Nicole Helbecque

Polymorphisms in the promoter regions of MMP-2, MMP-3, MMP-9 and MMP-12 genes as determinants of aneurysmal coronary artery disease

OBJECTIVES Our hypothesis was that functional polymorphisms in matrix metalloproteinase (MMP) genes may act as susceptibility factors for the development of coronary aneurysms (CAs). BACKGROUND Different forms of remodeling have been described at the level of coronary arteries; CA, reported in 1% to 5% of patients with angiographic evidence of coronary artery disease (CAD), are one of them. Matrix metalloproteinases have been implicated in the pathogenesis of aneurysm development through increased proteolysis of extracellular matrix proteins. METHODS We screened 3,862 patients who underwent coronary angiography and identified 113 patients with CAD with at least one CA (CA group); these patients were matched with 226 patients with CAD without CA (control group). The -1,306 C/T MMP-2, 5A/6A MMP-3, CA-repeat MMP-9 and -82 A/G MMP-12 polymorphisms were determined. RESULTS The MMP-2, MMP-9 and MMP-12 polymorphisms were not associated with CA. By contrast, the 5A/5A genotype of MMP-3 was significantly more frequent in the CA group than in the control group (31% vs. 18%, p = 0.015); similarly, the MMP-3 5A allele was more frequent in the CA group (p = 0.009). Three variables were independently associated with CA: the MMP-3 5A/5A genotype (odds ratio [OR] = 2.23, 95% confidence interval [CI] [1.27 to 3.93]), a previous myocardial infarction (OR = 1.91, 95% CI [1.14 to 3.20]) and a history of aortic aneurysm (OR = 21.06, 95% CI [2.35 to 188]). CONCLUSIONS The MMP-3 5A allele is associated with the occurrence of CA. Our results suggest that an increased proteolysis in the arterial wall may act as a susceptibility factor for the development of CA in patients with coronary atherosclerosis.

Impact of the Peroxisome Proliferator Activated Receptor γ2 Pro12Ala polymorphism on adiposity, lipids and non-insulin-dependent diabetes mellitus.

OBJECTIVE: The Pro12Ala polymorphism of the Peroxisome Proliferator Activated Receptor γ2 (PPARγ2) gene has been inconsistently associated with body mass index variations and non-insulin-dependent diabetes mellitus (NIDDM). We investigated the impact of this polymorphism on obesity markers, lipid and glucose variables in a sample of French subjects and evaluated its possible role in the onset of NIDDM.DESIGN AND SUBJECTS: Within the framework of the WHO-MONICA project, a population study composed of 1195 subjects aged 35–64 y was randomly sampled from the electoral rolls of the urban community of Lille, in northern France. Subjects receiving medical treatment for hypercholesterolemia, hypertension or diabetes mellitus were excluded for the analyses, to avoid any interferences between medical treatment and biological variables. This resulted in a sample size of 839 subjects (421 men/418 women, age=49.4±8.1 y, body mass index (BMI)=25.7±4.4 kg/m2). To evaluate the role of the Pro12Ala polymorphism in the onset of NIDDM, we evaluated its distribution in 170 Caucasian NIDDM subjects from a clinical series (117 men/53 women, age=62.3±9.0 y, BMI=30.1±3.6 kg/m2).MEASUREMENTS: The PPARγ2 Pro12Ala polymorphism genotyping was carried out with allele specific oligonucleotides hybridisation. Data were statistically analysed for association with various obesity markers (body weight (BW), BMI, waist-to-hip ratio (WHR), plasma leptin concentrations, lipid and glucose variables.RESULTS: In the WHO-MONICA population, the Ala allele frequency was 0.11. The presence of the Ala allele was significantly associated with higher body weight (P=0.002), BMI (P=0.02), height (P=0.02) and waist circumference (P=0.04). Increased plasma concentrations of total cholesterol (P=0.01), LDL-cholesterol (P=0.004) and apolipoprotein B (P=0.01) were also detected in Ala allele bearers. The distribution of the Pro12Ala polymorphism was similar in NIDDM subjects (Ala allele frequency: 0.10) and in the WHO-MONICA population subjects.CONCLUSION: Our results suggest that genetic variability of PPARγ2 affects body weight control and lipid homeostasis in humans and do not support a significant role for the PPARγ2 Pro12Ala polymorphism in the aetiology of NIDDM.

D Allele of the Angiotensin I–Converting Enzyme Is a Major Risk Factor for Restenosis After Coronary Stenting

BACKGROUND Although intracoronary stent implantation significantly reduces restenosis compared with balloon angioplasty, a minority of patients still develop restenosis predominantly due to neointimal hyperplasia. Experimental studies suggest that the renin-angiotensin system is involved in neointimal hyperplasia after arterial injury. In humans, the plasma and cellular levels of ACE are associated with an I/D genetic polymorphism in the ACE gene, DD patients having higher levels. METHODS AND RESULTS We investigated a possible relation between the ACE I/D polymorphism and restenosis in 146 patients who underwent successful implantation of a Palmaz-Schatz stent and had 6-month follow-up angiography. The minimal lumen diameter (MLD) before and after the procedure did not differ significantly among the three groups of genotypes (DD, ID, and II). At follow-up, MLD had a significant inverse relationship to the number of D alleles present (DD, 1.65 +/- 0.71 mm; ID, 1.84 +/- 0.60 mm; II, 2.05 +/- 0.61 mm; P < .007). Late luminal loss during the follow-up period was significantly related to the number of D alleles (DD, 0.89 +/- 0.61 mm; ID, 0.60 +/- 0.52 mm; II, 0.40 +/- 0.53 mm; P < .0001). The relative risk of restenosis (defined as a > 50% diameter stenosis at follow-up) approximated by the adjusted odds ratio was 2.00 per number of D alleles (95% confidence interval, 1.03 to 3.88, P < .04). CONCLUSIONS The ACE I/D polymorphism influences the level of late luminal loss after coronary stent implantation. These results suggest that the renin-angiotensin system may be implicated in the pathogenesis of restenosis after coronary stenting.

β2-adrenoceptor gene polymorphism, body weight, and physical activity

Lipolysis activation and inhibition modulate body weight, body fat, and obesity. These metabolic pathways are influenced by environmental factors, such as physical activity, and by genetic determinants associated with sequence polymorphisms of proteins involved in lipolysis. Among these proteins, adrenergic receptors, activated by catecholamines, play a major part: b-adrenoreceptors stimulate while a2adrenoreceptors inhibit lipolysis in fat. Polymorphisms in the coding sequence of the b2-adrenoreceptor ( B A R 2 ) gene have been associated with obesity, increased body mass index (BMI) and body fat. In a large representative sample of the northern French p o p u l a t i o n , we explored the influences of the B A R 2 Gln27Glu polymorphism and of physical activity on anthropometric variables and obesity (BMI >30 kg/m) . Individuals were randomly sampled from the electoral rolls between 1995 and 1997 (n=1195), equally distributed in tenyear age groups (35 to 64 y) and by gender. For each individual, weight, height, waist and hip circumferences, and physical activity were collected. Physical activity was defined as at least 15 min walk a day, and/or lifting or carrying heavy objects at work daily, and/or doing sport or physical exercise more than 2 h a week. Genotypes for the Gln27Glu polymorphism were obtained for 1152 men and women. Individuals who were taking no medical treatments likely to interfere with body weight were selected (n=836, age=49·5 [SD 8·1] years, BMI=25·7 [4·4] kg/m). Data were analysed by multivariate covariance and logistic regression. Statistical analyses were stratified on gender and were adjusted on age and consumption of cigarettes and of alcohol. Genotype and allele frequencies were in Hardy-Weinberg equilibrium (Gln27Gln 33·1%, Gln27Glu 51·0%, and Glu27Glu 15·9%, Gln allele frequency 0·59) and were similar in men and women. A statistically significant interaction was detected between the Gln27Glu polymorphism and physical activity for body weight (p=0·009), BMI (p=0·007), waist (p=0·03) and hip (p=0·01) circumference in men, but not in women. We analysed the effect of the Gln27Glu polymorphism in men, stratified on physical activity (figure). In men who did not take physical activity (n=255), Gln27Gln men (n=91), compared with Glu27 carriers (n=164), had higher body weight (adjusted mean 83·2 [SEM 1·3] v s 7 6 · 3 [1·0] kg, p=0·0001), BMI (27·2 [0·4] v s 25·2 [0·3] kg/m, p=0·0001), waist circumference (98·7 [1·0] v s 93·2 [0·7] cm, p=0·0001), hip circumference (103·0 [0·7] v s 100·0 [0·5] cm, p=0·0007) and waist to hip ratio (0·96 [0·01] v s 0·93 [0·01], p=0·002) (figure). Conversely, no effect of the Gln27Glu polymorphism was found in men who took regular physical activity (n=165). In men taking no physical activity, the risk of obesity associated with the Gln27Gln genotype was 3·45 (95% CI 1·56–7·80, p=0·002), while this risk was not significantly increased in men who took regular physical activity (OR 1·61, 95% CI 0·67–3·87, p=0·30). We have shown that physical activity may counterbalance the effect of a genetic predisposition to increase body weight, body fat, and obesity. Obese individuals with the B A R 2 Gln27Gln genotype may benefit from physical activity to reduce their weight. Genotyping may be a useful tool to target prevention such as physical activity, to individuals that have highest benefit from it. 1 Mauriege P, Prud’homme D, Marcotte M, Yoshioka M, Tremblay A, Despres JP. Regional differences in adipose tissue metabolism between Effects of the Gln27Glu polymorphism in men according to physical activity. Statistical tests were adjusted on age, and alcohol and tobacco consumptions. Data are mean and SEM. Black bars represent Gln27Gln individuals and white bars Gln27Glu+Glu27Glu individuals.

THE ANGIOTENSIN II TYPE 1 RECEPTOR GENE POLYMORPHISM IS ASSOCIATED WITH CORONARY ARTERY VASOCONSTRICTION

OBJECTIVES This study sought to assess the potential association of the angiotensin-converting enzyme (ACE) and angiotensin II type 1 (AT1) receptor gene polymorphisms on coronary vasomotion in humans. BACKGROUND Abnormal coronary vasomotion plays a role in the clinical expression of coronary atherosclerosis. The components of the renin-angiotensin system are important determinants of vasomotor tone. Furthermore, epidemiologic evidence suggests that these components are involved in the pathogenesis of coronary artery disease. Indeed, two genetic polymorphisms of the ACE and AT1 receptor genes were synergistically associated with the occurrence of myocardial infarction. The influence of these genetic polymorphisms on the risk of myocardial infarction may be related, at least in part, to a deleterious effect on coronary vasomotion. METHODS We studied the response of angiographically normal human coronary arteries after intravenous injection of methylergonovine maleate, a potent vasoconstrictor whose effects have been previously explored in various aspects of coronary artery disease. We characterized the ACE and AT1 receptor genotypes in a consecutive series of 140 patients with normal coronary arteries. Coronary vasomotion was assessed with quantitative coronary angiography. RESULTS No effect of the ACE gene polymorphism was detected. Conversely, the patients carrying the AT1 receptor CC genotype (n = 13) had significantly greater vasoconstriction in distal coronary vessels (p < 0.009). CONCLUSIONS The AT1 receptor gene polymorphism is associated with coronary vasomotion in humans.

Association between beta-1 and beta-2 adrenergic receptor gene polymorphisms and the response to beta-blockade in patients with stable congestive heart failure.

Previous studies have clearly demonstrated the beneficial effect of &bgr;-blockers in patients with stable congestive heart failure (CHF). &bgr;-blockers improve left ventricular ejection fraction (LVEF) and reduce cardiac mortality. However, there is an interindividual variability in the response to these agents. Two studies have suggested a possible impact of some functional &bgr;AR gene polymorphisms on the effects of &bgr;-blockade. The objective of the study is to analyse the association between genetic variations in the &bgr;1 or the &bgr;2 adrenoreceptor (AR) gene and the effects of &bgr;-blockade in patients with stable CHF. We studied 199 consecutive patients with stable CHF not treated with &bgr;-blockers. Before introduction of &bgr;-blockers and 3 months after the maximal tolerated dose was reached, patients underwent an echocardiography and a radionuclide angiography. The &bgr;1ARGly389Arg, &bgr;1ARSer49Gly, &bgr;2ARGly16Arg, &bgr;2ARGln27Glu and &bgr;2ARThr164Ile polymorphisms were determined: &bgr;-blockade resulted in a significant decrease in heart rate, a significant increase in LVEF (from 30±10% to 40±13%, P<0.0001). There was no association between the five polymorphisms and heart rate or LVEF, either before or after &bgr;-blockade. Heart rate and LVEF responses to &bgr;-blockade were not associated with the &bgr;1AR or the &bgr;2AR polymorphisms. &bgr;AR polymorphisms did not explain the interindividual variability in the response to &bgr;-blockers.

Distributions of C-reactive Protein Measured by High-Sensitivity Assays in Apparently Healthy Men and Women from Different Populations in Europe

C-reactive protein (CRP), the classic marker of acute-phase response, is an indicator of a variety of pathologic processes, including infections, tissue damage, and chronic inflammatory diseases (1)(2). The majority of more than 15 well-conducted prospective studies in initially healthy individuals have shown a strong and independent association between concentrations of CRP within the reference interval (<5 mg/L) and future major cardiovascular events (3), although in some of them, no such association could be established (4)(5)(6)(7). The summary estimate of the relative risk in formal metaanalysis was 2.0 (95% confidence interval, 1.6–2.5) (3). Furthermore, CRP has been shown to add to risk prediction beyond and above established cardiovascular risk factors (8). On the basis of data from the Physicians’ Health Study and the Nurses’ Health Study, an algorithm for risk assessment of future coronary events that combines both CRP concentration and the ratio of total cholesterol to HDL-cholesterol has recently been proposed (9). Because atherosclerosis represents a low-grade inflammatory process in the vascular bed, high-sensitivity (hs) assays are needed when using circulating CRP concentrations for risk prediction in cardiovascular diseases. Such assays have been developed and are now commercially available (10)(11). However, before screening of individuals at risk can be recommended, CRP distributions in apparently healthy adults in the general population must be known. Such information is scarce. Furthermore, in previous reports, women using oral contraceptives or receiving hormone replacement therapy (HRT), both of which have been shown to significantly increase CRP concentrations, had not been excluded (12)(13)(14)(15). In this report, we describe the frequency distribution of CRP concentrations in 13 527 adult men and women from different representative populations in Western Europe. Furthermore, for one area [the MONICA (Monitoring Trends and Determinants in …

Impact of polymorphisms of the human β2-adrenoceptor gene on obesity in a French population

OBJECTIVE: To investigate the impact of two common polymorphisms in the human β2-adrenoceptor gene (Gly16Arg and Gln27Glu substitutions) on obesity and anthropometric measurements as well as blood variables in a large sample of a French population.DESIGN AND SUBJECTS: Within the framework of the WHO-MONICA project, a population study composed of 1195 subjects aged 35–64 y was randomly sampled from the electoral rolls of the Urban Community of Lille, in northern France. Subjects without any medical treatment (for hypercholesterolaemia, hypertension or diabetes mellitus) susceptible to interfere with body weight and biological variables were selected (n=836, 419 men/417 women, age=49.5±8.1 y, body mass index (BMI)=25.7±4.4 kg/m2). Subjects with a body mass index ≥30 kg/m2 were considered as obese (n=119, age=49.5±8.2 y, BMI=33.9±3.3 kg/m2 range 30–44).MEASUREMENTS: Genotyping was carried out with allele-specific oligonucleotides hybridization. Association between genotypes and various obesity markers (body weight, body mass index, waist and waist-to-hip ratio), lipid, glucose and insulin variables were studied.RESULTS: The Gly16Arg and Gln27Glu polymorphisms were in complete linkage disequilibrium. Gln27Gln subjects had an increased risk of obesity (odds ratio (OR)=1.77, 95% CI 1.19–2.62, P=0.005). This effect was mainly detected in men (OR=2.40, 95% CI 1.34–4.27, P=0.003). Men bearing the Gln27Gln genotype had higher body weight, BMI, waist and hip circumferences and waist-to-hip ratio than others. Moreover, if Gln27Gln men carried in addition the Arg16 allele, the increase in body weight, BMI and waist-to-hip ratio was more important.CONCLUSION: Our results suggest that genetic variability of the β2-adrenoceptor gene is implicated in body weight regulation and in the onset of obesity in French men.

A Functional Polymorphism in a STAT5B Site of the Human PPARγ3 Gene Promoter Affects Height and Lipid Metabolism in a French Population

Objective—The peroxisome proliferator-activated receptor-&ggr; (PPAR&ggr;) plays a role in adipocyte differentiation and insulin sensitization. It has been shown that genetic variation in the PPAR&ggr; gene alters body weight control, lipid and insulin homeostasis, and the susceptibility to type 2 diabetes. Four PPAR&ggr; isoforms are generated by alternative splicing and promoter usage. PPAR&ggr;3 is only expressed in adipose tissue, colon, and macrophages and therefore seems to be a good candidate gene for metabolic and cardiovascular-associated diseases. In the present study, we looked for genetic variation in the PPAR&ggr;3 promoter. Methods and Results—The proximal PPAR&ggr;3 promoter was sequenced in 20 individuals. We detected a C/G polymorphism at position −681 from exon A2. Interestingly, it was located in a signal transducer and activator of transcription 5B (STAT5B) binding consensus site. In a French population (n=836), the −681G allele was associated with increased height and plasma low-density lipoprotein cholesterol concentrations. In vitro, we showed that the −681G allele completely abolished the binding of STAT5B to the cognate promoter element as well as the transactivation of the PPAR&ggr;3 promoter by the growth hormone/STAT5B pathway. Conclusions—Our results suggest that PPAR&ggr;3 may regulate the control of height and lipid homeostasis via the STAT5B pathway.

APOE genotyping and response to drug treatment in Alzheimer's disease

Although the use of apolipoprotein E (APOE) genotyping in the diagnosis of Alzheimer’s disease (AD) is controversial,’ the consensus statement on APOE genotyping in ADZ suggests that this test may be of some value in predicting response to drug treatments for AD. We carried out APOE genotyping in a multicentre, multinational, double-blind, randomised, placebo-controlled trial in AD. The drug S12024 tested in this phase IIb clinical trial facilitates brain noradrenergic and vasopressinergic activity. Experimental evidence of cognitive enhancement in animals suggested that this substance might lead to symptomatic improvement in some cases of AD. In people, the drug had a good clinical and biological safety profile, and increased speed and accuracy of response on computerised tests of memory and attention were ob~erved.~ In six countries, 404 patients with probable AD (NINCDS-ADRDA classification) were randomised to three groups: placebo, 100 mg daily of S12024, or 300 mg daily of S12024. The treatment period lasted 12 weeks. In 339 patients, the APOE genotype was done with the promise that no genetic data would be transferred back to the patient, carer, or physician whatever the circumstances. The mean (SD) age of the patients was 69-9 (7.9) years, with an age at onset of the disease of 66.6 (8.1) years. The mean (SD) Mini Mental State Examination score (MMSE) was 19.5 (3.5). No significant differences existed between the genotyped and non-genotyped patients; 60% of them carried at least one APOE ~4 allele, 14% were homozygous. The ~ 4 , ~ 3 , and ~ 2 , allele frequencies were 0.37, 0.60, and 0.03, respectively. The 300 mg daily dose produced frequent adverse effects and early withdrawals, and was not considered any further in the analyses. With an intention-to-treat analysis of the whole sample, the 100 mg daily dose did not produce results that differed from placebo. The sample was stratified for the presence or absence of the APOE ~4 allele. In those with the &4 allele,