title: Acetylcholine Inhibits LPS-Induced MMP-9 Production and Cell Migration via the α7 nAChR-JAK2/STAT3 Pathway in RAW264.7 Cells.
abstract: BACKGROUND
  Excessive activation of matrix metalloproteinase 9 (MMP-9) has been found in several inflammatory diseases. Previous studies have shown that acetylcholine (ACh) reduced the levels of pro-inflammatory cytokines and decreased tissue damage. Therefore, this study was designed to explore the potential effects and mechanisms of ACh on MMP-9 production and cell migration in response to lipopolysaccharide (LPS) stimulation in RAW264.7 cells.
  
  
  METHODS
  MMP-9 expression and activity were induced by LPS in RAW264.7 cells, and examined by real-time PCR, western blotting and gelatin zymography, respectively. ELISA was used to determine the changes in MMP-9 secretion among the groups. Macrophage migration was evaluated using transwell migration assay. Knockdown of α7 nicotinic acetylcholine receptor (α7 nAChR) expression was performed using siRNA transfection.
  
  
  RESULTS
  Pre-treatment with ACh inhibited LPS-induced MMP-9 production and macrophage migration in RAW264.7 cells. These effects were abolished by the α7 nAChR antagonist methyllycaconitine (MLA) and α7 nAChR siRNA. The α7 nAChR agonist PNU282987 was found to have an effect similar to that of ACh. Moreover, ACh enhanced the expression of JAK2 and STAT3, and the JAK2 inhibitor AG490 and the STAT3 inhibitor static restored the effect of ACh. Meanwhile, ACh decreased the phosphorylation and nuclear translocation of NF-κB, and this effect was abrogated in the presence of MLA. In addition, the JAK2 and STAT3 inhibitor abolished the inhibitory effects of ACh on phosphorylation of NF-κB.
  
  
  CONCLUSIONS
  Activation of α7 nAChR by ACh inhibited LPS-induced MMP-9 production and macrophage migration through the JAK2/STAT3 signaling pathway. These results provide novel insights into the anti-inflammatory effects and mechanisms of ACh.
authors.affiliation: Department of Pharmacology, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi China.
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Yang
authors.forename: Dong-Ling
authors.initials: DL
authors.lastname: Li
authors.forename: Xue-Yuan
authors.initials: XY
authors.lastname: Bi
authors.forename: Lei
authors.initials: L
authors.lastname: Sun
authors.forename: Xiao-Jiang
authors.initials: XJ
authors.lastname: Yu
authors.forename: Huan-Le
authors.initials: HL
authors.lastname: Fang
authors.forename: Yi
authors.initials: Y
authors.lastname: Miao
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Xi
authors.initials: X
authors.lastname: He
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Liu
authors.forename: Wei-Jin
authors.initials: WJ
authors.lastname: Zang
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D053614:Janus Kinase 2 / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis*; D051379:Mice; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D064569:alpha7 Nicotinic Acetylcholine Receptor / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D064569:alpha7 Nicotinic Acetylcholine Receptor; C507926:Jak2 protein, mouse; D053614:Janus Kinase 2; D020780:Matrix Metalloproteinase 9; D000109:Acetylcholine