Association of a common TLR-6 polymorphism with coronary artery disease - implications for healthy ageing?

The predictive value of the neutrophil/platelet ratio on in-hospital adverse events and long-term prognosis in patients with coronary artery disease after percutaneous coronary intervention and its possible internal mechanism

The neutrophil-to-platelet ratio (NPR) is considered to be an indicator of inflammatory status. The value of the NPR in predicting in-hospital adverse events (AEs) and long-term prognosis after percutaneous coronary intervention (PCI) in coronary artery disease (CAD) patients has not yet been reported. Meanwhile, the mechanisms behind its predictive value for long-term prognosis remain unreported as well. The study retrospectively enrolled 7284 consecutive patients with CAD undergoing PCI from January 2012 to December 2018. Multivariable logistic regression analysis, multivariable Cox regression analysis, Kaplan‒Meier (KM) curve analysis, restricted cubic spline (RCS) curve analysis, and sensitivity analysis were used in the study. All-cause death was the endpoint of the study. According to the median value of the NPR, the patients were divided into two groups: the high group (NPR ≥ 0.02, n = 3736) and the low group (NPR < 0.02, n = 3548). Multivariate logistic regression analysis demonstrated that a high NPR was a risk factor for in-hospital AEs [odds ratio (OR) = 1.602, 95% CI 1.347-1.909, p = 0.001]. During a mean follow-up period of 3.01 ± 1.49 years, the multivariate Cox regression analysis showed that a high NPR affected the long-term prognosis of patients (HR 1.22, 95% CI 1.03-1.45, p = 0.025) and cardiac death (HR 1.49, 95% CI 1.14-1.95, p = 0.003). The subgroup analysis showed that the NPR was affected by age and sex. The mediation analysis identified that the effect of the NPR on long-term outcomes is partially mediated by serum creatinine (Scr) and triglycerides. The NPR may be a convenient indicator of in-hospital AEs and poor long-term and cardiac outcomes in CAD patients. It might have impacted prognosis through effects on kidney function and lipid metabolism.

The Anti-Inflammatory Effect of Taurine on Cardiovascular Disease

Taurine is a non-protein amino acid that is expressed in the majority of animal tissues. With its unique sulfonic acid makeup, taurine influences cellular functions, including osmoregulation, antioxidation, ion movement modulation, and conjugation of bile acids. Taurine exerts anti-inflammatory effects that improve diabetes and has shown benefits to the cardiovascular system, possibly by inhibition of the renin angiotensin system. The beneficial effects of taurine are reviewed.

In silico analysis reveals interrelation of enriched pathways and genes in type 1 diabetes

Type 1 diabetes (T1D) is a multifactorial, polygenic complex autoimmune disease damaging pancreatic islet β cells. Numerous genes linked to T1D have been discovered through genetical studies, GWAS and polymorphisms. Most genetical studies focused on independent genes while others overemphasized on SNPs. Here, a collective analysis of documented T1D-associated genes was performed using bioinformatics tools. Enriched biological pathways, functions, enrichment clustering, networks and interactomes were analysed. Besides, meta-analyses of T1D-associated genes and T1D-related genes from SNPs were investigated to find common genes, pathways, enrichment and interrelationships. Notable enriched pathways comprised of cytokine-mediated signalling, cytokine production, interferon gamma production, myeloid leukocyte activation, activation of immune response, lymphocyte activation, adaptive immune response, Th17 cell differentiation etc. Enrichment analysis of T1D-associated genes emphasized the role of immune-linked machineries in metabolism, disease progression and aetiology of type 1 diabetes. Interactome analysis revealed overrepresentation of T1D-associated genes compared with T1D-related genes from SNPs. MCODE components highlighted the significance of pathways linked to vitamin D metabolism, signalling by interleukins, toll-like receptors, chemokines, PD-1, NOTCH, antigen processes etc. About 153 genes from MCODE complexes representing enriched pathways of T1D-associated genes and T1D-related genes from SNPs play a crucial role and may be important for further investigations. The information may be valuable for designing precision medicine-based therapeutics.

The Association of rs1898830 in Toll-Like Receptor 2 with Lipids and Blood Pressure

BACKGROUND AND OBJECTIVE

Toll-like receptors (TLRs) are important components of the innate immune system, involved in establishing immunity to infections. Apart from being implicated in immunity, numerous studies have reported that many TLRs, including TLR2, are involved in the pathogenesis of cardiovascular diseases and their risk factors. Since rs1898830 is associated with TLR2-mediated cellular activation, we aimed to study its association with CVD risk factors, such as lipid levels and hypertension.

METHODS

A cross-sectional study was conducted on 460 individuals free from chronic diseases. Clinical and biological data were collected and DNA was extracted and genotyped using Kompetitive allele specific PCR (KASP™). Multiple logistic regression models, adjusted for six covariates, were used. A power calculation analysis was also performed.

RESULTS

We found that rs1898830 in TLR2 was positively associated with hypertension (OR = 2.18, p = 0.03) and negatively associated with high-density lipoprotein cholesterol (OR = 0.66, p = 0.05). In contrast, no relation was found with total cholesterol and low-density lipoprotein cholesterol.

CONCLUSION

The present results provide additional evidence supporting the implication of TLR2 in CVD risk factors.

MMP9, CXCR1, TLR6, and MPO participant in the progression of coronary artery disease

Coronary artery disease (CAD) is the most frequent cardiovascular disease, which is induced by the decreased myocardial blood supply. The present study is conducted to understand the mechanisms of CAD. The GSE98583, GSE69587, and GSE71226 datasets from the Gene Expression Omnibus database were obtained. The differentially expressed genes (DEGs) were analyzed by the limma package, then the DEGs appeared in two or three datasets were selected as the coregulated genes using the VENNY tool, followed by enrichment analysis using DAVID tool. Protein-protein interaction (PPI) network, microRNA-transcription factor-target regulatory network, and drug-gene network were visualized. Finally, quantitative PCR and dual-luciferase reporter assay were conducted to validate the expression of key genes and the target relationship. There were 221 coregulated genes in GSE98583, GSE69587, and GSE71226. Besides, four pathways and 23 functional terms for co-upregulated genes, and 11 functional terms for co-downregulated genes were enriched. The degrees of PPI network nodes matrix metallopeptidase 9 (MMP9), C-X-C motif chemokine receptor 1 (CXCR1), toll-like receptor 6 (TLR6), and myeloperoxidase (MPO) were relatively higher. Moreover, MPO could interact with MMP9, CXCR1, and TLR6 in the PPI network. In the regulatory network, TLR6 and MMP9 separately were targeted by miR-3960 and v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA). Additionally, MMP9, CXCR1, and MPO were involved in the drug-gene network. The expression of MMP9, CXCR1, TLR6, and MPO were significantly upregulated in CAD samples than control, and miR-3960 could bind to TLR6 to inhibit its expression. CXCR1 and MPO might be involved in the progression of CAD. Besides, miR-3960 might function in the pathogenesis of CAD through targeting TLR6, and RELA might exert its role in CAD via targeting MMP9.

Toll-Interleukin 1 Receptor Domain-Containing Adaptor Protein 180L Single-Nucleotide Polymorphism Is Associated With Susceptibility to Recurrent Pneumococcal Lower Respiratory Tract Infections in Children

Lower respiratory tract infections (LRTI) are often caused by Streptococcus pneumoniae (Spn) and can be recurrent in 8% of children older than 2 years of age. Spn is recognized by pattern-recognition receptors (PRRs) of the innate immune system, in particular toll-like receptors (TLRs) 2 and 4. To assess whether a defect somewhere along this TLR signaling pathway increases susceptibility to recurrent pneumococcal LRTI, we conducted a prospective case-control study with 88 healthy individuals and 45 children with recurrent LRTI aged 2-5 years old. We examined cell surface expression of TLR2 and TLR4, as well as eight genetic variants of these receptors or associated co-receptors TLR1 and TLR6. Interleukin-6 production was measured after whole blood stimulation assays with specific agonists and heat-killed Spn. Our findings reveal that single-nucleotide polymorphisms within toll-interleukin 1 receptor domain-containing adaptor protein (TIRAP) alone or in combination with TLR1 N248S, TLR1 I602S, or TLR6 S249P polymorphisms contributes to various degree of susceptibility to recurrent pneumococcal LRTI in children by modulating the inflammatory response. In that respect, carriage of the TIRAP S180L heterozygous trait increases the likelihood to protect against pneumococcal LRTI, whereas children carrying the mutant homozygous TIRAP 180L polymorphism might be more likely susceptible to recurrent pneumococcal LRTI.

Microbial modulation of cardiovascular disease

Although diet has long been known to contribute to the pathogenesis of cardiovascular disease (CVD), research over the past decade has revealed an unexpected interplay between nutrient intake, gut microbial metabolism and the host to modify the risk of developing CVD. Microbial-associated molecular patterns are sensed by host pattern recognition receptors and have been suggested to drive CVD pathogenesis. In addition, the host microbiota produces various metabolites, such as trimethylamine-N-oxide, short-chain fatty acids and secondary bile acids, that affect CVD pathogenesis. These recent advances support the notion that targeting the interactions between the host and microorganisms may hold promise for the prevention or treatment of CVD. In this Review, we summarize our current knowledge of the gut microbial mechanisms that drive CVD, with special emphasis on therapeutic interventions, and we highlight the need to establish causal links between microbial pathways and CVD pathogenesis.

Genome-wide methylation profiles in coronary artery ectasia

Coronary artery ectasia (CAE) is a disease characterized by abnormally dilated coronary arteries. The mechanism of CAE remains unclear, and its treatment is limited. Previous studies have shown that risk factors for CAE were related to changes in DNA methylation. However, no systematic investigation of methylation profiles has been performed. Therefore, we compared methylation profiles between 12 CAE patients and 12 propensity-matched individuals with normal coronary arteries using microarrays. Wilcoxon's rank sum tests revealed 89 genes with significantly different methylation levels (P<0.05 and Δβ > |0.1|). Functional characterization using the DAVID database and gene set enrichment analysis indicated that these genes were involved in immune and inflammatory responses. Of these genes 6 were validated in 29 CAE patients and 87 matched individuals with CAE, using pyro-sequencing. TLR6 and NOTCH4 showed significant differences in methylation between the two groups, and lower protein levels of toll-like receptor 6 (TLR6) were detected in CAE patients. In conclusion, this genome-wide analysis of methylation profiles in CAE patients showed that significant changes in both methylation and expression of TLR6 deserve further study to elucidate their roles in CAE.

Association of TLR and TREM-1 gene polymorphisms with atherosclerosis severity in a Russian population

Local vascular immune response is primarily initiated via Toll-like receptors (TLRs) and triggering receptor expressed on myeloid cells-1 (TREM-1). We previously showed that certain TLR and TREM-1 gene polymorphisms are associated with coronary artery disease (CAD). Therefore, we hypothesized that these gene polymorphisms are associated with atherosclerosis severity. This study included 292 consecutive patients with CAD who were admitted to the Research Institute for Complex Issues of Cardiovascular Diseases (Kemerovo, Russian Federation) during 2011–2012. Sample genotyping was performed in 96-well format using the TaqMan SNP genotyping assay. We found that C/C genotype of the rs3804099 polymorphism within TLR2 gene and T/T genotype of the rs4711668 polymorphism within TREM-1 gene were significantly associated with severe coronary atherosclerosis while C allele of the rs5743551 polymorphism within TLR1 gene, A/G genotype of the rs4986790 polymorphism and C/T genotype of the rs4986791 polymorphism within TLR4 gene, and C allele of the rs3775073 polymorphism within TLR6 gene were significantly associated with severe noncoronary atherosclerosis. However, A/A genotype of the rs5743810 polymorphism within TLR6 gene was significantly associated with mild noncoronary atherosclerosis. We conclude that certain TLR and TREM-1 gene polymorphisms are significantly associated with atherosclerosis severity in a Russian population.

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Rs3804099 polymorphism of TLR2 gene is associated with severe coronary atherosclerosis.

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Rs4711668 polymorphism of TREM-1 gene is associated with severe coronary atherosclerosis.

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Rs5743551 polymorphism of TLR1 gene is associated with severe noncoronary atherosclerosis.

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Rs4986790 and rs4986791 polymorphisms of TLR4 gene are associated with severe noncoronary atherosclerosis.

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Rs3775073 polymorphism of TLR6 gene is associated with severe noncoronary atherosclerosis.

TLR-6 SNP P249S is associated with healthy aging in nonsmoking Eastern European Caucasians - A cohort study

BACKGROUND

To investigate mechanisms that determine healthy aging is of major interest in the modern world marked by longer life expectancies. In addition to lifestyle and environmental factors genetic factors also play an important role in aging phenotypes. The aged immune system is characterized by a chronic micro-inflammation, known as inflamm-aging, that is suspected to trigger the onset of age-related diseases such as cardiovascular disease, Alzheimer's disease, cancer, and Diabetes Mellitus Type 2 (DMT2). We have recently shown that a Toll-like receptor 6 variant (P249S) is associated with susceptibility to cardiovascular disease and speculated that this variant may also be associated with healthy aging in general by decreasing the process of inflamm-aging.

RESULTS

Analyzing the PolSenior cohort we show here that nonsmoking S allele carriers are significantly protected from age-related diseases (P = 0.008, OR: 0.654). This association depends not only on the association with cardiovascular diseases (P = 0.018, OR: 0.483) for homozygous S allele carriers, but is also driven by a protection from Diabetes Mellitus type 2 (P = 0.010, OR: 0.486) for S allele carriers. In addition we detect a trend but no significant association of this allele with inflamm-aging in terms of baseline IL-6 levels.

CONCLUSION

We confirm our previous finding of the TLR-6 249S variant to be protective regarding cardiovascular diseases. Furthermore, we present first evidence of TLR-6 249S being involved in DMT2 susceptibility and may be in general associated with healthy aging possibly by reducing the process of inflamm-aging.

Polymorphisms in Toll-like receptor genes are associated with vitiligo

Background: The members of Toll-like receptor (TLR) family are responsible for recognizing various molecular patterns associated with pathogens. Their expression is not confined to immune cells and have been detected in skin cells such as keratinocytes and melanocytes. As part of a generated response to pathogens, TLRs are involved in inducing inflammatory mediators to combat these threats. It is therefore not surprising that TLRs have been implicated in inflammatory skin diseases, including atopic dermatitis and psoriasis. Likewise, as key players in autoimmunity, they have been associated with a number of autoimmune diseases. Based on this, the role of TLRs in vitiligo could be suspected, but is yet to be clearly established.

Methods: In order to conduct a genetic association analysis, 30 SNPs were selected from TLR1-TLR8 and TLR10 regions to be genotyped in Estonian case-control cohort consisting of 139 vitiligo patients and 307 healthy control individuals. The patients were further analyzed in subgroups based on sex, age of onset, occurrence of vitiligo among relatives, extent of depigmented areas, vitiligo progression activity, appearance of Köbner's phenomenon, existence of halo naevi, and incidence of spontaneous repigmentation.

Results: The most notable finding came with SNP rs179020 situated in TLR7 gene, that was associated in entire vitiligo (Padj = 0.0065) and also several subgroup analyses. Other single marker and haplotype analyses pointed to TLR3, TLR4, and TLR10 genes.

Conclusions: This study investigated the genetic regions of nine TLR genes in relation to vitiligo susceptibility. The main results were the associations of TLR7 SNPs with vitiligo, while several other associations were obtained from the remaining TLR gene regions. This suggests that in addition to other inflammatory skin diseases, TLRs affect the development of vitiligo, thus making them interesting targets for future research.

Less functional variants of TLR-1/-6/-10 genes are associated with age

BACKGROUND

Determining the prerequisites for healthy aging is a major task in the modern world characterized by a longer lifespan of the individuals. Besides lifestyle and environmental influences genetic factors are involved as shown by several genome-wide association studies. Older individuals are known to have an impaired immune response, a condition recently termed "inflamm-aging". We hypothesize that the induction of this condition in the elderly is influenced by the sensitivity of the innate immune system. Therefore, we investigated genetic variants of the Toll-like receptor (TLR) family, one of the major family of innate immune receptors, for association with age in two cohorts of healthy, disease-free subjects.

RESULTS

According to sex we found a positive association of loss-of-function variants of TLR-1 and -6 with healthy aging with odds ratios of 1.54 in males for TLR-6 (249 S/S), and 1.41, 1.66, and 1.64 in females for TLR-1 prom., TLR-1 (248 S/S), and TLR-1 (602 S/S), respectively. Thus, the presence of these variants increases the probability of achieving healthy old age and indicates that a reduced TLR activity may be beneficial in the elderly.

CONCLUSIONS

This is the first report showing an association of TLR variants with age. While a loss of function of an important immune receptor may be a risk factor for acute infections as has been shown previously, in the setting of healthy ageing it appears to be protective, which may relate to "inflamm-aging". These first results should be reproduced in larger trials to confirm this hypothesis.

TLR2 and neutrophils potentiate endothelial stress, apoptosis and detachment: implications for superficial erosion

AIMS

Superficial erosion of atheromata causes many acute coronary syndromes, but arises from unknown mechanisms. This study tested the hypothesis that Toll-like receptor-2 (TLR2) activation contributes to endothelial apoptosis and denudation and thus contributes to the pathogenesis of superficial erosion.

METHODS AND RESULTS

Toll-like receptor-2 and neutrophils localized at sites of superficially eroded human plaques. In vitro, TLR2 ligands (including hyaluronan, a matrix macromolecule abundant in eroded lesions) induced endothelial stress, characterized by reactive oxygen species production, endoplasmic reticulum (ER) stress, and apoptosis. Co-incubation of neutrophils with endothelial cells (ECs) potentiated these effects and induced EC apoptosis and detachment. We then categorized human atherosclerotic plaques (n = 56) based on morphologic features associated with superficial erosion, 'stable' fibrotic, or 'vulnerable' lesions. Morphometric analyses of the human atheromata localized neutrophils and neutrophil extracellular traps (NETs) near clusters of apoptotic ECs in smooth muscle cell (SMC)-rich plaques. The number of luminal apoptotic ECs correlated with neutrophil accumulation, amount of NETs, and TLR2 staining in SMC-rich plaques, but not in 'vulnerable' atheromata.

CONCLUSION

These in vitro observations and analyses of human plaques indicate that TLR2 stimulation followed by neutrophil participation may render smooth muscle cell-rich plaques susceptible to superficial erosion and thrombotic complications by inducing ER stress, apoptosis, and favouring detachment of EC.

Association of Toll-like receptor polymorphisms with HIV status in North Americans

Single nucleotide polymorphisms (SNPs) in toll-like receptor (TLR) genes TLR2-4 and TLR7-9, but not in TLR1 and TLR6, have been previously evaluated regarding HIV acquisition and disease progression in various populations, most of which were European. In the present study, we examined associations between a total of 41 SNPs in 8 TLR genes (TLR1-4, TLR6-9) and HIV status in North American subjects (total n = 276 [Caucasian, n = 102; African American, n = 150; other, n = 24]). Stratification of the data by self-identified race revealed that a total of 9 SNPs in TLR1, TLR4, TLR6, and TLR8 in Caucasians, and 2 other SNPs, one each in TLR4 and TLR8, in African Americans were significantly associated with HIV status at P < 0.05. Concordant with the odds ratios of these SNPs, significant differences were observed in the SNP allele frequencies between HIV+ and HIV− subjects. Finally, in Caucasians, certain haplotypes of single (TLR1, TLR4) and heterodimer (TLR2_TLR6) genes may be inferred as “susceptible” or “protective”. Our study provides in-depth insight into the associations between TLR variants, particularly TLR1 and TLR6, and HIV status in North Americans, and suggests that these associations may be race-specific.

Relationship between toll-like receptor 2 Arg677Trp and Arg753Gln and toll-like receptor 4 Asp299Gly polymorphisms and cytomegalovirus infection

OBJECTIVES

The association among specific single-nucleotide polymorphisms (SNPs) in TLR2 (Arg677Trp, Arg753Gln) and TLR4 (Asp299Gln) and human cytomegalovirus (CMV) infection was studied in infants and adults.

METHODS

The TLR2 and TLR4 polymorphisms were genotyped in 151 patients with CMV infections and in 78 unrelated healthy individuals. Genotyping was performed by restriction fragment length polymorphism (RFLP) analysis of PCR-amplified fragments. The viral load was measured by quantitative real-time PCR.

RESULTS

Almost all of the patients with CMV infections were wild-type homozygotes without TLR2 and TLR4 polymorphisms. No significant differences in TLR2 and TLR4 polymorphisms were observed between infants with or without CMV infection. Compared with adults with CMV infections, heterozygosity for the TLR2 Arg677Trp and TLR4 Asp299Gly SNPs was detected more frequently in healthy individuals (p<0.05). Logistic regression analysis showed that the wild-type TLR2 genotype was associated with an increased risk of CMV infection and that heterozygosity for TLR2 and TLR4 SNPs diminished the risk of CMV infection in adult patients. An association between CMV load and the TLR4 SNP was found.

CONCLUSION

Our results suggest that the wild-type TLR2 genotype may be a risk factor for CMV replication in adult patients.