Graves’ Orbitopathy Models: Valuable Tools for Exploring Pathogenesis and Treatment

Abstract

AbstractGraves’ orbitopathy (GO) is the most common extrathyroidal complication of Graves’ disease (GD) and severely affects quality of life. However, its pathogenesis is still poorly understood, and therapeutic options are limited. Animal models are important tools for preclinical research. The animals in some previous models only exhibited symptoms of hyperthyroidism without ocular lesions. With the improvements achieved in modeling methods, some progressive animal models have been established. Immunization of mice with A subunit of the human thyroid stimulating hormone receptor (TSHR) by either adenovirus or plasmid (with electroporation) is widely used and convincing. These models are successful to identify that the gut microbiota influences the occurrence and severity of GD and GO, and sex-related risk factors may be key contributors to the female bias in the occurrence of GO rather than sex itself. Some data provide insight that macrophages and CD8+ T cells may play an important pathogenic role in the early stage of GO. Our team also replicated the time window from GD onset to GO onset and identified a group of CD4+ cytotoxic T cells. In therapeutic exploration, TSHR derived peptides, fingolimod, and rapamycin offer new potential options. Further clinical trials are needed to investigate these drugs. With the increasing use of these animal models and more in-depth studies of the new findings, scientists will gain a clearer understanding of the pathogenesis of GO and identify more treatments for patients.