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 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.

Helicobacter pylori plays a key role in gastric adenocarcinoma induced by spasmolytic polypeptide-expressing metaplasia.

Heliobacter pylori (H. pylori), a group 1 human gastric carcinogen, is significantly associated with chronic gastritis, gastric mucosal atrophy, and gastric cancer. Approximately 20% of patients infected with H. pylori develop precancerous lesions, among which metaplasia is the most critical. Except for intestinal metaplasia (IM), which is characterized by goblet cells appearing in the stomach glands, one type of mucous cell metaplasia, spasmolytic polypeptide-expressing metaplasia (SPEM), has attracted much attention. Epidemiological and clinicopathological studies suggest that SPEM may be more strongly linked to gastric adenocarcinoma than IM. SPEM, characterized by abnormal expression of trefoil factor 2, mucin 6, and Griffonia simplicifolia lectin II in the deep glands of the stomach, is caused by acute injury or inflammation. Although it is generally believed that the loss of parietal cells alone is a sufficient and direct cause of SPEM, further in-depth studies have revealed the critical role of immunosignals. There is controversy regarding whether SPEM cells originate from the transdifferentiation of mature chief cells or professional progenitors. SPEM plays a functional role in the repair of gastric epithelial injury. However, chronic inflammation and immune responses caused by H. pylori infection can induce further progression of SPEM to IM, dysplasia, and adenocarcinoma. SPEM cells upregulate the expression of whey acidic protein 4-disulfide core domain protein 2 and CD44 variant 9, which recruit M2 macrophages to the wound. Studies have revealed that interleukin-33, the most significantly upregulated cytokine in macrophages, promotes SPEM toward more advanced metaplasia. Overall, more effort is needed to reveal the specific mechanism of SPEM malignant progression driven by H. pylori infection.

Dual-product synergistically enhanced ratiometric fluorescence assay for alkaline phosphatase activity using core-shell lanthanide-based nanoprobe.

We developed a new core-shell ratiometric fluorescent nanoprobe simply prepared by a seeded growth method. The strong luminescence arising from the shell formed by coordination self-assembly of an alkaline phosphatase (ALP) substrate, l-ascorbic acid 2-phosphate (AAP), and Tb3+, together with the weak fluorescence of the core-a metal-organic framework, UiO-66-NH2, constitutes an ideal dual-emission characteristic. Since AAP can be specifically cleaved by ALP, the well-formulated core-shell nanostructure was destroyed upon exposure to ALP. In this case, the luminescence of Tb3+ was quenched due to the inefficient antenna effect, while the fluorescence of UiO-66-NH2 was strengthened by the synergistical enhancement of dual hydrolysates to inhibit the ligand-to-metal charge transfer (LMCT) process. Using the dual signal response, this nanoprobe was employed for ratiometric fluorescence detection of ALP activity in the range of 0.05-0.6 U mL-1 with a detection limit of 0.018 U mL-1, accompanied by a discernible fluorescence color evolution from turquoise to blue. In virtue of good properties in accuracy, sensitivity, selectivity and simplicity, this assay enabled quantitative detection of ALP activity in human serum and efficient screening of ALP inhibitors. More Importantly, a smartphone-assisted paper-based sensing platform was designed for on-site visual analysis of ALP activity in human serum, which may be very promising as a facile, portable, and robust format to facilitate relevant biological and clinical applications.

The thrombodynamic ratio as a predictor of 28-day mortality in sepsis patients.

BACKGROUND: The thrombodynamic ratio (TDR) as a composite thromboelastography (TEG) parameter, has been proven to be valuable in multiple diseases. However, the association between TDR and mortality in sepsis has not been studied. METHODS: One hundred forty-one patients were enrolled in this retrospectively study. TEG was performed immediately at admission. Two cox proportional hazards models were developed for the prediction of 28-day mortality. The C statistic, continuous net reclassification index (cNRI) and integrated discriminatory index (IDI) were calculated to compare the discrimination performance of clinical models with and without the TDR value. The integrated calibration index (ICI) and E50 were calculated to compare the calibration. RESULTS: Patients with lower TDR were more likely to have organ impairments and increased 28-day mortality. The TDR value improved discrimination performance in both Model 1 (C statistic, 0.745 vs 0.735; cNRI 19.4%, p = 0.044; IDI 5.6%, p = 0.012) and Model 2 (C statistic, 0.761 vs 0.751; IDI, 5.1%, p = 0.012). Compared to the calibration curve of Model 1 without TDR, addition of TDR displayed better calibration (ICI, 0.023; E50, 0.021). CONCLUSION: TDR value significantly predicts 28-day mortality in patients with sepsis and could improve the discrimination and calibration performance of clinical prediction models.

Association of ANKRD55 Gene Polymorphism with HT: A Protective Factor for Disease Susceptibility.

Purpose: Recent studies have shown that Ankyrin Repeat Domain 55 (ANKRD55) gene polymorphism is a risk factor for multiple autoimmune diseases, but its association with autoimmune thyroid diseases (AITDs) has not been reported. The purpose of this study was to investigate the potential relationship between polymorphism of the ANKRD55 gene and AITDs. Methods: For this study, we enrolled 2050 subjects, consisting of 1220 patients with AITD and 830 healthy subjects. Five loci (rs321776, rs191205, rs7731626, rs415407, and rs159572) of the ANKRD55 gene were genotyped using Multiplex PCR combined with high-throughput sequencing. Results: The results showed that the allele frequencies of rs7731626 and rs159572 loci in HT patients were lower than those in normal controls (P=0.048 and P=0.03, respectively). In different genetic model analyses, rs7731626 and rs159572 were also significantly correlated with HT in allele, dominant and additive models before and after age and sex adjustment. There were no differences in rs321776, rs191205, or rs415407 of the ANKRD55 gene in allele frequency or genotype frequency between AITDs patients and controls. Conclusions: This study for the first time found that rs7731626 and rs159572 of ANKRD55 were significantly correlated with HT, and individuals carrying the A allele at these two loci had a lower probability of developing HT.

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.

Synthesis, biological evaluation of chrysin derivatives as potential immunosuppressive agents.

A series of novel chrysin derivatives was firstly synthesized and evaluated on their immunosuppressive activity in the search for potential immunosuppressive agents. Among them, compounds 5c displayed the most potent immunosuppressive inhibitory activity with IC(50) of 0.78 µM, which was comparable to that of cyclosporin A (IC(50) = 0.06 µM). The preliminary mechanism of compound 5c inhibition effects was also detected by flow cytometry (FCM), and the compound exerted immunosuppressive activity via inducing the apoptosis of activated lymph node cells in a dose dependent manner. Furthermore, the estimated LD(50) (in mg/kg) in vivo of compound 5c is 738.2, which indicated that compound 5c was low toxic.

Novel immunomodulatory properties of cirsilineol through selective inhibition of IFN-gamma signaling in a murine model of inflammatory bowel disease.

Regulation of signal transducer and activator of transcription (STAT) 1 signaling is being explored as a new approach to the treatment of inflammatory bowel diseases. However, few chemicals have been reported to inhibit IFN-gamma/STAT1 signaling for Crohn's disease therapy. In the present study, we found that cirsilineol, a small natural compound isolated from Artemisia vestita, significantly ameliorated trinitro-benzene sulfonic acid (TNBS)-induced T-cell-mediated experimental colitis in mice, which was closely associated with reduced autoreactive T-cell proliferation and activation. Moreover, the regulatory action of pro-inflammatory and anti-inflammatory cytokine by cirsilineol treatment was found to decrease the activity of effector Th1 cells but increase the activity of regulatory T cells as characterized by down-regulation of IFN-gamma and corresponding up-regulation of IL-10 and TGF-beta. The therapeutic effect of cirsilineol was attributable to a novel regulatory mechanism with selective inhibiting IFN-gamma signaling in colonic lamina propria CD4(+) T cells, which was mediated through down-regulating STAT1 activation and T-bet expression. Furthermore, cirsilineol was found to down-regulate the activation of JAK2, a critical kinase for IFN-gamma/STAT1 signaling, and abrogate the expression of T-bet, resulting in markedly decreased proliferation and activation of T cells in vitro. Importantly, the inhibition of IFN-gamma/STAT1 signaling by cirsilineol was reversible in the presence of high level of IFN-gamma. These results strongly suggest that cirsilineol might be potentially useful for treating T-cell-mediated human inflammatory bowel diseases.

Saikosaponin a inhibits the proliferation and activation of T cells through cell cycle arrest and induction of apoptosis.

In the present study, we aimed at examining the immunosuppressive activity of saikosaponin a, a triterpene saponin derived from Bupleurum falcatum L. (Umbelliferae), and the underlying mechanisms. Saikosaponin a significantly inhibited the proliferation and activation of T cells activated by concanavalin A (Con A) in a concentration-dependent manner. Additionally, it potently suppressed Con A-stimulated IL-2, IFN-gamma and TNF-alpha production in mouse T cells. Saikosaponin a also caused G0/G1 arrest of activated T cells through down-regulating the protein levels of CDK6 and Cyclin D3 and up-regulating the protein level of p27(kip). Furthermore, the compound dose-dependently induced apoptosis of Con A-activated T cells rather than those non-activated, as determined by Annexin V/PI staining. Besides, it induced a remarkable collapse of mitochondrial membrane potential and caused significant release of cytochrome c from mitochondria to cytosol. In summary, these results suggest that the G0/G1 arrest as well as the induction of apoptosis via mitochondrial pathway are involved in the immunosuppressive activity of saikosaponin a against activated T cells. This may herald a novel approach for further studies of saikosaponin a as a candidate for the treatment of inflammatory and autoimmune diseases.

Dissection of the role of paeoniflorin in the traditional Chinese medicinal formula Si-Ni-San against contact dermatitis in mice.

AIMS: The roles of specific active ingredients in Chinese medicinal formulas have not been clearly elucidated. In this study, we selectively deleted and replenished paeoniflorin from Si-Ni-San, a traditional Chinese prescription, and aimed to identify the molecular basis of how paeoniflorin exerted its effect in Si-Ni-San. MAIN METHODS: Contact dermatitis was induced in mice with picryl chloride. Paeoniflorin was selectively deleted from Si-Ni-San by an immunoaffinity column. Quantitative real-time PCR, western blot, and enzyme-linked immunosorbent assay were used in this study. KEY FINDINGS: Both Si-Ni-San and paeoniflorin significantly reduced ear swelling in mice while the paeoniflorin-deleted Si-Ni-San (Si-Ni-San(PF-)) showed little ameliorative effect. In lipopolysaccharide-evoked macrophages, Si-Ni-San and paeoniflorin markedly inhibited tumor necrosis factor-alpha production, cyclooxygenase-2 activity, as well as extracellular signal-regulated kinase 1/2 phosphorylation while Si-Ni-San(PF-) exhibited no or slight inhibitory effect. Furthermore, the inhibitory effect on the production of tumor necrosis factor-alpha reappeared when different proportions of paeoniflorin were replenished in Si-Ni-San(PF-). In addition, the expression of macrophage migration inhibitory factor in T cells, rather than macrophages, was significantly inhibited by Si-Ni-San, but not Si-Ni-San(PF-). Our data indicate paeoniflorin is the principal component of Si-Ni-San, exerting negative regulation on the function of macrophages in contact dermatitis. SIGNIFICANCE: The present study suggests that dissecting the role of specific constituents in medicinal formulas through selective deletion and replenishment may be a useful strategy in recognizing and validating an active ingredient in traditional Chinese medicine.

Si-Ni-San, a traditional Chinese prescription, and its active ingredient glycyrrhizin ameliorate experimental colitis through regulating cytokine balance.

Si-Ni-San, a traditional Chinese medicinal formula, exerts an important function in the treatment of inflammatory bowel diseases based upon thousands of years of clinical practice, but the underlying mechanism is still unclear. In this study, we investigated the therapeutic potential of Si-Ni-San and its ingredient glycyrrhizin in trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis in mice, a well-characterized murine model for Crohn's disease. Si-Ni-San and glycyrrhizin significantly ameliorated TNBS-induced colitis with reduced mortality and recovery of body weights. In addition, Si-Ni-San and glycyrrhizin dose-dependently decreased macroscopic inflammation scores, microscopic histological scores, and myeloperoxidase activity. Furthermore, Si-Ni-San and glycyrrhizin caused a decrease in pro-inflammatory cytokines including IFN-gamma, IL-12, TNF-alpha and IL-17 and an increase in regulatory cytokine IL-10 in colon of the mice. It should be noticed the therapeutic effect of Si-Ni-San at 450 mg/kg was much better than that of its contained content of glycyrrhizin at 10 mg/kg. In conclusion, Si-Ni-San and glycyrrhizin significantly ameliorated TNBS-induced colitis in mice through regulating pro- and anti-inflammatory cytokine production.