Asp299Gly Polymorphism Research Articles

Association of two polymorphisms Asp299Gly and Thr399Ile in Toll‐like receptor 4 with rheumatoid arthritis: A meta‐analysis

Our meta-analysis aims to evaluate the association of Asp299Gly and Thr399Ile with rheumatoid arthritis (RA) susceptibility and severity. By manually searching 3 electronic databases (PubMed, Embase and Web of Science), relevant articles were collected. After checking eligibility for every study, this meta-analysis on eligible studies was performed under 5 genetic models: (1) allelic contrast; (2) heterozygous model; (3) homozygous model; (4) dominant model; (5) recessive model. In Spanish populations, a significantly decreased RA risk was identified in allelic comparison (odds ratio [OR]=0.73, 95% CI 0.55~0.96) and dominant model (OR=0.74, 95% CI 0.56~0.99) of Asp299Gly polymorphism. A trend of reduced risk was also observed under the heterozygous model (OR=0.77, 95% CI 0.58~1.03). As for Thr399Ile, it might also have a protective effect on Spanish populations in allelic comparison (OR=0.71, 95% CI 0.44~1.15). In contrast, for both Asp299Gly and Thr399Ile, a higher risk of RA was detected in Chinese Han populations. The frequency of both Asp299Gly and Thr399Ile increased in rheumatoid factor (RF)-positive subjects in Chinese patients (Asp299Gly, RF+:RF-=0.165:0.145; Thr399Ile, RF+:RF-=0.170:0.161) and decreased in Spanish patients (Asp299Gly, RF+:RF-=0.060:0.073; Thr399Ile, RF+:RF-=0.046:0.056), but not to a statistically significant extent. Our meta-analysis suggested that both Asp299Gly and Thr399Ile might have a protective effect on Spanish populations, but the 2 polymorphisms could act as a susceptible factor in Chinese Han populations. To confirm our results, further investigation concerning the functional impacts of Asp299Gly and Thr399Ile are still needed.

The impact of Toll-like receptors on the immune system functioning and on the immunopathogenesis of chronic hepatitis C: a modern view (literature review)

There exists a considerable body of literature on immunopathogenesis of chronic hepatitis C. Although results appear consistent with prior research in the area mentioned above, they appear inconsistent with the issues in the area of diagnosis, prognosis and treatment effectiveness. In this context the study addresses the research to receptors of the innate immune system – Toll-like receptors.The aim of the research is to analyze the data of current professional literature regarding the role of individual Toll-like receptors in the immunopathogenesis of chronic hepatitis C.Materials and methods. The method of reviewing and systematizing as well as the method of content analysis were used to overview the scientific literature as for the role of Toll-like receptors. For this purpose, we employ survey data collected from the world professional literature and analyzed the results of current researches.Conclusions. The innate immune system plays a prominent role in the primary protection of the body against pathogens which recognition depends on the Toll-like receptors family wheres the genetic analysis is considered as a promising method of preventive and personalized medicine. The advantage of genetic markers regardless of age and other factors contain information about the susceptibility to multifactorial diseases which can be used to create a «genetic passport» of a person. Perceptions about the impact of the Asp299Gly polymorphism of the Toll-like receptor 4 gene and Gln11Leu of the Toll-like receptor 7 gene on the immunopathogenesis of chronic hepatitis C are ambiguous and this research provides a good starting point for discussion and further study which will allow optimizing the therapeutic and diagnostic tactics for this disease based on the complex evaluation of immunity which are defined by the determined polymorphisms.

Association of the CD14 C159T and the Toll-like receptor 4 Asp299Gly polymorphisms with various phenotypes of asthma in adults from Crimea.

Background: This study assessed gene polymorphisms of the CD14 receptor (C-159T) and Toll-like receptor 4 (Asp299Gly) in a patient population in Crimea, Ukraine, stratified by clinical (early versus late onset; frequent versus occasional relapses; fixed versus reversible obstruction) and immunologic (atopic versus nonatopic; eosinophilic; neutrophilic or paucigranulocytic inflammation) subtype. Methods: Two polymorphisms, CD14 C-159T and TLR4 Asp299Gly, were assessed in 331 patients with asthma. The control group included 285 volunteers who were nonatopic. The single nucleotide polymorphisms were studied by using polymerase chain reaction with electrophoretic detection. Results: There were increased odds of asthma development in patients with the Asp299Gly TLR4 mutation compared with the general population underdominant odds ratio (OR) 1.52 [95% confidence interval (CI), 1.00-2.32] and overdominant (OR 1.55 [95% CI, 1.01-2.38]) models after adjustment for gender and age. In addition, mutations in this gene decreased the odds of nonatopic asthma in underdominant (OR 0.26 [95% CI, 0.07-0.93]; p = 0.027), overdominant (OR 0.27 [95% CI, 0.07-0.96]; p = 0.033), and log-additive models (OR 0.26 [95% CI, 0.07-0.93]; p = 0.026) compared with the atopic subgroup after adjustment for gender, age, number of exacerbations, and type of airway inflammation. Allele frequencies for CD14 and TLR4 polymorphisms did not show statistical differences between the patients with asthma and the control subjects. Conclusion: CD14 C-159T polymorphisms were not associated with asthma in the adult population in Crimea. TLR4 Asp299Gly polymorphisms were associated with asthma and with decreased odds of nonatopic asthma compared with atopic asthma in the adult population in Crimea.

The Influence Of Rs4986790 Polymorphism Of Tlr4 Gene On Clinical Manifestation Of Atherosclerosis In Patients With Familial Hypercholesterolemia

Background and Aims: The innate immune response elicited by activation of Toll-like receptors (TLRs) plays an important role in the atherogenesis. Nevertheless it was recently demonstrated that G allele of the rs4986790 polymorphism (Asp299Gly) of TLR4 Gene has been associated with decreased development of atherosclerosis. The aim of the study was to analyze the relationships between rs4986790 polymorphism of TLR4 Gene and clinical manifestation of atherosclerosis in patients with familial hypercholesterolemia (FH).

PECULIARITIES OF TLR-2 (ARG753GLN) AND TLR-4 (ASP299GLY) POLYMORPHISM PREVALENCE IN PATIENTS WITH ACUTE BRUCELLEIS AND CARDIOVASCULAR SYSTEM DISEASES

Currently, there are single data on the relationship between TLR-2 polymorphisms (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms and susceptibility to brucellosis. Therefore, the aim of the study was to determine the frequency of TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms in patients with acute brucellosis with cardiovascular lesions in the Republic of Azerbaijan. Materials and methods: 178 patients with a brucellosis clinic were examined. According to the criteria for inclusion in the study, only 120 people fully met all the criteria, which made up the main group. The control group consisted of 30 healthy individuals. TLR-2 (Arg753Gln) and TLR-4 (Asp299Gly) polymorphisms were also determined for all patients in both groups. In order to assess the state of the cardiovascular system, an electrocardiogram was recorded, blood pressure was measured, and an ultrasound scan of the heart was performed for all patients. Results: it was found that 93 patients (77.50±3.13 %) with acute brucellosis had some or other signs of impairment in the work of the cardiovascular system, identified clinically or as a result of functional examination. Among carriers of the Asp / Gly genotype of the TLR-4 gene, an increased risk of brucellosis with CVS diseases was determined (χ2=30.19; p <0.0001; OR=24.29; 95 % CI [5.45 – 108.37]), while the carriage of the homozygous genotype Asp / Asp, by contrast, had a protective effect on the development of brucellosis (OR=0.06, 95 % CI [0.02 – 0.20]). Among the carriers of the Arg / Gln genotype and the Gln / Gln genotype of the TLR-2 gene, a significantly increased risk of brucellosis with CVS diseases was determined (χ2=5.68; p=0.02; OR=3.10; 95 % CI [0.99 – 9.67]) and (OR=2.48; 95 % CI [0.53 – 11.61]), respectively. While the carriage of the homozygous Arg / Arg genotype, by contrast, was rarely seen in patients with brucellosis (OR=0.28, 95 % CI [0.10 – 0.74]). Conclusions: The Asp / Gly genotype of the TLR-4 gene was 12.7 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals and 9.5 times more often than in patients without CVS diseases (p<0.05). The Arg / Gln genotype of the TLR-2 gene was 2.4 times more frequently detected in patients with acute brucellosis with CVS diseases than in healthy individuals (p<0.05).

Investigation of the Asp299Gly and Thr399Ile polymorphisms of TLR4 gene in Rheumatoid Arthritis

Objective: Rheumatoid arthritis (RA) is a chronic and inflammatory disease characterized by synovial inflammation that causes cartilage and bone destruction as well as systemic defects, including cardiovascular, pulmonary, psychological, and skeletal disorders. The etiology of RA is unclear. Evidence suggests that RA is influenced by both genetic and environmental factors and the inflammatory and autoimmune activities take important roles in the development of this disease. In the onset of RA, an interaction between the resident cells of synovium and cells of the innate and adaptive immune system reported. Fibroblast-like synoviocytes (FLS) are one of the resident cells and they play a central role, with a tumor-like behavior, in joint destruction and development of chronic inflammation. Toll-like receptors (TLRs) are transmembrane glycoproteins that are related to inflammation via synthesis of proinflammatory cytokines like TNF-α, IL-6, and IL-1β. Some studies report an association between the activation of FLS and the cytokine environment, cell-to-cell contacts, or the activation of TLR2, TLR4, and TLR3. TLRs and especially TLR4 is involved in the recognition of endogenous molecules released by injured tissues and necrotic cells. TLR4 gene involved in a wide variety of both infectious and non-infectious diseases and two polymorphisms of TLR4, Asp299Gly and Thr399Ile, changed the binding capacity and electrical charge of the protein. There are conflicting or even contradictory results about these polymorphisms and we aimed to determine the distribution of the allele frequencies of these polymorphisms and compare the result of RA patients with healthy subjects. Methods: DNA extraction was realized by salting out method from peripheral blood lymphocytes of RA patients and healthy controls. PCR amplification carried out with appropriate primer pairs against the related DNA sequences. Genotyping performed by the restriction fragment length polymorphism method. Results and Conclusion: According to the results obtained from RA patients and healthy controls, we have not found any statistical difference between both groups. Including the other polymorphisms of the TLR family into this type of studies, will give more information about the role of TLR family in rheumatoid arthritis.

The role of TNF-α and TLR4 polymorphisms in the placenta of pregnant women complicated by preeclampsia and in silico analysis

Evidence showed that, pro inflammatory cytokines and mediators of innate immune responses may involve in the pathogenesis of preeclampsia (PE). Therefore, the present investigation aimed to examine the possible effects of placental TNF-α and TLR4 polymorphisms on PE susceptibility. MethodsThe placental tissues were collected after delivery from 111 PE and 115 healthy pregnant women. The TNF-α-308G/A (rs1800629), TNF-α-238G/A (rs361525), TLR4 Asp299Gly (rs4986790) and TLR4 Thr399Ile (rs4986791) polymorphisms were genotyped using PCR-RFLP method. Moreover, in-silico analysis was performed to evaluate the potential functions of these polymorphisms. ResultsThe TNF-α −308 GA genotype was associated with a decreased PE risk. The frequency of TNF-α −238G/A genotypes did not differ between two groups, however, the frequency of TNF-α −238A allele was significantly higher in controls. No relationship between TLR4 Thr399Ile and Asp299Gly polymorphisms and PE was found. In-silico analysis predicted that −308G to A substitution in the TNF-α promoter might lead to different allelic expressions. In addition, TLR4 Asp299Gly polymorphism would result in a major change in the mRNA and protein functions. ConclusionOur study for the first time presented evidence on the association of the placental TNF-α −308GA genotype and TNF-α −238A allele with decreased risk of PE in an Iranian population.

The Role of TLR4 Asp299Gly and TLR4 Thr399Ile Polymorphisms in the Pathogenesis of Urinary Tract Infections: First Evaluation in Infants and Children of Greek Origin.

Urinary tract infections are one of the most common and serious bacterial infections in a pediatric population. So far, they have mainly been related to age, gender, ethnicity, socioeconomic level, and the presence of underlying anatomical or functional, congenital, or acquired abnormalities. Recently, both innate and adaptive immunities and their interaction in the pathogenesis and the development of UTIs have been studied. The aim of this study was to assess the role and the effect of the two most frequent polymorphisms of TLR4 Asp299Gly and Thr399Ile on the development of UTIs in infants and children of Greek origin. We studied 51 infants and children with at least one episode of acute urinary tract infection and 109 healthy infants and children. We found that 27.5% of patients and 8.26% of healthy children carried the heterozygote genotype for TLR4 Asp299Gly. TLR4 Thr399Ile polymorphism was found to be higher in healthy children and lower in the patient group. No homozygosity for both studied polymorphisms was detected in our patients. In the group of healthy children, a homozygote genotype for TLR4 Asp299Gly (G/G) as well as for TLR4 Thr399Ile (T/T) was showed (1.84% and 0.92 respectively). These results indicate the role of TLR4 polymorphism as a genetic risk for the development of UTIs in infants and children of Greek origin.

Toll-like receptor-4 299Gly allele is associated with Guillain-Barré syndrome in Bangladesh.

ObjectiveTLR4 plays an important role in the pathogenesis of Guillain‐Barré syndrome (GBS). The relationships between TLR4 polymorphisms and susceptibility to GBS are poorly understood. We investigated the frequency and assessed the association of two single nucleotide polymorphisms (SNPs) in the extracellular domain of TLR4 (Asp299Gly and Thr399Ile) with disease susceptibility and the clinical features of GBS in a Bangladeshi cohort.MethodsA total of 290 subjects were included in this study: 141 patients with GBS and 149 unrelated healthy controls. The TLR4 polymorphisms Asp299Gly and Thr399Ile were genotyped using polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay.ResultsThe minor 299Gly allele was significantly associated with GBS susceptibility (P = 0.0137, OR = 1.97, 95% CI = 1.17–3.31), and was present at a significantly higher frequency in patients with the acute motor axonal neuropathy (AMAN) subtype of GBS (P = 0.0120, OR = 2.37, 95% CI = 1.26–4.47) than acute inflammatory demyelinating polyneuropathy (AIDP) subtype (P = 0.961, OR = 1.15, 95% CI = 0.38–3.48); when compared to healthy controls. The genotype frequency of the Asp299Gly polymorphism was not significantly different between patients with GBS and healthy controls. The Asp299‐Thr399 haplotype was associated with a significantly lower risk of developing GBS (P = 0.0451, OR = 0.63, 95% CI = 0.40–0.99). No association was observed between the Thr399Ile polymorphism and GBS disease susceptibility.InterpretationThe TLR4 minor 299Gly allele was associated with increased susceptibility to GBS and the axonal GBS subtype in the Bangladeshi population. However, no associations were observed between the genotypes of the Asp299Gly and Thr399Ile SNPs and antecedent C. jejuni infection or disease severity in Bangladeshi patients with GBS.

Asp299Gly polymorphism in TLR4 gene in patients with colorectal cancer

Background: Toll-like receptors play important roles in innate and adaptive immunity and polymorphisms within TLR-4 as Asp299Gly are reported to be associated with certain digestive cancers e.g. colorectal carcinoma. Aim: Investigate the association between Asp299Gly polymorphism and the risk of colorectal cancer development and progression. Setting: National cancer institute, Tanta City, Gharbia Governorate, Egypt and/Tanta University Hospitals, General surgery Dept. Study design: A case control study. Patients and Methods: the study included 40 newly diagnosed patients with colorectal cancer recruited from patients attending National Cancer Institute and 40 apparently healthy individuals from relatives/visitors of patients matched in age and sex. For each of patients and control group genotyping of TLR-4 gene by PCR/RFLP was done and confirmed by direct sequencing. Results: TLR-4 Asp299Gly homozygous and heterozygous genotypes were detected in 50% and 30% of the patients respectively. The difference was statistically significant; TLR-4 Asp299Gly homozygous and heterozygous genotypes were significantly associated with advanced stages. Conclusion: TLR-4 Asp299Gly polymorphism is associated with increased susceptibility for CRC development and progression.

THE ROLE OF ADIPONECTIN AND TOLL-LIKE RECEPTOR 4 GENE POLYMORPHISMS ON NON-PROLIFERATIVE RETINOPATHY IN TYPE 2 DIABETES MELLITUS PATIENTS. A CASE-CONTROL STUDY IN ROMANIAN CAUCASIANS PATIENTS.

Persistent inflammation and impaired neovascularization are important contributors to the development of diabetic retinopathy (DR). Gene polymorphisms of adiponectin (APN) were demonstrated to have an important role on the plasma level and activity of adiponectin. APN has anti-inflammatory, anti-diabetic and anti-atherogenic properties. Toll-Like Receptor 4 (TLR4) is a critical mediator of innate immunity. Polymorphisms in TLR-4 gene were shown to be associated with impaired inflammatory response in diabetes. The aim of the study was to analyze the association of +276G>T variant of APN gene and Asp299Gly and Thr399Ile of TLR-4 gene variants in relationship with T2DM and DR in an Eastern European population group. The distribution of the mutant alleles in 198 T2DM patients with DR and 200 non-T2DM controls was examined. Genomic DNA from T2DM patients and healthy controls genotyped through the use of PCR-RFPL assay. Genotype and allele frequencies of the Asp299Gly and Thr399Ile polymorphisms differed between T2DM patients and non diabetic subjects (P<0.001). Moreover, the presence of the minor alleles of these polymorphisms were significantly identified as protective factors against T2DM, under a dominant model of Fisher's exact test (χ2=4.988, phi=0.745, OR=0.767, 95% CI=0.602-0.867, P<0.001; respectively χ2=5.254, phi=0.820, OR=0.487, 95% CI=0.211-0.648, P<0.001). Genotype analysis for the adiponectin 276G>T gene polymorphism yielded no significant association with T2DM, but revealed a borderline significance for the association with DR (χ2=5.632, phi=0.423, OR =1.101, 95% CI=0.887-1.203, P=0.009). We found an association between the TLR4 Asp299Gly and Thr399Ile polymorphisms and protection for DR. The APN genetic polymorphism is not associated with T2DM.

Role of toll-like receptor 4 Asp299Gly polymorphism in the development of cardiovascular diseases in HIV-infected patients

Cardiovascular diseases (CVDs) are one of the main causes of morbimortality in HIV-infected patients on suppressive antiretroviral therapy. The objective of this work was to evaluate the role of single nucleotide polymorphisms (SNPs) in lipopolysaccharide (LPS) Toll-like receptor 4 (TLR4) and CVDs occurrence in HIV-infected patients. Additionally, the functional consequences of carrying these SNPs were analyzed. The association of TLR4 SNPs, Asp299Gly/Thr399Ile with CVDs occurrence was analyzed using multivariate logistic regression models. Clinical, immunological, and traditional cardiovascular risk factors were used as covariates. The monocyte phenotype and response were assessed by multiparametric flow cytometry comparing carriers with noncarriers of this SNP. Asp299Gly SNP, assayed in 253 HIV-infected patients, was independently associated with the occurrence of CVDs after adjusting for CD4+ T-cell nadir, HCV-coinfection, bacterial pneumonia, diabetes mellitus, and traditional cardiovascular risk factors [odds ratio (confidence interval 95%) = 3.672 (1.061-12.712), P = 0.04). Carriers of Asp299Gly SNP showed higher percentage of patrolling and intermediate monocytes producing a proinflammatory combination of cytokines compared with noncarriers (P = 0.037 and P = 0.046, respectively). Intermediate monocyte subset levels correlated with soluble interleukin-6 levels only in carriers (r = 0.89; P = 0.01). TLR4 Asp299Gly polymorphism is independently associated with the occurrence of CVDs in HIV-infected patients. The proinflammatory profile associated to this variant could be involved in the development of atherosclerotic pathologies.

The potential role of toll-like receptor 4 Asp299Gly polymorphism and its association with recurrent cystic echinococcosis in postoperative patients.

The study of pathogenesis mechanisms of larval stages in the Taeniidae has recently focused on host genetic factors, particularly toll-like receptor (TLR) variations. However, the potential role of TLR4 polymorphism in hydatidosis has not yet been sufficiently elucidated in postoperative patients. In this case-control investigation, 80 patients from Iran, including 40 with acute hydatidosis (AH) and 40 with recurrent hydatidosis (RH), and 80 ethnically matched controls were evaluated from February 2015 to February 2017. Hydatidosis patients were confirmed using radiological, immunological, and histopathological examinations. Genotyping of Asp299Gly and Thr399Ile of TLR4 single-nucleotide polymorphisms was determined by restriction fragment length polymorphism, sequencing, and phylogenetic strategies. The heterozygous mutant-type TLR4 Asp299Gly genotype indicated a tendency to be associated with the occurrence of RH (P = 0.060) and conferred a 3-fold risk for susceptibility. There was no difference in genotype frequency of Asp299Gly between patients with AH and healthy controls (P = 0.42; OR, 1.82; 95% CI, 0.11-30.1%). Interestingly, a frequency of the G allele (12%: Gly) was observed to be a risk factor for susceptibility to RH patients (P = 0.050; OR, 7.08; 95% CI, 0.97-51.5%). A relative genetic variability of TLR4 Asp299Gly was found in RH patients (haplotype diversity: 0.700) compared to AH patients and healthy controls (Hd: 0.000). The Asp299Gly genotype was dominantly identified in patients with hepatic hydatid cysts. The TLR4 Thr399Ile codon was not detected except in a patient with a pulmonary hydatid cyst. The current findings enhance our knowledge regarding the TLR4 Asp299Gly polymorphism potentially leading to the development of RH, by skewing the immune system towards a Th2 response. Identification of the Asp299Gly codon may be a diagnostic hallmark in RH patients who have undergone unsuccessful postoperative intervention. However, further studies with a higher case number are needed on ethnic population from various geographic regions, in order to confirm this hypothesis.

Association between Asp299Gly and Thr399Ile Polymorphisms in Toll-Like Receptor 4 Gene and Type 2 Diabetes Mellitus: Case-Control Study and Meta- Analysis

Objective: This paper describes a case-control study and a meta-analysis conducted to determine whether the TLR4 Asp299Gly (rs4986790) and Thr399Ile (rs4986791) polymorphisms are associated with type 2 diabetes mellitus (T2DM). Methods: In the case-control study were enrolled 1683 T2DM patients and 584 nondiabetic subjects from Brazil. A literature search was conducted in order to identify studies that investigated associations between the referred TLR4 polymorphisms and T2DM. Pooled odds ratios (OR) were calculated for allele contrast and dominant inheritance models. Results: In the case-control study, genotype and allele frequencies of the Asp299Gly and Thr399Ile polymorphisms differed between T2DM patients and nondiabetic subjects (P<0.05). Moreover, the presence of the minor alleles of these polymorphisms were significantly associated with protection for T2DM, after adjusting for ethnicity, under a dominant model [Asp299Gly: OR=0.68 (95% CI 0.49-0.94); Thr399Ile: OR=0.65 (95% CI 0.46-0.90)]. Seven studies were eligible for inclusion in the meta-analysis. Meta-analysis results showed that the Asp299Gly polymorphism was associated with T2DM protection [OR=0.68 (95% CI 0.46-1.00), allele contrast model]. Stratification by ethnicity revealed that both polymorphisms were associated with T2DM protection under allele contrast and dominant models in Brazilian population but not in Europeans. Conclusions: In our case-control study, we were able to demonstrate a possible association between the TLR4 Asp299Gly and Thr399Ile polymorphisms and protection for T2DM. In agreement, the meta-analysis results showed an association of the Asp299Gly polymorphism with T2DM protection in the whole group, and associations of the Asp299Gly and Thr399Ile polymorphisms with T2DM protection in the Brazilian group but not in European descendent. This is the largest TLR4 meta-analysis performed so far. In other ethnicities further studies with large sample size are necessary to confirm these associations in different ethnicities as well as to elucidate the roles possibly played by these polymorphisms in the pathogenesis of T2DM.

TLR4 Asp299Gly and Thr399Ile and TLR2 intron 2 microsatellite gene polymorphism in patients with acute biliary pancreatitis: Does it cause the disease?

There has been coverage of Toll-like receptor 4 and Toll-like receptor 2 gene polymorphisms in inflammatory episodes in a number of studies. In view of the inflammatory nature of acute pancreatitis, we aimed to determine the predictive value of mutations in Asp299Gly and Thr399Ile of the Toll-like receptor 4 gene, and the intron 2 microsatellite polymorphism of the Toll-like receptor 2 gene on the occurrence of acute biliary pancreatitis. The study included 86 patients for the Toll-like receptor 4 Thr399Ile polymorphism, 100 patients for the Toll-like receptor 4 Asp299Gly polymorphism with acute biliary pancreatitis, and 101 healthy volunteers. At the same time, 93 patients and 92 healthy volunteers were included in the study to research the Toll-like receptor 2 intron 2 microsatellite polymorphism. Genotypes were determined using the restriction fragment length polymorphism analysis of PCR products and by an allele-specific PCR. The Toll-like receptor 4 Thr399Ile homozygotes mutant variants (p=0.005) and Toll-like receptor 2 MM genotype (p<0.001) were detected with a significantly higher frequency in patients with acute biliary pancreatitis than in the healthy blood donors. The Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms and the Toll-like receptor 2 intron 2 microsatellite polymorphism are statistically associated with ABP.

Association of Helicobacter pylori infection with Toll-like receptor-4 Thr399Ile polymorphism increased the risk of peptic ulcer development in North of Iran.

Toll-like receptor-4 (TLR4) polymorphisms may influence host immune response against Helicobacter pylori (H.pylori). This study aimed to investigate whether TLR4 polymorphisms are associated with H.pylori susceptibility and risk of peptic ulcer development or not. The TLR4+3725G/C polymorphism was studied using polymerase chain reaction with confronting two-pair primers (PCR-CTPP). In addition, TLR4 Asp299Gly and Thr399Ile polymorphisms were evaluated by PCR-restriction fragment length polymorphism (RFLP). There was no significant difference in TLR4+3725G/C and Asp299Gly genotype frequencies between non-peptic ulcer (NPUD) and peptic ulcer (PUD) individuals in the context of peptic ulcer development and susceptibility to infection with H.pylori. Nevertheless, a significant association with increased risk for PUD development was observed for polymorphism TLR4 Thr399Ile [odds ratio (OR)=4.2; 95% confidence interval (CI)=1.35-13.26; p=0.01]. Correspondingly, TLR4 Thr399Ile polymorphism was associated with H.pylori susceptibility (OR=0.27; 95% CI=0.08-0.88; p=0.04). In addition, TLR4 Thr399Ile polymorphism increased 4.2-fold, the risk of peptic ulcer development in individuals infected by H.pylori carrying CT+TT genotype. Our results showed that TLR4 Thr399Ile polymorphism along with H.pylori infection may play critical roles in peptic ulcer development in North of Iran.

TLR4 polymorphisms seem not to be associated with prediabetes and type 2 diabetes but predispose to diabetic retinopathy; TLR4 polymorphisms in glucose continuum.

Compared to type 1 diabetes, the role of the immune and autoimmune pathogenetic mechanisms is much less studied in the type 2 diabetes. Toll-like receptors 4 (TLR4) have a leading role in inflammation, insulin resistance, and vascular damage. This study aimed to analyze the relationship between the polymorphisms in TLR4 gene and different stages in the glucose continuum from prediabetes to the type 2 diabetes and chronic microvascular complications. The study included 113 patients with the type 2 diabetes, 29 participants with prediabetes, and 28 controls. Polymerase chain reaction (PCR) was used for genotyping Asp299Gly and Thr399Ile polymorphism, followed by restriction analysis. The difference in the genotype frequency for both polymorphisms in patients with the type 2 diabetes or prediabetes compared to that in controls was not significant. Patients with heterozygous genotype of Asp299Gly polymorphism had a higher prevalence of diabetic retinopathy (42.9%) than participants with homozygous genotype (9.0%) (OR [95%CI]=7.61 [1.41-41.08]; p=0.018). No association was established for diabetic polyneuropathy and nephropathy. Prevalence of chronic diabetes complications was not related to Thr399Ile polymorphism. Our study demonstrates that Asp299Gly and Thr399Ile polymorphisms seem not to be associated with the type 2 diabetes and prediabetes but Asp299Gly may contribute to diabetic retinopathy predisposition.

Investigation of associations of ARMS2, CD14, and TLR4 gene polymorphisms with wet age-related macular degeneration in a Greek population.

BackgroundAge-related macular degeneration (AMD) is a multifactorial degenerative ocular disease that leads to loss of central vision. Functional gene polymorphisms have already been associated with the disease (for example, ARMS2 A69S, rs10490924).AimThe goal of our study was to verify the correlation of the aforementioned ARMS2 variation with the disease, to examine, for the first time, the role of the CD14 C260T variation (rs2569190), and to investigate the association of two TLR4 polymorphisms (Asp299Gly or rs4986790 and Thr399Ile or rs4986791) in a Greek population with the wet form of AMD.Patients and methodsGenomic DNAs were isolated from blood samples of 103 healthy controls and 120 Greek patients with wet AMD who were age- and sex-matched, and all of whom were clinically evaluated. For the genotyping of all selected polymorphisms, polymerase chain reaction–restriction fragment length polymorphism analysis was performed.Results and conclusionsThis study confirmed the association between the ARMS2 variation and AMD, detecting the T risk allele in a significantly higher frequency in the patient group, compared with the control subjects (45% vs 29.13%, P<0.001, odds ratio [OR] 1.99, confidence interval 1.34–2.95). For the CD14 polymorphism, no statistically significant correlation was observed. As for the TLR4 polymorphisms, the percentage of heterozygotes increased from 2.9% to 11.7% in the patient population for Asp299Gly and from 1.9% to 10% for the Thr399Ile polymorphism (ORs 4.40 [P=0.01] and 5.61 [P=0.0088], respectively). Although our ARMS2 and CD14 results provided definite conclusions, the role of innate immunity TLR4 gene awaits further investigation in larger AMD populations with more clinical data collected on past microbial infections.

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

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. One hundred and eighty-seven unrelated Mexican patients with POAG (94 men and 95 women; mean age 66.49 ± 14.3years) and 109 control subjects (40 men and 69 women; age, 63.28 ± 7.93years) 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. 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. 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.

Asp299Gly Polymorphism of the TLR-4 Gene in Adult Patients with Fixed and with Reversible Airflow Obstruction in the Population of Crimea, Ukraine

Asp299Gly Polymorphism of the TLR-4 Gene in Adult Patients with Fixed and with Reversible Airflow Obstruction in the Population of Crimea, Ukraine