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Judy Chou, Ph.D., Appointed to Governing Board of California’s Stem Cell & Gene Therapy Agency

/ Kevin McCormack / Leave a comment
Judy Chou, Ph.D.

Judy Chou, Ph.D. has been appointed to the Independent Citizens’ Oversight Committee (ICOC), the governing Board of the California Institute for Regenerative Medicine (CIRM).

Dr. Chou is the President, CEO and a member of the Board of Directors of AltruBio, Inc. a clinical stage biotech company that is focused on developing novel antibody therapeutics for the treatment of immune inflammatory diseases.

“I am excited to join the ICOC leveraging my experience both as a scientist in the the biopharmaceutical industry and as a corporate executive to support the research and funding of life changing medicines for patients in need,” said Dr. Chou.

Dr. Chou has more than 20 years experience in drug development and biomanufacturing. Before joining AltruBio she headed the global Biotech organization at Bayer Pharmaceuticals. At Bayer she oversaw the development, manufacturing and distribution of the company’s more than $3 billion product portfolio. She also oversaw more than 2,000 employees and led the drug development and launch activities for the biologics pipeline. In addition, she also served as the site head for Bayer’s facility in Berkeley, California, the company’s largest manufacturing site in the U.S.

“We are honored and delighted to have Dr. Chou take a seat on the Board,” says Jonathan Thomas, Ph.D., J.D., Chair of the CIRM Board. “She has a remarkable career in academia, industry and in promoting diversity, equity and inclusion and will be an invaluable addition to the ICOC. We are very much looking forward to working with her.”

Dr. Chou also has had leadership roles at Pfizer, Medivation Inc., Genentech and Wyeth Biopharma. She has won several awards and in 2018 was the recipient of the Most Influential Women in Business award by the San Francisco Business Times. She is currently an advisor at the UC Berkeley Engineering School and is working to promote diversity and inclusion through her advisory board position at Silicon Valley Women in Engineering.

Dr. Chou obtained her Ph.D., at Yale, her post-doctoral training at the Max-Planck Institute in Germany and was a research faculty member at Harvard University Medical School focusing on cell biology and neuroscience.

Dr. Chou was appointed to the CIRM Board by State Treasurer Fiona Ma, as the Executive Officer of a Commercial Life Science entity. She replaces Dave Martin.

Study shows sleep deprivation impairs stem cells in the cornea 

/ Esteban Cortez / 1 Comment

We spend around one third of our life sleeping—or at least we should. Not getting enough sleep can have serious consequences on many aspects of our health and has been linked to high blood pressure, heart disease and stroke. 

A study by the American Sleep Apnea Association found that some 70 percent of Americans report getting too little sleep at least one night a month, and 11 percent report not enough sleep every night. Over time that can take a big toll on your mental and physical health. Now a new study says that impact can also put you at increased risk for eye disease.  

The study published in the journal Stem Cell Reports, looked at how sleep deprivation affects corneal stem cells. These cells are essential in replacing diseased or damaged cells in the cornea, the transparent tissue layer that covers and protects the eye.  

Researchers Wei Li, Zugou Liu and colleagues from Xiamen University, China and Harvard Medical School, USA, found that, in mice short-term sleep deprivation increased the rate at which stem cells in the cornea multiplied. Having too many new cells created vision problems.  

They also found that long-term sleep deprivation had an even bigger impact on the health of the cornea. Sleep-deprived mice had fewer active stem cells and so were not as effective in replacing damaged or dying cells. That in turn led to a thinning of the cornea and a loss of transparency in the remaining cells.  

The cornea— the transparent tissue layer covering the eye—is maintained by stem cells, which divide to replace dying cells and to repair small injuries.

The findings suggest that sleep deprivation negatively affects the stem cells in the cornea, possibly leading to vision impairment in the long run. It’s not clear if these findings also apply to people, but if they do, the implications could be enormous.  

The California Institute for Regenerative Medicine (CIRM) is also heavily involved in searching for treatments for diseases or conditions that affect vision. We have invested almost $150 million in funding 31 projects on vision loss including a clinical trial with UCLA’s Dr. Sophie Deng targeting the cornea, and other clinical trials for age-related macular degeneration and retinitis pigmentosa. 

Shared with permission from International Society for Stem Cell Research. Read the source release here. 

Regulated, Reputable and Reliable: FDA’s Taking Additional Steps to Advance Safe and Effective Regenerative Medicine Products

/ Geoffrey Lomax Dr. PH / Leave a comment
Peter Marks, M.D., Ph.D., Director, Center for Biologics Evaluation and Research

In February 2020, CIRM presented a series of benchmarks for the responsible delivery of stem cell and regenerative medicine products. These benchmarks are outlined in the publication Regulated, reliable and reputable: Protect patients with uniform standards for stem cell treatments. In a nutshell, CIRM advocates for the delivery of regenerative medicine products in a context where:

  • The product is authorized by the Food and Drug Administration (FDA) and is overseen by an IRB or ethics board,
  • The treatment is delivered by qualified doctors, nurses, and technicians,
  • Treatment occurs at a clinical treatment center with expertise in regenerative medicine, and
  • There is ongoing monitoring and follow-up of patients.

On April 21 of 2021, Dr. Peter Marks, Director of the Center for Biologics Evaluation and Research, indicated the FDA’s intent to ensure new regenerative medicine products are FDA-authorized. Specifically, the FDA will require product developers to obtain an Investigational New Drug or IND authorization. In his news release Dr. Marks says the agency is willing to exercise more enforcement of these rules should clinics or therapy producers fail to follow these guidelines.

“These regenerative medicine products are not without risk and are often marketed by clinics as being safe and effective for the treatment of a wide range of diseases or conditions, even though they haven’t been adequately studied in clinical trials. We’ve said previously and want to reiterate here – there is no room for manufacturers, clinics, or health care practitioners to place patients at risk through products that violate the law, including by not having an IND in effect or an approved biologics license. We will continue to take action regarding unlawfully marketed products.”

IND authorization is particularly important as the agency pays close attention to how the product is produced and whether there is a scientific rationale and potential clinical evidence that it may be effective against the specific disease condition. All CIRM-funded clinical trials and all trials conducted in the CIRM Alpha Stem Cell Clinics Network must have IND authorization.

Regenerative medicine products are generally created from human cells or tissues. These products are frequently referred to as “living medicines.” The “living” nature of these products is what contributes to their remarkable potential to relieve, stop or reverse disease in a durable or sustainable manner.

The risk with unregulated products is that there is no assurance that they have been  produced in a quality controlled process or manner  where all components of the  injected material have been well characterized and studied for safety and efficacy for a given disease as well as a specific site in the body. In addition, there is no way to ensure that unregulated products meet standards or quality specifications such as ensuring that they have the active and beneficial component while making sure that they do not include harmful contaminants..  There have been documented examples of patients being severely injured by unregulated and inadequately characterized products. For example, in 2017 three Florida women were blinded by an unauthorized product.  Dr. George Daley, a stem cell expert and the Dean of Harvard Medical School, described the clinic operators as “charlatans peddling the modern equivalent of snake oil.”

To receive FDA authorization, detailed scientific data and well controlled clinical data are required to ensure safety and a demonstration that  the product is safe has the potential to improve or resolve the patient’s disease condition.

While it seems both important and self-evident that stem cell products be safe and effective and supported by evidence they can impact the patient’s disease condition, that doesn’t always happen. Unfortunately, too many patients have experienced unnecessary medical risks and financial harm from unauthorized treatments. CIRM applauds the FDA for taking additional steps to advance regenerative medicine products where the clinical benefits of such therapies outweigh any potential harms.

Charting a course for the future

/ Kevin McCormack / 1 Comment
A new home for stem cell research?

Have you ever been at a party where someone says “hey, I’ve got a good idea” and then before you know it everyone in the room is adding to it with ideas and suggestions of their own and suddenly you find yourself with 27 pages of notes, all of them really great ideas. No, me neither. At least, not until yesterday when we held the first meeting of our Scientific Strategy Advisory Panel.

This is a group that was set up as part of Proposition 14, the ballot initiative that refunded CIRM last November (thanks again everyone who voted for that). The idea was to create a panel of world class scientists and regulatory experts to help guide and advise our Board on how to advance our mission. It’s a pretty impressive group too. You can see who is on the SSAP here.  

The meeting involved some CIRM grantees talking a little about their work but mostly highlighting problems or obstacles they considered key issues for the future of the field as a whole. And that’s where the ideas and suggestions really started flowing hard and fast.

It started out innocently enough with Dr. Amander Clark of UCLA talking about some of the needs for Discovery or basic research. She advocated for a consortium approach (this quickly became a theme for many other experts) with researchers collaborating and sharing data and findings to help move the field along.

She also called for greater diversity in research, including collecting diverse cell samples at the basic research level, so that if a program advanced to later stages the findings would be relevant to a wide cross section of society rather than just a narrow group.

Dr. Clark also said that as well as supporting research into neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, there needed to be a greater emphasis on neurological conditions such as autism, bipolar disorder and other mental health problems.

(CIRM is already committed to both increasing diversity at all levels of research and expanding mental health research so this was welcome confirmation we are on the right track).

Dr. Mike McCun called for CIRM to take a leadership role in funding fetal tissue research, things the federal government can’t or won’t support, saying this could really help in developing an understanding of prenatal diseases.

Dr. Christine Mummery, President of ISSCR, advocated for support for early embryo research to deepen our understanding of early human development and also help with issues of infertility.

Then the ideas started coming really fast:

  • There’s a need for knowledge networks to share information in real-time not months later after results are published.
  • We need standardization across the field to make it easier to compare study results.
  • We need automation to reduce inconsistency in things like feeding and growing cells, manufacturing cells etc.
  • Equitable access to CRISPR gene-editing treatments, particularly for underserved communities and for rare diseases where big pharmaceutical companies are less likely to invest the money needed to develop a treatment.
  • Do a better job of developing combination therapies – involving stem cells and more traditional medications.

One idea that seemed to generate a lot of enthusiasm – perhaps as much due to the name that Patrik Brundin of the Van Andel Institute gave it – was the creation of a CIRM Hotel California, a place where researchers could go to learn new techniques, to share ideas, to collaborate and maybe take a nice cold drink by the pool (OK, I just made that last bit up to see if you were paying attention).

The meeting was remarkable not just for the flood of ideas, but also for its sense of collegiality.  Peter Marks, the director of the Food and Drug Administration’s Center for Biologics Evaluation and Research (FDA-CBER) captured that sense perfectly when he said the point of everyone working together, collaborating, sharing information and data, is to get these projects over the finish line. The more we work together, the more we will succeed.

An Atlas of the Human Heart that May Guide Development of New Therapies

/ Kevin McCormack / Leave a comment

By Lisa Kadyk, PhD. CIRM Senior Science Officer

Illustration of a man’s heart – Courtesy Science Photo

I love maps; I still have auto club maps of various parts of the country in my car.  But, to tell the truth, those maps just don’t have as much information as I can get by typing in an address on my cell phone.  Technological advances in global positioning systems, cellular service, data gathering and storage, etc. have made my beloved paper maps a bit of a relic.  

Similarly, technological advances have enabled scientists to begin making maps of human tissues and organs at a level of detail that was previously unimaginable.  Hundreds of thousands of single cells can be profiled in parallel, examining expression of RNA and proteins.  These data, in combination with new three-dimensional spatial analysis techniques and sophisticated computational algorithms, allow high resolution mapping of all the cells in a given tissue or organ.

Given these new capabilities, an international “Human Cell Atlas Consortium” published a white paper in 2017 outlining plans and strategies to build comprehensive reference maps of all human cells, organ by organ.  The intent of building such an atlas is to give a much better understanding of the biology and physiology of normal human tissues, as well as to give new insights into the nature of diseases affecting those tissues and to point the way to developing new therapies. 

One example of this new breed of cartography was published September 24 in the journal Nature, in a paper called simply “Cells of the Human Heart”.   This tour-de-force effort was led by scientists from Harvard Medical School, the Wellcome Sanger Institute, the Max Delbruck Center for Molecular Medicine in Berlin and Imperial College, London.  These teams and their collaborators analyzed about 500,000 cells from six different regions of the healthy adult human heart, using post-mortem organs from 14 donors.  They examined RNA and protein expression and mapped the distribution of different types of cells in each region of the heart.  In addition, they made comparisons of male and female hearts, and identified cells expressing genes known to be associated with different types of heart disease.  

One of the take-home messages from this study is that there is a lot of cellular complexity in the heart – with 11 major cell types (examples include atrial and ventricular cardiomyocytes, fibroblasts and smooth muscle cells), as well as multiple subpopulations within each of those types.  Also notable is the different distribution of cells between the atria (which are at the top of the heart and receive the blood) and ventricles (which are on the bottom of the heart and pump blood out): on average, close to half of the cells in the ventricles are cardiomyocytes, whereas only a third of the cells in the atria are cardiomyocytes.  Finally, there is a significantly higher percentage of cardiomyocytes in the ventricles of women (56%) than in the ventricles of men (47%).    The authors speculate that this latter difference might explain the higher volume of blood pumped per beat in women and lower rates of cardiovascular disease.  

The authors gave a few examples of how their data can be used for a better understanding of heart disease.  For example, they identified a specific subpopulation of cardiomyocytes that expresses genes associated with atrial fibrillation, suggesting that the defect may be associated with those cells.   Similarly, they found that a specific neuronal cell type expresses genes that are associated with a particular ventricular dysfunction associated with heart failure.    In addition, the authors identified which cells in the heart express the highest levels of the SARS-CoV-2 receptor, ACE2, including pericytes, fibroblasts and cardiomyocytes.  

Now that these data are accessible for exploration at www.heartcellatlas.org, I have no doubt that many scientific explorers will begin to navigate to a more complete understanding of both the healthy and diseased heart, and ultimately to new treatments for heart disease.

Stem Cell Roundup: Knowing the nose, stem cell stress and cell fate math.

/ Todd Dubnicoff / Leave a comment

The Stem Cellar’s Image of the Week.
Our favorite image this week, comes to us from researchers at Washington University School of Medicine in St. Louis. Looking like a psychedelic Rorschach test, the fluorescence microscopy depicts mouse olfactory epithelium (in green), a sheet of tissue that develops in the nose. The team identified a new stem cell type that controls the growth of this tissue. New insights from the study of these cells could help the team better understand why some animals, like dogs, have a far superior sense of smell than humans.

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Peering into the nasal cavity of a mouse. Olfactory epithelium is indicated by green. Image credit: Lu Yang, Washington University School of Medicine in St. Louis.

A Washington U. press release provides more details about this fascinating study which appears in Developmental Cell.

How stress affects blood-forming stem cells.
Stress affects all of us in different ways. Some people handle it well. Some crack up and become nervous wrecks. So, perhaps it shouldn’t come as a huge surprise that stress also affects some stem cells. What is a pleasant surprise is that knowing this could help people undergoing cancer therapy or bone marrow transplants.

First a bit of background. Hematopoietic, or blood-forming stem cells (HSCs) come from bone marrow and are supported by other cells that secrete growth factors, including one called pleiotrophin or PTN. While researchers knew PTN was present in bone marrow they weren’t sure precisely what role it played.

So, researchers at UCLA set out to discover what PTN did.

In a CIRM-funded study they took mice that lacked PTN in endothelial cells – these line the blood vessels – or in their stromal cells – which make up the connective tissue. They found that a lack of PTN in stromal cells caused a lack of blood stem cells, but a lack of PTN in endothelial cells had no impact.

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Expression of pleiotrophin (green) in bone marrow blood vessels (red) and stromal cells (white) is shown in normal mice (left) and in mice at 24 hours following irradiation (right). Image credit: UCLA

However, as Dr. John Chute explained in a news release, when they stressed the cells, by exposing them to radiation, they found something very different:

“The surprising finding was that pleiotrophin from stromal cells was not necessary for blood stem cell regeneration following irradiation — but pleiotrophin from endothelial cells was necessary.”

In other words, during normal times the stem cells rely on PTN from stromal cells, but after stress they depend on PTN from endothelial cells.

Dr. Chute says, because treatments like chemotherapy and radiation deplete bone marrow stem cells, this finding could have real-world implications for patients.

“These therapies for cancer patients suppress our blood cell systems over time. It may be possible to administer modified, recombinant versions of pleiotrophin to patients to accelerate blood cell regeneration. This strategy also may apply to patients undergoing bone marrow transplants.”

The study appears in the journal Cell Stem Cell.

Predicting the fate of cells with math
Researchers at Harvard Medical School and the Karolinska Institutet in Sweden reported this week that they have devised a mathematical model that can predict the fate of stem cells in the brain.

It may sound like science-fiction but the accomplished the feat by tracking changes in messenger RNA (mRNA), the genetic molecule that translates our DNA code into instructions for building proteins. As a brain stem cell begins specializing into specific cell types, hundreds of genes get turns on and off, which is observed by the rate of changes in mRNA productions.

The team built their predictive model by measuring these changes. In a press release, co-senior author, Harvard professor Peter Kharchenko, described this process using a great analogy:

“Estimating RNA velocity—or the rate of RNA change over time—is akin to observing the cooks in a restaurant kitchen as they line up the ingredients to figure out what dishes they’ll be serving up next.”

The team verified their mathematical model by inputting other data that was not use in constructing the model. Karolinkska Institutet professor, Sten Linnarsson, the other co-senior author on the study, described how such a model could be applied to human biomedical research:

“RNA velocity shows in detail how neurons and other cells acquire their specific functions as the brain develops and matures. We’re especially excited that this new method promises to help reveal how brains normally develop, but also to provide clues as to what goes wrong in human disorders of brain development, such as schizophrenia and autism.”

The study appears in the journal Nature.

Bioengineers Build 3D Model of Human Heart Ventricle

/ Adonica Shaw / 1 Comment

 

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Photo courtesy of Luke MacQueen/Disease Biophysics Group/Harvard SEAS.

After more than a decade, scientists at Harvard University finally made a breakthrough in their efforts to create a heart. According to a study published in Nature Biomedical Engineering, the researchers successfully bioengineered a three-dimensional model of a human left heart ventricle. This important development brings them one step closer to their goal, creating a life-like model of a heart which could ultimately help scientists study heart disease, test drugs and develop patient-specific treatments for other heart conditions such as arrhythmia.

The key to building a functional ventricle is recreating the tissue’s unique structure. In human hearts, myocardial fibers act as a scaffold, guiding brick-shaped heart cells to align and assemble end-to-end, forming a hollow, cone-shaped structure. When the heart beats, the cells expand and contract like an accordion.

To make the ventricle, the researchers used a combination of biodegradable polyester and gelatin fibers that were collected on a rotating collector shaped like a bullet. Because the collector is spinning, all of the fibers align in the same direction.

The tissue is engineered with a nanofiber scaffold seeded with human heart cells. The scaffold acts like a 3D template, guiding the cells and their assembly into ventricle chambers that beat in time with each other. This allowed researchers to study heart function in the lab, using many of the same tools used in the clinic, including pressure-volume loops and ultrasound.

After building the scaffold, the researchers cultured the ventricle with either rat muscle cells from rats or human heart muscle cells. Within three to five days, a thin wall of tissue covered the scaffold and cells were beating in synch. From there, researchers could control and monitor different aspects of the ventricle, such as pressure and volume of the beating.

To test the heart, the researchers exposed the tissue to isoproterenol, a drug similar to adrenaline, and measured as the beat-rate increased just as it would in human and rat hearts. The researchers also poked holes in the ventricle to mimic a heart attack and studied the effects in a petri dish. Using human heart muscle cells from induced stem cells, the researchers were even able to culture the ventricles for 6 months and measure stable pressure-volume loops.

“The long-term objective of this project is to replace or supplement animal models with human models and especially patient-specific human models,” said Luke MacQueen, Ph.D., first author of the study and postdoctoral fellow at the Wyss Institute and SEAS. “In the future, patient stem cells could be collected and used to build tissue models that replicate some of the features of their whole organ.”

While the applications for regenerative cardiovascular medicine are wide and varied, this advancement in their research is a step toward more accurate models of actual patient diseases.

In the future, we could see patient stem cells collected and used to build tissue models that replicate some or even all of the features of their entire organ.

A scalable, clinic-friendly recipe for converting skin cells to muscle cells

/ Todd Dubnicoff / 2 Comments

Way back in 1987, about two decades before Shinya Yamanaka would go on to identify four proteins that can reprogram skin cells into induced pluripotent stem cells (iPSCs), Harold Weintraub’s lab identified the first “master control” protein, MyoD, which can directly convert a skin cell into a muscle cell. Though MyoD opened up new approaches for teasing out the molecular mechanisms of a cell’s identity, it did not produce therapeutic paths for replacing muscle damaged by disease and injury.

That’s because MyoD-generated muscle cells are not amenable to a clinical setting. For a cell therapy to be viable, you need to manufacture large amounts of your product to treat many people. But these MyoD cells do not grow well enough to be effective to serve as a cell replacement therapy. Generating iPSC-derived muscle cells provides the potential of overcoming this limitation but the capacity of the embryonic stem cell-like iPSC for unlimited growth carries a risk of forming tumors after the transplanting iPSC-derived cell therapies into the muscle.

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This image shows iMPCs stained for markers of muscle stem, progenitor and differentiated cells. iMPCs recapitulate muscle differentiation in a dish. Credit: Ori Bar-Nur and Mattia Gerli

A recent study in Stem Cell Reports, by Konrad Hochedlinger’s lab at Massachusetts General Hospital and the Harvard Stem Cell Institute, may provide a work around. The team came up with a recipe that calls for the temporary activation of MyoD in mouse skin cells, along with the addition of three molecules that boost cell reprogramming. The result? Cells they dubbed induced myogenic progenitor cells, or iMPCs, that can make self-sustaining copies of themselves and can be scaled up for manufacturing purposes. On top of that, they show that these iMPCs carry the hallmarks of muscle stem cells and generate muscle fibers when transplanted into mice with leg injuries without signs of tumor formation.

A lot of work still remains to be done, like confirming that these iMPCs truly have the same characteristics as muscle stem cells. But if everything pans out, the potential applications for people suffering from various muscle disorders and injuries is very exciting, as co-first author Mattia FM Gerli, PhD points out in a press release:

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Mattia FM Gerli, PhD

“Patient-specific iMPCs could be used for personalized medicine by treating patients with their own genetically matched cells. If disease-causing mutations are known, as is the case in many muscular dystrophies, one could in principle repair the mutation in iMPCs prior to transplantation of the corrected cells back into the patient.”

Stem Cell Round: Improving memory, building up “good” fat, nanomedicine

/ Karen Ring / 2 Comments

Stem Cell Photo of the Week

roundup03618In honor of brain awareness week, our featured stem cell photo is of the brain! Scientists at the Massachusetts General Hospital and Harvard Stem Cell Institute identified a genetic switch that could potentially improve memory during aging and symptoms of PTSD. Shown in this picture are dentate gyrus cells (DGC) (green) and CA3 interneurons (red) located in the memory-forming area of the brain known as the hippocampus. By reducing the levels of a protein called abLIM3 in the DGCs of older mice, the researchers were able to boost the connections between DGCs and CA3 cells, which resulted in an improvement in the memories of the mice. The team believes that targeting this protein in aging adults could be a potential strategy for improving memory and treating patients with post-traumatic stress disorder (PTSD). You can read more about this study in The Harvard Gazette.

New target for obesity.
Fat cells typically get a bad rap, but there’s actually a type of fat cell that is considered “healthier” than others. Unlike white fat cells that store calories in the form of energy, brown fat cells are packed with mitochondria that burn energy and produce heat. Babies have brown fat, so they can regulate their body temperature to stay warm. Adults also have some brown fat, but as we get older, our stores are slowly depleted.

In the fight against obesity, scientists are looking for ways to increase the amount of brown fat and decrease the amount of white fat in the body. This week, CIRM-funded researchers from the Salk Institute identified a molecule called ERRg that gives brown fat its ability to burn energy. Their findings, published in Cell Reports, offer a new target for obesity and obesity-related diseases like diabetes and fatty liver disease.

The team discovered that brown fat cells produce the ERRg molecule while white fat cells do not. Additionally, mice that couldn’t make the ERRg weren’t able to regulate their body temperature in cold environments. The team concluded in a news release that ERRg is “involved in protection against the cold and underpins brown fat identity.” In future studies, the researchers plan to activate ERRg in white fat cells to see if this will shift their identity to be more similar to brown fat cells.

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Mice that lack ERR aren’t able to regulate their body temperature and are much colder (right) than normal mice (left). (Image credit Salk Institute)

Tale of two nanomedicine stories: making gene therapies more efficient with a bit of caution (Todd Dubnicoff).
This week, the worlds of gene therapy, stem cells and nanomedicine converged for not one, but two published reports in the journal American Chemistry Society NANO.

The first paper described the development of so-called nanospears – tiny splinter-like magnetized structures with a diameter 5000 times smaller than a strand of human hair – that could make gene therapy more efficient and less costly. Gene therapy is an exciting treatment strategy because it tackles genetic diseases at their source by repairing or replacing faulty DNA sequences in cells. In fact, several CIRM-funded clinical trials apply this method in stem cells to treat immune disorders, like severe combined immunodeficiency and sickle cell anemia.

This technique requires getting DNA into diseased cells to make the genetic fix. Current methods have low efficiency and can be very damaging to the cells. The UCLA research team behind the study tested the nanospear-delivery of DNA encoding a gene that causes cells to glow green. They showed that 80 percent of treated cells did indeed glow green, a much higher efficiency than standard methods. And probably due to their miniscule size, the nanospears were gentle with 90 percent of the green glowing cells surviving the procedure.

As Steve Jonas, one of the team leads on the project mentions in a press release, this new method could bode well for future recipients of gene therapies:

“The biggest barrier right now to getting either a gene therapy or an immunotherapy to patients is the processing time. New methods to generate these therapies more quickly, effectively and safely are going to accelerate innovation in this research area and bring these therapies to patients sooner, and that’s the goal we all have.”

While the study above describes an innovative nanomedicine technology, the next paper inserts a note of caution about how experiments in this field should be set up and analyzed. A collaborative team from Brigham and Women’s Hospital, Stanford University, UC Berkeley and McGill University wanted to get to the bottom of why the many advances in nanomedicine had not ultimately led to many new clinical trials. They set out looking for elements within experiments that could affect the uptake of nanoparticles into cells, something that would muck up the interpretation of results.

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imaging of female human amniotic stem cells incubated with nanoparticles demonstrated a significant increase in uptake compared to male cells. (Green dots: nanoparticles; red: cell staining; blue: nuclei) Credit: Morteza Mahmoudi, Brigham and Women’s Hospital.

In this study, they report that the sex of cells has a surprising, noticeable impact on nanoparticle uptake. Nanoparticles were incubated with human amniotic stem cells derived from either males or females. The team showed that the female cells took up the nanoparticles much more readily than the male cells.  Morteza Mahmoudi, PhD, one of the authors on the paper, explained the implications of these results in a press release:

“These differences could have a critical impact on the administration of nanoparticles. If nanoparticles are carrying a drug to deliver [including gene therapies], different uptake could mean different therapeutic efficacy and other important differences, such as safety, in clinical data.”

 

Stem Cell Tools: Helping Scientists Model Complex Diseases

/ Karen Ring / 1 Comment

This blog is part of the Month of CIRM series and the first of two blogs focused on how CIRM-funded infrastructure initiatives are developing useful tools to advance stem cell research. 

Human stem cells are powerful tools for studying human disease.  Animal models like mice have been and continue to be important for studying physiological systems, but they are still different than human systems.  Other types of human cells studied in the lab often are isolated from cancers or modified to multiply indefinitely.  However, the genetic DNA blueprint of these modified cells are irreparably altered from the normal tissues that they came from.

Human pluripotent stem cells are unique in that they can be grown in the lab and turned into any type of normal cell in the body.  Many scientists now believe that creating such stem cell lines from patients and developing ‘disease-in-a-dish’ models will provide important insights that will lead to treatments for the disorders from which they came.  Challenges still remain to develop these models to their fullest potential.  Because the genetics underlying human disease is complex, detailed genetic information about each stem cell line, as well as a large number of lines  to represent the genetic variability between patients will be needed to make progress.

To address this need, CIRM funded the creation of the world’s largest induced pluripotent stem cell bank, which we call the CIRM iPSC Repository.  iPSCs are similar to embryonic stem cells in that they can develop into any cell type found in the body, but they differ in how they are derived. Scientists can take human skin or blood cells and genetically reprogram them into iPSCs that have the same genetic makeup, including any disease-causing mutations, as the person from which the original cells were taken. Embryonic stem cells, on the other hand, are derived from left over embryos donated by couples undergoing in vitro fertilization (IVF) treatments.

The CIRM iPSC Repository was established to harness the power of iPSCs as tools for disease modeling and drug discovery. The Repository currently offers scientists around the world access to over 1500 high-quality iPSC lines covering diseases of the brain, heart, liver, lung, and eye, and the collection will eventually hold over 3000 lines.  All iPSC lines are linked to publicly-accessible demographic and clinical information.

Making the Cell Lines

Making the iPSC Repository was no easy task – it took a village of doctors, scientists, patients and healthy volunteers. First, clinicians across California collected blood and skin samples from over 2800 people including individuals with common diseases, rare diseases and healthy controls. CIRM then awarded a grant to Cellular Dynamics International to create iPSC lines from these donors, and a second grant to the Coriell Institute to store and distribute the lines to interested labs around the world. Creating such a large number of lines in a single concerted effort has been a challenging logistical feat that has taken almost five years and is projected to finish in early 2018.

Joachim Hallmayer

We spoke with one of the tissue collectors, a scientist named Dr. Joachim Hallmayer at Stanford University, about the effort it took to obtain tissue samples for the Repository. Hallmayer is a Professor of Psychiatry and Behavioral Sciences at Stanford who studies Autism Spectrum Disorder (ASD) in children. With funding from a CIRM Tissue Collection for Disease Modeling award, Hallmayer collected tissue samples from children with ASD and children with normal development. His efforts resulted in the 164 ASD and 134 control samples for the Repository.

Hallmayer emphasized that each sample donation required significant attention and education from the clinical staff to the donor.  Communicating with patients and walking them through the consent process for donating their tissue for this purpose is an extremely important issue that is often overlooked. “Conveying information about the tissue collection process to patients takes a lot of time. However, deconstructing the consent process is essential for patients to understand what they are donating and why,” explained Hallmayer.

Now that the ASD lines are available, Hallmayer and his colleague Dr. Ruth O’Hara are formulating a plan to model ASD in a dish by differentiating the iPSC lines into neurons affected by this disorder. Says O’Hara:

Ruth O’Hara

“While the examination of live tissue from other organ systems has become increasingly viable, examining live neurons from patients with brain disorders has simply not been possible. Using iPSC-derived neurons, for the first time we can study live nerve cells from actual patients and compare these cells to those from humans without the disorder.”

Using iPSCs to Model Psychiatric Disorders

Ultimately, the goal of iPSCs for modeling disease is to identify mechanisms and therapeutic targets for the disorders that they represent.  Studying a disease through a single iPSC line may not shed enough light on that disorder.  Just as people have diverse traits, the way that a disease can affect individuals is also diverse.  Studying large numbers of lines in a time and cost-efficient manner that represent these diverse traits, and the genetic causes that underlie them, can be a powerful method to understand and address diseases.

 To leverage the iPSC collection for this purpose, CIRM and a group of scientists at the Broad Institute’s Stanley Center for Psychiatric Research and Harvard University have entered into a collaboration to study psychiatric disorders such as ASD.  Because the donor samples were collected on the basis of clinical information, the genetic information about what caused their disease remains unknown.  Therefore, the Stanley Center will embark on whole genome sequencing (WGS) of hundreds of lines from the CIRM iPSC repository. Adding donor WGS sequence information to the CIRM repository will significantly increase its value, as scientists will be able to use DNA sequence information to select the ideal lines for disease modeling and therapeutic discovery efforts. The collaboration aims to identify the genes that shape neuronal phenotypes in iPSC-derived neurons from patients with psychiatric disorders.

“A central challenge today is to discover how inherited genetic variation gives rise to functional variation in the properties of neurons and other cells,” said Steven McCarroll, Director of Genetics at the Broad Institute’s Stanley Center for Psychiatric Research, and associate professor at Harvard Medical School’s Department of Genetics. “We hope with the analysis of cells from very large numbers of genetically diverse individuals will begin to address longstanding problems at the interface of human genetics and biology.”

iPSC derived neurons growing in a dish. (Image courtesy of Ralda Nehme, Research Scientist at the Broad Institute).

Such efforts require technologies such as Drop-seq, developed in the McCarroll lab, where genome-wide expression of thousands of separate cells can be analyzed in one experiment. These efforts also rely on scaling functional analysis of stem cell-based disease models, a vexing bottleneck for the field. “The CIRM iPSC Repository is the largest and most ambitious of its kind”, said Kevin Eggan, Professor of Stem Cell and Regenerative Biology at Harvard University, and Director of Stem Cell Biology at the Broad Institute’s Stanley Center for Psychiatric Research. Efforts underway in Dr. Eggan’s lab are directed at developing approaches to analyze large numbers of stem cell lines in parallel.

“The scale of the CIRM iPSC collection will allow us to investigate how variation that is common among many of us predisposes certain individuals to major mental illnesses such as autism and other neurodevelopmental disorders. We are incredibly excited about entering this long-term collaboration.”

Members of the Eggan and McCarroll labs at the Broad Institute’s Stanley Center for Psychiatric Research. (Image courtesy of Kiki Lilliehook)

From Cell Lines to Data

It’s clear from these stories, that the iPSC Repository is a unique and powerful tool for the stem cell research community. But for the rewards to be truly reaped, more tools are needed that will help scientists study these cell lines. This is where the CIRM Genomics Initiative comes into play.

Be sure to read Part 2 of our Stem Cell Tools series tomorrow to find out how our Genomics Initiative is funding the development of genomic and bioinformatics tools that will allow scientists to decipher complex stem cell data all the way from mapping the developmental states of cells to predicting the accuracy of stem cell-based models.

This blog was written in collaboration with Dr. Kiki Lilliehook, the Manager of the Stem Cell Program at the Stanley Center for Psychiatric Research at the Broad Institute in Cambridge, Massachusetts.