ALBERT

Beschreibung: Background: Previous studies have shown that inhibition of E-selectin can decrease thrombus formation and associated inflammation. E-selectin (CD-62E) is a cell adhesion molecule that is expressed on activated endothelial cells and plays an important role in leukocyte recruitment to the site of vascular injury. GMI-1271 is designed to mimic the bioactive conformation of the sialyl-Lex carbohydrate binding domain of E-selectin and is a specific E-selectin inhibitor. There remains an unmet medical need for a translatable therapeutic that can treat VT in combination with lower, safer levels of low molecular weight heparin (LMWH) anticoagulation. We hypothesize that E-selectin inhibition combined with LMWH will permit lower doses of therapeutic LMWH for the treatment of VT without increasing adverse bleeding events. Methods: Male C57BL/6J mice, 10 weeks old (23-28 grams, n5), underwent our electrolytic IVC model (EIM) to produce a non-occlusive thrombosis, via electrical free radical stimulation (250 µAmp) for 15 minutes. Experimental groups included non-treated controls (CTR-No Tx), animals given LMWH (3-6 mg/kg, SQ, once daily (qd), the E-selectin inhibitor GMI-1271 20/kg intraperitoneal (IP) twice daily (BID), and a combination of the agents. The dose range of LMWH that produced anti-Xa levels in the therapeutic range (0.5-1.0IU/mL) and significantly decreased thrombus weight in this mouse VT model was 5 and 6 mg/kg. Treated mouse groups received the first dose of experimental therapy immediately following thrombus induction and through day 2. Animals were euthanized 2 days post-thrombosis for tissue harvest and blood collection for the following evaluations: thrombus weight (grams), anti-Xa testing, and tail vein bleeding time (seconds). Results: GMI-1271 Works in Combination with LMWH to Decreases Venous Thrombosis : LMWH dosed at 6mg/kg and 5mg/kg alone, significantly decreased venous thrombus weight at 2 days, versus non-treated controls (73.0±7.5, 62.8±1.9 vs. 186.8±63.9 x10-4 grams, P

Beschreibung: Leukocytes and leukocyte-derived microparticles contain low levels of tissue factor (TF) and incorporate into forming thrombi. Although this circulating pool of TF has been proposed to play a key role in thrombosis, its functional significance relative to that of vascular wall TF is poorly defined. We tested the hypothesis that leukocyte-derived TF contributes to thrombus formation in vivo. Compared to wild-type mice, mice with severe TF deficiency (ie, TF–/–, hTF-Tg+, or “low-TF”) demonstrated markedly impaired thrombus formation after carotid artery injury or inferior vena cava ligation. A bone marrow transplantation strategy was used to modulate levels of leukocyte-derived TF. Transplantation of low-TF marrow into wild-type mice did not suppress arterial or venous thrombus formation. Similarly, transplantation of wild-type marrow into low-TF mice did not accelerate thrombosis. In vitro analyses revealed that TF activity in the blood was very low and was markedly exceeded by that present in the vessel wall. Therefore, our results suggest that thrombus formation in the arterial and venous macrovasculature is driven primarily by TF derived from the blood vessel wall as opposed to leukocytes.