Cartilage Repair using Embryonic Stem Cells: A Promising Path to Treating Millions of Osteoarthritis Sufferers

Bone scraping on bone — you can practically feel the excruciating pain just thinking about it. Sadly, that’s what happens to people suffering with osteoarthritis (OA), a degenerative joint disease. Except for joint replacement surgery, no cure exists and the available medicines only work on the symptoms, pain and swelling, and not the underlying cause. On top of that, long-term use of the drugs carries potential serious side effects including gastrointestinal bleeding and increased risk of a heart attack.

The statistics on this disease are just plain dreadful. It’s estimated that 250 million people worldwide have osteoarthritis of the knee. And 43 million globally have a moderate to severe form of OA. Based on a 2011 analysis, OA was the second-most expensive condition treated in U.S. hospitals amounting to nearly $15 billion in costs.

Imagine the increased quality of life for millions of people around world and the enormous health care savings if a cure were developed?

A study published on Tuesday in Stem Cells Translational Medicine may turn the tide toward a lasting treatment for osteoarthritis. A research team at the University of Manchester in England reported that they repaired knee joints in animal studies by implanting cartilage cells derived from human embryonic stem cells (hESC).

Osteoarthritis

As cartilage degrades in the joints of people with osteoarthritis, bone rubs against bone causing severe pain

In a healthy joint, the ends of the bones are capped with cartilage, a hard but slippery substance that allow the bones to slide smoothly against each other. The cartilage also acts as a shock absorber for the joints when the body is in motion.

 

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In X-rays, a healthy cartilage appears as an invisible gap between the bone joints. In the osteoarthritic joint that gap between the bones is mostly gone. (image credit: Mend My Knee)

This protective tissue in the joint gradually degrades in OA. The degradation in some cases is initiated by an injury even a minor one. Because cartilage lacks blood vessels, it doesn’t receive nourishment from the blood and is no good at repairing itself. And so eventually the bones at the joint are exposed and begin to rub against each other leading to severe pain, swelling, and reduced mobility.

In previous studies, the University of Manchester research team led by professor Sue Kimber, devised a method for specializing human embryonic stem cells into so-called chondroprogenitors, or cells with the potential to form cartilage.

The team implanted the cells into the knee joints of rats modeled with OA-like defects to test their ability to repair cartilage. By four weeks after the implant, the treated rats began to show signs of cartilage healing compared to an untreated group. By 12 weeks the treated joints revealed a shiny smooth surface characteristic of healthy cartilage while the untreated group still showed rough misshapen cartilage, a hallmark of OA.  In a press release, Professor Kimber put these results in perspective:

 “This work represents an important step forward in treating cartilage damage by using embryonic stem cells to form new tissue, although it’s still in its early experimental stages.”

Compared to this preliminary hESC work, the use of cartilage-producing cells derived from adult stem cells is already being tested but the source material is limited making that method ultimately very costly and not scalable. hESCs, on the other hand, can be grown in unlimited quantities for large-scale, off the shelf cell therapy for the millions of OA sufferers. If you’re still following along, you might be thinking “but wouldn’t those hESC-derived therapies be recognized as foreign and rejected by the OA patient’s immune system?” That is a serious hurdle, but data from other labs hint at the possibility that cartilage repair may be possible with minimal tissue matching between the donor cells and the patient.

There is also reason to believe the cartilage derived by embryonic stem cells (ESCs) might be superior to that created to-date from adult stem cells. The latter tends to produce a softer form of cartilage than the hard cartilage found in our knees called articular cartilage. Because the ESCs produce cells that are earlier in the development cycle it may be possible to push them to become the sturdier cartilage we want in our knees. CIRM grantee Darryl D’Lima at The Scripps Research Institute has shown that seems to be the case in his preliminary studies.

Finally, a big concern of using hESC derived cell therapies is that some unspecialized cells will remain in the implant with the potential of unlimited growth leading to tumor formation and cancer. But in this study the results were encouraging since no irregular cartilage formation or tumors were seen.

Clearly it’s still early days for a hESC approach to curing OA. But these results are promising enough to draw out this response from Stephen Simpson Director of research at Arthritis Research UK which funded this study:

“Embryonic stem cells offer an alternative source of cartilage cells to adult stem cells, and we’re excited about the immense potential of Professor Kimber’s work and the impact it could have for people with osteoarthritis.”

One-Time, Lasting Treatment for Sickle Cell Disease May be on Horizon, According to New CIRM-Funded Study

For the nearly 1,000 babies born each year in the United States with sickle cell disease, a painful and arduous road awaits them. The only cure is to find a bone marrow donor—an exceedingly rare proposition. Instead, the standard treatment for this inherited blood disorder is regular blood transfusions, with repeated hospitalizations to deal with complications of the disease. And even then, life expectancy is less than 40 years old.

In Sickle Cell Disease, the misshapen red blood cells cause painful blood clots and a host of other complications.

In Sickle Cell Disease, the misshapen red blood cells cause painful blood clots and a host of other complications.

But now, scientists at UCLA are offering up a potentially superior alternative: a new method of gene therapy that can correct the genetic mutation that causes sickle cell disease—and thus help the body on its way to generate normal, healthy blood cells for the rest of the patient’s life. The study, funded in part by CIRM and reported in the journal Blood, offers a great alternative to developing a functional cure for sickle cell disease. The UCLA team is about to begin a clinical trial with another gene therapy method, so they—and their patients—will now have two shots on goal in their effort to cure the disease.

Though sickle cell disease causes dangerous changes to a patient’s entire blood supply, it is caused by one single genetic mutation in the beta-globin gene—altering the shape of the red blood cells from round and soft to pointed and hard, thus resembling a ‘sickle’ shape for which the disease is named. But the UCLA team, led by Donald Kohn, has now developed two methods that can correct the harmful mutation. As he explained in a UCLA news release about the newest technique:

“[These results] suggest the future direction for treating genetic diseases will be by correcting the specific mutation in a patient’s genetic code. Since sickle cell disease was the first human genetic disease where we understood the fundamental gene defect, and since everyone with sickle cell has the exact same mutation in the beta-globin gene, it is a great target for this gene correction method.”

The latest gene correction technique used by the team uses special enzymes, called zinc-finger nucleases, to literally cut out and remove the harmful mutation, replacing it with a corrected version. Here, Kohn and his team collected bone marrow stem cells from individuals with sickle cell disease. These bone marrow stem cells would normally give rise to sickle-shaped red blood cells. But in this study, the team zapped them with the zinc-finger nucleases in order to correct the mutation.

Then, the researchers implanted these corrected cells into laboratory mice. Much to their amazement, the implanted cells began to replicate—into normal, healthy red blood cells.

Kohn and his team worked with Sangamo BioSciences, Inc. to design the zinc-finger nucleases that specifically targeted and cut the sickle-cell mutation. The next steps will involve improving the efficiency and safest of this method in pre-clinical animal models, before moving into clinical trials.

“This is a promising first step in showing that gene correction has the potential to help patients with sickle cell disease,” said UCLA graduate student Megan Hoban, the study’s first author. “The study data provide the foundational evidence that the method is viable.”

This isn’t the first disease for which Kohn’s team has made significant strides in gene therapy to cure blood disorders. Just last year, the team announced a promising clinical trial to cure Severe Combined Immunodeficiency Syndrome, also known as SCID or “Bubble Baby Disease,” by correcting the genetic mutation that causes it.

While this current study still requires more research before moving into clinical trials, Kohn and his team announced last month that their other gene therapy method, also funded by CIRM, has been approved to start clinical trials. Kohn argues that it’s vital to explore all promising treatment options for this devastating condition:

“Finding varied ways to conduct stem cell gene therapies is important because not every treatment will work for every patient. Both methods could end up being viable approaches to providing one-time, lasting treatments for sickle cell disease and could also be applied to the treatment of a large number of other genetic diseases.”

Find Out More:
Read first-hand about Sickle Cell Disease in our Stories of Hope series.
Watch Donald Kohn speak to CIRM’s governing Board about his research.

The search for a cure: how stem cells could eradicate the AIDS virus

It’s hard to overstate just how devastating the AIDS crisis was at its peak in the U.S. – and still is today in many parts of the world. In 1995 almost 51,000 Americans died from the disease, the numbers of new cases were at almost record highs, and there were few effective therapies against the virus.

HIV/AIDS medications

HIV/AIDS medications

Today that picture is very different. New medications and combination therapies have helped reduce the death rate, in some cases turning HIV into a chronic rather than fatal condition. But even now there is no cure.

That’s why the news that the Food and Drug Administration (FDA) has approved a clinical trial, that we are funding, aimed at eradicating HIV in the body, was so welcome. This could be an important step towards the Holy Grail of AIDS therapies, curing the disease.

The project is headed by Dr. John Zaia at City of Hope near Los Angeles. The team, with researchers from Keck Medicine of the University of Southern California (USC) and Sangamo BioSciences, plans on using an individual’s own stem cells to beat the virus.  They will remove some blood stem cells from HIV-infected individuals, then treat them with zinc finger nucleases (ZFNs), a kind of molecular scissors, snipping off a protein the AIDS virus needs to infect those cells.

It’s hoped the re-engineered stem cells, when returned to the body, will help create a new blood and immune system that is resistant to the virus. And if the virus can’t infect any new immune cells it could, theoretically, die off. Check out the video we produced a few years back about the project:

Studies in the lab show this approach holds a lot of promise. In a news release announcing the start of the clinical trial, Dr. Zaia said now it’s time to see if it will work in people:

“While we have a number of drugs that are effective in holding HIV at bay, we have nothing that cures it. In addition, for many patients, these medications come with significant long-term problems so there is a real need for a therapy that can help eradicate the virus from a patient completely. That is where our work is focused.”

Like all Phase 1 trials this one is focused on making sure this approach is safe for people, and identifying what, if any, side-effects there are from the treatment. The first group of patients to be treated consists of people with HIV/AIDS who have not responded well to the existing medications.

This is the second trial that CIRM is funding focused on curing HIV/AIDS. Our first, involving the company Calimmune, began its human clinical trial in July 2013. You can read more about that work here.

We know that the road to a cure will not be simple or straightforward. There have been too many false claims of cures or miracle therapies over the years for any of us to want to fall victim to hope and hype. It may even be that the most realistic goal for these approaches is what is called a “functional cure”, one that doesn’t eliminate the virus completely but does eliminate the need to take antiretroviral pills every day.

But when compared to the dark days of 1995, a functional cure is a world away from certain death.

Stem cell stories that caught our eye; viral genes in embryos, underuse of transplants and joint pain clinics

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.

Ancient viral invaders help make us, us. The cells of our ancestors millions of years ago may have found a way to turn viral invasion into a good thing. This genetic lemons-to-lemonade tale comes from a team in Singapore that meticulously looked at 650,000 bits of virus genes that have been left behind in our cells after viral infections.

Retroviruses like HIV can only replicate by integrating their genes into ours and getting our cellular machinery to make new copies of themselves. Biologists have long known that they often leave behind bits of their genes, but had assumed this became part of the “junk DNA” that does not serve any function and that makes up the bulk of the genetic material in our cells. That scenario has started to change over the past few years as teams have reported examples of those retroviral genetic elements playing a role in the regulation—the turning on and off—of our functional genes.
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Jonathan Goke, the lead researcher on the project at the Genome Institute of Singapore, wrote that roughly 1,400 of those viral gene elements were involved in the very early stages of embryo development, helping determine how cells decide to mature into different types of tissue. They seem to be needed for determining who we are.

In an article on the website science 2.0 Goke speculated that these viruses may have been able to speed-up evolution by making changes in gene function faster than random mutation.

Blood stem cell transplants under used. Even as the number of blood stem cell transplants ever performed has passed the one million mark, a new report warns that lives are at risk because too many patients that could benefit are not getting these transplants. Blood stem cell transplants, which started as bone marrow transplants, provide the only shot at life-saving therapy for many patients, mostly those with blood cancers.

An international team, led by Dietger Niederwieser of the University Hospital Leipzig in Germany, found a dramatic under use of donor cells for transplants that varied widely around the world. Writing in the Lancet they reported that just 0.4 people per 10 million in the Philippines get such transplants, but in Israel the number shoots up to 506. The report noted both uneven distribution of resources needed to perform the complex procedure and inconsistent support for and participation in donor registries. Niederwieser was quoted in a press release from the journal picked up by ScienceDaily:

“Patients, many of them children, are facing a life and death situation. Ultimately they will die if they cannot get the treatment they need. All countries need to provide adequate infrastructure for patients and donors to make sure that everyone who needs a transplant gets one, rather than the present situation in which access remains restricted to countries and people with sufficient resources.”

What is real with stem cells and joint pain? Bethesda Magazine, the local publication for the county that is home to the National Institutes of Health (NIH), produced a good piece giving the perspective of patients wanting to avoid joint replacement surgery as well as scientists leery of cell-based procedures that have very little evidence to back them up.

The magazine reached out to its neighbor, the NIH to provide some perspective. It quotes Pamela Robey, the co-coordinator of the NIH Bone Marrow Stromal Cell Transplantation Center—those stromal cells are one type of cell often touted by clinics offering to treat joint pain.

“There are a huge number of clinical trials, but there has been next to no published information. The bottom line is there’s no real rigorous data showing it is actually repairing the joint.”

The author also talked to CIRM grantee Larry Goldstein of the University of California, San Diego, in his role as a member of the Ethics and Public Policy Committee of the International Society for Stem Cell Research. He notes that what clinics are offering is unproven and the author directs readers to the ISSCR web site’s “Closer Look” section to get more information on how to evaluate potential therapies they may be considering.

Stay on Target: Scientists Create Chemical ‘Homing Devices’ that Guide Stem Cells to Final Destination

When injecting stem cells into a patient, how do the cells know where to go? How do they know to travel to a specific damage site, without getting distracted along the way?

Scientists are now discovering that, in some cases they do but in many cases, they don’t. So engineers have found a way to give stem cells a little help.

As reported in today’s Cell Reports, engineers at Brigham and Women’s Hospital (BWH) in Boston, along with scientists at the pharmaceutical company Sanofi, have identified a suite of chemical compounds that can help the stem cells find their way.

Researchers identified a small molecule that can be used to program stem cells (blue and green) to home in on sites of damage. [Credit: Oren Levy, Brigham and Women's Hospital]

Researchers identified a small molecule that can be used to program stem cells (blue and green) to home in on sites of damage. [Credit: Oren Levy, Brigham and Women’s Hospital]

“There are all kinds of techniques and tools that can be used to manipulate cells outside the body and get them into almost anything we want, but once we transplant cells we lose complete control over them,” said Jeff Karp, the paper’s co-senior author, in a news release, highlighting just how difficult it is to make sure the stem cells reach their destination.

So, Karp and his team—in collaboration with Sanofi—began to screen thousands of chemical compounds, known as small molecules, that they could physically attach to the stem cells prior to injection and that could guide the cells to the appropriate site of damage. Not unlike a molecular ‘GPS.’

Starting with more than 9,000 compounds, the Sanofi team narrowed down the candidates to just six. They then used a microfluidic device—a microscope slide with tiny glass channels designed to mimic human blood vessels. Stem cells pretreated with the compound Ro-31-8425 (one of the most promising of the six) stuck to the sides. An indication, says the team, Ro-31-8425 might help stem cells home in on their target.

But how would these pre-treated cells fare in animal models? To find out, Karp enlisted the help of Charles Lin, an expert in optical imaging at Massachusetts General Hospital. First, the team injected the pre-treated cells into mouse models each containing an inflamed ear. Then, using Lin’s optical imaging techniques, they tracked the cells’ journey. Much to their excitement, the cells went immediately to the site of inflammation—and then they began to repair the damage.

According to Oren Levy, the study’s co-first author, these results are especially encouraging because they point to how doctors may someday soon deliver much-needed stem cell therapies to patients:

“There’s a great need to develop strategies that improve the clinical impact of cell-based therapies. If you can create an engineering strategy that is safe, cost effective and simple to apply, that’s exactly what we need to achieve the promise of cell-based therapy.”

How the human genome is unlocking some of the secrets of stem cells, hopefully leading to new treatments

A little over a year ago we set aside $40 million to study how variations in the human genome – the complete map of our genetic information – can affect our ability to use stem cells to treat a wide variety of diseases and disorders.

Human-Genome-Project_finalThat money helped set up the Stanford/Salk Center of Excellence in Stem Cell Genomics (CESCG) with a goal of using genomic analysis to better understand how stem cells change as they grow and become different kinds of cells, and then use that knowledge to develop new treatments for a wide variety of conditions.

Now the CESCG has just announced it is investing $11.6 million on seven different projects aimed at gaining a deeper understanding of deadly or disabling diseases and conditions, such as heart disease and autism.

As Stanford’s Dr. Michael Snyder, a co-Principal Investigator on the project, said in a news release, a major part of CESCG’s mission is to “establish a Collaborative Research Program (CRP) to support the genomics research needs of stem cell investigators in California,”

‘We don’t just provide funds we also partner with the individual researchers, providing them with the support, expertise and resources they need to conduct successful genomics analyses. We received 30 applications from throughout the State, and after peer review 7 projects were identified as the best new collaborations for the Center.”

So how does this advance stem cell science? Well, in the past researchers often depended on animal models for their work; but because results in animals don’t always translate when applied to people this was not always an effective way to work. At the University of California, San Francisco and the University of California, Los Angeles researchers Arnold Kriegstein and Gay Crooks are using genomics to better understand normal human cell identities in the brain (UCSF) and the blood (UCLA) and then applying that knowledge to help develop more accurate and more detailed stem cell-based models for us to study.

Jonathan Thomas, the Chair of our Board, says one of the best ways to do great science, is to create a great team:

“The goal of the Board in creating this program and bringing together this group of researchers was to accelerate our fundamental understanding of human biology and the ways that disease work. That knowledge will help point the way not just to new treatments but also, hopefully, to ways that those treatments can potentially be tailored to meet the needs of individual patients.”

Heroic three-year study reveals safe methods for growing clinical-grade stem cells

Imagine seeking out the ideal pancake recipe: should you include sugar or no sugar? How about bleached vs. unbleached flour? Baking power or baking soda? When to flip the pancake on the skillet? You really have to test out many parameters to get that perfectly delicious light and fluffy pancake.

Essentially that’s what a CIRM-funded research team from both The Scripps Research Institute (TSRI) and UC San Diego accomplished but instead of making pancakes they were growing stem cells in the lab. In a heroic effect, they spent nearly three years systematically testing out different recipes and found conditions that should be safest for stem cell-based therapies in people. Their findings were reported today in PLOS ONE.

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Pluripotent stem cells. Courtesy of Andres Bratt-Leal from Jeanne Loring’s laboratory.

Let’s step back a bit in this story. If you’re a frequent reader of The Stem Cellar you know that one of the reasons stem cells are such an exciting field of biology is their pluripotency. That is, these nondescript cells have the capacity to become any type of cell in the body (pluri= many; potency = potential). This is true for embryonic stem cells and induced pluripotent cells (iPS). Several clinical trials underway or in development aim to harness this shape-shifting property to return insulin producing cells to people living with diabetes or to restore damaged nerves in victims of spinal cord injury, to name just two examples.

The other defining feature of pluripotent stem cell is their ability to make copies of themselves and grow indefinitely on petri dishes in the laboratory. As they multiply, the cells eventually take up all the real estate on the petri dish. If left alone the cells exhaust their liquid nutrients and die. So the cells must regularly be “passaged”; that is, removed from the dish and split into more dishes to provide new space to grow. This is also necessary for growing up enough quantities of cells for transplantation in people.

Previous small scale studies have observed that particular recipes for growing pluripotent cells can lead to genetic instability, such as deletion or duplication of DNA, that is linked with cancerous growth and tumor formation. This is perhaps the biggest worry about stem cell-based transplantation treatments: that they may cure disease but also cause cancer.

To find the conditions that minimize this genetic instability, the research team embarked on the first large-scale systematic study of the effects of various combinations of cell growth methods. One of the senior authors Louise Laurent, assistant professor at UC San Diego, explained in a press release the importance of this meticulous, quality control study:

“The processes used to maintain and expand stem cell cultures for cell replacement therapies needs to be improved, and the resulting cells carefully tested before use.”

To seek the ideal recipe, the team tested several parameters. For example, they grew some cells on top of so-called “feeder cells”, which help the stem cells grow while other cells used feeder-free conditions. Two different passaging methods were examined: one uses an enzyme solution to strip the cells off the petri dish while in the other method the cells are manually removed. Different liquid nutrients for the cell were included in the study as well. The different combinations of cells were grown continuously through 100 passages and changes in their genetic stability were periodically analyzed along the way.

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Jeanne Loring (above) is professor of developmental neurobiology at TSRI and senior author of the study with Louise Laurent of the University of California, San Diego.

The long-term experiment paid off: the team found that the stem cells grown on feeder free petri dishes and passaged using the enzyme solution accumulated more genetic abnormalities than cells grown on feeder cells and passaged manually. The team also observed genetic changes after many cells passages. In particular, a recurring deletion of a gene called TP53. This gene is responsible for making a protein that acts to suppress cancers. So without this suppressor, later cell passages have the danger of becoming cancerous.

Based on these results, the other senior author, Jeanne Loring, a professor of developmental neurobiology at TSRI, gave this succinct advice:

“If you want to preserve the integrity of the genome, then grow your cells under those conditions with feeder cells and manual passaging. Also, analyze your cells—it’s really easy.”

Shape-Shifting Pancreas Cells Set Stage for Development of Deadly Cancer

After being diagnosed with pancreatic cancer, the likely outcome is—in a word—bleak. At a time when cancers can be treated so successfully as to give the patient a good quality of life, pancreatic cancer remains one of the last holdouts. It is the fourth most deadly form of cancer in the United States. One in four patients won’t last a year.

Pancreatic cancer is one of the most deadly forms of cancer.

Pancreatic cancer is one of the most deadly forms of cancer.

One of the main hurdles for successfully treating this type of cancer is how quickly it spreads. Oftentimes, pancreatic cancer is not diagnosed until having spread to such an extent that even the most aggressive treatments can only delay the inevitable.

As a result, the goal of researchers has been to peer back in time to the origins of pancreatic cancer—in the hopes that they can find a way to halt the disease before it begins to wreak irreversible damage on the body. And now, an international team of researchers believes they have identified a gene that could be the key culprit.

Reporting in the latest issue of Nature Communications, a joint team of scientists from the Mayo Clinic and the University of Oslo, Norway, have pinpointed a gene—called PKD1—that causes normal, healthy pancreatic cells to literally morph into a new, duct-like cell structure. And it is this change in shape that can sometimes lead to pancreatic cancer.

“As soon as pancreatic cancer develops, it begins to spread, and PKD1 is key to both processes,” said Peter Storz, one of the study’s lead authors, in a news release. “Given this finding, we are busy developing a PKD1 inhibitor that we can test further.”

The purpose of the inhibitor, says Storz, is to neutralize PKD1—stopping the cancer in its tracks.

Using pancreatic cells derived from mouse models, the research team tested the effects of PKD1 by turning it on and off at specific intervals, similar to flipping a light switch. In the presence of PKD1, the team observed the pancreas cells rapidly changing shape into the more dangerous, duct-like cells. And when they shut off PKD1, the percentage of cells that underwent shape shifting dropped.

The team’s success at developing this model cannot be understated. As Storz explained:

“This model tells us that PKD1 is essential for the initial transformation…to duct-like cells, which can then become cancerous. If we can stop that transformation from happening—or perhaps reverse the process once it occurs—we may be able to block or treat cancer development and its spread.”

Currently, the teams are developing potential PDK1 inhibitors for further testing—and bring some hope that the prognosis for pancreatic cancer may not always be so dire.

Said Storz: “While these are early days, understanding one of the key drivers in this aggressive cancer is a major step in the right direction.”

Stem cell stories that caught our eye; progress toward artificial brain, teeth may help the blind and obesity

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.

More progress toward artificial brain. A team at the RIKEN Institute in Japan has used stem cells in a 3-D culture to create brain tissue more complex than prior efforts and from an area of the brain not produced before, the cerebellum—that lobe at the lower back of the brain that controls motor function and attention. As far back as 2008, a RIKEN team had created simple tissue that mimicked the cortex, the large surface area that controls memory and language.

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The Inquisitr web portal wrote a feature on a wide variety of efforts to create an artificial brain teeing off of this week’s publication of the cerebellum work in Cell Reports. The piece is fairly comprehensive covering computerized efforts to give robots intelligence and Europe’s Human Brain Project that is trying to map all the activity of the brain as a starting point for recapitulating it in the lab.

The experts interviewed included Robert Caplan of Tufts University in Massachusetts who is using 3-D scaffolding to build functional brain tissues that can process electrical signals. He is not planning any Frankenstein moments; he hopes to create models to improve understanding of brain diseases.

“Ideally we would like to have a laboratory brain system that recapitulates the most devastating diseases. We want to be able to take our existing toolkit of drugs and understand how they work instead of using trial and error.”

Teeth eyed as source of help for the blind. Today the European Union announced the first approval of a stem cell therapy for blindness. And already yesterday a team at the University of Pittsburg announced they had developed a new method to use stem cells to restore vision that could expand the number of patients who could benefit from stem cell therapy.

Many people have lost part or all their vision due to damage to the cornea on the surface of their eye. Even when they can gain vision back through a corneal transplant, their immune system often rejects the new tissue. So the ideal would be making new corneal tissue from the patient’s own cells. The Italian company that garnered the EU approval does this in patients by harvesting some of their own cornea-specific stem cells, called limbal stem cells. But this is only an option if only one eye is impacted by the damage.

The Pittsburgh team thinks it may have found an unlikely alternative source of limbal cells: the dental pulp taken from teeth that have be extracted. It is not as far fetched at it sounds on the surface. Teeth and the cornea both develop in the same section of the embryo, the cranial neural crest. So, they have a common lineage.

The researchers first treated the pulp cells with a solution that makes them turn into the type of cells found in the cornea. Then they created a fiber scaffold shaped like a cornea and seeded the cells on it. Many steps remain before people give up a tooth to regain their sight, but this first milestone points the way and was described in a press release from the journal Stem Cells Translational Medicine, which was picked up by the web site ClinicaSpace.

CIRM funds a project that also proposes to use the patient’s own limbal stem cells but using methods more likely to gain approval of the Food and Drug Administration than those used by the Italian company.

Stem cells and the fight against obesity. Of the two types of stem cells found in your bone marrow, one can form bone and cartilage and, all too often, fat. Preventing these stem cells from maturing into fat may be a tool in the fight against obesity according to a team at Queen Mary University of London.

The conversion of stem cells to fat seems to involve the cilia, or hair-like projections found on cells. When the cilia lengthen the stem cells progress toward becoming fat. But if the researchers genetically prevented that lengthening, they stopped the conversion to fat cells. The findings opens several different ways to think about understanding and curbing obesity says Melis Dalbay one of the authors of the study in a university press release picked up by ScienceNewsline.

“This is the first time that it has been shown that subtle changes in primary cilia structure can influence the differentiation of stem cells into fat. Since primary cilia length can be influenced by various factors including pharmaceuticals, inflammation and even mechanical forces, this study provides new insight into the regulation of fat cell formation and obesity.”

Clearing up chemobrain: cancer therapy-induced memory problems reversed by stem cells

You’d think receiving a cancer diagnosis and then suffering through chemo and/or radiation therapy would be traumatic enough. But as many as 75% of cancer survivors are afflicted by memory and attention problems long after their cancer therapy.

This condition, often called “chemobrain”, shouldn’t be misunderstood as being confined to cancers of the brain. A 2012 analysis of nearly 200 women who had been treated with chemotherapy for breast cancer showed they had ongoing memory and information processing deficits that persisted more than twenty years after their last round of treatment. And young cancer survivors are particularly vulnerable to reduced IQs, nonsocial behavior and an extremely lowered quality of life.

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CIRM grantee and UC Irvine professor Charles Limoli, PhD is senior author of this study

Chemotherapy drugs work by killing off cells that are dividing rapidly, a hallmark of cancer cells. But this brute force method also kills other rapidly dividing cells that are critical for normal bodily functions. In the case of chemobrain, it’s thought that damage to newly formed brain cells in the hippocampus, the memory center of the brain, is the culprit. A UC Irvine study published this week in Cancer Research supports that idea in experiments that test the effect of transplanting human nerve stem cells in rats. The research team leader Charles Limoli, a CIRM grantee and UC Irvine professor of radiation oncology, summarized the groundbreaking results in a press release (note: this study is not funded by CIRM):

“Our findings provide the first solid evidence that transplantation of human neural stem cells can be used to reverse chemotherapeutic-induced damage of healthy tissue in the brain.”

The novel place recognition test is evaluate memory function. Animal is initially presented with identical objects (red circles). Then a new object is introduced (blue square). A healthy mouse will investigate the blue square.

The novel place recognition test, one of several tests used in this study to evaluate memory function.  During training setup (left), the rodent is familiarized with identical objects (red circles). Later, rodent returns now in presence of a new object (blue square). A healthy mouse will investigate the new object during testing setup (right). Image credit: KnowingNeurons.com

So how the heck do you observe chemotherapy-induced cognitive problems in a rodent let alone show that stem cells can rescue the damage? In the study, the rats undergo a variety of recognition memory tasks after a typical chemotherapy drug treatment. For instance, in the novel place recognition test, an animal is familiarized with two identical objects inside a test “arena”. Later, the animal is returned to the arena but a new object is swapped in for one of the previous objects. Rats given chemotherapy treatment but no stem cell surgery (they’re implanted with a saline solution instead) do not show a preference for the novel object. But rats given chemotherapy and the human nerve stem cell surgery prefer the novel object. This novel seeking behavior is also seen in control rats given no chemotherapy. So these results demonstrate that the transplanted stem cells rescued normal memory recognition in the chemotherapy-treated rats.

The research team also saw differences within the brains of these groups of rats that match up with these behavioral results. First, they confirmed that the transplanted human stem cells had indeed survived and grafted into the rat brains and had matured into the correct type of brain cells. Next they looked at chemotherapy-induced inflammation of brain tissue. The brains of chemotherapy-treated rats with no stem cell transplantation showed increased number of active immune cells compared to the control and stem cell transplanted animals. In another experiment, a detailed analysis of the structure of individual nerve cells showed extensive damage in the chemotherapy treated rats compared to controls. Again, this damage was reversed in chemotherapy treated rats that also received the stem cell transplant.

Rat nerve cells (black structures) in memory center of the brain are damaged by chemotherapy (left); transplanting human nerve stem cells reverses the damage (right)

Rat nerve cells (black structures) in memory center of the brain are damaged by chemotherapy (left); transplanting human nerve stem cells reverses the damage (right). Image credit: Acharya et al. Cancer Research 75(4) p. 676

As many researchers can tell you, these exciting results in animals don’t guarantee a human therapy is around the corner. But still, says Limoli:

“This research suggests that stem cell therapies may one day be implemented in the clinic to provide relief to patients suffering from cognitive impairments incurred as a result of their cancer treatments. While much work remains, a clinical trial analyzing the safety of such approaches may be possible within a few years.”

For a more details about the role of stem cells in chemobrain, watch this recent presentation to the CIRM Governing Board by CIRM grantee and Stanford professor Michelle Monje.