Impact of Toll-like receptor 4 polymorphisms on risk of cancer

Toll-like Receptor 4 Signaling Mediates Gastritis and Gastric Cancer

The stomach is a crucial digestive organ in the human body, highly susceptible to inflammation or pathogen invasion, which can lead to various gastric diseases, including gastric cancer. Toll-like receptors (TLRs) are the first line of defense against pathogen invasion. TLR4, a member of the TLRs family, recognizes pathogen and danger-related molecular patterns to induce inflammatory responses. Helicobacter pylori (H. pylori) is a significant factor in gastric health, and TLR4 recognizes H. pylori -LPS to trigger an inflammatory response. Downstream TLR4 signaling generates proinflammatory cytokines that initiate inflammation in the gastric mucosa. In addition, TLR4 gene polymorphisms can increase health risks. This study aims to investigate the contribution of TLR4 to the inflammatory response in gastric diseases and the relation between TLR4 and H. pylori, TLR4 gene polymorphisms, and how TLR4 affects gastric diseases' possible pathways to provide further insight for future prevention and clinical treatment strategies.

Genetic association and functional implications of TLR4 rs1927914 polymorphism on colon cancer risk

BACKGROUND

Colon cancer remains a major health concern worldwide, with genetic factors playing a crucial role in its development. Toll-like receptors (TLRs) has been implicated in various cancers, but their role in colon cancer is not well understood. This study aims to identify functional polymorphisms in the promoter and 3'UTR regions of TLRs and evaluate their association with colon cancer susceptibility.

METHODS

We conducted a case-control study involving 410 colon cancer patients and 410 healthy controls from the Chinese population. Genotyping of polymorphisms in TLR3, TLR4, TLR5 and TLR7 was performed using PCR-RFLP and TaqMan MGB probes. Using logistic regression analysis, we evaluated the association of TLRs polymorphisms and the susceptibility to colon cancer. To understand the biological implications of the TLR4 rs1927914 polymorphism, we conducted functional assays, including luciferase reporter assay and electrophoretic mobility shift assay (EMSA).

RESULTS

Our results demonstrated that the G-allele of the TLR4 rs1927914 polymorphism is significantly associated with a decreased risk of colon cancer (OR = 0.68, 95%CI = 0.50-0.91). Stratified analysis showed that TLR4 rs1927914 AG or GG genotype contributed to a decreased risk of colon cancer among younger individuals (OR = 0.52, 95%CI = 0.34-0.81), males (OR = 0.58, 95%CI = 0.38-0.87), non-smokers (OR = 0.58, 95%CI = 0.41-0.83) and non-drinker with OR (95%CI) of 0.66 (0.46-0.93). Functional assays demonstrated that in HCT116 and LOVO colon cancer cells, the luciferase activity driven by the TLR4 promoter with the rs1927914A allele was 5.43 and 2.07 times higher, respectively, compared to that driven by the promoter containing the rs1927914G allele. Electrophoretic mobility shift assay (EMSA) results indicated that the rs1927914G allele enhanced transcription factor binding. Using the transcription factor prediction tool, we found that the G allele facilitates binding of the repressive transcription factor Oct1, while the A allele does not.

CONCLUSION

The TLR4 rs1927914 polymorphism influence the susceptibility to colon cancer, with the G allele offering a protective effect through modulation of gene expression. These insights enhance our understanding of the genetic determinants of colon cancer risk and highlight TLR4 as a promising target for cancer prevention strategies.

Pathogenesis and therapeutic implications of EBV-associated epithelial cancers

Epstein-Barr virus (EBV), one of the most common human viruses, has been associated with both lymphoid and epithelial cancers. Undifferentiated nasopharyngeal carcinoma (NPC), EBV associated gastric cancer (EBVaGC) and lymphoepithelioma-like carcinoma (LELC) are amongst the few common epithelial cancers that EBV has been associated with. The pathogenesis of EBV-associated NPC has been well described, however, the same cannot be said for primary pulmonary LELC (PPLELC) owing to the rarity of the cancer. In this review, we outline the pathogenesis of EBV-associated NPC and EBVaGCs and their recent advances. By drawing on similarities between NPC and PPLELC, we then also postulated the pathogenesis of PPLELC. A deeper understanding about the pathogenesis of EBV enables us to postulate the pathogenesis of other EBV associated cancers such as PPLELC.

Pathomorphological Manifestations and the Course of the Cervical Cancer Disease Determined by Variations in the TLR4 Gene

Cervical cancer (CC) is often associated with human papillomavirus (HPV). Chronic inflammation has been described as one of the triggers of cancer. The immune system fights diseases, including cancer. The genetic polymorphism of pathogen recognition receptors potentially influences the infectious process, development, and disease progression. Many candidate genes SNPs have been contradictory demonstrated to be associated with cervical cancer by association studies, GWAS. TLR4 gene activation can promote antitumor immunity. It can also result in immunosuppression and tumor growth. Our study aimed to investigate eight selected polymorphisms of the TLR4 gene (rs10759932, rs1927906, rs11536898, rs11536865, rs10983755, rs4986790, rs4986791, rs11536897) and to determine the impact of polymorphisms in genotypes and alleles on the pathomorphological characteristics and progression in a group of 172 cervical cancer subjects with stage I-IV. Genotyping was performed by RT-PCR assay. We detected that the CA genotype and A allele of rs11536898 were significantly more frequent in patients with metastases (p = 0.026; p = 0.008). The multivariate logistic regression analysis confirmed this link to be significant. The effect of rs10759932 and rs11536898 on progression-free survival (PFS) and overall survival (OS) has been identified as important. In univariate and multivariate Cox analyses, AA genotype of rs11536898 was a negative prognostic factor for PFS (p = 0.024; p = 0.057, respectively) and OS (p = 0.008; p = 0.042, respectively). Rs11536898 C allele predisposed for longer PFS (univariate and multivariate: p = 0.025; p = 0.048, respectively) and for better OS (univariate and multivariate: p = 0.010; p = 0.043). The worse prognostic factor of rs10759932 in a univariate and multivariate Cox analysis for survival was CC genotype: shorter PFS (p = 0.032) and increased risk of death (p = 0.048; p = 0.015, respectively). The T allele of rs10759932 increased longer PFS (univariate and multivariate: p = 0.048; p = 0.019, respectively) and longer OS (univariate and multivariate: p = 0.037; p = 0.009, respectively). Our study suggests that SNPs rs10759932 and rs11536898 may have the potential to be markers contributing to the assessment of the cervical cancer prognosis. Further studies, preferably with larger groups of different ethnic backgrounds, are needed to confirm the results of the current study.

Linking dysbiosis to precancerous stomach through inflammation: Deeper than and beyond imaging

Upper gastrointestinal endoscopy is considered the gold standard for gastric lesions detection and surveillance, but it is still associated with a non-negligible rate of missing conditions. In the Era of Personalized Medicine, biomarkers could be the key to overcome missed lesions or to better predict recurrence, pushing the frontier of endoscopy to functional endoscopy. In the last decade, microbiota in gastric cancer has been extensively explored, with gastric carcinogenesis being associated with progressive dysbiosis. Helicobacter pylori infection has been considered the main causative agent of gastritis due to its interference in disrupting the acidic environment of the stomach through inflammatory mediators. Thus, does inflammation bridge the gap between gastric dysbiosis and the gastric carcinogenesis cascade and could the microbiota-inflammation axis-derived biomarkers be the answer to the unmet challenge of functional upper endoscopy? To address this question, in this review, the available evidence on the role of gastric dysbiosis and chronic inflammation in precancerous conditions of the stomach is summarized, particularly targeting the nuclear factor-κB (NF-κB), toll-like receptors (TLRs) and cyclooxygenase-2 (COX-2) pathways. Additionally, the potential of liquid biopsies as a non-invasive source and the clinical utility of studied biomarkers is also explored. Overall, and although most studies offer a mechanistic perspective linking a strong proinflammatory Th1 cell response associated with, but not limited to, chronic infection with Helicobacter pylori, promising data recently published highlights not only the diagnostic value of microbial biomarkers but also the potential of gastric juice as a liquid biopsy pushing forward the concept of functional endoscopy and personalized care in gastric cancer early diagnosis and surveillance.

Screening and Bioinformatics Analyses of Key miRNAs Associated with Toll-like Receptor Activation in Gastric Cancer Cells

Background and Objectives: To screen key miRNAs and their target genes related to Toll-like receptor (TLR) activation in gastric cancer (GC) cells and analyze them bioinformatically. Materials and Methods: Venn diagrams were obtained to screen miRNAs that were upregulated/downregulated in both GSE54129 and GSE164174. The miRTarBase database was used to predict the target genes of upregulated miRNAs. The differentially expressed genes in the regulatory network were analyzed. miR-16-5p expression in different tissue samples and the variations in the methylation states of four hub genes were measured. Results: We found that GSE54129 included 21 normal gastric tissues and 111 gastric cancer tissues, GSE164174 included 1417 normal gastric tissues and 1423 gastric cancer tissues. Venn diagram analysis results showed that compared with the control group, a total of 68 DEmiRNAs were upregulated in the GSE54129 and GSE164174 datasets, and no common downregulated DEmiRNAs were found. On further analysis of the GSE108345 dataset, we obtained the competing endogenous RNA (ceRNA) network associated with the activation of TLRs, and listed the top 10 lncRNA–miRNA–mRNA networks, including 10 miRNAs, 86 mRNA and 134 lncRNAs. Cytological HuBBA scores yielded a total of 1 miRNA, 16 mRNAs and 45 lncRNAs, of which miR-16-5p scored the highest as it was considered a key miRNA for TLR activation in GC cells, which are important in response against microorganisms. The results of Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that endocytosis, microRNAs in cancer and the PI3K-Akt signaling pathway are related to TLR signaling. The results of in vivo experiments indicated that miR-16-5p was highly expressed in gastric cancer cells and tissues. Conclusions: Hsa-miR-16-5p’s target genes mainly play a role by regulating the expression of four genes—MCL1, AP2B1, LAMB1, and RAB11FIP2. The findings provide a scientific basis for the development of immunotherapy for GC.

Polymorphisms and haplotypes of TLR-4/9 associated with bacterial infection, gingival inflammation/recession and oral cancer

BACKGROUND

The expression and SNPs of innate immunity genes TLR-4/9 for bacterial infection, gingival inflammation/gingival recession (GIGR), and oral squamous cell carcinoma (OSCC) are largely unknown.

PATIENTS AND METHOD

235 specimens (120 OSCC cases, among which 85 cases with either Porphyromonas gingivalis, Fusobacterium nucleatum or Treponema denticola infection and GIGR) and 115 healthy controls were used to know the expression and polymorphisms (TLR-4: N1:rs10759931, N2:rs11536889, N3:rs1927911, N4:rs4986790; TLR-9: N5:rs5743836, N6:rs352140, N7:rs187084 and N8:rs352139) of TLR-4/9 by western blot, RT-PCR, and allele-specific (AS)-PCR followed by sequencing.

RESULTS

Increased TLR-4/9 mRNA/protein expression, bacterial infection (BI) and GIGR were associated with OSCC incidence. One of the three BI and GIGR was observed in 70.83% of OSCC cases, whereas all the HC used were free from any of these three BI/GIGR. The N3: CT-genotype (Odds Ratio hereafter as O.R.=1.811, p = 0.0338), TT-genotype (O.R.=3.094, p = 0.0124), 'T'-allele (O.R.=1.821, p = 0.003), N4: AG-genotype (O.R.=2.015, p = 0.0222) and 'G'-allele (O.R.=1.86, p = 0.018) of TLR-4 as well as the N5: CC-genotype (O.R.=3.939, p = 0.0017), 'C'-allele (O.R.=1.839, p = 0.0042), N6: AA-genotype (O.R.=2.195, p = 0.0234), 'A'-allele (O.R.=1.569, p = 0.0163), N7: TC-genotype (O.R.=2.083, p = 0.0136), CC-genotype (O.R.=2.984, p = 0.003) and 'C'-allele (O.R.=1.885, p = 0.0008) of TLR-9 were associated with increased OSCC risk. Similarly, the N2:'C'-allele (O.R.=1.615, p = 0.0382), N3: TT-genotype (O.R.=2.829, p = 0.0336), 'T'-allele (O.R.=1.742, p = 0.0115), N4: AG-genotype (O.R.=2.221, p = 0.0147) and 'G'-allele (O.R.=1.890, p = 0.0238) of TLR-4 as well as the N5: CC-genotype (O.R.=2.830, p = 0.031), N6: AA-genotype (O.R.=2.6, p = 0.0122) and 'A'-allele (O.R.=1.746, p = 0.0064), N7:CC-genotype (O.R.2.706, p = 0.0111) and 'C'-allele (O.R. 1.774, p = 0.0055) of TLR-9 were correlated with GIGR and BI. TLR-4 (N1-N2-N3-N4: A-C-T-A (O.R.=2.1, p = 0.0069) and TLR-9 (N5-N6-N7-N8: T-A-C-A (O.R.=2.019, p = 0.0263); C-A-C-A (O.R.=6.0, p = 0.0084); C-A-C-G (O.R.=4.957, p = 0.0452) haplotypes were linked with OSCC vulnerability, while the TLR-4 (N1-N2-N3-N4: G-C-C-A (O.R.=0.5752, p = 0.0131) and TLR-9 (N5-N6-N7-N8: T-G-T-A (O.R.=0.5438, p = 0.0314); T-G-T-G (O.R.=0.5241, p = 0.036) haplotypes offered protection.

CONCLUSION

TLR-4/9 expression, polymorphisms, and BI-induced GIGR could increase OSCC risk. This may be used in pathogenesis and oral cancer prediction.

TLR4 regulatory region variants reduce the susceptibility of small-cell lung cancer in Chinese population

OBJECTIVES

Toll-like receptors (TLRs) participate in the induction and regulation of immune responses and are closely related to the occurrence and development of small-cell lung cancer (SCLC). This study aimed to investigate the impact of polymorphisms in the regulatory regions of TLRs on the susceptibility of SCLC.

METHODS

The case-control study included 304 SCLC patients and 304 healthy controls. TLRs gene polymorphisms were genotyped by PCR-restrictive fragment length polymorphism analysis and TaqMan assay. Unconditional logistic regression was used to estimate odds ratio (OR) and its 95% confidence interval (95% CI).

RESULTS

Our results showed that TLR4 rs1927914 GG genotype and TLR4 rs7869402 TT genotype reduced the risk of SCLC with OR (95% CI) of 0.54 (0.32-0.90) and 0.47 (0.28-0.80), respectively. Stratified analysis suggested that TLR4 rs1927914 GG genotypes significantly reduced the risk of SCLC among male (OR = 0.35; 95% CI, 0.18-0.69; P < 0.01), the younger patients (OR = 0.49; 95% CI, 0.26-0.94; P = 0.03) and non-drinkers (OR = 0.47; 95% CI, 0.24-0.89; P = 0.02). TLR4 rs7869402 CT or TT genotype significantly reduced the susceptibility to SCLC among male patients (OR = 0.37; 95% CI, 0.19-0.71, P < 0.01), the younger patients (OR = 0.41; 95% CI, 0.22-0.79; P < 0.01), smokers (OR = 0.25; 95% CI, 0.10-0.60; P < 0.01) and drinkers (OR = 0.31; 95% CI, 0.11-0.88; P = 0.03). TLR3 rs5743303, TLR4 rs11536891, TLR5 rs1640816 and TLR7 rs3853839 had no significant correlation with the risk of SCLC.

CONCLUSIONS

These findings emphasized the important role of TLR4 in the development of SCLC.

TLR4 deficiency upregulates TLR9 expression and enhances irinotecan-related intestinal mucositis and late-onset diarrhoea

BACKGROUND AND PURPOSE

Severe diarrhoea, a common gastrointestinal manifestation of anticancer treatment with irinotecan, might involve single nucleotide polymorphisms (SNPs) of toll-like receptors (TLRs), described as critical bacterial sensors in the gut. Here, colorectal cancer patients carrying missense TLR4 A896G (rs4986790) or C1,196T (rs4986791) SNPs and Tlr4 knockout (Tlr4-/-) mice were given irinotecan to investigate the severity of the induced diarrhoea.

EXPERIMENTAL APPROACH

Forty-six patients treated with irinotecan-based regimens had diarrhoea severity analysed according to TLR4 genotypes. In the experimental setting, wild-type (WT) or Tlr4-/- mice were given irinotecan (45 or 75 mg·kg^-1 , i.p.) or saline (3 ml·kg^-1 ). Diarrhoea severity was evaluated by measuring intestinal injury and inflammatory markers expression after animals were killed.

KEY RESULTS

All patients with TLR4 SNPs chemotherapy-treated presented diarrhoea, whereas gastrointestinal toxicity was observed in 50% of the wild homozygous individuals. Mice injected with irinotecan presented systemic bacterial translocation and increased TLR4 immunostaining in the intestine. In line with the clinical findings, Tlr4 gene deficiency enhanced irinotecan-related diarrhoea and TLR9 expression in mice. An increased myeloperoxidase activity and Il-18 expression along with IL-10 decreased production in Tlr4-/- mice also indicated an intensified intestinal damage and inflammatory response.

CONCLUSION AND IMPLICATIONS

TLR4 deficiency upregulates TLR9 expression and enhances intestinal damage and the severity of late-onset diarrhoea during irinotecan-based treatment. Identifying patients genetically predisposed to chemotherapy-associated diarrhoea is a strategy toward precision medicine.

Toll-like receptor gene polymorphisms in patients with myeloproliferative neoplasms

Toll-like receptors (TLRs) are a family of transmembrane receptors whose signaling control cellular processes of cell proliferation, survival, apoptosis, angiogenesis, remodeling, and repair of tissues. Polymorphisms in TLR genes can change the balance between pro and anti-inflammatory cytokines, modulating the risk of infection, chronic inflammation, and cancer. Although many studies have demonstrated the direct involvement of TLR signaling in the benefit of tumor cells in certain cancers, little is known about the influence of these gene polymorphisms on myeloproliferative neoplasms (MPNs). In this context, the objective of the study was to investigate a possible association between the TLR polymorphisms and the development of MPNs. 167 patients diagnosed with MPN and 222 healthy controls from the same region were evaluated. Genomic DNA was extracted and the TLR2 (rs5743708), TLR4 (rs4986790, rs4986791), TLR9 (rs5743836, rs187084) and JAK2V617F polymorphisms were genotyped by PCR-RFLP. The statistical analysis was performed by OpenEpi and SNPstat software. The JAK2V617F mutation was found in 68.32% of patients. TLR9-1486C/T CT genotype was less frequent in patients with polycythemia vera (PV) (OR 0.39, 95% CI 0.20-0.78, P = 0.025). When haplotype frequencies were analyzed, -1237T/-1486C (TLR9) was also less frequent in men (OR 0.58, 95% CI 0.36-0.94) and JAK negative men patients (OR 0.43, 95% CI 0.21-0.88). We can infer that the TLR9-1486 CT genotype could be associated with protection for PV and the TLR9-1237T/-1486C haplotype, protection for men, as well as for JAK negative men patients with MPN. There were no associations between TLR2 and TLR4 gene polymorphisms and MPN.

Taurine ameliorates thioacetamide induced liver fibrosis in rats via modulation of toll like receptor 4/nuclear factor kappa B signaling pathway

Liver fibrosis is a significant health problem that can cause serious illness and death. Unfortunately, a standard treatment for liver fibrosis has not been approved yet due to its complicated pathogenesis. The current study aimed at assessing the anti-fibrotic effect of taurine against thioacetamide induced liver fibrosis in rats through the modulation of toll like receptor 4/nuclear factor kappa B signaling pathway. Both concomitant and late taurine treatment (100 mg/kg, IP, daily) significantly reduced the rise in serum ALT and AST activities and significantly reversed the decrease in serum albumin and total protein. These results were confirmed by histopathological examinations and immunehistochemical inspection of α-SMA, caspase-3 and NF-κB. The antioxidant potential of taurine was verified by a marked increase of GSH content and a reduction of MDA level in liver tissue. The anti-fibrotic effects of taurine were evaluated by investigating the expression of TLR4, NF-κB. The protein levels of IL-6, LPS, MyD88, MD2, CD14, TGF-β1 and TNF-α were determined. Docking studies were carried out to understand how taurine interacts inside TLR4-MD2 complex and it showed good binding with the hydrophobic binding site of MD2. We concluded that the anti-fibrotic effect of taurine was attributable to the modulation of the TLR4/NF-κB signaling.

TLR4 rs1927914 polymorphism contributes to serum TLR4 levels in patients with aortic aneurysm

Toll-like receptor 4 (TLR4) is a crucial regulator of inflammatory reactions and vascular remodeling. Elevated TLR4 expression has been proved to be correlated with an increased risk of aortic aneurysm (AA). This study aimed to explore the influence of TLR4 gene polymorphisms on TLR4 expression levels and its probable functional significance in AA disease. A total of 294 AA patients and 285 controls were enrolled in the study and serum TLR4 levels were detected by ELISA. All the participants were genotyped for two tag-SNPs in TLR4 (rs1927914 in the promoter region and rs11536889 in the 3'-untranslated region) using the KASP method. Relative luciferase activity was measured by the dual-luciferase reporter assay system. The rs1927914 TC, TC/CC genotypes and C allele showed associations with increased serum TLR4 levels in the total population and AA patients (all P<0.05). Further stratified analysis demonstrated that AA subjects with TC or TC/CC genotype of rs1927914 had significantly higher serum levels of TLR4 than those with TT genotype in male, age>60y, hypertension, diabetes, TAA type and size>5.0 cm subgroups (all P<0.05). In binary logistic analysis, rs1927914 TC genotype and dominant model presented significant associations with high TLR4 levels (OR = 1.579 and 1.431, P = 0.020 and 0.049, respectively) after adjusting age, hypertension and diabetes. However, rs11536889 polymorphism had no significant influence on serum TLR4 levels. Regarding rs1927914, luciferase activity of the C allele construct was significantly increased in comparison with the T allele construct (0.589 ± 0.004 vs. 0.340 ± 0.014, P<0.001). Our results provided evidence that rs1927914 polymorphism contributed to serum TLR4 levels, possibly by influencing promoter activity of TLR4, and could be a novel genetic factor in the formation of AA.

Higher Levels of Serum TLR2 and TLR4 in Patients with Hashimoto's Thyroiditis

OBJECTIVE

Hashimoto's thyroiditis (HT) is an autoimmune disorder caused by the interaction between genes and environmental triggers. HT is the most common endocrine disorder, as well as the most common cause of hypothyroidism. Autoimmunity plays a crucial role in the pathogenesis of HT and recent studies suggest that Toll-like receptor (TLR) signals lead to increased inflammatory response. The aim of our study is to investigate whether TLR-2 and TLR-4 levels and gene polymorphisms contribute to the damaged immune response leading to HT.

METHODS

Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, single-nucleotide polymorphisms (SNPs) of TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile were studied in 100 patients with HT and 100 healthy controls. Also, we investigated serum levels of TLR-2 and TLR-4 in the immunopathogenesis of HT. TLR-2 and TLR-4 serum levels were found to be significantly higher in HT patients than the control group. However, no statistical significance was found between patient and control groups in terms of genotype frequencies and allele frequency distribution of TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile polymorphisms.

RESULT

TLR2 gene Arg677Trp, Arg753Gln, 196-174 del and TLR4 gene Asp299Gly, Thr399Ile polymorphism do not appear to have a role in the development of HT disease. However, in our study, serum levels of TLR-2 and TLR-4 were found to be higher in HT patients than control groups.

CONCLUSION

These findings suggest that TLR-2 and TLR-4 play an important role in the immunopathologic mechanism of disease by causing an increase in proinflammatory response.

TLR4 polymorphisms may increase susceptibility to periodontitis in Pg-positive individuals

Objective

To investigate the correlation between the single nucleotide polymorphisms (SNPs) in the toll-like receptor 4 (TLR4) gene and the susceptibility to chronic periodontitis.

Design

241 Chinese subjects from the cohort of Beijing Shijingshan Community were recruited. Buccal swab samples, the whole unstimulated saliva and periodontal clinical parameters were collected. Human DNA extracted from buccal swab samples were used for genotyping eight SNPs of the TLR4 gene (rs11536889, rs1927906, rs1927911, rs2149356, rs4986790, rs4986791, rs2737190, rs787384) by the Sequenom MassARRAY system. Porphyromonas gingivalis (P. gingivalis) was detected from the deposition of the whole unstimulated saliva through polymerase chain reaction (PCR) method based on 16S rRNA. The correlation between SNPs of TLR4 and chronic periodontitis susceptibility in the whole subjects and the patients detected with P. gingivalis was investigated.

Results

The variants of rs4986790 and rs4986791 were not found in 241 Chinese subjects. Moreover, there was no significant difference in the distribution of theother6 SNPs of TLR4 between groups of none/mild -periodontitis and moderate/severe-periodontitis subjects. When combined with P. gingivalis infection, rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG) were independent risk factors of chronic periodontitis.

Conclusion

Three SNPs of TLR4, i.e., rs1927911 (TT/CC+CT), rs2149356 (TT/GG+GT) and rs2737190 (GG/AA+AG), were associated with moderate/severe chronic periodontitis in Chinese population infected with P. gingivalis. P. gingivalis, which interacted with TLR4 gene plays an important role in the pathogenesis of periodontitis.

The relationship between TLR4 rs4986790 and rs4986791 gene polymorphisms and Helicobacter pylori infection in children with gastritis

BACKGROUND

TLR4 is involved in H. pylori lipopolysaccharide recognition and its SNPs might be related to increased risk of developing premalignant conditions and gastric cancer. The objectives of the study were to evaluate the associations between both TLR4 rs4986790 and rs4986791 gene polymorphisms and H. pylori infection in children with gastritis.

METHODS

We performed a cross-sectional study on 150 children admitted in a Tertiary Centre from Romania, between March 2016 and July 2018 in order to evaluate them regarding demographic, endoscopic, histopathological and TLR4 gene polymorphisms.

RESULTS

Our final sample consisted of 50 children with H.pylori associated gastritis (group 1-Ghp group) and 97 children with gastritis without H.pylori infection (group 2). Poor socioeconomic status was a significant risk factor for H.pylori infection. We found no significant differences regarding the clinical symptoms and laboratory parameters between the two groups. Concordant results were found between the histopathological exam and rapid urease test. Variant genotypes of TLR4rs4986790 and TLR4rs4986791 gene polymorphisms acted as protective factors against H. pylori infection, without statistical significance.

CONCLUSIONS

The variant genotype of the TLR4 gene polymorphisms might be protective factors for H.pylori infection, while socioeconomic status is an risk factor for H. pylori infection. Urease test is a usefull diagnostic tool for H. pylori infection.

Hepatoprotective effects of vicenin-2 and scolymoside through the modulation of inflammatory pathways

The aim of this study was to investigate the effects of two structurally related flavonoids found in Cyclopia subternata, vicenin-2 (VCN) and scolymoside (SCL) on lipopolysaccharide (LPS)-induced liver failure in mice and to elucidate underlying mechanisms. Mice were treated intravenously with VCN or SCL at 12 h after LPS treatment. LPS significantly increased mortality, serum levels of alanine transaminase, aspartate transaminase, and inflammatory cytokines, and toll-like receptor 4 (TLR4) protein expression; these effects of LPS were inhibited by VCN or SCL. It also attenuated the LPS-induced activation of myeloid differentiation primary response gene 88 and TLR-associated activator of interferon-dependent signaling pathways of the TLR system. Our results suggest that VCN or SCL protects against LPS-induced liver damage by inhibiting the TLR-mediated inflammatory pathway, indicating its potential to treat liver diseases.

Toll-like receptor 2 and 4 polymorphisms associated with Helicobacter pylori susceptibility and gastric cancer

BACKGROUND/AIMS

Genetic polymorphisms in Toll-like receptors (TLRs) are important influence on gastric lesion development and Helicobacter pylori susceptibility.

MATERIALS AND METHODS

TLR2 rs3804099 and rs3804100 and TLR4 rs10759932 were determined in a total of 400 patients. The association among genotypes and the risk of gastric lesion development and H. pylori susceptibility were evaluated by the odds ratios (ORs) and 95% confidence intervals (95% CIs) from logistic regression analyses.

RESULTS

TLR4 rs10759932, C/C homozygous genotype was associated with an increased risk of premalignant/malignant (OR=2.48, 95% CI=1.96-4.62, p=0.015). The recessive model of TLR4 rs10759932 showed a decreased risk of H. pylori susceptibility (adjusted OR=0.52, 95% CI=0.38-0.82, p=0.046). Meanwhile, the recessive model was associated with an increased risk of non-malignant (OR=3.46, 95% CI=2.25-5.67, p=0.001). In subjects with H. pylori infection, the recessive model was associated with an increased risk of non-malignant (OR=2.28, 95% CI=1.24-3.57, p=0.001) and premalignant/malignant (OR=1.83, 95% CI=1.16-2.84, p=0.027).

CONCLUSION

TLR4 rs10759932, but not TLR2 rs3804099 and rs3804100, was associated with risk of premalignant and/or malignant and H. pylori susceptibility. H. pylori infection seems to contribute to chronic gastritis, and premalignant/malignant supported the development of the premalignant/malignant lesions involved in H. pylori infection that is critical to gastric cancer in Thai patients.

The interaction effects between TLR4 and MMP9 gene polymorphisms contribute to aortic aneurysm risk in a Chinese Han population

Background

A cross-talk between Toll-like receptor 4 (TLR4) and matrix metalloproteinase 9 (MMP9) plays a vital role in aortic pathophysiology. The objective of this study was to evaluate the interactions between TLR4 and MMP9 polymorphisms in the risk of aortic aneurysm (AA) and its subtypes.

Methods

KASP method was used to detect polymorphisms of TLR4 (rs11536889 and rs1927914) and MMP9 (rs17576) in 472 AA patients and 498 controls. According to location and size, AA patients were further classified into abdominal AA (AAA), thoracic AA (TAA), and large AA (>5.0 cm), small AA(≤5.0 cm), respectively.

Results

The significant interaction effect of TLR4rs1927914 with MMP9rs17576 polymorphisms was observed for the risk of TAA (P_interaction = 0.038, OR = 6.186) and large AA (P_interaction = 0.044, OR = 5.892). There were epistatic effects between TLR4rs1927914 and MMP9rs17576 polymorphisms on the risk of overall AA, AAA, TAA and large AA when they were present together. Moreover, the cumulative effects of the pairwise interaction TLR4rs1927914-MMP9rs17576 were associated with an increased risk of overall AA (P_trend = 0.032) and AAA (P_trend = 0.031).

Conclusions

The novel interaction between TLR4rs1927914 and MMP9rs17576 polymorphisms could increase the risk of AA disease or its subtypes by exerting epistatic and cumulative effects.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1049-8) contains supplementary material, which is available to authorized users.

The associations between Toll-like receptor 4 gene polymorphisms and hepatitis C virus infection: a systematic review and meta-analysis

Background and objective: The hepatitis C virus (HCV) is able to cause a life-threatening disease relating to lethal hepatocellular carcinoma. Previous, Toll-like receptor polymorphisms were proposed as promising biomarker for HCV-related hepatocellular carcinoma and disease progression. This study aimed to summarize the association of TLR4 polymorphisms and HCV infection through meta-analysis.

Methods: We applied a systematic review and meta-analysis performed by using PubMed, EMBASE and Web of Science searches. The Modified Newcastle-Ottawa scale was used for quality assessment. The odd-ratio (OR) and 95% confidence interval (CI) were calculated to assess the association. In silico analysis was applied for proposing the function as microRNA (miRNA) of non-coding polymorphism. Finally, the miRNA target was predicted and annotated to suggest the possible relationship between polymorphism and HCV infection.

Results: Our meta-analysis incorporated seven studies involving rs4986791, rs4986790 and rs2149356. No association exists between rs4986791 and HCV infection. However, the heterozygous model (AG vs GG) of rs4986790 significantly associates with HCV infection (OR = 0.33, 95% CI = 0.21–0.49, P<0.0001). Moreover, the rs2149356 TG genotype also associates with HCV infection in the over-dominant model (TG vs TT+TG: OR = 0.54, 95% CI = 0.40–0.75). In silico analysis of rs2149356G allele showed that this mutation is siRNA, which targets the set of genes, especially in the autophagy pathway.

Conclusion: We demonstrated that rs4986790 and rs2149356 are associated with HCV infection.

Genetic polymorphisms in TLR1, TLR2, TLR4, and TLR10 of Helicobacter pylori-associated gastritis: a prospective cross-sectional study in Thailand

The toll-like receptors (TLRs) mediate the recognition of Helicobacter pylori and initiate the innate immune response to infection. We hypothesized those genetic polymorphisms in the TLR1, TLR2, TLR4, and TLR10 influence bacterial infection, affecting susceptibility H. pylori to disease outcomes. Genomic DNA was extracted and genotypes of TLR1 (rs4833095), TLR2 (rs3804099 and rs3804100), TLR4(rs10759932), and TLR10 (rs10004195) polymorphism were detected by the TagMan single-nucleotide epolymorphisms genotyping assay using the real-time PCR hybridization probe method. The TLR1 (rs4833095), C allele and the TLR10 (rs10004195), A allele frequency was significantly increased risk in the H. pylori infection group (odds ratio=1.76, 95% confidence interval=1.84–2.15, P=0.01 and odds ratio=1.81, 95% confidence interval=1.18–3.26, P=0.04, respectively). The TLR1 (rs4833095), C allele and TLR10 (rs10004195), A allele are susceptible TLRs polymorphisms in the Thai population. These findings suggest that TLR1 rs4833095 and TLR10 rs10004195 may play crucial roles in H. pylori susceptibility and gastric pathogenesis.

Polymorphisms of TGFBR1, TLR4 are associated with prognosis of gastric cancer in a Chinese population

Background

Helicobacter pylori (H. pylori)-induced gastric cancer is an intricate progression of immune response against H. pylori infection. IL-16, TGF-β1 and TLR4 pathways were the mediators involved in the immune response. We hypothesized that genetic variations in genes of these pathways have potential susceptibility to gastric cancer risk, and predict clinical outcomes of patients.

Methods

To investigate the susceptibility and prognostic value of genetic variations of IL-16, TGFBR1 and TLR4 pathways to gastric cancer, we performed a case–control study combined a retrospective study in a Chinese population. Genotyping for all polymorphisms was based on the Sequenom’s MassARRAY platform, and H. pylori infection was determined by using an immunogold testing kit.

Results

We found rs10512263 CC genotype was found to be a decreased risk of gastric cancer (CC vs. TT: adjusted OR = 0.54, 95% CI 0.31–0.97); however, rs334348 GG genotype was associated with increased risk of gastric cancer (GG vs. AA: adjusted OR = 1.51, 95% CI 1.05–2.18). We found that carriers harboring rs1927911 A allele (GA/AA) or rs10512263 C allele (CT/CC) have unfavorable survival time than none carriers (rs1927911: GA/AA vs. GG: adjusted HR = 1.27, 95% CI 1.00–1.63; rs10512263: CT/CC vs. TT: adjusted HR = 1.29, 95% CI 1.02–1.63) and that individuals harboring both two minor alleles (rs1927911 GA/AA and rs10512263 CT/CC) suffered a significant unfavorable survival (adjusted HR = 1.64, 95% CI 1.17–2.31).

Conclusion

In short, we concluded that two polymorphisms (rs334348, rs10512263) in TGFBR1 were associated with risk of gastric cancer, and that TLR4 rs1927911 and TGFBR1 rs10512263 were associated with clinical outcomes of gastric cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0682-0) contains supplementary material, which is available to authorized users.

Protective Effects of Pelargonidin on Lipopolysaccharide-induced Hepatic Failure

Pelargonidin (PEL) is a well-known red pigment found in plants and has important biological activities that are potentially beneficial for human health. The aim of this study was to investigate the effect of PEL on lipopolysaccharide (LPS)-induced liver failure in mice, and to elucidate its underlying molecular mechanisms. Liver failure was induced by LPS (15 mg/kg, i.p) in mice, and 12 h later, they were treated intravenously with PEL. Administration of LPS significantly increased mortality, serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and inflammatory cytokines, and expression of toll-like receptor 4 (TLR4) protein; PEL treatment effectively countered these effects of LPS. Further, LPS treatment markedly increased the expression of myeloid differentiation primary response gene 88 (MyD88), phosphorylation of p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK), and expressions of nuclear proteins, such as nuclear factor (NF)-κB and phosphorylated c-Jun. Additionally, LPS increased the serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6. All these effects of LPS were attenuated by PEL. In addition, the LPS-mediated increase in the level of serum interferon (IFN)-β expression of the TLR-associated activator of IFN (TRIF) protein, and phosphorylation of IFN regulator factor 3 (IRF3) were reduced by PEL. Our results suggest that PEL attenuates LPS-induced liver damage by inhibition of the TLR-mediated inflammatory pathway and could be used to treat liver diseases.

Association of Toll-like receptor 4 single-nucleotide polymorphisms Asp299Gly and Thr399Ile with the risk of primary open angle glaucoma

PURPOSE

Toll-like receptor 4 (TLR4) is a transmembrane receptor that mediates immune responses to exogenous and endogenous ligands. Previously, non-coding single nucleotide polymorphisms (SNPs) in the TLR4 gene were related to primary open angle glaucoma (POAG). This study was undertaken to investigate whether coding TLR4 Asp299Gly (rs4986790 A/G) and Thr399Ile (rs4986791 C/T) are associated with POAG in a Mexican population.

METHODS

One hundred and eighty-seven unrelated Mexican patients with POAG (94 men and 95 women; mean age 66.49 ± 14.3 years) and 109 control subjects (40 men and 69 women; age, 63.28 ± 7.93 years) were included. SNPs Asp299Gly (rs4986790 A/G) and Thr399Ile (rs4986791 C/T) were genotyped by a Taqman® Allelic Discrimination Assayand. Allelic, genotypic, haplotypic, and model-based (dominant, recessive, and codominant) associations of the SNPs with POAG were analyzed using Chi-squared tests or Fisher exact tests and logistic regression.

RESULTS

Strong linkage disequilibrium was observed among the SNPs (D' = 0.8692), which were located in one haplotype block. With respect to allelic diversity, the minor allele of both SNPs generates a significantly increased risk of POAG. The minor allele of Asp299Gly conferred the highest increased risk of POAG (P = 0.0054, OR = 4.47, 95% CI = 1.46-13.70). With regard to genotypic diversity, individuals carrying the minor allele of Asp299Gly and Thr399Ile had a significant increased risk for POAG with OR of 4.47 (P = 0.054, 95% CI = 1.30-15.35) and 3.5, respectively (P = 0.012, 95% CI = 1.17-10.44). Haplotype analysis was non-significant.

CONCLUSIONS

TLR4 coding SNPs Asp299Gly and Thr399Ile might be used as genetic susceptibility alleles for POAG in Mexican population. Our findings support the role of TLR4 in the pathophysiology of glaucoma.

Toll-Like Receptor 4 Signaling in High Mobility Group Box-1 Protein 1 Mediated the Suppression of Regulatory T-Cells

BACKGROUND Treg cells play a central role in the suppression of immune response, and their suppressive capacity can be modulated by toll-like receptor (TLR) ligands. However, the detailed pathway of TLR ligand modulation is still unknown. The present study aimed to evaluate the effect of the high mobility group box-1 protein 1 (HMGB1) and lipopolysaccharide (LPS) on Treg cells through TLR4 signaling. MATERIAL AND METHODS Treg cells were purified from healthy human peripheral blood mononuclear cells (PBMCs) by magnetic-bead activity cell sorting (MACS), blocked by anti-TLR4 monoclonal antibody, and then incubated with different concentration of LPS or HMGB1. The level of gene expression of IL-1β, IL-10, IFN-γ, and TGF-β were detected using quantitative real-time polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA), and the proliferation of Treg cells after treating by LPS and HMGB1 was analyzed by flow cytometry. The NF-κB expression in Treg cells was examined by Western blotting. RESULTS LPS treated CD4 CD25 Treg cells directly increased the expression of IL-1b and IL-10 and decreased the expression of IFN-γ and TGF-β. However, HMGB1 treatment resulted in a marked decreased expression of IL-1β, IL-10, IFN-γ, and TGF-β. The proliferation of CD4+ T cells was significantly inhibited by Treg cells in the LPS treatment group, but weaken in the HMGB1 treatment group. These data suggest that HMGB1 and LPS stimulation could downregulate the expression NF-κB p65 in cytoplasmic proteins and increase the expression in nuclear proteins, thus leading to modulation of IL-1β, IL-10, IFN-γ, and TGF-β expression; moreover, the suppressive function of Treg cells could be regulated by TLR4. CONCLUSIONS TLR4 signaling in HMGB1 mediated the suppressive function of Treg cells through the activation of the NF-κB pathway.

Pathogen recognition and Toll-like receptor targeted therapeutics in innate immune cells

The innate immune system deploys a variety of pattern-recognition receptors (PRRs) which include Toll-like receptors (TLRs), RIG-I-like receptors, NOD-like receptors, and C-type lectin receptors to detect the invasion of pathogens and initiate protective responses. The intercellular and intracellular orchestration of signals from different PRRs, their endogenous or microbial ligands and accessory molecules determine the stimulatory or inhibitory responses. Progressing over the last two decades, considerable research on the molecular mechanisms underlying host-pathogen interactions has led to a paradigm shift of our understanding of TLR signaling in the innate immune system. Given that a significant amount of evidence implicates TLRs in the pathogenesis of immune diseases and cancer, and their activation occurs early in the inflammatory cascade, they are attractive targets for novel therapeutic agents. In this review, we discuss the recent advances in TLR signaling cross talks and the mechanism of pathogen recognition with special emphasis on the role of TLRs in tumor immunity and TLR-targeted therapeutics.

Association of Polymorphisms in Toll-Like Receptors 4 and 9 with Autoimmune Thyroid Disease in Korean Pediatric Patients

BACKGROUND

Toll-like receptors (TLRs) have been suggested to be associated with the development of AITD.

METHODS

Fifteen single-nucleotide polymorphisms in 7 TLR genes were analyzed in 104 Korean children (girls = 86, boys = 18) with AITD (Hashimoto disease (HD) = 44, Graves' disease (GD) = 60, thyroid-associated ophthalmopathy (TAO) = 29, and non-TAO = 31) with 183 controls.

RESULTS

GD showed higher frequencies of the TLR4 rs1927911 C allele than control. TAO showed a lower frequency of the TLR4 rs1927911 CT genotype and non-TAO showed a higher frequency of the TLR4 rs1927911 CC genotype than control. The frequency of the TLR9 rs187084 CC genotype in TAO was higher than that in non-TAO. GD females showed a higher frequency of the TLR4 rs10759932 T allele, rs1927911 CC genotype, and the rs1927911 C allele than controls. GD males showed a higher frequency of the TLR4 rs10759932 CC genotype and rs1927911 TT genotype and lower frequency of the rs1927911 CT genotype than control. The frequency of the TLR4 rs10759932 CC genotype, C allele and rs1927911 TT genotype, and T allele in a GD female were lower than in a GD male.

CONCLUSIONS

Our results suggest that TLR4 and 9 polymorphisms might contribute to the pathogenesis of GD and TAO.

Genetic variants of TLR4 and TLR9 are risk factors for chronic Helicobacter pylori infection in South Indian Tamils

Toll like receptors (TLRs) are a class of molecular pattern recognition receptors, elicits a strong inflammatory immune response against pathogens. Helicobacter pylori (H. pylori), a gram negative flagellate colonizes the human stomach, is responsible for the development of chronic gastritis and gastric carcinoma. The higher incidence of H. pylori infection and gastric cancer in South Indian Tamils demands a genetic study to unravel the influence of TLR4 and TLR9 polymorphisms associated with chronic H. pylori infection. In this study, 230 healthy individuals and 77 patients diagnosed with H. pylori infection were screened for TLR4 (rs1927914, rs4986790, rs4986791) and TLR9 (rs352140, rs34399053, rs150459369) polymorphisms by PCR-RFLP and ARMS-PCR. We observed that the individuals harboring heterozygous and homozygous polymorphic variants of TLR4 conferred a significant risk to develop chronic H. pylori infection and peptic ulcer disease [rs4986790 AG, p=0.001, OR-2.7, 95%CI: 1.5-5.03; GG, p=0.0006, OR-9.8, 95%CI: 2.4-39.4; rs4986791CT, p=0.0001, OR-7.2, 95%CI: 3.7-7.2; TT, p=0.0001, OR-7.9, 95%CI: 2.6-23.7]. Also, the heterozygous variant of TLR9 rs352140, favoured the persistence of the H. pylori infection [p=0.037, OR-1.87, 95%CI: 1.07-3.29]. Thus our findings suggest that TLR4 rs4986790, rs4986791 and TLR9 rs352140 polymorphisms are potential genetic risk factors influencing the disease susceptibility and clinical manifestation of chronic H. pylori infection in Indian Tamils.

Association of single-nucleotide polymorphisms in non-coding regions of the TLR4 gene with primary open angle glaucoma in a Mexican population

BACKGROUND

Toll-like receptor 4 (TLR4) non-coding polymorphisms are associated to primary open angle glaucoma (POAG), normal tension glaucoma, and pseudoexfoliation glaucoma. This study was performed to determine whether non-coding single nucleotide polymorphisms (SNPs) in the TLR4 gene contribute to POAG in a Mexican population.

MATERIAL AND METHODS

A total of 187 unrelated Mexican patients with POAG and 109 control subjects were included. Allelic, genotypic, and haplotypic diversity was assessed for the non-coding polymorphisms rs11536889, rs1927911, rs12377632, and rs2149356 of the TLR4 gene. Genotyping of target SNPs was performed by 5' exonuclease allelic discrimination assays.

RESULTS

Strong linkage disequilibrium was observed among the SNPs (D' > 0.818), which were located in one haplotype block. The rs11536889 polymorphism was not associated to POAG in any case. The frequency of the minor allele of rs2149356 was significantly higher in the glaucoma group, conferring an increased risk of POAG (p = 0.0018, OR = 1.803, 95% CI 1.2556-2.5890) whereas minor allele of rs12377632 was significantly lower, attributing a protective effect (p = 0.0001, OR = 0.6662, 95% CI 0.4753-0.9339). Subjects with genotypes carrying the minor allele of rs1927911 and rs2149356 shown an increased risk for POAG (p = 0.03, OR = 1.78, 95% CI 1.10-2.87, and p < 0.0004, OR =2.62, 95%CI 1.61-4.27 respectively). Finally, we found significant risk haplotypes. The GTT haplotype (constituted by rs1927911, rs12377632, and rs2149356) reached the higher OR (p = 0.0026, OR = 4.70, 95% CI 1.73-12.77).

CONCLUSIONS

We have identified intronic TLR4 SNPs as genetic susceptibility alleles for POAG in a Mexican population. Our findings support the association of the TLR4 gene with POAG.

Lipopolysaccharide-pathway proteins are associated with gallbladder cancer among adults in Shanghai, China with mediation by systemic inflammation

PURPOSE

We examined inflammation as a mediator of associations between bacterial infection markers and gallbladder cancer (GBC).

METHODS

Bacterial response proteins (lipopolysaccharide [LPS], soluble cluster of differentiation 14 [sCD14], and LPS-binding protein [LBP]) were measured in 40 GBC cases and 126 gallstone controls with data on 63 serum inflammation markers. The relationships of LPS, LBP, and sCD14 with GBC were examined by logistic regression, which also was used to evaluate whether these associations are influenced by systemic inflammation as measured by a combinatorial inflammation score.

RESULTS

The third versus the first tertiles of sCD14 and of LBP were associated with an increased GBC risk (odds ratio [95% confidence interval]: 5.41 [2.00-16.75] for sCD14, and 6.49 [2.24-23.79] for LBP). sCD14 and LBP were strongly associated with inflammation score (above vs. below the median), which itself was associated with a more than 21-fold increased risk of GBC for the third versus first tertiles. Associations between GBC and sCD14 and LBP were markedly attenuated when the inflammation score was included in the model. While LPS was not associated with GBC or inflammation, only 35% of cases and 22% of controls had detectable levels.

CONCLUSIONS

These findings suggest that these LPS-pathway proteins are associated with GBC via inflammation-related pathways.

The influence of cytokine gene polymorphisms on the risk of developing gastric cancer in patients with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection is the main cause of gastric cancer. The disease progression is influenced by the host inflammatory responses, and cytokine single nucleotide polymorphisms (SNPs) may have a role in the course of the disease. The aim of our study was to investigate proinflammatory cytokine polymorphisms, previously associated with the development of gastric cancer, in a Slovenian population.

PATIENTS AND METHODS

In total 318 patients and controls were selected for the study and divided into three groups: (i) patients with gastric cancer (n = 58), (ii) patients with chronic gastritis (n = 60) and (iii) healthy control group (n = 200). H. pylori infection in patient groups was determined by serology, histology and culture. Four proinflammatory gene polymorphisms were determined (IL-1β, IL-1ra, TNF-α, TLR-4) in all subjects.

RESULTS

We found a statistically significant difference between males and females for the groups (p = 0.025). Odds ratio (OR) for gastric cancer risk for females was 0.557 (95% confidence interval [CI]: 0.233-1.329) and for chronic gastritis 2.073 (95% CI: 1.005-4.277). IL-1B-511*T/T homozygous allele for cancer group had OR = 2.349 (95% CI: 0.583-9.462), heterozygous IL-1B-511*T had OR = 1.470 (95% CI: 0.583-3.709) and heterozygotes in TNF-A-308 genotype for chronic gastritis had OR = 1.402 (95% CI: 0.626-3.139). Other alleles had OR less than 1.

CONCLUSIONS

We could not prove association between gastric cancer and chronic gastritis due to H. pylori in any cytokine SNPs studied in Slovenian population. Other SNPs might be responsible besides infection with H. pylori for the progression from atrophy to neoplastic transformation.

Toll-Like Receptor 4 Wild Type Homozygozity of Polymorphisms +896 and +1196 Is Associated with High Gastrin Serum Levels and Peptic Ulcer Risk

Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790) and +1196 (rs4986791) in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001) and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390). Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion.

Role of TLR4 rs4986790A>G and rs4986791C>T Polymorphisms in the Risk of Inflammatory Bowel Disease

Objective. The present meta-analysis investigated the contribution of TLR4 rs4986790A>G and rs4986791C>T genetic polymorphisms in increasing the risk of inflammatory bowel disease (IBD). Methods. Databases were searched using a combination of keywords related to TLR4 and IBD. Relevant studies were selected based on strict inclusion and exclusion criteria. Meta-analysis of the data extracted from the selected studies was performed using CMA 2.0 statistical analysis software. Results. Out of the 70 studies retrieved by database search, only 13 studies were eligible for inclusion in this meta-analysis and these 13 studies contained a total number of 4409 IBD patients and 5693 healthy controls. The meta-analysis results demonstrated that TLR4 rs4986790A>G polymorphism is associated with an increased risk of IBD (allele model: OR = 1.268, 95% CI = 1.124~1.431, and P < 0.001; dominant model: OR = 1.240, 95% CI = 1.090~1.409, and P = 0.001). Similarly, TLR4 rs4986791C>T polymorphism also conferred an increased risk of IBD (allele model: OR = 1.259, 95% CI = 1.092~1.453, and P = 0.002; dominant model: OR = 1.246, 95% CI = 1.072~1.447, and P = 0.004). Conclusion. Our meta-analysis results demonstrate that TLR4 rs4986790A>G and rs4986791C>T genetic polymorphisms are associated with the etiopathogenesis of IBD.

Association of TLR4 gene polymorphisms with sporadic Parkinson's disease in a Han Chinese population

Parkinson's disease (PD) is considered as a multifactorial disorder involving complex interactions between genetic and environmental factors, while previous studies point to a pivotal role of neuroinflammation in the pathophysiology of PD. As a member of pattern recognition receptors, TLR4 plays an important role in the immune response and inflammatory responses. Growing evidences suggest that mutation of TLR4 gene may be connected with the development of PD. The objective of this study was to evaluate whether genetic polymorphisms of the TLR4 gene are associated with PD susceptibility. We genotyped three single-nucleotide polymorphisms of the TLR4 gene (rs1927911, rs1927914 and rs10116253) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in unrelated 380 PD patients and 380 healthy-matched controls. Our study revealed that rs1927914 C allele carriers and C allele were probably related to a decreased risk of PD (p = 0.032 and p = 0.028, respectively) as well as male PD (p = 0.034) and early-onset PD (EOPD) (p = 0.023). In addition, there were significant differences in genotype and allele distribution in male PD patients and its healthy-matched control subgroup (p = 0.035 and p = 0.012, respectively). For rs1927911 and rs10116253 polymorphisms, genotype or allele frequencies did not differ between groups. Our data suggest that the TLR4 gene might contribute to the risk of developing PD in Han Chinese and rs1927914 polymorphism may be a protective factor for sporadic PD, male PD and EOPD.

An association between single nucleotide polymorphisms within TLR and TREM-1 genes and infective endocarditis

Infective endocarditis (IE) is an inflammatory condition of the lining of the heart chambers and valves, which is generally caused by bacteria. Toll-like receptors (TLRs) and Triggering receptor expressed on myeloid cells (TREMs) are key effectors of the innate system that play a significant role in the recognition of infectious agents, particularly, bacteria. We hypothesised that inherited variation in TLR and TREM-1 genes may affect individual susceptibility to IE. The distribution of genotypes and alleles of the TLR1 (rs5743551, rs5743611), TLR2 (rs3804099, rs5743708), TLR4 (rs4986790, rs4986791), TLR6 (rs3775073, rs5743810), and TREM-1 (rs1817537, rs3804277, rs6910730, rs7768162, rs2234246, rs4711668, rs9471535, rs2234237) gene polymorphisms was investigated in 110 Caucasian (Russian) subjects with IE and 300 age-, sex-, and ethnicity-matched healthy blood donors. Odds ratios with 95% confidence intervals were calculated. We found that C/C genotype of the rs3775073 polymorphism within TLR6 gene was associated with a decreased risk of IE (OR=0.51, 95% CI=0.26-0.97, P=0.032) according to the recessive model; however, we observed no association between the other investigated SNPs within TLR and TREM-1 genes and IE. Further in-depth investigations in this field are necessary to shed the light on the impact of inherited variation within innate immune response genes on the development of IE.

Association of TLR and TREM-1 gene polymorphisms with risk of coronary artery disease in a Russian population

Atherosclerosis, manifesting itself as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic progressive inflammatory disease which is driven by responses of both innate and adaptive immunity. Toll-like receptors (TLRs) and Triggering Receptor Expressed on Myeloid Cells-1 (TREM-1) are important effectors of the innate immune system, and polymorphisms within genes encoding them may increase risk of occurrence of various pathologies including cardiovascular disorders. Thus, we carried out a genetic association study on the sample of 702 consecutive Caucasian (Russian) patients with coronary artery disease (CAD) and 300 age-, sex-, and ethnicity-matched healthy controls. We revealed that the C/C genotype of the TLR1 rs5743551 polymorphism was significantly associated with a reduced risk of CAD according to the recessive model (OR=0.41, 95% CI=0.20-0.84, P=0.017, adjusted by age and gender). Concerning TREM-1 gene polymorphisms, we found that A/A genotype of the rs2234237 polymorphism, the G/G genotype of the rs6910730 polymorphism, the C/C genotype of the rs9471535 polymorphism, and the T/T genotype of the rs4711668 polymorphism were significantly associated with elevated CAD risk according to the recessive model (OR=5.52, 95% CI=1.17-25.98, P=0.011; OR=4.28, 95% CI=1.09-16.81, P=0.021; OR=5.55, 95% CI=1.18-26.09, P=0.011, and OR=1.66, 95% CI=1.10-2.52, P=0.014, respectively, adjusted by age and gender). Conversely, the G allele of the rs1817537 polymorphism, the T allele of the rs2234246 polymorphism, and the T allele of the rs3804277 polymorphism significantly correlated with similarly decreased risk of CAD according to the dominant model (OR=0.57, 95% CI=0.40-0.81, P=0.0013; OR=0.59, 95% CI=0.42-0.84, P=0.003, and OR=0.58, 95% CI=0.41-0.81, P=0.0014, respectively, adjusted by age and gender). We conclude that certain TLR and TREM-1 gene polymorphisms may be associated with CAD in Russian population; however, their significance as predictive and pathogenic markers of CAD should be interpreted with caution in other populations.

Pattern-recognition receptors and gastric cancer

Chronic inflammation has been associated with an increased risk of several human malignancies, a classic example being gastric adenocarcinoma (GC). Development of GC is known to result from infection of the gastric mucosa by Helicobacter pylori, which initially induces acute inflammation and, in a subset of patients, progresses over time to chronic inflammation, gastric atrophy, intestinal metaplasia, dysplasia, and finally intestinal-type GC. Germ-line encoded receptors known as pattern-recognition receptors (PRRs) are critical for generating mature pro-inflammatory cytokines that are crucial for both Th1 and Th2 responses. Given that H. pylori is initially targeted by PRRs, it is conceivable that dysfunction within genes of this arm of the immune system could modulate the host response against H. pylori infection, and subsequently influence the emergence of GC. Current evidence suggests that Toll-like receptors (TLRs) (TLR2, TLR3, TLR4, TLR5, and TLR9), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) (NOD1, NOD2, and NLRP3), a C-type lectin receptor (DC-SIGN), and retinoic acid-inducible gene (RIG)-I-like receptors (RIG-I and MDA-5), are involved in both the recognition of H. pylori and gastric carcinogenesis. In addition, polymorphisms in genes involved in the TLR (TLR1, TLR2, TLR4, TLR5, TLR9, and CD14) and NLR (NOD1, NOD2, NLRP3, NLRP12, NLRX1, CASP1, ASC, and CARD8) signaling pathways have been shown to modulate the risk of H. pylori infection, gastric precancerous lesions, and/or GC. Further, the modulation of PRRs has been suggested to suppress H. pylori-induced inflammation and enhance GC cell apoptosis, highlighting their potential relevance in GC therapeutics. In this review, we present current advances in our understanding of the role of the TLR and NLR signaling pathways in the pathogenesis of GC, address the involvement of other recently identified PRRs in GC, and discuss the potential implications of PRRs in GC immunotherapy.

Genetic polymorphisms in the Toll-like receptor signalling pathway in Helicobacter pylori infection and related gastric cancer

BACKGROUND

Gastric cancer (GC) is a progressive process initiated by Helicobacter pylori-induced inflammation. Initial recognition of H. pylori involves Toll-like receptors (TLRs), central molecules in the host inflammatory response. Here, we investigated the association between novel polymorphisms in genes involved in the TLR signalling pathway, including TLR2, TLR4, LBP, MD-2, CD14 and TIRAP, and risk of H. pylori infection and related GC.

METHODS

A case-control study comprising 310 ethnic Chinese individuals (87 non-cardia GC cases and 223 controls with functional dyspepsia) was conducted. Twenty-five polymorphisms were detected by MALDI-TOF mass spectrometry, PCR, PCR-RFLP and real-time PCR.

RESULTS

Seven polymorphisms showed significant associations with GC (TLR4 rs11536889, TLR4 rs10759931, TLR4 rs1927911, TLR4 rs10116253, TLR4 rs10759932, TLR4 rs2149356 and CD14 -260 C/T). In multivariate analyses, TLR4 rs11536889 remained a risk factor for GC (OR: 3.58, 95% CI: 1.20-10.65). TLR4 rs10759932 decreased the risk of H. pylori infection (OR: 0.59, 95% CI: 0.41-0.86). Statistical analyses assessing the joint effect of H. pylori infection and the selected polymorphisms revealed strong associations with GC (TLR2, TLR4, MD-2, LBP and TIRAP polymorphisms).

CONCLUSIONS

Novel polymorphisms in TLR2, TLR4, MD-2, LBP, CD14 and TIRAP, genes encoding important molecules of the TLR signalling pathway, showed clear associations with H. pylori-related GC in Chinese.

Effects of polymorphisms in immunity-related genes on the immune system and successful aging

Aging is associated with the dysregulation of immune system. Despite a progressive decline in immune function resulting in hyporesponsiveness to infection and vaccination, aging is also characterized by a chronic, low-grade, pro-inflammatory condition. An elderly individual with a systemic inflammation is at an increased risk of age-related diseases. Polymorphisms in the genes coding for inflammatory or anti-inflammatory molecules associated with immune related processes can affect the balance between the pro-inflammatory and anti-inflammatory networks. An improved understanding of the interactions among endogenous and environmental factors and genetic polymorphisms in anti-inflammatory and immune-related genes will increase the possibility of treating major age-related diseases to achieve longevity. The major challenge is to fully understand the complex interactions between genetic variations and multiple factors and their relative contributions to immunosenescence and age-related diseases in various populations. The results of studies that examined polymorphisms in immune-related genes associated with successful aging are reviewed here.

Role of toll-like receptor 4 in colorectal carcinogenesis: a meta-analysis

OBJECTIVE

This meta-analysis was performed to evaluate the role of toll-like receptor 4 (TLR-4) in colorectal carcinogenesis.

METHODS

The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched from inception through November 1st, 2013 without language restrictions. Odds ratios (ORs) or standardized mean differences (SMD) with their 95% confidence intervals (CI) were calculated.

RESULTS

Fourteen case-control studies met the inclusion criteria for this meta-analysis. A total of 1,209 colorectal cancer (CRC) cases and 1,218 healthy controls were involved in this meta-analysis. Two common polymorphisms (299 A>G and 399 C>T) in the TLR-4 gene, TLR-4 mRNA and protein expression were assessed. Our meta-analysis results revealed that the TLR-4 399 C>T polymorphism might increase the risk of CRC (allele model: OR = 1.77, 95%CI = 1.32 ∼ 2.36, P<0.001; dominant model: OR = 1.83, 95%CI = 1.32 ∼ 2.52, P<0.001; respectively). However, we found no correlation between the TLR-4 299 A>G polymorphism and CRC risk (all P>0.05). A subgroup analysis by ethnicity suggested that TLR-4 genetic polymorphisms were associated with an increased risk of CRC among Asians (allele model: OR = 1.50, 95%CI = 1.19 ∼ 1.88, P = 0.001; dominant model: OR = 1.49, 95%CI = 1.16 ∼ 1.92, P = 0.002; respectively), but not among Caucasians and Africans (all P>0.05). Furthermore, our results showed that TLR-4 mRNA and protein levels in CRC patients were higher than those in healthy controls (TLR-4 mRNA: SMD = 2.51, 95%CI  = 0.98 ∼ 4.05, P = 0.001; TLR-4 protein: OR  = 4.75, 95%CI  = 1.16 ∼ 19.36, P = 0.030; respectively).

CONCLUSION

Our findings provide empirical evidence that TLR-4 may play an important role in colorectal carcinogenesis. Thus, TLR-4 is a promising potential biomarker for the early diagnosis of CRC.

Polymorphism of Toll-like receptor 4 gene in bipolar disorder

BACKGROUND

Bipolar disorder (BD) is considered as a multifactorial disorder involving complex interactions between genetic and environmental factors, where immune dysfunction is thought to play a key etiopathogenic role. In particular, excess of winter births associated with early-life infections raise the possibility of the implication of innate immunity. Given the pivotal role of Toll-like receptor 4 (TLR-4), a major innate immune sensor molecule, we hypothesized that genetic variations of TLR-4 may be associated to BD.

METHODS

Genomic DNAs from 572 BD patients and 202 healthy controls (HC) were analyzed for the distribution of six single nucleotides polymorphisms (SNPs) scattered along the TLR-4 locus (rs1927914, rs10759932, rs4986790, rs4986791, rs11536889 and rs11536891). Associations between BD and these polymorphisms were examined using the Chi-square test.

RESULTS

We found that rs1927914 AA and rs11536891 TT genotype are more frequent in BD patients than in controls (corrected p; pc=.02 and .02 respectively) particularly in early-onset BD patients (pc=.004 and .006) born during the summer season (pc=.02 and .002 respectively). We also found that rs4986790 AG and rs4986791 CT genotypes were significantly associated with presence of autoimmune thyroiditis (pc=.002).

LIMITATIONS

Our results are to be confirmed by replication in independent BD cohorts.

CONCLUSIONS

We report for the first time a genetic association between BD and TLR-4 a major player of innate immunity. Possible mechanisms underlying bipolar disorders linking altered TLR-4 expression and increased susceptibility to infections and/or autoimmunity are discussed.

Host genetic factors respond to pathogenic step-specific virulence factors of Helicobacter pylori in gastric carcinogenesis

The interindividual differences in risk of Helicobacter pylori (H. pylori)-associated gastric cancer involve significant heterogeneities of both host genetics and H. pylori strains. Several recent studies proposed a distinct sequence for H. pylori exerting its virulence in the host stomach: (i) adhering to and colonizing the surface of gastric epithelial cells, (ii) evading and attenuating the host defense, and (iii) invading and damaging the gastric mucosa. This review focuses on several key issues that still need to be clarified, such as which virulence factors of H. pylori are involved in the three pathogenic steps, which host genes respond to the step-specific virulence factors, and whether and/or how the corresponding host genetic variations influence the risk of gastric carcinogenesis. Urease, BabA and SabA in the adhesion-step, PGN and LPS in the immune evasion-step, and CagA, VacA and Tipα in the mucosal damage-step were documented to play an important role in step-specific pathogenicity of H. pylori infection. There is evidence further supporting a role of potentially functional polymorphisms of host genes directly responding to these pathogenic step-specific virulence factors in the susceptibility of gastric carcinogenesis, especially for urease-interacting HLA class II genes, BabA-interacting MUC1, PGN-interacting NOD1, LPS-interacting TLR4, and CagA-interacting PTPN11 and CDH1. With the continuous improvement of understanding the genetic profile of H. pylori-associated gastric carcinogenesis, a person at increased risk for gastric cancer may benefit from several aspects of efforts: (i) prevent H. pylori infection with a vaccine targeting certain step-specific virulence factor; (ii) eradicate H. pylori infection by blocking step-specific psychopathological characteristics of virulence factors; and (iii) adjust host physiological function to resist the carcinogenic role of step-specific virulence factors or interrupt the cellular signal transduction of the interplay between H. pylori and host in each pathogenic step, especially for the subjects with precancerous lesions in the stomach.

Effects of polymorphisms of innate immunity genes and environmental factors on the risk of noncardia gastric cancer

Purpose

Increasing evidence suggests that polymorphisms in innate immunity genes are associated with Helicobacter pylori-induced inflammation and may influence susceptibility in developing noncardia gastric cancer. Therefore, we investigate the effect of polymorphisms of innate immunity genes and interactions with environmental factors in the Korean population.

Materials and Methods

We genotyped four polymorphisms of TLR2 (rs1898830), TLR4 (rs10983755 and rs10759932), and CD14 (rs2569190) in a case-control study of 487 noncardia gastric cancer patients and 487 sex- and age-matched healthy controls. Polytomous logistic regression models were used to detect the effects of genetic polymorphisms and environmental factors, which were stratified by the histological type of gastric cancer.

Results

TLR4 rs10983755 A carriers were found to have higher risk of intestinal-type noncarida gastric cancer than G homozygotes (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.01 to 1.97), but other genetic variants showed no association with the risk of noncardia gastric cancer. Among H. pylori-positive participants, smokers carrying TLR4 rs10983755 A had a higher risk of intestinal-type gastric cancer than nonsmoking TLR4 rs10983755 G homozygotes (OR, 4.28; 95% CI, 2.12 to 8.64). In addition, compared with tap water, other drinking water sources during childhood were found to be associated with the elevated risk of intestinal-type gastric cancer, and these associations were slightly stronger among TLR4 rs10983755 A carriers.

Conclusion

The genetic polymorphisms of innate immunity genes are associated with the development of intestinal-type noncardia gastric cancer and these associations may differ in accordance to an exposure to certain environmental factors.