The power of the human bone in terms of healing itself is limited.Its capability for repairing fractures wanes along with age, while the cartilage of adults is almost impossible to undergo renewal.However, after 10 years of research, scientists at Stanford University have identified a human skeletal stem cell that can develop into bones, the cartilage and the spongy stroma of the bone's interior, opening the way to potential regenerative therapies.
Prior to this, the team have identified a similar skeletal stem cell in mice. However isolating its human counterpart turned out more difficult that they had expected.Previous efforts usually resulted in acquiring weak cells. Additionally, they were not capable for differentiating themselves into bones.
Charles Chan, the first author of the study, explained that they compared the gene expression of the mouse cell with various types of human ones that are present at endpoints of the developing bone.Afterwards, they identified markers present on the surface of human cells that could turn out helpful in terms of isolating a pure population.The outcome possessed all the traits that are characteristic for "true, multipotential, self-renewing, tissue-specific stem cells" that have potential for differentiating themselves into skeletal tissues.
Currently, the researchers are investigating the possibilities of using such acquired stem cells for repairing dysfunctions of bones.The discovery has proven that skeletal stem cells can be found in the fetal bone subject to growth, as well as in the proximity of sites where a healing process of a fractured adult bone takes place.They may also originate from induced pluripotent stem cells (iPSC) and fat cells with a protein called BMP-2, being of crucial importance for the development of the bone and cartilage.