CIRM-funded stem cell clinical trial for spinal cord injury expands patient recruitment

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It’s always great to start the week off with some good news. Today we learned that the Food and Drug Administration (FDA) has given Asterias Biotherapeutics approval to expand the number and type of people with spinal cord injuries that it treats in their CIRM-funded clinical trial.

Up till now, Asterias has been treating people who have injuries at the C5-C7 level, those are the lowest levels of the cervical spine, near the base of the neck. Now they will be able to treat people with injuries at the C4 level, that’s not only higher up the neck but it’s also the second most common form of spinal cord injury.

In a news release Dr. Ed Wirth, Asterias’ Chief Medical Officer, says this is a vote of confidence from the FDA in the company’s AST-OPC1 stem cell therapy:

“FDA’s decision to allow the company to enroll qualified patients with C-4 level injuries is the result of the data supporting the safety of both AST-OPC1 and the procedure to inject the cells and means that the second most common cervical spinal cord injury population can now be eligible to receive AST-OPC1. The overall changes to the study protocol will enhance our ability to enroll qualified patient candidates for our current SCiStar study and we also expect the changes to help enrollment rates in a future, larger clinical study.”

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Photo courtesy Shepherd Center, Atlanta

People who are injured at the C4 level are typically paralyzed from the neck down and need constant help, while people with C5-C7 injuries typically have some use of their hands and arms. Caring for someone with a C4 injury is expensive, with lifetime costs estimated around $5 million. Anything that could help people recover some movement would not only reduce those costs but would, more importantly, also increase the quality of life for people.

Asterias is not only expanding the patient population they are working with, they are also expanding the window for treating the injury. Currently patients have to be enrolled from 14 to 30 days post injury. In this new C4 group that window has been extended to 21 to 42 days post injury.

The reason for that change is that because C4 is higher up in the neck, newly injured people often need to be placed on a ventilator to help stabilize them. These patients take a little more time to recover from the initial trauma before they are ready to be treated.

We have blogged several times (here, here and here) about the encouraging news from the Asterias trial and how it appears to be helping people with injuries at the C5-C7 level recover some movement in their arms and hands. In some cases, such as with Kris Boesen for example, the improvement has been quite dramatic. Now the hope is that this new patient population will see similar benefits.

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Kris Boesen, CIRM spinal cord injury clinical trial patient.

The study is being conducted at six centers in the U.S., including some here in California,  and the company plans to increase this to up to 12 sites to accommodate the expanded patient enrollment.

Stories that caught our eye: smelling weight gain, colon cancer & diet and diabetes & broken bones

How smelling your food could cause weight gain (Karen Ring).
Here’s the headline that caught my eye this week: “Smelling your food first can make you fat…”

It’s a bizarre statement, but the claim is backed by scientific research coming from a new study in Cell Metabolism by researchers at the University of California Berkeley. The team found that obese mice who smelled their food before eating it were more likely to gain weight compared to obese mice that couldn’t smell their food.

Their experiments revealed a connection between the olfactory system, which is responsible for our sense of smell, and how the mice metabolize food into energy. Obese mice that lost their ability to smell actually lost weight on a high-fat diet, burned more fat, and became more sensitive to the hormone insulin. Insulin regulates how much glucose, or sugar, is in the blood by facilitating the absorption of glucose by fat, liver and muscle cells. In obese individuals, insulin resistance can occur where their cells are no longer sensitive to the hormone and therefore can’t regulate how much glucose is in the blood.

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Both mice in this picture were fed the same high-fat diet. The only difference: the lower mouse’s sense of smell was temporarily blocked. Image: UC Berkeley

For obese mice that could smell their food, the same high fat diet given to the “no-smellers” resulted in massive weight gain in the “smellers” because their metabolism was impaired. Even more interesting is the fact that other types of smells unrelated to food, such as the scent of other mice, influenced weight gain in the “smellers”.

The authors concluded that the centers in our brain that are responsible for smell (the olfactory system) and metabolism (the hypothalamus) are connected and that manipulating smell could be a future strategy to influence how the brain controls the balance of energy during food consumption.

In an interview with Tech Times, senior author on the study, Dr. Andrew Dillin, explained how their research could potentially lead to a new strategy to promote weight loss,

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Andrew Dillin. Image: HHMI

“Sensory systems play a role in metabolism. Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived. If we can validate this in humans, perhaps we can actually make a drug that doesn’t interfere with smell but still blocks that metabolic circuitry. That would be amazing.”

A link between colorectal cancer and a Western diet identified
Weight gain isn’t the only concern of a eating a high-fat diet. It’s thought that 80% of colorectal cases are associated with a high-fat, Western diet. The basis for this connection hasn’t been well understood. But this week, researchers at the Cleveland Clinic report in Stem Cell Reports that they’ve pinpointed a protein signaling network within cancer stem cells as a possible source of the link.

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Cancer stem cells have properties that resemble embryonic stem cells and are thought to be the source of a cancer’s unlimited growth and spread. A cancer stem cell maintains its properties by exploiting various cell signaling processes that when functioning abnormally can lead to inappropriate cell division and tumor growth. In this study, the team focused on one cell signaling process carried out by a protein called STAT3, known to promote tumor growth in a mouse model of colon cancer. When the team blocked STAT3 activity, high fat diet-induced cancer stem cell growth subsided.

In a press release, Dr. Matthew Kalady, a colorectal surgeon at the Cleveland Clinic and an author on this study, explained how this new insight can open new therapeutic avenues:

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Matthew Kalady. Image: Cleveland Clinic

“We have known the influence of diet on colorectal cancer. However, these new findings are the first to show the connection between high-fat intake and colon cancer via a specific molecular pathway. We can now build upon this knowledge to develop new treatments aimed at blocking this pathway and reducing the negative impact of a high-fat diet on colon cancer risk.”

 

 

Scientists connect dots between diabetes and broken bones.
Type 2 diabetes carries a whole host of long-term complications including heart disease, nerve damage, kidney dysfunction and even an increased risk for bone fractures. The connection between diabetes and fragile bones has not been well understood. But this week, researchers at New York University of Dentistry, Stanford University and China’s Dalian Medical University published a report, funded in part by CIRM, in this week’s Nature Communications showing a biochemical basis for this connection. The new insight may lead to treatment options to prevent fractures.

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Chemical structure of succinate.
Image: Wikimedia Commons.

Fundamentally, diabetes is a disease that causes hyperglycemia, or abnormally high levels of blood sugar. The team ran a systematic analysis of hyperglycemia’s effects on bone metabolism using bone marrow samples from diabetic and healthy mice. They found that the levels of succinate, a key molecule involved in energy production, are over 20 times higher in the diabetic mice. In turns out that succinate also acts as a stimulator of bone breakdown. Now, bone is continually in a process of turnover and, in a healthy state, the breakdown of old bone is balanced with the formation of new bone. So, it appears that the huge increase of succinate is tipping the balance of bone turnover. In fact, the team found that the porous, yet strong inner region of bone, called trabecular bone, was significantly reduced in the diabetic mice, making them more susceptible to fractures.

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The density of spongy bone, or trabecular bone, is reduced in type 2 diabetes.
Image: Wikimedia commons

Dr. Xin Li, the study’s lead scientist, explained the importance of these new insights for people living with type 2 diabetes in a press release:

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Xin Li.
Image: NYU Dentistry

“The results are important because diabetics have a significantly higher fracture risk and their healing process is always delayed. In our study, the hyperglycemic mice had increased bone resorption [the breakdown and absorption of old bone], which outpaced the formation of new bone. This has implications for bone protection, as well as for the treatment of diabetes-associated collateral bone damage.”

 

Lights, Camera, Stem Cells! How photo-responsive hydrogels can improve stem cell therapies

Watching a movie in IMAX 3D.

These days, going to the movie theater is like riding the wildest rollercoaster at your local theme park. It can be an IMAX 3D, surround sound, vibrating seat experience that makes you feel like you’re living the actual movie.

As the entertainment industry evolves towards more intense, realistic cinematic experiences, scientists are following a similar path towards 3D technologies that will improve stem cell-based therapies for biomedical applications. One such technology is called a hydrogel. Hydrogels are biological materials made of either synthetic polymers or natural molecules that scientists use to simulate the native environment in which cells and tissues develop.

Growing stem cells on a flat surface, such as a culture dish, is like watching a movie in a standard, less immersive 2D theater – the stem cells aren’t in their typical 3D environment where they receive biochemical and physical cues to develop into the appropriate cell types of the tissue they are destined to become.

With hydrogels, scientists can more closely mimic a stem cell’s natural environment, or what is called the “stem cell niche”. A lot of research has been dedicated towards fine-tuning hydrogels in a way that can control how stem cells behave and mature. We’ve blogged on this topic previously, and today we bring you an update on a new type of hydrogel that improves upon current technologies.

Scientists from The Hong Kong University of Science and Technology created photo-responsive or light-sensitive hydrogels that they used to grow human mesenchymal stem cells in 3D cultures. These hydrogels contain a vitamin B12-dependent, photo-responsive protein called CarHC. In the dark, coenzyme B12 binds to CarHC and triggers the protein to self-assemble into polymers that create an elastic hydrogel structure. When exposed to light, B12 is absorbed and can no longer bind CarHC, causing the hydrogel structure to dissolve into a liquid solution.

A hydrogel containing mesenchymal stem cells. (Image courtesy of Harvard Paulson School).

This photo-responsive hydrogel is the equivalent of a light-sensing switch that allows the scientists to capture or release stem cells without damaging them or affecting their viability. Senior author on the study, Dr. Fei Sun, elaborated in an interview with Phys.org,

“The resulting hydrogel composed of physically self-assembled CarHC polymers exhibited a rapid gel-solultion transition on light exposure, which enabled the facile release/recovery of 3T3 fibroblasts and human mesenchymal stem cells (hMSCs) from 3D cultures while maintaining their viability.”

Sun’s team is one of the first to report the development of photo-sensitive “smart” hydrogels for stem cell research applications. Looking forward, Sun believes that their technology will be useful for making “tunable materials” that will aid in the development of stem cell-based therapies.

He concluded,

“Given the growing demand for creating stimuli-responsive “smart” hydrogels, the direct assembly of stimuli-responsive proteins into hydrogels represents a versatile strategy for designing dynamically tunable materials.”

Making brain stem cells act more like salmon than bloodhounds

Like salmon swimming against a river current, brain stem cells can travel against their normal migration stream with the help of electrical stimuli, so says CIRM-funded research published this week in Stem Cell Reports. The research, carried out by a team of UC Davis scientists, could one day provide a means for guiding brain stem cells, or neural stem cells (NSCs), to sites of disease or injury in the brain.

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Human neural stem cells (green) guided by electrical stimulation migrated to and colonized the subventricular zone of rats’ brains. This image was taken three weeks after stimulation. Image: Jun-Feng Feng/UC DAVIS, Sacramento and Ren Ji Hospital, Shanghai.

NSCs are a key ingredient in the development of therapies that aim to repair damaged areas of the brain. Given the incredibly intricate structure of nerve connections, targeting these stem cells to their intended location is a big challenge for therapy development. One obstacle is mobility. Although resident NSCs can travel long distances within the brain, the navigation abilities of transplanted NSCs gets disrupted and becomes very limited.

In earlier work, the research team had shown that electrical currents could nudge NSCs to move in a petri dish (watch team lead Dr. Min Zhao describe this earlier work in the 30 second video below) so they wanted to see if this technique was possible within the brains of living rats. By nature, NSCs are more like bloodhounds than salmon, moving from one location to another by sensing an increasing gradient of chemicals within the brain. In this study, the researchers transplanted human NSCs in the middle of such a such gradient, called the rostral migration stream, that normally guides the cells to the olfactory bulb, the area responsible for our sense of smell.

Electrodes were implanted into the brains of the rats and an electrical current flowing in the opposite direction of the rostral migration stream was applied. This stimulus caused the NSCs to march in the direction of the electrical current. Even at three and four weeks after the stimulation, the altered movement of the NSCs continued. And there was indication that the cells were specializing into various types of brain cells, an important observation for any cell therapy meant to replace diseased cells.

The Scientist interviewed Dr. Alan Trounson, of the Hudson Institute of Australia, who was not involved in study, to get his take on the results:

“This is the first study I’ve seen where stimulation is done with electrodes in the brain and has been convincing about changing the natural flow of cells so they move in the opposite direction. The technique has strong possibilities for applications because the team has shown you can move cells, and you could potentially move them into seriously affected brain areas.”

Though it’s an intriguing proof-of-concept, much works remains to show this technique is plausible in the clinic. Toward that goal, the team has plans to repeat the studies in primates using a less invasive method that transmits the electrical signals through the skull.

Emotions and gratitude at changing of the guard at Stem Cell Agency

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Randy Mills and his family

Randy, as regular readers of this blog know, is, or rather was, the President and CEO of CIRM. James Harrison is less well known to the outside world but his imprint on CIRM, as our General Counsel and one of the key figures behind Proposition 71, is even bigger than that of Randy’s.

Randy came to the stem cell agency a little over three years ago and in pretty quick order completely refashioned us. Under his guidance CIRM 2.0 became a sleek, streamlined funding machine, turning what had been an almost two-year process from application to funding into one that took just 120 days. He revamped the frequency with which we offered specific programs, making it more predictable and so easier for researchers to know when the next round was coming up. He helped usher in a new Strategic Plan that is a blueprint for us until 2020.

But the changes he implemented were not just about the way we worked, it was also about how we worked and particularly how we worked together. He turned the agency into a true team, one where everyone felt they not only had a role to play but that what they did was important in determining the success of the agency.

Not surprisingly there was no shortage of people ready to praise him. CIRM Board Chair Jonathan Thomas (JT) thanked Randy for turning the agency around, transforming it into an organization that even the National Institutes of Health (NIH) now looks to as a model (more on that in a subsequent blog). Vice Chair Art Torres thanked Randy for his leadership and for his compassion toward patients, always putting them first in everything that he and the agency did. Board member Sherry Lansing called Randy “a genius and visionary”.

But perhaps the most moving tributes came from patients advocates.

Don Reed said; “When I first met Randy I didn’t like him. I thought CIRM was one of the best, if not the best, organization out there and who was this person to say they were going to come in and make it better. Well, you did Randy and we are all so very grateful to you for that.”

Adrienne Shapiro from Axis Advocacy, an organization dedicated to finding a cure for sickle cell disease, presented Randy with the “Heart of a Mother” award, thanking him for his tireless support of patients and their families.

Jake Javier, a participant in the Asterias spinal cord injury trial, wrote a note saying: “You positively affect so many through your amazing funding efforts for life changing research, and should be very proud of that. But something I will always remember is how personal and genuine you were while doing it. I hope you got the chance to meet as many of the people you helped as possible because I know they would remember the same.”

Randy – who is leaving to become President/CEO of the National Marrow Donor/Be The Match program – was clearly deeply moved by the tributes, but reminded everyone that he was leaving us in good hands. The Board named Dr. Maria Millan as the interim President and CEO, pending a meeting of a search committee to determine the steps for appointing a permanent replacement.

Randy praised Maria for her intelligence, compassion and vision:

“Maria Millan has been a great partner in all that we have achieved at CIRM. She was a key part of developing the Strategic Plan; she  understands it inside out and has been responsible for administering it. She is a wonderful leader and is going to be absolutely phenomenal.”

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James Harrison (left) with CIRM Board members Jonathan Thomas and Bert Lubin

The tributes for James Harrison were ever bit as moving. James has been a part of CIRM since before there was a CIRM. He helped draft Proposition 71, the ballot initiative that created the stem cell agency, and has played a key role since as General Counsel.

JT: “James has been a part of literally every decision and move that CIRM has made in its entire history. He’s been integral in everything. When I first came to CIRM, I was told by Bob Klein (JT’s predecessor as Chair) ‘Don’t brush your teeth without checking with James first’ suggesting a level of knowledge and expertise that was admirable.”

Jeff Sheehy “We would not be here without James. He organized the defense when we were sued by our opponents in the early days, through the various leadership challenges we had, all of the legal difficulties we had James was there to guide us and it’s been nothing short of extraordinary. Your brilliance and steadiness is amazing. While we are screaming and pulling our hair out there was James. Just saying his name makes me feel more relaxed.”

Sherry Lansing: “One thing I never worried about was our ethics, because you protected us at all times. You have such strong ethical values, you are always calm and rational and no matter what was going on you were always the rock who could explain things to everyone and deal with it with integrity.”

James is leaving to take a more active role in the law firm Remcho, Johansen & Purcell, where he is partner. Succeeding him as General Counsel is Scott Tocher, who has been at CIRM almost as long as James.

Randy; “To have someone like Scott come in and replace someone who wrote Proposition 71 speaks for the bench strength of the agency and how we are in very good hands.”

Art Torres joked “Scott has been waiting as long as Prince Charles has to take over the reins and we’re delighted to be able to work with him.”

We wish Randy and James great good luck in their next adventures.

 

Stem Cell Stories that Caught Our Eye: perfecting pluripotency, building a spinal cord, and CIRM Board funds new clinical trials

Here are the stem cell stories that caught our eye this week. 

Perfecting Pluripotency in stem cells.

The power of pluripotent stem cells lies in their ability to become any cell type in the body. But how did they get this impressive power?

Scientists from the University of Zurich in Switzerland think they might have an answer. In a study published in Nature Cell Biology, the team discovered that stem cells in the early stage embryo express a protein called Pramel7. This protein is like an eraser. Its presence ensures that a cell’s DNA is free of epigenetic marks, which are chemical tags that tell genes to switch on or off.

Embryonic stem cells have a blank slate meaning their genomes are free of epigenetic marks. This allows them to follow any developmental path and become any cell in the body. But as embryonic stem cells develop into more specialized adult cells, epigenetic marks called methyl groups are added to their genomes to effectively seal off genetic material containing genes that aren’t necessary to the fate of that cell.

The team found that Pramel7 was active in the stem cells of embryos that were only a few days old. Interestingly, when they studied embryonic stem cells grown in a petri dish outside of embryos, these stem cells didn’t express Pramel7 and consequently had more methyl marks on their DNA. These findings, which were captured in coverage by Phys.org, led the scientists to dub Pramel7 expressing embryonic stem cells as the “perfect allrounders.”

“Despite its short action period of just a few days, Pramel7 seems to play a vital role: When the researchers headed up by Cinelli and Santoro switched off the gene for this protein using genetic tricks, development remained stuck in the embryonic cell cluster stage. In the cultivated stem cells, on the other hand, Pramel7 is rarely found. This circumstance could also explain why the genetic material of these cells contains more methyl groups than that of natural embryonic cells.”

Just a few days old embryonic cell clusters: with functional Pramel7 (left), without the protein (right) – the development of the stem cells remains stuck and the embyos die. Credit: Paolo Cinelli, USZ

In future studies, the scientists will use their newly found knowledge about stem cell pluripotency to study how stem cells can regenerate bone fractures in patients. Before they can replace broken and damaged bones, they argue that “we have to know how stem cells work [first].”

CIRM Invests in Treatments for Stroke, Cancer and Blood Disorders.

Yesterday, the CIRM governing Board convened for our June ICOC meeting to consider the funding of stem cell research applications ranging from early, discovery stage studies to clinical trials.

Two new trials were added to our pipeline. SanBio was awarded $20 million to test a mesenchymal stem cell-based treatment for patients that have suffered from a stroke. UCSF received $12.1 million for a hematopoietic stem cell treatment for babies with a blood disorder called alpha thalassemia major. The stem cells are taken from the mother’s bone marrow and transplanted into the womb before the baby is born in hopes of improving the chances of a healthy birth.

The Board also approved 13 early stage research projects that are part of our Discovery Quest Awards Program, which promotes the discovery of promising new stem cell-based technologies that could be translated to enable broad use and ultimately improve patient care. You can read more about these studies in yesterday’s news release.

The Board meeting was particularly memorable one. A patient named Caleb Sizemore, who participated in the CIRM-funded Capricor trial for Duchenne muscular dystrophy, spoke to the Board about his experience in the trial and the importance of funding stem cell research for patients.

We also said an emotional goodbye to two important members of the CIRM team, President Randy Mills and General Counsel James Harrison. Randy will be the new President and CEO of the National Marrow Donor Program and James will be returning to his role as a partner at the law firm of Remcho, Johansen & Purcell, LLP.

We’ll be blogging more about the events of our Board meeting next week, so stay tuned!

CIRM President and CEO Dr. Randy Mills receives an award of appreciation and a CIRM plaque with his family.

Building a spinal cord comes down to location, location, location. (Todd Dubnicoff)

The spinal cord is an amazing part of our anatomy. Its long bundle of nerve cells acts like an elaborate highway starting from the brain, running down the spine and jutting out to countless “off-ramps” that make connections to our limbs and organs. These nerve cells are critical for bringing in sensory information from the body up to the brain and for sending out movement instructions from the brain down to our muscles. Assuming these cells aren’t equipped with their own GPS technology, how do they determine their precise location and turn into the right type of cell while building this information highway during embryo development?

A normal developing spinal cord (left) showing precise patterns of gene activity (red, blue, green demarcating different types of cells). In a spinal cord in which one of the signals is disrupted (right) the accuracy of gene activity has been lost. Image: Anna Kicheva

 

This week, a collaborative team of European scientists answered a large piece of that fundamental question. Reporting in Science, the researchers show evidence that progenitor, or early stage, nerve cells in developing mouse embryos sense the concentration of two proteins that spread out in opposite directions along the dorsal/ventral axis (from the belly to the back) of the body. Each progenitor nerve cell encounters a specific local concentration of these opposing protein gradients and then activates an appropriate set of genes in response.

Through some in-depth number crunching, the team showed that either gradient alone was not as precise in providing dorsal/ventral position information to cells compared to when both gradients are in place. They also showed that these gradients remained intact for the first 30 hours of development and then dissipated which indicates their importance in the earliest moments of life.

Anna Kicheva, the team lead for the research group the Institute of Science and Technology in Austria, explained the significance of these findings in a press release:

“We’ve made an important step in understanding how the diverse cell types in the spinal cord of a developing embryo are organized in a precise spatial pattern. The quantitative measurements and new experimental techniques we used, as well as the combined effort of biologists, physicists and engineers were key. This allowed us to gain new insight into the exquisite accuracy of embryonic development and revealed that cells have remarkable ability of to orchestrate precise tissue development.”

These new insights will not only provide a better understanding of how spinal cord development works but could also create new therapeutic approaches to diseases and injuries. James Briscoe, the senior author from the Francis Crick Institute in the United Kingdom, thinks these finding could also shed light on the development of other parts of the body:

“It’s likely that similar strategies are used in other developing tissues and our findings might be relevant to these cases. In the long run this will help inform the use of stem cells in approaches such as tissue engineering and regenerative medicine.”

Scientist grow diseased brain cells in bulk to study Alzheimer’s and Parkinson’s disease

Daily trips to the local grocery store have become a thing of the past for many with the rise of wholesale stores like Costco and online giants like Amazon. Buying in bulk is attractive for people who lead busy lives, have large families, or just love having endless pairs of clean socks.

Scientists who study neurodegenerative diseases like Alzheimer’s and Parkinson’s use disease-in-a-dish models that are much like the daily visits to the nearby Safeway. They can make diseased brain cells, or neurons, from human pluripotent stem cells and study them in the lab. But often, they can’t generate large enough quantities of cells to do important experiments like test new drugs or develop diagnostic platforms to identify disease at an earlier age.

What scientists need is a Costco for brain cells, a source that can make diseased brain cells in bulk. Such a method would open a new avenue of research into what causes neurodegeneration and how the aging process affects its progression.

This week, this need was answered. A team of researchers from Lund University in Sweden developed a method that can efficiently generate neurons from patients with a range of neurodegenerative diseases including Parkinson’s, Huntington’s and Alzheimer’s disease. The study was published in EMBO Molecular Medicine and was led by senior author Dr. Malin Parmar.

Diseased neurons made by the Lund University team. (Photo, Kennet Ruona)

Parmar and her team took an alternative approach to making their neurons. Their technology involves converting human skin cells into neurons without reprogramming the skin cells back to a pluripotent stem cell state first. This process is called “direct conversion” and is considered an effective shortcut for generating mature cells like neurons in a dish. Direct conversion of skin cells into neurons was first published by Dr. Marius Wernig, a CIRM-grantee and professor at Stanford University.

There is also scientific evidence suggesting that reprogramming patient cells back to a pluripotent state wipes out the effects of aging in those cells and has a Benjamin Button-like effect on the resulting neurons. By directly converting patient skin cells into neurons, many of these aging “signatures” are retained and the resulting neurons are more representative of the aging brain.

So how did they make brain cells in bulk? Parmar explained their method in a Lund University news release,

Malin Parmar

“Primarily, we inhibited a protein, REST, involved in establishing identity in cells that are not nerve cells. After limiting this protein’s impact in the cells during the conversion process, we’ve seen completely different results.”

 

Besides blocking REST, the team also turned on the production of two proteins, Ascl1 and Brn2, that are important for the development of neurons. This combination of activating pro-neural genes and silencing anti-neural genes was successful at converting skin cells into neurons on a large scale. Parmar further explained,

“We’ve been playing around with changing the dosage of the other components in the previous method, which also proved effective. Overall, the efficiency is remarkable. We can now generate almost unlimited amounts of neurons from one skin biopsy.”

As mentioned previously, this technology is valuable because it provides better brain disease models for scientists to study and to screen for new drugs that could treat or delay disease onset. Additionally, scientists can study the effects of the aging in the brain at different stages of neurodegeneration. Aging is a well-known risk factor for many neurodegenerative diseases, especially Alzheimer’s, so the ability to make large quantities of brain cells from elderly Alzheimer’s patients will unlock new clues into how age influences disease.

Co-author Dr. Johan Jakobsson concluded,

Johan Jakobsson

“This takes us one step closer to reality, as we can now look inside the human neurons and see what goes on inside the cell in these diseases. If all goes well, this could fundamentally change the field of research, as it helps us better understand the real mechanisms of the disease. We believe that many laboratories around the world would like to start testing on these cells to get closer to the diseases.”

For more on this study, check out this short video provided by Lund University.

Wall Street Journal features CIRM-funded clinical trials aiming for a diabetes cure

We think CIRM-funded clinical trials hold so much promise that it doesn’t surprise us when major news organizations publish stories about these projects that aim to provide stem cell treatments to patients with unmet medical needs. But we certainly don’t mind the attention!

This past Saturday, for example, the Wall Street Journal featured two CIRM-funded clinical trials, run by ViaCyte and Caladrius, in an article covering cutting-edge research approaches to tackling type 1 diabetes. Also mentioned was Semma Therapeutics, who have a CIRM-funded pre-clinical diabetes research grant.

ViaCyte is tackling diabetes with implantable devices containing stem cell-based products that release insulin on demand rather than requiring continual monitoring of blood sugar level. Image: ViaCyte.

People with type 1 diabetes lack insulin, a hormone that’s critical for transporting blood sugar, digested from the food we eat, into our energy-hungry organs and tissues. They lack insulin because the insulin-producing beta cells in the pancreas have been attacked and killed off by the body’s own immune system. Without insulin, blood sugar levels go through the roof and over time that build up can cause vision loss, kidney disease, nerve damage, heart disease and the list goes on.

Families unaffected by type 1 diabetes often mistake insulin injections as a cure for diabetes. But they’re not. Julia Greenstein, vice president of discovery research for the JDRF, states injected insulin’s limitation very concisely but clearly in the WSJ article:

“It is [in] no way an easy life trying to manage blood glucose.”

Her statement echoes the thoughts of Chris Stiehl who we interviewed for a video a few years ago:

“It’s a 24-hour a day job, 7 days a week you never get a day off. I would give anything for a day off. Just to not have to think about it. Besides all the things you have to do for your work and your family and everything, you have to be constantly thinking: “What’s my blood sugar? What have I eaten? Have I exercised too much or too little? How much insulin should I take based on the exercise I just did? Gee by the way is my insulin pump running out of insulin?

The WSJ article points out that a pancreas or beta cell transplant, received from a deceased donor, is currently the best option for long-term treatment of type 1 diabetes. But there are big drawbacks and limitations to this approach: the pancreas transplant requires major surgery, both require life-long immunosuppressing drugs that can cause serious infection and cancer and donor organs and cells are hard to come by.

That’s where regenerative medicine technology comes into the picture. The article goes on to highlight ViaCyte’s therapeutic product, PEC-EncapTM which is composed of embryonic stem cell-derived insulin-producing beta cells that are encased by a capsule that is transplanted under the skin. The capsule has pores that allow blood glucose and insulin to flow freely but protects the cell product from destruction from the body’s immune cells.

Because the cell product stems from, er, stem cells, there’s the potential of a limitless supply that doesn’t rely on cadavers.

Dr. Gordon Weir, a Harvard Medical School professor and diabetes researcher at the Joslin Diabetes Center in Boston, spoke about the excitement of such a device along with a reality check:

“Everyone’s waiting for the next generation of beta-cell replacement that hopefully will change the whole way in which we treat diabetes. In spite of the excitement and extraordinary things that have happened in the last 10 years, there are still a lot of challenges.”

Indeed, since beginning the clinical trial in 2014, ViaCyte has encountered some speed bumps. They had hoped that blood vessels growing around but not into the device would facilitate the transfer of blood sugar into the device where the beta cells would sense the level of sugar and release the appropriate amount of insulin. But it turns out that some cells of the immune system cells mucked up the blood vessel network. The company is working on improvements to the device to get the clinical trial back on track in the next 24 months. To jump start that effort they recently secured a partnership with the makers of Gore-Tex fabrics who also specialize in medical implantable devices.

That collaboration is also motivating a next generation device called PEC-DirectTM which contains larger pores that would allow direct interaction between the body’s blood vessels and the beta cells inside the device. Because of the larger openings, immune cells could infiltrate the device and so immunosuppressive drugs would be needed in this case. But for patients with severe type 1 diabetes, this approach would be a more available treatment source compared to cadaver cells or organs.

The WSJ article also discusses the CIRM-funded Caladrius clinical trial that takes quite a different approach to treating type 1 diabetes. The company is trying to disarm the T cells that attack the body’s own pancreatic beta cells. Because diabetics don’t lose all their beta cells at once, this approach could help maintain the insulin-producing cells that are still intact. The company’s strategy is to reprogram these attacking T-cells to convert them into so-called regulatory T-cells that act as a natural inhibitor of the immune response.

While each company works diligently on their own approach, eager patients are routing for both. Dara Melnick, of Woodbury, N.Y., who was diagnosed with type 1 diabetes at 8 years old and is now 36, summed up the patient’s perspective perfectly in the article:

“A cure would be the sweetest thing I could ever taste.”

Bridging the divide: stem cell students helping families with rare diseases become partners in research

Bridges & Rare Science

CIRM’s Bridges students and Rare Science’s families with rare diseases

Sometimes it’s the simplest things that make the biggest impact. For example, introducing a scientist to a patient can help them drive stem cell research forward faster than either one could do on their own.

Want proof? This year, students in CIRM’s Bridges to Stem Cell Research and Therapy program at California State University (CSU) San Marcos teamed up with parents of children with rare diseases, and the partnerships had a profound impact on all of them, one we hope might produce some long-term benefits.

Christina Waters, who helped create the partnerships, calls it “science with love.”

“We wanted to change the conversation and have researchers and families communicate, making families equal stakeholders in the research. The students bonded with the families and I truly feel that we made a difference in the lives of future researchers, in knowing how much their work can make a life changing impact on the lives of patients’ families who now have hope.”

The CIRM Bridges program helps prepare California’s undergraduate and master’s graduate students for highly productive careers in stem cell research. Students get a paid internship where they get hands-on training and education in stem cell research. They also work with patients and take part in outreach activities so they get an understanding of research that extends beyond the lab.

That’s where Christina Waters comes in. Christina is the founder of Rare Science, a non-profit group focused on rare diseases in children – we blogged about her work here – and she teamed up with CSU San Marcos to partner their Bridges students with five patient families with different rare diseases.

Cutting edge science

One of those families was Aaron Harding’s. Aaron’s son Jaxon has SYNGAP, a genetic disorder that can cause seizures, mental retardation, speech problems and autistic-like behavior. Two of the Bridges students who were doing their internship at ThermoFisher Scientific, Uju Nwizu and Emily Asbury, were given the task of using the gene-editing tool CRISPR Cas9 to help develop a deeper understanding of SYNGAP.

The students say it was an amazing experience:

Uju: “It had a huge impact on me. Every time I thought about SYNGAP I saw Jaxon’s face. This motivated me a lot.”

Emily: “People who work in labs everyday are most often working out the minutiae of research. They don’t often get a chance to see how their research can change or save the lives of real people. Meeting patients is so motivating because afterwards you aren’t just studying a mechanism, you now have a friend with the disease, so you can’t help but be personally invested in the search for a treatment.”

Emily and Uju are working to create iPSCs (induced pluripotent stem cells) that have the SYNGAP mutation. They hope these can be used to study the disease in greater depth and, maybe one day, lead to treatments for some of the symptoms.

Aaron says for families like his, knowing there are scientists working on his child’s disorder is a source of comfort, and hope:

“Personalizing diseases by connecting scientists with those they seek to impact is so important. Emily and Uju took this opportunity and ran with it, and that says a lot about them, and the team at ThermoFisher, taking on an exploring the unknown. That attitude is the heart of a scientist.”

Hearing stories like this is very gratifying, not just for the students and families involved, but for everyone here at CIRM. When we created the Bridges program our goal was to help students get the skills and experience needed to pursue a career in science. Thanks to the people at CSU San Marcos and Rare Science these students got a whole lot more.

Christina Waters: “We learned, we shared hope, we celebrated the courage of our families and the commitment of the students. It takes a village, and it is all of us working together that will make great changes for kids with rare diseases.”

For Uju and Emily, their experience in the Bridges program has made them doubly certain they want to pursue a career in science.

Uju: “I love stem cells and the promise they hold. After this program I hope to be part of a team that is committed to accelerating new stem cell therapies for rare and chronic diseases.”

Emily: “I’ve learned that I love research. After I finish my bachelor’s degree at CSU San Marcos I plan to pursue a graduate degree in molecular or cellular biology.”

 

Stem Cell Stories that Caught our Eye: finding the perfect match, imaging stem cells and understanding gene activity

Here are the stem cell stories that caught our eye this week. Enjoy!

LAPD officer in search of the perfect match.

LAPD Officer Matthew Medina with his wife, Angelee, and their daughters Sadie and Cassiah. (Family photo)

This week, the San Diego Union-Tribune featured a story that tugs at your heart strings about an LAPD officer in desperate need of a bone marrow transplant. Matthew Medina is a 40-year-old man who was diagnosed earlier this year with aplastic anemia, a rare disorder that prevents the bone marrow from producing enough blood cells and platelets. Patients with this disorder are prone to chronic fatigue and are at higher risk for infection and uncontrolled bleeding.

Matthew needs a bone marrow transplant to replace his diseased bone marrow with healthy marrow from a donor, but so far, he has yet to find a match. Part of the reason for this difficulty is the lack of diversity in the national bone marrow registry, which has over 25 million registered donors, the majority of which are white Americans of European decent. As a Filipino, Matthew has a 40% chance of finding a perfect match in the national registry compared to a 75% chance if he were white. An even more unsettling fact is that Filipinos make up less than 1% of donors on the national registry.

Matthew has a sister, but unfortunately, she wasn’t a match. For now, Matthew is being kept alive with blood transfusions at his home in Bellflower while he waits for good news. With the support of his family and friends, the hope is that he won’t have to wait for long. Already 1000 people in his local community have signed up to be bone marrow donors.

On a larger scale, organizations like A3M and Mixed Marrow are hoping to help patients like Matthew by increasing the diversity of the national bone marrow registry. A3M specifically recruits Asian donors while Mixed Match focuses on people with multi-ethnic backgrounds. Ayumi Nagata, a recruitment manager at A3M, said their main challenge is making healthy people realize the importance of being a bone marrow donor.

“They could be the cure for someone’s cancer or other disease and save their life. How often do we have that kind of opportunity?”

An algorithm that makes it easier to see stem cell development.

To understand how certain organs like the brain develop, scientists rely on advanced technologies that can track individual stem cells and monitor their fate as they mature into more specialized cells. Scientists can observe stem cell development with fluorescent proteins that light up when a stem cell expresses specific transcription factors that help decide the cell’s fate. Using a time-lapse microscope, these fluorescent stem cells can easily be identified and tracked throughout their lifetime.

But the pictures don’t always come out crystal clear. Just as a dirty camera lens makes for a dirty picture, images produced by time-lapse microscopy images can be plagued by shadows, artifacts and lighting inconsistencies, making it difficult to observe the orchestrated expression of transcription factors involved in a stem cell’s development.

This week in the journal Nature Communications, a team of scientists from Germany reported a solution that gives a clear view of stem cell development. The team developed a computer algorithm called BaSiC that acts like a filter and removes the background noise from time-lapse images of individual cells. Unlike previous algorithms, BaSiC requires fewer reference images to make its corrections.

The software BaSiC improves microscope images. (Credit: Tingying Peng / TUM/HMGU)

In coverage by Phys.org, author Dr. Tingying Peng explained the advantages of their algorithm,

“Contrary to other programs, BaSiC can correct changes in the background of time-lapse videos. This makes it a valuable tool for stem cell researchers who want to detect the appearance of specific transcription factors early on.”

The team proved that BaSiC is an effective image correcting tool by using it to study the development of hematopoietic or blood stem cells. They took time-lapse videos of blood stem cells over six days and observed that the stem cells chose between two developmental tracks that produced different types of mature blood cells. Using BaSiC, they found that blood stem cells that specialized into white blood cells expressed the transcription factor Pu.1 while the stem cells that specialized into red blood cells did not. Without the algorithm, they didn’t see this difference.

Senior author on the study, Dr. Nassir Navab, concluded by highlighting the importance of their technology and sharing his team’s vision for the future.

“Using BaSiC, we were able to make important decision factors visible that would otherwise have been drowned out by noise. The long-term goal of this research is to facilitate influencing the development of stem cells in a targeted manner, for example to cultivate new heart muscle cells for heat-attack patients. The novel possibilities for observation are bringing us a step closer to this goal.”

Silenced vs active genes: it’s like oil and water (Todd Dubicoff)

The DNA from just one of your cells would be an astounding six feet in length if stretched out end to end. To fit into a nucleus that is a mere 4/10,000th of an inch in diameter, DNA’s double helical structure is organized into intricate twists within twists with the help of proteins called histones.

Together the DNA and histones are called chromatin. And it turns out that chromatin isn’t just for stuffing all that genetic material into a tiny space. The amount of DNA folding also affects the regulation of genes. Areas of chromatin that are less densely packed are more accessible to DNA-binding proteins called transcription factors that activate gene activity. Other regions, called heterochromatin, are compacted which leads to silencing of genes because transcription factors are shut out.

But there’s a wrinkle in this story. More recently, scientists have shown that large proteins are able to wriggle their way into heterochromatin while smaller proteins cannot. So, there must be additional factors at play. This week, a CIRM-funded research project published in Nature provides a possible explanation.

Liquid-like fusion of heterochromatin protein 1a droplets is shown in the embryo of a fruit fly. (Credit: Amy Strom/Berkeley Lab)

Examining the nuclei of fruit fly embryos, a UC Berkeley research team report that various regions of heterochromatin coalesce into liquid droplets which physically separates them from regions where gene activity is high. This phenomenon, called phase-phase separation, is what causes oil droplets to fuse together when added to water. Lead author Dr. Amy Strom explained the novelty of this finding and its implications in a press release:

“We are excited about these findings because they explain a mystery that’s existed in the field for a decade. That is, if compaction [of chromatin] controls access to silenced [DNA] sequences, how are other large proteins still able to get in? Chromatin organization by phase separation means that proteins are targeted to one liquid or the other based not on size, but on other physical traits, like charge, flexibility, and interaction partners.”

Phase-phase separation can also affect other cell components, and problems with it have been linked to neurological disorders like dementia. In diseases like Alzheimer’s and Huntington’s, proteins aggregate causing them to become more solid than liquid over time. Strom is excited about how phase-phase separation insights could lead to novel therapeutic strategies:

“If we can better understand what causes aggregation, and how to keep things more liquid, we might have a chance to combat these types of disease.”