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

Genetics, Epigenetics, Cellular Immunology, and Gut Microbiota: Emerging Links With Graves' Disease

Graves’ disease (GD) is a well-known organ-specific autoimmune disease characterized by hyperthyroidism, goiter, and exophthalmos. The incidence of GD is approximately 2.0–3.0% in China and 0.5–2.0% in Western countries. Due to the complex pathogenesis and etiology of GD, current treatment methods have great side effects that seriously endanger human health. Therefore, it is particularly important to understand the pathogenesis of GD. Various studies have shown that genetics, epigenetics, cellular immunology, and gut microbiota are all involved in the development of GD. Genetically, CD25 gene and VDR gene polymorphisms are involved in the development of GD by increasing the ratio of Th17/Treg cells. Epigenetically, miR-23a-3p and lncRNA-MEG3 lead to Th17/Treg imbalance and participate in the progression of GD. Moreover, commensal microbe deletion can disrupt Th17/Treg balance and participate in the occurrence of GD. The imbalance of Th17/Treg cells induced by genetics, epigenetics, and gut microbiota plays a vital role in the pathogenesis of GD. Therefore, this article reviews the role of genetics, epigenetics, cellular immunology, and gut microbiota in the pathogenic mechanism of GD. This may lead to the development of novel therapeutic strategies and providing promising therapeutic targets.

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.

A Risk Score Model Based on Nine Differentially Methylated mRNAs for Predicting Prognosis of Patients with Clear Cell Renal Cell Carcinoma

Purpose

DNA methylation alterations play important roles in initiation and progression of clear cell renal cell carcinoma (ccRCC). In this study, we attempted to identify differentially methylated mRNA signatures with prognostic value for ccRCC.

Methods

The mRNA methylation and expression profiling data of 306 ccRCC tumors were downloaded from The Cancer Genome Atlas (TCGA) to screen differentially methylated lncRNAs and mRNAs (DMLs and DMMs) between bad and good prognosis patients. Uni- and multivariable Cox regression analyses and LASSO Cox-PH regression analysis were used to select prognostic lncRNAs and mRNAs. Corresponding risk scores were calculated and compared for predictive performance in the training set using Kaplan-Meier OS and ROC curve analyses. The optimal risk score was then identified and validated in the validation set. Function enrichment analysis was conducted.

Results

This study screened 461 DMMs and 63 DMLs between good prognosis and bad prognosis patients, and furthermore, nine mRNAs and six lncRNAs were identified as potential prognostic molecules. Compared to nine-mRNA status risk score model, six-lncRNA methylation risk score model, and six-lncRNA status risk score model, the nine-mRNA methylation risk score model showed superiority for prognosis stratification of ccRCC patients in the training set. The prognostic ability of the nine-mRNA methylation risk score model was validated in the validation set. The nine prognostic mRNAs were functionally associated with neuroactive ligand receptor interaction and inflammation-related pathways.

Conclusion

The nine-mRNA methylation signature (DMRTA2, DRGX, FAM167A, FGGY, FOXI2, KRTAP2-1, TCTEX1D1, TTBK1, and UBE2QL1) may be a useful prognostic biomarker and tool for ccRCC patients. The present results would be helpful to elucidate the possible pathogenesis of ccRCC.

An update on genetic susceptibility in lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multiple system involvement and positive serum autoantibodies. Lupus nephritis (LN) is the most common and serious complication of SLE, and it is the main cause of death in patients with SLE. Abnormalities in the immune system lead to LN and involve a variety of cells (T cells, B cells, macrophages, NK cells, etc.), cytokines (interleukin, tumor necrosis factor α, etc.) and their related pathways. Previous studies have shown that the interactions of genetic, epigenetic and environmental factors contribute to the pathogenesis and development of LN. In recent years, one genome-wide association study (GWAS) and a number of gene association studies have explored the susceptibility genes of LN, including immunization-, inflammation-, adhesion- and other pathway-related genes. These genes participate in or suggest the pathogenesis and progression of LN. In this review, we summarize the genetic susceptibility of LN and discuss the possible mechanism underlying the susceptibility genes of LN.

An update on genetic susceptibility in lupus nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by multiple system involvement and positive serum autoantibodies. Lupus nephritis (LN) is the most common and serious complication of SLE, and it is the main cause of death in patients with SLE. Abnormalities in the immune system lead to LN and involve a variety of cells (T cells, B cells, macrophages, NK cells, etc.), cytokines (interleukin, tumor necrosis factor α, etc.) and their related pathways. Previous studies have shown that the interactions of genetic, epigenetic and environmental factors contribute to the pathogenesis and development of LN. In recent years, one genome-wide association study (GWAS) and a number of gene association studies have explored the susceptibility genes of LN, including immunization-, inflammation-, adhesion- and other pathway-related genes. These genes participate in or suggest the pathogenesis and progression of LN. In this review, we summarize the genetic susceptibility of LN and discuss the possible mechanism underlying the susceptibility genes of LN.