Attractive new regenerative medicine tool uses magnets to shape and stimulate stem cells

The ultimate goal of tissue engineers who work in the regenerative medicine field is to replace damaged or diseased organs with new ones built from stem cells. To accomplish the feat, these researchers are developing new tools and techniques to manipulate and specialize stem cells into three dimensional structures. Some popular methods – which we’ve blogged about often – include the use of bioscaffolds as well as 3D bioprinting . This week, a research team at the Laboratoire Matière et Systèmes Complexes in France has developed an attractive (pun intended!) new tool that uses magnetized stem cells to both manipulate and stimulate the cells into 3D shapes.

The magnetic stretcher: this all-in-one system can both form and mechanically stimulate an aggregate of magnetized embryonic stem cells. Image: © Claire Wilhelm / Laboratoire Matière et systèmes complexes (CNRS/Université Paris Diderot).

The study, reported on Monday in Nature Communications, used embryonic stem cells which were incubated with magnetic nanoparticles. The cells readily take up the nanoparticles which allowed the scientists to group the individual cells using magnets. But first the team needed to show that the nanoparticles had no negative effects on the cells. Comparing the iron nanoparticle-laden stem cells to iron-free cells showed no difference in the cells’ survival and their ability to divide.

It was also important to make sure the introduction of nanoparticles had no impact on the stem cell’s pluripotency; that is, its ability to maintain its unspecialized state. A visual check of the cells through a microscope showed that they grew together in rounded clumps, a hallmark of undifferentiated, pluripotent cells. In addition, the key genes that bestow pluripotency onto embryonic stem cells were still active after the addition of the nanoparticles.

The stem cells’ ability to mature into various cell types, like heart muscle or nerve, is key to any successful tissue engineering project. So, the next important assessment of these magnetized cells was to make sure their ability to differentiate, or specialize, was still intact. The typical first step to differentiating embryonic stem cells is to form so-called embryoid bodies (EBs), which are 3D groups of pluripotent stem cells which begin differentiating into the three fundamental tissues types: mesoderm (gives rise to muscle, bone, fat), ectoderm (gives rise to nerve, hair, eyes), endoderm (gives rise to intestines, liver). Using a popular technique, called the hanging drop method, the team showed that the presence of the nanoparticles did not negatively affect embryoid body formation.

In fact, the use of magnets to form embryoid bodies provided several advantages over the hanging drop method. The hanging drop technique requires multiple, time-consuming steps and the resulting embryoid bodies tend to be inconsistent in size and shape. Use of the magnets, on the other hand, instantaneously assembled the stem cells into consistently round aggregates. And by precisely adjusting the magnetic force used, the scientists could also vary the size of the embyroid body, which is an important variable to control since the embryoid size can impact its ability to differentiate.

While the magnet used to form the embryoid bodies was kept stable, the researchers included another magnet which they could move. With this setup, the team was able to stretch and shape the group of cells without the need of scaffolds or the need to physically contact the cells. Several previous studies, using flat, 2-dimensional petri dishes, have shown that the stiffness and flexibility of the dish can stimulate gene activity by affecting cell shape. In this study, the researchers found that when the magnet was moved in a cyclical pattern that imitates the rhythm of a heart beat, the embryoid bodies were, if you can believe it, nudged toward a heart muscle fate. A press release by France’s National Center of Scientific Research (CNRS), which funded the study, explained the big picture implications of this new technique:

“This “all-in-one” approach, which makes it possible to build and manipulate tissue within the same system, could thus prove to be a powerful tool both for biophysical studies and tissue engineering.”

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Protein that turns normal cells into cancer stem cells offers target to fight colon cancer

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Colon cancer: Photo courtesy WebMD

Colon cancer is a global killer. Each year more than one million people worldwide are diagnosed with it; more than half a million die from it. If diagnosed early enough the standard treatment involves surgery, chemotherapy, radiation or targeted drug therapy to destroy the tumors. In many cases this may work. But in some cases, while this approach helps put people in remission, eventually the cancer returns, spreads throughout the body, and ultimately proves fatal.

Now researchers may have identified a protein that causes normal cells to become cancerous, and turn into cancer stem cells (CSCs). This discovery could help provide a new target for anti-cancer therapies.

Cancer stem cells are devilishly tricky. While most cancer cells are killed by chemotherapy or other therapies, cancer stem cells are able to lie dormant and hide, then emerge later to grow and spread, causing the person to relapse and the cancer to return.

In a study published in Nature Research’s Scientific Reports, researchers at SU Health New Orleans School of Medicine and Stanley S. Scott Cancer Center identified a protein, called SATB2, that appears to act as an “on/off” switch for specific genes inside a cancer cell.

In normal, healthy colorectal tissue SATB2 is not active, but in colorectal cancer it is highly active, found in around 85 percent of tumors. So, working with mice, the researchers inserted extra copies of the SATB2 gene, which produced more SATB2 protein in normal colorectal tissue. They found that this produced profound changes in the cell, leading to uncontrolled cell growth. In effect it turned a normal cell into a cancer stem cell.

As the researchers state in their paper:

“These data suggest that SATB2 can transform normal colon epithelial cells to CSCs/progenitor-like cells which play significant roles in cancer initiation, promotion and metastasis.”

When the researchers took colorectal cancer cells and inhibited SATB2 they found that this not only suppressed the growth of the cancer and it’s ability to spread, it also prevented those cancer cells from becoming cancer stem cells.

In a news release about the study Dr. Rakesh Srivastava,  the senior author on the paper, said the findings are important:

“Since the SATB2 protein is highly expressed in the colorectal cell lines and tissues, it can be an attractive target for therapy, diagnosis and prognosis.”

Because SATB2 is found in other cancers too, such as breast cancer, these findings may hold significance for more than just colorectal cancer.

The next step is to repeat the study in mice that have been genetically modified to better reflect the way colon cancer shows up in people. The team hope this will not only confirm their findings, but also give them a deeper understanding of the role that SATB2 plays in cancer formation and spread.

CIRM weekly stem cell roundup: stomach bacteria & cancer; vitamin C may block leukemia; stem cells bring down a 6’2″ 246lb football player

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This is what your stomach glands looks like from the inside:  Credit: MPI for Infection Biology”

Stomach bacteria crank up stem cell renewal, may be link to gastric cancer (Todd Dubnicoff)

The Centers for Disease Control and Prevention estimate that two-thirds of the world’s population is infected with H. pylori, a type of bacteria that thrives in the harsh acidic conditions of the stomach. Data accumulated over the past few decades shows strong evidence that H. pylori infection increases the risk of stomach cancers. The underlying mechanisms of this link have remained unclear. But research published this week in Nature suggests that the bacteria cause stem cells located in the stomach lining to divide more frequently leading to an increased potential for cancerous growth.

Tumors need to make an initial foothold in a tissue in order to grow and spread. But the cells of our stomach lining are replaced every four days. So, how would H. pylori bacterial infection have time to induce a cancer? The research team – a collaboration between scientists at the Max Planck Institute in Berlin and Stanford University – asked that question and found that the bacteria are also able to penetrate down into the stomach glands and infect stem cells whose job it is to continually replenish the stomach lining.

Further analysis in mice revealed that two groups of stem cells exist in the stomach glands – one slowly dividing and one rapidly dividing population. Both stem cell populations respond similarly to an important signaling protein, called Wnt, that sustains stem cell renewal. But the team also discovered a second key stem cell signaling protein called R-spondin that is released by connective tissue underneath the stomach glands. H. pylori infection of these cells causes an increase in R-spondin which shuts down the slowly dividing stem cell population but cranks up the cell division of the rapidly dividing stem cells. First author, Dr. Michal Sigal, summed up in a press release how these results may point to stem cells as the link between bacterial infection and increased risk of stomach cancer:

“Since H. pylori causes life-long infections, the constant increase in stem cell divisions may be enough to explain the increased risk of carcinogenesis observed.”

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Vitamin C may have anti-blood cancer properties

Vitamin C is known to have a number of health benefits, from preventing scurvy to limiting the buildup of fatty plaque in your arteries. Now a new study says we might soon be able to add another benefit: it may be able to block the progression of leukemia and other blood cancers.

Researchers at the NYU School of Medicine focused their work on an enzyme called TET2. This is found in hematopoietic stem cells (HSCs), the kind of stem cell typically found in bone marrow. The absence of TET2 is known to keep these HSCs in a pre-leukemic state; in effect priming the body to develop leukemia. The researchers showed that high doses of vitamin C can prevent, or even reverse that, by increasing the activity level of TET2.

In the study, in the journal Cell, they showed how they developed mice that could have their levels of TET2 increased or decreased. They then transplanted bone marrow with low levels of TET2 from those mice into healthy, normal mice. The healthy mice started to develop leukemia-like symptoms. However, when the researchers used high doses of vitamin C to restore the activity levels of TET2, they were able to halt the progression of the leukemia.

Now this doesn’t mean you should run out and get as much vitamin C as you can to help protect you against leukemia. In an article in The Scientist, Benjamin Neel, senior author of the study, says while vitamin C does have health benefits,  consuming large doses won’t do you much good:

“They’re unlikely to be a general anti-cancer therapy, and they really should be understood based on the molecular understanding of the many actions vitamin C has in cells.”

However, Neel says these findings do give scientists a new tool to help them target cells before they become leukemic.

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Bad toe forces Jordan Reed to take a knee: Photo courtesy FanRag Sports

Toeing the line: how unapproved stem cell treatment made matters worse for an NFL player  

American football players are tough. They have to be to withstand pounding tackles by 300lb men wearing pads and a helmet. But it wasn’t a crunching hit that took Washington Redskins player Jordan Reed out of the game; all it took to put the 6’2” 246 lb player on the PUP (Physically Unable to Perform) list was a little stem cell injection.

Reed has had a lingering injury problem with the big toe on his left foot. So, during the off-season, he thought he would take care of the issue, and got a stem cell injection in the toe. It didn’t quite work the way he hoped.

In an interview with the Richmond Times Dispatch he said:

“That kind of flared it up a bit on me. Now I’m just letting it calm down before I get out there. I’ve just gotta take my time, let it heal and strengthen up, then get back out there.”

It’s not clear what kind of stem cells Reed got, if they were his own or from a donor. What is clear is that he is just the latest in a long line of athletes who have turned to stem cells to help repair or speed up recovery from an injury. These are treatments that have not been approved by the Food and Drug Administration (FDA) and that have not been tested in a clinical trial to make sure they are both safe and effective.

In Reed’s case the problem seems to be a relatively minor one; his toe is expected to heal and he should be back in action before too long.

Stem cell researcher and avid blogger Dr. Paul Knoepfler wrote he is lucky, others who take a similar approach may not be:

“Fortunately, it sounds like Reed will be fine, but some people have much worse reactions to unproven stem cells than a sore toe, including blindness and tumors. Be careful out there!”

How mice and zebrafish are unlocking clues to repairing damaged hearts

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The Bee Gees, pioneers in trying to find ways to mend a broken heart. Photograph: Michael Ochs Archives

This may be the first time that the Australian pop group the Bee Gees have ever been featured in a blog about stem cell research, but in this case I think it’s appropriate. One of the Bee Gees biggest hits was “How can you mend a broken heart” and while it was a fine song, Barry and Robin Gibb (who wrote the song) never really came up with a viable answer.

Happily some researchers at the University of Southern California may succeed where Barry and Robin failed. In a study, published in the journal Nature Genetics, the USC team identify a gene that may help regenerate damaged heart tissue after a heart attack.

When babies are born they have a lot of a heart muscle cell called a mononuclear diploid cardiomyocyte or MNDCM for short. This cell type has powerful regenerative properties and so is able to rebuild heart muscle. However, as we get older we have less and less MNDCMs. By the time most of us are at an age where we are most likely to have a heart attack we are also most likely to have very few of these cells, and so have a limited ability to repair the damage.

Michaela Patterson, and her colleagues at USC, set out to find ways to change that. They found that in some adult mice less than 2 percent of their heart cells were MNDCMs, while other mice had a much higher percentage, around 10 percent. Not surprisingly the mice with the higher percentage of MNDCMs were better able to regenerate heart muscle after a heart attack or other injury.

So the USC team – with a little help from CIRM funding – dug a little deeper and did a genome-wide association study of these mice, that’s where they look at all the genetic variants in different individuals to see if they can spot common traits. They found one gene, Tnni3k, that seems to play a key role in generating MNDCMs.

Turning Tnni3K off in mice resulted in higher numbers of MNDCMs, increasing their ability to regenerate heart muscle. But when they activated Tnni3k in zebrafish it reduced the number of MNDCMs and impaired the fish’s ability to repair heart damage.

While it’s a long way from identifying something interesting in mice and zebrafish to seeing if it can be used to help people, Henry Sucov, the senior author on the study, says these findings represent an important first step in that direction:

“The activity of this gene, Tnni3k, can be modulated by small molecules, which could be developed into prescription drugs in the future. These small molecules could change the composition of the heart over time to contain more of these regenerative cells. This could improve the potential for regeneration in adult hearts, as a preventative strategy for those who may be at risk for heart failure.”

 

 

 

Stories that caught our eye: color me stem cells, delivering cell therapy with nanomagnets, and stem cell decisions

Nanomagnets: the future of targeted stem cell therapies? Your blood vessels are made up of tightly-packed endothelial cells. This barrier poses some big challenges for the delivery of drugs via the blood. While small molecules are able make their way through the small gaps in the blood vessel walls, larger drug molecules, including proteins and cells, are not able to penetrate the vessel to get therapies to diseased areas.

This week, researchers at Rice University report in Nature Communications on an ingenious technique using tiny magnets that may overcome this drug delivery problem.

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At left, the nanoparticles are evenly distributed among the microtubules that help give the cells their shape. At right, after a magnetic field is applied, the nanoparticles are pulled toward one end of the cells and change their shapes. Credit: Laboratory of Biomolecular Engineering and Nanomedicine/Rice University

Initial studies showed that adding magnetic nanoparticles to the endothelial cells and then applying a magnetic field affected the cells’ internal scaffolding, called microtubules. These structures are responsible for maintaining the tight cell to cell connections. The team took the studies a step further by growing the cells in specialized petri dishes containing tiny, tube-shaped channels. Applying a magnetic field to the cells caused the cell-cell junctions to form gaps, making the blood vessel structures leaky. Simply turning off the magnetic field closed up the gaps within a few hours.

Though a lot of research remains, the team aims to apply this on-demand induction of cell leakiness along with adding the magnetic nanoparticles to stem cell therapy products to help target the treatment to specific area. In a press release, team leader Dr. Gang Bao spoke about possible applications to arthritis therapy:

“The problem is how to accumulate therapeutic stem cells around the knee and keep them there. After injecting the nanoparticle-infused cells, we want to put an array of magnets around the knee to attract them.”

To differentiate or not differentiate: new insights During the body’s development, stem cells must differentiate, or specialize, into functional cells – like liver, heart, brain. But once that specialization occurs, the cells lose their pluripotency, or the ability to become any type of cell. So, stem cells must balance the need to differentiate with the need to make copies of itself to maintain an adequate supply of stem cells to complete the development process. And even after a fully formed baby is born, it’s still critical for adult stem cells to balance the need to regenerate damaged tissue versus stashing away a pool of stem cells in various organs for future regeneration and replacement of damaged or diseased tissues.

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Visualizing activation of Nanog gene activity (bright green spot) within cell nucleus. 
Image: Courtesy of Bony De Kumar, Ph.D., and Robb Krumlauf, Ph.D., Stowers Institute for Medical Research

A report this week in the Proceedings of the National Academy of Sciences finds evidence that the two separate processes – differentiation and pluripotency – directly communicate with each other as way to ensure a proper balance between the two states.

The study, carried out by researchers at Stowers Institute for Medical Research in Kansas City, Missouri, focused on the regulation of two genes: Nanog and Hox. Nanog is critical for maintaining a stem cell’s ability to become a specialized cell type. In fact, it’s one of the four genes initially used to reprogram adult cells back into induced pluripotent stem cells. The Hox gene family is responsible for generating a blueprint of the body plan in a developing embryo. Basically, the pattern of Hox gene activity helps generate the body plan, basically predetermining where the various body parts and organs will form.

Now, both Nanog and Hox proteins act by binding to DNA and turning on a cascade of other genes that ultimately maintain pluripotency or promote differentiation. By examining these other genes, the researchers were surprised to find that both Nanog and Hox were bound to both the pluripotency and differentiation genes. They also found that Nanog and Hox can directly inhibit each other. Taken together, these results suggest that exquisite control of both processes occurs cross regulation of gene activity.

Dr. Robb Krumlauf one of authors on the paper talked about the significance of the result in a press release:

“Over the past 10 to 20 years, biologists have shown that cells are actively assessing their environment, and that they have many fates they can choose. The regulatory loops we’ve found show how the dynamic nature of cells is being maintained.”

Color me stem cells Looking to improve your life and the life of those around you? Then we highly recommend you pay a visit to today’s issue of Right Turn, a regular Friday feature of  Signals, the official blog of CCRM, Canada’s public-private consortium supporting the development of regenerative medicine technologies.

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Collage sample of CCRM’s new coloring sheets. Image: copyright CCRM 2017

As part of an public outreach effort they have created four new coloring sheets that depict stem cells among other sciency topics. They’ve set up a DropBox link to download the pictures so you can get started right away.

Adult coloring has swept the nation as the hippest new pastime. And it’s not just a frivolous activity, as coloring has been shown to have many healthy benefits like reducing stressed and increasing creativity. Just watch any kid who colors. In fact, share these sheet with them, it’s intended for children too.

New stem cell technique gives brain support cells a starring role

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The Salk team. From left: Krishna Vadodaria, Lynne Moore, Carol Marchetto, Arianna Mei, Fred H. Gage, Callie Fredlender, Ruth Keithley, Ana Diniz Mendes. Photo courtesy Salk Institute

Astrocytes are some of the most common cells in the brain and central nervous system but they often get overlooked because they play a supporting role to the more glamorous neurons (even though they outnumber them around 50 to 1). But a new way of growing those astrocytes outside the brain could help pave the way for improved treatments for stroke, Alzheimer’s and other neurological problems.

Astrocytes – which get their name because of their star shape (Astron – Greek for “star” and “kyttaron” meaning cell) – have a number of key functions in the brain. They provide physical and metabolic support for neurons; they help supply energy and fuel to neurons; and they help with detoxification and injury repair, particularly in terms of reducing inflammation.

Studying these astrocytes in the lab has not been easy, however, because existing methods of producing them have been slow, cumbersome and not altogether effective at replicating their many functions.

Finding a better way

Now a team at the Salk Institute, led by CIRM-funded Professor Fred “Rusty” Gage, has developed a way of using stem cells to create astrocytes that is faster and more effective.

Their work is published in the journal Stem Cell Reports. In a news release, Gage says this is an important discovery:

“This work represents a big leap forward in our ability to model neurological disorders in a dish. Because inflammation is the common denominator in many brain disorders, better understanding astrocytes and their interactions with other cell types in the brain could provide important clues into what goes wrong in disease.”

Stylized microscopy image of an astrocyte (red) and neuron (green). (Salk Institute)

In a step by step process the Salk team used a series of chemicals, called growth factors, to help coax stem cells into becoming, first, generic brain cells, and ultimately astrocytes. These astrocytes not only behaved like the ones in our brain do, but they also have a particularly sensitive response to inflammation. This gives the team a powerful tool in helping develop new treatment to disorders of the brain.

But wait, there’s more!

As if that wasn’t enough, the researchers then used the same technique to create astrocytes from induced pluripotent stem cells (iPSCs) – adult cells, such as skin, that have been re-engineered to have the ability to turn into any other kind of cell in the body. Those man-made astrocytes also showed the same characteristics as natural ones do.

Krishna Vadodaria, one of the lead authors on the paper, says having these iPSC-created astrocytes gives them a completely new tool to help explore brain development and disease, and hopefully develop new treatments for those diseases.

“The exciting thing about using iPSCs is that if we get tissue samples from people with diseases like multiple sclerosis, Alzheimer’s or depression, we will be able to study how their astrocytes behave, and how they interact with neurons.”

Stem cell stories that caught our eye: update on Capricor’s heart attack trial; lithium on the brain; and how stem cells do math

Capricor ALLSTARToday our partners Capricor Therapeutics announced that its stem cell therapy for patients who have experienced a large heart attack is unlikely to meet one of its key goals, namely reducing the scar size in the heart 12 months after treatment.

The news came after analyzing results from patients at the halfway point of the trial, six months after their treatment in the Phase 2 ALLSTAR clinical trial which CIRM was funding. They found that there was no significant difference in the reduction in scarring on the heart for patients treated with donor heart-derived stem cells, compared to patients given a placebo.

Obviously this is disappointing news for everyone involved, but we know that not all clinical trials are going to be successful. CIRM supported this research because it clearly addressed an unmet medical need and because an earlier Phase 1 study had showed promise in helping prevent decline in heart function after a heart attack.

Yet even with this failure to repeat that promise in this trial,  we learned valuable lessons.

In a news release, Dr. Tim Henry, Director of the Division of Interventional Technologies in the Heart Institute at Cedars-Sinai Medical Center and a Co-Principal Investigator on the trial said:

“We are encouraged to see reductions in left ventricular volume measures in the CAP-1002 treated patients, an important indicator of reverse remodeling of the heart. These findings support the biological activity of CAP-1002.”

Capricor still has a clinical trial using CAP-1002 to treat boys and young men developing heart failure due to Duchenne Muscular Dystrophy (DMD).

Lithium gives up its mood stabilizing secrets

As far back as the late 1800s, doctors have recognized that lithium can help people with mood disorders. For decades, this inexpensive drug has been an effective first line of treatment for bipolar disorder, a condition that causes extreme mood swings. And yet, scientists have never had a good handle on how it works. That is, until this week.

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Evan Snyder

Reporting in the Proceedings of the National Academy of Sciences (PNAS), a research team at Sanford Burnham Prebys Medical Discovery Institute have identified the molecular basis of the lithium’s benefit to bipolar patients.  Team lead Dr. Evan Snyder explained in a press release why his group’s discovery is so important for patients:

“Lithium has been used to treat bipolar disorder for generations, but up until now our lack of knowledge about why the therapy does or does not work for a particular patient led to unnecessary dosing and delayed finding an effective treatment. Further, its side effects are intolerable for many patients, limiting its use and creating an urgent need for more targeted drugs with minimal risks.”

The study, funded in part by CIRM, attempted to understand lithium’s beneficial effects by comparing cells from patient who respond to those who don’t (only about a third of patients are responders). Induced pluripotent stem cells (iPSCs) were generated from both groups of patients and then the cells were specialized into nerve cells that play a role in bipolar disorder. The team took an unbiased approach by looking for differences in proteins between the two sets of cells.

The team zeroed in on a protein called CRMP2 that was much less functional in the cells from the lithium-responsive patients. When lithium was added to these cells the disruption in CRMP2’s activity was fixed. Now that the team has identified the molecular location of lithium’s effects, they can now search for new drugs that do the same thing more effectively and with fewer side effects.

The stem cell: a biological calculator?

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Can stem cells do math?

Stem cells are pretty amazing critters but can they do math? The answer appears to be yes according to a fascinating study published this week in PNAS Proceedings of the National Academy of Sciences.

Stem cells, like all cells, process information from the outside through different receptors that stick out from the cells’ outer membranes like a satellite TV dish. Protein growth factors bind those receptors which trigger a domino effect of protein activity inside the cell, called cell signaling, that transfers the initial receptor signal from one protein to another. Ultimately that cascade leads to the accumulation of specific proteins in the nucleus where they either turn on or off specific genes.

Intuition would tell you that the amount of gene activity in response to the cell signaling should correspond to the amount of protein that gets into the nucleus. And that’s been the prevailing view of scientists. But the current study by a Caltech research team debunks this idea. Using real-time video microscopy filming, the team captured cell signaling in individual cells; in this case they used an immature muscle cell called a myoblast.

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Behavior of cells over time after they have received a Tgf-beta signal. The brightness of the nuclei (circled in red) indicates how much Smad protein is present. This brightness varies from cell to cell, but the ratio of brightness after the signal to before the signal is about the same. Image: Goentoro lab, CalTech.

To their surprise the same amount of growth factor given to different myoblasts cells led to the accumulation of very different amounts of a protein called Smad3 in the cells’ nuclei, as much as a 40-fold difference across the cells. But after some number crunching, they discovered that dividing the amount of Smad3 after growth factor stimulation by the Smad3 amount before growth stimulation was similar in all the cells.

As team lead Dr. Lea Goentoro mentions in a press release, this result has some very important implications for studying human disease:

“Prior to this work, researchers trying to characterize the properties of a tumor might take a slice from it and measure the total amount of Smad in cells. Our results show that to understand these cells one must instead measure the change in Smad over time.”

Stem Cell Stories That Caught Our Eye: Free Patient Advocate Event in San Diego, and new clues on how to fix muscular dystrophy and Huntington’s disease

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Stem cell research is advancing so fast that it’s sometimes hard to keep up. That’s one of the reasons we have our Friday roundup, to let you know about some fascinating research that came across our desk during the week that you might otherwise have missed.

Of course, another way to keep up with the latest in stem cell research is to join us for our free Patient Advocate Event at UC San Diego next Thursday, April 20th from 12-1pm.  We are going to talk about the progress being made in stem cell research, the problems we still face and need help in overcoming, and the prospects for the future.

We have four great speakers:

  • Catriona Jamieson, Director of the CIRM UC San Diego Alpha Stem Cell Clinic and an expert on cancers of the blood
  • Jonathan Thomas, PhD, JD, Chair of CIRM’s Board
  • Jennifer Briggs Braswell, Executive Director of the Sanford Stem Cell Clinical Center
  • David Higgins, Patient Advocate for Parkinson’s on the CIRM Board

We will give updates on the exciting work taking place at UCSD and the work that CIRM is funding. We have also set aside some time to get your thoughts on how we can improve the way we work and, of course, answer your questions.

What: Stem Cell Therapies and You: A Special Patient Advocate Event

When: Thursday, April 20th 12-1pm

Where: The Sanford Consortium for Regenerative Medicine, 2880 Torrey Pines Scenic Drive, La Jolla, CA 92037

Why: Because the people of California have a right to know how their money is helping change the face of regenerative medicine

Who: This event is FREE and open to everyone.

We have set up an EventBrite page for you to RSVP and let us know if you are coming. And, of course, feel free to share this with anyone you think might be interested.

This is the first of a series of similar Patient Advocate Update meetings we plan on holding around California this year. We’ll have news on other locations and dates shortly.

 

Fixing a mutation that causes muscular dystrophy (Karen Ring)

It’s easy to take things for granted. Take your muscles for instance. How often do you think about them? (Don’t answer this if you’re a body builder). Daily? Monthly? I honestly don’t think much about my muscles unless I’ve injured them or if they’re sore from working out.

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Heart muscle cells (green) that don’t have dystrophin protein (Photo; UT Southwestern)

But there are people in this world who think about their muscles or their lack of them every day. They are patients with a muscle wasting disease called Duchenne muscular dystrophy (DMD). It’s the most common type of muscular dystrophy, and it affects mainly young boys – causing their muscles to progressively weaken to the point where they cannot walk or breathe on their own.

DMD is caused by mutations in the dystrophin gene. These mutations prevent muscle cells from making dystrophin protein, which is essential for maintaining muscle structure. Scientists are using gene editing technologies to find and fix these mutations in hopes of curing patients of DMD.

Last year, we blogged about a few of these studies where different teams of scientists corrected dystrophin mutations using CRISPR/Cas9 gene editing technology in human cells and in mice with DMD. One of these teams has recently followed up with a new study that builds upon these earlier findings.

Scientists from UT Southwestern are using an alternative form of the CRISPR gene editing complex to fix dystrophin mutations in both human cells and mice. This alternative CRISPR complex makes use of a different cutting enzyme, Cpf1, in place of the more traditionally used Cas9 protein. It’s a smaller protein that the scientists say can get into muscle cells more easily. Cpf1 also differs from Cas9 in what DNA nucleotide sequences it recognizes and latches onto, making it a new tool in the gene editing toolbox for scientists targeting DMD mutations.

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Gene-edited heart muscle cells (green) that now express dystrophin protein (Photo: UT Southwestern)

Using CRISPR/Cpf1, the scientists corrected the most commonly found dystrophin mutation in human induced pluripotent stem cells derived from DMD patients. They matured these corrected stem cells into heart muscle cells in the lab and found that they expressed the dystrophin protein and functioned like normal heart cells in a dish. CRISPR/Cpf1 also corrected mutations in DMD mice, which rescued dystrophin expression in their muscle tissues and some of the muscle wasting symptoms caused by the disease.

Because the dystrophin gene is one of the longest genes in our genome, it has more locations where DMD-causing mutations could occur. The scientists behind this study believe that CRISPR/Cpf1 offers a more flexible tool for targeting different dystrophin mutations and could potentially be used to develop an effective gene therapy for DMD.

Senior author on the study, Dr. Eric Olson, provided this conclusion about their research in a news release by EurekAlert:

“CRISPR-Cpf1 gene-editing can be applied to a vast number of mutations in the dystrophin gene. Our goal is to permanently correct the underlying genetic causes of this terrible disease, and this research brings us closer to realizing that end.”

 

A cellular traffic jam is the culprit behind Huntington’s disease (Todd Dubnicoff)

Back in the 1983, the scientific community cheered the first ever mapping of a genetic disease to a specific area on a human chromosome which led to the isolation of the disease gene in 1993. That disease was Huntington’s, an inherited neurodegenerative disorder that typically strikes in a person’s thirties and leads to death about 10 to 15 years later. Because no effective therapy existed for the disease, this discovery of Huntingtin, as the gene was named, was seen as a critical step toward a better understand of Huntington’s and an eventual cure.

But flash forward to 2017 and researchers are still foggy on how mutations in the Huntingtin gene cause Huntington’s. New research, funded in part by CIRM, promises to clear some things up. The report, published this week in Neuron, establishes a connection between mutant Huntingtin and its impact on the transport of cell components between the nucleus and cytoplasm.

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The pores in the nuclear envelope allows proteins and molecules to pass between a cell’s nucleus and it’s cytoplasm. Image: Blausen.com staff (2014).

To function smoothly, a cell must be able to transport proteins and molecules in and out of the nucleus through holes called nuclear pores. The research team – a collaboration of scientists from Johns Hopkins University, the University of Florida and UC Irvine – found that in nerve cells, the mutant Huntingtin protein clumps up and plays havoc on the nuclear pore structure which leads to cell death. The study was performed in fly and mouse models of HD, in human HD brain samples as well as HD patient nerve cells derived with the induced pluripotent stem cell technique – all with this same finding.

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Huntington’s disease is caused by the loss of a nerve cells called medium spiny neurons. Image: Wikimedia commons

By artificially producing more of the proteins that make up the nuclear pores, the damaging effects caused by the mutant Huntingtin protein were reduced. Similar results were seen using drugs that help stabilize the nuclear pore structure. The implications of these results did not escape George Yohrling, a senior director at the Huntington’s Disease Society of America, who was not involved in the study. Yohrling told Baltimore Sun reporter Meredith Cohn:

“This is very exciting research because we didn’t know what mutant genes or proteins were doing in the body, and this points to new areas to target research. Scientists, biotech companies and pharmaceutical companies could capitalize on this and maybe develop therapies for this biological process”,

It’s important to temper that excitement with a reality check on how much work is still needed before the thought of clinical trials can begin. Researchers still don’t understand why the mutant protein only affects a specific type of nerve cells and it’s far from clear if these drugs would work or be safe to use in the context of the human brain.

Still, each new insight is one step in the march toward a cure.

How Parkinson’s disease became personal for one stem cell researcher

April is Parkinson’s disease Awareness Month. This year the date is particularly significant because 2017 is the 200th anniversary of the publication of British apothecary James Parkinson’s “An Essay on the Shaking Palsy”, which is now recognized as a seminal work in describing the disease.

Schuele_headshotTo mark the occasion we talked with Dr. Birgitt Schuele, Director Gene Discovery and Stem Cell Modeling at the Parkinson’s Institute and Clinical Center in Sunnyvale, California. Dr. Schuele recently received funding from CIRM for a project using new gene-editing technology to try and halt the progression of Parkinson’s.

 

 

What got you interested in Parkinson’s research?

People ask if I have family members with Parkinson’s because a lot of people get into this research because of a family connection, but I don’t.  I was always excited by neuroscience and how the brain works, and I did my medical residency in neurology and had a great mentor who specialized in the neurogenetics of Parkinson’s. That helped fuel my interest in this area.

I have been in this field for 15 years, and over time I have gotten to know a lot of people with Parkinson’s and they have become my friends, so now I’m trying to find answers and also a cure for Parkinson’s. For me this has become personal.

I have patients that I talk to every couple of months and I can see how their disease is progressing, and especially for people with early or young onset Parkinson’s. It’s devastating. It has a huge effect on the person and their family, and on relationships, even how they have to talk to their kids about their risk of getting the disease themselves. It’s hard to see that and the impact it has on people’s lives. And because Parkinson’s is progressive, I get to see, over the years, how it affects people, it’s very hard.

Talk about the project you are doing that CIRM is funding

It’s very exciting. The question for Parkinson’s is how do you stop disease progression, how do you stop the neurons from dying in areas affected by the disease. One protein, identified in 1997 as a genetic form of Parkinson’s, is alpha-synuclein. We know from studying families that have Parkinson’s that if you have too much alpha-synuclein you get early onset, a really aggressive form of Parkinson’s.

I followed a family that carries four copies of this alpha-synuclein gene (two copies is the normal figure) and the age of onset in this family was in their mid 30’s. Last year I went to a funeral for one of these family members who died from Parkinson’s at age 50.

We know that this protein is bad for you, if you have too much it kills brains cells. So we have an idea that if you lower levels of this protein it might be an approach to stop or shield those cells from cell death.

We are using CRISPR gene editing technology to approach this. In the Parkinson’s field this idea of down-regulation of alpha-synuclein protein isn’t new, but previous approaches worked at the protein level, trying to get rid of it by using, for example, immunotherapy. But instead of attacking the protein after it has been produced we are starting at the genomic level. We want to use CRISPR as a way to down-regulate the expression of the protein, in the same way we use a light dimmer to lower the level of light in a room.

But this is a balancing act. Too much of the protein is bad, but so is too little. We know if you get rid of the protein altogether you get negative effects, you cause complications. So we want to find the right level and that’s complex because the right level might vary from person to person.

We are starting with the most extreme levels, with people who have twice as much of this protein as is normal. Once we understand that better, then we can look at people who have levels that are still higher than normal but not at the upper levels we see in early-onset Parkinson’s. They have more subtle changes in their production or expression of this protein. It’s a little bit of a juggling act and it might be different for different patients. We start with the most severe ones and work our way to the most common ones.

One of the frustrations I often hear from patients is that this is all taking so long. Why is that?

Parkinson’s has been overall frustrating for researchers as well. Around 100 years ago, Dr. Lewy first described the protein deposits and the main neuropathology in Parkinson’s. About 20 years ago, mutations in the alpha-synuclein gene were discovered, and now we know approximately 30 genes that are associated with, or can cause Parkinson’s. But it was all very descriptive. It told us what is going on but not why.

Maybe we thought it was straight forward and maybe researchers only focused on what we knew at that point. In 1957, the neurotransmitter dopamine was identified and since the 1960s people have focused on Parkinson’s as a dopamine-deficient problem because we saw the amazing effects L-Dopa had on patients and how it could help ease their symptoms.

But I would say in the last 15 years we have looked at it more closely and realized it’s more complicated than that. There’s also a loss of sense of smell, there’s insomnia, episodes of depression, and other things that are not physical symptoms. In the last 10 years or so we have really put the pieces together and now see Parkinson’s as a multi-system disease with neuronal cell death and specific protein deposits called Lewy Bodies. These Lewy Bodies contain alpha-synuclein and you find them in the brain, the gut and the heart and these are organs people hadn’t looked at because no one made the connection that constipation or depression could be linked to the disease. It turns out that Parkinson’s is much more complicated than just a problem in one particular region of the brain.

The other reason for slow progress is that we don’t have really good models for the disease that are predictive for clinical outcomes. This is why probably many clinical trials in the neurodegenerative field have failed to date. Now we have human induced pluripotent stem cells (iPSCs) from people with Parkinson’s, and iPSC-derived neurons allow us to better model the disease in the lab, and understand its underlying mechanisms  more deeply. The technology has now advanced so that the ability to differentiate these cells into nerve cells is better, so that you now have iPSC-derived neurons in a dish that are functionally active, and that act and behave like dopamine-producing neurons in the brain. This is an important advance.

Will this lead to a clinical trial?

That’s the idea, that’s our hope.

We are working with professor Dr. Deniz Kirik at the University of Lund in Sweden. He’s an expert in the field of viral vectors that can be used in humans – it’s a joint grant between us – and so what we learn from the human iPS cultures, he’ll transfer to an animal model and use his gene vector technology to see if we can see the same effects in vivo, in mice.

We are using a very special Parkinson’s mouse model – developed at UC San Francisco – that has the complete human genomic structure of the alpha-synuclein gene. If all goes well, we hope that ultimately we could be ready in a couple of years to think about preclinical testing and then clinical trials.

What are your hopes for the future?

My hope is that I can contribute to stopping disease progression in Parkinson’s. If we can develop a drug that can get rid of accumulated protein in someone’s brain that should stop the cells from dying. If someone has early onset PD and a slight tremor and minor walking problems, stopping the disease and having a low dose of dopamine therapy to control symptoms is almost a cure.

The next step is to develop better biomarkers to identify people at risk of developing Parkinson’s, so if you know someone is a few years away from developing symptoms, and you have the tools in place, you can start treatment early and stop the disease from kicking in, even before you clinically have symptoms.

Thinking about people who have been diagnosed with a disease, who are ten years into the disease, who already have side effects from the disease, it’s a little harder to think of regenerative medicine, using embryonic or iPSCs for this. I think that it will take longer to see results with this approach, but that’s the long-term hope for the future. There are many  groups working in this space, which is critical to advance the field.

Why is Parkinson’s Awareness Month important?

It’s important because, while a lot of people know about the disease, there are also a lot of misconceptions about Parkinson’s.

Parkinson’s is confused with Alzheimer’s or dementia and cognitive problems, especially the fact that it’s more than just a gait and movement problem, that it affects many other parts of the body too.

Raising awareness about Rare Disease Day

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One of the goals we set ourselves at CIRM in our 2016 Strategic Plan was to fund 50 new clinical trials over the next five years, including ten rare or orphan diseases. Since then we have funded 13 new clinical trials including four targeting rare diseases (retinitis pigmentosa, severe combined immunodeficiency, ALS or Lou Gehrig’s disease, and Duchenne’s Muscular Dystrophy). It’s a good start but clearly, with almost 7,000 rare diseases, this is just the tip of the iceberg. There is still so much work to do.

And all around the world people are doing that work. Today we have asked Emily Walsh, the Community Outreach Director at the Mesothelioma Cancer Alliance,  to write about the efforts underway to raise awareness about rare diseases, and to raise funds for research to develop new treatments for them.

“February 28th marks the annual worldwide event for Rare Disease Day. This is a day dedicated to raising awareness for rare diseases that affect people all over the world. The campaign works to target the general public as well as policy makers in hopes of bringing attention to diseases that receive little attention and funding. For the year 2017 it was decided that the focus would fall on “research,” with the slogan, “With research, possibilities are limitless.”

Getting involved for Rare Disease Day means taking this message and spreading it far and wide. Awareness for rare diseases is extremely important, especially among researchers, universities, students, companies, policy makers, and clinicians. It has long been known that the best advocates for rare diseases are the patients themselves. They use their specific perspectives to raise their voice, share their story, and shed light on the areas where additional funding and research are most necessary.

To see how you can help support the Rare Disease Day efforts this year, click here.

Groups like the Mesothelioma Cancer Alliance and the Mesothelioma Group are adding their voices to the cause to raise awareness about mesothelioma cancer, a rare form of cancer caused by exposure and inhalation of airborne asbestos fibers

Rare diseases affect 300 million people worldwide, but only 5% of them have an FDA approved treatment or cure. Malignant mesothelioma is among the 95 percent that doesn’t have a treatment or cure.

Asbestos has been used throughout history in building materials because of its fire retardant properties. Having a home with asbestos insulation, ceiling tiles, and roof shingles meant that the house was safer. However, it was found that once asbestos crumbled and became powder-like, the tiny fibers could become airborne and be inhaled and lodge themselves in lung tissue causing mesothelioma. The late stage discovery of mesothelioma is often what causes it to have such a high mortality rate. Symptoms can have a very sudden onset, even though the person may have been exposed decades prior.

Right now, treatment for mesothelioma includes the usual combination of chemotherapy, radiation, and surgery, but researchers are looking at other approaches to see if they can be more effective or can help in conjunction with the standard methods. For example one drug, Defactinib, has shown some promise in inhibiting the growth and spread of cancer stem cells – these are stem cells that can evade chemotherapy and cause patients to relapse.”

Some people might ask why spend limited resources on something that affects so few people. But the lessons we learn in developing treatments for a rare disease can often lead us to treatments for diseases that affect many millions of people.

But numbers aside, there is no hierarchy of need, no scale to say the suffering of people with Huntington’s disease is any greater or less than that of people with Alzheimer’s. We are not in the business of making value judgements about who has the greatest need. We are in the business of accelerating treatments to patients with unmet medical needs. And those suffering from rare disease are very clearly  people in need.

 


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