Stem cell therapy has the potential to rejuvenate Alzheimers-damaged brains, and has already helped cure some kinds of blindness. And there are two more reasons to be hopeful about stem cell treatments, announced this week.
Controlling Stem Cells
This morning Cell magazine published an intriguing article about a breakthrough made by several American scientists researching how stem cells get made. There is a small family of genes responsible for keeping stem cells "pluripotent," a state which allows the cell to turn into almost any other cell. Maintaining pluripotency is crucial for stem cell therapy.
Even more important is discovering how to restore pluripotency to cells that have already differentiated into a neurons or skin cells. Stem cells taken from blastocysts, or embryos, are pluripotent. But there is a limited supply of such cells for both practical and policy reasons (regulations against using embryos in experiments, for instance). So one of the gold rings of the stem cell research community is discovering how to make differentiated cells pluripotent agian.
And that's where today's discovery comes in. The research team led by UC Santa Barbara's Na Xu discovered that the family of genes which turns a stem cell pluripotent are themselves regulated by a small molecule called micro-RNA. They located the exact kind of micro-RNA responsible for controlling these stem cell genes, called miR-145. A rise in levels of miR-145 causes stem cells to differentiated. So keeping levels of miR-145 low may allow researchers more granular control of the pluripotency of cells.
The bottom line: Researchers have more control than ever over the process that turns ordinary cells into pluripotent stem cells and maintains them in that state. We've tightened our grip on the on/off switch for pluripotency.
Experimenting with Stem Cell Therapies
Great strides are also being made in applied therapies, too. This week H+ published an intriguing interview with Sean Hu, the head of a Chinese lab where people come from all over the world to get controversial treatments with stem cells drawn from umbilical cord blood. Hu founded Beike Biotechnology, located in Shenzhen, where he says doctors have had success in treating blindness caused by damaged optical nerves:
There have been many successful stories of stem cell therapy (SCT). One example is the recovery of a nearly blind sixteen-year-old girl, Macie Morse, who recently got her learner's permit and started driving. She came to one of our hospitals for treatment in July 2006, with 20/4,000 vision in one eye and only light perception in the other due to optic nerve hypoplasia. After treatment, Macie now has 20/80 vision in one eye and 20/400-plus in the other!
While the breakthroughs at Beike are not quite as spectacular as some excitable bloggers have suggested, the lab is part of a new wave of research centers that are already putting into practice some of the discoveries that rarely make it out of university labs in the West.
The bottom line: Beike Biotechnology and similar companies like Osiris and Geron are making strides towards applying stem cell therapies in the human population. It's likely that breakthroughs will come out of labs like these, where doctors are already working with human subjects.
Image of stem cells via University of Kansas Medical Center.