Fang K S, Farboud B, Nuccitelli R, Isseroff R R
Department of Dermatology, University of California, Davis 95616-8641, USA.
J Invest Dermatol. 1998 Nov;111(5):751-6. doi: 10.1046/j.1523-1747.1998.00366.x.
Currents that leak out of wounds generate electric fields lateral to the wound. These fields induce directional locomotion of human keratinocytes in vitro and may promote wound healing in vivo. We have examined the effects of growth factors and calcium, normally present in culture medium and the wound fluid, on the directional migration of human keratinocytes in culture. In electric fields of physiologic strength (100 mV per mm), keratinocytes migrated directionally towards the cathode at a rate of about 1 microm per min. This directional migration requires several growth factors. In the absence of these growth factors, the cell migration rate decreased but directionality was maintained. Epidermal growth factor alone restored cell migration rates at concentrations as low as 0.2 ng per ml. Insulin at 5-100 microg per ml or bovine pituitary extract at 0.2%-2% vol/vol also stimulated keratinocyte motility but was not sufficient to fully restore the migration rate. Keratinocyte migration in electric fields requires extracellular calcium. Changes in calcium concentrations from 3 microM to 3.3 mM did not significantly change keratinocyte migration rate nor directionality in electric fields; however, addition of the chelator ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to migration medium reduced, and eventually abolished, keratinocyte motility. Our results show that (i) growth factors and extracellular calcium are required for electric field-induced directional migration of human keratinocytes, and (ii) keratinocytes migrate equally well in low and high calcium media.
从伤口处泄漏的电流会在伤口侧面产生电场。这些电场在体外可诱导人角质形成细胞的定向移动，并可能在体内促进伤口愈合。我们研究了通常存在于培养基和伤口渗出液中的生长因子和钙对培养的人角质形成细胞定向迁移的影响。在生理强度（每毫米100毫伏）的电场中，角质形成细胞以约每分钟1微米的速度向阴极定向迁移。这种定向迁移需要多种生长因子。在没有这些生长因子的情况下，细胞迁移速率降低，但方向性得以维持。仅表皮生长因子在低至每毫升0.2纳克的浓度下就能恢复细胞迁移速率。每毫升5 - 100微克的胰岛素或体积分数为0.2% - 2%的牛垂体提取物也能刺激角质形成细胞的运动，但不足以完全恢复迁移速率。电场中的角质形成细胞迁移需要细胞外钙。钙浓度从3微摩尔/升变化到3.3毫摩尔/升时，在电场中角质形成细胞的迁移速率和方向性均无显著变化；然而，向迁移培养基中添加螯合剂乙二醇双（β - 氨基乙醚） - N,N,N',N'-四乙酸会降低并最终消除角质形成细胞的运动能力。我们的结果表明：（i）生长因子和细胞外钙是电场诱导人角质形成细胞定向迁移所必需的；（ii）角质形成细胞在低钙和高钙培养基中的迁移情况同样良好。
