tailieunhanh - Báo cáo khoa học: Altered expression of CD1d molecules and lipid accumulation in the human hepatoma cell line HepG2 after iron loading

Iron overload in the liver may occur in clinical conditions such as hemo-chromatosis and nonalcoholic steatohepatitis, and may lead to the deterior-ation of the normal liver architecture by mechanisms not well understood. Although a relationship between the expression of ICAM-1, and classical major histocompatibility complex (MHC) class I molecules, and iron over-load has been reported, no relationship has been identified between iron overload and the expression of unconventional MHC class I molecules | iFEBS Journal Altered expression of CD1d molecules and lipid accumulation in the human hepatoma cell line HepG2 after iron loading Marisa Cabrita1 Carlos F. Pereira1 Pedro Rodrigues1 3 Elsa M. Cardoso2 and Fernando A. Arosa1 3 1 Institute for Molecular and CellBiology IBMC Porto Portugal 2 Instituto Superior de Ciencias da Saude - Norte CESPU Gandra Portugal 3 Instituto de Ciencias Biomedicas AbelSalazar ICBAS Porto Portugal Keywords liver iron CD1d MHC lipids Correspondence F. A. Arosa Institute for Molecular and Cell Biology Rua do Campo Alegre 823 4150-180 Porto Portugal Fax 351 226092404 Tel 351 226074900 E-mail farosa@ These authors contributed equally to the paper Received 8 July 2004 revised 13 September 2004 accepted 18 September 2004 doi Iron overload in the liver may occur in clinical conditions such as hemochromatosis and nonalcoholic steatohepatitis and may lead to the deterioration of the normal liver architecture by mechanisms not well understood. Although a relationship between the expression of ICAM-1 and classical major histocompatibility complex MHC class I molecules and iron overload has been reported no relationship has been identified between iron overload and the expression of unconventional MHC class I molecules. Herein we report that parameters of iron metabolism were regulated in a coordinated-fashion in a human hepatoma cell line HepG2 cells after iron loading leading to increased cellular oxidative stress and growth retardation. Iron loading of HepG2 cells resulted in increased expression of CD1d molecules at the plasma membrane. Expression of classical MHC class I and II molecules ICAM-1 and the epithelial CD8 ligand gp180 was not significantly affected by iron. Considering that intracellular lipids regulate expression of CD1d at the cell surface we examined parameters of lipid metabolism in iron-loaded HepG2 cells. Interestingly increased expression of CD1d molecules by .