Promoter Region Of TNF-α Gene Research Articles

The Effect of TNF-Alpha Gene Polymorphisms At -376 G/A, -806 C/T, and -1031 T/C on The Likelihood of Becoming a Non-Responder to Etanercept in A Sample of Iraqi Rheumatoid Arthritis Patients

Tumor necrosis factor-alpha (TNF-α) antagonists’ therapy are expensive and has a non-responsive rate between 30% to 40% in rheumatoid arthritis patients. Genetic variation plays a vital role in the responsiveness to this type of therapy.The aim of this study is to investigate if the presence of genetic polymorphism in the TNF-α gene promoter region at locations -376 G/A (rs1800750), -806 C/T (rs4248158), and -1031 T/C (rs1799964) affects rheumatoid arthritis patient's tendency to be a non-responder to etanercept. Eighty RA patients on etanercept (ETN) for at least six months were recruited from the Rheumatology Unit at Baghdad Teaching Hospital. Based on The European League Against Rheumatism response (EULAR) criteria, patients were divided into two groups: responders and non-responders. After polymerase chain reaction amplification of their DNA, the amplified DNA was sequenced by Sanger method to determine the polymorphisms at the positions -376G/A, -806 C/T, and -1031T/C. The results of this study found that equally Phi correlation and binary logistic regression analysis revealed a non-significant association for all genotypes in the three polymorphic sites with the tendency for being non-responder. Moreover, there was no significant difference in TNF-α mean level or the change in disease activity score for 28 joints (DAS28) after six months of etanercept therapy between all genotypes for each polymorphic site. The present study concludes that there was no correlation between the polymorphisms in the TNF-α promoter region at -376G/A, -806 C/T, and -1031T/C with the tendency for being non-responder to ETN.

Epigenetic modifications of tumor necrosis factor-alpha in joint cartilage tissue from osteoarthritis patients - CONSORT.

Background:Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA.Methods:Totally, 37 OA patients’ cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples.Results:Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA.Conclusion:In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.

Synergetic Interaction of HLA-DRB1*07 Allele and TNF-Alpha - 863 C/A Single Nucleotide Polymorphism in the Susceptibility to Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease which is characterized by dysregulation of various cytokines propagating the inflammatory processes that is responsible for tissue damage. Tumor necrosis factor alpha (TNF-α) is one of the most important immunoregulatory cytokines that has been implicated in the different autoimmune diseases including SLE. Two hundred and two patients with SLE and 318 controls were included in the study. The TNF-α gene promoter region (from - 250 to - 1000 base pairs) was analyzed by direct Sanger's DNA sequencing method to find promoter variants associated with South Indian SLE patients. We have analyzed six TNF-α genetic polymorphisms including, - 863C/A (rs1800630), - 857C/T (rs1799724), - 806C/T (rs4248158), - 646G/A (rs4248160), - 572A/C (rs4248161) and - 308G/A (rs1800629) in both SLE patients and controls. We did not find association of TNF-α gene promoter SNPs with SLE patients. However, the - 863A (rs1800630) allele showed association with lupus nephritis phenotype in patients with SLE (OR: 1.62, 95%CI 1.04-2.53, P = 0.034). We found serum TNF-α level was significantly elevated in SLE cases as compared to control and found no association with any of the polymorphisms. The haplotype analysis revealed a significant protective association between the wild TNF-α alleles at positions - 863C, - 857C, - 806C, - 646G, - 572A and - 308G (CCCGAG) haplotype with lupus nephritis phenotype (OR 0.53, 95% CI 0.35-0.82, P = 0.004). Additionally, the TNF-α - 863 C/A (rs1800630) polymorphism and HLA-DRB1*07 haplotype showed significant differences between SLE patients and controls (OR 4.79, 95% CI 1.73-13.29, P = 0.0009). In conclusion, TNF-α - 863A allele (rs1800630) polymorphism is associated with increased risk of nephritis in South Indian SLE patients. We also found an interaction between HLA-DRB1*07 allele with TNF-α - 863 C/A promoter polymorphism giving supportive evidence for the tight linkage disequilibrium between TNF-α promoter SNPs and MHC class II DRB1 alleles.

Association between tumor necrosis factor-α gene-1031T/C promoter polymorphism and endometriosis in a European population.

Background Tumor necrosis factor-alpha (TNF-α) is a pro-inflammatory cytokine which plays an important role in the pathogenesis of many diseases. Endometriosis is one of the most common gynecological diseases. The purpose of this study was to investigate the association of TNF-α-1031T/C polymorphism with the genetic susceptibility of endometriosis in a European population. Materials and methods In this case-control study, 51 endometriosis patients and 67 healthy control women participated. We used endometrial tissue from the patients and peripheral blood from the healthy women to extract DNA. Polymerase chain reaction (PCR) analysis and the restriction enzyme Bbs I were used to analyze the -1031 T/C polymorphism in the TNF-α gene promoter region. Statistical analysis was performed using Fisher's exact test. We also calculated the odds ratios. Results In the group of patients, 66.7% of women were detected with the TT genotype, 33.3% with the TC genotype and 0% with the CC genotype while in the control group, 46.3% had the TT genotype, 47.8% had the TC genotype and 6% had the CC genotype. There was a significant association between the TT genotype with endometriosis (p = 0.03). There was no significant deviation from the Hardy-Weinberg equilibrium. Conclusions The TC and CC genotypes appeared more often in the healthy women than the endometriosis patients and this shows that the C allele might have a protective role in endometriosis in the Greek population. Further studies are needed to specify the role of this polymorphism in pathogenesis of endometriosis and the mechanisms that protect the patients from the disease.

DETECTION OF TUMOR NECROSIS FACTOR- (TNF- ) GENE PROMOTERS POLYMORPHISM AMONG LIVER CIRRHOSIS PATIENTS WITH CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IN SURABAYA, INDONESIA

Polymorphisms in TNF-α gene promoter region are known of its role in the production of TNF-α which may influences the pathogenesis of liver disease. SNPs in positions 238 and 308 of TNF-α gene promoters may affect the production of these cytokines. This study was aimed to detect Single Nucleotide Polymorphism (SNP) on -238 and -308 positions in the TNF-α gene promoter among liver cirrhosis patients with HBV infection in Surabaya, Indonesia. This was descriptive exploratory research with cross sectional study design using serum liver cirrhosis patients with HBV infection in Endoscopy Outpatient Clinic Dr. Soetomo General Hospital, Surabaya from April-May 2017. SNPs at -238 and -308 on TNF-α gene promoter (rs361525 and rs1800629 respectively) were detected using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) with primers specific for the TNF-α promoter region and restriction enzymes NcoI and MspI. The genotypes of TNF-α gene promoter were assessed according to the length of the fragments produced in RFLP. Serum TNF-α levels was measured by commercial ELISA. In this study, as much as 149 positive HBsAg patients was found in Endoscopy Outpatient Clinic, Dr. Soetomo General Hospital, Surabaya. From those amount, as much as 30 liver cirrhosis patients with positive HBsAg were obtained. From 2/30 (6.7%) patients showed the GA heterozygote SNP either position -238 or -308. No patient had the AA genotype. Median blood TNF-α level in women (38 ng / L) was higher than in men (33 ng / L). TNF-α levels in patients with GA heterozygote genotype at -238 and -308 in this research was not different than wild-type (GG genotype). Among patients with liver cirrhosis due to chronic HBV infection in Surabaya, Indonesia, Surabaya, we found GA polymorphisms the TNF-α promoter gene at positions -238 and -308 in 6.7% patients, and did not find homozygous AA polymorphisms. Further studies including larger numbers of patients from various ethnic backgrounds in Indonesia are needed to provide robust data on TNF-α gene promoter polymorphisms and their role in the pathogenesis of liver cirrhosis with HBV infection in this country.

Evolutionary interplay of single nucleotide polymorphisms at the promoter region of TNF-α gene in different clinical outcomes of malaria in India

Host genetic factors are frequently ascribed to differential malaria outcomes as a by-product of evolutionary adaptation. To this respect, Tumor Necrosis factor alpha (TNF-α), a human cytokine, is known to be associated with malaria through its differential regulation in diverse malaria manifestations. Since diversity in differential malaria outcome is uncommon in every endemic settings, possible association of TNF-α and malaria is not commonly established. In order to check for association between the occurrence of Single Nucleotide Polymorphisms (SNPs) in the TNF-α gene with different malaria manifestations, we have sequenced a 4011 bp region constituting the promoter and the whole gene of human TNF-α in 61 patients [(16 cerebral plus severe (SCM), 21 severe (SM) and 24 uncomplicated (UM)] samples in a highly malaria endemic state (Odisha) of India. Multiple sequence alignment revealed presence of six SNPs (−1031 T > C, −863C > A, −857C > T, −308G > A, −806C > T, +787C > A), out of which the -806C > T and +787C > A are novel in malaria patients in general and the +787C > A was detected for the first time in humans. Although alleles due to six different SNPs segregate differentially in the three groups of malaria (SCM, SM and UM) in the present study, interestingly, for the −1031 T > C position, the frequency of individuals possessing the homozygous rare allele was higher in the SCM group with a higher number of heterozygotes in the UM group. The Tajima's D values considering all the SNPs in a defined group were positive and statistically insignificant conforming no evolutionary constraint. However, statistically significant deviation from expectation under Hardy-Weinberg equilibrium for -1031 T > C SNP in the UM group points towards the probable role of natural selection providing some kind of protection to malaria in Odisha, India.

Association of tumor necrosis factor-alpha gene promoter polymorphism and its mRNA expression level in coronary artery disease

Backgroundumor necrosis factor-alpha (TNF-α) is a pro-inflammatory cytokine that may play an important role in inflammatory diseases like coronary artery disease (CAD). As a result of controversy on the impact of polymorphisms in the promoter region of TNF-α gene on transcription, this case control study was designed to evaluate the effects of TNF-α -308G > A (rs1800629) and TNF-α − 238G > A (rs361525) on mRNA expression level and risk of CAD. MethodsOverall, 379 patients with CAD and 461 healthy controls participated in this study. Subjects were matched in terms of age, sex and ethnic origin. Genotyping was performed using single specific primer-polymerase chain reaction (SSP-PCR) and TNF-α mRNA expression analysis was carried out by quantitative real time PCR. ResultsA/A and A/G genotypes in TNF-α (−308G > A) gene were significantly more frequent among patients than controls. The TNF-α (−238G > A) did not differ between CAD patients and controls (the TNF-α (−238G > A) genotypes and allele frequency showed no significant differences). Combination of AA TNF-α (−308) /GG TNF-α (−238) and AG TNF-α (−308) /AG TNF-α (−238) genotypes demonstrated higher frequencies in patients than in controls (P < .05). TNF-α mRNA expression level showed significantly higher in patients carrying A/A genotype at TNF-α (−308) compared to healthy individuals. ConclusionAlthough there was no significant association between TNF-α -238 G > A polymorphism with TNF-α expression level and pathogenesis of CAD in the studied population, The TNF-α (−308G > A) gene polymorphism was associated with its expression and development of CAD.

Association of tumor necrosis factor-α (TNF-α) gene promoter polymorphisms with aggressive and chronic periodontitis in the eastern Indian population.

Background: Periodontitis is a very common inflammatory oral disease. Tumor necrosis factor-α (TNF-α) is a cytokine that has been involved with the gingival tissue destruction and remodeling occurrence. We investigated the association of single nucleotide polymorphisms (SNPs) in TNF-α gene promoter region with the susceptibility of aggressive and chronic periodontitis in the eastern Indian population.Methods: A total of 397 DNA samples from venous blood were isolated. 40 individuals were aggressive periodontitis patients, 157 were identified chronic periodontitis patients, and the remaining 200 were healthy individuals. Five SNPs of TNF-α at promoter region (rs361525, rs1800629, rs1799724, rs1800630, and rs1799964) were genotyped by PCR-sequencing in periodontitis patients and control subjects.Results: rs1800629 (-308G/A) polymorphism was more frequent in both aggressive and chronic periodontitis patients compared with the control population, though the allele frequency was different only in aggressive periodontitis patients. On the other hand, both the genotypic and allelic variation of rs361525 (-238G/A) polymorphism were found significantly less frequently in aggressive and chronic periodontitis than in controls. The other polymorphisms like rs1799724 (-857C/T) and rs1799964 (-1031T/C) were significantly different between chronic periodontitis patients and control subjects.Conclusion: The findings suggest that the rs1800629 (-308G/A) polymorphism of TNF-α gene is associated with both aggressive and chronic periodontitis while rs1799724 (-857C/T) and rs1799964 (-1031T/C) polymorphisms of TNF-α gene is associated only with the increased susceptibility to chronic periodontitis.

Serum Level of Tumor Necrosis Factor-α and Its Gene Polymorphisms Has No Association with Susceptibility to Celiac Disease in Iranian Population

Background: TNFα is an important cytokine in celiac disease which causes the destruction of the intestinal tissue. It has been shown that polymorphisms in the promoter region of the TNFα gene increase its expression. In this study we investigated the -1031 C/T and -376 G/A gene polymorphisms of TNFα gene and also its serum level in Iranian celiac patients compared to healthy controls. Methods: In this cross sectional study, 104 newly diagnosed celiac disease and 102 healthy control were recruited during 2016. The DNA was extracted from peripheral blood. Specific primer pairs were designed and TNFα polymorphisms was determined by polymerase chain reaction (PCR) amplification followed by restriction fragment length polymorphism (RFLP). For confirmation of finding some samples were randomly sequenced. Also to determine the serum concentration of TNFα the ELISA method was used. Result: The mean age of cases and control was 32, 33 years respectively. No significant difference was observed between CD patients and healthy controls regarding -1031 C / T and -376 G / A gene polymorphisms (for -376 G/A; p= 0.8 and for -1031 C/T; p=0.35 respectively). Also there was no significant difference in serum level of TNFα between celiac patients and healthy subjects (p= 0.18). Conclusion: According to our results, it seems that the TNF-α (-1031 C/T, -376 G/A) gene polymorphisms in combination with serum level may not be associated with the risk of celiac disease.

Polymorphisms of Promoter Region of TNF-α Gene in Iranian Azeri Turkish Patients with Behçet's Disease.

Behçet’s disease (BD) is a complex chronic relapsing inflammatory disorder of unknown etiology. Alterations of the tumor necrosis factor (TNF) expression related to the polymorphic alleles of TNF gene may implicate a pathogenetic role in increased activity of this cytokine in BD. A current study aimed at investigating the possible association between BD and its clinical features in Iranian Azeri Turks with two functional TNF-α gene polymorphisms (at the positions of -238 and -857). A total number of 166 Iranian subjects were enrolled into two different groups; patients with BD (n = 64), and ethnically matched healthy controls (n = 101). The genotype distributions of BD patients and healthy controls were determined. The frequency of TNF-α -857C allele was significantly higher in Behçet’s patients than that of healthy controls (P = 0.001; odds ratio [OR] = 2.616; 95% confidence interval [CI] = 1.129–6.160), whereas the frequency of TNF-α -238A allele was similar in both groups. The sole TNF-α haplotype-857C-1031C, was associated with an increase in the risk of developing BD. The TNF-α -857C allele was considerably associated with BD in this cohort. The findings of this study, collectively, indicate that TNF-α -857C-1031C haplotype located in the promoter region of the gene could exert major influence on the susceptibility to BD.

308G/A and 238G/A polymorphisms in the TNF-α gene may not contribute to the risk of arthritis among Turkish psoriatic patients

IntroductionTumor necrosis factor-alpha (TNF-α) is an important proinflammatory cytokine playing a key role in the pathogenesis of psoriasis (Ps) and psoriatic arthritis (PsA). TNFα gene promoter region single nucleotide polymorphisms (SNPs) affect the clinical course, severity and the response to the treatment. Aim of the workTo find out whether TNF-α-238G/A and -308G/A promoter polymorphism in Ps patients increases arthritis risk. Patients and methodsThe study included 129 psoriatic patients (71 with psoriasis only and 58 with PsA). Two single nucleotide polymorphisms in the TNFα gene promoter region (238G/A and -308G/A) were genotyped by real-time polymerase chain reaction. ResultsPs patients without arthritis had a mean age of 44.20±13.85years (range 18–68years), while PsA patients had a mean age of 49.15±13.47years (range 18–82years) and presented by dactylitis (67.2%), enthesitis (62.1%) followed by spondylitis (60.3%). Periosteal reaction was present in 19%. The psoriatic arthritis severity index (PASI) was comparable between those with (8.2±7.1) and without (7.3±5.12.1) arthritis. The allele positivity of TNF-238A and -308A was not associated with the risk of arthritis among psoriatic patients (OR: 1.002; 95%CI: 0.38–2.6, p=0.99 and OR: 1.27; 95%CI: 0.51–3.2, p=0.6, respectively). In addition, none of the genotypes of the studied TNF-α polymorphisms were significantly associated with arthritis. Only spondylitis was significantly associated more frequently with the GG (67.3%) than the GA (22.2%) TNF-α-308G/A genotype (p=0.02). ConclusionNone of the haplotypes nor alleles of TNF-α-238G/A and -308G/A polymorphisms were significantly associated with arthritis development among psoriatic patients.

Study of TNF-α Polymorphism (308G/A) and the Role of NF-κB as an Novel Marker of Severity of Atherosclerosis: A Pilot Study in Indian Population

Background: Biallelic polymorphism of A/G variation at position 308 in the promoter region of TNF-α gene is an important genetic factor causing high TNF-α transcription which could influence the clinical outcome of atherosclerosis. Studies have also implicated the role of NF-κB in atherogenesis by regulating genes involved in the inflammatory response and insulin sensitivity. Material and Method: 50 cases of angiographically significant atherosclerosis (>50% obstruction in coronary arteries) and 50 age, sex, BMI matched patients with insignificant atherosclerosis (>50% obstruction) on angiography were selected from GB Pant Hospital. Polymorphism was studied by amplifying DNA using PCR and amplified segments were digested by restriction enzyme Nco-I and followed by RFLP. Serum NF-κB, TNF-α levels were estimated by sandwich ELISA. Results: The mean serum NF-κB and TNF-α levels were significantly (p=0.04, 0.000 respectively) raised in cases as compared to controls. Upon binomial logistic regression analysis, NF-κB emerged as the best predictor of severity of atherosclerosis (Odds ratio=27) among other markers. Our results showed no intergenotypic variation of 308-G/A polymorphism of the TNF-α gene between cases and controls. Conclusion: Our study establishes NF-κB as an emerging biomarker of severity of atherosclerosis in Indian population. No intergenotypic variation between cases and controls indicates that significantly high levels of TNF-α in the cases is attributed to cause other than polymorphism in Indian population. High prevalence of chronic low grade inflammation in population could be postulated as the possible cause.

Evaluation of Tumor Necrosis Factor Alpha Polymorphism Frequencies in Endometriosis.

The pro-inflammatory cytokine, tumor necrosis factor-alpha (TNF-α), is a pathogenic element for a number of disorders. Previous studies have reported that the -1031 T/C and -238 G/A polymorphisms in the promoter region of the TNF-α gene are important factors in reproductive-related disorders. One of the most common gynecological diseases of women during the reproductive years is endometriosis. This study aims to assess an association between the -1031 T/C, -238 G/A and -308 G/A polymorphisms of the TNF-α gene promoter region to endometriosis. In this case-control study, we enrolled 65 endometriosis patients and 65 matched healthy control women by simple sampling. Polymerase chain reaction (PCR) analysis was used to analyze -1031 T/C, -238 G/A and -308 G/A polymorphisms in the TNF-α gene promoter region. Statistical analysis was performed using the chi-square test. P values less than 0.05 were considered statistically significant. We found a strong association between the -1031 T/C polymorphism in the promoter region of the TNF-α gene with endometriosis (P=0.001). There were no significant associations between the -238 G/A (P=0.243) and -308 G/A (P=1) polymorphisms with endometriosis and again endometriosis stages have no association with these polymorphisms. The -1031 T/C polymorphism and CC genotype can be used as a relevant marker to identify women at risk of developing endometriosis.

Tumor necrosis factor-alpha gene promoter methylation in Japanese adults with chronic periodontitis and rheumatoid arthritis.

Over-expression of tumor necrosis factor-alpha (TNF-α) plays a pathological role in chronic periodontitis (CP) and rheumatoid arthritis (RA), which might be regulated by the epigenetic mechanism. The aim of the present study was to evaluate whether there is a unique methylation profile of the TNF-α gene promoter in blood cells of individuals with CP and RA. The study participants consisted of 30 Japanese adults with RA (RA group), 30 race-matched adults with CP only (CP group) and 30 race-matched healthy controls (H group). Genomic DNA isolated from peripheral blood was modified by sodium bisulfite and analyzed, by direct sequencing, to investigate DNA methylation of the TNF-α gene promoter region. The level of TNF-α produced in mononuclear cells stimulated with Porphyromonas gingivalis lipopolysaccharide was determined using ELISA. Twelve cytosine-guanine dinucleotide (CpG) motifs were identified in the TNF-α promoter fragment from -343 to +57bp. The CP group showed a significantly higher methylation rate and frequency at -72bp than the H group (p<0.01). The RA group exhibited significantly higher methylation rates at seven CpG motifs (-302, -163, -119, -72, -49, -38 and +10bp), and significantly higher methylation frequencies at six CpG motifs (-163, -119, -72, -49, -38 and +10bp), than the H group (p<0.01 for all comparisons). The levels of TNF-α produced were significantly different between individuals with and without methylation at -163bp (p=0.03). These results suggest that the hypermethylated status of CpG motifs in the TNF-α gene promoter in blood cells may be unique to Japanese adults with CP and RA.

Association of TNF-α gene promoter region polymorphisms in bovine leukemia virus (BLV)-infected cattle with different proviral loads.

Tumor necrosis factor alpha (TNF-α) is a pleiotropic cytokine involved in the immune response against viral and other infections. Its expression levels are affected by a polymorphism in the promoter region of the gene. Bovine leukemia virus is a retrovirus that infects cattle and develops two different infection profiles in the host. One profile is characterized by a high number of proviral copies integrated into the host genome and a strong immune response against the virus, while the most relevant property of the other profile is that the number of copies integrated into the host genome is almost undetectable and the immune response is very weak. We selected a population of cattle sufficiently large for statistical analysis and classified them according to whether they had a high or low proviral load (HPL or LPL). Polymorphisms in the promoter region were identified by PCR-RFLP. The results indicated that, in the HPL group, the three possible genotypes were normally distributed and that, in the LPL group, there was a significant association between the proviral load and a low frequency of the G/G genotype at position -824.

Isolation of human genomic DNA from archival dried blood spots for neonatal disease screening and its application to methylation detection

Objective To establish an effective DNA isolation method for neonatal disease screening, so as to explore its application to the methylation detection. Methods The 20 dried blood spots samples were randomly divided into 2 groups according to the gender: the traditional method group (n=10) and the improved kit method group(n=10). The DNA quality was evaluated based on its concentration, integrity and whether it could be used in polymerase chain reaction (PCR). These DNA samples with or without bisulfite treatment were used as template in the methylation-specific polymerase chain reaction (MSP). The methylation levels of Leptin and tumor necrosis factor-α (TNF-α) gene promoter region were detected. Results DNA concentration of the improved kit method [(5.70±0.81)mg/L] was significantly higher than that of the traditional method[(3.50±0.45) mg/L](t=2.79, P<0.05), and biochemical analyzer analysis showed a better DNA integrity.Agarose gel electrophoresis revealed that 18S gene fragment could be successfully amplified by PCR method, suggesting its potential application to PCR study.MSP results showed diffe-rent DNA methylation levels of Leptin and TNF-α genes promoter regions from various samples. Conclusions The improved kit method can effectively extract DNA from dried blood spots samples, and these DNA can be used in methy-lation research.The study can provide a new research direction and technical method to reveal the pathogenesis of disease from the perspective of DNA methylation. Key words: Archival dried blood spot; Isolation of human genomic DNA; Methylation; Methylation-specific polymerase chain reaction

Tumor necrosis factor-α and its role as a mediator in myocardial infarction: A brief review.

Tumor necrosis factor-α (TNF-α) contributes to myocardial infarction (MI) injury. Polymorphism of TNF-α gene promoter region and secretion and release of TNF-α and its transformation by a series of signaling pathways are all changed at different points of pathophysiological process in MI. Researches also investigated TNF-α antagonists and their potential therapeutic role in the setting of MI and heart failure at both molecular and clinical level. This article briefly reviews TNF-α and its mechanism as a mediator in MI.

Genetic variation in the promoter region of pro-inflammatory cytokine TNF-α in perinatal HIV transmission from Mumbai, India

Various host factors such as cytokines and HLA, regulate the immune system and influence HIV transmission to infants exposed to HIV-1 through their mothers. Tumor Necrosis Factor Alpha (TNF-α) is a strong pro-inflammatory mediator and thought to influence vulnerability to HIV infection (and/or) transmission. Polymorphisms in regulatory regions are known to govern the production of this cytokine. However, the association of these variations in perinatal HIV transmission is yet to be established. Present study aimed to evaluate if polymorphisms in promoter region of TNF-α gene is associated with perinatal HIV transmission. With informed consent from parents, infants’ blood was collected for HIV screening and SNPs analysis at 2 loci: TNF (rs1800629) and TNF (rs361525) using PCR-SSP method. HIV positive (n=27) and negative (n=54) children at the end of 18th month follow up were considered for this study. GG genotype, responsible for low expression of TNF (rs1800629) was significantly (p=0.005) higher in uninfected children, while higher GA genotype frequency was observed in infected children. The ‘G’ allele frequency was significantly higher in negative children (p=0.016). We conclude that genotypic variants of TNF (rs1800629) are a likely contributor to perinatal HIV transmission. This provides new insights in markers of differential susceptibility to perinatal HIV transmission.

Tumor necrosis factor-α promoter -308/238 polymorphism association with less severe disease in ankylosing spondylitis is unrelated to serum TNF-α and does not predict TNF inhibitor response.

Despite the clinical efficacy of tumor necrosis factor inhibitors (TNFi), the manner in which TNF-α contributes to disease in patients with ankylosing spondylitis (AS) remains unresolved. We investigated the relationship between TNF-α gene promoter region polymorphism, serum TNF-α levels, and clinical phenotype. We did a cross-sectional and longitudinal cohort study in TNFi-naive patients with AS (n = 335). Clinical data and biological samples were collected during a research visit with genotyping for TNF-α -238 A/G and -308 A/G performed by Taqman RT-PCR and TNF levels determined by sandwich ELISA. Longitudinal TNF levels were monitored in unselected patients (n = 61). TNF-α -308 GA/AA genotype was present in 14% and TNF-α -238 GA/AA genotype in 1% of patients. TNF-α -308 GA/AA genotype was associated with a reduced risk of uveitis and better spinal function, while TNF-α -238 GA/AA genotype was associated with later age of onset and lower erythrocyte sedimentation rate (ESR). Serum TNF-α level was lower in patients with AS (151 pg/ml) than in controls (263 pg/ml), because more patients with AS had undetectable serum TNF-α (66 vs 25%, p < 0.001). TNFi treatment did not influence serum TNF-α. There was no effect of TNF-α -308/-238 or HLA-B27 genotype on serum TNF-α or subsequent initiation of TNFi. TNF-α -238 or -308 GA/AA genotypes in patients with AS are associated with signs of less severe disease. Serum TNF-α is, however, undetectable in two-thirds of patients with AS and is not influenced by TNF-α promoter genotype or TNFi therapy. These data suggest a more significant role for TNF-α at local sites of inflammation in AS than through systemic effects.

High producer haplotype (CAG) of -863C/A, -308G/A and -238G/A polymorphisms in the promoter region of TNF-α gene associate with enhanced apoptosis of lymphocytes in HIV-1 subtype C infected individuals from North India.

IntroductionThe natural history of HIV-1 infection and its progression towards AIDS vary considerably among individuals. Host genetic factors may be one of the possible reasons for variable HIV-1 disease progression. Single nucleotide polymorphisms (SNPs) in the promoter region of TNF-α gene can influence its production. The aim of the present study was to determine the association of functional TNF-α SNPs and its associated parameters related to apoptosis that may influence the rate of HIV-1 disease progression.MethodsTherapy naive, 100 HIV slow progressors (SPs), 100 HIV fast progressors (FPs), 50 HIV exposed but seronegative individuals (ESNs) and 260 healthy controls from same ethnic origin were recruited. Genotyping of TNF-α variants (−863C/A, -308G/A and -238G/A) was done using PCR-RFLP. CD4 counts were determined by flow cytometry. Plasma viral load was estimated by COBAS AMPLICOR HIV-1 monitor test. Plasma TNF-α concentration was estimated by Human CBA Th1/Th2 cytokine kit. The lymphocyte mitochondrial membrane potential was measured by JC-1 dye by flow cytometry.ResultsGenotype and allele frequency of TNF-α -238G/A and -863C/A was not significantly different in HIV-1-infected patients when compared to controls, while that of TNF-α -308G/A variant (high TNF-α producer) was significantly higher in FPs compared to SPs (p<0.01, OR = 3.43). Haplotype analyses also showed that carriers of high TNF-α producing haplotype CAG was significantly more common among FPs compared to SPs (p<0.01, OR = 3). The circulating TNF-α levels in blood also correlated well with genotypes. The lymphocyte mitochondrial membrane potential of FPs having CAG haplotype was significantly low as compared to wild type (CGG) haplotype (417±22 vs 571±28, p<0.01).ConclusionHigh producer haplotype, CAG of TNF-α gene associates with enhanced apoptosis of lymphocytes in HIV-1 infected individuals, hence faster progression to AIDS. However, further functional studies are needed to confirm this association and this knowledge may help clinicians to better understand the disease outcome.