APOE and Alzheimer disease: a major gene with semi-dominant inheritance.

Apolipoprotein E (APOE) dependent lifetime risks (LTRs) for Alzheimer Disease (AD) are currently not accurately known and odds ratios alone are insufficient to assess these risks. We calculated AD LTR in 7351 cases and 10 132 controls from Caucasian ancestry using Rochester (USA) incidence data. At the age of 85 the LTR of AD without reference to APOE genotype was 11% in males and 14% in females. At the same age, this risk ranged from 51% for APOE44 male carriers to 60% for APOE44 female carriers, and from 23% for APOE34 male carriers to 30% for APOE34 female carriers, consistent with semi-dominant inheritance of a moderately penetrant gene. Using PAQUID (France) incidence data, estimates were globally similar except that at age 85 the LTRs reached 68 and 35% for APOE 44 and APOE 34 female carriers, respectively. These risks are more similar to those of major genes in Mendelian diseases, such as BRCA1 in breast cancer, than those of low-risk common alleles identified by recent GWAS in complex diseases. In addition, stratification of our data by age groups clearly demonstrates that APOE4 is a risk factor not only for late-onset but for early-onset AD as well. Together, these results urge a reappraisal of the impact of APOE in Alzheimer disease.

Tumor necrosis factor-alpha antagonists: differential clinical effects by different biotechnological molecules.

Inhibitors of tumor necrosis factor-alpha have deeply changed the therapy of several inflammatory human diseases. For instance, clinical management of rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis have profoundly benefited after the introduction of new therapeutic tools, such as antagonist of TNF-alpha molecule. These drugs include etanercept, a soluble TNF-alpha receptor antagonist, three anti-TNF-alpha antibodies, adalimumab, infliximab, golimumab and certolizumab a humanized Fab fragment combined with polyethylene glycol. These compounds efficiently inhibit several TNF-alpha biological-mediated effects, however, they have also shown differential clinical efficacy in several trials from different autoimmune diseases. It is of clinical relevance that non-responders to one of these drugs often positively responded to another. Different mechanisms of action and diversity in pharmacokinetics of these three compounds may partially explain different clinical effects. However, partially diverse pathogenetic mechanisms in different diseases also contribute to differential therapeutic responses. Therefore, these apparently homogeneous agents can not be considered equivalent in their clinically efficacy. Differential therapeutic actions of these drugs may be advantageously used in clinical practice and further improve the great potential of individual TNF-alpha inhibitors.

Altered vessel signalling molecules in subjects with Downs syndrome.

Downs syndrome (DS) is the most frequent human chromosomal abnormality and is associated with mental retardation. Some evidence indicates that certain inflammatory molecules may be increased in DS. Proinflammatory and vasoactive molecules in the blood of non demented subjects with DS were measured in the present investigation. Plasma levels of interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1) and C reactive protein (CRP) were measured in child (2-14 years), adult (20-50 yrs) and elderly (> 60 yrs) DS subjects. Increased plasma levels of IL-6 and MCP-1 were present in DS. Plasma levels of VEGF were increased only in DS adults. Positive linear correlation between IL-6 and MCP-1 levels was present. However, no subclinical inflammation was apparent in DS, since neopterin and CRP levels were within the normal range. An altered regulation of these molecules might interfere with some processes involved in cognitive performances of DS subjects.

Genetic factors regulating inflammation and DNA methylation associated with prostate cancer.

BACKGROUND: Prostate cancer (PCa) displays a strong familiarity component and genetic factors; genes regulating inflammation may have a pivotal role in the disease. Epigenetic changes control chromosomal integrity, gene functions and ultimately carcinogenesis. The enzyme glycine-N-methyltransferase (GNMT) contributes to S-adenosylmethionine level regulation and, by affecting DNA methylation, influences gene expression. The genotype and allele distribution of single-nucleotide polymorphisms (SNPs) in the promoter regions of vascular endothelial growth factor (VEGF), interleukin (IL)-10, IL-1ß, alpha-1-antichymotrypsin (ACT) and GNMT genes, the level of global DNA methylation and the influence of GNMT SNP upon DNA methylation in a PCa case-control study have been investigated. METHODS: SNPs of VEGF (rs699947), ACT (rs1884082), IL-1ß (rs16944), IL-10 (rs1800896) and GNMT (rs9462856) genes were assessed by PCR or by real-time PCR methods. DNA methylation was assessed by an ELISA assay. RESULTS: Frequencies of the VEGF AA genotype, the IL-10 A allele and GNMT T allele were higher in PCa. The concomitant presence of the AA genotype of VEGF, the A allele of IL-10 and T allele of GNMT increased the risk of PCa. Total DNA methylation was decreased in PCa; control GNMT T carriers (T+) showed the highest level of DNA methylation. CONCLUSIONS: SNPs in VEGF, IL-10 and GNMT genes might have a synergistic role in the development of PCa. The GNMT T allele may influence PCa risk by affecting DNA methylation and prostate gene expression. Our observations might help implement the screening of unaffected subjects with an increased susceptibility to develop PCa.

Gene-gene and gene - clinical factors interaction in acute myocardial infarction: a new detailed risk chart.

AIMS: The complex pathogenesis of acute myocardial infarction (AMI) implicates phenotypic and genetic heterogeneity. In this pilot case-control study single nucleotide polymorphism (SNP) in several inflammatory genes, such as interleukin (IL)-1beta, IL-6, IL-10, alpha-1-antichymotrypsin (ACT), tumor necrosis factor alpha (TNF)-alpha and interferon gamma (IFN)-gamma genes along with SNPs of genes regulating vascular functions (vascular endothelial growth factor; VEGF) and cholesterol synthesis (hydroxy-methyl-glutaryl CoA reductase; HMGCR) were investigated. METHODS: Patients were genotyped with RT-PCR technique and data were analyzed with a new mathematical algorithm named Auto Contractive Map. RESULTS: The Auto Contractive Map (AutoCM), was applied in AMI patients with the aim to detect and evaluate the relationships among genetic factors, clinical variables and classical risk factors. Genes were selected because their strong regulatory effect on inflammation and SNP in these gene were located in the promoter region. In the connectivity map generated by AutoCM a group of variables was directly linked with the AMI status; these were: gender (male), early age at onset (50-65 years), HMGCR gene (CC wild type genotype), IL-1betaCT, IL-6 GG and VEGF CC genotypes. This direct link suggested a possible pathogenetic association with AMI. Other genetic, clinical and phenotypic variables were associated to the disease under a statistically defined hierarchy showed in the new connectivity map generated by AutoCM. CONCLUSION: These analyses suggested that genotypes of few inflammatory genes, a SNP in HMGCR gene, middle age, gender, low HDL and diabetes were very informative variables to predict the risk of AMI.

Elevated plasma levels of alpha-1-anti-chymotrypsin in age-related cognitive decline and Alzheimer's disease: a potential therapeutic target.

alpha-1-antichymotrypsin (ACT), is an acute phase protein and a protease inhibitor produced by the liver and brain. ACT is involved in the pathogenesis of Alzheimer's disease (AD), since elevated ACT concentration was found in cerebrospinal fluid (CSF) and brain from AD. ACT has also been shown to influence amyloid deposition in vitro and in animal models of AD. In this investigation 830 healthy controls, 69 subjects with cognitive impairment and not dementia (CIND), 53 patients with severe clinical AD and 142 patients with mild AD were investigated. Plasma levels of ACT were measured with a new competitive immune enzyme linked immune-assay (ELISA). ACT levels were higher in AD patients than in CIND or controls. An age dependent increase of plasma ACT was present in both healthy elderly and CIND. Patients with mild clinical AD were followed up for two years and stratified according to the rate of clinical deterioration. CT plasma levels were elevated in AD patients that showed an accelerated rate of cognitive deterioration during the follow up; this increment being prominent in AD with the Apolipoprotein E (APOE) epsilon 4 allele. Therefore, increased peripheral ACT levels in APOE 4 positive patients appear to predict an accelerated clinical progression. Plasma ACT might be used as a surrogate marker to monitor the conversion of pre-dementia stages to AD and the progression of the disease. The development of compounds able to interfere with the ACT biological activity (protease inhibition and/or promotion of amyloid deposition) might have therapeutic relevance for the disease.

Polymorphisms of fas gene: relationship with Alzheimer's disease and cognitive decline.

The Fas antigen (CD95) is a cell surface receptor that mediates cell apoptosis signalling. Recent investigations have shown that Fas-regulated apoptosis was linked to neurodegenerative lesions in the brain of patients with Alzheimer's disease (AD). Here data regarding the association of two polymorphisms of the Fas promoter region with AD patient's cognitive deterioration are reported. The polymorphism at position -1377 was associated with the risk of developing AD and with a differential rate of cognitive decline during a 2-year follow-up. The polymorphism at position -670 was not associated with the risk of AD and with the cognitive decline during the follow-up. Our data suggest that different genetic background in the Fas gene may influence the risk and clinical progression of the disease by affecting neurodegenerative processes leading to neuronal loss.

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.