Farboud B, Nuccitelli R, Schwab I R, Isseroff R R
Department of Molecular and Cellular Biology, University of California, Davis 95616, USA.
Exp Eye Res. 2000 May;70(5):667-73. doi: 10.1006/exer.2000.0830.
After an epithelium is wounded, multiple soluble and extracellular matrix-associated signals induce a repair response. An often-overlooked signal is the endogenous electrical field established in the vicinity of the wound immediately upon disruption of epithelial integrity. Previous studies have detected lateral electric fields of approximately 42 mV mm-1 near bovine corneal wounds. In addition, electric fields on the order of 100-200 mV mm-1 have been measured lateral to wounds in mammalian epidermis. Here we report the migratory response of human corneal epithelial cells to DC electric fields of similar, physiologic magnitude. Our findings demonstrate that in a 100 mV mm-1 DC field, corneal epithelial cells demonstrate directed migration towards the cathode. The migratory speed and distances traversed by cultured human corneal epithelial cells is remarkably similar to those of cultured skin-derived keratinocytes under similar conditions; however, corneal epithelial cells demonstrate a more rapid directional response to the field than keratinocytes. These findings suggest that endogenous, wound-induced electric fields present in the cornea play an important role in human corneal wound healing, by orienting the directional response of migratory cells so that they efficiently re-epithelialize the wounded area.
上皮组织受伤后，多种可溶性信号和细胞外基质相关信号会引发修复反应。一个常被忽视的信号是上皮完整性遭到破坏后立即在伤口附近形成的内源性电场。此前的研究已在牛角膜伤口附近检测到约42 mV/mm-1的横向电场。此外，在哺乳动物表皮伤口外侧也测量到了100 - 200 mV/mm-1量级的电场。在此，我们报告人角膜上皮细胞对类似生理强度的直流电场的迁移反应。我们的研究结果表明，在100 mV/mm-1的直流电场中，角膜上皮细胞会朝着阴极方向定向迁移。在类似条件下，培养的人角膜上皮细胞的迁移速度和迁移距离与培养的皮肤角质形成细胞非常相似；然而，角膜上皮细胞对电场的定向反应比角质形成细胞更快。这些发现表明，角膜中内源性的、由伤口诱导产生的电场在人角膜伤口愈合过程中发挥着重要作用，它通过引导迁移细胞的定向反应，使它们能够有效地重新上皮化受伤区域。
