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.

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Advancing Stem Cell Research at the CIRM Bridges Conference

Where will stem cell research be in 10 years?

What would you say to patients who wanted stem cell therapies now?

What are the most promising applications for stem cell research?

Why is it important for the government to fund regenerative medicine?

These challenging and thought-provoking questions were posed to a vibrant group of undergraduate and masters-level students at this year’s CIRM Bridges to Stem Cell Research and Therapy conference.

Educating the next generation of stem cell scientists

The Bridges program is one of CIRM’s educational programs that offers students the opportunity to take coursework at California state schools and community colleges and conduct stem cell research at top universities and industry labs. Its goal is to train the next generation of stem cell scientists by giving them access to the training and skills necessary to succeed in this career path.

The Bridges conference is the highlight of the program and the culmination of the students’ achievements. It’s a chance for students to showcase the research projects they’ve been working on for the past year, and also for them to network with other students and scientists.

Bridges students participated in a networking pitch event about stem cell research.

Bridges students participated in a networking pitch event about stem cell research.

CIRM kicked off the conference with a quick and dirty “Stem Cell Pitch” networking event. Students were divided into groups, given one of the four questions above and tasked with developing a thirty second pitch that answered their question. They were only given ten minutes to introduce themselves, discuss the question, and pick a spokesperson, yet when each team’s speaker took the stage, it seemed like they were practiced veterans. Every team had a unique, thoughtful answer that was inspiring to both the students and to the other scientists in the crowd.

Getting to the clinic and into patients

The bulk of the Bridges conference featured student poster presentations and scientific talks by leading academic and industry scientists. The theme of the talks was getting stem cell research into the clinic and into patients with unmet medical needs.

Here are a few highlights and photos from the talks:

On the clinical track for Huntington’s disease

Leslie Thompson, Professor at UC Irvine, spoke about her latest research in Huntington’s disease (HD). She described her work as a “race against time.” HD is a progressive neurodegenerative disorder that’s associated with multiple social and physical problems and currently has no cure. Leslie described how her lab is heading towards the clinic with human embryonic stem cell-derived neural (brain) stem cells that they are transplanting into mouse models of HD. So far, they’ve observed positive effects in HD mice that received human neural stem cell transplants including an improvement in the behavioral and motor defects and a reduction in the accumulation of toxic mutant Huntington protein in their nerve cells.

Leslie Thompson

Leslie Thompson

Leslie noted that because the transplanted stem cells are GMP-grade (meaning their quality is suitable for use in humans), they have a clear path forward to testing their potential disease modifying activity in human clinical trials. But before her team gets to humans, they must take the proper regulatory steps with the US Food and Drug Administration and conduct further experiments to test the safety and proper dosage of their stem cells in other mouse models as well as test other potential GMP-grade stem cell lines.

Gene therapy for SCID babies

Morton Cowan, a pediatric immunologist from UC San Francisco, followed Leslie with a talk about his efforts to get gene therapy for SCID (severe combined immunodeficiency disease) off the bench into the clinic. SCID is also known as bubble-baby disease and put simply, is caused by a lack of a functioning immune system. SCID babies don’t have normal T and B immune cell function and as a result, they generally die of infection or other conditions within their first year of life.

Morton Cowan

Morton Cowan, UCSF

Morton described how the gold standard treatment for SCID, which is hematopoietic or blood stem cell transplantation, is only safe and effective when the patient has an HLA matched sibling donor. Unfortunately, many patients don’t have this option and face life-threatening challenges of transplant rejection (graft-versus host disease). To combat this issue, Morton and his team are using gene therapy to genetically correct the blood stem cells of SCID patients and transplant those cells back into these patients so that they can generate healthy immune cells.

They are currently developing a gene therapy for a particularly hard-to-treat form of SCID that involves deficiency in a protein called Artemis, which is essential for the development of the immune system and for repairing DNA damage in cells. Currently his group is conducting the necessary preclinical work to start a gene therapy clinical trial for children with Artemis-SCID.

Treating spinal cord injury in the clinic

Casey Case, Asterias Biotherapeutics

Casey Case, Asterias Biotherapeutics

Casey Case, Senior VP of Research and Nonclinical Development at Asterias Biotherapeutics, gave an update on the CIRM-funded clinical trial for cervical (neck) spinal cord injury (SCI). They are currently testing the safety of transplanting different doses of their oligodendrocyte progenitor cells (AST-OPC1) in a group of SCI patients. The endpoint for this trial is an improvement in movement greater than two motor levels, which would offer a significant improvement in a patient’s ability to do some things on their own and reduce the cost of their healthcare. You can read more about these results and the ongoing study in our recent blogs (here, here).

Opinion: Scientists should be patient advocates

David Higgins gave the most moving speech of the day. He is a Parkinson’s patient and the Patient Advocate on the CIRM board and he spoke about what patient advocates are and how to become one. David explained how, these days, drug development and patient advocacy is more patient oriented and patients are involved at the center of every decision whether it be questions related to how a drug is developed, what side effects should be tolerated, or what risks are worth taking. He also encouraged the Bridges students to become patient advocates and understand what their needs are by asking them.

David Higgins, Parkinson's advocate and CIRM Board member

David Higgins

“As a scientist or clinician, you need to be an ambassador. You have a job of translating science, which is a foreign language to most people, and you can all effectively communicate to a lay audience without being condescending. It’s important to understand what patients’ needs are, and you’ll only know that if you ask them. Patients have amazing insights into what needs to be done to develop new treatments.”

Bridging the gap between research and patients

The Bridges conference is still ongoing with more poster presentations, a career panel, and scientific talks on discovery and translational stem cell research and commercializing stem cell therapies to all patients in need. It truly is a once in a lifetime opportunity for the Bridges students, many of whom are considering careers in science and regenerative medicine and are taking advantage of the opportunity to talk and network with prominent scientists.

If you’re interested in hearing more about the Bridges conference, follow us on twitter (@CIRMnews, @DrKarenRing, #CIRMBridges2016) and on Instagram (@CIRM_Stemcells).

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

Adding new stem cell tools to the Parkinson’s disease toolbox

Understanding a complicated neurodegenerative disorder like Parkinson’s disease (PD) is no easy task. While there are known genetic risk factors that cause PD, only about 10 percent of cases are linked to a genetic cause. The majority of patients suffer from the sporadic form of PD, where the causes are unknown but thought to be a combination of environmental, lifestyle and genetic factors.

Unfortunately, there is no cure for PD, and current treatments only help PD patients manage the symptoms of their disease and inevitably lose their effectiveness over time. Another troubling issue is that doctors and scientists don’t have good ways to predict who is at risk for PD, which closes an important window of opportunity for delaying the onset of this devastating disease.

Scientists have long sought relevant disease models that mimic the complicated pathological processes that occur in PD. Current animal models have failed to truly represent what is going on in PD patients. But the field of Parkinson’s research is not giving up, and scientists continue to develop new and improved tools, many of them based on human stem cells, to study how and why this disease happens.

New Stem Cell Tools for Parkinson’s

Speaking of new tools, scientists from the Buck Institute for Research on Aging published a study that generated 10 induced pluripotent stem cell (iPS cell) lines derived from PD patients carrying well known genetic mutations linked to PD. These patient cell lines will be a useful resource for studying the underlying causes of PD and for potentially identifying therapeutics that prevent or treat this disorder. The study was partly funded by CIRM and was published today in the journal PLOS ONE.

Dr. Xianmin Zeng, the senior author on the study and Associate Professor at Buck Institute, developed these disease cell lines as tools for the larger research community to use. She explained in a news release:

Xianmin Zeng, Buck Institute

Xianmin Zeng, Buck Institute

“We think this is the largest collection of patient-derived lines generated at an academic institute. We believe the [iPS cell] lines and the datasets we have generated from them will be a valuable resource for use in modeling PD and for the development of new therapeutics.”

 

The datasets she mentions are part of a large genomic analysis that was conducted on the 10 patient stem cell lines carrying common PD mutations in the SNCA, PARK2, LRRK2, or GBA genes as well as control stem cell lines derived from healthy patients of the same age. Their goal was to identify changes in gene expression in the Parkinson’s stem cell lines as they matured into the disease-affected nerve cells of the brain that could yield clues into how PD develops at the molecular level.

Using previous methods developed in her lab, Dr. Zeng coaxed the iPS cell lines into neural stem cells (brain stem cells) and then further into dopaminergic neurons – the nerve cells that are specifically affected and die off in Parkinson’s patients. Eight of the ten patient lines were able to generate neural stem cells, and all of the neural stem cell lines could be coaxed into dopaminergic neurons – however, some lines were better at making dopaminergic neurons than others.

Dopaminergic neurons derived from induced pluripotent stem cells. (Xianmin Zeng, Buck Institute)

Dopaminergic neurons derived from induced pluripotent stem cells. (Xianmin Zeng, Buck Institute)

When they analyzed these lines, surprisingly they found that the overall gene expression patterns were similar between diseased and healthy cell lines no matter what cell stage they were at (iPS cells, neural stem cells, and neurons). They next stressed the cells by treating them with a drug called MPTP that is known to cause Parkinson’s like symptoms in humans. MPTP treatment of dopaminergic neurons derived from PD patient iPS cell lines did cause changes in gene expression specifically related to mitochondrial function and death, but these changes were also seen in the healthy dopaminergic neurons.

Parkinson’s, It’s complicated…

These interesting findings led the authors to conclude that while their new stem cell tools certainly display some features of PD, individually they are not sufficient to truly model all aspects of PD because they represent a monogenic (caused by a single mutation) form of the disease.

They explain in their conclusion that the power of their PD patient iPS cell lines will be achieved when combined with additional patient lines, better controls, and more focused data analysis:

“Our studies suggest that using single iPSC lines for drug screens in a monogenic disorder with a well-characterized phenotype may not be sufficient to determine causality and mechanism of action due to the inherent variability of biological systems. Developing a database to increase the number of [iPS cell] lines, stressing the system, using isogenic controls [meaning the lines have identical genes], and using more focused strategies for analyzing large scale data sets would reduce the impact of line-to-line variations and may provide important clues to the etiology of PD.”

Brian Kennedy, Buck Institute President and CEO, also pointed out the larger implications of this study by commenting on how these stem cell tools could be used to identify potential drugs that specifically target certain Parkinson’s mutations:

Brian Kennedy, Buck Institute

Brian Kennedy, Buck Institute

“This work combined with dozens of other control, isogenic and reporter iPSC lines developed by Dr. Zeng will enable researchers to model PD in a dish. Her work, which we are extremely proud of, will help researchers dissect how genes interact with each other to cause PD, and assist scientists to better understand what experimental drugs are doing at the molecular level to decide what drugs to use based on mutations.”

Overall, what inspires me about this study is the author’s mission to provide a substantial number of PD patient stem cell lines and genomic analysis data to the research community. Hopefully their efforts will inspire other scientists to add more stem cell tools to the Parkinson’s tool box. As the saying goes, “it takes an army to move a mountain”, in the case of curing PD, the mountain seems more like Everest, and we need all the tools we can get.


Related links:

A step forward for Parkinson’s disease?

Imagine how frustrating it would be to not know whether you could physically sit through a dinner with friends or to worry about getting stuck in the grocery isle, fighting against a body that refuses to move. These nightmare-like experiences are what many Parkinson’s disease (PD) patients deal with on a daily basis.

PD affects approximately one million people in the US, and there is no prevention or cure. While substantial funding efforts are being dedicated to PD research (CIRM, Michael J. Fox Foundation, Parkinson’s Disease Foundation, to name a few), a cure is still years or maybe even decades away.

However, a new stem cell therapy from Australia has the potential to make waves in what’s been a relatively flat sea of PD stem cell therapies that haven’t yet secured the funding or jumped the regulatory hurdles to make it into clinical trials. Biotech journalist Bradley Fikes broke the story yesterday in the San Diego Union Tribune. Fikes is one of my favorite science writers so instead of attempting to re-write an already eloquent piece, I’ll just mention a few highlights.

Stem cells down under

International Stem Cell Corporation (ISCO), a company based in Carlsbad, California, has developed a stem cell therapy that involves transplanting brain stem cells into the brains of PD patients. While stem cell therapy is viewed by some as the holy grail for PD – having the potential to replace lost dopamine-producing nerve cells in the brain – so far, no stem cell-derived therapy has been approved for testing in PD patients. (Previous clinical trials using fetal stem cells didn’t pan out.)

The Australian government approved the use of ISCO’s parthenogenic stem cell therapy in twelve PD patients in a clinical trial that is slated to start in the first quarter of 2016 (pending final approval from the Royal Melbourne Hospital review board). This therapy uses brain stem cells derived from pluripotent stem cells obtained from unfertilized human eggs, thus avoiding the ethical issues attached to use of embryonic stem cells. (For sciency details check out the ISCO website).

The goal of the trial will be to determine if ISCO’s stem cell therapy is safe and also effective at reducing PD symptoms like tremors and stunted movement. Fikes explained that ISCO chose Australia for it’s proposed clinical trial for regulatory reasons.

“The nation’s clinical trial system is more ‘interactive’, which allows for better collaboration with Australia’s Therapeutic Goods Administration on trial design.”

A comparison of primate brains to show an increase in the number of neurons after treatment with ISCO's stem cells. The left side is a control sample. The right side is from a treated brain. — International Stem Cell Corp.

A comparison of primate brains to show an increase in the number of neurons after treatment with ISCO’s stem cells. The left side is a control sample. The right side is from a treated brain. — International Stem Cell Corp.

Great minds think alike

ISCO’s is only one of a handful of groups proposing stem cell therapies for PD. Fikes mentioned other therapies currently being tested that are derived from embryonic stem cells, induced pluripotent stem cells (iPSCs), and adult stem cells like the mesenchymal and fat stem cells.

Jeanne Loring, Scripps Research Institute

Jeanne Loring, Scripps Research Institute

He also highlighted important ongoing research by CIRM grantee Dr. Jeanne Loring from the Scripps Research Institute. Loring founded the Summit for Stem Cell organization that’s generating iPSCs from PD patients with hopes of treating these patients with a dose of their own brain stem cells.

When asked about the ISCO study, she told Fikes that she sees ISCO as a “partner in fighting Parkinson’s.”

“The whole idea is to treat patients by whatever means possible.” – Loring


Related Links:

 

CIRM Scholar Spotlight: Berkeley’s Maroof Adil on stem cell transplants for Parkinson’s disease

Maroof Adil, CIRM Scholar

Maroof Adil, CIRM Scholar

Stem cell therapy has a lot of potential for Parkinson’s patients and the scientists that study it. One of our very own CIRM scholars, Maroof Adil, is making it his mission to develop stem cell based therapies to treat brain degenerating diseases like Parkinson’s.

Maroof got his undergraduate degrees from MIT in both Chemical Engineering and Biology, and a PhD in Chemical Engineering from the University of Minnesota. As a graduate student, he dived into the world of cancer research and explored ways of delivering cancer-killing genes specifically to cancer cells in the body while leaving healthy tissues in the body unharmed.

While he enjoyed his time spent on cancer research, he realized his main interest was to apply his skills in chemical engineering and materials science to understand biological problems. This brought him to his current position as a postdoc at UC Berkeley in the Schaffer lab.

Maroof is doing some pretty cutting edge research to develop 3D biomaterials that will vastly improve the transplantation and survival of stem cell derived neurons (nerve cells) in the brain. Check out our exclusive interview with this talented scientist below!


Q: What are you working on and why?

MA: I have always been excited about finding engineering solutions to medically relevant problems. I decided to do a postdoc at UC Berkeley in David Schaffer’s lab because I wanted to combine chemical and materials engineering skills from my graduate research with stem cell technologies to solve biological problems. One of the exciting parts of Dave’s lab, and a reason why I joined, is that he is working on translational stem cell-based regenerative therapies for central nervous system diseases such as Parkinson’s and Huntington’s.

My current research is motivated by the need to find better therapies for these neurodegenerative diseases. While stem cell-based regenerative medicine is an up-and-coming field, there are still a lot of challenges that need to be addressed before stem cells can be successfully used in the clinic. There are three main challenges that are most relevant to my research. First, we need to improve the efficiency of stem cell differentiation, i.e. how well we can convert these stem cells to the mature, functional neurons that we need to treat neurodegenerative diseases. Second, after implanting these cells into the body, we need to increase their survival efficiency. This is because one of the main issues with stem cell-based transplants right now is that after implantation, most of these cells die. Given these first two challenges, we need to generate a lot of cells in order to effectively treat degenerative diseases. The third challenge is to make good quality, functional, transplantable cells in a large-scale fashion.

So given my chemical and materials engineering background, I wanted to see if we could use biologically inspired materials (biomaterials) to address some of these issues with stem cell differentiation and transplantation. In brief, we are developing functionalized biomaterials, differentiating stem cells within these biomaterials into neurons, characterizing the quality of these neurons, and testing the function of these stem cell-derived neurons in animal models of disease.

A major focus of our lab is to develop 3D biomaterials to increase the efficiency of large-scale production of clinical-grade stem cells [and the mature cells that are derived from them]. Our preliminary results suggest that we can get higher numbers of better quality neurons when we differentiate and grow them in 3D biomaterials compared to when they are traditionally grown on a flat, 2D tissue culture surface. Presently, I’m trying to verify that our 3D method works in the lab. If it does, this technology could help us save a lot of time and resources in generating the type of cells we need for effective cell replacement therapies.

Stem cells growing as clusters in 3D[1]Neurons generated in 3D platforms 1[1]

Stem cell derived neurons grown in 3D cultures (left) and generated on 3D biomaterials (right). Images courtesy of Maroof Adil.

Q: Your research sounds fascinating but complicated. How are you doing it?

MA: It’s certainly a multidisciplinary project, and constantly requires us to draw ideas from diverse fields including polymer chemistry, developmental biology and chemical engineering. I am very grateful to be part of a resourceful lab, to my mentors, and to have amazing, motivated people working with me. UC Berkeley provides a highly collaborative work environment. So for some of the follow-up work that further characterizes the quality of these stem cells and their mature cell derivatives, we are collaborating with other labs at UC Berkeley and at UCSF.

Q: Are you interested in applying this work to other brain diseases?

MA: Certainly. Although we are primarily working on generating stem cell-derived dopaminergic neurons, which are the major cell type that die in Parkinson’s patients, I’m also interested in applying similar biomaterials to derive other types of neurons, for instance medium spiny neurons for Huntington’s disease.

The advantage of some of the materials we are working with is their modular nature. That is, we can tune their properties so that they are useful for other applications.

Q: In your opinion what is the future of stem cells in your field? Will they bring cures?

MA: I am very hopeful given what I’m seeing right now in the scientific literature, and in clinical trials for stem cell-based therapies in general. Right now, there are several trials that are testing the benefit and safety of stem cell-based transplants in different diseases. However, right now there are no clinical trials applying stem cell-derived neurons to treat brain diseases. But I think there’s certainly a lot of promise. There are challenges that we need to address in this field, and some of these I outlined earlier. Researchers are working on finding solutions to these problems, and I think that if we find them, the chances of successfully finding cures will be higher.

Q: Tell us about your experience as a CIRM Scholar.

MA: I started as a CIRM scholar in 2014. It was really great to have a source of funding that lined up with what I was interested in, which was doing translational work in regenerative medicine.

I first began working with stem cells when I started my postdoc career, but I didn’t really have a background in this area. So being new to the stem cell field, I felt that CIRM provided the support structure that I needed. And I’m not just referring to funding. CIRM brings scientists with different scientific backgrounds together in one place, where we can learn from one another, and initiate fruitful collaborations. Being a CIRM scholar makes me feel like I’m part of a bigger community, with other scientists conducting very different, but related stem cell research.

Also, I am a big fan of the CIRM blog. I am able to learn about patients and about other researcher’s backgrounds. It helps you realize that patients and researchers are part of the same field. And I like that concept of bringing the field closer: patients towards researchers and researchers towards patients. I think that is useful to boost motivation for researchers, and to give patients a better idea of what we do.

Through CIRM, we’ve had a chance to go out into the local community and present some of our research. For example, the past two years I’ve talked to local high school students during Stem Cell Awareness Week, and that was a really great experience.  I’ve presented to other professionals before, but never to those as young as high school students.  To me, it was quite exciting to realize that these kids are very much interested in the type of work we are doing, and to feel like I was able to influence them to potentially pursue science as a career.

Q: What are your career goals?

MA: I definitely want to stay in science and solve medically relevant problems. It could be nice to be faculty at a research university and in a position to pursue my own independent ideas at the interface of biomaterials and stem cell based therapies. An industry position working towards regenerative medicine or other biologically relevant applications is also an exciting possibility. At this point, being in science is my priority.

Q: What’s your favorite thing about being a scientist?

MA: The excitement you get when your experiments work out, and the joy of making new discoveries. I also like the thrill of designing experiments that may advance the field, and the feeling that what you’re doing day-to-day is contributing to a body of knowledge that others may find useful. I find it especially rewarding to be a scientist in the medical field, working on translational projects closely related to finding cures for diseases.

Keeping elderly cells old to understand the aging process

Aging is a key risk factor for many diseases, particularly disorders of the brain like Alzheimer’s or Parkinson’s, which primarily occur in the elderly. So a better understanding of the aging process should provide a better understanding of these neurodegenerative diseases.

The induced pluripotent stem cell (iPSC) technique makes it possible to grow human brain cells, or neurons, in the lab from elderly patient skin samples. Unfortunately, this method has a major pitfall when it comes to aging research: reprogramming skin cells back into the embryonic stem cell-like state of iPSCs strips away many of their old age-related characteristics.

Based on data published last week in Cell Stem Cell, Salk Institute researchers used a different technique called direct reprogramming as a means to keep old cells old. This alternative method sidesteps the need to make iPSCs (which brings cells all the way back to the pluripotent state) and instead converts a skin cell directly into the desired cell type.

First author Jerome Mertens and senior author Rusty Gage (Courtesy of the Salk Institute for Biological Studies).

First author Jerome Mertens and senior author Rusty Gage (Courtesy of the Salk Institute for Biological Studies).

iPSC and direct reprogramming go head-to-head

The study, funded in part by CIRM, relied on skin samples from people ranging in age from newly born to 89 years. The team generated iPSC and iPSC-derived neurons from these samples. They also made so-called induced neurons (iNs) from the skin cells using the direct reprogramming method. Other CIRM grantees have pioneered direct reprogramming of skin into nerve cells (see link below).

Skin cell samples from elderly human donors are directly converted into induced neurons (iNs), shown. (image: Courtesy of the Salk Institute for Biological Studies)

Skin cells from elderly human donors are directly converted into induced neurons (iNs), shown. (Image courtesy of the Salk Institute for Biological Studies).

When comparing skin cells from donors younger than 40 years old versus cells from the over 40 group, the team found several genes had age-dependent activity patterns. Those differences virtually disappeared in the iPSCs and iPSC-derived neurons from the same individuals. However, unlike iPSCs, direct reprogramming of the skin cells to neurons (iNs) hung on to age-dependent differences in gene activity.

Loss of RanBP17 protein a fountain of youth in reverse

A deeper analysis identified one gene called RanBP17 whose activity levels declined with increased age of the donor in both the original skin cells and those directly converted into iNs. But when those same donor skin cells were turned into iPSCs or even iPSC-derived neurons, RanBP17 levels in the older cells were no longer reduced and were on par with RanBP17 levels in the younger cells. In follow up experiments, a reduction in RanBP17 protein led to glitches in the transport of proteins into the cell’s nucleus, which other studies have linked to neurodegenerative diseases as well as the aging process.

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Gene expression patterns of age-related factors like RanBP17 are maintained in induced neurons but not iPSCs. (Mertens et al., 2015)

Altogether, these results encourage researchers to select iNs over iPSC-derived neurons when it comes to faithfully representing the aging process of brain cells. Based on a Salk Institute press release, you can tell that professor Martin Hezter, a contributing author, is excited about future studies with iNs:

By using this powerful approach, we can begin to answer many questions about the physiology and molecular machinery of human nerve cells–not just around healthy aging but pathological aging as well.

 


Related links:

Stem cell stories that caught our eye: Parkinson’s in a dish, synthetic blood, tracking Huntington’s and cloning

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

3D nerve model for Parkinson’s. The wave of successes in making more complex tissues in three dimensional lab cultures continues this week with a team in Luxembourg creating nerves from stem cells derived from Parkinson’s patients that assembled into complex connections in the lab.

Nerve cells made from skin cells. Credit: Luxembourg Centre for Systems Biomedicine (LCSB), 2015

Nerve cells made from skin cells. Credit: Luxembourg Centre for Systems Biomedicine (LCSB), 2015

The name of the journal where the group published their results, Lab on a Chip, says a lot about where the field is going. While many have grown the dopamine-producing nerves lost in Parkinson’s disease in two dimensional cultures, the new technique better replicates the disease state and does it about 10-fold cheaper because the 3D bioreactors used can be automated and use less of the reagents needed to grow the cells and to tell them to become the right nerves.

They started with skin samples from patients and reprogrammed them into iPS-type stem cells. After those cells are placed in the vessel, they are matured into 90 percent pure dopamine-nerves. At that point they are ideal for testing potential drugs for any impact on the disease. The senior researcher, Ronan Fleming, explained the benefit in a press release from the University of Luxembourg, picked up by ScienceDaily:

“In drug development, dozens of chemical substances can therefore be tested for possible therapeutic effects in a single step. Because we use far smaller amounts of substances than in conventional cell culture systems, the costs drop to about one tenth the usual.”

Synthetic blood from stem cells. Making synthetic blood, particularly for people with rare blood types for which there are few donors, has long been a goal of science. Now, the British National Health Service (NHS) says it expects to begin giving patients at least one component of lab-made blood—red cells—by 2017.

Starting with adult stem cells grown in just the right solution they hope to produce large quantities of red blood cells. Initially they plan to give only small quantities to healthy individuals with rare blood types to compare them to donor blood.

“These trials will compare manufactured cells with donated blood,” said Nick Warkins of the NHS. “The intention is not to replace blood donation but provide specialist treatment for specific patient groups.”

The story got wide pick up in the British press including in the Daily Mail and in several web portals including Rocket News.

Tracking Huntington’s spread in the brain. A CIRM-funded team at the University of California, Irvine, has developed a way to track the spread of the mutant protein responsible for progression of Huntington’s disease. They were able to accurately detect the mutant protein in cerebrospinal fluid and distinguish between people who carried the mutation but were pre-symptomatic from those that had advanced disease.

The protein appears to be released by diseased cells and migrates to other cells, seeding additional damage there. Measuring levels of the protein should allow physicians to monitor progression of the disease ahead of symptoms.

“Determining if a treatment modifies the course of a neurodegenerative disease like Huntington’s or Alzheimer’s may take years of clinical observation,” said study leader Dr. Steven Potkin. “This assay that reflects a pathological process can play a key role in more rapidly developing an effective treatment. Blocking the cell-to-cell seeding process itself may turn out to be an effective treatment strategy.”

Medical News Today wrote up the research that the team published in the journal Molecular Psychiatry.

Good overview of cloning. Writing for Medical Daily, Dana Dovey has produced a good overview of the history of cloning, and more important, the reasons why reproductive cloning of human is not likely to happen any time soon.

She describes the important role a number of variations on cloning play in scientific research, and the potential to create personalized cells for patients through a process known as therapeutic cloning. But she also describes the many problems with reproductive cloning as it is practiced in animals. It is very inefficient with dozens of eggs failing to mature and often results in animals that have flaws. She quotes Robert Lanza of Advanced Cell Technologies (now Ocata Therapeutics):

“It’s like sending your baby up in a rocket knowing there’s a 50-50 chance it’s going to blow up. It’s grossly unethical.”

 

Mutation Morphs Mitochondria in Models of Parkinson’s Disease, CIRM-Funded Study Finds

There is no singular cause of Parkinson’s disease, but many—making this disease so difficult to understand and, as a result, treat. But now, researchers at the Buck Institute for Research on Aging have tracked down precisely how a genetic change, or mutation, can lead to a common form of the disease. The results, published last week in the journal Stem Cell Reports, point to new and improved strategies at tackling the underlying processes that lead to Parkinson’s.

Mitochondria from iPSC-derived neurons. On the left is a neuron derived from a healthy individual, while the image on the right shows a neuron derived from someone with the Park2 mutation, the most common mutation in Parkinson's disease (Credit: Akos Gerencser)

Mitochondria from iPSC-derived neurons. On the left is a neuron derived from a healthy individual, while the image on the right shows a neuron derived from someone with the Park2 mutation, the most common mutation in Parkinson’s disease (Credit: Akos Gerencser)

The debilitating symptoms of Parkinson’s—most notably stiffness and tremors that progress over time, making it difficult for patients to walk, write or perform other simple tasks—can in large part be linked to the death of neurons that secrete the hormone dopamine. Studies involving fruit flies in the lab had identified mitochondria, cellular ‘workhorses’ that churn out energy, as a key factor in neuronal death. But this hypothesis had not been tested using human cells.

Now, scientists at the Buck Institute have replicated the process in human cells, with the help of stem cells derived from patients suffering from Parkinson’s, a technique called induced pluripotent stem cell technology, or iPSC technology. These newly developed neurons exactly mimic the disease at the cellular level. This so-called ‘disease in a dish’ is one of the most promising applications of stem cell technology.

“If we can find existing drugs or develop new ones that prevent damage to the mitochondria we would have a potential treatment for PD,” said Dr. Xianmin Zeng, the study’s senior author, in a press release.

And by using this technology, the Buck Institute team confirmed that the same process that occurred in fruit fly cells also occurred in human cells. Specifically, the team found that a particular mutation in these cells, called Park2, altered both the structure and function of mitochondria inside each cell, setting off a chain reaction that leads to the neurons’ inability to produce dopamine and, ultimately, the death of the neuron itself.

This study, which was funded in part by a grant from CIRM, could be critical in the search for a cure for a disease that, as of yet, has none. Current treatment regimens aimed at slowing or reducing symptoms have had some success, but most begin to fail overtime—or come with significant negative side effects. The hope, says Zeng, is that iPSC technology can be the key to fast-tracking promising drugs that can actually target the disease’s underlying causes, and not just their overt symptoms. Hear more from Dr. Xianmin Zeng as she answers your questions about Parkinson’s disease and stem cell research:

Stem Cell Stories that Caught our Eye: Multiple Sclerosis, Parkinson’s and Reducing the Risk of Causing Tumors

Here are some stem cell stories that caught our eye this past week. Some are groundbreaking science, others are of personal interest to us, and still others are just fun.

Cell therapy for Parkinson’s advancing to the clinic. A decade-long moratorium on the transplant of fetal nerve tissue into Parkinson’s patient will end in two months when the first patients in a large global trial will receive the cells. BioScience Technology did a detailed overview on the causes for the moratorium and the optimism about the time being right to try again. The publication also talks about what most people in the field believe will be the long-term solution: moving from scarce fetal tissue to nerve cells grown from readily available embryonic stem cells. The author’s jumping off point was a pair of presentations at the International Society for Stem Cell Research in June, which we wrote about at the time. But the BioScience piece provides more background on the mixed results of earlier studies and references to recent journal publications showing long term—as much as 20 year—benefit for some of those patients.

It goes on to describe multiple reasons why, once the benefit is confirmed with fetal cells, moving to stem cells might be the better way to go. Not only are they more readily available, they can be purified in the lab as they are matured into the desired type of early-stage nerve cell. Researchers believe that some of the side effects seen in the early fetal trials stemmed from the transplants containing a second type of cell that caused jerking movements known as dyskinesias. One stem cell trial is expected to start in 2017, which we discussed in June.

Immunity persists through a special set of stem cells. Our immune system involves so many players and so much cell-to-cell interaction that there are significant gaps in our understanding of how it all works. One of those is how we can have long-term immunity to certain pathogens. The T-cells responsible for destroying invading bugs remember encountering specific ones, but they only live for a few years, generally estimated at five to 15. The blood-forming stem cells that are capable of generating all our immune cells would not have memory of specific invaders so could not be responsible for the long term immunity.

Now, an international team from Germany and from the Hutchison Center in Washington has isolated a subset of so-called “memory T-cells” that have stem cell properties. They can renew themselves and they can generate diverse offspring cells. Researchers have assumed cells like this must exist, but could not confirm it until they had some of the latest gee-wiz technologies that allow us to study single cells over time. ScienceDaily carried a story derived from a press release from the university in Munich and it discusses the long-term potential benefits from this finding, most notably for immune therapies in cancer. The team published their work in the journal Immunity.

Method may reduce the risk of stem cells causing tumors. When teams think about transplanting cells derived from pluripotent stem cells, either embryonic or iPS cells, they have to be concerned about causing tumors. While they will have tried to mature all the cells into a specific desired adult tissue, there may be a few pluripotent stem cells still in the mix that can cause tumors. A team at the Mayo Clinic seems to have developed a way to prevent any remaining stem cells in transplants derived from iPS cells from forming tumors. They treated the cells with a drug that blocks an enzyme needed for the stem cells to proliferate. Bio-Medicine ran a press release from the journal that published the finding, Stem Cells and Development. Unfortunately, that release lacks sufficient detail to know exactly what they did and its full impact. But it is nice to know that someone is developing some options of ways to begin to address this potential roadblock.

Multiple sclerosis just got easier to study. While we often talk about the power of iPS type stem cells to model disease, we probably devote too few electrons to the fact that the process is not easy and often takes a very long time. Taking a skin sample from a patient, reprogramming it to be an iPS cell, and then maturing those into the adult tissue that can mimic the disease in a dish takes months. It varies a bit depending on the type of adult tissue you want, but the nerve tissue that can mimic multiple sclerosis (MS) takes more than six months to create. So a team at the New York Stem Cell Foundation has been working on ways to speed up that process for MS. They now report that they have cut the time in half. This should make it much easier for more teams to jump into the effort of looking for cures for the disease. ScienceCodex ran the foundations press release.