Caveda L, Martin-Padura I, Navarro P, Breviario F, Corada M, Gulino D, Lampugnani M G, Dejana E
Istituto de Ricerche Farmacologiche Mario Negri, Milano, Italy.
J Clin Invest. 1996 Aug 15;98(4):886-93. doi: 10.1172/JCI118870.
Endothelial cell proliferation is inhibited by the establishment of cell to cell contacts. Adhesive molecules at junctions could therefore play a role in transferring negative growth signals. The transmembrane protein VE-cadherin (vascular endothelial cadherin/cadherin-S) is selectively expressed at intercellular clefts in the endothelium. The intracellular domain interacts with cytoplasmic proteins called catenins that transmit the adhesion signal and contribute to the anchorage of the protein to the actin cytoskeleton. Transfection of VE-cadherin in both Chinese hamster ovary (CHO) and L929 cells confers inhibition of cell growth. Truncation of VE-cadherin cytoplasmic region, responsible for linking catenins, does not affect VE-cadherin adhesive properties but abolishes its effect on cell growth. Seeding human umbilical vein endothelial cells or VE-cadherin transfectants on a recombinant VE-cadherin amino-terminal fragment inhibited their proliferation. These data show that VE-cadherin homotypic engagement at junctions participates in density dependent inhibition of cell growth. This effect requires both the extracellular adhesive domain and the intracellular catenin binding region of the molecule.
细胞间接触的建立会抑制内皮细胞增殖。因此,连接处的黏附分子可能在传递负性生长信号中发挥作用。跨膜蛋白血管内皮钙黏蛋白(VE-钙黏蛋白/钙黏蛋白-S)在内皮细胞的细胞间裂隙处选择性表达。其胞内结构域与称为连环蛋白的胞质蛋白相互作用,这些连环蛋白传递黏附信号并有助于将该蛋白锚定到肌动蛋白细胞骨架上。在中国仓鼠卵巢(CHO)细胞和L929细胞中转入VE-钙黏蛋白均可抑制细胞生长。负责连接连环蛋白的VE-钙黏蛋白胞质区域的截短并不影响VE-钙黏蛋白的黏附特性,但会消除其对细胞生长的影响。将人脐静脉内皮细胞或VE-钙黏蛋白转染细胞接种在重组VE-钙黏蛋白氨基末端片段上会抑制其增殖。这些数据表明,连接处的VE-钙黏蛋白同型结合参与了细胞生长的密度依赖性抑制。这种效应需要该分子的细胞外黏附结构域和细胞内连环蛋白结合区域。