Hyperplasia and hypertrophy of airway smooth muscle in asthma [ 2005 - 2007 ]

Research Grant

Researchers: Prof Alan James (Principal investigator) ,  Neil Carroll

Brief description Asthma is common in Australia with significant morbidity and it is the 6th Australian National Health Priority. Examination of the airways in asthma shows increased thickness of the airway wall (remodeling), and inflammation. Most long-term asthma treatment is currently focussed on treating inflammation. Since the contribution of smooth muscle to remodeling and excessive airway narrowing is crucial and may be largely independent of airway inflammation, new treatments aimed at the smooth muscle are needed. Treatments must be based on knowledge of the factors which result in more smooth muscle - hypertrophy (enlargement of cells), hyperplasia (more cells) or deposition of proteins (extracellular matrix) between the muscle cells. Matrix is produced by airway myofibroblasts which are more numerous in asthma. These various contributing factors have different signals that can be targeted for treatment, however, information regarding their relative importance is scant. We propose to examine cases of mild and severe asthma using archived tissue blocks in a multi-centre collaborative study using stereological techniques not previously applied to the airway in man. This study is important because it will: 1. Yield new data regarding the degree to which hyperplasia, hypertrophy and increased extracellular matrix vary in the airways; 2. Provide direction for the development of treatments of increased smooth muscle in asthma; 3. Provide relevance and direction to animal and tissue studies of airway smooth muscle; 4. Yield new information on the number of myofibroblasts in mild and severe asthma; 5. Yield new information on the effects of corticosteroids on smooth muscle, extracellular matrix and myofibroblasts in severe, fatal asthma, and 6. Relate increased smooth muscle to increased extracellular matrix, numbers of myofibroblasts and other airway wall dimensions including those close to the airway surface. These may be used to monitor airway pathology in asthma.

Funding Amount $AUD 286,250.00

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant