A research team from the University of Alabama at Birmingham conducted a study on mice intended to discover why age-related bone loss occurs, Harrison Wein, Ph.D., writes for the National Institutes of Health.
Bones are made of a mineral and protein casing filled with bone cells. Bones weaken when the rate of bone production cannot keep up with bone loss. Hormonal changes, aging and certain medications can cause bone loss.
Mesenchymal stem cells in the bone marrow can change into other types of cells, such as osteoblasts or fat cells. Older people have fewer osteoblasts—cells that build bone—and more fat cells than their younger counterparts, and scientists aren’t sure why, Wein writes.
The study by Drs. Yi-Ping Li and Wei Chen at the University of Alabama examined “the signals that determine whether marrow mesenchymal stem cells develop or ‘differentiate’ into osteoblasts or fat cells,” Wein reports. Previous studies by the team indicated that the protein CbfB played a key role in skeletal development and bone healing.
In the study, published in Proceedings of the National Academy of Sciences, researchers removed the CbfB gene in three states of osteoblast development: in mesenchymal stem cells, in the intermediate stage and in early osteoblasts.
All of the mice whose CbfB was removed had increased fat content in their bone marrow. “These results suggest that a drop in CbfB could contribute to the age-related shift from osteoblast to fat cell production,” Wein writes.
“[Our results] suggest that maintaining CbfB might be an effective way to prevent age-associated osteoporosis in people,” said Li. The concept still needs to be tested in humans.