Thyroid Peroxidase Forms Thionamide-sensitive Homodimers: Relevance for Immunomodulation of Thyroid Autoimmunity

Overview

Journal J Mol Med (Berl)

Specialty General Medicine

Date 2009 Aug 12

PMID 19669106

Citations 4

Authors

David O McDonald

Simon H S Pearce

Affiliations

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Abstract

Thyroid peroxidase (TPO) is the key enzyme in thyroid hormone production and a universal autoantigen in Graves' and other autoimmune thyroid diseases. We wished to explore the expression of TPO and whether it was affected by thionamide antithyroid drugs. We studied recombinant TPO, stably expressed by a Chinese hamster ovary cell line (CHO-TPO) and transiently expressed TPO-enhanced green fluorescent protein (eGFP) and -FLAG fusion proteins. Immunoblotting of CHO-TPO cell extracts showed high-molecular weight (HMW) TPO isoforms that were resistant to reduction, as well as 110 kDa monomeric TPO. Co-immunoprecipitation and enzyme-linked-immunosorbent assay (ELISA) binding studies of FLAG- and eGFP-tagged TPO demonstrated TPO dimerisation. CHO-TPO cells cultured in methimazole (MMI) for 10 days showed a significant reduction in HMW-TPO isoforms at MMI concentrations of 1 microM and above (p < 0.01), whereas monomeric TPO expression was unchanged. We observed a similar reduction in HMW-TPO in CHO-TPO cells cultured in propylthiouracil (10 microM and above). Binding of Graves' disease patient sera and TPO-Fabs to enzymatically active TPO that was captured onto solid phase was not abrogated by MMI. The cellular localisation of TPO in CHO-TPO cells was unchanged by MMI treatment. Our demonstration of homodimeric TPO and the reduction in HMW-TPO isoforms during thionamide treatment of CHO-TPO cells shows, for the first time, an effect of thionamides on TPO structure. This suggests a structural correlate to the effect of thionamides on TPO enzymatic activity and opens up a novel potential mechanism for thionamide immunomodulation of autoimmune thyroid disease.

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References

Marcocci C, Chiovato L, Mariotti S, Pinchera A . Changes of circulating thyroid autoantibody levels during and after the therapy with methimazole in patients with Graves' disease. J Endocrinol Invest. 1982; 5(1):13-9. DOI: 10.1007/BF03350476. View

Guo J, McLachlan S, Rapoport B . Localization of the thyroid peroxidase autoantibody immunodominant region to a junctional region containing portions of the domains homologous to complement control protein and myeloperoxidase. J Biol Chem. 2002; 277(43):40189-95. DOI: 10.1074/jbc.M205524200. View

Libert F, Ruel J, Ludgate M, Swillens S, Alexander N, Vassart G . Thyroperoxidase, an auto-antigen with a mosaic structure made of nuclear and mitochondrial gene modules. EMBO J. 1987; 6(13):4193-6. PMC: 553903. DOI: 10.1002/j.1460-2075.1987.tb02766.x. View

Guo J, Jaume J, Rapoport B, McLachlan S . Recombinant thyroid peroxidase-specific Fab converted to immunoglobulin G (IgG) molecules: evidence for thyroid cell damage by IgG1, but not IgG4, autoantibodies. J Clin Endocrinol Metab. 1997; 82(3):925-31. DOI: 10.1210/jcem.82.3.3831. View

Abramowicz M, Targovnik H, Varela V, Cochaux P, Krawiec L, Pisarev M . Identification of a mutation in the coding sequence of the human thyroid peroxidase gene causing congenital goiter. J Clin Invest. 1992; 90(4):1200-4. PMC: 443160. DOI: 10.1172/JCI115981. View

Gora M, Gardas A, Wiktorowicz W, Hobby P, Watson P, Weetman A . Evaluation of conformational epitopes on thyroid peroxidase by antipeptide antibody binding and mutagenesis. Clin Exp Immunol. 2004; 136(1):137-44. PMC: 1809007. DOI: 10.1111/j.1365-2249.2004.02422.x. View

Volpe R . Evidence that the immunosuppressive effects of antithyroid drugs are mediated through actions on the thyroid cell, modulating thyrocyte-immunocyte signaling: a review. Thyroid. 1994; 4(2):217-23. DOI: 10.1089/thy.1994.4.217. View

Cohen S, Weetman A . Antithyroid drugs ameliorate thymectomy-induced experimental autoimmune thyroiditis. Autoimmunity. 1988; 1(1):51-8. DOI: 10.3109/08916938808997176. View

REINWEIN D, Benker G, Lazarus J, Alexander W . A prospective randomized trial of antithyroid drug dose in Graves' disease therapy. European Multicenter Study Group on Antithyroid Drug Treatment. J Clin Endocrinol Metab. 1993; 76(6):1516-21. DOI: 10.1210/jcem.76.6.8501160. View

10.

Bresson D, Rebuffat S, Peraldi-Roux S . Localization of the immunodominant region on human thyroid peroxidase in autoimmune thyroid diseases: an update. J Autoimmune Dis. 2005; 2(1):2. PMC: 1084359. DOI: 10.1186/1740-2557-2-2. View

11.

Baker J, Arscott P, Johnson J . An analysis of the structure and antigenicity of different forms of human thyroid peroxidase. Thyroid. 1994; 4(2):173-8. DOI: 10.1089/thy.1994.4.173. View

12.

Davies T, Weiss I, Gerber M . Influence of methimazole on murine thyroiditis. Evidence for immunosuppression in vivo. J Clin Invest. 1984; 73(2):397-404. PMC: 425030. DOI: 10.1172/JCI111225. View

13.

Khoury E, Hammond L, Bottazzo G, Doniach D . Presence of the organ-specific 'microsomal' autoantigen on the surface of human thyroid cells in culture: its involvement in complement-mediated cytotoxicity. Clin Exp Immunol. 1981; 45(2):316-28. PMC: 1537363. View

14.

Weetman A, McGregor A, Hall R . Evidence for an effect of antithyroid drugs on the natural history of Graves' disease. Clin Endocrinol (Oxf). 1984; 21(2):163-72. DOI: 10.1111/j.1365-2265.1984.tb03456.x. View

15.

Kaufman K, Rapoport B, Seto P, Chazenbalk G, Magnusson R . Generation of recombinant, enzymatically active human thyroid peroxidase and its recognition by antibodies in the sera of patients with Hashimoto's thyroiditis. J Clin Invest. 1989; 84(2):394-403. PMC: 548896. DOI: 10.1172/JCI114179. View

16.

Bogner U, Schleusener H, Wall J . Antibody-dependent cell mediated cytotoxicity against human thyroid cells in Hashimoto's thyroiditis but not Graves' disease. J Clin Endocrinol Metab. 1984; 59(4):734-8. DOI: 10.1210/jcem-59-4-734. View

17.

Andrews P, Krinsky N . The reductive cleavage of myeloperoxidase in half, producing enzymically active hemi-myeloperoxidase. J Biol Chem. 1981; 256(9):4211-8. View

18.

TAUROG A . The mechanism of action of the thioureylene antithyroid drugs. Endocrinology. 1976; 98(4):1031-46. DOI: 10.1210/endo-98-4-1031. View

19.

Rennie D, McGregor A, Keast D, Weetman A, Foord S, Dieguez C . The influence of methimazole on thyroglobulin-induced autoimmune thyroiditis in the rat. Endocrinology. 1983; 112(1):326-30. DOI: 10.1210/endo-112-1-326. View

20.

Allen E, Rajatanavin R, Nogimori T, Cushing G, Ingbar S, Braverman L . The effect of methimazole on the development of spontaneous lymphocytic thyroiditis in the diabetes-prone BB/W rat. Am J Med Sci. 1986; 292(5):267-71. DOI: 10.1097/00000441-198611000-00003. View