Gene expression in Graves' ophthalmopathy and arm lymphedema: similarities and differences

The crossroad between autoimmune disorder, tissue remodeling and cancer of the thyroid: The long pentraxin 3 (PTX3)

Thyroid is at the crossroads of immune dysregulation, tissue remodeling and oncogenesis. Autoimmune disorders, nodular disease and cancer of the thyroid affect a large amount of general population, mainly women. We wondered if there could be a common factor behind three processes (immune dysregulation, tissue remodeling and oncogenesis) that frequently affect, sometimes coexisting, the thyroid gland. The long pentraxin 3 (PTX3) is an essential component of the humoral arm of the innate immune system acting as soluble pattern recognition molecule. The protein is found expressed in a variety of cell types during tissue injury and stress. In addition, PTX3 is produced by neutrophils during maturation in the bone-marrow and is stored in lactoferrin-granules. PTX3 is a regulator of the complement cascade and orchestrates tissue remodeling and repair. Preclinical data and studies in human tumors indicate that PTX3 can act both as an extrinsic oncosuppressor by modulating complement-dependent tumor-promoting inflammation, or as a tumor-promoter molecule, regulating cell invasion and proliferation and epithelial to mesenchymal transition, thus suggesting that this molecule may have different functions on carcinogenesis. The involvement of PTX3 in the regulation of immune responses, tissue remodeling and oncosuppressive processes led us to explore its potential role in the development of thyroid disorders. In this review, we aimed to highlight what is known, at the state of the art, regarding the connection between the long pentraxin 3 and the main thyroid diseases i.e., nodular thyroid disease, thyroid cancer and autoimmune thyroid disorders.

Single and combined impacts of irradiation and surgery on lymphatic vasculature and fibrosis associated to secondary lymphedema

Lymphedema (LD) refers to a condition of lymphatic dysfunction associated with excessive fluid accumulation, fibroadipose tissue deposition and swelling. In industrialized countries, LD development mainly results from a local disruption of the lymphatic network by an infection or cancer-related surgery (secondary LD). In the absence of efficient therapy, animal models are needed to decipher the cellular and molecular mechanisms underlying LD and test putative drugs. In this study, we optimized and characterized a murine model of LD that combines an irradiation of the mice hind limb and a radical surgery (lymph node resection associated to lymphatic vessel ligation). We investigated the respective roles of irradiation and surgery in LD formation by comparing their impacts, alone or in combination (with different intervention sequences), on eight different features of the pathology: swelling (paw thickness), indocyanine green (ICG) clearance, lymphatic vasculature remodeling, epidermal and dermal thickening, adipocyte accumulation, inflammatory cell infiltration and collagen deposition. This study supports the importance of radiation prior to surgery to experimentally induce a rapid, severe and sustained tissue remodeling harboring the different hallmarks of LD. We provide the first experimental evidence for an excessive deposition of periostin (POSTN) and tenascin-C (TNC) in LD. Through a computerized method of digital image quantification, we established the spatial map of lymphatic expansion, as well as collagen, POSTN and TNC deposition in papillary and reticular dermis of lymphedematous skins. This mouse model is available to study the patho-physiology of LD and test potential therapeutic targets.

Lymphedema alters lipolytic, lipogenic, immune and angiogenic properties of adipose tissue: a hypothesis-generating study in breast cancer survivors

Later stages of secondary lymphedema are associated with the massive deposition of adipose tissue (AT). The factors driving lymphedema-associated AT (LAT) expansion in humans remain rather elusive. We hypothesized that LAT expansion could be based on alterations of metabolic, adipogenic, immune and/or angiogenic qualities of AT. AT samples were acquired from upper limbs of 11 women with unilateral breast cancer-related lymphedema and 11 healthy women without lymphedema. Additional control group of 11 female breast cancer survivors without lymphedema was used to assess systemic effects of lymphedema. AT was analysed for adipocyte size, lipolysis, angiogenesis, secretion of cytokines, immune and stem cell content and mRNA gene expression. Further, adipose precursors were isolated and tested for their proliferative and adipogenic capacity. The effect of undrained LAT- derived fluid on adipogenesis was also examined. Lymphedema did not have apparent systemic effect on metabolism and cytokine levels, but it was linked with higher lymphocyte numbers and altered levels of several miRNAs in blood. LAT showed higher basal lipolysis, (lymph)angiogenic capacity and secretion of inflammatory cytokines when compared to healthy AT. LAT contained more activated CD4+ T lymphocytes than healthy AT. mRNA levels of (lymph)angiogenic markers were deregulated in LAT and correlated with markers of lipolysis. In vitro, adipose cells derived from LAT did not differ in their proliferative, adipogenic, lipogenic and lipolytic potential from cells derived from healthy AT. Nevertheless, exposition of preadipocytes to LAT-derived fluid improved their adipogenic conversion when compared with the effect of serum. This study presents results of first complex analysis of LAT from upper limb of breast cancer survivors. Identified LAT alterations indicate a possible link between (lymph)angiogenesis and lipolysis. In addition, our in vitro results imply that AT expansion in lymphedema could be driven partially by exposition of adipose precursors to undrained LAT-derived fluid.

Transforming growth factor-β1 suppress pentraxin-3 in human orbital fibroblasts

PURPOSE

Transforming growth factor-β (TGF-β), recognized as a crucial factor in regulating fibrosis and tissue remodeling, plays a role in thyroid-associated ophthalmopathy (TAO). Pentraxin-3 (PTX3), a member of pentraxins, was recently implicated in many autoimmune and fibrotic diseases. Thus, we hypothesize if there is a potential correlation between TGF-β and PTX3 in orbital fibroblasts (OFs).

METHODS

Several strains of OFs obtained from patients with TAO (n = 8) and healthy donors (n = 3) were established as the study model. Recombinant TGF-β1 was exerted as an intervention and the expression of PTX3 was detected. To uncover the underlying mechanism, specific inhibitors of TGF-β and siRNA knockdown of Smads were utilized.

RESULTS

We found that TGF-β1 can reduce PTX3 protein expression in OFs. We also demonstrated that this downregulation was mediated at a pretranslational level, and PTX3 mRNA was inhibited in a time- and concentration-dependent manner by TGF-β1. Interestingly, the basic level of PTX3 and the magnitude of suppression were not significantly different between TAO and control groups. Furthermore, the TGF-β receptor complex (type I:type II) and the Smad2/3-Smad4-dependent pathway are essential for TGF-mediated PTX3 repression.

CONCLUSION

These findings indicated that TGF-β1 can inhibit PTX3 expression in human OFs, which may participate in inflammation and fibrosis in patients with TAO and provide a potential target for the antifibrotic treatment.

Immunohistochemical analysis of human orbital tissue in Graves' orbitopathy

PURPOSE

Immunohistochemistry of orbital tissues offers a correlation between the microscopic changes and macroscopic clinical manifestation of Graves' orbitopathy (GO). Summarizing the participation of different molecules will help us to understand the pathogenesis of GO.

METHODS

The pertinent and current literature on immunohistochemistry of human orbital tissue in GO was reviewed using the NCBI PubMed database.

RESULTS

33 articles comprising over 700 orbital tissue samples were included in this review. The earliest findings included the demonstration of HLA-DR and T cell (to a lesser extent B cell) markers in GO orbital tissues. Subsequent investigators further contributed by characterizing cellular infiltration, confirming the presence of HLA-DR and TSHR, as well as revealing the participation of cytokines, growth factors, adhesion molecules and miscellaneous substances. HLA-DR and TSHR are over-expressed in orbital tissues of GO patients. The inflammatory infiltration mainly comprises CD4 + T cells and macrophages. Cytokine profile suggests the importance of Th1 (especially in early active phase) and Th17 immunity in the pathogenesis of GO. Upregulation of proinflammatory/profibrotic cytokines, adhesion molecules and growth factors finally culminate in activation of orbital fibroblasts and perpetuation of orbital inflammation. The molecular status of selected parameters correlates with the clinical presentation of GO.

CONCLUSION

Further investigation is warranted to define precisely the role of different molecules and ongoing search for new players yet to be discovered is also important. Unfolding the molecular mechanisms behind GO will hopefully provide insights into the development of novel therapeutic strategies and optimize our clinical management of the disease.

Simvastatin downregulates adipogenesis in 3T3-L1 preadipocytes and orbital fibroblasts from Graves' ophthalmopathy patients

BACKGROUND

Smoking is a strong risk factor for the development of Graves' ophthalmopathy (GO). Immediate early genes (IEGs) are overexpressed in patients with active GO compared to healthy controls. The aim of this study was to study the effects of tobacco smoking and simvastatin on preadipocytes and orbital fibroblasts (OFs) in the adipogenic process.

METHODS

Cigarette smoke extract (CSE) was generated by a validated pump system. Mouse 3T3-L1 preadipocytes or OFs were exposed to 10% CSE with or without simvastatin. Gene expression was studied in preadipocytes and OFs exposed to CSE with or without simvastatin and compared to unexposed cells or cells treated with a differentiation cocktail.

RESULTS

In 3T3-L1 preadipocytes, Cyr61, Ptgs2, Egr1 and Zfp36 expression levels were two-fold higher in cells exposed to CSE than in unexposed cells. Simvastatin downregulated the expression of these genes (1.6-fold, 5.5-fold, 3.3-fold, 1.4-fold, respectively). CSE alone could not stimulate preadipocytes to differentiate. Scd1, Ppar-γ and adipogenesis were downregulated in simvastatin-treated preadipocytes compared to nontreated preadipocytes 18-, 35- and 1.7-fold, respectively. In OFs, similar effects of CSE were seen on the expression of CYR61 (1.4-fold) and PTGS2 (3-fold). Simvastatin downregulated adipogenesis, PPAR-γ (2-fold) and SCD (27-fold) expression in OFs.

CONCLUSION

CSE upregulated early adipogenic genes in both mouse 3T3-L1 preadipocytes and human OFs but did not by itself induce adipogenesis. Simvastatin inhibited the expression of both early and late adipogenic genes and adipogenesis in preadipocytes and human OFs. The effect of simvastatin should be investigated in a clinical trial of patients with GO.

Molecular biomarkers of Graves' ophthalmopathy

Graves' ophthalmopathy (GO), a complication of Graves' disease (GD), is typified by orbital inflammation, ocular tissue expansion and remodeling and, ultimately, fibrosis. Orbital fibroblasts are key effectors of GO pathogenesis exhibiting exaggerated inflammatory and fibroproliferative responses to cytokines released by infiltrating immune cells. Activated orbital fibroblasts also produce inflammatory mediators that contribute to disease progression, facilitate the orbital trafficking of monocytes and macrophages, promote differentiation of matrix-producing myofibroblasts and stimulate accumulation of a hyaluronan-rich stroma, which leads to orbital tissue edema and fibrosis. Proteomic and transcriptome profiling of the genomic response of ocular and non-ocular fibroblasts to INF-γ and TGF-β1 focused on identification of translationally-relevant therapeutic candidates. Induction of plasminogen activator inhibitor-1 (PAI-1, SERPINE1), a clade E member of the serine protease inhibitor (SERPIN) gene family and a prominent regulator of the pericellular proteolytic microenvironment, was one of the most highly up-regulated proteins in INF-γ- or TGF-β1-stimulated GO fibroblasts as well as in severe active GD compared to patients without thyroid disease. PAI-1 has multifunctional roles in inflammatory and fibrotic processes that impact tissue remodeling, immune cell trafficking and survival as well as signaling through several receptor systems. This review focuses on the pathophysiology of the GO fibroblast and possible targets for effective drug therapy.

Liposuction Treatment of Lymphedema

In the Western world, lymphedema most commonly occurs following treatment of cancer. Limb reductions have been reported utilizing various conservative therapies including manual lymph and pressure therapy, as well as by microsurgical reconstruction involving lymphovenous shunts and transplantation of lymph vessels or nodes. Failure of these conservative and surgical treatments to provide complete reduction in patients with long-standing pronounced lymphedema is due to the persistence of excess newly formed subcutaneous adipose tissue in response to slow or absent lymph flow, which is not removed in patients with chronic non-pitting lymphedema. Traditional surgical regimes utilizing bridging procedures, total excision with skin grafting, or reduction plasty seldom achieved acceptable cosmetic and functional results. Liposuction removes the hypertrophied adipose tissue and is a prerequisite to achieve complete reduction, and this reduction is maintained long-term through constant (24 h) use of compression garments postoperatively. This article describes the techniques and evidence basis for the use of liposuction for treatment of lymphedema.

PTX3: A Potential Biomarker in Thyroid Associated Ophthalmopathy

Background

Thyroid associated ophthalmopathy (TAO) is an autoimmune disease, which involves inflammation and tissue remodeling. Pentraxin-3 (PTX3) is a component of innate immune system and recently implicated in autoimmunity. This observation may indicate that PTX3 participates in the inflammatory process of TAO.

Methods

All studies were performed on TAO patients and healthy controls (45: 28 in total). RNA-seq was used to detect differential gene expression of orbital adipose-connective tissue. Quantitative PCR was performed to verify the results. PTX3 protein in orbital adipose-connective tissues was visualized by immunohistochemistry (IHC). PTX3 concentration in serum was determined by enzyme-linked immunosorbent assay (ELISA).

Results

RNA-seq showed 1.86-log⁡2FC higher PTX3 expression in the orbital adipose-connective tissues from TAO group than controls (FDR = 0.0059). qPCR confirmed the difference (5.59-fold increase, p = 0.0012). The presence of PTX3 protein was demonstrated. Orbital adipose tissue from healthy controls showed weak staining for PTX3 while tissue from TAO group was strongly positive. Serum PTX3 concentration was significantly elevated in patients when compared to the control group (1.9-fold increase; p < 0.0001).

Conclusions

Patients with TAO showed increased presence of PTX3 in orbital tissue and serum, which may suggest a potential relationship of PTX3 and TAO.

RNA-Sequencing Gene Expression Profiling of Orbital Adipose-Derived Stem Cell Population Implicate HOX Genes and WNT Signaling Dysregulation in the Pathogenesis of Thyroid-Associated Orbitopathy

Purpose

The purpose of this study was to characterize the intrinsic cellular properties of orbital adipose-derived stem cells (OASC) from patients with thyroid-associated orbitopathy (TAO) and healthy controls.

Methods

Orbital adipose tissue was collected from a total of nine patients: four controls and five patients with TAO. Isolated OASC were characterized with mesenchymal stem cell-specific markers. Orbital adipose-derived stem cells were differentiated into three lineages: chondrocytes, osteocytes, and adipocytes. Reverse transcription PCR of genes involved in the adipogenesis, chondrogenesis, and osteogenesis pathways were selected to assay the differentiation capacities. RNA sequencing analysis (RNA-seq) was performed and results were compared to assess for differences in gene expression between TAO and controls. Selected top-ranked results were confirmed by RT-PCR.

Results

Orbital adipose-derived stem cells isolated from orbital fat expressed high levels of mesenchymal stem cell markers, but low levels of the pluripotent stem cell markers. Orbital adipose-derived stem cells isolated from TAO patients exhibited an increase in adipogenesis, and a decrease in chondrogenesis and osteogenesis. RNA-seq disclosed 54 differentially expressed genes. In TAO OASC, expression of early neural crest progenitor marker (WNT signaling, ZIC genes and MSX2) was lost. Meanwhile, ectopic expression of HOXB2 and HOXB3 was found in the OASC from TAO.

Conclusion

Our results suggest that there are intrinsic genetic and cellular differences in the OASC populations derived from TAO patients. The upregulation in adipogenesis in OASC of TAO may be is consistent with the clinical phenotype. Downregulation of early neural crest markers and ectopic expression of HOXB2 and HOXB3 in TAO OASC demonstrate dysregulation of developmental and tissue patterning pathways.

Comparative proteomic analysis of tear fluid in Graves' disease with and without orbitopathy

BACKGROUND

Graves' orbitopathy (GO) is a severe organ-specific autoimmune inflammatory ocular complication most often associated with Graves' disease (GD). Besides the cosmetic problems these patients develop, GO may also cause severe, sight-threatening complications. Additionally, GO complicates the treatment of patients with GD, making the identification of Graves patients at risk for eye disease before they develop symptoms a critical step in the clinical management and quality of life of these patients. The high concentration of proteins in tear fluid makes it an important source for studying potential protein biomarkers for GO.

PATIENTS AND METHODS

The aim of this study was to quantitatively compare tear fluid from GD patients with moderate/severe GO (GO) and patients with GD without GO (controls) using untargeted quantitative proteomics based on dimethyl labelling in combination with two-dimensional liquid chromatography-mass spectrometry.

RESULTS

Among the 1212 proteins identified, 16 showed significant alterations in abundance between the two groups. Thus, in this study, we reveal a number of novel dysregulated proteins in GO which may contribute to a better understanding of the disease. In particular, upregulation of lacrimal gland proteins such as lysozyme C, lacritin, antileukoproteinase and zinc-alpha-2-glycoprotein 1 suggests involvement of the lacrimal gland in the pathogenesis of GO.

CONCLUSIONS

It remains to be elucidated whether some of these proteins can be used as markers for patients at risk for developing GO as well as useful indicators for disease activity.

Molecular diagnosis: Implications for ophthalmology

The effort to subdivide diseases and to individualize therapies based on characteristics of the patient has been labeled precision medicine. Jameson and Longo define precision medicine as "treatments targeted to the needs of individual patients on the basis of genetic, biomarker, phenotypic or psychosocial characteristics that distinguish a given patient from other patients with similar clinical presentations" (Jameson and Longo, 2015). We illustrate how molecular diagnosis can be applied to orbital inflammatory disease to achieve the goals of precision medicine.

Pentraxin-3 Is a TSH-Inducible Protein in Human Fibrocytes and Orbital Fibroblasts

CD34(+) fibrocytes are bone marrow-derived monocyte progenitor cells that traffic to sites of tissue injury and repair. They putatively infiltrate the orbit in thyroid-associated ophthalmopathy where they appear to transition into CD34(+) orbital fibroblasts (OFs) that interact with residential CD34(-) fibroblasts. A unique phenotypic attribute of fibrocytes and CD34(+) OFs is their expression of the functional thyrotropin receptor (TSHR) and other "thyroid-specific" proteins. When activated through TSHR, fibrocytes express a number of cytokines and other inflammatory genes. Here we sought to determine whether pentraxin-3 (PTX-3), an acute-phase protein involved in inflammation and autoimmunity, might be induced by TSH in fibrocytes and OFs. These cells were collected from patients with Graves disease and healthy individuals. PTX-3 mRNA levels were determined by real-time PCR, protein was determined by ELISA and Western blot, and PTX-3 gene promoter activity was assessed with reporter assays. PTX-3 expression was induced by TSH in both cell types, regardless of the health status of the donor and was a consequence of increased steady-state PTX-3 mRNA levels. M22, a TSHR-activating monoclonal antibody, also induced PTX-3. The induction could be attenuated by dexamethasone and by IGF-I receptor-blocking antibodies, teprotumumab and 1H7. TSH effects were mediated through phosphatidylinositol 3-kinase/AKT, mammalian target of rapamycin/p70(s6k), Janus tyrosine kinase 2 pathways, and enhanced PTX-3 mRNA stability. These findings indicate that PTX-3 is a TSH target gene, the expression of which can be induced in fibrocytes and OFs. They suggest that PTX-3 might represent a previously unidentified nexus between the thyroid axis and the mechanisms involved in tissue remodeling.

The Role of the Immune Response in the Pathogenesis of Thyroid Eye Disease: A Reassessment

Background

Although thyroid eye disease is a common complication of Graves’ disease, the pathogenesis of the orbital disease is poorly understood. Most authorities implicate the immune response as an important causal factor. We sought to clarify pathogenesis by using gene expression microarray.

Methods

An international consortium of ocular pathologists and orbital surgeons contributed formalin fixed orbital biopsies. RNA was extracted from orbital tissue from 20 healthy controls, 25 patients with thyroid eye disease (TED), 25 patients with nonspecific orbital inflammation (NSOI), 7 patients with sarcoidosis and 6 patients with granulomatosis with polyangiitis (GPA). Tissue was divided into a discovery set and a validation set. Gene expression was quantified using Affymetrix U133 Plus 2.0 microarrays which include 54,000 probe sets.

Results

Principal component analysis showed that gene expression from tissue from patients with TED more closely resembled gene expression from healthy control tissue in comparison to gene expression characteristic of sarcoidosis, NSOI, or granulomatosis with polyangiitis. Unsupervised cluster dendrograms further indicated the similarity between TED and healthy controls. Heat maps based on gene expression for cytokines, chemokines, or their receptors showed that these inflammatory markers were associated with NSOI, sarcoidosis, or GPA much more frequently than with TED.

Conclusion

This is the first study to compare gene expression in TED to gene expression associated with other causes of exophthalmos. The juxtaposition shows that inflammatory markers are far less characteristic of TED relative to other orbital inflammatory diseases.

Induction of DKK1 by ox-LDL negatively regulates intracellular lipid accumulation in macrophages

Dickkopf1 (DKK1), a canonical Wnt/β-catenin pathway antagonist, is closely associated with cardiovascular disease and adipogenesis. We performed an in vitro study to determine whether oxidized low-density lipoprotein (ox-LDL) increased the expression of DKK1 in macrophages and whether β-catenin and liver X receptor α (LXRα) were involved in this regulation. Induction of DKK1 expression by ox-LDL decreased the level of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) via a Wnt/β-catenin pathway and increased ATP-binding cassette transporter A/G1 (ABCA/G1) levels via a signal transducer and activator of transcription 3 (STAT3) pathway. Lower LOX-1 and higher ABCA/G1 levels inhibited cholesterol loading in macrophages. In conclusion, ox-LDL may induce DKK1 expression in macrophages to inhibit the accumulation of lipids through a mechanism that involves downregulation of LOX-1-mediated lipid uptake and upregulation of ABCA/G1-dependent cholesterol efflux.

Smoking induces overexpression of immediate early genes in active Graves' ophthalmopathy

BACKGROUND

Cigarette smoking is a risk factor for the development of Graves' ophthalmopathy (GO). In a previous study of gene expression in intraorbital fat, adipocyte-related immediate early genes (IEGs) were overexpressed in patients with GO compared to controls. We investigated whether IEGs are upregulated by smoking, and examined other pathways that may be affected by smoking.

METHODS

Gene expression in intraorbital fat was studied in smokers (n=8) and nonsmokers (n=8) with severe active GO, as well as in subcutaneous fat in thyroid-healthy smokers (n=5) and nonsmokers (n=5) using microarray and real-time polymerase chain reaction (PCR).

RESULTS

With microarray, eight IEGs were upregulated more than 1.5-fold in smokers compared to nonsmokers with GO. Five were chosen for confirmation and were also overexpressed with real-time PCR. Interleukin-1 beta/IL-1B/(2.3-fold) and interleukin-6/IL-6/(2.4-fold) were upregulated both with microarray and with real-time PCR in smokers with GO compared to nonsmokers. Major histocompatibility complex, class II, DR beta 1/HLA-DRB1/was upregulated with microarray (2.1-fold) and with borderline significance with real-time PCR. None of these genes were upregulated in smokers compared to nonsmokers in subcutaneous fat.

CONCLUSIONS

IEGs, IL-1B, and IL-6 were overexpressed in smokers with severe active GO compared to nonsmokers, suggesting that smoking activates pathways associated with adipogenesis and inflammation. This study underlines the importance of IEGs in the pathogenesis of GO, and provides evidence for possible novel therapeutic interventions in GO. The mechanisms activated by smoking may be shared with other conditions such as rheumatoid arthritis.

Association of BTG2, CYR61, ZFP36, and SCD gene polymorphisms with Graves' disease and ophthalmopathy

BACKGROUND

Environmental and genetic factors predispose an individual to the development of Graves' disease (GD). In an expression study of intraorbital tissue, adipocyte-related immediate early genes (IEGs) and immunomodulatory genes were found to be overexpressed in patients with Graves' ophthalmopathy (GO). We hypothesized that genetic variations in these genes could be associated with GD and/or GO.

METHODS

A total of 98 single nucleotide polymorphisms (SNPs) in 12 genes were genotyped in 594 GD patients with (n=267) or without (n=327) GO and 1147 sex- and ethnicity-matched controls from Malmö, Sweden.

RESULTS

Ten SNPs in four genes (BTG family, member 2 [BTG2], cysteine-rich, angiogenic inducer 61 [CYR61], zinc finger protein 36, C3H type, homolog mouse [ZFP36], and stearoyl-coenzyme A desaturase [SCD]) showed an association with GD and/or GO. SNPs rs12136280 (odds ratio [OR] 1.29, p=0.002), rs6663606 (OR 1.26, p=0.004), and rs17534202 (OR 1.21, p=0.02) in BTG2 and rs3753793 (OR 1.21, p=0.03) in CYR61 were associated with GD. An association with GO was shown for SNPs rs3753793 (OR 1.45, p=0.008), rs6682848 (OR 1.55, p=0.03), rs12756618 (OR 1.77, p=0.049), and rs1378228 (OR 1.29, p=0.049) in CYR61, rs1057745 (OR 1.56, p=0.03) and rs11083522 (OR 1.32, p=0.04) in ZFP36, and rs1393491 (OR 1.38, p=0,048) in SCD. Smoking and CYR61 rs12756618 interacted to increase the risk of GO.

CONCLUSIONS

We found associations of SNPs in IEGs and SCD with GD and/or GO; however, confirmation in a different population is required.

Transcriptome-level microarray expression profiling implicates IGF-1 and Wnt signalling dysregulation in the pathogenesis of thyroid-associated orbitopathy

AIMS

The pathogenesis of thyroid-associated orbitopathy (TAO) remains unclear. The aim of this study is to elucidate the gene expression profile of orbital fat from patients with active, but untreated, TAO.

METHODS

A case-control gene expression study was conducted using test samples of orbital fat from TAO patients and control orbital fat specimens; apart from drugs to control thyrotoxicosis, the TAO patients had received no treatment for orbital disease. cDNA expression analysis was performed using the Affymetrix GeneChip Human Genome U133 Plus 2.0 platform and validated using quantitative PCR.

RESULTS

The highest-ranked differentially expressed genes were dominated by IGF-1 signalling genes. These include IGF-1, IGF-1 receptor binding/signalling genes, such as SOCS3 and IRS2, and downstream signalling and transcriptional regulators, such as SGK (PDK/Akt signalling) and c-JUN. Our microarray data also demonstrate dysregulation of wingless-type MMTV (Wnt) signalling gene expression, including Wnt5a, sFRPs and DKK.

CONCLUSION

Altered Wnt signalling confirms previous array findings. Further investigation of the role of Wnt signalling in TAO pathogenesis is warranted. These data also provide the first evidence of dysregulation of IGF-1 pathway genes in TAO tissue, further strengthening the evidence for the role of IGF-1 signalling in the pathogenesis and potential treatment of TAO.

Differential microRNA expression in peripheral blood mononuclear cells from Graves' disease patients

CONTEXT

Graves' disease (GD) is a common autoimmune disease that affects the thyroid gland. As a new class of modulators of gene expression, microRNA (miRNA) have been reported to play a vital role in immune functions and in the development of autoimmunity and autoimmune disease.

OBJECTIVE

This study sought to characterize the different miRNA expression in peripheral blood mononuclear cells (PBMC) from GD patients and healthy individuals and examine their direct responses to T(3) treatment.

METHODS

Forty-one patients who met criteria for initial GD, 13 GD patients in remission, and 35 healthy controls were recruited. Microarray was used to analyze the expression patterns of miRNA in PBMC obtained from initial GD patients and healthy controls. Three top-ranked miRNA were selected and validated by TaqMan-based real-time PCR in healthy controls, initial GD patients, and GD patients in remission. Furthermore, we cultured PBMC from healthy donors with or without T(3) treatment to examine direct effects of T(3) on selective miRNA.

RESULTS

There were sixteen miRNA expressed differently in PBMC from initial GD patients compared with normal subjects. Further analysis consistently showed that the expression of miR-154*, miR-376b, and miR-431* were suppressed in PBMC from initial GD patients. In addition, their expression levels were recovered in GD patients in remission. Meanwhile, T(3) treatment could directly inhibit the expression of these miRNA in cultured PBMC from healthy subjects.

CONCLUSIONS

The present work revealed that differentially expressed miRNA were associated with GD and T(3) exposure, which might serve as novel biomarkers of GD and potential targets for GD treatment.