Tight junctions and adherens junctions in endothelial Cells: structure and regulation

Abstract

Endothelial cells lining the vasculature provide a crucial interface between plasma and tissue environments, separating the solute, macromolecular and cellular composition of the plasma from that of the interstitial fluid [1–3]. This chapter will focus on the role of endothelial cell-cell adhesion as relates to this function. In particular, the tight junction plays the most important role in the separation of plasma and tissue environments. The tight junction also plays a crucial role in the establishment and maintenance of cellular polarity, the separation of the plasma membrane into apical and basolateral compartments, important for the vectorial transport of essential nutrients and factors across endothelia with especially well developed tight junctions [4]. An example of such a differentiated endothelium is the blood-brain barrier, where tight junctions are so well developed that even ionic permeability is severely limited [5]. In epithelial cells [6] and endothelial cells [3, 7, 8], the establishment of tight junctions is dependent on the prior formation of intercellular adherens junctions. For this reason, the adherens junction will also be discussed. Both tight and adherens junctions are composed of transmembrane proteins with associated cytoplasmic components. Also, both junctions are linked to the actin-based cytoskeleton which in itself is subject to complex regulation.KeywordsTight JunctionTyrosine PhosphorylationAdherens JunctionTight Junction ProteinBrain Endothelial CellThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.