Vein wall remodeling after deep vein thrombosis involves matrix metalloproteinases and late fibrosis in a mouse model.
OBJECTIVE
Deep venous thrombosis (DVT) confers vein wall injury associated with fibrosis and extracellular matrix (ECM) turnover, likely mediated by matrix proteases. This study investigated the expression of proteases and collagen involved in early vein wall remodeling.


METHODS
In the mouse, DVT was produced by ligation of the infrarenal inferior vena cava (IVC) or sham operation, and tissue was harvested at 4, 8, and 12 days. The vein wall tissue was processed for real-time reverse transcriptase-polymerase chain reaction (6 to 8 per time point), Western immunoblotting (5 per time point), and gelatin zymography (5 per time point). Analysis of variance was used for multiple comparisons, and a P < .05 was significant.


RESULTS
Thrombus resolution was documented by a 38% decrease in the thrombosed IVC weight from day 4 to day 12 (P = .007). Total vein wall collagen increased over time, with a corresponding increase in procollagen I and III, and expression peaked at 12 days (24-fold and 6.1-fold, respectively, P < .02). Matrix metalloproteinase-2 (MMP-2) gene expression was 23-fold greater at 12 days after thrombus formation compared with sham or 4 days after thrombosis (P < .05). Total MMP-2 activity was also significantly elevated at 12 days compared with sham (P < .05). MMP-9 expression was 19-fold and 27-fold higher at days 4 and 8, respectively, relative to sham (P < .05), with no difference in activity. MMP-14 expression was twofold to 3.6-fold greater at day 12 compared with earlier time points and shams (P < .001), but no differences in protein levels were found. Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) protein levels were not significantly different from sham over time; however, the ratio of uPA to PAI-1 was decreased through 8 days.


CONCLUSIONS
Vein wall remodeling after DVT is similar to wound healing and is associated with increased procollagen gene expression and total collagen. It is also associated with increased early MMP-9 expression, followed by MMP-2 expression and activity after DVT resolution.


CONCLUSIONS
Deep vein thrombosis is an often neglected problem that long term is associated with the postphlebitic syndrome of limb swelling, pain, and often ulceration. The basic mechanisms of the vein wall damage that results have not been delineated. The following study describes the vein wall matrix metalloproteinase gene and activity response induced over time in the vein wall after DVT. Additionally, the corresponding collagen upregulation and proximate plasmin system mediators are determined. With this knowledge, potential therapies to reduce vein wall injury directly might be possible.
Deatrick
Kristopher B
KB
Jobst Vascular Laboratory, Section of Vascular Surgery, University of Michigan Medical School, Ann Arbor, 48109, USA.
Eliason
Jonathan L
JL
Lynch
Erin M
EM
Moore
Andrea J
AJ
Dewyer
Nicholas A
NA
Varma
Manu R
MR
Pearce
Charles G
CG
Upchurch
Gilbert R
GR
Wakefield
Thomas W
TW
Henke
Peter K
PK
D000818:Animals; D015153:Blotting, Western; D003094:Collagen / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006025:Glycosaminoglycans / Q000378:metabolism; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D023421:Models, Animal; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000502:physiology; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism; D014682:Vena Cava, Inferior; D020246:Venous Thrombosis / Q000378:metabolism*
D006025:Glycosaminoglycans; D017395:Plasminogen Activator Inhibitor 1; D003094:Collagen; D014568:Urokinase-Type Plasminogen Activator; D020782:Matrix Metalloproteinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9