Impact of TNF-α and LTα gene polymorphisms on genetic susceptibility in Indian SLE patients

Th1-related transcription factors and cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an inflammatory disorder related to immunity dysfunction. The Th1 cell family including Th1 cells, transcription factor T-bet, and related cytokines IFNγ, TNFα, IL-2, IL-18, TGF-β, and IL-12 have been widely discussed in autoimmunity, such as SLE. In this review, we will comprehensively discuss the expression profile of the Th1 cell family in both SLE patients and animal models and clarify how the family members are involved in lupus development. Interestingly, T-bet-related age-associated B cells (ABCs) and low-dose IL-2 treatment in lupus were emergently discussed as well. Collection of the evidence will better understand the roles of the Th1 cell family in lupus pathogenesis, especially targeting IL-2 in lupus.

The etiological effect and genetic risk of +252 A/G variant of TNF-β gene related to the susceptibility of urinary tract infection in a sample of Iraqi patients with type 2 diabetes: A case control study

Background and aim

Urinary tract infection (UTI) is the most common infection in type 2 diabetes patients. TNF-β is a cytokine with multiple functions in immunomodulatory and inflammatory mechanisms. The variation at position +252 A/G of TNF-β impacts both gene expression and plasma concentration of TNF-β proteins. The findings may shed light on the genetic factors that predispose diabetic patients in Iraq to UTIs.

Methods

A total of 200 individuals were divided into 100 patients with type 2 diabetes, categorized according to UTI, and 100 control subjects. Genetic analysis of +252 A/G of the TNF-β gene was carried out using the TaqMan probe allele discrimination method. The level of TNF-β was estimated by the ELISA technique.

Results

In the recessive model (GG vs. AA/AG) of TNF-β + 252 A/G in T2D/UTI patients compared to controls, a significant association p = 0.029 (OR: 2.8; CI 95% = 1.14-7.09): E = 15.6% was observed. Furthermore, in T2D patients without UTI, the dominant model AA versus AG/GG was associated with a preventive role P: 31.3% (OR: 0.4; CI 95% = 0.22-0.88) and a p value = (0.02). Overall, AG proportions showed a high level of TNF-β within the control group p = 0.03, while all proportions of the +252 A/G showed significant differences in TNF-β level between groups p ≤ 0.05. Pearson's correlation analysis observed a link between TNF- levels, fasting plasma glucose (FPG), and HbA1c.

Conclusion

In T2D patients, the G allele may be linked to a higher probability of UTI, as well as an increased level of TNF-β in a genotype-dependent manner.

Investigating the Molecular Mechanism of Xijiao Dihuang Decoction for the Treatment of SLE Based on Network Pharmacology and Molecular Docking Analysis

Objective

To elucidate the main mechanism of Xijiao Dihuang decoction (XJDHT) for the treatment of systemic lupus erythematosus (SLE).

Methods

TCMSP, BATMAN-TCM, ETCM, and TCMID databases and literature search were used to screen the potential active compounds of XJDHT, and TCMSP and SwissProt databases were searched to predict the targets of the compounds. The targets of SLE were obtained from Genegards, OMIM, and DisGeNET databases, and Venn online platform was used to obtain the intersection targets of XJDHT and SLE. Afterwards, the PPI network was constructed by using the STRING database, and the core targets were identified by network topology analysis. GO and KEGG enrichment analyses were performed through R software, and molecular docking of the top three core targets and their corresponding compounds were accomplished by Autodock Vina and Pymol softwares.

Results

There were 30 potential active ingredients, 289 potential targets, and 129 intersection targets screened from the above databases. Network topology analysis identified 23 core targets, such as AKT1, TNF, IL6, IL1B, and INS. GO enrichment analysis obtained 2555 terms and mainly clustering on the react to lipopolysaccharide, membrane raft, and ubiquitin-like protein ligase binding. KEGG enrichment analysis obtained 187 signaling pathways, mainly concentrating on the lipid and atherosclerosis, AGE-RAGE signaling pathway in diabetic complications, fluid shear stress, and atherosclerosis. Molecular docking verified that the active compounds of XJDHT have the strong binding activity to the core targets.

Conclusion

This study preliminarily uncovers the mechanism of XJDHT acting on SLE through a “multicompound, multitarget, and multipathway” manner. XJDHT may achieve the treatment of SLE by inhibiting the proinflammatory factors, inflammatory signal cvtokines, proliferation, injury, and apoptosis processes. In summary, the present study would provide a promising theoretical basis for further clinical and experimental studies.

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.

IL-38: A novel cytokine in systemic lupus erythematosus pathogenesis

IL‐38 is a newly identified cytokine that belongs to the IL‐1 family. In our previous study, we found elevated plasma levels of IL‐38 in patients with systemic lupus erythematosus (SLE). However, the clear relationship of IL‐38 expression in plasma, peripheral blood mononuclear cells (PBMCs) and clinical and laboratory features needs elucidation. Additionally, we evaluated the possible role of IL‐38 in regulating production of inflammatory cytokines in PBMCs in vitro. A pristane‐induced murine lupus model was used to further demonstrate the effects of IL‐38 on cytokines in vivo and discuss the significance of IL‐38 in lupus development. The results showed that mRNA expression of IL‐38 in PBMCs of patients with SLE was elevated compared with volunteers, and expression of IL‐38 in both plasma and PBMCs was strongly related to clinical features, such as haematuria and proteinuria, and correlated with a SLEDAI score. Plasma levels of TNF‐α, IL‐1β, IL‐6 and IL‐23 were elevated in patients with SLE and were related to plasma levels of IL‐38. In vitro, PBMCs of patients with SLE stimulated with IL‐38 showed a decreased expression of the four inflammatory cytokines compared with PBMCs of patients without treatment. Interestingly, IL‐38 administration in lupus mice significantly reduced the development of lupus, such as reduced proteinuria, improved histological examinations of the kidneys and down‐regulated inflammatory cytokines. In conclusion, IL‐38 may suppress synthesis of pro‐inflammatory cytokines and therefore regulate lupus pathogenesis.

Is individual genetic susceptibility a link between silica exposure and development or severity of silicosis? A systematic review

BACKGROUND

Silicosis is a lung disease of fibrotic nature resulting from the inhalation and deposition of dust containing crystalline silica. Subjects exposed to the same environmental factors may show distinct radiological manifestations, and since silicosis is known as a multifactorial disease, it is plausible that individual genetic susceptibility may play a role in the pathology. This review of the literature aims to provide an assessment of the present data on the genetic association studies in silicosis and describe the genes that potentially might influence silicosis susceptibility in silica-exposed individuals.

METHODS

We accessed the database of PubMed for articles published in English about interindividual genetic susceptibility to silicosis using terms related to the subject matter.

RESULTS

Following the evaluation process, 28 studies were included in this systematic review, including 23 original studies and 5 meta-analyses.

CONCLUSIONS

Regardless of the advances in the knowledge of the importance of gene variations in silicosis, more studies need to be performed, in particular, special polygenic and genome-wide investigations.

Cytokine genes multi-locus analysis reveals synergistic influence on genetic susceptibility in Indian SLE - A multifactor-dimensionality reduction approach

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with unclear etiology. Several loci associated with genetic susceptibility for lupus have been described. However, it lacks reports on cytokine gene-gene interactions among SLE patients from Asian population. Epistasis interaction among single nucleotide polymorphisms (SNPs) of cytokine genes in Indian SLE patients was tested using multifactor-dimensionality reduction (MDR) analysis. A total of fourteen SNPs lacking linkage disequilibrium among different cytokines genes were genotyped in a cohort of 200 SLE patients and 201 healthy individuals as controls of Indian origin. A high degree of synergism among Lymphotoxin-α (LT-α), Interleukin-1β (IL-1β) and Interleukin-10 (IL-10) gene polymorphisms was detected in our SLE patients. Furthermore, by virtue of biological inter-relations among different cytokines, a high strength of interactions was observed among pro-inflammatory (IL-1β, IL-6) and anti-inflammatory (IL-10) cytokine gene SNPs. Also, among studied pro-inflammatory cytokines and chemokines, a strong synergistic effect among Tumor Necrosis Factor-α (TNF-α), LT-α and Monocyte Chemo-attractant Protein-1 (MCP-1) SNPs was occurred. A nature of strong interaction among the candidate cytokine genes may speculate a proactive role in causing genetic susceptibility to the disease in SLE patients with Indian origin.

Associations of lymphotoxin-a (LTA) rs909253 A/G gene polymorphism, plasma level and risk of ankylosing spondylitis in a Chinese Han population

Lymphotoxin-a (LTA) may be associated with the pathogenesis of inflammatory diseases. To assess the association of the LTA rs909253 A/G polymorphism with plasma level and risk of ankylosing spondylitis (AS) in a Chinese Han population. Genotyping and LTA plasma were tested by mass spectroscopy and enzyme-linked immunosorbent assay (ELISA), respectively. The results showed that the average plasma level of LTA in AS was significantly lower than in the controls (P = 0.000). Our results also indicated that LTA rs909253 A/G was associated with a decreased risk of AS (G vs. A: P = 0.014). Significant differences were also found between the rs909253 A/G genotype and down-regulated plasma level in AS patients, compared with controls. After stratification analysis, a decreased risk of AS was associated with the LTA rs909253 G allele (G vs. A) among female patients, younger patients (Yr. < 30), HLA-B27-positive patients. In addition, In conclusion, LTA rs909253 A/G genotype has a significant relationship with decreased susceptibility to AS.

Th1, Th2, and Th17 cytokines in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the breakdown of immune tolerance leading to excessive inflammation and tissue damage. Imbalance in the levels of cytokines represents one of the multifactorial causes of SLE pathogenesis and it contributes to disease severity. Deregulated levels of T helper type 1 (Th1), type 2 (Th2), and type 17 (Th17) cytokines have been associated with autoimmune inflammation. Growing evidence has shown deregulated levels of Th1, Th2, and Th17 cytokines in SLE patients compared to healthy controls associated with disease activity and severity. In this review, we describe and discuss the levels of Th1, Th2, and Th17 cytokines in SLE patients, and clinical trials involving Th1, Th2, and Th17 cytokines in SLE patients. In particular, with the exception of IL-2, IL-4, and TGF-β1, the levels of Th1, Th2, and Th17 cytokines are increased in SLE patients associated with disease severity. Current phase II or III studies involve therapeutic antibodies targeting IFN-α and type I IFN receptor, while low-dose IL-2 therapy is assessed in phase II clinical trials.

TNF-α promoter polymorphisms (G-238A and G-308A) are associated with susceptibility to Systemic Lupus Erythematosus (SLE) and P. falciparum malaria: a study in malaria endemic area

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine associated with autoimmune and infectious diseases. Importance of TNF-α in P. falciparum malaria and systemic lupus erythematosus (SLE) have been demonstrated. However, association of functional promoter variants with SLE and malaria is lacking in malaria endemic population. A total of 204 female SLE patients and 224 age and sex matched healthy controls were enrolled in the study. Three hundred fourteen P. falciparum infected patients with different clinical phenotypes were included. TNF-α polymorphisms (G-238A & G-308A) were genotyped by PCR-RFLP. Plasma levels of TNF-α was quantified by ELISA. Heterozygous mutants and minor alleles of TNF-α (G-238A and G-308A) polymorphisms were significantly higher in SLE patients compared to healthy controls and associated with development of lupus nephritis. In addition, both promoter variants were associated with severe P. falciparum malaria. SLE patients demonstrated higher levels of plasma TNF-α compared to healthy controls. TNF-α (G-238A and G-308A) variants were associated with higher plasma TNF-α. In conclusion, TNF-α (G-238A & G-308A) variants are associated with higher plasma TNF-α levels in SLE patients residing in malaria endemic areas and could be a contributing factor in the development of SLE and susceptibility to severe P. falciparum malaria.

TNF-β +252 A>G (rs909253) polymorphism is independently associated with presence of autoantibodies in rheumatoid arthritis patients

The TNF-β +252 A>G (rs909253) polymorphism has been associated with a risk of development of rheumatoid arthritis (RA) and could influence plasma tumor necrosis factor alpha (TNF-α) levels. The aim of the present study was to evaluate the association between the TNF-β +252 A>G polymorphism with plasma TNF-α levels, the presence of autoantibodies, and the susceptibility for RA. This cross-sectional study included 261 patients with RA and 292 controls. The polymorphism was studied using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Soluble TNF-α and receptors swere measured by multiplex assay. Rheumatoid factor (RF) and anticyclic citrullinated peptide antibodies (anti-CCP) were measured using immunoassay. No differences were observed in allele frequency and genotype distribution among patients and controls. The presence of RF (p = 0.020) and anti-CCP (p = 0.001) increased 4.23-fold and 8.13-fold, respectively, in patients with B1 allele (B1/B2 + B1/B1 genotypes) independently of demographic, clinical, and inflammatory markers. Among patients with B1/B2 + B1/B1 genotypes, higher TNF-α levels were associated with positive RF (p = 0.040), anti-CCP (p = 0.011), or both (p = 0.038). In patients carrying B1 allele, the increased sTNFR1 together with RF or anti-CCP or both explained about 39.0% the variations in TNF-α level. However, in B2/B2 genotype, the presence of those autoantibodies was not associated with TNF-α level. Our findings indicate that the TNF-β +252 A>G polymorphism was not associated with RA susceptibility and TNF-α plasma levels. However, B1 allele was associated with the presence of autoantibodies. In addition, interaction between the presence of B1 allele and autoantibodies was associated with the increase of plasma TNF-α level in RA patients.

NOTCH4 is a possible novel susceptibility gene for dilated cardiomyopathy in the Chinese population: A case-control study

BACKGROUND

The incidence of dilated cardiomyopathy (DCM) has increased in recent years, and many studies have sought to further improve the general understanding of this condition. Previous studies have demonstrated that some single nucleotide polymorphisms (SNPs) associated with systemic lupus erythematosus also affect susceptibility to DCM, suggesting that immune-related diseases may share similar genetic susceptibility. Recent large-scale and genome-wide association studies have identified NCR3, NOTCH4, CYP1A2, ITGA1, OPRM1, ST8SIA2, and LINC00704 as genetic risk factors associated with cardiac manifestations of neonatal lupus. Here, we aimed to determine whether these SNPs conferred susceptibility to DCM in the Chinese Han population.

METHODS

We investigated the relationship between these polymorphisms and DCM risk in 273 patients with DCM and 548 healthy controls. Genotyping was performed using MassArray iPLEX system.

RESULTS

Logistic regression analysis indicated that the T allele of rs3134942 in NOTCH4 gene increased the risk of DCM by 61% compared with the G allele (P_a  = 6.57 × 10^-3 ). The SNP rs3134942 was also significantly associated with increased DCM risk in the additive (P_a  = 6.57 × 10^-3 ) and dominant models (P_a  = 1.01 × 10^-2 ). Additionally, rs2472299 in CYP1A2 gene showed suggestive association with reduced risk of DCM in the dominant model (P_a  = 4.24 × 10^-2 ) and was correlated with smoking status in patients with DCM (P_a  = 1.56 × 10^-2 ).

CONCLUSIONS

Our findings suggested that rs3134942 in NOTCH4 may be involved in DCM risk. Further, studies in larger and ethnically diverse populations are required to confirm the results reported in this study.