title: Multiple changes in peptide and lipid expression associated with regeneration in the nervous system of the medicinal leech.
abstract: BACKGROUND
  The adult medicinal leech central nervous system (CNS) is capable of regenerating specific synaptic circuitry after a mechanical lesion, displaying evidence of anatomical repair within a few days and functional recovery within a few weeks. In the present work, spatiotemporal changes in molecular distributions during this phenomenon are explored. Moreover, the hypothesis that neural regeneration involves some molecular factors initially employed during embryonic neural development is tested.
  
  
  RESULTS
  Imaging mass spectrometry coupled to peptidomic and lipidomic methodologies allowed the selection of molecules whose spatiotemporal pattern of expression was of potential interest. The identification of peptides was aided by comparing MS/MS spectra obtained for the peptidome extracted from embryonic and adult tissues to leech transcriptome and genome databases. Through the parallel use of a classical lipidomic approach and secondary ion mass spectrometry, specific lipids, including cannabinoids, gangliosides and several other types, were detected in adult ganglia following mechanical damage to connected nerves. These observations motivated a search for possible effects of cannabinoids on neurite outgrowth. Exposing nervous tissues to Transient Receptor Potential Vanilloid (TRPV) receptor agonists resulted in enhanced neurite outgrowth from a cut nerve, while exposure to antagonists blocked such outgrowth.
  
  
  CONCLUSIONS
  The experiments on the regenerating adult leech CNS reported here provide direct evidence of increased titers of proteins that are thought to play important roles in early stages of neural development. Our data further suggest that endocannabinoids also play key roles in CNS regeneration, mediated through the activation of leech TRPVs, as a thorough search of leech genome databases failed to reveal any leech orthologs of the mammalian cannabinoid receptors but revealed putative TRPVs. In sum, our observations identify a number of lipids and proteins that may contribute to different aspects of the complex phenomenon of leech nerve regeneration, establishing an important base for future functional assays.
authors.affiliation: Université Lille Nord de France, Laboratoire de Spectrométrie de Masse Biologique Fondamentale et Appliquée (FABMS), EA 4550, Université Lille 1, Villeneuve d'Ascq, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Meriaux
authors.forename: Karim
authors.initials: K
authors.lastname: Arafah
authors.forename: Aurélie
authors.initials: A
authors.lastname: Tasiemski
authors.forename: Maxence
authors.initials: M
authors.lastname: Wisztorski
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Bruand
authors.forename: Céline
authors.initials: C
authors.lastname: Boidin-Wichlacz
authors.forename: Annie
authors.initials: A
authors.lastname: Desmons
authors.forename: Delphine
authors.initials: D
authors.lastname: Debois
authors.forename: Olivier
authors.initials: O
authors.lastname: Laprévote
authors.forename: Alain
authors.initials: A
authors.lastname: Brunelle
authors.forename: Terry
authors.initials: T
authors.lastname: Gaasterland
authors.forename: Eduardo
authors.initials: E
authors.lastname: Macagno
authors.forename: Isabelle
authors.initials: I
authors.lastname: Fournier
authors.forename: Michel
authors.initials: M
authors.lastname: Salzet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019771:Axotomy; D002186:Cannabinoids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D016000:Cluster Analysis; D004625:Embryo, Nonmammalian / Q000378:metabolism; D017952:Ganglia, Invertebrate / Q000378:metabolism / Q000473:pathology; D047709:Hirudo medicinalis / Q000196:embryology / Q000378:metabolism*; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D009416:Nerve Regeneration / Q000502:physiology*; D009420:Nervous System / Q000378:metabolism* / Q000473:pathology; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D010802:Phylogeny; D020543:Proteome / Q000378:metabolism; D043882:Receptors, Cannabinoid / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology; D013314:Stress, Mechanical; D050916:TRPV Cation Channels / Q000378:metabolism; D013997:Time Factors
chemical_list: D002186:Cannabinoids; D010455:Peptides; D020543:Proteome; D043882:Receptors, Cannabinoid; D050916:TRPV Cation Channels