Repression of osteoblast maturation by ERRα accounts for bone loss induced by estrogen deficiency.

ERRα is an orphan member of the nuclear receptor family, the complete inactivation of which confers resistance to bone loss induced by ageing and estrogen withdrawal to female mice in correlation with increased bone formation in vivo. Furthermore ERRα negatively regulates the commitment of mesenchymal cells to the osteoblast lineage ex vivo as well as later steps of osteoblast maturation. We searched to determine whether the activities of ERRα on osteoblast maturation are responsible for one or both types of in vivo induced bone loss.

Interleukin-33: a novel player in osteonecrosis of the femoral head?

Osteonecrosis of the femoral head (ONFH) is a disabling disease affecting young adults, which usually leads to the destruction of the hip joint. It is mainly due to an inadequate blood supply that causes the death of osteocytes and bone marrow cells. Joint salvaging procedures are numerous but relatively inefficient, justifying the need for new therapeutic strategies.

Distal control of the pig whey acidic protein (WAP) locus in transgenic mice.

Distal control of the whey acidic protein (WAP) locus was studied using a transgenic approach. A series of pig genomic fragments encompassing increasing DNA lengths upstream of the mammary specific whey acidic protein (WAP) gene transcription start point (tsp) and 5 kb downstream were used for microinjection in mouse fertilized eggs. Our data pointed out three regions as potent regulators for WAP but not for RAMP3 gene expression (a non mammary-specific gene located 30 kb upstream of the WAP gene).