American Society of Hirudotherapy

Identifying genes for neuron survival and axon outgrowth in Hirudo medicinalis

Research article published in Journal of anatomy (2004)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Narrative reviewGenomics & ProteomicsBlackshaw S et al. · Journal of anatomy, 2004

Abstract

We have studied the molecular basis of nervous system repair in invertebrate (Hirudo medicinalis) nerve cells. Unlike in mammals, neurons in invertebrates survive injury and regrow processes to restore the connections that they held before the damage occurred. To identify genes whose expression is regulated after injury, we have used subtractive probes, constructed from regenerating and non-regenerating ganglia from the leech Hirudo medicinalis, to screen cDNA libraries made from whole leech CNS or from identified microdissected neurons. We have identified genes of known or predicted function as well as novel genes. Known genes up-regulated within hours of injury and that are widely expressed in invertebrate and mammalian cells include thioredoxin and tubulin. Other known genes, e.g. Cysteine Rich Intestinal Protein (CRIP), have previously been identified in mammalian cells though not in regenerating adult neurons. Two regulated genes identified, myohemerythrin and the novel protein ReN3 are exclusively expressed in invertebrates. Thus our approach has enabled us to identify genes, present in a neuron of known function, that are up- and down-regulated within hours of axotomy, and that may underpin the intrinsic ability of invertebrate neurons to survive damage and initiate regrowth programmes.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, Non-U.S. Gov'tReview
Indexed MeSH termsAnimalsAxonsCell SurvivalGene Expression RegulationGene LibraryLeechesModels, AnimalNerve RegenerationNeuronsOligonucleotide Array Sequence Analysis

Summary

We have studied the molecular basis of nervous system repair in invertebrate (Hirudo medicinalis) nerve cells. Unlike in mammals, neurons in invertebrates survive injury and regrow processes to restore the connections that they held before the damage occurred.

Why This Matters for Hirudotherapy

This study examined the molecular basis of nervous system repair in Hirudo medicinalis, using subtractive probes from regenerating and non-regenerating ganglia to screen cDNA libraries and identify genes—including thioredoxin, tubulin, CRIP, myohemerythrin, and a novel protein ReN3—that are up- or down-regulated within hours of axotomy in identified leech neurons. For ASH's domain, this work is relevant because it characterizes fundamental molecular biology of the medicinal leech, specifically the gene expression programs that may underpin this species' notable capacity to survive neuronal injury and regenerate neural processes. However, the connection to hirudotherapy is indirect: the study investigates the leech's own neurobiology rather than salivary secretome components or therapeutic applications, and its findings concern basic comparative neurobiology with no direct clinical implications for leech therapy practice.

Citation

Identifying genes for neuron survival and axon outgrowth in Hirudo medicinalis.

Blackshaw S et al. · Journal of anatomy, 2004

DOI

Added to ASH library: March 18, 2026 · Site last updated: June 18, 2026

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