Pathogenesis Of Graves' Ophthalmopathy Research Articles

A Review of Pathophysiology and Therapeutic Strategies Targeting TGF-β in Graves' Ophthalmopathy.

TGF-β plays a pivotal role in the pathogenesis of GO by promoting orbital tissue remodeling and fibrosis. This process involves the stimulation of orbital fibroblasts, leading to myofibroblast differentiation, increased production of inflammatory mediators, and hyaluronan accumulation. Studies have elucidated TGF-β's role in driving fibrosis and scarring processes through both canonical and non-canonical pathways, particularly resulting in the activation of orbital myofibroblasts and the excessive accumulation of extracellular matrix. Additionally, recent in vitro and in vivo studies have been summarized, highlighting the therapeutic potential of targeting TGF-β signaling pathways, which may offer promising treatment interventions for GO. This review aims to consolidate the current understanding of the multifaceted role of TGF-β in the molecular and cellular pathophysiology in Graves' ophthalmopathy (GO) by exploring its contributions to fibrosis, inflammation, and immune dysregulation. Additionally, the review investigates the therapeutic potential of inhibiting TGF-β signaling pathways as a strategy for treating GO.

Comparison of orbital fibroblasts from Graves’ ophthalmopathy and healthy control

Graves' ophthalmopathy (GO) is an extrathyroidal manifestation of Graves' disease, Orbital fibroblasts (OFs) are recognized as key players in GO pathogenesis, involved in orbital inflammation, tissue remodeling, and fibrosis. This study offers a primary exploration of cell behavior and characteristics on OFs from GO (GO-OFs), and compared to OFs from healthy control (HC-OFs). Results reveal that GO-OFs exhibit delayed migration from tissue fragments, while no significant difference in cell proliferation is observed between GO-OFs and HC-OFs. Aberrant expression pattern of surface proteins Thy-1, TSHR, and IGF-1R suggests shared autoantigens and pathways between GO and GD, contributing to inflammation and fibrosis. Investigations into cytokine responses unveil elevated secretion of hyaluronic acid (HA) and prostaglandin E2 (PGE2) in GO-OFs, emphasizing their role in tissue remodeling. These findings deepen our understanding of OFs in GO pathogenesis, offering potential therapeutic avenues.

Current and promising therapies based on the pathogenesis of Graves' ophthalmopathy.

Graves' ophthalmopathy (GO) is a hyperthyroidism-related and immune-mediated disease that poses a significant threat to human health. The pathogenesis of GO primarily involves T cells, B cells, and fibroblasts, suggesting a pivotal role for the thyrotropin-antibody-immunocyte-fibroblast axis. Traditional treatment approaches for Graves' disease (GD) or GO encompass antithyroid drugs (ATDs), radioactive iodine, and beta-blockers. However, despite decades of treatment, there has been limited improvement in the global incidence of GO. In recent years, promising therapies, including immunotherapy, have emerged as leading contenders, demonstrating substantial benefits in clinical trials by inhibiting the activation of immune cells like Th1 and B cells. Furthermore, the impact of diet, gut microbiota, and metabolites on GO regulation has been recognized, suggesting the potential of non-pharmaceutical interventions. Moreover, as traditional Chinese medicine (TCM) components have been extensively explored and have shown effective results in treating autoimmune diseases, remarkable progress has been achieved in managing GO with TCM. In this review, we elucidate the pathogenesis of GO, summarize current and prospective therapies for GO, and delve into the mechanisms and prospects of TCM in its treatment.

Construction of predictive ceRNA network and identification of the patterns of immune cells infiltrated in Graves' ophthalmopathy.

Graves' ophthalmopathy (GO) is a multifactorial disease, and the mechanism of non coding RNA interactions and inflammatory cell infiltration patterns are not fully understood. This study aims to construct a competing endogenous RNA (ceRNA) network for this disease and clarify the infiltration patterns of inflammatory cells in orbital tissue to further explore the pathogenesis of GO. The differentially expressed genes were identified using the GEO2R analysis tool. The Kyoto encyclopedia of genes and genomes (KEGG) and gene ontology analysis were used to analyze differential genes. RNA interaction relationships were extracted from the RNA interactome database. Protein-protein interactions were identified using the STRING database and were visualized using Cytoscape. StarBase, miRcode, and DIANA-LncBase Experimental v.2 were used to construct ceRNA networks together with their interacted non-coding RNA. The CIBERSORT algorithm was used to detect the patterns of infiltrating immune cells in GO using R software. A total of 114 differentially expressed genes for GO and 121 pathways were detected using both the KEGG and gene ontology enrichment analysis. Four hub genes (SRSF6, DDX5, HNRNPC,and HNRNPM) were extracted from protein-protein interaction using cytoHubba in Cytoscape, 104 nodes and 142 edges were extracted, and a ceRNA network was identified (MALAT1-MIR21-DDX5). The results of immune cell analysis showed that in GO, the proportions of CD8+ T cells and CD4+ memory resting T cells were upregulated and downregulated, respectively. The proportion of CD4 memory resting T cells was positively correlated with the expression of MALAT1, MIR21, and DDX5. This study has constructed a ceRNA regulatory network (MALAT1-MIR21-DDX5) in GO orbital tissue, clarifying the downregulation of the proportion of CD4+ stationary memory T cells and their positive regulatory relationship with ceRNA components, further revealing the pathogenesis of GO.

Establishment and Comparison of Two Different Animal Models of Graves' Orbitopathy.

The purpose of this study was to construct an animal model of Graves' ophthalmopathy (GO) by comparing recombinant adenovirus expressing human thyrotropin receptor A subunit (Ad-TSHR A) gene immunization and dendritic cell (DC) immunization. We evaluated the animal models that are closer to the pathology of human GO, and laid the foundation for the study of GO. Ad-TSHR A was injected intramuscularly into female BALB/c mice to induce the GO animal model. A GO animal model was constructed using TSHR combined with IFN-γ-modified primary DC immunized female BALB/c. The animal models constructed by the above two methods were evaluated in terms of ocular appearance, serology, pathology, and imaging to assess the modeling rate of the animal models, respectively. Both modeled mice exhibited increased serological indexes of free thyroxine (FT4) and TSH receptor antibodies (TRAbs) levels and decreased TSH (P < 0.01). Thyroid pathology analysis revealed the number of thyroid follicles increases, the size varies, and the follicular epithelial cells proliferate to varying degrees in a cuboidal or tall columnar pattern, with a small amount of lymphocytic infiltration visible. Adipose tissue behind the eyeball was accumulated, the muscle outside the eyeball was broken and fibrotic, and hyaluronic acid (HA) behind the eyeball was increased. The animal model of GO constructed by immunization of TSHR with IFN-γ-modified DC had a modeling rate of 60%, whereas that of Ad-TSHR A gene immunization was 72%. Both gene immunization and cellular immunization can be used to construct GO models, and the modeling rate of gene immunization is higher than that of cellular immunization. In this study, two innovative methods, cellular immunity and gene immunity, were used to establish GO animal models, which improved the success rate to a certain extent. To our knowledge, this study presents the first cellular immunity modeling idea of TSHR combined with IFN-γ for the GO animal model, which provides an animal model basis for understanding the pathogenesis of GO and developing new treatment methods.

Autophagy in graves' ophthalmopathy.

Graves' ophthalmopathy (GO) is an inflammatory autoimmune disease that affects the eyes. It can significantly alter the quality of life in patients because of its distinctive pathological appearance and the effect on vision. To date, the exact pathological mechanism of GO has not been explicitly discovered. However, several studies have associated autophagy with this disease. Autophagy is a catabolic process that helps maintain homeostasis in all organisms by protecting the cells and tissues from various endogenous and exogenous stress factors. Based on our results, patients affected with GO have comparatively elevated levels of autophagy, which critically affects the pathological mechanism of the GO. In this review, we have summarized the autophagy mechanism in the pathogenesis of GO.

Tear-derived exosomal biomarkers of Graves' ophthalmopathy.

Graves' ophthalmopathy (GO), the most frequent extrathyroidal manifestation of Graves' disease (GD), can lead to a significant decline in the quality of life in patients. Exosomes, which contain proteins, lipids and DNA, play important roles in the pathological processes of various diseases. However, their roles in Graves' ophthalmopathy are still unclear. We aimed to isolate exosomes and analyze the different exosomal proteins. Tear fluids were collected from twenty-four GO patients, twenty-four GD patients and sixteen control subjects. The numbers of tear exosomes were assayed using nanoparticle tracking analysis. A Luminex 200 kit and ELISA kit were used to confirm the different cytokine concentrations in serum. Extraocular muscle from GO patients and controls was extracted, and western blotting was used to assay the levels of Caspase-3 and complement C4A. Our study demonstrated that the number of tear exosomes differ from GD patients and control. The expression levels of cytokines, including IL-1 and IL-18, were significantly increased in the tear exosomes and serum from GO patients compared with GD patients and controls. The levels of the exosomal proteins Caspase-3, complement C4A and APOA-IV were significantly increased in GO patients compared to GD patients and controls. Orbital fibroblasts from GO patients showed significantly higher levels of Caspase-3 and complement C4A than those from controls. The levels of serum APOA-IV in GO patients were significantly higher than those in GD patients and controls. Specific proteins showed elevated expression in tear exosomes from GO patients, indicating that they may play important roles in GO pathogenesis.

Research progress on the pathogenesis of Graves' ophthalmopathy: Based on immunity, noncoding RNA and exosomes.

Graves’ ophthalmopathy (GO), also known as thyroid-associated ophthalmopathy, is a common potentially vision-threatening organ-specific autoimmune disease and the most common extrathyroidal manifestation of Graves’ disease. It can happen to those who have hyperthyroidism or euthyroidism. At present, the pathogenesis of GO has not been fully elucidated, and the majority of clinical treatments are symptomatic. Therefore, we are eager to discover any new therapeutic strategies that target the etiology of GO. To provide fresh ideas for the creation of new therapeutic techniques, this study primarily discusses the research state and progress of GO-related pathogenesis from the perspectives of GO’s cellular immunity, autoantigens, non-coding RNAs, and exosomes.

Dihydroartemisinin Exerts Antifibrotic and Anti-Inflammatory Effects in Graves' Ophthalmopathy by Targeting Orbital Fibroblasts.

Graves’ ophthalmopathy (GO) is a common orbital disease that threatens visual function and appearance. Orbital fibroblasts (OFs) are considered key target and effector cells in GO. In addition, hyaluronan (HA) production, inflammation, and orbital fibrosis are intimately linked to the pathogenesis of GO. In this study, we explored the therapeutic effects of dihydroartemisinin (DHA), an antimalarial drug, on GO-derived, primary OFs. CCK8 and EdU assays were applied to evaluate the antiproliferative effect of DHA on OFs. Wound healing assays were conducted to assess OF migration capacity, while qRT-PCR, western blotting, ELISA, and immunofluorescence were used to determine the expression of fibrosis-related and pro-inflammatory markers in these cells. Moreover, RNA sequencing was conducted to identify differentially expressed genes (DEGs) in DHA-treated OFs, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs was performed to explore potential mechanisms mediating the antifibrotic effect of DHA on GO-derived OFs. Results showed that DHA dose-dependently inhibited OF proliferation and downregulated, at the mRNA and protein levels, TGF-β1-induced expression of fibrosis markers, including alpha smooth muscle actin (α-SMA) and connective tissue growth factor (CTGF). Furthermore, DHA inhibited TGF-β1 induced phosphorylation of extracellular signal-regulated protein kinase 1/2 (ERK1/2) and signal transducer and activator of transcription 3 (STAT3), which suggested that DHA exerted antifibrotic effects via suppression of the ERK and STAT3 signaling pathways. In addition, DHA suppressed the expression of pro-inflammatory cytokines and chemokines, including IL-6, IL-8, CXCL-1, MCP-1, and ICAM-1, and attenuated HA production induced by IL-1β in GO-derived OFs. In conclusion, our study provides first-time evidence that DHA may significantly alleviate pathogenic manifestations of GO by inhibiting proliferation, fibrosis- and inflammation-related gene expression, and HA production in OFs. These data suggest that DHA may be a promising candidate drug for treatment of GO.

Emerging Insights Into the Role of Epigenetics and Gut Microbiome in the Pathogenesis of Graves' Ophthalmopathy.

Graves’ Ophthalmopathy (GO) is an organ-specific autoimmune disease that is often characterized by infiltration of orbital tissues and is considered as the most common extra-thyroid manifestation of Graves’ disease (GD). Although genetic susceptibility has been found to be critical for the phenotype of GO, the associated risk alleles in a single gene are generally insufficient to cause the disease. Accruing evidence has shown that epigenetic disorders can act as the potentially missing link between genetic risk and clinically significant disease development. Abnormal epigenetic modifications can lead to pro-inflammatory cascades and activation of orbital fibroblasts (OFs) by promoting the various inflammatory response pathways and regulating the diverse signaling molecules that are involved in the fibrogenesis and adipogenesis, thereby leading to the significant expansion of orbital tissues, fibrosis and inflammation infiltration. Additionally, emerging evidence has shown that the gut microbiome can possibly drive the pathogenesis of GO by influencing the secretion of Thyrotropin receptor antibody (TRAb) and T-helper 17 (Th17)/regulatory T cells (Treg) imbalance. This paper describes the latest epigenetic research evidence and progress made in comprehending the mechanisms of GO development, such as DNA methylation, histone modification, non-coding RNAs, and the gut microbiome.

The Role of Oxidative Stress and Therapeutic Potential of Antioxidants in Graves' Ophthalmopathy.

Graves’ ophthalmopathy (GO) is the most common extrathyroidal manifestation of Graves’ disease. It is characterized initially by an inflammatory process, followed by tissue remodeling and fibrosis, leading to proptosis, exposure keratopathy, ocular motility limitation, and compressive optic neuropathy. The pathogenic mechanism is complex and multifactorial. Accumulating evidence suggests the involvement of oxidative stress in the pathogenesis of GO. Cigarette smoking, a major risk factor for GO, has been shown to induce reactive oxygen species (ROS) generation and oxidative damage in GO orbital fibroblasts. In addition, an elevation in ROS and antioxidant enzymes is observed in tears, blood, and urine, as well as orbital fibroadipose tissues and fibroblasts from GO patients. In vitro and in vivo studies have examined the efficacy of various antioxidant supplements for GO. These findings suggest a therapeutic role of antioxidants in GO patients. This review summarizes the current understanding of oxidative stress in the pathogenesis and potential antioxidants for the treatment of GO.

The Potential Role of Osteopontin in the Pathogenesis of Graves’ Ophthalmopathy

PurposeThe aim of this study is to evaluate the expression of osteopontin (OPN) and its relationship with relative cytokines in patients with Graves’ ophthalmopathy (GO), and to observe the effect of OPN on orbital fibroblasts (OFs) proliferation, migration, and the expression of relative cytokines, as well as the signaling pathways involved in its effect.MethodsThe orbital adipose connective tissue was obtained from 24 patients with GO (12 cases of active GO, and 12 cases of inactive GO) and 12 healthy controls. OFs were isolated from orbital tissues obtained from patients with active GO who were undergoing orbital decompression surgery. Quantitative PCR and Western blot were performed to detect RNA and protein expression. The proliferation and cell migration rates of OFs were measured by methylthiazol tetrazolium (MTT) and the cell scratch test. Signaling pathway inhibitors, such as OPN monoclonal antibody 1A12, ERK1/2 inhibitor PD98059, and PI3K inhibitor LY294002, were applied to determine the involved pathways.ResultsThe mRNA and protein levels of OPN were increased in orbital adipose connective tissue from patients with active GO than those from patients with inactive GO (2.83-fold increase, P < 0.001; 1.91-fold increase, P < 0.05). The OPN mRNA level was positively correlated with CD40 ligand (CD40L) and hyaluronan synthases 2 (HAS2) mRNA in patients with GO. OPN promoted proliferation and migration rate of OFs and induced vascular endothelial growth factor (VEGF) and collagen I mRNA expression, and the effects were inhibited by 1A12 or LY294002.ConclusionsOPN in orbital adipose connective tissues were significantly increase in active GO, and there were significant correlations of OPN with CD40L and HAS2 mRNA levels in patients with GO. OPN promoted proliferation and migration of OFs and induced VEGF and collagen I mRNA expression in OFs through PI3K/Akt signaling pathway. This suggested a role for OPN in the pathogenesis of GO through the activation of OFs.

Histone Deacetylase 4 Controls Extracellular Matrix Production in Orbital Fibroblasts from Graves' Ophthalmopathy Patients.

Background: Graves' ophthalmopathy (GO) is an autoimmune eye disease with the characteristic symptoms of eyelid retraction and proptosis. Orbital fibroblast activation induced by platelet-derived growth factor-BB (PDGF-BB) stimulation plays a crucial role in GO pathogenesis, leading to excessive proliferation and extracellular matrix production by orbital fibroblasts. Currently, GO treatment options remain limited and novel therapies including targeted drugs are needed. Histone deacetylases (HDACs) are associated with the development and progression of several cancers and autoimmune diseases by epigenetically controlling gene transcription, and HDAC inhibitors (HDACis) may have therapeutic potential. Nevertheless, the role of HDACs in orbital fibroblasts from GO is unknown. Therefore, we studied the expression of HDACs as well as their contribution to extracellular matrix production in orbital fibroblasts. Methods: Orbital tissues were obtained from GO patients (n = 18) who underwent decompression surgery with approval from the Institutional Review Board of the Faculty of Medicine (Protocol number 401/61), Chulalongkorn University (Bangkok, Thailand). Furthermore, orbital tissue was obtained from control patients (n = 3) without inflammatory or thyroid disease who underwent surgery for cosmetic reasons. Orbital fibroblast cultures were established from the orbital tissues. HDAC mRNA and protein expression in orbital fibroblasts was analyzed by reverse transcription-quantitative real-time PCR and Western blot. PDGF-BB-activated orbital fibroblast and orbital tissues were treated with HDACis or HDAC4 small-interfering RNA. Results: PDGF-BB-stimulated orbital fibroblasts had upregulated HDAC4 mRNA and protein expression. HDAC4 mRNA expression was significantly higher in GO compared with healthy control orbital fibroblasts. Histone H3 lysine 9 acetylation (H3K9ac) decreased upon PDGF-BB stimulation. Treatment with HDAC4i (tasquinimod) and HDAC4/5i (LMK-235) significantly decreased both proliferation and hyaluronan production in PDGF-BB-stimulated orbital fibroblasts. HDAC4 silencing reduced mRNA expression of hyaluronan synthase 2 (HAS2), collagen type I alpha 1 chain (COL1A1), Ki67, and α-smooth muscle actin (α-SMA), as well as hyaluronan production in PDGF-BB-stimulated orbital fibroblasts. Tasquinimod significantly reduced HAS2 and α-SMA mRNA expression in whole orbital tissue. Conclusion: Our data indicated, for the first time, that altered HDAC4 regulation along with H3K9 hypoacetylation might represent a mechanism that contributes to excessive proliferation and extracellular matrix production by orbital fibroblasts in GO. HDAC4 might represent a novel target for GO therapy.

RAGE and HMGB1 Expression in Orbital Tissue Microenvironment in Graves' Ophthalmopathy.

Graves' ophthalmopathy (GO) is a chronic autoimmune inflammatory disorder involving orbital tissues. A receptor for advanced glycation end products (RAGE) and its ligand high mobility group box 1 (HMGB1) protein trigger inflammation and cell proliferation and are involved in the pathogenesis of various chronic inflammatory diseases. This study was aimed to evaluate RAGE and HMGB1 expression in GO to determine its potential clinical significance. To the best of our knowledge, this is the first study showing RAGE and HMGB1 expression in orbital tissue using immunohistochemistry. Sections of orbital adipose tissue obtained from patients diagnosed with GO (23 patients; 36 orbits) and normal controls (NC) (15 patients; 15 orbits) were analyzed by immunohistochemistry for RAGE and HMGB1 expression. Expression profiles were then correlated with clinical data of the study group. RAGE and HMGB1 expression were elevated in GO patients in comparison with NC (p = 0.001 and p = 0.02, respectively). We observed a correlation between RAGE expression and occurrence of dysthyroid optic neuropathy (DON) (p = 0.05) and levels of TSH Receptor Antibodies (TRAb) (p = 0.01). Overexpression of RAGE and HMGB1 might be associated with GO pathogenesis. In addition, RAGE and HMGB1 proteins may be considered as promising therapeutic targets, but this requires further research.

Microarray Data of Lacrimal Gland Implicates Dysregulated Protein Processing in Endoplasmic Reticulum in Graves' Ophthalmopathy.

Graves’ ophthalmopathy (GO) has become one of the most common orbital diseases. Although some evidences announced the potential mechanism of pathological changes in extraocular muscle and orbital adipose tissue, little is known about that in lacrimal enlargement of GO patients. Thus, gene expression profiles of lacrimal gland derived from GO patients and normal controls were investigated using the microarray datasets of GSE105149 and GSE58331. The raw data and annotation files of GSE105149 and GSE58331 were downloaded from Gene Expression Omnibus (GEO) database. Bioinformatics including differentially expressed genes (DEGs), Gene Ontology, Kyoto Encyclopedia of Gene and Genome (KEGG) pathway, protein-protein interaction (PPI) network construction, hub gene identification, and gene set variation analysis (GSVA) were successively performed. A total of 173 overlapping DEGs in GSE105149 and GSE58331 were screened out, including 20 up-regulated and 153 down-regulated genes. Gene Ontology, KEGG and GSVA analyses of these DEGs showed that the most significant mechanism was closely associated with endoplasmic reticulum (ER). Moreover, we identified 40 module genes and 13 hub genes which were also enriched in the ER-associated terms and pathways. Among the hub genes, five genes including HSP90AA1, HSP90B1, DNAJC10, HSPA5, and CANX may be involved in the dysfunction of protein processing in ER. Taken together, our observations revealed a dysregulated gene network which is essential for protein processing in ER in GO patients. These findings provided a potential mechanism in the progression of lacrimal enlargement in GO patients, as a new insight into GO pathogenesis.

Simvastatin Inhibits CYR61 Expression in Orbital Fibroblasts in Graves' Ophthalmopathy through the Regulation of FoxO3a Signaling.

Graves' ophthalmopathy (GO), which is characterized by orbital tissue inflammation, expansion, and fibrosis, is the ocular manifestation in 25% to 50% of patients with Graves' disease. As the pathology of GO is driven by autoimmune inflammation, many proinflammatory cytokines/chemokines, including TNF-α, IL-1β, IL-6, and CCL20, are crucial in the pathogenesis of GO to activate the orbital fibroblasts. Cysteine-rich protein 61 (CYR61), which is known to regulate cell proliferation, adhesion, and migration, plays a proinflammatory role in the pathogenesis of many inflammatory diseases, such as rheumatoid arthritis. CYR61 was considered a potential biomarker of GO in recent studies. Statins, which are cholesterol-lowering drugs, were found to reduce the risk of GO, probably through their anti-inflammatory and immunomodulatory effects. In this study, we established a link between CYR61 and statins in the pathogenesis and potential treatment for GO. Firstly, our data showed the overexpression of CYR61 in the orbital tissue (n = 4) and serum specimens (n = 6) obtained from the patients with inactive GO. CYR61 could induce the production of IL-6 and CCL20 in cultured GO orbital fibroblasts. The expression of CYR61 in cultured GO orbital fibroblasts was upregulated via TNF-α stimulation. Secondly, we pretreated cultured GO orbital fibroblasts using simvastatin, a statin, followed by TNF-α stimulation. The data revealed that simvastatin could inhibit TNF-α-induced CYR61 expression by modulating the activity of transcription factor FoxO3a. Our results provided insights into some cellular mechanisms that may explain the possible protective effects of simvastatin against the development of GO.

The critical role of m6A methylation in the pathogenesis of Graves' ophthalmopathy

PurposeTo investigate the role of N6-methyladenosine (m6A) RNA modification in the pathogenesis of Graves' ophthalmopathy (GO).MethodsSurgically excised extraocular muscles from 7 patients with GO and 5 subjects without GO were used. The global m6A levels in the specimens were determined using an m6A RNA methylation quantification kit. RNA sequencing (RNA-seq) was used to analyze the molecules involved in the regulation of m6A RNA methylation and the differential expression of mRNAs between the two groups (4 eyes, respectively). The expression of m6A RNA modification genes was evaluated by real-time PCR. The functional implications of the gene alterations between the GO and control specimens were determined by Gene Ontology analysis.ResultsThe m6A level was significantly increased in the specimens of GO patients compared to the control specimens (P < 0.05). The expression of m6A methylation regulators, such as WT1 associated protein (WTAP), alkylation repair homolog protein 5 (ALKBH5), E74 like ETS transcription factor 3 (ELF3), YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), YTHDF3 and YTH domain containing 2 (YTHDC2), was significantly upregulated (P < 0.05). Gene Ontology enrichment analysis showed that the most highly upregulated genes and biological pathways were related to the immune response and inflammatory processes such as lymphocyte activation, leukocyte differentiation, cytokine production and cytokine-mediated signaling pathways.ConclusionsOur results suggest that m6A methylation may play a critical role in the pathogenesis of GO and that targeting genes that regulate m6A methylation may provide a new therapeutic approach for GO.

The Th1 chemokine MIG in Graves' ophthalmopathy.

Chemokine (C-X-C motif) ligand (CXCL)9/monokine induced by interferon (IFN)-γ (MIG) and its receptor, chemokine (C-X-C motif) receptor (CXCR)3, are involved in the pathogenesis of Graves' ophthalmopathy (GO). In tissues, recruited Type 1 helper (Th1) lymphocytes could cause an increased production of IFN-γ and tumor necrosis factor (TNF)-α, which in turn stimulate MIG secretion from these cells; all this creates an amplification feedback loop, and perpetuates the autoimmune process. In particular, MIG is secreted by fibroblasts and preadipocytes under the influence of IFN-γ. The IFN-γ induced MIG secretion in vitro, in GO fibroblasts and preadipocytes can be modulate by peroxisome proliferator-activated receptors (PPAR)-γ and PPAR-α activators. High levels of MIG in peripheral liquids could be considered as a marker of an especially Th1 orientated immune response. The presence of circulating MIG is associated with the active phase of GO. An increased concentrations of MIG in patients with GO reflect, at least in part, the orbital inflammation activity. Since MIG concentrations are significantly reduced during corticosteroids and/or radiotherapy treatments, with respect to control group and basal values of patients with GO, MIG has been proposed as a marker in the therapy choice for patients with GO. More studies are needed to investigate interactions between chemokines and cytokines in the GO pathogenesis and to evaluate whether MIG is a novel therapeutic target in these autoimmune disorders.

Inhibiting thyrotropin/insulin-like growth factor 1 receptor crosstalk to treat Graves' ophthalmopathy: studies in orbital fibroblasts in vitro.

Crosstalk between thyrotropin (TSH) receptors and insulin-like growth factor 1 (IGF-1) receptors initiated by activation of TSH receptors could be important in the development of Graves' ophthalmopathy (GO). Specifically, TSH receptor activation alone is sufficient to stimulate hyaluronic acid (HA) secretion, a major component of GO, through both IGF-1 receptor-dependent and -independent pathways. Although an anti-IGF-1 receptor antibody is in clinical trials, its effectiveness depends on the relative importance of IGF-1 versus TSH receptor signalling in GO pathogenesis. TSH and IGF-1 receptor antagonists were used to probe TSH/IGF-1 receptor crosstalk in primary cultures of Graves' orbital fibroblasts (GOFs) following activation with monoclonal TSH receptor antibody, M22. Inhibition of HA secretion following TSH receptor stimulation was measured by modified HA elisa. TSH receptor antagonist, ANTAG3 (NCGC00242364), inhibited both IGF-1 receptor -dependent and -independent pathways at all doses of M22; whereas IGF-1 receptor antagonists linsitinib and 1H7 (inhibitory antibody) lost efficacy at high M22 doses. Combining TSH and IGF-1 receptor antagonists exhibited Loewe additivity within the IGF-1 receptor-dependent component of the M22 concentration-response. Similar effects were observed in GOFs activated by autoantibodies from GO patients' sera. Our data support TSH and IGF-1 receptors as therapeutic targets for GO, but reveal putative conditions for anti-IGF-1 receptor resistance. Combination treatments antagonizing both receptors yield additive effects by inhibiting crosstalk triggered by TSH receptor stimulatory antibodies. Combination therapy may be an effective strategy for dose reduction and/or compensate for any loss of anti-IGF-1 receptor efficacy.

Expression and clinical significance of connective tissue growth factor (CTGF) in Graves' ophthalmopathy

AimsTo examine the expression of connective tissue growth factor (CTGF) in human cultured orbital fibroblasts from patients with Graves' ophthalmopathy (GO) and investigate whether a correlation exists between the presence...