Up-regulation of Neurohemerythrin Expression in the Central Nervous System of the Medicinal Leech, Hirudo medicinalis,

We report here some results of a proteomic analysis of changes in protein expression in the leech Hirudo me-dicinalis in response to septic injury. Comparison of two-dimensional protein gels revealed several signifi-cant differences between normal and experimental tis-sues. 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, brachio-pods, and annelids. We found by in situ hybridization and immunocytochemistry that the new leech protein, which we have called neurohemerythrin, is indeed ex-pressed in the leech central nervous system. Both mes