Thrombomodulin-Induced Prevention of Peripheral Neuropathy in Oxaliplatin-Treated Mice Involves Complement C5a Inactivation and PAR1 Activation in Addition To HMGB1 Degradation
Research article published in Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology (2025)
Abstract
High mobility group box 1 (HMGB1), a nuclear protein, once released to the extracellular space, participates in the pathogenesis of chemotherapy-induced peripheral neuropathy (CIPN). Thrombomodulin alfa (TMα), a recombinant soluble protein of endothelial thrombomodulin, prevents CIPN by promoting thrombin-dependent HMGB1 degradation and activation of protein C and thrombin-activatable fibrinolysis inhibitor (TAFI/plasma carboxypeptidase B/CPB2). We thus investigated the downstream molecules of activated protein C (APC) and TAFI (TAFIa), for prevention of oxaliplatin-induced peripheral neuropathy (OIPN) in mice. OIPN was prevented by TMα and by each of an anti-HMGB1-neutralizing antibody (HAb), APC and porcine pancreatic carboxypeptidase B (ppCPB, used as a stable surrogate of TAFIa), or their combination at subeffective doses. Intraplantar administration of HMGB1 induced mechanical allodynia, which was abolished by TMα, but not APC or ppCPB. The anti-OIPN effects of TMα and APC were reversed by an antagonist of proteinase-activated receptor 1 (PAR1), targetable by APC, and the effect of TMα was also reversed by a CPB inhibitor. Intraplantar administration of mouse C5a (mC5a), targetable by TAFIa, caused mechanical allodynia, an effect blocked by TMα, a mC5a receptor (mC5aR) antagonist or HAb. The mC5aR antagonist prevented OIPN development. Oxaliplatin significantly increased plasma C5a levels in the mice treated with argatroban, a thrombin inhibitor, capable of reducing the degradation of HMGB1 by the endogenous thrombin-thrombomodulin axis. Our data thus suggest that the anti-OIPN effect of TMα involves APC-induced PAR1 activation and TAFIa-induced degradation of C5a that induces HMGB1-dependent pain, in addition to HMGB1 degradation.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Peer-reviewed clinical and outcomes research relevant to medicinal leech therapy and its biology. Indexed in PubMed and verified against the NCBI record.
Why This Matters for Hirudotherapy
In this mechanistic mouse study, thrombomodulin alfa (TMα, a recombinant soluble endothelial thrombomodulin) prevented oxaliplatin-induced peripheral neuropathy, and the authors dissected the pathway: the protective effect involved thrombin-dependent degradation of the pain mediator HMGB1 plus activated-protein-C-driven PAR1 activation and TAFIa-mediated inactivation of complement C5a, with PAR1 antagonism and a CPB inhibitor reversing the benefit. The relevance to hirudotherapy is indirect but legitimate to the leech-secretome drug-discovery narrative: it centers on the thrombin/anticoagulant signaling axis (thrombin, PAR1, the thrombomodulin system) that the canonical medicinal-leech salivary anticoagulant hirudin acts upon, illustrating how modulating thrombin-related pathways can have analgesic/neuroprotective consequences. Caveat: this is a preclinical animal study of a recombinant human protein — not a leech-derived compound and not a clinical trial — so any link to leech therapy is mechanistic and hypothesis-generating only, with no human efficacy implied.
Citation
Thrombomodulin-Induced Prevention of Peripheral Neuropathy in Oxaliplatin-Treated Mice Involves Complement C5a Inactivation and PAR1 Activation in Addition To HMGB1 Degradation.
Maruo et al. · Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology, 2025
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