Enrico Hoffmann

Role of the pyrin M694V (A2080G) allele in acute myocardial infarction and longevity: a study in the Sicilian population

A proinflammatory genotype seems to contribute significantly to the risk of developing coronary heart disease (CHD). Conversely, the susceptibility alleles to inflammatory disease should be infrequent in the genetic background favoring longevity. In fact, in a modern environment, attainment of longevity is facilitated by an anti‐inflammatory status. To evaluate whether inflammatory alleles of pyrin, the gene responsible for familial Mediterranean fever (FMF) may play an opposite role in CHD and in longevity, we examined three FMF‐associated mutations, M694V (A2080G), M694I (G2082A), and V726A (T2177C), encoded by the FMF gene (MEFV) in 121 patients affected by acute myocardial infarction (AMI), in 68 centenarians, and in 196 age‐matched controls from Sicily. None of the Sicilian subjects studied carried the V726A and the M694I FMF‐related mutations. The proinflammatory M694V (A2080G) mutation was the only one we found, which was over‐represented significantly in CHD patients and under‐represented in oldest old, and intermediate values were in healthy, young controls. After adjustment for well‐recognized AMI risk factors, the M694V allele still predicted a significant risk to develop AMI. So, according to these results, we suggest that carrying the proinflammatory M694V pyrin allele may increase the risk to develop AMI. Conversely, the wild‐type pyrin genotype may predispose to a greater chance to live longer in a modern environment with reduced pathogen load and improved control of severe infections by antibiotics. All these data indicate a strong relationship among inflammation, genetics, CHD, and longevity.

Interleukin-6 gene polymorphism is an age-dependent risk factor for myocardial infarction in men.

Several studies show that inflammatory components may contribute to atherosclerosis and increase the risk for myocardial infarction (MI). Interleukin‐6 (IL‐6) is a key pro‐inflammatory and immune‐modulatory cytokine of relevance for cardiovascular diseases. In this case‐control study, 200 patients with MI and 257 healthy controls were genotyped for the polymorphism present in −174 promoter region of the IL‐6 gene. Plasma concentrations of IL‐6 and C‐reactive protein (CRP) in a group of patients and controls were measured. The −174 C allele was associated with an increased risk of developing MI (OR = 2.886, c.i. = 1.801–4.624, P = 0.0001) in older patients, while no association was found in younger ones. The IL‐6 plasma levels were higher in patients with MI carrying the CC genotype than in GG patients (CC carriers, IL‐6 = 2.97 pg mL−1 vs. GG carriers = 1.81 pg mL−1, P = 0.016). A positive correlation of IL‐6 levels with those of CRP in serum from patients with MI was also found. Data from this study suggest that the C allele of the promoter polymorphism in the IL‐6 gene is a risk factor for MI in the elderly, and the production of the IL‐6 is differentially affected by different genotypes of the IL‐6 −174 promoter polymorphism.

Plasma endothelin-1 levels in patients with angina pectoris and normal coronary angiograms

BACKGROUND Some patients with typical angina and electrocardiographic evidence of ischemia have normal coronary angiograms. These patients have a reduced coronary flow reserve and abnormal endothelium-dependent vasodilator responses; this syndrome is known as microvascular angina. Among endothelium-derived peptides, endothelin-1 (ET-1) is a potent vasoconstrictor and an important modulator of microvascular function. METHODS Plasma ET-1 was measured in 13 patients with typical angina, instrumental evidence of ischemia, and normal arteriograms and in 20 normal control subjects. RESULTS Mean concentration of ET-1 was 2.89+/-1.24 pmol/L in patients with angina and normal angiograms and 1.99+/-0.81 pmol/L in normal control subjects (p < 0.02). Plasma levels of ET-1 values were significantly higher in patients with angina, positive exercise test results for ischemia, and normal coronary arteriograms compared with the group of patients with no clinical or instrumental evidence of ischemia. CONCLUSIONS This is consistent with the hypothesis that in patients with microvascular angina, an endothelial dysfunction in the coronary vascular area caused by impaired endothelium-derived ET-1 could play an active role in the disease process.

Opposite role of pro-inflammatory alleles in acute myocardial infarction and longevity: results of studies performed in a Sicilian population.

Abstract:  The major trait characterizing offspring in centenarians is a reduction in the prevalence of cardiovascular disease. Because a pro‐inflammatory genotype seems to contribute significantly to the risk of coronary heart disease, alleles associated with disease susceptibility would not be included in the genetic background favoring longevity, as suggested by our previous studies on inflammatory cytokines. To confirm whether genotypes of inflammatory molecules play an opposite role in atherosclerosis and longevity, we are studying the role of other proinflammatory alleles, such as pyrin and CCR5, in acute myocardial infarction and longevity. The results support the hypothesis that the genetic background favoring cardiovascular diseases is detrimental to longevity. In addition, they suggest that the centenarian genetic background may be useful for investigating genetic key components of age‐associated diseases that are characterized by a multifactorial etiology.

Association between +1059G/C CRP polymorphism and acute myocardial infarction in a cohort of patients from Sicily: a pilot study.

Abstract:  Inflammation plays a role in all the phases of atherosclerosis, and increased production of the acute‐phase reactant, C‐reactive protein (CRP), predicts future cardiovascular events. Furthermore, CRP has been claimed to play a role in the pathogenesis of atherosclerosis; therefore, CRP polymorphisms might be associated with acute myocardial infarction (AMI). We have analyzed male patients affected by AMI and healthy age‐related male controls from Sicily for +1059G/C CRP single‐nucleotide polymorphism (SNP). There was a significantly higher frequency of +1059C SNP (P= 0.0008; OR 3.86) in patients compared to controls. CRP serum levels were significantly higher in C+ healthy subjects rather than in C− subjects (P= 0.0075). The results of the present pilot case–control study performed in a homogeneous caucasoid population suggest that +1059C CRP gene SNP is associated with AMI. In any case, the results of the present study should add to the growing body of evidence on the role of pro‐inflammatory genotypes in unsuccessful aging, determining susceptibility to immune‐inflammatory diseases such as coronary heart disease.

Role of genetic polymorphisms in myocardial infarction at young age.

Acute myocardial infarction (AMI) in young adult presents a typical pattern of risk factors, clinical, angiographic and prognostic characteristics. In the last years we demonstrated that hemorheological profile is altered in these patients in a persistent way and independently of the number of risk factors and of the extent of coronary lesions. Thus, the hyperviscosity syndrome following AMI could be considered an intrinsic characteristic of these patients. Consequently it is possible to hypothesise the presence of a genetic background at the origin of this predisposition. If this background is able to influence the risk of ischemic heart disease, this should be particularly evident in young subjects. Since inflammatory mechanisms play a central role in mediating all phases of atherosclerosis, genes encoding for inflammatory or anti-inflammatory molecules are candidates for the risk of developing atherosclerosis. As atherosclerosis is the first cause of mortality in Western countries and if pro-inflammatory genotypes contribute to risk of coronary heart disease, alleles associated to disease susceptibility should not be included in the genetic background favouring longevity: People genetically predisposed to a weak inflammatory activity have fewer chances to develop cardiovascular disease and, therefore, have better chance for a long-life. According to this hypothesis, we studied in our population of young patients with AMI, the distribution of some polymorphisms influencing a inflammation and found an higher prevalence of pro-inflammatory polymorphisms (SNP A2080G of pyrin gene, SNP Gly670Arg of PECAM gene, C1019T of Cx 37 gene, SNP G1059C of PCR gene) and a lower prevalence of anti-inflammatory polymorphisms (Asp299Gly of TLR4 gene, SNP -1082 G/A of IL10 gene, CCR5Δ32). Results of these studies show that early myocardial infarction could be associated with a genetic predisposition to an intense inflammatory response, associated also to an hyperviscosity syndrome.

Association between HFE mutations and acute myocardial infarction: a study in patients from Northern and Southern Italy.

There is interest in the role of iron in age-related diseases such as atherosclerosis. Tissue iron deposition could be harmful, because Fe(2+) can react with H(2)O(2) to form OH(-) radicals and Fe(2+) can react with O(2) to form reactive oxygen species. Free radicals react with cell membranes and cell organelles and could lead to the development of atherosclerosis by initiating lipid peroxidation. Hereditary hemochromatosis provides an opportunity for studying the effects of iron on cardiovascular disease. Some studies have shown that individuals who carried HFE mutations may be at greater risk of developing coronary heart disease than those without the mutations. In contrast, a large number of studies have reported no association between HFE mutations and coronary heart disease. These studies have possible confounding factors, such as the homogeneity of the population in term of geographical origin among others. We studied the relation between HFE mutations and acute myocardial infarction in two case-control studies involving two sets of subjects representing different age groups from different geographic regions in Italy. The first one was composed of 172 older patients (139 males and 33 females; mean age 67) and 207 healthy controls (91 males and 116 females; mean age 46) from Emilia-Romagna. The second one was composed of younger 77 patients (75 males and 2 females; mean age 41) and 172 healthy controls (75 males and 97 females, mean age: 38) from Sicily. All patients were genotyped for ApoE alleles, since the ApoE- epsilon 4 allele is considered a risk factor for cardiovascular diseases and can interfere with other genetic and environmental factors by modifying susceptibility to this disease. DNA typing for C282Y and H63D HFE alleles was performed also. There were no significant differences in frequencies of the different HFE alleles between acute myocardial infarction patients and controls in cohorts of both old and young patients. Also taking into account the presence or absence of the ApoE- epsilon 4 allele, no significant differences in H63D allele frequencies were observed. Thus, our study, performed in two samples of genetically homogeneous patients and controls, does not support the suggestion that HFE mutations may be associated with acute myocardial infarction in susceptible individuals.

Circulating endothelin-1 levels in type 2 diabetic patients with ischaemic heart disease

To investigate whether circulating endothelin-1 (Et-1) may be related to the increased incidence and severity of ischaemic heart disease in type 2 diabetes mellitus, we compared the concentrations in type 2 diabetic patients and in non-diabetic patients with coronary artery disease (CAD) angiographically documented. Plasma levels of Et-1 were determined in 34 type 2 diabetic patients with CAD (16 with stable angina, 6 with unstable angina, 12 with previous myocardial infarction) and in 19 non-diabetic patients with CAD (4 with stable angina, 5 with unstable angina, 10 with previous myocardial infarction). Fifteen diabetic patients without CAD and 9 healthy volunteers served as control subjects. In the type 2 diabetic patients, the mean Et-1 levels were 3.19±1.61 pmol/l in those with stable angina, 3.58±1.92 pmol/l in those with unstable angina, 4.24±2.53 pmol/l in those with myocardial infarction. These values were not significantly different one another, nor from the values obtained from type 2 diabetic controls (3.64±2.13 pmol/l). In the non-diabetic patients, the mean Et-1 levels were 3.92±0.73 pmol/l in those with stable angina, 4.35±1.67 pmol/l in those with unstable angina, 4.33±1.66 pmol/l in those with myocardial infarction. These values were not significantly different one another, but significantly higher than those obtained from healthy controls (2.07±0.67 pmol/l;P<0.001). No significant differences were found in Et-1 levels between diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction. In contrast, a statistically significant difference was found in Et-1 levels between diabetic and non-diabetic control subjects (P<0.05). In conclusion, similar raised concentrations of Et-1 in diabetic and non-diabetic patients with stable, unstable angina and previous myocardial infarction do not support the hypothesis that higher levels of Et-1 in diabetic patients are responsible for the increased incidence of CAD in diabetes mellitus. However, the raised Et-1 levels found in diabetic patients in the absence of CAD strongly suggest that a generalised endothelial dysfunction, documented in our study by increased levels of Et-1, most probably precedes subsequent cardiovascular diseases.

Role of proinflammatory alleles in longevity and atherosclerosis: results of studies performed on -1562C/T MMP-9 in centenarians and myocardial infarction patients from Sicily.

Abstract:  Centenarians are characterized by marked delay or escape from age‐associated diseases that cause mortality at earlier ages. Jointly, atherosclerosis and its complications, such as myocardial infarction (AMI), significantly contribute to mortality in the elderly. Inflammation is a key component of atherosclerosis and inflammatory genes are good candidates for the risk of the development of atherosclerosis. Genetic traits contribute to the risk of AMI and allelic variations in inflammatory genes should boost the risk of disease. If proinflammatory genotypes significantly contribute to the risk of AMI, alleles associated with disease susceptibility should not be included in the genetic background favoring longevity. Hence, genotypes of natural immunity should play an opposite role in atherosclerosis and longevity. Metalloproteinase (MMPs) are involved in tissue remodeling and therefore play a remarkable role in inflammation‐based disease. MMPs are a family of Zn2+‐dependent enzymes with proteolytic activity against connective tissue proteins such as collagens, proteoglycans, and elastin, which appear to play important roles in the development and progression of the atherosclerotic lesion. There is evidence indicating a role played by the MMPs in the weakening of atherosclerotic plaque which predisposes to lesion disruption. In this study we performed a genetic study on −1562C/T MMP‐9 single nucleotide polymorphism (SNP) in order to discern a possible role in AMI. We analyzed the distribution of this SNP in 115 AMI patients, 123 controls, and 34 centenarians from Sicily. We found no significant differences in the genetic distribution and allelic frequency of −1562C/T MMP‐9 SNP between the studied groups. The present results are not in agreement with our previous findings, strengthening our hypothesis that genetic background protection against cardiovascular disease is a relevant component of the longevity trait, at least in the generation of Italian male centenarians under study. However, present results do not exclude that differential expression of MMP‐9 playing an opposite role in AMI and longevity because other kinds of regulation might be more relevant than those linked to the SNP under study.

Pro-inflammatory gene variants in myocardial infarction and longevity: implications for pharmacogenomics.

Inflammation and genetics play an important role in the pathogenesis of coronary heart disease (CHD). However, despite the increasing appreciation of the role of genetics in CHD and myocardial infarction (MI) pathogenesis, pharmacogenomic approaches to uncover drug target have not been extensively explored. Cyclo-oxygenases (COXs) and 5-lipoxygenase (5-LO) are the key enzymes in the conversion of arachidonic acid to prostaglandins (PG) and leukotrienes (LT) and are implicated in a wide variety of inflammatory disorders, including atherosclerosis. In fact, PGE2 activates Matrix Metallo-proteinases whereas LTB4 is a chemoactractant for monocytes and activates gene expression in inflammatory cells. We have tested the hypothesis that anti-inflammatory variants of these genes confer genetic resistance to MI and conversely favour longevity. So, we analyzed MI patients, age-related controls and centenarians. The pro-inflammatory alleles of COX-2 and 5-LO were overrepresented in MI and under-represented in centenarians whereas age-related controls displayed intermediate values. MI is a multifactorial disease, hence MI might be the result of a cumulative effect which contributes with different timing to achieve a threshold where the chance to develop the diseases is very high. In particular, differences in inflammatory status can contribute to the chance of developing a risk phenotype. However, these studies might contribute to the determination of a risk profile which may allow both the early identification of individuals susceptible to disease and the possible discovery of potential targets for drug.