Endocrine Abstracts

The glycoprotein hormone, TSH, is synthesized and secreted by thyrotrophs in the anterior pituitary gland. It acts at the TSH receptor (TSHR), a 7-transmembrane G-protein coupled cell membrane receptor expressed in thyroid follicular cells. The TSHR, thus, plays a key role in the regulation of thyroid status and growth of the thyroid gland. In recent years TSHR expression has also been identified in a wide variety of extra-thyroidal tissues including: anterior pituitary; hypot...

G R Williams, Imperial College London, London, UK. AbstractGraham R Williams obtained a BSc in Anatomy and MBBS from St Thomas’s Hospital, London and undertook PhD studies in Molecular Endocrinology at Birmingham University. He trained as a Howard Hughes and MRC Fellow at Harvard Medical School, USA and was an MRC Clinician Scientist Fellow in Birmingham. He was appointed Senior Lecturer at the Royal Postgraduate...

Osteoporosis is characterised by bone fragility with increased susceptibility to fracture. The burden of osteoporosis already costs the NHS over £1.7 billion per annum but its prevalence is increasing. The skeleton is continually remodelled in response to endocrine, paracrine and mechanical signals by the coupled activities of osteoclasts and osteoblasts. Nevertheless, the continuous process of bone turnover results in an inexorable loss of bone because osteoblast-mediate...

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...

Bone loss in anorexia nervosa and following bariatric surgery is associated with an elevated circulating concentration of the gastrointestinal anorexigenic hormone peptide YY (PYY), which acts principally via the Y1R and Y2R receptors. Selective deletion of Y1R in osteoblasts or Y2R in the hypothalamus results in high bone mass, but deletion of PYY has resulted in conflicting skeletal phenotypes leading to uncertainty regarding its role in the regulation of bone mass. We hypot...

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...