Peroxiredoxins : Its pathophysiological roles in the treatment of autoimmune thyroid diseses

Shong, Minho,Kim, Ho,Lee, Tae-Hoon,Kim, Kang Hwa 이화여자대학교 세포신호전달연구센터 2001 고사리 세포신호전달 심포지움 Vol. No.3

Thyroid epithelial cells are constantly exposed to reactive oxygen species because they produce a large amount of hydrogen peroxide(H₂O₂) in response to thyrotropin. A high level of H₂O₂ can induce an oxidative stress response in thyrocytes which signals the cell nucleus to arrest growth and undergo apoptosis. Because H₂O₂ can directly damage DNA and other biological macromolecules, it has been suggested that thyrocytes should have mechanisms to control the intracellular level of H₂O₂. Although thyroid cells utilize several cellular defense systems against oxidative damage including antioxidant proteins, superoxide dismutase, catalase and glutathione, the exact mechanisms involved in regulating intracellular H₂O₂ are not known. Peroxiredoxins(Prx) play an important role in regulating cellular differentiation and proliferation in several types of mammalian cells. One mechanism for this action involves modulation of hydrogen peroxide(H₂O₂)-mediated cellular responses. This report examines the expression of PrxⅠ and PrxⅡ in thyroid cells and their roles in eliminating H₂O₂ produced in response to TSH. PrxⅠ and PrxⅡ are constitutively expressed in FRTL-5 thyroid cells. PrxⅠ expression, but not PrxⅡ expression, is stimulated by exposure to TSH and H₂O₂. In addition, methimazole(MMI) induces a high level of Prx I mRNA and protein in these cells. Overexpression of PrxⅠ and Prx II enhance the elimination of H₂O₂ produced by TSH in FRTL-5 cells. Treatment with 500μM H₂O₂ causes apoptosis in FRTL-5 cells as evidenced by standard assays of apoptosis(i.e., terminal deoxynucleotidyl transferase deoxyuridine triphosphate-biotin nick end-labeling(TUNEL), BAX expression and PARP cleavage. Overexpression of PrxⅠ and PrxⅡ reduces the amount of H₂O₂-induced apoptosis measured by these assays. These results suggest that PrxⅠ and PrxⅡ are involved in the removal of H₂O₂ in thyroid cells, and can protect these cells from undergoing apoptosis. These proteins are likely to be involved in the normal physiological response to TSH-induced production of H₂O₂ in thyroid cells. The antithyroid drug, methimazole(MMI) is used to treat patients with Graves' hyperthyroidism. The major action of MMI is to inhibit synthesis of thyroid hormone in the thyroid gland. However, MMI also has antioxidant and immunomodulatory effects on thyrocytes and/or immune cells. This study identifies novel antioxidant and immunomodulatory effects of MMI involving the IFN-γ signaling pathway in thyroid cells. MMI inhibits transcription of the ICAM-1 gene by modulating the function of transcription factor STAT1 which binds to the IFN-γ activated site of the ICAM-1 promoter. Furthermore, MMI rapidly eliminates H₂O₂ produced by IFN-γ treatment in thyroid cells, and thus inhibits the H₂O₂-mediated phosphorylation of tyrosine Y701 in STAT1. MMI also eliminates H₂O₂ in vitro. MMI facilitates electron transfer from NADPH to H₂O₂ using thioredoxin or glutathione, fulfilling a role similar to peroxiredoxin or glutathione peroxidase, respectively. MMI prevents the IFN-γ and H₂O₂-mediated reversible inactivation of phosphateases. These effects attenuates full activation of IFN-γ-induced JAK/STAT signaling pathway in FRTL-5 thyroid cells. These results may in part explain the antioxidant and immunomodulatory effects of MMI in thyroid cells of Graves' disease patients.

THYROID CARCINOGENESIS : CURRENT FINDINGS AND FUTURE PERSPECTIVES

Shong, Minho 이화여자대학교 세포신호전달연구센터 2006 고사리 세포신호전달 심포지움 Vol. No.8

Differentiated thyroid cancers, including papillary and follicular carcinomas, frequently develop as a result of genetic alterations. Papillary thyroid cancers(PTC) show balanced inversions or translocations that usually involve the 3.0 kb intron 11 of the tyrosine kinase receptor protein RET. These rearrangements result in the formation of RET/PTC through the fusion of the tyrosine kinase domain of the RET proto-oncogene with the 5'-end of activating heterologous sequences belonging to the RET-fused genes. RET/PTC has been reported to be a constitutively active kinase in thyroid epithelial cells. Although RET/PTC has intrinsic tyrosine kinase activity, the direct substrates of RET/PTC in thyroid cells are largely unknown. We have examined the interaction of RET/PTC and STAT3, and the phosphorylation activity of RET/PTC on the Y705 residue of STAT3. STAT3 is a direct substrate for RET/PTC tyrosine kinase and that Y705 phosphorylation in STAT3 by RET/PTC is a critical signaling pathway for the specific induction of genes in the RET/PTC-mediated transformation process. Here we show that LKB1 act as a suppressor of stat3 in RET/PTC mediated processes of transformation. The mutations of LKB I protein kinase in human results in a disorder termed Peutz-Jeghers syndrome(PJS), which predisposes to a wide spectrum of benign and malignant tumours. LKB1+/- heterozygous mice develop tumours resembling those found in PJS in humans. The overexpression of LKB1 in LKB1-deficient cancer cells induced a G1 cell cycle arrest and genetic studies in Caenorhabditis elegans, Drosophila and Xenopus indicated that the LKB1 homologue in these organisms plays a role in regulating cell polarity. We have reported that RET/PTC is able to activated STAT3 and it involved in transformation in thyroid carcinogenesis. The wild type and kinase dead mutant LKB1 decreased stat3 transcriptional activity in RET/PTC transfected cells. LKB1 showed interactions with STAT3 inimmunoprecipitation experiments. The LKB1 and activated STAT3 colocalized within the nucleus. The GAL4-fused LKB1 showed intrinsic repressor activities. However the repressor activities were not affected by treatment of HDAC inhibitors. The LKB1-mediated suppression of STAT3 transciption was not dependent on S727 residue in transactivation domain of STAT3. These observation indicate that LKB1 is transcriptional co-repressor of STAT3 which is activated by thyroid specific oncogenic tyrosine kinase, RET/PTC. In addition, we showed that 2-indolinone compounds; SU5416, SU6668 and SU11248 showed variable activities on the inhibition of RET/PTC tyrosine kinases. SU11248 showed the most potent and very specific properties for the inhibition of RET/PTC. These findings suggest that 2-indolinone-derivates, SU11248 might be a potential therapeutic candidate by inhibiting RET/PTC in papillary thyroid cancer.

Regulation of Major Histocompatibility Class Ⅱ Gene Expressino in FRTL-5 Thyrocytes : Opposite Effects of Interferon and Methimazole

MONTANI, VALERIA,SHONG, MINHO,TANIGUCHI, SHIN-ICHI,SUZUKI, KOICHI,GIULIANI, CESIDIO,NAPOLITANO, GIORGIO,SAITO, JUN,SAJI, MOTOYASU,FIORENTINO, BRUNO,REIMOLD, ANDREAS M.,SINGER, DINAH S.,KOHN, LEONARD D 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

Aberrant expression of major histocompatibility complex (MHC) classⅡ antigens is associated with autoimmune thyroid disease; aberrant expression duplicating the autoimmune state can be induced by interferon-γ (IFNγ). We have studied IFNγ-induced human leukocyte antigen (HLA)-DRα gene expression in rat FRTL-5 thyroid cells to identify the elements and factors important for aberrant expression. Using an HLA-DRα 5'-flanking region construct from-176 to +45 bp coupled to the chloramphenicol acetyltransferase reporter gene, we show that there is no basal classⅡ gene expression in FRTL-5 thyroid cells, that IFNγ can induce expression, and, as is the case for antigen-presenting cells from the immune system, that IFNγ-induced expression requires several highly conserved elements on the 5'-flanking region, which, from 5' to 3', are the S, X_1, X_2, and Y boxes. Methimazole (MMI), a drug used to treat patients with Graves' disease and experimental thyroiditis in rats or mice, can suppress the IFNγ-induced increase in HLA-DRα gene expression as a function of time and concentration; MMI simultaneously decreases IFNγ-induced endogenous antigen presentation by the cell. Using gel shift assays and the HLA-DRα 5'-flanking region from -176 or -137 to +45 bp as radiolabeled probes, we observed the formation of a major protein-DNA complex with extracts from FRTL-5 cells untreated with IFNγ, termed the basal or constitutive complex, and formation of an additional complex with a slightly faster mobility in extracts from cells treated with IFNγ. MMI treatment of cells prevents IFNγ from increasing the formation of this faster migrating complex. Formation of both complexes is specific, as evidenced in competition studies with unlabeled fragments between -137 and -38 bp from the start of transcription; nevertheless, they can be distinguished in such studies. Thus, high concentrations of double stranded oligonucleotides containing the sequence of the Y box, but not S, X_1, or X_2 box sequences, can prevent formation of the IFNγ-increased faster migrating complex, but not the basal complex. Both complexes involve multiple proteins and can be distinguished by differences in their protein composition. Thus, using specific antisera, we show that two cAMP response element-binding proteins, activating transcription factor-1 and/or -2, are dominant proteins in the upper or basal complex. The upper or basal complex also includes c-Fos, Fra-2, Ets-2, and Oct-1. A dominant protein that distinguishes the IFNγ-increased lower complex is CREB-binding protein (CBP), a coactivator of cAMP response element-binding proteins. We, therefore, show that aberrant expression of MHC classⅡ in thyrocytes, induced by IFNγ, is associated with the induction or increased formation of a novel portein-DNA complex and that its formation as well as aberrant classⅡ expression are suppressed by MMI, a drug used to treat human and experimental autoimmune thyroid disease. Its component proteins differ from those in a major, basal, or constitutive protein-DNA complex formed with the classⅡ 5'-flanking region in cells that are not treated with IFNγ and that do not express the classⅡ gene. (Endocrinology 139: 290-302, 1998)

Iodide Suppression of Major Histocompatibility Class I Gene Expression in Thyroid Cells Involves Enhancer A and the Transcription Factor NF-kB

Taniguchi, Shin-Ichi,Shong, Minho,Giuliani, Cesidio,Napolitano, Giorgio,Saji, Motoyasu,Montani, Valeria,Suzuki, Koichi,Singer, Dinah S.,Kohn, Leonard D. 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

Increased MHC class I expression on thyrodytes is evident in ATD (4, 21) and has been suggested to be an important causal factor in the development or perpetuation of disease expression (3). The hypothesis has been offered that the elevations result in abnormal presentation of thyroid antigens to immune cells, thereby breaking tolerance, and that this elicits the clonal expansion of autoreactive T cells associated with disease expression (3).

산후 갑상선염의 경과에 관한 임상적 고찰

노흥규,송치운,송민호 충남대학교 의과대학 지역사회의학연구소 1994 충남의대잡지 Vol.21 No.2

Postpartum thyroiditis is a disease with transient changes of thyroid function as hyperthyroidism, hypothyroidism and normal recovery 2-4 months after delivery. It occurs in 7-9% of postpartum women, is needed careful differential diagnosis from Graves' disease or Hashimoto's thyroiditis because of quite different clinical course. In order to establish the points for differentiation, we evaluated 30 cases of postpartum thyroiditis patients with the following results. 1. 14 patients were diagnosed as hyperthyroidism 4.4±1.6 months after delivery with mild degree of thyrotoxic symptoms. The anti-thyroglobulin antibody and anti-microsomal antibody were positive but thyrotropin receptor antibody were negative. 2. 16 cases were diagnosed as hypothyroidism with enlarged goiter 6.1±0.9 months after delivery and the ATA and AMA were positive both but TBII was negative in all cases. 3. The thyroid function of 71.4% of hyperthyroid patients became hypothyroidism in 1-3 months and recovered to normal in 1-3.5 months thereafter. In 68.8% of hypothyroid patients became euthyroidism within 1-8 months and 21.4% 1(3 cases) of the patients remained as hypothroidism untill 12 months' observation. In conclusion, the thyroid function changes as hyperthyroidism, hypothyroidism and euthyroidism stepwise in most cases of pospartum thyroiditis and serum TBII is negative, which are the most important features in differentiating from other autoimmune thyroid disease.

GRP94는 thyroglobulin의 folding에 관여한다.

Seong, Yeon-Mun,Shong, MinHo,Kwon, O-Yu Korean Society of Life Science 1999 생명과학회지 Vol.9 No.1

Endoplasmic reticulum (ER)내에 단백질의 folding과 안정화에 관여하는 단백질을 molecular cha-perone이라고 한다. GRP94 역시 ER내에 존재하는 molecular chaperone으로 알려지고 있지만 갑상선세포에서 단백질의 folding에 관여한다는 증거는 아직 불충분하다. 본 설험은 molecular chaperone을 세포내에서 overexpression시킬 수 있는 system을 확립하였다. 그 중에서 GRP94가 단백질의 folding에 직접적으로 관여한다는 증거를 얻기 위하여, endogenous GRP94를 code한 cDNA를 overexpression vector에 의해서 forced expression시킴으로 신생thyroglobulin의 folding에 직접적으로 관여하는 증거를 immun-oprecipitation으로 증명하였다. Mammalial expression vectors containing GRP94, BiP, ERp72, and PDI, were introduced into FRTL5 cells. Transfected cells were selected by neomycin resistance for exogenously overexpressed proteins in the ER. The use of a reducible cross-linker, DSP, markedly improved the ability to detect noncovalent interactions of PDI, BiP and GRP94 with newly-synthesized thyroglobulin. Under normal conditions, GRP94 was found to associate transiently with early Tg folding intermediates, displaying interaction kinetics similar to those reported for another ER chaperones of BiP.

Major Histocompatibility Class Ⅱ HLA-DRα Gene Expression in Thyrocytes : Counter Regulation by the Class Ⅱ Transactivator and the Thyroid Y Box Protein

MONTANI, VALERIA,TANIGUCHI, SHIN-ICHI,SHONG, MINHO,SUZUKI, KOICHI,OHMORI, MASAYUKI,GIULIANI, CESIDIO,NAPOLITANO, GIORGIO,SAJI, MOTOYASU,FIORENTINO, BRUNO,REIMOLD, ANDREAS M.,TING, JENNY P.-Y,KOHN, LEO 충남대학교 생물공학연구소 1999 생물공학연구지 Vol.7 No.-

Aberrant expression of major histocompatibility complex(MHC) classⅡ proteins on thyrocytes, which is associated with autoimmune thyroid disease, is mimicked by γ-interferon (γ-IFN). To define elements and factors that regulate classⅡ gene expression in thyrocytes and that might be involved in aberrant expression, we have studied γ-IFN-induced HLA-DRα gene expression in rat FRTL-5 thyroid cells. The present report shows that classⅡ expression in FRTL-5 thyrocytes is positively regulated by the classⅡ transactivator (CIITA), and that CIITA mimics the action of γ-IFN. Thus as is the case for γ-IFN, several distinct and highly conserved elements on the 5'-flanking region of the HLA-DRα gene, the S, X_1, X_2, and Y boxes between -137 to -65 bp, are required for classⅡ gene expression induced by pCIITA transfection in FRTL-5 thyroid cells. CIITA and γ-IFN do not cause additive increases in HLA-DRα gene expression in FRTL-5 cells, consistent with the possibility that CIITA is an intermediate factor in the γ-IFN pathway to increased classⅡ gene expression. Additionally, γ-IFN treatment of FRTL-5 cells induces an endogenous CIITA transcript; pCIITA transfection mimics the ability of γ-IFN treatment of FRTL-5 thyroid cells to increase the formation of a specific and novel protein/DNA complex containing CBP, a coactivator of CRE binding proteins important for cAMP-induced gene expression; and the action of both γ-IFN and CIITA to increase classⅡ gene expression and increase complex formation is reduced by cotransfection of a thyroid Y box protein, which suppresses MHC classⅠ gene expression in FRTL-5 thyroid cells and is a homolog of human YB-1, which suppresses MHC classⅡ expression in human glioma cells. we conclude that CIITA and TSH receptor suppressor element binding protein-1 are components of the γ-IFN-regulated transduction system which, respectively, increase or decrease classⅡ gene expression in thyrocytes and may, therefore, be involved in aberrant classⅡ expression associated with autoimmune thyroid disease. (Endocrinology 139: 280-289, 1998)

The mitochondrial unfolded protein response and mitohormesis: a perspective on metabolic diseases

Yi, Hyon-Seung,Chang, Joon Young,Shong, Minho Bioscientifica Ltd 2018 Journal of molecular endocrinology Vol.61 No.3

<P>Mitochondria perform essential roles as crucial organelles for cellular and systemic energy homeostasis, and as signaling hubs, which coordinate nuclear transcriptional responses to the intra- and extra-cellular environment. Complex human diseases, including diabetes, obesity, fatty liver disease and aging-related degenerative diseases are associated with alterations in mitochondrial oxidative phosphorylation (OxPhos) function. However, a recent series of studies in animal models have revealed that an integrated response to tolerable mitochondrial stress appears to render cells less susceptible to subsequent aging processes and metabolic stresses, which is a key feature of mitohormesis. The mitochondrial unfolded protein response (UPR<SUP>mt</SUP>) is a central part of the mitohormetic response and is a retrograde signaling pathway, which utilizes the mitochondria-to-nucleus communication network. Our understanding of the UPR<SUP>mt</SUP> has contributed to elucidating the role of mitochondria in metabolic adaptation and lifespan regulation. In this review, we discuss and integrate recent data from the literature on the present status of mitochondrial OxPhos function in the development of metabolic diseases, relying on evidence from human and other animal studies, which points to alterations in mitochondrial function as a key factor in the regulation of metabolic diseases and conclude with a discussion on the specific roles of UPR<SUP>mt</SUP> and mitohormesis as a novel therapeutic strategy for the treatment of obesity and insulin resistance.</P>

EID-1 Interacts with Orphan Nuclear Receptor SF-1 and Represses Its Transactivation

Yun-Yong Park,Ki Cheol Park,Minho Shong,Soon-Jung Lee,Young-Ho Lee,Hueng-Sik Choi 한국분자세포생물학회 2007 Molecules and cells Vol.24 No.3

갑상선유두암의 병인에 근거한 치료제의 개발과 문제점

이민희 ( Min Hee Lee ),조영석 ( Young Suk Jo ),송민호 ( Minho Shong ) 대한갑상선학회 2010 International Journal of Thyroidology Vol.3 No.2

Papillary thyroid cancer (PTC) is the most common endocrine malignancy. The prognosis of PTC is defined primarily by the principal clinical features such as patient’s age, tumor size, histological subtypes, regional nodal metastasis, extra-thyroidal invasion and distant metastasis. Although PTC prognosis is excellent, adverse clinical features increase the probability of recurrence and progression. To improve patients’ survival and reduce recurrence and progression, advances in molecular biological insights for principal clinical features will beneeded. It has been recognized for years that aberrant kinase activation can induce cellular transformation, carcinogenesis and disease progression. Based on this concept, many investigators have been focusing on the development of new small molecules to inhibit the aberrant kinase activation and conducted clinical trials. In this review article, we describe the background for development of new targeted therapy and define molecular biological insights into the carcinogenesis of PTC.