K Vadivel1, Y Kumar1, G I Ogueli1, S M Ponnuraj1, P Wongkongkathep2, J A Loo2,3, M S Bajaj4, S P Bajaj1,3. 1. Department of Orthopaedic Surgery, University of California, Los Angeles, CA, USA. 2. Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA. 3. Molecular Biology Institute, University of California, Los Angeles, CA, USA. 4. Division of Pulmonology and Critical Care, Department of Medicine, University of California, Los Angeles, CA, USA.
Abstract
Essentials Current antifibrinolytics - aminocaproic acid and tranexamic acid-can cause seizures or renal injury. KD1L17R -KT , aprotinin and tranexamic acid were tested in a modified mouse tail-amputation model. S2'-subsite variations between human and mouse factor XIa result in vastly different inhibition profiles. KD1L17R -KT reduces blood loss and D-dimer levels in mouse with unobserved seizures or renal injury. SUMMARY: Background Using tissue factor pathway inhibitor (TFPI)-2 Kunitz domain1 (KD1), we obtained a bifunctional antifibrinolytic molecule (KD1L17R -KT ) with C-terminal lysine (kringle domain binding) and P2'-residue arginine (improved specificity towards plasmin). KD1L17R -KT strongly inhibited human plasmin (hPm), with no inhibition of human kallikrein (hKLK) or factor XIa (hXIa). Furthermore, KD1L17R -KT reduced blood loss comparable to aprotinin in a mouse liver-laceration model of organ hemorrhage. However, effectiveness of these antifibrinolytic agents in a model of hemorrhage mimicking extremity trauma and their inhibition efficiencies for mouse enzymes (mPm, mKLK or mXIa) remain to be determined. Objective To determine potential differences in inhibition constants of various antifibrinolytic agents against mouse and human enzymes and test their effectiveness in a modified mouse tail-amputation hemorrhage model. Methods/Results Unexpectedly, mXIa was inhibited with ~ 17-fold increased affinity by aprotinin (Ki ~ 20 nm) and with measurable affinity for KD1L17R -KT (Ki ~ 3 μm); in contrast, KD1WT -VT inhibited hXIa or mXIa with similar affinity. Compared with hPm, mPm had ~ 3-fold reduced affinity, whereas species specificity for hKLK and mKLK was comparable for each inhibitor. S2'-subsite variations largely accounted for the observed differences. KD1L17R -KT and aprotinin were more effective than KD1WT -VT or tranexamic acid in inhibiting tPA-induced mouse plasma clot lysis. Further, KD1L17R -KT was more effective than KD1WT -VT and was comparable to aprotinin and tranexamic acid in reducing blood loss and D-dimer levels in the mouse tail-amputation model. Conclusions Inhibitor potencies differ between antifibrinolytic agents against human and mouse enzymes. KD1L17R -KT is effective in reducing blood loss in a tail-amputation model that mimics extremity injury.
Essentials Current antifibrinolytics - aminocaproic acid and tranexamic acid-can cause seizures or renal injury. KD1L17R -KT , aprotinin and tranexamic acid were tested in a modified mouse tail-amputation model. S2'-subsite variations between human and mouse factor XIa result in vastly different inhibition profiles. KD1L17R -KT reduces blood loss and D-dimer levels in mouse with unobserved seizures or renal injury. SUMMARY: Background Using tissue factor pathway inhibitor (TFPI)-2 Kunitz domain1 (KD1), we obtained a bifunctional antifibrinolytic molecule (KD1L17R -KT ) with C-terminal lysine (kringle domain binding) and P2'-residuearginine (improved specificity towards plasmin). KD1L17R -KT strongly inhibited humanplasmin (hPm), with no inhibition of humankallikrein (hKLK) or factor XIa (hXIa). Furthermore, KD1L17R -KT reduced blood loss comparable to aprotinin in a mouse liver-laceration model of organ hemorrhage. However, effectiveness of these antifibrinolytic agents in a model of hemorrhage mimicking extremity trauma and their inhibition efficiencies for mouse enzymes (mPm, mKLK or mXIa) remain to be determined. Objective To determine potential differences in inhibition constants of various antifibrinolytic agents against mouse and human enzymes and test their effectiveness in a modified mouse tail-amputation hemorrhage model. Methods/Results Unexpectedly, mXIa was inhibited with ~ 17-fold increased affinity by aprotinin (Ki ~ 20 nm) and with measurable affinity for KD1L17R -KT (Ki ~ 3 μm); in contrast, KD1WT -VT inhibited hXIa or mXIa with similar affinity. Compared with hPm, mPm had ~ 3-fold reduced affinity, whereas species specificity for hKLK and mKLK was comparable for each inhibitor. S2'-subsite variations largely accounted for the observed differences. KD1L17R -KT and aprotinin were more effective than KD1WT -VT or tranexamic acid in inhibiting tPA-induced mouse plasma clot lysis. Further, KD1L17R -KT was more effective than KD1WT -VT and was comparable to aprotinin and tranexamic acid in reducing blood loss and D-dimer levels in the mouse tail-amputation model. Conclusions Inhibitor potencies differ between antifibrinolytic agents against human and mouse enzymes. KD1L17R -KT is effective in reducing blood loss in a tail-amputation model that mimics extremity injury.
Authors: Paula M Bokesch; Gabor Szabo; Ryszard Wojdyga; Hilary P Grocott; Peter K Smith; C David Mazer; Santosh Vetticaden; Alistair Wheeler; Jerrold H Levy Journal: J Thorac Cardiovasc Surg Date: 2011-07-02 Impact factor: 5.209
Authors: I Raza; R Davenport; C Rourke; S Platton; J Manson; C Spoors; S Khan; H D De'Ath; S Allard; D P Hart; K J Pasi; B J Hunt; S Stanworth; P K MacCallum; K Brohi Journal: J Thromb Haemost Date: 2013-02 Impact factor: 5.824
Authors: Galina Florova; René A Girard; Ali O Azghani; Krishna Sarva; Ann Buchanan; Sophia Karandashova; Christian J DeVera; Danna Morris; Mignote Chamiso; Kathleen Koenig; Douglas B Cines; Steven Idell; Andrey A Komissarov Journal: Physiol Rep Date: 2021-05
Authors: Kanagasabai Vadivel; Anne K Zaiss; Yogesh Kumar; Frank M Fabian; Ayman E A Ismail; Mark A Arbing; Wallace G Buchholz; William H Velander; S Paul Bajaj Journal: J Clin Med Date: 2020-11-17 Impact factor: 4.241