title: Neurokinin (NK)-1 receptor expression in monocytes from bipolar disorder patients: a pilot study.
abstract: BACKGROUND
  Neurokinin 1 receptors (NK-1R) have been involved in several psychiatric disorders including major depression, but less is known for bipolar disorder (BD).
  
  
  METHODS
  We compared NK-1R expression and Substance P (SP) ability to induce NF-κB activation in monocytes from BD patients and healthy donors (HD), also looking for the effects of tobacco smoke. After informed written consent, 20 euthymic BD patients, either bipolar type 1 (BDI) or type 2 (BDII), and 14 age-matched healthy donors (HD) were enrolled. NK-1R expression in monocytes was evaluated by Western blot and expressed as the ratio between NK-1R and Na(+)/K(+)-ATPase protein expressions. NF-κB activation was assessed by measuring the nuclear content of the p50 subunit (ELISA kit).
  
  
  RESULTS
  NK-1R expression was significantly reduced (P<0.001) in monocytes from BD patients as compared to HD, with no major differences between BDI and BDII patients. Tobacco smoke enhanced NK-1R expression in HD, but not in BD patients. Un-stimulated monocytes from BD patients presented a constitutively higher (P<0.05) content of nuclear p50 subunit as compared to HD. SP and an NK-1R agonist induced NF-κB activation, with a higher effect in HD: this effect was receptor-mediated as it was abrogated by an NK-1R antagonist.
  
  
  CONCLUSIONS
  As a pilot study enrolling 20 BD patients, an obvious limitation is the sample size.
  
  
  CONCLUSIONS
  Our results show the existence of a relevant alteration in NK-1R expression in BD patients and further suggest SP involvement in BD, so improving our understanding of the underlying mechanisms of this disease.
authors.affiliation: Department of Health Sciences, School of Medicine, University "A. Avogadro", Via Solaroli, 17, 28100 Novara, Italy.
authors.forename: Angela
authors.initials: A
authors.lastname: Amoruso
authors.affiliation: Department of Health Sciences, School of Medicine, University "A. Avogadro", Via Solaroli, 17, 28100 Novara, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bardelli
authors.affiliation: Department of Mental Health, ASL NO, Centre of Mental Health, Viale Zoppis, 8, 28021 Borgomanero, Novara, Italy.
authors.forename: Carlo Ignazio
authors.initials: CI
authors.lastname: Cattaneo
authors.affiliation: Department of Health Sciences, School of Medicine, University "A. Avogadro", Via Solaroli, 17, 28100 Novara, Italy.
authors.forename: Luigia Grazia
authors.initials: LG
authors.lastname: Fresu
authors.affiliation: Department of Mental Health, ASL NO, Centre of Mental Health, Viale Zoppis, 8, 28021 Borgomanero, Novara, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Manzetti
authors.affiliation: Department of Health Sciences, School of Medicine, University "A. Avogadro", Via Solaroli, 17, 28100 Novara, Italy; Interdisciplinary Research Center of Autoimmune Diseases (IRCAD), School of Medicine, Novara, Italy. Electronic address: sandra.brunelleschi@med.unipmn.it.
authors.forename: Sandra
authors.initials: S
authors.lastname: Brunelleschi
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000378:metabolism*; D015153:Blotting, Western; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D010865:Pilot Projects; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D015398:Signal Transduction; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D013373:Substance P / Q000378:metabolism*
chemical_list: D016328:NF-kappa B; D018040:Receptors, Neurokinin-1; D013373:Substance P; D000254:Sodium-Potassium-Exchanging ATPase
keywords: Bipolar disorder; Human monocytes; NF-κB activation; NK-1 receptors; Substance P; Tobacco smoke