An international team of researchers has discovered a population of stem cells that can generate new bone. These cells reside along the vascular channels that stretch across bone and connect its inner and outer parts.
“This is a new discovery of perivascular cells residing within the bone itself that can generate new bone-forming cells,” said lead investigator Ivo Kalajzic, MD, PhD, professor of reconstructive sciences at the University of Connecticut School of Dental Medicine. “These cells likely regulate bone formation or participate in bone mass maintenance and repair.”
Stem cells for bone have long been thought to be present within bone marrow and the outer surface of bone, serving as reserve cells that constantly generate new bone or participate in bone repair. Recent studies have described the existence of a network of vascular channels that help distribute blood cells out of the bone marrow, but no research has proved the existence of cells within these channels that have the ability to form new bones.
The researchers say they are the first to report the existence of these progenitor cells within cortical bone that can generate new bone-forming cells, or osteoblasts, that can be used to help remodel a bone.
To reach this conclusion, the researchers observed the stem cells within an ex vivo bone transplantation model. These cells migrated out of the transplant and began to reconstruct the bone marrow cavity and form new bone. But while this study shows there is a population of cells that can help aid bone formation, the researchers said, more studies are needed to determine the cells’ potential to regulate bone formation and resorption.
The study, “Perivascular Osteoprogenitors Are Associated With Transcortical Channels of Long Bones,” was published by Stem Cells.