Human stem cells are specialized cells that can be harvested from the body and engineered to turn into various tissues and organs. Perhaps the greatest potential use of stem cells is the generation of new tissues for organ transplants. Unfortunately, scientists have long struggled to find skeletal stem cells that can reliably turn into bone, cartilage, and supportive tissues of the skeleton. In a study published in the latest issue of Cell, the Longaker group at Stanford University identified these cells for the first time.

Previously, so-called “mesenchymal stem cells” had been discovered in human bone. These cells not only turn into skeletal tissues, but also fat, muscle, and blood vessels. To pinpoint a more specific class of skeletal stem cells, Longaker’s group performed DNA sequencing on human fetal bone to look for cells that had a similar genetic makeup to previously identified mouse skeletal stem cells.   When the identified cells were isolated and grown in a dish, they indeed turned into new bits of bone and cartilage. Importantly, these cells did not turn into fat, thereby distinguishing them from mesenchymal stem cells and establishing them as bona fide skeletal stem cells.

Although skeletal stem cells had previously been identified in mice, this study confirms their existence in humans, a critical step towards combating skeletal diseases. Future work should aim to identify subclasses of skeletal stem cells that specifically turn into bone or cartilage tissue, which could be invaluable in developing tissue transplants to treat osteoporosis and osteoarthritis, respectively.

Managing Correspondent: Benjamin Andreone

News Article: Human Skeletal Stem Cells Found. The Scientist

 Original Article: Identification of the Human Skeletal Stem Cell. Cell

 Image Credit: Pixabay