Thromb Haemost 2010; 104(06): 1174-1183
DOI: 10.1160/TH10-03-0184
Blood Coagulation, Fibrinolysis and Cellular Haemostasis
Schattauer GmbH

Urokinase plasminogen activator independent early experimental thrombus resolution: MMP2 as an alternative mechanism

Vikram Sood
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Catherine E. Luke
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Joseph Baldwin
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Erin M. Miller
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Megan Elfline
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Gilbert R. Upchurch Jr.
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Thomas W. Wakefield
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
,
Peter K. Henke*
1   Jobst Vascular Surgery Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, Michigan, USA
› Institutsangaben

Financial support:This study was supported by NIH HL083918 (PKH) and support from the NIH 2T32 076123 (BD) and SVS Lifeline Student Research Fellowship.
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Publikationsverlauf

Received: 22. März 2010

Accepted after major revision: 20. August 2010

Publikationsdatum:
24. November 2017 (online)

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Summary

Deep-vein thrombosis (DVT) resolution is thought to be primarily a urokinase plasminogen activator (uPA) -dependent mechanism, although observations suggest other non-fibrinolytic mechanisms may exist. We explored the role of matrix metalloproteinase (MMP) -2 and –9 in early DVT resolution in uPA-deficient mice. Male B6/SVEV (WT) and genetically matched uPA -/- mice underwent inferior vena cava (IVC) ligation to create stasis venous thrombi, with IVC and thrombus harvest. Thrombus size was similar between WT and uPA -/- mice at day 4, suggesting early non uPA-dependent resolution. Intrathrombus neutrophils and monocytes were reduced 3- and 3.5-fold in uPA -/- mice as compared with WT. By ELISA, tumour necrosis factor α and interleukin 1β were not altered, while interferon (IFN)γ was significantly elevated in uPA -/- mice. A compensatory increase in thrombus tPA was not observed, plasmin activity was reduced and PAI-1 was elevated 2.5-fold in uPA -/- mice. Active MMP2, but not MMP9, was elevated 3-fold in uPA-/- mice as compared with WT as well as MMP-14, an MMP2 activator. Collagen type IV and fibrinogen were reduced in uPA -/- mice thrombi as compared with WT. IFNγ induces MMP2, and blockade of IFNγ was associated with larger venous thrombi and reduced active MMP2, as compared with WT. Consistently, MMP2 -/- mice had larger VT as compared with WT controls, despite normal thrombus plasmin levels. Taken together, early experimental venous thrombus resolution is independent of uPA, and, in part, inflammatory cell influx. MMP2-dependent thrombolysis is an important compensatory mechanism of venous thrombus resolution, possibly by collagen type IV metabolism, and may represent an exploitable therapeutic avenue.

* Presented in part at the 94th Annual Clinical Congress of the American College of Surgeons, Surgical Research Forum, October 14, 2008.