thrombin (ThrombiRAAS)

Platelet-released polyphosphate controls thrombin generation.

Kurth Jack M JM, Zhang Xu X, Aslan Joseph E JE, McCarty Owen J T OJT

Low-Density Lipoprotein Modulates Plasma Fibrin Network Architecture and Impairs Fibrinolysis.

Nameny Arezoo A, DeSmet Austin A, Cai Can C, Baker Stephen R SR et al.

Low-density lipoprotein (LDL) is a major atherogenic lipoprotein, yet its potential to directly modify the fibrin scaffold of blood clots is incompletely understood. Here, we investigated how LDL alters plasma fibrin network architecture and internal fibrinolysis across defined fibrinogen/thrombin conditions. Pooled normal human plasma was supplemented with LDL and clotted with controlled concentrations of fibrinogen and thrombin. Fibrin architecture was visualized by confocal microscopy and quantified by pore-size analysis; clot formation and lysis were monitored turbidimetrically in the presence of tissue plasminogen activator (tPA). Increasing LDL produced a pronounced reduction in fibrin-network pore size across the tested fibrinogen/thrombin conditions. The LDL dependence of pore diameter was well described by a power-law relationship, D_pore = (6.54 ± 0.11)[ LDL ] -0.12 ± 0.02 , (R 2 = 0.90), with a significant negative LDL exponent (p = 4 × 10 -5 ). Increasing LDL also prolonged clot lysis time and altered turbidity kinetics. These findings extend epidemiologic and clinical associations between ApoB-containing lipoproteins and hypofibrinolytic clot phenotypes by demonstrating, in a controlled plasma system, that LDL itself can modify fibrin network architecture and fibrinolytic susceptibility. The results support a structure-function role for LDL within the fibrin biomaterial and motivate direct tests of LDL incorporation, protofibril packing, fibrinolytic-protein binding, and single-fiber mechanics.

Time-Resolved Multidimensional NMR Spectroscopy Reveals the Bifurcated Folding Pathway of a Thrombin-Binding DNA G4-Azobenzene Derivative Complex.

Martins Jason J, Wirmer-Bartoschek Julia J, Schwalbe Harald H

Resolving the complex folding landscape of biomolecules contributes greatly to understanding cellular function, since cellular regulation and signal transduction are often linked to their conformational dynamics. We here investigate conformational transitions of a DNA deoxyguanosine G-quadruplex (G4) induced by binding of a low molecular weight azobenzene derivative. This ligand acts as a photoswitch that triggers conformational rearrangements of the thrombin binding aptamer (TBA) G4 in a reversible manner pending on the photoisomeric state of the ligand (E- or Z-configuration). We exploit the reversible association-dissociation of the photoactive ligand to extend current real-time NMR experiments, allowing the in-depth characterization of the folding pathways for the ligand association and dissociation processes and induction of G4 refolding. The folding pathway features kinetic partitioning and significant population of G4 folding intermediates.

Adjunctive Autologous Platelet-Rich Plasma Activated with Autologous Thrombin Serum for a Refractory Below-Knee Amputation Stump Wound: A Case Report.

Shara Khansa K, AlAjmi Hasan H, Baatiah Nada N, Darag Sara S et al.

Background and Clinical Significance: Refractory below-knee amputation (BKA) stump wounds can delay prosthetic rehabilitation. This report describes wound healing during multimodal care that included autologous platelet-rich plasma (PRP) activated with autologous thrombin serum (ATS); Case Presentation: A 33-year-old man with Charcot-Marie-Tooth disease and a persistent right BKA stump wound after surgical revisions underwent three PRP-ATS applications on 16 and 23 February and 8 March 2026. Collagen dressings were applied on 2 and 15 March, and compression was continued thereafter. The estimated wound volume decreased from 14.18 cm3 at baseline to 0.48 cm3 at week 3 (approximately 97%); advanced epithelialization was observed at week 4. Complete closure was documented on 16 April 2026, approximately eight weeks after treatment began. No treatment-related adverse events were reported. After closure, the patient was referred for prosthetic rehabilitation assessment; fitting and functional use were not documented; Conclusions: Healing was temporally associated with PRP-ATS as part of a multimodal treatment course. This single case supports the feasibility of the approach but cannot establish the independent efficacy of PRP-ATS.