A new small-molecule antagonist inhibits Graves' disease antibody activation of the TSH receptor

J Clin Endocrinol Metab. 2011 Feb;96(2):548-54. doi: 10.1210/jc.2010-1935. Epub 2010 Dec 1.


Context: Graves' disease (GD) is caused by persistent, unregulated stimulation of thyrocytes by thyroid-stimulating antibodies (TSAbs) that activate the TSH receptor (TSHR). We previously reported the first small-molecule antagonist of human TSHR and showed that it inhibited receptor signaling stimulated by sera from four patients with GD.

Objective: Our objective was to develop a better TSHR antagonist and use it to determine whether inhibition of TSAb activation of TSHR is a general phenomenon.

Design: We aimed to chemically modify a previously reported small-molecule TSHR ligand to develop a better antagonist and determine whether it inhibits TSHR signaling by 30 GD sera. TSHR signaling was measured in two in vitro systems: model HEK-EM293 cells stably overexpressing human TSHRs and primary cultures of human thyrocytes. TSHR signaling was measured as cAMP production and by effects on thyroid peroxidase mRNA.

Results: We tested analogs of a previously reported small-molecule TSHR inverse agonist and selected the best NCGC00229600 for further study. In the model system, NCGC00229600 inhibited basal and TSH-stimulated cAMP production. NCGC00229600 inhibition of TSH signaling was competitive even though it did not compete for TSH binding; that is, NCGC00229600 is an allosteric inverse agonist. NCGC00229600 inhibited cAMP production by 39 ± 2.6% by all 30 GD sera tested. In primary cultures of human thyrocytes, NCGC00229600 inhibited TSHR-mediated basal and GD sera up-regulation of thyroperoxidase mRNA levels by 65 ± 2.0%.

Conclusion: NCGC00229600, a small-molecule allosteric inverse agonist of TSHR, is a general antagonist of TSH receptor activation by TSAbs in GD patient sera.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Antigen-Antibody Reactions
  • Cells, Cultured
  • Graves Disease / immunology*
  • Graves Disease / pathology
  • Humans
  • Immunochemistry
  • Immunoglobulins, Thyroid-Stimulating / biosynthesis
  • Immunoglobulins, Thyroid-Stimulating / metabolism*
  • Iodide Peroxidase / biosynthesis
  • Iodide Peroxidase / blood
  • Iodine Radioisotopes
  • Pyridines / chemical synthesis
  • Pyridines / pharmacology*
  • Quinazolinones / chemical synthesis
  • Quinazolinones / pharmacology*
  • Receptors, Thyrotropin / agonists*
  • Receptors, Thyrotropin / biosynthesis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction / physiology
  • Thyroid Gland / drug effects
  • Thyroid Gland / metabolism
  • Thyroid Gland / pathology
  • Thyrotropin / blood
  • Thyroxine / blood


  • Immunoglobulins, Thyroid-Stimulating
  • Iodine Radioisotopes
  • NCGC 00229600
  • Pyridines
  • Quinazolinones
  • Receptors, Thyrotropin
  • Thyrotropin
  • Iodide Peroxidase
  • Thyroxine