August 31, 2016 Lucy Ingham
Re-growing damaged bone could become a standard practice in the future, thanks to a new technique involving nothing more than stem cells and a single molecule that naturally occurs in the human body.
Scientists from the University of California San Diego have discovered that by feeding the molecule adenosine to human pluripotent stem cells, they could make them regenerate bone tissue.
The research has already been successfully demonstrated in mice, and could in the future lead to a quick and affordable treatment for bone defects and injuries, a key aspect of the scientists’ research.
“One of the broader goals of our research is to make regenerative treatments more accessible and clinically relevant by developing easy, efficient and cost-effective ways to engineer human cells and tissues,” explained study lead author Shyni Varghese, a bioneering professor at UC San Diego.
A 3D microcomputed tomography model of the generated bone tissue at 3 weeks. Courtesy of Kang et al. Sci. Adv. 2016; 2 : e1600691
The research, which was published today in the journal Science Advances, is extremely significant for bioengineering because of how simply it achieves differentiation: the process where pluripotent stem cells transform into a cell specific a particular part of the body.
Normally this is an immensely complicated process, often involving many steps and ingredients to produce the desired results. There is also a risk of teratomas; tumours that can develop when the tissue is transplanted.
However all the scientist needed to do in this case was to add adenosine to the growth medium, causing the human pluripotent stem cells to develop into functional osteoblasts – the cells that build bone in the body. These osteoblasts were implanted into mice with bone defects, where they developed bone tissue with blood vessels, while showing no signs of teratomas.
“It’s amazing that a single molecule can direct stem cell fate,” marvelled Verghese. “We don’t need to use a cocktail of small molecules, growth factors or other supplements to create a population of bone cells from human pluripotent stem cells like induced pluripotent stem cells.”
Bone tissue visualised through a polarised light microscope
While considerable work will need to be done to make the approach a viable treatment for humans, Verghese also wants to determine exactly how and why adenosine can make stem cells turn into bone-building tissue – an insight that may have wider implications for the differentiation of other cell types.
So far the scientists have determined that adenosine signals the stem cells through a receptor on their surface known as the A2bR receptor, but more work needs to be done to get the full picture.