title: Induction of apoptosis by thrombin in the cultured neurons of dorsal motor nucleus of the vagus.
abstract: BACKGROUND
  A previous study demonstrated the presence of protease-activated receptor (PAR) 1 and 2 in the dorsal motor nucleus of vagus (DMV). The aim of this study is to characterize the effect of thrombin on the apoptosis of DMV neurons.
  
  
  METHODS
  The dorsal motor nucleus of vagus neurons were isolated from neonatal rat brainstems using micro-dissection and enzymatic digestion and cultured. Apoptosis of DMV neurons were examined in cultured neurons. Apoptotic neuron was examined by TUNEL and ELISA. Data were analyzed using anova and Student's t-test.
  
  
  RESULTS
  Exposure of cultured DMV neurons to thrombin (0.1 to 10 U mL(-1)) for 24 h significantly increased apoptosis. Pretreatment of DMV neurons with hirudin attenuated the apoptotic effect of thrombin. Similar induction of apoptosis was observed for the PAR1 receptor agonist SFLLR, but not for the PAR3 agonist TFRGAP, nor for the PAR4 agonist YAPGKF. Protease-activated receptors 1 receptor antagonist Mpr(Cha) abolished the apoptotic effect of thrombin, while YPGKF, a specific antagonist for PAR4, demonstrated no effect. After administration of thrombin, phosphorylation of JNK and P38 occurred as early as 15 min, and remained elevated for up to 45 min. Pretreatment of DMV neurons with SP600125, a specific inhibitor for JNK, or SB203580, a specific inhibitor for P38, significantly inhibited apoptosis induced by thrombin.
  
  
  CONCLUSIONS
  Thrombin induces apoptosis in DMV neurons through a mechanism involving the JNK and P38 signaling pathways.
authors.affiliation: Department of Surgery, Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
authors.forename: X
authors.initials: X
authors.lastname: Wu
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: J-Y
authors.initials: JY
authors.lastname: Li
authors.forename: B-X
authors.initials: BX
authors.lastname: Chai
authors.forename: J
authors.initials: J
authors.lastname: Peng
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: M W
authors.initials: MW
authors.lastname: Mulholland
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D020287:In Situ Nick-End Labeling; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D009046:Motor Neurons / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D044463:Receptor, PAR-1 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013917:Thrombin / Q000494:pharmacology*; D014630:Vagus Nerve / Q000166:cytology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D044463:Receptor, PAR-1; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D013917:Thrombin