Wednesday, January 19
211 Chemical Sciences & Engineering Building
Presenter: Zannatul Ferdous, Ph.D., Parker H. Petit Institute of Bioengineering and Bioscience Georgia Institute of Technology
Abstract: My research uses unique model systems to study mechanisms and causes of cardiovascular diseases, particularly pathologies of heart valves. Valve diseases and defects are major causes of mortality in the elderly population and children in the US. Since altered expression of decorin has been observed in diseased heart valves, for my graduate research, the roles of proteoglycan decorin on extracellular matrix remodeling and tissue mechanics were investigated. Using tissueengineered collagen gels, we demonstrated that decorin-mediated matrix remodeling was heavily modulated by decorin-transforming growth factor beta (TGF-β) interaction. In addition, cyclic strain promoted compensatory behavior in collagen gels containing decorin-deficient cells, suggesting the influence of tissue mechanics on cellular function. We also showed the utility of a proper chemical and mechanical environment for studying ex vivo tissue systems. For my postdoctoral research, the contributions of mechanical forces to the initiation and progression of vascular and valvular calcification are being studied using cells isolated from non-sclerotic human tissues. We have observed that expression of osteogenic and matrix remodeling markers are dependent on both cell source (vascular versus valvular) and mechanical strain. In addition, calcification is observed to be modulated by the magnitude of strain (physiological versus pathological) applied to either cell types. We anticipate that the tissue-engineered model would help determine biomarkers for early detection and prevention of valve calcification. Additionally, the roles of microRNAs (miRNAs) in valvular diseases are also being investigated using RNAs isolated from endothelial cells in freshly isolated porcine valves. We hope that this research would lead to the discovery of important miRNAs and their roles in aortic valve biology and diseases. Continued research would therefore improve our knowledge of the complex heart valve environment and help determine treatment options for the large population of elderly and children in need for valve replacement.