Associations of TNFRSF1A Polymorphisms with Autoimmune Thyroid Diseases: A Case-Control Study.

Previous studies have shown associations of polymorphisms in the tumor necrosis factor (TNF) receptor super family member 1A (TNFRSF1A) gene with several groups of inflammatory and autoimmune related diseases, but associations of TNFRSF1A polymorphisms with autoimmune thyroid diseases (AITD), mainly including two sub-types of Hashimoto's thyroiditis (HT) and Graves' disease (GD), in the Chinese Han population is unclear. A case-control study of 1812 subjects (965 AITD patients and 847 unrelated healthy controls) was conducted to assess AITD associations with five single nucleotide polymorphisms (SNPs), including rs4149576, rs4149577, rs4149570, rs1800693, and rs767455 in the TNFRSF1A gene locus. Genotyping was performed and evaluated using the platform of ligase detection reaction. No significant difference was observed in the allele and genotype frequencies between HT or GD patients and controls in any of the five SNPs in the TNFRSF1A gene (all p values >0.05). However, a moderate association of rs4149570 with HT was found after adjusting for age and gender [odds ratio (OR)=1.40, p=0.03]. No obvious difference was found in the haplotype distribution of any of the five SNPs in the TNFRSF1A gene between the AITD patients and controls. These data suggest that these five SNPs in the TNFRSF1A gene are not associated with AITD in the Chinese Han population, but rs4149570 shows a weak association with HT after adjusting for gender and age.

Differential cytokine expression detected by protein microarray screening in peripheral blood of patients with refractory Graves' disease.

OBJECTIVE: The prognosis of Graves' disease (GD) varies among patients. However, the immune pathogenesis of refractory GD is still unknown. The aim of this study was to explore the cytokine expression profile associated with refractory GD. METHODS: Preliminary cytokine protein microarray screening was performed to detect differentially expressed cytokines in the plasma of four patients with refractory GD and four patients with stable GD. Some differentially expressed cytokines were then validated in plasma by enzyme-linked immunosorbent assay (ELISA) and in peripheral blood mononuclear cells (PBMCs) by quantitative real-time polymerase chain reaction (qRT-PCR) on another independent set of samples. RESULTS: We found that 21 cytokines were differentially expressed between patients with intractable GD and those in remission, including 18 upregulated and 3 downregulated cytokines with a fold change >1·30 and <0·77, respectively. Intractability-related elevation of three cytokines (IL-4, IL-6 and IL-10) was validated by ELISA in plasma on another GD cohort with 30 patients in recurrence and 14 in remission (t-test, P = 0·035, 0·033 and 0·041, respectively). Furthermore, mRNA expression of IL-4, IL-6 and IL-10 in PBMCs, detected by qRT-PCR, was significantly elevated in patients with refractory GD compared with those in remission (P = 0·039, 0·047 and 0·042, respectively). CONCLUSION: The severity of GD is associated with the aberrant expression and secretion of several cytokines that may serve as potential biomarkers and predictors for disease prognosis. Targeting these cytokines or their receptors may also lead to a novel therapeutic intervention for GD.

Gene-gene and gene-sex epistatic interactions of DNMT1, DNMT3A and DNMT3B in autoimmune thyroid disease.

The aim of this study was to investigate the associations of DNA methyltransferases (DNMTs) polymorphisms with susceptibility to autoimmune thyroid diseases (AITDs) and to test gene-gene/gene-sex epistasis interactions. Eight single-nucleotide polymorphisms (SNPs) in DNMT1, DNMT3A and DNMT3B were selected and genotyped by multiplex polymerase chain reaction combined with ligase detection reaction method (PCR-LDR). A total of 685 Graves' disease (GD) patients, 353 Hashimoto's thyroiditis (HT) patients and 909 healthy controls were included in the final analysis. Epistasis was tested by additive model, multiplicative model and general multifactor dimensionality reduction (general MDR). Rs2424913 (DNMT3B) and rs2228611 (DNMT1) were associated with susceptibility to AITD and GD in the dominant and overdominant model, respectively (rs2424913: P=0.009 for AITD, P=0.0041 for GD; rs2228611: P=0.035 for AITD, P=0.043 for GD). Multiplicative and multiple high dimensional gene-gene or gene-sex interactions were also observed in this study. We have found evidence for a potential role of rs2424913 (DNMT3B) and rs2228611 (DNMT1) in AITD susceptibility and identified novel gene-gene/gene-sex interactions in AITD. Our study may highlight sex and genes of DNMTs family as contributors to the pathogenesis of AITD.

Genome-wide DNA methylation analysis in Graves' disease.

As an autoimmune disease, Graves' disease (GD) is associated with many genetic and environmental risk factors. Although the exact mechanism remains unclear, epigenetic determinants, such as DNA methylation, are thought to contribute to the pathogenesis of GD. Here, we for the first time reported the DNA methylation pattern in GD through a high-throughput analysis. In order to investigate genome-wide DNA methylation profile of GD, methyl-DNA immunoprecipitation (MeDIP) and Nimblegen human DNA methylation 3 × 720 K promoter plus CpG island microarrays were used to identify differentially methylated regions (DMRs) from blood samples in GD patients. Quantitative methylation-specific PCR (qMSP) was used to validate the methylation state of candidate genes. Transcription level of each gene was estimated by quantitative real-time PCR (qRT-PCR). A total of 132 hypermethylated and 133 hypomethylated regions were identified in GD. The methylation of ICAM1 in GD patients and normal controls was significantly different (p<0.05). In the female group, significantly decreased methylation was observed in GD patients compared with normal controls (p<0.05). The transcription of ICAM1 at the mRNA level was significantly higher in GD patients compared with normal controls (p<0.05). Besides, the transcription of DNMT1 and MECP2 at the mRNA level was significantly decreased in GD patients compared with normal controls (p<0.05). Our findings revealed that the DNA methylation pattern in GD was distinct from that of controls. These results provided new molecular insights into the pathogenesis of GD.

TNFSF4 Gene Variations Are Related to Early-Onset Autoimmune Thyroid Diseases and Hypothyroidism of Hashimoto's Thyroiditis.

The aim of the current study was to examine whether the polymorphism loci of the tumor necrosis factor superfamily member 4 (TNFSF4) gene increase the risk of susceptibility to autoimmune thyroid diseases (AITDs) in the Han Chinese population, and a case-control study was performed in a set of 1,048 AITDs patients and 909 normal healthy controls in the study. A total of four tagging single nucleotide polymorphisms (SNPs) in the TNFSF4 region, including rs7514229, rs1234313, rs16845607 and rs3850641, were genotyped using the method of ligase detection reaction. An association between GG genotype of rs3850641 in TNFSF4 gene and AITDs was found (p = 0.046). Additionally, the clinical sub-phenotype analysis revealed a significant association between GG genotype in rs7514229 and AITDs patients who were ≤18 years of age. Furthermore, rs3850641 variant allele G was in strong association with hypothyroidism in Hashimoto's thyroiditis (HT) (p = 0.018). The polymorphisms of the TNFSF4 gene may contribute to the susceptibility to AITDs pathogenesis.

Aberrant expression of miRNA and mRNAs in lesioned tissues of Graves' disease.

BACKGROUND AND AIMS: Abnormal microRNA (miRNA) expression is found in many diseases including autoimmune diseases. However, little is known about the role of miRNA regulation in Graves' disease (GD). Here, we simultaneously detected different expressions of miRNA and mRNAs in thyroid tissues via a high-throughput transcriptomics approach, known as microarray, in order to reveal the relationship between aberrant expression of miRNAs and mRNAs spectrum and GD. METHODS: Totally 7 specimens of thyroid tissue from 4 GD patients and 3 controls were obtained by surgery for microarray analysis. Then, 30 thyroid specimens (18 GD and 12 controls) were also collected for further validation by quantitative real-time PCR ( qRT-PCR ). RESULTS: Statistical analysis showed that the expressions of 5 specific miRNA were increased significantly while those of other 18 miRNA were decreased in thyroid tissue of GD patients (FC ≥ 1.3 or ≤ 0.77 and p<0.05). In addition, the transcription of 1271 mRNAs was up-regulated, while the expression of 777 mRNAs transcripts was down-regulated (FC ≥ 2.0 or ≤ 0.5 and p<0.05). Furthermore, integrated analysis of differentially expressed miRNA and their target mRNAs demonstrated that 2 miRNA (miR-22 and miR-183) were increased while their potential target mRNAs were decreased. 3 miRNA (miR-101, miR-197 and miR-660) were decreased while their potential target mRNAs were increased. The above findings from microarray screening were confirmed by qRT-PCR in more samples. The results were consistent with those observed in the microarray assays. CONCLUSION: Our study highlights the possibility that miRNA-target gene network may be involved in the pathogenesis of GD and could provide new insights into understanding the pathophysiological mechanisms of GD.

Association of single-nucleotide polymorphisms in the STAT3 gene with autoimmune thyroid disease in Chinese individuals.

The aim of this study was to investigate the association between signal transducer and activator of transcription 3 (STAT3) polymorphisms and autoimmune thyroid diseases and clinical features. We genotyped six single-nucleotide polymorphisms (SNPs) rs1053005, rs2293152, rs744166, rs17593222, rs2291281, and rs2291282 of STAT3 gene in 667 patients with autoimmune thyroid disease (417 Graves' disease (GD) and 250 Hashimoto's thyroiditis (HT)) and 301 healthy controls. The allele A from rs1053005 was significantly less frequent in both GD and HT patients (P = 0.0024, OR = 0.6958, 95%CI = 0.5508-0.8788; P = 0.0091, OR = 0.7013, 95%CI = 0.5397-0.9112, respectively). The AA genotype of rs1053005 was less in GD and HT patients too (P = 0.0025,OR = 0.6278, 95%CI = 0.466-0.847) and (P = 0.0036,OR = 0.601, 95%CI = 0.428-0.843). The allele G from rs17593222 increased the susceptibility to the ophthalmopathy development both in autoimmune thyroid disease (AITD) and GD patients (P = 0.0007, OR = 3.980, 95%CI = 1.871-8.464; P = 0.0081, OR = 3.378, 95%CI = 1.441-7.919, respectively). The allele A and AA genotype of SNP rs1053005 may protect individuals from the susceptibility to AITD and their frequency decreased in AITD patients. In addition, the allele G of rs17593222 may increase the ophthalmopathy risk in AITD patients. Our findings suggest the existence of association between STAT3 gene and AITD, thus adding STAT3 gene to the list of the predisposing genes to AITD.

High-throughput T cell receptor sequencing reveals differential immune repertoires in autoimmune thyroid diseases.

BACKGROUND: Autoimmune thyroid diseases (AITDs) are chronic autoimmune diseases specific to thyroid and mainly include Graves' disease (GD) and Hashimoto' thyroiditis (HT). The adaptive immunoreactivity of CD4+ T cells plays a crucial role in the pathogenesis of AITDs, but very little has been known about its changes in disease status. METHODS: We collected peripheral CD4+ T cells from 12 GD patients, including 6 newly diagnosed GD (NGD) and 6 refractory GD (RGD) patients, 6 HT patients and 6 healthy controls, and examined the gene expression profiles and colon types of T cells receptor (TCR) ß chain complementarity determining region 3 (CDR3) using high-throughput sequencing. RESULTS: The TCR repertoire were significantly expanded in AITDs groups, and some TCR genes were expressed more preferentially in AITDs group than in the healthy control group, including TRBV15 (P = 0.001), TRBV4-2 (P = 0.003), TRBV9 (P = 0.007), TRBV3-2 (P = 0.012), TRBV7-8 (P = 0.015), TRBV25-1 (P = 0.019), TRBV12-4 (P = 0.019) and TRBV27 (P = 0.02) in GD patients as well as TRBV29-1 (P = 0.004), TRBV12-4 (P = 0.004), TRBV6-5 (P = 0.011), TRBV7-2 (P = 0.012), TRBV27 (P = 0.012), TRBV9 (P = 0.031) and TRBV4-2 (P = 0.032) in HT patients. Moreover, subgroup analysis showed that the difference in the TCR spectrum between the normal group and NGD was not obvious, but a large number of differential genes appeared in the RGD group. CONCLUSION: TCR spectrum has changed in patients with AITDs with expanded repertoire and many upregulated TRBV genes. Moreover, this difference is not apparent in GD patients at the initial stage, but as the disease progresses, the differences in TCR profiles became more pronounced.

Polymorphisms of ATG5 Gene Are Associated with Autoimmune Thyroid Diseases, Especially Thyroid Eye Disease.

Objective: To explore the association of ATG5 gene polymorphisms with autoimmune thyroid diseases (AITDs) including Hashimoto's thyroiditis (HT) and Graves' illness (GD) as well as their clinical features. Methods: rs6568431, rs548234, and rs6937876 were selected to investigate the correlation of single-nucleotide polymorphisms of ATG5 gene with AITDs. Their frequencies in 824 AITD patients, including 271 HT patients and 553 GD patients, and 764 healthy controls were tested using both ligase detection reaction and multiplex polymerase chain reaction. Results: Allele A frequency of rs6568431 in AITDs patients (p = 0.016, OR = 1.201, 95% CI = 1.034 - 1.394) and allele G frequency of rs6937876 in AITDs patients (p = 0.009, OR = 1.223, 95% CI = 1.052 - 1.422) and in GD patients (p = 0.009, OR = 1.247, 95% CI = 1.056 - 1.473) were significantly higher than those in the healthy controls. The frequency of G allele (p = 5.42E - 18, OR = 0.242, 95% CI = 0.173 - 0.339) of rs6937876 was significantly higher in GD patients with ophthalmopathy. However, no relationship was found between family history, age onset, and the three SNPs. Conclusion: The study is the first to reveal the association between AITDs and ATG5 polymorphisms, and ATG5 gene is considered as a predisposing gene to AITDs, especially GDs.

An Update Evolving View of Copy Number Variations in Autoimmune Diseases.

Autoimmune diseases (AIDs) usually share possible common mechanisms, i.e., a defect in the immune tolerance exists due to diverse causes from central and peripheral tolerance mechanisms. Some genetic variations including copy number variations (CNVs) are known to link to several AIDs and are of importance in the susceptibility to AIDs and the potential therapeutic responses to medicines. As an important source of genetic variants, DNA CNVs have been shown to be very common in AIDs, implying these AIDs may possess possible common mechanisms. In addition, some CNVs are differently distributed in various diseases in different ethnic populations, suggesting that AIDs may have their own different phenotypes and different genetic and/or environmental backgrounds among diverse populations. Due to the continuous advancement in genotyping technology, such as high-throughput whole-genome sequencing method, more susceptible variants have been found. Moreover, further replication studies should be conducted to confirm the results of studies with different ethnic cohorts and independent populations. In this review, we aim to summarize the most relevant data that emerged in the past few decades on the relationship of CNVs and AIDs and gain some new insights into the issue.

METTL3 Is Involved in the Development of Graves' Disease by Inducing SOCS mRNA m6A Modification.

Objective: Epigenetic modifications in RNA are known to play critical roles in cell differentiation through regulating expressions of some key genes including members of the suppressor of cytokine signaling (SOCS) family. The present study aimed to unveil the relationship of SOCS mRNA methylation induced by methyltransferase like 3 (METTL3) with Graves' disease (GD). Methods: Differently expressed genes (DEG) in GD tissues were identified using microarray analysis and further validated using CD4+ T cell microarray of GD tissues and isolated peripheral blood mononuclear cells (PBMCs). Furthermore, expressions of METTL3 targeted genes were detected using METTL3 knock-down experiment in RAW264.7 cells. Results: High throughput microarrays revealed that METTL3 and SOCS molecules were aberrantly expressed in thyroid tissues and CD4+T cells of GD compared to the controls. Bioinformatic analysis was undertaken by searching databases of found genes of the SOCS family that possessed many mRNA m6A modification loci. METTL3 knock-down experiment revealed that expressions of SOCS family members SOCS1, SOCS2, SOCS4, SOCS5, and SOCS6 were increased after METTL3 knock-down. Conclusions: For the first time, the present study revealed the relationship between m6A modification and GD and indicated that METTL3 may be involved in the development of GD by inducing mRNA m6A methylation modification of SOCS family members.

Inclusion of ALKBH5 as a candidate gene for the susceptibility of autoimmune thyroid disease.

PURPOSE: RNA demethylase AlkB homolog 5 (ALKBH5) gene is pivotal in N6-methyladenosine (m6A) modification. Therefore, this study aimed to explore the potential relationship between polymorphisms of ALKBH5 gene and the development of autoimmune thyroid disease (AITD). MATERIAL AND METHODS: A case-control study of 979 AITD patients, including 620 Graves' disease (GD) and 359 Hashimoto's thyroiditis (HT), and 732 normal controls of the Chinese Han population was performed using high-throughput sequencing (HiSeq) genotyping method for detecting 5 variants in ALKBH5 gene (rs12936694, rs2124370, rs4925144, rs8068517, and rs9913266). In addition, the associations between ALKBH5 single nucleotide polymorphisms (SNPs) and clinical phenotypes of AITD were investigated. RESULTS: Compared to normal controls, rs9913266 displayed significant differences in allele and genotype distributions in AITD and GD. rs12936694 also showed significantly different frequencies of alleles in AITD and GD. The link of these 2 loci polymorprhisms to AITD and GD also existed after adjusting for age and gender. When stratified by sex, the minor allele of rs9913266 was associated with the risk of female AITD and HT development before and after adjusting for age and gender. There was a significant association between rs8068517 locus and GD in females after adjusting for the confounders. Finally, we observed significant correlations of haplotypes CGACA and CAGCG to the susceptibility of AITD and GD. CONCLUSIONS: Our results provided evidence of association of polymorphisms in ALKBH5 gene with AITD, GD, and HT patients, and hence ALKBH5 might be the candidate gene for susceptibility to AITD.

METTL3 gene polymorphisms contribute to susceptibility to autoimmune thyroid disease.

PURPOSE: Autoimmune thyroid disease (AITD) is a classic autoimmune disorder that mainly includes Graves' disease (GD) and Hashimoto's thyroiditis (HT). In this study, we explored the potential relationship between single-nucleotide polymorphisms (SNPs) of methyltransferase like 3 (METTL3) gene and the development of AITD. METHODS: The distribution of METTL3 genotypes at seven loci (rs1139130, rs1263790, rs1263791, rs17197156, rs2242526, rs3752411, and rs4417466) in 960 AITD (599 GD and 361 HT) patients and 732 unrelated healthy volunteers was examined using high-throughput sequencing technology in a case-controlled manner and their correlations with AITD development were statistically analyzed. RESULTS: METTL3 genotypes at these seven SNPs were not correlated with both GD and HT except a borderline association between rs3752411and GD after adjusted for age, sex, and thyroid function under the recessive model. Subgroup analysis demonstrated that the minor allele frequencies of rs2242526 and rs4417466 were higher in male AITD patients than in healthy volunteers before adjusted for confounding factors and the genotype distribution of rs4417466 was significantly different between the two groups. Additionally, the genotype frequencies of rs1139130, rs1263791, rs2242526, and rs4417466 were positively related with GD in male patients. Likewise, the allele distribution of rs1263791, rs2242526, and rs4417466 in male GD patients differed significantly from that in male controls. Multivariate logistic regression analyses revealed a significant association between allele frequencies of these three loci and GD in male patients after adjusted for the confounding factors. Moreover, the genotype of rs3752411 was strongly associated with GD in females as well. Furthermore, distribution of rs3752411 genotype was significantly associated with hypothyroidism in HT patients. CONCLUSION: Our study for the first time revealed a strong correlation between METTL3 mutations and AITD predisposition, implying that METTL3 may be a new candidate gene for AITD treatment.

Proteomics Screening of Differentially Expressed Cytokines in Tears of Patients with Graves' Ophthalmopathy.

BACKGROUND: The current study aimed at exploring the cytokine profile in the tears of patients with Graves' ophthalmopathy (GO). METHODS: Tears were sampled from the eyes of 7 patients with active GO and 7 healthy volunteers using filter paper. Then the levels of up to 34 cytokines in the tears of each subject were detected using high-throughput protein microarray technology in line with the introduction. RESULTS: The results of cytokine protein microarray screening showed that 10 proteins, namely, CD40, CD40 Ligand, GITR, IL-12p70, IL-1 beta, IL-2, IL-21, IL-6, MIP-3 alpha and TRANCE, were overexpressed (with fold change >1.20) and 3 proteins, namely, GM-CSF, IL-1 sRI and IL-13 were downregulated (with fold change < 0.83) in GO patients. In addition, the protein levels of CD40 and CD40 ligand (CD40L) were significantly different between GO patients and healthy controls (P=0.028 and 0.011, respectively). Further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of differently expressed proteins showed that these proteins were involved in biological functions including biological processes (positive regulation of cytokine production, JAK-STAT cascade and leukocyte proliferation), molecular functions (cytokine and growth factor receptors binding and cytokine activity), and other important pathways (cytokine-cytokine receptor interaction, JAK-STAT signaling pathway, IL-17 signaling pathway, NF-kappa B signaling pathway, Th17 cell differentiation, and intestinal immune network for IgA production), all of which might be involved in the pathology of GO. CONCLUSION: Our cytokine protein microarray analysis indicated that several proteins were differentially expressed in GO patients, which provides potential targets for GO prevention.

The Impact of Obesity on Thyroid Autoimmunity and Dysfunction: A Systematic Review and Meta-Analysis.

Background: To help inform decision making in the clinical setting, we carried out a systematic review and meta-analysis to estimate the association of thyroid disease risks with obesity. Methods: Pubmed, Embase, Web of Science, Cochrane database and Google Scholar electronic databases were searched from inception to October 31, 2018 without language restrictions to explore the relationship between thyroid disorders and obesity. The relative risk (RR) or odds risk (OR) for thyroid disorders were pooled using the SPSS and STATA software. Results: A total of 22 studies were included in the study. (1) Meta-analysis showed that obesity was significantly associated with an increased risk of hypothyroidism (RR = 1.86, 95% CI 1.63-2.11, P < 0.001). Meta-analyses after stratification further showed that obese population had increased risks of overt hypothyroidism (RR = 3.21, 95% CI 2.12-4.86, P < 0.001) and subclinical hypothyroidism (RR = 1.70, 95% CI 1.42-2.03, P < 0.001). (2) Further meta-analysis also showed obesity was clearly associated with Hashimoto's thyroiditis (RR = 1.91, 95% CI 1.10-3.32, P = 0.022), but not with Graves' disease. (3) In the meta-analysis of antibodies, obesity was correlated with positive thyroid peroxidase antibody (TPOAb) (RR = 1.93, 95% CI 1.31-2.85, P = 0.001), but not with positive thyroglobulin antibody (TGAb). Conclusions: Obesity was significantly related to hypothyroidism, HT, and TPOAb, implying that prevention of obesity is crucial for thyroid disorders. Systematic Review Registration: PROSPERO: CRD42018096897.

Thyroid disorders in patients with myasthenia gravis: A systematic review and meta-analysis.

BACKGROUND: Our purpose was to determine the prevalence of thyroid disorders in myasthenia gravis (MG) or whether MG was associated with an increased risk of thyroid disorders. METHODS: Pubmed, Embase, Web of Science, Cochrane database, Google Scholar and the Chinese Biomedical Databases were searched about the relationship between thyroid disorders and myasthenia gravis up to November 30, 2018, without language restrictions. The prevalence and relative risk (RR) for thyroid disorders were pooled by the R and STATA software. RESULTS: 39 papers with 24,927 MG patients were ultimately included for analysis in this meta-analysis. The pooled estimate of thyroid autoimmunity prevalence in MG patients was 10.1% (95%CI 6.7%-15.1%). Subgroups in patients with thyroid autoimmunity showed the prevalence of positive TGAb was the highest in MG patients (12.6%, 95%CI 8.1%-19.1%), followed by GD (6.0%, 95%CI 4.2%-8.5%), HT (4.6%, 95%CI 1.9%-10.5%). Moreover, the pooled estimated prevalence of thyroid dysfunction in MG patients was 6.8% (95%CI 4.6%-9.8%). After stratification, the results showed the prevalence of hyperthyroidism and hypothyroidism in MG cases were 5.6% (95%CI 3.9%-8.0%) and 2.6% (95%CI 1.7%-4.1%), respectively. In addition, meta-analysis of 2 studies showed that MG was significantly associated with the increased risk of thyroid autoimmunity (OR = 2.86; 95%CI 1.54-5.28, P = .001). CONCLUSIONS: This systemic review and meta-analysis provides reliable evidence that thyroid disorders are prevalent in MG, especially TGAb positivity, GD, hyperthyroidism, and HT, and MG is associated with increased risk for thyroid autoimmunity.

Aberrant Histone Methylation in Patients with Graves' Disease.

BACKGROUND: Graves' disease (GD) is an organ-specific autoimmune disease. Accumulated data have indicated that aberrant epigenetic modifications are associated with many autoimmune disorders. However, it remains unknown whether histone methylation plays a role in the pathogenesis of GD. In the present study, we aimed to assess histone modification patterns in peripheral blood mononuclear cells (PBMCs) from GD patients. The rate (degree) of H3K4 and H3K9 methylation and the expressions of histone-modifying genes were investigated. METHODS: A total of 68 GD patients and 32 healthy controls were enrolled in this study. Global histone H3K4/H3K9 methylation of PBMCs was evaluated by the EpiQuik™ global histone H3K4/H3K9 methylation assay kit. The expressions of histone methyltransferases (HMTs) and histone demethylases (HDMs) at the mRNA level were determined by real-time quantitative polymerase chain reaction. RESULTS: Global histone H3K9 methylation in PBMCs of GD patients was significantly decreased compared with that in the healthy controls (P=0.007). The expressions of HMTs (SUV39H1 and SUV39H2) at the mRNA level were significantly decreased in PBMCs from GD patients compared with healthy controls (P<0.001), whereas the SETD1A expression at the mRNA level was significantly increased in GD patients compared with healthy controls (P=0.004). In addition, the expressions of HDMs, including JHDM2A and JMJD2A, at the mRNA level were significantly increased in GD patients compared with healthy controls (P<0.001; P=0.007). Moreover, the mRNA expression levels of JARID1A and LSD1 did not significantly differ in GD patients and healthy controls (P>0.05). CONCLUSIONS: These findings firstly suggested that the histone methylation was aberrant in PBMCs of GD patients, which could be possibly attributed to the deregulation of epigenetic modifier genes. Abnormal histone methylation modification may be involved in the pathogenesis of GD.

Polymorphisms of FAM167A-BLK Region Confer Risk of Autoimmune Thyroid Disease.

The present study was to explore whether the polymorphisms of FAM167 A-BLK region are associated with the susceptibility to autoimmune thyroid disease (AITD). The second sequencing technology was undertaken for seven tag loci mapping of the FAM167 A-BLK region, namely, rs11250144, rs2618431, rs4840568, rs13277113, rs2248932, rs2736340, and rs922483, in 999 AITD patients, including 624 Graves' disease (GD) and 375 Hashimoto's thyroiditis individuals, and 797 healthy cohorts. In contrast to those in controls, allele C of rs11250144 and allele G of rs2618431 both showed increased frequencies in GD patients. Consistent with this, the frequency of genotype GG in rs2618431 was increased in GD patients. Similarly, compared with that in female controls, allele G of rs2618431 was increased in the female AITD patients. Likewise, the frequency of allele G in rs2618431 obviously declined in the female GD patients. Allele A of rs4840568 linked to the susceptibility of the AITD teenagers. Besides, allele C in rs11250144 was correlated with thyroid-associated ophthalmopathy (TAO). Moreover, allele C in rs11250144 increased the risk to TAO by 56.3%. Genetic variants of FAM167 A-BLK region may contribute to the susceptibility to AITD, which can be added as the genetic candidates for this disease.

Polymorphisms in Autophagy-Related Gene IRGM Are Associated with Susceptibility to Autoimmune Thyroid Diseases.

BACKGROUND: To date, studies have shown that polymorphisms in an autophagy-related gene, IRGM, are linked with different diseases, especially autoimmune diseases. The present study aimed to examine the roles of IRGM polymorphisms in autoimmune thyroid diseases (AITD). METHODS: Three polymorphisms in IRGM gene (rs10065172, rs4958847, and rs13361189) were genotyped in 1569 participants (488 with Graves' disease, 292 with Hashimoto's thyroiditis, and 789 healthy controls) using PCR-based ligase detection reaction method. Gene-disease associations were evaluated for the three SNPs. RESULTS: T allele of rs10065172, A allele of rs4958847, and C allele of rs13361189 were all higher in Graves' disease patients than controls, and the ORs were OR = 1.207 (P = 0.022), OR = 1.207 (P = 0.027), and OR = 1.200 (P = 0.027), respectively. After adjusting for sex and age, rs10065172 and rs13361189 were still associated with GD under both the allele model and dominant model, and the adjusted ORs for rs10065172 were 1.20 (P = 0.033) and 1.33 (P = 0.024), while the adjusted ORs for rs13361189 were 1.19 (P = 0.042) and 1.33 (P = 0.026), respectively. No significant difference was found between Hashimoto's thyroiditis patients and controls. Haplotype analysis found that CTA frequency was distinguishingly higher in Graves' disease patients (OR = 1.195, P = 0.030). The frequency of TCG haplotype was distinguishingly lower in AITD and Graves' disease patients (OR = 0.861, P = 0.044; OR = 0.816, P = 0.017). CONCLUSIONS: Our study reveals IRGM as a susceptibility gene of AITD and Graves' disease for the first time.

Variants of Interleukin-22 Gene Confer Predisposition to Autoimmune Thyroid Disease.

As there are no previous studies on the interleukin-22 (IL-22) variants in autoimmune thyroid disease (AITD), the present study aimed to explore the association between polymorphisms of IL-22 and the predisposition to AITD. The study had 975 AITD patients, including 639 Graves' disease (GD) and 336 Hashimoto's thyroiditis (HT) individuals and 851 healthy cohorts. Ligase detection reaction (LDR) and direct sequencing method were used for genotyping the IL-22 gene polymorphisms at rs2046068, rs2227478, rs2227485, rs11611206, and rs1179251. In comparison to female controls, genotype CC of rs1179251 was increased in the female AITD patients. Alleles C at rs2046068, C at rs2227478, and C at rs1179251 linked to the susceptibility of HT males. Genotype CC in rs1179251 was higher in male HT. Variants at rs2046068, rs2227478, and rs1179251 were associated with the AITD teenagers. Besides, genotype GG in rs11611206 was correlated with thyroid-associated ophthalmopathy (TAO). Moreover, allele G at rs11611206 was associated with decreased risk for TAO by 28.9%. Similarly, genotype CC of rs1179251 and genotype GG of rs11611206 were associated with Graves' ophthalmopathy (GO). Allele G in rs11611206 increased people with HT towards the predisposition of hypothyroidism. In conclusion, genetic variants of IL-22 are associated with the occurrence of AITD.