The endothelial cytoskeleton: Multifunctional role of the endothelial actomyosin cytoskeleton

The mammalian cytoskeleton plays an essential role in providing the mechanical support necessary to maintain cell shape, cell motility and movement and in signaling transducing functions. The key cytoskeletal components are three inter-communicating networking protein filaments: actin microfilaments, microtubules, and intermediate filaments. Endothelial cells comprise the lining of the inner vessel wall and display a highly dynamic regulation of vascular integrity via opening and closing of paracellular gaps in response to infiltrating cells, ischemia or inflammatory processes (Dudek and Garcia 2001). As endothelial cells have direct contact with circulating blood cells and lymphatic fluid, the cytoskeleton plays a critical role in mechanotransduction, angiogenesis and apoptosis and in the vascular response to inflammation, serving as the major regulator of the endothelial “gate-keeper” function via effects on paracellular gap regulation, leukocyte diapedesis and barrier regulation (Dudek and Garcia 2001, Garcia et al. 1986, Hirata et al. 1995, Majno and Palade 1961).