title: [HMGB1-mediated activation of TLR4 signaling in hepatic stellate cells].
abstract: To determine the potential of the high mobility group box-1 protein 1 (HMGB1) to activate Toll-like receptor 4 (TLR4) signaling in hepatic stellate cells (HSCs) and investigate the subsequent transition of HSC towards the inflammatory phenotype. Three immortalized mouse HSC cell lines, wild-type (JS1), TLR4-/- (JS2) and MyD88-/- (JS3), were subcultured in plates and divided into groups of normal control (untreated), postive control (lipopolysaccaride, LPS treatment), and experimental (HMGB1 treatment). All groups were transfected with luciferase reporter plasmids carrying responsive elements for either the nuclear factor-kappa B (NF-kB) or activator protein-1 AP-1 transcription factors. Following stimulation with normal saline, LPS (100 ng/mL) or HMGB1 (100 ng/mL), the activation of NF-kB or AP-1 was detected by a dual-luciferase reporter assay system. The induction of monocyte chemotactic protein-1 (MCP-1) transcription was determined by measuring the mRNA levels using real time quantitative reverse transcription PCR (qRT-PCR). The secreted protein levels of MCP-1 were determined by enzyme-linked immunosorbent assay (ELISA) of the culture supernatants. Activation of NF-kB- and AP-1-responsive reporters was significantly up-regulated in JS1 cells treated with HMGB1 or LPS, and the activation was coincident with markedly up-regulated transcription and secretion of MCP-1. However, HMGB1 and LPS treatment produced no responsive of the NF-kB and AP-1 reporters, and no increase in expression or secretion of MCP-1, in JS2 or JS3 cells. As an endogeous ligand of TLR4, HMGB1 may activate TLR4 signaling and the TLR4-mediated inflammatory response of HSC.
authors.affiliation: Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Zhang
authors.forename: Cheng-zhao
authors.initials: CZ
authors.lastname: Lin
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Peng
authors.forename: Yang-yang
authors.initials: YY
authors.lastname: Ouyang
authors.forename: Yi-rong
authors.initials: YR
authors.lastname: Cao
authors.forename: Jin-sheng
authors.initials: JS
authors.lastname: Guo
mesh_terms: D000818:Animals; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D055786:Gene Knockout Techniques; D024243:HMGB1 Protein / Q000494:pharmacology*; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D018932:Chemokine CCL2; D024243:HMGB1 Protein; D008070:Lipopolysaccharides; D016328:NF-kappa B; D012333:RNA, Messenger; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D018808:Transcription Factor AP-1