Researchers have announced the birth of three unusual, though healthy, baby monkeys. They are the first non-mouse chimeras—creatures made up of cells from multiple other parents—to be created by science.
Making chimeric mice is a time-consuming but fairly routine part of biology these days: embryos are injected with modified cultured stem cells containing the traits the researchers desire (like glowing in the dark). Those embryos grow up into mice who have some glow-in-the-dark cells and some normal cells, called chimeras. These chimeras are useful because if any of them have glow-in-the-dark sperm or eggs, they can be bred with each other to produce babies who are 100% glow-in-the-dark.
Their spinal cord trial to assess whether a low dose of cells in a newly injured spine is safe, which had enrolled four patients, had been progressing as expected, so it’s not that they’ve lost faith in the science. It’s all about the money: Geron has two cancer drugs in clinical trials, and according to their announcement, this was the only way to continue supporting that research without having to raise more funds. They’ll be laying off 38% of their employees as a result of the decision. The four patients will continue to be monitored.
What’s the News: Scientists have reversed Parkinson’s disease-like brain damage and motor problems in mice and rats using neurons grown from human embryonic stem cells. The new technique, described online in Nature earlier this week, brings scientists closer to similar treatments for people with Parkinson’s.
What’s the News: Making stem cells without using embryos can be a difficult process, and scientists have had to cope with numerous failures. But a new discovery may help them home in on what’s missing from their biochemical recipes.
Biologist George Church, examining a molecular model.
George Church, the geneticist behind the Personal Genome Project, is envisioning a package deal: get your genome sequenced, and he and his collaborators will develop a line of induced pluripotent stem cells (IPS) from your tissue, so in the future, you’ll be able upgrade your system with organs and tissues bearing both your genes and special extras like genes from centenarians. It’s combining stem cells with gene therapy. In an interview with Church, David Ewing Duncan over at Technology Review asks him to elaborate. Why does he think this science fiction scenario is in our near future?
With only seven northern white rhinos left in the world, creating eggs and sperm from stem cells offers the possibility of salvaging some of the species.
What’s the News: In an effort to help preserve endangered rhinos and primates, biologists have converted skin cells taken from the animals into pluripotent stem cells, which can grow into nearly anything, given the right conditions. They might even grow into egg and sperm cells, eventually, the researchers think, suggesting a cell biological route to conservation.
What’s the News: Researchers at Kyoto University in Japan have created fully functioning sperm from mouse embryonic stem cells. The sperm cells were able to fertilize mouse eggs in vitro, and when the scientists implanted the embryos into surrogate mothers, the mice gave birth to healthy offspring. The research, published in the journal Cell, may someday help treat infertility in humans.
What’s the News: An African man’s new trachea is the world’s first synthetic organ to be transplanted. Made from a polymer scaffold coated with the patient’s own cells, the windpipe seems to be working out well, more than a month after the surgery.
What’s the News: Reprogrammed stem cells—cells taken from an adult and turned back into stem cells—can be rejected by the body, at least in mice, suggests a new Nature study. Donated tissues and organs are often attacked by a patient’s immune system, since reprogrammed stem cells can be made from a patient’s own skin, researchers had hoped these cells offered a way to avoid such rejection by letting patients, in essence, donate tissue to themselves. But the new finding may be a significant setback to what is a promising line of treatment.
What’s the Context: What’s the News: Researchers have grown neurons from the cells of people with schizophrenia, in a study published online yesterday in Nature, the first time a complex mental illness has been modeled with living cells in a lab. This approach provides a new way to probe the little-understood biological processes underlying the disease and to test potential drug treatments. In preliminary experiments, the researchers found that the neurons weren’t as interconnected as healthy neurons are, and that individual patients’ neurons differ in their reaction to various drugs used to treat schizophrenia.
If you send stem cells just the right signals, they’ll develop into any one of a wide range of tissues, from retina to spinal cord to heart muscle. But which signals to send? A team at John Hopkins has painstakingly gone over more than 30 techniques for getting cells to differentiate and consolidated them into a simple procedure that has successfully been used to turn at least 11 lines of stem cells into healthy, beating heart cells—all without introducing the cancer-causing mutations that can plague this kind of work.
The stem cells formed a sac that then folded in half
a couple days later (see image above, courtesy of Nature),
forming the optic cup.
What’s the News: Give a blob of cells the right environment—lots of nutrients, special chemical signals, and a comfy gel cushion—and they just might grow you a body part. In a feat of bioengineering, scientists at the RIKEN Center for Developmental Biology in Japan have grown a retina from mouse embryonic stem cells. Remarkably, much of the development happened spontaneously, indicating that even undifferentiated cells have a blueprint in mind. Researchers hope the work will someday yield transplantable retinas for people with diseases like retinitis pigmentosa.
“When I received the manuscript, I was stunned, I really was,” commented human molecular geneticist Robin Ali (via Nature News). “I never though I’d see the day where you have recapitulation of development in a dish.”
Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.
The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.
“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]
Embryonic stem cell treatments are edging closer to mainstream medicine. An experimental treatment just approved for clinical trials may provide hope to the 10 to 15 million elderly patients in the United States who suffer from a common form of macular degeneration, which causes gradual blindness.
The biotech company behind the treatment, Advanced Cell Technology, Inc., previously won FDA approval to try an embryonic stem cell treatment on patients with a rare, juvenile form of macular degeneration. The new FDA-approved trial will use similar techniques, but targets a much broader patient base.
“ACT is now the first company to receive FDA clearance for two hESC (human embryonic stem cell) trials, and is now a true translational leader in the field of regenerative medicine,” said chief executive Gary Rabin. “It marks a major step forward, not just within the stem cell sector, but, potentially for modern healthcare techniques.” [AFP]
80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles on the day's most compelling topics.
80beats is written by Veronique Greenwood and Valerie Ross. This team darts through each day's science news faster than the ruby-throated hummingbird that beats its wings 80 times per second. Send ideas, tips, suggestions, and complaints to [azeeberg at discovermagazine dot com].
Mouse embyronic stem cells
What’s the Context:
Embryonic stem cell treatments are edging closer to mainstream medicine. An experimental treatment just approved for clinical trials may provide hope to the 10 to 15 million elderly patients in the United States who suffer from a common form of macular degeneration, which causes gradual blindness.
