Hart Francis X, Palisano John R
Department of Physics, The University of the South, Sewanee, Tennessee.
Department of Biology, The University of the South, Sewanee, Tennessee.
Bioelectromagnetics. 2017 Sep;38(6):482-493. doi: 10.1002/bem.22060. Epub 2017 May 24.
The application of physiological strength electric fields may produce a wide range of effects on cells. The mechanisms by which cells detect the presence of these fields, however, are not fully understood. Previous experiments have shown that directionality of cells in the field is governed by an electromechanical mechanism in which the field exerts a torque on the negatively charged, inner glycocalyx that is then transmitted as a force on the cytoskeleton. This mechanism is similar to that by which cells detect fluid shear forces. Several authors, however, have reported that cell directionality and motility behave differently in an electric field. We propose here a second electromechanical mechanism in which the field bends the negatively charged, outer glycocalyx in proximity to the substrate, increasing cell adhesion and, thus, cell motility. The increase in motility depends not only on the field strength, but also on the adhesion of the cell to the substrate prior to application of the field. We show that these mechanisms are common to both human cells and amoebae and, hence, are evolutionarily conserved. Furthermore, the mechanism for detection of electric fields is simply an extension of the mechanism for detecting fluid shears. Bioelectromagnetics. 38:482-493, 2017. © 2017 Wiley Periodicals, Inc.
生理强度电场的应用可能会对细胞产生广泛的影响。然而,细胞检测这些电场存在的机制尚未完全明了。先前的实验表明,电场中细胞的方向性受一种机电机制支配,在这种机制中,电场会对带负电荷的内层糖萼施加扭矩,然后该扭矩作为一种力传递到细胞骨架上。这种机制类似于细胞检测流体剪切力的机制。然而,几位作者报告称,细胞在电场中的方向性和运动性表现有所不同。我们在此提出另一种机电机制,即电场使靠近底物的带负电荷的外层糖萼发生弯曲,从而增加细胞黏附力,进而提高细胞运动性。运动性的增加不仅取决于电场强度,还取决于施加电场之前细胞与底物的黏附情况。我们表明,这些机制在人类细胞和变形虫中都很常见,因此在进化上是保守的。此外,检测电场的机制仅仅是检测流体剪切力机制的一种延伸。《生物电磁学》。2017年,第38卷,第482 - 493页。© 2017威利期刊公司