Prolonged hypercholesterolemia-induced tissue factor expression in rabbit vein grafts: a potential mechanism for graft failure

Genetic duplication of tissue factor reveals subfunctionalization in venous and arterial hemostasis

Tissue factor (TF) is an evolutionarily conserved protein necessary for initiation of hemostasis. Zebrafish have two copies of the tissue factor gene (f3a and f3b) as the result of an ancestral teleost fish duplication event (so called ohnologs). In vivo physiologic studies of TF function have been difficult given early lethality of TF knockout in the mouse. We used genome editing to produce knockouts of both f3a and f3b in zebrafish. Since ohnologs arose through sub- or neofunctionalization, they can unmask unknown functions of non-teleost genes and could reveal whether mammalian TF has developmental functions distinct from coagulation. Here we show that a single copy of either f3a or f3b is necessary and sufficient for normal lifespan. Complete loss of TF results in lethal hemorrhage by 2-4 months despite normal embryonic and vascular development. Larval vascular endothelial injury reveals predominant roles for TFa in venous circulation and TFb in arterial circulation. Finally, we demonstrate that loss of TF predisposes to a stress-induced cardiac tamponade independent of its role in fibrin formation. Overall, our data suggest partial subfunctionalization of TFa and TFb. This multigenic zebrafish model has the potential to facilitate study of the role of TF in different vascular beds.

Peach Kernel Oil Downregulates Expression of Tissue Factor and Reduces Atherosclerosis in ApoE knockout Mice

Atherosclerosis is the pathological process in arteries due to the plaque formation that is responsible for several diseases like heart disease, stroke and peripheral arterial disease. In this study, we performed in vitro and in vivo assays to evaluate the potential anti-atherosclerosis activity of peach kernel oil. For the in vitro assay, we incubated human umbilical vein endothelial cells (HUVEC) with tumor necrosis factor-α (TNF-α) to induce tissue factors (TF, an essential mediator of hemostasis and trigger of thrombosis) elevation. We found that TNF-α-induced TF elevation was suppressed by peach kernel oil in a dose-dependent manner at both mRNA and protein levels. Peach kernel oil can significantly improve HUVEC viability, protect the endothelial cells, which achieved the goal of prevention of thrombotic diseases. For the in vivo assay, we investigated the effect and mechanism of peach kernel oil on preventing atherosclerotic lesion formation in ApoE knockout mice. Results show that peach kernel oil could reduce total cholesterol, triglyceride, low-density lipoprotein cholesterol levels, elevate the high-density lipoprotein cholesterol level in serum, and reduce the area of the aortic atherosclerotic lesions in high-fat diet fed ApoE knockout mice. Moreover, peach kernel oil treatment can significantly down regulate the expression of TF protein to inhibit the formation of atherosclerotic plaque. In conclusion, peach kernel oil may be a potential health food to prevent atherosclerosis in cardiovascular diseases.