Figure 1
From: Characterization of coagulation factor synthesis in nine human primary cell types
General structure of blood vessels and the factors involved in coagulation.
The layers above the lumen show an intact blood vessel, while those below the lumen show a blood vessel after injury. The blood vessel is divided into four major sections: 1) tunica adventitia, 2) tunica media, 3) tunica intima and 4) lumen. The tunica adventitia is composed of fibroblasts, connective tissue and collagen and is separated from the tunica media by the external elastic lamina. The tunica media contains fibroblasts, smooth muscle cells (SMCs), connective tissue and collagen and is isolated from the tunica intima by the internal elastic lamina. The tunica intima, which is bordered on one side by the tunica media and on the other side by the lumen, contains endothelial cells and in the case of new intima, the internal elastic lamina is damaged and therefore their contents leaks into the tunica media. In a normal vascular system, blood cells circulate in a regulated way (including monocytes, platelets and others). After a vascular injury, the wound healing and repair process will be immediately activated. However, OX-LDL particles are one of the major causes of chronic vascular injury. After a vascular injury, TF is released by the wound and forms a complex with the activated FVII (FVIIa) present in circulation, as shown by the black arrow at the site of injury (indicated in the middle of the lumen). At the same time, monocytes and platelets arrive quickly to the site of the injury to stop bleeding and repair the injury via the direct activation of coagulation cascade components (FV/FVIII). These two cofactors are involved in the optimal activation of FXa. Both platelets and monocytes ensure the stability of the fibrin network via cross-linking with FXIIIA, which is delivered by these two cell types. Thrombomodulin (TM) is also expressed by monocytes, macrophages, endothelial cells and fibroblasts. When monocytes enter the tissue at the site of injury, they are converted to macrophages (Mφ). Macrophages do not express FV or FX, while fibroblasts express FX but not FV.
