Endocrine Abstracts

Local regulation of T3 action in bone and cartilage is a novel mechanism underlying the pathogenesis of osteoarthritis (OA). Accelerated chondrocyte differentiation is a hallmark of OA and T3 regulates this process. The type 1 and 2 deiodinases (D1, D2) convert the pro-hormone T4 to the active hormone T3 whilst D3 inactivates both T3 and T4. D1 contributes to circulating T3 levels and local T3</s...

Articular cartilage maintenance and repair is regulated by numerous endocrine and paracrine factors. Investigation of molecular mechanisms underlying osteoarthritis (OA) is limited by inability to identify early stage disease and individuals at risk of progression. Susceptibility to OA is genetically determined and the availability of mice from the International Knockout Mouse Consortium with deletions of every known gene provides a unique opportunity to investigate its pathop...

Mice with dominant-negative mutations of thyroid hormone receptor α1 (TRα1) are euthyroid but display growth retardation and delayed bone age as juveniles and increased bone mass during adulthood, indicating impaired skeletal thyroid hormone responsiveness. The first autosomal dominant mutations affecting TRα1 in humans were recently described in two unrelated children and one parent who were euthyroid apart from a low T4:T3 ratio. Consiste...