Calcium channel blockers inhibit galvanotaxis in human keratinocytes

J Cell Physiol. 2002 Oct;193(1):1-9. doi: 10.1002/jcp.10144.

Abstract

Directed migration of keratinocytes is essential for wound healing. The migration of human keratinocytes in vitro is strongly influenced by the presence of a physiological electric field and these cells migrate towards the negative pole of such a field (galvanotaxis). We have previously shown that the depletion of extracellular calcium blocks the directional migration of cultured human keratinocytes in an electric field (Fang et al., 1998; J Invest Dermatol 111:751-756). Here we further investigate the role of calcium influx on the directionality and migration speed of keratinocytes during electric field exposure with the use of Ca(2+) channel blockers. A constant, physiological electric field strength of 100 mV/mm was imposed on the cultured cells for 1 h. To determine the role of calcium influx during galvanotaxis we tested the effects of the voltage-dependent cation channel blockers, verapamil and amiloride, as well as the inorganic Ca(2+) channel blockers, Ni(2+) and Gd(3+) and the Ca(2+) substitute, Sr(2+), on the speed and directionality of keratinocyte migration during galvanotaxis. Neither amiloride (10 microM) nor verapamil (10 microM) had any effect on the galvanotaxis response. Therefore, calcium influx through amiloride-sensitive channels is not required for galvanotaxis, and membrane depolarization via K(+) channel activity is also not required. In contrast, Sr(2+) (5 mM), Ni(2+) (1-5 mM), and Gd(3+) (100 microM) all significantly inhibit the directional migratory response to some degree. While Sr(2+) strongly inhibits directed migration, the cells exhibit nearly normal migration speeds. These findings suggest that calcium influx through Ca(2+) channels is required for directed migration of keratinocytes during galvanotaxis and that directional migration and migration speed are probably controlled by separate mechanisms.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amiloride / pharmacology
  • Calcium / metabolism
  • Calcium Channel Blockers / pharmacology*
  • Cell Movement / physiology*
  • Cells, Cultured
  • Electric Stimulation / methods
  • Gadolinium / pharmacology
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / drug effects*
  • Keratinocytes / physiology*
  • Microscopy, Video
  • Nickel / pharmacology
  • Static Electricity
  • Strontium / pharmacology
  • Verapamil / pharmacology

Substances

  • Calcium Channel Blockers
  • Amiloride
  • Nickel
  • Gadolinium
  • Verapamil
  • Calcium
  • Strontium