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1.
Cancers (Basel) ; 13(11)2021 May 28.
Article in English | MEDLINE | ID: mdl-34071395

ABSTRACT

Prolactin (PRL) is a protein hormone which in humans is secreted by pituitary lactotrophs as well as by many normal and malignant non-pituitary sites. Many lines of evidence demonstrate that both circulating and locally produced PRL increase breast cancer (BC) growth and metastases and confer chemoresistance. Our objective was to identify and then characterize small molecules that block the tumorigenic actions of PRL in BC. We employed three cell-based assays in high throughput screening (HTS) of 51,000 small molecules and identified two small molecule inhibitors (SMIs), named SMI-1 and SMI-6. Both compounds bound to the extracellular domain (ECD) of the PRL receptor (PRLR) at 1-3 micromolar affinity and abrogated PRL-induced breast cancer cell (BCC) invasion and malignant lymphocyte proliferation. SMI-6 effectively reduced the viability of multiple BCC types, had much lower activity against various non-malignant cells, displayed high selectivity, and showed no apparent in vitro or in vivo toxicity. In athymic nude mice, SMI-6 rapidly and dramatically suppressed the growth of PRL-expressing BC xenografts. This report represents a pre-clinical phase of developing novel anti-cancer agents with the potential to become effective therapeutics in breast cancer patients.

2.
J Biol Chem ; 291(8): 4079-90, 2016 Feb 19.
Article in English | MEDLINE | ID: mdl-26703475

ABSTRACT

We previously showed that an HLA-DR variant containing arginine at position 74 of the DRß1 chain (DRß1-Arg74) is the specific HLA class II variant conferring risk for autoimmune thyroid diseases (AITD). We also identified 5 thyroglobulin (Tg) peptides that bound to DRß1-Arg74. We hypothesized that blocking the binding of these peptides to DRß1-Arg74 could block the continuous T-cell activation in thyroiditis needed to maintain the autoimmune response to the thyroid. The aim of the current study was to identify small molecules that can block T-cell activation by Tg peptides presented within DRß1-Arg74 pockets. We screened a large and diverse library of compounds and identified one compound, cepharanthine that was able to block peptide binding to DRß1-Arg74. We then showed that Tg.2098 is the dominant peptide when inducing experimental autoimmune thyroiditis (EAT) in NOD mice expressing human DRß1-Arg74. Furthermore, cepharanthine blocked T-cell activation by thyroglobulin peptides, in particular Tg.2098 in mice that were induced with EAT. For the first time we identified a small molecule that can block Tg peptide binding and presentation to T-cells in autoimmune thyroiditis. If confirmed cepharanthine could potentially have a role in treating human AITD.


Subject(s)
Alkaloids/pharmacology , Antigen Presentation/drug effects , HLA-DRB1 Chains/immunology , Thyroiditis, Autoimmune/immunology , Alkaloids/chemistry , Animals , HLA-DRB1 Chains/genetics , Humans , Lymphocyte Activation/drug effects , Mice , Mice, Transgenic , Peptides/genetics , Peptides/immunology , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Thyroglobulin/genetics , Thyroglobulin/immunology , Thyroiditis, Autoimmune/genetics , Thyroiditis, Autoimmune/pathology
3.
Expert Rev Endocrinol Metab ; 6(3): 411-422, 2011 May.
Article in English | MEDLINE | ID: mdl-21731573

ABSTRACT

Tumor resistance to chemotherapy in advanced breast cancer is a major impediment to treatment success. Resistance can be induced by the drugs themselves or result from the action of internal factors. The role of hormones in chemoresistance has received little attention. This article focuses on two classes of hormones: lactogens and estrogens. Lactogens include prolactin, growth hormone and placental lactogen, all of which can activate the prolactin receptor. Estrogens include endogenous steroids and nonsteroidal compounds from the environment termed endocrine disruptors, all of which can activate 'classical' estrogen receptors (ERα and ERß), as well as other types of receptors. Both lactogens and estrogens antagonize cytotoxicity of multiple chemotherapeutic agents through complementary mechanisms. The implications of chemoresistance by these hormones to patients with breast cancer, and the potential benefits of developing combinatorial anti-lactogen/anti-estrogen treatment regimens, are discussed.

4.
J Biol Chem ; 286(36): 31168-79, 2011 Sep 09.
Article in English | MEDLINE | ID: mdl-21757724

ABSTRACT

Autoimmune thyroid diseases (AITD) arise from complex interactions between genetic, epigenetic, and environmental factors. Whole genome linkage scans and association studies have established thyroglobulin (TG) as a major AITD susceptibility gene. However, the causative TG variants and the pathogenic mechanisms are unknown. Here, we describe a genetic/epigenetic mechanism by which a newly identified TG promoter single-nucleotide polymorphism (SNP) variant predisposes to AITD. Sequencing analyses followed by case control and family-based association studies identified an SNP (-1623A→G) that was associated with AITD in the Caucasian population (p = 0.006). We show that the nucleotide substitution introduced by SNP (-1623A/G) modified a binding site for interferon regulatory factor-1 (IRF-1), a major interferon-induced transcription factor. Using chromatin immunoprecipitation, we demonstrated that IRF-1 binds to the 5' TG promoter motif, and the transcription factor binding correlates with active chromatin structure and is marked by enrichment of mono-methylated Lys-4 residue of histone H3, a signature of active transcriptional enhancers. Using reporter mutations and siRNA approaches, we demonstrate that the disease-associated allele (G) conferred increased TG promoter activity through IRF-1 binding. Finally, treatment of thyroid cells with interferon α, a known trigger of AITD, increased TG promoter activity only when it interacted with the disease-associated variant through IRF-1 binding. These results reveal a new mechanism of interaction between environmental (IFNα) and genetic (TG) factors to trigger AITD.


Subject(s)
Autoimmunity/genetics , Epigenesis, Genetic , Interferon-alpha/genetics , Polymorphism, Single Nucleotide , Promoter Regions, Genetic , Thyroglobulin/genetics , Thyroid Diseases/genetics , Binding Sites , Case-Control Studies , Cell Line , Humans , Interferon Regulatory Factor-1/genetics , Interferon Regulatory Factor-1/metabolism , Thyroid Diseases/immunology
5.
PLoS One ; 6(4): e19200, 2011 Apr 29.
Article in English | MEDLINE | ID: mdl-21559421

ABSTRACT

Thyroglobulin (Tg) represents one of the largest known self-antigens involved in autoimmunity. Numerous studies have implicated it in triggering and perpetuating the autoimmune response in autoimmune thyroid diseases (AITD). Indeed, traditional models of autoimmune thyroid disease, experimental autoimmune thyroiditis (EAT), are generated by immunizing mice with thyroglobulin protein in conjunction with an adjuvant, or by high repeated doses of Tg alone, without adjuvant. These extant models are limited in their experimental flexibility, i.e. the ability to make modifications to the Tg used in immunizations. In this study, we have immunized mice with a plasmid cDNA encoding the full-length human Tg (hTG) protein, in order to generate a model of Hashimoto's thyroiditis which is closer to the human disease and does not require adjuvants to breakdown tolerance. Human thyroglobulin cDNA was injected and subsequently electroporated into skeletal muscle using a square wave generator. Following hTg cDNA immunizations, the mice developed both B and T cell responses to Tg, albeit with no evidence of lymphocytic infiltration of the thyroid. This novel model will afford investigators the means to test various hypotheses which were unavailable with the previous EAT models, specifically the effects of hTg sequence variations on the induction of thyroiditis.


Subject(s)
Autoimmunity , T-Lymphocytes/immunology , Thyroglobulin/metabolism , Animals , B-Lymphocytes/cytology , DNA, Complementary/metabolism , Electroporation , Female , Hashimoto Disease/genetics , Humans , Immune Tolerance , Mice , Mice, Inbred C3H , Models, Animal , Models, Genetic , Plasmids/metabolism , T-Lymphocytes/cytology , Thyroiditis, Autoimmune/genetics
6.
Discov Med ; 11(59): 315-24, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21524385

ABSTRACT

Prostate and breast cancers affect millions of men and women, respectively. Advanced forms of the disease, which can no longer be controlled by hormonal disruption or chemotherapy, have very limited treatment options. Consequently, there is a major benefit to identify new targets for therapy in both types of cancer. The prolactin (PRL) signaling cascade, by virtue of its importance to the pathology of both diseases, has emerged as a potential treatment target. To date, several methods for antagonizing the PRL receptor (PRLR) and its signaling pathways have been developed which include protein-based and small molecule antagonists. However, a better understanding of the genetic and molecular characteristics of the PRL cascade is needed for the successful therapeutic application of antagonists. At the level of genetics, it is necessary to determine the functional significance of non-synonymous single nucleotide polymorphisms of the PRLR and their association with disease prevalence and severity. At the molecular level, a comprehensive knowledge of interactions of the PRL signaling pathway with other oncogenic molecules is warranted so as to identify beneficial combinatorial strategies. This review discusses multiple features of the PRL signaling cascade and how they can be exploited in the search for effective therapies for patients with breast and prostate cancers.


Subject(s)
Breast Neoplasms/genetics , Prolactin/genetics , Prostatic Neoplasms/genetics , Female , Humans , Male , Prolactin/metabolism , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism
7.
Trends Endocrinol Metab ; 21(11): 691-8, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20846877

ABSTRACT

Breast and prostate cancers are hormone-sensitive malignancies that afflict millions of women and men. Although prolactin (PRL) is known as a survival factor that supports tumor growth and confers chemoresistance in both cancers, its precise role in these tumors has not been studied extensively. Growth hormone and placental lactogen also bind PRL receptor (PRLR) and mimic some of the actions of PRL. Blockade of the PRLR represents a novel treatment for patients with advanced breast or prostate cancer with limited therapeutic options. This review discusses different approaches for generating PRLR antagonists. Emphasis is placed on technological advances which enable high-throughput screening for small molecule inhibitors of PRLR signaling that could serve as oral medications.


Subject(s)
Breast Neoplasms/therapy , Carcinoma/therapy , Molecular Targeted Therapy/methods , Prostatic Neoplasms/therapy , Receptors, Prolactin/antagonists & inhibitors , Animals , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Female , High-Throughput Screening Assays/methods , Hormone Antagonists/isolation & purification , Hormone Antagonists/therapeutic use , Humans , Male , Models, Biological , Models, Molecular , Prostatic Neoplasms/genetics , Prostatic Neoplasms/metabolism , Receptors, Prolactin/chemistry , Receptors, Prolactin/metabolism , Receptors, Prolactin/physiology , Therapies, Investigational/methods
8.
J Autoimmun ; 35(1): 45-51, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20303712

ABSTRACT

An HLA-DR variant containing Arginine at position 74 of the DRbeta1 chain confers a strong genetic susceptibility to autoimmune thyroid diseases (AITD), Graves' disease (GD) and Hashimoto's thyroiditis (HT), while Glutamine at position DRbeta1-74 is protective. We hypothesized that the DRbeta1-Arg74 variant is able to present pathogenic thyroglobulin (Tg) peptides to T-cells more efficiently, thereby triggering thyroid autoimmunity. Indeed, we have previously identified 4 human Tg (hTg) peptides that bind specifically to DRbeta1-Arg74 with much weaker binding to the protective variant DRbeta1-Gln74. The aim of our study was to examine in vivo whether an hTg peptide that binds strongly and specifically to DRbeta1-Arg74 is capable of stimulating T-cells during the induction of thyroiditis in a "humanized" mouse expressing human DR3, and in patients positive for Tg antibodies. Sequencing of exon 2 of the DR transgene in the DR3 mice, null for endogenous MHC II molecules, confirmed that they expressed the disease-associated DRbeta1-Arg74 variant, thus making them an ideal in vivo model to test the presentation of hTg peptides by DRbeta1-Arg74 HLA-DR. Induction of EAT in the DR3 mice lead to T-cell stimulation and proliferation to Tg.2098, a strong and specific DRbeta1-Arg74 binder, while a non-binding control peptide, Tg.2766 did not induce this response. Moreover, Tg.2098 stimulated T-cells from 4 individuals who were positive for thyroglobulin antibodies, demonstrating that Tg.2098 is an immunogenic peptide capable of being presented in vivo and activating T-cells in EAT and AITD. Energetic analysis of the complex formed by Tg.2098 and DRbeta-Arg74 has shown that the origin of the affinity was determined by residues 1, 7 and 9 in the peptide, while the selectivity of the peptide for the MHC was determined by the Asp in position 4. The disease-protective substitution R74Q, leads to reduction in affinity due to changes in local interaction with D4 as well as non-local interaction with other residues. The electrostatic potential on the surface of the DRbeta-Arg74-Tg.2098 complex has a unique signature which may be recognized by T-cell receptors leading to autoimmune thyroiditis. Taken together these findings suggest that Tg.2098, a strong and specific binder to the disease-associated HLA-DRbeta-Arg74, is a major human T-cell epitope and participant in the pathoetiology of AITD.


Subject(s)
Epitopes, T-Lymphocyte/immunology , Peptide Fragments/immunology , T-Lymphocytes/metabolism , Thyroglobulin/immunology , Thyroiditis, Autoimmune/immunology , Animals , Antigen Presentation/genetics , Cell Proliferation , Epitope Mapping , Genetic Predisposition to Disease , HLA-DR3 Antigen/genetics , Histocompatibility Antigens Class II/genetics , Interleukin-2/metabolism , Lymphocyte Activation/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Polymorphism, Genetic , Protein Binding/genetics , Protein Binding/immunology , T-Lymphocytes/immunology , T-Lymphocytes/pathology , Thyroiditis, Autoimmune/genetics
9.
J Biol Chem ; 284(49): 34231-43, 2009 Dec 04.
Article in English | MEDLINE | ID: mdl-19776016

ABSTRACT

Previously, we have shown that statistical synergism between amino acid variants in thyroglobulin (Tg) and specific HLA-DR3 pocket sequence signatures conferred a high risk for autoimmune thyroid disease (AITD). Therefore, we hypothesized that this statistical synergism mirrors a biochemical interaction between Tg peptides and HLA-DR3, which is key to the pathoetiology of AITD. To test this hypothesis, we designed a recombinant HLA-DR3 expression system that was used to express HLA-DR molecules harboring either AITD susceptibility or resistance DR pocket sequences. Next, we biochemically generated the potential Tg peptidic repertoire available to HLA-DR3 by separately treating 20 purified human thyroglobulin samples with cathepsins B, D, or L, lysosomal proteases that are involved in antigen processing and thyroid biology. Sequences of the cathepsin-generated peptides were then determined by matrix-assisted laser desorption ionization time-of-flight-mass spectroscopy, and algorithmic means were employed to identify putative AITD-susceptible HLA-DR3 binders. From four predicted peptides, we identified two novel peptides that bound strongly and specifically to both recombinant AITD-susceptible HLA-DR3 protein and HLA-DR3 molecules expressed on stably transfected cells. Intriguingly, the HLA-DR3-binding peptides we identified had a marked preference for the AITD-susceptibility DR signatures and not to those signatures that were AITD-protective. Structural analyses demonstrated the profound influence that the pocket signatures have on the interaction of HLA-DR molecules with Tg peptides. Our study suggests that interactions between Tg and discrete HLA-DR pocket signatures contribute to the initiation of AITD.


Subject(s)
Gene Expression Regulation , HLA-DR3 Antigen/metabolism , Recombinant Proteins/chemistry , Algorithms , Animals , Autoimmune Diseases , Cathepsins/chemistry , Cell Line , HeLa Cells , Histocompatibility Antigens Class II , Humans , Peptides/chemistry , Rats , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Thyroglobulin/chemistry , Thyroid Diseases/immunology , Thyroid Gland/metabolism
10.
Proc Natl Acad Sci U S A ; 105(37): 14034-9, 2008 Sep 16.
Article in English | MEDLINE | ID: mdl-18779568

ABSTRACT

Hashimoto's thyroiditis (HT) is associated with HLA, but the associated allele is still controversial. We hypothesized that specific HLA-DR pocket-sequence variants are associated with HT and that similar variants in the murine I-E locus (homologous to HLA-DR) predispose to experimental autoimmune thyroiditis (EAT), a classical mouse model of HT. Therefore, we sequenced the polymorphic exon 2 of the HLA-DR gene in 94 HT patients and 149 controls. In addition, we sequenced exon 2 of the I-E gene in 22 strains of mice, 12 susceptible to EAT and 10 resistant. Using logistic regression analysis, we identified a pocket amino acid signature, Tyr-26, Tyr-30, Gln-70, Lys-71, strongly associated with HT (P = 6.18 x 10(-5), OR = 3.73). Lys-71 showed the strongest association (P = 1.7 x 10(-8), OR = 2.98). This association was seen across HLA-DR types. The 5-aa haplotype Tyr-26, Tyr-30, Gln-70, Lys-71, Arg-74 also was associated with HT (P = 3.66 x 10(-4)). In mice, the I-E pocket amino acids Val-28, Phe-86, and Asn-88 were strongly associated with EAT. Structural modeling studies demonstrated that pocket P4 was critical for the development of HT, and pockets P1 and P4 influenced susceptibility to EAT. Surprisingly, the structures of the HT- and EAT-susceptible pockets were different. We conclude that specific MHC II pocket amino acid signatures determine susceptibility to HT and EAT by causing structural changes in peptide-binding pockets that may influence peptide binding, selectivity, and presentation. Because the HT- and EAT-associated pockets are structurally different, it is likely that distinct antigenic peptides are associated with HT and EAT.


Subject(s)
HLA-DR Antigens/immunology , HLA-DR Antigens/metabolism , Peptides/immunology , Peptides/metabolism , Thyroiditis, Autoimmune/immunology , Thyroiditis, Autoimmune/metabolism , Amino Acids/metabolism , Animals , Binding Sites , Disease Models, Animal , HLA-DR Antigens/chemistry , HLA-DR Antigens/genetics , Humans , Mice , Peptides/chemistry , Sequence Analysis , Thyroiditis, Autoimmune/genetics
11.
Endocr Rev ; 29(6): 697-725, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18776148

ABSTRACT

Type 1 diabetes (T1D) and autoimmune thyroid diseases (AITD) frequently occur together within families and in the same individual. The co-occurrence of T1D and AITD in the same patient is one of the variants of the autoimmune polyglandular syndrome type 3 [APS3 variant (APS3v)]. Epidemiological data point to a strong genetic influence on the shared susceptibility to T1D and AITD. Recently, significant progress has been made in our understanding of the genetic association between T1D and AITD. At least three genes have been confirmed as major joint susceptibility genes for T1D and AITD: human leukocyte antigen class II, cytotoxic T-lymphocyte antigen 4 (CTLA-4), and protein tyrosine phosphatase non-receptor type 22. Moreover, the first whole genome linkage study has been recently completed, and additional genes will soon be identified. Not unexpectedly, all the joint genes for T1D and AITD identified so far are involved in immune regulation, specifically in the presentation of antigenic peptides to T cells. One of the lessons learned from the analysis of the joint susceptibility genes for T1D and AITD is that subset analysis is a key to dissecting the etiology of complex diseases. One of the best demonstrations of the power of subset analysis is the CTLA-4 gene in T1D. Although CTLA-4 showed very weak association with T1D, when analyzed in the subset of patients with both T1D and AITD, the genetic effect of CTLA-4 was significantly stronger. Gene-gene and genetic-epigenetic interactions most likely play a role in the shared genetic susceptibility to T1D and AITD. Dissecting these mechanisms will lead to a better understanding of the etiology of T1D and AITD, as well as autoimmunity in general.


Subject(s)
Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 1/genetics , Thyroiditis, Autoimmune/epidemiology , Thyroiditis, Autoimmune/genetics , Genetic Predisposition to Disease/epidemiology , Humans
12.
J Autoimmun ; 30(1-2): 58-62, 2008.
Article in English | MEDLINE | ID: mdl-18178059

ABSTRACT

The autoimmune thyroid diseases (AITD) comprise a cadre of complex diseases whose underlying pathoetiology stems from a genetic-environmental interaction, between susceptibility genes (e.g. CTLA-4, HLA-DR, thyroglobulin) and environmental triggers (e.g. dietary iodine), that orchestrates the initiation of an autoimmune response to thyroid antigens, leading to the onset of disease. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence on the development of AITD. Several AITD susceptibility genes have been identified, with HLA genes, in particular, appearing to be of major importance. Early studies showed association of HLA-DR3 with Graves' disease (GD) in Caucasians. More recently, the importance of an amino acid substitution at position 74 of the DR beta 1 chain of HLA-DR3 (DRb1-Arg74), in susceptibility to Graves' disease, has been shown. Furthermore, there is increasing evidence for a genetic interaction between thyroglobulin variants and DRb1-Arg74 in conferring risk for GD. Mechanistically, the presence of an arginine at position 74 elicits a significant structural change in the peptide binding pocket of HLA-DR, potentially affecting the binding of pathogenic thyroidal peptides. Future therapeutic interventions may attempt to exploit this new bolus of knowledge by endeavoring to block or modulate pathogenic peptide presentation by HLA-DR.


Subject(s)
Genes, MHC Class II , Genes, MHC Class I , Graves Disease/genetics , HLA-DR Antigens/genetics , Hashimoto Disease/genetics , Autoantibodies/immunology , Autoimmunity , Genetic Predisposition to Disease , Graves Disease/epidemiology , Graves Disease/immunology , Hashimoto Disease/epidemiology , Hashimoto Disease/immunology , Humans , Polymorphism, Genetic , Thyroglobulin/chemistry , Thyroglobulin/immunology , Thyroid Gland/immunology
13.
J Clin Endocrinol Metab ; 93(3): 1077-81, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18073300

ABSTRACT

CONTEXT: IL-23 and its receptor (IL-23R) guide T cells toward the T-helper 17 phenotype. IL-23R single nucleotide polymorphisms (SNPs) have been associated with several autoimmune diseases, including Crohn's disease and rheumatoid arthritis. OBJECTIVE: Our objective was to determine whether variants in the IL-23R gene are associated with Graves' disease (GD) and Graves' ophthalmopathy (GO). DESIGN AND PARTICIPANTS: A total of 216 North American Caucasian GD patients and 368 healthy controls were genotyped for four SNPs spanning the IL-23R gene. SNPs rs11209026 and rs7530511 were genotyped using the TaqMan allelic discrimination assays (Applied Biosystems, Foster City, CA), and SNPs rs2201841 and rs10889677 were genotyped using a fluorescent-based restriction fragment length polymorphism method. RESULTS: The A allele of rs2201841 was present in 78.8% of GD patients with GO and 64.7% of controls [P=1.1x10(-4); odds ratio (OR)=2.04]; the AA genotype was also significantly increased in GO patients compared with controls (62.5 and 41%, respectively; P=1.0x10(-4); OR=2.4). The C allele of rs10889677 was present in 78.6% of GO patients and 64.5% of controls (P=1.3x10(-4); OR=2.03), and the CC genotype was also significantly increased in GO patients vs. controls (62.1 and 41.0%, respectively; P=1.4x10(-4); OR=2.36). The TT genotype of rs7530511 was significantly associated with GD, but not specifically with GO; it was present in 2.5% of GD patients and 0.3% of controls (P=0.02; OR=9.4). The rs11209026 SNP, which is the most strongly associated with Crohn's disease, was not associated with GD or GO in our data set. CONCLUSIONS: Variants in the IL-23R gene are strongly associated with GO. These variants may predispose to GO by changing the expression and/or function of IL-23R, thereby promoting a proinflammatory signaling cascade.


Subject(s)
Autoimmunity , Genetic Predisposition to Disease , Graves Ophthalmopathy/genetics , Interleukin-23/physiology , Receptors, Interleukin/genetics , Th1 Cells/immunology , Thyroid Gland/immunology , Female , Humans , Male , Polymorphism, Single Nucleotide , STAT4 Transcription Factor/physiology , Th1 Cells/classification
14.
Thyroid ; 17(10): 949-61, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17824829

ABSTRACT

Autoimmune thyroid diseases (AITDs), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), are prevalent autoimmune diseases, affecting up to 5% of the general population. AITDs arise due to interplay between environmental and genetic factors. In the past decade, significant progress has been made in our understanding of the genetic contribution to the etiology of AITDs. Excitingly, several AITD susceptibility genes have been identified and characterized. Some of these susceptibility genes are specific to either GD or HT, while others confer susceptibility to both conditions. The first AITD susceptibility gene locus identified was the Human-Leukocyte-Antigen DR (HLA-DR) gene locus. Subsequently, a quintet of non-HLA genes, including the cytotoxic T lymphocyte antigen (CTLA-4), CD40, protein tyrosine phosphatase-22 (PTPN22), thyroglobulin, and thyroid-stimulating hormone receptor (TSHR) gene, has been shown to contribute to the susceptibility to AITDs. Recently, the mechanisms by which these new AITD genes predispose to AITDs have been dissected. In this review, we overview and highlight the recent data on the genes predisposing to AITDs and the putative mechanisms by which they confer susceptibility to disease.


Subject(s)
Autoimmunity/genetics , Thyroid Gland/immunology , Antigens, CD/genetics , Antigens, Differentiation/genetics , CD40 Antigens/genetics , CTLA-4 Antigen , Genetic Predisposition to Disease , HLA-DR Antigens/genetics , Humans , Protein Tyrosine Phosphatase, Non-Receptor Type 22/genetics
15.
J Autoimmun ; 28(4): 201-7, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17418529

ABSTRACT

FOXP3 is a key gene in the development of regulatory T cells (Treg). FOXP3 expression commits naïve T cells to become Treg cells. Indeed, mutations in the FOXP3 gene cause severe systemic autoimmune diseases in humans and in mice. Therefore, we hypothesized that the FOXP3 gene may be associated with thyroid autoimmunity which is among the typical autoimmune diseases that develop in individuals with FOXP3 mutations. Moreover, the FOXP3 gene is located within an X-chromosome locus (Xp11.23) previously shown to be linked with autoimmune thyroid diseases (AITD). We tested the FOXP3 gene locus for association with AITD in two large cohorts of US Caucasians and Japanese AITD patients. We analyzed 269 Caucasian AITD patients (52 males and 217 females) and 357 Caucasian controls (159 males and 198 females), as well as 377 female Japanese AITD patients and 179 female Japanese controls. The FOXP3 gene locus was analyzed using four microsatellite polymorphisms [(GT)n; (TC)n; DXS573; DXS1208] flanking the FOXP3 gene locus. Interestingly, while no association was found between FOXP3 polymorphisms and AITD in the Japanese cohort there was a significant association in the Caucasian cohort. There was a significant association of the (TC)n polymorphism with AITD in the Caucasian male AITD patients (p=0.011; 5 degrees of freedom [df]). Similarly, there was an association between the DXS573 microsatellite and AITD in the Caucasian female AITD patients (p=0.00023; 4 df). These results suggest that polymorphisms of the FOXP3 gene may play a role in the genetic susceptibility to AITD in Caucasians, perhaps by altering FOXP3 function and/or expression.


Subject(s)
Asian People , Forkhead Transcription Factors/genetics , Genetic Predisposition to Disease , T-Lymphocytes, Regulatory , Thyroiditis, Autoimmune/genetics , White People , Animals , Chromosomes, Human, X/genetics , Chromosomes, Human, X/immunology , Cohort Studies , Female , Forkhead Transcription Factors/immunology , Humans , Male , Mice , Microsatellite Repeats , Polymorphism, Genetic/immunology , Quantitative Trait Loci/immunology , Sex Factors , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/pathology , Thyroiditis, Autoimmune/ethnology , Thyroiditis, Autoimmune/immunology , Thyroiditis, Autoimmune/pathology
16.
J Autoimmun ; 28(2-3): 85-98, 2007.
Article in English | MEDLINE | ID: mdl-17369021

ABSTRACT

Autoimmune thyroid diseases (AITD) are common autoimmune diseases, affecting up to 5% of the general population. Thyroid-directed autoimmunity is manifested in two classical autoimmune conditions, Hashimoto's thyroiditis, resulting in hypothyroidism and Graves' disease resulting in hyperthyroidism. Autoimmune thyroid diseases arise due to an interplay between environmental and genetic factors. In the past decade significant progress has been made in our understanding of the genetic contribution to the etiology of AITD. Indeed, several AITD susceptibility genes have been identified. Some of these susceptibility genes are specific to either Graves' disease or Hashimoto's thyroiditis, while others confer susceptibility to both conditions. Both immunoregulatory genes and thyroid specific genes contribute to the pathogenesis of AITD. The time is now ripe to examine the mechanistic basis for the contribution of genetic factors to the etiology of AITD. In this review, we will focus on the contribution of non-MHC II genes.


Subject(s)
Antigens, CD/genetics , Antigens, Differentiation/genetics , CD40 Antigens/genetics , Graves Disease/genetics , Hashimoto Disease/genetics , Protein Tyrosine Phosphatases/genetics , Receptors, Thyrotropin/genetics , Thyroglobulin/genetics , Animals , Antigens, CD/immunology , Antigens, CD/metabolism , Antigens, Differentiation/immunology , Antigens, Differentiation/metabolism , CD40 Antigens/metabolism , CTLA-4 Antigen , Genetic Predisposition to Disease , Graves Disease/etiology , Graves Disease/immunology , Hashimoto Disease/etiology , Hashimoto Disease/immunology , Humans , Polymorphism, Single Nucleotide , Protein Tyrosine Phosphatase, Non-Receptor Type 22 , Protein Tyrosine Phosphatases/metabolism , Receptors, Thyrotropin/metabolism , Thyroglobulin/metabolism
17.
Endocrinology ; 146(6): 2684-91, 2005 Jun.
Article in English | MEDLINE | ID: mdl-15731360

ABSTRACT

We analyzed the mechanism by which a Graves' disease-associated C/T polymorphism in the Kozak sequence of CD40 affects CD40 expression. CD40 expression levels on B cells in individuals with CT and TT genotypes were decreased by 13.3 and 39.4%, respectively, compared with the levels in CC genotypes (P = 0.012). Similarly, Rat-2 fibroblasts transfected with T-allele cDNA expressed 32.2% less CD40 compared with their C-allele-transfected counterparts (P = 0.004). Additionally, an in vitro transcription/translation system showed that the T-allele makes 15.5% less CD40 than the C-allele (P < 0.001), demonstrating that the effect of the single-nucleotide polymorphism (SNP) on CD40 expression is at the level of translation. However, the SNP did not affect transcription, because the mRNA levels of CD40, as measured by quantitative RT-PCR, were independent of genotype. Therefore, our results may suggest that the C allele of the CD40 Kozak SNP, which is associated with Graves' disease, could predispose to disease by increasing the efficiency of translation of CD40 mRNA.


Subject(s)
CD40 Antigens/genetics , Graves Disease/genetics , Polymorphism, Single Nucleotide , Protein Biosynthesis/physiology , 5' Untranslated Regions/genetics , Animals , B-Lymphocytes/physiology , Cells, Cultured , Fibroblasts/cytology , Fibroblasts/physiology , Graves Disease/physiopathology , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred C3H , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Inbred DBA , RNA, Messenger/analysis , Rats , Transcription, Genetic/physiology , Transfection
18.
J Am Chem Soc ; 125(39): 11804-5, 2003 Oct 01.
Article in English | MEDLINE | ID: mdl-14505387

ABSTRACT

An improved forward chemical genetics approach was successfully demonstrated using a tagged library concept. A small-molecule triazine library with linkers was used to screen for brain/eye developmental phenotypes in a zebrafish embryo system. This approach enabled the rapid isolation of the target proteins by facile affinity matrix preparation and elucidated the first small-molecule inhibitors for several ribosomal accessory proteins or their complex as the target.


Subject(s)
Drug Evaluation, Preclinical/methods , Triazines/chemistry , Zebrafish/genetics , Animals , Combinatorial Chemistry Techniques/methods , Zebrafish/embryology
19.
Acta Crystallogr D Biol Crystallogr ; 59(Pt 8): 1493-5, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12876363

ABSTRACT

The SfiI endonuclease from Streptomyces fimbriatus (EC 3.1.21.4) is a tetrameric enzyme that binds simultaneously to two recognition sites and cleaves both sites concertedly. It serves as a good model system for studying both specificity and cooperative DNA binding. Crystals of the enzyme were obtained by the hanging-drop vapor-diffusion method in complex with a 21-mer oligonucleotide. The crystals are trigonal, with unit-cell parameters a = b = 85.7, c = 202.6 A, and diffract to 2.6 A resolution on a rotating-anode X-ray generator. Preliminary X-ray analysis reveals the space group to be either P3(1)21 or P3(2)21. Interestingly, the crystals change to space group P6(1)22, with unit-cell parameters a = b = 85.5, c = 419.6 A, when the selenomethionyl (SeMet) derivative of the enzyme is co-crystallized with the same DNA. Phase information is currently being derived from this SeMet SfiI-DNA complex.


Subject(s)
Deoxyribonucleases, Type II Site-Specific/chemistry , Crystallization , Crystallography, X-Ray , DNA/chemistry , Oligonucleotides/chemistry , Protein Binding , Streptomyces/enzymology , X-Rays
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