Tumor necrosis factor-alpha G-308A gene polymorphism and coronary heart disease susceptibility: an updated meta-analysis

Bioinformatics Analysis of Potential Biomarkers and Pathway Identification for Major Depressive Disorder

Aiming at a more comprehensive understanding of the molecular biomarkers and potential mechanisms of major depressive disorder (MDD), from the Gene Expression Omnibus (GEO) database, we first obtained mRNA expression profiles and identified 585 differentially expressed genes (DEGs) through the R software, including 263 upregulated genes and 322 downregulated genes. Then, through the Kyoto Encyclopedia of Genome and Genome (KEGG) pathway and biological process (BP) analysis, we found that the upregulated and downregulated DEGs were abundant in different pathways, respectively. It was noteworthy that upregulated DEGs were the most significantly enriched in the mTOR signaling pathway. Subsequently, through the protein-protein interaction (PPI) network, we identified seven hub genes, namely, EXOSC2, CAMK2A, PRIM1, SMC4, TYMS, CDK6, and RPA2. Finally, through gene set enrichment analysis (GSEA), we obtained that hypoxia, epithelial-mesenchymal transition, hedgehog signaling, and reactive oxygen species pathway were the enriched pathways for MDD patients. The above data results would provide a new direction for the treatment of MDD patients.

Association of xenobiotic-metabolizing enzymes (GSTM1 and GSTT 1), and pro-inflammatory cytokines (TNF-α and IL-6) genetic polymorphisms with non-alcoholic fatty liver disease

Previous studies have revealed that genetic polymorphisms of the Glutathione S-transferase M1 and T1 (GSTM1 and GSTT1), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) are associated with the presence of non-alcoholic fatty liver disease (NAFLD) in many populations. This study was conducted to investigate the association of the GSTM1, GSTT1, TNF-α rs1800629, and IL-6 rs1800795 with NAFLD in the general Iranian population. A case-control analysis included 242 NAFLD patients and 324 healthy controls from Iranian adults. After the physical examination, the genotypes were determined by polymerase chain reaction(PCR). The GSTM1 null, GSTT1 null, TNF-α AG/AA, and IL-6 CG/CC genotypes were deemed to be high-risk. The null allele of GSTM1 and A allele of TNF-α were more frequent in NAFLD patients even after Bonferroni's correction (P values<0.005, adjusted odds ratio (OR), 1.66 and 2.02; 95% confidence intervals (CI), (1.18-2.32) and (1.34-3.34), respectively. The IL-6 CC/CG genotype association with NAFLD was not significant after correction (P value = 0.04) Polymorphisms of xenobiotic and pro-inflammatory genes are associated with NAFLD in the Iranian population and seem to be a useful tool for NAFLD prevention and care.

Ethnicity-Stratified Analysis of the Association between TNF-α Genetic Polymorphisms and Acute Kidney Injury: A Systematic Review and Meta-Analysis

Background

Several studies have reported conflicting findings regarding the association between tumor necrosis factor-alpha (TNF-α) genetic polymorphisms and acute kidney injury (AKI). Therefore, we performed this meta-analysis to further investigate whether TNF-α variants are related to AKI susceptibility.

Methods

A comprehensive search of observational studies on the association of TNF-α polymorphism with AKI susceptibility was conducted in the PubMed, Cochrane, and Embase databases through February 10, 2020. Pooled odds ratios (ORs) and 95% corresponding confidence intervals (95% CIs) were analyzed to evaluate the strength of the relationship.

Results

A total of 8 studies involving 6694 patients (2559 cases and 4135 controls) were included. Pooled analysis showed a trend of increased risk between the TNF-α rs1800629 variant and AKI (A vs. G: OR [95%CI] = 1.33 [0.98‐1.81]) among the overall population. Ethnicity-stratified analysis indicated that the TNF-α rs1800629 variant was a risk factor for Asians (OR [95%CI] = 1.93 [1.59‐2.35]) while it is not for Caucasians (OR [95%CI] = 1.04 [0.91‐1.20]). Additionally, we also found that TNF-α rs1799964 polymorphism was observed to have a significant relationship with AKI risk in Asian patients (C vs. T, OR [95%CI] = 1.26 [1.11‐1.43]).

Conclusions

The TNF rs1800629 polymorphism exhibited a trend toward AKI susceptibility with ethnic differences. The relationship was found to be significant among the Asian population, but not among those of Caucasian origin. Additionally, the TNF-α rs1799964 polymorphism was also related to a significantly increased risk of AKI in Asians.

The effect of tumor necrosis factor alpha (-308G/a) and interferon gamma (+874T/a) polymorphisms on susceptibility to coronary heart disease

Background: Coronary heart disease (CHD) is a chronic inflammatory disease, which is still regarded as a major cause of morbidity and mortality worldwide. Several studies have suggested that polymorphisms in cytokine genes are associated with the pathogenesis of CHD. The genotype distribution of Tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) genes polymorphisms have been shown to be different in various ethnic populations. This study was aimed to investigate the association of TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms with risk of CHD in an Iranian population. Methods: A total of 187 unrelated subjects comprised 96 CHD patients and 91 healthy controls were enrolled in this cross-sectional study. The TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms were genotyped using amplification refractory mutation system-PCR (ARMS-PCR). The chi-square and logistic regression tests were used to calculate the odds ratios (ORs) as a measure of differences in genotype frequencies. Results: A significant differences in the allelic and genotypic distribution of TNF-α-308 G/A and IFN-γ + 874T/A polymorphisms was found between CHD patients and healthy controls (P = 0.017, P = 0.011, P = 0.006 and P = 0.002, respectively). Logistic regression analyses were also revealed statistically significant risk for CHD with respect to TNF-α-308 A and IFN-γ + 874 T carriers either in crude or after adjustment for potential confounders (P = 0.003 and P = 0.006, respectively). Conclusion: This study provides strong evidence supporting the association of TNF-α-308G/A and IFN-γ + 874T/A polymorphisms with the increased risk of CHD. Therefore, these two cytokine polymorphisms may play a role in predisposition to coronary heart disease.

Acute coronary syndrome: Relationship between genetic variants and TIMI risk

Acute Coronary Syndrome (ACS) is a multifactorial disease, including the genetic factor, caused by coronary artery obstruction by atheroma. Some genetic variants have been described as risk factors for this disease. Its early diagnosis and stratification of risk of death by Thrombolysis in Myocardial Infarction (TIMI) are important. Therefore, we evaluated variants in the IL6R (c950-1722C>T), TNFa (c.-488G>A), LEPR (c.2673+1118C>T) and IL1b (c.-598T>C) genes in relation to TIMI risk, cytokine serum levels, and risk factors for ACS. We selected 200 patients with ACS, 50 without ACS from the Real Hospital Português, Recife - PE, and 295 blood donors at the Fundação de Hematologia e Hemoterapia de Pernambuco (Hemope). Variants were determined by DNA sequencing or enzymatic cleavage. Cytokine levels were measured by ELISA. The most frequent risk factors found in the patients were dyslipidemia and hypertension, this latter associated with high TIMI risk (p = 0.003). Genotype frequencies of IL6R and TNFa differed between patients with ACS and the blood donors (p = 0.0002 and p = 0.01, respectively), and TNF-α levels differed between genotypes. The TT genotype of the IL6R gene is as a possible protective factor for ACS because it was significantly more present in blood donors (32.2%) than in patients with ACS (18.0%), and was more frequent in low TIMI risk (22.9%) than in the intermediate (20.2%) or high (4.9%). In patients with ACS, the TT genotype in IL6R was related to a lower concentration of c-reactive protein (p = 0.03) and troponin (p = 0.02), showing a less inflammatory reaction and tissue damage. The differences in the frequencies of variants in genes of medical interest among the groups show the importance of studies in specific populations groups to establish the relationship between genes and diseases.

Effect of pocket irrigation with antimicrobial on prevention of pacemaker pocket infection: a meta-analysis

Background

The presence of cardiac implantable electronic devices (CIEDs) pocket infection is difficult to treat, causing serious clinical outcomes, but little is known for prevention. Results from some studies suggested that pocket irrigation could reduce infection while others showed conflicting results. We pooled the effects of pocket irrigations on the prevention of pocket infection by meta-analysis methods.

Method

Relevant studies published before June, 2017 were retrieved mainly by the computer-based search of PubMed, Cochrane, EMBASE, Web of Science, Chinese BioMedical, Global Health and BIOSIS Previews databases. Estimations of relative ratios (RRs) and 95% confidence intervals (95% CIs) were pooled. Subgroup analyses according to potential key factors affecting the effects were conducted, which was confirmed by meta-regression. Sensitivity analysis and test for publication bias were also performed.

Results

We identified 10 studies providing data of 5467 patients receiving CIEDs implantations. Pooled infection rates were 1.48 and 3.49% respectively for medication and saline irrigation groups. Meta-analysis showed that medication irrigation conferred protection to pocket infection (RR = 0.44, 95% CI: 0.31-0.63). Subgroup analysis showed that antibiotics, rather than non-antibiotics (antiseptics) exerting the protection. The first and second lines antibiotics against staphylococcus aureus, which is the main pathogen for pocket infection, were both effective (RR = 0.42, 95% CI: 0.24-0.75 and RR = 0.34, 95% CI: 0.20-0.58 respectively for first line and second line therapies). Meta-regression revealed that region and class of irrigation medication completely explained the variance among studies and implied that effects of region were masked by medication types. Sensitivity analysis did not showed any significant change of the result and publication bias were not statistical significance.

Conclusion

Pocket irrigation with antibiotics were effective for reducing pocket infection and should be encouraged in CIEDs implantation.

Tumor necrosis factor-alpha gene polymorphisms and susceptibility to ischemic heart disease: A systematic review and meta-analysis

BACKGROUND

A number of studies had reported the association between tumor necrosis factor-alpha (TNF-α) gene polymorphisms and ischemic heart disease (IHD) risk. However, the results remained controversial. Therefore, we performed a systematic review with multiple meta-analyses to provide the more precise estimations of the relationship.

METHODS

We systematically searched electronic databases (PubMed, the Web of Science, EMBASE, Medline, Chinese National Knowledge Infrastructure, WanFang and ChongQing VIP Database) for relevant studies published up to February 2017. The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for assessing the association. The present meta-analysis was performed using STATA 12.0 software.

RESULTS

In total, 45 articles with 17,375 cases and 15,375 controls involved were included. Pooled ORs revealed a significant association between TNF-α -308G/A gene polymorphism and IHD (A vs. G: OR = 1.22, 95% CI = 1.10-1.35; (AA + GA) vs. GG: OR = 1.18, 95% CI = 1.03-1.36; (AA vs. (GA+GG): OR = 1.37, 95% CI = 1.08-1.75)), indicating that the TNF-α -308A allele might be an important risk factor for IHD. No association between other TNF-α gene polymorphisms and susceptibility to IHD were observed. No publication bias were found. Sensitivity analyses indicated that our results were stable.

CONCLUSION

The present study indicated a possible association between the TNF-α -308G/A gene polymorphism and IHD risk. However, evidence was limited to confirm the role of TNF-α -238G/A, -857C/T, -863C/A, -1031T/C and other TNF-α gene polymorphisms in the risk of IHD.

Association of age-related macular degeneration and reticular macular disease with cardiovascular disease

Age-related macular degeneration is the leading cause of adult blindness in the developed world. Thus, major endeavors to understand the risk factors and pathogenesis of this disease have been undertaken. Reticular macular disease is a proposed subtype of age-related macular degeneration correlating histologically with subretinal drusenoid deposits located between the retinal pigment epithelium and the inner segment ellipsoid zone. Reticular lesions are more prevalent in females and in older age groups and are associated with a higher mortality rate. Risk factors for developing age-related macular degeneration include hypertension, smoking, and angina. Several genes related to increased risk for age-related macular degeneration and reticular macular disease are also associated with cardiovascular disease. Better understanding of the clinical and genetic risk factors for age-related macular degeneration and reticular macular disease has led to the hypothesis that these eye diseases are systemic. A systemic origin may help to explain why reticular disease is diagnosed more frequently in females as males suffer cardiovascular mortality at an earlier age, before the age of diagnosis of reticular macular disease and age-related macular degeneration.

Integrated probability of coronary heart disease subject to the -308 tumor necrosis factor-alpha SNP: a Bayesian meta-analysis

We present a meta-analysis of independent studies on the potential implication in the occurrence of coronary heart disease (CHD) of the single-nucleotide polymorphism (SNP) at the −308 position of the tumor necrosis factor alpha (TNF-alpha) gene. We use Bayesian analysis to integrate independent data sets and to infer statistically robust measurements of correlation. Bayesian hypothesis testing indicates that there is no preference for the hypothesis that the −308 TNF-alpha SNP is related to the occurrence of CHD, in the Caucasian or in the Asian population, over the null hypothesis. As a measure of correlation, we use the probability of occurrence of CHD conditional on the presence of the SNP, derived as the posterior probability of the Bayesian meta-analysis. The conditional probability indicates that CHD is not more likely to occur when the SNP is present, which suggests that the −308 TNF-alpha SNP is not implicated in the occurrence of CHD.

Tumor necrosis factor-alpha G-238A polymorphism and coronary artery disease risk: a meta-analysis of 4,222 patients and 4,832 controls

BACKGROUND

The aim of the present study was to investigate the association between tumor necrosis factor-alpha (TNF-α) gene G-238A polymorphism and risk of coronary artery disease (CAD) using a meta-analytical approach.

METHODS

The PubMed and Embase databases were searched for relevant publications up to January 13, 2015. Four authors (XPH, XDZ, XTZ, and ZJZ) independently selected the studies, extracted, and analyzed the data using the Comprehensive Meta-Analysis software. The sensitivity and subgroups analyses were also performed. Either a fixed effects or a random effects model was used to estimate pooled odds ratios (ORs) and their 95% confidence intervals (CIs).

RESULTS

Finally, ten articles including eleven case-control studies involving 4,222 patients and 4,832 controls were yielded. The results indicated no significant association between G-238A polymorphism and CAD risk (A vs G: OR =1.08, 95% CI =0.89-1.30; AA vs GG: OR =1.15, 95% CI =0.59-2.25; GA vs GG: OR =1.14, 95% CI =0.88-1.48; AA vs [GG + GA]: OR =1.09, 95% CI =0.56-2.14; (GA + AA) vs GG: OR =1.11, 95% CI =0.90-1.38). In the subgroup analyses, similar results were obtained with overall populations. The sensitivity analyses showed that the overall results were robust. No publication bias was detected.

CONCLUSION

Based on current evidence, we can conclude that TNF-α G-238A polymorphism might not be associated with CAD risk.

Obesity and coronary microvascular disease - implications for adipose tissue-mediated remote inflammatory response

It is believed that obesity has detrimental effects on the coronary circulation. These include immediate changes in coronary arterial vasomotor responsiveness and the development of occlusive large coronary artery disease. Despite its critical role in regulating myocardial perfusion, the altered behavior of coronary resistance arteries, which gives rise to coronary microvascular disease (CMD) is poorly understood in obesity. A chronic, low-grade vascular inflammation has been long considered as one of the main underlying pathology behind CMD. The expanded adipose tissue and the infiltrating macrophages are the major sources of pro-inflammatory mediators that have been implicated in causing inadequate myocardial perfusion and, in a long term, development of heart failure in obese patients. Much less is known the mechanisms regulating the release of these cytokines into the circulation that enable them to exert their remote effects in the coronary microcirculation. This mini review aims to examine recent studies describing alterations in the vasomotor function of coronary resistance arteries and the role of adipose tissue-derived pro-inflammatory cytokines and adipokines in contributing to CMD in obesity. We provide examples of regulatory mechanisms by which adipokines are released from adipose tissue to exert their remote inflammatory effects on coronary microvessels. We identify some of the important challenges and opportunities going forward.

Polymorphisms of tumor necrosis factor-alpha and interleukin-6 gene and C-reactive protein profiles in patients with idiopathic dilated cardiomyopathy

BACKGROUND AND OBJECTIVES

The tumor necrosis factor-alpha (TNF-a) and interleukin (IL)-6 gene polymorphism has a controversial role in the pathogenesis of cardiovascular disease among different populations. The effect of the cytokine's gene polymorphism on idiopathic dilated cardiomyopathy (IDCM) is still unresolved. The current study aimed to evaluate the association of the TNF-a -308 G/A and IL-6 -174 G/C polymorphism with IDCM in a Pakistani population.

DESIGN AND SETTINGS

Blood samples for this case-control study were collected from the cardiology out.patient department of multiple cardiology centers of Rawalpindi/Islamabad, Pakistan, between July 2012 and December 2012.

PATIENTS AND METHODS

IDCM cases (number [n]=250) and healthy controls (n=300) were genotyped using polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

The TNF-a -308 variant genotypes GA and AA were more prevalent in patients compared with the control group (P < .0001). Similarly, the IL-6 -174 variant genotypes GC and CC showed a high prevalence in patients with IDCM compared with healthy controls (P=.0019). IDCM cases had a higher prevalence of the TNFa-308A (P < .0001) and the IL-6 -174C (P=.0008) mutant alleles than did the control group. The IDCM cases bearing the TNF-a-308 and IL-6 variant genotypes revealed elevated levels of high-sensitivity C-reactive protein (hs-CRP) when compared with the corresponding controls (P < .05).

CONCLUSION

The TNF-a -308 G/A and IL-6 -174 G/C gene polymorphisms and high levels of hs-CRP may be associated with the pathogenesis of IDCM in the study population.

Promoter variants in interleukin-6 and tumor necrosis factor alpha and risk of coronary artery disease in a population from Western India

INTRODUCTION:

A central component of the atherosclerotic process is inflammation. Single nucleotide polymorphisms (SNPs) present in the promoter region of various cytokines can lead to altered levels of the transcript and a state of low-grade inflammation exacerbating the risk of coronary artery disease (CAD). The present work tries to understand the role of permissive promoter variants in the interleukin-6 gene (IL-6-174G/C) and the tumor necrosis factor alpha (TNFα-308G/A) in the causation of CAD and also dyslipidemia.

MATERIALS AND METHODS:

Genotyping was conducted on 100 cases of CAD and 150 controls by the allele termination assay SNaPshot. Biochemical parameters were determined by routine enzymatic endpoint methods. The results were analyzed by appropriate statistical methods.

RESULTS:

No differences in the minor allele frequency IL-6-174G/C SNP were seen between cases and controls (0.13 vs. 0.12). The differences in the allele frequency of TNFα-308A between cases (6%) and controls (2%) have led to an odds ratio, 3.370; 95% confidence interval, 1.039-11.543; P=0.033 in the univariate analysis. In the final logistic regression analysis, however none of the variants were associated with an increased risk of CAD.

CONCLUSIONS:

In summary, no association of the permissive promoter variants in the IL-6 gene and the TNFα gene were seen with an increased CAD risk. These and other studies highlight the importance of doing population specific studies.

Pro-inflammatory genetic markers of atherosclerosis

Atherosclerosis (AS) is a chronic, progressive, multifactorial disease mostly affecting large and medium-sized elastic and muscular arteries. It has formerly been considered a bland lipid storage disease. Currently, multiple independent pathways of evidence suggest this pathological condition is a peculiar form of inflammation, triggered by cholesterol-rich lipoproteins and influenced both by environmental and genetic factors. The Human Genome Project opened up the opportunity to dissect complex human traits and to understand basic pathways of multifactorial diseases such as AS. Population-based association studies have emerged as powerful tools for examining genes with a role in common multifactorial diseases that have a strong environmental component. These association studies often estimate the risk of developing a certain disease in carriers and non-carriers of a particular genetic polymorphism. Dissecting out the influence of pro-inflammatory genes within the complex pathophysiology of AS and its complications will help to provide a more complete risk assessment and complement known classical cardiovascular risk factors. The detection of a risk profile will potentially allow both the early identification of individuals susceptible to disease and the possible discovery of potential targets for drug or lifestyle modification; i.e. it will open the door to personalized medicine.

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.

Glycoxydation promotes vascular damage via MAPK-ERK/JNK pathways

Oxidation and glycation enhance foam cell formation via MAPK/JNK in euglycemic and diabetic subjects. Here, we investigated the effects of glycated and oxidized LDL (glc-oxLDL) on MAPK-ERK and JNK signaling pathways using human coronary smooth muscle cells. Glc-oxLDL induced a broad cascade of MAPK/JNK-dependent signaling transduction pathways and the AP-1 complex. In glc-oxLDL treated coronary arterioles, tumor necrosis factor (TNF) α increased JNK phosphorylation, whereas protein kinase inhibitor dimethylaminopurine (DMAP) prevented the TNF-induced increase in JNK phosphorylation. The role of MKK4 and JNK were then investigated in vivo, using apolipoprotein E knockout (ApoE(-/-)) mice. Peritoneal macrophages, isolated from spontaneously hyperlipidemic but euglycemic mice showed increases in both proteins and phosphorylated proteins. Compared to streptozotocin-treated diabetic C57BL6 and nondiabetic C57BL6 Wt mice, in streptozotocin-diabetic ApoE(-/-) mice, the increment of foam cell formation corresponded to an increment of phosphorylation of JNK1, JNK2, and MMK4. Thus, we provide a first line of evidence that MAPK-ERK/JNK pathways are involved in vascular damage induced by glycoxidation.