Bonakdar Navid, Schilling Achim, Spörrer Marina, Lennert Pablo, Mainka Astrid, Winter Lilli, Walko Gernot, Wiche Gerhard, Fabry Ben, Goldmann Wolfgang H
Department of Physics, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany.
Department of Molecular Cell Biology, Max F. Perutz Laboratories, University of Vienna, Austria.
Exp Cell Res. 2015 Feb 15;331(2):331-7. doi: 10.1016/j.yexcr.2014.10.001. Epub 2014 Oct 14.
Plectin is the prototype of an intermediate filament (IF)-based cytolinker protein. It affects cells mechanically by interlinking and anchoring cytoskeletal filaments and acts as scaffolding and docking platform for signaling proteins to control cytoskeleton dynamics. The most common disease caused by mutations in the human plectin gene, epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), is characterized by severe skin blistering and progressive muscular dystrophy. Therefore, we compared the biomechanical properties and the response to mechanical stress of murine plectin-deficient myoblasts and keratinocytes with wild-type cells. Using a cell stretching device, plectin-deficient myoblasts exhibited lower mechanical vulnerability upon external stress compared to wild-type cells, which we attributed to lower cellular pre-stress. Contrary to myoblasts, wild-type and plectin-deficient keratinocytes showed no significant differences. In magnetic tweezer measurements using fibronectin-coated paramagnetic beads, the stiffness of keratinocytes was higher than of myoblasts. Interestingly, cell stiffness, adhesion strength, and cytoskeletal dynamics were strikingly altered in plectin-deficient compared to wild-type myoblasts, whereas smaller differences were observed between plectin-deficient and wild-type keratinocytes, indicating that plectin might be more important for stabilizing cytoskeletal structures in myoblasts than in keratinocytes. Traction forces strongly correlated with the stiffness of plectin-deficient and wild-type myoblasts and keratinocytes. Contrary to that cell motility was comparable in plectin-deficient and wild-type myoblasts, but was significantly increased in plectin-deficient compared to wild-type keratinocytes. Thus, we postulate that the lack of plectin has divergent implications on biomechanical properties depending on the respective cell type.
网蛋白是一种基于中间丝（IF）的细胞连接蛋白的原型。它通过连接和锚定细胞骨架丝在机械方面影响细胞，并作为信号蛋白的支架和对接平台来控制细胞骨架动力学。人类网蛋白基因突变导致的最常见疾病，即伴有肌营养不良的单纯性大疱性表皮松解症（EBS-MD），其特征为严重的皮肤水疱和进行性肌营养不良。因此，我们比较了小鼠网蛋白缺陷型成肌细胞和角质形成细胞与野生型细胞在生物力学特性及对机械应力的反应方面的差异。使用细胞拉伸装置，与野生型细胞相比，网蛋白缺陷型成肌细胞在外部应力作用下表现出较低的机械脆弱性，我们将其归因于较低的细胞预应激。与成肌细胞相反，野生型和网蛋白缺陷型角质形成细胞没有显著差异。在使用纤连蛋白包被的顺磁珠进行的磁镊测量中，角质形成细胞的硬度高于成肌细胞。有趣的是，与野生型成肌细胞相比，网蛋白缺陷型成肌细胞的细胞硬度、黏附强度和细胞骨架动力学发生了显著改变，而网蛋白缺陷型和野生型角质形成细胞之间的差异较小，这表明网蛋白对于稳定成肌细胞中的细胞骨架结构可能比对角质形成细胞更为重要。牵引力与网蛋白缺陷型和野生型成肌细胞及角质形成细胞的硬度密切相关。与此相反，网蛋白缺陷型和成肌细胞的细胞运动性相当，但与野生型角质形成细胞相比，网蛋白缺陷型角质形成细胞的运动性显著增加。因此，我们推测网蛋白的缺失对生物力学特性的影响因细胞类型而异。
