Abstract
Batroxobin, isolated from Bothrops moojeni, is a defibrinogenating agent used as a thrombin-like serine protease against fibrinogen for improving microcirculation. Here, we investigated whether, and if so, how batroxobin restores ischemic tissue injury in terms of anti-inflammatory effects. In an in vitro flow cytometry assay for human neutrophil extracellular traps (NETs), batroxobin (DF-521; Defibrase) inhibited human NETs induced by tumor necrosis factor-α (TNF-α) in the presence of human fibrinogen. Next, the effect of batroxobin was investigated by immunohistochemistry of the anterior tibial muscle (ATM) in an ischemic hindlimb model using C57BL/6J mice intraperitoneally injected with DF-521 versus the saline control. NETs and fibrinogen deposition in the ischemic ATM decreased in DF-521-treated mice on day 2 after ischemia. Meanwhile, reverse transcription-quantitative PCR assay of the ischemic ATM unveiled continuous downregulation in the expression of the genes; Tnf-α and nitric oxide synthase2 (Nos2) with hypoxia-inducible factor-1α (Hif-1α) and vascular endothelial growth factor-a (Vegf-a) from day 3 to day 7, but the upregulation of arginase-1 (Arg-1) and placental growth factor (Plgf) with myogenin (Myog) on day 7. Daily intraperitoneal DF-521 injection for the initial 7 days into mice with ischemic hindlimbs promoted angiogenesis and arteriogenesis on day 14. Moreover, DF-521 injection accelerated myofiber maturation after day 14. Laser doppler imaging analysis revealed that blood perfusion in DF-521-injected mice significantly improved on day 14 versus the saline control. Thus, DF-521 improves microcirculation by protecting NETs with tissue defibrinogenation, thereby protecting against severe ischemic tissue injury and accelerating vascular and skeletal muscular regeneration. To our knowledge, batroxobin might be the first clinically applicable NET inhibitor against ischemic diseases.
Highlights
Batroxobin (Defibrase) is a thrombin-like serine protease extracted from the venom of the snake Bothrops moojeni, known as the Brazilian lancehead, and it exerts defibrinogenating and anti-inflammatory effects [1,2,3,4]
Batroxobin reduced the area of Fgn deposition in ischemic anterior tibial muscle (ATM) (16% in DF-521 vs. 21% in control; P = 0.01) (Fig 2D and 2E)
The findings indicate that batroxobin as a dysfibrinogenic agent decreases Fgn deposition and protects against neutrophil extracellular traps (NETs) in ischemic tissue to alleviate acute inflammation
Summary
Batroxobin (Defibrase) is a thrombin-like serine protease extracted from the venom of the snake Bothrops moojeni, known as the Brazilian lancehead, and it exerts defibrinogenating and anti-inflammatory effects [1,2,3,4]. Considering the effect of defibrinogenation in improving peripheral circulation [7,8], batroxobin is clinically applied to manage conditions like vibration disease [9], sudden deafness (in Japan) [10,11], stroke, and transient ischemic attack (in China) [12,13]. Regarding batroxobin-inducing defibrinogenation, Wang et al reported that thrombin first releases fibrinopeptide A and fibrinopeptide B from fibrinogen (Fgn). The release of both the peptides triggers a polymerizing reaction for fibrin monomers to form a polymer with a tight linking ability. Batroxobin cleaves fibrinopeptide A, but not ibrinopeptide B, from Fgn, which triggers the des-A fibrin monomer to form a polymer with a looser linking ability than that of the fibrin polymer. The des-A fibrin polymer evokes easy degradation by plasmin in the fibrinolytic system, and the degraded product is excluded by the reticuloendothelial system [14], resulting in the actualized defibrinogenation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
