Search

Introduction Factor VII activating protease (FSAP) is a plasma protease with FVII and pro-urokinase (pro-uPA) activating properties. A single nucleotide polymorphism (SNP) (Marburg I, MI) in the FSAP gene (HABP-2) leads to a low activity of the MI-FSAP towards pro-uPA, but supposedly not towards FVII and is described as a risk factor for athero-thrombosis and liver fibrosis. Recently we found, however, that FVII is an extremely poor substrate of FSAP and identified tissue factor pathway inhibitor (TFPI) as a novel substrate for FSAP. This prompted us to re-investigate the proteolytic activity profile of FSAP and to re-define its role in haemostasis. Material and Methods Using purified protein and genotyped plasma samples, we systematically compared the activities of wild type (WT) and MI-FSAP towards natural plasma substrates. The influence of FSAP on coagulation was studied in prothrombin time assays. Results FSAP from homozygous MI-carriers has a general low proteolytic activity making this variant a natural “knock-down”. In human plasma WT-FSAP, but not MI-FSAP, accelerated the extrinsic coagulation by inactivation of TFPI. The diminished ability of MI-FSAP to cleave TFPI is reflected by a positive correlation between the FSAP enzymatic activity and cleaved TFPI in the circulation. Conclusion Most likely TFPI cleavage by WT-FSAP occurs in vivo and contributes to an elevated level of endogenous FVIIa. This may explain why MI-FSAP is not a clear indicator for deep vein thrombosis in population studies. The loss of the pro-fibrinolytic protective function of FSAP in carriers of the MI-SNP may account for the association of the MI-SNP with atherosclerosis and thromboembolic complications.

Percutaneous coronary intervention (PCI) has become an effective therapy to treat coronary artery diseases. However, one of the major drawbacks of PCI is the occurrence of restenosis in 8 to 40% of all treated patients. The GENetic Determinants of Restenosis (GENDER) project was designed to study the association between genetic polymorphisims and clinical restenosis. The discovery of genetic variants associated to the occurrence of restenosis after PCI may provide a more tailored therapy and may serve as rationale for new antirestenotic therapies. So far, several candidate gene approaches had already been performed in the GENDER samples but a Genome Wide Association Scan (GWAS) was still lacking. Here, we present preliminary results from the GWAS we are currently carrying out in the GENDER population. (Neth Heart J 2009;17:262-4.).

Late-acquired stent malapposition (LASM) is a common finding after sirolimus-eluting stent (SES) implantation and may be the cause for late stent thrombosis. Inflammation may play a pivotal role in LASM just as it plays in stent restenosis. We have therefore investigated seven polymorphisms involved in inflammatory processes, related in previous reports to restenosis, on the risk of LASM in SES patients. Patients with ST-elevation myocardial infarction who underwent SES implantation and had intravascular ultrasonography (IVUS) data available for both immediate post-intervention and 9-month follow-up were included in the present study. In total, 104 patients from the MISSION! Intervention Study were genotyped for the caspase-1 5352 G/A, eotaxin 1382 A/G, CD14 260 A/G, colony stimulating factor 2 1943 C/T, IL10 −1117 C/T, IL10 4251 C/T, and the tumor necrosis factor alpha 1211 C/T polymorphisms. LASM occurred in 26/104 (25%) of patients. We found a significantly higher risk for LASM in patients carrying the caspase-1 (CASP1) 5352 A allele (RR = 2.32; 95% CI 1.22–4.42). In addition, mean neointimal growth was significantly lower in patients carrying this LASM risk allele (1.6 vs. 4.1%, p = 0.014). The other six polymorphisms related to inflammation were not significantly related to the risk of LASM. In conclusion, carriers of the 5352 A allele in the caspase-1 gene are at increased risk of developing LASM after SES implantation. If this is confirmed in larger studies, then screening for this polymorphism in patients undergoing percutaneous coronary interventions could eventually help cardiologists to better select between commercially available stents.

Introduction. The FSAP-Marburg I polymorphism (1704G > A), which reduces FSAP activity, is associated with late complications of carotid stenosis in humans. Therefore, this study examines the influence of the Marburg I polymorphism and the closely linked Marburg II polymorphism (1280G > C) on various cardiovascular outcomes in two large independent study populations.Methods. The two Marburg polymorphisms in the HABP2 gene encoding FSAP were genotyped in a large population of elderly patients at risk for vascular disease (the PROSPER-study,n=5804) and in a study population treated with a percutaneous coronary intervention (the GENDER-study,n=3104).Results. In the PROSPER study, the Marburg I polymorphism was associated with an increased risk of clinical stroke (HR: 1.60, 95% CI: 1.13–2.28) and all-cause mortality (HR: 1.33, 95% CI: 1.04–1.71). In the GENDER study carriers of this variant seemed at lower risk of developing restenosis (HR: 0.59, 95% CI: 0.34–1.01). The Marburg II polymorphism showed similar but weaker results.Conclusion. The increase in stroke risk in Marburg I carriers could be due to differential effects on smooth muscle cells and on matrix metalloproteinases, thereby influencing plaque stability. The possible protective effect on restenosis could be the result of reduced activation of zymogens, which are involved in hemostasis and matrix remodeling.

Objective Restenosis after percutaneous coronary intervention (PCI) remains an issue even in the drug-eluting stent era. Genetic polymorphisms may provide insight in the pathogenesis of restenosis and may help in the stratification of patients at risk for restenosis. The aim of this study was to examine whether polymorphisms at the toll-like receptor 4 (TLR4) locus, that are associated with impaired innate immune system and with an increased risk of cardiovascular events, were associated with clinical and/or angiographic restenosis after PCI.Methods The GENetic Determinants of Restenosis (GENDER) project was a prospective, multicenter study that enrolled 3146 consecutive patients after successful PCI. Frequencies of the TLR4 896A/G (Asp299Gly; rs4986790) and 1196C/T (Thr399Ile; rs4986791) polymorphisms and haplotypes were assessed. Patients were followed up for 1 year and in a subgroup of 406 patients angiographic follow-up was obtained.Results We included a total of 2682 patients that underwent successful PCI. There was no association between genotypes and the risk of target vessel revascularization at 1-year or late luminal loss at 6-months angiographic follow-up (P = 0.53 and 0.44, respectively). Absence of association with target lesion revascularization and late luminal loss was replicated in the GEnetic risk factors for In-Stent Hyperplasia study Amsterdam (GEISHA) cohort study of 674 patients and in a subgroup of 550 patients with angiographic follow-up available (P = 0.26, and 0.86, respectively). Moreover, in both the studies, no significant differences between haplotypes A/C and G/T were observed for target vessel revascularization at late luminal loss.Conclusion Although inflammation has been implicated in the pathophysiology of restenosis, the 896A/G and 1196C/T polymorphisms or haplotypes based on these polymorphisms at the TLR4 locus are not associated with an increased risk of target vessel revascularization or angiographic restenosis after PCI. These polymorphisms are not useful for pre-PCI identification of patients at risk for restenosis. Pharmacogenetics and Genomics 20: 544-552 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Research into the pathologic mechanisms of neurodegenerative diseases has revealed that CREB binding protein (CBP) plays an important role in cognitive dysfunction. Loss of one copy of this gene leads to a syndrome with severe cognitive dysfunction. We investigated the association between four common variants in the CBP gene and cognitive function in 5804 participants of the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER). Baseline associations between genetic variation and cognitive function were assessed with linear regression. Longitudinal associations were assessed with linear mixed models. All analyses were adjusted for sex, age, education, country, version of test, and pravastatin use. The intron 4CT and intron 3AC polymorphisms in the CBP gene were associated with better cognitive performance at baseline and during follow-up. Furthermore, the haplotype with the variant alleles of these two polymorphisms also showed a protective effect on cognitive function in all cognitive domains (all p < 0.03). Genetic variation in the CBP gene is associated with better cognitive performance in an elderly population. Future research is necessary to investigate the effect of these polymorphisms on the expression of CBP levels and how these polymorphisms affect the gene expression mediated by CBP.

SummarySince activation of the haemostatic system is an important feature of the wound healing response triggered by arterial injury, variations in genes involved in thrombus formation may play a role in restenosis after percutaneous coronary interventions (PCI). Therefore, our aim was to examine the relationship between polymorphisms that are known to play a role in the haemostatic system and the risk of clinical restenosis in the GENetic DEterminants of Restenosis (GENDER) study,a multicenter prospective study design that enrolled 3,104 consecutive patients after successful PCI. Target vessel revascularization (TVR) was the primary endpoint. All patients were genotyped for six polymorphisms in the Factor II, Factor V, Factor VII and PAI-1 genes. The PAI-1 4G variant was associated with an increased risk ofTVR. When compared to 5G/5G homozygotes, heterozygous patients were at higher risk for TVR (HR: 1.46, 95%CI: 1.05–2.03), whereas patients with the 4G/4G genotype had an even further increased risk (HR: 1.69, 95%CI: 1.19–2.41). In contrast, the factor V 506Gln (factor V Leiden) amino acid substitution was associated with a decreased risk of TVR (HR: 0.41, 95%CI: 0.19–0.86). Our findings indicate that polymorphisms in the factorV and PAI-1 genes may play a role in the process of restenosis.

Objectives Genetic factors appear to be important in the development of restenosis after percutaneous coronary intervention, as well as in the process of inflammation, a pivotal factor in restenosis. Caspase-1, interleukin-1-receptor and protein tyrosine phosphatase nonreceptor type 22 are important mediators in the inflammatory response and caspase-1 also in apoptosis. Therefore, we examined whether polymorphisms in these candidate genes are related to the risk of developing restenosis after percutaneous coronary intervention. Methods The GENetic DEterminants of Restenosis-project is a multicenter prospective follow-up study. The 5352G/A (L235L) caspase-1-polymorphism, the 7464C/G (A124G) interleukin-1r-polymorphism and the 1858C/T (R620W) protein tyrosine phosphatase nonreceptor type 22-polymorphism were genotyped. To examine the functional effect of the caspase-1 polymorphism, mature plasma interleukin-1 beta levels were measured by enzyme-linked immunosorbent assay in lipopolysaccharide-stimulated whole blood from a subpopulation of patients. Results A total of 3104 patients, age 62.1 +/- 10.7 years, were included after successful percutaneous coronary intervention. A significant association between the 5352AA genotype of the caspase-1 gene and target vessel revascularization (relative risk 2.2, 95% confidence interval 1.32-3.76) was observed after correcting for clinical variables. Angiographic analysis of a subgroup of patients (N=478) also showed an increased risk for developing restenosis for patients having the 5352GA/AA genotype (P=0.001). The results were corroborated, although they were not statistically significant, by somewhat higher mature interleukin-1 beta levels in patients with the 5352AA genotype. Conclusions The present study shows that patients with the 5352AA genotype in the caspase-1 gene are at increased risk of developing restenosis. If confirmed by other studies, screening patients for this genotype can lead to better risk stratification and provide indications for improving individual treatment; for instance, by providing a new target for drug-eluting stents.