Researchers identify a hitherto elusive population of craniofacial stem cells. This fosters hope for cell therapy approaches against diseases like craniosynostosis.
Craniosynostosis is a surprisingly common condition. Up to 1 in 2000 newborns in the US are suffering from this congenital disease that results in the premature closing of one or more of the six sutures of the cranium. These sutures are fibrous tissue layers that separate the free-flowing bones of an infant’s skull. If they close before the brain has stopped growing, the expanding brain exerts more and more pressure on the skull, which gives then way in form of irregular deformities. Mental retardation, hearing or vision loss and breathing problems may accompany the disease. Treatment options include surgical removal of skull parts or, if caught early, endoscopical procedures followed by use of a shaping helmet. If this sounds a lot like bare-bones torture to you, you are not entirely incorrect.
Stem cell treatments may have been an enticing option to treat this disease if it hadn’t been for one essential detail: known stem cell populations, such as those in the bone marrow, do not form craniofacial bone structures. And nobody had yet identified the craniofacial stem cells that can repair these special bones.
Up until now. Scientists from The University of Rochester, New York recently reported that their hunt for such craniofacial stem cells may have been successful.  In their search the researchers focused on a population of cells that resided near the midline of the sutures. These cells expressed a gene named Axin-2 and were characterized by quiescence, that is, a very slow turnover rate - a feature important for stem cells, because it ensures that these cells do not exhaust themselves prematurely (see our previous blog on how they keep their cell division under control).
Using clever labeling techniques to trace this particular cell population, the scientists discovered that these cells were able to give rise to skeletal progenitors and mature osteocytes (bone cells) over a long period of time. This process was markedly enhanced in an injury repair model where the parietal bone had been deliberately damaged in mice. Bone regeneration experiments further showed that one of these founder cells can give rise to complete bone structures. Furthermore, these cells can also develop into chondrocytes (cartilage cells). Overall, the researchers estimated that about 0.13% of the cells in the suture midline were craniofacial stem cell material, all of which expressed Axin-2.
The identification of the craniofacial stem cell population may represent a turning point not just for therapy of craniosynostosis, but also for patients after traumatic head injuries due to accidents or after surgical procedures affecting craniofacial areas. At HemaCare, we are excited about these prospects, and do our part to help push benefits of stem cell research from enticing concept to clinical routine, by providing a wide variety of stem cells (for example, CD133+ progenitor cells or CD34+ stem cells) from variable sources for research and clinical applications. Give us a call at (877) 397-3087 if you have any questions or would like to place an order. We’d love to help you any way we can.
 Maruyama T, Jeong J, Sheu TJ, Hsu W. Stem cells of the suture mesenchyme in craniofacial bone development, repair and regeneration. Nat Commun. 2016 Feb 1;7:10526.