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.

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 between STAT4 gene polymorphisms and autoimmune thyroid diseases in a Chinese population.

The STAT4 gene encodes a transcriptional factor that transmits signals induced by several key cytokines which play important roles in the development of autoimmune diseases. The aim of this study was to explore the association of STAT4 polymorphism with Graves' disease (GD) and Hashimoto's thyroiditis (HT). A total of 1048 autoimmune thyroid diseases (AITDs) patients (693 with GD and 355 with HT) and 909 age- and gender-matched controls were examined. STAT4 polymorphisms (rs7574865/rs10181656/ rs7572482) were genotyped by multiplex polymerase chain reaction (PCR) and ligase detection reaction (LDR). The results indicated that the frequencies of rs7574865 genotypes in patients with GD differed significantly from the controls (p=0.028), the T allele frequency of GD patients was also significantly higher than the controls (p=0.020). The genotypes of rs10181656 differed significantly in GD patients from controls (p=0.012); G allele frequencies were significantly higher in AITD patients than the controls (p=0.014 and 0.031, respectively). The frequencies of haplotype GC with GD and HT patients were significantly lower than their controls (p=0.015 and 0.030, respectively). In contrast, the frequencies of haplotype TG with GD and HT patients were significantly higher than their controls (p=0.016 and 0.048, respectively). These findings strongly suggest that STAT4 rs7574865/rs10181656 polymorphisms increase the risk of AITD in a Chinese population.

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.

Polymorphisms of interleukin-21 and interleukin-21-receptor genes confer risk for autoimmune thyroid diseases.

BACKGROUND: The abnormality of interleukin-21 (IL-21)-IL-21-receptor (IL-21R) system has been found in many autoimmune diseases including autoimmune thyroid diseases (AITDs). In this study, we investigated whether polymorphisms of the IL-21 and IL-21R are associated with Graves' disease (GD) and Hashimoto's thyroiditis (HT), two major forms of AITDs, among a Chinese population. METHODS: Rs907715, rs4833837, rs2221903 and rs2055979 of the IL-21 gene and rs3093301 and rs2285452 of the IL-21R gene were explored in a case-control study including 405 GD, 228 HT patients and 242 controls. These genes were genotyped by the PCR and restriction fragment length polymorphism (RFLP) analysis and the MASS spectrometry method. RESULTS: For IL-21 gene, we identified and confirmed a higher prevalence of A alleles of rs2221903 (P = 0.018, OR = 1.50 95% CI = 1.07-2.09) in GD patients. We also found a significant association between rs2221903 and HT (allele: P = 0.009, OR = 1.69 95% CI = 1.13-2.51; genotype: recessive P = 0.021, OR = 11.72 95% CI = 1.46-94.13). For the IL-21R gene, compared with controls, the genotype frequencies of rs3093301 and rs2285452 were significantly different in HT patients using dominant genetic model (P = 0.023, OR = 1.61 95% CI = 1.07-2.42; P = 0.031, OR = 1.71 95% CI = 1.05-2.80, respectively). Furthermore, the haplotype AA containing the major alleles of rs4833837 and rs2221903 was associated with increased susceptibility to GD with an OR of 1.50(95% CI =1.08-2.09, P = 0.016), and to HT with an OR of 1.69(95% CI =1.14-2.52, P = 0.009). CONCLUSION: Our results indicated that the SNPs of the IL-21 gene is associated with the development of GD. In addition, we found that individuals with the SNPs of the common IL-21 and IL-21R may have higher risk of HT.

Proteomic analysis reveals aberrant expression of CALR and HSPA5 in thyroid tissues of Graves' disease.

OBJECTIVES: To explore the proteomic changes in thyroid tissue from GD patients and find new biomarkers for the prevention, diagnosis as well as the treatment of GD. DESIGN AND METHODS: Group1 included five thyroid specimens of GD cases and 5 normal thyroid tissue samples which were removed surgically and collected. The proteins were extracted from these thyroid tissues and then the differentially expressed protein spots were identified by MALDI-TOF-MS. The interested proteins were further validated in more specimens (group2: 11 pathological thyroid specimens and 7 normal thyroid tissue samples). RESULTS: A total of 34 differentially expressed proteins were observed, and the majority of these proteins were involved in endoplasmic reticulum stress (ER-stress), oxidative stress, energy metabolism, cytoskeleton and movement. The overexpression of calreticulin(CALR) and heat shock 70kDa protein 5(HSPA5) was further validated. CONCLUSION: Alltogether, abundant new candidate molecules, especially proteins related to ER-stress, were found to be involved in the pathogenesis of GD.

Variants in IRAK1-MECP2 region confer susceptibility to autoimmune thyroid diseases.

Our objective was to investigate whether interleukin-1 receptor-associated kinase (IRAK1) and methyl-CpG-binding protein 2 (MECP2) are associated with autoimmune thyroid diseases (AITDs). We selected four single nucleotide polymorphisms (SNPs), rs3027898, rs1059703 in IRAK1 and rs2075596, rs2239464 in MECP2, for genotyping using PCR-based ligase detection reaction (LDR) method in 1042 AITDs patients and 897 controls. Minor alleles in the four SNPs were strongly associated with AITDs, and similar associations were found in Graves' disease (GD). In Hashimoto's thyroiditis (HT) patients, a significantly increased risk of T allele in rs1059703 was found. There were obvious differences in allele and genotype distributions in female AITDs, GD and HT patients. Moreover, the haplotypes CCAA and ATGG were the associated variants for AITDs and GD. Besides, these two haplotypes showed similar associations with AITDs and GD in female patients. Our results firstly indicated that IRAK1 and MECP2 genes are crucial risk factors for AITDs.

Histone hypoacetylation and increased histone deacetylases in peripheral blood mononuclear cells from patients with Graves' disease.

The objective of this study was to investigate histone modification patterns in peripheral blood mononuclear cells (PBMCs) of patients with Graves' disease (GD). Thirty GD patients and 20 healthy controls were enrolled in this study. Global histone H3/H4 acetylation levels of PBMCs in all subjects were detected by enzyme-linked immunosorbent assay. mRNA levels of histone-related chromatin modifier genes were measured by real-time quantitative reverse transcription-polymerase chain reaction. Global histone H4 acetylation level in PBMCs of GD patients was significantly decreased compared with controls (p=0.005). The mRNA expression of histone deacetylases HDAC1 and HDAC2 were significantly increased in PBMCs of GD patients compared with controls (p=0.004 and 0.018; respectively). No significant difference was observed either in SIRT1 or in HATs mRNA including p300, CREBBP between GD patients and controls (p>0.05). Our findings firstly suggested that histone acetylation modifications are aberrant in PBMCs of GD patients, possibly due to the deregulation of epigenetic modifier genes.

Lack of association between polymorphisms in the UBASH3A gene and autoimmune thyroid disease: a case control study.

OBJECTIVE: The aim of this study was to investigate UBASH3A gene variation association with autoimmune thyroid disease and clinical features in a Chinese Han population. SUBJECTS AND METHODS: A total of 667 AITD patients (417 GD and 250 HT) and 301 healthy controls were genotyped for two single nucleotide polymorphisms (SNPs) rs11203203, rs3788013 of UBASH3A gene, utilizing the Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF-MS) Platform. RESULTS: Between the control group and AITD, GD and HT group, no statistically significant difference was observed in the genotypic and allelic frequencies of the two SNPs. There was no significant difference in allelic frequencies of the two SNPs between GD with and without ophthalmopathy. There was no significant difference in haplotype distributions between the control group and AITD, GD or HT group. CONCLUSION: Rs11203203 and rs3788013 in UBASH3A gene may not be associated with AITD patients in Chinese Han population.

Polymorphisms of CLEC16A region and autoimmune thyroid diseases.

To investigate the association of CLEC16A gene polymorphisms and autoimmune thyroid diseases (AITDs). Six hundred sixty seven Han Chinese patients with AITDs were selected as study subjects, including 417 patients with Graves' disease (GD), 250 patients with Hashimoto's thyroiditis (HT) and 301 healthy control patients. Polymerase chain reaction-restriction fragment length polymorphism (RFLP) and the mass spectrometry technique were used to genotype five CLEC16A single-nucleotide polymorphisms (SNPs) (rs12708716, rs12917716, rs12931878, rs2903692, and rs6498169). Higher frequency of G allele of rs6498169 CLEC16A gene in AITDs patients [P = 0.029, odds ratio (OR) 1.29 and 95% confidence interval 1.022-1.505] was observed. In addition an association between rs6498169 and HT was observed with statistical significance (P = 0.018, OR 1.335, 95% confidence interval 1.051-1.696). Furthermore, the GG haplotype containing the major allele of (rs12708716 and rs6498169) was associated with an increased risk of HT (P = 0.0148, OR 1.344). When patients with HT and controls were compared, results from the dominant and recessive models showed that the genotype frequency of rs6498169 were at borderline levels (P = 0.054 and P = 0.05), and the other four SNPs of CLEC16A gene showed no significant association with AITDs. Our results suggest that polymorphisms rs6498169 of CLEC16A gene confers susceptibility to AITDs. We therefore disclose for the first time the association of rs6498169 SNP with AITDs.

Lack of association of IRF5 gene polymorphisms with autoimmune thyroid disease: a case-control study. IRF5 gene and AITD.

BACKGROUND: Several studies support a link between autoimmunity and interferon regulatory factor 5 (IRF5) gene polymorphisms. We have taken the opportunity to examine association of the autoimmune disease risk gene, the interferon regulatory factor 5 (IRF5) to survey its susceptibility to autoimmune thyroid disease. "A total of 667 patients with autoimmune thyroid diseases and 301 healthy controls were genotyped for rs10954213, rs2004640, rs3807306, rs752637 and rs7808907 of IRF5 gene polymorphisms". We further investigated the association between BANK1 gene and IRF5 gene in AITD patients. RESULTS: For IRF5 gene, both in allele and genotype frequencies from both GD and HT patients were not significantly different from those of controls. Association between rs7808907C allele and Graves' disease showed trend towards significance (P=0.067). Haplotype results in IRF5 represented in the same block, without significant association. No significant association was found between all IRF5 SNPs and ophthalmopathy in Graves' patients. Additive interaction analysis revealed no interactions between IRF5 and BANK1 gene in AITD patients. CONCLUSION: Our data fail to reveal IRF5 as a susceptibility gene to AITD and do not support additive effect of IRF5 to BANK1 gene.

Different levels of circulating Th22 cell and its related molecules in Graves' disease and Hashimoto's thyroiditis.

PURPOSE: The aim of this study was to make a comparative analysis of the possible different expression of Th22 cells in two subtypes of autoimmune thyroid diseases (AITDs), i.e., Graves' disease (GD) and Hashimoto's thyroiditis (HT). METHODS: We recruited 61 AITDs patients (31 GD and 30 HT) and 22 controls. Serum level of IL-22 was measured by enzyme linked immunosorbent assay (ELISA). The proportion of Th22 cells in peripheral blood mononuclear cells (PBMCs) was analyzed by flow cytometry. The messenger RNA (mRNA) expressions of IL-22, its receptors (IL10R2, IL22R1) and key transcription factor (aryl hydrocarbon receptor, AHR) in PBMCs were assayed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Several cytokines of the cultured PBMCs were also measured under IL-22 stimulation. RESULTS: The proportion of Th22 cells, serum IL22 level and IL-22 mRNA expression were significantly higher in patients with GD than in healthy controls. Additionally, AHR increased in GD patients compared to healthy controls. However, the elevation of Th22 cells and their relative cytokines was not found in patients with HT. Consistent with specific mRNAs expression of cultured PBMCs, IL-4 increment in supernatant was much higher in GD group than in control group, while IFN-γ levels were decreased under IL-22 stimulation. CONCLUSION: Th22 cells may participate in the pathogenesis of AITDs as a proinflammatory factor, especially in GD, through expressing and secreting IL-22.

Polymorphisms of the TNFAIP3 region and Graves' disease.

Autoimmune thyroid disease (AITD) is a multifactorial organ-specific autoimmune disorder, and both genetic susceptibility and environmental factors are involved in its etiology. TNFAIP3 encodes the ubiquitin-modifying enzyme (A20), a key regulator of inflammatory signaling pathways. The aim of the present study was to evaluate the association between TNFAIP3 gene polymorphisms and AITD in Chinese Han population. Three single nucleotide polymorphisms (SNPs) in TNFAIP3 gene locus (rs598493, rs610604 and rs661561) were detected in a set of 667 patients with AITD and 301 controls in Han Chinese population using the Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF-MS) Platform. Compared with those of the controls, the frequencies of GG genotype of rs598493, the AA genotype of rs610604, the allele G and GG genotype of rs661561 were significantly increased in Graves' disease (GD) patients. However, the frequencies of AG genotype of rs598493 and AC genotype of rs610604 were significantly decreased in GD patients. The ATC haplotype (rs598493, rs661561 and rs610604) was associated with a decreased risk of GD. No significant differences in the three SNPs were observed between HT patients and controls. Our study shows a clear association between the polymorphisms of TNFAIP3 gene and GD, not HT, suggesting that TNFAIP3 gene is likely to be a genetic susceptibility factor to GD.

Lack of association between polymorphisms in the UBASH3A gene and autoimmune thyroid disease: a case control study / Falta de associação entre polimorfismos do gene UBASH3A e doença tiroidiana autoimune: estudo caso controle

Objective: The aim of this study was to investigate UBASH3A gene variation association with autoimmune thyroid disease and clinical features in a Chinese Han population. Subjects and methods: A total of 667 AITD patients (417 GD and 250 HT) and 301 healthy controls were genotyped for two single nucleotide polymorphisms (SNPs) rs11203203, rs3788013 of UBASH3A gene, utilizing the Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometer (MALDI-TOF-MS) Platform. Results: Between the control group and AITD, GD and HT group, no statistically significant difference was observed in the genotypic and allelic frequencies of the two SNPs. There was no significant difference in allelic frequencies of the two SNPs between GD with and without ophthalmopathy. There was no significant difference in haplotype distributions between the control group and AITD, GD or HT group. Conclusion: Rs11203203 and rs3788013 in UBASH3A gene may not be associated with AITD patients in Chinese Han population. .

Objetivo: O objetivo deste estudo foi investigar a variação no gene UBASH3A com a doença tiroidiana autoimune e características clínicas na população chinesa Han. Sujeitos e métodos: Um total de 667 pacientes com DTAI (417 com DG e 250 com TH) e 301 controles saudáveis foi genotipado para dois polimorfismos de nucleotídeo simples (SNPs) rs11203203, rs3788013 do gene UBASH3A, usando-se a plataforma MALDI-TOF-MS (Ionização/Dessorção de Matriz Assistida por Laser – Tempo de Voo/Espectrômetro de Massa). Resultados: Não foram observadas diferenças significativas entre as frequências genotípicas e alélicas dos dois SNPs nos grupos controle e DTAI, DG e TH. Não houve diferenças significativas entre as frequências alélicas dos dois SNPs em pacientes com DG com ou sem olftalmopatia. Não houve diferenças significativas nas distribuições de haplótipos no grupo controle e nos grupos DTAI, DG e TH. Conclusão: Os SNPs rs11203203 e rs3788013 do gene UBASH3A podem não estar associados a pacientes com DTAI na população chinesa Han. .