Rhythmic brain circuits built from stem cells

The TV commercial is nearly 20 years old but I remember it vividly: a couple is driving down a street when they suddenly realize the music on their tape deck is in sync with the repetitive activity on the street. From the guy casually dribbling a basketball to people walking along the sidewalk to the delivery people passing packages out of their truck, everything and everyone is moving rhythmically to the beat.

The ending tag line was, “Sometimes things just come together,” which is quite true. Many of our basic daily activities like breathing and walking just come together as a result of repetitive movement. It’s easy to take them for granted but those rhythmic patterns ultimately rely on very intricate, interconnected signals between nerve cells, also called neurons, in the brain and spinal cord.

Circuitoids: a neural network in a lab dish

A CIRM-funded study published yesterday in eLife by Salk Institute scientists reports on a method to mimic these repetitive signals in a lab dish using neurons grown from embryonic stem cells. This novel cell circuitry system gives the researchers a tool for gaining new insights into neurodegenerative diseases, like Parkinson’s and ALS, and may even provide a means to fix neurons damaged by injury or disease.

The researchers changed or specialized mouse embryonic stem cells into neurons that either stimulate nerve signals, called excitatory neurons, or neurons that block nerve signals, called inhibitory neurons. Growing these groups of cells together led to spontaneous rhythmic nerve signals. These clumps of cells containing about 50,000 neurons each were dubbed circuitoids by the team.

pfaff-circutoid-cropped

Confocal microscope immunofluorescent image of a spinal cord neural circuit made entirely from stem cells and termed a “circuitoid.” Credit: Salk Institute.

Making neural networks dance to a different beat

A video produced by the Salk Institute (see below), shows some fascinating microscopy visualizations of these circuitoids’ repetitive signals. In the video, team leader Samuel Pfaff explains that changing the ratio of excitatory vs inhibitory neurons had noticeable effects on the rhythm of the nerve impulses:

“What we were able to do is combine different ratios of cell types and study properties of the rhythmicity of the circuitoid. And that rhythmicity could be very tightly control depending on the cellular composition of the neural networks that we were forming. So we could regulate the speed [of the rhythmicity] which is kind of equivalent to how fast you’re walking.”

It’s possible that the actual neural networks in our brains have the flexibility to vary the ratio of the active excitatory to inhibitory neurons as a way to allow adjustments in the body’s repetitive movements. But the complexity of those networks in the human brain are staggering which is why these circuitoids could help:

Samuel Pfaff. (Salk Institute)

Samuel Pfaff. (Salk Institute)

“It’s still very difficult to contemplate how large groups of neurons with literally billions if not trillions of connections take information and process it,” says Pfaff in a press release. “But we think that developing this kind of simple circuitry in a dish will allow us to extract some of the principles of how real brain circuits operate. With that basic information maybe we can begin to understand how things go awry in disease.”

Wishing You and Your Stem Cells a Happy Valentine’s Day!

cirm-valentines-day

Roses are Red, 

Violets are Blue,

 Let’s thank pluripotent stem cells,

For making humans like me and you

Happy Valentine’s Day from me and everyone at CIRM! Today, we are celebrating this day of love by sending our warmest wishes to you our readers. We’re grateful for your interest in learning more about stem cells and your steadfast support for the advancement of stem cell research.

We also want to wish a Happy Valentine’s Day to your stem cells, yes that’s right the stem cells you have in your body. Without pluripotent stem cells, which are embryonic cells that generate all the cells in your body, humans wouldn’t exist. And without adult stem cells, which live in your tissues and organs, we wouldn’t have healthy, functioning bodies.

So, as you’re wishing your loved ones, friends, and colleagues a Happy Valentine’s Day, take a moment to thank your body and the stem cells living in it for keeping you alive.

I’ll leave you with a few Valentine’s Day themed stem cell blogs for you to enjoy. Have a wonderful day!


Valentine’s Day Themed Blogs:

1) Toronto Scientists Have an Affair with the Heart by OIRMexpression

Ventricular heart muscle cells. Image courtesy of Dr. Michael Laflamme

Ventricular heart muscle cells. Image courtesy of Dr. Michael Laflamme

2) A Cardiac Love Triangle: How Transcription Factors Interact to Make a Heart by the Stem Cellar

© Gladstone Institutes photo credit: Kim Cordes / Gladstone Institute Lay Description: In this image, human embryonic stem cells have been differentiated into cardiomyocytes, or heart muscle cells, and stained to show the expression of cardiac Troponin T (red), a protein that helps cardiomyocytes to contract, and cell nuclei (blue). Scientific Description: Cultured human iPSCs reprogrammed into CMs. Stain for cTnT (red), and DAPI (blue). Original caption: cardiomyocytes.tif

Heart cells made from human induced pluripotent stem cells. © Gladstone Institutes
photo credit: Kim Cordes / Gladstone Institute

3) Stem Cells on Valentine’s Day: Update on Cardiac Regenerative Medicine by Paul Knoepfler on the Niche Blog

4) Hope For Broken Hearts this Valentine’s Day – a Clinical Trial to Repair the Damage by the Stem Cellar


Special thanks to Samantha Yammine for letting us her her “Icy Astrocytes” photo in our Valentine’s Day graphic.

Stem Cell Stories That Caught our Eye: Making blood and muscle from stem cells and helping students realize their “pluripotential”

Stem cells offer new drug for blood diseases. A new treatment for blood disorders might be in the works thanks to a stem cell-based study out of Harvard Medical School and Boston Children’s hospital. Their study was published in the journal Science Translational Medicine.

The teams made induced pluripotent stem cells (iPSCs) from the skin of patients with a rare blood disorder called Diamond-Blackfan anemia (DBA) – a bone marrow disease that prevents new blood cells from forming. iPSCs from DBA patients were then specialized into blood progenitor cells, the precursors to blood cells. However, these precursor cells were incapable of forming red blood cells in a dish like normal precursors do.

Red blood cells were successfully made via induced pluripotent stem cells from a Diamond-Blackfan anemia patient. Image: Daley lab, Boston Children’s

Red blood cells were successfully made via induced pluripotent stem cells from a Diamond-Blackfan anemia patient. Image: Daley lab, Boston Children’s

The blood progenitor cells from DBA patients were then used to screen a library of compounds to identify drugs that could get the DBA progenitor cells to develop into red blood cells. They found a compound called SMER28 that had this very effect on progenitor cells in a dish. When the compound was tested in zebrafish and mouse models of DBA, the researchers observed an increase in red blood cell production and a reduction of anemia symptoms.

Getting pluripotent stem cells like iPSCs to turn into blood progenitor cells and expand these cells into a population large enough for drug screening has not been an easy task for stem cell researchers.

Co-first author on the study, Sergei Doulatov, explained in a press release, “iPS cells have been hard to instruct when it comes to making blood. This is the first time iPS cells have been used to identify a drug to treat a blood disorder.”

In the future, the researchers will pursue the questions of why and how SMER28 boosts red blood cell generation. Further work will be done to determine whether this drug will be a useful treatment for DBA patients and other blood disorders.

 

Students realize their “pluripotential”. In last week’s stem cell stories, I gave a preview about an exciting stem cell “Day of Discovery” hosted by USC Stem Cell in southern California. The event happened this past Saturday. Over 500 local middle and high school students attended the event and participated in lab tours, poster sessions, and a career resource fair. Throughout the day, they were engaged by scientists and educators about stem cell science through interactive games, including the stem cell edition of Family Feud and a stem cell smartphone videogame developed by USC graduate students.

In a USC press release, Rohit Varma, dean of the Keck School of Medicine of USC, emphasized the importance of exposing young students to research and scientific careers.

“It was a true joy to welcome the middle and high school students from our neighboring communities in Boyle Heights, El Sereno, Lincoln Heights, the San Gabriel Valley and throughout Los Angeles. This bright young generation brings tremendous potential to their future pursuits in biotechnology and beyond.”

Maria Elena Kennedy, a consultant to the Bassett Unified School District, added, “The exposure to the Keck School of Medicine of USC is invaluable for the students. Our students come from a Title I School District, and they don’t often have the opportunity to come to a campus like the Keck School of Medicine.”

The day was a huge success with students posting photos of their experiences on social media and enthusiastically writing messages like “stem cells are our future” and “USC is my goal”. One high school student acknowledged the opportunity that this day offers to students, “California currently has biotechnology as the biggest growing sector. Right now, it’s really important that students are visiting labs and learning more about the industry, so they can potentially see where they’re going with their lives and careers.”

You can read more about USC’s Stem Cell Day of Discovery here. Below are a few pictures from the event courtesy of David Sprague and USC.

Students have fun with robots representing osteoblast and osteoclast cells at the Stem Cell Day of Discovery event held at the USC Health Sciences Campus in Los Angeles, CA. February 4th, 2017. The event encourages students to learn more about STEM opportunities, including stem cell study and biotech, and helps demystify the fields and encourage student engagement. Photo by David Sprague

Students have fun with robots representing osteoblast and osteoclast cells at the USC Stem Cell Day of Discovery. Photo by David Sprague

Dr. Francesca Mariana shows off a mouse skeleton that has been dyed to show bones and cartilage at the Stem Cell Day of Discovery event held at the USC Health Sciences Campus in Los Angeles, CA. February 4th, 2017. The event encourages students to learn more about STEM opportunities, including stem cell study and biotech, and helps demystify the fields and encourage student engagement. Photo by David Sprague

Dr. Francesca Mariana shows off a mouse skeleton that has been dyed to show bones and cartilage. Photo by David Sprague

USC masters student Shantae Thornton shows students how cells are held in long term cold storage tanks at -195 celsius at the Stem Cell Day of Discovery event held at the USC Health Sciences Campus in Los Angeles, CA. February 4th, 2017. The event encourages students to learn more about STEM opportunities, including stem cell study and biotech, and helps demystify the fields and encourage student engagement. Photo by David Sprague

USC masters student Shantae Thornton shows students how cells are held in long term cold storage tanks at -195 celsius. Photo by David Sprague

Genesis Archila, left, and Jasmine Archila get their picture taken at the Stem Cell Day of Discovery event held at the USC Health Sciences Campus in Los Angeles, CA. February 4th, 2017. The event encourages students to learn more about STEM opportunities, including stem cell study and biotech, and helps demystify the fields and encourage student engagement. Photo by David Sprague

Genesis Archila, left, and Jasmine Archila get their picture taken at the USC Stem Cell Day of Discovery. Photo by David Sprague

New stem cell recipes for making muscle: new inroads to study muscular dystrophy (Todd Dubnicoff)

Embryonic stem cells are amazing because scientists can change or specialize them into virtually any cell type. But it’s a lot easier said than done. Researchers essentially need to mimic the process of embryo development in a petri dish by adding the right combination of factors to the stem cells in just the right order at just the right time to obtain a desired type of cell.

Making human muscle tissue from embryonic stem cells has proven to be a challenge. The development of muscle, as well as cartilage and bone, are well characterized and known to form from an embryonic structure called a somite. Researches have even been successful working out the conditions for making somites from animal stem cells. But those recipes didn’t work well with human stem cells.

Now, a team of researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA has overcome this roadblock by carrying out a systematic approach using human tissue. As described in Cell Reports, the scientists isolated somites from early human embryos and studied their gene activity. By comparing somites that were just beginning to emerge with fully formed somites, the researchers pinpointed differences in gene activity patterns. With this data in hand, the team added factors to the cells that were known to affect the activity of those genes. Through some trial and error, they produced a recipe – different than those used in animal cells – that could convert 90 percent of the human stem cells into somites in only four days. Those somites could then readily transform into muscle or bone or cartilage.

This new method for making human muscle will be critical for the lab’s goal to develop therapies for Duchenne muscular dystrophy, an incurable muscle wasting disease that strikes young boys and is usually fatal by their 20’s.

The new protocol turned 90 percent of human pluripotent stem cells into somite cells in just four days; those somite cells then generated (left to right) cartilage, bone and muscle cells.  Image: April Pyle Lab/UCLA

The new protocol turned 90 percent of human pluripotent stem cells into somite cells in just four days; those somite cells then generated (left to right) cartilage, bone and muscle cells. Image: April Pyle Lab/UCLA

Curing the Incurable through Definitive Medicine

“Curing the Incurable”. That was the theme for the first annual Center for Definitive and Curative Medicine (CDCM) Symposium held last week at Stanford University, in Palo Alto, California.

The CDCM is a joint initiative amongst Stanford Healthcare, Stanford Children’s Health and the Stanford School of Medicine. Its mission is to foster an environment that accelerates the development and translation of cell and gene therapies into clinical trials.

The research symposium focused on “the exciting first-in-human cell and gene therapies currently under development at Stanford in bone marrow, skin, cardiac, neural, pancreatic and neoplastic diseases.” These talks were organized into four different sessions: cell therapies for neurological disorders, stem cell-derived tissue replacement therapies, genome-edited cell therapies and anti-cancer cell-based therapies.

A few of the symposium speakers are CIRM-funded grantees, and we’ll briefly touch on their talks below.

Targeting cancer

The keynote speaker was Irv Weissman, who talked about hematopoietic or blood-forming stem cells and their value as a cell therapy for patients with blood disorders and cancer. One of the projects he discussed is a molecule called CD47 that is found on the surface of cancer cells. He explained that CD47 appears on all types of cancer cells more abundantly than on normal cells and is a promising therapeutic target for cancer.

Irv Weissman

Irv Weissman

“CD47 is the first gene whose overexpression is common to all cancer. We know it’s molecular mechanism from which we can develop targeted therapies. This would be impossible without collaborations between clinicians and scientists.”

 

At the end of his talk, Weissman acknowledged the importance of CIRM’s funding for advancing an antibody therapeutic targeting CD47 into a clinical trial for solid cancer tumors. He said CIRM’s existence is essential because it “funds [stem cell-based] research through the [financial] valley of death.” He further explained that CIRM is the only funding entity that takes basic stem cell research all the way through the clinical pipeline into a therapy.

Improving bone marrow transplants

judith shizuru

Judith Shizuru

Next, we heard a talk from Judith Shizuru on ways to improve current bone-marrow transplantation techniques. She explained how this form of stem cell transplant is “the most powerful form of cell therapy out there, for cancers or deficiencies in blood formation.” Inducing immune system tolerance, improving organ transplant outcomes in patients, and treating autoimmune diseases are all applications of bone marrow transplants. But this technique also carries with it toxic and potentially deadly side effects, including weakening of the immune system and graft vs host disease.

Shizuru talked about her team’s goal of improving the engraftment, or survival and integration, of bone marrow stem cells after transplantation. They are using an antibody against a molecule called CD117 which sits on the surface of blood stem cells and acts as an elimination signal. By blocking CD117 with an antibody, they improved the engraftment of bone marrow stem cells in mice and also removed the need for chemotherapy treatment, which is used to kill off bone marrow stem cells in the host. Shizuru is now testing her antibody therapy in a CIRM-funded clinical trial in humans and mentioned that this therapy has the potential to treat a wide variety of diseases such as sickle cell anemia, leukemias, and multiple sclerosis.

Tackling stroke and heart disease

img_1327We also heard from two CIRM-funded professors working on cell-based therapies for stroke and heart disease. Gary Steinberg’s team is using human neural progenitor cells, which develop into cells of the brain and spinal cord, to treat patients who’ve suffered from stroke. A stroke cuts off the blood supply to the brain, causing the death of brain cells and consequently the loss of function of different parts of the body.  He showed emotional videos of stroke patients whose function and speech dramatically improved following the stem cell transplant. One of these patients was Sonia Olea, a young woman in her 30’s who lost the ability to use most of her right side following her stroke. You can read about her inspiring recover post stem cell transplant in our Stories of Hope.

Dr. Joe Wu. (Image Source: Sean Culligan/OZY)

Dr. Joe Wu. (Image Source: Sean Culligan/OZY)

Joe Wu followed with a talk on adult stem cell therapies for heart disease. His work, which is funded by a CIRM disease team grant, involves making heart cells called cardiomyocytes from human embryonic stem cells and transplanting these cells into patient with end stage heart failure to improve heart function. His team’s work has advanced to the point where Wu said they are planning to file for an investigational new drug (IND) application with the US Food and Drug Administration (FDA) in six months. This is the crucial next step before a treatment can be tested in clinical trials. Joe ended his talk by making an important statement about expectations on how long it will take before stem cell treatments are available to patients.

He said, “Time changes everything. It [stem cell research] takes time. There is a lot of promise for the future of stem cell therapy.”

Let’s Be Clear: Stem Cells and Popular Culture

The following is a guest blog from Matt Donne, PhD. Thoughts expressed here are not necessarily those of CIRM.

It was during winter break of my Junior year in college that the gap between the general public’s understanding of embryonic stem cell biology and the reality of that research quickly came into focus for me.

I was out to lunch with my grandmother and excited to see her to share my new research project I had started with human embryonic stem cells (hESCs). While enjoying our lunch together discussing school, relationships, and such, a friend of hers approached to say hello. Immediately my grandmother proclaimed, “This is my grandson Matthew and he is a scientist. He just started working with stem cells to cure cancer.”  Now this statement was not true, but harmless enough so I figured I would let it go. Her friend’s eyes immediately grew large and she quickly felt it necessary to educate us on what exactly I was doing by working with “stem cells”. In her friend’s words I was, “killing babies and sucking out their brains to make stem cells.”

My grandmother and I were both silenced and confused, for different reasons, as her friend quickly walked away in disgust. My grandmother asked concernedly if this was in fact true. I explained that this could not be farther from the truth, and that this friend was extremely misinformed. We then discussed the difference between a developing fetus and the 3 to 5 day old embryos from which these hESC lines were derived. We also discussed these embryos were donated by couples who seek in vitro fertilization (IVF) treatments. Specifically, the donated embryos were those which the couple no longer needed and therefore decided to donate them for research proposes to help advance both science and medicine rather than discard them. This fact-based explanation eased many of the fears my grandmother had as to the research. This, however, left in me a fear that over 10 years later I still see playing out in popular culture.

Most recently my frustration toward this misinformation came when I saw a posting by VICE of a carton entitled ‘Magical Stem Cells’. The cartoon was a truly gross and inaccurate representation of where embryonic stem cells are derived, as it portrayed a unicorn fetus essentially being harvested to create “magical” stem cells that can turn into any other cell, tissue or organ in the body. This is wholly inaccurate. It is possible that the cartoon was created to positively promote the potential of stem cell biology, however anyone somewhat versed in the field would find it misleading, disgusting, scary and dangerous.

Vice comic: Magical Stem Cells

Vice comic: Magical Stem Cells

Similarly, the creators of South Park several years back had an episode in which Christopher Reeves was essentially a spokesperson for the research and its potential to cure spinal cord injury. They equated stem cell therapies, like the VICE cartoon, to the use of fetal tissue for therapeutic purposes. Let’s be clear, stem cell biology and stem cell research does not universally mean the use of fetal tissue. In fact, most often the fields of stem cell biology are broken down into three main groups: hESCs, induced pluripotent stem cells (iPSCs, which are adult cells that have been re-engineered to have embryonic-like qualities), and the broader category of adult stem cells. Use of cells taken from aborted human fetuses, either for research or clinical trials, is in fact the exception to the rule.

The term “stem cell” was first used in 1877 when German biologist Ernst Haeckel wrote about a “stem cell” being the fertilized egg from which all cells of the placenta and body arise.1 In 1981, U.C. San Francisco’s Gail Martin became the first scientist to isolate pluripotent cells (which can turn into any other cell in the body) from mouse embryos and coined the term “embryonic stem cells” to describe them.2 It was not until 1998 that James Thomson created the first hESC lines.3

A few interesting facts about blastocyst stage embryos, which were the source of the first embryonic stem cell lines, are that they look the same in mice, humans, dogs, horses, and cows and are typically comprised of no more than several hundred cells. It is also important to note that embryonic stem cells, by definition, can only come from up to blastocyst stage embryos (about 5-7 days after fertilization). Cells taken from embryos older than the blastocyst stage have already begun specializing into specific cell lineages, and are no longer capable of making all cell types.

This, I think, is extremely important to emphasize, as too many people seem to believe that we get our embryonic stem cells from fetuses. I think it is also important to point out that now several groups have published on potential “embryo-safe” methods of embryonic stem cell derivation4-6, which use a single cell from the early, cleavage stage embryo for derivation. This removal of a single cell from such an early stage embryo has been demonstrated to have no negative consequences to the developing embryo, as it has been used for years in IVF clinics. Development of this technique in turn can help alleviate some of the ethical concerns that people have about the use of donated human embryos for research. Lastly, advances in the techniques and use of both iPSCs and adult stem cells alleviate any potential concerns raised by hESCs.

What I hope to achieve in this opinion piece is to raise a general awareness that some commonly held views on stem cells need to be overturned. This can only happen through continued open conversations and discussions. An important way to achieve this is through outreach and education of young students to get them excited about science and the potential of stem cell biology. Resources such as CIRM’s free online education portal and Outschool’s online teaching platform are great example of how to make this happen. Using social media, such as Facebook and Twitter, to post peer-reviewed publications or review articles is another way to make a positive impact.

There are so many amazing things happening in the various fields of stem cell biology that now, more than ever, it is important we lean on facts and push for communicating truths to further our progress of educating the public. What I ask of you at this point is to not sit back and shake your head when you see or read something you know is wrong, such as VICE’s “magical stem cells” cartoon. Please say something, and teach someone.   

Matt Donne

Matt Donne

Matt Donne recently finished his PhD in Developmental and Stem Cell Biology at the University of California, San Francisco, where he was awarded a CIRM Fellowship. Previously he was a CIRM student at San Francisco State University.  He has shared his passion for stem cell biology with students of all ages for over 10 years. His passion for stem cell biology and animals has brought him to VitroLabs, where he is changing how leather is manufactured.


Citations:

1          Ramalho-Santos, M. & Willenbring, H. On the origin of the term “stem cell”. Cell Stem Cell 1, 35-38, doi:10.1016/j.stem.2007.05.013 (2007).

2          Martin, G. R. Isolation of a pluripotent cell line from early mouse embryos cultured in medium conditioned by teratocarcinoma stem cells. Proc Natl Acad Sci U S A 78, 7634-7638 (1981).

3          Thomson, J. A. et al. Embryonic stem cell lines derived from human blastocysts. Science 282, 1145-1147 (1998).

4          Klimanskaya, I., Chung, Y., Becker, S., Lu, S. J. & Lanza, R. Human embryonic stem cell lines derived from single blastomeres. Nature 444, 481-485, doi:10.1038/nature05142 (2006).

5          Zdravkovic, T. et al. Human stem cells from single blastomeres reveal pathways of embryonic or trophoblast fate specification. Development 142, 4010-4025, doi:10.1242/dev.122846 (2015).

6          Chung, Y. et al. Human Embryonic Stem Cell Lines Generated without Embryo Destruction. Cell Stem Cell 2, 113-117, doi:http://dx.doi.org/10.1016/j.stem.2007.12.013 (2008).

Good news from Asterias’ CIRM-funded spinal cord injury trial

This week in the stem cell field, all eyes are on Asterias Biotherapeutics, a California-based company that’s testing a stem cell based-therapy in a CIRM-funded clinical trial for spinal cord injury patients. The company launched its Phase 1/2a clinical trial back in 2014 with the goal of determining the safety of the therapy and the optimal dose of AST-OPC1 cells to transplant into patients.

astopc1AST-OPC1 cells are oligodendrocyte progenitor cells derived from embryonic stem cells. These are cells located in the brain and spinal cord that develop into support cells that help nerve cells function and communicate with each other.

Asterias is transplanting AST-OPC1 cells into patients that have recently suffered from severe spinal cord injuries in their neck. This type of injury leaves patients paralyzed without any feeling from their neck down. By transplanting cells that can help the nerve cells at the injury site reform their connections, Asterias hopes that their treatment will allow patients to regain some form of movement and feeling.

And it seems that their hope is turning into reality. Yesterday, Asterias reported in a news release that five patients who received a dose of 10 million cells showed improvements in their ability to move after six months after their treatment. All five patients improved one level on the motor function scale, while one patient improved by two levels. A total of six patients received the 10 million cell dose, but so far only five of them have completed the six-month follow-up study, three of which have completed the nine-month follow-up study.

We’ve profiled two of these six patients previously on the Stem Cellar. Kris Boesen was the first patient treated with 10 million cells and has experienced the most improvement. He has regained the use of his hands and arms and can now feed himself and lift weights. Local high school student, Jake Javier, was the fifth patient in this part of the trial, and you can read about his story here.

Kris Boesen, CIRM spinal cord injury clinical trial patient.

Kris Boesen, CIRM spinal cord injury clinical trial patient.

jake_javier_stories_of_hope

Jake Javier and his Mom

The lead investigator on this trial, Dr. Richard Fessler, explained the remarkable progress that these patients have made since their treatment:

“With these patients, we are seeing what we believe are meaningful improvements in their ability to use their arms, hands and fingers at six months and nine months following AST-OPC1 administration. Recovery of upper extremity motor function is critically important to patients with complete cervical spinal cord injuries, since this can dramatically improve quality of life and their ability to live independently.”

Asterias will continue to monitor these patients for changes or improvements in movement and will give an update when these patients have passed the 12-month mark since their transplant. However, these encouraging preliminary results have prompted the company to look ahead towards advancing their treatment down the regulatory approval pathway, out of clinical trials and into patients.

Asterias CEO, Steve Cartt, commented,

Steve Cartt, CEO of Asterias Biotherapeutics

Steve Cartt, CEO of Asterias Biotherapeutics

“These results to date are quite encouraging, and we look forward to initiating discussions with the FDA in mid-2017 to begin to determine the most appropriate clinical and regulatory path forward for this innovative therapy.”

 

Talking with the US FDA will likely mean that Asterias will need to show further proof that their stem cell-based therapy actually improves movement in patients, rather than the patients spontaneously regaining movement (which has been observed in patients before). FierceBiotech made this point in a piece they published yesterday on this trial.

“Those discussions with FDA could lead to a more rigorous examination of the effect of AST-OPC1. Some patients with spinal injury experience spontaneous recovery. Asterias has put together matched historical data it claims show “a meaningful difference in the motor function recovery seen to date in patients treated with the 10 million cell dose of AST-OPC1.” But the jury will remain out until Asterias pushes ahead with plans to run a randomized controlled trial.”

In the meantime, Asterias is testing a higher dose of 20 million AST-OPC1 cells in a separate group of spinal cord injury patients. They believe this number is the optimal dose of cells for achieving the highest motor improvement in patients.

2017 will bring more results and hopefully more good news about Asterias’ clinical trial for spinal cord injury. And as always, we’ll keep you informed with any updates on our Stem Cellar Blog.

Eye on the prize: two stem cell studies restore vision in blind mice

For the 39 million people in the world who are blind, a vision-restoring therapy would be the ultimate prize. So far, this prize has remained out of reach, but two studies published this week have entered the ring as promising contenders in the fight against blindness.

In the red corner, we have a study published in Stem Cell Reports from the RIKEN Institute in Japan led by scientist Masayo Takahashi. Her team restored vision in blind mice with an advanced stage of retinal disease by transplanting sheets of light-sensing photoreceptor cells that were made from induced pluripotent stem cells (iPSCs).

In the blue corner, we have a study published in Cell Stem Cell from the Buck Institute in California led by scientist Deepak Lamba. His team restored long-term vision in blind mice by transplanting embryonic stem cell-derived photoreceptor cells and preventing the immune system from rejecting the transplant.

Transplanting Retinal sheets

webfig

Synaptic integration of graft retina into model mouse
Credit: RIKEN

Let’s first talk about the Riken study led by Masayo Takahashi. She is well known for her pioneering work on iPSC-derived treatments for macular degeneration – a disease that damages the retina and causes blindness.

In previous work, Takahashi and her team transplanted sheets of mouse stem cell-derived retinal progenitor cells, which mature into light-sensing cells called photoreceptors, into the eyes of mice. The cells within the sheet formed connections with the resident cells in the mouse eye, proving the feasibility of transplanting retinal sheets to restore vision.

In their current study, published in Stem Cell Reports, Takahashi’s team found that the retinal sheets could restore vision in mice that had a very severe form of retinal disease that left them unable to see light. After the mice received the retinal transplants, they responded to light, which they were unable to do previously. Like their other findings, they found that the cells in the transplant made connections with the host cells in the eye including nerve cells that send light-sensing signals to the brain.

First author on the study, Michiko Mandai explained the importance of their findings and their future plans in a news release,

“These results are a proof of concept for using iPSC-derived retinal tissue to treat retinal degeneration. We are planning to proceed to clinical trials in humans after a few more necessary studies using human iPSC-derived retinal tissue in animals. Clinical trials are the only way to determine how many new connections are needed for a person to be able to ‘see’ again.”

While excited by their results, Mandai and the rest of the RIKEN team aren’t claiming the prize for a successful treatment that will cure blindness in people just yet. Mandai commented,

“We cannot expect to restore practical vision at the moment. We will start from seeing a simple light, then possibly move on to larger figures in the next stage.”

Blocking the immune system

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Image showing transplanted GFP-expressing human stem cell derived photoreceptors (green) integrated in a host rodent retina stained for Otx2 (red).
Credit Jie Zhu, Buck Institute for Research on Aging

In the Buck Institute study, Lamba and his team took on the challenge of answering a controversial question about why retinal cell transplants typically don’t survive long-term in the eye. Some scientists think that the transplanted cells die off over time because they don’t integrate into the eye while others think that they are rejected and killed off by the immune system.

To answer this question, Lamba transplanted human embryonic stem cell-derived retinal cells into immunodeficient mice that lacked a protein receptor that’s vital for a functioning immune system. The retinal cells transplanted into immunodeficient mice survived much better than retinal cells transplanted into normal mice and developed into ten times as many photoreceptors that integrated themselves into the host eye.

Their next step was to transplant the retinal cells into mice that were blind and also lacked the same immune receptor as the other mice. After the transplant, the blind mice became responsive to light and showed brain activity associated with sensing light. Their newfound ability to see lasted for nine months to a year following the transplant.

Lamba believes that backing down the immune response is responsible for the long-term vision restoration in the blind mice. He explained the importance of their findings in a Buck Institute news release,

“That finding gives us a lot of hope for patients, that we can create some sort of advantage for these stem cell therapies so it won’t be just a transient response when these cells are put in, but a sustained vision for a long time. Even though the retina is often considered to be ‘immune privileged,’ we have found that we can’t ignore cell rejection when trying to transplant stem cells into the eye.”

In the future, Lamba will explore the potential for using drugs that target the specific protein receptor they blocked earlier to improve the outcome of embryonic stem cell-derived retinal transplants,

“We can also potentially identify other small molecules or recombinant proteins to reduce this interleukin 2 receptor gamma activity in the body – even eye-specific immune responses – that might reduce cell rejection. Of course it is not validated yet, but now that we have a target, that is the future of how we can apply this work to humans.”

Who will be the winner?

The Buck Institute study is interesting because it suggests that embryonic stem cell-based transplants combined with immunosuppression could be a promising strategy to improve vision in patients. But it also begs the question of whether the field should focus instead on iPSC-based therapies where a patient’s own stem cells are used to make the transplanted cells. This strategy would side step the immune response and prevent patients from a taking a lifetime of immunosuppressive drugs.

However, I’m not saying that RIKEN’s iPSC-based strategy is necessarily the way to go for treating blindness (at least not yet). It takes a lot of time and money to make iPSC lines and it’s not feasible given our current output to generate iPSC lines for every blind patient.

So, it sounds like a winner in this fight to cure blindness won’t be announced any time soon. In the meantime, both teams need to conduct further preclinical studies before they can move on to testing these treatments in human clinical trials.

Here at CIRM, we’re funding a promising Phase 1 clinical trial sponsored by jCyte for a form of blindness called Retinis Pigmentosa. Based on preliminary results with a small cohort of patient, the treatment seems safe and may even be showing hints of effectiveness in some patients.

Ultimately, more is better. As the number of stem cell clinical trials for blindness grows, the sooner we can find out which therapies work best for which patients.

Cured by Stem Cells

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To get anywhere you need a good map, and you need to check it constantly to make sure you are still on the right path and haven’t strayed off course. A year ago the CIRM Board gave us a map, a Strategic Plan, that laid out our course for the next five years. Our Annual Report for 2016, now online, is our way of checking that we are still on the right path.

I think, without wishing to boast, that it’s safe to say not only are we on target, but we might even be a little bit ahead of schedule.

The Annual Report is chock full of facts and figures but at the heart of it are the stories of the people who are the focus of all that we do, the patients. We profile six patients and one patient advocate, each of whom has an extraordinary story to tell, and each of whom exemplifies the importance of the work we support.

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Brenden Whittaker: Cured

Two stand out for one simple reason, they were both cured of life-threatening conditions. Now, cured is not a word we use lightly. The stem cell field has been rife with hyperbole over the years so we are always very cautious in the way we talk about the impact of treatments. But in these two cases there is no need to hold back: Evangelina Padilla Vaccaro and Brenden Whittaker have been cured.

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Evangelina: Cured

 

In the coming weeks we’ll feature our conversations with all those profiled in the Annual Report, giving you a better idea of the impact the stem cell treatments have had on their lives and the lives of their family. But today we just wanted to give a broad overview of the Annual Report.

The Strategic Plan was very specific in the goals it laid out for us. As an agency we had six big goals, but each Team within the agency, and each individual within those teams had their own goals. They were our own mini-maps if you like, to help us keep track of where we were individually, knowing that every time an individual met a goal they helped the Team get closer to meeting its goals.

As you read through the report you’ll see we did a pretty good job of meeting our targets. In fact, we missed only one and we’re hoping to make up for that early in 2017.

But good as 2016 was, we know that to truly fulfill our mission of accelerating treatments to patients with unmet medical needs we are going to have do equally well, if not even better, in 2017.

That work starts today.

 

Stem cell heroes: patients who had life-saving, life-changing treatments inspire CIRM Board

 

It’s not an easy thing to bring an entire Board of Directors to tears, but four extraordinary people and their families managed to do just that at the last CIRM Board meeting of 2016.

The four are patients who have undergone life-saving or life-changing stem cell therapies that were funded by our agency. The patients and their families shared their stories with the Board as part of CIRM President & CEO Randy Mill’s preview of our Annual Report, a look back at our achievements over the last year.

The four included:

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Jake Javier, whose life changed in a heartbeat the day before he graduated high school, when he dove into a swimming pool and suffered a spinal cord injury that left him paralyzed from the chest down. A stem cell transplant is giving him hope he may regain the use of his arms and hands.

 

 

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Karl Trede who had just recovered from one life-threatening disease when he was diagnosed with lung cancer, and became the first person ever treated with a new anti-tumor therapy that helped hold the disease at bay.

 

brenden_stories_of_hopeBrenden Whittaker, born with a rare immune disorder that left his body unable to fight off bacterial or fungal infections. Repeated infections cost Brenden part of his lung and liver and almost killed him. A stem cell treatment that gave him a healthy immune system cured him.

 

 

evangelinaEvangelina Padilla Vaccaro was born with severe combined immunodeficiency (SCID), also known as “bubbly baby” disease, which left her unable to fight off infections. Her future looked grim until she got a stem cell transplant that gave her a new blood system and a healthy immune system. Today, she is cured.

 

 

Normally CIRM Board meetings are filled with important, albeit often dry, matters such as approving new intellectual property regulations or a new research concept plan. But it’s one thing to vote to approve a clinical trial, and a very different thing to see the people whose lives you have helped change by funding that trial.

You cannot help but be deeply moved when you hear a mother share her biggest fear that her daughter would never live long enough to go to kindergarten and is now delighted to see her lead a normal life; or hear a young man who wondered if he would make it to his 24th birthday now planning to go to college to be a doctor

When you know you played a role in making these dreams happen, it’s impossible not to be inspired, and doubly determined to do everything possible to ensure many others like them have a similar chance at life.

You can read more about these four patients in our new Stories of Hope: The CIRM Stem Cell Four feature on the CIRM website. Additionally, here is a video of those four extraordinary people and their families telling their stories:

We will have more extraordinary stories to share with you when we publish our Annual Report on January 1st. 2016 was a big year for CIRM. We are determined to make 2017 even bigger.

Stem cell-derived pacemaker cells could help weak hearts keep the beat

In an average lifetime, the human heart dutifully beats more than 2.5 billion times. You can thank an area of the heart called the sinoatrial node, or SAN, which acts as the heart’s natural pacemaker. The SAN is made up of specialized heart muscle cells that, like a conductor leading an orchestra, dictates the rate which all other heart muscle cells will follow. But instead of a conductor’s baton, the cells of the SAN send out an electrical signal which stimulates the heart muscle cells to beat in unison.

Stem cell-derived pacemaker cells (blob in center) stimulate the layer of heart muscle cells  underneath to beat in unison (video: McEwen Centre for Regenerative Medicine).

Artificial pacemakers: an imperfect remedy for irregular heart beats
Certain inherited mutations as well as the aging process can foul up this natural pacemaker signal which usually results in slower, erratic heart rates and leads to poor blood circulation. The current remedy for irregular heart rhythm in these cases is the implantation of an artificial electronic pacemaker into the body. But these devices have their drawbacks: they can’t respond to hormone signals received by the heart, the implantation itself carries a risk of infection and the pacemaker’s battery life is limited to about 7 years so replacement surgeries are needed. Also, for children needing artificial pacemakers, there’s no effective way to adjust the device to adapt to a child’s growing heart.

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X-Ray of implanted electronic pacemaker (Image: Wikipedia)

Now, a Canadian research team at the McEwen Centre for Regenerative Medicine in Toronto aims to create a pacemaker from stem cells to one day provide a biological alternative to current electronic options. In their Nature Biotechnology report published last week, the team describes how they used their expertise in the developmental biology of the heart to successfully devise a method for transforming human embryonic stem cells into functioning pacemaker cells.

If you’ve been following the stem cell field for a while, you’ve probably watched lots of cool videos and read countless stories about beating heart cells grown from stem cells. Then what’s so special about this report? It’s true, you can readily make beating heart muscle cells, or cardiomyocytes, from embryonic stem cells. But usually these methods generate a mixture of various types of cardiomyocytes. The current report instead focused on specifically transforming the stem cells into the SAN pacemaker cells.

Look Ma, no genes inserted!
In 2015, another research team published work showing they had nudged stem cells to become cells with SAN-like pacemaker activity. But that study relied on the permanent insertion of a gene into the cells’ DNA which carries a risk of promoting tumor formation and would not be suitable for clinical use in the future. To generate cells that more closely correspond to the natural pacemaker found in healthy individuals, the researchers in this study created their cells by relying on a gene insertion-free recipe that included the addition of various hormones and growth factors. Stephanie Protze, the first author in the report, explained in a University Health Network press release, the challenge of finding the right ingredients:

“It’s tricky, you have to determine the right signaling molecules, at the right concentration, at the right time to stimulate the stem cells.”

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First author Dr. Stephanize Protze and senior author Gordon Keller, Director of the McEwen Centre
(Photo: McEwen Centre for Regenerative Medicine)

A replacement biological pacemaker: one step closer to reality
Analysis of their method showed that 90% of the human stem cell-derived SAN cells had the correct pacemaker activity. They went on to show that these cells could act as a natural pacemaker both in the petri dish and in rats. These results are an exciting step towards providing a natural pacemaker for people with irregular heartbeat disorders. Still, it’s important to realize that human clinical trials are at least 5 to 10 years down the road because a lot of preclinical animal studies will need to examine safety and effectiveness of such a therapy.

In the meantime, the team is eager to use their new method to grow patient specific pacemaker cells from human induced pluripotent stem cells. This approach will give the researchers a chance to study heart arrhythmia in a petri dish to better understand this health problem and to test drugs that could potentially improve symptoms.