Isolation and Characterization of Poecistasin, an Anti-Thrombotic Antistasin-Type Serine Protease Inhibitor from Leech Poecilobdella manillensis
Biochemistry and in vivo study published in Toxins (2018)
Abstract
Antistasin, first identified as a potent inhibitor of the blood coagulation factor Xa, is a novel family of serine protease inhibitors. In this study, we purified a novel antistasin-type inhibitor from leech Poecilobdella manillensis called poecistasin. Amino acid sequencing of this 48-amino-acid protein revealed that poecistasin was an antistasin-type inhibitor known to consist of only one domain. Poecistasin inhibited factor XIIa, kallikrein, trypsin, and elastase, but had no inhibitory effect on factor Xa and thrombin. Poecistasin showed anticoagulant activities. It prolonged the activated partial thromboplastin time and inhibited FeCl₃-induced carotid artery thrombus formation, implying its potent function in helping Poecilobdella manillensis to take a blood meal from the host by inhibiting coagulation. Poecistasin also suppressed ischemic stroke symptoms in transient middle cerebral artery occlusion mice model. Our results suggest that poecistasin from the leech Poecilobdella manillensis plays a crucial role in blood-sucking and may be an excellent candidate for the development of clinical anti-thrombosis and anti-ischemic stroke medicines.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
A 48-residue antistasin-family serine protease inhibitor named poecistasin was purified from Poecilobdella manillensis; it inhibited factor XIIa, kallikrein, trypsin, and elastase, prolonged APTT, reduced FeCl3-induced carotid thrombus, and attenuated ischemic stroke in a mouse model.
Why This Matters for Hirudotherapy
This study isolated and characterized poecistasin, a novel antistasin-type serine protease inhibitor from the leech Poecilobdella manillensis. The researchers found that this 48-amino acid protein exhibits anticoagulant properties by inhibiting factor XIIa and prolonging activated partial thromboplastin time, which subsequently reduced artery thrombus formation and suppressed ischemic stroke symptoms in a mouse model. These findings are highly relevant to the American Society of Hirudotherapy as they highlight a newly identified component of the leech secretome that aids in blood-feeding and holds potential for developing new anti-thrombotic therapies. However, the data are entirely preclinical, derived from animal models and in vitro assays, requiring further research to determine any clinical applicability in humans.
Citation
Reference (Vancouver style)
Tang X, Chen M, Duan Z, Mwangi J, Li P, Lai R. Isolation and Characterization of Poecistasin, an Anti-Thrombotic Antistasin-Type Serine Protease Inhibitor from Leech Poecilobdella manillensis. Toxins (Basel). 2018;10(11):429. doi:10.3390/toxins10110429. PMID: 30373118
Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.
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