3D map of the human corneal endothelial cell

Human corneal endothelial cells (CECs) are highly polarized flat cells that separate the cornea from the aqueous humor. Their apical surface, in contact with aqueous humor is hexagonal, whereas their basal surface is irregular. Here, the authors characterized the structure of human CECs in 3D using confocal microscopy of immunostained whole corneas in which cells and their interrelationships remain intact. Hexagonality of the apical surface was maintained by the interaction between tight junctions and a submembraneous network of actomyosin. Lateral membranes presented complex expansions resembling interdigitated foot processes at the basal surface. Integrin α3β1 was the only protein found exclusively at the basal surface, forming an almost homogenous layer that follows the slightly bumpy surface of Descemet’s membrane. Ligands of integrin α3β1, such as laminin-332, laminin-511, and laminin-521 constitute efficient coating substances that improve the yield of in vitro CEC cultures. This first 3D map aids our understanding of the morphologic and functional specificity of CECs and could be used as a reference for characterizing future cell therapy products destined to treat endothelial dysfunctions.