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

Abstract

Objective-Tissue factor (TF) triggers arterial thrombosis. TF is also able to initiate cellular signaling mechanisms leading to angiogenesis. Because high cardiovascular risk atherosclerotic plaques show significant angiogenesis, our objective was to investigate whether TF is able to trigger and stabilize atherosclerotic plaque neovessel formation. Methods and Results-In this study, we showed, by real-time confocal microscopy in 3-dimensional basement membrane cocultures, that TF in human microvascular endothelial cells (HMEC-1) and in human vascular smooth muscle cells (HVSMCs) plays an important role in the formation of capillary-like networks. TF silencing in endothelial cells and smooth muscle cells inhibits the formation of tube-like structures with stable phenotype. Using an in vivo model, we observed that TF inhibition in either HMEC-1 or HVSMCs reduced their shared ability to form new capillaries. The phenotypic changes induced by TF silencing were linked to reduced chemokine (C-C motif) ligand 2 (CCL2) expression in endothelial cells. Wound healing and chemotactic assays demonstrated that TF-induced release of CCL2 stimulated HVSMC migration to HMEC-1. Key Words: angiogenesis Ⅲ atherosclerosis Ⅲ cytokines Ⅲ endothelial function Ⅲ vascular biology A therosclerotic plaque angiogenesis, the outgrowth of new capillaries from preexisting vascular networks, is a pathological feature of advanced complicated plaques. 1,2 Interestingly, coronary type VI plaques, according to the American Heart Association classification, are those with higher amount of microvessels and those with higher risk of inducing a clinical cardiovascular event. 3 In advanced plaques, inflammatory cell infiltration and concomitant production of proangiogenic cytokines may be responsible for induction of uncontrolled neointimal microvessel proliferation resulting in production of immature and fragile neovessels. The final stage of microvessel formation occurs when maturation requires the formation of tight endothelial cell-tocell contacts, 4 the downregulation of endothelial proliferation, and the deposition of a basal lamina to which the endothelium tightly adheres, as well as the recruitment of supporting cells to the vessel wall, such as pericytes and smooth muscle cells (SMCs). 5,6 During angiogenesis, the communication between endothelial cells (ECs) and SMCs requires a precise temporal and spatial regulation of pro-and antiangiogenic molecules, but the process is not yet fully understood. Conclusion-Endogenous See accompanying article on page 2364In recent years, it has become clear that the angiogenesis process is highly dependent on components of the blood coagulation cascade. One of these proteins is tissue factor (TF). 7-9 TF is the cellular receptor and cofactor for blood coagulation factor VII (FVII). 10,11 In addition to its primary role in blood coagulation, accumulating evidence has transformed our view of TF from the cellular receptor for activated FVII (FVIIa) to a multifaceted transmembrane signaling receptor. The bioch...

Early endothelial progenitor cells as a source of myeloid cells to improve the pre-vascularisation of bone constructs

“…The latest was also investigated in real time as described before. Tissue factor is also involved in the formation of complex and stable microvessels characterised by the stabilisation of vascular structures through mesenchymal cells (Carmeliet et al, 1996), which is mediated by the regulation of MCP-1 as described before in the literature (Arderiu et al, 2011) and in accordance with our observations for MCP-1, as described above. Pentraxin-3 is a negative regulator of angiogenesis due to its binding to the proangiogenic molecule fibroblast growth factor-2 (Basile et al, 2013), which is an important factor in the cellular cross talk of endothelial cells, pericytes and stromal cells.…”

Angiogenic Microvascular Endothelial Cells Release Microparticles Rich in Tissue Factor That Promotes Postischemic Collateral Vessel Formation

“…Our previous work showed that microvascular endothelial TF induces CCL2 expression and secretion that recruit SMC toward ECs by an intracrine signaling activation process. 22 Here, we show that mECs in addition to microparticles release exerts a paracrine regulation to induce angiotube formation.…”

“…22 Here, we investigated whether the released TF-rich mEMPs were able to induce endothelial angiotube formation. …”

“…16,17 In addition, during the past decades, TF has also shown to be involved in intracellular signaling pathways in cell function regulation (ie, proliferation, 18 migration, 19,20 gene expression, 21 and mature microvessel formation). 22,23 Our previous work showed that proangiogenic microvascular ECs (mECs) regulate intracellular TF expression and by intracrine AKT-ETS signaling induce chemokine (C-C motif) ligand 2 (CCL2) expression and secretion to recruit SMC toward the mECs to form mature neovessels. 23,24 TF is found in 2 different molecular forms: full-length TF (flTF), an integral membrane protein; and alternatively spliced TF, a protein that lacks a transmembrane domain and is secreted in a soluble form.…”

Nonproteolytic Properties of Murine Alternatively Spliced Tissue Factor: Implications for Integrin-Mediated Signaling in Murine Models

“…The tenet that the flTF/asTF synergy promotes primary tumor growth, and possibly spread, is supported by the effects of monoclonal antibody 10H10, an flTF-specific antibody that disrupts constitutive binding of flTF to integrins and also inhibits tumor growth in xenograft models (45). Moreover, the Ccl2-dependent nature of masTF-elicited angiogenesis further supports the notion that asTF and flTF are likely to act in concert to trigger the formation of new vessels, using proteolytic as well as nonproteolytic signaling (32). Inasmuch as exogenous flTF on microparticles and lipid vesicles stimulates cell proliferation largely in a β1 integrin-dependent manner (46), it is reasonable to propose that asTF similarly promotes integrinmediated tumorigenesis, yet with a far more pronounced engagement of β3 integrins.…”