title: Lipopolysaccharide-induced stem cell factor messenger RNA expression and production in odontoblast-like cells.
abstract: BACKGROUND
  This study was done to evaluate the mechanism involved in stem cell factor (SCF) expression and production by lipopolysaccharide (LPS)-stimulated odontoblast (OD)-like cells and to investigate the signal transduction pathway activated in the process.
  
  
  METHODS
  ODs-like cells (MDPC-23) were stimulated with different LPS concentrations for 1, 6, and 24 hours. SCF expression in OD-like cells was analyzed by reverse-transcriptase polymerase chain reaction, and SCF production was assessed by enzyme-linked immunosorbent assay. In another set of experiments, OD-like cells were pretreated with dexamethasone (DEX), MK886 (MK), p42/44 inhibitor (PD 98059 [PD]), p38 inhibitor (SB 202190 [SB]), or PI3K inhibitor (wortmannin [Wort]) for 30 minutes followed by stimulation with LPS (0.1 μg/mL) for 1 hour.
  
  
  RESULTS
  OD-like cells stimulated with LPS (0.1 μg/mL) for 1 hour expressed SCF, but SCF production decreased with increasing LPS concentrations (1, 10, and 100 μg/mL). DEX and MK were able to inhibit SCF messenger RNA (mRNA) expression. PD, SB, and Wort inhibited the SCF mRNA expression.
  
  
  CONCLUSIONS
  LPS-induced SCF mRNA expression and production in OD-like cells occur via leukotriene production or cytokine and/or chemokine formation, activating the p42/44, p38, and PI3K pathways. Data suggest that SCF released by OD-like cells may act as immune response modulators.
authors.affiliation: Department of Basic Sciences, School of Dentistry of Araçatuba, Universidade Estadual Paulista, Araçatuba, São Paulo, Brazil. shpoliv@foa.unesp.br
authors.forename: Sandra Helena Penha
authors.initials: SH
authors.lastname: Oliveira
authors.forename: Vanessa Aparecida Carvalho
authors.initials: VA
authors.lastname: Santos
mesh_terms: D000730:Androstadienes / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D018929:Cell Culture Techniques; D002460:Cell Line; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D019950:Mitogen-Activated Protein Kinase 1 / Q000187:drug effects; D048052:Mitogen-Activated Protein Kinase 3 / Q000187:drug effects; D009804:Odontoblasts / Q000187:drug effects* / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D019089:Stem Cell Factor / Q000187:drug effects* / Q000235:genetics; D013997:Time Factors; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D002722:Chlorobenzenes
chemical_list: D000730:Androstadienes; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D003907:Dexamethasone; D005419:Flavonoids; D005938:Glucocorticoids; D007093:Imidazoles; D007211:Indoles; D008070:Lipopolysaccharides; D016859:Lipoxygenase Inhibitors; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011725:Pyridines; D012333:RNA, Messenger; D019089:Stem Cell Factor; D000077191:Wortmannin; D048051:p38 Mitogen-Activated Protein Kinases; C060893:MK-886; D002722:Chlorobenzenes; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one