Leucine-rich glioma inactivated 3 promotes HaCaT keratinocyte migration

Our finding that human skin expresses leucine-rich glioma inactivated 3 (LGI3) raises the question of the function of this cytokine in keratinocytes. We have shown that LGI3 stimulates human HaCaT keratinocyte migration without affecting viability or proliferation. Western blot analysis showed that LGI3 induced focal adhesion kinase activation, Akt phosphorylation, and glycogen synthase kinase 3β (GSK3β) phosphorylation in these cells. Using the scratch wound assay and a modified Boyden chamber, we found that LY294002, a selective phosphatidylinositol 3-kinase inhibitor, and LiCl, a selective GSK3β inhibitor, abolished LGI3-induced cell migration. We tested β-catenin levels after LGI3 treatment because the Akt-GSK3β pathway regulates β-catenin accumulation, and β-catenin promotes cell migration. LGI3 treatment increased β-catenin protein and nuclear localization, whereas LY294002 prevented LGI3-induced focal adhesion kinase and Akt activation as well as β-catenin accumulation. Overall, these data suggest that LGI3 stimulates HaCaT cell migration following β-catenin accumulation through the Akt pathway.