Abstract 32: Ly6C
            Lo
            Monocyte/Macrophages Are Essential for Thrombus Resolution in a Murine Model of Venous Thrombosis

Venous thrombosis (VT) results in vein wall injury by promoting inflammation and fibrosis leading to venous reflux, swelling, pain, and potentially, recurrent thrombosis. While prior work has shown that infiltrating leukocytes are important for VT resolution, as of yet, the precise roles of different leukocyte subsets are not well understood. Monocyte/macrophages (Mo/MΦs) are essential for the repair and resolution of tissue injury in other models, and come in inflammatory (Ly6C Hi ) or pro-resolution (Ly6C Lo ) subtypes. We hypothesized that infiltrating Mo/MΦs would be critical to VT resolution. In order to study this in vivo , we utilized a conditional macrophage depletion technique, using CD11b-DTR mice, to examine the effects of Mo/MΦs in a murine model of stasis VT by inferior vena cava ligation. Administration of 10ng/g diphtheria toxoid (DTx) every 48 hours by intra-peritoneal injection in CD11b-DTR mice resulted in an 89% and 55% decrease in circulating monocytes at 24hrs and 48hrs, respectively. When compared to saline controls, DTx injection had no effects on thrombogenic response or IVC thrombus cell populations in C57BL/6 control mice. At 8 days’ post-ligation, DTx treated CD11b-DTR mice had preferentially decreased vein wall-thrombus Ly6C Lo Mo/MΦs as compared with controls. DTx treated mice had significantly larger thrombi (1.7-fold) and less TGF-β, FSP-1, and plasminogen by western immunoblotting (all P-values ≤ 0.01). Consistent with a reduction in Ly6C Lo Mo/MΦs was a significant decrease in cellular TGF-β by intra-cellular flow cytometry. These findings suggest that Ly6C Lo Mo/MΦs are essential for normal VT resolution and may promote thrombus resolution via a plasminogen-mediated mechanism.

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Untargeted Metabolomic Profiling Reveals Metabolic Changes in Serum and Vein Wall of the Inferior Vena Cava Murine Model of Deep Venous Thrombosis

Journal of Vascular Surgery Venous and Lymphatic Disorders ◽

10.1016/j.jvsv.2016.10.013 ◽

2017 ◽

Vol 5 (1) ◽

pp. 146

Author(s):

Marina Kafeza ◽

Yeji Sung ◽

Konstantina Spagou ◽

Michael Kyriakides ◽

Brhahman Dharmarajah ◽

...

Keyword(s):

Inferior Vena Cava ◽

Venous Thrombosis ◽

Deep Venous Thrombosis ◽

Murine Model ◽

Inferior Vena ◽

Vena Cava ◽

Metabolic Changes ◽

Vein Wall ◽

Metabolomic Profiling

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Neutrophils modulate post-thrombotic vein wall remodeling but not thrombus neovascularization

Thrombosis and Haemostasis ◽

10.1160/th05-02-0099 ◽

2006 ◽

Vol 95 (02) ◽

pp. 272-281 ◽

Cited By ~ 42

Author(s):

Manu Varma ◽

K. Deatrick ◽

Nicholas Dewyer ◽

Erin Lynch ◽

Andrea Moore ◽

...

Keyword(s):

Inferior Vena ◽

Vena Cava ◽

Fold Increase ◽

Western Immunoblotting ◽

Vein Wall ◽

Gelatinase Activity ◽

Wall Stiffness ◽

Control Serum ◽

Wall Injury

SummaryEarly deep venous thrombosis (DVT) resolution is associated with neutrophil (PMN) influx. This study examined the role of PMNs in thrombus neovascularization and vein wall injury after DVT. A rat model of DVT by inferior vena cava (IVC) ligation was performed with control serum or rabbit anti-rat PMN serum administered perioperatively with sacrifice at 2 and 7 days. At 2 days, neutropenic rats had 1.6-fold larger thrombi (P = .04) and 1.4-fold higher femoral venous pressures by water manometry (P = .008) but no difference in thrombus neovascularization was observed. By7 days, DVT sizes were similar, but vein wall injury persisted in the neutropenic rats with a 2.0-fold increase in vein wall stiffness by microtensiometry (P< .05), as well asa 1.2-fold increased thickness (P = .04). Collagen and profibrotic growth factors were significantly increased in neutropenic IVC at7 days (all P< .05).Vein wall and intrathrombus uPA by Western immunoblotting, and intrathrombus MMP-9 gelatinase activity were significantly less in neutropenic rats than controls (P < .001). Conversely, MMP-2 was significantly elevated in neutropenic IVC at 2 days after DVT. However, neutropenia induced 24 hours after DVT formation resulted in no significant increase in vein wall stiffness or collagen levels at 7 days, despite 1.4-fold larger thrombi (P < .05). These data suggest a critical early role for PMN in post DVT vein wall remodeling.

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In Vivo Monitoring of Venous Thrombosis In Mice Using Ultrasonography

Blood ◽

10.1182/blood.v116.21.4214.4214 ◽

2010 ◽

Vol 116 (21) ◽

pp. 4214-4214

Author(s):

Meghedi Aghourian ◽

Catherine Lemarie ◽

Mark Blostein

Keyword(s):

Venous Thrombosis ◽

Murine Model ◽

Conflicts Of Interest ◽

Genetically Modify ◽

Vena Cava ◽

Venous Stasis ◽

Clinical Aspects ◽

Reliable Technique ◽

Over Time

Abstract Abstract 4214 Deep venous thrombosis is an important cause of morbidity and mortality in clinical medicine. There has been extensive research dedicated to the clinical aspects of venous thrombosis, especially with regards to its diagnosis and treatment. However, animal models studying this phenomenon are scarce and, in most cases, very crude, relying on sacrificing animals to excise the formed thrombi. Developing an in vivo murine model of venous thrombosis, detecting and monitoring thrombi non-invasively as is done in humans can be a powerful tool given our ability to genetically modify the murine genome. Therefore, we developed such a murine model using the Vevo770®, a microimaging ultrasound system previously developed to study the arterial circulation of mice. Two different thrombosis models were employed to generate clots in the inferior vena cava (IVC) of wild type C57Bl6 mice: 1) ligation of the IVC to generate venous stasis and 2) application of Ferric Chloride (FeCl3) to the outer layer of the IVC to injure the endothelium. Using both of these techniques, adequate thromboses were generated in the IVCs of mice as determined pathologically. Other mice were allowed to recover after surgery, and the development of venous thrombosis was assessed by ultrasonography using the Vevo 770®. In order to assess the precision of clot measurements using this novel technique, we then sacrificed the mice and excised the clots. In both models, the measurement of the clot pathologically correlates favorably (R2= 0, 9116 for the ligation model, and R2 = 0,905 for the FeCl3 model) with measurements done by ultrasonography (n=20 for the ligation model, and n=5 for the FeCl3 injury model). In the ligation model, a thrombus develops less than an hour after ligation of the IVC, and the size of the clot increases over time. For example, five hours after the ligation of the IVC, a clot develops and has a cross sectional area of 4,5 mm2. The clot size increases significantly (p=0.001) over time to 6.2 mm2 at 24 hours post ligation (n=20). Treatment of these mice with an anticoagulant (dalteparin at a dose of 200 u/kg) prior to the procedure prevented the development of IVC thrombosis as determined by ultrasonagraphy. These data suggest that the Vevo770® can be used as a reliable technique for the non-invasive assessment of venous thrombosis in mice. Developing a murine model for thrombosis using more accurate, and clinically more relevant techniques such as ultrasonography, is a step towards better understanding the pathophysiology of venous thromboembolism. Figure 1. Clot length correlation using histology and ultrasonography, 24 hrs post ligation of the IVC in 20 mice. R2= 0,9116. Figure 1. Clot length correlation using histology and ultrasonography, 24 hrs post ligation of the IVC in 20 mice. R2= 0,9116. Disclosures: No relevant conflicts of interest to declare.

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In Vivo Monitoring of Venous Thrombosis in Mice.

Blood ◽

10.1182/blood.v114.22.5061.5061 ◽

2009 ◽

Vol 114 (22) ◽

pp. 5061-5061

Author(s):

Meghedi Aghourian ◽

Mark Blostein

Keyword(s):

Venous Thromboembolism ◽

Venous Thrombosis ◽

Murine Model ◽

Conflicts Of Interest ◽

Vena Cava ◽

Reliable Technique ◽

Non Invasive ◽

Post Surgery ◽

Ultrasound Technology

Abstract Abstract 5061 Venous thromboembolism afflicts 117 people per 100,000 each year and is an important cause of morbidity and mortality. There has been extensive research dedicated to the clinical aspect of venous thrombosis, especially with regards to its diagnosis and treatment. However, animal models studying this phenomenon are scarce and, in most cases, very crude. Developing a murine model of venous thrombosis using techniques similar to the ones used to detect thrombosis in humans can be a constructive step in studying this phenomenon in more detail. The model developed in our lab uses ultrasound imaging to visualize venous clots in the Inferior Vena Cava (IVC) of mice, allowing for precise measurements of the formed clot. Ligation of the IVC is one of the well established models for studying thrombosis in mice. We ligated the IVC of wild type C57B6 mice, and allowed them to recover. We then followed clot formation at several time points after the operation using micro-ultrasonography, the Vevo 770®, a novel imaging ultrasound technology designed to monitor murine vasculature. To assess the precision of the clot measurements, we then sacrificed the mice, and dissected out the thrombi in order to precisely measure and weigh them. A thrombosis develops only after 5 hours of ligation post surgery when a clot is visualized in the IVC. The clot increases slightly over the next 24 hours. The measurements of the clot after dissection correlates favourably with the measurements done by ultrasonagraphy using the Vevo770®. These data suggest that the Vevo770® can be used as a reliable technique for non-invasive assessment of venous thromboembolism in mice. Developing a murine model for thrombosis using more accurate, and clinically more relevant techniques such as ultrasonography, is a step towards better understanding and treatment of venous thromboembolism. Disclosures No relevant conflicts of interest to declare.

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Endotoxaemia-augmented murine venous thrombosis is dependent on TLR-4 and ICAM-1, and potentiated by neutropenia

Thrombosis and Haemostasis ◽

10.1160/th16-03-0218 ◽

2017 ◽

Vol 117 (02) ◽

pp. 339-348 ◽

Cited By ~ 12

Author(s):

Andrea T. Obi ◽

Elizabeth Andraska ◽

Yogendra Kanthi ◽

Chase W. Kessinger ◽

Megan Elfline ◽

...

Keyword(s):

Venous Thrombosis ◽

Inferior Vena ◽

Leukocyte Adhesion ◽

Vena Cava ◽

Toll Like Receptor ◽

Toll Like Receptor 4 ◽

Supplementary Material ◽

Pai 1

SummaryVenous thromboembolism is a major cause of death during and immediately post-sepsis. Venous thrombosis (VT) is mediated by cell adhesion molecules and leukocytes, including neutrophil extracellular traps (NETs). Sepsis, or experimentally, endotoxaemia, shares similar characteristics and is modulated via toll like receptor 4 (TLR4). This study was undertaken to determine if endotoxaemia potentiates early stasis thrombogenesis, and secondarily to determine the role of VT TLR4, ICAM-1 and neutrophils (PMNs). Wild-type (WT), ICAM-1-/- and TLR4-/- mice underwent treatment with saline or LPS (10 mg/kg i.p.) alone, or followed by inferior vena cava (IVC) ligation to generate stasis VT. In vivo microscopy of leukocyte trafficking was performed in non-thrombosed mice, and tissue and plasma were harvested during early VT formation. Pre-thrombosis, circulating ICAM-1 was elevated and increased leukocyte adhesion and rolling occurred on the IVC of LPS-treated mice. Post-thrombosis, endotoxaemic mice formed larger, platelet-poor thrombi. Endotoxaemic TLR4-/- mice did not have an augmented thrombotic response and exhibited significantly decreased circulating ICAM-1 compared to endotoxaemic WT controls. Endotoxaemic ICAM-1-/- mice had significantly smaller thrombi compared to controls. Hypothesising that PMNs localised to the inflamed endothelium were promoting thrombosis, PMN depletion using anti-Ly6G antibody was performed. Paradoxically, VT formed without PMNs was amplified, potentially related to endotoxaemia induced elevation of PAI-1 and circulating FXIII, and decreased uPA. Endotoxaemia enhanced early VT occurs in a TLR-4 and ICAM-1 dependent fashion, and is potentiated by neutropenia. ICAM-1 and/or TLR-4 inhibition may be a unique strategy to prevent sepsis-associated VT.Supplementary Material to this article is available online at www.thrombosis-online.com.

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Perforation of inferior vena cava during filter placement

VASA ◽

10.1024/0301-1526/a000087 ◽

2011 ◽

Vol 40 (2) ◽

pp. 157-162 ◽

Cited By ~ 6

Author(s):

Piecuch ◽

Wiewiora ◽

Nowowiejska-Wiewiora ◽

Szkodzinski ◽

Polonski

Keyword(s):

Pulmonary Embolism ◽

Inferior Vena Cava ◽

Venous Thrombosis ◽

Deep Venous Thrombosis ◽

Inferior Vena ◽

Vena Cava ◽

Retroperitoneal Hematoma ◽

Ivc Filter ◽

Filter Placement ◽

Therapeutic Method

The placement of an inferior vena cava (IVC) filter is a therapeutic method for selected patients with deep venous thrombosis and pulmonary embolism. However, insertion and placement of the filter may be associated with certain complications. For instance, retroperitoneal hematoma resulting from perforation of the wall by the filter is such a very rare but serious complication. We report the case of a 64-year-old woman with perforation of the IVC wall and consecutive hematoma caused by the filter who was treated surgically.

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