Genetic polymorphisms of inflammatory cytokines and myocardial infarction in the elderly

Aging amplifies multiple phenotypic defects in mice with zinc transporter Zip14 (Slc39a14) deletion

Inflammation and zinc dyshomeostasis are two common hallmarks of aging. A major zinc transporter ZIP14 (slc39a14) is upregulated by proinflammatory stimuli, e.g. interleukin-6. We have evaluated the influence of age on the Zip14 KO phenotype using wild-type (WT) and Zip14 knockout (KO) mice. Aging produced a major increase in serum IL-6 concentrations that was dramatically augmented in the Zip14 KO mice. In keeping with enhanced serum IL-6 concentrations, aging produced tissue-specific increases in zinc concentration of skeletal muscle and white adipose tissue. Metabolic endotoxemia produced by Zip14 ablation is maintained in aged KO mice. Muscle non-heme iron (NHI) was increased in aged WT mice but not in aged Zip14 KO mice demonstrating NHI uptake by muscle is ZIP14-dependent and increases with age. NF-κB and STAT3 activation was greater in aged mice, but was tissue specific and inversely related to tissue zinc. Micro-CT analysis revealed that Zip14 KO mice had markedly reduced trabecular bone that was greatly amplified with aging. These results demonstrate that the inflammation-responsive zinc transporter ZIP14 has phenotypic effects that are amplified with aging.

TLR4 Asp299Gly (rs4986790) polymorphism and coronary artery disease: a meta-analysis

Background. Previous studies have shown conflicting results on the association between toll-like receptor 4 (TLR4) Asp299Gly (rs4986790) polymorphism and coronary artery disease (CAD). The aim of this study was to evaluate the influence of TLR4 Asp299Gly polymorphism on CAD risk, CRP level and the number of stenotic coronary arteries, as well as to investigate whether G allele carriers would benefit more from statin treatment. Methods. PubMed, EMBASE, and CNKI databases were searched until May 2015. All the statistical tests were performed using R version 3.1.2. Odds ratio (OR) and 95% confidence interval (CI) were used to assess the association between TLR4 Asp299Gly polymorphism and CAD risk, the number of stenotic vessels, and the incidence of cardiovascular events according to statin-treated patients. Weighted mean difference (WMD) was calculated for the association between Asp299Gly and CRP level. Results. Overall, 12 case-control studies with 10,258 cases and 5,891 controls were included, and no association of TLR4Asp299Gly polymorphism with CAD was found (G allele vs. A allele: OR = 0.97, 95% CI [0.81-1.17], P = 0.75; AA vs. GG + AG: OR = 0.97, 95% CI [0.80-1.18], P = 0.76; GG vs. AG + AA: OR = 1.08, 95% CI [0.57-2.02], P = 0.82; AG vs. AA + GG: OR = 1.03, 95% CI [0.85-1.25], P = 0.74). Also, no association was noted between Asp299Gly and CRP level (WMD = -0.10, 95% CI [-0.62, 0.41], P = 0.69). Furthermore, no synergistic effect of statin and 299Gly was reported (Statin_AA vs. Statin_

AG/GG

OR = 1.12, 95% CI [0.41-3.09], P = 0.82). Discussion. This meta-analysis suggests no association of TLR4 Asp299Gly polymorphism with CAD and CRP level. It is further indicated that the G allele carriers may not benefit more from statin treatment. Further studies should include large sample size and high-quality literature to understand this issue in depth.

Thymol attenuates inflammation in isoproterenol induced myocardial infarcted rats by inhibiting the release of lysosomal enzymes and downregulating the expressions of proinflammatory cytokines

Inflammation plays an important role in the development of myocardial infarction (MI). The current study dealt with the protective effects of thymol on inflammation in isoproterenol (ISO) induced myocardial infarcted rats. Male albino Wistar rats were pre and co-treated with thymol (7.5mg/kg body weight) daily for 7 days. ISO (100mg/kg body weight) was injected subcutaneously into rats at an interval of 24h for two days (6th and 7th day) to induce MI. ISO induced myocardial infarcted rats showed increased levels of serum cardiac troponin-T, high sensitive C-reactive protein (hsCRP), lysosomal thiobarbituric acid reactive substances (TBARS) and elevated ST-segments. Also, the activities of lysosomal enzymes such as β-glucuronidase, β-galactosidase, cathepsin-B and D, the stimulators of inflammatory mediators were increased in the serum and heart of ISO induced myocardial infarcted rats. Furthermore, ISO up regulates the expressions of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) genes in the myocardium of rats analyzed by reverse transcription polymerase chain reaction (RT-PCR). Pre and co-treatment with thymol (7.5mg/kg body weight) near normalized the levels of lysosomal TBARS, activities of serum and heart lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines in the myocardium of ISO induced myocardial infarcted rats. Histopathological and transmission electron microscopic findings were also found in line with biochemical findings. Thus, the results of our study revealed that thymol attenuates inflammation by inhibiting the release of lysosomal enzymes and downregulates the expressions of pro-inflammatory cytokines by its potent anti-inflammatory effect.

Evaluation of Toll-Like receptor 2 and 4 RNA expression and the cytokine profile in postmenopausal women with metabolic syndrome

OBJECTIVE

To evaluate the gene expression of Toll-Like (TLR-2 and TLR-4) receptors and cytokine profile in postmenopausal women with or without metabolic syndrome (MetS).

METHODS

In this cross-sectional study, 311 Brazilian women (age≥45 years and amenorrhea≥12 months) were included. Women showing three or more of the following diagnostic criteria were diagnosed as positive for MetS: waist circumference>88 cm, triglycerides≥150 mg/dL, HDL cholesterol<50 mg/dL, blood pressure≥130/85 mmHg, and fasting glucose≥100 mg/dL. The expression of TLR-2 and TLR-4 in peripheral blood was evaluated by RNA extraction and subsequent real time PCR analysis. The cytokine profile, tumor necrosis factor alpha (TNF-α) and interleukins 1β, 6, and 10, were measured by ELISA.

RESULTS

The expression of TLR-2 RNA was demonstrated in 32.5% and TLR-4 in 20.6% of the subjects. There was no association between the expression of TLR-2 and TLR-4 and the presence or absence of MetS (P>0.05). A greater production of IL-6 was associated with TLR-2 and TLR-4 expressions and greater production of TNF-α was associated only with TLR-2 expression (P>0.05). Only the lower quartile of IL-10 was associated with the presence of the MetS (P>0.05).

CONCLUSIONS

TLR-2 and TLR-4 expressions were associated with increased pro-inflammatory cytokines, IL-6 and TNF-α, with no association with biomarkers of MetS. The low concentrations of IL-10 may suggest an anti-inflammatory modulation in postmenopausal women with MetS.

Mannose-binding lectin gene polymorphism and risk factors for cardiovascular disease in postmenopausal women

BACKGROUND

Inflammatory responses may be altered in postmenopausal women and predispose to cardiovascular disease (CVD). Genetic factors can also influence susceptibility to CVD. Mannose-binding lectin (MBL) is a component of the innate immune system and an activator of the complement cascade. We evaluated the association of genetic polymorphism of MBL (MBL2) on risk factors for CVD in postmenopausal women.

METHODS

In this cross-sectional study, 311 Brazilian women (age ≥45 years and amenorrhea ≥12 months) were included.

EXCLUSION CRITERIA

presence of previous or current CVD, insulin dependent diabetes, chronic kidney disease, autoimmune diseases and cancer. Clinical, anthropometric and biochemical assessments were performed to evaluate the cardiovascular risk factors. DNA was extracted from buccal cell and polymorphisms at codons 54 and 57 in the MBL2 were determined by polymerase chain reaction (PCR). For statistical analysis, the chi-square and logistic regression (odds ratio, OR) were used.

RESULTS

The presence of the polymorphic allele for codon 54 was found in 25.8% of women (A/B=22.6%, B/B=3.2%) and for codon 57 in 12.2% (A/C=10.8%, C/C=1.4%). The polymorphism at codon 54 was significantly associated with the presence of hypertension (OR 0.55, 95% CI 0.31-0.99, p=0.044) and insulin resistance assessed by HOMA-IR (OR 0.46, 95% CI 0.24-0.91, p=0.025). No significant associations were observed between the polymorphism at codon 57 with risk factors for CVD.

CONCLUSION

In postmenopausal women, the polymorphism at codon 54 of the MBL2 was associated with lower risk for hypertension and insulin resistance that are important risk factors for CVD.

Interaction between air pollution exposure and genes in relation to levels of inflammatory markers and risk of myocardial infarction

OBJECTIVES

Air pollution exposure induces cardiovascular effects, possibly via systemic inflammation and coagulation misbalance. Genetic variation may determine individual susceptibility. Our aim was to investigate effect modification by inflammation (Interleukin6 (IL6), tumour necrosis factor-α (TNF-α)) and coagulation (fibrinogen Bβ, plasminogen activator inhibitor-1 (PAI-1)) gene variants on the effect of long-term or short-term air pollution exposure on both blood marker levels and non-fatal myocardial infarction (MI) risk.

DESIGN

Population-based case-control study with a nested case-crossover study. Gene-environment interactions for short-term and long-term air pollution on blood marker levels were studied in population controls, for long-term exposure on MI risk using case-control design, and for short-term exposure on MI onset using case-crossover design.

SETTING

The Stockholm Heart Epidemiology Programme (SHEEP) conducted in 1992-1994 in Stockholm, Sweden. Spatial modelling was used to assess long-term (up to 30 years retrospectively) air pollution exposure to traffic-NO2 and heating-SO2 emissions at home addresses. Urban background NO2, SO2, PM10 and O3 measurements were used to estimate short-term (up to 5 days) air pollution exposure.

PARTICIPANTS

1192 MI cases and 1506 population controls aged 45-70 years.

OUTCOMES

The levels of blood markers of inflammation (IL-6, TNF-α) and coagulation (fibrinogen, PAI-1) and MI risk.

RESULTS

We observed gene-environment interaction for several IL6 and TNF SNPs in relation to inflammation blood marker levels. One-year traffic-NO2 exposure was associated with higher IL-6 levels with each additional IL6-174C allele, and 1-year heating-SO2 exposure with higher levels of TNF-α in TNF-308AA homozygotes versus -308G carriers. Short-term air pollution exposure also interacted with IL6 and TNF in relation to marker levels. The risk of MI followed the effect on blood markers in each genotype group.

CONCLUSIONS

Genetic variants in IL6 and TNF may modify effects of long-term and short-term air pollution exposure on inflammatory marker levels and MI risk.

Age-related differences in the expression of circulating microRNAs: miR-21 as a new circulating marker of inflammaging

Circulating microRNAs (miRs) have been investigated as diagnostic/prognostic biomarkers in human diseases. However, little is known about their expression throughout the aging process. Eleven healthy individuals aged 20, 80 and 100 years underwent miR plasma profiling. The validation cohort consisted of 111 healthy adults (CTR) aged 20-105 years and included 30 centenarians. In addition, 34 patients with cardiovascular disease (CVD) and 15 healthy centenarian offspring (CO) were enrolled. An exploratory factorial analysis grouped the miRs into three main factors: factor 1 primarily higher in 20-year-old subjects, but these differences did not reach statistical significance, factor 2 primarily higher in octogenarians and factor 3 primarily higher in centenarians. MiR-21, the most highly expressed miR of factors 2 and 3, was further validated, confirming the differences in the age groups. MiR-21 expression was higher in the CVD patients and lower in the CO compared to the age-matched CTR. MiR-21 was correlated with C-reactive protein and fibrinogen levels. TGF-β signaling was the predicted common pathway targeted by miRs of factors 2 and 3. TGF-βR2 mRNA, a validated miR-21 target, showed the highest expression in the leukocytes from a subset of the octogenarians. Our findings suggest that miR-21 may be a new biomarker of inflammation.

LBP and CD14 polymorphisms correlate with increased colorectal carcinoma risk in Han Chinese

AIM: To explore the associations of polymorphisms of lipopolysaccharide binding protein (LBP), cluster of differentiation 14 (CD14), toll-like receptor 4 (TLR-4), interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) with the colorectal carcinoma (CRC) risk in Han Chinese.

METHODS: Polymorphisms of LBP (rs1739654, rs2232596, rs2232618), CD14 (rs77083413, rs4914), TLR-4 (rs5030719), IL-6 (rs13306435) and TNF-α (rs35131721) were genotyped in 479 cases of sporadic colorectal carcinoma and 486 healthy controls of Han Chinese in a case-control study. Single-nucleotide polymorphisms (SNPs) between cases and controls were analyzed by unconditional logistic regression.

RESULTS: GA and GG genotypes of LBP rs2232596 were associated with a significantly increased risk of CRC [odds ratio (OR) = 1.51, 95% confidence interval (CI) 1.15-1.99, P = 0.003; OR = 2.49, 95% CI 1.16-5.38, P = 0.016, respectively]. A similar association was also observed for the CG genotype of CD14 rs4914 (OR= 1.69, 95% CI 1.20-2.36, P = 0.002). In addition, a combination of polymorphisms in LBP rs2232596 and CD14 rs4914 led to a 3.4-fold increased risk of CRC (OR = 3.44, 95% CI 1.94-6.10, P = 0.000).

CONCLUSION: This study highlights the LBP rs2232596 and CD14 rs4914 polymorphisms as biomarkers for elevated CRC susceptibility in the Chinese Han population.

Identification of single nucleotide polymorphisms in the p21 (CDKN1A) gene and correlations with longevity in the Italian population

Longevity in humans is determined by multiple environmental and genetic factors. We have investigated possible associations between longevity and Single Nucleotide Polymorphisms (SNPs) in the p21 (CDKN1A) gene, a stress-inducible senescence-associated cell cycle inhibitor, expression of which upregulates genes implicated in several age-related diseases. By sequencing the promoter and exons of p21 in genomic DNA of ten individuals over 90 years old, we have identified 30 SNPs, many of which had not been previously characterized. A cluster of minor alleles within the -4547/-3489 bp region did not alter the basal activity or p53 responsiveness of the p21 promoter. We then compared the frequency of 41 p21 SNPs between 184 centenarians and 184 younger subjects in the Italian population. Rare alleles of two exon-derived SNPs, rs1801270 and rs1059234, were significantly under-represented among the centenarians; no significant differences were found for 39 non-exonic SNPs. SNP rs1801270 causes Ser to Arg substitution at amino acid 31 and SNP rs1059234 leads to a nucleotide change in the 3'-untranslated region. Previous studies showed that the rare alleles of these two SNPs may play a role in cancer. These p21 alleles may be potentially detrimental to longevity and therefore are rare in centenarians.

Essential oil composition and antioxidant activity of Pterocarya fraxinifolia

Current research into free radicals has confirmed that plants rich in antioxidants play an essential role in the prevention of many diseases. The potential antioxidant activities of Pterocarya fraxinifolia bark and leaves investigated employing six in vitro assay systems. IC50 for DPPH radical-scavenging activities were 3.89 +/- 0.09 for leaves and 41.57 +/- 1.30 microg mL(-1) for bark, respectively. The leaf extract exhibited a good reducing power at 2.5 and 80 microg mL(-1) that was comparable with Vit C (p > 0.05). The extracts also showed weak nitric oxide-scavenging activity and Fe2+ chelating ability. The peroxidation inhibition of extracts exhibited values from 92 to 93% at 72nd h, almost at the same pattern of Vitamin C activity (p > 0.05). Based on higher total phenol and flavonoid contents in leaves, higher antioxidant activities were observed in leaf extract. In addition, chemical composition of leaf essential oil was determined. The major compound was bisabolol oxide A (23.6%). Sesquiterpenes and monoterpenes are the major compounds in leaves essential oil. Presence of these compounds may be a reason for the good antioxidant activity of leaf extract.

Dangers, and benefits of the cytokine mediated response to injury and infection

The inflammatory response is essential for survival in an environment where continuous exposure to noxious events threaten the integrity of the organism. However, the beneficial effects of the response are influenced by factors, which disadvantage individuals within a population. These factors include malnutrition, infection, genotype, gender, pre-existing inflammation, and chronic intoxication. Although the inflammatory response is generally successful in dealing with noxious events, life-long exposure to these events takes its toll on the integrity of the body and becomes apparent as chronic disease, atherosclerosis, organ failure, and frailty. Progress in ameliorating the consequences of lifetime exposure to inflammatory events can only occur if a fuller understanding can be obtained of the factors, which influence the persistence and outcome of the inflammatory response at an individual level. A multitude of studies has shown that specific nutrients, diets, and dietary restriction are able to modulate the inflammatory response in the population as a whole. To advance in this area, precise knowledge is needed of how the disadvantageous factors, mentioned above, affect the individual's response to anti-inflammatory nutrients.

Inflammatory cytokine gene variants in coronary artery disease patients in Greece

OBJECTIVE

Abundant evidence supports the central role of inflammatory cytokines in immune responses mediating the pathogenesis of atherosclerosis, coronary artery disease, and its complications, such as myocardial infarction and unstable angina.

METHODS

We investigated the association of genetic polymorphisms of the inflammatory cytokines, IL-10, TGF-beta1, IFN-gamma, IL-6, and TNF-alpha with the clinical presentation of coronary artery disease in 26 patients with stable angina, 45 patients with unstable angina and 58 patients who had experienced nonfatal myocardial infarction. Genotyping was performed by the sequence-specific primer polymerase chain reaction method.

RESULTS

A significant difference in the frequencies of -174G/C IL-6 alleles was observed, with the low in-vitro producing -174*C allele predominating in patients with myocardial infarction, compared with stable angina and unstable angina patients, after the analysis of genotypes (P=0.024 and 0.022, respectively), phenotypes [P=0.0099, odds ratio (OR)=0.271, 95% confidence interval (CI)=0.1012-0.7292; P=0.03, OR=0.40, respectively] and haplotypes (P=0.007, OR=3.028, 95% CI=1.347-6.806; P=0.0096, OR=2.368, 95% CI=1.262-4.444; respectively). In addition, a predominance of the -1082ACC/ATA IL-10 genotype in the myocardial infarction group compared with the unstable angina group and the -874 A/A IFN-gamma genotype in the stable angina group compared with the unstable angina and the myocardial infarction group, was found. No significant differences in the distribution of genotypes, phenotypes and haplotypes in the three study groups, for the TNF-alpha-308 A/G and TGF-beta1-codon 25 G/C, codon 10 T/C polymorphisms were detected.

CONCLUSION

Our data provide evidence that the IL-6-174G/C polymorphism may be involved in the pathogenesis of coronary artery disease, contributing to genetic susceptibility for myocardial infarction.

Effect of zinc supplementation on plasma IL-6 and MCP-1 production and NK cell function in healthy elderly: interactive influence of +647 MT1a and -174 IL-6 polymorphic alleles

Pro-inflammatory cytokine response and NK activity are controlled by the availability of zinc ion, whose intra-cellular transport is regulated by metallothioneins. In order to closely examine the importance of circulating zinc in the modulation of immune response during ageing, in the balance of Th2/Th1 equilibrium and finally in the reversibility of systemic low grade inflammation, we evaluated the changes occurring in plasma IL-6 and MCP-1 concentrations and NK lytic activity in a healthy low grade inflamed elderly population, following zinc-aspartate supplementation. In addition, we aimed to highlight the potential interaction among circulating zinc increments, changes in immunological parameters and +647 MT1a and -174 IL-6 polymorphic alleles. Thirty-nine healthy individuals (60-83 years) from the ZINCAGE cohort (previously typed for +647 MT1a and -174 IL-6 polymorphisms) were supplied with zinc-aspartate. Blood samples collected before and after supplementation underwent basal laboratory determinations (circulating zinc, albumin and C-reactive protein) and immunological studies (plasma IL-6 and MCP-1 and NK lytic activity). Zinc supplementation in subjects with low or borderline-normal circulating zinc increased the concentration of this ion and modulated plasmatic IL-6 and MCP-1 as well as NK lytic activity. An interactive effect of polymorphic alleles of MT1a and IL-6 genes on zinc, IL-6, MCP-1 and NK activity was evidenced following supplementation, indicating the genetic background as one of the determinants for identifying groups of subjects that can take advantage of therapeutic intervention.

Validation of the association between the gene encoding proteasome subunit alpha type 6 and myocardial infarction in a Japanese population

BACKGROUND

Recently, a large case-control study (2,851 cases and 2,592 controls) reported that a functional single nuclear polymorphism (SNP) in the proteasome subunit alpha type 6 gene (PSMA6) conferred a risk of myocardial infarction (MI) in a Japanese population. The SNP (exon 1, -8C/G) is located in the 5' untranslated region of exon 1, and the risk-conferring allele G appears to enhance the transcription of PSMA6, which may exaggerate inflammation through activation of nuclear factor-kappa beta protein. The frequency of the risk conferring genotype (GG) in cases was reported to be greater than that in controls (12.4% vs 8.9%). The purpose of the present study was to validate this observation in our study population.

METHODS AND RESULTS

Subjects with MI (n=433) were recruited from the outpatient clinic of the National Cardiovascular Center. Control subjects (n=2,186) were recruited from the Suita study. The frequencies of the GG genotype did not significantly differ between the control (9.8%) and MI groups (10.6%). Moreover, this genotype was not associated with C reactive protein levels in the Suita study. However, the GG genotype was significantly associated with greater intima-media thickness (n=2,051, p=0.015) after adjusting for blood pressure, sex, body mass index and age in the Suita study.

CONCLUSION

The reported genotype in PSMA6 appears not to contribute appreciably to MI, but may contribute slightly to atherosclerosis in the present study population.

Genes, ageing and longevity in humans: problems, advantages and perspectives

Many epidemiological data indicate the presence of a strong familial component of longevity that is largely determined by genetics, and a number of possible associations between longevity and allelic variants of genes have been described. A breakthrough strategy to get insight into the genetics of longevity is the study of centenarians, the best example of successful ageing. We review the main results regarding nuclear genes as well as the mitochondrial genome, focusing on the investigations performed on Italian centenarians, compared to those from other countries. These studies produced interesting results on many putative "longevity genes". Nevertheless, many discrepancies are reported, likely due to the population-specific interactions between gene pools and environment. New approaches, including large-scale studies using high-throughput techniques, are urgently needed to overcome the limits of traditional association studies performed on a limited number of polymorphisms in order to make substantial progress to disentangle the genetics of a trait as complex as human longevity.