Ath1 is a quantitative trait locus on mouse chromosome 1 that renders C57BL/6 mice susceptible and C3H/He mice resistant to diet-induced atherosclerosis. The quantitative trait locus region encompasses 11 known genes, including Tnfsf4 (also called Ox40l or Cd134l), which encodes OX40 ligand. Here we report that mice with targeted mutations of Tnfsf4 had significantly (P

Environmental exposures filtered through the genetic make-up of each individual alter the transcriptional repertoire in organs central to metabolic homeostasis, thereby affecting arterial lipid accumulation, inflammation, and the development of coronary artery disease (CAD). The primary aim of the Stockholm Atherosclerosis Gene Expression (STAGE) study was to determine whether there are functionally associated genes (rather than individual genes) important for CAD development. To this end, two-way clustering was used on 278 transcriptional profiles of liver, skeletal muscle, and visceral fat (n = 66/tissue) and atherosclerotic and unaffected arterial wall (n = 40/tissue) isolated from CAD patients during coronary artery bypass surgery. The first step, across all mRNA signals (n = 15,042/12,621 RefSeqs/genes) in each tissue, resulted in a total of 60 tissue clusters (n = 3958 genes). In the second step (performed within tissue clusters), one atherosclerotic lesion (n = 49/48) and one visceral fat (n = 59) cluster segregated the patients into two groups that differed in the extent of coronary stenosis (P = 0.008 and P = 0.00015). The associations of these clusters with coronary atherosclerosis were validated by analyzing carotid atherosclerosis expression profiles. Remarkably, in one cluster (n = 55/54) relating to carotid stenosis (P = 0.04), 27 genes in the two clusters relating to coronary stenosis were confirmed (n = 16/17, P<10−27and−30). Genes in the transendothelial migration of leukocytes (TEML) pathway were overrepresented in all three clusters, referred to as the atherosclerosis module (A-module). In a second validation step, using three independent cohorts, the A-module was found to be genetically enriched with CAD risk by 1.8-fold (P<0.004). The transcription co-factor LIM domain binding 2 (LDB2) was identified as a potential high-hierarchy regulator of the A-module, a notion supported by subnetwork analysis, by cellular and lesion expression of LDB2, and by the expression of 13 TEML genes in Ldb2–deficient arterial wall. Thus, the A-module appears to be important for atherosclerosis development and, together with LDB2, merits further attention in CAD research.

Abstract-The thrombin-activatable fibrinolysis inhibitor (TAFI) is a recently described inhibitor of fibrinolysis that decreases plasminogen binding to the fibrin surface. The plasma TAFI concentration is almost entirely genetically determined. We investigated whether plasma TAFI levels and polymorphisms located in the TAFI gene could constitute risk markers of myocardial infarction (MI). Plasma TAFI antigen (Ag) levels were assayed by ELISA and 2 TAFI gene polymorphisms (Ala147Thr and Cϩ1542G in the 3Ј untranslated region) were determined in a large European case-control study. This study compared 598 men recruited 3 to 6 months after MI with 653 age-matched controls from North Europe (Stockholm, Sweden, and London, England) and South Europe (Marseilles, France, and San Giovanni Rotondo, Italy). A TAFI Ag value above the 90th percentile was associated with a significantly lower risk of MI (odds ratio 0.55, PϽ0.02), indicating that elevated TAFI may be protective against MI. As previously shown, the 2 TAFI gene polymorphisms were in strong linkage disequilibrium and were associated with the TAFI Ag concentration, with carriers of the Thr147 and 1542C alleles having higher levels (PϽ0.0005). These effects were similar in controls and cases and in each center. There was a difference in allele frequency between cases and controls for the Ala147Thr polymorphism, with Thr147 allele carriers being more frequent in controls than in cases in 2 centers, Stockholm (Pϭ0.03) and San Giovanni Rotondo (Pϭ0.03); the odds ratio for the entire cohort was 0.78 (PϽ0.05). In conclusion, patients with a recent MI presented lower values of TAFI Ag and higher frequencies of the "TAFI-decreasing" alleles. The geographical differences observed do not contribute to explaining the North-South gradient in MI risk in Europe. Key Words: thrombin-activatable fibrinolysis inhibitors Ⅲ myocardial infarction Ⅲ genetic polymorphisms Ⅲ fibrinolysis T he thrombin-activatable fibrinolysis inhibitor (TAFI), also known as procarboxypeptidase B and procarboxypeptidase U, has been recently described. 1-3 It can potently inhibit fibrinolysis by removing carboxy-terminal lysine residues from partially degraded fibrin, decreasing plasminogen binding on its surface. 4 -7 Because of its role in the fibrinolytic system, TAFI may be implicated in atherothrombotic diseases. Studies conducted in different animal models support a physiological role of TAFI in the regulation of fibrinolysis. 8 -11 In humans, van Tilburg et al, 12 have shown that an increased plasma TAFI antigen (Ag) concentration could be a risk marker for venous thrombosis. 12 In a pilot study of men with stable angina pectoris and angiographically verified coronary artery disease, it was found that the plasma levels of TAFI were significantly higher in the patients than in healthy population-based age-matched men. 13 The between-individual differences in plasma TAFI concentration are only partly explained by environmental factors, suggesting a strong influence of genetic factors. 14,15 The hum...

Objectives. Matrix metalloproteinase-3 (MMP-3) is implicated in the formation of atherosclerotic plaques, and the MMP-3 )1612 5A/6A polymorphism is associated with myocardial infarction (MI) and stable coronary artery disease (CAD). The present study examined whether the )1612 5A/6A polymorphism in the promoter region of the MMP-3 gene influences serum concentrations of MMP-3 and whether serum concentrations of MMP-3 are related to extent of coronary atherosclerosis and risk of MI. Design and subjects. This case-control study was conducted in three hospitals in the northern part of Stockholm. A total of 755 MI patients aged below 60 were screened, 433 entered and 387 completed the study. Three hundred and eighty-seven sex-and age-matched control subjects were recruited from the general population of the same county. Methods. The MMP-3 genotype was determined by Pyrosequencing TM and the serum MMP-3 concentration was quantified with an immunoassay. Severity and extension of CAD was assessed by quantitative coronary angiography in a subgroup of patients (n ¼ 243). Results. Patients had lower serum MMP-3 concentration than controls. There was a strong association between MMP-3 )1612 5A/6A genotype and serum concentrations of MMP-3. The presence of one or two copies of the 6A-allele was associated with a graded increase in serum MMP-3. In female patients there was an inverse correlation (r ¼ )0.39, P < 0.05) between serum MMP-3 concentration and plaque area. Conclusion. In conclusion, the serum concentration of MMP-3 is influenced by MMP-3 )1612 5A/6A genotype and associated with MI.

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Summary. Background: Fibrinogen c¢, a fibrinogen c-chain variant generated via alternative mRNA processing, has been associated with susceptibility to thrombotic disease. Objective: The present case-control study searched for potential determinants of the plasma fibrinogen c¢ concentration and examined the relationship between this variant and risk of myocardial infarction (MI). Patients and methods: The Stockholm Coronary Artery Risk Factor study, comprising 387 postinfarction patients and 387 healthy individuals, was employed. The fibrinogen gamma (FGG) 9340T > C [rs1049636], fibrinogen alpha (FGA) 2224G > A [rs2070011] and fibrinogen beta (FGB) 1038G > A [rs1800791] polymorphisms were determined. The plasma fibrinogen c¢ concentration was measured by enzyme-linked immunosorbent assay. The multifactor dimensionality reduction method was used for interaction analyses on risk of MI. Results: The FGG 9340T > C and FGA 2224G > A polymorphisms, total plasma concentrations of fibrinogen, insulin and high-density lipoprotein, and gender appeared to be independent determinants of plasma fibrinogen c¢ concentration in patients, and the corresponding determinants in controls included FGG 9340T > C and FGA 2224G > A polymorphisms and plasma fibrinogen concentration. An elevated plasma fibrinogen c¢ concentration proved to be an independent predictor of MI [adjusted odds ratio (OR) (95% CI): 1.24 (1.01, 1.52)]. The plasma fibrinogen c¢ concentration was involved in a high-order interaction with total plasma fibrinogen and the FGG 9340T > C and FGA 2224G > A polymorphisms, associated with a further increased risk of MI [OR (95% CI): 3.22 (2.35, 4.39)]. Conclusions: Plasma fibrinogen c¢ concentration influences the risk of MI, and this relationship seems to be strengthened by the presence of an elevated total plasma fibrinogen concentration and the FGG 9340T and FGA 2224G alleles.

Objective-Overexpression of elastolytic cysteine and aspartic proteases, known as cathepsins, is implicated in atherogenesis. The potential significance of imbalance in expression between cathepsins and their inhibitor cystatin C in cardiovascular disease has been highlighted by the demonstration of cystatin C deficiency in human atherosclerosis and abdominal aortic aneurysms. Methods and Results-We identified and characterized physiologically relevant polymorphisms in the promoter region of the cystatin C gene that influence cystatin C production and used these polymorphisms as a tool to examine the significance of cystatin C in coronary atherosclerosis in vivo in humans. Seven polymorphisms, all in strong-linkage disequilibrium, were identified in the cystatin C gene, of which 2 promoter polymorphisms (Ϫ82G/C and Ϫ78T/G) were functional in vitro in electromobility shift and transient transfection assays. Genotyping of 1105 individuals (237 survivors of a first myocardial infarction before age 60 and 2 independent groups comprising a total of 868 healthy individuals) revealed that the plasma cystatin C concentration was significantly lower in carriers of the mutant haplotype. Furthermore, the mutant haplotype was associated with a higher average number of stenoses per coronary artery segment in unselected postinfarction patients (Nϭ237) undergoing routine coronary angiography. Conclusions-These results provide human evidence for an important role of cystatin C in coronary artery disease.(Arterioscler Thromb Vasc Biol. 2004;24:551-557.)

Myocardial infarction (MI) is commonly caused by atherosclerotic plaque rupture following excessive degradation of collagen fibers in the atherosclerotic lesion. We investigated whether interindividual variability in risk of MI was related to polymorphisms in the gene encoding matrix metalloproteinase (MMP)-1, a key fibrillar collagen-degrading enzyme. Several single nucleotide polymorphisms in the MMP1 gene promoter were identified following sequencing DNA samples from 30 individuals. An analysis of the polymorphisms in a cohort of British whites with coronary atherosclerosis, including 639 patients with MI and 538 non-MI subjects, revealed a haplotype effect of the -519A>G and -340T>C polymorphisms on risk of MI, with the A(-519)-C(-340) and G(-519)-T(-340) haplotypes being protective (odds ratio=0.70 [0.57 to 0.86]; P=0.0007), whereas the G(-519)-C(-340) haplotype increased MI risk (odds ratio=1.94 [1.15 to 3.28]; P=0.013). This finding was replicated in a subsequent analysis of 387 Swedish MI patients and 387 healthy controls (odds ratio=0.70 [0.55 to 0.89], P=0.003, for A(-519)-C(-340) and G(-519)-T(-340); odds ratio=1.54 [0.97 to 2.46], P=0.07, for G(-519)-C(-340)). In vitro assays showed that compared with the A(-519)-T(-340) haplotype, the A(-519)-C(-340) and G(-519)-T(-340) haplotypes had lower promoter activity, whereas the G(-519)-C(-340) haplotype had greater promoter strength, in driving gene expression in human macrophages. Haplotype-specific differences in MMP1 mRNA level in atherosclerotic tissues were also detected. The data indicate that MMP1 gene variation is a genetic factor contributing to interindividual differences in MI risk.