Shear stress and tensile forces are now well recognized as factors that regulate endothelial signaling, cytoskeletal remodeling, gene expression, and physiological responses. A rapidly growing body of evidence indicates that endothelial cell discriminate between laminar and spatial gradients of shear stress, steady and pulsatile laminar flow, and low-and high-amplitude cyclic stretch. Moreover, the pattern of mechanical stimulation determines whether endothelial cells will develop pro- or anti-inflammatory cell response and also may differentially regulate endothelial barrier properties (Figure 2). Experimental and analytical tools are being developed to assess the stress distribution throughout cell structures that might be involved in mechanotransduction. Further studies will address the role of specific patterns of mechanical forces experienced by endothelium in physiological and pathological conditions (acute injury, inflammation, hypertension, ventilator-induced lung injury) and will identify key cellular targets for drug design and gene therapy.
Mechanical strain or stretch: Change in length in relation to initial length.
Shear stress: Force per unit surface area in the direction of flow exerted at the fluid-surface interface. Stress: Force per unit area.
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Dr. Konstantin Birukov has been studying the role of mechanical factors in vascular endothelial and smooth muscle cell biology since 1989. His group primarily focuses on mechanochemical regulation of signaling, phe-notypic expression and endothelial permeability. His work is supported by grants from the NHLBI and NIH (HL075349, HL076259).
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