Searchable abstracts of presentations at key conferences in endocrinology

ea0054is8 | (1) | NuclearReceptors2018

Direct and indirect effects of androgens on the musculoskeletal system

Claessens Frank , Michael Laurent , Dubois Vanessa , Khalil Rougin , Jardi Ferran , Vanderschueren Dirk

Global knockout models of the androgen receptor (ARKO) illustrates the many roles androgens and their receptor have in the development of male reproductive organs and the gender differences in many features like the musculoskeletal system. However, neither the global ARKO nor orchidectomy models discriminate between direct and indirect effects of androgens. To determine direct and indirect effects of androgens on muscle, we developed a muscle-specific ARKO (called satARKO for ...

ea0042oc11 | (1) | Androgens2016

Sex steroid deficiency alters renal calcium transporter expression independently of its effect on bone resorption

Khalil Rougin , Jardi Ferran , Laurent Michael , Claessens Frank , Vanderschueren Dirk , Decallonne Brigitte

It is well established that sex steroid deficiency induces bone loss, resulting in osteoporosis. Consequently, global androgen receptor knock out (ARKO) mice have trabecular and cortical osteopenia. Bone cell-specific ARKOs however, have a much less pronounced bone phenotype, suggesting that androgens have an influence on processes in other systems or organs which in turn have an impact on bone metabolism. The kidney is a likely candidate, as it plays an important role in calc...

ea0057005 | The effect of androgens on renal calcium and phosphate handling, independent of bone and in circumstances of low dietary calcium | BES2018

The effect of androgens on renal calcium and phosphate handling, independent of bone and in circumstances of low dietary calcium

Rougin Khalil , Ri Kim Na , Ferran Jardi , Frank Claessens , Dirk Vanderschueren , Brigitte Decallonne

Aims: We have previously shown that orchidectomy (ORX) in adult mice induces hypercalciuria and upregulation of renal Ca2+ and PO43− transporters, but also bone loss already after 2 weeks. Pretreatment with risedronate inhibited bone resorption and hypercalciuria but confirmed the upregulation of renal Ca2+ and PO43− transporters, suggesting bone-independent renal effects of androgens. We hypothesize...

ea0064002 | Sexual Dimorphism in Bone Size is Mediated by Neuronal ER alpha (ERα) Signaling in Females during Late Puberty | BES2019

Sexual Dimorphism in bone size is mediated by neuronal ER alpha (ERα) signaling in females during late puberty

Nari Kim , Ferran Jardi , Rougin Khalil , Leen Antonio , Dieter Schollaert , Ludo Deboel , van Lenthe GH , Brigitte Decallonne , Geert Carmeliet , Claes Ohlsson , Lagerquist Marie K , Frank Claessens , Dirk Vanderschueren

Introduction: Pubertal sex steroids are indispensable for peak bone mass acquisition as well as skeletal sexual dimorphism. In males, both androgen receptor (AR) and estrogen receptor alpha (ERα) are required for optimal periosteal cortical bone expansion, while estrogens limit bone size in females. In early puberty, estrogens directly stimulate longitudinal growth via ERα in cartilage, but also indirectly via growth hormone (GH) and insulin-like growth factor I (IGF...

ea0042oc2 | (1) | Androgens2016

Control of androgen bioactivity by sex hormone-binding globulin

Laurent Michael R , Antonio Leen , Blokland Marco H , Sterk Saskia S , Jardi Ferran , Dubois V , Kaufman Jean-Mark , Fiers Tom , Huhtaniemi Ilpo T , Hammond Geoffrey T. , Vanderschueren Dirk , Claessens Frank

Sex hormone-binding globulin (SHBG) is a high-affinity binding protein for androgens and estrogens. According to the “free hormone hypothesis”, SHBG regulates the free sex steroid fraction and restricts androgen bioactivity. SHBG has also been independently associated with diabetes, osteoporosis etc., but whether this represents causality or residual confounding remains unconfirmed. We studied mice overexpressing human SHBG. Using multiligand liquid chromatography ta...