Stem Cells Could Be Directed To Increase Bone Formation
A bone growth molecule has now been developed by the scientific community which once injected into the bloodstream, ‘directs’ stem cells in the bone marrow to form more bones. The UC Davis Health System scientists have created this novel technique.
The bone growth molecule which is injected is a hybrid molecule (or a double-stranded nucleic acid molecule which is made by man from two different single-stranded nucleic acid molecules of different sources). This hybrid molecule is called the LLP2A-alendronate. It was ‘created’ by Kit Lam, professor and chair of the UC Davis Department of Biochemistry and Molecular Medicine. (1)
The hybrid molecule consists for two distinct parts:
- LLP2A – which attaches itself to mesenchymal stem cells in the bone marrow, and
- Alendronate – which is a bone-homing chemical
Though the experiments conducted by the researchers were on mouse model, they hold promise as an osteoporosis treatment for human beings especially in cases where bone density and strength are compromised with aging, estrogen deficiency and long-term use of steroid for treatment of chronic conditions.
During the study, it was observed that once LLP2A-alendronate entered the bloodstream it attached itself to the mesenchymal stem cells present in the bone marrow and ‘directed’ those cells to travel to the surface of the bone. Once on the bone surface, the mesenchymal stem cells performed functions of bone formation and repair. In addition, the mesenchymal stem cells also manufactured proteins that aided the process of bone growth. Thus, the mesenchymal stem cells were being ‘exploited’ to remodel the bone through repair and strengthening (thickening).
According to the lead author of the study and the chief investigator, Wei Yao, “There are many stem cells, even in elderly people, but they do not readily migrate to bone. Finding a molecule that attaches to stem cells and guides them to the targets we need is a real breakthrough.” (2)
What made the findings even more striking were that beneficial effects of the therapy could be seen as early as twelve weeks after the injection of the hybrid molecule into aging and menopausal mice. The difference in bone mass at the thigh and spine were measurable and there was overall increase in bone strength when compared to the group of mice which was not injected with the hybrid molecule.
Clearly this research holds a huge promise in the treatment of bone rehabilitation beyond osteoporosis such as in healing of bone injuries, in treatment of peripheral artery disease as well as those of macular degeneration to blood disorders, skin wounds and diseased organs. Getting the stem cells to bind exactly at the site where therapy is required has always been a near-impossible goal but this study has made this type of stem cell therapy a reality.
According to Jan Nolta, professor of internal medicine, an author of the study and director of the UC Davis Institute for Regenerative Cures, “These results are very promising for translating into human therapy. We have shown this potential therapy is effective in rodents, and our goal now is to move it into clinical trials.” (3)
- Researchers Develop Method of Directing Stem Cells to Increase Bone Formation and Bone Strength; Science Daily News; February 2012; http://www.sciencedaily.com/releases/2012/02/120206092631.htm
- UC Davis Investigators Develop Method of Directing Stem Cells to Increase Bone Formation and Bone Strength; UC Davis Health System – News; February 2012; http://www.ucdmc.ucdavis.edu/publish/news/newsroom/6195
- New Technology Directs Stem Cells To Increase Bone Formation, Bone Strength; Stem Cell Research News; February 2012; http://www.stemcellresearchnews.com/absolutenm/anmviewer.asp?a=2799
*Technical report of the study may be had at:
- Directing mesenchymal stem cells to bone to augment bone formation and increase bone mass; Nature Medicine (Journal); February 2012; http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.2665.html