title: Bacterial DNA promotes proliferation of rat pancreatic stellate cells thorough toll-like receptor 9: potential mechanisms for bacterially induced fibrosis.
abstract: OBJECTIVE
  We hoped to clarify the possible role of CpG DNA as a trigger factor for overt pancreatic inflammation of pancreatic stellate cells (PSCs).
  
  
  METHODS
  Pancreatic stellate cells were isolated from the male Lewis rat. The expression of Toll-like receptor 9 (TLR9) messenger RNA and protein were evaluated by reverse transcription-polymerase chain reaction and immunofluorescent cytochemistry. Internalization of CpG DNA was analyzed by confocal laser scanning microscopy. Pancreatic stellate cells were incubated with CpG DNA, and then cell proliferation and migration were assessed.
  
  
  RESULTS
  Constitutive expression of TLR9 occurs at the messenger RNA and protein levels. After several minutes of CpG DNA administration, CpG DNA was observed on the cell membrane surface and in the cytoplasm and found to be translocating into the perinucleus of PSCs. Pancreatic stellate cells migrated and proliferated in dose- and time-dependent manners in response to simulation by CpG DNA. Proliferation of PSCs was observed 3 hours after administration (earlier than platelet-derived growth factor-induced proliferation), suggesting that PSCs respond readily to provide innate immunity. Endosomal acidification inhibitors attenuated CpG DNA-induced signaling, leading to suppression of DNA synthesis by PSCs.
  
  
  CONCLUSIONS
  Our findings demonstrate that bacterial DNA promotes migration and proliferation of PSCs and suggest that bacterial DNA can initiate and sustain pancreatic inflammation and fibrosis by means of TLR9.
authors: Department of Medicine and Bioregulatory Science, Kyushu University, Fukuoka, Japan.
authors: Taichi
authors: T
authors: Nakamura
authors: Tetsuhide
authors: T
authors: Ito
authors: Takamasa
authors: T
authors: Oono
authors: Hisato
authors: H
authors: Igarashi
authors: Nao
authors: N
authors: Fujimori
authors: Masahiko
authors: M
authors: Uchida
authors: Yusuke
authors: Y
authors: Niina
authors: Mikihiko
authors: M
authors: Yasuda
authors: Koichi
authors: K
authors: Suzuki
authors: Ryoichi
authors: R
authors: Takayanagi
mesh_terms: D000818:Animals; D001483:Base Sequence; D002465:Cell Movement; D049109:Cell Proliferation; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000276:immunology*; D004705:Endocytosis; D005355:Fibrosis; D007113:Immunity, Innate; D066298:In Vitro Techniques; D008024:Ligands; D020935:MAP Kinase Signaling System; D008297:Male; D018448:Models, Immunological; D009838:Oligodeoxyribonucleotides / Q000276:immunology; D058954:Pancreatic Stellate Cells / Q000276:immunology* / Q000378:metabolism / Q000473:pathology*; D050500:Pancreatitis, Chronic / Q000209:etiology / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D051217:Toll-Like Receptor 9 / Q000235:genetics / Q000378:metabolism*
chemical_list: C408982:CPG-oligonucleotide; D017931:DNA Primers; D004269:DNA, Bacterial; D008024:Ligands; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; C489640:Tlr9 protein, rat; D051217:Toll-Like Receptor 9