The protein C pathway and sepsis.
Review published in Thrombosis research (2011)
Abstract
After the discovery of the key components of the protein C (PC) pathway a beneficial effect on survival of the infusion of activated protein C (APC) in animal models of sepsis was demonstrated, leading to the development of recombinant human activated protein C (rh-APC) as a therapeutic agent. It soon became clear that rather than the anticoagulant and profibrinolytic activities of APC, its anti-inflammatory and cytoprotective properties played a major role in the treatment of patients with severe sepsis. Such properties affect the response to inflammation of endothelial cells and leukocytes and are exerted through binding of APC to at least five receptors with intracellular signaling. The main APC protective mechanism involves binding of the Gla-domain to the endothelial protein C receptor (EPCR) and cleavage of protease activated receptor 1 (PAR-1), eliciting suppression of proinflammatory cytokines synthesis and of intracellular proapoptotic pathways and activation of endothelial barrier properties. However, thrombin cleaves PAR-1 with much higher catalytic efficiency, followed by pro-inflammatory, pro-apoptotic and barrier disruptive intracellular signaling, and it is unclear how APC can exert a protective activity through the cleavage of PAR-1 when thrombin is also present in the same environment. Interestingly, in endothelial cell cultures, PAR-1 cleavage by thrombin results in anti-inflammatory and barrier protective signaling provided occupation of EPCR by the PC gla-domain, raising the possibility that the beneficial effects of rh-APC might be recapitulated in vivo by administration of h-PC zymogen to patients with severe sepsis. Recent reports of h-PC infusion in animal models of sepsis support this hypothesis.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
After the discovery of the key components of the protein C (PC) pathway a beneficial effect on survival of the infusion of activated protein C (APC) in animal models of sepsis was demonstrated, leading to the development of recombinant human activated protein C (rh-APC) as a therapeutic agent. It...
Por qué esto importa para la hirudoterapia
This review examined the protein C pathway in sepsis, focusing on activated protein C's anti-inflammatory and cytoprotective signaling through EPCR binding and PAR-1 cleavage, and raising the hypothesis that protein C zymogen infusion might recapitulate benefits of recombinant APC. The relevance to ASH is minimal — the abstract discusses anticoagulant physiology but involves no leeches, hirudin, or leech secretome components. Caveat: no leech or hirudotherapy content; this serves only as indirect background on the broader anticoagulant landscape relevant to ASH's library.
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Añadido a la biblioteca ASH: May 28, 2026 · Última actualización del sitio: June 18, 2026