Key stem cell gene controlled from afar, Canadian scientists discover

Embryonic stem cells can, by definition, mature into any cell type in the body. They are able to maintain this state of so-called pluripotency with the help of a gene called Sox2. And now, researchers at the University of Toronto (U of T) have discovered the unseen force that controls it. These findings, reported in the latest issue of Genes & Development, offer much-needed understanding of the steps a cell must take as it grows up.

Mouse embryonic stem cells grown in a round colony of cells (A) and express Sox2 (B), shown in red. Sox2 control region (SCR)-deleted cells have lost the typical appearance of embryonic stem cells (C) and do not express Sox2 (D). [Credit: Jennifer Mitchell/University of Toronto]

Mouse embryonic stem cells grown in a round colony of cells (A) and express Sox2 (B), shown in red. Sox2 control region (SCR)-deleted cells have lost the typical appearance of embryonic stem cells (C) and do not express Sox2 (D). [Credit: Jennifer Mitchell/University of Toronto]

Led by U of T Professor Jennifer Mitchell, the research team were, for the first time, able to identify the specific molecular regulator that switched the Sox2 gene on and off at specific times during an embryonic cell’s lifetime. As Mitchell explained:

“We studied how the Sox2 gene is turned on in mice, and found the region of the genome that is needed to turn the gene on in embryonic stem cells. Like the gene itself, this region of the genome enables these stem cells to maintain their ability to become any type of cell.”

The team named this region the Sox2 control region, or SCR.

For the last decade scientists have been using knowledge gleaned from the Human Genome Project to map how and when genes are switched on and off. Interestingly, the regions that control the gene in question aren’t always located close by.

This was the case with Sox2, said Mitchell. Early on, researchers had argued that Sox2 was regulated from nearby. But in this study, the team found the SCR, which controls Sox2, to be located more than 100,000 DNA base pairs away. According to Mitchell, the process by which the SCR activates Sox2 is fascinating:

“To contact the gene, the DNA makes a loop that brings the SCR close to the gene itself only in embryonic stem cells… It is possible that the formation of the loop needed to make contact with the Sox2 gene is an important final step in the process by which researchers practicing regenerative medicine can generate pluripotent cells from adult cells.”

Indeed, despite a flurry of research breakthroughs and a promising number of clinical trials moving forward, there are still some fundamental aspects of stem cell biology that remain unknown. This discovery, argues Mitchell, is an important step towards reaching toward improving the way in which scientists manipulate stem cells to treat disease.

A time to kill, a time to heal: cells linked to aging also help heal wounds

Senescent cells, so called because of the role they play in the aging process, have acquired a bit of a bad reputation.

Yet new research from the Buck Institute suggests that these cells may not be so bad after all.

Buck Institute faculty Judith Campisi and Postdoc Marco Demaria. [Credit: The Buck Institute]

Buck Institute Professor Judith Campisi and Postdoc Marco Demaria. [Credit: The Buck Institute]

Reporting in today’s issue of Developmental Cell, Buck Institute scientists have found that, while senescent cells do indeed contribute to cellular aging and age-related diseases, they also play an important role in healing wounds. Furthermore, the team has identified the specific molecule in senescent cells that does the healing—pointing to a new therapy that could harness the good aspects of senescent cells, while flushing out the bad.

As we age, so do our cells. During cellular senescence, cells begin to lose their ability to grow and divide. The number of so-called senescent cells accumulates over time, releasing molecules thought to contribute to aging and age-related diseases such as arthritis and some forms of cancer.

But experiments led by Buck Institute Professor Judith Campisi and postdoctoral fellow Marco Demaria revealed that following a skin wound, cells that produce collagen and that line the blood vessels become senescent, and lose the ability to divide. Instead, they accelerate wound healing by secreting a growth factor called PDGF-AA. And once the wound was healed, the cells lost their senescence and shifted back into their normal state.

Because cellular senescence has long been linked to aging and age-related diseases, some research has been focused on finding ways to flush out senescent cells entirely. But the findings by the Buck Institute team throw a wrench in that idea, by revealing that these cells do in fact serve an important purpose.

According to Campisi, there is still a lot to learn:

“It is essential that we understand the full impact of senescence. The possibility of eliminating senescent cells holds great promise and is one of the most exciting avenues currently being explored in efforts to extend healthspan. This study shows that we can likely harness the positive aspects of senescence to ensure that future treatments truly do no harm.”

Finding the Sweet Spot: shifting metabolism keeps stem cells in suspended animation

The future is bright for a stem cell: it has the potential to become almost anything. This potential is one of its two defining characteristics. The second is that it can create copies of itself over and over again.

Researchers are announcing a new breakthrough on how best to keep embryonic stem cells (above) in a state of suspended animation.

Researchers are announcing a new breakthrough on how best to keep embryonic stem cells (above) in a state of suspended animation.

This second characteristic, known as the ability to self-renew, is of particular importance to researchers. After all, if they are to use stem cell technology to heal injury and treat disease, they must figure out how to keep them suspended in this embryonic state, so that large quantities can be grown in order to manufacture enough treatments for all who need them.

Unfortunately, that is easier said than done. But scientists have made extraordinary progress, developing a specific, nutrient-rich environment—a ‘medium’ called 2i—that can keep cells in a suspended, animation-like state.

The only problem was that they didn’t know why it worked.

Enter a joint team of scientists from The Rockefeller University and Memorial Sloan Kettering Cancer Center in New York, who today announce in the journal Nature that they may have cracked the case. According to team leader C. David Allis, it all comes down to the cell’s metabolism.

A cell’s metabolism is not unlike our body’s metabolism, though on a much smaller scale. Cellular metabolism refers to the process by which chemical reactions transform food into energy and other cellular products through something called the Citric Acid Cycle. The faster the cells’ metabolism, the faster the cycle produces energy, and vice versa.

Previously, scientists had observed a connection between the Citric Acid Cycle and the way in which a cell’s DNA was bundled into what is known as chromatin.

Embryonic stem cells (ES cells) have a different chromatin structure than mature, differentiated cells. This allows for heightened gene expression. [Credit: stembook.org]

Embryonic stem cells (ES cells) have a different chromatin structure than mature, differentiated cells. This allows for heightened gene expression. [Credit: stembook.org]

Chromatin is made by winding DNA strands around proteins called histones, much like winding strands of yarn around a tennis ball. The pattern in which DNA is organized into the chromatin structure is crucial: it affects which genes are switched on and off, and when.

For genes to become activated, or ‘expressed,’ they must be physically accessible within the chromatin structure. Postdoctoral researcher and co-first author Bryce Carey hypothesized that speeding up or slowing down a cell’s metabolism was responsible for which genes were accessible, and could therefore become activated. As he explained in a news release:

“What if, in stem cells, the changes to chromatin reflect a unique metabolism that helps to drive reactions that help to keep chromatin accessible? This connection would explain how embryonic stem cells are uniquely poised to activate so much of their genomes.”

To pinpoint the exact connection between metabolism and gene expression, Carey and co-first author Lydia Finley compared the metabolic functions of embryonic stem cells grown in the 2i medium and compared them to cells grown in a traditional medium made from bovine serum.

When study authors Bryce Carey (left) and Lydia Finley (right) exposed mouse embryonic stem cells to the metabolite alpha-ketoglutarate, those cells became more likely to renew themselves, appearing as pink colonies on the screen. This is one of the first demonstrations that a metabolite can influence the fate of stem cells. [Credit: Zach Veilleux / The Rockefeller University]

When study authors Bryce Carey (left) and Lydia Finley (right) exposed mouse embryonic stem cells to the metabolite alpha-ketoglutarate, those cells became more likely to renew themselves, appearing as pink colonies on the screen. This is one of the first demonstrations that a metabolite can influence the fate of stem cells. [Credit: Zach Veilleux / The Rockefeller University]

Surprisingly, the team found that the 2i cells were producing energy at staggering levels—through a molecular shortcut that cut out an entire step of the Citric Acid Cycle. This shortcut boosted the production of a protein called alpha-ketoglutarate, which in turn spurred more efficient energy production. It was as if the 2i medium instilled these embryonic stem cells with super powers.

Alpha-ketoglutarate appeared to be the key to shifting cells’ metabolism so that the right genes are expressed—thus keeping the cell in an embryonic state. Even cells growing in the traditional, bovine serum medium became supercharged when given a healthy dose of alpha-ketoglutarate.

These results not only solve a long-standing mystery of why the 2i medium was so superior for growing stem cells, they also pinpoint the particular protein—alpha-ketoglutarate—that is at the heart of this difference. This discovery, according to Allis, moves us closer to developing stem cell-based treatments in the clinic:

“This newly established link between metabolism and stem cell fate improves our understanding of development and regeneration, which may, in turn, bring us a little closer to harnessing stem cells’ ability to generate new tissue as a way to, for example, heal spinal cord injuries or cure Type 1 diabetes. It may also add a new dimension to our understanding of cancer, in which differentiated cells erroneously take on stem-cell like properties.”

Stem Cell Stories that Caught our Eye: Stem Cell Summit Roundup, Spinal Cords in a Dish and Stem Cell Tourism in the NFL

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.

Success at the World Stem Cell Summit. This week some of the biggest names in regenerative medicine descended upon San Antonio, Texas for the annual summit. Along with researchers from the world’s top universities, institutions and companies were members of CIRM, including CIRM President and CEO C. Randall Mills.

We’ve been publishing top highlights from the Summit all week here on the Stem Cellar. There’s also been detailed coverage in the local San Antonio press, including the local ABC station. And if you’d like to find out more about this year’s conference, be sure to visit @WSCSummit and #WSC14 on Twitter.

Scientists have found a way to grow spinal cords from embryonic stem cells in a petri dish. [Credit: Abigail Tucker/ MRC Centre for Developmental Neurobiology/ Wellcome Images.]

Scientists have found a way to grow spinal cords from embryonic stem cells in a petri dish. [Credit: Abigail Tucker/ MRC Centre for Developmental Neurobiology/ Wellcome Images.]

Growing Spinal Cords in the Lab. Tissue engineering, the process of using stem cells to build new tissues and organs, has been the Holy Grail for regenerative medicine. And while there has been some progress with engineering some organs, others—especially the spinal cord—have proven far more difficult. This is because the biodegradable scaffolding cannot be made correctly to grow complex and intricately connected nerve cells.

But now, a research team in Germany has grown complete spinal cords in the lab, pointing to a new strategy for treating those with irreparable spinal cord injuries.

As reported in The Guardian this week, Andrea Meinhardt of the Dresden University of Technology and her colleagues worked around the problem of scaffolding by employing a new method called self-directed morphogenesis, first developed by the late Yoshiki Sasai. According to The Guardian‘s Mo Costandi:

“Self-directed morphogenesis is a method for growing embryonic stem cells in a three-dimensional suspension. Cells grown in this way can, when fed the right combination of signaling molecules, go through the motions of development and organize themselves to form complex tissues such as eyes, glands and bits of brain.”

While preliminary, this research offers immense promise towards the ultimate goal: reversing the devastating effects of spinal cord injuries.

Stem Cells and the NFL. Despite the best efforts of experts, stem cell tourism continues to proliferate. A new study published this week in 2014 World Stem Cell Report (a special supplement to Stem Cells and Development) describes the latest example of people seeking unproven stem cell treatments: this time in the NFL.

New research from Rice University is suggesting that some NFL players are seeking out unproven stem cell treatments—oftentimes traveling abroad without fully understanding the risks. This poses serious problems not only for players but also for the NFL as a whole. As Co-lead author Kirsten Matthews elaborated in a news release:

“With the rise of new and unproven stem cell treatments, the NFL faces a daunting task of trying to better understand and regulate the use of these therapies in order to protect the health of its players.”

Specifically, 12 NFL players are known to have received unproven treatments at some point during the last five years, including star quarterback Peyton Manning who we’ve blogged about before The authors caution that high-profile players broadcasting that they are receiving these unproven therapies could influence regular patients who are also desperate for cures.

In order to fix this growing problem, the authors recommend the NFL review and investigate these unproven stem cell treatments with the help of an independent committee of medical professionals. Finally, they suggest that the NFL could support stem cell research here in the United States—so that proven, effective stem cell-based treatments could more quickly enter the clinic.

At World Stem Cell Summit improvements in the precision with which we can edit our genes grabs spotlight

Just a day and a half into this year’s World Stem Cell Summit in San Antonio and there have been numerous highlights. But a pair of sessions on gene editing grabbed the attention of many of the scientists at the meeting. One of the renown leaders in the field, Harvard’s George Church wowed the scientists, but I fear the heavy dose of scientific detail may have overwhelmed many of the patient advocates that make the attendee mix at this meeting special.

George Church speaking recently [Credit: PopTech.org]

George Church speaking recently [Credit: PopTech.org]

In 2013, Church first published results using a new gene-editing tool he helped perfect called CRISPR, and almost immediately it became the most talked-about tool for advancing stem cell research. As powerful as stem cells may be by themselves, in many situations, they become even more powerful—especially if you use them to deliver a gene that corrects an error in a patient’s cells. Before 2013 we had a few ways to edit genes in living cells and all were modestly effective at making the desired change and relatively specific in making only a few unwanted changes, called “off target” edits.

In some uses, particularly when cells are being modified in the lab for specific and small targets, these other editing techniques are probably OK. This is what several CIRM-funded teams (links) are doing with diseases like sickle cell anemia and HIV, where you can target blood-forming stem cells and even giving a small percentage the proper gene edit may be sufficient to cure the disease. But with something like muscular dystrophy where the gene editing would be required throughout the body and have to be done in the patient not in the lab, you need to improve the efficiency and precision.

CRISPR/Cas9 [Credit: University of California, San Francisco]

CRISPR/Cas9 [Credit: University of California, San Francisco]

After that first publication CRISPR was viewed as a home run in efficiency, taking the number of cells with the gene correction from a few percent to 50 percent or more. But it still had off-target effects. Yet only a year after the technology was introduced, a few teams developed so-called “next generation” CRISPR that comes close to perfect precision, causing an unintended edit in just one in a billion cells, by Church’s estimate.

I have never seen the full name of CRISPR spelled out in a scientific presentation, and after a visit to Wikipedia I know why. Here it is: Clustered Regularly Interspersed Short Palindromic Repeats. Basically, Church took advantage of something that occurs naturally in many bacteria. Just as we are susceptible to viruses, bacteria have their version known as phages. When those parasites integrate their DNA into the bacteria’s genes, part of the bacterial DNA forms CRISPRs that can partner with a protein called Cas to cut the phage DNA and keep the phage from hurting the host bacteria.

In a research setting, creating that “nick” in the DNA is the first step in harnessing CRISPR to insert a desired gene. So, that extreme precision in finding spots on our DNA where we want to create an opening for inserting a new gene became this valuable research tool. It can create a nick as precise as a single nucleotide base, the building blocks of our DNA.

Church and two additional speakers gave detailed descriptions about how the technology has improved and how it is being used to model disease today and is expected to be used to treat disease in the near future. An exciting future is in store.

Don Gibbons

Truth or Consequences: how to spot a liar and what to do once you catch them

Nothing undermines the credibility of science and scientists more than the retraction a high profile paper. Earlier this year there was a prime example of that when researchers at one of Japan’s most prestigious research institutions, the Riken Center for Developmental Biology in Kobe, had to retract a study that had gathered worldwide attention. The study, about a new method for creating embryonic-like stem cells called stimulus triggered acquisition of pluripotency or STAP, was discredited after it was discovered that the lead author had falsified data.

Publication retractions have increased dramatically in recent years [Credit: PMRetract]

Publication retractions have increased dramatically in recent years [Credit: PMRetract]

The STAP incident drew international coverage and condemnation and raised the question, how common is this and what can be done to combat it? A panel discussion at the World Stem Cell Summit in San Antonio, Texas entitled “Reproducibility and rigor in research: What have we learned from the STAP debacle” tackled the subject head on.

Ivan Oransky, medical journalist and the co-founder of the website Retraction Watch posed the question “Does stem cell research have a retraction problem?” He says:

“The answer to my question is yes. But so does everyone else. All of science has a retraction problem, not just stem cells.”

Oransky says the number of retractions has doubled from 2001 to 2010. One author has retracted 183 times – the record so far – but to break into the top 5 you need to have at least 50 retractions. These come from all over the world from the US to Germany and Japan and most recently Azerbaijan.

Oransky says part of the problem is the system itself. Getting your research results published is critical to advancing a career in science and those kinds of pressures force people to cut corners, take risks or even just falsify data and manipulate images in order to get a paper into a high profile journal. In most cases, journals charge a fee of several hundred to thousands of dollars to publish studies, so they have no incentive to dig too deeply into findings looking for flaws, as it might undermine their own business model.

“Some authors, more than 100, have been caught reviewing their own papers. When the journal they were submitting their paper to asked for the names of recommended reviewers they would submit the names of people who are legitimate reviewers in the field but instead of giving real email addresses they would give fake email addresses, ones they controlled so they could submit their own reviews under someone else’s name.”

What gave them away is that all the potential “reviewers” didn’t first reply and say “yes, I’ll review”, instead they responded by sending back a full review of the paper, raising suspicions and ultimately to detection.

Graham Parker, a researcher at Wayne State University School of Medicine and the editor of Stem Cell and Development says spotting the problem is not always easy:

“As an editor I regard scientific misconduct as fabrication, falsification or plagiarism of data but there are lots of other areas where it’s not always so clear – there are often shades of gray”

He says researchers may make an honest mistake, or include duplicative images and in those cases should be allowed to fix the problems without any stigma attached. But when serious cases of falsification of data are uncovered they can have a big impact by retarding scientific progress and sapping public confidence in the field as a whole.

Jeanne Loring, a stem cell scientist at The Scripps Research Institute and a recipient of funding from CIRM, says the STAP incident was actually a sign of progress in this area. Ten years ago when a Korean researcher named Hwang Woo-Suk claimed to have cloned human embryos it took more than a year before he was found to have falsified the data. But in the STAP case it took a little over a week for other researchers to start raising red flags:

“One of the real heroes in this story is Paul Knoepfler (a CIRM-funded researcher at UC Davis) who takes on difficult issues in his blog. It took Paul just 8 days to post a request for people to crowdsource this study, asking people who were trying to replicate the findings to report their results – and they did, showing they failed over and over again”

Parker said it’s getting easier for editors and others in the field to double check data in studies. For example new software programs allow him to quickly check submitted manuscripts for plagiarism. And he says there is a growing number of people who enjoy looking for problems.

“Nowadays it’s so easy for people to dig very deeply into papers and check up on every aspect of it, from the content to the methodology to the images they use and whether those images were in any way manipulated to create a false impression. Once they find a problem with one paper they’ll dig back through papers in that scientist’s past to see if they can find other problems dating back years that were never found at the time.”

He says that in most cases researchers caught falsifying data or deliberately misleading journals faced few consequences:

“Often the consequences of misconduct are very mild, the equivalent of a slap on the wrist, which does not discourage others from trying to do the same.”

Each panel member says that tougher penalties are needed. For example, in extreme cases a threat of criminal action could be warranted, if the falsified research could lead to serious consequences for patients.

But the panel ended on an encouraging note. Oransky says, for example, that medical journals are now paying more attention and imposing stricter rules and he says there’s even scientific evidence that “doing the right thing might pay off.”

“One study recently showed that if you made an honest error and corrected it publicly not only does the stigma of retraction not apply to you, you don’t get a decrease in your citations—you actually get an increase. So we’d like to think that doing the right thing is a good thing and might actually be a positive thing.”

Taking Promising Therapies out of the Lab and into People: Tips from Experts at the World Stem Cell Summit on How to Succeed

Having a great idea for a stem cell therapy is the easy part. Getting it to work in the lab is tougher. But sometimes the toughest part of all is getting it out of the lab and into clinical trials in patients. That’s natural and sensible, after all we need to make sure that something seems safe before even trying it in people. But how do you overcome all the challenges you face along the way? That was the topic of one of the panel discussions at the World Stem Cell Summit in San Antonio, Texas.

Rick Blume is the Managing Director at Excel Venture Management, and someone with decades of experience in investing in healthcare companies. He says researchers face numerous hurdles in trying to move even the most promising therapies through the approval and regulatory process, only some of which are medical. Blume says:

“Great ideas can become great companies. And good Venture Capitalists (VCs) can help with that process, but the researchers have to overcome technical, funding and logistical hurdles before VCs are usually ready to move in and help.”

Of course that’s where agencies and organizations like CIRM come in. We help fund the early stage research, helping researchers overcome those hurdles and getting promising therapies to a point where VCs and other large investors are willing to step in.

Left to right: Geoff Crouse CEO of Cord Blood Registry, C. Randal Mills, President and CEO of CIRM, Rick Blume of Excel Venture Management and Anthony Atala of Wake Forest University Medical Center

Left to right: Geoff Crouse CEO of Cord Blood Registry, C. Randal Mills, President and CEO of CIRM, Rick Blume of Excel Venture Management and Anthony Atala of Wake Forest University Medical Center

Geoff Crouse, the CEO of the Cord Blood Registry, says researchers need to be increasingly imaginative when looking for funding these days.

“While Federal funding for this kind of research is drying up, there are alternatives such as CIRM and philanthropic investors who are not just seeking to make active investments but are also trying to change the world, so they offer alternatives to more traditional sources of funding. You have to look broadly at your funding opportunities and see what you want to do.”

C. Randal Mills, the President and CEO of CIRM said too many people get caught up looking at the number of challenges that any project faces when it starts out:

“The single most important thing that you need to do is to show that the treatment works in people with unmet medical needs, that it is safe. If you can do that, all the other problems, the cost of the therapy, how to market it, how to get reimbursed for it, those will all be resolved in time. But first you have to make it work, then you can make it work better and more efficiently.”

The panel all agreed that one of the areas that needs attention is the approval and regulatory process saying the Food and Drug Administration (FDA) the regulatory body governing this field, needs to adjust its basic “one size fits all” paradigm.”

Mills says the FDA is in a difficult position:

“Everyone wants three things; they want fast drugs, they want cheap drugs and they want perfect drugs. The problem is you can’t have all three. You can have two but not all three and that puts the FDA into an almost impossible position because if therapies aren’t approved quickly they are criticized but if they are approved and later show problems then the FDA is criticized again.”

Often the easiest way to get a traditional drug therapy approved for use is to ask for a “humanitarian exemption”, particularly for an orphan disease that has a relatively small number of people suffering from it and no alternative therapies. But when it comes to more complex products knows as biologics, which includes stem cell therapies, this humanitarian exemption does not exist making approval much harder to obtain, slowing down the field.

Mills says other countries, such as Japan, have made adjustments to the way they regulate new therapies such as stem cells and he hopes the FDA will learn from that and make similar modifications to the way they see these therapies.

All three panelists were optimistic that the field is making good progress, and will continue to advance. Good news for the many patient advocates attending the World Stem Cell Summit who are waiting for treatments for themselves or loved ones.

At World Stem Cell Summit: Why results in trials repairing hearts are so uneven

Just as no two people are the same, neither are the cells in their bone marrow, the most common source of stem cells in clinical trials trying to repair damage after a heart attack. Doris Taylor of the Texas Heart Institute in Houston, which is just a couple hours drive from the site of this year’s World Stem Cell Summit in San Antonio, gave a key note address this morning that offered some good reasons for the variable and often disappointing results in those trials, as well as some ways to improve on those results.

THI's Dr. Doris Taylor

THI’s Dr. Doris Taylor

The cells given in a transplant derived from the patient’s own bone marrow contain just a few percent stem cells and a mix of adult cells, but for both the stem and adult cells the mix is highly variable. Taylor said that in essence we are giving each patient a different drug. She discussed a series of early clinical trials in which cell samples from each patient were banked at the National Heart and Lung and Blood Institute. There they could do genetic and other analysis on the cells and compare that data with how each individual patient faired.

In looking at the few patients in each trial that did better on any one of three measures of improved heart function, they were indeed able to find certain markers that predicted better outcome. In particular they looked at “triple responders,” those who improved in all three measures of heart function. They found there were both certain types of adult cells and certain types of stem cells that seemed to result in improved heart health.

They also found that two of the strongest predictors were gender and age. Women generally develop degenerative diseases of aging like heart disease at an older age than men and since many consider aging to be a failure of our adult stem cells, it would make sense that women have healthier stem cells.

Taylor went on to discuss ways to use this knowledge to improve therapy outcomes. One way would be to select for the more potent cells identified in the NHLBI analysis. She mentioned a couple trials that did show better outcomes using cells derived from heart tissue. One of those is work that CIRM funds at Cedars-Sinai in Los Angeles.

Another option is replace the whole heart and she closed with a review of what is probably her best-known work, trying to just that. In rats and pigs, she has taken donor hearts and used soap-like solutions to wash away the living cells so that all that is left behind are the proteins and sugars that make of the matrix between cells. She then repopulates the scaffolds that still have the outlines of the chambers of the heart and the blood vessels that feed them, with cells from the recipient animal. She has achieved partially functional organs but not fully functional ones. She—along with other teams around the world—is working on the remaining hurdles to get a heart suitable for transplant.

Don Gibbons

Searching for a Cure for HIV/AIDS: Stem Cells and World AIDS Day

World-AIDS-Day

It’s been 26 years since the first World AIDS Day was held in 1988—and the progress that the international scientific community has made towards eradicating the disease has been unparalleled. But there is much more work to be done.

One of the most promising areas of HIV/AIDS research has been in the field of regenerative medicine. As you observe World AIDS Day today, we invite you to take a look at some recent advances from CIRM-funded scientists and programs that are well on their way to finding ways to slow, halt and prevent the spread of HIV/AIDS:

Calimmune’s stem cell gene modification study continues to enroll patients, show promise:
Calimmune Approved to Treat Second Group in HIV Stem Cell Gene Modification Study

Is a cure for HIV/AIDS possible? Last year’s public forum discusses the latest on HIV cure research:


Town Hall: HIV Cure Research

The Stem Cell Agency’s HIV/AIDS Fact Sheet summarizes the latest advances in regenerative medicine to slow the spread of the disease.

And for more on World AIDS Day, follow #WorldAIDSDay on Twitter and visit WorldAIDSDay.org.

Using stem cells paves new approach to treating a blistering skin disease

Imagine a child not being able to run or jump or just roll around, for fear that any movement could strip away their skin and leave them with open, painful wounds. That’s what life is like for children with a nasty genetic disease called epidermolysis bullosa or EB. The slightest touch can cause their skin to peel off. People with the disease often die in their late teens or early 20’s from skin cancer, caused by repeated cycles of skin wounding and healing.

Now Stanford researchers, funded by the stem cell agency, have found a way to correct the faulty gene and grow healthy skin, a technique that could completely change the lives of children with EB. This new approach, which the researchers call “therapeutic reprogramming”, is reported in the journal Science Translational Medicine

In the study the researchers took skin cells from patients with EB and reprogrammed them to become induced pluripotent stem (iPS) cells that have the ability to become any of the other cells in the body. They then replaced the faulty gene that caused that particular form of EB and then turned the cells into keratinocytes, the cells that make up most of our outer layer of skin. When they grafted these cells onto the back of laboratory mice they grew into normal human skin.

In a news release about the work, Dr. Anthony Oro, one of the senior authors of the paper, says the work represents a completely different approach to treating EB.

“Normally, treatment has been confined to surgical approaches to repair damaged skin, or medical approaches to prevent and repair damage. But by replacing the faulty gene with a correct version in stem cells, and then converting those corrected stem cells to keratinocytes, we have the possibility of achieving a permanent fix — replacing damaged areas with healthy, perfectly matched skin grafts.”

One of the key words in that quote is “healthy”. Because the skin cells that they got from the patient probably already included some that had a skin cancer-causing mutation, the researchers carefully screened the cells to make sure they removed any that looked suspicious.

Oro says tests showed the resulting skin from these iPS cells was very similar to human skin made from normal keratinocytes.

“The most difficult part of this procedure is to show not just that you can make keratinocytes from the corrected stem cells, but that you can then use them to make graftable skin. What we’d love to do is to be able to give patients healthy skin grafts on the areas that they bang a lot, such as hands and feet and elbows — those places that don’t heal well. That alone would significantly improve our patients’ lives. We don’t know how long these grafts might last in humans; we may need some improvements. But I think we’re getting very close.”

Having seen that this works in mice the team are now eager to see if they can replicate their results in people. With CIRM support they have already been working with the Food and Drug Administration (FDA) to pave the way for that to happen. Dr. Marius Wernig, one of the senior authors of the paper, says that focus on patients is driving their work:

“CIRM made sure that we were always keeping in mind the need to translate our results to the clinic. Now we’ve shown that this approach that we call ‘therapeutic reprogramming’ works well with human cells. We can indeed take skin cells from people with epidermolysis bullosa, convert them to iPS cells, replace the faulty collagen 7 gene with a new copy, and then finally convert these cells to keratinocytes to generate human skin. It is almost like a fountain of youth that, in principle, produces an endless supply of new, healthy skin from a patient’s own cells.”