Mifepristone improved bone formation in mice with bone loss

In an experiment in mice, researchers modelled osteoporosis, a condition that weakens bones, alongside hyperlipidemia, high blood fat levels. They removed the animals’ ovaries and fed them a high-fat diet. They also studied bone marrow stem cells grown in the lab, testing their development into bone-forming cells or fat cells.

The researchers identified a pathway involving SPNS3, a protein that transports certain fats, as a key regulator of this development. Mifepristone stabilised this protein. In the lab-grown cells, the drug enhanced development into bone-forming cells and inhibited development into fat cells. In mice with both conditions, it improved bone formation and reduced fat in bone marrow. The authors suggested repurposing mifepristone for the combined conditions.