Regulation of HGF/SF gene expression in MRC-5 cells by N-acetylcysteine.
The effect of N-acetylcysteine (NAC) on levels of hepatocyte growth factor/scatter factor (HGF/SF) gene transcripts was investigated in the human lung embryonic fibroblast cell line, MRC-5. NAC increased expression of HGF/SF mRNA, in a dose- and time-dependent fashion, by a mechanism independent of glutathione synthesis but sensitive to oxidant stress induced by H(2)O(2). Using actinomycin D to block RNA synthesis, it was observed that NAC had no effect on the stability of the HGF/SF mRNA transcripts. NAC increased HGF/SF promoter activity in cells transiently transfected with chloramphenicol acetyltransferase (CAT) reporter genes driven by HGF/SF gene 5'-flanking sequences. Primer extension analysis demonstrated that NAC enhanced the expression of HGF/SF mRNA transcribed from the main transcription initiation site. Although the 5' flanking region of the HGF/SF gene contains a sequence at -1019 to -1011 with homology to the NF-kappaB response element, electrophoretic mobility shift assay demonstrated that this site did not bind nuclear factors in MRC-5 cells in the presence or absence of NAC. In contrast to the effect on HGF/SF mRNA, NAC did not increase HGF/SF protein production by MRC-5 cells.
Harrison
P M
PM
Institute of Liver Studies, GKT School of Medicine, King's Denmark Hill Campus, Bessemer Road, London, SE5 9PJ, United Kingdom. phillip.harrison@kcl.ac.uk
Farzaneh
F
F
D000111:Acetylcysteine / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D017931:DNA Primers; D004586:Electrophoresis / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects*; D017228:Hepatocyte Growth Factor / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics
D017931:DNA Primers; D012333:RNA, Messenger; D017228:Hepatocyte Growth Factor; D015500:Chloramphenicol O-Acetyltransferase; D000111:Acetylcysteine