One functional variant in the 3′-untranslated region of TLR4 is associated with the elevated risk of ventilator-associated pneumonia in the patients with chronic obstructive pulmonary disease

The aim of this study was to identify the association polymorphism (rs11536889) in the 3′-untranslated region (3′-UTR) of Toll-like receptors 4 (TLR4) and the risk for ventilator-associated pneumonia (VAP). miRNA database online and luciferase assays were used to validate TLR4 as the target gene of miR-1236. Enzyme-linked immunosorbent assay analysis and western blot were used to analyze the level of TLR4 in different genotype groups. In the present study, miR-1236 was predicted to bind to the rs11536889 G allele rather than the rs11536889 C allele, which was further confirmed by the luciferase activity suppressed by a fragment of 3′-UTR containing the rs11536889 G allele induced by lipopolysaccharide (LPS) and interleukin-6 (IL-6). Bronchial epithelial cells isolated from participants genotyped as GG, GC, and CC, with no remarkable difference in TLR4 messenger RNA (mRNA) levels were observed among these genotype groups. After stimulating by LPS, a TLR4 ligand, the CC-genotyped cells expressed higher levels of IL-8, IL-6, and tumor necrosis factor alpha (TNF-α) on their surfaces than cells with the other genotypes. Finally, the western blot analysis results showed that the expression level of IL-8, IL-6, and TNF-α protein was much higher in the CC group than the GC and GG groups subsequent to stimulation by LPS, and the IL-8, IL-6, and TNF-α protein levels in the GC were grouped much lower compared with the GG group. These findings indicated the regulatory association of miR-1236 with TLR4 and the abnormal expression of TLR4 caused by the presence of rs11536889 in the 3′-UTR of mRNA, which interfere with its interaction with the miR-1236, contributing to the risk of VAP.     

Common TLR1 Genetic Variation Is Not Associated with Death from Melioidosis,a Common Cause of Sepsis in Rural Thailand

Melioidosis, infection caused by the Gram-negative bacterium Burkholderia pseudomallei, is a common cause of sepsis in northeast Thailand. In white North Americans, common functional genetic variation in TLR1 is associated with organ failure and death from sepsis. We hypothesized that TLR1 variants would be associated with outcomes in Thais with melioidosis. We collated the global frequencies of three TLR1 variants that are common in white North American populations: rs5743551 (-7202A/G), rs4833095 (742A/G), and rs5743618 (1804G/T). We noted a reversal of the minor allele from white North American subjects to Asian populations that was particularly pronounced for rs5743618. In the Utah residents of European ancestry, the frequency of the rs5743618 T allele was 17% whereas in Vietnamese subjects the frequency was >99%. We conducted a genetic association study in 427 patients with melioidosis to determine the association of TLR1 variation with organ failure or death. We genotyped rs5743551 and rs4833095. The variants were in high linkage disequilibrium but neither variant was associated with organ failure or in-hospital death. In 300 healthy Thai individuals we further tested the association of TLR1 variation with ex vivo blood responses to Pam3CSK4, a TLR1 agonist. Neither variant was robustly associated with blood cytokine responses induced by Pam3CSK4. We identified additional common variation in TLR1 by searching public databases and the published literature and screened three additional TLR1 variants for associations with Pam3CSK4-induced responses but found none. We conclude that the genetic architecture of TLR1 variation differs substantially in southeast Asians compared to other populations and common variation in TLR1 in Thais is not associated with outcome from melioidosis or with altered blood responses to Pam3CSK4. Our findings highlight the need for additional studies of TLR1 and other innate immune genetic modulators of the inflammatory host response and determinants of sepsis in southeast Asian populations.     

Effect of Single Nucleotide Polymorphisms of Toll-Like Receptor 4 (TLR 4) on Reproductive Performance and Immune Function in Dairy Cows

In dairy cows, inflammatory diseases caused by infection with pathogenic bacteria post calving affect ovarian functions. This study examined the relationship between single-nucleotide polymorphisms (SNPs) of Toll-like receptor 4 (TLR4), reproductive performances [the number of artificial insemination (AI) application and days open], and immune cell functions (apoptosis and migration). Two hundred Holstein cows from the Obihiro University farm were included. The SNPs of TLR4 were genotyped by PCR-restriction fragment length polymorphism (PCR–RFLP) method. Polymorphonuclear leukocytes (PMNs) and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. The number of AI application in the animals with T/C genotype in the TLR4 exon3 was lower than that in animals with C/C genotype (1.6 ± 0.2 and 2.2 ± 0.2, respectively). Among the animals with TLR4 exon3 polymorphisms, the days open was shorter for the T/C cows than that for C/C cows (100.7 ± 6.9 days and 136.6 ± 9.0 days, respectively). The SNPs in the TLR4 intron did not affect the number of AI and days open. The apoptosis percentage of PMNs treated with lipopolysaccharide (LPS; 0.001 and 1 μg/ml) tended to be lower in the T/C genotype compared to that in the C/C genotype. The transmigration rates of PMNs, and IL-1β production in PBMCs were tended to be higher for the animals with the T/C genotype compared to those for animals with the C/C genotype. Taken together, these results suggest that TLR4 polymorphisms offer a meaningful tool to judge the reproductive potential and immune activity in individual cows.     

广西壮族人群EBI3 基因rs6613A/T, rs4905A/G多态性分布特点

目的:分析广西壮族人群EBI3基因rs6613A/T、rs4905A/G多态性分布特点。方法:采用单碱基延伸的PCR技术对168例广西壮族人群EBI3 rs6613 A/T和EBI3 rs4905A/G进行多态性检测,对比国际人类基因组计划(Hap Map)公布的中国北京人、日本人、非洲人和意大利人的SNP分型数据,分析5个人群rs6613 A/T、rs4905A/G位点的基因型和等位基因频率差异。结果:在广西壮族人群中,EBI3基因rs6613 A/T位点AT基因型最常见,约为49.4%;T等位基因频率最高,约为52.1%;rs4905A/G多态性位点AC基因型最常见,约为48.2%;C等位基因频率最高,约为50.9%。EBI3基因型及等位基因频率分布于性别无显著相关性(P0.05)。广西壮族人群EBI3基因rs6613A/T位点基因型和等位基因频率与北京人差异无统计学意义(P0.05),但与非洲人、日本人、意大利人差异具有统计学意义(P0.05);EB-13基因rs4905A/G位点基因型和等位基因频率与北京人和日本人差异无统计学意义(P0.05),但与非洲人和意大利人比较差异具有统计学意义(P0.01)。结论:EBI3基因rs6613 A/T和EB-13 rs4905A/G多态性位点基因型和等位基因在广西壮族人群中的分布频率与其他种族和地区人群相比存在差异,这种差异可能是导致某些疾病在不同人群发病率和临床表现存在差异的原因之一。     

Fibroblast growth factor receptor 4 polymorphisms and coronary artery disease: a case control study

Fibroblast growth factors (FGFs) and their receptors (FGFRs) play important roles in vascular system. FGFR4 rs351855 (Gly388Arg) polymorphism has shown to be a risk factor for many diseases. The aim of this study was to investigate the association between FGFR4 polymorphisms and the susceptibility to coronary artery disease (CAD) in the Chinese population. We identified three polymorphisms in the FGFR4 gene, rs351855G/A (Gly388Arg), rs145302848C/G and rs147603016G/A, by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 658 CAD cases and 692 healthy controls. Results showed that frequencies of GA genotype, AA genotype and A allele in rs351855 (Gly388Arg) polymorphism were significantly lower in CAD patients than in controls [odds ratio (OR) = 0.79, 95 % confidence intervals (CI) 0.62-0.99, P = 0.042; OR = 0.58, 95 % CI 0.41-0.81, P = 0.002; and OR = 0.77, 95 % CI 0.66-0.90, P = 0.001, respectively]. The rs147603016GA genotype and A allele also showed lower numbers in CAD cases (OR = 0.58, 95 % CI 0.36-0.93, P = 0.025; and OR = 0.59, 95 % CI 0.40-0.95, P = 0.028). The rs145302848C/G polymorphism did not show any correlation with CAD. Haplotype analysis revealed that the prevalence of ACG haplotype (rs351855, rs145302848 and rs147603016) was significantly decreased in CAD patients (P = 0.002). Our data suggested that the FGFR4 rs351855G/A (Gly388Arg) and rs147603016G/A polymorphisms could act as protective factors against CAD in the Chinese population and indicated that a single gene polymorphism could have diverse functions in different diseases.     

Human microRNA-155 on chromosome 21 differentially interacts with its polymorphic target in the AGTR1 3' untranslated region: a mechanism for functional single-nucleotide polymorphisms related to phenotypes

Animal microRNAs (miRNAs) regulate gene expression through base pairing to their targets within the 3' untranslated region (UTR) of protein-coding genes. Single-nucleotide polymorphisms (SNPs) located within such target sites can affect miRNA regulation. We mapped annotated SNPs onto a collection of experimentally supported human miRNA targets. Of the 143 experimentally supported human target sites, 9 contain 12 SNPs. We further experimentally investigated one of these target sites for hsa-miR-155, within the 3' UTR of the human AGTR1 gene that contains SNP rs5186. Using reporter silencing assays, we show that hsa-miR-155 down-regulates the expression of only the 1166A, and not the 1166C, allele of rs5186. Remarkably, the 1166C allele has been associated with hypertension in many studies. Thus, the 1166C allele may be functionally associated with hypertension by abrogating regulation by hsa-miR-155, thereby elevating AGTR1 levels. Since hsa-miR-155 is on chromosome 21, we hypothesize that the observed lower blood pressure in trisomy 21 is partially caused by the overexpression of hsa-miR-155 leading to allele-specific underexpression of AGTR1. Indeed, we have shown in fibroblasts from monozygotic twins discordant for trisomy 21 that levels of AGTR1 protein are lower in trisomy 21.     

Polymorphisms in vitamin D receptor,toll-like receptor 2 and Toll-Like receptor 4 genes links with Dengue susceptibility

Host genetic factors are known to determine disease susceptibility in dengue virus infection. Therefore, in this study association of gene polymorphisms of Vitamin D Receptor [rs731236 (Taq) and rs7975232 (Apa1)], Toll-like receptor 2 [rs5743708 (Arg735Gln) and rs5743704 (Pro631His)] and Toll-like receptor 4 [rs4986790A/G(Asp299Gly13843) and rs4986791 C/T(Thr399Ile)] were studied in cases with dengue as compared to controls. Total 98 cases of confirmed dengue virus infection and 98 age, sex and geographically matched healthy controls were enrolled and their genetic polymorphisms for the above mentioned regions were studied by Sanger sequencing. Mutant genotypes CC of VDR rs731236 (Taq1) [(OR 3.808, p value =0.02, CI 1.160-12.498)], GG of VDR rs7975232 (Apa1) [(OR 3.485, p value =0.02, CI 1.162-10.45)] and heterozygous genotypes of TLR4 rs4986790 A/G Asp299Gly [OR 2.40, p value= 0.02, CI 1.12-5.14], TLR4 rs4986791 C/T Thr399Ile [OR 2.09, p value=0.02, CI 1.12-5.14] were found to be significantly more in cases with dengue virus infection as compared to the controls. Also, at these positions mutant alleles were observed in significantly higher number of cases than controls. The values for C allele at VDR rs731236 (Taq1) were OR 1.86, p value 0.009, CI 1.162-3.001; for allele G at rs7975232( Apa1) were OR 2.71, p value 0.006, CI 1.196-2.98 for allele G at TLR4s rs4986790 A/G Asp299Gly were OR 2.35, p value 0.009, CI 1.23-4.50 and for allele T at rs4986791 C/T Thr399Ile were OR 2.36, p value=0.006, CI 1.28-4.38. VDR and TLR4 but not TLR2 gene polymorphisms were found to be associated with dengue susceptibility in Indian population.     

Interleukin 4 receptor is associated with an increase in body mass index in Koreans

A body of evidence indicates obesity is an inflammatory state with chronic activation of the immune system. The interleukin 4 receptor (IL4R) single nucleotide polymorphism (SNP), rs 180275 (1902A>G) is well recognized for its association with atopy and other inflammatory diseases. We assessed the possible association of rs 180275 and rs 1805010 with obesity in Korean population. Study subject consisting of 876 Koreans were divided into three groups: subjects with 1) BMI<25, 2) BMI between 25 and 27, and 3) BMI>27. Analyses of genotype distributions and allele frequencies of study subjects revealed that rs 180275 polymorphism was associated with an increase in BMI in Korean population (P=0.009 and 0.011, respectively) while no association was found between rs 1805010 and obesity. We observed significantly lower percentage of rs 180275 G allele in subjects with BMI>27 than in subjects with BMI< or =27 (9.9% vs. 16.0%). Logistic regression analysis revealed that the odds ratio (OR) for an increase in BMI associated with the G vs. A allele was 0.57 [95% Confidence interval (CI)=0.39-0.85, p=0.002], which strongly implicates the protective role of rs 180275 G allele against an increase in BMI. Haplotype analysis revealed no association was present between rs 180275 and rs 1805010 polymorphisms. The frequency of rs 180275 G allele is significantly lower in subjects with BMI>27, suggesting the protective role of IL4R rs 180275 G allele against an increase in BMI in Korean population.     

Genetic variations of TLRs and their association with HPV/EBV,co-infection along with nicotine exposure in the development of premalignant/malignant lesions of the oral cavity in Indian population

Background: Despite being most preventable malignancies associated with smoked and smokeless tobacco products, squamous cell carcinoma of oral cavity is one of the most common malignancy in India. The aim of the present study was to evaluate the role of TLRs in oral pre-cancerous, cancerous cases and their genotypic correlation with HPV/EBV, co-infection & lifestyle habits in Indian population.Methods: The present study was conducted on 300 subjects (100 OSCC, 50 pre-cancer & 150 controls). The amplification of TLRs gene and HPV/EBV co-infection was assessed by Nested PCR, PCR–RFLP and further confirmation by direct sequencing.Results: The TLR 9(−1486 T/C), revealed that the TT vs. CT + CC genotype had a ˜5-fold increased risk for the development of pre-cancerous lesions as compared to controls (p = 0.0001). Further analysis showed that the risk of cancer was extremely pronounced in HPV/EBV, co-infection (p = 0.0141), implicating the possible interaction between TLR 9(−1486T/C) genotype and HPV infection in increasing cancer/pre-cancer risk. The ‘G’ allele of TLR 4(+896A/G) was also a higher risk of developing pre-cancerous lesions with 4.5 fold and statistically significant (p = 0.0001). The genotypic association of TLR 9(-1486T/C) in OSMF cases showed ˜8 fold increased risk and TLR 4(+896A/G) showed fourteen fold higher risk for leukoplakia (p < 0.0001, OR = 14.000).Conclusion: Genetic polymorphism of TLR 9(−1486 T/C) and TLR 4(+896A/G) may influence the effects of HPV/EBV, co-infection and play the significant role in development of the disease. The significance of these TLRs seemed to be enhanced by tobacco chewing and smoking habits also, which act as an important etiological risk factor for OSCC.     

A phosphatidylserine species inhibits a range of TLR- but not IL-1beta-induced inflammatory responses by disruption of membrane microdomains

TLRs detect conserved molecular patterns that are unique to microbes, enabling tailored responses to invading pathogens and modulating a multitude of immunopathological conditions. We investigated the ability of a naturally occurring stearoyl-arachidonoyl form of phosphatidylserine (SAPS) to inhibit the proinflammatory effects of TLR agonists in models of inflammation investigating the interaction of leukocytes with epithelial and endothelial cells. The responses to LPS of both epithelial and endothelial cells were highly amplified in the presence of PBMCs. Coincubation with SAPS markedly inhibited activation of cocultures by LPS, principally through inhibition of the TLR4 signaling pathway in PBMCs; however, this was not through downmodulation of TLR4 or coreceptor expression, nor was IL-1beta-induced cytokine release affected. SAPS also impaired Pam(3)CSK(4) (TLR2/1), Gardiquimod (TLR7/8), and Streptococcus pneumoniae-induced cytokine release, but had only modest effects on poly(I:C) (TLR3)-induced responses. Fluorescence resonance energy transfer analysis of molecular associations revealed that SAPS disrupted the association of both TLR4 and TLR2 with their respective membrane partners that are required for signaling. Thus, our data reinforce the existence and importance of cooperative networks of TLRs, tissue cells, and leukocytes in mediating innate immunity, and identify a novel disrupter of membrane microdomains, revealing the dependence of TLR signaling on localization within these domains.     

Association of the Genetic Polymorphisms in Pre-MicroRNAs with Risk of Ischemic Stroke in a Chinese Population

microRNA (miRNA) plays a role in the pathogenesis of ischemic stroke, and single nucleotide polymorphisms in miRNA genes may contribute to disease susceptibility. However, the effect of miR-146a, miR-196a2, and miR-499 polymorphisms on ischemic stroke susceptibility has been rarely reported. Using the TaqMan assay, we evaluated the association of hsa-miR-146a/rs2910164, hsa-miR-196a2/rs11614913, and hsa-miR-499/rs3746444 polymorphisms with the risk of ischemic stroke in a Chinese population with 531 ischemic stroke patients and 531 control subjects. Rs2910164 C/G genotypes were significantly associated with increased risk of ischemic stroke in different genetic model (homozygote comparison: OR = 2.00, 95% CI, 1.29–3.12, P = 0.002; additive model: OR = 1.35, 95% CI, 1.10–1.65, P = 0.004;dominant model: OR = 1.33, 95% CI, 1.00–1.75, P = 0.049; recessive model: OR = 1.82, 95% CI, 1.20–2.74, P = 0.004). Subjects with allele G of hsa-miR-146a/ rs2910164 also showed increased risk of ischemic stroke (OR = 1.33, 95% CI, 1.09–1.62, P = 0.005). Stratification analysis showed that the association between rs2910164 and the risk of ischemic stroke was more pronounced in subjects over 60 years old, females, non-drinkers, subjects without hypertension or diabetes mellitus. There were significant combined effects between miR-146a/rs2910164 and fasting glucose/low-density lipoprotein cholesterol levels on ischemic stroke susceptibility. However, we failed to find any association between the alleles/genotypes of rs11614913 T/C and ischemic stroke, respectively (P> 0.05). In summary, this study provides evidence that miR-146a/rs2910164 might be associated with a significantly increased risk of ischemic stroke in a Chinese population, and the combined effects between miRNA polymorphism and fasting glucose /blood lipid levels may contribute to stroke pathogenesis.     

Scavenger receptor A (SR-A) is required for LPS-induced TLR4 mediated NF-κB activation in macrophages

Recent evidence suggests that the macrophage scavenger receptor class A (SR-A, aka, CD204) plays a role in the induction of innate immune and inflammatory responses. We investigated whether SR-A will cooperate with Toll-like receptors (TLRs) in response to TLR ligand stimulation. Macrophages (J774/a) were treated with Pam2CSK4, (TLR2 ligand), Polyinosinic:polycytidylic acid (Poly I:C) (TLR3 ligand), and Lipopolysaccharides (LPS) (TLR4 ligand) for 15 min in the presence or absence of fucoidan (the SR-A ligand). The levels of phosphorylated IκBα (p-IκBα) were examined by Western blot. We observed that Poly I:C and LPS alone, but not Pam2CSK4 or fucoidan increased the levels of p-IκBα. However, LPS-induced increases in p-IκBα levels were further enhanced when presence of the fucoidan. Immunoprecipitation and double fluorescent staining showed that LPS stimulation promotes SR-A association with TLR4 in the presence of fucoidan. To further confirm our observation, we isolated peritoneal macrophages from SR-A deficient (SR-A(-/-)), TLR4(-/-) and wild type (WT) mice, respectively. The peritoneal macrophages were treated with LPS for 15min in the presence and absence of fucoidan. We observed that LPS-stimulated TNFα and IL-1β production was further enhanced in the WT macrophages, but did not in either TLR4(-/-) or SR-A(-/-) macrophages, when fucoidan was present. Similarly, in the presence of fucoidan, LPS-induced IκBα phosphorylation, NF-κB binding activity, and association between TLR4 and SR-A were significantly enhanced in WT macrophages compared with LPS stimulation alone. The data suggests that SR-A is needed for LPS-induced inflammatory responses in macrophages.     

The C allele of rs5743836 polymorphism in the human TLR9 promoter links IL-6 and TLR9 up-regulation and confers increased B-cell proliferation

In humans, allelic variants in Toll-like receptors (TLRs) associate with several pathologies. However, the underlying cellular and molecular mechanisms of this association remain largely unknown. Analysis of the human TLR9 promoter revealed that the C allele of the rs5743836 polymorphism generates several regulatory sites, including an IL-6-responding element. Here, we show that, in mononuclear cells carrying the TC genotype of rs5743836, IL-6 up-regulates TLR9 expression, leading to exacerbated cellular responses to CpG, including IL-6 production and B-cell proliferation. Our study uncovers a role for the rs5743836 polymorphism in B-cell biology with implications on TLR9-mediated diseases and on the therapeutic usage of TLR9 agonists/antagonists.     

Serotonergic genes and amygdala activity in response to negative affective facial stimuli in Korean women

Serotonergic genes have been implicated in mood disorders, alcoholism and certain personality traits. We investigated the possible relationship between several polymorphisms in the serotonin (5-HT) system and amygdala responses to negative facial stimuli in Korean women using functional magnetic resonance imaging. All participants were genotyped with regard to the following polymorphisms: the serotonin transporter-gene-linked polymorphic region (5-HTTLPR), tryptophan hydroxylase 2 (TPH2) G(-703)T, 5-HT(1A) C(-1019)G and 5-HT(2A) single nucleotide polymorphism (SNP) rs6311. We found increased activations in response to angry facial stimuli in the bilateral amygdala of subjects with the long allele of 5-HTTLPR compared with those with two copies of the short allele. Higher activations in response to sad facial stimuli were found in the bilateral amygdala of subjects with the T/T genotype of 5-HT(2A) SNP rs6311, compared with C allele carriers, and in subjects with the G/G genotype of TPH2 G(-703)T, compared with those with T/T and G/T genotypes. Our results for individuals from an Asian population countered a previous finding for a Caucasian population and identified the moderating role of genetic background in the relationships between these serotonergic gene polymorphisms and amygdala function elicited by negative emotional stimuli.     

Association between single-nucleotide polymorphisms in pre-miRNAs and the risk of asthma in a Chinese population

Single-nucleotide polymorphisms (SNPs) in pre-miRNAs may alter microRNA (miRNA) expression levels or processing and contribute to susceptibility to a wide range of diseases. We investigated the correlation between four SNPs (rs11614913, rs3746444, rs2910164, and rs229283) in pre-miRNAs and the risk of asthma in 220 asthma patients and 540 controls using polymerase chain reaction-restriction fragment length polymorphism methodology and DNA-sequencing. There were significant differences in the genotype and allelic distribution of rs2910164G/C and rs2292832C/T polymorphisms among cases and controls. The CC genotype and C allele of rs2910164G/C were significantly associated with a decreased risk of asthma (CC vs. GG, odds ratio [OR]?= 0.51, 95% confidence interval [CI]: 0.31-0.82; C vs. G, OR = 0.74, 95% CI: 0.59-0.93). Similarly, the TT genotype and T allele of rs2292832C/T were significantly associated with a decreased risk of asthma (TT vs. CC, OR = 0.56, 95% CI: 0.33-0.95; T vs. C, OR = 0.71, 95% CI: 0.53-0.95). However, no significant association between the other two polymorphisms (i.e., rs11614913C/T and rs3746444C/T) and the risk of asthma was observed. Our data indicate that rs2910164G/C and rs2292832C/T may play a role in the development of asthma.     

Functional Characterization of TLR4 +3725 G/C Polymorphism and Association with Protection against Overweight

Subclinical low-grade systemic inflammation has been associated with obesity, insulin resistance and metabolic syndrome (MS). Recent studies have highlighted the role of gut microbiota in these disorders. The toll-like receptor 4 (TLR4) plays a key role in the innate immune response activation. We studied two polymorphisms (+3725G/C and 11350G/C) in the 3′ untranslated region (3′UTR) of the TLR4 gene that may alter its expression and their association with metabolic disorders related to systemic inflammation. We cloned the 3′UTR into a luciferase reporter system and compared wild-type 3′UTR (WT) and +3725C variant (MUT) constructs luciferase activities. MUT construct reduced the reporter gene activity by 30% compared to WT (P = 0.0001). To evaluate the association between these polymorphisms with biochemical and clinical overweight related variables, we conducted a population cross-sectional study in 966 men of Argentine general population. Considering smoking as a confounding variable that causes systemic inflammation, we studied these possible effects in both, smokers and nonsmokers. The 11350G/C polymorphism was not detected in our sample whereas the CC genotype of +3725 polymorphism was associated with lean subjects (p = 0.011) and higher Adiponectin levels (p = 0.021). Subjects without any NCEP/ATP III MS component were associated with this genotype as well (p = 0.001). These results were strengthened in nonsmokers, in which CC genotype was associated with lean subjects (p = 0.003) and compared with G carriers showed significantly lower BMI (25.53 vs. 28.60 kg/m2; p = 0.023) and waist circumference (89.27 vs. 97.51 cm; p = 0.025). None of these associations were found in smokers. These results showed that +3725C variant has a functional effect down-regulating gene expression and it could be considered as a predictive factor against overweight, particularly in nonsmokers. Considering the role of TLR4 in inflammation, these findings would suggest that the presence of +3725C variant could predict a lower prevalence of chronic metabolic disorders.     

Toll-Like Receptor 4 +3725 G/C Polymorphism, Helicobacter pylori Seropositivity, and the Risk of Gastric Atrophy and Gastric Cancer in Japanese

Background:  Toll-like receptor 4 (TLR4) Asp299Gly and Thr399Ile polymorphisms were reported to be a risk factor of gastric carcinoma or its precursors in Caucasian and Indian population, but these polymorphisms are absent in Japanese. We investigated the associations of TLR4 +3725 G/C polymorphism, another functional polymorphism of TLR4 , with risk of gastric cancer and gastric atrophy in Japanese.
Materials and Methods:  Study subjects were 583 histologically diagnosed gastric cancer patients and age- and sex-matched 1592 control outpatients, who visited Aichi Cancer Center Hospital from 2001 to 2005. Serum anti- H. pylori IgG antibody and pepsinogens were measured to evaluate H. pylori infection and gastric atrophy, respectively. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by a logistic model.
Results:  Among the seropositive subjects, the age- and sex-adjusted OR of gastric atrophy was 1.17 (95%CI: 0.91–1.50) for G/C , 1.20 (95%CI: 0.76–1.89) for C/C , and 1.18 (95%CI: 0.93–1.49) for G/C + C/C relative to G/G genotype. The age- and sex-adjusted OR of severe gastric atrophy among H. pylori seropositive subjects was 1.43 (95%CI: 0.99–2.06) for G/C , 1.47 (95%CI: 0.76–2.88) for C/C , and 1.43 (95%CI: 1.01–2.04) for G/C + C/C . The OR of gastric cancer compared with gastric atrophy controls was not statistically significant.
Conclusion:  Our study found that TLR4 +3725 G/C polymorphism was a risk factor of severe gastric atrophy in H. pylori seropositive Japanese. Our results underscored the significance of the variations in host innate immunity due to TLR4 polymorphism as genetic predispositions to gastric precancerous lesions in Eastern Asian populations with the same backgrounds.     

The Role of TLR2, TLR4 and CD14 Genetic Polymorphisms in Gastric Carcinogenesis: A Case-Control Study and Meta-Analysis

Background

In addition to Helicobacter pylori infection, host genetic factors contribute to gastric cancer (GC). Recognition of H. pylori is known to involve Toll-like receptors (TLR), which subsequently leads to activation of NF-κB. Thus, the overall aim of this study was to estimate for the first time the pooled effect size of polymorphisms in TLR2, TLR4 and CD14 on GC development through a meta-analysis.

Methods

A case-control study comprising 284 ethnic Chinese individuals (70 non-cardia GC cases and 214 functional dyspepsia controls) was conducted for the genotyping of TLR2 -196 to -174del, CD14 -260 C/T and TLR4 rs11536889 using PCR, RT-PCR and mass spectrometry. Case-control studies of TLR2, TLR4 and CD14 polymorphisms and GC were searched up to June 2012. Pooled odds ratios and 95% confidence intervals were obtained by means of the random effects model.

Results

In our ethnic Chinese case-control study, the TLR4 rs11536889 C allele increased the risk of GC (OR: 1.89, 95%CI: 1.23–2.92) while the CD14 -260 T allele was protective (OR: 0.62, 95%CI: 0.42–0.91). TLR2 -196 to -174 increased the risk of GC only in H. pylori-infected individuals (OR: 3.10, 95%CI: 1.27–7.60). In the meta-analysis, TLR4 Asp299Gly showed borderline results in the general analysis (pooled OR: 1.58, 95%CI: 0.98–2.60), nevertheless, stratified analysis by ethnicity showed that the mutant allele was a definitive risk factor for GC in Western populations (pooled OR: 1.87, 95%CI: 1.31–2.65). There was a potential association between the TLR2 -196 to -174 deletion allele and GC in Japanese (pooled OR: 1.18, 95%CI: 0.96–1.45). TLR4 Thr399Ile did not provide significant results.

Conclusions

TLR4 rs11536889 and CD14 -260 C/T are associated with non-cardia GC in Chinese. Based on our meta-analysis, the TLR signalling pathway is involved in gastric carcinogenesis, TLR4 Asp299Gly and TLR2 -196 to -174del showing associations with GC in an ethnic-specific manner.