Endocrine Abstracts

T3 regulates bone development and its actions are mediated by TRα and TRβ. Using TR knockout mice we demonstrated that TRα1 is the predominant mediator of T3 action in bone, although TRα2 (a non-T3 binding isoform of unknown function) and TRβ1 are also expressed in the skeleton. We show that mice lacking TRα2 have characteristic skeletal abnormalities of delayed closure of the skull sutures, abnormal clavicle development and reduced bone mineraliz...

Recent studies suggest TSH inhibits bone remodeling, indicating that TSH deficiency rather than thyroid hormone excess could cause bone loss in thyrotoxicosis. The findings predict that TSH receptor (TSHR) stimulating antibodies (TSHRAb) should inhibit bone turnover, whereas Graves’ disease patients exhibit high bone turnover with increased fracture susceptibility. We characterized TSH-action in primary human and mouse osteoblasts and osteoclasts, and explored whether a p...