapies involving pluripotent and multipotent cells.