Tissue factor and tissue factor pathway inhibitor levels in coronary artery disease: Correlation with the severity of atheromatosis

Tissue factor pathway inhibitor in atherosclerosis

Tissue factor pathway inhibitor (TFPI) reduces the development of atherosclerosis by regulating tissue factor (TF) mediated coagulation pathway. In this review, we focus on recent findings on the inhibitory effects of TFPI on endothelial cell activation, vascular smooth muscle cell (VSMC) proliferation and migration, inflammatory cell recruitment and extracellular matrix which are associated with the development of atherosclerosis. Meanwhile, we are also concerned about the impact of TFPI levels and genetic polymorphisms on clinical atherogenesis. This article aims to explain the mechanism in inhibiting the development of atherosclerosis and clinical effects of TFPI, and provide new ideas for the clinical researches and mechanism studies of atherothrombosis.

Genome-Wide Linkage Analysis of Large Multiple Multigenerational Families Identifies Novel Genetic Loci for Coronary Artery Disease

Coronary artery disease (CAD) is the leading cause of death, and genetic factors contribute significantly to risk of CAD. This study aims to identify new CAD genetic loci through a large-scale linkage analysis of 24 large and multigenerational families with 433 family members (GeneQuest II). All family members were genotyped with markers spaced by every 10 cM and a model-free nonparametric linkage (NPL-all) analysis was carried out. Two highly significant CAD loci were identified on chromosome 17q21.2 (NPL score of 6.20) and 7p22.2 (NPL score of 5.19). We also identified four loci with significant NPL scores between 4.09 and 4.99 on 2q33.3, 3q29, 5q13.2 and 9q22.33. Similar analyses in individual families confirmed the six significant CAD loci and identified seven new highly significant linkages on 9p24.2, 9q34.2, 12q13.13, 15q26.1, 17q22, 20p12.3, and 22q12.1, and two significant loci on 2q11.2 and 11q14.1. Two loci on 3q29 and 9q22.33 were also successfully replicated in our previous linkage analysis of 428 nuclear families. Moreover, two published risk variants, SNP rs46522 in UBE2Z and SNP rs6725887 in WDR12 by GWAS, were found within the 17q21.2 and 2q33.3 loci. These studies lay a foundation for future identification of causative variants and genes for CAD.

Natural Products for Antithrombosis

Thrombosis is considered to be closely related to several diseases such as atherosclerosis, ischemic heart disease and stroke, as well as rheumatoid arthritis, hyperuricemia, and various inflammatory conditions. More and more studies have been focused on understanding the mechanism of molecular and cellular basis of thrombus formation as well as preventing thrombosis for the treatment of thrombotic diseases. In reality, there is considerable interest in the role of natural products and their bioactive components in the prevention and treatment of thrombosis related disorders. This paper briefly describes the mechanisms of thrombus formation on three aspects, including coagulation system, platelet activation, and aggregation, and change of blood flow conditions. Furthermore, the natural products for antithrombosis by anticoagulation, antiplatelet aggregation, and fibrinolysis were summarized, respectively.

Plasma tissue factor pathway inhibitor levels in angiographically defined coronary artery disease among saudis

OBJECTIVES

This study was aimed to determine plasma levels of total (TFPI-T) and free (TFPI-F) tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA) in a cohort of Saudi patients with chronic stable angiographically defined coronary artery disease (CAD) and to determine its correlation with its severity.

METHODS

This cross sectional study was conducted in the department of physiology and department of cardiology, College of Medicine, and King Khalid University Hospital and King Saud University, Riyadh. Sixty known cases of CAD who had undergone angiography (35 males and 25 females) were selected. A control group included 39 (20 males and 19 females) healthy subjects. Fasting venous blood samples were analyzed for total (TFPI-T) and free (TFPI-F) tissue factor pathway inhibitor, plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA). Gensini scores and vessel scores were determined for assessing CAD severity.

RESULTS

There were non-significant differences between age, body mass index (BMI) and Blood pressure between the controls and CAD subjects. A comparison of hemostatic markers between control and CAD patients showed significantly higher levels of Fibrinogen, PAI-1, TFPI-T and TFPI-F in CAD patients compared to control subjects. But there was no difference in plasma t-PA levels. TFPI-T had a significant positive correlation with severity of disease determined by Gensini Scores (r=0.344; p=0.006) and vessel scores (r=0.338; p=0.015).

CONCLUSION

Plasma levels of total tissue factor pathway inhibitor are significantly related with the presence and severity of CAD. Elevated levels of TFPI-T may be considered as useful diagnostic and prognostic markers in patients with CAD.

CRP regulates the expression and activity of tissue factor as well as tissue factor pathway inhibitor via NF-kappaB and ERK 1/2 MAPK pathway

It was found that C-reactive protein (CRP) could significantly increase the expression and activity of tissue factor (TF), but decrease that of tissue factor pathway inhibitor (TFPI) in human umbilical vein endothelial cells (HUVECs) in dose- and time-dependent manners, which could be antagonized by PDTC and U0126. CRP could also increase protein expression of phosphorylated nuclear factor-kappaB (NF-kappaB), IkappaB-alpha and ERK1/2 in dose- and time-dependent manner. In addition, neutralizing antibody to CD32 (FcgammaR II) could significantly attenuate the expression and activity of TF and TFPI induced by CRP. These results suggest that CRP may promote coagulation by enhancing the expression and activity of TF and reducing that of TFPI by activating NF-kappaB and extracellular signal-regulated kinase via FcgammaR II.

Vitamin K epoxide reductase complex subunit 1 gene polymorphism is associated with atherothrombotic complication after drug-eluting stent implantation: 2-Center prospective cohort study

BACKGROUND

Single nucleotide polymorphisms of vitamin K epoxide reductase complex subunit 1 (VKORC1) was reported to have association with arterial vascular disease. We investigated whether single nucleotide polymorphism of VKORC1 +2255 is associated with clinical outcomes among patients who underwent drug-eluting stent (DES) implantation.

METHODS

We prospectively collected genomic DNA in patients who underwent DES deployment from September 2003 to December 2006 and compared clinical outcomes according to their VKORC1 genotype at the locus + 2255 (rs 2359612). The primary end point was composite of atherothrombotic events (cardiac death, myocardial infarction, and nonhemorrhagic stroke).

RESULTS

Mean follow-up duration was 631 +/- 251 days. Genotyping was completed in 764 cases (TT genotype [n = 640, 83.8%] vs non-TT [CC or CT] genotype [n = 124, 16.2%]). Non-TT group showed more composite events than TT group (7.3% vs 3.0%, P = .032). In the Cox regression analysis, non-TT genotype of VKORC gene was a significant predictor of atherothrombotic events (hazard ratio 2.56, 95% confidence interval 1.14-5.78). In the event-free survival analysis, non-TT group also showed significantly poorer cardiovascular events-free survival rate than TT group (P = .02).

CONCLUSIONS

VKORC1 genotype is associated with cardiovascular events in patients with DES implantation, suggesting the role of coagulation system.