Zhao M, Agius-Fernandez A, Forrester J V, McCaig C D
Department of Biomedical Sciences, Marischal College, Aberdeen, Scotland, UK.
J Cell Sci. 1996 Jun;109 ( Pt 6):1405-14. doi: 10.1242/jcs.109.6.1405.
Reorientation and migration of cultured bovine corneal epithelial cells (CECs) in an electric field were studied. Electric field application was designed to model the laterally directed, steady direct current electric fields which arise in an injured corneal epithelium. Single cells cultured in media containing 10% foetal bovine serum showed significant galvanotropism, reorienting to lie perpendicular to electric field vector with a threshold field strength of less than 100 mV/mm. Cells cultured in serum-free medium showed no reorientation until 250 mV/mm. Addition of EGF, bFGF or TGF-beta 1 singly or in combination to serum free medium significantly restored the reorientation response at low field strengths. Both the mean translocation rate and directedness of cell migration were serum dependent. Cultured in medium with serum or serum plus added EGF, single cells showed obvious cathodal migration at 100 mV/mm. Increasing electric field strength enhanced the cathodal directedness of single cell migration. Supplementing serum free medium with growth factors restored the cathodal directed migration of single cells and highest directedness was found for the combination of EGF and TGF-beta 1. Corneal epithelial sheets also migrated towards the cathode in electric fields. Serum or individual growth factors stimulated CEC motility (randomly directed). Applied fields did not further augment migration rates but added a vector to stimulated migration. Electric fields which are present in wounded cornea interact with other environmental factors and may impinge on CECs migration during wound healing. Therapies which combine the application of growth factors and electric fields may be useful clinically.
研究了培养的牛角膜上皮细胞（CECs）在电场中的重新定向和迁移。电场应用旨在模拟受伤角膜上皮中出现的横向定向、稳定的直流电场。在含有10%胎牛血清的培养基中培养的单细胞表现出显著的向电性，以小于100 mV/mm的阈值场强重新定向，使其垂直于电场矢量排列。在无血清培养基中培养的细胞直到场强达到250 mV/mm时才出现重新定向。单独或联合向无血清培养基中添加表皮生长因子（EGF）、碱性成纤维细胞生长因子（bFGF）或转化生长因子-β1（TGF-β1）能在低场强下显著恢复重新定向反应。细胞迁移的平均转运速率和方向性均依赖于血清。在含有血清或血清加添加的EGF的培养基中培养时，单细胞在100 mV/mm场强下表现出明显的阴极迁移。增加电场强度增强了单细胞迁移的阴极方向性。用生长因子补充无血清培养基可恢复单细胞的阴极定向迁移，且发现EGF和TGF-β1联合使用时方向性最高。角膜上皮片在电场中也向阴极迁移。血清或单个生长因子刺激CECs运动（随机定向）。施加的电场没有进一步提高迁移速率，但为刺激的迁移增加了一个矢量。受伤角膜中存在的电场与其他环境因素相互作用，可能在伤口愈合过程中影响CECs迁移。联合应用生长因子和电场的治疗方法在临床上可能有用。
