Greenwood J A, Murphy-Ullrich J E
Department of Pathology, University of Alabama at Birmingham, 35294-0019, USA.
Microsc Res Tech. 1998 Dec 1;43(5):420-32. doi: 10.1002/(SICI)1097-0029(19981201)43:5<420::AID-JEMT8>3.0.CO;2-B.
Adhesion is a process that can be divided into three separate stages: (1) cell attachment, (2) cell spreading, and (3) the formation of focal adhesions and stress fibers. With each stage the adhesive strength of the cell increases. De-adhesion can be defined as the process involving the transition of the cell from a strongly adherent state, characterized by focal adhesions and stress fibers, to a state of intermediate adherence, represented by a cell that is spread, but that lacks stress fibers terminating at adhesion plaques. We propose that this modification of the structural link between the actin cytoskeleton and the extracellular matrix results in a more malleable cellular state conducive for dynamic processes such as cytokinesis, mitogenesis, and motility. Anti-adhesive proteins, including thrombospondin, tenascin, and SPARC, rapidly signal de-adhesion, potentially mediating proliferation and migration during development and wound healing. Intracellular signaling molecules involved in the regulation of de-adhesion are only beginning to be identified. Interestingly, many of the same signaling proteins recognized to play important roles during the process of adhesion have also been found to act during de-adhesion. Characterization of the precise mechanisms by which these signals modulate adhesive structures and the cytoskeleton will further our understanding of the regulation of adhesive strength and its function in cellular physiology.
(1) 细胞附着，(2) 细胞铺展，以及 (3) 黏着斑和应力纤维的形成。随着每个阶段的进展，细胞的黏附强度会增加。去黏附可定义为涉及细胞从以黏着斑和应力纤维为特征的强黏附状态转变为中间黏附状态的过程，这种中间黏附状态由一个铺展但缺乏终止于黏附斑的应力纤维的细胞所代表。我们提出，肌动蛋白细胞骨架与细胞外基质之间结构连接的这种改变会导致一种更具可塑性的细胞状态，有利于诸如胞质分裂、有丝分裂和细胞运动等动态过程。包括血小板反应蛋白、腱生蛋白和富含半胱氨酸的酸性分泌蛋白（SPARC）在内的抗黏附蛋白会迅速发出去黏附信号，可能在发育和伤口愈合过程中介导细胞增殖和迁移。参与去黏附调节的细胞内信号分子才刚刚开始被确定。有趣的是，许多在黏附过程中被认为起重要作用的信号蛋白在去黏附过程中也有作用。表征这些信号调节黏附结构和细胞骨架的精确机制，将增进我们对黏附强度调节及其在细胞生理学中功能的理解。
