Bradykinin Induces Actin Reorganization and Enhances Cell Motility in HaCaT Keratinocytes

Abstract

In HaCaT keratinocytes bradykinin-triggered actin reorganization was inhibited by quinacrine, a phospholipase A2inhibitor, and restored by addition of arachidonic acid. Bradykinin-induced actin breakdown and cortical actin formation were respectively prevented by indomethacin, a cyclooxygenase inhibitor, and nordihydroguaiaretic acid, a lipoxygenase inhibitor. Addition of prostaglandins or leukotrienes, respectively, reversed the effects of inhibitors. This suggested a crucial role for a cyclooxygenase product in actin depolymerization and for a lipoxygenase product in cortical actin formation. Furthermore, we found that bradykinin stimulated HaCaT keratinocyte migration. This event was blocked by quinacrine, indomethacin or nordihydroguaiaretic acid, and restored by addition of prostaglandins or leukotrienes, respectively. We also showed that genistein, a tyrosine kinase inhibitor, inhibited HaCaT cell locomotion. In conclusion, bradykinin modulated actin reorganization and cell motility in keratinocytes, probably by a mechanism involving arachidonic acid metabolites and a tyrosine kinase activity.