title: Neurokinin-1 receptor antagonists CP-96,345 and L-733,060 protect mice from cytokine-mediated liver injury.
abstract: Previously, we have shown that primary afferent sensory neurons are necessary for disease activity in T cell-mediated immune hepatitis in mice. In the present study, we analyzed the possible role of substance P (SP), an important proinflammatory neuropeptide of these nerve fibers, in an in vivo mouse model of liver inflammation. Liver injury was induced by bacterial lipopolysaccharide (LPS) in D-galactosamine (GalN)-sensitized mice. Depletion of primary afferent nerve fibers by neonatal capsaicin treatment down-regulated circulating levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma) and protected mice from GalN/LPS-induced liver injury. Likewise, pretreatment of mice with antagonists of the SP-specific neurokinin-1 receptor (NK-1R), i.e., (2S,3S)-cis-2-(diphenylmethyl)-N-((2-methoxyphenyl)-methyl)-1-azabicyclo(2.2.2.)-octan-3-amine (CP-96,345) and (2S,3S)3-([3,5-bis(trifluoromethyl)phenyl]methoxy)-2-phenylpiperidine (L-733,060), dose dependently protected mice from GalN/LPS-induced liver injury. The presence of the NK-1R in the murine liver was demonstrated by reverse transcription-polymerase chain reaction, sequence analysis, and immunocytochemistry. NK-1R blockade reduced inflammatory liver damage, i.e., edema formation, neutrophil infiltration, hepatocyte apoptosis, and necrosis. To get further insight into the mechanism by which receptor blockade attenuated GalN/LPS-induced liver damage, we analyzed plasma levels and intrahepatic expression of TNFalpha, IFNgamma, interleukin (IL)-6, and IL-10. NK-1R blockade clearly inhibited GalN/LPS-induced production of TNFalpha and IFNgamma, whereas synthesis of the hepatoprotective cytokines IL-6 and IL-10 was increased. NK-1 receptor antagonists might be potent drugs for treatment of inflammatory liver disease, most likely by inhibiting SP effects.
authors.affiliation: Institute of Experimental and Clinical Pharmacology and Toxicology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: Renate
authors.initials: R
authors.lastname: Bang
authors.forename: Gabriele
authors.initials: G
authors.lastname: Sass
authors.forename: Alexandra K
authors.initials: AK
authors.lastname: Kiemer
authors.forename: Angelika M
authors.initials: AM
authors.lastname: Vollmar
authors.forename: Winfried L
authors.initials: WL
authors.lastname: Neuhuber
authors.forename: Gisa
authors.initials: G
authors.lastname: Tiegs
mesh_terms: D000818:Animals; D001483:Base Sequence; D001713:Biphenyl Compounds / Q000627:therapeutic use*; D002211:Capsaicin / Q000494:pharmacology; D056486:Chemical and Drug Induced Liver Injury; D016207:Cytokines / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects; D008070:Lipopolysaccharides; D008107:Liver Diseases / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D064729:Neurokinin-1 Receptor Antagonists; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D010880:Piperidines / Q000627:therapeutic use*; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D012689:Sequence Homology, Nucleic Acid; D013997:Time Factors; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D001713:Biphenyl Compounds; D016207:Cytokines; D008070:Lipopolysaccharides; D064729:Neurokinin-1 Receptor Antagonists; D010880:Piperidines; D012333:RNA, Messenger; C103788:3-((3,5-bis(trifluoromethyl)phenyl)methyloxy)-2-phenylpiperidine; D002211:Capsaicin; C066892:CP 96345