NFKB1−94 Insertion/Deletion ATTG Polymorphism Contributes to Risk of Systemic Lupus Erythematosus

NFKB1 variants were associated with the risk of Parkinson´s disease in male

The NF-κB pathway is involved in the pathogenesis of neurological disorders that have inflammation as a hallmark, including Parkinson's disease (PD). Our objective was to determine whether common functional variants in the NFKB1, NFKBIA and NFKBIZ genes were associated with the risk of PD. A total of 532 Spanish PD cases (61% male; 38% early-onset, ≤ 55 years) and 300 population controls (50% ≤55 years) were genotyped for the NFKB1 rs28362491 and rs7667496, NFKBIA rs696, and NFKBIZ rs1398608 polymorphisms. We compared allele and genotype frequencies between early and late-onset, male and female, and patient's vs. controls. We found that the two NFKB1 alleles were significantly associated with PD in our population (p = 0.01; total patients vs. controls), without difference between Early and Late onset patients. The frequencies of the NFKB1 variants significantly differ between male and female patients. Compared to controls, male patients showed a significantly higher frequency of rs28362491 II (p = 0.02, OR = 1.52, 95%CI = 1.10-2.08) and rs28362491 C (p = 0.003, OR = 1.62, 95%CI = 1.18-2.22). The two NFKB1 variants were in strong linkage disequilibrium and the I-C haplotype was significantly associated with the risk of PD among male (p = 0.002). In conclusion, common variants in the NF-kB genes were associated with the risk of developing PD in our population, with significant differences between male and female. These results encourage further studies to determine the involvement of the NF-kB components in the pathogenesis of Parkinson´s disease.

A multilayered post-GWAS analysis pipeline defines functional variants and target genes for systemic lupus erythematosus (SLE)

Objectives

Systemic lupus erythematosus (SLE), an autoimmune disease with incompletely understood etiology, has a strong genetic component. Although genome-wide association studies (GWAS) have revealed multiple SLE susceptibility loci and associated single nucleotide polymorphisms (SNPs), the precise causal variants, target genes, cell types, tissues, and mechanisms of action remain largely unknown.

Methods

Here, we report a comprehensive post-GWAS analysis using extensive bioinformatics, molecular modeling, and integrative functional genomic and epigenomic analyses to optimize fine-mapping. We compile and cross-reference immune cell-specific expression quantitative trait loci ( cis - and trans -eQTLs) with promoter-capture Hi-C, allele-specific chromatin accessibility, and massively parallel reporter assay data to define predisposing variants and target genes. We experimentally validate a predicted locus using CRISPR/Cas9 genome editing, qPCR, and Western blot.

Results

Anchoring on 452 index SNPs, we selected 9,931 high-linkage disequilibrium (r 2 >0.8) SNPs and defined 182 independent non-HLA SLE loci. 3,746 SNPs from 143 loci were identified as regulating 564 unique genes. Target genes are enriched in lupus-related tissues and associated with other autoimmune diseases. Of these, 329 SNPs (106 loci) showed significant allele-specific chromatin accessibility and/or enhancer activity, indicating regulatory potential. Using CRISPR/Cas9, we validated rs57668933 as a functional variant regulating multiple targets, including SLE risk gene ELF1 , in B-cells.

Conclusion

We demonstrate and validate post-GWAS strategies for utilizing multi-dimensional data to prioritize likely causal variants with cognate gene targets underlying SLE pathogenesis. Our results provide a catalog of significantly SLE-associated SNPs and loci, target genes, and likely biochemical mechanisms, to guide experimental characterization.

Assessment of genetic polymorphisms within nuclear factor-κB signaling pathway genes in rheumatoid arthritis: Evidence for replication and genetic interaction

OBJECTIVE

This study was performed to replicate the associations of genetic polymorphisms within nuclear factor-κB (NF-κB) signaling pathway genes with rheumatoid arthritis (RA), and to further examine genetic interactions in a Chinese population.

METHODS

A total of eleven single-nucleotide polymorphisms (SNPs) were genotyped in 594 RA patients and 604 healthy controls.

RESULTS

Genetic association analysis revealed that NFKBIE rs2233434, TNIP1 rs10036748 and BLK rs13277113 were significantly associated with RA, cyclic citrullinated peptide (CCP)-positive RA and rheumatoid factor (RF)-positive RA, and TNFAIP3 rs2230926 was significantly associated with CCP-positive RA. Significant additive interaction was observed between NFKB1 rs28362491 and IKBKE rs12142086 (RERI = 0.76, 95% CI 0.13-1.38; AP = 0.57, 95% CI 0.11-1.03), NFKBIE rs2233434 and BLK rs13277113 (RERI = 1.41, 95% CI 0.88-1.94; AP = 0.85, 95% CI 0.50-1.20), NFKBIL rs2071592 and TNIP1 rs10036748 (RERI = 0.59, 95% CI 0.17-1.02; AP = 0.46, 95% CI 0.05-0.87), UBE2L3 rs5754217 and TNFSF4 rs2205960 (RERI = 0.50, 95% CI 0.16-0.84; AP = 0.57, 95% CI 0.09-1.05). Significant multiplicative interaction was detected between BLK rs13277113 and UBE2L3 rs5754217 (p = 0.02), BLK rs13277113 and TNFSF4 rs2205960 (p = 0.03).

CONCLUSIONS

Our results lent further support to the role of NF-κB signaling pathway in the pathogenesis of RA from a genetic perspective.

Germline Genetic Variants of Viral Entry and Innate Immunity May Influence Susceptibility to SARS-CoV-2 Infection: Toward a Polygenic Risk Score for Risk Stratification

The ongoing COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2 has affected all aspects of human society with a special focus on healthcare. Although older patients with preexisting chronic illnesses are more prone to develop severe complications, younger, healthy individuals might also exhibit serious manifestations. Previous studies directed to detect genetic susceptibility factors for earlier epidemics have provided evidence of certain protective variations. Following SARS-CoV-2 exposure, viral entry into cells followed by recognition and response by the innate immunity are key determinants of COVID-19 development. In the present review our aim was to conduct a thorough review of the literature on the role of single nucleotide polymorphisms (SNPs) as key agents affecting the viral entry of SARS-CoV-2 and innate immunity. Several SNPs within the scope of our approach were found to alter susceptibility to various bacterial and viral infections. Additionally, a multitude of studies confirmed genetic associations between the analyzed genes and autoimmune diseases, underlining the versatile immune consequences of these variants. Based on confirmed associations it is highly plausible that the SNPs affecting viral entry and innate immunity might confer altered susceptibility to SARS-CoV-2 infection and its complex clinical consequences. Anticipating several COVID-19 genomic susceptibility loci based on the ongoing genome wide association studies, our review also proposes that a well-established polygenic risk score would be able to clinically leverage the acquired knowledge.

Association of polymorphisms in NFκB1 promoter and NFκBIA gene with the development of antibodies against HHV-8 in HIV-infected individuals

Human gammaherpesvirus 8 (HHV-8) is the etiologic agent of Kaposi's sarcoma, multicentric Castleman's disease and primary effusion lymphoma. Like other herpesviruses, the HHV-8 may exhibit latent or lytic cycle, both regulated by viral and host factors. Regarding host factors, we analysed the association of polymorphisms in NFkB1 promoter (NFkB1-94 ins/del ATTG) and NFκBIA gene (NFκBIA 3'UTR A→G) with the development of antibodies against latent or lytic antigens from HHV-8. The ins/del [OR 7.9 (95% CI 3.3-19.1), p < 0.001], AG [OR 12.3 (95% CI 4.3-34.9) p < 0.001], GG [OR 9.4 (95% CI 3.2-27.9), p < 0.001], ins/del + AG [OR 94.5 (95% CI 9.6-924.4), <0.0001], ins/del + GG [OR 50.4 (95% CI 5.2-482.2, p < 0.0001] and G allele [OR 3.3 (95% CI 2.0-5.6), p < 0.001] were strongly related with the presence of antibodies to lytic antigens. This is the first association of polymorphisms in NFκB1 promoter and NFκBIA gene with the development of antibodies against HHV-8.

NFKB1 gene rs28362491 polymorphism is associated with the susceptibility of acute coronary syndrome

The acute coronary syndrome (ACS) is a complex disease where genetic and environmental factors are involved. NF-κB, a central regulator of inflammation, is involved in various inflammatory diseases. The aim of the present study was to explore the association between NFKB1 gene rs28362491 (-94ATTGins/del) polymorphism and ACS. A total of 778 ACS patients and 1112 healthy subjects were included in our study. The TaqMan SNP genotyping assays was used to analyze the rs28362491 polymorphism. The lesion extent of coronary artery was assessed by Gensini Score and lesion vessel number in ACS patients. For total and males, the frequencies of the mutant DD genotype and D allele were significantly higher in ACS patients than that in control subjects (total: DD genotype: 18.0 vs 14.1%, P=0.009, D allele: 43.0 vs 37.9%, P=0.002, males: DD genotype: 20.6 vs 15.3%, P=0.042, D allele: 44.2 vs 38.8%, P=0.013). After multivariate logistic regression analysis, we found that individuals with mutant DD genotype had 1.329-fold higher risk of ACS compared with individuals with ID and II genotypes. Moreover, ACS patients with DD genotype were worse stenosis of coronary artery compared with patients carrying II or ID genotype. In conclusion, our study demonstrated that the mutant DD genotype of NFKB1 gene was associated with the risk and severity of ACS in Han population in Xinjiang, northwest of China.

Application of Single-Tube Tri-Primer ARMS-PCR to Detect the NFKB1 ATTG Insertion/Deletion Polymorphism

AIMS

The -94 ATTG insertion/deletion polymorphism (rs28362491) is an important functional polymorphism in the NFKB1 gene. It has been shown that rs28362491 is associated with many diseases. The purpose of this study was to establish a simple and reliable method to detect the ATTG insertion/deletion polymorphism.

METHODS

On the basis of the amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) method, a single-tube tri-primer ARMS-PCR method was developed to detect the ATTG insertion/deletion polymorphism in 93 samples. The results of the single-tube tri-primer ARMS-PCR method were validated by DNA sequencing.

RESULTS

After optimization of the PCR conditions, the single-tube tri-primer ARMS-PCR was established to detect the insertion/deletion polymorphism using agarose gel electrophoresis. In 93 volunteers, the genotype frequencies were 30.1% for Ins/Ins, 19.4% for Del/Del, and 50.5% for Ins/Del, respectively. The results of the single-tube tri-primer ARMS-PCR method were consistent with the results of DNA sequencing.

CONCLUSIONS

This single-tube tri-primer ARMS-PCR is a reliable, simple, and cost-efficient genotyping method for the detection of the ATTG insertion/deletion polymorphism in the NFKB1 gene.

The link between immunity, autoimmunity and endometriosis: a literature update

Endometriosis (EMS), an estrogen-dependent inflammatory disorder affects approximately 5-10% of the general female population of reproductive age and 20-90% of women with pelvic pain and infertility. Many immunological factors are known to contribute significantly to the pathogenesis and pathophysiology of EMS, and both chronic local inflammation and autoantibodies in EMS shares many similarities with autoimmune diseases (AD). However, the autoimmune etiology in EMS remains controversial, and its evidence on autoimmune basis may be limited. Here we aim to review the current understanding between autoimmunity and EMS to provide important knowledge to develop future potential immunomodulatory therapy for the treatment of EMS.

The association between NFKB1 -94ATTG ins/del and NFKB1A 826C/T genetic variations and coronary artery disease risk

Coronary artery disease (CAD) is considered as a chronic inflammatory disease initiated from early childhood. Nuclear factor κB (NF κB) and κB1A (NF κB1A) are the key regulators of inflammatory responses. The NFKB1 -94ATTG ins/del and NFKB1A -826C/T polymorphisms may contribute to the development of CAD. The aim of the present study was to investigate the association of these polymorphisms with the risk of CAD. The study population included 120 patients with angiographically confirmed CAD and 100 matched controls. Genotyping of NFKB1 -94ATTG ins/del and NFKB1A -826C/T polymorphism was performed using PCR-RFLP method. Lipid level was determined by routine colorimetric methods. Statistical analysis was done by SPSS 16 software. Results indicated that the genotypic (P=0.041) and allelic (P=0.009) distribution of the NFKB1-94ATTG ins/del polymorphism was significantly different between the two groups. In the univariate analysis (ins/ins genotype as reference), the del/del genotype (OR=2.88, 95% CI=1.21-6.84, P=0.015) but not ins/del genotype (OR=1.48, 95% CI=0.83-2.64, P=0.191) was significantly associated with the increased risk of CAD. In the multiple binary logistic regression analysis, diabetes, hypertension, smoking, LDL-cholesterol, total cholesterol, HDL-cholesterol and NFKB1 -94ATTG del/del genotype were identified as significant and independent risk factors for CAD development. The distribution of genotypes and alleles of NFKB1A -826C/T polymorphism was not significantly different between the two groups. In conclusion the present study identified NFKB1 -94ATTG ins/del polymorphism but not NFKB1A -826C/T polymorphism as a significant and independent risk factor for development and severity of CAD.

[Clinical and molecular genetic analysis of a case of familial multiple sclerosis in the Republic of Bashkortostan]

AIM

To investigate clinical manifestations of multiple sclerosis (MS) and the genetic makeup of six affected members of one family.

MATERIAL AND METHODS

Six members of the family of Russian ethnic origin were examined. Pedigree analysis and genotyping of polymorphic markers of candidate genes for multiple sclerosis were performed.

RESULTS AND CONCLUSION

The accumulation of alleles that were associated with autoimmune diseases according to the results of genome-wide association studies (rs1109670*C, rs3129934*T, rs9523762*G, rs1570538*T) was found in the family. The results confirm the contribution of several genetic variants to familial forms of MS.

Genetic Variation in NFKB1 and NFKBIA and Susceptibility to Coronary Artery Disease in a Chinese Uygur Population

OBJECTIVES

Coronary artery disease (CAD) is the most common chronic inflammatory disease worldwide. NF-κB, a central regulator of inflammation, is involved in various inflammatory diseases. The aim of this study was to investigate the association between NFKB1 and NFKBIA polymorphisms and the susceptibility to CAD and their impact on plasma levels of IL-6 in a Chinese Uygur population.

METHODS

We genotyped NFKB1-94ins/del ATTG (rs28362491) and NFKBIA3' UTR A/G (rs696) using TaqMan SNP genotyping assays in 960 Uygur CAD cases and Uygur 1060 CAD-negative controls. IL-6 plasma levels were measured in 360 stable angina pectoris (SAP) cases and 360 controls using ELISA method.

RESULTS

There was no significant difference in the distribution of the genotypes and alleles of rs696 polymorphism in CAD cases and controls. Significant difference in the frequency of genotypes (P = 0.001) and alleles (P = 0.001) of rs28362491 polymorphism was observed in CAD cases compared to controls. In multivariate logistic regression analysis, SNP rs28362491 was consistently associated with CAD risk in a recessive model after adjustment for cardiovascular risk factors (OR = 1.581, 95% CI 1.222 to 2.046, P<0.001). SAP cases had significantly higher plasma levels of IL-6 compared to controls (P<0.001). General linear model analysis showed rs28362491 was independently associated with increased IL-6 levels by analyses of a recessive model (P<0.001) after adjustment for covariates.

CONCLUSIONS

Our study indicates that NFKB1-94 ins/del ATTG polymorphism may play a role in CAD susceptibility in Chinese Uygur population and is functionally associated with IL-6 expression, suggesting a mechanistic link between NFKB1-94 ins/del ATTG polymorphism and CAD susceptibility.

Association of NFKB1 and NFKBIA polymorphisms in relation to susceptibility of Behçet's disease

Behçet's disease (BD) is a chronic inflammatory autoimmune disease. Although raised levels of proinflammatory cytokines in BD have been reported, the pathogenesis is still unknown. The aim of this study was to investigate the association of NFKB1 and NFKBIA polymorphisms and their single and combined analysis effects on susceptibility of BD in Turkish population. We analysed the distribution of NFKB1 -94 ins/del ATTG (rs28362491) and NFKBIA 3' UTR A→G (rs696) polymorphisms using PCR-RFLP method in 89 patients with BD and 190 controls in this population. Statistical analysis of the results was performed by calculating OR, and 95% CI via χ(2) test and using Bonferroni correction. According to the significant results of both single and combined genotype analysis, the frequencies of ins/ins genotype and ins allele of rs28362491 were significantly higher in patients with BD (Pc = 0.003, 0.004, respectively). Also, higher frequencies of the rs696 variant containing AA genotype was found in patients with BD (Pc = 0.0033), whereas no statistical significant differences in distribution of the alleles of rs696 polymorphism in patients and controls. In addition, according to the combined genotype analysis, the wild type of both rs28362491 and rs696 polymorphisms (ins/ins/AA genotype) was also significantly higher in BD cases (Pc = 0.044). Our findings prove that both single and combined genotype analysis of rs28362491 and rs696 polymorphisms indicate that the wild genotypes of both two SNPs (ins/ins and AA genotypes) and ins/ins/AA combined genotype are strongly associated with enhanced risk of BD in a Turkish population.

Genetic interaction between genes involved in NF-κB signaling pathway in systemic lupus erythematosus

Recently, multiple genetic associations have been found between genes involved in nuclear factor-kappaB (NF-κB) signaling pathway and systemic lupus erythematosus (SLE) or other autoimmune diseases. This study was undertaken to replicate some of these associations and further test for genetic interactions among these genes in SLE in a Chinese population. Ten single-nucleotide polymorphisms (SNPs) in NFKB1, REL, inhibitor of κB-like (IκBL), IκB kinase β (IKBKB), tumor necrosis factor receptor associated factor 6 (TRAF6), tumor necrosis factor a-induced protein 3 (TNFAIP3), TNFAIP3 interacting protein 1 (TNIP1) were genotyped in 898 Chinese patients with SLE and 988 healthy controls by Sequenom MassArray technology. Single-marker genetic association analysis was performed, and additive and multiplicative interactions were analyzed. Associations of TNFAIP3 rs2230926 (p=1.43 × 10(-3)) and TNIP1 rs10036748 (p=4.33 × 10(-3)) with SLE were replicated in our study. Two other SNPs, NFKB1 rs28362491 and IκBL rs2071592, showed nominal evidence for association (p=4.70 × 10(-2) and p=5.90 × 10(-3), respectively) but these were not significant after applying Bonferroni correction. Additive interaction analysis revealed significant interaction between NFKB1 rs28362491 and TNFAIP3 rs2230926 (RERI=0.98, 95%CI=0.02-1.93; AP=43.2%, 95%CI=0.12-0.74). Significant multiplicative interaction was observed between NFKB1 rs28362491 and TNIP1 rs3792783 (p=0.03). Our results provide evidence for gene-gene interactions, which further support the important role of NF-κB signaling pathway in the genetic basis of SLE and the notion of genetic interactions accounting for missing heritability.

Risk factors of fecal toxigenic or non-toxigenic Clostridium difficile colonization: impact of Toll-like receptor polymorphisms and prior antibiotic exposure

BACKGROUND

This study is to investigate the significance and risk factors of fecal toxigenic (tCdC) or non-toxigenic Clostridium difficile colonization (ntCdC) among hospitalized patients.

METHODS

Adults admitted to medical wards in a district hospital between January 2011 and June 2012 were enrolled, and those with a history of colectomy, C. difficile fecal colonization or infection or receipt of either metronidazole or oral vancomycin within 3 months, were excluded. Stools collected within 48 hours after admission and every week during hospitalization were cultured for C. difficile.

FINDINGS

Among the 441 enrolled patients, 84 (20.0%) had CdC at initial screening, including 58 (13.2%) with tCdC and 26 (6.8%) with ntCdC. Among patients with initial negative fecal screening for CdC, it took an average of 70.6 days or 66.5 days to develop tCdC or ntCdC during the study period. Finally 78 (17.7%) had tCdC and 34 (7.7%) had ntCdC. During the follow-up period, the patients with tCdC had a higher risk of CDAD (11/79, 14.1%) than those without CdC (3/328, 0.9%) and those with ntCdC (0/34, 0%) (P<0.001). In multivariate analysis, the TLR4 rs1927914 polymorphism (GG genotype) (odds ratio [OR] 4.4, 95% confidence interval [CI] 1.6-11.8, P = 0.003) and recent cefepime therapy (OR 5.3, 95% CI 2.1-13.2, P<0.001) were independently associated with tCdC, whereas recent cefuroxime (OR 11.7, 95% CI 2.3-60.2, P = 0.003) and glycopeptide therapy (OR 10.9, CI: 2.1-57.2, P = 0.005) associated with ntCdC.

CONCLUSION

The incidence of CDAD is highest in patients with tCdC and lowest in patients with ntCdC, and the TLR4 rs1927914 polymorphism GG genotype and recent cefepime therapy were independently associated with tCdC.

Relationship between NF-κB1 -94 ins/del ATTG polymorphism and susceptibility of multiple sclerosis in Iranian MS patients

Multiple sclerosis (MS) is one of the most common neurological diseases of the central nervous system (CNS) which is mediated by the autoimmune reactions against myelin sheath. Both genetic and environmental factors are thought to be involved in the pathogenesis of MS. NF-κB1 is one of the most important molecules which regulates the immune functions. NF-κB1 -94 ins/del ATTG promoter polymorphism is a well-studied region in NF-κB1 gene associated with several common autoimmune diseases such as systemic lupus erythematosus (SLE). Our hypothesis was aimed to address the potential association of NF-κB polymorphism and MS. Therefore, we analyzed 200 sex and age matched MS patients along with 200 healthy individuals using PCR-RFLP. The data revealed no significant differences in the frequency of the -94 ins/del ATTG polymorphism in multiple sclerosis patients compared with the control group. To conclude, our study showed no association between -94 ins/del ATTG polymorphism and risk of multiple sclerosis in Iranian patients.

The NFKB1 -94 ATTG insertion/deletion polymorphism (rs28362491) contributes to the susceptibility of congenital heart disease in a Chinese population

Congenital heart disease (CHD) is the most frequently occurring congenital disorder in newborns and is the most frequent cause of infant death from birth defects. Human genetic studies have identified that numerous genes encoding transcription factors that regulate specific events in heart development are responsible for inherited and sporadic CHD. Nuclear factor-kappa B (NF-κB) is a major transcription regulator of immune response, apoptosis and cell-growth control genes. The aim of this study was to investigate whether the functional -94 insertion/deletion ATTG polymorphism (rs28362491) in the promoter of nuclear factor κB gene (NFKB1) is associated with susceptibility to CHD. Polymerase chain reaction (PCR)-polyacrylamide gel electrophoresis (PAGE) method was used to genotype rs28362491 in 122 atrial septal defect (ASD) patients, 114 ventricular septal defect (VSD) patients, and 412 controls. The frequencies of II (Insertion/Insertion) genotype in the ASD and VSD patients were significantly higher than that of controls (p=0.004 for ASD Vs. controls, and p=0.009 for VSD Vs. controls, respectively), and the frequencies for I allele in CHD patients were also significantly higher than that in controls (p=0.01 for ASD Vs. controls, and p=0.009 for VSD Vs. controls, respectively). This study suggests that the functional -94 insertion/deletion ATTG polymorphism in the promoter of NFKB1 is associated with CHD.

Identification of CSK as a systemic sclerosis genetic risk factor through Genome Wide Association Study follow-up

Systemic sclerosis (SSc) is complex autoimmune disease affecting the connective tissue; influenced by genetic and environmental components. Recently, we performed the first successful genome-wide association study (GWAS) of SSc. Here, we perform a large replication study to better dissect the genetic component of SSc. We selected 768 polymorphisms from the previous GWAS and genotyped them in seven replication cohorts from Europe. Overall significance was calculated for replicated significant SNPs by meta-analysis of the replication cohorts and replication-GWAS cohorts (3237 cases and 6097 controls). Six SNPs in regions not previously associated with SSc were selected for validation in another five independent cohorts, up to a total of 5270 SSc patients and 8326 controls. We found evidence for replication and overall genome-wide significance for one novel SSc genetic risk locus: CSK [P-value = 5.04 × 10(-12), odds ratio (OR) = 1.20]. Additionally, we found suggestive association in the loci PSD3 (P-value = 3.18 × 10(-7), OR = 1.36) and NFKB1 (P-value = 1.03 × 10(-6), OR = 1.14). Additionally, we strengthened the evidence for previously confirmed associations. This study significantly increases the number of known putative genetic risk factors for SSc, including the genes CSK, PSD3 and NFKB1, and further confirms six previously described ones.