Stories that caught our eye: $20.5 million in new CIRM discovery awards, sickle cell disease cell bank, iPSC insights

CIRM Board launches a new voyage of Discovery (Kevin McCormack).
Basic or early stage research is the Rodney Dangerfield of science; it rarely gets the respect it deserves. Yesterday, the CIRM governing Board showed that it not only respects this research, but also values its role in laying the foundation for everything that follows.

The CIRM Board approved 11 projects, investing more than $20.5 million in our Discovery Quest, early stage research program. Those include programs using gene editing techniques to develop a cure for a rare but fatal childhood disease, finding a new approach to slowing down the progress of Parkinson’s disease, and developing a treatment for the Zika virus.

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Electron micrograph of Zika virus (red circles). Image: CDC/Cynthia Goldsmith

The goal of the Discovery Quest program is to identify and explore promising new stem cell therapies or technologies to improve patient care.

In a news release Randy Mills, CIRM’s President & CEO, said we hope this program will create a pipeline of projects that will ultimately lead to clinical trials:

“At CIRM we never underestimate the importance of early stage scientific research; it is the birth place of groundbreaking discoveries. We hope these Quest awards will not only help these incredibly creative researchers deepen our understanding of several different diseases, but also lead to new approaches on how best to use stem cells to develop treatments.”

Creating the world’s largest stem cell bank for sickle cell disease (Karen Ring).
People typically visit the bank to deposit or take out cash, but with advancements in scientific research, people could soon be visiting banks to receive life-saving stem cell treatments. One of these banks is already in the works. Scientists at the Center for Regenerative Medicine (CReM) at Boston Medical Center are attempting to generate the world’s largest stem cell bank focused specifically on sickle cell disease (SCD), a rare genetic blood disorder that causes red blood cells to take on an abnormal shape and can cause intense pain and severe organ damage in patients.

To set up their bank, the team is collecting blood samples from SCD patients with diverse ethnic backgrounds and making induced pluripotent stem cells (iPSCs) from these samples. These patient stem cell lines will be used to unravel new clues into why this disease occurs and to develop new potential treatments for SCD. More details about this new SCD iPSC bank can be found in the latest edition of the journal Stem Cell Reports.

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Gustavo Mostoslavsky, M.D., PH.D., Martin Steinberg, M.D., George Murphy PH.D.
Photo: Boston Medical Center

In a news release, CReM co-founder and Professor, Gustavo Mostoslavsky, touched on the future importance of their new stem cell bank:

“In addition to the library, we’ve designed and are using gene editing tools to correct the sickle hemoglobin mutation using the stem cell lines. When coupled with corrected sickle cell disease specific iPSCs, these tools could one day provide a functional cure for the disorder.”

For researchers interested in using these new stem cell lines, CReM is making them available to researchers around the world as part of the NIH’s NextGen Consortium study.

DNA deep dive reveals ways to increase iPSC efficiency (Todd Dubnicoff)
Though the induced pluripotent stem (iPS) cell technique was first described ten years ago, many researchers continue to poke, prod and tinker with the method which reprograms an adult cell, often from skin, into an embryonic stem cell-like state which can specialize into any cell type in the body. Though this breakthrough in stem cell research is helping scientists better understand human disease and develop patient-specific therapies, the technique is hampered by its low efficiency and consistency.

This week, a CIRM-funded study from UCLA reports new insights into the molecular changes that occur during reprogramming that may help pave the way toward better iPS cell methods. The study, published in Cell, examined the changes in DNA during the reprogramming process.

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Senior authors Kathrin Plath and Jason Ernst and first authors Petko Fiziev and Constantinos Chronis.
Photo: UCLA

In a skin cell, the genes necessary for embryonic stem cell-like, or pluripotent, characteristics are all turned off. One way this shut down in gene activity occurs is through tight coiling of the DNA where the pluripotent genes are located. This physically blocks proteins called transcriptions factors from binding the DNA and activating those pluripotent genes within skin cells. On the other hand, regions of DNA carrying skin-related genes are loosely coiled, so that transcription factors can access the DNA and turn on those genes.

The iPS cell technique works by artificially adding four pluripotent transcriptions factors into skin cells which leads to changes in DNA coiling such that skin-specific genes are turned off and pluripotent genes are turned on. The UCLA team carefully mapped the areas where the transcription factors are binding to DNA during the reprogramming process. They found that the shut down of the skin genes and activation of the pluripotent genes occurs at the same time. The team also found that three of the four iPS cell factors must physically interact with each other to locate and activate the areas of DNA that are responsible for reprogramming.

Using the findings from those experiments, the team was able to identify a fifth transcription factor that helps shut down the skin-specific gene more effectively and, in turn, saw a hundred-fold increase in reprogramming efficiency. These results promise to help the researchers fine-tune the iPS cell technique and make its clinical use more practical.

Stem cell stories that caught our eye: designer socks for cancer patients, stem-cell derived stomachs and fighting off bone infections

Inspiring cancer patients with designer socks. (Karen Ring)
Here’s a motivating story we found in the news this week about a cancer survivor who’s bringing inspiration to other cancer patients with designer socks. Yes, you read that correctly, socks.

Jake Teitelbaum is a student at Wake Forest University and suffers from a rare form of blood cancer called Refractory Hodgkin’s lymphoma. Since his diagnosis, Jake has been admitted to hospitals multiple times. Each time he received a welcome package of a gown and a pair of beige, “lifeless” socks. After his fifth welcome package, this time to receive a life-saving stem cell treatment, Jake had had enough of the socks.

He explained in a story by USA Today College,

“[Those socks] represented chemotherapy and being in isolation. They were the embodiment of that experience.”

Jake ditched the hospital socks and started bringing his own to prove that his cancer didn’t define him. Even though his cancer kept coming back, Jake wanted to prove he was just as resilient.

Jake Teitelbaum

Jake Teitelbaum

Feeling liberated and in control, Jake decided to share his socks with other patients by starting the Resilience Project. Patients can go to the Resilience website and design their own socks that represent their experiences with cancer. The Resilience project also raises money for cancer patients and their families.

“We provide tangible benefits and create fun socks, but what we’re doing comes back to the essence of resilience,” said Jake. “These terrible circumstances where we’re at our most vulnerable also give us the unique opportunity to grow.”

Jake was declared cancer free in October of 2016. You can learn more about the Resilience project on their website and by watching Jake’s video below.

 

Feeding disease knowledge with stem cell-derived stomach cells.
Using educated guess work and plenty of trial and error in the lab, researchers around the world have successfully generated many human tissues from stem cells, including heart muscle cells, insulin-producing cells and nerve cells to name just a few. Reporting this week in Nature, stem cell scientists at Cincinnati’s Children Hospital have a new cell type under their belt. Or maybe I should say above their belt, because they have devised a method for coaxing stem cells to become stomach mini organs that can be studied in a petri dish.

Confocal microscopic image shows tissue-engineered human stomach tissues from the corpus/fundus region, which produce acid and digestive enzymes. Image: Cincinnati Children’s Hospital Medical Center

Confocal microscopic image shows tissue-engineered human stomach tissues from the corpus/fundus region, which produce acid and digestive enzymes. Image: Cincinnati Children’s Hospital Medical Center

With this method in hand, the team is poised to make new discoveries about how the stomach forms during human development and to better understand stomach diseases. In a press release, team lead Jim Wells pointed out the need to find new therapies for stomach disease:

“Diseases of the stomach impact millions of people in the United States and gastric [stomach] cancer is the third leading cause of cancer-related deaths worldwide.”

The cells they generated are those found in the corpus/fundus area of the stomach which releases enzymes and hydrochloric acid to help us break down and digest the food we eat. The team is particularly interested to use the mini organs to study the impact of H. pylori infection, a type of bacteria that causes ulcers and has been linked to stomach cancers.

In an earlier study, Wells’ group devised stem cell recipes for making cells from an area of the stomach, called the antrum, that produces hormones that affect digestion and appetite. Wells thinks having both tissue types recreated in a petri dish may help provide a complete picture of stomach function:

James Wells

James Wells

“Now that we can grow both antral- and corpus/fundic-type human gastric mini-organs, it’s possible to study how these human gastric tissues interact physiologically, respond differently to infection, injury and react to pharmacologic treatments.”

 

 

A silver bullet for antibiotic-resistant bone infections?
Alexander Fleming’s discover of penicillin in the 1920’s marked the dawn of antibiotics – drugs which kill off bacteria and help stop infections. Rough estimates suggest that over 200 million lives have been saved by these wonder drugs. But over time there’s been a frightening rise in bacteria that are resistant to almost all available antibiotics.

These super resistant “bugs” are particularly scary for people with chronic bone infections because the intense, long term antibiotic medication required to keep the infection in check isn’t effective. But based on research published this week in Tissue Engineering, the use of stem cells and silver may provide a new treatment option.

Scanning Electron micrograph of methicillin-resistant Staphylococcus aureus (MRSA, brown spheres) surrounded by cellular debris. MRSA, the bacteria examined in this study, is resistant by many antibiotics

Scanning Electron micrograph of methicillin-resistant Staphylococcus aureus (MRSA, brown spheres) surrounded by cellular debris. MRSA, the bacteria examined in this study, is resistant by many antibiotics. (Wikimedia)

It’s been known for many years that silver in liquid form can kill bacteria and scientists have examined ways to deliver a controlled release of silver nanoparticles at the site of the bone infection. But there has been a lot of concern, including by the Food and Drug Administration (FDA), about the toxicity of silver nanoparticles to human cells.

In this study, a team led by Elizabeth Loboa from the University of Missouri instead looked at the use of silver ions which are safer than the nanoparticles. The team developed a three-dimensional cell culture system that resembles bone by growing human bone-forming stem cells on a tissue engineered scaffold, which also slowly releases silver ions.

The researchers stimulated the stem cells within the scaffold to specialize into bone cells and included a strain of bacteria that’s resistant to multiple antibiotics. They found that the silver ions effectively killed the bacteria and at the same time did not block the bone-forming stem cells. If this work holds up, doctors may one day use this silver ion-releasing, biodegradable scaffold to directly treat the area of bone infection. And to help prevent infection after joint replacement procedures, surgeons may rely on implants that are coated with these scaffolds.

Stem Cell Stories that caught our eye: a womb with a view, reversing aging and stabilizing stem cells

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.

Today we bring you a trifecta of stem cell stories that were partially funded by grants from CIRM.

A womb with a view: using 3D imaging to observe embryo implantation. Scientists have a good understanding of how the beginning stages of pregnancy happen. An egg cell from a woman is fertilized by a sperm cell from a man and the result is a single cell called a zygote. Over the next week, the zygote divides into multiple cells that form the developing embryo. At the end of that period, the embryo hatches out of its protective membrane and begins implanting itself into the lining of the mother’s uterus.

It’s possible to visualize the early stages of embryo development in culture dishes, which has helped scientists understand the biological steps required for an embryo to survive and develop into a healthy fetus. However, something that is not easy to observe is the implantation stage of the embryo in the uterus. This process is complex and involves a restructuring of the uterine wall to accommodate the developing embryo. As you can imagine, replicating these events would be extremely complicated and difficult to do in a culture dish, and current imaging techniques aren’t adequate either.

That’s where new CIRM-funded research from a team at UCSF comes to the rescue. They developed a 3D imaging technology and combined it with a previously developed “tissue clearing” method, which uses chemicals to turn tissues translucent, to provide clear images of the uterine wall during embryo implantation in mice. Their work was published this week in the journal Development.

According to a UCSF news release,

“Using their new approach, the team observed that the uterine lining becomes extensively folded as it approaches its window of receptivity for an embryo to implant. The geometry of the folds in which the incoming embryos dwell is important, the team found, as genetic mutants with defects in implantation have improper patterns of folding.”

Ultimately, the team aims to use their new imaging technology to get an inside scoop on how to prevent or treat pregnancy disorders and also how to improve the outcome of pregnancies by in vitro fertilization.

Senior author on the study, UCSF professor Diana Laird concluded:

“This new view of early pregnancy lets us ask fundamentally new questions about how the embryo finds its home within the uterus and what factors are needed for it to implant successfully. Once we can understand how these processes happen normally, we can also ask why certain genetic mutations cause pregnancies to fail, to study the potential dangers of environmental toxins such as the chemicals in common household products, and even why metabolic disease and obesity appears to compromise implantation.”

If you want to see this womb with a view, check out the video below.

Watch these two videos for more information:

Salk scientists reverse signs of aging in mice. For our next scintillating stem cell story, we’re turning back the clock – the aging clock that is. Scientists from the Salk Institute in La Jolla, reported an interesting method in the journal Cell  that reverses some signs of aging in mice. They found that periodic expression of embryonic stem cell genes in skin cells and mice could reverse some signs of aging.

The Salk team made use of cellular reprogramming tools developed by the Nobel Prize winning scientist Shinya Yamanaka. He found that four genes normally expressed in embryonic stem cells could revert adult cells back to a pluripotent stem cell state – a process called cellular reprogramming. Instead of turning adult cells back into stem cells, the Salk scientists asked whether the Yamanaka factors could instead turn back the clock on older, aging cells – making them healthier without turning them back into stem cells or cancer-forming cells.

The team found that they could rejuvenate skin cells from mice without turning them back into stem cells if they turned on the Yamanaka genes on for a short period of time. These skin cells were taken from mice that had progeria – a disease that causes them to age rapidly. Not only did their skin cells look and act younger after the treatment, but when the scientists used a similar technique to turn on the Yamanaka genes in progeria mice, they saw rejuvenating effects in the mice including a more rapid healing and regeneration of muscle and pancreas tissue.

(Left) impaired muscle repair in aged mice; (right) improved muscle regeneration in aged mice subjected to reprogramming. (Salk Institute)

(Left) impaired muscle repair in aged mice; (right) improved muscle regeneration in aged mice subjected to reprogramming. (Salk Institute)

The senior author on the study, Salk Professor Juan Carlos Izpisua Belmonte, acknowledged in a Salk news release that this is early stage work that focuses on animal models, not humans:

“Obviously, mice are not humans and we know it will be much more complex to rejuvenate a person. But this study shows that aging is a very dynamic and plastic process, and therefore will be more amenable to therapeutic interventions than what we previously thought.”

This story was very popular, which is not surprising as aging research is particularly fascinating to people who want to live longer lives. It was covered by many news outlets including STATnews, Scientific American and Science Magazine. I also recommend reading Paul Knoepfler’s journal club-style blog on the study for an objective take on the findings and implications of the study. Lastly, you can learn more about the science of this work by watching the movie below by the Salk.

Movie:

Stabilizing unstable stem cells. Our final stem cell story is brought to you by scientists from the UCLA Broad Stem Cell Research Center. They found that embryonic stem cells can harbor genetic instabilities that can be passed on to their offspring and cause complications, or even disease, later in life. Their work was published in two separate studies in Cell Stem Cell and Cell Reports.

The science behind the genetic instabilities is too complicated to explain in this blog, so I’ll refer you to the UCLA news release for more details. In brief, the UCLA team found a way to reverse the genetic instability in the stem cells such that the mature cells that they developed into turned out healthy.

As for the future impact of this research, “The research team, led by Kathrin Plath, found a way to correct the instability by resetting the stem cells from a later stage of development to an earlier stage of development. This fundamental discovery could have great impact on the creation of healthy tissues to cure disease.”

Stem cell stories that caught our eye: insights into stem cell biology through telomeres, reprogramming and lung 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.

Telomeres and stem cell stability: too much of a good thing

Just like those plastic tips at the end of shoelaces (fun fact: they’re called aglets), telomeres form a protective cap on the end of chromosomes. Because of the way DNA replication works, the telomeres shorten each time a cell divides. Trim away enough of the telomere over time and, like a frayed shoelace, the chromosomes become unstable and an easy target for damage which eventually leads to cell death.

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Telomeres (white dots) form a protective cap on chromsomes (gray). (Wikimedia) 

Stem cells are unique in that they contain an enzyme called telomerase that lengthens telomeres. Telomerase activity and telomere lengthening are critical for a stem cell’s ability to maintain virtually limitless cell divisions. So you’d assume the longer the telomere, the more stable the cell. But Salk Institute scientists reported this week that too much telomere can be just as bad, if not worse, than too little.

The CIRM-funded work, which was published in Nature Structural & Molecular Biology, used genetic engineering to artificially vary telomerase activity in human embryonic stem cells. Cells with low telomerase activity had shorter telomeres and died. This result wasn’t a surprise since the short telomeres-cell death observation has been well documented. Based on those results, the team was expecting cells with boosted telomerase activity and, in turn, extended telomeres would be especially stable. But that’s not what happened as senior author Jan Karlseder mentioned in a Salk press release:

“We were surprised to find that forcing cells to generate really long telomeres caused telomeric fragility, which can lead to initiation of cancer. These experiments question the generally accepted notion that artificially increasing telomeres could lengthen life or improve the health of an organism.”

The researchers also examined induced pluripotent stem (iPS) cells in the study and found that the cells contain “footprints” of telomere trimming. So the team is in a position to study how a cell’s telomere history relates to how well it can be reprogrammed into iPS cells. First author Teresa Rivera pointed out the big picture significance of this finding:

“Stem cell reprogramming is a major scientific breakthrough, but the methods are still being perfected. Understanding how telomere length is regulated is an important step toward realizing the promise of stem cell therapies and regenerative medicine.”

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Jan Karlseder and Teresa Rivera

Lego set of gene activators takes trial and error out of cellular reprogramming

To convert one cell type into another, stem cell researchers rely on educated guesses and a lot of trial and error. In fact, that’s how Shinya Yamanaka identified the four Yamanaka Factors which, when inserted into a skin cell, reprogram it into the embryonic stem cell-like state of an iPS cell. That ground-breaking discovery ten years ago has opened the way for researchers worldwide to specialize iPS cells into all sorts of cell types from nerve cells to liver cells. While some cell types are easy to generate this way, others are much more difficult.

Reporting this week in PNAS, a University of Wisconsin–Madison research team has developed a nifty systematic, high-throughput method for identifying the factors necessary to convert a cell from one type to another. Their strategy promises to free researchers from the costly and time consuming trial and error approach still in use today.

The centerpiece of their method is artificial transcription factors (ATFs). Now, natural transcription factors – Yamanaka’s Factors are examples – are proteins that bind DNA and activate or silence genes. Their impact on gene activity, in turn, can have a cascading effects on other genes and proteins ultimately causing, say a stem cell, to start making muscle proteins and turn into a muscle cell.

Transcription factors are very modular proteins – one part is responsible for binding DNA, another part for affecting gene activity and other parts that bind to other proteins. The ATFs generated in this study are like lego versions of natural transcription factors – each are constructed from combinations of different transcription factor parts. The team made nearly 3 million different ATFs.

As a proof of principle, the researchers tried reproducing Yamanaka’s original, groundbreaking iPS cell experiment. They inserted the ATFs into skin cells that already had 3 of the 4 Yamanaka factors, they left out Oct4. They successfully generated iPS with this approach and then went back and studied the makeup of the ATFs that had caused cells to reprogram into iPS cells. Senior author Aseem Ansari gave a great analogy in a university press release:

“Imagine you have millions of keys and only a unique key or combination of keys can turn a motor on. We test all those keys in parallel and when we see the motor fire up, we go back to see exactly which key switched it on.”

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Micrograph of induced pluripotent stem cells generated from artificial transcription factors. The cells express green fluorescent protein after a key gene known as Oct4 is activated. (ASUKA EGUCHI/UW-MADISON)

The analysis showed that these ATFs had stimulated gene activity cascades which didn’t directly involve Oct4 but yet ultimately activated it. This finding is important because it suggests that future cell conversion experiments could uncover some not so obvious cell fate pathways. Ansari explains this point further:

“It’s a way to induce cell fate conversions without having to know what genes might be important because we are able to test so many by using an unbiased library of molecules that can search nearly every corner of the genome.”

This sort of brute force method to accelerate research discoveries is music to our ears at CIRM because it ultimately could lead to therapies faster.

Search for clues to treat deadly lung disease

When researchers don’t understand what causes a particular disease, a typical strategy is to compare gene activity in diseased vs healthy cells and identify important differences. Those differences may lead to potential paths to developing a therapy. That’s the approach a collaborative team from Cincinnati Children’s Hospital and Cedars-Sinai Medical took to tackle idiopathic pulmonary fibrosis (IPF).

IPF is a chronic lung disease which causes scarring, or fibrosis, in the air sacs of the lung. This is the spot where oxygen is taken up by tiny blood vessels that surround the air sacs. With fibrosis, the air sacs stiffen and thicken and as a result less oxygen gets diffused into the blood and starves the body of oxygen.  IPF can lead to death within 2 to 5 years after diagnosis. Unfortunately, no cures exist and the cause is unknown, or idiopathic.

(Wikimedia)

(Wikimedia)

The transfer of oxygen from air sacs to blood vessels is an intricate one with many cell types involved. So pinpointing what goes wrong in IPF at a cellular and molecular level has proved difficult. In the current study, the scientists, for the first time, collected gene sequencing data from single cells from healthy and diseased lungs. This way, a precise cell by cell analysis of gene activity was possible.

One set of gene activity patterns found in healthy sample were connected to proper formation of a particular type of air sac cell called the aveolar type 2 lung cell. Other gene patterns were linked to abnormal IPF cell types. With this data in hand, the researchers can further investigate the role of these genes in IPF which may open up new therapy approaches to this deadly disease.

The study funded in part by CIRM was published this week in Journal of Clinical Investigation Insight and a press release about the study was picked up by PR Newswire.

Stem cell stories that caught our eye: glowing stem cells and new insights into Zika and SCID

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.

Glowing stem cells help scientists understand how cells work. (Karen Ring)
It’s easy to notice when something is going wrong. It’s a lot harder to notice when something is going right. The same thing can be said for biology. Scientists dedicate their careers to studying unhealthy cells, trying to understand why people get certain diseases and what’s going wrong at the cellular level to cause these problems. But there is a lot to be said for doing scientific research on healthy cells so that we can better understand what’s happening when cells start to malfunction.

A group from the Allen Institute for Cell Science is doing just this. They used a popular gene-editing technology called CRISPR/Cas9 to genetically modify human stem cell lines so that certain parts inside the cell will glow different colors when observed under a fluorescent microscope. Specifically, the scientists inserted the genetic code to produce fluorescent proteins in both the nucleus and the mitochondria of the stem cells. The final result is a tool that allows scientists to study how stem cells specialize into mature cells in various tissues and organs.

Glowing human stem cells. The edges of the cells are shown in purple while the DNA in the cell’s nucleus is in blue. (Allen Institute for Cell Science).

Glowing human stem cells. The edges of the cells are shown in purple while the DNA in the cell’s nucleus is in blue. (Allen Institute for Cell Science).

The director of stem cells and gene editing at the Allen Institute, Ruwanthi Gunawardane, explained how their technology improves upon previous methods for getting cells to glow in an interview with Forbes:

 “We’re trying to understand how the cell behaves, how it functions, but flooding it with some external protein can really mess it up. The CRISPR system allows us to go into the DNA—the blueprint—and insert a gene that allows the cell to express the protein in its normal environment. Then, through live imaging, we can watch the cell and understand how it works.”

The team has made five of these glowing stem cell lines available for use by the scientific community through the Coriell Institute for Medical Research (which also works closely with the CIRM iPSC Initiative). Each cell line is unique and has a different cellular structure that glows. You can learn more about these cell lines on the Coriell Allen Institute webpage and by watching this video:

 

Zika can take multiple routes to infect a child’s brain. (Kevin McCormack)
One of the biggest health stories of 2016 has been the rapid, indeed alarming, spread of the Zika virus. It went from an obscure virus to a global epidemic found in more than 70 countries.

The major concern about the virus is its ability to cause brain defects in the developing brain. Now researchers at Harvard have found that it can do this in more ways than previously believed.

Up till now, it was believed that Zika does its damage by grabbing onto a protein called AXL on the surface of brain cells called neural progenitor cells (NPCs). However, the study, published in the journal Cell Stem Cell, showed that even when AXL was blocked, Zika still managed to infiltrate the brain.

Using induced pluripotent stem cell technology, the researchers were able to create NPCs and then modify them so they had no AXL expression. That should, in theory, have been able to block the Zika virus. But when they exposed those cells to the virus they found they were infected just as much as ordinary brain cells exposed to the virus were.

Caption: Zika virus (light blue) spreads through a three-dimensional model of a developing brain. Image by Max Salick and Nathaniel Kirkpatrick/Novartis

Caption: Zika virus (light blue) spreads through a three-dimensional model of a developing brain. Image by Max Salick and Nathaniel Kirkpatrick/Novartis

In a story in the Harvard Gazette, Kevin Eggan, one of the lead researchers, said this shows scientists need to re-think their approach to countering the virus:

“Our finding really recalibrates this field of research because it tells us we still have to go and find out how Zika is getting into these cells.”

 

Treatment for a severe form of bubble baby disease appears on the horizon. (Todd Dubnicoff)
Without treatment, kids born with bubble baby disease typically die before reaching 12 months of age. Formally called severe combined immunodeficiency (SCID), this genetic blood disorder leaves infants without an effective immune system and unable to fight off even minor infections. A bone marrow stem cell transplant from a matched sibling can treat the disease but this is only available in less than 20 percent of cases and other types of donors carry severe risks.

In what is shaping up to be a life-changing medical breakthrough, a UCLA team has developed a stem cell/gene therapy treatment that corrects the SCID mutation. Over 40 patients have participated to date with a 100% survival rate and CIRM has just awarded the team $20 million to continue clinical trials.

There’s a catch though: other forms of SCID exist. The therapy described above treats SCID patients with a mutation in a gene responsible for producing a protein called ADA. But an inherited mutation in another gene called Artemis, leads to a more severe form of SCID. These Artemis-SCID infants have even less success with a standard bone marrow transplant compared to those with ADA-SCID. Artemis plays a role in DNA damage repair something that occurs during the chemo and radiation therapy sessions that are often necessary for blood marrow transplants. So Artemis-SCID patients are hyper-sensitive to the side of effects of standard treatments.

A recent study by UCSF scientists in Human Gene Therapy, funded in part by CIRM, brings a lot of hope to these Artemis-SCID patient. Using a similar stem cell/gene therapy method, this team collected blood stem cells from the bone marrow of mice with a form of Artemis-SCID. Then they added a good copy of the human Artemis gene to these cells. Transplanting the blood stem cells back to mice, restored their immune systems which paves the way for delivering this approach to clinic to also help the Artemis-SCID patients in desperate need of a treatment.

Stem cell stories that caught our eye: Horse patients, Brain cancer stem cells, and a Bony Heart

Horsing around at the World Stem Cell Summit
The World Stem Cell Summit (WSCS) is coming up very shortly (December 6-9) in lovely downtown West Palm Beach, Florida. And this year it has an added attraction; horses.

For my money the WSCS is the most enjoyable of the many conferences held around the US focusing on stem cells. Most conferences have either scientists or patients and patient advocates. This brings them both together creating an event that highlights the science, the people doing it, and the people who hope to benefit from it.

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Eadweard Muybridge’s Galloping Horse
Image: Wikimedia Commons

And this year it’s not just about people, it’s also about horses. For the first time the event will feature the Equine World Stem Cell Summit. This makes sense on so many levels. Animals, large and small, have always been an important element in advancing scientific research, enabling us to test treatments and make sure they are safe before trying them out on people.

But horses are also athletes and sports has always been a powerful force in accelerating research. When you think about the “Sport of Kings” and how much money is involved in breeding and racing horses it’s not surprising that rich owners are always looking for new treatments that can help their thoroughbreds recover from injuries.

And if they help repair damaged bones and tendons in thoroughbreds, who’s to say those techniques and that research couldn’t help the rest of us.

Loss of gene allows cancer stem cells to invade the brain
A fundamental property of stem cells is their ability to self-renew and make unlimited copies of themselves. That ability is great for repairing the body but in the case of cancer stem cells, it is thought to be responsible for the uncontrolled, lethal growth of tumors.

Both stem cells and cancer stem cells rely on special cellular neighborhoods, or “niches”, to support their function. Outside of those niches, the cells don’t survive well. But cancer stem cells somehow overcome this barrier which allows them to spread and do damage to whole organs.

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Brain MRI showing glioblastoma tumor
Image: Wikimedia Commons

A study this week at The University of Texas MD Anderson Cancer Center zeroed in on the gene QK1 that, when deleted in mice, provides cancer stem cells in the brain the ability to thrive outside their niches.  They team also showed that the loss of the gene slowed a cell process called endocytosis, which normally acts to break down and recycle protein receptors on the cell surface. Those receptors are critical for the cancer stem cell’s self-renew function. So by blocking endocytosis, the gene deletion leads to an accumulation of receptors on the cell surface and in turn that boosts the cancer stem cells’ ability to divide and grow outside of its niche.

In a university press release picked up by Science Daily, team lead Jian Hu talked about exploiting this result to find new ways to defeat glioblastoma, the deadliest form of brain cancer:

“This study may lead to cancer therapeutic opportunities by targeting the mechanisms involved in maintaining cancer stem cells. Although loss of QKI allows glioma stem cells to thrive, it also renders certain vulnerabilities to the cancer cells. We hope to design new therapies to target these.”

CIRM-funded scientists uncover mystery of bone growth in the heart
Calcium helps keep our bones strong but a build-up of the mineral in our soft tissues, like the heart, is nothing but bad news for our health. The origins of this abnormal process called ectopic calcification have been a mystery to scientists because the cells responsible for forming bone and secreting calcium, called osteoblasts, are not found in the heart. So where is the calcium coming from?

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Bone-forming osteoblasts. They’re bad news when found in the heart.
Image: Amgen

This week, a CIRM-funded team at UCLA found the answer: cardiac fibroblasts. The researchers suspected that this most abundant cell in the heart was the culprit behind ectopic calcification. So, using some genetic engineering tricks, they were able to track cardiac fibroblasts with a red fluorescent tag inside mice after a heart injury.

Within a week or so after injury, the team observed that cardiac fibroblasts had clustered around the areas of calcium deposits in the heart. It turns out that those cardiac fibroblasts had taken on the properties of heart stem cells and then became bone-forming osteoblasts. To prove this finding, they took some of those cells and transplanted them into healthy mice. Sure enough, the injection sites where the cells were located began to accumulate calcium deposits.

A comparison of gene activity in these abnormal cells versus healthy cells identified a protein called EPPN1 whose levels were really elevated when these calcium deposits occurred. Blocking EPPN1 put a stop to the calcification in the heart. In a university press release, lead author Arjun Deb explained that this detective work may lead to long sought after therapies:

Everyone recognizes that calcification of the heart and blood vessels and kidneys is abnormal, but we haven’t had a single drug that can slow down or reverse calcification; our study points to some therapeutic targets.

Stem cell stories that caught our eye: Amy Schumer’s MS fundraising; healing traumatic brain injury; schizophrenia iPS insights

Amy Schumer and Paul Shaffer raise money for MS. (Karen Ring)
Two famous individuals, one a comedian/movie star, the other a well-known musician, have combined forces to raise money for an important cause. Amy Schumer and Paul Shaffer have pledged to raise $2.5 million dollars to help support research into multiple sclerosis (MS). This disease affects the nerve cells in both the brain and spinal cord. It eats away at the protective myelin sheaths that coat and protect nerve cells and allow them to relay signals between the brain and the rest of the body. As a result, patients experience a wide range of symptoms including physical, mental and psychiatric problems.

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Comedian Amy Schumer and her Dad who has MS.
(National MS Society)

The jury is still out on the exact cause of MS and there is no cure available. But the Tisch MS Research Center of New York is trying to change that. It is “dedicated to finding the cause and cure for MS” and recently announced, at its annual Future Without MS Gala, that it has pledged to raise $10 million to fund the stem cell research efforts ongoing at the Center. Currently, Tisch is “the only center with an FDA approved stem cell clinical trial for MS in the United States.” You can read more about this clinical trial, which is transplanting mesenchymal stem cell-derived brain progenitor cells into the spinal cord, on the Tisch website.

At the gala, both Amy Schumer and Paul Shaffer were present to show their support for MS research. In an interview with People magazine, Amy revealed that her father struggles with MS. She explained, “Some days he’s really good and he’s with it and we’re joking around. And some days I go to visit my dad and it’s so painful. I can’t believe it.” Her experience watching her dad battle with MS inspired her to write and star in the movie TRAINWRECK, and also to get involved in supporting MS research. “If I can help at all I’m gonna try, even if that means I’ll get hurt,” she said.

Stem cells may help traumatic brain injuries (Kevin McCormack
Traumatic brain injury (TBI) is a huge problem in the US. According to the Centers for Disease Control and Prevention around 1.7 million Americans suffer a TBI every year; 250,000 of those are serious enough to result in a hospitalization; 52,000 are fatal. Even those who survive a TBI are often left with permanent disabilities, caused by swelling in the brain that destroys brain cells.

Now researchers at the University of Texas Health Science Center at Houston say using a person’s own stem cells could help reduce the severity of a TBI.

The study, published in the journal Stem Cells, found that taking stem cells from a person’s own bone marrow and then re-infusing them into the bloodstream, within 48 hours of the injury, can help reduce the swelling and inflammation that damages the brain.

In an interview with the Houston Chronicle Charles Cox, the lead researcher – and a member of CIRM’s Grants Working Group panel of experts – says the results are not a cure but they are encouraging:

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Charles Cox
(Drew Donovan / UTHealth)

“I’m talking about the difference between someone who recovers to the point that they can take care of themselves, and someone who is totally dependent on someone else for even simple tasks, like using the bathroom and bathing. That’s a dramatic difference.”

Schizophrenia: an imbalance of brain cell types?

Schizophrenia is a chronic mental disorder with a wide range of disabling symptoms such as delusional thoughts, hearing voices, anxiety and an inability to experience pleasure. It’s estimated that half of those with schizophrenia abuse drugs and alcohol, which likely contributes to increased incidence of unemployment, homelessness and suicide. No cure exists for the disorder because scientists don’t fully understand what causes it, and available treatments only mask the symptoms.

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A patient’s artistic representation of living with schizophrenia
(Wikipedia)

This week, researchers at the RIKEN Brain Science Institute in Japan reported new clues about what goes wrong at a cellular and molecular level in the brains of people with schizophrenia. The scientists created induced pluripotent stem cells (iPSCs) from healthy donors, as well as patients with schizophrenia, and then changed or specialized them into nerve cells, or neurons. They found that fewer iPSCs developed into neurons when comparing the cells from people with schizophrenia to the healthy donor cells. Instead, more iPSCs specialized into astrocytes, another type of brain cell. This fewer neurons/more astrocytes shift was also seen in brains of deceased donors who had schizophrenia.

Looking inside the cells, the researchers found higher levels of a protein called p38 in the neurons derived from the people with schizophrenia. Inhibiting the activity of p38 led to increased number of neurons and fewer astrocytes, which resembles the healthy state. These results, published in Translational Psychiatry and picked up by Health Canal, point to inhibitors of p38 activity as a potential path for developing new treatments.

Stem cell stories that caught our eye: How Zika may impact adult brains; Move over CRISPR there’s a new kid in town; How our bodies store fat

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.

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Zika mosquito

Zika virus could impact adult brains

It’s not just a baby’s developing brain that is vulnerable to the Zika virus, adult brains may be too. A new study shows that some stem cells that help repair damage in the adult brain can be impacted by Zika. This is the first time we’ve had any indication this could be a problem in a fully developed brain.

The study, in the journal Cell Stem Cell, looked at neural progenitors, a  stem cell that plays an important role in helping replace or repair damaged neurons, or nerve cells, in the brain. The researchers exposed the cells to the Zika virus and found that it infected the cells, causing some of the cells to die, and also limited the ability of the cells to proliferate.

In an interview in Healthday, Sujan Shresta, a researcher at the La Jolla Institute for Allergy and Immunology and one of the lead authors of the study, says although their work was done in adult mice, it may have implications for people:

“Zika can clearly enter the brains of adults and can wreak havoc. But it’s a complex disease, it’s catastrophic for early brain development, yet the majority of adults who are infected with Zika rarely show detectable symptoms. Its effect on the adult brain may be more subtle and now we know what to look for.”

Move over CRISPR, there’s a new gene-editing tool in town

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Jennifer Lopez: Photo courtesy MTV

For much of the last year the hottest topic in stem cell and gene editing research has been CRISPR and the ease with which it can be used to edit genes. It’s so hot that apparently it’s the title of an upcoming TV show starring Jeniffer Lopez.

But hold on J-Lo, a new study in Nature Communications says by the time the show is on the air it may be old hat. Researchers at Carnegie Mellon and Yale University have developed a new gene-editing system, one they claim is easier to use and more accurate than CRISPR. And to prove it, they say they have successfully cured a genetic blood disorder in mice, using a simple IV approach.

Tools like CRISPR use enzymes to cut open sections of DNA to edit a specific gene. It’s like using a pair of scissors to cut a piece of string that has a big knot in the middle; you cut out the knot then join the ends of the string together. The problem with CRISPR is that the enzymes it uses are quite large and hard to use in a living animal – let alone a human – so they have to remove the target cells from the body and do the editing in the lab. Another problem is that CRISPR sometimes cuts sections of DNA that the researchers don’t want cut and could lead to dangerous side effects.

Greater precision

The Carnegie Mellon/Yale team say their new method avoids both problems. They use nanoparticles that contain molecules made from peptide nucleic acid (PNA), a kind of artificial form of DNA. This PNA is engineered to be able to cut open DNA and bind to a specific target without cutting anything else.

The team used this approach to target the mutated gene in beta thalassemia, a blood disorder that can be fatal if left untreated. The therapy binds to the malfunctioning gene, enabling the body’s own DNA repair system to correct the problem.

In a news story in Science Daily Danith Ly, one of the lead authors on the study, says even though the technique was successful in editing the target genes just 7 percent of the time, that is way more than the 0.1 percent rate most other gene editing tools achieve.

“The effect may only be 7 percent, but that’s curative. In the case of this particular disease model, you don’t need a lot of correction. You don’t need 100 percent to see the phenotype return to normal.”

Hormone that controls if and when fat cells mature

Obesity is one of the fastest growing public health problems in the US and globally. Understanding the mechanisms behind how that happens could be key to finding ways to address it. Now researchers at Stanford University think they may have uncovered an important part of the answer.

Their findings, reported in Science Signaling, show that mature fat cells produce a hormone called Adamts1 which acts like a switch for surrounding stem cells, determining if they change into fat-storing cells.   People who eat a high-fat diet experience a change in their Adamst1 production, and that triggers the nearby stem cells to specialize and start storing fat.

There are still a lot of questions to be answered about Adamst1, including whether it acts alone or in conjunction with other as yet unknown hormones. But in an article in Health Canal, Brian Feldman, the senior author of the study, says they can now start looking at potential use of Adamst1 to fight obesity.

“That won’t be a simple answer. If you block fat formation, extra calories have to go somewhere in the body, and sending them somewhere else outside fat cells could be more detrimental to metabolism. We know from other researchers’ work that liver and muscle are both bad places to store fat, for example. We do think there are going to be opportunities for new treatments based on our discoveries, but not by simply blocking fat formation alone.”

 

Stem cell stories that caught our eye: Blood stem cells on a diet, Bladder control after spinal cord injuries, new ALS insights

Putting blood stem cells on a diet. (Karen Ring)

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Valine. Image: BMRB

Scientists from Stanford and the University of Tokyo have figured out a new way to potentially make bone marrow transplants more safe. Published yesterday in the journal Science, the teams discovered that removing an essential amino acid, called valine, from the diets of mice depleted their blood stem cells and made it easier for them to receive bone marrow transplants from other mice without the need for radiation or chemotherapy. Removing valine from human blood stem cells yielded similar results suggesting that this therapeutic approach could potentially change and improve the way that certain cancer patients are treated.

In an interview with Science Magazine, senior author Satoshi Yamazaki explained how current bone marrow transplants are toxic to patients and that an alternative, safer form of treatment is needed.

“Bone marrow transplantation is a toxic therapy. We have to do it to treat diseases that would otherwise be fatal, but the quality of life afterward is often not good. Relative to chemotherapy or radiation, the toxicity of a diet deficient in valine seems to be much, much lower. Mice that have been irradiated look terrible. They can’t have babies and live for less than a year. But mice given a diet deficient in valine can have babies and will live a normal life span after transplantation.”

The scientists found that the effects of a valine-deficient diet were mostly specific to blood stem cells in the mice, but also did affect hair stem cells and some T cells. The effects on these other populations of cells were not as dramatic however as the effects on blood stem cells.

Going forward, the teams are interested to find out whether valine deficiency will be a useful treatment for leukemia stem cells, which are stem cells that give rise to a type of blood cancer. As mentioned before, this alternative form of treatment would be very valuable for certain cancer patients in comparison to the current regimen of radiation treatment before bone marrow transplantation.

Easing pain and improving bladder control in spinal cord injury (Kevin McCormack)
When most people think of spinal cord injuries (SCI) they focus on the inability to walk. But for people with those injuries there are many other complications such as intense nerve or neuropathic pain, and inability to control their bladder. A CIRM-funded study from researchers at UCSF may help point at a new way of addressing those problems.

The study, published in the journal Cell Stem Cell, zeroed in on the loss in people with SCI of a particular amino acid called GABA, which acts as a neurotransmitter in the central nervous system and inhibits nerve transmission in the brain, calming nervous activity.

Here’s where we move into alphabet soup, but stick with me. Previous studies showed that using cells called inhibitory interneuron precursors from the medial ganglionic eminence (MGE) helped boost GABA signaling in the brain and spinal cord. So the researchers turned some human embryonic stem cells (hESCs) into MGEs and transplanted those into the spinal cords of mice with SCI.

Six months after transplantation those cells had integrated into the mice’s spinal cord, and the mice not only showed improved bladder function but they also seemed to have less pain.

Now, it’s a long way from mice to men, and there’s a lot of work that has to be done to ensure that this is safe to try in people, but the researchers conclude: “Our findings, therefore, may have implications for the treatment of chronically spinal cord-injured patients.”

CIRM-funded study reveals potential new ALS drug target (Todd Dubnicoff)
Of the many diseases CIRM-funded researchers are tackling, Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s Disease, has got to be one of the worst.

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Motor neurons derived from skin cells of a healthy donor
Image: UC San Diego

This neurodegenerative disorder attacks and kills motor neurons, the nerve cells that control voluntary muscle movement. People diagnosed with ALS, gradually lose the ability to move their limbs, to swallow and even to breathe. The disease is always fatal and people usually die within 3 to 5 years after initial diagnosis. There’s no cure for ALS mainly because scientists are still struggling to fully understand what causes it.

Stem cell-derived “disease in a dish” experiments have recently provided many insights into the underlying biology of ALS. In these studies, skin cells from ALS patients are reprogrammed into an embryonic stem cell-like state called induced pluripotent stem cells (iPSCS). These iPS cells are grown in petri dishes and then specialized into motor neurons, allowing researchers to carefully look for any defects in the cells.

This week, a UC San Diego research team using this disease in a dish strategy reported they had uncovered a cellular process that goes haywire in ALS cells. The researchers generated motor neurons from iPS cells that had been derived from the skin samples of ALS patients with hereditary forms of the disease as well as samples from healthy donors. The team then compared the activity of thousands of genes between the ALS and healthy motor neurons. They found that a particular hereditary mutation doesn’t just impair a protein called hnRNP A2/B1, it actually gives the protein new toxic activities that kill off the motor neurons.

Fernando Martinez, the first author on this study in Neuron, told the UC San Diego Health newsroom that these news results reveal an important context for their on-going development of therapeutics that target proteins like hnRNP:

“These … therapies [targeting hnRNP] can eliminate toxic proteins and treat disease. But this strategy is only viable if the proteins have gained new toxic functions through mutation, as we found here for hnRNP A2/B1 in these ALS cases.”

Stem cell stories that caught our eye: relief for jaw pain, vitamins for iPSCs and Alzheimer’s insights

Jaw bone stem cells may offer relief for suffers of painful joint disorder
An estimated 10 million people in the US – mostly women –  suffer from problems with their temporomandibular joint (TMJ) which sits between the jaw bone and skull. TMJ disorders can lead to a number of symptoms such as intense pain in the jaw, face and head; difficulty swallowing and talking; and dizziness.

ds00355_im00012_mcdc7_tmj_jpgThe TMJ is made up of fibrocartilage which, when healthy, acts as a cushion to enable a person to move their jaw smoothly. But this cartilage doesn’t have the capacity to heal or regenerate so treatments including surgery and pain killers only mask the symptoms without fixing the underlying damage of the joint.

Reporting this week in Nature Communications, researchers at Columbia University’s College of Dental Medicine identified stem cells within the TMJ that can form cartilage and bone – in cell culture studies as well as in animals. The research team further showed that the signaling activity of a protein called Wnt leads to a reduction of these fibrocartilage stem cells (FSCSs) in animals and as a result causes deterioration of cartilage. But injecting a known inhibitor of Wnt into the animals’ damaged TMJ spurred growth and healing of the joint.

The team is now in search of other Wnt inhibitors that could be used in a clinical setting. In a university press release, Jeremy Mao, a co-author on the paper, talked about the implications of these results:

“They suggest that molecular signals that govern stem cells may have therapeutic applications for cartilage and bone regeneration. Cartilage and certain bone defects are notoriously difficult to heal.”

Take your vitamins: good advice for people and iPS cells
From a young age, we’re repeatedly told how getting enough vitamins each day is important for a healthy life. Our bodies don’t produce these naturally occurring chemicals but they carry out critical biochemical activities to keep our cells and organs functioning properly.

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Carrots: a great source of vitamin A. Image source: Wikimedia Commons

Well, it turns out that vitamins are also an important ingredient in stem cell research labs. Results published the Proceedings of the National Academy of Sciences (PNAS) this week by scientists in the UK and New Zealand show that vitamin A and C work together synergistically to improve the efficiency of reprogramming adult cells, like skin or blood, into the embryonic stem cell-like state of induced pluripotent stem cells (iPSCs).

By the time a stem cell has specialized into, let’s say, a skin cell, only skin cell-specific genes are active while others genes, like those needed for liver function, are shut down. Those non-skin genes are silenced through the attachment of chemical tags on the DNA, a process called methylation. It essentially provides the DNA with the means of maintaining a skin cell “memory”. To convert a skin cell back into a stem cell-like state, researchers in the lab must erase this “memory” by adding factors which demethylate, or remove the methylation tags on the silenced, non-skin related genes.

In the current research picked up by Science Daily, the researchers found that both vitamin A and C increase demethylation but in different ways. The study showed that vitamin A acts to increase the production of proteins that are important for demethylation while vitamin C acts to enhance the enzymatic activity of demethylation.

These insights may help add to the growing knowledge on how to most efficiently reprogram adult cells into iPSCs. And they may prove useful for a better understanding of certain cancers which contain cells that are essentially reprogrammed into a stem cell-like state.

New angles for dealing with the tangles in the Alzheimer’s brain
The memory loss and overall degradation of brain function seen in people with Alzheimer’s Disease (AD) is thought to be caused by the accumulation of amyloid and tau proteins which form plaques and tangles in the brain. These abnormal structures are toxic to brain cells and ultimately lead to cell death.

But other studies of post-mortem AD brains suggest a malfunction in endocytosis – a process of taking up and transporting proteins to different parts of the cell – may also play a role. While follow up studies corroborated this initial observation, they didn’t look at endocytosis in nerve cells so it remained unclear how much of a role it played in AD.

In a CIRM-funded study published this week in Cell Reports, UC San Diego researchers made nerve cells from human iPSCs and used the popular CRISPR and TALEN gene editing techniques to generate mutations seen in inherited forms of AD. One of those inherited mutations is in the PS1 gene which has been shown to play a role in transporting amyloid proteins in nerve cells. The research confirmed that this mutation as well as a mutation in the amyloid precursor protein (APP) led to a breakdown in the proper trafficking of APP within the mutated nerve cells. In fact, they found an accumulation of APP in a wrong area of the nerve cell. However, blocking the action of a protein called secretase that normally processes the APP protein helped restore proper protein transport. In a university press release, team leader Larry Goldstein, explained the importance of these findings:

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Larry Goldstein.
Image: UCSD

“Our results further illuminate the complex processes involved in the degradation and decline of neurons, which is, of course, the essential characteristic and cause of AD. But beyond that, they point to a new target and therapy for a condition that currently has no proven treatment or cure.”