Meta-analysis of microRNA-146a rs2910164 G>C polymorphism association with autoimmune diseases susceptibility, an update based on 24 studies

The Association of miRNA-146a Gene Variation and Multiple Sclerosis in The Iranian Population

Background

Multiple sclerosis (MS) is a complex human autoimmune-type inflammatory disease of the central nervous system (CNS). MicroRNA-146a (miR-146a) belongs to an endogenous and non-coding RNA family with 18-22 nucleotides long, which modulates the innate and adaptive immune response.

Methods

Our study aimed to investigate a possible association between rs2910164 and rs2431697 polymorphisms of the miR-146a gene and multiple sclerosis in the Iranian population. A total of 60 MS cases and 100 controls were recruited. Single nucleotide polymorphism (SNP) rs2431697 was genotyped by utilizing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and SNP rs2910164 was genotyped by using Tetra-primer ARMS-PCR. Statistical Analysis conducted by the chi-squared test utilizing SPSS version 21.0 Software. The Hardy-Weinberg equilibrium assumption was evaluated.

Results

The results of the present study suggest the miR-146a gene rs2431697 polymorphism is not associated with multiple sclerosis. However, there is a significant relationship between polymorphism rs2910164 of the miR-146a gene and multiple sclerosis in the population studied (P = 0.012).

Conclusion

Our data provide evidence that the miR-146a gene may be involved in creating the susceptibility to MS in the Iranian population.

MicroRNAs in Macrophages: Regulators of Activation and Function

Macrophages are sentinels of the innate immune system that maintain tissue homeostasis and contribute to inflammatory responses. Their broad scope of action depends on both functional heterogeneity and plasticity. Small noncoding RNAs called microRNAs (miRNAs) contribute to macrophage function as post-transcriptional inhibitors of target gene networks. Genetic and pharmacologic studies have uncovered genes regulated by miRNAs that control macrophage cellular programming and macrophage-driven pathology. miRNAs control proinflammatory M1-like activation, immunoregulatory M2-like macrophage activation, and emerging macrophage functions in metabolic disease and innate immune memory. Understanding the gene networks regulated by individual miRNAs enhances our understanding of the spectrum of macrophage function at steady state and during responses to injury or pathogen invasion, with the potential to develop miRNA-based therapies. This review aims to consolidate past and current studies investigating the complexity of the miRNA interactome to provide the reader with a mechanistic view of how miRNAs shape macrophage behavior.

Meta-Analysis of miRNA Variants Associated with Susceptibility to Autoimmune Disease

Purpose

Various studies have shown an association between miRNA polymorphisms and susceptibility to autoimmune disease (AD); however, the results are inconclusive. To evaluate whether miRNA polymorphisms account for a significant risk of AD, a total of 87 articles, including 39431 patients and 56708 controls, were identified to estimate their association with 12 AD subtypes.

Methods

Several electronic databases were searched to analyze population-based studies on the relationship between miRNA variants and AD risk. Fixed effects or random effect models were used in the meta-analysis for the risk assessment.

Results

In our meta-analysis, miR-146a rs2910164/rs57095329 conferred a marginally elevated risk for AD (allele model, OR = 1.08, 95% CI: 1.01-1.15, P = 0.019; allele model, OR = 1.09, 95 CI: 1.05-1.15, P < 0.001, respectively). Furthermore, miR-196a2 rs11614913 was also associated with AD risk (allele model, OR = 0.92, 95% CI: 0.88-0.97, P = 0.001) as well as miR-499 rs3746444 (allele model, OR = 1.16, 95% CI: 1.03-1.29, P = 0.011). In addition, associations were observed between miR-149 rs2292832/miR-27a rs895819 and AD susceptibility in the overall population (allele model, OR = 1.15, 95% CI: 1.06-1.24, P < 0.001; allele model, OR = 1.11, 95% CI:1.01-1.22, P = 0.043, respectively).

Conclusions

Evidence from our systematic review suggests that miR-146a, miR-196a2, miR-499, miR-149, and miR-27a polymorphisms are associated with susceptibility to AD.

Variants of MIRNA146A rs2910164 and MIRNA499 rs3746444 are associated with the development of cutaneous leishmaniasis caused by Leishmania guyanensis and with plasma chemokine IL-8

Leishmania are intracellular protozoan parasites that cause a wide spectrum of clinical manifestations in genetically susceptible individuals with an insufficient or balanced Th1 immune response to eliminate the parasite. MiRNAs play important regulatory role in numerous biological processes including essential cellular functions. miR146-a acts as an inhibitor of interleukin 1 receptor associated kinase 1 (IRAK1) and tumour necrosis factor (TNF) receptor associated factor 6 (TRAF6) present in the toll-like receptors pathway while miR499a modulates TGF-β and TNF signalling pathways. Here, we investigated whether MIRNA146A rs2910164 and MIRNA499 rs3746444 variants are associated with the development of L. guyanensis (Lg)-cutaneous leishmaniasis (CL). The variants MIR146A rs2910164 and MIR499A rs3746444 were assessed in 850 patients with Lg-CL and 891 healthy controls by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Plasma cytokines were measured using the BioPlex assay. Carriers of rs2910164 CC genotype have 30% higher odds of developing CL (ORadj_age/sex = 1.3 [95%CI 0.9–1.8]; Padj_age/sex 0.14) compared to individuals with the genotype GG (ORadj_age/sex = 0.77 [95%CI 0.56–1.0]; Padj_age/sex 0.14) if exposed to Lg-infection. Heterozygous GC individuals also showed lower odds of developing CL (ORadj_age/sex = 0.77 [95%CI 0.5–1.1]; Padj_age/sex 0.09). Homozygosity for the allele C is suggestive of an association with the development of Lg-CL among exposed individuals to Lg-infection. However, the odds of developing CL associated with the CC genotype was evident only in male individuals (OR_adjage = 1.3 [95% CI = 0.9–2.0]; P_adjage = 0.06). Individuals homozygous for the G allele tend to have higher plasma IL-8 and CCL5. Similarly, for the MIR499A rs3746444, an association with the G allele was only observed among male individuals (OR = 1.4 [1.0–1.9]; P = 0.009). In a dominant model, individuals with the G allele (GG-GA) when compared to the AA genotype reveals that carriers of the G allele have 40% elevated odds of developing Lg-CL (ORadj_age = 1.4 [1.1–1.9]). Individuals with the GG genotype have higher odds of developing Lg-CL (ORadj_age/sex = 2.0 [95%CI 0.83–5.0]; P_adjage = 0.01. Individuals homozygous for the G allele have higher plasma IL-8. Genetic combinations of both variants revealed that male individuals exposed to Lg bearing three or four susceptible alleles have higher odds of developing Lg-CL (OR = 2.3 [95% CI 1.0–4.7]; p = 0.017). Both MIR146A rs2910164 and MIR499A rs3746444 are associated with the development of Lg-CL and this association is prevalent in male individuals.

Leishmaniasis is caused by infection with Leishmania parasites. In regions with the presence of Leishmania parasites, all people do not develop the disease despite similar exposure. Only a proportion of inhabitants progress to the development of disease. Clinical manifestations depend on the vector and Leishmania species, as well the host genetic background and genetically determined immune responses. miRNAs play important roles in regulating gene expression and many biological processes including immune pathways. miR-146a targets TRAF6 and IRAK1 genes, that encode key adaptor molecules downstream of toll-like receptors (TLRs). TLRs are critical in immune response to Leishmania-infection. miR499-a modulates inflammation-related signalling pathways such as TGFβ, TNFα and TLR pathways. In this study, we showed that MIR146A and MIR499A variants are risk factors to developing cutaneous leishmaniasis caused by L. guyanensis in Amazonas state of Brazil. Individuals with these variants are susceptible to the development of CL.

miR-155 T/A (rs767649) and miR-146a A/G (rs57095329) single nucleotide polymorphisms as risk factors for chronic hepatitis B virus infection among Egyptian patients

Genetic variants in microRNAs (miRNAs) can alter the miRNAs expression and/or function, accordingly, affecting the related biological pathways and disease risk. Dysregulation of miR-155 and miR-146a expression levels has been well-described in viral hepatitis B (HBV). In the current study, we aimed to assess rs767649 T/A and rs57095329 A/G polymorphisms in miR-155, and miR-146a genes, respectively, as risk factors for Chronic HBV (CHBV) in the Egyptian population. Also, we aimed to do in silico analysis to investigate the molecules that primarily target these miRNAs. One hundred patients diagnosed as CHBV and one hundred age and sex-matched controls with evidence of past HBV infection were genotyped for miR-155 (rs767649) and miR-146a (rs57095329) using real-time polymerase chain reaction. The rs767649 AT and AA genotypes in CHBV patients confer four folds and ten folds risk respectively, as compared to control subjects [(AOR = 4.245 (95%CI 2.009–8.970), p<0.0001) and AOR = 10.583 (95%CI 4.012–27.919), p<0.0001, respectively)]. The rs767649 A allele was associated with an increased risk of developing CHBV (AOR = 2.777 (95%CI 1.847–4.175), p<0.0001). There was a significant difference in the frequency of rs57095329 AG and GG genotypes in CHBV patients compared to controls. AG and GG genotypes showed an increase in the risk of developing CHBV by about three and six folds respectively [AOR = 2.610 (95%CI 1.362–5.000), p = 0.004] and [AOR = 5.604 (95%CI 2.157–14.563), p<0.0001].We concluded that rs57095329 and rs767649 SNPs can act as potential risk factors for the development of CHBV in the Egyptian population.

Association study between immune-related miRNAs and mixed connective tissue disease

Background

Mixed connective tissue disease (MCTD) is a rare condition that is distinguished by the presence of specific U1-RNP antibodies. Information about its etiopathology and diagnostics is still unclear. miRNAs such as miR-146, miR-155, and miR-143 emerged as key regulators of the immune system, known to be involved in the development of autoimmune diseases and cancers. We performed an association study between immune-related miRNAs and MCTD severity and susceptibility.

Methods

A total of 169 MCTD patients and 575 healthy subjects were recruited to the case–control study. The miRNA polymorphisms were genotyped using TaqMan SNP genotyping assay. TNF-α, IL-6, and IFN-γ levels in serum were determined using ELISA. qRT-PCR of TRAF6, IRAK1, and microRNAs was performed using Taqman miRNA assays and TaqMan Gene Expression Assays.

Results

miR-146a rs2910164 G allele and GG genotype as well as miR-143 rs713147 A allele were more frequent in healthy subjects than in MCTD patients. miR-146a rs2910164 CC genotype and miR-143 T-rs353299*T-rs353291*T-rs713147*G-rs353298 and C-rs353299*C-rs353291*T-rs713147*A-rs353298 haplotypes were associated with MCTD susceptibility. miR-146a rs2910164 C/T was associated with scleroderma and lymphadenopathy. miR-143 rs353299 C/T was associated with swollen fingers or hands, the presence of enlarged lymph nodes, and pericarditis/pleuritis. miR-143 rs353298 A/G was associated with the occurrence of pericarditis/pleuritis and scleroderma. miR-143 rs353291 T/C showed association with pericarditis/pleuritis. The serum TNF-α, IFN-γ, and IL-6 levels were significantly higher in MCTD patients compared to healthy subjects. miR-143 SNPs were associated with higher proinflammatory cytokine concentration in serum only in healthy controls. IRAK1 and TRAF6 expression were higher in the MCTD patients compared to controls.

Conclusions

The results of our case–control study indicate the possible significance of miR-146a and miR-143/145 in the susceptibility and clinical picture of MCTD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-020-02403-9.

Polymorphisms of Pre-miR-499 rs3746444 T/C and Pre-miR-146a rs2910164 C/G in the Autoimmune Diseases of Rheumatoid Arthritis and Systemic Lupus Erythematosus in the West of Iran

BACKGROUND

The present research is a case-control study to analyze the influence of pre-miRNA-146a rs2910164 and pre-miRNA-499 rs3746444 polymorphisms as candidate susceptibility factors for both rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

Polymorphism in miR146 and miR499 using ARMS-PCR was genotyped on 139 autoimmune disease (AD) patients (89 RA and 50 SLE) referred to Educational Hospitals of Khorramabad, Lorestan Province, west of Iran in 2018-2019 and 237 healthy control subjects.

RESULTS

A significant increase in the likelihood of carrying the GC vs. GG of pre-miR146-rs2910164 and T vs C allele of pre-miR499- rs3746444 in patients with RA was found. On the contrary, patients with RA were less likely to carry the TC + CC vs TT genotype and the C vs T allele of pre-miR499- rs374644. In females with the GC vs GG and GC+ CC vs GG genotypes, a significant association was found with the increased risk of RA. Interestingly, the genotypic combination of TC of the pre-miR499-rs374644 with GG of pre-miR146-rs2910164 more strongly decreased the risk of RA. In patients with SLE, no notable associations were found between both pre-miRNA-146a rs2910164 and pre-miRNA-499 rs3746444 with risk of disease.

CONCLUSION

Genetic polymorphisms of miR146 rs2910164 is associated with RA susceptibility especially in females. Interestingly, there is a potential in miR499 to reduce the risk with the protective effect of gene-gene interactions on miR146 in RA disease.

Nuclear factor-κB1 and MicroRNA-146a polymorphisms and risk of acute graft versus host disease post allogeneic stem cell transplantation

Acute graft-versus-host disease (aGVHD) is a severe inflammatory complication of haematopoeitic stem cell transplantation. The nuclear factor- Kappa Beta (NF-κB) signaling pathway regulates T cell activation. The NF-κB controls the expression of microRNA-146a (miR-146a) that in turn regulates NF-κB activation through a negative feedback loop. We aim to analyze the association between NF-κB1 encoding p50 (rs28362491, -94 in.ertion/deletion ATTG) and miR-146a (rs2910164, G > C) polymorphisms and risk of aGVHD. Genotyping was performed for 135 HLA-matched donors using polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP).The incidence of aGVHD grades II-IV was 24/135 (17.8 %). NF-κB1 genotype and cytomegalovirus infection were significantly associated with risk of aGVHD II-IV (p = 0.022, HR = 3.17, 95 % CI:1.18-8.51 and p = 0.048, HR = 2.56, 95 % CI:1.01-6.52, respectively). In multivariate analysis, NF-κB1homozygous deletion/deletion genotype was the only independent risk factor associated with aGVHD II-IV (p = 0.013, HR = 3.50, 95 % CI:1.30-9.44). No significant association could be observed between miR-146a polymorphism and aGVHD. Combined NF-κB1 and miR146a genotype analysis warrants investigation in a larger cohort. Our preliminary data do not support the association between miR146a and aGVHD, but suggest an association between NF-κB1 and risk of aGVHD that may pave the way for the development of a novel targeted therapy if proved in a larger cohort.

Association of microRNAs genes polymorphisms with arthritis: a systematic review and meta-analysis

Objective: To investigate whether microRNAs genes’ polymorphisms are associated with arthritis. Methods: The PubMed, Cochrane Library et al. were systematically searched to identify case–control studies, systematic reviews and meta-analyses. A meta-analysis was performed to calculate odds ratios (ORs), and confidence intervals (CIs) at 95% using fixed-effect model or random-effects model. Results: Twenty-two case–control studies involving 10489 participants fulfilled the inclusion criteria. MiR-146a rs2910164 (G/C) was not significantly associated with the risk of rheumatoid arthritis (RA) in any model. Significant associations were found between miR-146a rs2910164 (G/C) and the risk of psoriatic arthritis (PsA) in the heterozygous model and the dominant model. The heterozygous model showed a significant association between the miR-146a rs2910164 (G/C) polymorphism and ankylosing spondylitis (AS). And there was no significant association of miR-146a rs2910164 (G/C) with risk of juvenile rheumatoid arthritis (JRA) at any model. Additionally, there was a significant association of miR-499 rs3746444 (T/C) with risk of RA at two genetic models, and with a moderate heterogeneity. When subgroup analysis by ethnicity, significant associations were almost found between miR-499 rs3746444 (T/C) and the risk of RA in any model in Caucasian populations, and there is no heterogeneity. Conclusions: The association of miR-146a rs2910164 (G/C) with RA was not found. And there was a significant association between miR-146a rs2910164(G/C) and PsA or AS. MiR-499 rs3746444 (T/C) was associated with RA in Caucasian populations. These findings did not support the genetic association between miR-146a rs2910164 (G/C) and JRA susceptibility, as well as the association of miR-196a-2 rs11614913 (C/T), miR-146a rs2431697, miR-146a rs57095329, miR-149 rs22928323 with arthritis.

Maternal miRNA-146a G/C rs2910164 variation, HIV/AIDS and nitrogen oxide pollution exposure collectively affects foetal growth

OBJECTIVE:

Nitrogen oxide (NOx) pollution and human immunodeficiency virus (HIV)/AIDS intensify inflammation during pregnancy and linked with adverse birth outcomes (ABOs). MicroRNA (miRNA)-146a plays a crucial role in regulating inflammation in the NF-κB pathway. The G/C rs2910164 dampens miRNA-146a activity and linked with inflammatory diseases. The present study investigated whether HIV/AIDS and NOx exposure throughout pregnancy further intensifies ABO in Black South African women genotyped for the rs2910164.

METHODS:

Pregnant women ( n = 300) were subdivided into low, medium and high NOx exposure groups, genotyped for the miRNA-146a G/C rs2910164 using polymerase chain reaction-restriction fragment length polymorphism, and further stratified based on HIV status.

RESULTS:

Unstratified data (HIV+ and HIV- mothers combined): Mothers from the high NOx group with the variant C-allele had low blood iron levels ( p = 0.0238), and had babies with reduced birthweights ( p = 0.0283). As NOx increased, the prevalence of preterm birth and low birth weight also increased in mothers with the variant C-allele versus wildtype G-allele. HIV-infected mothers: In all NOx exposure groups, mothers with the variant C-allele had higher systolic blood pressure (low: p = 0.0386, medium: p = 0.0367 and high: p = 0.0109) and had babies with lower Appearance, Pulse, Grimace, Activity and Respiration scores at 1 min (low: p = 0.0190, medium: p = 0.0301 and high: p = 0.0361).

CONCLUSION:

Maternal rs2910164 variant C-allele, NOx pollution and HIV/AIDS might collectively play a role in intensifying gestational hypertension and ABO.

The rs2910164 variant is associated with reduced miR-146a expression but not cytokine levels in patients with type 2 diabetes

PURPOSE

Previous reports have demonstrated that genetic variations in microRNAs regulome could affect microRNAs-mediated regulation. Therefore, in the present study we were aimed at (1) comparison of microRNA 146-a (miR-146a) peripheral blood mononuclear cells (PBMCs) and plasma levels between diabetic patients and controls, and (2) investigating the possible association of rs2910164 with miR-146a and its related target genes expression and also serum cytokine levels.

METHODS

The study population consisted of 60 subjects including 30 type 2 diabetes (T2D) patients and 30 controls with determined genotypes for rs2910164. The RNA expression levels were determined by real-time PCR. Moreover, TNF-α, IL-6, IL-10 and IL-1β serum levels were measured using ELISA method.

RESULTS

Our results showed that the miR-146a expression levels were significantly decreased in PBMCs (P = 0.004) and plasma (P = 0.008) samples of patients with T2D compared to healthy participants. In addition, we observed that IRAK1 mRNA expression-but not TLR4, TRAF6 and NFĸB-was significantly increased in patients with T2D compared to controls (P = 0.028). The relative expression levels of miR-146a in plasma and PBMCs samples of diabetic patients with the rs2910164 GG genotypes were significantly higher than that in CC (P < 0.05). Moreover, no significant differences were found in miR-146a targets and cytokine levels between the rs2910164 different genotypes.

CONCLUSION

Our study demonstrated that miR-146a circulating levels were significantly elevated in controls compared with T2D patients. In addition, we identified that rs2910164-C allele is associated with reduced expression levels of the miR-146a but not its mRNAs targets and cytokine levels in diabetic patients.

Association of Three Polymorphisms rs11614913, rs2910146, and rs3746444 in miRNA-196a2, miRNA-146a, and miRNA-499 with Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

Background

It has been found that single-nucleotide polymorphisms (SNPs) of microRNA might be involved in the development of inflammatory bowel diseases (IBDs). However, the related retrospective research has not been reported. In this work, we performed a meta-analysis to derive a more precise estimation of the associated relationship.

Methods

We searched the studies on the association of SNPs of microRNA with the hereditary susceptibility of IBD in PubMed and Embase; eligible research was selected by screening the abstract and full text. The meta-analysis was performed based on the statistical software Stata 14.0, and besides, the odds ratio and 95% confidence interval were calculated to evaluate the strength of the association.

Results

159 papers were acquired from the PubMed and Embase databases, and five eligible articles containing nine case-control studies were selected. In the study, we first found that the association between miRNA-196a2 rs11614913 and IBD was insignificant. Then, the susceptibility of miRNA-146a rs2910146 to IBD increased significantly in allelic comparison, homozygote model, heterozygote model, and dominant model. Moreover, a positive relationship between miRNA-499 rs3746444 and IBD was identified in the homozygote model.

Conclusion

Our findings demonstrated that miRNA-146a rs2910146 (G>C) polymorphism was associated with the susceptibility to IBD and miRNA-196a2 rs11614913 (T>C) and miRNA-499 rs3746444 (A>G) did not reveal an obvious relationship with the IBD susceptibility.

miR-146b Probably Assists miRNA-146a in the Suppression of Keratinocyte Proliferation and Inflammatory Responses in Psoriasis

miR-146a inhibits inflammatory responses in human keratinocytes and in different mouse models of skin inflammation. Little is known about the role of miR-146b in the skin. In this study, we confirmed the increased expression of miR-146a and miR-146b (miR-146a/b) in the lesional skin of patients with psoriasis. The expression of miR-146a was approximately twofold higher than that of miR-146b in healthy human skin, and it was more strongly induced by stimulation of proinflammatory cytokines in keratinocytes and fibroblasts. miR-146a/b target genes regulating inflammatory responses or proliferation were altered in the skin of patients with psoriasis, among which FERMT1 was verified as a direct target of miR-146a. In silico analysis of genome-wide data from >4,000 psoriasis cases and >8,000 controls confirmed a moderate association between psoriasis and genetic variants in the miR-146a encoding gene. Transfection of miR-146a/b suppressed and inhibition enhanced keratinocyte proliferation and the expression of psoriasis-related target genes. Enhanced expression of miR-146a/b-influenced genes was detected in cultured keratinocytes from miR-146a-/- and skin fibroblasts from miR-146a-/- and miR-146b-/- mice stimulated with psoriasis-associated cytokines as compared with wild-type mice. Our results indicate that besides miR-146a, miR-146b is expressed and might be capable of modulation of inflammatory responses and keratinocyte proliferation in psoriatic skin.

Polymorphisms in genes encoding miR-155 and miR-146a are associated with protection to type 1 diabetes mellitus

AIMS

Type 1 diabetes mellitus (T1DM) is characterized by severe autoimmune destruction of pancreatic beta-cells. The triggering of autoimmunity against beta-cells is probably caused by a combination of environmental and genetic risk factors. Even though much is known about the genetic of T1DM, more information is needed to completely unravel this tangled disease. MicroRNAs (miRNAs) are a class of small noncoding RNAs molecules that negatively regulate gene expression by inducing target mRNA cleavage or by inhibiting protein translation. Abnormal miRNA expressions have been described in autoimmune diseases and T1DM. Polymorphisms in genes codifying miRNAs may alter the expression of the corresponding miRNA and, thus, confer susceptibility for a given disease. Therefore, the aim of this study was to investigate whether polymorphisms in genes encoding miR-155, miR-146a, and miR-375 are associated with T1DM.

METHODS

Frequencies of the miRNA-146a rs2910164, miRNA-155 rs767649 and miRNA-375 rs6715345 polymorphisms were analyzed in 490 T1DM patients and in 469 nondiabetic subjects.

RESULTS

The miR-146a rs2910164 and miR-155 rs767649 polymorphisms were associated with protection for T1DM, and the strongest association was observed for the dominant model [odds ratio (OR) = 0.557 95% CI 0.355-0.874 and OR = 0.508, 95% CI 0.265-0.973, respectively, after adjustment for age, ethnicity, and risk HLA loci]. However, miR-375 rs6715345 frequencies did not differ between cases and controls.

CONCLUSION

MiR-146a rs2910164 and miR-155 rs767649 polymorphisms were associated with protection for T1DM.

MicroRNA-146a suppresses IL-17-mediated skin inflammation and is genetically associated with psoriasis

BACKGROUND

Psoriasis is an immune-mediated inflammatory skin disease with a strong genetic background in which activation of IL-17 signaling is central in the pathogenesis. Little has been known about the role of noncoding RNAs, including microRNAs (miRNAs), in predisposition to the disease.

OBJECTIVE

We sought to investigate the genetic association of single nucleotide polymorphisms in microRNA-146a (miR-146a) to psoriasis and to explore its function in the initiation and resolution of the disease.

METHODS

Analysis of the genetic association of miR-146a rs2910164 and psoriasis was carried out on 1546 patients with psoriasis and 1526 control subjects. The role of miR-146a in patients with psoriasis was assessed by using miR-146a^-/- mice in conjunction with the imiquimod-induced mouse model of psoriasis. The severity of psoriasis-like skin inflammation was evaluated at morphologic, histologic, and molecular levels. miR-146a was ectopically overexpressed and inhibited in keratinocytes treated with IL-17. Synthetic miR-146a was injected intradermally into mice.

RESULTS

Here we report protective association of a functional polymorphism in the miR-146a precursor (rs2910164). Genetic deficiency in miR-146a leads to earlier onset and exacerbated pathology of skin inflammation, with increased expression of IL-17-induced keratinocyte-derived inflammatory mediators, epidermal hyperproliferation, and increased neutrophil infiltration. Moreover, miR-146a-deficient mice do not resolve inflammation after discontinuation of imiquimod challenge. The overexpression of miR-146a suppressed, whereas its inhibition enhanced, IL-17-driven inflammation in keratinocytes. Functionally, miR-146a impairs the neutrophil chemoattractant capacity of keratinocytes. Finally, delivery of miR-146a mimics into the skin leads to amelioration of psoriasiform skin inflammation, decreased epidermal proliferation, and neutrophil infiltration.

CONCLUSIONS

Our results define a crucial role for miR-146a in modulating IL-17-driven inflammation in the skin.

Association between the three functional miR-146a single-nucleotide polymorphisms, rs2910164, rs57095329, and rs2431697, and autoimmune disease susceptibility: A meta-analysis

Studies suggest associations between the miR-146a single nucleotide polymorphisms (SNPs) and susceptibility to autoimmune diseases. However, the results are inconsistent and inconclusive. Therefore, the aim of this study was to arrive at a conclusion about the association between the three functional miR-146a SNPs and autoimmune disease risk. Studies were identified through PubMed/MEDLINE searches for studies published up to January 2016 using as keywords rs2910164, rs57095329, rs2431697, and miR-146a polymorphisms. Thirty studies were included in the meta-analysis. The SNP rs2910164 G > C was found to be associated with increased risk of multiple sclerosis (CC + CG versus GG, OR = 1.25, 95% CI: 1.01-1.55), with decreased risks of psoriasis (C versus G, OR = 0.81, 95% CI: 0.69-0.96; CC versus GC + GG, OR = 0.73, 95% CI: 0.56-0.94), Behcet's disease (CC versus GC + GG, OR = 0.60, 95% CI: 0.50-0.73), asthma (C versus G, OR = 0.80, 95% CI: 0.69-0.93; CC versus GC + GG, OR = 0.65, 95% CI: 0.48-0.86), and uveitis (CC + CG versus GG, OR = 0.61, 95% CI: 0.49-0.77). The SNP rs2431697 C > T was found to be associated with an increased risk of SLE (T versus C, OR = 1.26, 95% CI: 1.15-1.38; TC + TT versus CC, OR = 1.28, 95% CI: 1.03-1.58; TT versus TC + CC, OR = 1.40, 95% CI: 1.21-1.62). The SNP rs57095329 A > G was found to be associated with an increased risk of SLE (G versus C, OR = 1.25, 95% CI: 1.17-1.35). The miR-146a SNPs rs2910164, rs57095329, rs2431697 are associated with susceptibility to certain autoimmune diseases. However, for other autoimmune diseases, they may be protective or insignificant.

Association between promoter polymorphisms of matrix metalloproteinase-1 and risk of gastric cancer

Growing evidences show that matrix metalloproteinase-1 (MMP1) plays important roles in tumorigenesis and cancer metastasis. The interactions between MMP1-1607 1G>2G polymorphism and risk of gastric cancer (GC) have been reported, but results remained ambiguous. To determine the association between MMP1-1607 1G>2G polymorphism and risk of GC, we conducted a meta-analysis and identified the outcome data from all the research papers estimating the association between MMP1-1607 1G>2G polymorphism and GC risk, which was based on comprehensive searches using databases such as PubMed, Elsevier Science Direct, Excerpta Medica Database (EMBASE), and Chinese National Knowledge Infrastructure (CNKI). The fixed-effects model was used in this meta-analysis. Data were extracted, and pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. In this meta-analysis, six studies involving 1,377 cases and 1,543 controls were included. We identified the significant association between MMP1-1607 1G>2G polymorphism and GC risk for allele model (OR =1.05; 95% CI, 1.01-1.08), for dominant model (OR =1.11; 95% CI, 1.08-1.15), and for recessive model (OR =1.06; 95% CI, 0.98-1.14). In summary, our analysis demonstrated that MMP1-1607 1G>2G polymorphism was significantly associated with an increased risk of GC.

Impact of V-ets Erythroblastosis Virus E26 Oncogene Homolog 1 Gene Polymorphisms Upon Susceptibility to Autoimmune Diseases: A Meta-Analysis

V-ets erythroblastosis virus E26 oncogene homolog 1 (ETS1) is recognized as a gene of risk to autoimmune diseases (ADs). Two single nucleotide polymorphisms (SNPs) in ETS1 (rs1128334 G>A and rs10893872 T>C) were considered associated with ADs risk. However, the results remain conflicting.We performed a meta-analysis to evaluate more precise estimations of any relationship. We searched PubMed, OvidSP, and Chinese National Knowledge Infrastructure databases (papers published prior to September 12, 2014) and extracted data from eligible studies. Meta-analysis was performed using the STATA 12.0 software. Random effect model or fixed effect model were chosen according to the study heterogeneities.A total of 11 studies including 7359 cases (9660 controls) for rs1128334 and 8 studies including 5419 cases (7122 controls) for rs10893872 were involved in this meta-analysis. Overall, our results showed that there were significant associations for rs1128334 with AD risk in 5 genetic models, both in pooled analysis and in systemic lupus erythematous (SLE) subgroup, and in 3 genetic models of the uveitis subgroup. Although for rs10893872, the results showed that there were significant associations in allele model both in pooled analysis and in SLE subgroup. As a conclusion, this meta-analysis demonstrated that these 2 SNPs (rs1128334 and rs10893872) in ETS1 were associated with ADs risk.