Microbial challenge promotes the regenerative process of the injured central nervous system of the medicinal leech by inducing the synthesis of antimicrobial peptides in neurons and microglia
Research article published in Journal of immunology (Baltimore, Md. : 1950) (2008)
Abstract
Following trauma, the CNS of the medicinal leech, unlike the mammalian CNS, has a strong capacity to regenerate neurites and synaptic connections that restore normal function. In this study, we show that this regenerative process is enhanced by a controlled bacterial infection, suggesting that induction of regeneration of normal CNS function may depend critically upon the coinitiation of an immune response. We explore the interaction between the activation of a neuroimmune response and the process of regeneration by assaying the potential roles of two newly characterized antimicrobial peptides. Our data provide evidence that microbial components differentially induce the transcription, by microglial cells, of both antimicrobial peptide genes, the products of which accumulate rapidly at sites in the CNS undergoing regeneration following axotomy. Using a preparation of leech CNS depleted of microglial cells, we also demonstrate the production of antimicrobial peptides by neurons. Interestingly, in addition to exerting antibacterial properties, both peptides act as promoters of the regenerative process of axotomized leech CNS. These data are the first to report the neuronal synthesis of antimicrobial peptides and their participation in the immune response and the regeneration of the CNS. Thus, the leech CNS appears as an excellent model for studying the implication of immune molecules in neural repair.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Following trauma, the CNS of the medicinal leech, unlike the mammalian CNS, has a strong capacity to regenerate neurites and synaptic connections that restore normal function.
Why This Matters for Hirudotherapy
This study shows that controlled bacterial infection enhances regeneration of the medicinal leech central nervous system after axotomy, and characterizes two antimicrobial peptides whose transcription is differentially induced in microglial cells, with the peptide products accumulating at regenerating CNS sites; in microglia-depleted preparations, neurons were also shown to produce these peptides. Both peptides exert antibacterial activity and promote regeneration of the axotomized leech CNS. This is relevant to ASH's domain because it concerns the medicinal leech and describes bioactive molecules with dual immune and reparative functions in leech neural tissue. The findings are from an invertebrate CNS model and do not directly translate to human therapy; the abstract does not address the anticoagulant salivary secretome or hirudotherapy applications.
Citation
Microbial challenge promotes the regenerative process of the injured central nervous system of the medicinal leech by inducing the synthesis of antimicrobial peptides in neurons and microglia
Schikorski D et al. · Journal of immunology (Baltimore, Md. : 1950), 2008
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