Stem cells reveal common cause of mental retardation. In science it can be frustrating to know what defect causes a condition, but not know how that defect causes the damage. Researchers have been stuck in that limbo with fragile X syndrome for more than two decades. We have known that this form of mental retardation happens because one gene is repeated hundreds of times, and at some point while the baby is developing, the repeats cause the gene to malfunction and stop producing a needed protein. It turns out to be a middleman problem. The DNA in our genes is read by RNA that in turn makes the needed protein, but in fragile X the RNA reading of DNA gets gummed up like a stuck zipper according to work published today in Science by researchers at Weill Cornell Medical College.
Researchers have never been able to mimic fragile X in mice, because no matter how many extra copies of the gene they cram into the animals, they can’t get the gene to turn off. So, the Cornell team used human embryonic stem cells that had the mutation, which they grew and monitored in the lab for signs of fragile X. This work highlights the value of using pre-implant genetic diagnosis (PGD) to help parents undergoing in vitro fertilization. It allows them to avoid having a disabled child by selecting only healthy embryos for implantation, while at the same time providing researchers with a valuable model of the disease—the embryos with the defect that would have been discarded.
A year ago we wrote about an Israeli team that also created a fragile X disease model using stem cells from PGD embryos. But the current team took this further by both finding the “how” in the cause, and testing an existing drug that seems to prevent the RNA from causing the gene to be turned off. The team’s work was written about on Yahoo Health.
Turning cancer cells into fat cells. For most people the only cell in their body more hated than a fat cell is a cancer cell. Now, a Japanese team suggests we might be able to get rid of those cancer cells by turning them into fat cells. Their work involves a fascinating process. They manipulate an often-overlooked part of the cell, the cytoskeleton, the fibers that help it hold its shape. In work published February 26 in Nature Communications they showed they could change stem cells into fat by changing their shape. They used a protein to disassemble the skeleton in mouse stem cells and reconfigured the fibers into the shape they would have in a fat cell, which is like a crescent. The cells then matured into fat. Since stem cells and cancer cells share some properties, the team speculated that it may be possible to turn cancer into fat in this article in the Japanese publication The Asahi Shimbun, which is in English.
Stem cells yield back pain relief—at least short term. A team from Emory in Atlanta reports that in a 100-patient international clinical trial a single injection of stem cells from bone marrow reduced back pain for at least 12 months. The researchers reported that, on average, the pain was reduced greater than 50 percent. They were using the type of bone marrow stem cell called mesenchymal stem cells and said they could see evidence of restored disc structure in degenerative disc disease.
The study does require some caveats. Some research shows that this type of stem cell may not produce bone and cartilage that is hard enough to withstand the long-term pressure that occurs in our joints and backs. But this was a relatively large study and with longer observation of the patients it might start to shed light on that issue. HealthCanal picked up the university's press release. And CIRM has several projects using stem cells to try to correct bone and cartilage disorders.
Interview with a leading Parkinson’s researcher. For folks following efforts to grow dopamine-producing nerve cells from stem cells this interview provides a nice review of the progress and the hurdles that still need to be crossed. The discussion is with Malin Parmar of Lund University in Sweden about the NeroStemCell project which was funded by the European Union and completed its initial phase last May. She describes their success in generating replacement cells for the dopamine-producing nerves lost in Parkinson’s and getting those cells to restore function in mice. But she also details the many remaining steps, particularly producing the cells in sterile conditions that could be used in humans, and scaling up the production of cells to a quantity that could be a meaningful therapy. First published on a European web site devoted to innovation, YourIs.com, the interview was picked up by PhysOrg here.
Last year CIRM convened an international group of experts to discuss the status of using stem cells for Parkinson’s and the report from that workshop is available here.
Don Gibbons
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