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John Shyy

Professor, Medicine, UC San Diego

The major aim of my research is to elucidate the molecular mechanisms by which fluid shear stress and mechanical stretch activate gene expression in cells in the cardiovascular system. A variety of devices have been designed and engineered to subject a monolayer of cultured endothelial cells, vascular smooth muscle cells, and cardiac myocytes to well-defined mechanical forces. These include a rectangular flow channel with a uniform shear stress, a tapered flow channel with shear stress varying along the channel length, a step flow channel with disturbed flow patterns to stimulate vessel branch regions, and a cyclic stretch device to apply uniform biaxial strain to simulate oscillatory pressure. The expression of a number of genes related to atherogenesis, hypertension and hypertrophy, as well as the upstream signal transduction in response to variations in the magnitude of shear stress and stretch and flow pattern is studied.