Listen Up: A stem cell-based solution for hearing loss

Can you hear me now?

If you’re old enough, you probably recognize this phrase from an early 2000’s Verizon Wireless commercial where the company claims to be “the nation’s largest, most reliable wireless network”. However, no matter how hard wireless companies like Verizon try, there are still dead zones where cell phone reception is zilch and you can’t in fact hear me now.

This cell phone coverage is a good analogy for the 5% of the world population, or 360 million people, that suffer from hearing loss. There are many causes for hearing loss including genetic predispositions, birth defects, constant exposure to loud noises, infectious diseases, certain drugs, ear infections and aging. There is no cure that fully restores hearing, but patients can benefit from hearing aids, cochlear implants and other hearing devices.

But listen to this. A new stem cell-based technique developed by the Massachusetts Eye and Ear Infirmary may restore hearing in patients with hearing loss. The team discovered that stem cells in the inner ear can be manipulated in a culture dish to expand and develop into large quantities of cochlear hair cells, which make it possible for your brain to detect sound. Their work was published this week in the journal Cell Reports.

In a previous study, the Boston team found that stem cells in the inner ears of mice could be directly converted into cochlear hair cells, but they weren’t able to generate enough hair cells to fully restore hearing in these mice. Building on this work, the team isolated these stem cells, which express a protein called LGR5, and developed an augmentation technique consisting of drugs and growth factors to expand these stem cells and then specialize them into larger populations of hair cells.

A new technique converts stems cells into hair cells. Image credit Will McLean, Albert Edge, Massachusetts Eye and Ear

A new technique converts stems cells into hair cells. Image credit Will McLean, Albert Edge, Massachusetts Eye and Ear.

From a single mouse cochlea, they made more than 11,500 hair cells using their new augmentation method, which is more than 50 times the number of hair cells they made using a more basic method.

In a news release, senior author on the study, Dr. Albert Edge, explained the importance of their findings for patients with hearing loss:

Albert Edge

Albert Edge

“We have shown that we can expand Lgr5-expressing cells to differentiate into hair cells in high yield, which opens the door for drug discovery for hearing. We hope that by stimulating these cells to divide and differentiate that we will improve on our previous results in restoring hearing. With this knowledge, we can make better shots on goal, which is critical for repairing damaged ears. We have identified the cells of interest and have identified the pathways and drugs to target to improve on previous results. These clues may lead us closer to finding drugs that could treat hearing loss in adults.”

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.

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.”

Stories that caught our eye: stem cell transplants help put MS in remission; unlocking the cause of autism; and a day to discover what stem cells are all about

multiple-sclerosis

Motor neurons

Stem cell transplants help put MS in remission: A combination of high dose immunosuppressive therapy and transplant of a person’s own blood stem cells seems to be a powerful tool in helping people with relapsing-remitting multiple sclerosis (RRMS) go into sustained remission.

Multiple sclerosis (MS) is an autoimmune disorder where the body’s own immune system attacks the brain and spinal cord, causing a wide variety of symptoms including overwhelming fatigue, blurred vision and mobility problems. RRMS is the most common form of MS, affecting up to 85 percent of people, and is characterized by attacks followed by periods of remission.

The HALT-MS trial, which was sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), took the patient’s own blood stem cells, gave the individual chemotherapy to deplete their immune system, then returned the blood stem cells to the patient. The stem cells created a new blood supply and seemed to help repair the immune system.

Five years after the treatment, most of the patients were still in remission, despite not taking any medications for MS. Some people even recovered some mobility or other capabilities that they had lost due to the disease.

In a news release, Dr. Anthony Fauci, Director of NIAID, said anything that holds the disease at bay and helps people avoid taking medications is important:

“These extended findings suggest that one-time treatment with HDIT/HCT may be substantially more effective than long-term treatment with the best available medications for people with a certain type of MS. These encouraging results support the development of a large, randomized trial to directly compare HDIT/HCT to standard of care for this often-debilitating disease.”

scripps-campus

Scripps Research Institute

Using stem cells to model brain development disorders. (Karen Ring) CIRM-funded scientists from the Scripps Research Institute are interested in understanding how the brain develops and what goes wrong to cause intellectual disabilities like Fragile X syndrome, a genetic disease that is a common cause of autism spectrum disorder.

Because studying developmental disorders in humans is very difficult, the Scripps team turned to stem cell models for answers. This week, in the journal Brain, they published a breakthrough in our understanding of the early stages of brain development. They took induced pluripotent stem cells (iPSCs), made from cells from Fragile X syndrome patients, and turned these cells into brain cells called neurons in a cell culture dish.

They noticed an obvious difference between Fragile X patient iPSCs and healthy iPSCs: the patient stem cells took longer to develop into neurons, a result that suggests a similar delay in fetal brain development. The neurons from Fragile X patients also had difficulty forming synaptic connections, which are bridges that allow for information to pass from one neuron to another.

Scripps Research professor Jeanne Loring said that their findings could help to identify new drug therapies to treat Fragile X syndrome. She explained in a press release;

“We’re the first to see that these changes happen very early in brain development. This may be the only way we’ll be able to identify possible drug treatments to minimize the effects of the disorder.”

Looking ahead, Loring and her team will apply their stem cell model to other developmental diseases. She said, “Now we have the tools to ask the questions to advance people’s health.”

A Day to Discover What Stem Cells Are All about.  (Karen Ring) Everyone is familiar with the word stem cells, but do they really know what these cells are and what they are capable of? Scientists are finding creative ways to educate the public and students about the power of stem cells and stem cell research. A great example is the University of Southern California (USC), which is hosting a Stem Cell Day of Discovery to educate middle and high school students and their families about stem cell research.

The event is this Saturday at the USC Health Sciences Campus and will feature science talks, lab tours, hands-on experiments, stem cell lab video games, and a resource fair. It’s a wonderful opportunity for families to engage in science and also to expose young students to science in a fun and engaging way.

Interest in Stem Cell Day has been so high that the event has already sold out. But don’t worry, there will be another stem cell day next year. And for those of you who don’t live in Southern California, mark your calendars for the 2017 Stem Cell Awareness Day on Wednesday, October 11th. There will be stem cell education events all over California and in other parts of the country during that week in honor of this important day.

 

 

Mini-guts made from stem cells uncover mechanisms of viral infection in infants

Newborns: so precious, so vulnerable. Image: Wikimedia commons

Newborns: so precious, so vulnerable. Image: Wikimedia commons

Besides their chubby cheeks and cute little toes, I think what makes newborns so precious is how vulnerable they are in those first few days and months of life. For instance, infants are particularly easy targets for infections of the gut caused by enteroviruses. While healthy adults infected with these viruses may exhibit mild cold or flu-like symptoms, infants can have serious complications including sudden onset paralysis, infection of the heart and brain, even death.

Not much is known about how these viruses enter the gut and gain entry to other parts of the body. Reporting this week in PNAS, a research team at the Washington University School of Medicine in St. Louis used human stem cell-derived “mini-guts” to uncover some clues.

enteroid

Mini-gut grown from human intestinal stem cells. Image: Cliff Luke/Misty Good, U. Washington – St. Louis

The intestine is a very complex organ with several different cell types that work in concert to keep bacteria and viruses out, and to allow food to be absorbed into the bloodstream. This complexity has made it difficult to carry out human studies in the lab that adequately mimic enterovirus infection. To overcome these challenges, the team isolated stem cells from the small intestine of a premature infant and successfully generated mini-intestines in petri dishes.

The researchers then tested the ability of various enteroviruses to infect the mini-guts and observed they were most vulnerable to infection by enterovirus E11, the most common enterovirus infection seen in premature infants. The team went on to show that the E11 virus infects some cell types of the mini-gut but not others.

In a press release, Co-senior author Carolyn Coyne, an associate professor at the University of Pittsburgh School of Medicine, described the importance of this work for the 10 to 15 million enterovirus infections and tens of thousands of hospitalizations each year in the U.S.:

“Despite their major global impact, especially on the health of children, little is known about the route that these viruses take to cross the intestine, their primary point of entry. Our approach has for the first time shed some light on this process. This model also could be used for developing anti-enterovirus therapeutics targeting the gastrointestinal tract, given that no therapeutic approaches exist to combat infections of these viruses.”

Stem Cells Profiles in Courage: Frank’s final gift

frank-st-clair

Not every story has a happy ending. But they do all have something to teach us. In the case of Frank St. Clair the lesson was simple: live life fully and freely, love those around you, and never give up.

We were fortunate enough to get to know Frank as one of the people we profiled in our 2016 Annual Report. Frank was a patient in a clinical trial we are funding to test a new kind of bioengineered vein needed by people undergoing hemodialysis, the most common form of dialysis.

It was an all too brief friendship. Frank passed away on December 17th due to complications from heart disease. But in that time he touched us with his warmth, his kindness, his sense of humor and his generosity. Frank never gave up. He kept fighting to the end. His courage, and compassion for others is a reminder to us that we need to work as hard as we can, to bring treatments to those who need them most.

This is Frank’s story, in his own words:

“I have kidney disease. Had it about four years. When I first started dialysis I had a shunt in my chest.  I had to be careful with the shunt, especially at night, in case I pulled it out. It kept clogging up on me and I’d have to go in and get it reopened and that was a terrible thing.

One time when they were opening up the shunt in my chest I ran into the doctor and I got talking to him. He knew how miserable I was and he asked if I wanted to take part in this clinical trial. I said I did and they arranged for me to get this, the device. I just lucked out and was in the right place at the right time. Best move I ever made. Didn’t know anything about stem cells then, sure didn’t, I just knew I was miserable and if there was any way to make life better I just wanted to do it or try it.

And then I did this and it was like day and night.

Since I’ve done this my life has improved 100%. I can do a lot now that I couldn’t do before. My wife and I are so grateful that we can have this. Now we can go out to dinner and do anything we want. We could go out before but we had to always be careful because of the thing in my chest. But now I don’t even think about it. It’s like getting my life back.

I don’t notice it all. I don’t feel it at all. I hate to say it, but I can’t believe I’m on dialysis. I would like to have a kidney but I’ll be honest with you this is the next best thing.

When I go to the clinic there’s a lot of old people there and I just try to make them laugh, tell them jokes, I just can’t believe how good I feel and I want to make others feel good too.

I take the time to talk to them, and give them gum and that cheers them up. My wife has to keep me supplied with gum.

I’ve been married 45 years. We met in high school chorus. I didn’t care too much about singing but I went to chorus because I wanted to meet girls. That’s where I met Paula. Best move I ever made.

I sure don’t feel old. My wife and I are two people that love each other very dearly, that’s my blessing, with her help I couldn’t get old.

I’m a workaholic but until I got the Humacyte device I couldn’t work. I had to sell my business.

I used to be a private detective. It had its moments. My wife used to get mad because I got up at 2 or 3 in the morning to get someone who was in hiding. I had one guy, he was about 6’ 7”, big guy. I knocked at the door and said the name of the guy I was looking for, and asked if he was there. He asked why, so I told him why I was there and he said “It’s me,” and ran right over me and knocked me on the ground and ran away. But I managed to talk him into coming back.

We served a lot of papers on foreclosures and I hated that, and I would always try and help those people if I could.

One time I ran into an old lady, she was a nice woman, and her husband handled all the bills but he died and they had stock in Bernie Madoff’s company and when he went under it left her broke.  They had $1.7 million in a company that went bankrupt. She lost it all. She didn’t know what to do. When I went to serve her papers she hadn’t eaten in two days,  so I went and bought her and brought some groceries and made sure the electric bill got paid and then called her son and made sure she was taken care of.

My wife said we were going broke helping so many people, but I felt that if you help people it comes back to you and it has.

I volunteer at the VA, help out there when I can. Just trying to give back. Always have. I think if you can help someone you need to do it.

I feel damn lucky, really lucky, more ways than one. You have to understand I have lived 50 years longer than I should have; I could have died in Vietnam, so I would just say do not give up. Don’t give up. My wife wouldn’t let me give up, and things happen. If they are meant to be, of course. Something will happen and I’m telling you. The key is making people around you feel like they want to be around you.”

We are forever grateful to Frank for being willing to be part of a clinical trial that will, hopefully, improve the quality of life for many others. That is his legacy. Our thoughts and wishes go out to his wife Paula

Stories that caught our eye: new target for killing leukemia cancer stem cells and stem cell vesicles halt glaucoma

New stem cell target for acute myeloid leukemia (Karen Ring).  A new treatment for acute myeloid leukemia, a type of blood cancer that turns bone marrow stem cells cancerous, could be in the works in the form of a cancer stem cell destroying antibody.

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Acute Myeloid Leukemia (Credit: Medscape)

Scientists from the NYU Langone Medical Center and the Memorial Sloan Kettering Cancer Center identified a protein called CD99 that appears more abundantly on the surface of abnormal blood cancer stem cells compared to healthy blood stem cells. They developed an antibody that specifically recognizes and kills the CD99 wielding cancer stem cells while leaving the healthy blood stem cells unharmed.

The CD99 antibody was effective at killing human AML stem cells in a dish and in mice that were transplanted with the same type of cancer stem cells. Further studies revealed that the CD99 antibody when attached to the surface of cancer stem cells, sets off a cascade of enzyme activity that causes these cells to die. These findings suggest that cancer stem cells express more CD99 as a protective mechanism against cell death.

In an interview with Genetic Engineering and Biotechnology News, Chris Park, senior author on the Science Translational Medicine study, explained the importance of their work:

“Our findings not only identify a new molecule expressed on stem cells that drive these human malignancies, but we also show that antibodies against this target can directly kill human AML stem cells. While we still have important details to work out, CD99 is likely to be an exploitable therapeutic target for most AML and MDS patients, and we are working urgently to finalize a therapy for human testing.”

While this work is still in the early stages, Dr. Park stressed that his team is actively working to translate their CD99 antibody therapy into clinical trials.

“With the appropriate support, we believe we can rapidly determine the best antibodies for use in patients, produce them at the quality needed to verify our results, and apply for permission to begin clinical trials.”

 

Peculiar stem cell function may help treat blindness (Todd Dubnicoff). Scientists at the National Eye Institute (NEI) have uncovered a novel function that stem cells use to carry out their healing powers and it may lead to therapies for glaucoma, the leading cause of blindness in United States. Reporting this week in Stem Cells Translational Medicine, the researchers show that stem cells send out regenerative signals by shedding tiny vesicles called exosomes. Once thought to be merely a garbage disposal system, exosomes are now recognized as an important means of communication between cells. As they bud off from the cells, the exosomes carry proteins and genetic material that can be absorbed by other cells.

Microscopy image shows exosomes (green) surrounding retinal ganglion cells (orange and yellow). Credit: Ben Mead

Microscopy image shows exosomes (green) surrounding retinal ganglion cells (orange and yellow). Credit: Ben Mead

The researchers at NEI isolated exosomes from bone marrow stem cells and injected them into the eyes of rats with glaucoma symptoms. Without treatment, these animals lose about 90 percent of their retinal ganglion cells, the cells responsible for forming the optic nerve and for sending visual information to the brain. With the exosome treatment, the rats only lost a third of the retinal ganglion cells. The team determined that microRNAs – small genetic molecules that can inhibit gene activity – inside the exosome were responsible for the effect.

Exosomes have some big advantages over stem cells when comes to developing and manufacturing therapies which lead author Ben Mead explains in a press release picked up by Eureka Alert:

“Exosomes can be purified, stored and precisely dosed in ways that stem cells cannot.”

We’ll definitely keep our eyes on this development. If these glaucoma studies continue to look promising it stands to reason that there would be exosome applications in many other diseases.

Stories that caught our eye: $20.5 million in new CIRM discovery awards, sickle cell disease cell bank, iPSC insights

CIRM Board launches a new voyage of Discovery (Kevin McCormack).
Basic or early stage research is the Rodney Dangerfield of science; it rarely gets the respect it deserves. Yesterday, the CIRM governing Board showed that it not only respects this research, but also values its role in laying the foundation for everything that follows.

The CIRM Board approved 11 projects, investing more than $20.5 million in our Discovery Quest, early stage research program. Those include programs using gene editing techniques to develop a cure for a rare but fatal childhood disease, finding a new approach to slowing down the progress of Parkinson’s disease, and developing a treatment for the Zika virus.

Zika_EM_CDC_20538 copy.jpg

Electron micrograph of Zika virus (red circles). Image: CDC/Cynthia Goldsmith

The goal of the Discovery Quest program is to identify and explore promising new stem cell therapies or technologies to improve patient care.

In a news release Randy Mills, CIRM’s President & CEO, said we hope this program will create a pipeline of projects that will ultimately lead to clinical trials:

“At CIRM we never underestimate the importance of early stage scientific research; it is the birth place of groundbreaking discoveries. We hope these Quest awards will not only help these incredibly creative researchers deepen our understanding of several different diseases, but also lead to new approaches on how best to use stem cells to develop treatments.”

Creating the world’s largest stem cell bank for sickle cell disease (Karen Ring).
People typically visit the bank to deposit or take out cash, but with advancements in scientific research, people could soon be visiting banks to receive life-saving stem cell treatments. One of these banks is already in the works. Scientists at the Center for Regenerative Medicine (CReM) at Boston Medical Center are attempting to generate the world’s largest stem cell bank focused specifically on sickle cell disease (SCD), a rare genetic blood disorder that causes red blood cells to take on an abnormal shape and can cause intense pain and severe organ damage in patients.

To set up their bank, the team is collecting blood samples from SCD patients with diverse ethnic backgrounds and making induced pluripotent stem cells (iPSCs) from these samples. These patient stem cell lines will be used to unravel new clues into why this disease occurs and to develop new potential treatments for SCD. More details about this new SCD iPSC bank can be found in the latest edition of the journal Stem Cell Reports.

crem_boston_130996_web

Gustavo Mostoslavsky, M.D., PH.D., Martin Steinberg, M.D., George Murphy PH.D.
Photo: Boston Medical Center

In a news release, CReM co-founder and Professor, Gustavo Mostoslavsky, touched on the future importance of their new stem cell bank:

“In addition to the library, we’ve designed and are using gene editing tools to correct the sickle hemoglobin mutation using the stem cell lines. When coupled with corrected sickle cell disease specific iPSCs, these tools could one day provide a functional cure for the disorder.”

For researchers interested in using these new stem cell lines, CReM is making them available to researchers around the world as part of the NIH’s NextGen Consortium study.

DNA deep dive reveals ways to increase iPSC efficiency (Todd Dubnicoff)
Though the induced pluripotent stem (iPS) cell technique was first described ten years ago, many researchers continue to poke, prod and tinker with the method which reprograms an adult cell, often from skin, into an embryonic stem cell-like state which can specialize into any cell type in the body. Though this breakthrough in stem cell research is helping scientists better understand human disease and develop patient-specific therapies, the technique is hampered by its low efficiency and consistency.

This week, a CIRM-funded study from UCLA reports new insights into the molecular changes that occur during reprogramming that may help pave the way toward better iPS cell methods. The study, published in Cell, examined the changes in DNA during the reprogramming process.

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Senior authors Kathrin Plath and Jason Ernst and first authors Petko Fiziev and Constantinos Chronis.
Photo: UCLA

In a skin cell, the genes necessary for embryonic stem cell-like, or pluripotent, characteristics are all turned off. One way this shut down in gene activity occurs is through tight coiling of the DNA where the pluripotent genes are located. This physically blocks proteins called transcriptions factors from binding the DNA and activating those pluripotent genes within skin cells. On the other hand, regions of DNA carrying skin-related genes are loosely coiled, so that transcription factors can access the DNA and turn on those genes.

The iPS cell technique works by artificially adding four pluripotent transcriptions factors into skin cells which leads to changes in DNA coiling such that skin-specific genes are turned off and pluripotent genes are turned on. The UCLA team carefully mapped the areas where the transcription factors are binding to DNA during the reprogramming process. They found that the shut down of the skin genes and activation of the pluripotent genes occurs at the same time. The team also found that three of the four iPS cell factors must physically interact with each other to locate and activate the areas of DNA that are responsible for reprogramming.

Using the findings from those experiments, the team was able to identify a fifth transcription factor that helps shut down the skin-specific gene more effectively and, in turn, saw a hundred-fold increase in reprogramming efficiency. These results promise to help the researchers fine-tune the iPS cell technique and make its clinical use more practical.

Avalanches of exciting new stem cell research at the Keystone Symposia near Lake Tahoe

From January 8th to 13th, nearly 300 scientists and trainees from around the world ascended the mountains near Lake Tahoe to attend the joint Keystone Symposia on Neurogenesis and Stem Cells at the Resort at Squaw Creek. With record-high snowfall in the area (almost five feet!), attendees had to stay inside to stay warm and dry, and even when we lost power on the third day on the mountain there was no shortage of great science to keep us entertained.

Boy did it snow at the Keystone Conference in Tahoe!

Boy did it snow at the Keystone Conference in Tahoe!

One of the great sessions at the meeting was a workshop chaired by CIRM’s Senior Science Officer, Dr. Kent Fitzgerald, called, “Bridging and Understanding of Basic Science to Enable/Predict Clinical Outcome.” This workshop featured updates from the scientists in charge of three labs currently conducting clinical trials funded and supported by CIRM.

Regenerating injured connections in the spinal cord with neural stem cells

Mark Tuszynski, UCSD

Mark Tuszynski, UCSD

The first was a stunning talk by Dr. Mark from UCSD who is investigating how neural stem cells can help outcomes for those with spinal cord injury. The spinal cord contains nerves that connect your brain to the rest of your body so you can sense and move around in your environment, but in cases of severe injury, these connections are cut and the signal is lost. The most severe of these injuries is a complete transection, which is when all connections have been cut at a given spot, meaning no signal can pass through, just like how no cars could get through if a section of the Golden Gate Bridge was missing. His lab works in animal models of complete spinal cord transections since it is the most challenging to repair.

As Dr. Tuszynski put it, “the adult central nervous system does not spontaneously regenerate [after injury], which is surprising given that it does have its own set of stem cells present throughout.” Their approach to tackle this problem is to put in new stem cells with special growth factors and supportive components to let this process occur.

Just as most patients wouldn’t be able to come in for treatment right away after injury, they don’t start their tests until two weeks after the injury. After that, they inject neural stem cells from either the mouse, rat, or human spinal cord at the injury site and then wait a bit to see if any new connections form. Their group has shown very dramatic increases in both the number of new connections that regenerate from the injury site and extend much further than previous efforts have shown. These connections conduct electrochemical messages as normal neurons do, and over a year later they see no functional decline or tumors forming, which is often a concern when transplanting stem cells that normally like to divide a lot.

While very exciting, he cautions, “this research shows a major opportunity in neural repair that deserves proper study and the best clinical chance to succeed”. He says it requires thorough testing in multiple animal models before going into humans to avoid a case where “a clinical trial fails, not because the biology is wrong, but because the methods need tweaking.”

Everyone needs support – even dying cells

The second great talk was by Dr. Clive Svendsen of Cedars-Sinai Regenerative Medicine Institute on how stem cells might help provide healthy support cells to rescue dying neurons in the brains of patients with neurodegenerative diseases like Amyotrophic Lateral Sclerosis (ALS) and Parkinson’s. Some ALS cases are hereditary and would be candidates for a treatment using gene editing techniques. However, around 90 percent of ALS cases are “sporadic” meaning there is no known genetic cause. Dr. Svendsen explained how in these cases, a stem cell-based approach to at least fix the cellular cause of the disease, would be the best option.

While neurons often capture all the attention in the brain, since they are the cells that actually send messages that underlie our thoughts and behaviors, the Svendsen lab spends a great deal of time thinking about another type of cell that they think will be a powerhouse in the clinic: astrocytes. Astrocytes are often labeled as the support cells of the brain as they are crucial for maintaining a balance of chemicals to keep neurons healthy and functioning. So Dr. Svendsen reasoned that perhaps astrocytes might unlock a new route to treating neurodegenerative diseases where neurons are unhealthy and losing function.

ALS is a devastating disease that starts with early muscle twitches and leads to complete paralysis and death usually within four years, due to the rapid degeneration of motor neurons that are important for movement all over the body. Svendsen’s team found that by getting astrocytes to secrete a special growth factor, called “GDNF”, they could improve the survival of the neurons that normally die in their model of ALS by five to six times.

After testing this out in several animal models, the first FDA-approved trial to test whether astrocytes from fetal tissue can slow spinal motor neuron loss will begin next month! They will be injecting the precursor cells that can make these GDNF-releasing astrocytes into one leg of ALS patients. That way they can compare leg function and track whether the cells and GDNF are enough to slow the disease progression.

Dr. Svendsen shared with us how long it takes to create and test a treatment that is committed to safety and success for its patients. He says,

Clive Svendsen has been on a 15-year quest to develop an ALS therapy

Clive Svendsen 

“We filed in March 2016, submitted the improvements Oct 2016, and we’re starting our first patient in Feb 2017. [One document is over] 4500 pages… to go to the clinic is a lot of work. Without CIRM’s funding and support we wouldn’t have been able to do this. This isn’t easy. But it is doable!”

 

Improving outcomes in long-term stroke patients in unknown ways

Gary Steinberg

Gary Steinberg

The last speaker for the workshop, Dr. Gary Steinberg, a neurosurgeon at Stanford who is looking to change the lives of patients with severe limitations after having a stroke. The deficits seen after a stroke are thought to be caused by the death of neurons around the area where the stroke occurred, such that whatever functions they were involved with is now impaired. Outcomes can vary for stroke patients depending on how long it takes for them to get to the emergency department, and some people think that there might be a sweet spot for when to start rehabilitative treatments — too late and you might never see dramatic recovery.

But Dr. Steinberg has some evidence that might make those people change their mind. He thinks, “these circuits are not irreversibly damaged. We thought they were but they aren’t… we just need to continue figuring out how to resurrect them.”

He showed stunning videos from his Phase 1/2a clinical trial of several patients who had suffered from a stroke years before walking into his clinic. He tested patients before treatment and showed us videos of their difficulty to perform very basic movements like touching their nose or raising their legs. After carefully injecting into the brain some stem cells taken from donors and then modified to boost their ability to repair damage, he saw a dramatic recovery in some patients as quickly as one day later. A patient who couldn’t lift her leg was holding it up for five whole seconds. She could also touch her arm to her nose, whereas before all she could do was wiggle her thumb. One year later she is even walking, albeit slowly.

He shared another case of a 39 year-old patient who suffered a stroke didn’t want to get married because she felt she’d be embarrassed walking down the aisle, not to mention she couldn’t move her arm. After Dr. Steinberg’s trial, she was able to raise her arm above her head and walk more smoothly, and now, four years later, she is married and recently gave birth to a boy.

But while these studies are incredibly promising, especially for any stroke victims, Dr. Steinberg himself still is not sure exactly how this stem cell treatment works, and the dramatic improvements are not always consistent. He will be continuing his clinical trial to try to better understand what is going on in the injured and recovering brain so he can deliver better care to more patients in the future.

The road to safe and effective therapies using stem cells is long but promising

These were just three of many excellent presentations at the conference, and while these talks involved moving science into human patients for clinical trials, the work described truly stands on the shoulders of all the other research shared at conferences, both present and past. In fact, the reason why scientists gather at conferences is to give one another feedback and to learn from each other to better their own work.

Some of the other exciting talks that are surely laying down the framework for future clinical trials involved research on modeling mini-brains in a dish (so-called cerebral organoids). Researchers like Jürgen Knoblich at the Institute of Molecular Biotechnology in Austria talked about the new ways we can engineer these mini-brains to be more consistent and representative of the real brain. We also heard from really fundamental biology studies trying to understand how one type of cell becomes one vs. another type using the model organism C. elegans (a microscopic, transparent worm) by Dr. Oliver Hobert of Columbia University. Dr. Austin Smith, from the University of Cambridge in the UK, shared the latest about the biology of pluripotent cells that can make any cell type, and Stanford’s Dr. Marius Wernig, one of the meeting’s organizers, told us more of what he’s learned about the road to reprogramming an ordinary skin cell directly into a neuron.

Stay up to date with the latest research on stem cells by continuing to follow this blog and if you’re reading this because you’re considering a stem cell treatment, make sure you find out what’s possible and learn about what to ask by checking out closerlookatstemcells.org.


Samantha Yammine

Samantha Yammine

Samantha Yammine is a science communicator and a PhD candidate in Dr. Derek van der Kooy’s lab at the University of Toronto. You can learn more about Sam and her research on her website.

Stories that caught our eye: frail bones in diabetics, ethics of future IVF, Alzheimer’s

The connection between diabetes and frail bones uncovered
Fundamentally, diabetes is defined by abnormally high blood sugar levels. But that one defect over time carries an increased risk for a wide range of severe health problems. For instance, compared to healthy individuals, type 2 diabetics are more prone to poorly healing bone fractures – a condition that can dramatically lower one’s quality of life.

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Bones of the healthy animals (top) form larger calluses during healing which lead to stronger repaired bones. Bones of the diabetic mice (bottom) have smaller calluses and the healed bones are more brittle. Image: Stanford University

To help these people, researchers are trying to tease out how diabetes impacts bone health. But it’s been a complicated challenge since there are many factors at play. Is it from potential side effects of diabetes drugs? Or is the increased body weight associated with type 2 diabetes leading to decreased bone density? This week a CIRM-funded team at Stanford pinpointed skeletal stem cells, a type of adult stem cell that goes on to make all the building blocks of the bone, as important pieces to this scientific puzzle.

Reporting in Science Translational Medicine, the team, led by Michael Longaker – co-director of Stanford’s Institute for Stem Cell Biology and Regenerative Medicine – found that, compared to healthy animals, type 2 diabetic mice have a reduced number of skeletal stem cells after bone fracture. A study of the local cellular “neighborhood” of these stem cells showed that the diabetic mice also had a reduction in the levels of a protein called hedgehog. Blocking hedgehog activity in healthy mice led to the slow bone healing seen in the diabetic mice. More importantly, boosting hedgehog levels near the site of the fracture in diabetic mice lead to bone healing that was just as good as in the healthy mice.

To see if this result might hold up in humans, the team analyzed hedgehog levels in bone samples retrieved from diabetics and non-diabetics undergoing joint replacement surgeries. Sure enough, hedgehog was depleted in the diabetic bone exactly reflecting the mouse results.

Though more studies will be needed to develop a hedgehog-based treatment in humans, Longaker talked about the exciting big picture implications of this result in a press release:

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Michael Longaker

“We’ve uncovered the reason why some patients with diabetes don’t heal well from fractures, and we’ve come up with a solution that can be locally applied during surgery to repair the break. Diabetes is rampant worldwide, and any improvement in the ability of affected people to heal from fractures could have an enormously positive effect on their quality of life.”

 

Getting the ethics ahead of the next generation of fertility treatments
The Business Insider ran an article this week with a provocative title, “Now is the time to talk about creating humans from stem cells.” I initially read too much into that title because I thought the article was advocating the need to start the push for the cloning of people. Instead, author Rafi Letzter was driving at the importance for concrete, ethical discussion right now about stem cell technologies for fertility treatments that may not be too far off.

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These mice were born from artificial eggs that were made from stem cells in a dish.
It’s great news for infertility specialist but carries many ethical dilemmas. 
(Image: K. Hayashi, Kyushu University)

In particular, he alludes to a paper from October (read our blog about it) that reported the creation of female mouse eggs from stem cells. These eggs were fertilized, implanted into the mother and successfully developed into living mice. What’s more, one set of stem cells were derived from mouse skin samples via the induced pluripotent stem cell method. This breakthrough could one day make it possible for an infertile woman to simply go through a small skin biopsy or mouth swab to generate an unlimited number of eggs for in vitro fertilization (IVF). Just imagine how much more efficient, less invasive and less costly this procedure could be compared to current IVF methods that require multiple hormone injections and retrieval of eggs from a woman’s ovaries.

But along with that hope for couples who have trouble conceiving a child comes a whole host of ethical issues. Here, Letzter refers to a perspective letter published on Wednesday in Science Translation Medicine by scientists and ethicists about this looming challenge for researchers and policymakers.

It’s an important read that lays out the current science, the clinical possibilities and regulatory and ethical questions that must be addressed sooner than later. In an interview with Letzter, co-author Eli Adashi, from the Alpert Medical School at Brown University, warned against waiting too long to heed this call to action:

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Eli Adashi

“Let’s start the [ethical] conversation now. Like all conversations it will be time consuming. And depending how well we do it, and we’ve got to do it well, it will be demanding. It will not be wise to have that conversation when you’re seeing a paper in Science or Nature reporting the complete process in a human. That would not be wise on our collective part. We should be as much as possible ready for that.”

 

 

Tackling Frontotemporal dementia and Alzheimer’s by hitting the same target.
To develop new disease therapies, you usually need to understand what is going wrong at a cellular level. In some cases, that approach leads to the identification of a specific protein that is either missing or in short supply. But this initial step is just half the battle because it may not be practical to make a drug out of the protein itself. So researchers instead search for other proteins or small molecules that lead to an increase in the level of the protein.

A CIRM-funded project at the Gladstone Institutes has done just that for the protein called progranulin. People lacking one copy of the progranulin gene carry an increased risk for  frontotemporal dementia (FTD), a degenerative disease of the brain that is the most common cause of dementia in people under 60 years of age. FTD symptoms are often mistaken for Alzheimer’s. In fact, mutations in progranulin are also associated with Alzheimer’s.

Previous studies have shown that increasing levels of progranulin in animals with diseases that mimic FTP and Alzheimer’s symptoms can reverse symptoms. But little was known how progranulin protein levels were regulated in the cells. Amanda Mason, the lead author on the Journal of Biological Chemistry report, explained in a press release how they tackled this challenge:

“We wanted to know what might regulate the levels of progranulin. Many processes in biology are controlled by adding or removing a small chemical group called phosphate, so we started there.”

These phosphate groups hold a lot of energy in their chemical bonds and can be harnessed to activate or turn off the function of proteins and DNA. The team systematically observed the effects of enzymes that add and remove phosphate groups and zeroed in on one called Ripk1 that leads to increases in progranulin levels. Now the team has set their sights on Ripk1 as another potential target for developing a therapeutic that could be effective against both FTP and Alzheimer’s. Steve Finkbeiner, the team lead, gave a big picture perspective on these promising results:

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Steve Finkbeiner

“This is an exciting finding. Alzheimer’s disease was discovered over 100 years ago, and we have essentially no drugs to treat it. To find a possible new way to treat one disease is wonderful. To find a way that might treat two diseases is amazing.”