title: M3 mAChR-mediated IL-8 expression through PKC/NF-κB signaling pathways.
abstract: OBJECTIVE
  M3 muscarinic acetylcholine receptor (mAChR) plays an important role in the regulation of cytokine production in inflammatory diseases. In this study, we explored the precise role of M3 mAChR under stimulation with agonist in IL-8 expression and of the signaling pathway involved in this process.
  
  
  METHODS
  Recombinant U2OS cells stably expressing M3 mAChR as a model system were stimulated by carbachol to evaluate the role of M3 mAChR in the expression of IL-8.
  
  
  RESULTS
  Activation of M3 mAChR with carbachol increased both IL-8 mRNA and protein expression in a concentration-dependent manner. Elevated IL-8 expression was completely antagonized by atropine, 4-DAMP and tiotropium. M3 mAChR-mediated IL-8 expression was almost completely inhibited by the NF-κB inhibitor BAY11-7082 and, to a lesser extent, by U0126, SB203580, and SP600125, which are inhibitors for ERK1/2, p38, and JNK, respectively. Furthermore, M3 mAChR-mediated NF-κB activation and IL-8 expression were simultaneously attenuated by the PKC inhibitor calphostin C, whereas PMA, a PKC activator, mimicked the effects of carbachol, inducing IL-8 expression.
  
  
  CONCLUSIONS
  Our findings offer insights into the specific and critical role of M3 mAChR in regulating inflammatory response and indicate M3 mAChR/PKC/NF-κB signaling axis driven by endogenous acetylcholine as a potential therapeutic targets for inflammatory diseases.
authors: Department of Pharmacology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China.
authors: Zu-Peng
authors: ZP
authors: Xu
authors: Yun
authors: Y
authors: Song
authors: Kai
authors: K
authors: Yang
authors: Wei
authors: W
authors: Zhou
authors: Li-Na
authors: LN
authors: Hou
authors: Liang
authors: L
authors: Zhu
authors: Hong-Zhuan
authors: HZ
authors: Chen
authors: Yong-Yao
authors: YY
authors: Cui
mesh_terms: D002217:Carbachol / Q000494:pharmacology; D045744:Cell Line, Tumor; D018679:Cholinergic Agonists / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D043587:Receptor, Muscarinic M3 / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C508606:CXCL8 protein, human; D018679:Cholinergic Agonists; D016209:Interleukin-8; D016328:NF-kappa B; D043587:Receptor, Muscarinic M3; D002217:Carbachol; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases