Lipoteichoic Acid Isolated from Induces Both Epithelial-Mesenchymal Transition and Wound Healing in HaCaT Cells.

Lipoteichoic acid (LTA)， a cell wall component of gram-positive bacteria， is recognized by Toll-like receptor 2， expressed on certain mammalian cell surfaces， initiating signaling cascades that include nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase. There are many structural and functional varieties of LTA， which vary according to the different species of gram-positive bacteria that produce them. In this study， we examined whether LTA isolated from (aLTA) affects the expression of junction proteins in keratinocytes. In HaCaT cells， tight junction-related gene expression was not affected by aLTA， whereas adherens junction-related gene expression was modified. High doses of aLTA induced the phosphorylation of extracellular signal-regulated protein kinases 1 and 2， which in turn induced the epithelial-mesenchymal transition (EMT) of HaCaT cells. When cells were given a low dose of aLTA， however， NF-κB was activated and the total cell population increased. Taken together， our study suggests that LTA from infections in the skin may contribute both to the outbreak of EMT-mediated carcinogenesis and to the genesis of wound healing in a dose-dependent manner.