title: Complete inhibition of rhTSH-, Graves' disease IgG-, and M22-induced cAMP production in differentiated orbital fibroblasts by a low-molecular-weight TSHR antagonist.
abstract: The TSH receptor (TSHR) on orbital fibroblasts (OF) is a proposed target of the autoimmune attack in Graves' ophthalmopathy. In the present study, we tested whether the novel low-molecular-weight (LMW) TSHR antagonist Org-274179-0 inhibits cAMP production induced by rhTSH, Graves' disease IgG (GD-IgG), or M22 (a potent human monoclonal TSHR stimulating antibody) in cultured and differentiated OF from Graves' ophthalmopathy patients. cAMP production significantly increased after incubation either with 10 mU/ml rhTSH (3-fold; P ≤ 0.05), 1 mg/ml GD-IgG (2-fold; P ≤ 0.05), or 500 ng/ml M22 (5-fold; P ≤ 0.05). Incubation with the LMW TSHR antagonist dose dependently inhibited rhTSH, GD-IgG as well as the M22-induced cAMP production at nanomolar concentrations; complete blockade was affected at 10(-6) M. Our results suggest that GD-IgG- and M22-induced cAMP production in differentiated OF is exclusively mediated via the TSHR because it can be completely blocked by the LMW TSHR antagonist, Org 274179-0.
authors.affiliation: Department of Endocrinology and Metabolism, Academic Medical Center, University of Amsterdam, 1105 AZ The Netherlands.
authors.forename: Clementine J J
authors.initials: CJ
authors.lastname: van Zeijl
authors.forename: Chris J
authors.initials: CJ
authors.lastname: van Koppen
authors.forename: Olga V
authors.initials: OV
authors.lastname: Surovtseva
authors.forename: Marcel E
authors.initials: ME
authors.lastname: de Gooyer
authors.forename: Ralf
authors.initials: R
authors.lastname: Plate
authors.forename: Paolo
authors.initials: P
authors.lastname: Conti
authors.forename: Willem-Jan
authors.initials: WJ
authors.lastname: Karstens
authors.forename: Marco
authors.initials: M
authors.lastname: Timmers
authors.forename: Peerooz
authors.initials: P
authors.lastname: Saeed
authors.forename: Wilmar M
authors.initials: WM
authors.lastname: Wiersinga
authors.forename: André M M
authors.initials: AM
authors.lastname: Miltenburg
authors.forename: Eric
authors.initials: E
authors.lastname: Fliers
authors.forename: Anita
authors.initials: A
authors.lastname: Boelen
mesh_terms: D000634:Aminoquinolines / Q000494:pharmacology*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D016466:CHO Cells; D006224:Cricetinae; D000242:Cyclic AMP / Q000096:biosynthesis*; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006111:Graves Disease / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology*; D009915:Orbit / Q000166:cytology; D011989:Receptors, Thyrotropin / Q000037:antagonists & inhibitors*; D013972:Thyrotropin / Q000494:pharmacology*
chemical_list: D000634:Aminoquinolines; D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; C573712:N-(1-acetyl-4-methyl-4-phenyl-1,2,3,4-tetrahydro-quinolin-6-yl)-3-(3-trifluoromethyl-phenyl)propionamide; D011989:Receptors, Thyrotropin; D013972:Thyrotropin; D000242:Cyclic AMP