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Brailsford JA, Stockdill JL, Axelrod AJ, Peterson MT, Vadola PA, Johnston EV, Danishefsky SJ. Total Chemical Synthesis of Human Thyroid-Stimulating Hormone (hTSH) β-Subunit: Application of Arginine-tagged Acetamidomethyl (Acm R) Protecting Groups. Tetrahedron 2018; 74:1951-1956. [PMID: 30853725 PMCID: PMC6402344 DOI: 10.1016/j.tet.2018.02.067] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The β-subunit of human thyroid stimulating hormone (hTSH) has been synthesized as a single glycoform bearing a chitobiose disaccharide at the native glycosylation site. Key to the successful completion of this synthesis was the introduction of an arginine-tagged acetamidomethyl group, which served to greatly facilitate handling of a glycopeptide fragment with poor aqueous solubility. This general solution to the challenge of working with intractable peptides is expected to find wide use in protein synthesis.
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Affiliation(s)
- John A Brailsford
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Jennifer L Stockdill
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Abram J Axelrod
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Michael T Peterson
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Paul A Vadola
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Eric V Johnston
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
| | - Samuel J Danishefsky
- Laboratory for Bioorganic Chemistry, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065
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2
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Sant'Ana PM, Oliveira JE, Lima ER, Soares CRJ, Peroni CN, Bartolini P, Ribela MTCP. Human thyroid-stimulating hormone synthesis in human embryonic kidney cells and related N-glycoprofiling analysis for carbohydrate composition determination. Appl Microbiol Biotechnol 2017; 102:1215-1228. [PMID: 29247366 DOI: 10.1007/s00253-017-8684-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/27/2017] [Accepted: 11/29/2017] [Indexed: 12/01/2022]
Abstract
A strain of embryonic human kidney cells (HEK293) was transiently co-transfected with the expression vectors coding for the α- and β-subunits of human thyroid-stimulating hormone (hTSH), and, for the first time, a human cell-derived recombinant hTSH was synthesized and extensively characterized. The purification strategy involving two steps provided an overall yield of 55% and a purity level > 90%. The purified material (hTSH-HEK) was analyzed and compared to a CHO-derived recombinant preparation (hTSH-CHO) and to a pituitary-derived (hTSH-Pit) preparation. The three preparations showed an equivalent purity (> 95%) with a hTSH-HEK molecular mass 2.1% lower than that of hTSH-CHO and 2.7% higher than that of hTSH-Pit. Remarkable differences were found in the carbohydrate moiety, the lowest sialic acid content and highest fucose content being observed in hTSH-HEK. In vivo biological activity was confirmed for the three preparations, the hTSH-HEK bioactivity being 39 and 16% lower than those of hTSH-CHO and hTSH-Pit, respectively. The hTSH-HEK circulatory half-life (t 1/2) was also shorter than those of hTSH-CHO (1.5-fold) and hTSH-Pit (1.2-fold). According to these findings, HEK-293-derived hTSH can be considered to be useful for clinical applications, in view as well of its human origin and particular carbohydrate composition.
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Affiliation(s)
- P M Sant'Ana
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - J E Oliveira
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - E R Lima
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - C R J Soares
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - C N Peroni
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - P Bartolini
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - Maria Teresa C P Ribela
- Biotechnology Department, IPEN-CNEN, Av. Prof. Lineu Prestes 2242, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
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3
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Ribela MTCP, Damiani R, Silva FD, Lima ER, Oliveira JE, Peroni CN, Torjesen PA, Soares CR, Bartolini P. N-Glycoprofiling Analysis for Carbohydrate Composition and Site-Occupancy Determination in a Poly-Glycosylated Protein: Human Thyrotropin of Different Origins. Int J Mol Sci 2017; 18:ijms18020131. [PMID: 28165356 PMCID: PMC5343769 DOI: 10.3390/ijms18020131] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 12/22/2016] [Accepted: 12/28/2016] [Indexed: 11/16/2022] Open
Abstract
Human thyrotropin (hTSH) is a glycoprotein with three potential glycosylation sites: two in the α-subunit and one in the β-subunit. These sites are not always occupied and occupancy is frequently neglected in glycoprotein characterization, even though it is related to folding, trafficking, initiation of inflammation and host defense, as well as congenital disorders of glycosylation (CDG). For the first time N-glycoprofiling analysis was applied to the site-occupancy determination of two native pituitary hTSH, in comparison with three recombinant preparations of hTSH, a widely used biopharmaceutical. A single methodology provided the: (i) average N-glycan mass; (ii) mass fraction of each monosaccharide and of sulfate; and (iii) percent carbohydrate. The results indicate that the occupancy (65%–87%) and carbohydrate mass (12%–19%) can be up to 34%–57% higher in recombinant hormones. The average glycan mass is 24% lower in pituitary hTSH and contains ~3-fold fewer moles of galactose (p < 0.005) and sialic acid (p < 0.01). One of the two native preparations, which had the smallest glycan mass together with the lowest occupancy and GalNAc, sulfate, Gal and sialic acid contents, also presented the lowest in vivo bioactivity and circulatory half-life. The methodology described, comparing a recombinant biopharmaceutical to its native equivalent, can be applied to any physiologically or clinical relevant glycoprotein.
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Affiliation(s)
- Maria Teresa C P Ribela
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Renata Damiani
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Felipe D Silva
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Eliana R Lima
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - João E Oliveira
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Cibele N Peroni
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Peter A Torjesen
- Hormone Laboratory, Oslo University Hospital, 0424 Oslo, Norway.
| | - Carlos R Soares
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
| | - Paolo Bartolini
- Biotechnology Center, Instituto de Pesquisas Energéticas e Nucleares, IPEN-CNEN/SP-Avenida Prof. Lineu Prestes, 2242-Cidade Universitária, 05508-000 São Paulo, Brazil.
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4
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Congenital nephrotic syndrome with dysmorphic features and death in early infancy: Answers. Pediatr Nephrol 2016; 31:1283-6. [PMID: 25956699 DOI: 10.1007/s00467-015-3070-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 02/10/2015] [Accepted: 02/10/2015] [Indexed: 10/23/2022]
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5
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Pechersky A. Features of diagnostics and treatment of partial androgen deficiency of aging men. Cent European J Urol 2014; 67:397-404. [PMID: 25667762 PMCID: PMC4310881 DOI: 10.5173/ceju.2014.04.art16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 03/10/2014] [Accepted: 06/28/2014] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION Decreasing of testosterone level is an important part of a male elderly. MATERIAL AND METHODS To describe this phenomenon a PubMed and national databases were searched for 17β-dehydrotestosterone, common testosterone, free testosterone, 17β-estradiol, luteinizing hormone, partial androgen deficiency of aging men. RESULTS The reduction in intensity of the processes of tissue renewal of the testicles results in a partial androgen deficiency of aging men. A decrease in the levels of total and free testosterone and an increase in the levels of 5α-dihydrotestosterone, 17β-estradiol, sex hormone binding globulin, LH and FSH, along with a decrease in the amplitude of the rhythm of incretion of LH, FSH and total testosterone will testify to a deficiency of testosterone. CONCLUSIONS It is very important to make an individualized selection of the dose of testosterone preparation which enters the blood plasma.
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Affiliation(s)
- Alexander Pechersky
- Department of Urology, North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia
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6
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Ikegami K, Liao XH, Hoshino Y, Ono H, Ota W, Ito Y, Nishiwaki-Ohkawa T, Sato C, Kitajima K, Iigo M, Shigeyoshi Y, Yamada M, Murata Y, Refetoff S, Yoshimura T. Tissue-specific posttranslational modification allows functional targeting of thyrotropin. Cell Rep 2014; 9:801-10. [PMID: 25437536 PMCID: PMC4251493 DOI: 10.1016/j.celrep.2014.10.006] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/04/2014] [Accepted: 09/30/2014] [Indexed: 10/24/2022] Open
Abstract
Thyroid-stimulating hormone (TSH; thyrotropin) is a glycoprotein secreted from the pituitary gland. Pars distalis-derived TSH (PD-TSH) stimulates the thyroid gland to produce thyroid hormones (THs), whereas pars tuberalis-derived TSH (PT-TSH) acts on the hypothalamus to regulate seasonal physiology and behavior. However, it had not been clear how these two TSHs avoid functional crosstalk. Here, we show that this regulation is mediated by tissue-specific glycosylation. Although PT-TSH is released into the circulation, it does not stimulate the thyroid gland. PD-TSH is known to have sulfated biantennary N-glycans, and sulfated TSH is rapidly metabolized in the liver. In contrast, PT-TSH has sialylated multibranched N-glycans; in the circulation, it forms the macro-TSH complex with immunoglobulin or albumin, resulting in the loss of its bioactivity. Glycosylation is fundamental to a wide range of biological processes. This report demonstrates its involvement in preventing functional crosstalk of signaling molecules in the body.
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Affiliation(s)
- Keisuke Ikegami
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Xiao-Hui Liao
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Yuta Hoshino
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hiroko Ono
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Wataru Ota
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Yuka Ito
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Taeko Nishiwaki-Ohkawa
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Chihiro Sato
- Laboratory of Animal Cell Function, Bioscience and Biotechnology Center and Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Ken Kitajima
- Laboratory of Animal Cell Function, Bioscience and Biotechnology Center and Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Masayuki Iigo
- Department of Applied Biological Chemistry, Faculty of Agriculture, C-Bio, and CORE, Utsunomiya University, 350 Mine-machi, Utsunomiya 321-8505, Japan
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511, Japan
| | - Masanobu Yamada
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan
| | - Yoshiharu Murata
- Department of Genetics, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Samuel Refetoff
- Department of Medicine, The University of Chicago, Chicago, IL 60637, USA; Department of Pediatrics and Committee on Genetics, The University of Chicago, Chicago, IL 60637, USA.
| | - Takashi Yoshimura
- Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Avian Bioscience Research Center, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; Division of Seasonal Biology, National Institute for Basic Biology, 38 Nishigonaka, Myodaiji, Okazaki 444-8585, Japan.
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7
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Park A, Honey DM, Hou L, Bird JJ, Zarazinski C, Searles M, Braithwaite C, Kingsbury JS, Kyazike J, Culm-Merdek K, Greene B, Stefano JE, Qiu H, McPherson JM, Pan CQ. Carbohydrate-mediated polyethylene glycol conjugation of TSH improves its pharmacological properties. Endocrinology 2013; 154:1373-83. [PMID: 23389953 DOI: 10.1210/en.2012-2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thyrogen (thyrotropin alfa for injection), recombinant human TSH (rhTSH), has been successfully used to enhance diagnostic radioiodine scanning and thyroglobulin testing in the follow-up of patients with thyroid cancer and as an adjunctive treatment for radioiodine thyroid remnant ablation. However, the short half-life of rhTSH in the circulation requires a multidose regimen. We developed novel sialic acid-mediated and galactose-mediated conjugation chemistries for targeting polyethylene glycol (PEG) to the three N-linked glycosylation sites on the protein, to prolong plasma half-life by eliminating kidney filtration and potential carbohydrate-mediated clearance. Conjugates of different PEG sizes and copy numbers were screened for reaction yield, TSH receptor binding, and murine phamacokinetics/pharmacodynamics studies. The best performing of these products, a 40-kDa mono-PEGylated sialic acid-mediated conjugate, exhibited a 3.5-fold longer duration of action than rhTSH in rats, as a 5-fold lower affinity was more than compensated by a 23-fold extension of circulation half-life. Biochemical characterization confirmed conjugation through the sialic acids. Correlation of PEG distribution on the three N-linked glycosylation sites and the PEG effect on receptor binding supported the previously reported structure-function relationship of rhTSH glycosylation. This long-acting rhTSH has the potential to significantly improve patient convenience and provider flexibility while reducing potential side effects associated with a sudden elevation of serum TSH.
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Affiliation(s)
- Anna Park
- Genzyme Corp., a Sanofi Company, Framingham, MA 01701, USA.
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8
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Bonnema SJ, Hegedüs L. Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome. Endocr Rev 2012; 33:920-80. [PMID: 22961916 DOI: 10.1210/er.2012-1030] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.
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Affiliation(s)
- Steen Joop Bonnema
- Department of Endocrinology, Odense University Hospital, DK-5000 Odense C, Denmark.
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Neumann S, Raaka BM, Gershengorn MC. Human TSH receptor ligands as pharmacological probes with potential clinical application. Expert Rev Endocrinol Metab 2009; 4:669. [PMID: 20161662 PMCID: PMC2819035 DOI: 10.1586/eem.09.36] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The biologic role of thyroid-stimulating hormone (TSH; thyrotropin) as an activator (agonist) of the TSH receptor (TSHR) in the hypothalamic-pituitary-thyroid axis is well known and activation of TSHR by recombinant human TSH is used clinically in patients with thyroid cancer. TSHR ligands other than TSH could be used to probe TSHR biology in thyroidal and extrathyroidal tissues, and potentially be employed in patients. A number of different TSHR ligands have been reported, including TSH analogs, antibodies and small-molecule, drug-like compounds. In this review, we will provide an update on all these classes of TSHR agonists and antagonists but place emphasis on small-molecule ligands.
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Affiliation(s)
- Susanne Neumann
- Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6324, Fax: +1 301 480 4214
| | - Bruce M Raaka
- Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6307, Fax: +1 301 480 4214
| | - Marvin C Gershengorn
- Author for correspondence: Clinical Endocrinology Branch, NIDDK, NIH, 50 South Drive, Bethesda, MD 20892-28029, USA, Tel.: +1 301 451 6305, Fax: +1 301 480 4214,
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10
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Recombinant human TSH and ablation of post-surgical thyroid remnants in differentiated thyroid cancer: the effect of pre-treatment with furosemide and furosemide plus lithium. Eur J Nucl Med Mol Imaging 2009; 37:242-9. [DOI: 10.1007/s00259-009-1254-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Accepted: 07/31/2009] [Indexed: 10/20/2022]
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11
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Rebecchi KR, Wenke JL, Go EP, Desaire H. Label-free quantitation: a new glycoproteomics approach. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2009; 20:1048-1059. [PMID: 19278867 DOI: 10.1016/j.jasms.2009.01.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 12/08/2008] [Accepted: 01/19/2009] [Indexed: 05/27/2023]
Abstract
We demonstrate herein a method for quantifying glycosylation changes on glycoproteins. This novel method uses MS data of characterized glycopeptides to analyze glycosylation profiles, and several quality control tests were done to demonstrate that the method is reproducible, robust, applicable to different types of glycoproteins, and tolerant of instrumental variability during ionization of the analytes. This method is unique in that it is the first label-free quantitative method specifically designed for glycopeptide analysis. It can be used to monitor changes in glycosylation in a glycosylation site-specific manner on a single glycoprotein, or it can be used to quantify glycosylation in a glycoprotein mixture. During mixture analysis, the method can discriminate between changes in glycosylation of a given protein, and changes in the glycoprotein's concentration in the mixture. This method is useful for quantitative analyses in biochemical studies of glycoproteins, where changes in glycosylation composition can be linked to functional differences; it could also be implemented in the pharmaceutical industry, where glycosylation profiles of glycoprotein-based therapeutics must be quantified. Finally, quantification of glycopeptides is an important aspect of glycopeptide-based biomarker discovery, and our quantitative approach could be a valuable asset to this field as well, provided the compositions of the glycopeptides to be quantified are identifiable using other methods.
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Affiliation(s)
- Kathryn R Rebecchi
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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12
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Gramza A, Schuff KG. Recombinant human thyroid stimulating hormone in 2008: focus on thyroid cancer management. Onco Targets Ther 2009; 1:87-101. [PMID: 21127756 PMCID: PMC2994210 DOI: 10.2147/ott.s3480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Radioiodine (RAI) ablation following thyroidectomy is standard of care treatment for patients with intermediate or high risk differentiated thyroid cancer. Traditionally, this has been achieved by forgoing thyroid hormone replacement postoperatively, allowing endogenous thyroid stimulating hormone (TSH) levels to rise. This rise in TSH provides the stimulus for RAI uptake by the thyroid remnant, but is associated with clinical hypothyroidism and its associated morbidities. Recombinant human TSH (rhTSH, thyrotropin alfa [Thyrogen®], Genzyme Corporation, Cambridge, MA, USA) was developed to provide TSH stimulation without withdrawal of thyroid hormone and clinical hypothyroidism. Phase III studies reported equivalent detection of recurrent or residual disease when rhTSH was used compared with thyroid hormone withdrawal (THW). These trials led to its approval as an adjunctive diagnostic tool for serum thyroglobulin (Tg) testing with or without RAI imaging in the surveillance of patients with differentiated thyroid cancer. Recently, rhTSH was given an indication for adjunctive preparation for thyroid remnant ablation after phase III studies demonstrated comparable outcomes for rhTSH preparation when compared with THW. Importantly, rhTSH stimulation has been found to be safe, well tolerated, and to result in improved quality of life. Here, we review the efficacy and tolerability studies leading to the approval for the use of rhTSH in well-differentiated thyroid cancer management.
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Affiliation(s)
- Ann Gramza
- Division of Medical Oncology, Oregon Health and Science University, Portland, OR USA
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13
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Pacini F, Castagna MG. Diagnostic and therapeutic use of recombinant human TSH (rhTSH) in differentiated thyroid cancer. Best Pract Res Clin Endocrinol Metab 2008; 22:1009-21. [PMID: 19041828 DOI: 10.1016/j.beem.2008.09.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Traditionally, withdrawal of thyroid hormone to increase serum levels of thyroid-stimulating hormone (TSH) has been used in patients with differentiated thyroid carcinoma (DTC) to optimize radio-iodine uptake and serum thyroglobulin (Tg) stimulation during follow-up and in preparation for radio-iodine therapy. However, this procedure is associated with signs and symptoms of hypothyroidism which negatively affect the patient's quality of life. Recombinant human thyrotropin (rhTSH) has provided an effective alternative to thyroid hormone withdrawal. After favourable experimental trials in humans, rhTSH obtained regulatory approval in North America and in Europe as a diagnostic tool, and more recently as a preparation for radio-iodine thyroid remnant ablation. Since then, rhTSH has radically changed the diagnostic and therapeutic management of DTC patients. This review will focus on the clinical application of rhTSH in the management of DTC, highlighting current indications and future perspectives.
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Affiliation(s)
- Furio Pacini
- Department of Internal Medicine, Endocrinology & Metabolism and Biochemistry, Section of Endocrinology & Metabolism, University of Siena, Italy.
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14
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Paz-Filho GJ, Graf H. Recombinant human thyrotropin in the management of thyroid disorders. Expert Opin Biol Ther 2008; 8:1721-32. [PMID: 18847307 DOI: 10.1517/14712598.8.11.1721] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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van Hoek IM, Peremans K, Vandermeulen E, Duchateau L, Gommeren K, Daminet S. Effect of recombinant human thyroid stimulating hormone on serum thyroxin and thyroid scintigraphy in euthyroid cats. J Feline Med Surg 2008; 11:309-14. [PMID: 18848482 DOI: 10.1016/j.jfms.2008.07.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2008] [Indexed: 11/18/2022]
Abstract
This study investigated the thyroidal response to administration of recombinant human thyroid stimulating hormone (rhTSH) by means of serum total thyroxine (TT(4)) concentration and pertechnetate uptake by the thyroid gland in six healthy euthyroid spayed female cats. A pertechnetate scan was performed on day 1 to calculate thyroid/salivary gland (T/S) uptake ratio. On day 3, 25 microg rhTSH was injected intravenously. Six hours later the thyroid scan was repeated as on day 1. Blood was drawn for serum TT(4) measurement prior to injection of rhTSH and performance of the pertechnetate scan. Statistically significant differences in mean serum TT(4) concentration, T/S uptake ratio before and 6h after rhTSH administration and T/S uptake ratio between left and right lobes were noted. We can conclude that 25 microg rhTSH increases pertechnetate uptake in the thyroid glands of cats, this should be taken into account when thyroid scintigraphy after rhTSH administration is interpreted.
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Affiliation(s)
- Ingrid M van Hoek
- Department of Medicine and Clinical Biology of Small Animals, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
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16
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Influence of a Reduced CO2 Environment on the Secretion Yield, Potency and N-Glycan Structures of Recombinant Thyrotropin from CHO Cells. Mol Biotechnol 2008; 39:159-66. [DOI: 10.1007/s12033-008-9047-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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Boretti FS, Sieber-Ruckstuhl NS, Willi B, Lutz H, Hofmann-Lehmann R, Reusch CE. Comparison of the biological activity of recombinant human thyroid-stimulating hormone with bovine thyroid-stimulating hormone and evaluation of recombinant human thyroid-stimulating hormone in healthy dogs of different breeds. Am J Vet Res 2006; 67:1169-72. [PMID: 16817738 DOI: 10.2460/ajvr.67.7.1169] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate whether use of recombinant human (rh) thyroid-stimulating hormone (TSH) induces equivalent stimulation, compared with bovine TSH (bTSH), and to evaluate activity of rhTSH in dogs of various large breeds. ANIMALS 18 healthy research Beagles and 20 healthy client-owned dogs of various breeds with body weight > 20 kg. PROCEDURES The 18 Beagles were randomly assigned to 3 groups, and each dog received either 75 microg of rhTSH, IM or IV, or 1 unit of bTSH, IM, respectively, in a crossover design. The 20 client-owned dogs received 75 microg of rhTSH, IV. Blood samples were taken before and 6 hours after TSH administration for determination of total serum thyroxine (T(4)) concentration. Additional blood samples were taken after 2 and 4 hours in Beagles that received rhTSH, IM. RESULTS There was a significant increase in T(4) concentration in all dogs, but there were no differences between values obtained after administration of bTSH versus rhTSH or IV versus IM administration of rhTSH. Although there was a significant difference in age and body weight between Beagles and non-Beagles, there was no difference in post-TSH simulation T(4) concentration between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated an equivalent biological activity of rhTSH, compared with bTSH. Use of 75 microg of rhTSH, IV, did not induce a different magnitude of stimulation in large-breed dogs, compared with Beagles. Euthyroidism was confirmed if post-TSH simulation T(4) concentration was > or = 2.5 microg/dL and at least 1.5 times basal T(4) concentration.
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Affiliation(s)
- Felicitas S Boretti
- Clinic for Small Animal Internal Medicine, Vetsuisse Faculty, University of Zurich, Switzerland
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18
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Morelle W, Donadio S, Ronin C, Michalski JC. Characterization of N-glycans of recombinant human thyrotropin using mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:331-45. [PMID: 16372382 DOI: 10.1002/rcm.2289] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Thyroid-stimulating hormone is a vital component of the regulatory mechanism that maintains the structure and function of the thyroid gland and governs thyroid hormone release. In this paper we report the first detailed structural characterization of the N-linked oligosaccharides of recombinant human thyroid-stimulating hormone (rhTSH). Using a strategy combining mass spectrometric analysis and sequential exoglycosidase digestion, we have defined the structures of the N-glycans released from recombinant human thyrotropin by peptide N-glycosidase F. All glycans are complex-type glycans and are mainly of the bi- and triantennary type with variable degrees of fucosylation and sialylation. The major non-reducing epitope in the complex-type glycans is: NeuAcalpha2-3Galbeta1-4GlcNAc (sialylated LacNAc). The carbohydrate microheterogeneity at the three glycosylation sites was studied using reversed-phase high-performance liquid chromatography (RP-HPLC), concanavalin A affinity chromatography and mass spectrometric techniques, including both matrix-assisted laser desorption/ionization (MALDI) and electrospray. rhTSH was reduced, carboxymethylated and then digested with trypsin. The mixture of peptides and glycopeptides was subjected to RP-HPLC and the structures of the glycopeptides were determined by MALDI in conjunction with on-target exoglycosidase digestions. After PNGase F digestion, the peptide moiety of the glycopeptide was determined by the presence of the b- and y-series ions derived from its amino acid sequence in the quadrupole time-of-flight tandem mass (QTOF-MS/MS) spectrum. Glycosylation sites Asn-alpha52 and Asn-alpha78 contain mainly bi- and triantennary complex-type glycans. Only glycosylation site Asn-alpha52 bears fucosylated N-glycans. Minor tetraantennary complex structures were also observed on both glycosylation sites. Profiling of the carbohydrate moieties of Asn-beta23 indicates a large heterogeneity. Bi-, tri-, and tetraantennary N-glycans were present at this site. These data demonstrate site-specificity of glycosylation in the alpha subunit but not in the beta subunit of rhTSH with Asn-alpha52 bearing essentially di- and triantennary glycans with or without core fucosylation and bi- and triantennary glycans with no core fucosylation being attached to Asn-alpha78.
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Affiliation(s)
- Willy Morelle
- Unité Mixte de Recherche CNRS/USTL 8576, Glycobiologie Structurale et Fonctionnelle, IFR 118, Université des Sciences et Technologies de Lille 1, 59655 Villeneuve d'Ascq Cedex, France.
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19
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Lipscomb ML, Palomares LA, Hernández V, Ramírez OT, Kompala DS. Effect of production method and gene amplification on the glycosylation pattern of a secreted reporter protein in CHO cells. Biotechnol Prog 2005; 21:40-9. [PMID: 15903239 DOI: 10.1021/bp049761m] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have investigated the independent effects of selective gene amplification (using the dhfr amplifiable selection marker) and culture operating strategy (batch vs repeated fed-batch vs semicontinuous perfusion) on the glycosylation of a recombinant reporter protein (secreted alkaline phosphatase, SEAP) produced in transfected Chinese hamster ovary (CHO) cells. HPLC analyses coupled with susceptibility to various exoglycosidases were used to determine the N-glycosylation profile of SEAP samples. The dhfr amplified cell line yielded an almost 10-fold increase in specific productivity as compared to that of the unamplified cell line. The glycosylation pattern of the reporter protein produced in batch bioreactor cultures of the amplified cell line showed only slight differences as compared to the glycosylation pattern of the protein from batch bioreactor cultures of the unamplified cell line. In contrast, analysis of SEAP glycosylation structures from the protein isolated from semicontinuous perfusion cultures indicated that both relative glycan content and extent of sialylation were increased as compared to samples isolated from repeated fed-batch cultures. These results suggest that the slow growing perfusion cultures produce more completely glycosylated proteins than the faster growing repeated fed-batch cultures.
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Affiliation(s)
- Matthew L Lipscomb
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CB 424, Boulder, Colorado 80309-0424, USA
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20
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Zhou Q, Park SH, Boucher S, Higgins E, Lee K, Edmunds T. N-linked oligosaccharide analysis of glycoprotein bands from isoelectric focusing gels. Anal Biochem 2004; 335:10-6. [PMID: 15519566 DOI: 10.1016/j.ab.2004.07.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Indexed: 11/23/2022]
Abstract
Glycoproteins often display a complex isoelectric focusing profile because of the presence of negatively charged carbohydrates, such as sialic acid, phosphorylated mannose, and sulfated GalNAc. Until now, understanding the role of these charged carbohydrates in determining the isoelectric focusing profile has been limited to observing pattern shifts following complete removal of the sugars in question. We have developed a simple and sensitive method for analyzing N-linked oligosaccharides from the individual isoelectric focusing bands of a glycoprotein using recombinant human thyroid-stimulating hormone as a model system. N-linked oligosaccharides were released and profiled from individual bands following electroblotting of isoelectric focusing gels. As might be predicted, high-pH anion-exchange chromatography-pulsed amperometric detection and matrix-assisted laser desorption/ionization-time of flight analyses indicated that the bands that migrated closer to the positive electrode contained more sialylated N-linked oligosaccharides. The sialic acid content of these bands correlated with that predicted from the corresponding oligosaccharide analyses.
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Affiliation(s)
- Qun Zhou
- Therapeutic Protein Research, Genzyme Corporation, P.O. Box 9322, Framingham, MA 01701, USA.
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21
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Emerson CH, Torres MST. Recombinant human thyroid-stimulating hormone: pharmacology, clinical applications and potential uses. BioDrugs 2003; 17:19-38. [PMID: 12534318 DOI: 10.2165/00063030-200317010-00003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The major functions of pituitary thyroid-stimulating hormone (TSH) are to maintain the biosynthesis and secretion of the thyroid hormones L-thyroxine (T4) and L-3,5,3'triidothyronine (T3). The TSH core contains two apoproteins, the alpha and beta subunits. The alpha subunit is identical to that of pituitary follitropin, pituitary lutropin and placental chorionic gonadotropin, whereas the beta subunit is unique. TSH is a glycoprotein; the glycoprotein components of the alpha and beta subunits account for more than 10% of their mass and are essential for normal thyrotropic action and intravascular kinetics. The hypothalamic tripeptide, TSH-releasing hormone (TRH) is required for optimum TSH biosynthesis, particularly as far as addition of the glycoprotein components is concerned. TRH deficiency is associated with secretion of TSH molecules that are appropriately measured in most assays but have reduced bioactivity. In previous years the TSH used in clinical practice was obtained and purified from bovine pituitaries. Bovine TSH was used to test thyroid function and to augment the uptake of radioiodine in patients with thyroid cancer. Bovine TSH has been largely abandoned as a clinical agent because of adverse immune reactions. A recombinant human TSH (rhTSH; Thyrogen), has been approved by the US FDA for diagnostic use in patients with thyroid cancer. The alpha and beta subunits of Thyrogen are identical to those of human pituitary TSH. Thyrogen has a specific activity of approximately 4 IU/mg and is a potent stimulator of T4, T3 and thyroglobulin (Tg) secretion in healthy volunteers. It also increases thyroid iodide uptake in patients with thyroid cancer or multinodular goitre and in volunteers, even those exposed to large amounts of stable iodide. Thyroid cancer patients who have been treated by thyroidectomy and radioiodine ablation but are at risk of harbouring residual thyroid cancer are candidates for Thyrogen administration to prepare them for whole body iodide scans and serum Tg measurements. In thyroidectomised thyroid cancer patients who are unable to secrete pituitary TSH upon thyroid hormone withdrawal, Thyrogen is the only acceptable method to prepare them for these procedures. Thyrogen has been used on a compassionate basis to prepare patients for radioiodine ablation. rhTSH, in addition to being useful in the management of patients with thyroid cancer, is potentially useful to test thyroid reserve and to aid in thyroid-related nuclear medicine procedures. In the future, TSH analogues that have superagonist or antagonist properties may become available as therapeutic agents.
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Affiliation(s)
- Charles H Emerson
- Department of Medicine, University of Massachusetts School of Medicine, Worcester, Massachusetts 01655, USA.
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22
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Abstract
The sulfonation of endogenous molecules is a pervasive biological phenomenon that is not always easily understood, and although it is increasingly recognized as a function of fundamental importance, there remain areas in which significant cognizance is still lacking or at most minimal. This is particularly true in the field of endocrinology, in which the sulfoconjugation of hormones is a widespread occurrence that is only partially, if at all, appreciated. In the realm of steroid/sterol sulfoconjugation, the discovery of a novel gene that utilizes an alternative exon 1 to encode for two sulfotransferase isoforms, one of which sulfonates cholesterol and the other pregnenolone, has been an important advance. This is significant because cholesterol sulfate plays a crucial role in physiological systems such as keratinocyte differentiation and development of the skin barrier, and pregnenolone sulfate is now acknowledged as an important neurosteroid. The sulfonation of thyroglobulin and thyroid hormones has been extensively investigated and, although this transformation is better understood, there remain areas of incomplete comprehension. The sulfonation of catecholamines is a prevalent modification that has been extensively studied but, unfortunately, remains poorly understood. The sulfonation of pituitary glycoprotein hormones, especially LH and TSH, does not affect binding to their cognate receptors; however, sulfonation does play an important role in their plasma clearance, which indirectly has a significant effect on biological activity. On the other hand, the sulfonation of distinct neuroendocrine peptides does have a profound influence on receptor binding and, thus, a direct effect on biological activity. The sulfonation of specific extracellular structures plays an essential role in the binding and signaling of a large family of extracellular growth factors. In summary, sulfonation is a ubiquitous posttranslational modification of hormones and extracellular components that can lead to dramatic structural changes in affected molecules, the biological significance of which is now beginning to be appreciated.
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Affiliation(s)
- Charles A Strott
- Section on Steroid Regulation, Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-4510, USA.
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23
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Szkudlinski MW, Fremont V, Ronin C, Weintraub BD. Thyroid-stimulating hormone and thyroid-stimulating hormone receptor structure-function relationships. Physiol Rev 2002; 82:473-502. [PMID: 11917095 DOI: 10.1152/physrev.00031.2001] [Citation(s) in RCA: 296] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This review focuses on recent advances in the structure-function relationships of thyroid-stimulating hormone (TSH) and its receptor. TSH is a member of the glycoprotein hormone family constituting a subset of the cystine-knot growth factor superfamily. TSH is produced by the pituitary thyrotrophs and released to the circulation in a pulsatile manner. It stimulates thyroid functions using specific membrane TSH receptor (TSHR) that belongs to the superfamily of G protein-coupled receptors (GPCRs). New insights into the structure-function relationships of TSH permitted better understanding of the role of specific protein and carbohydrate domains in the synthesis, bioactivity, and clearance of this hormone. Recent progress in studies on TSHR as well as studies on the other GPCRs provided new clues regarding the molecular mechanisms of receptor activation. Such advances are a result of extensive site-directed mutagenesis, peptide and antibody approaches, detailed sequence analyses, and molecular modeling as well as studies on naturally occurring gain- and loss-of-function mutations. This review integrates expanding information on TSH and TSHR structure-function relationships and summarizes current concepts on ligand-dependent and -independent TSHR activation. Special emphasis has been placed on TSH domains involved in receptor recognition, constitutive activity of TSHR, new insights into the evolution of TSH bioactivity, and the development of high-affinity TSH analogs. Such structural, physiological, pathophysiological, evolutionary, and therapeutic implications of TSH-TSHR structure-function studies are frequently discussed in relation to concomitant progress made in studies on gonadotropins and their receptors.
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Affiliation(s)
- Mariusz W Szkudlinski
- Section of Protein Engineering, Laboratory of Molecular Endocrinology, Medical Biotechnology Center, University of Maryland Biotechnology Institute, Baltimore, Maryland, USA.
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24
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Hearn MT, Gomme PT. Molecular architecture and biorecognition processes of the cystine knot protein superfamily: part I. The glycoprotein hormones. J Mol Recognit 2000; 13:223-78. [PMID: 10992290 DOI: 10.1002/1099-1352(200009/10)13:5<223::aid-jmr501>3.0.co;2-l] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In this review article, the reader is introduced to recent advances in our knowledge on a subset of the cystine knot superfamily of homo- and hetero-dimeric proteins, from the perspective of the endocrine glycoprotein hormone family of proteins: follitropin (FSH), Iutropin (LH), thyrotropin. (TSH) and chorionic gonadotropin (CG). Subsequent papers will address the structure-function behaviour of other members of this increasingly significant family of proteins, including various members of the transforming growth factor-beta (TGF-beta) family of proteins, the activins, inhibins, bone morphogenic growth factor, platelet derived growth factor-beta, nerve growth factor and more than 35 other proteins with similar topological features. In the present review article, specific emphasis has been placed on advances with the glycoprotein hormones (GPHs) that have facilitated greater insight into their physiological functions, molecular structures and most importantly the basis of the molecular recognition events that lead to the formation of hetero-dimeric structures as well as their specific and selective recognition by their corresponding receptors and antibodies. Thus, this review article focuses on the structural motifs involved in receptor recognition and the current techniques available to identify these regions, including the role of immunological methodology, peptide fragment design and synthesis and mutagenesis to delineate their structure-function relationships and molecular recognition behaviour.
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Affiliation(s)
- M T Hearn
- Centre for Bioprocess Technology, Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3168, Australia.
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25
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Nutting C, Hyer S, Vini L, Harmer C. Failure of TSH rise prior to radio-iodine therapy for thyroid cancer: implications for treatment. Clin Oncol (R Coll Radiol) 2000; 11:269-71. [PMID: 10473725 DOI: 10.1053/clon.1999.9061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We describe three patients with well-differentiated thyroid carcinoma in whom no rise in serum thyroid-stimulating hormone (TSH) was observed after the discontinuation of thyroid hormone. In one patient, TSH deficiency was due to panhypopituitarism secondary to the empty sella syndrome. This patient initially failed to respond to (131)I but was subsequently given purified porcine TSH prior to further (131)I therapy. This resulted in a significant fall in the thyroglobulin level. In two further patients, TSH levels were suppressed by functioning follicular thyroid cancer. There was an unexpectedly good (131)I uptake by metastases and they responded clinically. The failure of TSH levels to rise after thyroid hormone withdrawal should prompt investigation of the pituitary-thyroid axis. In patients with hypopituitarism, exogenous TSH is recommended, to increase the (131)I uptake. In contrast, when TSH is suppressed by functioning tumour, radio-iodine treatment may still be effective.
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26
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Morrison CJ, Easton RL, Morris HR, McMaster WR, Piret JM, Dell A. Modification of a recombinant GPI-anchored metalloproteinase for secretion alters the protein glycosylation. Biotechnol Bioeng 2000; 68:407-21. [PMID: 10745209 DOI: 10.1002/(sici)1097-0290(20000520)68:4<407::aid-bit6>3.0.co;2-s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The N-linked glycans of recombinant leishmanolysin (GP63) expressed as a glycosylphosphatidylinositol (GPI)-anchored membrane protein or modified for secretion in Chinese hamster ovary (CHO) cells were analyzed by fast atom bombardment-mass spectrometry (FAB-MS). The glycans isolated from both membrane and secreted protein were predominantly complex biantennary structures. However other aspects of the glycan profiles showed striking differences. The degree of sialylation of the membrane form was greatly reduced and the core fucosylation of biantennary structures was increased compared to the secreted form. Glycans isolated from membrane expressed protein also contained a higher proportion of lactosamine repeats. Residence times in the secretory pathway were similar for both secreted and membrane protein. Glycosylation differences may therefore be due to differences in protein conformation and accessibility to glycosyltransferases or glycosidases. These differences in glycosylation represent an important factor when considering modifying membrane expressed proteins for secreted production.
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Affiliation(s)
- C J Morrison
- Biotechnology Laboratory, University of British Columbia, Vancouver, British Columbia, Canada
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27
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Szkudlinski MW, Grossmann M, Leitolf H, Weintraub BD. Human thyroid-stimulating hormone: structure-function analysis. Methods 2000; 21:67-81. [PMID: 10764608 DOI: 10.1006/meth.2000.0976] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This article provides the reader with an overview of methodological strategies to investigate structure-function relationships of human thyroid-stimulating hormone (hTSH). Various aspects of hTSH production, purification, and characterization described here in more detail are not only relevant to studies on other members of the glycoprotein hormone family, but also applicable to studies of other glycosylated proteins. Knowledge of structure-function relationships of specific hTSH domains is important for a better understanding of the molecular mechanisms of its action. New insights from such studies permit the design of glycoprotein hormone analogs with specific pharmacological properties and potential clinical applications.
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Affiliation(s)
- M W Szkudlinski
- Laboratory of Molecular Endocrinology, Department of Medicine, University of Maryland School of Medicine and the Institute of Human Virology, Medical Biotechnology Center, 725 West Lombard Street, Baltimore, Maryland 21201-1009, USA.
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28
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Ladenson PW. Recombinant thyrotropin versus thyroid hormone withdrawal in evaluating patients with thyroid carcinoma. Semin Nucl Med 2000; 30:98-106. [PMID: 10787190 DOI: 10.1053/nm.2000.4599] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Patients with previously treated thyroid carcinoma require lifelong monitoring for recurrent disease. Two diagnostic tests that play a central role in follow-up of these patients--radioiodine whole body scanning and serum thyroglobulin measurement--are most accurate during thyroid-stimulating hormone (TSH) stimulation. Temporary discontinuation of thyroid hormone therapy was previously the sole effective approach for TSH-stimulated testing. However, hormone withdrawal was associated with the morbidity of hypothyroidism and occasional tumor progression. The introduction of recombinant TSH (rTSH)-stimulated testing offers an alternative therapy. Recent clinical trials have shown that the sensitivity of combined rTSH-stimulated radioiodine scanning and serum thyroglobulin measurement has equivalent sensitivity to testing after thyroid hormone withdrawal. Furthermore, measurement of the rTSH-stimulated thyroglobulin concentration is a more sensitive way to detect residual thyroid cancer or normal tissue than thyroglobulin measurement on thyroid hormone therapy alone. The results of these trials are reviewed and strategies for implementing rTSH-mediated testing are presented.
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Affiliation(s)
- P W Ladenson
- Division of Endocrinology and Metabolism, The Johns Hopkins University School of Medicine, Baltimore, MD 21287-0003, USA
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29
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Skarulis MC. The use of recombinant human thyrotropin (rhTSH) in the management of differentiated thyroid cancer. Rev Endocr Metab Disord 2000; 1:147-54. [PMID: 11705000 DOI: 10.1023/a:1010018829345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- M C Skarulis
- Division of Intramural Research, National Institute of Diabetes, Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive MSC 1771, Building 10 Room 8S235B, Bethesda, MD 20892-1771, USA.
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30
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Rafferty B, Gaines Das R. Comparison of Pituitary and Recombinant Human Thyroid-stimulating Hormone (rhTSH) in a Multicenter Collaborative Study: Establishment of the First World Health Organization Reference Reagent for rhTSH. Clin Chem 1999. [DOI: 10.1093/clinchem/45.12.2207] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
AbstractBackground: The increasing use of recombinant-DNA-derived materials in therapy and diagnosis poses a new challenge for biological standardization, that of developing reference preparations appropriate for both the native and recombinant products. Here we report the results of an international collaborative study that was carried out under the auspices of WHO to assess the suitability of a preparation of recombinant thyroid-stimulating hormone (rTSH; 94/674) to serve as a potential standard for the calibration of diagnostic immunoassays compared with the International Reference Preparation (IRP) for human TSH (80/558).Methods: Coded samples were provided to the 33 laboratories in the study, and participants were asked to perform TSH assays currently in use in their laboratories. Twenty-eight laboratories contributed 93 immunoassays in 41 different method-laboratory combinations, and an additional 5 laboratories contributed bioassay data. All data were analyzed centrally at the National Institute for Biological Standards and Control.Results: The results obtained in different laboratories and with different assay systems revealed significant variability between estimates of rTSH relative to the IRP. These ranged from 5.51 mIU (95% limits, 3.95–7.67 mIU) per ampoule by RIA to 7.15 mIU (95% limits, 6.7–7.63 mIU) per ampoule by immunofluorometric assay. However, the results showed that the assignment of a value of 6.70 mIU per ampoule of 94/674 would give reasonable continuity with the IRP in many assay systems.Conclusions: The preparation was established as the First WHO Reference Reagent for TSH, human, recombinant, to provide a means of validating assay performance and to maintain continuity with the IRP without compromising clinical data.
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Affiliation(s)
| | - Rose Gaines Das
- Informatics, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Herts EN6 3QG, UK
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31
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Henkin RI, Martin BM, Agarwal RP. Efficacy of exogenous oral zinc in treatment of patients with carbonic anhydrase VI deficiency. Am J Med Sci 1999; 318:392-405. [PMID: 10616164 DOI: 10.1097/00000441-199912000-00006] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND We previously described a disorder in 18 patients with decreased parotid saliva gustin/carbonic anhydrase (CA) VI secretion associated with loss of taste (hypogeusia) and smell (hyposmia) and distorted taste (dysgeusia) and smell (dysosmia). Because gustin/CAVI is a zinc-dependent enzyme we instituted a study of treatment with exogenous zinc to attempt to stimulate synthesis/secretion of gustin/CAVI and thereby attempt to correct the symptoms of this disorder. METHODS Fourteen of the 18 patients with this disorder completed the study. They were treated with 100 mg of exogenous zinc daily for 4 to 6 months, in an open clinical trial. Both before and after treatment, measurements were obtained of parotid saliva gustin/CAVI, parotid saliva, serum and urine zinc, taste and smell function, and, in some patients, examination of circumvallate taste buds by electron microscopy. RESULTS Treatment success was predicated upon significant increases in parotid saliva gustin/CAVI. This occurred in 10 of the 14 patients who were labeled responders; they also exhibited improvement in taste and smell acuity, a diminution in dysgeusia and dysosmia and increased zinc concentrations in parotid saliva, serum, and urine. Taste bud morphology returned to normal in each responder in whom it was measured. No increase in gustin/CAVI occurred in 4 patients who were labeled nonresponders; they exhibited no improvement in taste or smell acuity and no increases in parotid saliva zinc. However, serum and urine zinc increased to levels similar to those measured in the 10 responders. Two of 4 nonresponders reported diminution in dysgeusia and dysosmia. Taste bud morphology did not change from the abnormal state in the 1 nonresponder in whom it was measured. CONCLUSIONS Zinc treatment is effective in patients in whom this trace metal increases synthesis/secretion of gustin/CAVI and ineffective in those in whom it does not. Increased gustin/CAVI in this disorder is probably associated with zinc stimulation of the gene responsible for the synthesis/secretion of gustin/CAVI. Among nonresponders, zinc was ineffective for several possible reasons, including resistance to zinc and possible sialylation of gustin/CAVI, which may render it functionally ineffective. Results suggest the hypothesis that gustin/CAVI is a trophic factor that promotes growth and development of taste buds through its action on taste bud stem cells.
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Affiliation(s)
- R I Henkin
- The Taste and Smell Clinic, Washington, DC 20016, USA
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Henkin RI, Martin BM, Agarwal RP. Efficacy of Exogenous Oral Zinc in Treatment of Patients with Carbonic Anhydrase VI Deficiency. Am J Med Sci 1999. [DOI: 10.1016/s0002-9629(15)40664-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Haugen BR, Pacini F, Reiners C, Schlumberger M, Ladenson PW, Sherman SI, Cooper DS, Graham KE, Braverman LE, Skarulis MC, Davies TF, DeGroot LJ, Mazzaferri EL, Daniels GH, Ross DS, Luster M, Samuels MH, Becker DV, Maxon HR, Cavalieri RR, Spencer CA, McEllin K, Weintraub BD, Ridgway EC. A comparison of recombinant human thyrotropin and thyroid hormone withdrawal for the detection of thyroid remnant or cancer. J Clin Endocrinol Metab 1999; 84:3877-85. [PMID: 10566623 DOI: 10.1210/jcem.84.11.6094] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recombinant human TSH has been developed to facilitate monitoring for thyroid carcinoma recurrence or persistence without the attendant morbidity of hypothyroidism seen after thyroid hormone withdrawal. The objectives of this study were to compare the effect of administered recombinant human TSH with thyroid hormone withdrawal on the results of radioiodine whole body scanning (WBS) and serum thyroglobulin (Tg) levels. Two hundred and twenty-nine adult patients with differentiated thyroid cancer requiring radioiodine WBS were studied. Radioiodine WBS and serum Tg measurements were performed after administration of recombinant human TSH and again after thyroid hormone withdrawal in each patient. Radioiodine whole body scans were concordant between the recombinant TSH-stimulated and thyroid hormone withdrawal phases in 195 of 220 (89%) patients. Of the discordant scans, 8 (4%) had superior scans after recombinant human TSH administration, and 17 (8%) had superior scans after thyroid hormone withdrawal (P = 0.108). Based on a serum Tg level of 2 ng/mL or more, thyroid tissue or cancer was detected during thyroid hormone therapy in 22%, after recombinant human TSH stimulation in 52%, and after thyroid hormone withdrawal in 56% of patients with disease or tissue limited to the thyroid bed and in 80%, 100%, and 100% of patients, respectively, with metastatic disease. A combination of radioiodine WBS and serum Tg after recombinant human TSH stimulation detected thyroid tissue or cancer in 93% of patients with disease or tissue limited to the thyroid bed and 100% of patients with metastatic disease. In conclusion, recombinant human TSH administration is a safe and effective means of stimulating radioiodine uptake and serum Tg levels in patients undergoing evaluation for thyroid cancer persistence and recurrence.
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Affiliation(s)
- B R Haugen
- Division of Endocrinology, University of Colorado Health Sciences Center, Denver 80262, USA
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Abstract
Detection of residual and recurrent thyroid carcinoma requires long-term monitoring of patients with serum thyroglobulin measurement and radioiodine scanning during temporary thyrotropin (TSH) stimulation. Recombinant thyrotropin (rTSH) permits these studies to be performed without the morbidity associated with withdrawal of thyroid hormone therapy. A protocol for rTSH use is proposed, beginning with measurement of serum thyroglobulin during TSH suppression. Patients at significant risk of recurrence with a low initial thyroglobulin level then have rTSH stimulation testing. Patients with positive rTSH-stimulated thyroglobulin concentrations and/or radioiodine scans can then be directed for appropriate therapy. The previously studied 2-dose rTSH protocol with imaging at 48 hours after 131I dosing requires Monday-through-Friday testing in most settings, but new regimens may be established. rTSH-stimulated testing may be less accurate in patients with thyroglobulin autoantibodies and those with residual normal thyroid tissue, and is generally unnecessary when there is other evidence of residual disease. Physicians should consider patients' pretest probability of disease in deciding whether and how often to perform rTSH-stimulated testing after primary treatment for thyroid carcinoma.
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Affiliation(s)
- P W Ladenson
- Division of Endocrinology and Metabolism, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Sievi E, Helin J, Heikinheimo R, Makarow M. Glycan engineering of proteins with whole living yeast cells expressing rat liver alpha2,3-sialytransferase in the porous cell wall. FEBS Lett 1998; 441:177-80. [PMID: 9883879 DOI: 10.1016/s0014-5793(98)01550-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The N-glycans of recombinant proteins produced via the secretory pathway of cultured mammalian cells are often undersialylated, and insect cells lack sialytransferases. Undersialylated glycoproteins are rapidly cleared from the circulation, compromising the effect of pharmaceuticals. We show that incubation with living Saccharomyces cerevisiae cells expressing the catalytic ectodomain of rat liver alpha2,3-sialyltransferase (ST3Ne) in the porous cell wall resulted in sialylation of glycoproteins. The Km values of the yeast enzyme for several substrates were similar to those of recombinant ST3Ne from insect cells and of authentic ST3N. The yeast strain provides an inexpensive self-perpetuating source of ST3N activity for glycan engineering of recombinant proteins.
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Affiliation(s)
- E Sievi
- Institute of Biotechnology, University of Helsinki, Finland
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Adler ML, Macapinlac HA, Robbins RJ. Radioiodine Treatment of Thyroid Cancer with the Aid of Recombinant Human Thyrotropin. Endocr Pract 1998; 4:282-6. [PMID: 15251726 DOI: 10.4158/ep.4.5.282] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To update endocrinologists on the use of recombinant human thyrotropin (thyroid-stimulating hormone or TSH) (rhTSH) in thyroid diseases, with an emphasis on thyroid cancer. METHODS We reviewed the available literature on potential uses of rhTSH, including published studies and case reports. RESULTS Clinical trials have shown that rhTSH injections stimulate radioiodine uptake into normal and malignant thyroid tissue almost as well as that found in the hypothyroid state. The benefit to the athyreotic patient is the avoidance of the disability of hypothyroidism. When rhTSH is used in the doses currently recommended for scanning, few negative side effects occur. The more rapid clearance of iodine in the euthyroid state, however, may necessitate the use of more radioiodine to achieve the same amount of irradiation to metastatic lesions. We have used rhTSH for both dosimetric studies and therapy. This approach is essential in patients who cannot make sufficient endogenous TSH (because of hypothalamic-pituitary disease or medications that suppress TSH). Other patients with widespread metastatic lesions who have serious complications when allowed to become hypothyroid also benefit from rhTSH. Finally, we have found that rhTSH may provide new insights into the biologic features of thyroid cancer when used in combination with positron emission tomographic scanning. Use in the treatment of nonmalignant thyroid conditions such as toxic multinodular goiter is also feasible. CONCLUSION Overall, rhTSH provides a new and clinically important advance for patients with thyroid disease, especially thyroid cancer.
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Affiliation(s)
- M L Adler
- Section of Endocrinology, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York, USA
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37
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Richard F, Robert P, Remy JJ, Martinat N, Bidart JM, Salesse R, Combarnous Y. High-level secretion of biologically active recombinant porcine follicle-stimulating hormone by the methylotrophic yeast Pichia pastoris. Biochem Biophys Res Commun 1998; 245:847-52. [PMID: 9588203 DOI: 10.1006/bbrc.1998.8532] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An active recombinant glycoprotein hormone, porcine follicle-stimulating hormone (recFSH), has been produced for the first time in the methylotrophic yeast, Pichia pastoris. The yield of secreted recFSH (10 mg/l) was the highest ever reached. RecFSH displayed an apparent molecular mass of 41 kDa by SDS-PAGE and was found to bear only N-linked carbohydrates of the high-mannose type. Its in vitro binding and cell-stimulating activities were identical to those of pituitary porcine FSH. The large availability and the noncharged N-glycans of FSHrec should render it highly valuable for structural studies.
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Affiliation(s)
- F Richard
- Unité Récepteurs et Communications Cellulaires, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
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38
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Grossmann M, Weintraub BD, Szkudlinski MW. Novel insights into the molecular mechanisms of human thyrotropin action: structural, physiological, and therapeutic implications for the glycoprotein hormone family. Endocr Rev 1997; 18:476-501. [PMID: 9267761 DOI: 10.1210/edrv.18.4.0305] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- M Grossmann
- Department of Medicine, University of Maryland School of Medicine, Baltimore, USA
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Hakola K, Boogaart PV, Mulders J, de Leeuw R, Schoonen W, Heyst JV, Swolfs A, Casteren JV, Huhtaniemi I, Kloosterboer H. Recombinant rat luteinizing hormone; production by Chinese hamster ovary cells, purification and functional characterization. Mol Cell Endocrinol 1997; 128:47-56. [PMID: 9140075 DOI: 10.1016/s0303-7207(97)04018-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Rat recombinant (rec) luteinizing hormone (LH) was produced in Chinese hamster ovary (CHO) cells, to enable studies on LH physiology in this species with homologous hormone. The synthesized hormone was purified, and characterized physico-chemically and biologically in comparison with highly purified preparations of rat pituitary (pit) LH (NIDDK-rLH-I-7 and I-9) and to highly purified urinary (NIH, CR-121) and rec forms of human chorionic gonadotropin (hCG). The 33 kD molecular mass of rat recLH, as determined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot, was comparable with the 32 kD size of pitLH. In chromatofocusing, the isoforms of rat recLH distributed in the pI range 6.5-7.8, similar to rat pitLH. In receptor binding assays using rat testicular membranes, and physiologic salt concentration, rat recLH displayed a 5-10-fold higher affinity than rat pitLH, but about 100-fold lower affinity than hCG. In contrast, in low salt concentrations the affinities of rat recLH and rechCG to rat LH receptor were rather similar. The differences in potency in the mouse Leydig cell in vitro bioassay were in agreement with the receptor binding data at physiologic salt concentration. Neither rat recLH nor pitLH stimulated cAMP production or bound specifically to HEK 293 cells expressing the rec human LH receptor. When injected subcutaneously on four consecutive days to male rats (8.4-33.7 microg/rat/day) rat recLH did not induce seminal vesicle growth in comparison with a significant effect of human menopausal gonadotropin (hMG; 12.5-50 IU/rat/day). In contrast, ovulation was induced in 5/6 and 6/6 female rats following single injections of 3.75 and 7.5 microg of rat recLH, respectively, after pretreatment with 10 microg/kg of a GnRH-antagonist (Org 30850). In conclusion, rat recLH displays clearly lower in vivo and in vitro bioactivity than hCG. Nevertheless, it binds effectively to the rat LH receptor (with affinity dependent on salt concentration) and is bioactive in the mouse Leydig cell bioassay. This newly synthesized recombinant hormone provides a useful tool for further studies on the physiology of LH action in the rat, the most common animal model in reproduction research.
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Affiliation(s)
- K Hakola
- Department of Physiology, University of Turku, Finland.
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40
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Reynolds JC, Robbins J. The changing role of radioiodine in the management of differentiated thyroid cancer. Semin Nucl Med 1997; 27:152-64. [PMID: 9144857 DOI: 10.1016/s0001-2998(97)80045-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
This article discusses several aspects of the evaluation and management of differentiated thyroid carcinoma that are changing or may change in the near future. Although conventional treatment of this disease is highly effective, some modification may improve the welfare of patients and the overall results. Because the symptoms of hypothyroidism are vexing, there has been great interest in using recombinant human thyroid-stimulating hormone (rhTSH) to prepare patients for iodine 131 imaging. rhTSH has been about as effective as thyroid hormone withdrawal for diagnostic imaging so that approval for this use is expected. Another topic of interest is the administration of 131I therapy to patients whose serum thyroglobulin levels are abnormal but whose diagnostic 131I scans are negative. Because the 131I scans after therapy are often abnormal in these patients and a reduction of serum thyroglobulin can occur, this approach seems effective. The long-term impact of this therapy on recurrence and survival, however, is unknown. A third issue that is currently under review is the amount of 131I that should be used for diagnostic scanning. Although past opinion favored larger doses, "stunning" of thyroid remnant and tumor can occur with diagnostic 131I imaging. Substituting iodine 123 is an alternative for postthyroidectomy scanning, but when administered as 300 uCi it is less accurate than 131I for recurrent disease or distant metastases. Related to these issues, two other topics are reviewed: the use of other radiopharmaceuticals for imaging patients with thyroid cancer, and 131I dosimetry.
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Affiliation(s)
- J C Reynolds
- Nuclear Medicine Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA
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41
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Lustbader JW, Pollak S, Lobel L, Trakht I, Homans S, Brown JM, Canfield RE. Three-dimensional structures of gonadotropins. Mol Cell Endocrinol 1996; 125:21-31. [PMID: 9027340 DOI: 10.1016/s0303-7207(96)03952-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Most secreted proteins are modified post-translationally with the addition of carbohydrate. It has been difficult to use crystallography to solve the structures of these proteins due to the inherent heterogeneity of the carbohydrate. The structure of the chemically deglycosylated form (hydrogen fluoride treated) of human chorionic gonadotropin (hCG) has been solved through crystallographic techniques. Unfortunately this form of hCG is not biologically active, and exhibits immunochemical differences from native hormone. In addition, subunit interactions appear altered after chemical deglycosylation as indicated by the increased thermal stability of the HF-treated hormone. The Asn 52 glycan on the alpha-subunit of hCG has been identified as being required for biological activity, it is, therefore, of physiological importance to determine the structure of the hormone with its carbohydrate intact. Also, it has not been possible to obtain crystals of the individual glycosylated subunits of hCG. Therefore an alternative method to solve the structure of the biologically active form of the hormone in solution as well as its separated subunits is necessary. Structural information utilizing NMR techniques can be obtained from native hCG subunits in solution if they can be uniformly labeled with 13C and 15N isotopes. We have developed a universal nonradioactive isotope, labeling medium enriched in 13C and 15N which can be used to express uniformly labeled hCG from Chinese hamster ovary cells suitable for solving the structure of the individual subunits and ultimately that of the native, biologically active hormone. The isotopically labeled recombinant hCG and its purified subunits are essentially identical to urinary hCG on comparison by biochemical, immunochemical, biological activity and the ability of the isolated subunits to recombine to form a biologically active dimer. Mass spectrometric analysis and preliminary structural NMR data indicate that the labeling is uniform and there is greater than 90% incorporation, sufficient for complete structural determination studies. This labeled growth medium represents a technological advance which will enable the rapid solution of the structures of the other glycoprotein hormones, as well as other glycoproteins which have proven unsuitable for crystallographic study.
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Affiliation(s)
- J W Lustbader
- Columbia University, College of Physicians and Surgeons, New York 10032, USA
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42
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Szkudlinski MW, Teh NG, Grossmann M, Tropea JE, Weintraub BD. Engineering human glycoprotein hormone superactive analogues. Nat Biotechnol 1996; 14:1257-63. [PMID: 9631089 DOI: 10.1038/nbt1096-1257] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We report the generation of superactive analogues of human glycoprotein hormones, with potential applications in thyroid and reproductive disorders. Current biological and structural data were used to rationalize mutagenesis. The 11-20 region in the alpha-subunit with a cluster of lysine residues forms a previously unrecognized domain critical for receptor binding and signal transduction, as well as an important motif in the evolution of glycoprotein hormone activities. The gradual elimination of basic residues in the alpha-subunit coincided with the evolutionary divergence of the hominids from the Old World monkeys. By selective reconstitution of certain critical residues present in homologous nonhuman hormones we have developed human thyroid stimulating hormone and chorionic gonadotropin analogues with substantial increases in receptor binding affinity and bioactivity, thus providing a paradigm for the design of novel therapeutic protein analogues.
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Affiliation(s)
- M W Szkudlinski
- Department of Medicine, University of Maryland School of Medicine, Baltimore 21201, USA.
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43
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van der Kallen CJ, Coes JH, van Grafhorst JP, Schuuring EM, Ossendorp FA, Thijssen JH, Blankenstein MA, de Bruin TW. Dissociation of thyrotropin receptor function and thyrotropin dependency in rat thyroid tumour cell lines derived from FRTL-5. Br J Cancer 1996; 74:606-12. [PMID: 8761378 PMCID: PMC2074668 DOI: 10.1038/bjc.1996.409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Spontaneously transformed somatic thyrocyte mutants, FRTL-5/TA and FRTL-5/TP, are thyrotropin (TSH) independent for growth and show loss of the thyroid-specific phenotype, with absent thyroglobulin and thyroid peroxidase gene expression. To investigate the role of TSH-receptor (TSH-R) activation in rat thyroid growth and function, binding of TSH and TSH-induced cAMP production were measured in intact cells under identical assay conditions. TSH binding did not differ in terms of affinity and receptor number and presence of 5.6 kb and 3.3 kb mRNA rat TSH-R transcripts was determined in all variants. By contrast, basal cAMP was 11-fold lower in FRTL-5/TA and 6-fold lower in FRTL-5/TP than in wild-type FRTL-5 (1.1 +/- 0.4; P < 0.01). Maximal cAMP production was similar between wild-type and cell variants and stimulation by bovine, rat and recombinant human TSH revealed normal activation patterns. Therefore, a dissociation was present between the loss of TSH control on growth and function, and the presence of a normally functioning TSH-R. Subsequent to TSH incubation FRTL-5/TP and FRTL-5/TA cells showed a different expression pattern of TSH-R and the proto oncogenes c-myc and fos than FRTL-5 wild-type. The data indicated that the cause of the TSH-independency is located down-stream of the cAMP cascade, influencing genes that control the expression of cell cycle-related proto-oncogenes and thyroid-specific genes.
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44
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Grossmann M, Szkudlinski MW, Tropea JE, Bishop LA, Thotakura NR, Schofield PR, Weintraub BD. Expression of human thyrotropin in cell lines with different glycosylation patterns combined with mutagenesis of specific glycosylation sites. Characterization of a novel role for the oligosaccharides in the in vitro and in vivo bioactivity. J Biol Chem 1995; 270:29378-85. [PMID: 7493973 DOI: 10.1074/jbc.270.49.29378] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We used a novel approach to study the role of the Asn-linked oligosaccharides for human thyrotropin (hTSH) activity. Mutagenesis of Asn (N) within individual glycosylation recognition sequences to Gln (Q) was combined with expression of wild type and mutant hTSH in cell lines with different glycosylation patterns. The in vitro activity of hTSH lacking the Asn alpha 52 oligosaccharide (alpha Q52/TSH beta) expressed in CHO-K1 cells (sialylated oligosaccharides) was increased 6-fold compared with wild type, whereas the activities of alpha Q78/TSH beta and alpha/TSH beta Q23 were increased 2-3-fold. Deletion of the Asn alpha 52 oligosaccharide also increased the thyrotropic activity of human chorionic gonadotropin, in contrast to previous findings at its native receptor. The in vitro activity of wild type hTSH expressed in CHO-LEC2 cells (sialic acid-deficient oligosaccharides), CHO-LEC1 cells (Man5GlcNAc2 intermediates), and 293 cells (sulfated oligosaccharides) was 5-8-fold higher than of wild type from CHO-K1 cells. In contrast to CHO-K1 cells, there was no difference in the activity between wild type and selectively deglycosylated mutants expressed in these cell lines. Thus, in hTSH, the oligosaccharide at Asn alpha 52 and, specifically, its terminal sialic acid residues attenuate in vitro activity, in contrast to the previously reported stimulatory role of this chain for human chorionic gonadotropin and human follitropin activity. The increased thyrotropic activity of alpha Q52/CG beta suggests that receptor-related mechanisms may be responsible for these differences among the glycoprotein hormones. Despite their increased in vitro activity, alpha Q52/TSH beta, and alpha Q78/TSH beta from CHO-K1 cells had a faster serum disappearance rate and decreased effect on T4 production in mice. These findings highlight the importance of individual oligosaccharides in maintaining circulatory half-life and hence in vivo activity of hTSH.
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Affiliation(s)
- M Grossmann
- Molecular and Cellular Endocrinology Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-1758, USA
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Szkudlinski MW, Thotakura NR, Weintraub BD. Subunit-specific functions of N-linked oligosaccharides in human thyrotropin: role of terminal residues of alpha- and beta-subunit oligosaccharides in metabolic clearance and bioactivity. Proc Natl Acad Sci U S A 1995; 92:9062-6. [PMID: 7568073 PMCID: PMC40924 DOI: 10.1073/pnas.92.20.9062] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The recombinant human thyroid stimulating hormone (rhTSH) containing oligosaccharides terminated with NeuAc(alpha 2-3)Gal(beta 1-4)GlcNAc beta 1 showed higher in vivo activity and lower metabolic clearance rate (MCR) than pituitary human TSH (phTSH), which contains oligosaccharides terminating predominantly in SO(4)4GalNAc(beta 1-4)GlcNAc beta 1. To elucidate the relative contribution of the sulfated and sialylated carbohydrate chains of each subunit in the MCR and bioactivity of the hormone, the alpha and beta subunits of phTSH, rhTSH, and enzymatically desialylated rhTSH (asialo-rhTSH; asrhTSH) were isolated, their oligosaccharides were analyzed, and the respective subunits were dimerized in various combinations. The hybrids containing alpha subunit from phTSH or asrhTSH showed higher in vitro activity than those with alpha subunit from rhTSH, indicating that sialylation of alpha but not beta subunit attenuates the intrinsic activity of TSH. In contrast, hybrids with beta subunit from rhTSH displayed lower MCR compared to those with beta subunit from phTSH. The phTSH alpha-rhTSH beta hybrid had the highest in vivo bioactivity followed by rhTSH alpha-rhTSH beta, rhTSH alpha-phTSH beta, phTSH alpha-phTSH beta, and asrhTSH dimers. These differences indicated that hybrids with beta subunit from rhTSH displayed the highest in vivo activity and relatively low MCR, probably due to higher sialylation, more multiantennary structure, and/or the unique location of the beta-subunit oligosaccharide chain in the molecule. Thus, the N-linked oligosaccharides of the beta subunit of glycoprotein hormones have a more pronounced role than those from the alpha subunit in the metabolic clearance and thereby in the in vivo bioactivity. In contrast, the terminal residues of alpha-subunit oligosaccharides have a major impact on TSH intrinsic potency.
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Affiliation(s)
- M W Szkudlinski
- Molecular and Cellular Endocrinology Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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