Advancements in gene editing make blind rats see light

Gene editing is a rapidly advancing technology that scientists are using to manipulate the genomes of cells with precision and accuracy. Many of these experiments are being conducted on stem cells to genetic mutations in an attempt to find cures for various diseases like cancer, HIV and blindness.

Speaking of blindness, researchers from the Salk Institute reported today that they’ve improved upon the current CRISPR/Cas9 gene editing technology and found a more efficient way to edit the genomes of cells in living animals. They used their technology on blind rats that had a genetic disease called retinitis pigmentosa (RP) and found that the rats were able to see light following the treatment.

The really exciting part about their findings is that their CRISPR technology works well on dividing cells like stem cells and progenitor cells, which is typically how scientists use the CRISPR technology, but it also works on adult cells that do not divide – a feat that hasn’t been accomplished before.

Their results, which were published today in the journal Nature, offer a new tool that scientists can use to target cells that no longer divide in tissues and organs like the eye, brain, pancreas and heart.

According to a Salk news release:

“The new Salk technology is ten times more efficient than other methods at incorporating new DNA into cultures of dividing cells, making it a promising tool for both research and medicine. But, more importantly, the Salk technique represents the first time scientists have managed to insert a new gene into a precise DNA location in adult cells that no longer divide, such as those of the eye, brain, pancreas or heart, offering new possibilities for therapeutic applications in these cells.”

CRISPR gene edited neurons, which are non-dividing brain cells, are shown in green while cell nuclei are shown in blue. (Salk)

CRISPR gene edited neurons, which are non-dividing brain cells, are shown in green while cell nuclei are shown in blue. (Salk)

Salk Professor and senior author on the study, Juan Carlos Izpisua Belmonte, explained the big picture of their findings:

“We are very excited by the technology we discovered because it’s something that could not be done before. For the first time, we now have a technology that allows us to modify the DNA of non-dividing cells, to fix broken genes in the brain, heart and liver. It allows us for the first time to be able to dream of curing diseases that we couldn’t before, which is exciting.”

If you want to learn more about the science behind their new CRISPR gene editing technology, check out the Salk news release and coverage in Genetic Engineering & Biotechnology News. You can also watch this short three minute video about the study made by the Salk Institute.

Measuring depression with non-invasive imaging of new brain cells

For most of the 20th century, scientists thought you’re basically stuck with the brain cells you’re born with. “Everything may die, nothing may be regenerated”, is how Santiago Ramón y Cajal, the father of modern neuroscience, described nerve cells, aka neurons, in the adult brain. But, over the past few decades, it’s become clear that stem cells are present in the brain and produce new neurons over the course of our lives.

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Hippocampus (in red)
Image: Life Science Databases

This better understanding of brain biology opened up new insights into brain function. For instance, a reduced volume of the hippocampus, an area of the brain important for learning and memory, is linked to depression and the use of anti-depressant drugs like Prozac have been shown to trigger the growth of new neurons in this part of the brain.

Now, researchers at the RIKEN institute in Japan have developed a non-invasive imaging method – so far, just in rats – to track the generation of new neurons from brain stem cells.  This study, reported in the Journal of Neuroscience, may provide new means to diagnose depression and to monitor the effectiveness of drugs in ways that aren’t currently possible.

A PET project to track new brain cells

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PET scan of human brain
Image: Wikipedia

The scientists focused on the use of positron emitting tomography (PET) imaging, which involves the injecting a radioactive tracer, designed to target an organ or a specific area of an organ, into the blood. The use of this type of tracer is routine in medical imaging and the radioactivity decays so fast that it’s essentially gone within 24 hours. The radioactive signal that’s emitted out from the body is then detected with PET scanning and reveals the precise location of the tracer within the body or organ. But PET scanning of neurogenesis in the brain had proved to be difficult – no definitive signals were observed. Magnetic resonance imaging (MRI) is also a no-go because it requires the risky injection of a tracer directly into the brain.

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PET scanner. Image: Jacoby Werther

The RIKEN team pinpointed the stumbling block: the lack of signal was due to the presence of proteins, called drug transporters, that continually pump the radioactive tracers out of the brain and back into the blood. When they re-ran the PET scan using a clinically available drug that blocks the transporter proteins, a neurogenesis signal was picked up.

Prozac helps stimulate new brain cell growth
With this obstacle overcome, the team tested out their technique. They gave one group of rats corticosterone, a stress hormone, for a month. This hormone is known to reduce neurogenesis and create depression-like behavior in the animals. They gave a second group of rats corticosterone plus Prozac. Sure enough, the PET scan signal was able to measure a decrease in neurogenesis in the corticosterone only group but also a recovery in neurogenesis in the group that received the hormone plus Prozac. Follow up analysis of rat brain slices confirmed that compared to untreated animals, neurogenesis was reduced 45% in the corticosterone group but no reduction was observed when Prozac was also included.

In a news release picked up by Nanowerk, team lead Yosky Kataoka discussed the game-changer possibilities of their new method:

“This is a very interesting finding because it has been a long-time dream to find a noninvasive test that can give objective evidence of depression and simultaneously show whether drugs are working in a given patient. We have shown that it is possible, at least in experimental animals, to use PET to show the presence of depression and the effectiveness of drugs… Since it is known that these same brain regions are involved in depression in the human brain, we would like to try this technique in the clinic and see whether it turns out to be effective in humans as well.”

A new and improved method for making healthy heart tissue is here

Scientists from the Gladstone Institutes have done it again. They’ve made a better and faster way of generating healthy heart tissue in mice with damaged hearts. With further advancements, their findings could potentially be translated into a new way of treating heart failure in patients.

Previously, the Gladstone team discovered that they could transform scar tissue in the damaged hearts of mice into healthy, beating heart muscle cells by a process called direct reprogramming. The team found that turning on three transcription factors, Gata4, Mef2c and Tbx5 (collectively called GMT), in the damaged hearts of mice activated heart genes that turned scar tissue cells, also known as cardiac fibroblasts, into beating heart cells or cardiomyocytes.

Their GMT direct cardiac reprogramming technology was only able to turn 10 percent of cardiac fibroblasts into cardiomyocytes in mice over the period of six to eight week. In their new CIRM-funded study published in Circulation, they improved upon their original reprogramming method by identifying two chemicals that improved the efficiency of making new heart cells. Not only were they able to create eight times the number of beating cardiomyocytes from mouse cardiac fibroblasts, but they were also able to speed up the reprogramming process to a period of just one week.

To find these chemicals, they screened a library of 5,500 small molecules. The chemicals that looked most promising for cardiac reprogramming were inhibitors of the TGF-β and WNT signaling pathways. The importance of these chemicals was explained in a Gladstone news release:

“The first chemical inhibits a growth factor that helps cells grow and divide and is important for repairing tissue after injury. The second chemical inhibits an important pathway that regulates heart development. By combining the two chemicals with GMT, the researchers successfully regenerated heart muscle and greatly improved heart function in mice that had suffered a heart attack.”

Senior author on the study, Deepak Srivastava, further explained:

“While our original process for direct cardiac reprogramming with GMT has been promising, it could be more efficient. With our screen, we discovered that chemically inhibiting two biological pathways active in embryonic formation improves the speed, quantity, and quality of the heart cells produced from our original process.”

Encouraged by their studies in mice, the scientists also tested their new and improved direct reprogramming method on human cells. Previously they found that while the same GMT transcription factors could reprogram human cardiac fibroblasts into cardiomyocytes, a combination of seven factors was required to make quality cardiomyocytes comparable to those seen in mice. But with the addition of the two inhibitors, they were able to reduce the number of reprogramming factors from seven to four, which included the GMT factors and one additional factor called Myocardin. These four factors plus the two chemical inhibitors were capable of reprograming human cardiac fibroblasts into beating heart cells.

With heart failure affecting more than 20 million people globally, the need for new therapies that can regenerate the heart is pressing. The Gladstone team is hoping to advance their research to a point where it could be tested in human patients with heart failure. First author on the study, Tamer Mohamed, concluded:

“Heart failure afflicts many people worldwide, and we still do not have an effective treatment for patients suffering from this disease. With our enhanced method of direct cardiac reprogramming, we hope to combine gene therapy with drugs to create better treatments for patients suffering from this devastating disease.”

Tamer Mohamed and Deepak Srivastava, Gladstone Institutes

Tamer Mohamed and Deepak Srivastava. Photo courtesy of Chris Goodfellow, Gladstone Institutes


Related Links:

Throwback Thursday: Progress to a Cure for Type 1 Diabetes

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of valuable stem cell stories on our blog. Some of these stories represent crucial advances towards stem cell-based cures for serious diseases and deserve a second look.

novemberawarenessmonthThis week in honor of Diabetes Awareness Month, we are featuring type 1 diabetes (T1D), a chronic disease that destroys the insulin-producing beta cells in your pancreas. Without these important cells, patients cannot maintain the proper levels of glucose, a fancy name for sugar, in their blood and are at risk for many complications including heart disease, blindness, and even death.

Cell replacement therapy is evolving into an attractive option for patients with T1D. Replacing lost beta cells in the pancreas is a more permanent and less burdensome solution than the daily insulin shots (or insulin pumps) that many T1D patients currently take.

So let’s take a look at the past year’s advances in stem cell research for diabetes.

Making Insulin-Producing Cells from Stem Cells and Skin

This year, there were a lot of exciting studies that improved upon previous methods for generating pancreatic beta cells in a dish. Here’s a brief recap of a few of the studies we covered on our blog:

  • Make pancreatic cells from stem cells. Scientists from the Washington University School of Medicine in St. Louis and the Harvard Stem Cell Institute developed a method that makes beta cells from T1D patient-derived induced pluripotent stem cells (iPSCs) that behave very similarly to true beta cells both in a dish and when transplanted into diabetic mice. Their discovery has the potential to offer personalized stem cell treatments for patients with T1D in the near future and the authors of the study predicted that their technology could be ready to test in humans in the next three to five years.
  • Making functional pancreatic cells from skin. Scientists from the Gladstone Institutes used a technique called direct reprogramming to turn human skin cells directly into pancreatic beta cells without having to go all the way back to a pluripotent stem cell state. The pancreatic cells looked and acted like the real thing in a dish (they were able to secrete insulin when exposed to glucose), and they functioned normally when transplanted into diabetic mice. This study is exciting because it offers a new and more efficient method to make functioning human beta cells in mass quantities.

    Functioning human pancreatic cells after they’ve been transplanted into a mouse. (Image: Saiyong Zhu, Gladstone)

    Functioning human pancreatic cells after they’ve been transplanted into a mouse. (Image: Saiyong Zhu, Gladstone)

  • Challenges of stem cell-derived diabetes treatments. At this year’s Ogawa-Yamanaka Stem Cell Award ceremony Douglas Melton, a well-renowned diabetes researcher from Harvard, spoke about the main challenges for developing stem cell-derived diabetes treatments. The first is the need for better control over the methods that make beta cells from stem cells. The second was finding ways to make large quantities of beta cells for human transplantation. The last was finding ways to prevent a patient’s immune system from rejecting transplanted beta cells. Melton and other scientists are already working on improving techniques to make more beta cells from stem cells. As for preventing transplanted beta cells from being attacked by the patient’s immune system, Melton described two possibilities: using an encapsulation device or biological protection to mask the transplanted cells from an attack.

Progress to a Cure: Clinical Trials for Type 1 Diabetes

Speaking of encapsulation devices, CIRM is funding a Phase I clinical trial sponsored by a San Diego-based company called ViaCyte that’s hoping to develop a stem cell-based cure for patients with T1D. The treatment involves placing a small encapsulated device containing stem cell-derived pancreatic precursor cells under the skin of T1D patients. Once implanted, these precursor cells should develop into pancreatic beta cells that can secrete insulin into the patient’s blood stream. The goal of this trial is first to make sure the treatment is safe for patients and second to see if it’s effective in improving a patient’s ability to regulate their blood sugar levels.

To learn more about this exciting clinical trial, watch this fun video made by Youreka Science.

ViaCyte is still waiting on results for their Phase 1 clinical trial, but in the meantime, they are developing a modified version of their original device for T1D called PEC-Direct. This device also contains pancreatic precursor cells but it’s been designed in a way that allows the patient’s blood vessels to make direct connections to the cells inside the device. This vascularization process hopefully will improve the survival and function of the insulin producing beta cells inside the device. This study, which is in the last stage of research before clinical trials, is also being funded by CIRM, and we are excited to hear news about its progress next year.

ViaCyte's PEC-Direct device allows a patient's blood vessels to integrate and make contact with the transplanted beta cells.

ViaCyte’s PEC-Direct device allows a patient’s blood vessels to integrate and make contact with the transplanted beta cells.


Related Links:

With CRISPR-Cas9, Stanford Team Looks for Landslide Victory over Sickle Cell Disease

The results are in folks. Though it’s too early to declare a winner, it looks very likely that sickle cell disease is going to be soundly defeated by CRISPR-Cas9.

Reporting in Nature on Monday, Stanford researchers devised a method to efficiently correct the sickle cell mutation in human blood stem cells using the super-popular, user-friendly CRISPR-Cas9 genetic editing technology. Speaking to Reuters, lead scientist Matthew Porteus forecasted that clinical trials are just around the corner:

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Matthew Porteus
Image: Stanford Medicine

We think we have a complete data set to present to the FDA (Food and Drug Administration) to say we’ve done all pre-clinical experiments to show this is ready for a clinical trial

Sickle Cell Disease 101
Sickle cell disease is an inherited blood disorder that causes the generation of abnormal, sickle-shaped red blood cells in people afflicted with the disease. As a result, the misshapen cells become sticky and clump up inside blood vessels which can cause debilitating pain, anemia and organ failure. Besides pain medicine and frequent blood transfusions, the only other treatment available is a blood stem cell transplant which can be curative but carries significant risks including a high mortality rate.

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Sickle cell disease leads to abnormally shaped red blood cells (watch our video for more info)

Because the disease arises from a single DNA mutation, scientists have been working hard to use gene editing techniques as a treatment strategy. In this procedure, the patient’s stem cells are collected from their bone marrow and then the mutation is corrected in the lab. The repaired cells are transplanted back into the patient which avoids risk of immune rejection due to mismatched donor blood.

CRISPR-Cas9: the New Kid in Gene Therapy Town
Other gene therapy techniques have been successful at fixing the sickle cell mutation and are currently in clinical trials. But the more recent CRISPR-Cas9 method is much easier to carry out. Cas9 is an enzyme with an attached piece of RNA, a genetic molecule, that can be engineered to bind specifically to the sickle cell gene and, like molecular scissors, snip the DNA. This break in the DNA activates the cell’s natural DNA repair functions. At the same time, the correct sickle cell gene is delivered to the stem cells with the help of a harmless virus.

The researchers were able to correct 30 to 50% of the mutated cells using this method. That’s well over the 10% threshold that’s thought to be needed to get a clinical benefit in people. And 16 weeks after transplanting the cells into mice, the cells were still intact and healthy in the animal’s bone marrow. Just a few weeks ago, a group at UC Berkeley reported a slightly different CRISPR-Cas9 method to correct the sickle cell gene and found that about 25% of cells were corrected.

According to the Reuters interview, Porteus hopes to begin clinical trials in 2018. Add that to the sickle cell gene therapy trials already underway, including a CIRM-funded trial sponsored by UCLA, and you can’t help feeling optimistic that sickle cell disease will be voted out of the existence in the not so distance future.

First spinal cord injury trial patient gets maximum stem cell dose

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Kris Boesen, CIRM spinal cord injury clinical trial patient.

There comes a pivotal point in every experiment where you say “ok, now we are going to see if this really works.” We may be at that point in the clinical trial we are funding to see if stem cells can help people with spinal cord injuries.

Today Asterias Biotherapeutics announced they have given the first patient in the clinical trial the highest dose of 20 million cells. The therapy was administered at Santa Clara Valley Medical Center (SCVMC) in San Jose, California where Jake Javier – a young man who was treated at an earlier stage of the trial – was treated. You can read Jake’s story here.

The goal of the trial is to test the safety of transplanting three escalating doses of AST-OPC1 cells. These are a form of cell called oligodendrocyte progenitors, which are capable of becoming several different kinds of nerve cells, some of which play a supporting role and help protect nerve cells in the central nervous system – the area damaged in spinal cord injury.

In a news release, Dr. Edward Wirth, Asterias’ Chief Medical Officer, says this could be a crucial phase in the trial:

“We have been very encouraged by the early clinical efficacy and safety data for AST-OPC1, and we now look forward to evaluating the 20 million cell dose in complete cervical spinal cord injury patients. Based on extensive pre-clinical research, this is in the dosing range where we would expect to see optimal clinical improvement in these patients.”

To be eligible, individuals have to have experienced a severe neck injury in the last 30 days, one that has left them with no sensation or movement below the level of their injury, and that means they have typically lost all lower limb function and most hand and arm function.

In the first phase individuals were given 2 million cells. This was primarily to make sure that this approach was safe and wouldn’t cause any problems for the patients. The second phase boosted that dose to ten million cells. That was thought to be about half the therapeutic dose but it seemed to help all those enrolled. By 90 days after the transplant all five patients treated with ten million cells had shown some level of recovery of at least one motor level, meaning they had regained some use of their arms and/or hands on at least one side of their body. Two of the patients experienced an improvement of two motor levels. Perhaps the most impressive was Kris Boesen, who regained movement and strength in both his arms and hands. He says he is even experiencing some movement in his legs.

All this is, of course, tremendously encouraging, but we also have to sound a note of caution. Sometimes individuals experience spontaneous recovery after an accident like this. The fact that all five patients in the 10 million cell group did well suggests that this may be more than just a coincidence. That’s why this next group, the 20 million cell cohort, is so important.

As Steve McKenna, Chief of the Trauma Center at SCVMC, says; if we are truly going to see an improvement in people’s condition because of the stem cell transplant, this is when we would expect to see it:

“The early efficacy results presented in September from the 10 million cell AIS-A cohort were quite encouraging, and we’re looking forward to seeing if those meaningful functional improvements are maintained through six months and beyond. We are also looking forward to seeing the results in patients from the higher 20 million cell AST-OPC1 dose, as well as results in the first AIS-B patients.”

For more information about the Asterias clinical trial, including locations and eligibility requirements, go here: www.clinicaltrials.gov, using Identifier NCT02302157, and at the SCiStar Study Website (www.SCiStar-study.com).

We can never talk about this clinical trial without paying tribute to a tremendous patient advocate and a great champion of stem cell research, Roman Reed. He’s the driving force behind the Roman Reed Spinal Cord Injury Research Act  which helped fund the pioneering research of Dr. Hans Keirstead that laid the groundwork for this clinical trial.

 

 

Discovering stem cells and science at Discovery Day

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The CIRM booth at Discovery Day at AT&T Park

Someone stole my thigh bone. One minute it was there. The next, gone. I have narrowed down the list of suspects to the more than 25,000 people attending Discovery Day at San Francisco’s AT&T Park.

To be honest, the bone was just a laminated image of a bone, stuck to the image of a person drawn on a white board. We were using it, along with laminated images of a brain, liver, stomach and other organs and tissues, to show that there are many different kinds of stem cells in the body, and they all have different potential uses.

The white board and its body parts were gimmicks that we used to get kids to come up to the CIRM booth and ask what we were doing. Then, as they played with the images, and tried to guess which stem cells went where, we talked to their parents about stem cell research, and CIRM and the progress being made.

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Dr. Karen Ring explaining embryonic development to kids

We also used Play Doh so that the kids could model cell division and specialization during embryonic development. But mostly it was so the kids could play with the Play Doh while we talked to their parents.

It is shameless I know but when you are competing against more than 130 other booths for people’s attention – and some of these booths had live snakes, virtual reality devices, or they just let kids throw and hit things – you have to be creative.

And creativity was certainly the key word, because Discovery Day – part of the annual week-long Bay Area Science Fair – was filled with booths from companies and academic institutions promoting every imaginable aspect of science.

So why were we there? Well, first, education has been an important part of CIRM’s mission ever since we were created. Second, we’re a state agency that gets public funding so we feel we owe it to the public to explain how their money is being used. And third, it’s just a lot of fun.

NASA was there, talking about exploring deep space. And there were booths focused on exploring the oceans, and saving them from pollution and over-fishing. You could learn about mathematics and engineering by building wacky-looking paper airplanes that flew long distances, or you could just sit in the cockpit of a fighter jet.

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And everywhere you looked were families, with kids running up to the different booths to see what was there. All they needed was a little draw to get them to stick around for a few minutes, so you could talk to them and explain to them what stem cells are and why they are so amazing. Some of the kids were fascinated and wanted to know more: some just wanted to use the Play Doh;  at least one just wanted to eat the Play Doh, but fortunately we were able to stop that happening.

It was an amazing sight to see a baseball stadium filled with tens of thousands of people, all there to learn about science. At a time when we are told that kids don’t care about science, that they don’t like math, this was the perfect response. All you had to do was look around and see that kids were fascinated by science. They were hungry to learn how pouring carbon dioxide on a candle puts out the flame. They delighted in touching an otter pelt and feeling how silky smooth it is, and then looking at the pelt under a microscope to see just how extraordinarily dense the hairs are and how that helps waterproof the otter.

And so yes, we used Play Doh and a white board person to lure the kids to us. But it worked.

There was another booth where they had a couple of the San Francisco 49er’s cheerleaders in full uniform. I don’t actually know what that had to do with teaching science but it was very popular with some of the men. Maybe next year I could try dressing up like that. It would certainly draw a crowd.

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.

Three stories give us a glimpse of the real possibilities for stem cell therapies

Today we’re featuring a guest blog by Lisa Willemse about the Till and McCulloch Stem Cell Meeting in Canada. Enjoy!

Stem cell treatments should be incredibly easy. Or rather, that’s what some clinics or products would have you believe. Because, on the surface, a one-stop-shop for injectable cells to cure just about any condition or topical creams to peel away the scourge of time are very easy.

Attend one stem cell research conference and you’ll be convinced that it’s much more complicated. It’s a sea of reagents and transcription factors and unknown cause-and-effect. Many researchers will spend their entire career working on just one unknown and their caution and concern when it comes to the notion of a cure is justifiable.

Whistler (Courtesy of Lisa Willemse)

Whistler (Courtesy of Lisa Willemse)

Which makes it all the more impactful when you attend a research conference and hear three talks, back-to-back, that demonstrate that we’re ticking off some of those unknowns and getting much closer to real – not sham – therapies. Therapies with a sound scientific basis that are well planned and done with patient safety (not sales) in mind. Last week’s Till and McCulloch Meetings, held in Whistler, British Columbia gave us a sense of what is possible for three conditions: macular degeneration (vision), septic shock and a rare neurologic disease (Stiff Person Syndrome). Other blogs have covered  different aspects of this meeting here and here.

Vision Repair – Age-related Macular Degeneration (AMD)

As the world’s first clinical trial to use induced pluripotent stem cells launched amid sweeping regulatory changes in Japan, Dr. Masayo Takahashi’s treatment protocol for AMD has received no small amount of scrutiny. After a brief hiatus, the trial was back on track earlier this year and Takahashi’s presentation at this meeting was highly anticipated.

Dr. Masayo Takahashi

Dr. Masayo Takahashi

It did not disappoint. Takahashi spent the better part of her time outlining the steps taken to reach the point where the clinical trial was possible, including multiple studies in mice and further refinement of the treatment to ensure it would be stable in humans even with genetic changes over time. Given that one of the reasons the trial was put on hold was due to genetic mutations found in the cells prepared for the second potential human transplant, Takahashi’s careful work in ensuring the product was safe bodes well for the future of this trial.

The first patient was treated in 2014, a 78-year-old woman with wet AMD in the right eye, and although only minimal visual improvement was documented, the patient anonymously told the Japan Times, “I’m glad I received the treatment. I feel my eyesight has brightened and widened.”

Takahashi also alluded to some of the other challenges she’d had to overcome to make this trial a reality, including would-be critics who told her that the nervous system and the retina were too complicated to regenerate. Takahashi’s response? “You don’t know stem cells [and] you don’t understand the needs of the patient.”

While it was unclear when the next patient will receive treatment, Takahashi did say that three new applications for clinical trials using her refined protocols have been submitted for approval.

Septic shock  

Septic shock is not a condition that gets a lot of attention, most likely because it’s not a primary illness, but a secondary one; a drastic and often fatal immune response that severely reduces blood pressure and cell metabolism. It accounts for 20% of all intensive care unit (ICU) admissions and is the most common cause of non-coronary mortality in the ICU. For those who survive septic shock, there are significant and long-term health consequences.

Over 100 clinical trials have attempted to improve outcomes for patients with septic shock, but not one has been successfully translated into the clinical setting. Supportive care remains the mainstay of therapy.

Dr. Lauralyn McIntyre

Dr. Lauralyn McIntyre

This was the sober backdrop painted by critical care physician, Dr. Lauralyn McIntyre as she began her talk on the world’s first stem cell clinical trial for septic shock she is co-leading in Ottawa with Dr. Duncan Stewart.

Like Takahashi, McIntyre spent a good deal of time explaining the rationale and research that underpin the trial, which takes advantage of the immune-modulating properties of mesenchymal stromal cells (also called mesenchymal stem cells or MSCs) to suppress and reverse the effects of septic shock. This work includes reviews of more than 50 studies that looked at the effects of MSCs in both human trials and animal studies.

McIntyre also discussed research she did with mice in 2010 as a proof-of-concept, where the MSC therapy was delayed for six days. This delay is important as it better simulates the time frame in which most patients arrive in the hospital. As McIntryre pointed out, if the therapy only worked when given within hours of disease development, what good would it be for patients who come in on day six?

Fortunately, the therapy worked in the mice, even after a delayed timeframe, providing a green light for safety testing in humans. The small first human trial is currently underway for nine patients (with a control arm of 21) with results not yet published – although one of the patients shared his experience earlier this year. McIntyre relayed that the early data is very encouraging – enough that the team is moving ahead with a Phase 2 randomized trial in 10 centres across Canada in 2017.

Stiff Person Syndrome

Tina Ceroni’s story is much more personal. She is only the second person in the world to have received an experimental stem cell treatment for Stiff Person Syndrome, a rare neurologic condition that causes uncontrolled and sustained contractions of the arm, leg or other muscles. Often misdiagnosed initially as Multiple Sclerosis or anxiety/depression, SPS is also an autoimmune disease for which the cause is unknown.

Tina Ceroni

Tina Ceroni (The Ottawa Hospital)

I’ve written about Tina’s story before – about how she was hospitalized 47 times in one year and how a chance meeting with another SPS patient propelled Ceroni on a journey that included an intensive stem cell therapy under the guidance of Dr. Harry Atkins at the Ottawa Hospital, in which her blood stem cells were harvested from her bone marrow and used to repopulate her system after her immune system was wiped clean with chemotherapy.

Now a stem cell advocate, Ceroni’s story keeps getting better – not merely in how powerfully and passionately she tells it, but in the continued good health she enjoys after her treatment and in her efforts to share it more broadly.

Most importantly, she drives home a key message:

“My story underscores the importance of clinical trials…. My experience will help to change the future for others. I am living proof that a clinical trial for stem cell therapy can have a life-changing outcome.”

“Often hope is the only medicine we have.”

It’s important that patients like Ceroni continue share their story, not just with the research community to give a human face to the work they do, but to show that solid research is making an impact, one that can be measured in lives saved.


Lisa Willemse

Lisa Willemse

This article is published simultaneously, with permission by the author, Lisa Willemse, on the Ontario Institute for Regenerative Medicine (OIRM) Expression blog.

Deleting a single gene can boost blood stem cell regeneration

A serious side effect that cancer patients undergoing chemotherapy experience is myelosuppression. That’s a big word for a process that involves the decreased production of the body’s immune cells from hematopoietic stem cells (HSCs) or blood stem cells in the bone marrow. Without these important cells that make up the immune system, patients are at risk for major infections and even death.

Human blood (red) and immune cells (green) are made from hematopoietic/blood stem cells. Photo credit: ZEISS Microscopy.

Human blood (red) and immune cells (green) are made from hematopoietic/blood stem cells. Photo credit: ZEISS Microscopy.

Scientists are trying to find ways to treat cancer patients that have undergone myelosuppressive therapies, as well as patients that need bone marrow transplants to replace their own bone marrow that’s been damaged or removed. One possible solution is boosting the regenerative capacity of HSCs. Transplanting HSCs that are specially primed to reproduce rapidly into cells of the immune system could improve the outcome of bone marrow transplants in patients.

Deleting Grb10 boost blood stem cell regeneration

A CIRM-funded team from the UCLA Broad Stem Cell Institute and the Jonsson Comprehensive Cancer Center has identified a single gene that can be manipulated to boost HSC regeneration in mice. The study, which was published in Cell Reports, found that deleting or turning off expression of an imprinted gene called Grb10 in HSCs caused these blood stem cells to reproduce more robustly after being transplanted into mice that had their bone marrow removed.

I just used another big word in that last paragraph, so let me explain. An imprinted gene is a gene that is expressed or activated based on which parent it was inherited from. Typically, you receive one copy of a gene from your mother and one from your father and both are expressed – a process called Mendelian inheritance. But imprinted genes are different – they are marked with specific epigenetic tags that silence their expression in the sperm or egg cells of the parents. Thus if you inherited an imprinted gene from your mother, the other copy of that gene from your father would be expressed and vice versa.

Scientists have discovered that imprinted genes are important for human development and also for directing what cell types adult stem cells like HSCs develop into. The team from UCLA led by senior author Dr. John Chute, was interested in answering a different question: are imprinted genes involved in determining the function of HSCs? They compared two different populations of HSCs derived from mouse bone marrow: a normal, healthy population and HSCs exposed to total body irradiation (TBI), which destroys the immune system. They discovered that the expression of an imprinted gene called Grb10 was dramatically higher in HSCs exposed to TBI compared to healthy HSCs.

Cell Reports

Deleting Grb10  increases blood stem cell regeneration in the bone marrow of irradiated mice (bottom) compared to normal mice (top). Cell Reports

Because Grb10 is an imprinted gene, the scientists deleted either the paternal or maternal copy of that gene in mice. While deleting the paternal Grb10 gene had no effect on the function of HSCs, maternal deletion dramatically boosted the capacity of HSCs to divide and make more copies of themselves. Without the maternal copy of Grb10, HSCs were able to regenerate at a much faster scale than normal HSCs.

To further prove their point, the team transplanted normal HSCs and HSCs that lacked Grb10 into TBI or fully irradiated mice. HSCs that lacked Grb10 were able to regenerate themselves and produce other immune cells more robustly 20 weeks after transplantation compared to normal HSCs.

Potential applications and future studies

This study offers two important findings. First, they discovered that Grb10 plays an important role “in regulating HSC self-renewal following transplantation and HSC regeneration in response to injury.” Second, they found that inhibiting Grb10 function in HSCs could have potential therapeutic applications for boosting “hematopoietic regeneration in the setting of HSC transplantation or following myelosuppressive injury.” Patients in need of bone marrow transplants could potentially receive more benefit from transplants of HSCs that don’t express the Grb10 gene.

In my opinion, further studies should be done to further understand the role of Grb10 in regulating HSC self-renewal and regeneration. What is the benefit of having this gene expressed in HSCs if inhibiting its expression leads to an increased regenerative capacity? Is it to prevent cancer from forming? Additionally, the authors will need to address the potential long-term side effects of inhibiting Grb10 expression in HSCs. They did report that mice that lacked the Grb10 gene did not develop blood cancers at one year of age which is good news. They also suggested that instead of deleting Grb10, new drugs could be identified that inhibit Grb10 function in HSCs.