Pommerenke H, Schreiber E, Dürr F, Nebe B, Hahnel C, Möller W, Rychly J
Department of Internal Medicine, University of Rostock, Germany.
Eur J Cell Biol. 1996 Jun;70(2):157-64.
Mechanical loading of cells is of fundamental relevance in physiological processes and induces several functional responses in cells. Integrins, a family of adhesion receptors, which are responsible for the interaction with the extracellular matrix, may play a role in transmission of mechanical signals into cells. The osteogenic cell line U-2 OS expresses different integrin subunits which are uniformly distributed over the cell surface. We applied defined physical forces on individual integrin receptor subunits using paramagnetic microbeads coated with anti-integrin antibodies. Application of an inhomogeneous magnetic field consequently leads to a mechanical stress on the receptor. Intracellular Ca2+ increased when the alpha 2 or the beta 1 integrin subunits were stressed, whereas mechanical loading of the transferrin receptor had a significantly lower effect. This result indicates that forces specifically exerted to individual integrin receptors induce signal transduction pathways.
细胞的机械加载在生理过程中具有根本相关性，并在细胞中诱导多种功能反应。整合素是一类负责与细胞外基质相互作用的黏附受体家族，可能在将机械信号传递到细胞中发挥作用。成骨细胞系U-2 OS表达不同的整合素亚基，这些亚基均匀分布在细胞表面。我们使用包被抗整合素抗体的顺磁性微珠对单个整合素受体亚基施加确定的物理力。因此，施加不均匀磁场会导致受体受到机械应力。当α2或β1整合素亚基受到应力时，细胞内Ca2+增加，而转铁蛋白受体的机械加载效果明显较低。这一结果表明，专门施加于单个整合素受体的力会诱导信号转导途径。
