title: Nerve injury evoked loss of latexin expression in spinal cord neurons contributes to the development of neuropathic pain.
abstract: Nerve injury leads to sensitization mechanisms in the peripheral and central nervous system which involve transcriptional and post-transcriptional modifications in sensory nerves. To assess protein regulations in the spinal cord after injury of the sciatic nerve in the Spared Nerve Injury model (SNI) we performed a proteomic analysis using 2D-difference gel electrophoresis (DIGE) technology. Among approximately 2300 protein spots separated on each gel we detected 55 significantly regulated proteins after SNI whereof 41 were successfully identified by MALDI-TOF MS. Out of the proteins which were regulated in the DIGE analyses after SNI we focused on the carboxypeptidase A inhibitor latexin because protease dysfunctions contribute to the development of neuropathic pain. Latexin protein expression was reduced after SNI which could be confirmed by Western Blot analysis, quantitative RT-PCR and in-situ hybridisation. The decrease of latexin was associated with an increase of the activity of carboxypeptidase A indicating that the balance between latexin and carboxypeptidase A was impaired in the spinal cord after peripheral nerve injury due to a loss of latexin expression in spinal cord neurons. This may contribute to the development of cold allodynia because normalization of neuronal latexin expression in the spinal cord by AAV-mediated latexin transduction or administration of a small molecule carboxypeptidase A inhibitor significantly reduced acetone-evoked nociceptive behavior after SNI. Our results show the usefulness of proteomics as a screening tool to identify novel mechanisms of nerve injury evoked hypernociception and suggest that carboxypeptidase A inhibition might be useful to reduce cold allodynia.
authors.affiliation: Pharmazentrum frankfurt/ZAFES, Institut für Klinische Pharmakologie, Klinikum der Goethe-Universität Frankfurt am Main, Frankfurt am Main, Germany.
authors.forename: Hilmar Nils
authors.initials: HN
authors.lastname: Kühlein
authors.forename: Irmgard
authors.initials: I
authors.lastname: Tegeder
authors.forename: Christine
authors.initials: C
authors.lastname: Möser
authors.forename: Hee-Young
authors.initials: HY
authors.lastname: Lim
authors.forename: Annett
authors.initials: A
authors.lastname: Häussler
authors.forename: Katharina
authors.initials: K
authors.lastname: Spieth
authors.forename: Ingo
authors.initials: I
authors.lastname: Jennes
authors.forename: Rolf
authors.initials: R
authors.lastname: Marschalek
authors.forename: Tobias
authors.initials: T
authors.lastname: Beckhaus
authors.forename: Michael
authors.initials: M
authors.lastname: Karas
authors.forename: Markus
authors.initials: M
authors.lastname: Fauth
authors.forename: Corina
authors.initials: C
authors.lastname: Ehnert
authors.forename: Gerd
authors.initials: G
authors.lastname: Geisslinger
authors.forename: Ellen
authors.initials: E
authors.lastname: Niederberger
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000941:Antigens / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D043422:Carboxypeptidases A / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D015180:Electrophoresis, Gel, Two-Dimensional; D006930:Hyperalgesia / Q000378:metabolism / Q000503:physiopathology; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009437:Neuralgia / Q000378:metabolism* / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012584:Sciatic Nerve / Q000293:injuries* / Q000503:physiopathology; D020426:Sciatic Neuropathy / Q000503:physiopathology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism*; D013386:Succinates / Q000494:pharmacology; D013497:Sural Nerve / Q000503:physiopathology
chemical_list: D000941:Antigens; C086812:Lxn protein, rat; D013386:Succinates; C000249:benzylsuccinic acid; D043422:Carboxypeptidases A