Up-regulation of neurohemerythrin expression in the central nervous system of the medicinal leech, Hirudo medicinalis, following septic injury.
We report here some results of a proteomic analysis of changes in protein expression in the leech Hirudo medicinalis in response to septic injury. Comparison of two-dimensional protein gels revealed several significant differences between normal and experimental tissues. One protein found to be up-regulated after septic shock was identified, through a combination of Edman degradation, mass spectrometry, and molecular cloning, as a novel member of the hemerythrin family, a group of non-heme-iron oxygen transport proteins found in four invertebrate phyla: sipunculids, priapulids, brachiopods, and annelids. We found by in situ hybridization and immunocytochemistry that the new leech protein, which we have called neurohemerythrin, is indeed expressed in the leech central nervous system. Both message and protein were detected in the pair of large glia within the ganglionic neuropile, in the six packet glia that surround neuronal somata in each central ganglion, and in the bilateral pair of glia that separate axonal fascicles in the interganglionic connective nerves. No expression was detected in central neurons or in central nervous system microglia. Expression was also observed in many other, non-neuronal tissues in the body wall. Real-time PCR experiments suggest that neurohemerythrin is up-regulated posttranscriptionaly. We consider potential roles of neurohemerythrin, associated with its ability to bind oxygen and iron, in the innate immune response of the leech nervous system to bacterial invasion.
Vergote
David
D
Laboratoire de Neuroimmunologie des Annélides, UMR 8017 CNRS, IFR 17 INSERM, Université des Sciences et Technologies de Lille, 59655 Villeneuve d'Ascq, France.
Sautière
Pierre-Eric
PE
Vandenbulcke
Franck
F
Vieau
Didier
D
Mitta
Guillaume
G
Macagno
Eduardo R
ER
Salzet
Michel
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005786:Gene Expression Regulation; D006422:Hemerythrin / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D047709:Hirudo medicinalis; D008969:Molecular Sequence Data; D009420:Nervous System / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry; D018805:Sepsis; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D006422:Hemerythrin; D010446:Peptide Fragments