Bone Abstracts

Selenium (Se) is an essential trace element active in the catalytic sites of many redox enzymes, including glutathione peroxidase and the iodothyronine deiodinases that metabolize thyroid hormones. In humans 25 genes encode selenoproteins, in which a specific tRNA incorporates the amino acid selenocysteine during protein translation. Although specific roles for many selenoproteins are unclear, studies suggest an important role for Se in skeletal development and bone maintenanc...

Hypothyroidism delays bone development and linear growth, whereas thyrotoxicosis accelerates skeletal development and is an important risk factor for osteoporosis in adulthood. Even sub-clinical thyrotoxicosis is associated with fracture, and treatment with thyroxine at doses that suppress TSH results in increased bone turnover and low BMD in postmenopausal women.To investigate the mechanism of T3 action in the skeleton, we characterized mice ...

Childhood hypothyroidism results in delayed skeletal maturation and impaired growth. Thyroid hormones act via temporo-spatially regulated thyroid hormone receptors α (TRα) and (TRβ).In the skeleton, TRα is the predominant receptor and we hypothesise that the skeletal effects of hypothyroidism are mediated by TRα.To investigate this we assessed the response of wild-type (WT), TRα knockout (TRα...

Thyrotoxicosis results in osteoporosis, and thyroid hormone (T3) stimulates osteoclastic bone resorption by unknown mechanisms. We previously demonstrated that knockout mice lacking thyroid hormone receptor α (TRα0/0) are euthyroid but have high bone mass, whereas mice lacking TRβ (TRβ−/−) are thyrotoxic and osteoporotic. Tartrate resistant acid phosphatase (TRAcP) staining revealed osteoclast numbers were reduced by 13% (<...