화학공학소재연구정보센터
Biochemical and Biophysical Research Communications, Vol.404, No.1, 57-61, 2011
Intermedilysin induces EGR-1 expression through calcineurin/NFAT pathway in human cholangiocellular carcinoma cells
Intermedilysin (ILY) is a cholesterol-dependent cytolysin produced by Streptococcus intermedius, which is associated with human brain and liver abscesses. Although intrahepatic bile duct cells play a valuable role in the pathogenesis of liver abscess, the molecular mechanism of ILY-treated intrahepatic bile duct cells remains unknown. In this study, we report that ILY induced a nuclear accumulation of intracellular calcium ([Ca2+]i) in human cholangiocellular cells HuCCT1. We also demonstrate that 10 ng/ml ILY induced NFAT1 dephosphorylation and its nuclear translocation in HuCCT1 cells. In contrast to the result that ILY induced NF-kappa B translocation in human hepatic HepG2 cells, ILY did not affect NF-kappa B localization in HuCCT1 cells. Dephosphorylation and nuclear translocation of NFAT1 caused by ILY were prevented by [Ca2+]i calcium chelator, BAPTA/AM, and calcineurin inhibitors, cyclosporine A and tacrolimus. ILY induced early growth response-1 (EGR-1) expression and it was inhibited by the pre-treatment with cyclosporine A, indicating that the calcineurin/NFAT pathway was involved in EGR-1 expression in response to ILY. ILY-induced calcineurin/NFAT1 activation and sequential EGR-1 expression might be related to the pathogenesis of S. intermedius in human bile duct cells. (C) 2010 Elsevier Inc. All rights reserved.