Genetic Variations in the Tissue Factor Gene Are Associated With Clinical Outcome in Acute Coronary Syndrome and Expression Levels in Human Monocytes

Human Genetic Variation in F3 and Its Impact on Tissue Factor-Dependent Disease

Tissue factor (TF) is the primary initiator of blood coagulation in humans. As improper intravascular TF expression and procoagulant activity underlie numerous thrombotic disorders, there has been longstanding interest in the contribution of heritable genetic variation in F3, the gene encoding TF, to human disease. This review seeks to comprehensively and critically synthesize small case-control studies focused on candidate single nucleotide polymorphisms (SNPs), as well as modern genome-wide association studies (GWAS) seeking to discover novel associations between variants and clinical phenotypes. Where possible, correlative laboratory studies, expression quantitative trait loci, and protein quantitative trait loci are evaluated to glean potential mechanistic insights. Most disease associations implicated in historical case-control studies have proven difficult to replicate in large GWAS. Nevertheless, SNPs linked to F3, such as rs2022030, are associated with increased F3 mRNA expression, monocyte TF expression after endotoxin exposure, and circulating levels of the prothrombotic biomarker D-dimer, consistent with the central role of TF in the initiation of blood coagulation.

The Role of Secretory Activity Molecules of Visceral Adipocytes in Abdominal Obesity in the Development of Cardiovascular Disease: A Review

Adipose tissue is considered one of the endocrine organs in the body because of its ability to synthesize and release a large number of hormones, cytokines, and growth and vasoactive factors that influence a variety of physiological and pathophysiological processes, such as vascular tone, inflammation, vascular smooth muscle cell migration, endothelial function, and vascular redox state. Moreover, genetic factors substantially contribute to the risk of obesity. Research into the biochemical effects of molecules secreted by visceral adipocytes as well as their molecular genetic characteristics is actively conducted around the world mostly in relation to pathologies of the cardiovascular system, metabolic syndrome, and diabetes mellitus. Adipokines could be developed into biomarkers for diagnosis, prognosis, and therapeutic targets in different diseases. This review describes the relevance of secretory activity molecules of visceral adipocytes in cardiovascular disease associated abdominal obesity.

Genetic Polymorphisms in Sepsis and Cardiovascular Disease: Do Similar Risk Genes Suggest Similar Drug Targets?

Genetic variants are associated with altered clinical outcome of patients with sepsis and cardiovascular diseases. Common gene signaling pathways may be involved in the pathophysiology of these diseases. A better understanding of genetic commonality among these diseases may enable the discovery of important genes, signaling pathways, and therapeutic targets for these diseases. We investigated the common genetic factors by a systematic search of the literature. Twenty-four genes (ADRB2, CD14, FGB, FV, HMOX1, IL1B, IL1RN, IL6, IL10, IL17A, IRAK1, MASP2, MBL, MIR608, MIF, NOD2, PCSK9, PPARG, PROC, SERPINE1, SOD2, SVEP1, TF, TIRAP, TLR1) were extracted as reported genetic variations associated with altered outcome of both sepsis and cardiovascular diseases. Of these genes, the adverse allele (or combinations) was same in nine (ADRB2, FV, HMOX1, IL6, MBL, MIF, NOD2, PCSK9, SERPINE1), and the effect appears to be in the same direction in both sepsis and cardiovascular disease. Shared gene signaling pathways suggest that these are true biological results and could point to overlapping drug targets in sepsis and cardiovascular disease.

Overexpression of tissue factor induced atherothrombosis in apolipoprotein E-/- mice via both enhanced plaque thrombogenicity and plaque instability

The mechanisms leading to atherothrombosis from "vulnerable plaque" are more complex than initially proposed. We aimed to clarify whether plaque thrombogenicity is critical in atherothrombosis in mice. In a murine model of plaque destabilization, we enhanced plaque thrombogenicity by systemically overexpressing murine tissue factor (TF) by adenovirus-mediated gene transfer. The potential effects and mechanisms of TF on plaque destabilization were examined in cultured human aortic smooth muscle cells (HASMCs), RAW264.7 cells and human umbilical vein endothelial cells (HUVECs). To elucidate the TF noncoagulant effects on plaque destabilization, TF-overexpressed mice were treated with the protease-activated receptor 2 (PAR-2) antagonist ENMD-1068. In TF-overexpressing apolipoprotein (E)-deficient (ApoE-/-) mice, 67% (8 of 12) of carotid plaques exhibited plaque disruption and atherothrombosis. Moreover, 58% (7 of 12) showed plaque hemorrhage, including 1 due to plaque disruption, 4 neovascularization and 2 both. In contrast, only 17% (2 of 12) of control mice showed atherothrombosis, both with plaque hemorrhage but no neovascularization. On PCR, TF overexpression increased the expression of inflammatory factors. In cultured cells, the TF-FVIIa complex enhanced the expression of inflammatory factors and a vicious cycle of inflammation. Also, TF-FVIIa complex induced intra-plaque angiogenesis via PAR-2. ENMD-1068 treatment significantly inhibited the expression of inflammatory factors and neovascularization, and the incidence of intra-plaque hemorrhage decreased in TF-overexpressing mice. In conclusions, TF overexpression enhanced plaque thrombogenicity, which played a pivotal role in atherothrombosis in ApoE-/- mice. In addition, TF promoted plaque instability by activating inflammatory and proangiogenic effects via TF-FVIIa/PAR-2 signaling.

Genetic risk factors in thrombotic primary antiphospholipid syndrome: A systematic review with bioinformatic analyses

BACKGROUND

Antiphospholipid Syndrome (APS) is an autoimmune multifactorial disorder. Genetics is believed to play a contributory role in the pathogenesis of APS, especially in thrombosis development and pregnancy morbidity. In the last 20 years, extensive research on genetic contribution on APS indicates that APS is a polygenic disorder, where a number of genes are involved in the development of its clinical manifestations.

AIMS

The aim of this systematic review is to evaluate the genetic risk factors in thrombotic primary APS. Additionally, to assess the common molecular functions, biological processes, pathways, interrelations with the gene encoded proteins and RNA-Seq-derived expression patterns over different organs of the associated genes via bioinformatic analyses.

METHODS

Without restricting the year, a systematic search of English articles was conducted (up to 4th September 2017) using Web of Science, PubMed, Scopus, ScienceDirect and Google Scholar databases. Eligible studies were selected based on the inclusion criteria. Two researchers independently extracted the data from the included studies. Quality assessment of the included studies was carried out using a modified New-Castle Ottawa scale (NOS).

RESULTS

From an initial search result of 2673 articles, 22 studies were included (1268 primary APS patients and 1649 healthy controls). Twenty-two genes were identified in which 16 were significantly associated with thrombosis in primary APS whereas six genes showed no significant association with thrombosis. Based on the NOS, 14 studies were of high quality while 6 were low quality studies. From the bioinformatic analyses, thrombin-activated receptor activity (q = 6.77 × 10^-7), blood coagulation (q = 2.63 × 10^-15), formation of fibrin clot (q = 9.76 × 10^-10) were the top hit for molecular function, biological process and pathway categories, respectively. With the highest confidence interaction score of 0.900, all of the thrombosis-associated gene encoded proteins of APS were found to be interconnected except for two. Based on the pathway analysis, cumulatively all the genes affect haemostasis [false discovery rate (FDR) = 1.01 × 10^-8] and the immune system [FDR = 9.93 × 10^-2]. Gene expression analysis from RNA-Seq data revealed that almost all the genes were expressed in 32 different tissues in the human body.

CONCLUSION

According to our systematic review, 16 genes contribute significantly in patients with thrombotic primary APS when compared with controls. Bioinformatic analyses of these genes revealed their molecular interconnectivity in protein levels largely by affecting blood coagulation and immune system. These genes are expressed in 32 different organs and may pose higher risk of developing thrombosis anywhere in the body of primary APS patients.

Novel hydroxybutyl chitosan nanoparticles for siRNA delivery targeting tissue factor inhibits proliferation and induces apoptosis in human vascular smooth muscle cells

Chitosan, a polysaccharide isolated from shrimp and other crustacean shells, has been widely investigated for DNA and siRNA delivery. Despite substantial effort having been made to improve chitosan as a non-viral gene delivery vector, the application is severely limited by its poor solubility under physiological conditions. Hydroxybutyl chitosan (HBC), a modified chitosan, is soluble under neutral conditions. Tissue factor (TF) is involved in the pathogenesis of cardiovascular diseases by promoting thrombus formation and inducing the migration and proliferation of vascular smooth muscle cells. Targeting TF is an attractive therapeutic strategy for cardiovascular diseases. In the present study, the use of HBC for the transfer of TF-siRNAs into human umbilical vein smooth muscle cells (HUVSMCs) was investigated, and the effects of TF knockdown on cell proliferation and apoptosis were examined. HBC/siRNA nanoparticles were produced by mixing HBC and siRNA solutions with the assistance of tripolyphosphate buffer. The transfection efficiency with these nanoparticles was 74±2.5%, which was determined using a fluorescence-labeled siRNA under fluorescence microscopy. The delivery of HBC/TF-siRNA resulted in reductions in the production of cellular and soluble TF protein in HUVMSCs, which were measured using western blotting and enzyme-linked immunosorbent assay, respectively. TF knockdown led to inhibited cell proliferation, as assessed using a Cell Counting Kit-8 assay, and increased cell apoptosis, determined using Annexin V-fluorescein isothiocyanate staining. These findings suggested that HBC may be a promising vector for siRNA delivery, and that in vivo HBC/siRNA nanoparticle delivery targeting TF may be a potential option for the treatment of cardiovascular diseases, which warrants further investigation.

Genetic polymorphisms and plasma levels of tissue factor and tissue factor pathway inhibitor in venous thromboembolism

Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) play important roles in coagulation. The aim of this study was to investigate the distributions of TF and TFPI polymorphisms in Koreans and to analyze the association of these genetic polymorphisms with plasma levels and development of venous thromboembolism (VTE). The polymorphisms TF 5466 A > G, TF -603 A > G, TFPI -287 T > C and TFPI -33 T > C were investigated in 40 Korean VTE patients and 40 age-matched and sex-matched controls by real-time PCR followed by melting curve analysis and DNA sequence analysis. Plasma levels of TF and TFPI were measured by enzyme-linked immunosorbent assay. The G allele of TF 5466 was not detected, and allelic frequencies of TF -603 G, TFPI -287 C and TFPI -33 C were 27.5, 67.5 and 16.2%, respectively. The distributions of TF and TFPI polymorphisms were not different between patients and controls. The presence of TF -603 G allele was correlated with low plasma TF levels (P = 0.029). Mean plasma TFPI levels were similar between TFPI genotypic groups. Although not statistically significant, plasma TF and TFPI levels were higher in patients than controls. The distributions of TF and TFPI polymorphisms in Koreans were considerably different from whites, suggesting ethnic variations. The TF -603 A > G polymorphism was significantly correlated with decreased plasma TF levels. Neither genetic polymorphisms in TF and TFPI nor their plasma levels seem to act as direct risk factors for VTE.

Circulating Tissue Factor Levels and Risk of Stroke

Background and Purpose—

Tissue factor (TF) expression is increased in inflammatory atherosclerotic plaques and has been related to their thrombogenicity. Blood-borne TF has been also demonstrated to contribute to thrombogenesis. However, few studies have evaluated the association of circulating levels of TF with stroke. We investigated the association of baseline circulating levels of TF with stroke events occurred in the European Prospective Investigation into Cancer and Nutrition-Italy cohort.

Methods—

Using a nested case–cohort design, a center-stratified random sample of 839 subjects (66% women; age range, 35–71 years) was selected as subcohort and compared with 292 strokes in a mean follow-up of 9 years. Blood samples were collected at baseline in citrate, plasma was stored in liquid nitrogen and TF was measured by ELISA (IMUBIND, TF ELISA, Instrumentation Laboratory, Milan, Italy). The odd ratios and 95% confidence intervals, adjusted by relevant confounders (covariates of TF) and stratified by center, were estimated by a Cox regression model using Prentice method.

Results—

Individuals in the highest compared with the lowest quartile of TF plasma levels had significantly increased risk of stroke (odds ratio IVvsI quartile , 2.01; 95% confidence interval, 1.25–3.23). The association was independent from several potential confounders (odds ratio IVvsI quartile , 1.91; 95% confidence interval, 1.15–3.19). No differences were observed between men and women. The increase in risk was restricted to ischemic strokes (odds ratio IVvsI quartile , 2.13; 95% confidence interval, 1.10–4.12; fully adjusted model), whereas high levels of TF were not associated with the risk of hemorrhagic stroke (odds ratio IVvsI quartile , 1.12; 95% confidence interval, 0.49–2.55; fully adjusted model).

Conclusions—

Our data provide evidence that elevated levels of circulating TF are potential risk factors for ischemic strokes.

Genetic variation in the tissue factor gene is associated with clinical outcome in severe sepsis patients

Introduction

Activation of inflammation and coagulation was closely related and mutually interdependent in sepsis. Tissue factor (TF) and its endogenous inhibitor, tissue factor pathway inhibitor (TFPI) was the main regulators of the initiation of coagulation process. Altered plasma levels of TF and TFPI have been related to worse outcome in sepsis. The objective of this study was to investigate whether single nucleotide polymorphisms (SNPs) in the TF and TFPI genes were associated with risk and outcome for patients with severe sepsis.

Methods

Seventeen SNPs in TF and TFPI were genotyped in samples of sepsis (n =577) and severe sepsis patients (n =476), and tested for association in this case–control collection. We then investigated correlation between the associated SNPs and the mRNA expression, and protein level of the corresponding gene. The mRNA levels of TF were determined using real-time quantitative reverse transcription-polymerase chain reaction and the soluble plasma levels of TF were measured using enzyme linked immunosorbent assay (ELISA) method.

Results

Association analysis revealed that three TF SNPs in perfect linkage disequilibrium, rs1361600, rs3917615 and rs958587, were significantly associated with outcome of severe sepsis. G allele frequency of rs1361600 in survivor patients was significantly higher than that in nonsurvivor severe sepsis patients (P =4.91 × 10^-5, odds ratio (OR) =0.48, 95% confidence interval (CI) 0.33 to 0.69). The association remained significant after adjustment for covariates in multiple logistic regression analysis and for multiple comparisons. Lipopolysaccharide-induced TF-mRNA expression levels in peripheral blood mononuclear cells from subjects carrying rs1361600 AG and GG genotypes, were significantly lower than those subjects carrying AA genotype (P =0.0012). Moreover, severe sepsis patients of GG and GA genotypes showed lower serum levels of TF than patients with AA genotype (P_adj =0.02). The plasma levels of TF were also associated with outcome of severe sepsis patients (P_adj =0.01). However, genotype and allele analyses did not show any significant difference between sepsis and severe sepsis patients.

Conclusions

Our findings indicate that common genetic variation in TF was significantly associated with outcome of severe sepsis in Chinese Han population.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0631-9) contains supplementary material, which is available to authorized users.

Sex is associated with the presence of atherosclerotic plaque hemorrhage and modifies the relation between plaque hemorrhage and cardiovascular outcome

BACKGROUND AND PURPOSE

Plaque hemorrhage (PH) may lead to accelerated progression of atherosclerotic disease. The presence of local PH in the carotid plaque predicts future cardiovascular events in any vascular territory. We investigated the prevalence of local PH and the predictive value of PH for the occurrence of cardiovascular events in men and women separately.

METHODS

Atherosclerotic plaques from 1422 patients (969 men, 453 women) who underwent carotid endarterectomy were analyzed histologically for the presence of PH. Patients were monitored for 3 years for cardiovascular events (nonfatal stroke, nonfatal myocardial infarction, vascular death, and vascular intervention).

RESULTS

Plaques from men showed a significantly higher prevalence of PH compared with women (67% versus 54%; P<0.001). In 1353 patients with available follow-up data, with a median duration of 2.9 years, 270 events had occurred in men (29%) and 94 in women (22%). Stratified by presence of PH, the event rate was 32% in men with PH versus 23% in men without PH, and 23% in women with PH versus 21% in women without PH. A multivariable Cox proportional hazards model found a significant interaction between sex and PH. PH was significantly associated with events in men (adjusted hazard ratio, 1.9; 95% CI, 1.2-2.8) but not in women (adjusted hazard ratio, 1.0; 95% CI, 0.6-1.7).

CONCLUSIONS

Atherosclerotic carotid plaques obtained from men reveal a higher prevalence of PH compared with women. Local PH is strongly related to secondary manifestations of cardiovascular disease in men but not in women.

Evaluation of microparticles in whole blood by multicolour flow cytometry assay

OBJECTIVE

To develop and evaluate a multicolour flow cytometry method for analysis of microparticles (MPs) in fresh whole blood without any centrifugation steps or freezing/thawing procedure.

MATERIALS AND METHODS

Flow cytometry was performed using a FC500 MPL cytometer. The compensation in the protocol was performed based on the platelet population. Polystyrene microspheres 0.50-1.27 μm were used for size position, and the MP gate was set as particles 0.5-1.0 μm. Whole blood was incubated with annexin V and antibodies to tissue factor (TF), platelets (CD41 and CD62P), monocyte (CD14) and endothelial cells (CD144). For comparison, MPs from platelet free supernatant was used. The TF activity was evaluated by Calibrated Automated Thrombogram.

RESULTS

Annexin V was used to distinguish true events from background noise. For standardization, each analysis included 10,000 events in the gate of platelets. There were 622(462-1001) MP(annV+)/10,000 platelets and of these, 66 (49-82)/10,000 platelets expressed TF. After correction for the individual platelet counts, the amount of circulating MP(annV+) was 17.1 (12.1-24.9) × 10(9)/L in whole blood, and of these, 10% (6-12%) expressed TF. The majority of the MPs expressed CD41, and 5.6% (2.2-6.9%) of these co-expressed TF. The amount of CD41 + MP(annV+) tended to correlate to the TF activity in whole blood. There was no correlation between the MP(annV+) in whole blood and MPs derived from platelet free supernatant. Patients with pulmonary arterial hypertension and stable coronary artery disease had increased concentrations of CD41 + MP(annV+) in whole blood.

CONCLUSION

This multicolour flow cytometry assay in whole blood mimics the in vivo situation by avoiding several procedure steps interfering with the MP count. By standardized quantification of MPs a reference interval of MPs can be created.

Associations of polymorphisms in the apolipoprotein APOA1-C3-A5 gene cluster with acute coronary syndrome

Background. Acute coronary syndromes (ACSs) are clinically cardiovascular events associated with dyslipidemia in common. Single nucleotide polymorphisms (SNPs) and haplotypes in the APOA1/C3/A5 gene cluster are associated with diabetes and familial combined hyperlipidaemia (FCH). Little is known about whether the polymorphisms in these genes affect lipid homeostasis in patients with ACSs. The present paper aimed to examine these associations with 4 SNPs in the APOA1 −75G > A, the APOC3 −455T > C, and APOA5 −1131T > C, c.553G > T variant to ACSs in Chinese Han. Methods. Chinese Han of 229 patients with ACSs and 254 unrelated controls were analyzed. Four SNPs in APOA1/C3/A5 cluster were genotyped and lipid was determined. Results. Our data show that minor allelic frequencies of APOC3 −455T > C, APOA5 −1131T > C, and c.553G > T polymorphisms in patients with ACSs were significantly higher than control group (P < 0.05). Furthermore, the 3 polymorphic sites were strongly of linkage disequilibrium, and minor alleles of 3 SNP sites had higher TG level than wild alleles (P < 0.05), APOC3 −455C and APOA5 c.553T allele carriers also had lower level of HDL-C. Conclusions. The minor alleles of APOC3 −455T > C, APOA5 −1131T > C, and c.553G > T polymorphisms are closely associated with ACSs.

Candidate gene polymorphisms and the risk for pregnancy-related venous thrombosis

Venous thrombosis (VT) is one of the leading causes of maternal death in the western world, but the genetic causes of pregnancy-related VT are insufficiently understood. The aim of this study was to investigate the association between common genetic variations in candidate genes and pregnancy-related VT. We undertook a hospital based case-control study of women with VT during pregnancy or puerperium; controls were women giving birth without having VT. Single nucleotide polymorphisms (SNPs) were selected in 49 pre-specified candidate genes involved in coagulation, inflammation, and hormonal metabolism in 313 cases and 353 controls. We found new associations between SNPs and total pregnancy-related VT in the genes encoding coagulation factors V and VIII, and p-selectin. Additional new associations between SNPs and antenatal VT were found in the genes encoding the epidermal growth factor receptor, the pregnane X receptor, and protein S. Of 21 SNPs previously associated with thrombotic disease, rs2289252 in F11 and rs3917643 in F3 were associated with pregnancy-related VT, while rs4524 in F5 was associated with antenatal VT.

The Interface between Inflammation and Coagulation in Cardiovascular Disease

The intimate connection between coagulation and inflammation in the pathogenesis of vascular disease has moved more and more into focus of clinical research. This paper focuses on the essential components of this interplay in the settings of cardiovascular disease and acute coronary syndrome. Tissue factor, the main initiator of the extrinsic coagulation pathway, plays a central role via causing a proinflammatory response through activation of coagulation factors and thereby initiating coagulation and downstream cellular signalling pathways. Regarding activated clotting factors II, X, and VII, protease-activated receptors provide the molecular link between coagulation and inflammation. Hereby, PAR-1 displays deleterious as well as beneficial properties. Unravelling these interrelations may help developing new strategies to ameliorate the detrimental reciprocal aggravation of inflammation and coagulation.

The influence of tissue factor and tissue factor pathway inhibitor polymorphisms on thrombin generation in stable coronary artery disease

In patients with stable coronary heart disease (n = 1,001) we investigated the influence of tissue factor (TF) and TF pathway inhibitor (TFPI) polymorphisms on thrombin generation in vivo, measured by prothrombin fragment (F) 1 and 2, and the potential to generate thrombin ex vivo, measured by the calibrated automated thrombogram assay. Additionally, circulating levels of TF and TFPI were correlated to the different parameters of thrombin generation. The TF 5466 and TFPI -399 polymorphisms associated with higher thrombin generation in vivo, the latter also with a prolonged lag time of the thrombin generation ex vivo(p < 0.05 for all).The TF -1812 TT and the TF -603 GG genotypes were associated with lower peak thrombin and a decreased average net rate of thrombin activation during the propagation phases (p ≤ 0.05), and the TFPI -33 TC genotype with prolonged lag time (p < 0.05) and additionally time to peak (p = 0.06). Strong correlations between TFPI levels, prothrombin fragment 1 and 2 as well as calibrated automated thrombogram parameters were observed.

Pathophysiological role of blood-borne tissue factor: should the old paradigm be revisited?

The term "vulnerable plaque" identifies atherosclerotic lesions prone to rupture. Plaque disruption facilitates the interaction of the inner components of the lesion, tissue factor (TF) among them, with the flowing blood. This results in activation of the coagulation cascade, ultimately leading to thrombus formation, and abrupt vascular occlusion. Despite the central role of vulnerable plaques in the onset of acute coronary syndromes (ACS), there are certain conditions (e.g., eroded plaques) where a hyperactive, "vulnerable" blood, may play a predominant pathophysiological role. Recently, two distinct pools of circulating TF have been identified. One, associated with cell-derived microparticles probably originating from apoptotic cells, such as macrophages, smooth muscle cells, and endothelium. The most recent, blood-borne TF, circulates in an "inactive" form (encryption) and has to be activated (decryption) to exert its thrombogenic activity. Certain pathological conditions associated with an increased rate of thrombotic complications have been associated with high levels of circulating TF. It is thought that the blood-borne TF perpetuates the initial thrombogenic stimulus, leading to the formation of larger or more stable thrombus, and thus, more severe ACS. Thus, the concept of vulnerable blood could represent a new link between the vulnerable lesion and the high-risk patient. Therefore, the assessment of selected biomarkers associated with "vulnerable or hyperreactive blood", e.g., blood-borne tissue factor, may represent a useful tool to identify patients with a high-risk profile of developing major cardiovascular events.

Niemann-Pick C1 modulates hepatic triglyceride metabolism and its genetic variation contributes to serum triglyceride levels

OBJECTIVE

To study how Niemann-Pick disease type C1 (NPC1) influences hepatic triacylglycerol (TG) metabolism and to determine whether this is reflected in circulating lipid levels.

METHODS AND RESULTS

In Npc1(-/-) mice, the hepatic cholesterol content is increased but the TG content is decreased. We investigated lipid metabolism in Npc1(-/-) mouse hepatocytes and the association of NPC1 single-nucleotide polymorphisms with circulating TGs in humans. TGs were reduced in Npc1(-/-) mouse serum and hepatocytes. In Npc1(-/-) hepatocytes, the incorporation of [3H]oleic acid and [3H]acetate into TG was decreased, but shunting of oleic acid- or acetate-derived [3H]carbons into cholesterol was increased. Inhibition of cholesterol synthesis normalized TG synthesis, content, and secretion in Npc1(-/-) hepatocytes, suggesting increased hepatic cholesterol neogenesis as a cause for the reduced TG content and secretion. We found a significant association between serum TG levels and 5 common NPC1 single-nucleotide polymorphisms in a cohort of 1053 men, with the lowest P=8.7 x 10(-4) for the single-nucleotide polymorphism rs1429934. The association between the rs1429934 A allele and higher TG levels was replicated in 2 additional cohorts, which included 8041 individuals.

CONCLUSIONS

This study provides evidence of the following: (1) in mice, loss of NPC1 function reduces hepatocyte TG content and secretion by increasing the metabolic flux of carbons into cholesterol synthesis; and (2) common variation in NPC1 contributes to serum TG levels in humans.

Gender differences of polymorphisms in the TF and TFPI genes, as related to phenotypes in patients with coronary heart disease and type-2 diabetes

Background

Tissue factor (TF) and its inhibitor tissue factor pathway inhibitor (TFPI) are the main regulators of the initiation of the coagulation process, important in atherothrombosis. In this study we have investigated the frequency of six known TF and TFPI single nucleotide polymorphisms (SNPs) in CHD patients as compared to healthy individuals. These genotypes and the phenotypes (TF, TFPI free and total antigen) were evaluated with special reference to gender and diabetes in the CHD population.

Methods

Patients with angiographically verified CHD (n = 1001; 22% women, 20% diabetics), and 204 healthy controls (28% women), were included. The investigated SNPs were: TF -1812C/T and TF -603A/G in the 5'upstream region, TF 5466A/G in intron 2, TFPI -399C/T and TFPI -287T/C in the 5'upstream region and the TFPI -33T/C in intron 7.

Results

No significant differences in frequencies between the CHD population and the controls of any polymorphisms were observed. In the CHD population, the TF 5466 A/G SNP were significantly more frequent in women as compared to men (p < 0.001). The TF-1812C/T and the TF-603A/G SNPs were significantly more frequent in women without type-2 diabetes compared to those with diabetes (p < 0.018, both), and the heterozygous genotypes were associated with significantly lower TF plasma levels compared to the homozygous genotypes (p < 0.02, both).

The TFPI-399C/T and the TFPI-33T/C SNPs were associated with lower and higher TFPI total antigen levels, respectively (p < 0.001, both).

Conclusion

Genetic variations in the TF and TFPI genes seem to be associated with gender and type-2 diabetes, partly affecting their respective phenotypes.

Tissue factor gene polymorphisms and haplotypes and the risk of ischemic vascular events: four studies and a meta-analysis

OBJECTIVE

The exposure of tissue factor (TF) to blood flow is the initial step in the coagulation process and plays an important role in thrombogenesis. We investigated the role of genetic polymorphisms and haplotypes of the TF gene in the risk of ischemic vascular disease.

METHODS

Four hundred and twenty-two Italian patients with juvenile myocardial infarction (MI) and 434 controls, 808 US cases with MI and 1005 controls, 267 Italian cases with juvenile ischemic stroke and 209 controls and 148 German cases with juvenile ischemic stroke and 191 controls were studied. rs1361600, rs3917629 (rs3354 in the US population), rs1324214 and rs3917639 Tag single nucleotide polymorphisms were genotyped. Additionally, a meta-analysis of all previous studies on TF loci and the risk of ischemic coronary disease (ICD) was performed.

RESULTS

After multivariable analysis none of the SNPs, major SNP haplotypes or haplotype-pairs showed any consistent association with MI. Pooled meta-analysis of six studies also suggested that TF polymorphisms are not associated with CHD. A significant, independent association between SNP rs1324214 (C/T) and juvenile stroke was found in Italian and German populations (OR for TT homozygotes = 0.47, 95% CI 0.24-0.92, in combined analysis). Pooled analysis also showed a significant association for haplotype H3 (OR = 0.76, 95% CI 0.57-1.00) and haplotype-pair H3-H3 (OR = 0.43, 95% CI 0.20-0.92).

CONCLUSIONS

TF genetic variations were associated with the risk of ischemic stroke at young age, but did not affect ischemic coronary disease.

Plasma TF activity predicts cardiovascular mortality in patients with acute myocardial infarction

Objectives and Background

Tissue factor (TF) contributes to thrombosis following plaque disruption in acute coronary syndromes (ACS). Aim of the study was to investigate the impact of plasma TF activity on prognosis in patients with ACS.

Methods and Results

One-hundred seventy-four patients with unstable Angina pectoris (uAP) and 112 patients with acute myocardial infarction (AMI) were included with a mean follow up time of 3.26 years. On admission, plasma TF activity was assessed. Patients were categorized into 2 groups: a high-TF activity group with TF >24 pmol/L and low TF activity group with TF ≤ 24 pmol/L. Fifteen cardiovascular deaths occurred in the uAP group and 16 in the AMI group. In AMI TF activity was 24,9 ± 2,78 pmol/l (mean ± SEM) in survivors and 40,9 ± 7,96 pmol/l in nonsurvivors (P = 0.024). In uAP no differences were observed (25.0 ± 8.04 pmol/L nonsurvivors vs. 25.7 ± 2.14 pmol/L survivors; P = 0.586). Kaplan-Meier estimates of survival at 3.26 years regarding TF activity in AMI were 81.3% and 92.2% with an hazard ratio of 3.02 (95% CI [1.05–8.79], P = 0.03). The Cox proportional hazards model adjusting for correlates of age and risk factors showed that plasma TF activity was an independent correlate of survival (hazard ratio 9.27, 95% CI [1.24–69.12], P = 0.03). In an additional group of patients with uAP and AMI, we identified circulating microparticles as the prevailing reservoir of plasma TF activity in acute coronary syndromes.

Conclusion

Systemic TF activity in AMI has an unfavorable prognostic value and as a marker for dysregulated coagulation may add to predict the atherothrombotic risk.

Plasma level of growth arrest-specific 6 (GAS6) protein and genetic variations in the GAS6 gene in patients with acute coronary syndrome

Growth arrest-specific gene 6 (GAS6) encodes a vitamin K-dependent protein that regulates inflammation, angiogenesis, and atherosclerotic plaque formation. The level of GAS6 expression is associated with plaque stability and stroke. We explored the role of GAS6 in cardiovascular disease, particularly in acute coronary syndrome (ACS). We determined the plasma levels of GAS6 protein by using an enzyme-linked immunosorbent assay method and investigated the role of the single nucleotide polymorphism (c.834+7G>A) in ACS. The median (interquartile range) plasma GAS6 levels were 16.9 microg/L (13-28 microg/L) in healthy control subjects and 10.65 microg/L (5.7-27.5 microg/L) in patients with ACS. The genotype frequencies for GG, AG, and AA, respectively, in patients with ACS were 66% (37/56), 29% (16/56), and 5% (3/56) and were 35% (14/40), 45% (18/40), 20% (8/40) in the control group. The AA genotype and A allele were less frequent in patients with ACS than in control subjects (P < .001). Our study indicates that GAS6 plasma concentrations at admission reflect the presence of common cardiovascular risk factors and can predict cardiovascular events. In addition, the AA genotype and A allele of the GAS6 gene relate to ACS, which may have a protective role against ACS.

Monocytes in acute coronary syndromes

The aim of this overview is to summarize the available data on the involvement of monocytes in the pathological processes related to the development of acute coronary syndromes and the recovery of damaged areas, the prevention of excessive inflammatory and procoagulant response, and the restoration of microcirculation (angiogenesis).

Tissue factor +5466A>G polymorphism determines thrombin formation following vascular injury and thrombin-lowering effects of simvastatin in patients with ischemic heart disease

OBJECTIVE

We examined the hypothesis that the +5466A>G variant (rs3917643) of the tissue factor (TF) gene is associated with thrombin formation following simvastatin in patients with ischemic heart disease (IHD).

METHODS AND RESULTS

Prothrombin 1.2 fragments (F1.2) and thrombin-antithrombin complexes (TAT) were assessed in 95 men with stable IHD, aged 54.4+/-6.8 years, in blood collected every 60s from the bleeding-time wounds before and after a 3-month simvastatin administration (40 mg/day). We identified 16 patients with the TF +5466AG genotype and 79 subjects with the +5466AA genotype. Baseline maximum rates of F1.2 and TAT formation and their maximum levels at the site of vascular injury, but not in venous blood, were higher in +5466G allele carriers than in those with +5466AA genotype (P<0.0001). The magnitude of reduction in maximum rates of F1.2 and TAT formation following simvastatin was larger (P<0.001) in +5466G allele carriers than in +5466AA subjects. The degree of decrease in maximum local levels of F1.2 and TAT after simvastatin was similar in both genotype groups. The presence of the +5466G allele was independently associated with the maximum velocity of F1.2 and TAT generation and maximum levels of both markers before and after simvastatin in multiple regression models (P<0.01 for all analyses). Local thrombin generation, in +5466AG and +5466AA subjects, showed no significant correlations with lipid variables.

CONCLUSIONS

Thrombin formation following vascular injury and thrombin-lowering effect of statins in patients with IHD are at least in part genetically determined by the TF +5466A>G polymorphism.

Genetic variations of Mrf-2/ARID5B confer risk of coronary atherosclerosis in the Japanese population

A phenotypic change of smooth muscle cells (SMCs) is considered to be critical in the pathogenesis of atherosclerotic lesions such as coronary artery disease (CAD). Mrf-2/ARID5B, a member of the AT-rich interaction domain family of transcription factors, is highly expressed in the cardiovascular system and is believed to play essential roles in the phenotypic change of SMCs through its regulation of SMC differentiation. In addition, recent studies on gene-engineered mice suggested that this transcriptional factor is involved in obesity and adipogenesis, which are critical aspects for the pathogenesis of atherosclerosis. Thus, we hypothesized that genetic variations of the Mrf-2 gene might be associated with susceptibility to CAD. We investigated 11 common genetic variations of Mrf-2 to determine whether they were associated with susceptibility to CAD in 475 CAD subjects and 310 control subjects. The prevalence of homozygotes for the minor allele G of SNP4 (rs2893880) and minor allele G of SNP6 (rs7087507) were significantly more frequent in the control subjects than in patients with CAD (P=0.0002, rs2893880, P=0.0058, rs7087507). Four nearby SNPs (SNP4 to SNP7) (rs2893880, rs10740055, rs7087507 and rs10761600) showed almost complete linkage disequilibrium, and haplotype analysis revealed that the haplotype G (rs2893880)-C (rs10740055)-G (rs7087507)-A (rs10761600) was also significantly negatively associated with susceptibility to CAD (P=0.049). Moreover, these negative disease associations still existed after logistic regression analysis was taken into account to eliminate confounding conventional coronary risk factors. The results implicate possible disease relevance of the polymorphisms in the Mrf-2 gene with susceptibility to CAD. However, a larger scale prospective study is needed to clarify these findings.

Non-traditional biomarkers of atherosclerosis in stable and unstable coronary artery disease, do they differ?

BACKGROUND

Biomarkers of atherosclerosis are emerging as a potential tool for assessment of coronary artery disease (CAD) patients. As acute coronary syndrome (ACS), and stable CAD are distinguished in their pathophysiology it is conceivable that they are also characterized by different biomarkers of atherosclerosis.

METHODS

We systematically reviewed the literature for clinical studies of several non-traditional biomarkers of atherosclerosis reflecting various pathophysiological processes, namely macrophage-activity, oxidative-stress, tissue remodeling, and thrombosis in ACS and stable CAD to determine whether circulating biomarkers are differently expressed/predict outcome in these two clinical conditions.

RESULTS

Macrophage-activity (monocyte chemoattractant protein-1, neopterin), tissue-remodeling (matrix metalloproteinase-9) and thrombosis (tissue-factor) related biomarkers were consistently elevated in ACS compared to stable CAD, in accordance with the pathophysiological role of these mediators in plaque rupture, characterizing ACS. Thus, these biomarkers may be applicable for diagnosis of ACS. Additionally, neopterin was consistently shown to predict outcome in both stable and ACS patients and myeloperoxidase was strongly shown to predict outcome in ACS, implying for their potential role in risk stratification of these patients.

CONCLUSIONS

As ACS and stable CAD are characterized by different pathophysiological processes, it appears that the biomarkers that are associated with them are differently expressed in these two clinical conditions

Variation in 24 hemostatic genes and associations with non-fatal myocardial infarction and ischemic stroke

BACKGROUND

Arterial thrombosis involves platelet aggregation and clot formation, yet little is known about the contribution of genetic variation in fibrin-based hemostatic factors to arterial clotting risk. We hypothesized that common variation in 24 coagulation-fibrinolysis genes would contribute to risk of incident myocardial infarction (MI) or ischemic stroke (IS).

METHODS

We conducted a population-based, case-control study. Subjects were hypertensive adults and postmenopausal women 30-79 years of age, who sustained a first MI (n = 856) or IS (n = 368) between 1995 and 2002, and controls matched on age, hypertension status, and calendar year (n = 2,689). We investigated the risk of MI and IS associated with (i) global variation within each gene as measured by common haplotypes and (ii) individual haplotypes and single nucleotide polymorphisms (SNPs). Significance was assessed using a 0.2 threshold of the false discovery rate q-value, which accounts for multiple testing.

RESULTS

After accounting for multiple testing, global genetic variation in factor (F) VIII was associated with IS risk. Two haplotypes in FVIII and one in FXIIIa1 were significantly associated with increased IS risk (all q-values < 0.2). A plasminogen gene SNP was associated with MI risk. All are new discoveries not previously reported. Another 24 tests had P-values < 0.05 and q-values > 0.2 in MI and IS analyses, 23 of which are new and hypothesis generating.

CONCLUSIONS

Apart from the association of FVIII variation with IS, we found little evidence that common variation in the 24 candidate fibrin-based hemostasis genes strongly influences arterial thrombotic risk, but our results cannot rule out small effects.

Association of polymorphisms in platelet and hemostasis system genes with acute myocardial infarction

BACKGROUND

Genetic polymorphisms may affect the balance between coagulation and fibrinolysis and thereby affect individual vulnerability to acute myocardial infarction (MI) among patients with underlying coronary atherosclerosis.

METHODS

We enrolled 1375 patients with an initial clinical presentation of coronary disease. We genotyped 49 single nucleotide polymorphisms (SNPs) in 9 coagulation system genes and compared patients who had an initial acute MI with patients who presented with stable exertional angina.

RESULTS

An SNP in CD36 (rs3211956) was significantly (P = .04) more common among patients who presented with acute MI (minor allele frequency 10.5%) than patients with stable exertional angina (minor allele frequency 8.0%). This association became marginally significant, however, after adjustment for conventional cardiac risk factors in an additive genetic model (odds ratio 1.34, CI 1.00-1.88, P = .053). An SNP in ITGB3 (Leu59Pro, rs5918) was slightly, but not significantly (P = .083), more common among patients with acute MI (minor allele frequency 14.5%) than among patients with stable exertional angina (minor allele frequency 12.0%). Two linked SNPs in THBD (Ala473Val, rs1042579; and rs3176123) were slightly, but not significantly (P = .079 and 0.052, respectively), less common among patients with acute MI (minor allele frequency 16.1%) than among patients with stable exertional angina (18.7% and 19.0%, respectively).

CONCLUSIONS

Four SNPs in platelet glycoprotein and hemostatic genes were nominally associated with acute MI rather than stable exertional angina as the initial clinical presentation of coronary artery disease. These findings are suggestive but require independent confirmation in larger studies.

Raised interleukin-10 is an indicator of poor outcome and enhanced systemic inflammation in patients with acute coronary syndrome

Objectives:

To re-evaluate the relation between plasma interleukin-10 (IL-10) concentration at hospital admission and outcome and to investigate the impact of single nucleotide polymorphisms (SNP) in the IL-10 gene in patients with non-ST elevation acute coronary syndrome (ACS).

Design:

Determination of IL-10 plasma concentrations and genotyping of SNPs in the IL-10 gene in a prospective trial of patients with ACS and in a group of healthy controls.

Patients:

3179 patients in the Fragmin and fast revascularisation during InStability in Coronary artery disease II (FRISC II) trial and 393 healthy controls.

Main outcome measures:

Mortality and incidence of myocardial infarction (MI) at 12 months.

Results:

The median and interquartile ranges of IL-10 were 0.8 (0.5–1.0) pg/ml in healthy controls and 1.1 (0.7–1.9) pg/ml in patients (p<0.001). In patients, IL-10 predicted a crude risk increase of death/MI, with the highest risk observed in the fourth quartile (adjusted odds ratio 1.7 (95% confidence interval 1.2 to 2.3)). Adjustment for common risk indicators, including C-reactive protein and interleukin-6, weakened the association to a non-significant level. The 1170 CC genotype weakly predicted increased plasma concentrations of IL-10 in patients (p = 0.04) and in controls (p = 0.03), which was consistent with the modest association of this variant with coronary disease (p = 0.01).

Conclusion:

In contrast with some previous reports, we conclude that IL-10 reflects a proinflammatory state in patients with ACS and we therefore suggest that IL-10 is as effective a biomarker for the risk prediction of future cardiovascular events as other markers of systemic inflammation.

Gene polymorphisms and susceptibility to coronary artery disease

As pediatric cancer survivors age, long-term cardiovascular complications related to chemotherapeutic toxicities, as well as development of premature coronary artery disease (CAD) from radiation and increased prevalence of CAD risk factors such as obesity, are likely to become more prevalent. Despite advances in our understanding of CAD in the general population, a large amount of the variance in development of disease is unexplained. Given the strong heritability of CAD, some of this may be attributable to genetics. Premature CAD in particular segregates in families, and twin studies have shown that the genetic contribution is greater in premature CAD. In this article, we present a brief review of the literature on the genetics of CAD. Over 30 monogenic disorders feature CAD phenotypes. Recently, however, interest has shifted to understanding the genetic variation contributing to common, complex disease, where disease risk is polygenic and characterized by environmental factors, and gene-environment interactions. CAD epitomizes such a disease, and highlights the inherent difficulties in understanding the underlying genetic architecture of such diseases. Long-term cardiovascular complications in patients who survive pediatric cancers result in significant morbidity and mortality in this population. Clinicians need to be aware of screening and treatment strategies for primary and secondary prevention of cardiovascular complications in this group. Further research is necessary to define the epidemiology and risk factors of premature CAD in survivors of pediatric cancers, and to determine whether candidate genes for cardiovascular disease in the general population are also susceptibility genes in this vulnerable population.

Prognostic value of plasma tissue factor and tissue factor pathway inhibitor for cardiovascular death in patients with coronary artery disease: the AtheroGene study

BACKGROUND

Tissue factor (TF) and its specific inhibitor, tissue factor pathway inhibitor (TFPI), are important contributors to the initiation of the coagulation process.

OBJECTIVES

To compare plasma levels of soluble TF (sTF) and free-TFPI (f-TFPI) between patients with stable angina pectoris (SAP) and acute coronary syndrome (ACS) and to assess the impact of the two variables on long-term prognosis.

PATIENTS/METHODS

Patients with SAPs (n = 1146) and acute coronary syndrome (n = 523) from the AtheroGene study were included and followed for 2.3 years. Because of the strong impact of unfractionated heparin (UFH) on f-TFPI levels, but not on sTF levels, patients having received UFH before blood drawing were excluded from the analyses on f-TFPI (n = 226).

RESULTS

On admission, no significant differences in sTF levels were observed between SAP and ACS patients. By comparison to patients with stable angina, f-TFPI levels significantly increased in patients with acute unstable angina and further increased in patients presenting with non-ST-elevation myocardial infarction and ST-elevation myocardial infarction (P < 10(-4)). Among the 1669 individuals with a coronary artery disease, 56 died from a cardiovascular cause. In prospective analyses, high sTF levels were independently associated with an increased risk of cardiovascular death in individuals with ACS (fully adjusted hazard ratio associated with one quartile increase = 2.06; 95% confidence interval 1.24-3.45; P = 0.006) but not in those with SAP (hazard ratio = 1.07; 95% confidence interval 0.78-1.46; P = 0.67). In SAP and ACS patients, high f-TFPI levels were not independently associated with an increased risk of cardiovascular death.

CONCLUSIONS

Plasma sTF levels were predictive of cardiovascular mortality in individuals with ACS, whereas f-TFPI levels were associated with the severity of myocardial damage on admission but were not independently related to outcome.

The intersubject variability of tissue factor mRNA production in human monocytes—relation with the toll-like receptor 4

OBJECTIVE

Tissue factor (TF) is known as the primary initiator of blood coagulation. Previous studies have suggested a considerable variation in the monocytic lipopolysaccharide (LPS) stimulated TF antigen levels and procoagulant activities between different individuals. Our aim with the present study was to investigate the replicability of LPS induced TF mRNA production in a series of standardised experiments with the purpose to identify putative factors influencing the TF high and low response.

RESULTS

A constant and reproducible production of LPS induced TF mRNA was identified in five high responders and three low responders (out of 42 individuals) and followed-up in three subsequent experiments performed over 2 years. The LPS induced TF mRNA production correlated with the corresponding expressions of interleukin-8, tumor necrosis factor-alfa and interleukin-1 beta, indicating a common pathway with the TF high and low response. A strong and significant correlation between the LPS induced TF and toll-like receptor 4 mRNA expressions was subsequently identified and replicated.

CONCLUSIONS

We demonstrated a high and low responder phenomenon of LPS induced TF mRNA in human monocytes. The production of toll-like receptor 4 mRNA was significantly enhanced in TF high responders.

Genetic variation in the interleukin-6 gene in relation to risk and outcomes in acute coronary syndrome

BACKGROUND

The concept of inflammation in the acute coronary syndrome (ACS) is today well established. Interleukin-6 (IL-6), a pleiotropic, proinflammatory cytokine, seems to play an important role in the development and progression of ACS.

AIM

The aim was to investigate whether IL6 polymorphisms are associated with patient/control status, outcome in patients with ACS and plasma concentrations of IL-6 and C-reactive protein (CRP).

METHODS

Samples for citrated plasma and DNA were obtained on admission from 3027 patients with non-ST-elevation ACS in the FRISC-II study. A group of 447 healthy controls of similar age and gender as the patients was also recruited. Eight IL6 polymorphisms were genotyped and plasma concentrations of IL-6 and CRP measured in patients and controls.

RESULTS

No associations between patient/control status, clinical outcome, ST-depression, troponin-T elevation or a history of myocardial infarction and IL6 polymorphisms were observed. In the full patient group, there was a trend towards association of the -572 G>C polymorphism with plasma concentrations of IL-6 (p=0.07). This association was statistically significant in patients with available high-sensitivity measurements of IL-6 (p=0.01). The -572 CG genotype was predictive for IL-6 levels above 5 ng/L in patients with a subsequent cardiovascular event, 2.3 (1.1-4.3) (adjusted odds ratio, 95% confidence interval). Comparison with data from HapMap showed that our panel of polymorphisms covered information on approximately 30 other IL6 variants.

CONCLUSION

The -572 G>C and other polymorphisms in the study were not associated with outcome in ACS patients. However, the -572 CG genotype may contribute to a more distinct inflammatory response in patients with ACS.

Tissue Factor and Coagulation Factor VII Levels During Acute Myocardial Infarction

Objective— We investigated in patients with ongoing myocardial infarction (MI) whether coagulation factor VII (FVII) and tissue factor (TF) levels are affected at admission by genetic components and whether they may predict subsequent cardiovascular events.

Methods and Results— 256 patients admitted for MI were evaluated for FVII and TF antigen levels before any treatment at entry, and were genotyped for FVII and TF polymorphisms. FVII gene insertions at −323, 11293 and the −402G/A change predicted FVII levels and explained 14% of variance. The −603 TF gene polymorphism failed to affect significantly TF levels ( P =0.07). These variables were correlated with the incidence of death (36 patients) and reinfarction (9 patients) after a median follow-up of 397 days. Events were independently predicted by FVII (HR 2.1, 95% CI 1.2 to 5.7) and TF (HR 4.1, 95% CI 2 to 11) levels. Composite end point was significantly worse when both parameters were above the receiver-operating characteristics (ROC) values (HR 8.3, 95% CI 5 to 18, compared with FVII and TF below), and above the ROC value of TF (>630 pg/mL) it differed among FVII genotype groups.

Conclusions— Admission FVII and TF antigen levels, partially predicted by polymorphisms, are independent predictors of mortality and reinfarction in patients with acute MI.

Genetic susceptibility to thrombosis

Thrombosis is associated with atherosclerosis, sepsis, cancer, and numerous other inflammatory diseases. Complications of thrombosis, such as myocardial infarction, stroke, and venous thromboembolism, contribute significantly to morbidity and mortality. Susceptibility to thrombosis is conferred by both genetic and environmental factors. Tissue factor is the primary cellular initiator of blood coagulation and is a major contributor to thrombosis. In this review, we discuss the association between various polymorphisms and the risk for thrombosis.

Tissue Factor in Cardiovascular Diseases

Tissue factor (TF), formerly known as thromboplastin, is the key initiator of the coagulation cascade; it binds factor VIIa resulting in activation of factor IX and factor X, ultimately leading to fibrin formation. TF expression and activity can be induced in endothelial cells, vascular smooth muscle cells, and monocytes by various stimuli such as cytokines, growth factors, and biogenic amines. These mediators act through diverse signal transduction mechanisms including MAP kinases, PI3-kinase, and protein kinase C. Cellular TF is present in three pools as surface, encrypted, and intracellular protein. TF can also be detected in the bloodstream, referred to as circulating or blood-borne TF. Elevated levels of TF are observed in patients with cardiovascular risk factors such as hypertension, diabetes, dyslipidemia, and smoking as well as in those with acute coronary syndromes. TF may indeed be involved in the pathogenesis of atherosclerosis by promoting thrombus formation; in addition, it can induce migration and proliferation of vascular smooth muscle cells. As a consequence, therapeutic strategies have been developed to specifically interfere with the action of TF such as antibodies against TF, site-inactivated factor VIIa, or recombinant TF pathway inhibitor. Inhibition of TF action appears to be an attractive target for the treatment of cardiovascular diseases.