Dose-dependent thrombus resolution due to oral plasminogen activator inhibitor (PAI)-1 inhibition with tiplaxtinin in a rat stenosis model of venous thrombosis

Summary

This study aimed to evaluate a small-molecule PAI-1 inhibitor (PAI-039; tiplaxtinin) in a rodent stenosis model of venous thrombosis in a two-phase experiment. Phase 1 determined the efficacy of tiplaxtinin against Lovenox (LOV), while phase 2 determined the dose-dependent efficacy. For both phases, drug treatment began 24 hours after surgically induced venous thrombosis and continued for four days. Phase 1 animals (n = 24) receiving low-dose (LD; 1 mg/kg oral gavage) PAI-1 inhibitor demonstrated a 52% decrease in thrombus weight (TW) versus controls (p < 0.05) with significant reductions in active plasma PAI-1, while the high-dose (HD; 10 mg/kg oral gavage) group demonstrated a 23% reduction in TW versus controls. Animals treated subcutaneously with LOV (3 mg/kg) showed a 39% decrease in TW versus controls (p < 0.05). Coagulation tests (aPTT and TCT) were significantly different in LOV compared to PAI-1 inhibitor groups. PAI-039 treatment was also associated with significantly increased return of inferior vena cava blood flow four days post-thrombosis versus controls (p < 0.05). In phase 2 (n = 30), TW was reduced from the 0.5 mg/kg to 5 mg/ kg experimental groups, with the 10 mg/kg group demonstrating a paradoxical increase. The 5 mg/kg group showed statistically significant decreases in TW versus controls after four treatment days (p < 0.05). This is the first study to demonstrate dose related effects of PAI-039 on increasing thrombus resolution and inferior vena cava blood flow without adverse effects on anti-coagulation in a rat stenosis model of venous thrombosis.

Keywords

Venous thrombosis - plasminogen activator inhibitors - animal models - stenosis - deep vein thrombosis

^* Dr. Thomas R. Meier is currently affiliated with the Mayo Clinic, Rochester, MN, USA.

^** Dr. Robert G. Schaub is currently affiliated with the Archemix Corp., Cambridge, MA, USA.

^† Deceased January 13, 2008.

• References

• 1 Coon WW, Willis PW, 3rd Keller JB. Venous thromboembolism and other venous disease in the Tecumseh community health study. Circulation 1973; 48: 839-846.
• 2 Anderson FA, Jr. Wheeler HB, Goldberg RJ. et al. A population-based perspective of the hospital incidence and case-fatality rates of deep vein thrombosis and pulmonary embolism. The Worcester DVT Study. Arch Intern Med 1991; 151: 933-938.
• 3 Peterson KL. Acute pulmonary thromboembolism: has its evolution been redefined?. Circulation 1999; 99: 1280-1283.
• 4 Launius BK, Graham BD. Understanding and preventing deep vein thrombosis and pulmonary embolism. AACN Clin Issues 1998; 9: 91-99.
• 5 De Lissovoy G. Economic issues in the treatment and prevention of deep vein thrombosis from a managed care perspective. Am J Man Care 2001; 7 (Suppl. 17) S535-544.
• 6 Heit JA, Silverstein MD, Mohr DN. et al. The epidemiology of venous thromboembolism in the community. Thromb Haemost 2001; 86: 452-463.
• 7 Hull RD, Pineo GF, Raskob GE. The economic impact of treating deep vein thrombosis with low-molecular-weight heparin: Outcome of therapy and health economy aspects. Low-molecular-weight heparin versus unfractionated heparin. Haemostasis 1998; 28 S3 8-16.
• 8 Wille-Jorgensen P, Jorgensen LN, Crawford M. Asymptomatic postoperative deep vein thrombosis and the development of postthrombotic syndrome. A systematic review and meta-analysis. Thromb Haemost 2005; 93: 236-241.
• 9 Hull R, Delmore T, Genton E. et al. Warfarin sodium versus low-dose heparin in the long-term treatment of venous thrombosis. N Engl J Med 1979; 301: 855-858.
• 10 Lagerstedt CI, Olsson CG, Fagher BO. et al. Need for long-term anticoagulant treatment in symptomatic calf-vein thrombosis. Lancet 1985; 2: 515-518.
• 11 Kearon C, Hirsh J. Management of anticoagulation before and after elective surgery. N Engl J Med 1997; 336: 1506-1511.
• 12 Hirsh J. Heparin. N Engl J Med 1991; 324: 1565-1574.
• 13 Lensing AW, Prandoni P, Prins MH. et al. Deep-vein thrombosis. Lancet 1999; 353: 479-485.
• 14 van Den Belt AG, Prins MH, Lensing AW. et al. Fixed dose subcutaneous low molecular weight heparins versus adjusted dose unfractionated heparin for venous thromboembolism. Cochrane Database Syst Rev 2000; 2: CD001100.
• 15 Schiele F, Lindgaerde F, Eriksson H. et al. Subcutaneous recombinant hirudin (HBW 023) versus intravenous sodium heparin in treatment of established acute deep vein thrombosis of the legs: a multicentre prospective dose-ranging randomized trial. International Multicentre Hirudin Study Group. Thromb Haemost 1997; 77: 834-838.
• 16 Douketis JD, Kearon C, Bates S. et al. Risk of fatal pulmonary embolism in patients with treated venous thromboembolism. J Am Med Assoc 1998; 279: 458-462.
• 17 Elliott G, Stevens S. Temporary vena caval interruption and thrombolysis in the management of deepvein thrombosis. Curr Treat Options Cardiovasc Med 2005; 7: 149-158.
• 18 Elokdah H, Abou-Gharbia M, Hennan JK. et al. Tiplaxtinin, a novel, orally efficacious inhibitor of plasminogen activator inhibitor-1: design, synthesis, and preclinical characterization. J Med Chem 2004; 47: 3491-3494.
• 19 Hennan JK, Elokdah H, Leal M. et al. Evaluation of PAI-039 [{1-benzyl-5-[4-(trifluoromethoxy)phenyl]- 1H-indol-3-yl}(oxo)acetic acid], a novel plasminogen activator inhibitor-1 inhibitor, in a canine model of coronary artery thrombosis. J Pharmacol Exp Therap 2005; 314: 710-716.
• 20 Gorlatova NV, Cale JM, Elokdah H. et al. Mechanism of inactivation of plasminogen activator inhibitor-1 by a small molecule inhibitor. J Biol Chem 2007; 282: 9288-9296.
• 21 Myers DD, Jr. Henke PK, Bedard PW. et al. Treatment with an oral small molecule inhibitor of P selectin (PSI-697) decreases vein wall injury in a rat stenosis model of venous thrombosis. J Vasc Surg 2006; 44: 625-632.
• 22 Banks WJ. Applied veterinary histology.. Baltimore: Williams & Wilkins; 1981
• 23 Myers D, Wrobleski S, Londy F. et al. New and effective treatment of experimentally induced venous thrombosis with anti-inflammatory rPSGL-Ig. Thromb Haemost 2002; 87: 374-382.
• 24 Dano K, Andreasen PA, Grondahl-Hansen J. et al. Plasminogen activators, tissue degradation, and cancer. Adv Cancer Res 1985; 44: 139-266.
• 25 Vassalli JD, Sappino AP, Belin D. The plasminogen activator/plasmin system. J Clin Invest 1991; 88: 1067-1072.
• 26 Kohler HP, Grant PJ. Plasminogen-activator inhibitor type 1 and coronary artery disease. N Engl J Med 2000; 342: 1792-1801.
• 27 Schulman S, Wiman B. The significance of hypofibrinolysis for the risk of recurrence of venous thromboembolism. Duration of Anticoagulation (DURAC) Trial Study Group. Thromb Haemost 1996; 75: 607-611.
• 28 Crowther MA, Roberts J, Roberts R. et al. Fibrinolytic variables in patients with recurrent venous thrombosis: a prospective cohort study. Thromb Haemost 2001; 85: 390-394.
• 29 Grubic N, Stegnar M, Peternel P. et al. A novel G/A and the 4G/5G polymorphism within the promoter of the plasminogen activator inhibitor-1 gene in patients with deep vein thrombosis. Thromb Res 1996; 84: 431-443.
• 30 Sartori MT, Wiman B, Vettore S. et al. 4G/5G polymorphism of PAI-1 gene promoter and fibrinolytic capacity in patients with deep vein thrombosis. Thromb Haemost 1998; 80: 956-960.
• 31 Smith LH, Dixon JD, Stringham JR. et al. Pivotal role of PAI-1 in a murine model of hepatic vein thrombosis. Blood 2006; 107: 132-134.
• 32 Lijnen HR, Alessi MC, Frederix L. et al. Tiplaxtinin impairs nutritionally induced obesity in mice. Thromb Haemost 2006; 96: 731-737.
• 33 Naski MC, Lawrence DA, Mosher DF. et al. Kinetics of inactivation of alpha-thrombin by plasminogen activator inhibitor-1. Comparison of the effects of native and urea-treated forms of vitronectin. J Biol Chem 1993; 268: 12367-12372.
• 34 Stoop AA, Lupu F, Pannekoek H. Colocalization of thrombin, PAI-1, and vitronectin in the atherosclerotic vessel wall: A potential regulatory mechanism of thrombin activity by PAI-1/vitronectin complexes. Arteriosclerosis Thromb Vasc Biol 2000; 20: 1143-1149.
• 35 Loskutoff DJ, Quigley JP. PAI-1, fibrosis, and the elusive provisional fibrin matrix. J Clin Invest 2000; 106: 1441-1443.
• 36 Rezaie AR. Vitronectin functions as a cofactor for rapid inhibition of activated protein C by plasminogen activator inhibitor-1. Implications for the mechanism of profibrinolytic action of activated protein C. J Biol Chem 2001; 276: 15567-15570.
• 37 Cao C, Lawrence DA, Li Y. et al. Endocytic receptor LRP together with tPA and PAI-1 coordinates Mac-1-dependent macrophage migration. EMBO J 2006; 25: 1860-1870.
• 38 McMahon GA, Petitclerc E, Stefansson S. et al. Plasminogen activator inhibitor-1 regulates tumor growth and angiogenesis. J Biol Chem 2001; 276: 33964-33968.
• 39 Downing LJ, Strieter RM, Kadell AM. et al. Neutrophils are the initial cell type identified in deep venous thrombosis induced vein wall inflammation. Asaio J 1996; 42: M677-682.
• 40 Wakefield TW, Strieter RM, Wilke CA. et al. Venous thrombosis-associated inflammation and attenuation with neutralizing antibodies to cytokines and adhesion molecules. Arteriosclerosis Thromb Vasc Biol 1995; 15: 258-268.
• 41 Leik CE, Su EJ, Nambi P. et al. Effect of pharmacologic plasminogen activator inhibitor-1 inhibition on cell motility and tumor angiogenesis. J Thromb Haemost 2006; 4: 2710-2715.
• 42 Weisberg AD, Albornoz F, Griffin JP. et al. Pharmacological inhibition and genetic deficiency of plasminogen activator inhibitor-1 attenuates angiotensin II/ salt-induced aortic remodeling. Arteriosclerosis Thromb Vasc Biol 2005; 25: 365-371.