Vascular Remodeling in Mice Lacking the Cytoplasmic Domain of Tissue Factor

Abstract

Abstract-Tissue factor (TF), the cell surface receptor for the serine protease FVIIa supports cell migration by interaction with the cytoskeleton. Intracellular signaling pathways dependent on the cytoplasmic domain of TF modify cell migration and may alter vascular remodeling. Key Words: arterial injury Ⅲ tissue factor Ⅲ smooth muscle cells Ⅲ restenosis T issue factor (TF) is a transmembrane glycoprotein that initiates the clotting cascade and is considered to be a major regulator of coagulation and hemostasis. Previous studies have shown that TF is important in mediating acute arterial thrombosis and intimal hyperplasia in several animal models. [1][2][3][4] Previous studies suggest an additional role for TF in tumor metastasis, angiogenesis, and cell migration. [5][6][7][8][9] After binding TF FVII is activated to FVIIa, a serine protease. The complex TF-FVIIa induces gene transcription and activates signaling cascades. 10 -14 Independent of the proteolytic activity TF ligand binding supports cell spreading and migration. 5,15 Furthermore, phosphorylation of the cytoplasmic domain serves as a regulator for angiogenic responses. [7][8][9] Because mice lacking the cytoplasmic domain of TF exhibit normal development we sought to investigate if deletion of the cytoplasmic domain of TF in mice alters vascular responses to arterial injury. Materials and Methods Mouse Injury ModelMice with a deletion of 18 amino acids of the cytoplasmic domain of TF (TF ⌬ct/⌬ct ) were generated by Cre-lox recombination technique on a MF1/129S/v/Swiss strain background. 16 These animals displayed normal embryonic and postnatal development, fertility, and coagulation parameters. Mice were bred and housed under specific pathogen-free conditions. All studies were approved by the institutional Animal Care and Use Committee (Bayerisches Wissenschaftsministerium, München, Germany). Mice underwent carotid ligation and femoral-artery wire injury model as described. 17,18 Before surgery, all mice were anesthetized by intraperitoneal injection with a solution composed of ketamine (80 mg/kg body weight) and xylazine (5 mg/kg body weight) for carotid ligation we used a midline neck incision, the right external carotid artery was looped proximally and tied off distally. Additional silk ties were looped round the common and internal carotid arteries for temporary vascular control during the procedure. For the femoral artery injury model a 0.014-in flexible angioplasty guide wire was introduced into the right femoral artery and endothelial denudation injury was performed using wire withdrawal injury and 3 passes along the artery. After removal of the wire the arteriotomy was closed and normal blood flow restored. At the time of euthanasia (14 days for carotid ligation and 28 days for femoral wire injury), the animals were reanesthetized, and after an overdose of pentobarbital (210 mg/kg IP) in situ perfusion fixation was achieved with phosphatebuffered paraformaldehyde (4%, 0.1 mol/L sodium phosphate buffer, pH 7.3). Both injured right and uninjure...

Tissue Factor Regulates Microvessel Formation and Stabilization by Induction of Chemokine (C-C motif) Ligand 2 Expression

“…28 Indeed, TF cytoplasmic domain signaling alters vascular remodeling. 29 In addition to the full-length TF isoform, a second isoform, soluble alternatively spliced TF, has been described in humans and mice. 30,31 Recently, alternatively spliced TF has been found to promote tumor growth and to be a proangiogenic factor.…”

Guggulsterone, an anti-inflammatory phytosterol, inhibits tissue factor and arterial thrombosis

“…This study demonstrates that guggulsterone effectively inhibits VSMC proliferation and migration. In addition to VSMC, TF has been implicated in the pathogenesis of neointima formation and stent thrombosis [20,24,27]. The pronounced inhibition of both VSMC activation and TF expression renders guggulsterone an attractive candidate for application on drug-eluting stents.…”

Prothrombotic Gene Expression Profile in Vascular Smooth Muscle Cells of Human Saphenous Vein, but Not Internal Mammary Artery

“…11,12 TF/FVIIa is known to stimulate migration of VSMCs; accordingly, mice lacking the cytoplasmic domain of TF exhibit reduced neointima formation and vascular remodeling after femoral artery injury. 13 Hence, mediators primarily regulating thrombus formation in bypass grafts may affect the development of later stages of bypass graft disease as well.…”