A stem cell that can generate both bone and marrow tissue has been found in the bone marrow of mice. The discovery by researchers at Columbia University Medical Center and the Stanford University School of Medicine is published in the journal Cell.

The stem cells, called osteochondroreticular, generate bone and cartilage cells, including osteoblasts and chondrocytes. These cells, when transferred to a fracture site, were found to contribute to bone repair. In mice, if a fracture is introduced, these cells generate both the bone and cartilage required to repair the fracture. But it is not known whether this could happen in humans.

Mice and humans have similar bone biology, therefore, these osteochondroreticular stem cells should be found in human bone tissue. The scientists hope that drugs and therapies can be developed to stimulate the production of these stem cells and thus improve the body's ability to repair bone injury, a natural ability of the human body that declines significantly with old age.

While these cells were found to be particularly active during development they also increase in number in adulthood when a person sustains a bone injury.

It was earlier believed that mesenchymal stem cells play a role in the development of all bone, cartilage and fat, but studies have shown that these cells do not generate young bone and cartilage. The latest study shows that these cells are distinct from osteochondroreticular stem cells and that both these types of cells contribute in bone maintenance and repair in adults.

The newly discovered osteochondroreticular stem cells may also play a role in soft tissue cancers, for which the researchers hope to find a treatment.

The resarchers have also charted the chemical signals that can create skeletal stem cells and steer their development into specific tissue.

The discovery could help develop therapies for skeletal disorders such as bone fractures, brittle bones, osteosarcoma or damaged cartilage.

It is possible that in future fat cells could be redirected to act as skeletal stem cells.

To contact the writer, email: sonali.raj@gmail.com