Multi-Talented Stem Cells: The Many Ways to Use Them in the Clinic

CIRM kicked off the 2016 International Society for Stem Cell Research (ISSCR) Conference in San Francisco with a public stem cell event yesterday that brought scientists, patients, patient advocates and members of the general public together to discuss the many ways stem cells are being used in the clinic to develop treatments for patients with unmet medical needs.

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, Gladstone Institutes & UCSF

Bruce Conklin, an Investigator at the Gladstone Institutes and UCSF Professor, moderated the panel of four scientists and three patient advocates. He immediately captured the audience’s attention by showing a stunning video of human heart cells, beating in synchrony in a petri dish. Conklin explained that scientists now have the skills and technology to generate human stem cell models of cardiomyopathy (heart disease) and many other diseases in a dish.

Conklin went on to highlight four main ways that stem cells are contributing to human therapy. First is using stem cells to model diseases whose causes are still largely unknown (like with Parkinson’s disease). Second, genome editing of stem cells is a new technology that has the potential to offer cures to patients with genetic disorders like sickle cell anemia. Third, stem cells are known to secrete healing factors, and transplanting them into humans could be beneficial. Lastly, stem cells can be engineered to attack cancer cells and overcome cancer’s normal way of evading the immune system.

Before introducing the other panelists, Conklin made the final point that stem cell models are powerful because scientists can use them to screen and develop new drugs for diseases that have no treatments or cures. His lab is already working on identifying new drugs for heart disease using human induced pluripotent stem cells derived from patients with cardiomyopathy.

Scientists and Patient Advocates Speak Out

Malin Parmar, Lund University

Malin Parmar, Lund University

The first scientist to speak was Malin Parmar, a Professor at Lund University. She discussed the history of stem cell development for clinical trials in Parkinson’s disease (PD). Her team is launching the first in-human trial for Parkinson’s using cells derived from human pluripotent stem cells in 2016. After Parmar’s talk, John Lipp, a PD patient advocate. He explained that while he might look normal standing in front of the crowd, his PD symptoms vary wildly throughout the day and make it hard for him to live a normal life. He believes in the work that scientists like Parmar are doing and confidently said, “In my lifetime, we will find a stem cell cure for Parkinson’s disease.”

Adrienne Shapiro, Patient Advocate

Adrienne Shapiro, Patient Advocate

The next scientist to speak was UCLA Professor Donald Kohn. He discussed his lab’s latest efforts to develop stem cell treatments for different blood disorder diseases. His team is using gene therapy to modify blood stem cells in bone marrow to treat and cure babies with SCID, also known as “bubble-boy disease”. Kohn also mentioned their work in sickle cell disease (SCD) and in chronic granulomatous disease, both of which are now in CIRM-funded clinical trials. He was followed by Adrienne Shapiro, a patient advocate and mother of a child with SCD. Adrienne gave a passionate and moving speech about her family history of SCD and her battle to help find a cure for her daughter. She said “nobody plans to be a patient advocate. It is a calling born of necessity and pain. I just wanted my daughter to outlive me.”

Henry Klassen (UC Irvine)

Henry Klassen, UC Irvine

Henry Klassen, a professor at UC Irvine, next spoke about blinding eye diseases, specifically retinitis pigmentosa (RP). This disease damages the photo receptors in the back of the eye and eventually causes blindness. There is no cure for RP, but Klassen and his team are testing the safety of transplanting human retinal progenitor cells in to the eyes of RP patients in a CIRM-funded Phase 1/2 clinical trial.

Kristen MacDonald, RP patient

Kristen MacDonald, RP patient

RP patient, Kristen MacDonald, was the trial’s first patient to be treated. She bravely spoke about her experience with losing her vision. She didn’t realize she was going blind until she had a series of accidents that left her with two broken arms. She had to reinvent herself both physically and emotionally, but now has hope that she might see again after participating in this clinical trial. She said that after the transplant she can now finally see light in her bad eye and her hope is that in her lifetime she can say, “One day, people used to go blind.”

Lastly, Catriona Jamieson, a professor and Alpha Stem Cell Clinic director at UCSD, discussed how she is trying to develop new treatments for blood cancers by eradicating cancer stem cells. Her team is conducting a Phase 1 CIRM-funded clinical trial that’s testing the safety of an antibody drug called Cirmtuzumab in patients with chronic lymphocytic leukemia (CLL).

Scientists and Patients need to work together

Don Kohn, Catriona Jamieson, Malin Parmar

Don Kohn, Catriona Jamieson, Malin Parmar

At the end of the night, the scientists and patient advocates took the stage to answer questions from the audience. A patient advocate in the audience asked, “How can we help scientists develop treatments for patients more quickly?”

The scientists responded that stem cell research needs more funding and that agencies like CIRM are making this possible. However, we need to keep the momentum going and to do that both the physicians, scientists and patient advocates need to work together to advocate for more support. The patient advocates in the panel couldn’t have agreed more and voiced their enthusiasm for working together with scientists and clinicians to make their hopes for cures a reality.

The CIRM public event was a huge success and brought in more than 150 people, many of whom stayed after the event to ask the panelists more questions. It was a great kick off for the ISSCR conference, which starts today. For coverage, you can follow the Stem Cellar Blog for updates on interesting stem cell stories that catch our eye.

CIRM Public Stem Cell Event

CIRM Public Stem Cell Event

Good from bad: UCSF scientists turn scar-forming cells into healthy liver cells

Most people know that a healthy liver is key for survival. Unfortunately, maintaining a healthy liver isn’t always easy. There are more than 100 different types of liver disease caused by various factors like viral infection, obesity, and genetics. If left untreated, they can progress to end-stage liver disease, also known as cirrhosis, which effects more than 600,000 Americans and has a high mortality rate. While there is a cure in the form of liver transplantation, there aren’t enough healthy donors available to help out the number of patients who desperately need new livers.

Cirrhosis occurs when liver damage accumulates over time causing the development of scar tissue that eventually replaces healthy liver tissue and impairs liver function. The liver is an amazing organ and can function even with the build-up of scar tissue as long as at least 20% of its composition is healthy cells. This impressive nature is actually a problem because most patients with liver disease aren’t aware of their condition until its progressed past the point of no return.

What’s a damaged liver to do?

So what do patients with end-stage liver disease do if they can’t get a liver transplant? One answer comes in the form of regenerative medicine. Scientists can generate new healthy liver cells in a dish from stem cells derived from the skin cells of patients and could eventually transplant these cells into the damaged liver. However, a major roadblock that prevents this type of cell transplantation therapy from helping patients with liver disease is the built-up scar tissue that prevents the integration of these healthy cells into the damaged liver.

Scientists from UC San Francisco (UCSF) have come up with a new solution to this problem. In a CIRM-funded study published today in journal Cell Stem Cell, UCSF professor Holger Willenbring details a new approach to repairing damaged livers in mice – one that generates good, healthy liver cells from bad, scar-tissue forming cells already present in the damaged liver.

The bad cells in this case are called myofibroblasts. Initially, these cells play an important role in repairing injuries in the liver. They secrete proteins called collagen that form a support structure that helps maintain composition of the liver as it repairs itself. However, if liver damage persists as is the case with chronic injury, the excess buildup of collagen secreted by myofibroblasts causes the accumulation of permanent scar tissue or fibrosis, which can negatively impact liver function.

Reducing damage by improving function

Cirrhosis causing myofibroblast cells (red) are converted into healthy liver cells (green) to regenerate the damaged liver. (Willenbring lab)

Cirrhosis causing myofibroblast cells (red) are converted into healthy liver cells (green) to regenerate the damaged liver. (Willenbring lab)

In an “Ah-Ha” moment, Willenbring proposed that they could stop myofibroblasts in the damaged livers of mice from causing more fibrosis by turning them into healthy liver cells. Willenbring and his team used a specific type of virus called an adeno-associated virus that only infects myofibroblasts to deliver a cocktail of liver-specific genes that have the ability to transform cells into liver cells called hepatocytes. When they treated mice with end-stage liver disease with their viral cocktail, they observed that a small percentage of myofibroblasts were converted into hepatocytes that developed into new healthy liver tissue, which improved the overall liver function of these mice. They also tested their viral method on human myofibroblasts and found that it was successful in converting these cells into functional hepatocytes.

Willenbring explained the science behind their new technique in a UCSF news release:

“Part of why this works is that the liver is a naturally regenerative organ, so it can deal with new cells very well. What we see is that the converted cells are not only functionally integrated in the liver tissue, but also divide and expand, leading to patches of new liver tissue.”

Solution to a healthy liver?

It’s important to realize that these studies are still in their early stages. The UCSF team has plans to expand on their human cell studies and to improve their viral delivery method so that it is more specific to myofibroblasts and more efficient at converting these cells into functioning hepatocytes.

They also recognize that their strategy will not be the panacea for liver disease and cirrhosis. Willenbring commented:

“A liver transplant is still the best cure. This is more of a patch. But if it can boost liver function by just a couple percent, that can hopefully keep patients’ liver function over that critical threshold, and that could translate to decades more of life.”

However, their study does offer a number of advantages over cell transplant therapies for liver disease including repairing the liver and improving its function from within the organ itself and also offering a simpler and cheaper form of treatment that would be accessible to more patients.

Willenbring puts it best:

Holger Willenbring, UCSF

Holger Willenbring, UCSF

“The new results suggest that in the fibrotic liver, this approach could produce a more efficient and stable improvement of liver function than cell transplant approaches. Once the viral packaging is optimized, such a treatment could be done cheaply at a broad range of medical facilities, not just in the specialized research hospitals where stem-cell transplants could be conducted.”

UCSF Scientists find molecular link between brain stem cells and Zika Infection

The Zika virus scare came to a head in 2015, prompting the World Health Organization to declare the outbreak a global health emergency earlier this year. From a research standpoint, much of the effort has centered on understanding whether the Zika infection is actually a cause of birth defects like microcephaly and how the virus infects mothers and their unborn children.

The Zika Virus is spread by a specific type of mosquito, the Aedes aegypti.

The Zika Virus is spread to humans by mosquitos.

What’s known so far is that the Zika virus can pass from the mother to the fetus through the placenta and it can infect the developing brain of the fetus. But how exactly the virus infects brain cells is less clear.

Brain stem cells are vulnerable to Zika

Scientists from UC San Francisco (UCSF) are tackling this question and have unraveled one more piece to the Zika infection puzzle. UCSF professor Dr. Arnold Kriegstein and his team reported yesterday in the journal Cell Stem Cell that they’ve identified a protein receptor on the surface of brain stem cells that could be the culprit for Zika virus infection.

Based on previous studies that showed that the Zika virus specifically infects brain stem cells, Kriegstein and his colleagues hypothesized that these cells expressed specific proteins that made them vulnerable to Zika infection. They looked to see which genes were turned on and off in brain stem cells derived from donated fetal tissue as well as other cell types in the developing brain to identify proteins that would mediate Zika virus entry.

AXL is to blame

They found a protein receptor called AXL that was heavily expressed in a type of brain stem cell called the radial glial cell, which gives rise to the outer layer of the brain called the cerebral cortex. AXL piqued their interest because it was identified in other studies as an entry point for Zika and other similar viruses like dengue in human skin cells. Furthermore, the team confirmed that radial glial cells produce a lot of AXL protein during development and it appears during a specific window of time – the second trimester of pregnancy.

A link between radial glial cells and Zika infection made sense to first author Tomasz Nowakowski who explained in a UCSF news release,

“In the rare cases of congenital microcephaly, these [radial glial cells] are the cells that die or differentiate prematurely, which is one of the reasons we became interested in the possible link.”

The team also found that AXL was expressed in mature brain cells including astrocytes and microglia and in retinal progenitor cells in the eye. They pointed out that the presence of AXL in the developing eye could help explain why many cases of Zika infection are associated with eye defects.

Modeling Zika infection using mini-brains

The bulk of the study used stem cells isolated from donated human fetal tissue, but the team also developed a different stem cell model to confirm their results. They generated brain organoids, also coined as “mini-brains”, in a dish from human induced pluripotent stem cells. These mini-brains contain structures and cell types that closely resemble parts of the developing brain. The team studied radial glial like cells in the mini-brains and found that they also expressed AXL on their surface.

An image of tissue that’s grown in a dish shows radial glia stem cells that are red, neurons in blue and the AXL receptor in green. Photo by Elizabeth DiLullo

Mini-brains grown in a dish have radial glia stem cells (red), neurons (blue) and the AXL receptor (green). Photo by Elizabeth DiLullo, UCSF

Kriegstein and his team believe they now have a working stem cell model for how viruses like Zika can infect the brain. Using their brain organoid model, they plan to collaborate with other UCSF researchers to learn more about how Zika infection occurs and whether it really causes birth defects.

“If we can understand how Zika may be causing birth defects,” Kriegstein said, “we can start looking for compounds to protect pregnant women who become infected.”

What’s next?

While the evidence points towards AXL as one of the major entry points for Zika infection in the developing brain, the UCSF team and other scientists still need to confirm that this receptor is to blame.

Kriegstein explained:

Arnold Kriegstein, UCSF

Arnold Kriegstein, UCSF

“While by no means a full explanation, we believe that the expression of AXL by these cell types is an important clue for how the Zika virus is able to produce such devastating cases of microcephaly, and it fits very nicely with the evidence that’s available. AXL isn’t the only receptor that’s been linked with Zika infection, so next we need to move from ‘guilt by association’ and demonstrate that blocking this specific receptor can prevent infection.”

If AXL turns out to be the culprit, scientists will have to be careful about testing drugs that block its function given that AXL is important for the proliferation of brain stem cells during development. There might be a way however that such treatments could be given to at risk women before they get pregnant.


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A Win for Diabetes: Scientists Make Functional Pancreatic Cells From Skin

Today is an exciting day for diabetes research and patients. For the first time, scientists have succeeded in making functional pancreatic beta cells from human skin. This new method for making the insulin-producing cells of the pancreas could produce a new, more effective treatment for patients suffering from diabetes.

Researchers at the Gladstone Institutes and the University of California, San Francisco published these promising findings today in the journal Nature Communications.

Making pancreatic cells from skin

They 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 skin cells were treated with factors used to generate induced pluripotent stem cells (iPSCs) and with pancreatic-specific molecules. This cocktail of factors and molecules shut off the skin genes and turned on genes of the pancreas.

The end product was endoderm progenitor cells, which are like stem cells but can only generate cell types specific to organs derived from the endoderm layer (for example: lungs, thyroid, pancreas). The scientists took these endoderm progenitors and further coaxed them into mature, pancreatic beta cells after treatment with another cocktail of molecules.

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)

While the pancreatic cells they made looked and acted like the real thing in a dish (they were able to secrete insulin when exposed to glucose), the authors needed to confirm that they functioned properly in animals. They transplanted the mature beta cells into mice that were engineered to have diabetes, and observed that the human beta cells protected the mice from becoming diabetic by properly regulating their blood glucose levels.

Importantly, none of the mice receiving human cells got tumors, which is always a concern when transplanting reprogrammed cells or cells derived from pluripotent stem cells.

What does this mean?

This study is groundbreaking because it offers a new and more efficient method to make functioning human beta cells in mass quantities.

Dr. Sheng Ding, a CIRM funded senior investigator at the Gladstone and co-senior author, explained in a Gladstone news release:

Sheng Ding

Sheng Ding

“This new cellular reprogramming and expansion paradigm is more sustainable and scalable than previous methods. Using this approach, cell production can be massively increased while maintaining quality control at multiple steps. This development ensures much greater regulation in the manufacturing process of new cells. Now we can generate virtually unlimited numbers of patient-matched insulin-producing pancreatic cells.”

 

Matthias Hebrok, director of the Diabetes Center at UCSF and co-senior author on paper discussed the potential research and clinical applications of their findings:

Mattias Hebrok

Matthias Hebrok

“Our results demonstrate for the first time that human adult skin cells can be used to efficiently and rapidly generate functional pancreatic cells that behave similar to human beta cells. This finding opens up the opportunity for the analysis of patient-specific pancreatic beta cell properties and the optimization of cell therapy approaches.”

 

The study does mention the caveat that their direct reprogramming approach wasn’t able to generate all the cell types of the pancreas. Having these support cells would better recreate the pancreatic environment and likely improve the function of the transplanted beta cells.

Lastly, I find this study exciting because it kills two birds with one stone. Scientists can use this technique to make better cellular models of diabetes to understand why the disease happens, and they could also develop new cell replacement therapies in humans. Already, stem cell derived pancreatic beta cells are being tested in human clinical trials for type 1 diabetes (one of them is a CIRM-funded clinical trial by Viacyte) and it seems likely that beta cells derived from skin will follow suit.


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Glimpse the future at a fun-filled Festival of Science

Hands-on science and fun

Hands-on science and fun

Imagine a giant circus but instead of performing animals you have a Robot Zoo; instead of scary clowns you have colorful chemicals in glass beakers. That’s what AT&T Park will look like this Saturday when the 5th Annual Discovery Day opens its doors.  It’s a hands-on, eye-opening, brain-engaging celebration of science for everyone.

It’s a lot of fun

You’ll get a chance to learn about the science of sports – an appropriate subject as you’ll be doing it at the home of the 3-time World Champions of baseball, the San Francisco Giants. You’ll also be able to experience some of the training it takes to become an astronaut, without any of that pesky going-into-space business.

All in all you’ll be able to visit more than 150 hands-on exhibits and activities spread throughout the park, put together by the top science organizations, institutions and companies from all over the Bay Area. We’re talking Stanford University, UCSF, The Tech Museum, the Exploratorium, KQED, US Geological Society and the list goes on and on.

Meet the future right now

Today's scientists inspiring tomorrow's

Today’s scientists inspiring tomorrow’s

You’ll get to meet the scientists who are exploring outer space and the depths of the ocean, who are doing cutting edge research into health and who are pushing the boundaries of scientific knowledge.

And you will get a chance to meet us, the CIRM Team. We’re going to be there all day talking about the exciting progress being made in the field of stem cell research, and about the 15 clinical trials we are currently funding in heart disease, diabetes, cancer, HIV/AIDS and blindness (to name just a few).

You can find us on the Promenade level at booth P50. We’re easy to spot. We’re the coolest ones around. And if you have kids who enjoy PlayDoh, we will give them a chance to use the fun stuff to make stem cells.

But best of all Discovery Day is a chance for kids to learn how amazing science can be, to meet the scientists who are helping shape their future, and to consider a future as scientists themselves. And for the rest of us, it’s a chance to remind ourselves why we fell in love with science to start with.

And as if that wasn’t enough, the whole shebang is FREE.

The event is this Saturday, November 7 from 10am – 4pm. For details on where it is and how to get there – go to Discovery Day

Fun on the field at AT&T Park

Fun on the field at AT&T Park

CIRM Scholar Spotlight: Matt Donne on Lung Stem Cells

CIRM has funded a number of educational and research training programs over the past ten years to give younger students and graduate/postdoc scholars the opportunity to explore stem cell science.

Two of the main programs we support are the Bridges and the CIRM Scholars Training Program. These programs fund future scientists from an undergraduate to postdoctoral level with a goal of creating “training programs that will significantly enhance the technical skills, knowledge, and experience of a diverse cohort of… trainees in the development of stem cell based therapies.”

The Stem Cellar team was interested to hear from Bridges and CIRM scholars themselves about their experience with these programs, how their careers have benefited from CIRM funding, and what research accomplishments they have under their belt. We were able to track some of these scholars down, and will be publishing a series of interview-style blogs featuring them over the next few months.

Matt Donne

Matt Donne

We start off with a Matt Donne, a PhD student at the University of California, San Francisco (UCSF) in the Developmental and Stem Cell Biology graduate program. Matt is a talented scientist and has a pretty cool story about his research training path. I sat down with Matt to ask him a few questions.


Q: Tell us how you got into a Stem Cell graduate program at UCSF.

MD: I was fortunate to have Dr. Carmen Domingo from San Francisco State support my application into the CIRM Bridges Program. I’d been working for Dr. Susan Fisher at UCSF for a couple of years and realized that I wanted to get a PhD and go to UCSF. I thought the best way to do that was improve my GPA and get a masters degree in stem cell biology. I applied to the CIRM program at SF State, and was accepted.

The Bridges Program has been a great feeder platform to get students more science experience exposure than they would have otherwise received, and prepares them well to move on to competitive graduate schools.

After receiving my Masters degree, I was admitted into the first year of the Developmental and Stem Cell Biology program at UCSF. When the opportunity to apply for a training grant from CIRM came about between my first and second year of at UCSF, I knew I had to give it a chance and apply. With the help of my mentor, Dr. Jason Rock, I wrote a solid proposal and was awarded the fellowship.

While at SF State, Carmen was extremely supportive and always available for her students. Since then, many of us still keep in touch and more have joined the UCSF graduate school community.

Q: Can you describe your graduate research?

MD: The field of regenerative medicine is searching for ways to allow us to repair injuries similar to how the Marvel Comic Wolverine can repair his wounds in the movies. One interesting fact which has been known for several decades, but has not been able to be investigated more deeply until now, is the innate ability for the adult lung to regrow lost lung tissue without any sort of intervention. My thesis focuses on defining the molecular mechanisms and stem cell niches that allow for this normal, healthy adult lung tissue growth. The working hypothesis is if we can understand what makes a cell undergo healthy tissue proliferation and differentiation, we could stimulate this response to cure individuals who suffer from diseases such as chronic obstructive pulmonary disease (COPD). Similarly, if we understand how a cell decides to respond in a diseased way, we could stop or revert the disease process from occurring.

One of the models we use in our lab is a “pneumosphere” culture. We essentially grow alveoli, which are the site of gas exchange in the lung, in a dish to attempt to understand how specific alveolar stem cells signal and interact with one another. This information will teach us how these cells behave so we can in turn either promote a healthy response to injury or, potentially, stop the progression of unhealthy cell responses. The technique of growing alveoli in a dish allows us to cut down on the “noise” and focus on major cellular pathways, which we can then more selectively apply to our mouse model systems.

Pneumospheres. (Photo by Matt Donne)

Pneumospheres or “lung cells in a dish”. (Photo by Matt Donne)

Lung cells.

Lung pneumospheres under a microscope. (Photo by Matt Donne)

We are now in the process of submitting a paper demonstrating some of the molecular players that are involved in this regenerative lung response. Hopefully the reviewers will think our paper is as awesome we as believe it to be.

Q: How has being a CIRM scholar benefited your graduate research career?

MD: Starting in my second year at UCSF, I was awarded the CIRM fellowship. I think it helped the lab to have the majority of my stipend covered through the CIRM fellowship, and personally I was very excited about the $5,000 discretionary budget. These monies allowed me to go to conferences every year for the past three years, and also have helped to support the costs of my experiments.

The first conference I attended was a Gordon Conference in Italy on Developmental Biology. There I was able to learn more about the field and also make friends with many professors, students, and postdocs from around the world. Last year, I went to my first lung-specific conference, and attended again this year. That has been one of the highlights of my PhD career. While there, one is able to speak and interact with professors whose names are seen in many textbooks and published papers. I never thought I would be able to so casually interact with them and develop relationships. Since then, I have been able to work on small collaborations with professors from across the US.

It was great that I could go to these conferences and establish important relationships with professors without being a major financial burden to my Professor. Plus, it has been hugely beneficial for my career as I now have professors whom I can reach out to as I look towards my future as a scientist.

Q: What other benefits did the CIRM scholars program provide you?

MD: Dr. Susan Fisher has been in charge of the CIRM program at UCSF. She organized lunch-time research talks that involved both academic as well as non-academic leaders in the field. I enjoyed the extra exposure to new fields of stem cell biology as well as the ability to learn more about the start-up and non-academic world. There are not many programs that offer this type of experience, and I felt fortunate to be a part of it. Also, the free lunches on occasion were a nice perk for a grad student living in San Francisco!

I attended the CIRM organized conferences whenever they happened. It’s always great presenting at or attending poster sessions at these events, seeing familiar faces and meeting new people. I took full advantage of the learning and networking that CIRM allowed me to do. The CIRM elevator pitch competition was really cool too. I didn’t win, came in third, but I enjoyed the challenge of trying to break down my thesis project into a digestible one-minute pitch.

Q: Where do you see the field of lung biology and regenerative medicine heading?

MD: My take away from the research conferences I have attended with the help of CIRM-funding is that we are in a very exciting time for lung stem cell research. The field overall is still young, but there are many labs across the world now working on a “lung mapping project” to better define stem cell populations in the lung. I see this research in the future translating in to regenerative therapies by which diseased cells/tissue will be targeted to actually stop the disease progression, and in turn possibly repair and regenerate healthy new tissue. This research has wide reaching implications as it has the potential to help everyone from a premature baby more quickly develop mature healthy lungs, to adults suffering from COPD brought on by environmental factors, such as air pollution. As many scientists are often quoted, “This is a very exciting time for our field.”

Q: What are your future plans?

MD: I expect to graduate in about a year’s time. In the future, I want to pursue a career focusing on the social impact of science. I aspire to be someone like UCSF’s former chancellor Dr. Susan Desmond-Hellmand. It’s really cool to go from someone who was the president of product development at Genentech, to chancellor at UCSF, to now president of the Bill and Melinda Gates Foundation. Bringing science to impact society in that way is what I hope to do with my future.


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Using satellites to build bigger biceps

Arnold Schwarzenegger: Photo courtesy Awesome-Body.info

Arnold Schwarzenegger:
Photo courtesy Awesome-Body.info

There are several ways you can build bigger, stronger muscles. You can take the approach favored by our former Governor, Arnold Schwarzenegger, and pump iron till your biceps are as inflated as a birthday balloon. Or you could follow the lead of a research team we are funding and try to use stem cells to do the trick.

Our muscles contain a group of stem cells called satellite cells. These normally lie dormant until the muscle is damaged and then they spring into action to repair the injury. However, satellite cells are relatively rare and are hidden in the muscle itself, making them hard to find and notoriously difficult to study. In the past researchers have struggled to get these satellite cells to grow outside the body, which made it difficult to study muscle regeneration and develop new ways of treating muscle problems.

Finding a solution

Now a team at the University of California, San Francisco has found a solution to the problem. They started by analyzing samples of 7 different kinds of muscles (in the body, legs and head) from 43 patients. In all but two samples they found that the gene PAX7 was specifically turned on in satellite cells and the PAX7 protein was present with little variation from one muscle group to another.

Upon further sleuthing, they discovered that PAX7-positive satellite cells were the real deal because they also expressed two common cell surface markers of human satellite cells: CD29 and CD56.

The researchers then transplanted PAX7-positive cells into mice that had experienced muscle injuries. As they report in the journal Stem Cell Reports these cells not only engrafted in the mice but they also created hundreds of human-derived muscle fibers. This finding shows that satellite cells were regenerating and potentially helping to heal the damaged muscle.

What’s next

As always, anything done in mice is interesting but still needs to be replicated in people before we know for sure we are on to something.

In their conclusion the team freely admit this is just a first step but, compared to where we were before, it’s a very important step. As senior author Jason Pomerantz says:

“This is the first definitive experimental description of adult human endogenous muscle stem cell function.”

Harnessing the power of satellite cells would be of tremendous benefit to people suffering from facial paralysis, loss of hand function or muscle-wasting diseases such as sarcopenia, and could even be used as a way to deliver gene therapy to people with muscular dystrophies.

Using satellite cells to do all that, would be out of this world.

Moving Beyond Current CIRM Funding

Delivering on CIRM’s mission of “accelerating stem cell treatments to patients with unmet medical needs” requires the participation of multiple stakeholders to span the research, development, and commercialization phases of bringing a new product to market. In this post, I am pleased to highlight two recent examples of CIRM-funded projects moving beyond their period of CIRM funding by establishing partnerships with industry and investors to further develop the underlying CIRM-funded technology.

In 2000, Dr. Jill Helms, an academic investigator at Stanford University, received a $6.5 million grant from CIRM under an Early Translational award. The title of Dr. Helms’ project was Enhancing Healing via Wnt-Protein Mediated Activation of Endogenous Stem Cells,” and the goal of the award was to develop a novel, protein-based therapeutic platform to accelerate and enhance tissue regeneration through activation of adult stem cells. The five-year award achieved many critical milestones along the way, including the initiation of two preclinical studies aimed at demonstrating the effectiveness of a protein called L-WNT3A to improve the success of spinal fusion surgery and to treat a degradative bone disease called osteonecrosis, both of which represent unmet medical needs.

Helms_bonegraft

Through CIRM funding, Dr. Jill Helms’ team was able to demonstrate that treatment with a protein called L-Wnt3a regenerates and promotes bone formation in animals models (Figs D,F: untreated; Figs E,G: Wnt3a treated). (image credit: Leucht et al. J Bone Joint Surg Am. 2013;95:1278-88)

Dr. Helms’ work attracted considerable interest from the investor community during the lifespan of her grant, and during the final year of her award Dr. Helms’ WNT3A technology platform was successfully spun out of Stanford into a newly created company called Ankasa Regenerative Therapeutics. Ankasa was established with the financial support of Avalon Ventures – a La Jolla based life sciences venture capital firm, Correlation Ventures – an analytics driven venture capital firm, and Heraeus Medical – a diversified global medical device company based in Germany with over $1 billion of annual revenue. Ankasa has raised an initial $8.5 million in the first round of the total $17 million Series A financing to continue the development of the previously CIRM-funded technology.

Moving Radially Branched Deployment_Neurosurgery_Lim

Dr. Daniel Lim’s CIRM-funded BranchPoint Device allows neurosurgeons to deliver cell based therapies to multiple areas of the brain with just one needle penetration.  (image credit: Silvestrini et al. Stereotact Funct Neurosurg 2013;91:92–103)

The second recent example comes from a CIRM Tools & Technology grant to Dr. Daniel Lim, a neurosurgeon at UCSF. Dr. Lim was awarded a $1.8 million grant to develop a more efficient device for transplanting stem cells into the brain, titled Development and Preclinical Testing of New Devices for Cell Transplantation to the Brain.” Dr. Lim successfully developed a platform technology that enables Radially Branched Deployment (RBD) of cells to multiple target locations at variable radial distances and depths along the initial brain penetration tract with real-time interventional magnetic resonance image (iMRI) guidance. This technology is a huge leap forward over the conventional and crude syringe and needle device that are typically used to inject living cells into the brain.

Dr. Lim’s work attracted the attention of Accurexa, a publicly traded medical device company that licensed the CIRM-funded technology from UCSF. Under the guidance of Accurexa, a 510(k) application was submitted to the FDA for the newly coined “BranchPoint Device.” In June of this year, Accurexa successfully raised $2.5 million in equity financing to continue the development and for commercialization of the BranchPoint Device.

Overall, there remains a lack of industry pull for early stage stem cell technologies, however, both Drs. Helms and Lim’s stories represent successful examples of CIRM providing public dollars for early stage research with the resulting potentially life-saving applications attracting interest from investors and companies. These new investors will further fund and develop the technologies well beyond current CIRM funding and, assuming they are successful, deliver them to patients with unmet medical needs.

Creaky Cell Machinery Affects the Aging Immune System, CIRM-Funded Study Finds

Why do our immune systems weaken over time? Why are people over the age of 60 more susceptible to life-threatening infections and many forms of cancer? There’s no one answer to these questions—but scientists at the University of California, San Francisco (UCSF), have uncovered an important mechanism behind this phenomenon.

Reporting in the latest issue of the journal Nature, UCSF’s Dr. Emmanuelle Passegué and her team describe how blood and immune cells must be continually replenished over the lifetime of an organism. As that organism ages the complex cellular machinery that churns out new cells begins to falter. And when that happens, the body can become more susceptible to deadly infections, such as pneumonia.

As Passegué so definitively put it in a UCSF news release:

“We have found the cellular mechanism responsible for the inability of blood-forming cells to maintain blood production over time in an old organism, and have identified molecular defects that could be restored for rejuvenation therapies.”

The research team, which examined this mechanism in old mice, focused their efforts on hematopoetic stem cells—a type of stem cell that is responsible for producing new blood and immune cells. These stem cells are present throughout an organism’s lifetime, regularly dividing to preserve their own numbers.

Molecular tags of DNA damage are highlighted in green in blood-forming stem cells. [Credit: UCSF]

Molecular tags of DNA damage are highlighted in green in blood-forming stem cells. [Credit: UCSF]

But in an aging organism, these cells’ ability to generate new copies is not as good as it used to be. When the research team dug deeper they found a key bit of cellular machinery, called the mini-chromosome maintenance helicase, breaks down. When that happens, the DNA inside the cell can’t replicate itself properly—and the newly generated cell is not running on all cylinders.

One of the first things that these old stem cells lose as a result is their ability to make B cells. B cells, a key component of the immune system, normally make antibodies that fight infection. As B cell numbers dwindle in an aging organism, so too does their ability to fight infection. As a result the organism’s risk for contracting dangerous illnesses skyrockets.

This research, which was funded in part by CIRM, not only informs what goes wrong in an aging organism at the molecular level, but also points to new targets that could keep these stem cells functioning at full capacity, helping promote so-called ‘healthy aging.’ As Passegué added:

“Everybody talks about healthier aging. The decline of stem-cell function is a big part of age-related problems. Achieving longer lives relies in part on achieving a better understanding of why stem cells are not able to maintain optimal functioning.”