Cell Biology/Signaling Soluble Guanylate Cyclase Agonists Inhibit Expression and Procoagulant Activity of Tissue Factor

Objective—Tissue factor (TF), a major initiator of blood coagulation, contributes to inflammation, atherosclerosis, angiogenesis, and vascular remodeling. Pharmacological agonists of soluble guanylate cyclase (sGC) attenuate systemic and pulmonary hypertension, vascular remodeling, and platelet aggregation. However, the influence of these novel pharmacophores on TF is unknown. Methods and Results—We evaluated effects of BAY 41-2272 and BAY 58-2667 on expression and activity of TF in human monocytes and umbilical vein endothelial cells (HUVECs). Both compounds reduced expression of active TF protein in monocytes stimulated with lipopolysaccharide, as demonstrated by immunoblotting and a TF procoagulant activity assay. In-cell Western assay revealed that this effect was associated with a marked reduction of total and surface TF presentation. Furthermore, BAY 41-2272 and BAY 58-2667 decreased TF protein expression and the TF-dependent procoagulant activity in HUVECs stimulated with TNF-␣. The sGC agonists also suppressed transcriptional activity of NF-␬B. A siRNA-mediated knockdown of the ␣1-subunit of sGC in monocytes and HUVECs confirmed that the inhibitory effect of BAY 41-2272 and BAY 58-2667 on TF expression is mediated through the sGC-dependent mechanisms. Conclusions—Inhibition of TF expression and activity by sGC agonists might provide therapeutic benefits in cardiovascular diseases associated with enhanced procoagulant and inflammatory response. Key Words: tissue factor Ⅲ procoagulant activity Ⅲ soluble guanylate cyclase Ⅲ BAY 41-2272 Ⅲ BAY 58-2667 T issue factor (TF), a transmembrane glycoprotein, is a major initiator of the extrinsic blood coagulation pathway. Tissue factor binds to factor FVII/FVIIa, and this complex activates factors FIX and FX, leading to generation of thrombin and fibrin deposition. 1 In addition to its prominent role in coagulation, TF-dependent signaling pathways contribute to a variety of pathological processes, including inflammation, atherosclerosis, angiogenesis, and vascular remodeling. 2,3 Tissue factor is expressed in the vascular wall, 4,5 whereas monocytes seem to be its major source in circulating human blood. 6 An increased TF expression in monocytes is associated with disseminated intravascular co-agulation, acute coronary syndrome, sepsis, and other pro-thrombotic conditions. 7 Expression of TF is also markedly upregulated in the lung vasculature in pulmonary arterial hypertension, 8 a disease associated with pulmonary vascular remodeling and localized thrombosis. Because TF is an important player in vascular remodeling, 9 inhibition of TF expression could be beneficial to offset the progression of pulmonary arterial hypertension and other cardiovascular diseases. Earlier studies have indicated an inhibitory effect of cyclic guanosine 3Ј-5Ј monophosphate (cGMP) on expression of TF in monocytes. 10 Cyclic GMP …