1
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Siffo S, Gomes Pio M, Martínez EB, Lachlan K, Walker J, Weill J, González-Sarmiento R, Rivolta CM, Targovnik HM. The p.Pro2232Leu variant in the ChEL domain of thyroglobulin gene causes intracellular transport disorder and congenital hypothyroidism. Endocrine 2023; 80:47-53. [PMID: 36547798 DOI: 10.1007/s12020-022-03284-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022]
Abstract
Thyroglobulin (TG), the predominant glycoprotein of the thyroid gland, functions as matrix protein in thyroid hormonegenesis. TG deficiency results in thyroid dyshormonogenesis. These variants produce a heterogeneous spectrum of congenital goitre, with an autosomal recessive mode of inheritance. The purpose of this study was to identify and functionally characterize new variants in the TG gene in order to increase the understanding of the molecular mechanisms responsible for thyroid dyshormonogenesis. A total of four patients from two non-consanguineous families with marked alteration of TG synthesis were studied. The two families were previously analysed in our laboratory, only one deleterious allele, in each one, was detected after sequencing the TG gene (c.2359 C > T [p.Arg787*], c.5560 G > T [p.Glu1854*]). These findings were confirmed in the present studies by Next-Generation Sequencing. The single nucleotide coding variants of the TG gene were then analyzed to predict the possible variant causing the disease. The p.Pro2232Leu (c.6695 C > T), identified in both families, showing a low frequency population in gnomAD v2.1.1 database and protein homology, amino acid prediction, and 3D modeling analysis predict a potential pathogenic effect of this variant. We also transiently express p.Pro2232Leu in a full-length rat TG cDNA clone and confirmed that this point variant was sufficient to cause intracellular retention of mutant TG in HEK293T cells. Consequently, each family carried a compound heterozygous for p.Arg787*/p.Pro2232Leu or p.Glu1854*/p.Pro2232Leu variants. In conclusion, our results confirm the pathophysiological importance of altered TG folding as a consequence of missense variants located in the ChEL domain of TG.
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Affiliation(s)
- Sofia Siffo
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Mauricio Gomes Pio
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Elena Bueno Martínez
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL. Universidad de Salamanca-CSIC, Salamanca, España
| | - Katherine Lachlan
- Wessex Clinical Genetics Service, University Hospital Southampton, Princess Anne Hospital, SO16 5YA, Southampton, UK
| | - Joanna Walker
- Portsmouth Hospitals NHS Trust, Queen Alexandra Hospital, Cosham, PO6 3LY, Portsmouth, UK
| | - Jacques Weill
- Clinique de Pédiatrie, Hôpital Jeanne de Flandre, Centre Hospitalier Regional Universitaire de Lille, Lille, France
| | - Rogelio González-Sarmiento
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL. Universidad de Salamanca-CSIC, Salamanca, España
| | - Carina M Rivolta
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.
- CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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2
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Zhang X, Young C, Morishita Y, Kim K, Kabil OO, Clarke OB, Di Jeso B, Arvan P. Defective Thyroglobulin: Cell Biology of Disease. Int J Mol Sci 2022; 23:13605. [PMID: 36362390 PMCID: PMC9657758 DOI: 10.3390/ijms232113605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/30/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
The primary functional units of the thyroid gland are follicles of various sizes comprised of a monolayer of epithelial cells (thyrocytes) surrounding an apical extracellular cavity known as the follicle lumen. In the normal thyroid gland, the follicle lumen is filled with secreted protein (referred to as colloid), comprised nearly exclusively of thyroglobulin with a half-life ranging from days to weeks. At the cellular boundary of the follicle lumen, secreted thyroglobulin becomes iodinated, resulting from the coordinated activities of enzymes localized to the thyrocyte apical plasma membrane. Thyroglobulin appearance in evolution is essentially synchronous with the appearance of the follicular architecture of the vertebrate thyroid gland. Thyroglobulin is the most highly expressed thyroid gene and represents the most abundantly expressed thyroid protein. Wildtype thyroglobulin protein is a large and complex glycoprotein that folds in the endoplasmic reticulum, leading to homodimerization and export via the classical secretory pathway to the follicle lumen. However, of the hundreds of human thyroglobulin genetic variants, most exhibit increased susceptibility to misfolding with defective export from the endoplasmic reticulum, triggering hypothyroidism as well as thyroidal endoplasmic reticulum stress. The human disease of hypothyroidism with defective thyroglobulin (either homozygous, or compound heterozygous) can be experimentally modeled in thyrocyte cell culture, or in whole animals, such as mice that are readily amenable to genetic manipulation. From a combination of approaches, it can be demonstrated that in the setting of thyroglobulin misfolding, thyrocytes under chronic continuous ER stress exhibit increased susceptibility to cell death, with interesting cell biological and pathophysiological consequences.
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Affiliation(s)
- Xiaohan Zhang
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA
| | - Crystal Young
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA
| | - Yoshiaki Morishita
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
| | - Kookjoo Kim
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Omer O. Kabil
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA
- Department of Natural Sciences, Lindenwood University, Saint Charles, MO 63301, USA
| | - Oliver B. Clarke
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Bruno Di Jeso
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan, Ann Arbor, MI 48105, USA
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3
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Zhang X, Malik B, Young C, Zhang H, Larkin D, Liao XH, Refetoff S, Liu M, Arvan P. Maintaining the thyroid gland in mutant thyroglobulin-induced hypothyroidism requires thyroid cell proliferation that must continue in adulthood. J Biol Chem 2022; 298:102066. [PMID: 35618019 PMCID: PMC9213252 DOI: 10.1016/j.jbc.2022.102066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 11/14/2022] Open
Abstract
Congenital hypothyroidism with biallelic thyroglobulin (Tg protein, encoded by the TG gene) mutation is an endoplasmic reticulum (ER) storage disease. Many patients (and animal models) grow an enlarged thyroid (goiter), yet some do not. In adulthood, hypothyroid TGcog/cog mice (bearing a Tg-L2263P mutation) exhibit a large goiter, whereas adult WIC rats bearing the TGrdw/rdw mutation (Tg-G2298R) exhibit a hypoplastic thyroid. Homozygous TG mutation has been linked to thyroid cell death, and cytotoxicity of the Tg-G2298R protein was previously thought to explain the lack of goiter in WIC-TGrdw/rdw rats. However, recent studies revealed that TGcog/cog mice also exhibit widespread ER stress–mediated thyrocyte death, yet under continuous feedback stimulation, thyroid cells proliferate in excess of their demise. Here, to examine the relative proteotoxicity of the Tg-G2298R protein, we have used CRISPR–CRISPR-associated protein 9 technology to generate homozygous TGrdw/rdw knock-in mice in a strain background identical to that of TGcog/cog mice. TGrdw/rdw mice exhibit similar phenotypes of defective Tg protein folding, thyroid histological abnormalities, hypothyroidism, and growth retardation. TGrdw/rdw mice do not show evidence of greater ER stress response or stress-mediated cell death than TGcog/cog mice, and both mouse models exhibit sustained thyrocyte proliferation, with comparable goiter growth. In contrast, in WIC-TGrdw/rdw rats, as a function of aging, the thyrocyte proliferation rate declines precipitously. We conclude that the mutant Tg-G2298R protein is not intrinsically more proteotoxic than Tg-L2263P; rather, aging-dependent difference in maintenance of cell proliferation is the limiting factor, which accounts for the absence of goiter in adult WIC-TGrdw/rdw rats.
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Affiliation(s)
- Xiaohan Zhang
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Bhoomanyu Malik
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Crystal Young
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Hao Zhang
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Xiao-Hui Liao
- Departments of Medicine, Pediatrics, and Committee on Genetics, The University of Chicago, Chicago Illinois, USA
| | - Samuel Refetoff
- Departments of Medicine, Pediatrics, and Committee on Genetics, The University of Chicago, Chicago Illinois, USA
| | - Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA.
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4
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Pio MG, Siffo S, Scheps KG, Molina MF, Adrover E, Abelleyro MM, Rivolta CM, Targovnik HM. Curating the gnomAD database: Report of novel variants in the thyrogobulin gene using in silico bioinformatics algorithms. Mol Cell Endocrinol 2021; 534:111359. [PMID: 34119605 DOI: 10.1016/j.mce.2021.111359] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 01/09/2023]
Abstract
Thyroglobulin (TG) is a large glycosylated protein of 2767 amino acids, secreted by the thyrocytes into the follicular lumen. It plays an essential role in the process of thyroid hormone synthesis. TG gene variants lead to permanent congenital hypothyroidism. In the present work, we report a detailed population and bioinformatic prediction analyses of the TG variants indexed in the Genome Aggregation Database (gnomAD). The results showed a clear predominance of nonsense variants in the European (Finnish), European (Non-Finnish) and Ashkenazi Jewish ethnic groups, whereas the splice site variants predominate in South Asian and African/African-American populations. In total, 282 novel TG variants were described (47 missense involving the wild-type cysteine residues, 177 missense located in the ChEL domain and 58 splice site variants) which were not reported in the literature and that would have deleterious effects in prediction programs. In the gnomAD population, the estimated prevalence of heterozygous carriers of the potentially damaging variants was 1:320. In conclusion, we provide an updated and curated reference source for the diagnosis of thyroid disease, mainly to congenital hypothyroidism due to TG deficiency. The identification and characterization of TG variants is undoubtedly a valuable approach to study the TG structure/function relations and an important tool for clinical diagnosis and genetic counseling.
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Affiliation(s)
- Mauricio Gomes Pio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Maricel F Molina
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Ezequiela Adrover
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Miguel M Abelleyro
- CONICET-Academia Nacional de Medicina, Instituto de Medicina Experimental (IMEX), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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5
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Rios JJ, Denton K, Russell J, Kozlitina J, Ferreira CR, Lewanda AF, Mayfield JE, Moresco E, Ludwig S, Tang M, Li X, Lyon S, Khanshour A, Paria N, Khalid A, Li Y, Xie X, Feng JQ, Xu Q, Lu Y, Hammer RE, Wise CA, Beutler B. Germline Saturation Mutagenesis Induces Skeletal Phenotypes in Mice. J Bone Miner Res 2021; 36:1548-1565. [PMID: 33905568 PMCID: PMC8862308 DOI: 10.1002/jbmr.4323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 04/07/2021] [Accepted: 04/21/2021] [Indexed: 12/28/2022]
Abstract
Proper embryonic and postnatal skeletal development require coordination of myriad complex molecular mechanisms. Disruption of these processes, through genetic mutation, contributes to variation in skeletal development. We developed a high-throughput N-ethyl-N-nitrosourea (ENU)-induced saturation mutagenesis skeletal screening approach in mice to identify genes required for proper skeletal development. Here, we report initial results from live-animal X-ray and dual-energy X-ray absorptiometry (DXA) imaging of 27,607 G3 mice from 806 pedigrees, testing the effects of 32,198 coding/splicing mutations in 13,020 genes. A total of 39.7% of all autosomal genes were severely damaged or destroyed by mutations tested twice or more in the homozygous state. Results from our study demonstrate the feasibility of in vivo mutagenesis to identify mouse models of skeletal disease. Furthermore, our study demonstrates how ENU mutagenesis provides opportunities to create and characterize putative hypomorphic mutations in developmentally essential genes. Finally, we present a viable mouse model and case report of recessive skeletal disease caused by mutations in FAM20B. Results from this study, including engineered mouse models, are made publicly available via the online Mutagenetix database. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jonathan J Rios
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA.,Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA.,McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Orthopaedic Surgery, UT Southwestern Medical Center, Dallas, TX, USA.,Simmons Comprehensive Cancer Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Kristin Denton
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA
| | - Jamie Russell
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Julia Kozlitina
- McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA
| | - Carlos R Ferreira
- Skeletal Genomics Unit, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amy F Lewanda
- Rare Disease Institute, Children's National Hospital, Washington, DC, USA
| | - Joshua E Mayfield
- Department of Pharmacology, University of California, San Diego, CA, USA
| | - Eva Moresco
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sara Ludwig
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Miao Tang
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Xiaohong Li
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Stephen Lyon
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
| | - Anas Khanshour
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA
| | - Nandina Paria
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA
| | - Aysha Khalid
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA
| | - Yang Li
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA
| | - Xudong Xie
- Department of Restorative Sciences, School of Dentistry, Texas A&M University, Dallas, TX, USA
| | - Jian Q Feng
- Department of Restorative Sciences, School of Dentistry, Texas A&M University, Dallas, TX, USA
| | - Qian Xu
- Department of Restorative Sciences, School of Dentistry, Texas A&M University, Dallas, TX, USA
| | - Yongbo Lu
- Department of Restorative Sciences, School of Dentistry, Texas A&M University, Dallas, TX, USA
| | - Robert E Hammer
- Department of Biochemistry, UT Southwestern Medical Center, Dallas, TX, USA
| | - Carol A Wise
- Center for Pediatric Bone Biology and Translational Research, Scottish Rite for Children, Dallas, TX, USA.,Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA.,McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Orthopaedic Surgery, UT Southwestern Medical Center, Dallas, TX, USA
| | - Bruce Beutler
- Center for Genetics of Host Defense, UT Southwestern Medical Center, Dallas, TX, USA
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6
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Zhang X, Kellogg AP, Citterio CE, Zhang H, Larkin D, Morishita Y, Targovnik HM, Balbi VA, Arvan P. Thyroid hormone synthesis continues despite biallelic thyroglobulin mutation with cell death. JCI Insight 2021; 6:148496. [PMID: 33914707 PMCID: PMC8262357 DOI: 10.1172/jci.insight.148496] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/28/2021] [Indexed: 11/17/2022] Open
Abstract
Complete absence of thyroid hormone is incompatible with life in vertebrates. Thyroxine is synthesized within thyroid follicles upon iodination of thyroglobulin conveyed from the endoplasmic reticulum (ER), via the Golgi complex, to the extracellular follicular lumen. In congenital hypothyroidism from biallelic thyroglobulin mutation, thyroglobulin is misfolded and cannot advance from the ER, eliminating its secretion and triggering ER stress. Nevertheless, untreated patients somehow continue to synthesize sufficient thyroxine to yield measurable serum levels that sustain life. Here, we demonstrate that TGW2346R/W2346R humans, TGcog/cog mice, and TGrdw/rdw rats exhibited no detectable ER export of thyroglobulin, accompanied by severe thyroidal ER stress and thyroid cell death. Nevertheless, thyroxine was synthesized, and brief treatment of TGrdw/rdw rats with antithyroid drug was lethal to the animals. When untreated, remarkably, thyroxine was synthesized on the mutant thyroglobulin protein, delivered via dead thyrocytes that decompose within the follicle lumen, where they were iodinated and cannibalized by surrounding live thyrocytes. As the animals continued to grow goiters, circulating thyroxine increased. However, when TGrdw/rdw rats age, they cannot sustain goiter growth that provided the dying cells needed for ongoing thyroxine synthesis, resulting in profound hypothyroidism. These results establish a disease mechanism wherein dead thyrocytes support organismal survival.
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Affiliation(s)
- Xiaohan Zhang
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Aaron P Kellogg
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Cintia E Citterio
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA.,Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Buenos Aires, Argentina
| | - Hao Zhang
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Yoshiaki Morishita
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA.,Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Nagakute, Japan
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo, Buenos Aires, Argentina
| | - Viviana A Balbi
- Department of Endocrinology and Growth, Hospital de Niños Sor María Ludovica, La Plata, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
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7
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Citterio CE, Rivolta CM, Targovnik HM. Structure and genetic variants of thyroglobulin: Pathophysiological implications. Mol Cell Endocrinol 2021; 528:111227. [PMID: 33689781 DOI: 10.1016/j.mce.2021.111227] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/22/2021] [Accepted: 02/23/2021] [Indexed: 02/07/2023]
Abstract
Thyroglobulin (TG) plays a main role in the biosynthesis of thyroid hormones (TH), and, thus, it is involved in a wide range of vital functions throughout the life cycle of all vertebrates. Deficiency of TH production due to TG genetic variants causes congenital hypothyroidism (CH), with devastating consequences such as intellectual disability and impaired growth if untreated. To this day, 229 variations in the human TG gene have been identified while the 3D structure of TG has recently appeared. Although TG deficiency is thought to be of autosomal recessive inheritance, the introduction of massive sequencing platforms led to the identification of a variety of monoallelic TG variants (combined with mutations in other thyroid gene products) opening new questions regarding the possibility of oligogenic inheritance of the disease. In this review we discuss remarkable advances in the understanding of the TG architecture and the pathophysiology of CH associated with TG defects, providing new insights for the management of congenital disorders as well as counseling benefits for families with a history of TG abnormalities. Moreover, we summarize relevant aspects of TH synthesis within TG and offer an updated analysis of animal and cellular models of TG deficiency for pathophysiological studies of thyroid dyshormonogenesis while highlighting perspectives for new investigations. All in all, even though there has been sustained progress in understanding the role of TG in thyroid pathophysiology during the past 50 years, functional characterization of TG variants remains an important area of study for future advancement in the field.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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8
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Morishita Y, Kellogg AP, Larkin D, Chen W, Vadrevu S, Satin L, Liu M, Arvan P. Cell death-associated lipid droplet protein CIDE-A is a noncanonical marker of endoplasmic reticulum stress. JCI Insight 2021; 6:143980. [PMID: 33661766 PMCID: PMC8119190 DOI: 10.1172/jci.insight.143980] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 03/02/2021] [Indexed: 01/05/2023] Open
Abstract
Secretory protein misfolding has been linked to ER stress and cell death. We expressed a TGrdw transgene encoding TG-G(2298)R, a misfolded mutant thyroglobulin reported to be linked to thyroid cell death. When the TGrdw transgene was expressed at low level in thyrocytes of TGcog/cog mice that experienced severe ER stress, we observed increased thyrocyte cell death and increased expression of CIDE-A (cell death-inducing DFFA-like effector-A, a protein of lipid droplets) in whole thyroid gland. Here we demonstrate that acute ER stress in cultured PCCL3 thyrocytes increases Cidea mRNA levels, maintained at least in part by increased mRNA stability, while being negatively regulated by activating transcription factor 6 - with similar observations that ER stress increases Cidea mRNA levels in other cell types. CIDE-A protein is sensitive to proteasomal degradation yet is stabilized by ER stress, and elevated expression levels accompany increased cell death. Unlike acute ER stress, PCCL3 cells adapted and surviving chronic ER stress maintained a disproportionately lower relative mRNA level of Cidea compared with that of other, classical ER stress markers, as well as a blunted Cidea mRNA response to a new, unrelated acute ER stress challenge. We suggest that CIDE-A is a novel marker linked to a noncanonical ER stress response program, with implications for cell death and survival.
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Affiliation(s)
- Yoshiaki Morishita
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Aichi, Japan
| | - Aaron P. Kellogg
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Dennis Larkin
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Wei Chen
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Suryakiran Vadrevu
- Department of Pharmacology, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Leslie Satin
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Pharmacology, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
- Department of Endocrinology & Diabetes, Tianjin Medical University, Tianjin, China
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
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9
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Johansson E, Liang S, Moccia C, Carlsson T, Andersson D, Fagman H, Nilsson M. Asynchrony of Apical Polarization, Luminogenesis, and Functional Differentiation in the Developing Thyroid Gland. Front Endocrinol (Lausanne) 2021; 12:760541. [PMID: 34975747 PMCID: PMC8719337 DOI: 10.3389/fendo.2021.760541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/12/2021] [Indexed: 12/02/2022] Open
Abstract
Follicular thyroid tissue originates from progenitors derived from a midline endodermal primordium. Current understanding infers that folliculogenesis in the embryonic thyroid designates the latest morphogenetic event taking place after the final anatomical shape and position of the gland is established. However, this concept does not consider the fact that the thyroid isthmus develops chronologically before the lobes and also contains all progenitors required for lobulation. To elucidate whether cells committed to a thyroid fate might be triggered to differentiate asynchronously related to maturation and developmental stage, mouse embryonic thyroid tissues from E12.5-17.5 were subjected to immunofluorescent labeling of biomarkers (progenitors: NKX2-1; differentiation: thyroglobulin/TG); folliculogenesis: E-cadherin/CDH1; luminogenesis: mucin 1/MUC1; apical polarity: pericentrin/PCNT; basement membrane: laminin; growth: Ki67), quantitative RT-PCR analysis (Nkx2.1, Tg, Muc1) and transmission electron microscopy. Tg expression was detectable as early as E12.5 and gradually increased >1000-fold until E17.5. Muc1 and Nkx2.1 transcript levels increased in the same time interval. Prior to lobulation (E12.5-13.5), MUC1 and TG distinguished pre-follicular from progenitor cells in the developing isthmus characterized by intense cell proliferation. Luminogenesis comprised redistribution of MUC1+ vesicles or vacuoles, transiently associated with PCNT, to the apical cytoplasm and the subsequent formation of MUC1+ nascent lumens. Apical polarization of pre-follicular cells and lumen initiation involved submembraneous vesicular traffic, reorganization of adherens junctions and ciliogenesis. MUC1 did not co-localize with TG until a lumen with a MUC1+ apical membrane was established. MUC1 delineated the lumen of all newly formed follicles encountered in the developing lobes at E15.5-17.5. Folliculogenesis started before establishment of a complete follicular basal lamina. These observations indicate that embryonic thyroid differentiation is an asynchronous process consistent with the idea that progenitors attaining a stationary position in the connecting isthmus portion undergo apical polarization and generate follicles already at a primordial stage of thyroid development, i.e. foregoing growth of the lobes. Although the thyroid isthmus eventually comprises minute amounts of the total thyroid volume and contributes little to the overall hormone production, it is of principal interest that local cues related to the residence status of cells - independently of a prevailing high multiplication rate - govern the thyroid differentiation program.
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Affiliation(s)
- Ellen Johansson
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
| | - Shawn Liang
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
| | - Carmen Moccia
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
| | - Therese Carlsson
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
| | - Daniel Andersson
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
| | - Henrik Fagman
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
- Department of Laboratory Medicine, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
- Department of Clinical Pathology, Sahlgrenska University Hospital, Göteborg, Sweden
| | - Mikael Nilsson
- Sahlgrenska Center for Cancer Research, Institute of Biomedicine, University of Gothenburg, Göteborg, Sweden
- *Correspondence: Mikael Nilsson,
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10
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Wright MT, Kouba L, Plate L. Thyroglobulin Interactome Profiling Defines Altered Proteostasis Topology Associated With Thyroid Dyshormonogenesis. Mol Cell Proteomics 2020; 20:100008. [PMID: 33581410 PMCID: PMC7950113 DOI: 10.1074/mcp.ra120.002168] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/15/2020] [Accepted: 11/18/2020] [Indexed: 12/02/2022] Open
Abstract
Thyroglobulin (Tg) is a secreted iodoglycoprotein serving as the precursor for triiodothyronine and thyroxine hormones. Many characterized Tg gene mutations produce secretion-defective variants resulting in congenital hypothyroidism. Tg processing and secretion is controlled by extensive interactions with chaperone, trafficking, and degradation factors comprising the secretory proteostasis network. While dependencies on individual proteostasis network components are known, the integration of proteostasis pathways mediating Tg protein quality control and the molecular basis of mutant Tg misprocessing remain poorly understood. We employ a multiplexed quantitative affinity purification-mass spectrometry approach to define the Tg proteostasis interactome and changes between WT and several congenital hypothyroidism variants. Mutant Tg processing is associated with common imbalances in proteostasis engagement including increased chaperoning, oxidative folding, and engagement by targeting factors for endoplasmic reticulum-associated degradation. Furthermore, we reveal mutation-specific changes in engagement with N-glycosylation components, suggesting distinct requirements for 1 Tg variant on dual engagement of both oligosaccharyltransferase complex isoforms for degradation. Modulating dysregulated proteostasis components and pathways may serve as a therapeutic strategy to restore Tg secretion and thyroid hormone biosynthesis.
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Affiliation(s)
- Madison T Wright
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Logan Kouba
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Lars Plate
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee, USA; Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA.
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11
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Citterio CE, Siffo S, Moya CM, Pio MG, Molina MF, Scheps KG, Rey OA, Arvan P, Rivolta CM, Targovnik HM. p.L571P in the linker domain of rat thyroglobulin causes intracellular retention. Mol Cell Endocrinol 2020; 505:110719. [PMID: 31972331 DOI: 10.1016/j.mce.2020.110719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 12/14/2022]
Abstract
Thyroglobulin (TG), a large glycosylated protein secreted by thyrocytes into the thyroid follicular lumen, plays an essential role in thyroid hormone biosynthesis. Rattus norvegicus TG (rTG) is encoded by a large single copy gene, 186-kb long, located on chromosome 7 composed of 48 exons encoding a 8461-kb mRNA. Although the TG gene displays sequence variability, many missense mutations do not impose any adverse effect on the TG protein, whereas other nucleotide substitutions may affect its TG stability and/or TG intracellular trafficking. In order to gain a further understanding of the protein domains regulating its intracellular fate, we cloned a full-length cDNA from rTG into the pcDNA6/V5-His B expression vector. However, transient expression of the cDNA in HEK293T cells showed that the encoded protein was not a wild-type molecule, as it was unable to be secreted in the culture supernatant. Sequencing analyses revealed three random mutations, which accidentally emerged during the course of cloning: c.1712T>C [p.L571P] in the linker domain (amino acid positions 360 to 604), c.2027A>G [p.Q676R] in TG type 1-6 repeat and c.2720A>G [p.Q907R] in the TG type 1-7 repeat. Expression of cDNAs encoding a combination of two mutations [p.Q676R-p.Q907R], [p.L571P-p.Q907R] or [p.L571P-p.Q676R] indicated that any TG bearing the p.L571P substitution was trapped intracellularly. Indeed, we expressed the single point mutant p.L571P and confirmed that this point mutation was sufficient to cause intracellular retention of mutant TG in HEK293T cells. Endo H analysis showed that the p.L571P mutant is completely sensitive to the enzyme, whereas the will-type TG acquires full N-glycan modifications in Golgi apparatus. This data suggest that the p.L571P mutant contains the mannose-type N-glycan, that was added at the first stage of glycosylation. Complex-type N-glycan formation in the Golgi apparatus does not occur, consistent with defective endoplasmic reticulum exit of the mutant TG. Moreover, predictive analysis of the 3D linker domain showed that the p.L571P mutation would result in a significant protein conformational change. In conclusion, our studies identified a novel amino acid residue within the linker domain of TG associated with its conformational maturation and intracellular trafficking.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Christian M Moya
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina
| | - Mauricio Gomes Pio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Maricel F Molina
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Osvaldo A Rey
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, USA
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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12
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Morishita Y, Kabil O, Young KZ, Kellogg AP, Chang A, Arvan P. Thyrocyte cell survival and adaptation to chronic endoplasmic reticulum stress due to misfolded thyroglobulin. J Biol Chem 2020; 295:6876-6887. [PMID: 32241916 DOI: 10.1074/jbc.ra120.012656] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/29/2020] [Indexed: 01/06/2023] Open
Abstract
The large secretory glycoprotein thyroglobulin is the primary translation product of thyroid follicular cells. This difficult-to-fold protein is susceptible to structural alterations that disable export of the misfolded thyroglobulin from the endoplasmic reticulum (ER), which is a known cause of congenital hypothyroidism characterized by severe chronic thyrocyte ER stress. Nevertheless, individuals with this disease commonly grow a goiter, indicating thyroid cell survival and adaptation. To model these processes, here we continuously exposed rat PCCL3 thyrocytes to tunicamycin, which causes a significant degree of ER stress that is specifically attributable to thyroglobulin misfolding. We found that, in response, PCCL3 cells down-regulate expression of the "tunicamycin transporter" (major facilitator superfamily domain containing-2A, Mfsd2a). Following CRISPR/Cas9-mediated Mfsd2a deletion, PCCL3 cells could no longer escape the chronic effects of high-dose tunicamycin, as demonstrated by persistent accumulation of unglycosylated thyroglobulin; nevertheless, these thyrocytes survived and grew. A proteomic analysis of these cells adapted to chronic ER protein misfolding revealed many hundreds of up-regulated proteins, indicating stimulation of ER chaperones, oxidoreductases, stress responses, and lipid biosynthesis pathways. Further, we noted increased phospho-AMP-kinase, suggesting up-regulated AMP-kinase activity, and decreased phospho-S6-kinase and protein translation, suggesting decreased mTOR activity. These changes are consistent with conserved cell survival/adaptation pathways. We also observed a less-differentiated thyrocyte phenotype with decreased PAX8, FOXE1, and TPO protein levels, along with decreased thyroglobulin mRNA levels. In summary, we have developed a model of thyrocyte survival and growth during chronic continuous ER stress that recapitulates features of congenital hypothyroid goiter caused by mutant thyroglobulin.
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Affiliation(s)
- Yoshiaki Morishita
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105.,Division of Diabetes, Department of Internal Medicine, Aichi Medical University, Aichi 480-1195 Japan
| | - Omer Kabil
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105
| | - Kelly Z Young
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105
| | - Aaron P Kellogg
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105
| | - Amy Chang
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109
| | - Peter Arvan
- The Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48105
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13
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Targovnik HM, Scheps KG, Rivolta CM. Defects in protein folding in congenital hypothyroidism. Mol Cell Endocrinol 2020; 501:110638. [PMID: 31751626 DOI: 10.1016/j.mce.2019.110638] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/21/2019] [Accepted: 11/01/2019] [Indexed: 12/26/2022]
Abstract
Primary congenital hypothyroidism (CH) is the most common endocrine disease in children and one of the most common preventable causes of both cognitive and motor deficits. CH is a heterogeneous group of thyroid disorders in which inadequate production of thyroid hormone occurs due to defects in proteins involved in the gland organogenesis (dysembryogenesis) or in multiple steps of thyroid hormone biosynthesis (dyshormonogenesis). Dysembryogenesis is associated with genes responsible for the development or growth of thyroid cells: such as NKX2-1, FOXE1, PAX8, NKX2-5, TSHR, TBX1, CDCA8, HOXD3 and HOXB3 resulting in agenesis, hypoplasia or ectopia of thyroid gland. Nevertheless, the etiology of the dysembryogenesis remains unknown for most cases. In contrast, the majority of patients with dyshormonogenesis has been linked to mutations in the SLC5A5, SLC26A4, SLC26A7, TPO, DUOX1, DUOX2, DUOXA1, DUOXA2, IYD or TG genes, which usually originate goiter. About 800 genetic mutations have been reported to cause CH in patients so far, including missense, nonsense, in-frame deletion and splice-site variations. Many of these mutations are implicated in specific domains, cysteine residues or glycosylation sites, affecting the maturation of nascent proteins that go through the secretory pathway. Consequently, misfolded proteins are permanently entrapped in the endoplasmic reticulum (ER) and are translocated to the cytosol for proteasomal degradation by the ER-associated degradation (ERAD) machinery. Despite of all these remarkable advances in the field of the CH pathogenesis, several points on the development of this disease remain to be elucidated. The continuous study of thyroid gene mutations with the application of new technologies will be useful for the understanding of the intrinsic mechanisms related to CH. In this review we summarize the present status of knowledge on the disorders in the protein folding caused by thyroid genes mutations.
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Affiliation(s)
- Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
| | - Karen G Scheps
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
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14
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Morishita Y, Arvan P. Lessons from animal models of endocrine disorders caused by defects of protein folding in the secretory pathway. Mol Cell Endocrinol 2020; 499:110613. [PMID: 31605742 PMCID: PMC6886696 DOI: 10.1016/j.mce.2019.110613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/26/2019] [Accepted: 10/04/2019] [Indexed: 02/06/2023]
Abstract
Most peptide hormones originate from secretory protein precursors synthesized within the endoplasmic reticulum (ER). In this specialized organelle, the newly-made prohormones must fold to their native state. Completion of prohormone folding usually occurs prior to migration through the secretory pathway, as unfolded/misfolded prohormones are retained by mechanisms collectively known as ER quality control. Not only do most monomeric prohormones need to fold properly, but many also dimerize or oligomerize within the ER. If oligomerization occurs before completion of monomer folding then when a poorly folded peptide prohormone is retained by quality control mechanisms, it may confer ER retention upon its oligomerization partners. Conversely, oligomerization between well-folded and improperly folded partners might help to override ER quality control, resulting in rescue of misfolded forms. Both scenarios appear to be possible in different animal models of endocrine disorders caused by genetic defects of protein folding in the secretory pathway. In this paper, we briefly review three such conditions, including familial neurohypophyseal diabetes insipidus, insulin-deficient diabetes mellitus, and hypothyroidism with defective thyroglobulin.
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Affiliation(s)
- Yoshiaki Morishita
- Division of Diabetes, Department of Internal Medicine, Aichi Medical University, 1-1 Yazakokarimata, Nagakute, Aichi, 480-1195, Japan.
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan School of Medicine, Brehm Tower Room 5112, 1000, Wall St., Ann Arbor, MI, USA.
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15
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Abstract
In humans, the thyroid hormones T3 and T4 are synthesized in the thyroid gland in a process that crucially involves the iodoglycoprotein thyroglobulin. The overall structure of thyroglobulin is conserved in all vertebrates. Upon thyroglobulin delivery from thyrocytes to the follicular lumen of the thyroid gland via the secretory pathway, multiple tyrosine residues can become iodinated to form mono-iodotyrosine (MIT) and/or di-iodotyrosine (DIT); however, selective tyrosine residues lead to preferential formation of T4 and T3 at distinct sites. T4 formation involves oxidative coupling between two DIT side chains, and de novo T3 formation involves coupling between an MIT donor and a DIT acceptor. Thyroid hormone synthesis is stimulated by TSH activating its receptor (TSHR), which upregulates the activity of many thyroid gene products involved in hormonogenesis. Additionally, TSH regulates post-translational changes in thyroglobulin that selectively enhance its capacity for T3 formation - this process is important in iodide deficiency and in Graves disease. 167 different mutations, many of which are newly discovered, are now known to exist in TG (encoding human thyroglobulin) that can lead to defective thyroid hormone synthesis, resulting in congenital hypothyroidism.
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Affiliation(s)
- Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología y Biotecnología/Cátedra de Genética, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA.
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16
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Pickard A, Chang J, Alachkar N, Calverley B, Garva R, Arvan P, Meng QJ, Kadler KE. Preservation of circadian rhythms by the protein folding chaperone, BiP. FASEB J 2019; 33:7479-7489. [PMID: 30888851 PMCID: PMC6529331 DOI: 10.1096/fj.201802366rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Dysregulation of collagen synthesis is associated with disease progression in cancer and fibrosis. Collagen synthesis is coordinated with the circadian clock, which in cancer cells is, curiously, deregulated by endoplasmic reticulum (ER) stress. We hypothesized interplay between circadian rhythm, collagen synthesis, and ER stress in normal cells. Here we show that fibroblasts with ER stress lack circadian rhythms in gene expression upon clock-synchronizing time cues. Overexpression of binding immunoglobulin protein (BiP) or treatment with chemical chaperones strengthens the oscillation amplitude of circadian rhythms. The significance of these findings was explored in tendon, where we showed that BiP expression is ramped preemptively prior to a surge in collagen synthesis at night, thereby preventing protein misfolding and ER stress. In turn, this forestalls activation of the unfolded protein response in order for circadian rhythms to be maintained. Thus, targeting ER stress could be used to modulate circadian rhythm and restore collagen homeostasis in disease.—Pickard, A., Chang, J., Alachkar, N., Calverley, B., Garva, R., Arvan, P., Meng, Q.-J., Kadler, K. E. Preservation of circadian rhythms by the protein folding chaperone, BiP.
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Affiliation(s)
- Adam Pickard
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Joan Chang
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Nissrin Alachkar
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom.,School of Mathematics, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Ben Calverley
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom.,School of Mathematics, Faculty of Science and Engineering, University of Manchester, Manchester, United Kingdom
| | - Richa Garva
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Peter Arvan
- Division of Metabolism, Endocrinology, and Diabetes, University of Michigan, Ann Arbor, Michigan, USA
| | - Qing-Jun Meng
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
| | - Karl E Kadler
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine, and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, United Kingdom
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17
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Faustino LC, Lombardi A, Madrigal-Matute J, Owen RP, Libutti SK, Tomer Y. Interferon-α Triggers Autoimmune Thyroid Diseases via Lysosomal-Dependent Degradation of Thyroglobulin. J Clin Endocrinol Metab 2018; 103:3678-3687. [PMID: 30113675 PMCID: PMC6179164 DOI: 10.1210/jc.2018-00541] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/27/2018] [Indexed: 12/16/2022]
Abstract
CONTEXT Autoimmune thyroid diseases (AITDs) arise from complex interactions among genetic, epigenetic, and environmental factors. Thyroglobulin (TG) is a major susceptibility gene for both Graves disease and Hashimoto thyroiditis. Interferon-α (IFNα), a cytokine secreted during viral infections, has emerged as a key trigger of AITD. We have shown that IFNα upregulates TG transcription; however, how the upregulation of TG transcription by IFNα triggers AITD is still unknown. OBJECTIVE To evaluate how IFNα triggers AITD by testing its effects on TG processing. DESIGN We exposed human thyroid cells to IFNα and evaluated its effects on TG expression and processing. RESULTS Human thyroid cells exposed to INFα had increased levels of TG mRNA but reduced TG protein levels, indicating TG protein degradation. IFNα induced endoplasmic reticulum stress, but surprisingly, neither the use of chemical chaperones nor proteasome inhibitor prevented IFNα-induced TG degradation. IFNα also increased LysoTracker staining and autophagy flux measured by net light chain 3 (LC3)-II and p62 fluxes. In addition, expression of autophagy markers LC3 and autophagy-related gene 5 was higher in thyroid tissues from patients with AITD. Finally, blocking lysosomal degradation prevented IFNα-induced degradation of TG. CONCLUSION We have shown in this study IFNα-induced lysosomal-dependent degradation of TG in human thyroid cells. Our findings suggest that during viral infections, local thyroidal IFNα production can lead to lysosomal TG degradation, releasing pathogenic TG peptides that can trigger AITD.
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Affiliation(s)
- Larissa C Faustino
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
- Correspondence and Reprint Requests: Larissa C. Faustino, PhD, Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, Forchheimer 702, Bronx, New York 10461. E-mail:
| | - Angela Lombardi
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
| | - Julio Madrigal-Matute
- Department of Developmental and Molecular Biology and Institute for Aging Studies, Albert Einstein College of Medicine, Bronx, New York
| | - Randall P Owen
- Department of Surgery, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Steven K Libutti
- Rutgers Cancer Institute of New Jersey, New Brunswick, New Jersey
| | - Yaron Tomer
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York
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18
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Siffo S, Adrover E, Citterio CE, Miras MB, Balbi VA, Chiesa A, Weill J, Sobrero G, González VG, Papendieck P, Martinez EB, Gonzalez-Sarmiento R, Rivolta CM, Targovnik HM. Molecular analysis of thyroglobulin mutations found in patients with goiter and hypothyroidism. Mol Cell Endocrinol 2018; 473:1-16. [PMID: 29275168 DOI: 10.1016/j.mce.2017.12.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 11/22/2017] [Accepted: 12/18/2017] [Indexed: 01/23/2023]
Abstract
Thyroid dyshormonogenesis due to thyroglobulin (TG) gene mutations have an estimated incidence of approximately 1 in 100,000 newborns. The clinical spectrum ranges from euthyroid to mild or severe hypothyroidism. Up to now, one hundred seventeen deleterious mutations in the TG gene have been identified and characterized. The purpose of the present study was to identify and characterize new mutations in the TG gene. We report eight patients from seven unrelated families with goiter, hypothyroidism and low levels of serum TG. All patients underwent clinical, biochemical and image evaluation. Sequencing of DNA, genotyping, as well as bioinformatics analysis were performed. Molecular analyses revealed three novel inactivating TG mutations: c.5560G>T [p.E1835*], c.7084G>C [p.A2343P] and c.7093T>C [p.W2346R], and four previously reported mutations: c.378C>A [p.Y107*], c.886C>T [p.R277*], c.1351C>T [p.R432*] and c.7007G>A [p.R2317Q]. Two patients carried homozygous mutations (p.R277*/p.R277*, p.W2346R/p.W2346R), four were compound heterozygous mutations (p.Y107*/p.R277* (two unrelated patients), p.R432*/p.A2343P, p.Y107*/p.R2317Q) and two siblings from another family had a single p.E1835* mutated allele. Additionally, we include the analysis of 48 patients from 31 unrelated families with TG mutations identified in our present and previous studies. Our observation shows that mutations in both TG alleles were found in 27 families (9 as homozygote and 18 as heterozygote compound), whereas in the remaining four families only one mutated allele was detected. The majority of the detected mutations occur in exons 4, 7, 38 and 40. 28 different mutations were identified, 33 of the 96 TG alleles encoded the change p.R277*. In conclusion, our results confirm the genetic heterogeneity of TG defects and the pathophysiological importance of the predicted TG misfolding and therefore thyroid hormone formation as a consequence of truncated TG proteins and/or missense mutations located within its ACHE-like domain.
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Affiliation(s)
- Sofia Siffo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Ezequiela Adrover
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Cintia E Citterio
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Mirta B Miras
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, Córdoba, Argentina
| | - Viviana A Balbi
- Servicio de Endocrinología, Hospital de Niños "Sor María Ludovica", La Plata, Argentina
| | - Ana Chiesa
- Centro de Investigaciones Endocrinológicas, CEDIE-CONICET, División Endocrinología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Jacques Weill
- Clinique de Pédiatrie, Hôpital Jeanne de Flandre, Centre Hospitalier Regional Universitaire de Lille, Lille, France
| | - Gabriela Sobrero
- Servicio de Endocrinología, Hospital de Niños Santísima Trinidad, Córdoba, Argentina
| | - Verónica G González
- Servicio de Endocrinología, Hospital de Niños "Sor María Ludovica", La Plata, Argentina
| | - Patricia Papendieck
- Centro de Investigaciones Endocrinológicas, CEDIE-CONICET, División Endocrinología, Hospital de Niños "Ricardo Gutiérrez", Buenos Aires, Argentina
| | - Elena Bueno Martinez
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - Rogelio Gonzalez-Sarmiento
- Unidad de Medicina Molecular-Departamento de Medicina, IBMCC and IBSAL, Universidad de Salamanca-CSIC, Salamanca, Spain
| | - Carina M Rivolta
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina
| | - Héctor M Targovnik
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética/Cátedra de Genética, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires, Instituto de Inmunología, Genética y Metabolismo (INIGEM), Buenos Aires, Argentina.
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19
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Löf C, Patyra K, Kero A, Kero J. Genetically modified mouse models to investigate thyroid development, function and growth. Best Pract Res Clin Endocrinol Metab 2018; 32:241-256. [PMID: 29779579 DOI: 10.1016/j.beem.2018.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The thyroid gland produces thyroid hormones (TH), which are essential regulators for growth, development and metabolism. The thyroid is mainly controlled by the thyroid-stimulating hormone (TSH) that binds to its receptor (TSHR) on thyrocytes and mediates its action via different G protein-mediated signaling pathways. TSH primarily activates the Gs-pathway, and at higher concentrations also the Gq/11-pathway, leading to an increase of intracellular cAMP and Ca2+, respectively. To date, the physiological importance of other G protein-mediated signaling pathways in thyrocytes is unclear. Congenital hypothyroidism (CH) is defined as the lack of TH at birth. In familial cases, high-throughput sequencing methods have facilitated the identification of novel mutations. Nevertheless, the precise etiology of CH yet remains unraveled in a proportion of cases. Genetically modified mouse models can reveal new pathophysiological mechanisms of thyroid diseases. Here, we will present an overview of genetic mouse models for thyroid diseases, which have provided crucial insights into thyroid gland development, function, and growth with a special focus on TSHR and microRNA signaling.
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Affiliation(s)
- C Löf
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - K Patyra
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland
| | - A Kero
- Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20521, Turku, Finland
| | - J Kero
- Research Centre for Integrative Physiology and Pharmacology, Institute of Biomedicine, Turku Center for Disease Modeling, University of Turku, Kiinamyllynkatu 10, 20520, Turku, Finland; Department of Pediatrics, Turku University Hospital, Kiinamyllynkatu 4-8, 20521, Turku, Finland.
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20
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Watanabe Y, Sharwood E, Goodwin B, Creech MK, Hassan HY, Netea MG, Jaeger M, Dumitrescu A, Refetoff S, Huynh T, Weiss RE. A novel mutation in the TG gene (G2322S) causing congenital hypothyroidism in a Sudanese family: a case report. BMC MEDICAL GENETICS 2018; 19:69. [PMID: 29720101 PMCID: PMC5932782 DOI: 10.1186/s12881-018-0588-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 04/19/2018] [Indexed: 01/02/2023]
Abstract
Background Congenital hypothyroidism (CH) has an incidence of approximately 1:3000, but only 15% have mutations in the thyroid hormone synthesis pathways. Genetic analysis allows for the precise diagnosis. Case presentation A 3-week old girl presented with a large goiter, serum TSH > 100 mIU/L (reference range: 0.7–5.9 mIU/L); free T4 < 3.2 pmol/L (reference range: 8.7–16 pmol/L); thyroglobulin (TG) 101 μg/L. Thyroid Tc-99 m scan showed increased radiotracer uptake. One brother had CH and both affected siblings have been clinically and biochemically euthyroid on levothyroxine replacement. Another sibling had normal thyroid function. Both Sudanese parents reported non-consanguinity. Peripheral blood DNA from the proposita was subjected to whole exome sequencing (WES). WES identified a novel homozygous missense mutation of the TG gene: c.7021G > A, p.Gly2322Ser, which was subsequently confirmed by Sanger sequencing and present in one allele of both parents. DNA samples from 354 alleles in four Sudanese ethnic groups (Nilotes, Darfurians, Nuba, and Halfawien) failed to demonstrate the presence of the mutant allele. Haplotyping showed a 1.71 centiMorgans stretch of homozygosity in the TG locus suggesting that this mutation occurred identical by descent and the possibility of common ancestry of the parents. The mutation is located in the cholinesterase-like (ChEL) domain of TG. Conclusions A novel rare missense mutation in the TG gene was identified. The ChEL domain is critical for protein folding and patients with CH due to misfolded TG may present without low serum TG despite the TG gene mutations. Electronic supplementary material The online version of this article (10.1186/s12881-018-0588-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Y Watanabe
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA
| | - E Sharwood
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - B Goodwin
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Medical Imaging and Nuclear Medicine, Lady Cilento Children's Hospital, Brisbane, QLD, Australia
| | - M K Creech
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA
| | - H Y Hassan
- Banoon ART & Cytogenetics Centre, Bahrain Defence Force Hospital, West Riffa, Kingdom of Bahrain
| | - M G Netea
- Department of Internal Medicine, Radboud University Medical Cente, Nijmegen, The Netherlands
| | - M Jaeger
- Department of Internal Medicine, Radboud University Medical Cente, Nijmegen, The Netherlands
| | - A Dumitrescu
- Departments of Medicine, The University of Chicago, Chicago, IL, USA
| | - S Refetoff
- Departments of Medicine, Pediatrics and Genetics, The University of Chicago, Chicago, IL, USA
| | - T Huynh
- Department of Endocrinology and Diabetes, Lady Cilento Children's Hospital, Brisbane, QLD, Australia.,Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Department of Chemical Pathology, Pathology Queensland, Herston, Brisbane, Queensland, Australia
| | - R E Weiss
- Department of Medicine, University of Miami Miller School of Medicine, 1120 NW 14th St., Room 310F, Miami, FL, 33136, USA.
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21
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Lisi S, Botta R, Rotondo Dottore G, Leo M, Latrofa F, Vitti P, Marinò M. Intracellular retention of thyroglobulin in the absence of the low-density lipoprotein receptor-associated protein (RAP) is likely due to premature binding to megalin in the biosynthetic pathway. J Endocrinol Invest 2016; 39:1039-44. [PMID: 27094046 DOI: 10.1007/s40618-016-0464-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 03/30/2016] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The low-density lipoprotein receptor associated protein (RAP) is expressed by thyroid epithelial cells (TEC) in a TSH-dependent manner. In the thyroid RAP functions as a molecular chaperone for the thyroglobulin (Tg) endocytic receptor megalin/LRP2, which is retained intracellularly in RAP KO mice rather than being expressed on the apical membrane of TEC, its usual location. RAP binds also to Tg, which is also retained intracellularly in RAP KO mice, thereby suggesting a role of RAP in Tg secretion. Here we investigated whether Tg intracellular retention in the absence of RAP is due to premature Tg-megalin interactions during the biosynthetic pathway or to a direct action of RAP on Tg secretion. METHODS We performed immunoprecipitation experiments in thyroid extracts from RAP KO and WT mice. In addition, we investigated Tg secretion in COS-7 cells co-transfected with human RAP (hRAP) and mouse Tg (mTg). RESULTS An anti-megalin megalin precipitated greater amounts of Tg in thyroid extracts from RAP KO than from WT mice, suggesting increased intracellular interactions between megalin and Tg in the absence of RAP. COS-7 cells transiently transfected with hRAP, mTg or both, expressed the two proteins accordingly. RAP was found almost exclusively in cell extracts, whereas Tg was found both in extracts and media, as expected from the knowledge that RAP is ER-resident and that Tg is secreted. Regardless of whether cells were transfected with mTg alone or were co-transfected with hRAP, similar proportions of the total Tg synthesized were detected in cell extracts and media. CONCLUSIONS The intracellular retention of Tg in the absence of RAP is likely due to its premature interaction with megalin, whereas RAP does not seem to affect Tg secretion directly.
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Affiliation(s)
- S Lisi
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
- Neurobiology Laboratory of Biology, Scuola Normale Superiore, Piazza Dei Cavalieri 1, Pisa, Italy
| | - R Botta
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
- DiaSorin S.p.A, Saluggia, Italy
| | - G Rotondo Dottore
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - M Leo
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - F Latrofa
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - P Vitti
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy
| | - M Marinò
- Department of Clinical and Experimental Medicine, Endocrinology Unit I, University of Pisa and University Hospital of Pisa, Via Paradisa 2, 56124, Pisa, Italy.
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22
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Abstract
Thyroglobulin (Tg) is a vertebrate secretory protein synthesized in the thyrocyte endoplasmic reticulum (ER), where it acquires N-linked glycosylation and conformational maturation (including formation of many disulfide bonds), leading to homodimerization. Its primary functions include iodide storage and thyroid hormonogenesis. Tg consists largely of repeating domains, and many tyrosyl residues in these domains become iodinated to form monoiodo- and diiodotyrosine, whereas only a small portion of Tg structure is dedicated to hormone formation. Interestingly, evolutionary ancestors, dependent upon thyroid hormone for development, synthesize thyroid hormones without the complete Tg protein architecture. Nevertheless, in all vertebrates, Tg follows a strict pattern of region I, II-III, and the cholinesterase-like (ChEL) domain. In vertebrates, Tg first undergoes intracellular transport through the secretory pathway, which requires the assistance of thyrocyte ER chaperones and oxidoreductases, as well as coordination of distinct regions of Tg, to achieve a native conformation. Curiously, regions II-III and ChEL behave as fully independent folding units that could function as successful secretory proteins by themselves. However, the large Tg region I (bearing the primary T4-forming site) is incompetent by itself for intracellular transport, requiring the downstream regions II-III and ChEL to complete its folding. A combination of nonsense mutations, frameshift mutations, splice site mutations, and missense mutations in Tg occurs spontaneously to cause congenital hypothyroidism and thyroidal ER stress. These Tg mutants are unable to achieve a native conformation within the ER, interfering with the efficiency of Tg maturation and export to the thyroid follicle lumen for iodide storage and hormonogenesis.
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Affiliation(s)
- Bruno Di Jeso
- Laboratorio di Patologia Generale (B.D.J.), Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy; and Division of Metabolism, Endocrinology, and Diabetes (P.A.), University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Peter Arvan
- Laboratorio di Patologia Generale (B.D.J.), Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy; and Division of Metabolism, Endocrinology, and Diabetes (P.A.), University of Michigan Medical School, Ann Arbor, Michigan 48105
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23
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Lee MH, Lee JU, Joung KH, Kim YK, Ryu MJ, Lee SE, Kim SJ, Chung HK, Choi MJ, Chang JY, Lee SH, Kweon GR, Kim HJ, Kim KS, Kim SM, Jo YS, Park J, Cheng SY, Shong M. Thyroid dysfunction associated with follicular cell steatosis in obese male mice and humans. Endocrinology 2015; 156:1181-93. [PMID: 25555091 PMCID: PMC5393324 DOI: 10.1210/en.2014-1670] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Adult thyroid dysfunction is a common endocrine disorder associated with an increased risk of cardiovascular disease and mortality. A recent epidemiologic study revealed a link between obesity and increased prevalence of hypothyroidism. It is conceivable that excessive adiposity in obesity might lead to expansion of the interfollicular adipose (IFA) depot or steatosis in thyroid follicular cells (thyroid steatosis, TS). In this study, we investigated the morphological and functional changes in thyroid glands of obese humans and animal models, diet-induced obese (DIO), ob/ob, and db/db mice. Expanded IFA depot and TS were observed in obese patients. Furthermore, DIO mice showed increased expression of lipogenesis-regulation genes, such as sterol regulatory element binding protein 1 (SREBP-1), peroxisome proliferator-activated receptor γ (PPARγ), acetyl coenzyme A carboxylase (ACC), and fatty acid synthetase (FASN) in the thyroid gland. Steatosis and ultrastructural changes, including distension of the endoplasmic reticulum (ER) and mitochondrial distortion in thyroid follicular cells, were uniformly observed in DIO mice and genetically obese mouse models, ob/ob and db/db mice. Obese mice displayed a variable degree of primary thyroid hypofunction, which was not corrected by PPARγ agonist administration. We propose that systemically increased adiposity is associated with characteristic IFA depots and TS and may cause or influence the development of primary thyroid failure.
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Affiliation(s)
- Min Hee Lee
- Research Center for Endocrine and Metabolic Diseases (M.H.L., K.H.J., Y.K.K., M.J.R., S.E.L., S.J.K., H.K.C., M.J.C., J.Y.C., H.J.K., K.S.K., Y.S.J., M.C.), Chungnam National University School of Medicine, Daejeon 301-721, Republic of Korea; Department of Pathology (J.U.L.), Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon 301-723, Republic of Korea; Department of Biomedical Science (S.-H.L.), Korea Advanced Institute of Biological Science, Daejeon 305-701, Korea; Department of Biochemistry (G.R.K.), Chungnam National University School of Medicine, Daejeon 301-721, Republic of Korea; Department of Nuclear Medicine (S.-M.K.), Chungnam National University and Hospital, Daejeon 301-721, Republic of Korea; and Laboratory of Molecular Biology (J.P., S.-Y.C.), National Cancer Institute, Bethesda, Maryland 20892
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24
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Kung LHW, Rajpar MH, Preziosi R, Briggs MD, Boot-Handford RP. Increased classical endoplasmic reticulum stress is sufficient to reduce chondrocyte proliferation rate in the growth plate and decrease bone growth. PLoS One 2015; 10:e0117016. [PMID: 25693198 PMCID: PMC4334961 DOI: 10.1371/journal.pone.0117016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/17/2014] [Indexed: 01/14/2023] Open
Abstract
Mutations in genes encoding cartilage oligomeric matrix protein and matrilin-3 cause a spectrum of chondrodysplasias called multiple epiphyseal dysplasia (MED) and pseudoachondroplasia (PSACH). The majority of these diseases feature classical endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) as a result of misfolding of the mutant protein. However, the importance and the pathological contribution of ER stress in the disease pathogenesis are unknown. The aim of this study was to investigate the generic role of ER stress and the UPR in the pathogenesis of these diseases. A transgenic mouse line (ColIITgcog) was generated using the collagen II promoter to drive expression of an ER stress-inducing protein (Tgcog) in chondrocytes. The skeletal and histological phenotypes of these ColIITgcog mice were characterised. The expression and intracellular retention of Tgcog induced ER stress and activated the UPR as characterised by increased BiP expression, phosphorylation of eIF2α and spliced Xbp1. ColIITgcog mice exhibited decreased long bone growth and decreased chondrocyte proliferation rate. However, there was no disruption of chondrocyte morphology or growth plate architecture and perturbations in apoptosis were not apparent. Our data demonstrate that the targeted induction of ER stress in chondrocytes was sufficient to reduce the rate of bone growth, a key clinical feature associated with MED and PSACH, in the absence of any growth plate dysplasia. This study establishes that classical ER stress is a pathogenic factor that contributes to the disease mechanism of MED and PSACH. However, not all the pathological features of MED and PSACH were recapitulated, suggesting that a combination of intra- and extra-cellular factors are likely to be responsible for the disease pathology as a whole.
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Affiliation(s)
- Louise H. W. Kung
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - M. Helen Rajpar
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Richard Preziosi
- Environment, Ecology and Evolution Research Group, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
| | - Michael D. Briggs
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle Upon Tyne, United Kingdom
| | - Raymond P. Boot-Handford
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, The University of Manchester, Manchester, United Kingdom
- * E-mail:
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25
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Sato A, Abe K, Yuzuriha M, Fujii S, Takahashi N, Hojo H, Teramoto S, Aoyama H. A novel mutation in the thyroglobulin gene that causes goiter and dwarfism in Wistar Hannover GALAS rats. Mutat Res 2014; 762:17-23. [PMID: 24582622 DOI: 10.1016/j.mrfmmm.2014.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/23/2014] [Accepted: 02/18/2014] [Indexed: 06/03/2023]
Abstract
Outbred stocks of rats have been used extensively in biomedical, pharmaceutical and/or toxicological studies as a model of genetically heterogeneous human populations. One of such stocks is the Wistar Hannover GALAS rat. However, the colony of Wistar Hannover GALAS rat has been suspected of keeping a problematic mutation that manifests two distinct spontaneous abnormalities, goiter and dwarfism, which often confuses study results. We have successfully identified the responsible mutation, a guanine to thymine transversion at the acceptor site (3' end) of intron 6 in the thyroglobulin (Tg) gene (Tgc.749-1G>T), that induces a complete missing of exon 7 from the whole Tg transcript by mating experiments and subsequent molecular analyses. The following observations confirmed that Tgc.749-1G>T/Tgc.749-1G>T homozygotes manifested both dwarfism and goiter, while Tgc.749-1G>T/+ heterozygotes had only a goiter with normal appearance, suggesting that the mutant phenotypes inherit as an autosomal semi-dominant trait. The mutant phenotypes, goiter and dwarfism, mimicked those caused by typical endocrine disrupters attacking the thyroid. Hence a simple and reliable diagnostic methodology has been developed for genomic DNA-based genotyping of animals. The diagnostic methodology reported here would allow users of Wistar Hannover GALAS rats to evaluate their study results precisely by carefully interpreting the data obtained from Tgc.749-1G>T/+ heterozygotes having externally undetectable thyroidal lesions.
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Affiliation(s)
- Akira Sato
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Kuniya Abe
- Technology and Development Team for Mammalian Genome Dynamism, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Misako Yuzuriha
- Technology and Development Team for Mammalian Genome Dynamism, RIKEN BioResource Center, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
| | - Sakiko Fujii
- Safety Research Division, Safety Research Institute for Chemical Compounds Co., Ltd., 363-24 Shin-ei, Kiyota-ku, Sapporo, Hokkaido 004-0839, Japan
| | - Naofumi Takahashi
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Hitoshi Hojo
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Shoji Teramoto
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan
| | - Hiroaki Aoyama
- Toxicology Division, Institute of Environmental Toxicology, 4321 Uchimoriya-machi, Joso, Ibaraki 303-0043, Japan.
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Kopp P. Mutations in the Pendred Syndrome (PDS/SLC26A) gene: an increasingly complex phenotypic spectrum from goiter to thyroid hypoplasia. J Clin Endocrinol Metab 2014; 99:67-9. [PMID: 24384016 DOI: 10.1210/jc.2013-4319] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Peter Kopp
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611
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Andrews TD, Whittle B, Field MA, Balakishnan B, Zhang Y, Shao Y, Cho V, Kirk M, Singh M, Xia Y, Hager J, Winslade S, Sjollema G, Beutler B, Enders A, Goodnow CC. Massively parallel sequencing of the mouse exome to accurately identify rare, induced mutations: an immediate source for thousands of new mouse models. Open Biol 2013; 2:120061. [PMID: 22724066 PMCID: PMC3376740 DOI: 10.1098/rsob.120061] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 04/16/2012] [Indexed: 01/17/2023] Open
Abstract
Accurate identification of sparse heterozygous single-nucleotide variants (SNVs) is a critical challenge for identifying the causative mutations in mouse genetic screens, human genetic diseases and cancer. When seeking to identify causal DNA variants that occur at such low rates, they are overwhelmed by false-positive calls that arise from a range of technical and biological sources. We describe a strategy using whole-exome capture, massively parallel DNA sequencing and computational analysis, which identifies with a low false-positive rate the majority of heterozygous and homozygous SNVs arising de novo with a frequency of one nucleotide substitution per megabase in progeny of N-ethyl-N-nitrosourea (ENU)-mutated C57BL/6j mice. We found that by applying a strategy of filtering raw SNV calls against known and platform-specific variants we could call true SNVs with a false-positive rate of 19.4 per cent and an estimated false-negative rate of 21.3 per cent. These error rates are small enough to enable calling a causative mutation from both homozygous and heterozygous candidate mutation lists with little or no further experimental validation. The efficacy of this approach is demonstrated by identifying the causative mutation in the Ptprc gene in a lymphocyte-deficient strain and in 11 other strains with immune disorders or obesity, without the need for meiotic mapping. Exome sequencing of first-generation mutant mice revealed hundreds of unphenotyped protein-changing mutations, 52 per cent of which are predicted to be deleterious, which now become available for breeding and experimental analysis. We show that exome sequencing data alone are sufficient to identify induced mutations. This approach transforms genetic screens in mice, establishes a general strategy for analysing rare DNA variants and opens up a large new source for experimental models of human disease.
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Affiliation(s)
- T D Andrews
- Immunogenomics Laboratory, Australian National University, GPO Box 334, Canberra City, Australian Capital Territory, 2601 , Australia.
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Wright J, Wang X, Haataja L, Kellogg AP, Lee J, Liu M, Arvan P. Dominant protein interactions that influence the pathogenesis of conformational diseases. J Clin Invest 2013; 123:3124-34. [PMID: 23722904 DOI: 10.1172/jci67260] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 03/28/2013] [Indexed: 02/06/2023] Open
Abstract
Misfolding of exportable proteins can trigger endocrinopathies. For example, misfolding of insulin can result in autosomal dominant mutant INS gene-induced diabetes of youth, and misfolding of thyroglobulin can result in autosomal recessive congenital hypothyroidism with deficient thyroglobulin. Both proinsulin and thyroglobulin normally form homodimers; the mutant versions of both proteins misfold in the ER, triggering ER stress, and, in both cases, heterozygosity creates potential for cross-dimerization between mutant and WT gene products. Here, we investigated these two ER-retained mutant secretory proteins and the selectivity of their interactions with their respective WT counterparts. In both cases and in animal models of these diseases, we found that conditions favoring an increased stoichiometry of mutant gene product dominantly inhibited export of the WT partner, while increased relative level of the WT gene product helped to rescue secretion of the mutant partner. Surprisingly, the bidirectional consequences of secretory blockade and rescue occur simultaneously in the same cells. Thus, in the context of heterozygosity, expression level and stability of WT subunits may be a critical factor influencing the effect of protein misfolding on clinical phenotype. These results offer new insight into dominant as well as recessive inheritance of conformational diseases and offer opportunities for the development of new therapies.
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Affiliation(s)
- Jordan Wright
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan, USA
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29
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Meitzler JL, Hinde S, Bánfi B, Nauseef WM, Ortiz de Montellano PR. Conserved cysteine residues provide a protein-protein interaction surface in dual oxidase (DUOX) proteins. J Biol Chem 2013; 288:7147-57. [PMID: 23362256 DOI: 10.1074/jbc.m112.414797] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Intramolecular disulfide bond formation is promoted in oxidizing extracellular and endoplasmic reticulum compartments and often contributes to protein stability and function. DUOX1 and DUOX2 are distinguished from other members of the NOX protein family by the presence of a unique extracellular N-terminal region. These peroxidase-like domains lack the conserved cysteines that confer structural stability to mammalian peroxidases. Sequence-based structure predictions suggest that the thiol groups present are solvent-exposed on a single protein surface and are too distant to support intramolecular disulfide bond formation. To investigate the role of these thiol residues, we introduced four individual cysteine to glycine mutations in the peroxidase-like domains of both human DUOXs and purified the recombinant proteins. The mutations caused little change in the stabilities of the monomeric proteins, supporting the hypothesis that the thiol residues are solvent-exposed and not involved in disulfide bonds that are critical for structural integrity. However, the ability of the isolated hDUOX1 peroxidase-like domain to dimerize was altered, suggesting a role for these cysteines in protein-protein interactions that could facilitate homodimerization of the peroxidase-like domain or, in the full-length protein, heterodimeric interactions with a maturation protein. When full-length hDUOX1 was expressed in HEK293 cells, the mutations resulted in decreased H2O2 production that correlated with a decreased amount of the enzyme localized to the membrane surface rather than with a loss of activity or with a failure to synthesize the mutant proteins. These results support a role for the cysteine residues in intermolecular disulfide bond formation with the DUOX maturation factor DUOXA1.
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Affiliation(s)
- Jennifer L Meitzler
- Laboratory of Molecular Pharmacology of the Center for Cancer Research, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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30
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Kolypetri P, Jiang H, Carayanniotis G. Identification of pathogenic T cell epitopes near cathepsin cleavage sites in thyroglobulin. THE JOURNAL OF IMMUNOLOGY 2013; 190:1466-71. [PMID: 23315080 DOI: 10.4049/jimmunol.1202529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Experimental autoimmune thyroiditis, induced in mice after challenge with thyroglobulin (Tg), is known to be under the genetic control of the H2A(k) locus. Because cathepsins are known to influence proteolytic processing of Tg in vivo, we examined in this study whether putative H2A(k)-binding Tg epitopes, located near cathepsin cleavage sites within mouse Tg, have immunopathogenic properties. Cathepsin L, B, and D cleavage sites in mouse Tg were predicted based on homology with known cathepsin cleavage sites in rabbit Tg. We used an algorithm-based approach to identify H2A(k)-binding motifs within 20-aa residue segments adjacent to cathepsin cleavage sites, and five 12mer peptides encompassing these sequences were synthesized. Two of them, p2369 (aa 2369-2380) and p2439 (aa 2439-2450) were immunogenic, eliciting significant proliferative T cell responses using lymph node cells from peptide-primed mice and production of IL-2 and IFN-γ in recall assays in vitro. Both peptides induced experimental autoimmune thyroiditis upon direct challenge of CBA/J mice with peptide in CFA and by adoptive transfer of peptide-primed lymph node cells into naive recipient hosts, but neither peptide was characterized as dominant.
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Affiliation(s)
- Panayota Kolypetri
- Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3V6, Canada
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31
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De Jaco A, Dubi N, Camp S, Taylor P. Congenital hypothyroidism mutations affect common folding and trafficking in the α/β-hydrolase fold proteins. FEBS J 2012; 279:4293-305. [PMID: 23035660 DOI: 10.1111/febs.12019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 12/19/2022]
Abstract
The α/β-hydrolase fold superfamily of proteins is composed of structurally related members that, despite great diversity in their catalytic, recognition, adhesion and chaperone functions, share a common fold governed by homologous residues and conserved disulfide bridges. Non-synonymous single nucleotide polymorphisms within the α/β-hydrolase fold domain in various family members have been found for congenital endocrine, metabolic and nervous system disorders. By examining the amino acid sequence from the various proteins, mutations were found to be prevalent in conserved residues within the α/β-hydrolase fold of the homologous proteins. This is the case for the thyroglobulin mutations linked to congenital hypothyroidism. To address whether correct folding of the common domain is required for protein export, we inserted the thyroglobulin mutations at homologous positions in two correlated but simpler α/β-hydrolase fold proteins known to be exported to the cell surface: neuroligin3 and acetylcholinesterase. Here we show that these mutations in the cholinesterase homologous region alter the folding properties of the α/β-hydrolase fold domain, which are reflected in defects in protein trafficking, folding and function, and ultimately result in retention of the partially processed proteins in the endoplasmic reticulum. Accordingly, mutations at conserved residues may be transferred amongst homologous proteins to produce common processing defects despite disparate functions, protein complexity and tissue-specific expression of the homologous proteins. More importantly, a similar assembly of the α/β-hydrolase fold domain tertiary structure among homologous members of the superfamily is required for correct trafficking of the proteins to their final destination.
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Affiliation(s)
- Antonella De Jaco
- Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.
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32
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Belkadi A, Jacques C, Savagner F, Malthièry Y. Phylogenetic analysis of the human thyroglobulin regions. Thyroid Res 2012; 5:3. [PMID: 22549183 PMCID: PMC3464141 DOI: 10.1186/1756-6614-5-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 05/01/2012] [Indexed: 02/02/2023] Open
Abstract
Thyroglobulin is a large protein present in all vertebrates. It is synthesized in the thyrocytes and exported to lumen of the thyroid follicle, where its tyrosine residues are iodinated . The iodinated thyroglobulin is reintegrated into the cell and processed (cleaved to free its two extremities) for thyroid hormone synthesis. Thyroglobulin sequence analysis has identified four regions of the molecule: Tg1, Tg2, Tg3 and ChEL. Structural abnormalities and mutations result in different pathological consequences, depending on the thyroglobulin region affected. We carried out a bioinformatic analysis of thyroglobulin, determining the origin and the function of each region. Our results suggest that the Tg1 region acts as a binding protein on the apical membrane, the Tg2 region is involved in protein adhesion and the Tg3 region is involved in determining the three-dimensional structure of the protein. The ChEL domain is involved in thyroglobulin transport, dimerization and adhesion. The presence of repetitive domains in the Tg1, Tg2 and Tg3 regions suggests that these domains may have arisen through duplication.
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Affiliation(s)
- Abdelaziz Belkadi
- INSERM U694, Institut Biologie Santé (IBS), rue des Capucins, F-49100 Angers, France.
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Yan Z, Hoffmann A, Kaiser EK, Grunwald WC, Cool DR. Misfolding of Mutated Vasopressin Causes ER-Retention and Activation of ER-Stress Markers in Neuro-2a Cells. ACTA ACUST UNITED AC 2011; 4:136-146. [PMID: 24567768 PMCID: PMC3932059 DOI: 10.2174/1876528901104010136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Arginine-vasopressin (AVP) is a peptide hormone normally secreted from neuroendocrine cells via the regulated secretory pathway. In Familial Neurohypophyseal Diabetes Insipidus (FNDI), an autosomal dominant form of central diabetes insipidus, mutations of pro-vasopressin appear to accumulate in the endoplasmic reticulum (ER) causing a lack of biologically active AVP in the blood. To investigate the effect of pro-vasopressin mutations regarding intracellular functions of protein targeting and secretion, we created two FNDI-associated amino acid substitution mutants, e.g., G14R, and G17V in frame with green fluorescent protein (GFP) and pro-vasopressin (VP) in frame with red fluorescent protein (VP-RFP). Fluorescence microscopy of Neuro-2a cells expressing these constructs revealed co-localization of VP-GFP and VP-RFP to punctate granules along the length and accumulating at the tips of neurites, characteristic of regulated secretory granules. In contrast, the two FNDI-associated amino acid substitution mutants, e.g., G14R-GFP, and G17VGFP, were localized to a perinuclear region of the Neuro-2a cells characteristic of the endoplasmic reticulum. Co-expression of these mutants with VP-RFP showed VP-RFP was retained in the ER, co-localized with the mutants suggesting the formation of heterodimers as found in FNDI. Stimulated secretion experiments indicated that VP-GFP was secreted in an inducible manner whereas, G14R-GFP and G17V-GFP were retained to nearly 100% within the cells. Analysis by western blotting and semi-quantitative RT-PCR indicated an increased protein and mRNA expression for an ER resident molecular chaperone, BiP. Further analysis of ER-storage disease-associated proteins such as caspase 12 and CHOP showed an increase in these as well. The results suggest that G14R-GFP and G17V-GFP are retained in the ER of Neuro-2a cells, resulting in up-regulation of the molecular chaperone BiP, and activation of the ER-storage disease-associated caspase cascade system.
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Affiliation(s)
- Zhongyu Yan
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - Andrea Hoffmann
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - Erin Kelly Kaiser
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - William C Grunwald
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - David R Cool
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
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Peters LR, Raghavan M. Endoplasmic reticulum calcium depletion impacts chaperone secretion, innate immunity, and phagocytic uptake of cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 187:919-31. [PMID: 21670312 PMCID: PMC3371385 DOI: 10.4049/jimmunol.1100690] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A number of immunological functions are ascribed to cell surface-expressed forms of the endoplasmic reticulum (ER) chaperone calreticulin (CRT). In this study, we examined the impact of ER stress-inducing drugs upon cell surface CRT induction and the resulting immunological consequences. We showed that cell surface expression of CRT and secretion of CRT, BiP, gp96, and PDI were induced by thapsigargin (THP) treatment, which depletes ER calcium, but not by tunicamycin treatment, which inhibits protein glycosylation. Surface expression of CRT in viable, THP-treated fibroblasts correlated with their enhanced phagocytic uptake by bone marrow-derived dendritic cells. Incubation of bone marrow-derived dendritic cells with THP-treated fibroblasts enhanced sterile IL-6 production and LPS-induced generation of IL-1β, IL-12, IL-23, and TNF-α. However, extracellular CRT is not required for enhanced proinflammatory responses. Furthermore, the pattern of proinflammatory cytokine induction by THP-treated cells and cell supernatants resembled that induced by THP itself and indicated that other ER chaperones present in supernatants of THP-treated cells also do not contribute to induction of the innate immune response. Thus, secretion of various ER chaperones, including CRT, is induced by ER calcium depletion. CRT, previously suggested as an eat-me signal in dead and dying cellular contexts, can also promote phagocytic uptake of cells subject to ER calcium depletion. Finally, there is a strong synergy between calcium depletion in the ER and sterile IL-6, as well as LPS-dependent IL-1β, IL-12, IL-23, and TNF-α innate responses, findings that have implications for understanding inflammatory diseases that originate in the ER.
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Affiliation(s)
- Larry Robert Peters
- Graduate Program in Immunology, University of Michigan Medical School, Ann Arbor MI 48109
| | - Malini Raghavan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor MI 48109
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Dedieu A, Gaillard JC, Pourcher T, Darrouzet E, Armengaud J. Revisiting iodination sites in thyroglobulin with an organ-oriented shotgun strategy. J Biol Chem 2010; 286:259-69. [PMID: 20978121 DOI: 10.1074/jbc.m110.159483] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Thyroglobulin (Tg) is secreted by thyroid epithelial cells. It is essential for thyroid hormonogenesis and iodine storage. Although studied for many years, only indirect and partial surveys of its post-translational modifications were reported. Here, we present a direct proteomic approach, used to study the degree of iodination of mouse Tg without any preliminary purification. A comprehensive coverage of Tg was obtained using a combination of different proteases, MS/MS fragmentation procedures with inclusion lists and a hybrid mass high-resolution LTQ-Orbitrap XL mass spectrometer. Although only 16 iodinated sites are currently known for human Tg, we uncovered 37 iodinated tyrosine residues, most of them being mono- or diiodinated. We report the specific isotopic pattern of thyroxine modification, not recognized as a normal peptide pattern. Four hormonogenic sites were detected. Two donor sites were identified through the detection of a pyruvic acid residue in place of the initial tyrosine. Evidence for polypeptide cleavages sites due to the action of cathepsins and dipeptidyl proteases in the thyroid were also detected. This work shows that semi-quantitation of Tg iodination states is feasible for human biopsies and should be of significant medical interest for further characterization of human thyroid pathologies.
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Affiliation(s)
- Alain Dedieu
- Commissariat à l'Energie Atomique, DSV, iBEB, Laboratoire des Transporters en Imagerie et Radiothérapie en Oncologie, Bagnols-sur-Cèze F-30207, France.
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Wang X, Lee J, Di Jeso B, Treglia AS, Comoletti D, Dubi N, Taylor P, Arvan P. Cis and trans actions of the cholinesterase-like domain within the thyroglobulin dimer. J Biol Chem 2010; 285:17564-73. [PMID: 20353937 PMCID: PMC2878521 DOI: 10.1074/jbc.m110.111641] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 03/26/2010] [Indexed: 11/06/2022] Open
Abstract
Thyroglobulin (Tg, precursor for thyroid hormone synthesis) is a large secreted glycoprotein composed of upstream regions I-II-III, followed by the approximately 570 residue cholinesterase-like (ChEL) domain. ChEL has two identified functions: 1) homodimerization, and 2) binding to I-II-III that facilitates I-II-III oxidative maturation required for intracellular protein transport. Like its homologs in the acetylcholinesterase (AChE) family, ChEL possesses two carboxyl-terminal alpha-helices. We find that a Tg-AChE chimera (swapping AChE in place of ChEL) allows for dimerization with monomeric AChE, proving exposure of the carboxyl-terminal helices within the larger context of Tg. Further, we establish that perturbing trans-helical interaction blocks homodimerization of the Tg ChEL domain. Additionally, ChEL can associate with neuroligins (a related family of cholinesterase-like proteins), demonstrating potential for Tg cross-dimerization between non-identical partners. Indeed, when mutant rdw-Tg (Tg-G2298R, defective for protein secretion) is co-expressed with wild-type Tg, the two proteins cross-dimerize and secretion of rdw-Tg is partially restored. Moreover, we find that AChE and soluble neuroligins also can bind to the upstream Tg regions I-II-III; however, they cannot rescue secretion, because they cannot facilitate oxidative maturation of I-II-III. These data suggest that specific properties of distinct Tg ChEL mutants may result in distinct patterns of Tg monomer folding, cross-dimerization with wild-type Tg, and variable secretion behavior in heterozygous patients.
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Affiliation(s)
- Xiaofan Wang
- From the Division of Metabolism, Endocrinology and Diabetes, and
| | - Jaemin Lee
- From the Division of Metabolism, Endocrinology and Diabetes, and
- Program of Cell and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678
| | - Bruno Di Jeso
- the Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Facolta di Scienze MFN, Università degli Studi di Lecce, Strada Provincale Lecce-Monteroni, 73100 Lecce, Italy, and
| | - A. Sonia Treglia
- the Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Facolta di Scienze MFN, Università degli Studi di Lecce, Strada Provincale Lecce-Monteroni, 73100 Lecce, Italy, and
| | - Davide Comoletti
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Noga Dubi
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Palmer Taylor
- the Department of Pharmacology, University of California San Diego, La Jolla, California 92093
| | - Peter Arvan
- From the Division of Metabolism, Endocrinology and Diabetes, and
- Program of Cell and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678
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Raef H, Al-Rijjal R, Al-Shehri S, Zou M, Al-Mana H, Baitei EY, Parhar RS, Al-Mohanna FA, Shi Y. Biallelic p.R2223H mutation in the thyroglobulin gene causes thyroglobulin retention and severe hypothyroidism with subsequent development of thyroid carcinoma. J Clin Endocrinol Metab 2010; 95:1000-6. [PMID: 20089614 DOI: 10.1210/jc.2009-1823] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
CONTEXT Dyshormonogenesis due to genetic defect in thyroglobulin (Tg) synthesis and secretion can lead to congenital hypothyroidism. OBJECTIVES The aim of the study was to analyze the TG gene for the presence of mutations and to study the underlying mechanisms leading to dyshormonogenesis. CASES Two siblings aged 25 and 31 yr presented with recurrent goitrous hypothyroidism with undetectable serum Tg. The older sibling was diagnosed with follicular variant of papillary thyroid carcinoma (FVPTC) at age 21 and metastatic FVPTC 8 yr later. METHODS The entire coding region of TG gene was sequenced. BRAF, RAS, and P53 mutations or PAX8/PPAR-gamma rearrangement were screened in the FVPTC. Tg expression was studied by immunohistochemistry. RESULTS Biallelic c.6725G>A (p.R2223H) and c.6396C>T (p.S2113L) sequence variations were detected in both patients and monoallelic variations in their family members. The c.6396C>T (p.S2113L) sequence variation was found in 14% of 100 population controls, whereas c.6725G>A variation was not present in the controls. Two previously reported polymorphisms (c.2200T>G and c.3082A>G) were present in all the family members. Strong cytoplasmic immunostaining of Tg was observed in the hyperplastic thyroid epithelial cells and weak or no staining in the follicular lumen. Cytoplasmic staining was localized in the endoplasmic reticulum. Reduced staining was found in the FVPTC. Neither RAS, BRAF, or P53 gene mutation nor a PAX8/PPAR-gamma rearrangement was detected in the tumor tissue. CONCLUSIONS Biallelic c.6725G>A (p.R2223H) mutation causes Tg retention in the endoplasmic reticulum, resulting in dyshormonogenesis. Prolonged TSH stimulation may promote malignant transformation and development of thyroid cancer. The c.6396C>T (p.S2113L) is a novel polymorphism.
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Affiliation(s)
- Hussein Raef
- Department of Genetics (MBC-03), King Faisal Specialist Hospital and Research Centre, P.O. Box 3354, Riyadh 11211, Saudi Arabia
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Machiavelli GA, Caputo M, Rivolta CM, Olcese MC, Gruñeiro-Papendieck L, Chiesa A, González-Sarmiento R, Targovnik HM. Molecular analysis of congenital goitres with hypothyroidism caused by defective thyroglobulin synthesis. Identification of a novel c.7006C>T [p.R2317X] mutation and expression of minigenes containing nonsense mutations in exon 7. Clin Endocrinol (Oxf) 2010; 72:112-21. [PMID: 19438905 DOI: 10.1111/j.1365-2265.2009.03621.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Thyroglobulin (TG) deficiency is an autosomal-recessive disorder that results in thyroid dyshormonogenesis. A number of distinct mutations have been identified as causing human hypothyroid goitre. OBJECTIVES The purpose of this study was to identify and characterize new mutations in the TG gene in an attempt to increase the understanding of the genetic mechanism responsible for this disorder. A total of six patients from four nonconsanguineous families with marked impairment of TG synthesis were studied. METHODS Single-strand conformation polymorphism (SSCP) analysis, sequencing of DNA, genotyping, expression of chimeric minigenes and bioinformatic analysis were performed. RESULTS Four different inactivating TG mutations were identified: one novel mutation (c.7006C>T [p.R2317X]) and three previously reported (c.886C>T [p.R277X], c.6701C>A [p.A2215D] and c.6725G>A [p.R2223H]). Consequently, one patient carried a compound heterozygous for p.R2223H/p.R2317X mutations; two brothers showed a homozygous p.A2215D substitution and the remaining three patients, from two families with typical phenotype, had a single p.R277X mutated allele. We also showed functional evidences that premature stop codons inserted at different positions in exon 7, which disrupt exonic splicing enhancer (ESE) sequences, do not interfere with exon definition and processing. CONCLUSIONS In this study, we have identified a novel nonsense mutation p.R2317X in the acetylcholinesterase homology domain of TG. We have also observed that nonsense mutations do not interfere with the pre-mRNA splicing of exon 7. The results are in accordance with previous observations confirming the genetic heterogeneity of TG defects.
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Affiliation(s)
- Gloria A Machiavelli
- Laboratorio de Biología Molecular, Cátedra de Genética y Biología Molecular, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
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Niu DM, Hsu JH, Chong KW, Huang CH, Lu YH, Kao CH, Yu HC, Lo MY, Jap TS. Six new mutations of the thyroglobulin gene discovered in taiwanese children presenting with thyroid dyshormonogenesis. J Clin Endocrinol Metab 2009; 94:5045-52. [PMID: 19837936 DOI: 10.1210/jc.2009-0646] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND Thyroglobulin (TG) defect is a rare cause of congenital hypothyroidism. Although only 44 mutations of the human TG gene have been identified, we have suspected a TG defect in 38% of Taiwan Chinese children/adolescents presenting with moderate or severe thyroidal dyshormonogenesis. STUDY OBJECTIVE The aim of the study is to report the discovery of new TG gene mutations and associated clinical manifestations of the defective TG protein. PATIENTS AND RESULTS In seven patients from six families, we detected six new TG gene mutations, including c.1348delT, p.R432X (c.1351C>T), g.IVS3 + 2T>G, c.1712delT, p.Q1765X (c.5350C>T), and c.6047delA. The c.1348delT and p.R432X mutations were the most common, detected in 33 and 25%, respectively, of alleles studied. Haplotype analysis suggested that the c.1348delT and g.IVS3 + 2T>G mutations are due to founder effects, whereas p.R432X is probably due to independently recurrent de novo mutations. mRNA transcript of the g.IVS3 + 2T>G mutant, detected in whole blood by reverse transcription-nested PCR, showed skipping of exon 3 (98-bp deletion) and a frameshift, with a terminal signal after 17 altered amino acid residues. CONCLUSIONS TG defects have an important role in severe thyroidal dyshormonogenesis (pretreatment, or after a 3-wk T(4) withdrawal, plasma T(4) < or = 30 nmol/liter) in Taiwanese. Its genetic characteristics are markedly different from those described in other populations presenting with mutations of the TG gene.
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Affiliation(s)
- Dau-Ming Niu
- Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan.
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Pardo V, Vono-Toniolo J, Rubio IGS, Knobel M, Possato RF, Targovnik HM, Kopp P, Medeiros-Neto G. The p.A2215D thyroglobulin gene mutation leads to deficient synthesis and secretion of the mutated protein and congenital hypothyroidism with wide phenotype variation. J Clin Endocrinol Metab 2009; 94:2938-44. [PMID: 19509106 DOI: 10.1210/jc.2009-0150] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Thyroglobulin (TG) is a large glycoprotein and functions as a matrix for thyroid hormone synthesis. TG gene mutations give rise to goitrous congenital hypothyroidism (CH) with considerable phenotype variation. OBJECTIVES The aim of the study was to report the genetic screening of 15 patients with CH due to TG gene mutations and to perform functional analysis of the p.A2215D mutation. DESIGN Clinical evaluation and DNA sequencing of the TG gene were performed in all patients. TG expression was analyzed in the goitrous tissue of one patient. Human cells were transfected with expression vectors containing mutated and wild-type human TG cDNA. RESULTS All patients had an absent rise of serum TG after stimulation with recombinant human TSH. Sequence analysis revealed three previously described mutations (p.A2215D, p.R277X, and g.IVS30+1G>T), and two novel mutations (p.Q2142X and g.IVS46-1G>A). Two known (g.IVS30+1G/p.A2215D and p.A2215D/p.R277X) and one novel (p.R277X/g.IVS46-1G>A) compound heterozygous constellations were also identified. Functional analysis indicated deficiency in TG synthesis, reduction of TG secretion, and retention of the mutant TG within the cell, leading to an endoplasmic reticulum storage disease, whereas small amounts of mutant TG were still secreted within the cell system. CONCLUSION All studied patients were either homozygous or heterozygous for TG gene mutations. Two novel mutations have been detected, and we show that TG mutation p.A2215D promotes the retention of TG within the endoplasmic reticulum and reduces TG synthesis and secretion, causing mild hypothyroidism. In the presence of sufficient iodine supply, some patients with TG mutations are able to compensate the impaired hormonogenesis and generate thyroid hormone.
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Affiliation(s)
- Viviane Pardo
- Thyroid Unit (LIM 25), University of São Paulo Medical School, Av. Dr. Arnaldo 455-4A, São Paulo, SP, Brazil
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Abstract
Recent studies have increased the number of known thyroiditogenic sites in thyroglobulin (Tg) to thirteen. These sites contain T-cell epitopes and are scattered throughout Tg, with nine of them localized toward the carboxyl terminal third of the molecule. So far, no pathogenic determinant has been found to be dominant, i.e. to be readily and consistently generated in extrathyroidal antigen-presenting cells (APC) following processing of intact Tg in vivo and in vitro. However, certain conditions, such as internalization of Tg-antibody complexes or enhanced iodination of Tg, have been described to promote generation of cryptic pathogenic peptides in APC, in vitro. These findings support the view that post-translational events can "unmask the cryptic self' and suggest mechanisms that may contribute to the pathogenesis of thyroiditis.
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Affiliation(s)
- George Carayanniotis
- Division of Endocrinology, Faculty of Medicine, Memorial University of Newfoundland, St. John's Nfld, Canada A1B 3V6.
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Lee J, Wang X, Di Jeso B, Arvan P. The cholinesterase-like domain, essential in thyroglobulin trafficking for thyroid hormone synthesis, is required for protein dimerization. J Biol Chem 2009; 284:12752-61. [PMID: 19276074 DOI: 10.1074/jbc.m806898200] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The carboxyl-terminal cholinesterase-like (ChEL) domain of thyroglobulin (Tg) has been identified as critically important in Tg export from the endoplasmic reticulum. In a number of human kindreds suffering from congenital hypothyroidism, and in the cog congenital goiter mouse and rdw rat dwarf models, thyroid hormone synthesis is inhibited because of mutations in the ChEL domain that block protein export from the endoplasmic reticulum. We hypothesize that Tg forms homodimers through noncovalent interactions involving two predicted alpha-helices in each ChEL domain that are homologous to the dimerization helices of acetylcholinesterase. This has been explored through selective epitope tagging of dimerization partners and by inserting an extra, unpaired Cys residue to create an opportunity for intermolecular disulfide pairing. We show that the ChEL domain is necessary and sufficient for Tg dimerization; specifically, the isolated ChEL domain can dimerize with full-length Tg or with itself. Insertion of an N-linked glycan into the putative upstream dimerization helix inhibits homodimerization of the isolated ChEL domain. However, interestingly, co-expression of upstream Tg domains, either in cis or in trans, overrides the dimerization defect of such a mutant. Thus, although the ChEL domain provides a nidus for Tg dimerization, interactions of upstream Tg regions with the ChEL domain actively stabilizes the Tg dimer complex for intracellular transport.
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Affiliation(s)
- Jaemin Lee
- Cell and Molecular Biology Program, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
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43
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Lee J, Di Jeso B, Arvan P. The cholinesterase-like domain of thyroglobulin functions as an intramolecular chaperone. J Clin Invest 2008; 118:2950-8. [PMID: 18596923 DOI: 10.1172/jci35164] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 05/21/2008] [Indexed: 11/17/2022] Open
Abstract
Thyroid hormonogenesis requires secretion of thyroglobulin, a protein comprising Cys-rich regions I, II, and III (referred to collectively as region I-II-III) followed by a cholinesterase-like (ChEL) domain. Secretion of mature thyroglobulin requires extensive folding and glycosylation in the ER. Multiple reports have linked mutations in the ChEL domain to congenital hypothyroidism in humans and rodents; these mutations block thyroglobulin from exiting the ER and induce ER stress. We report that, in a cell-based system, mutations in the ChEL domain impaired folding of thyroglobulin region I-II-III. Truncated thyroglobulin devoid of the ChEL domain was incompetent for cellular export; however, a recombinant ChEL protein ("secretory ChEL") was secreted efficiently. Coexpression of secretory ChEL with truncated thyroglobulin increased intracellular folding, promoted oxidative maturation, and facilitated secretion of region I-II-III, indicating that the ChEL domain may function as an intramolecular chaperone. Additionally, we found that the I-II-III peptide was cosecreted and physically associated with secretory ChEL. A functional ChEL domain engineered to be retained intracellularly triggered oxidative maturation of I-II-III but coretained I-II-III, indicating that the ChEL domain may also function as a molecular escort. These insights into the role of the ChEL domain may represent potential therapeutic targets in the treatment of congenital hypothyroidism.
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Affiliation(s)
- Jaemin Lee
- Division of Metabolism, Endocrinology and Diabetes and Program of Cellular and Molecular Biology, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0678, USA
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44
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Pardo V, Rubio IGS, Knobel M, Aguiar-Oliveira MH, Santos MM, Gomes SA, Oliveira CRP, Targovnik HM, Medeiros-Neto G. Phenotypic variation among four family members with congenital hypothyroidism caused by two distinct thyroglobulin gene mutations. Thyroid 2008; 18:783-6. [PMID: 18631008 DOI: 10.1089/thy.2007.0321] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Thyroglobulin (Tg) is a large glycoprotein that is intimately involved in the biosynthesis of thyroxine and triiodothyronine. At least 38 mutations have been described in the Tg gene that are associated with varying degrees of hypothyroidism. We studied the Tg gene in four related subjects with congenital hypothyroidism. SUMMARY We found a novel compound heterozygous constellation (IVS30 + 1G>T/A2215D) in a brother and sister and one previously described related mutation (IVS30+1G>T) in their two sibling second degree cousins. The brother with the IVS30 + 1G>T/A2215D mutation and the two siblings with the IVS30+1G>T mutation had fetal or neonatal goiter and all had hypothyroidism. CONCLUSIONS This study further confirms the association of the IVS30+G>T mutation of the Tg gene with hypothyroidism. Computer analysis predicts that the A2215D mutation, first reported here, should cause structural instability of Tg but when present as a compound heterozygous mutation with IVS30+G>T/A its effect is unclear but is likely to be influenced by iodine intake.
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Affiliation(s)
- Viviane Pardo
- Thyroid Study Unit (LIM-25), Division of Endocrinology, University of São Paulo Medical School, São Paulo, Brazil
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45
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Westmuckett AD, Hoffhines AJ, Borghei A, Moore KL. Early postnatal pulmonary failure and primary hypothyroidism in mice with combined TPST-1 and TPST-2 deficiency. Gen Comp Endocrinol 2008; 156:145-53. [PMID: 18243191 PMCID: PMC2323209 DOI: 10.1016/j.ygcen.2007.12.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 12/04/2007] [Accepted: 12/10/2007] [Indexed: 10/22/2022]
Abstract
Protein-tyrosine sulfation is a post-translational modification of an unknown number of secreted and membrane proteins mediated by two known Golgi tyrosylprotein sulfotransferases (TPST-1 and TPST-2). Tpst double knockouts were generated to investigate the importance of tyrosine sulfation in vivo. Double knockouts were born alive at the expected frequency, were normal in size, and their tissues do not synthesize sulfotyrosine. However, most pups die in the early postnatal period with signs of cardiopulmonary insufficiency. A combination of clinical, magnetic resonance imaging, and histological data indicated that lungs of Tpst double knockouts fail to expand at birth resulting in acute pulmonary hypertension, right-to-left shunting, and death by asphyxia in the early postnatal period. Some double knockouts survive the postnatal period, but fail to thrive and display delayed growth that is due in part to hypothyroidism. In addition, we find that Tpst2-/- mice have primary hypothyroidism, but that Tpst1-/- mice are euthyroid. This suggests that a protein(s) required for thyroid hormone production is sulfated and cannot be sulfated in the absence of TPST-2. Thus, Tpst1 and Tpst2 are the only Tpst genes in mice, tyrosine sulfation is required for normal pulmonary function at birth, and TPST-2 is required for normal thyroid gland function.
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Affiliation(s)
- Andrew D. Westmuckett
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Adam J. Hoffhines
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Atefeh Borghei
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Kevin L. Moore
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Oklahoma Center for Medical Glycobiology, Oklahoma City, Oklahoma
- Corresponding author: Kevin L. Moore, M.D., Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, Phone: (405) 271-7314, FAX: (405) 271-7417, E-Mail:
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46
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Roth J, Yam GHF, Fan J, Hirano K, Gaplovska-Kysela K, Le Fourn V, Guhl B, Santimaria R, Torossi T, Ziak M, Zuber C. Protein quality control: the who's who, the where's and therapeutic escapes. Histochem Cell Biol 2008; 129:163-77. [PMID: 18075753 PMCID: PMC2228381 DOI: 10.1007/s00418-007-0366-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2007] [Indexed: 01/01/2023]
Abstract
In cells the quality of newly synthesized proteins is monitored in regard to proper folding and correct assembly in the early secretory pathway, the cytosol and the nucleoplasm. Proteins recognized as non-native in the ER will be removed and degraded by a process termed ERAD. ERAD of aberrant proteins is accompanied by various changes of cellular organelles and results in protein folding diseases. This review focuses on how the immunocytochemical labeling and electron microscopic analyses have helped to disclose the in situ subcellular distribution pattern of some of the key machinery proteins of the cellular protein quality control, the organelle changes due to the presence of misfolded proteins, and the efficiency of synthetic chaperones to rescue disease-causing trafficking defects of aberrant proteins.
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Affiliation(s)
- Jürgen Roth
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Gary Hin-Fai Yam
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, University Eye Centre, Mongkok, Kowloon Hong Kong
| | - Jingyu Fan
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
- Department of Biophysics, Peking University Health Science Center, 100083 Beijing, P. R. China
| | - Kiyoko Hirano
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
- The Noguchi Institute, 1-8-1 Kaga, Itabashi, Tokyo 173-0003 Japan
| | - Katarina Gaplovska-Kysela
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Valerie Le Fourn
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Bruno Guhl
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Roger Santimaria
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Tania Torossi
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Martin Ziak
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
| | - Christian Zuber
- Division of Cell and Molecular Pathology, Department of Pathology, University of Zurich, 8091 Zurich, Switzerland
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47
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Kim PS, Lee J, Jongsamak P, Menon S, Li B, Hossain SA, Bae JH, Panijpan B, Arvan P. Defective protein folding and intracellular retention of thyroglobulin-R19K mutant as a cause of human congenital goiter. Mol Endocrinol 2007; 22:477-84. [PMID: 17916655 DOI: 10.1210/me.2007-0183] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
It has been suggested that a thyroglobulin (Tg)-R19K missense mutation may be a newly identified cause of human congenital goiter, which is surprising for this seemingly conservative substitution. Here, we have examined the intracellular fate of recombinant mutant Tg expressed in COS-7 cells. Incorporation of the R19K mutation largely blocked Tg secretion, and this mutant was approximately 90% degraded intracellularly over a 24-h period after synthesis. Before its degradation, the Tg-R19K mutant exhibited abnormally increased association with molecular chaperones BiP, calnexin, and protein disulfide isomerase, and was unable to undergo anterograde advance from the endoplasmic reticulum (ER) through the Golgi complex. Inhibitors of proteasomal proteolysis and ER mannosidase-I both prevented ER-associated degradation of the Tg-R19K mutant and increased its association with ER molecular chaperones. ER quality control around Tg residue 19 is not dependent upon charge but upon side-chain packing, because Tg-R19Q was efficiently secreted. Whereas a Tg mutant truncated after residue 174 folds sufficiently well to escape ER quality control, introduction of the R19K point mutation blocked its secretion. The data indicate that the R19K mutation induces local misfolding in the amino-terminal domain of Tg that has global effects on Tg transport and thyroid hormonogenesis.
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Affiliation(s)
- Paul S Kim
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, MI 48109, USA
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48
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Johnson KR, Marden CC, Ward-Bailey P, Gagnon LH, Bronson RT, Donahue LR. Congenital hypothyroidism, dwarfism, and hearing impairment caused by a missense mutation in the mouse dual oxidase 2 gene, Duox2. Mol Endocrinol 2007; 21:1593-602. [PMID: 17440044 DOI: 10.1210/me.2007-0085] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Dual oxidases generate the hydrogen peroxide needed by thyroid peroxidase for the incorporation of iodine into thyroglobulin, an essential step in thyroid hormone synthesis. Mutations in the human dual oxidase 2 gene, DUOX2, have been shown to underlie several cases of congenital hypothyroidism. We report here the first mouse Duox2 mutation, which provides a new genetic model for studying the specific function of DUOX2 in the thyroid gland and in other organ systems where it is hypothesized to play a role. We mapped the new spontaneous mouse mutation to chromosome 2 and identified it as a T>G base pair change in exon 16 of Duox2. The mutation changes a highly conserved valine to glycine at amino acid position 674 (V674G) and was named "thyroid dyshormonogenesis" (symbol thyd) to signify a defect in thyroid hormone synthesis. Thyroid glands of mutant mice are goitrous and contain few normal follicles, and anterior pituitaries are dysplastic. Serum T(4) in homozygotes is about one-tenth the level of controls and is accompanied by a more than 100-fold increase in TSH. The weight of adult mutant mice is approximately half that of littermate controls, and serum IGF-I is reduced. The cochleae of mutant mice exhibit abnormalities characteristic of hypothyroidism, including a delayed formation of the inner sulcus and tunnel of Corti and an abnormally thickened tectorial membrane. Hearing thresholds of adult mutant mice are on average 50-60 decibels (dB) above those of controls.
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Affiliation(s)
- Kenneth R Johnson
- The Jackson Laboratory, 600 Main Street, Bar Harbor, Maine 04609, USA.
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Lee JY, Uzuka Y, Tanabe S, Sarashina T, Suzuki H, Sato M. Cloning and characterization of canine thyroglobulin complementary DNA. Domest Anim Endocrinol 2007; 32:178-89. [PMID: 16806791 DOI: 10.1016/j.domaniend.2006.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 02/21/2006] [Accepted: 02/23/2006] [Indexed: 11/15/2022]
Abstract
Canine thyroglobulin (cTg) is one of the thyroid autoantigens associated with hypothyroidism caused by autoimmune thyroiditis in dog. To identify canine-specific areas in cTg, we cloned, by reverse transcriptase PCR, and sequenced the complete cDNA of cTg. It revealed an open reading frame of 8289 nucleotides, which encode a polypeptide of 2762 amino acids that is 78.9 and 78.1% identical to bovine and human thyroglobulin, respectively. This complete cTg sequence may be useful to promote the understanding of the primary structure of cTg and, it will be informative data in the further search about antigenic epitopes associated with autoimmune thyroiditis and pathogenesis of cTg-associated thyroid diseases in dog.
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Affiliation(s)
- J-Y Lee
- Department of Clinical Veterinary Science, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
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50
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Menon S, Lee J, Abplanalp WA, Yoo SE, Agui T, Furudate SI, Kim PS, Arvan P. Oxidoreductase interactions include a role for ERp72 engagement with mutant thyroglobulin from the rdw/rdw rat dwarf. J Biol Chem 2007; 282:6183-91. [PMID: 17200118 PMCID: PMC2542443 DOI: 10.1074/jbc.m608863200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Newly synthesized thyroglobulin (Tg), the secretory glycoprotein that serves as precursor in thyroid hormone synthesis, normally forms transient covalent protein complexes with oxidoreductases of the endoplasmic reticulum (ER). The Tg-G2320R mutation is responsible for congenital hypothyroidism in rdw/rdw rats, in which a lack of secondary thyroid enlargement (goiter) implicates death of thyrocytes as part of disease pathogenesis. We found that mutant Tg-G2320R was retained within the ER with no detectable synthesis of thyroxine, had persistent exposure of free cysteine thiols, and was associated with activated ER stress response but incomplete ER-associated degradation (ERAD). Tg-G2320R associated with multiple ER resident proteins, most notably ERp72, including covalent Tg-ERp72 interactions. In PC Cl3 thyrocytes, inducible overexpression of ERp72 increased the ability of cells to maintain Tg cysteines in a reduced state. Noncovalent interactions of several ER chaperones with newly synthesized Tg-G2320R diminished over time in parallel with ERAD of the mutant protein, yet a small ERAD-resistant Tg fraction remained engaged in covalent association with ERp72 even 2 days post-synthesis. Such covalent protein aggregates may set the stage for apoptotic thyrocyte cell death, preventing thyroid goiter formation in rdw/rdw rats.
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Affiliation(s)
- Shekar Menon
- Program in Cell and Molecular Biology and Division of Endocrinology, University of Cincinnati, Ohio 45267
| | - Jaemin Lee
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48109
| | - William A. Abplanalp
- Program in Cell and Molecular Biology and Division of Endocrinology, University of Cincinnati, Ohio 45267
| | - Sung-Eun Yoo
- Program in Cell and Molecular Biology and Division of Endocrinology, University of Cincinnati, Ohio 45267
| | - Takashi Agui
- Laboratory of Experimental Animal Science, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido 060-0818, Japan
| | - Sen-ichi Furudate
- Department of Laboratory Animal Science, Kitasato University School of Medicine, Sagamihara, Kanagawa 228-8555, Japan
| | - Paul S. Kim
- Program in Cell and Molecular Biology and Division of Endocrinology, University of Cincinnati, Ohio 45267
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of Michigan Medical Center, Ann Arbor, Michigan 48109
- To whom correspondence should be addressed: Div. of Metabolism, Endocrinology & Diabetes, University of Michigan Medical School, 5560 MSRB2, 1150 W. Medical Center Dr., Ann Arbor, MI 48109-0678. Tel.: 734-936-5505; Fax: 718-936-6684; E-mail:
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