title: The CYP2E1 inhibitor DDC up-regulates MMP-1 expression in hepatic stellate cells via an ERK1/2- and Akt-dependent mechanism.
abstract: DDC (diethyldithiocarbamate) could block collagen synthesis in HSC (hepatic stellate cells) through the inhibition of ROS (reactive oxygen species) derived from hepatocyte CYP2E1 (cytochrome P450 2E1). However, the effect of DDC on MMP-1 (matrix metalloproteinase-1), which is the main collagen degrading matrix metalloproteinase, has not been reported. In co-culture experiments, we found that DDC significantly enhanced MMP-1 expression in human HSC (LX-2) that were cultured with hepatocyte C3A cells either expressing or not expressing CYP2E1. The levels of both proenzyme and active MMP-1 enzyme were up-regulated in LX-2 cells, accompanied by elevated enzyme activity of MMP-1 and decreased collagen I, in both LX-2 cells and the culture medium. H2O2 treatment abrogated DDC-induced MMP-1 up-regulation and collagen I decrease, while catalase treatment slightly up-regulated MMP-1 expression. These data suggested that the decrease in ROS by DDC was partially responsible for the MMP-1 up-regulation. ERK1/2 (extracellular signal-regulated kinase 1/2), Akt (protein kinase B) and p38 were significantly activated by DDC. The ERK1/2 inhibitor (U0126) and Akt inhibitor (T3830) abrogated the DDC-induced MMP-1 up-regulation. In addition, a p38 inhibitor (SB203580) improved MMP-1 up-regulation through the stimulation of ERK1/2. Our data indicate that DDC significantly up-regulates the expression of MMP-1 in LX-2 cells which results in greater MMP-1 enzyme activity and decreased collagen I. The enhancement of MMP-1 expression by DDC was associated with H2O2 inhibition and coordinated regulation by the ERK1/2 and Akt pathways. These data provide some new insights into treatment strategies for hepatic fibrosis.
authors.affiliation: Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, People's Republic of China.
authors.forename: Tianhui
authors.initials: T
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Min
authors.initials: M
authors.lastname: Cong
authors.forename: Youqing
authors.initials: Y
authors.lastname: Xu
authors.forename: Jidong
authors.initials: J
authors.lastname: Jia
authors.forename: Hong
authors.initials: H
authors.lastname: You
mesh_terms: D002460:Cell Line; D018920:Coculture Techniques; D003094:Collagen / Q000378:metabolism; D065691:Cytochrome P-450 CYP2E1 Inhibitors; D004050:Ditiocarb / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D020781:Matrix Metalloproteinase 1 / Q000235:genetics*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors
chemical_list: D065691:Cytochrome P-450 CYP2E1 Inhibitors; D004791:Enzyme Inhibitors; D017382:Reactive Oxygen Species; D003094:Collagen; D004050:Ditiocarb; D051057:Proto-Oncogene Proteins c-akt; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases; D020781:Matrix Metalloproteinase 1