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Biomedical subjects

G Luc

Publications and source records attributed to G Luc.

At least 19 recordsLinked to original sources

The effect of sensitisation to insulin with pioglitazone on fasting and postprandial lipid metabolism, lipoprotein modification by lipases, and lipid transfer activities in type 2 diabetic patients.

AIMS/HYPOTHESIS: Insulin resistance is thought to be central to the pathogenesis of diabetic dyslipidaemia. We hypothesised that improving insulin sensitivity would improve fasting and postprandial triglyceride metabolism in patients with type 2 diabetes. To this aim we studied fasting and postprandial lipaemia in type 2 diabetic patients before and after sensitisation to insulin with pioglitazone, compared with that observed in patients on an insulin-providing regime. METHODS: In a double-blind placebo-controlled protocol, 22 patients with type 2 diabetes were randomly allocated to receive either pioglitazone (45 mg/day) or glibenclamide (5 mg/day), for a 20-week period. Fasting and postprandial lipid metabolism were investigated at baseline and at the end of the treatment period. A group of non-diabetic subjects was also studied. RESULTS: Compared with glibenclamide treatment, pioglitazone treatment decreased fasting triglyceride, glucose and insulin levels and the homeostasis model assessment score of insulin resistance. Decreased fasting triglyceride after pioglitazone treatment was due to reduced VLDL triglyceride, particularly VLDL-2. Lipoprotein lipase activity was unchanged by pioglitazone treatment but hepatic lipase showed a significant decrease. Pioglitazone treatment lowered total postprandial triglyceride, as well as chylomicron- and chylomicron-remnant retinyl palmitate levels to normal. Glucose disposal improved but remained abnormal. CONCLUSIONS/INTERPRETATION: Insulin sensitisation with pioglitazone has major effects in restoring postprandial lipaemia to normal, while also correcting fasting hypertriglyceridaemia; both factors may have consequences for atherogenic risk in diabetes.

Blood Glucose↗

Contributions of depressive mood and circulating inflammatory markers to coronary heart disease in healthy European men: the Prospective Epidemiological Study of Myocardial Infarction (PRIME).

BACKGROUND: Data on the possible association between depressive disorders and inflammatory markers are scarce and inconsistent. We investigated whether subjects with depressive mood had higher levels of a wide range of inflammatory markers involved in coronary heart disease (CHD) incidence and examined the contribution of these inflammatory markers and depressive mood to CHD outcome. METHODS AND RESULTS: We built a nested case-referent study within the Prospective Epidemiological Study of Myocardial Infarction (PRIME) study of healthy middle-aged men from Belfast and France. We considered the baseline plasma sample from 335 future cases (angina pectoris, nonfatal myocardial infarction, coronary death) and 670 matched controls (2 controls per case). Depressive mood characterized men whose baseline depression score (13-item modification of the Welsh depression subscale) was in the fourth quartile (mean score, 5.75; range, 4 to 12). On average, men with depressive mood had 46%, 16%, and 10% higher C-reactive protein, interleukin-6, and intercellular adhesion molecule-1 levels, respectively, independently of case-control status, social characteristics, and classic cardiovascular risk factors; no statistical difference was found for fibrinogen. The odds ratios of depressive mood for CHD were 1.35 (95% CI, 1.05 to 1.73) in univariate analysis and 1.50 (95% CI, 1.04 to 2.15) after adjustment for social characteristics and classic cardiovascular risk factors. The latter odds ratio remained unchanged when each inflammatory marker was added separately, and in this analysis, each inflammatory marker contributed significantly to CHD event risk. CONCLUSIONS: These data support an association of depressive mood with inflammatory markers and suggest that depressive mood is related to CHD even after adjustment for these inflammatory markers.

Biomarkers↗

TAFI gene haplotypes, TAFI plasma levels and future risk of coronary heart disease: the PRIME Study.

OBJECTIVES: To evaluate the association of thrombin-activatable fibrinolysis inhibitor (TAFI) gene polymorphisms with the risk of coronary heart disease (CHD) and with TAFI levels measured by a newly developed enzyme-linked immunosorbent assay (ELISA) (TAFI-1B1), shown to be a reliable method for detecting quantitative variations in circulating TAFI. PATIENTS/METHODS: Six polymorphisms (C-2599G, G-438A, Ala147Thr, Thr325Ile, C + 1542G and T + 1583A) were genotyped and baseline plasma concentrations of TAFI were measured in a nested case-control design as part of the Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study. Participants from France and Northern Ireland who had developed a CHD event during a 5-year follow-up (n = 321) were compared with 645 population- and age-matched control subjects. RESULTS: In France, the Thr147 allele was more frequent in cases than in controls (0.41 vs. 0.32; P = 0.02), whereas the reverse was observed in Northern Ireland (0.33 vs. 0.38; P = 0.19) (P = 0.01 for interaction). No other polymorphism was associated with CHD risk. Consistent with the results derived from the single-locus analysis, haplotype analysis revealed that the haplotype carrying the Thr147 allele was associated with increased risk of CHD in France while the reverse tended to hold in the Northern Ireland population. Single-locus and haplotype analyses revealed that two polymorphisms, C-2599G and Ala147Thr (or T + 1583A that is in nearly complete association with it), had additive effects on TAFI levels and explained >18% of TAFI variability. This effect was homogeneous in France and Northern Ireland, and in cases and controls who exhibited similar TAFI levels. CONCLUSIONS: Thrombin-activatable fibrinolysis inhibitor gene polymorphisms are strongly associated to plasma TAFI levels, but the relation to CHD risk is less clear.

Alleles↗

Endothelial cell markers and the risk of coronary heart disease: the Prospective Epidemiological Study of Myocardial Infarction (PRIME) study.

BACKGROUND: Tissue factor pathway inhibitor (TFPI), von Willebrand factor (vWF), and thrombomodulin (TM) are 3 major hemostatic regulatory molecules synthesized by endothelium. Data from epidemiological studies aiming to evaluate the relation between plasma levels of these molecules and the development of coronary heart disease (CHD) are sparse or contradictory. METHODS AND RESULTS: We examined the association between these endothelial-cell markers and the incidence of fatal or nonfatal myocardial infarction (hard CHD) and stable or unstable angina (angina pectoris) in a prospective cohort (the PRIME Study) of nearly 10 000 healthy men recruited in France and Northern Ireland. We measured baseline plasma concentration of the free form of TFPI (f-TFPI), vWF, and the soluble form of TM (sTM) among 296 participants who subsequently developed CHD over the 5-year follow-up (158 with hard CHD and 142 with angina pectoris) and in 563 control subjects by use of a nested case-control design. Individuals with plasma vWF levels in the highest quartile showed a 3.04-fold increase in the risk of hard CHD compared with those in the lowest quartile (95% CI, 1.59 to 5.80). Individuals with f-TFPI levels below the 10th percentile had a 2.13-fold increased risk of hard CHD compared with those with levels above it (95% CI, 1.08 to 4.18). The risk for both molecules persisted after control for inflammatory parameters. Individuals with vWF levels in the highest quartile and f-TFPI levels below the 10th percentile presented a 6.9-fold increased risk of hard CHD compared with those with vWF levels in the lowest quartile and f-TFPI levels above the 10th percentile (95% CI, 1.3 to 37.8). CONCLUSIONS: vWF and f-TFPI plasma levels were independent risk factors for hard CHD events.

Angina Pectoris↗

TLR4/Asp299Gly, CD14/C-260T, plasma levels of the soluble receptor CD14 and the risk of coronary heart disease: The PRIME Study.

TLR4 and CD14 are two components of the LPS receptor complex, which are considered to play a key role in the pathogenesis of atherosclerosis. TLR4/Asp299Gly and CD14/C-260T polymorphisms are thought to modulate the activity of this complex. The aim of the study was to examine the association between the TLR4/Asp299Gly and CD14/C-260T polymorphisms, plasma levels of the soluble receptor CD14 (sCD14), and the incidence of coronary heart disease (CHD) in a prospective cohort (the PRIME Study) of 9758 healthy men aged 50-59 years recruited in France and Northern Ireland. A nested case-control design was used, comparing the 249 participants who developed a CHD event during the 5-year follow-up with 492 population- and age-matched control subjects. The two polymorphisms were genotyped and baseline plasma concentrations of sCD14 were measured. None of the two polymorphisms, or sCD14 levels, either considered alone or in combination, were associated with the risk of CHD. The CD14/C-260T allele was associated with increased plasma concentrations of soluble thrombomodulin and vascular cell adhesion molecule-1 and, to a lesser extent, sCD14. No relationship was observed between the TLR4 polymorphism and, any of the inflammatory and endothelial markers measured. The TLR4/Asp299Gly and CD14/C-260T polymorphisms and plasma sCD14 concentrations do not appear as significant predictors of the risk of CHD in healthy individuals.

Amino Acid Substitution↗

The transcriptional regulating protein of 132 kDa (TReP-132) differentially influences steroidogenic pathways in human adrenal NCI-H295 cells.

Steroid hormones synthesized from cholesterol in the adrenal gland are important regulators of many physiological processes. It is now well documented that the expression of many genes required for steroid biosynthesis is dependent on the coordinated expression of the nuclear receptor steroidogenic factor-1 (SF-1). However, transcriptional mechanisms underlying the species-specific, developmentally programmed and hormone-dependent modulation of the adrenal steroid pathways remain to be elucidated. Recently, we demonstrated that the transcriptional regulating protein of 132 kDa (TReP-132) acts as a coactivator of SF-1 to regulate human P450scc gene transcription in human adrenal NCI-H295 cells. The present study shows that overexpression of TReP-132 increases the level of active steroids produced in NCI-H295 cells. The conversion of pregnenolone to downstream steroids following TReP-132 expression showed increased levels of glucocorticoids, C(19) steroids and estrogens. Correlating with these data, TReP-132 increases P450c17 activities via the induction of transcript levels and promoter activity of the P450c17 gene, an effect that is enhanced in the presence of cAMP or SF-1. In addition, P450aro activity and mRNA levels are highly induced by TReP-132, whereas 3beta-hydroxysteroid dehydrogenase type II and P450c11aldo transcript levels are only slightly modulated. Taken together, these results demonstrate that TReP-132 is a trans-acting factor of genes involved in adrenal glucocorticoid, C(19) steroid and estrogen production.

3-Hydroxysteroid Dehydrogenases↗

[Biological banks of the prospective cohort PRIME Study].

BACKGROUND: Cardiovascular disease is the leading cause of mortality in westernized countries. Learning more about the cause of coronary heart disease (CHD) is an essential step in the search for effective CHD prevention, both at the individual and population levels. Prospective cohort studies are particularly well suited to the study of risk markers. However, the high cost of mounting such studies, along with the newer hypotheses generated during the period of follow-up necessitates the use of plasma and serum banks for analyses of many biological parameters. METHODS: The prospective, cohort PRIME Study has recruited 10,592 men, aged 50-59 years in France and Northern Ireland, to establish new risk markers for CHD. A plasma serum bank was established comprising 240,000 samples, either in straws or tubes, which have been stored in liquid nitrogen for over 5 years. The use of straws was required to store the largest number of aliquots in the smallest possible space. Storage validation was carried out for a number of key parameters. The validity of freezing of plasma in straws was established for a number of key measurements under investigation. Simultaneously, a DNA bank was set up to facilitate genetic analyses. In contrast to the DNA bank, which enables the performance of a very large number of analyses on a small amount of material, the plasma/serum bank has to be managed very frugally, requiring laboratories to use the smallest volume possible in each analysis. RESULTS AND CONCLUSION: Problems and difficulties solved during building and use of biological banks are presented. The initial results obtained using this plasma bank have demonstrated its validity.

Blood Banks↗

Haemostasis in relation to dietary fat as estimated by erythrocyte fatty acid composition: the prime study.

We investigated whether haemostatic variables were related with dietary fatty acid composition as estimated by the fatty acid content of erythrocytes. Subjects were a subsample (n=283) of the participants in the Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study. Factor VII, fibrinogen, tissue-type plasminogen activator antigen (tPA-ag), plasminogen activator inhibitor type 1 (PAI-1), D-dimer and von Willebrand factor (vWf) were measured and the fatty acid composition was determined in the phospholipids of total erythrocytes by gas chromatography. Statistical analyses were performed using multiple linear regression analyses with adjustment for age, center and body mass index. tPA-ag was significantly related to the n-3 fatty acids derived from fish. This was reflected in an inverse association of all n-3 fatty acids combined with tPA-ag (beta=-0.37 ng/ml/%, 95% confidence intervals: -0.45, -0.29, P<.01). Positive and significant associations of D-dimer with arachidic and eicosamonoenoic acid were observed (P<.01). No relationships were found between fatty acids and fibrinogen, vWf, PAI-1 or factor VII. The results of this study suggest that consumption of n-3 fatty acids derived from fish may favourably influence tPA-ag.

Body Mass Index↗

Induction of the phospholipid transfer protein gene accounts for the high density lipoprotein enlargement in mice treated with fenofibrate.

Fibrate treatment in mice is known to modulate high density lipoprotein (HDL) metabolism by regulating apolipoprotein (apo)AI and apoAII gene expression. In addition to alterations in plasma HDL levels, fibrates induce the emergence of large, cholesteryl ester-rich HDL in treated transgenic mice expressing human apoAI (HuAITg). The mechanisms of these changes may not be restricted to the modulation of apolipoprotein gene expression, and the aim of the present study was to determine whether the expression of factors known to affect HDL metabolism (i.e. phospholipid transfer protein (PLTP), lecithin:cholesterol acyltransferase, and hepatic lipase) are modified in fenofibrate-treated mice. Significant rises in plasma PLTP activity were observed after 2 weeks of fenofibrate treatment in both wild-type and HuAITg mice. Simultaneously, hepatic PLTP mRNA levels increased in a dose-dependent fashion. In contrast to PLTP, lecithin:cholesterol acyltransferase mRNA levels in HuAITg mice were not significantly modified by fenofibrate despite a significant decrease in plasma cholesterol esterification activity. Fenofibrate did not induce any change in hepatic lipase activity. Fenofibrate significantly increased HDL size, an effect that was more pronounced in HuAITg mice than in wild-type mice. This effect in wild-type mice was completely abolished in PLTP-deficient mice. Finally, fenofibrate treatment did not influence PLTP activity or hepatic mRNA in peroxisome proliferator-activated receptor-alpha-deficient mice. It is concluded that 1) fenofibrate treatment increases plasma phospholipid transfer activity as the result of up-regulation of PLTP gene expression through a peroxisome proliferator-activated receptor-alpha-dependent mechanism, and 2) increased plasma PLTP levels account for the marked enlargement of HDL in fenofibrate-treated mice.

Animals↗

Interleukin-6 gene polymorphisms and susceptibility to myocardial infarction: the ECTIM study. Etude Cas-Témoin de l'Infarctus du Myocarde.

There is growing evidence that interleukin (IL) 6 plays an important role in the atherosclerotic process because of its role in mediating immune and inflammatory responses and inducing cell proliferation. The present study examined whether molecular variations at the IL-6 locus are involved in the predisposition to myocardial infarction. The entire coding region, 1,158 bp of the 5' flanking region and 237 bp of the 3' flanking region of the IL-6 gene were screened. We detected three nucleotide substitutions in the 5' region at positions -174 (G/C), -572 (G/C), and -596 (G/A) from the transcription start site, and one insertion/deletion in the 3' region at position +528 after the Stop codon. These polymorphisms were genotyped in the Etude Cas-Témoin de l'Infarctus du Myocarde study comparing male patients (n=640) and age-matched controls (n=719) from Northern Ireland and France. The IL-6/G-174C and IL-6/G-596A polymorphisms were in nearly complete association. Carriers of the IL-6/-174 C allele were more frequent in patients than in controls. The population-adjusted odds ratio for myocardial infarction associated with genotype CC+CG vs. GG was estimated as 1.34. In French patients the number of coronary arteries with greater than 50% stenosis was assessed by angiography. The IL-6/-174 C allele was more frequent in patients with two or fewer stenosed vessels than in patients with three-vessel lesions. These results suggest that genetic variation at the IL-6 locus is associated with susceptibility to myocardial infarction, especially events occurring on less extended lesions. These findings would be compatible with a lower IL-6 secretion associated with the IL-6/-174 C allele, itself or in combination with other promoter polymorphisms, leading to more unstable plaques.

Adult↗

Relationships between alcoholic beverages and cardiovascular risk factor levels in middle-aged men, the PRIME Study. Prospective Epidemiological Study of Myocardial Infarction Study.

The relationships between alcoholic beverages and cardiovascular risk factors were assessed in 6730 men living in France or Northern Ireland. In France, all alcoholic beverages were significantly correlated with body mass index (BMI), systolic (SBP) and diastolic blood pressure (DBP), high density lipoprotein (HDL) parameters, PAI-1 and Factor VII, whereas only wine was negatively related with fibrinogen levels. After adjusting for center, age, BMI, educational level, smoking and marital status, wine had a lesser effect on blood pressure, triglyceride, apo B and LpE:B levels than beer. Wine was associated with lower fibrinogen levels and beer with higher PAI-1 activity levels independent of the amount of alcohol consumed. In Northern Ireland, wine was negatively correlated with BMI, triglycerides, LpE:B and fibrinogen, whereas beer was positively correlated with SBP and DBP, triglycerides, HDL, apoprotein A-I and fibrinogen. Multivariate analysis showed wine to be positively associated with HDL parameters, and negatively with fibrinogen levels. Wine was also associated with higher LpA-I levels and lower fibrinogen levels independent of the amount of alcohol consumed. We conclude that alcohol consumption is related to lipid, lipoprotein and haemostatic variables, but the magnitude of the relationships depends on the type of alcoholic beverage. Also, some effects might be related to non-alcoholic components.

Alcohol Drinking↗

Associations between classical cardiovascular risk factors and coronary artery disease in two countries at contrasting risk for myocardial infarction: the PRIME study.

PURPOSE: In two countries with contrasting risk for coronary artery disease (CAD)-Northern Ireland and France-a case-control study was performed on baseline data within a cohort study to compare the strength of the associations between CAD prevalence and classical risk factors. METHOD AND RESULTS: A sample of 9561 men, aged 50-60 years, was studied: 382 had had myocardial infarction or angina, and 9179 were controls. In both countries, variables associated with CAD were age, body mass index, hypertension, diabetes, family history of myocardial infarction (MI), tobacco consumption, triglycerides, HDL-cholesterol, apolipoprotein A-I and B levels. Logistic regression analyses were conducted using standardized odds ratios. The strength of the associations with CAD was rather similar in the two countries (Northern Ireland versus France) for age [1.26 (1.10-1. 45) vs. 1.41 (1.17-1.69)], family history of MI [1.50 (1.04-2.15) vs. 1.83 (0.99-3.37)], hypertension [1.49 (1.13-1.97) vs. 1.67 (1.14-2. 44)], diabetes [5.42 (2.53-11.60) vs. 2.24 (1.06-4.73)], tobacco consumption [1.43 (1.27-1.60) vs. 1.39 (1.22-1.58)], HDL-cholesterol [0.80 (0.68-0.94) vs. 0.86 (0.70-1.06)] and triglyceride levels [1. 17 (1.01-1.36) vs. 1.10 (0.91-1.32)]. Discrepancies concerned lipoprotein(a) [1.22 (1.06-1.40) vs. 0.96 (0.81-1.15), P<0.01], with stronger associations in Northern Ireland than in France. CONCLUSION: It is concluded that the higher prevalence of CAD in Northern Ireland cannot be explained by major differences in the susceptibility to classical risk factors; the difference in risk of CAD appears mainly related in Northern Ireland to other risk factors including a worse lipid profile and genetic/environmental interactions.

Apolipoproteins↗

Independent association of an APOE gene promoter polymorphism with increased risk of myocardial infarction and decreased APOE plasma concentrations-the ECTIM study.

Apolipoprotein E (APOE) is a major protein in lipid metabolism existing in three common isoforms: APOE2, -3 and -4. The varepsilon4 allele of the APOE gene ( APOE ) coding for the APOE4 isoform is associated with an increased risk of myocardial infarction (MI) and of Alzheimer's disease (AD). Recently, several polymorphisms in the APOE regulatory region have been reported. Some of these have been associated with AD and modified APOE allelic mRNA expression in AD brains. Here, we have investigated whether three of these promoter polymorphisms (-491AT, -427CT and -219GT) can also modify cardiovascular risk. The hypothesis was tested in a large multicentre case-control study of MI, the ECTIM Study, on 567 cases and 678 controls. Among the three APOE promoter polymorphisms tested, only the-219T allele was associated with a significantly increased risk of MI (OR = 1.29, 95% CI: 1.09-1.52, P < 0.003) and the effect was shown to be independent of the presence of the other mutations, including the APOE epsilon2/epsilon3/epsilon4 polymorphism. Moreover, the-219T allele greatly decreased the APOE plasma concentrations in a dose-dependent manner ( P < 0.008). These data indicate that the-219GT polymorphism of the APOE regulatory region emerges as a new genetic susceptibility risk factor for MI and constitutes another common risk factor for both neurodegenerative and cardiovascular diseases.

Adult↗

Extensive association analysis between the CETP gene and coronary heart disease phenotypes reveals several putative functional polymorphisms and gene-environment interaction.

An extensive association analysis of a candidate gene for coronary heart disease, Cholesteryl Ester Transfer Protein (CETP) gene, was performed. Ten polymorphisms, out of which three were newly identified in regulatory regions, were investigated for association with myocardial infarction (MI) and 2 MI endophenotypes (CETP mass and HDL-cholesterol level) in 568 MI patients and 668 controls. The polymorphisms affecting codon 405 (Ile(405)Val) and the nucleotide 524 downstream from the stop codon (G(+524)T) were almost completely concordant and associated with plasma CETP mass (P < 0.001). The polymorphisms -629 (located in promoter), intron1 (Taq1B) and intron7 were almost completely concordant and associated with plasma CETP mass (P < 0.0001) and HDL-cholesterol levels (P < 0.0001). This latter association was not found in teetotalers and increased with the quantity of alcohol consumed. Heavy drinkers (>75g/day) homozygous for the (-628)A allele had a reduced risk of MI (OR = 0. 33, P < 0.02). Subjects both homozygous for (451)Arg and heterozygous for (373)Pro had decreased plasma HDL-cholesterol levels and this effect increased with alcohol consumption. The results illustrate the complexity of polymorphism-phenotype associations. They suggest that the CETP gene may carry several functional polymorphisms. Observed interactions between alcohol consumption and polymorphisms associated with HDL-cholesterol level constitute concrete examples of gene-environment interactions. Furthermore, the pattern of association between HDL-cholesterol levels and the polymorphisms at codons 373 and 451 illustrated how two polymorphisms may be confounders (in the usual epidemiological sense) one for the other: their marginal effects are neutralized because of linkage disequilibrium and thus are not detectable by standard univariate association analysis.

Adult↗

Identification of two polymorphisms in the early growth response protein-1 gene: possible association with lipid variables.

Early growth response factor (EGR)-1 may play an important role in the development of atherosclerosis by inducing the expression of several relevant genes which contribute to the complex modulation of vascular structure and function, leading to vascular occlusive lesions. To investigate the possible role of molecular variants in the human EGR-1 gene for the predisposition to atherosclerosis or coronary heart disease we screened the 5'- and 3'- flanking regions and the entire coding sequence for polymorphisms by polymerase chain reaction/single-strand conformation polymorphism analysis and sequencing. Male patients (n=615) with myocardial infarction and 720 age-matched, male control subjects of the Etude Cas-Témoin de l'Infarctus du Myocarde were genotyped for two newly identified polymorphisms in the 5'- (C-151T) and 3'- (T+861C) flanking region of the EGR-1 gene using hybridization with allele-specific oligonucleotides. Allele and genotype frequencies did not significantly differ between patients with myocardial infarction and control subjects without coronary heart disease. In controls not taking hypolipidemic drugs there was a significant association of the -151T allele with lower plasma levels of total cholesterol (P=0.029), low-density lipoprotein cholesterol (P=0.025) and apolipoprotein B (P=0.038) and a higher ratio of high-density to low-density lipoprotein (P=0.049) than with the C-151 allele. We conclude that the C-151T polymorphism of the EGR-1 gene may contribute to modifications of the lipid metabolism. Our findings need to be replicated in independent studies, and in vitro promoter studies should evaluate the functional consequence of the -151T allele, which disrupts a consensus core sequence for the ubiquitous transcription factor activator protein 4.

Adult↗

Polymorphisms in the genes encoding platelet-derived growth factor A and alpha receptor.

Platelet-derived growth factors (PDGFs) may play an important role in the development of atherosclerosis acting as chemoattractants and mitogens for vascular smooth muscle cells and macrophages. Three dimeric forms of PDGF (AA, AB, BB) have different activities due to distinct binding properties mediated by two types of PDGF receptors (Ralpha, Rbeta). To investigate the possible contribution of molecular variants in the human PDGF-A and PDGF-Ralpha genes to coronary heart disease we screened these genes for polymorphisms by polymerase chain reaction/single-strand conformation polymorphism analysis. A total of 600 men with myocardial infarction and 717 age-matched male controls from four populations in Northern Ireland and France (the ECTIM Study) were gneotyped for newly identified polymorphisms in the genes encoding PDGF-A (C-26IN3T, H69H, C+12IN5T) and PDGF-Ralpha [-1630 I/D (+/-AACTT), A-1506G, C-1390G, G-956A, C-908A, G-793T, +69 I/D (+/-GA)] using allele-specific oligonucleotides. All PDGF-Ralpha polymorphisms, except C-908A, involving a nucleotide change in a common consensus site for GCF and SP-1 transcription factors, were in nearly complete association, generating two major haplotypes. The PDGF-A and PDGF-Ralpha polymorphisms provided a heterozygosity of 0.69 and 0.40, respectively. Genotype and allele frequencies of the PDGF-A and PDGF-Ralpha polymorphisms did not differ between patients with myocardial infarction and controls in either country. None of the polymorphisms investigated was associated with blood pressure, coronary artery stenosis, or any biochemical parameter available in the ECTIM Study.

Adult↗