Effect of leukotriene D 4 on mouse embryonic stem cell migration and proliferation: Involvement of PI3K/Akt as well as GSK‐3β/β‐catenin signaling pathways

The actual leukotriene D 4 (LTD 4 ) signaling pathways that regulate cell proliferation have not been elucidated thoroughly although fatty acid and its metabolites play a key role in regulations of embryonic functions. Thus, this study investigated the response of mouse embryonic stem (ES) cells exposed to LTD 4 and elucidated the signaling pathways as well. LTD 4 increased DNA synthesis in concentration‐dependent (≥10 −7  M) and time‐dependent (≥12 h) manners, as determined by [ 3 H] thymidine incorporation and increased cell number. LTD 4 induced the phosphorylation of signal transducer and activator of transcription‐3 (STAT3) and the increase of intracellular Ca 2+ levels via cysteinyl leukotriene (CysLT) 1 and 2 receptors. LTD 4 increased Akt activation and calcineurin expression, which were blocked by STAT3 inhibitor and calcium chelators. LTD 4 ‐induced glycogen synthase kinase (GSK)‐3β phosphorylation was decreased by LY294002, Akt inhibitor, and cyclosporine A. LTD 4 inhibited the phosphorylation of β‐catenin. In addition, LTD 4 ‐stimulated migration through increased activation of focal adhesion kinase (FAK) and paxillin which were blocked by Akt inhibitor and cyclosporine A. LTD 4 ‐induced increases in protooncogene and cell cycle regulatory proteins were blocked by cyclosporine A, FAK siRNA, and β‐catenin siRNA. In conclusion, LTD 4 ‐stimulated mouse ES cell proliferation and migration via STAT3, phosphoinositide 3‐kinases (PI3K)/Akt, Ca 2+ ‐calcineurin, and GSK‐3β/β‐catenin pathway. J. Cell. Biochem. 111: 686–698, 2010. © 2010 Wiley‐Liss, Inc.