Caveolin‐1 redistribution in human endothelial cells induced by laminar flow and cytokine

Abstract

Caveolin‐1 is a principal component of caveolae and is involved in signaling transduction in a number of cells. A hypothesis was proposed in this work that mechanical forces due to flow induce caveolin‐1 translocation. So the changes of caveolin‐1 expression and distribution in cultured endothelial cells (HUVECs) exposed to a steady laminar flow were studied. For comparing with the influence of cytokine, caveolin‐1 in the cells stimulated by TNF‐α was also investigated. Indirect immunofluorescence and double fluorescence labeling showed that in control cells, caveolin‐1 was primarily localized on the cell surface, which corresponded to the peripheral distribution of F‐actin, and presented some local concentrations. In the cells exposed to a laminar flow (1.0 Pa), caveolin‐1 distribution showed a time‐dependent variation. After 24 h of shear, the local concentration of caveolin‐1 was found, in the most cells, at upstream side of cell body. Also more caveolin‐1 molecules were observed in the cells. In contrast, TNF‐α induced a decrease of caveolin‐1 in cells. The redistribution of caveolin‐1 seems to be correlated to F‐actin organization.