Stem cell stories that caught our eye: sickle cell patient data, vaccine link to leukemia protection, faster cell analysis

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Good news from sickle cell clinical trial. It is always satisfying to report positive results from human clinical trials using stem cells even when we don’t fund the work. Bluebird Bio released the first data on a patient treated for sickle cell anemia using the same procedure the company had earlier used to get good outcomes for two patients with beta thalassemia.

Both diseases result from defects—though different defects—in the gene for hemoglobin, the protein our red blood cells use to carry needed oxygen. So, in both cases they use a modified, deactivated virus to carry a correct version of the gene into patients’ own blood-forming stem cells in the lab. They then re-infused those cells into the patients to provide a ready supply of cells able to make the needed protein.

In the sickle cell patient, after the transplant a third of his red cells were making the right protein and that was enough to wean him off blood transfusions that had been keeping him alive and prevented any further hospitalizations due to the disease. The company also announced that the two previously reported patients treated for beta thalassemia had continued to improve. Reuters ran a story on the new data.

CIRM funds a similar project about to begin treating patients for sickle cell disease (link to video), also using a viral vector but a somewhat different one, so it is reassuring to see viral gene carriers working without side effects.

Another reason to vaccinate, prevent leukemia. While it has been known for some time that infant vaccination seems to have driven down the rate of childhood leukemia, no one has known why. A CIRM-funded team at the University of California, San Francisco, thinks they have figured it out. Viral infections trigger inflammation and the production of enzymes in cells that cause genetic mutations that lead to the cancer.

They worked with Haemophilus influenza Type b (Hib) vaccine but suggest a similar mechanism probably applies to other viral infections, and correspondingly, protection from other vaccines. The senior author on the paper, Marcus Muschen, explained the process in a university press release posted at Press-News.org

“These experiments help explain why the incidence of leukemia has been dramatically reduced since the advent of regular vaccinations during infancy. Hib and other childhood infections can cause recurrent and vehement immune responses, which we have found could lead to leukemia, but infants that have received vaccines are largely protected and acquire long-term immunity through very mild immune reactions.”

Barcoding individual cells. Our skin cells all pretty much look the same, but in the palm of your hand there are actually several different types of cells, even a tiny scratch of the fingernail. As scientist work to better understand how cells function, and in particular how stem cells mature, they increasingly need to know precisely what genes are turned on in individual cells.

Both techniques use tiny channels to isolate individual cells and introduce beads with "bar codes."

Both techniques use tiny channels to isolate individual cells and introduce beads with “bar codes.”

Until recently, all this type of analysis blended up a bunch of cells and asked what is in the collective soup. And this did not get the fine-tuned answers today’s scientists are seeking. Numerous teams over the past couple years have reported on tools to get down to single-cell gene analysis. Now, two teams at Harvard have independently developed ways to make this easier. They both use a type of DNA barcode on tiny beads that gets incorporated into individual cells before analysis.

Allan Klein, part of one team based at the Harvard Medical School’s main campus, described why the work is needed in a detailed narrative story released by the school:

“Does a population of cells that we initially think is uniform actually have some substructure. What is the nature of an early developing stem cell? . . . How is [a cell’s] fate determined? “

Even Macosko who worked with the other team centered at the Broad Institute of Harvard and MIT, noted the considerable increase in ease and decrease in cost with the new methods compared to some of the early methods of single cell gene analysis:

“If you’re a biologist with an interesting question in mind, this approach could shine a light on the problem without bankrupting you. It finally makes gene expression profiling on a cell-by-cell level tractable and accessible. I think it’s something biologists in a lot of fields will want to use.”

The narrative provides a good example of what we called the “bump rate” when I was at Harvard Med. Good science often moves forward when scientists bump into each other, and with Harvard Medical faculty scattered at 17 affiliated hospitals and research institutes scattered across Boston and Cambridge we were always looking for ways to increase the bump rate with conferences and cross department events. Macosko and Klein found out they were both working on similar systems at a conference.

Stem cell stories that caught our eye: a new type of stem cell, stomach cancer and babies—stem cell assisted and gene altered

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

New type of stem cell easier to grow, more versatile. Both the professional scientific media and the lay science media devoted considerable ink and electrons this week to the announcement of a new type of stem cell—and not just any stem cell, a pluripotent one, so it is capable of making all our tissues. On first blush it appears to be easier to grow in the lab, possibly safer to use clinically, and potentially able to generate whole replacement organs.

The newly found stem cells (shown in green) integrating into a mouse embryo.

The newly found stem cells (shown in green) integrating into a mouse embryo.

How a team at the Salk Institute made the discovery was perhaps best described in the institute’s press release picked up by HealthCanal. They sought to isolate stem cells from a developing embryo after the embryo had started to organize itself spatially into compartments that would later become different parts of the body. By doing this they found a type of stem cell that was on the cusp of maturing into specific tissue, but was still pluripotent. Using various genetic markers they verified that these new cells are indeed different from embryonic stem cells isolated at a particular time in development.

The Scientist did the best job of explaining why these cells might be better for research and why they might be safer clinically. They used outside experts, including Harvard stem cell guru George Daly and CIRM-grantee from the University of California, Davis, Paul Knoepfler, to explain why. Paul described the cells this way:

“[They] fit nicely into a broader concept that there are going to be ‘intermediate state’ stem cells that don’t fit so easily into binary, black-and-white ways of classifying [pluripotent cells].”

The Verge did the best job of describing the most far-reaching potential of the new cells. Unlike earlier types of human pluripotent cells, these human stem cells, when transplanted into a mouse embryo could differentiate into all three layers of tissue that give rise to the developing embryo. This ability to perform the full pluripotent repertoire in another species—creating so called chimeras—raises the possibility of growing full human replacement organs in animals, such as pigs. The publication quotes CIRM science officer Uta Grieshammer explaining the history of the work in the field that lead up to this latest finding.

Stem cells boost success in in vitro fertilization.  Veteran stem cell reporter and book author Alice Park wrote about a breakthrough in Time this week that could make it much easier for older women to become pregnant using in vitro fertilization. The new technique uses the premise that one reason older women’s eggs seem less likely to produce a viable embryo is they are tired—the mitochondria, the tiny organs that provide power to cells, just don’t have it in them to get the job done.

The first baby was born with the assistance of the new procedure in Canada last month. The process takes a small sample of the mother-to-be’s ovarian tissue, isolates egg stem cells from it, extracts the mitochondria from those immature cells and then injects them into the woman’s mature, but tired eggs. Park reports that eight women are currently pregnant using the technique. She quotes the president of the American Society of Reproductive Medicine on the potential of the procedure:

“We could be on the cusp of something incredibly important. Something that is really going to pan out to be revolutionary.”

But being the good reporter that she is, Park also quotes experts that note no one has done comparison studies to see if the process really is more successful than other techniques.

Why bug linked to ulcers may cause cancer. The discovery of the link between the bacteria H. pylori and stomach ulcers is one of my favorite tales of the scientific process. When Australian scientists Barry Marshall and Robin Warren first proposed the link in the early 1980s no one believed them. It took Marshall intentionally swallowing a batch of the bacteria, getting ulcers, treating the infection, and the ulcers resolving, before the skeptics let up. They went on to win the Nobel Prize in 1995 and an entire subsequent generation of surgeons no longer learned a standard procedure used for decades to repair stomach ulcers.

In the decades since, research has produced hints that undiagnosed H. pylori infection may also be linked to stomach cancer, but no one knew why. Now, a team at Stanford has fingered a likely path from bacteria to cancer. It turns out the bacteria interacts directly with stomach stem cells, causing them to divide more rapidly than normal.

They found this latest link through another interesting turn of scientific process. They did not feel like they could ethically take samples from healthy individuals’ stomachs, so they used tissue discarded after gastric bypass surgeries performed to treat obesity. In those samples they found that H. pylori clustered at the bottom of tiny glands where stomach stem cells reside. In samples positive for the bacteria, the stem cells were activated and dividing abnormally. HealthCanal picked up the university’s press release on the work.

Rational balanced discussion on gene-edited babies.   Wired produced the most thoughtful piece I have read on the controversy over creating gene-edited babies since the ruckus erupted April 18 when a group of Chinese scientists published a report that they had edited the genes of human eggs. Nick Stockton wrote about the diversity of opinion in the scientific community, but most importantly, about the fact this is not imminent. A lot of lab work lies between now and the ability to create designer babies. Here is one particular well-written caveat:

“Figuring out the efficacy and safety of embryonic gene editing means years and years of research. Boring research. Lab-coated shoulders hunched over petri dishes full of zebrafish DNA. Graduate students staring at chromatographs until their eyes ache.”

He discusses the fears of genetic errors and the opportunity to layer today’s existing inequality with a topping of genetic elitism. But he also discusses the potential to cure horrible genetic diseases and the possibility that all those strained graduate student eyes might bring down the cost to where the genetic fixes might be available to everyone, not just the well heeled.

The piece is worth the read. As he says in his closing paragraph, “be afraid, be hopeful, and above all be educated.”

Stem cell stories that caught our eye: spina bifida, review of heart clinical trials, tracking cells and cell switches

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Stem cells boost fetal surgery for spina bifida. Fetal surgery to correct the spinal defect that causes spina bifida has revolutionized treatment for the debilitating birth defect in the past few years. But for one of the researchers who pioneered the surgery it was only a half fulfilled hope. While the surgery let most of the treated kids grow up without cognitive deficits it did not improve their ability to walk.

spina_bifida-webNow that researcher, Diana Farmer at the University of California, Davis, has found a way to complete the job. Though it has only been used in an animal model so far, she found that when you engineer a stem cell patch that you insert into the gap before you push the protruding spinal cord back in its place during surgery, the animals are able to walk within a few hours of birth.

Specifically, she used a type of stem cell found in the placenta that has been shown to protect nerves. She incased those cells in a gel and placed them on a scaffold to hold them in place after transplant. All six lambs that had surgery plus the cell transplant walked. None of the ones who just had surgery did.

“Fetal surgery provided hope that most children with spina bifida would be able to live without (brain) shunts,” Farmer said. “Now, we need to complete that process and find out if they can also live without wheelchairs.”

CIRM awarded Farmer’s team funds in March to carry this work forward and prepare it for a possible clinical trial. The animal study appeared in Stem Cells Translational Medicine this week and the university’s press release was picked up by HealthCanal.

Thorough, digestible review of heart trials. Kerry Grens, writing in The Scientist, has produced the most complete and understandable review of the clinical trials using stem cells to treat heart disease that I have read. More important she provides significant detail about the three large Phase 3 trials that are ongoing that could provide make-or-break outcomes for using bone marrow stem cells for patients developing heart failure.

The bulk of the piece focuses on research using various types of mesenchymal stem cells found in bone marrow. All three of the late stage clinical trials use those cells, two use cells from the patient’s own marrow and one uses cells from donors. Grens uses a broad spectrum of the research community describe what we currently know about how those cells may work and more importantly, what we don’t know. The experts provide a good point-counter-point on why there are so many clinical trials when we don’t really know those stem cells’ “method of action,” why they might make someone’s heart stronger.

However she leads and ends with work CIRM funds at Cedars-Sinai and Capricor Therapeutics in Los Angeles. That work uses cells derived from the heart called cardiosphere-derived cells. Early trials suggested these cells might be better at reducing scar tissue and triggering regrowth of heart muscle. Those cells are currently being tested in a Phase 2 study to try to get a better handle on exactly what their benefit might be.

Monitoring stem cells after transplants. Early attempts to use stem cells as therapies have been hampered by an inability to see where the cells go after transplant and if they stay the desired location and function. A team at Stanford has used some ingenious new technologies to get over this hurdle, at least in laboratory animals.

Using a homegrown technology that recently won a major innovation prize for a Stanford colleague, optogenetics, the team was able to selectively activate the transplanted cells. Then they used the older technology, functional Magnetic Resonance Imaging (fMRI), to see if the cells were working. Because cell transplants in the brain have led to some of the most difficult to interpret results in humans, they chose to work with nerve stem cells transplanted into the brains of rats. The work was partially funded by CIRM.

Starting with iPS type stem cells made from Parkinson’s patients’ skin, they inserted a gene for a protein that is sensitive to certain wavelengths of light. They then matured those cells into nerve stem cells and implanted them along with a tube that could transmit the right wavelength of light. Over the course of many months they measured the activity of the cells via fMRI with and without the light stimulation. Because the fMRI measures blood flow it by default detects active nerve cells that require more nutrients from blood than inactive cells. Senior researcher, Jin Hyung Lee described the value of this imaging in the university’s press release picked up by HealthCanal:

“If we can watch the new cells’ behaviors for weeks and months after we’ve transplanted them, we can learn — much more quickly and in a guided way rather than a trial-and-error fashion — what kind of cells to put in, exactly where to put them, and how.”

Understanding cell’s switchboard may speed therapy. Cells function by switching genes on and off. Learning which switches to hit to maximize stem cells’ ability to multiply and mature into desired cell types has occupied a significant part of the stem cell research community for years. Now, a team at the Salk Institute has shown that two known genetic switches pack an additive punch when working together.

Both those signaling processes, one called Wnt and one called Activin, are needed for stem cells to mature into specific adult tissue. The Salk team led by Kathy Jones found that when working together the two signals activate some 200 genes. Wnt seems to load the cellular equipment needed for copying the cells and Activin increases the speed and efficiency of the process. In an institute press release picked up by Science Newsline, Jones discussed the practical implications of the finding:

“Now we understand stem cell differentiation at a much finer level by seeing how these cellular signals transmit their effects in the cells. Understanding these details is important for developing more robust stem cell protocols and optimizing the efficiency of stem cell therapies.”

Stem cell stories that caught our eye: multiple sclerosis, virus genes in embryos and preventing cancer’s spread to the brain

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Drugs activate brain stem cells in MS. We have frequently written that in some situations our own stem cells may do a better job at repairing the body than transplanted cells. A team at Case Western in Cleveland has done just that with lab and animal models of Multiple Sclerosis (MS). Even better, they did it with drugs that are already approved for other uses.

They used a steroid, clobetasol, and an antifungal, miconazole, to get a type of stem cell found in the brain to more effectively produce the myelin sheets that protect our nerves and that get destroyed in MS. But in a story in Science Blog the researchers cautioned that patients should not go ask a doctor to inject those drugs. They are currently used only as topical agents on the skin and no one knows what they would do internally in people.

“Off-label use of the current forms of these drugs is more likely to increase other health concerns than alleviate multiple sclerosis symptoms. We are working tirelessly to ready a safe and effective drug for clinical use,” said Paul Tesar who led the study.”

Specifically, the team worked with stem cells called oligodendrocyte progenitor cells. Growing them in the lab they tested hundreds of approved drugs to see if any would nudge those cells into producing myelin. They found these two and tested them in a mouse model of MS and saw improved function in the mice. They are now looking to test other drugs hoping to find one safe for internal use in humans.

Viral genes active in early embryos. Virus genes, mostly left over from infections of our ancestors thousands of years ago, make up some eight percent of the genetic material in our chromosomes. In general those genes just sit there and don’t do anything. But a CIRM funded team at Stanford has found that in the early days of embryo development some of them become quite active.

In fact, they seem to commandeer the growing embryo’s cellular machinery to produce whole virus particles that the researchers detected in the interior of the cells. What they could not determine is whether that activity is benign or somehow directs the development of the embryo—or might be the virus reasserting its parasitic ways.

“It’s both fascinating and a little creepy,” said Joanna Wysocka, the senior author on the study that appeared this week in Nature. “We’ve discovered that a specific class of viruses that invaded the human genome during recent evolution becomes reactivated in the early development of the human embryo, leading to the presence of viral-like particles and proteins in the human cells.”

In the press release, Stanford’s Krista Conger does a nice job of laying out some of the prior research about the origins and nature of all the viral genes hidden amongst our DNA. The release, picked up by HealthCanal makes it clear the finding raises more questions than it provides answers. Edward Grow, the graduate student who was first author on the paper put it this way:

“Does the virus selfishly benefit by switching itself on in these early embryonic cells? Or is the embryo instead commandeering the viral proteins to protect itself? Can they both benefit? That’s possible, but we don’t really know.”

Stem cells with multiple genetic tricks fight cancer. Breast cancer wreaks the most havoc when it spreads and about a third of the time it spreads to the brain. To fight that insidious spread a team a Massachusetts General Hospital and the Harvard Stem Cell Institute has rigged nerve stem cells with multiple genetic tricks to prevent breast cancer cells from growing after they get to the brain.

Certain types of nerve stem cells are naturally attracted to tumors. So the team led by Khalid Shah genetically manipulated those stem cells to express a gene called TRAIL. That gene produces a protein that activates a receptor on the surface of cancer cells that causes them to self-destruct. Then to make sure those stem cells did not stick around and multiply when they are no longer needed, the researchers added another gene that made them susceptible to a common antiviral drug. That drug could be given once the cells had done their work of delivering the suicide note to the cancer cells and the stem cells themselves would then be eliminated.

A press release on the work from MGH was picked up by ScienceNewsline and quoted Shah on the significance of the findings:

“Our results are the first to provide insight into ways of targeting brain metastases with stem-cell-directed molecules that specifically induce the death of tumor cells and then eliminating the therapeutic stem cells.”

In order to measure their results the team started with yet another genetic trick. They wanted to make sure the loaded stem cells were getting to the tumors. So, before they injected breast cancer cells into the carotid arteries in the necks of mice, they modified the cells so that they would express fluorescent markers. That glow could be tracked allowing the researchers to monitor the disappearance of the cancer cells.

This mouse work is obviously many steps away from use in humans, but it provides an ingenious path to follow.

Stem cell stories that caught our eye: iPS cells guide ALS trial, genetic link to hearing loss and easier to use stem cell

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

An ALS clinical trial with a twist.
It is well known that the disease we call ALS, or Lou Gehrig’s Disease, behaves differently in different people, so it makes sense that a potential medication might help some people more than others. Now a collaborative group in the North East wants to use iPS-type stem cells to predict who will respond to a medication at the outset of a clinical trial.

The drug to be tested is already used to calm hyper excitable nerves in people with epilepsy. Hyper excitable nerves also seem to play a role in ALS, at least in some patients. So the team, lead by a researcher at Massachusetts General Hospital with others from Harvard, the Northeast ALS Consortium and GlaxoSmithKline, will reprogram the patients’ blood cells to be iPS type stem cells and grow them into nerve cells in the lab and test their response to the drug, Retigabine.

The ALS Association is providing part of the funding for the effort, and the association’s chief scientist, Lucie Bruijn noted the unique nature of this effort in the association’s press release picked up by Bloomberg.

“This powerful collaboration of leaders in the fields of stem cells, clinical neurology, ALS research and GSK will be the first time that lab data from patient derived stem cells with disease-specific properties that respond to drugs have formed the basis for a clinical trial.”

Do stem cells prefer wearing a coat? One of our grantees and the editor of the journal Stem Cells, Jan Nolta, likes to refer to mesenchymal stem cells as little ambulances that run around the body delivering first aid supplies. These cells found in bone marrow and fat are being tested in many different disease, but in most cases they are not expected to actually make repairs themselves. Instead researchers use them to deliver a variety of protein factors that trigger various components of the body’s natural healing machinery.

Mesenchymal stem cells captured in microcapsules

Mesenchymal stem cells captured in microcapsules

One problem is the cells often do not stick around very long delivering their needed medical supplies. A team at Cornell University in New York thinks they may have found a way to improve the performance of these stem cells, by giving them a coat. By enclosing the stem cells in a capsule the cells stay in place better and more effectively help wounds heal, at least in the lab model the team used.

The university’s press release was picked up by Medical Design Technology.

Noise plus bad genes bad for hearing. Some people can spend years of Saturday nights attending loud rock concerts and have no issue with their hearing. Others end up constantly adjusting the battery on their hearing aids. A CIRM-funded team at the University of Southern California thinks they have fingered a genetic explanation for the difference.

Hearing is a complex process involving many components, which has resulted in no clear answers from previous attempts to find genetic links to hearing loss. The USC team performed a more complex analysis known as a GWAS, genome-wide association study. The result provided strong evidence that variations in the gene Nox3, which is normally turned on only in the inner ear, account for the differences in susceptibility.

Researchers now have a clear target to look for opportunities for prevention and therapy. Futurity picked up the University’s press release.

Accident creates new type of stem cell.
Much of the work with embryonic stem cells centers on figuring out what proteins and other factors to expose them to in order to get them to mature into a desired type of cell. One such attempt at the University of Missouri resulted in creating a new type of stem cell that may be easier to work with than embryonic stem cells (ESCs).

They call their new cells BMP-primed stem cells because one of the various factors they were adding to their ESCs in a lab dish was Bone Morphogenetic Protein. Michael Roberts, the leader of the team, described the potential value of the new stem cells in an article in Genetic Engineering & Biotechnology News:

“These new cells, which we call BMP-primed stem cells, are much more robust and easily manipulated than standard embryonic stem cells. BMP-primed cells represent a transitional stage of development between embryonic stem cells and their ultimate developmental fate, whether that is placenta cells, or skin cells or brain cells.”

For hardcore biologyphiles, the new cells offer a chance to better understand the early stages of embryo development. ESCs can form any part of the body but they cannot form the placenta and other early tissues needed to support the embryo. The BMP-primed stem cells can. So they may yield some long-sought answers about what determines cell fate in the early days after fertilization and perhaps some practical information on diseases related to the placenta like pre-eclampsia.

Stem cell stories that caught our eye; converting bad fat to good, Parkinson’s and X-linked disease

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Which fat for you, white, brown or beige.
Those who read up on those pesky fat cells that accumulate in our bodies probably have heard about white fat and brown fat. White is the bad guy linked to obesity and diabetes and brown is the good guy that burns energy and fosters leanness. Add one more color. A team at the University of California, San Francisco, has isolated beige fat that can convert white to brown.

body fatThey now want to see if they can figure out the molecular mechanism behind this conversion to see if they can develop a therapy to combat obesity. I heard a presentation on similar work at the International Society for Stem Cell Research last June, and there were suggestions that the stem cell known to reside in fat may play a role, but no one seems to be sure.

The current research made it into Nature Medicine and ScienceDaily picked up the university’s press release, which quotes the senior researcher, Shingo Kajimura:

“This finding brings us another step closer to the goal of our laboratory, which is engineering fat cells to fight obesity. We are trying to learn how to convert white fat into brown fat, and until now, it had not been demonstrated that this recruitable form of brown fat is actually present in humans.”


A wonkish revelation on reprogrammed stem cells.
When Shinya Yamanaka first discovered how to reprogram adult cells into embryonic-like stem cells, the resulting iPS cells won him the Nobel Prize. But neither he nor anyone else knew exactly how this reprogramming actually happened. It was assumed that by adding genes that are normally only active during embryo development we were turning back the clock and letting the cells sort of start over.

Now, CIRM-funded researchers at Stanford have discovered the cells first go through a clearly identifiable intermediate state that does not have any of the markers of early stem cells, so called pluripotency genes. The leader of the team, Marius Wernig, described his surprise in a university press release picked up by HealthCanal:

“This was completely unexpected. It’s always been assumed that reprogramming is simply a matter of pushing mature cells backward along the developmental pathway. These cells would undergo two major changes: They’d turn off genes corresponding to their original identity, and begin to express pluripotency genes. Now we know there’s an intermediary state we’d never imagined before.”

The research, published in Nature, used a clever new technique that lets cells grow in individual tiny wells on a laboratory plate. Wernig hopes the finding will help his group and others find ways to improve reprogramming efficiency, which is commonly in single percentage points and rarely in the teens.

Chemical trick yields nerves needed in Parkinson’s.
It’s relatively easy to get stem cells to mature into nerves, but can be quite difficult sometimes to get them to grow into just the right kind of nerves. The dopamine-producing nerves needed in Parkinson’s disease turn out to be one of the difficult ones.

Now, a team from Brazil has used an approved drug to treat stem cells in the lab and get them to consistently mature into dopamine-producing nerves. What’s better, the cells survived and continued to produce dopamine for 15 months after being transplanted into mice. ScienceDaily picked up the press release from D’Or Institute for Research and Education.

The X chromosome and disease? Researchers have long sought answers to why when a disease gene resides on the X chromosome, it often causes more harm in boys than girls. A likely culprit is the process a developing embryo uses to shut down one of the two X chromosomes in females, and a team at Stanford thinks they have found a way to discover how.

The CIRM-funded team lead by Howard Chang used a new molecular tool to study in detail all the components of the cell involved in silencing one of the X chromosomes.

Calico cats are female due to X-chromosome silencing.

Calico cats are female due to X-chromosome silencing.

Researchers have known for some time that one particular genetic component, an RNA called Xist, plays a lead role. But Chang’s team discovered 80 different proteins it interacts with in order to completely shut down one X chromosome. They hope that learning more about the process will let researchers figure out how this selective silencing protects females from some of the mutations on the X chromosome.

The Stanford press release, picked up by HealthCanal, starts with a fun explanation of X silencing and how it can lead to calico female cats, but not males—sorry Garfield you don’t exist.

Stem cell stories that caught our eye; creating bone, turning data into sound, cord blood and path of a stem cell star

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

A better ratio of bone to fat
. Most of us at any age would prefer a little less fat and older folks, particularly ones plagued by the bone loss of osteoporosis, could use a bit more bone. Since both types of tissues come from mesenchymal stem cells (MSCs) a team at the University of Miami decided to look for chemical triggers that tells those stem cells whether to become fat or bone.

They found an enzyme that seems to do just that. In mice that were born with a mutation in the gene for that enzyme they saw increased bone growth, less fat production and a leaner body mass. HealthCanal picked up the university’s press release that quoted the leader of the team Joshua Hare:

“The production of bone could have a profound effect on the quality of life for the aging population.”

He goes on to note that there are many hurdles to cross before this becomes a therapeutic reality, but the current work points to lots of potential.

Path to becoming a star stem cell scientist. D, the city magazine for Dallas, published a lengthy—nearly 4,000-word—feature on Sean Morrison, one of the undisputed leaders of our field. While it starts out talking about his latest role of creating a multi-pronged center for innovation at

Sean Morrison

Sean Morrison

Children’s Medical Center Dallas and UT Southwestern, it spends most of its words on how he got there.

It’s fun reading how someone gets into a field as new as stem cell science and what keeps them in the field. Initially, for him it seems to originate from an immense curiosity about what was not known about the powerful little stem cells.

“Fifteen years ago, there was nothing known at the molecular level about how stem cells replicate. And I really felt it was a fundamental question in biology to understand. It was a question that was central to a lot of important issues, because the ability of stem cells to self-renew is critical to form your tissues throughout development, to maintain your tissues throughout adulthood.”

There is also a good retelling of Morrison’s role in the protracted and hard-fought battle to make embryonic stem cell research legal during his years in Michigan. He started working on the campaign to overturn the ban in 2006 and in 2008 the voters agreed. The article makes a compelling case for something I have advocated for years: scientists need to practice speaking for the public and get out and do it.

Turning stem cell data into sound. Interpreting scientific data through sound, sonification, is a bit trendy now. But the concept is quite old. Think of the Geiger counter and the speed of the click changing based on the level of radiation.

Researchers tend to consider sonification when dealing with large data sets that have some level of repetitive component. Following the differentiation of a large number of stem cells as they mature into different types of tissue could lend itself to the genre and a team at Cardiff University in Scotland reports they have succeeded. In doing just that.

HealthCanal picked up the university’s piece talking about the project. Unfortunately it does a very poor job of explaining how the process actually works. I did find this piece on ocean microbes that describes the concept of sonification of data pretty well.

Cord blood poised for greater use. I get very uncomfortable when friends ask for medical advice around stem cells. I usually try to give a lay of the land that comes short of direct advice. A common question centers on the value of paying the annual storage fees to freeze their baby’s cord blood. To which, I typically say that for current uses the value is marginal, but for the uses that could come in five to 10 years, it could be quite significant.

So, it was not surprising to read a headline on a Scientific American Blog last December reading “Vast Majority of Life-Saving Cord Blood Sits Unused.” But it was also fun to read a well-documented counter point guest blog on the site this morning by our former President, Alan Trounson. He suggested a better headline would be: “Vast Majority of Life-Saving Cord Blood Sits Poised for Discovery.”

He details how cord blood has become a valuable research tool and lists some of the FDA-approved clinical trials that could greatly expand the indication of cord blood therapy. While some of those trials will likely produce negative results, some will succeed and they all will start to show how to turn those frozen vials into a more valuable resource.

Stem cell stories that caught our eye; cystic fibrosis, brain repair and Type 2 diabetes

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

“Organoids” screen for cystic fibrosis drugs
. Starting with iPS-type stem cells made by reprogramming skin cells from cystic fibrosis (CF) patients a team at the University of Cambridge in the U.K. created mini lungs in a dish. These organoids should provide a great tool for screening drugs to treat the disease.

The researchers pushed the stem cells to go through the early stages of embryo development and then on to become 3-D distal airway tissue, the part of the lung that processes gas exchange. They were able to use a florescent marker to show an aspect of the cells’ function that was different in cells from CF patients and those from normal individuals. When they treated the CF cells with a drug that is being tested in CF patients, they saw the function correct to the normal state.

Bioscience Technology
picked up the university’s press release about the work published in the journal Stem Cells and Development. It quotes the scientist who led the study, Nick Hannon, on the application of the new tool:

“We’re confident this process could be scaled up to enable us to screen tens of thousands of compounds and develop mini-lungs with other diseases such as lung cancer and idiopathic pulmonary fibrosis.”

To repair a brain knock its “pinky” down. A team at the University of California, San Francisco, has discovered a molecule that when it is shut down nerve stem cells can produce a whole lot more nerves. They call the molecule Pnky, named after the cartoon Pinky and the Brain.

Pinky_and_the_Brain_vol1Pkny belongs to a set of molecules known as long noncoding RNAs (lncRNAs), which researchers are finding are more abundant and more important than originally thought. The most familiar RNAs are the intermediary molecules between the DNA in our genes and the proteins that let our cells function. Initially, all the noncoding RNAs were thought to have no function, but in recent years many have been found to have critical roles in determining which genes are active. And Pnky seems to tamp down the activity of nerve stem cells. In a university press release picked up by HealthCanal Daniel Lim, the head researcher explained what happens when they shut down the gene:

“It is remarkable that when you take Pnky away, the stem cells produce many more neurons. These findings suggest that Pnky, and perhaps lncRNAs in general, could eventually have important applications in regenerative medicine and cancer treatment.”

Lim went onto explain the cancer connection. Since Pnky binds to a protein found in brain tumors, it might be involved in regulating the growth of brain tumors. A lot more work needs to happen before that hunch—or the use of Pnky blockers in brain injury—can lead to therapies, but this study certainly paints an intriguing path forward.

Stem cells and Type 2 diabetes. A few teams have succeeded in using stem cells to produce insulin-secreting tissue to correct Type 1 diabetes in animals, but it has been uncertain if the procedure would work for Type 2 diabetes. Type 1 is marked by a lack of insulin production, while resistance to the body’s own insulin, not lack of insulin, is the hallmark of type 2. A team at the University of British Columbia has new data showing stem cell therapy may indeed have a place in treating Type 2.

In mice fed a high fat diet until they developed the symptoms of Type 2 diabetes the stem cell-derived cells did help, but they did not fully correct the metabolism of the mice until they added one of the drugs commonly used to treat diabetes today. The drugs alone, also did not restore normal metabolism, which is often the case with human Type 2 diabetics.

The combination of drugs and cells improved the mice’s sugar metabolism, body weight and insulin sensitivity. The research appeared in the journal Stem Cell Reports and the University’s press release was picked up by several outlets including Fox News.

They transplanted cells from humans and even though the mice were immune suppressed, they took the added measure of protecting the cells in an encapsulation device. They noted that this would be required for use in humans and showing that it worked in mice would speed up any human trials. They also gave a shout out to the clinical trial CIRM funds at Viacyte, noting that since the Food and Drug Administration has already approved use of a similar device by Viacyte, the work might gain more rapid approval.

Stem cell stories that caught our eye; drug screening, aging stem cells in brain repair and blood diseases

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Heart-on-a-chip used to screen drugs. With CIRM funding, a team at the University of California, Berkeley, has used stem cell technology to create a virtual heart on an inch-long piece of silicon. The cells in that “chip” mimic the physiology of a human heart and have shown that they can accurately show how drugs will impact the heart.
HeartChip4196107801
Starting with iPS-type stem cells made from reprogramming adult cells the researchers grew them into heart muscle that could beat and align in multiple layers with microscopic channels that mimic blood vessels. They tested three drugs currently used to treat heart disease and found the changes seen in the heart-on-a-chip were consistent with what is seen in patients. For example, they tested isoproterenol, a drug used to treat slow heart rate and saw a dramatic increase in heart rate.

But the real value in the silicon-housed heart will be in screening potential new drugs and finding out adverse impacts before taking them into costly human clinical trials. Genetic Engineering & Biotechnology News wrote up the work and quoted a member of the team, Kevin Healy:

“It takes about $5 billion on average to develop a drug, and 60 percent of that figure comes from upfront costs in the research and development phase. Using a well-designed model of a human organ could significantly cut the cost and time of bringing a new drug to market.”

Brain stem cell activity decreases with age. We have known for some time that the adult stem cells that reside in most of our tissues and spend our lives repairing those tissues are less effective as we age. But the stemness of those cells—their ability to regenerate themselves—has not generally been questioned, rather we have assumed they just lost some of their ability to mature into the type of cell needed to make the repair.

Now, a team at the Ludwig-Maximilians-Universitat in Munich has published data suggesting that brain stem cells over time loose both their ability to renew themselves and some of their ability to become certain kinds of nerves. ScienceDaily picked up a press release from the institution and it quoted one of the authors, Magdalena Gotz, on the implications of their finding for therapy.

“In light of the fact that the stem cell supply is limited, we must now also look for ways to promote the self-renewal rate of the stem cells themselves and maintain the supply for a longer time.”

Another alternative for correcting genetic blood disease. CIRM funds a few programs that are trying to treat blood diseases such as sickle cell anemia and beta thalassemia by genetically altering blood forming stem cells. The goal being to correct defects in the gene for hemoglobin, the protein that carries oxygen in red blood cells.

Instead of starting with a patient’s own blood stem cells, which can require a somewhat traumatic harvest procedure, a new approach by a team at the Salk Institute in La Jolla creates iPS type stem cells by reprogramming the cells in a small skin sample. They mature those into blood stem cells and genetically modify them so that they can produce red blood cells that have the correct hemoglobin.

The Salk team uses a modified cold virus to carry the gene into the cell. ScienceDaily picked up the institute’s press release, which quotes one of the co-first authors on the study Mo Li on how the process works:

“It happens naturally, working like a zipper. The good gene just zips in perfectly, pushing the bad one out.”

CIRM funds other work by the senior author, Juan Carlos Izpisua Belmonte, but not this project. Because you never know which technology is going to work out best in the long term, it is nice to see other funders stepping up and pushing this alternative forward.

Stem cell stories that caught our eye; Parkinson’s, drug boosts stem cells in MS and gender equity in science

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Stem cells survive and aid Parkinson’s in monkey.
Ole Isacson, a pioneer in the effort to figure out how to use stem cells to treat Parkinson’s Disease, has published new research that suggests a good option. His Harvard team used nerves grown from reprogrammed iPS type stem cells created from the monkey’s own skin.

Dopamine producing nerves created from skin cells of primates

Dopamine producing nerves created from skin cells of primates

His earlier efforts using nerves grown from embryonic stem cells did not result in production of the dopamine that Parkinson’s patients need. He speculates that this was because they were donor cells and required immune suppression to avoid rejection. With the iPS-derived nerves no immune suppressants were needed and the cells survived two years and reversed much of the Parkinson’s symptoms in the one animal that got that type of cell.

ScienceBlog picked up the university’s press release, which described the therapeutic benefit this way:

Isacson said the conclusion of this experiment marks “the first time that an animal has recovered to the same activity level he had before.” He noted that the animal was “able to move as fast around its home cage” as an animal without Parkinson’s, and had normal agility, though individual motions were still slowed by the disease.

He also cautioned that it would be at least three years before he could do the experiments needed to prove the procedure was safe enough to use in patients.

Nerve cells for memory created from stem cells.
The cerebral cortex is the most complex part of our brains. This large outer layer processes memory, vision and language. Its complexity has always given researcher pause in thinking about ways to use stem cells to repair damage in it. Now, an international team working in Belgium and France has grown cortex nerves in the lab, transplanted them in mice with damaged cortices and seen the nerves survive and integrate into the healthy neighboring tissue.

In these experiments the damaged area in the mice was in the visual cortex and some of the animals did show a return of visual stimulus after the transplants. The researchers published their results in the journal Neuron and Science Daily picked up a release from the Belgium university, Libre de Bruxelles.

Drug gets brain stem cells to do better job. We retain a few brain stem cells throughout our life, but they are often not up to the task of repairing large areas of damage. This is the case in multiple sclerosis when our immune system destroys much of the myelin sheath that coats and protects the nerves.

Using a drug already approved by the Food and Drug Administration for other uses, researchers at the University of Buffalo were able to increase the production of myelin in a mouse model of the disease. The drug targets the middleman cells that are half way between stem cells and mature myelin called oligodendrocyte progenitor cells.

They found the drug by first stepping back to look to see what molecules inside the cell are normally active as the stem cells mature to progenitors and then to myelin. They identified a specific molecular pathway needed for this maturation and then looked for drugs that might impact that pathway. They hit upon solifenacin, an agent used for overactive bladder, which results from activity in that same molecular pathway. They told Genetic Engineering & Biotechnology News that they are now looking for funding to conduct human clinical trails.

Stem cell foundation pushes for gender equality. The New York Stem Cell Foundation launched its “Initiative on Women in Science and Engineering (IWISE)” in February 2014 and this week the journal Cell Stem Cell published the resulting recommendations.

The IWISE working group’s first meeting a year ago resulted in seven actionable strategies to advance women in science, medicine and engineering. The group continued to refine those over the year, met again last month to finalize them prior to publication.

The seven strategies include:
1) Implement flexible family care spending
2) Provide “extra hands” awards
3) Recruit gender-balanced external review committees and speaker selection committees
4) Incorporate implicit bias statements
5) Focus on education as a tool
6) Create an institutional report card for gender equality
7) Partner to expand upon existing searchable databases of women in science, medicine, and engineering

The press release from NYSCF was picked up on the web site ECN and has a quote from former CIRM governing board member, Claire Pomeroy, who is now president of the Lasker Foundation.

“The brain power provided by women in science is essential to sustaining a thriving US society and economy. It is time to move beyond just lamenting its loss and embrace the actions called for in this timely report.”