title: [Lactoferrin downregulates the expression of toll like receptor 4 stimulated by lipopolysaccharide in human periodontal ligament cells].
abstract: OBJECTIVE
  To examine the role of lactoferrin (LF) on Toll like receptor 4 (TLR4) stimulated by lipopolysaccharide (LPS) in human periodontal ligament cells (hPDLCs).
  
  
  METHODS
  Primary hPDLCs were cultured by tissue block enzymolytic method. Cells obtained from four passages were identified and used in this experiment. Cells without stimulation served as the controls and cells treated with LPS (0.1 microg x mL(-1)) comprised the LPS group. The LPS + LF group was pretreated with LPS (0.1 microg x mL(-1)) for 2 h, and then treated with LF (10 microg x mL(-1)). Four hours after LF stimulation, the mRNA expression levels of TLR4 were examined by real-time quantitative polymerase chain reaction (RT-PCR). The protein expression of TLR4 was observed by cell immunofluorescence staining after LF stimulation of 24 hours.
  
  
  RESULTS
  TLR4 mRNA expression in the LPS + LF group was significantly more decreased than that in the LPS group (P < 0.05), but exhibited no difference with that in the control group (P > 0.05). Cell immunofluorescence staining showed that the protein expression of TLR4 in the LPS + LF group was significantly more decreased than that in the LPS group (P < 0.05), but exhibited no difference with that in the control group (P > 0.05).
  
  
  CONCLUSIONS
  LF can decrease the expression of TLR4 stimulated by LPS in hPDLCs, thus presenting potential application for controlling the TLR4 immune pathway of periodontitis.
authors.forename: Xueling
authors.initials: X
authors.lastname: Zhan
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Jiao
authors.initials: J
authors.lastname: Hu
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Xue
authors.forename: Buling
authors.initials: B
authors.lastname: Wu
mesh_terms: D015536:Down-Regulation; D006801:Humans; D007781:Lactoferrin; D008070:Lipopolysaccharides; D010513:Periodontal Ligament; D010518:Periodontitis; D051197:Toll-Like Receptor 4
chemical_list: D008070:Lipopolysaccharides; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D007781:Lactoferrin