Stem cell stories that caught our eye: spinal cord injury trial update, blood stem cells in lungs, and using parsley for stem cell therapies

More good news on a CIRM-funded trial for spinal cord injury. The results are now in for Asterias Biotherapeutics’ Phase 1/2a clinical trial testing a stem cell-based therapy for patients with spinal cord injury. They reported earlier this week that six out of six patients treated with 10 million AST-OPC1 cells, which are a type of brain cell called oligodendrocyte progenitor cells, showed improvements in their motor function. Previously, they had announced that five of the six patients had shown improvement with the jury still out on the sixth because that patient was treated later in the trial.

 In a news release, Dr. Edward Wirth, the Chief Medical officer at Asterias, highlighted these new and exciting results:

 “We are excited to see the sixth and final patient in the AIS-A 10 million cell cohort show upper extremity motor function improvement at 3 months and further improvement at 6 months, especially because this particular patient’s hand and arm function had actually been deteriorating prior to receiving treatment with AST-OPC1. We are very encouraged by the meaningful improvements in the use of arms and hands seen in the SciStar study to date since such gains can increase a patient’s ability to function independently following complete cervical spinal cord injuries.”

Overall, the trial suggests that AST-OPC1 treatment has the potential to improve motor function in patients with severe spinal cord injury. So far, the therapy has proven to be safe and likely effective in improving some motor function in patients although control studies will be needed to confirm that the cells are responsible for this improvement. Asterias plans to test a higher dose of 20 million cells in AIS-A patients later this year and test the 10 million cell dose in AIS-B patients that a less severe form of spinal cord injury.

 Steve Cartt, CEO of Asterias commented on their future plans:

 “These results are quite encouraging, and suggest that there are meaningful improvements in the recovery of functional ability in patients treated with the 10 million cell dose of AST-OPC1 versus spontaneous recovery rates observed in a closely matched untreated patient population. We look forward to reporting additional efficacy and safety data for this cohort, as well as for the currently-enrolling AIS-A 20 million cell and AIS-B 10 million cell cohorts, later this year.”

Lungs aren’t just for respiration. Biology textbooks may be in need of some serious rewrites based on a UCSF study published this week in Nature. The research suggests that the lungs are a major source of blood stem cells and platelet production. The long prevailing view has been that the bone marrow was primarily responsible for those functions.

The new discovery was made possible by using special microscopy that allowed the scientists to view the activity of individual cells within the blood vessels of a living mouse lung (watch the fascinating UCSF video below). The mice used in the experiments were genetically engineered so that their platelet-producing cells glowed green under the microscope. Platelets – cell fragments that clump up and stop bleeding – were known to be produced to some extent by the lungs but the UCSF team was shocked by their observations: the lungs accounted for half of all platelet production in these mice.

Follow up experiments examined the movement of blood cells between the lung and bone marrow. In one experiment, the researchers transplanted healthy lungs from the green-glowing mice into a mouse strain that lacked adequate blood stem cell production in the bone marrow. After the transplant, microscopy showed that the green fluorescent cells from the donor lung traveled to the host’s bone marrow and gave rise to platelets and several other cells of the immune system. Senior author Mark Looney talked about the novelty of these results in a university press release:

Mark Looney, MD

“To our knowledge this is the first description of blood progenitors resident in the lung, and it raises a lot of questions with clinical relevance for the millions of people who suffer from thrombocytopenia [low platelet count].”

If this newfound role of the lung is shown to exist in humans, it may provide new therapeutic approaches to restoring platelet and blood stem cell production seen in various diseases. And it will give lung transplants surgeons pause to consider what effects immune cells inside the donor lung might have on organ rejection.

Add a little vanilla to this stem cell therapy. Typically, the only connection between plants and stem cell clinical trials are the flowers that are given to the patient by friends and family. But research published this week in the Advanced Healthcare Materials journal aims to use plant husks as part of the cell therapy itself.

Though we tend to focus on the poking and prodding of stem cells when discussing the development of new therapies, an equally important consideration is the use of three-dimensional scaffolds. Stem cells tend to grow better and stay healthier when grown on these structures compared to the flat two-dimensional surface of a petri dish. Various methods of building scaffolds are under development such as 3D printing and designing molds using materials that aren’t harmful to human tissue.

Human fibroblast cells growing on decellularized parsley.
Image: Gianluca Fontana/UW-Madison

But in the current study, scientists at the University of Wisconsin-Madison took a creative approach to building scaffolds: they used the husks of parsley, vanilla and orchid plants. The researchers figured that millions of years of evolution almost always leads to form and function that is much more stable and efficient than anything humans can create. Lead author Gianluca Fontana explained in a university press release how the characteristics of plants lend themselves well to this type of bioengineering:

Gianluca Fontana, PhD

“Nature provides us with a tremendous reservoir of structures in plants. You can pick the structure you want.”

The technique relies on removing all the cells of the plant, leaving behind its outer layer which is mostly made of cellulose, long chains of sugars that make up plant cell walls. The resulting hollow, tubular husks have similar shapes to those found in human intestines, lungs and the bladder.

The researchers showed that human stem cells not only attach and grow onto the plant scaffolds but also organize themselves in alignment with the structures’ patterns. The function of human tissues rely on an organized arrangement of cells so it’s possible these plant scaffolds could be part of a tissue replacement cell product. Senior author William Murphy also points out that the scaffolds are easily altered:

William Murphy, PhD

“They are quite pliable. They can be easily cut, fashioned, rolled or stacked to form a range of different sizes and shapes.”

And the fact these scaffolds are natural products that are cheap to manufacture makes this a project well worth watching.

Stem Cell Stories that Caught our Eye: stem cell insights into anorexia, Zika infection and bubble baby disease

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

Stem cell model identifies new culprit for anorexia.

Eating disorders like anorexia nervosa are often thought to be caused by psychological disturbances or societal pressure. However, research into the genes of anorexia patients suggests that what’s written in your DNA can be associated with an increased vulnerability to having this disorder. But identifying individual genes at fault for a disease this complex has remained mostly out of scientists’ reach, until now.

A CIRM-funded team from the UC San Diego (UCSD) School of Medicine reported this week that they’ve developed a stem cell-based model of anorexia and used it to identify a gene called TACR1, which they believe is associated with an increased likelihood of getting anorexia.

They took skin samples from female patients with anorexia and reprogrammed them into induced pluripotent stem cells (iPSCs). These stem cells contained the genetic information potentially responsible for causing their anorexia. The team matured these iPSCs into brain cells, called neurons, in a dish, and then studied what genes got activated. When they looked at the genes activated by anorexia neurons, they found that TACR1, a gene associated with psychiatric disorders, was switched on higher in anorexia neurons than in healthy neurons. These findings suggest that the TACR1 gene could be an identifier for this disease and a potential target for developing new treatments.

In a UCSD press release, Professor and author on the study, Alysson Muotri, said that they will follow up on their findings by studying stem cell lines derived from a larger group of patients.

Alysson Muotri UC San Diego

“But more to the point, this work helps make that possible. It’s a novel technological advance in the field of eating disorders, which impacts millions of people. These findings transform our ability to study how genetic variations alter brain molecular pathways and cellular networks to change risk of anorexia nervosa — and perhaps our ability to create new therapies.”

Anorexia is a disease that affects 1% of the global population and although therapy can be an effective treatment for some, many do not make a full recovery. Stem cell-based models could prove to be a new method for unlocking new clues into what causes anorexia and what can cure it.

Nature versus Zika, who will win?

Zika virus is no longer dominating the news headlines these days compared to 2015 when large outbreaks of the virus in the Southern hemisphere came to a head. However, the threat of Zika-induced birth defects, like microcephaly to pregnant women and their unborn children is no less real or serious two years later. There are still no effective vaccines or antiviral drugs that prevent Zika infection but scientists are working fast to meet this unmet need.

Speaking of which, scientists at UCLA think they might have a new weapon in the war against Zika. Back in 2013, they reported that a natural compound in the body called 25HC was effective at attacking viruses and prevented human cells from being infected by viruses like HIV, Ebola and Hepatitis C.

When the Zika outbreak hit, they thought that this compound could potentially be effective at preventing Zika infection as well. In their new study published in the journal Immunity, they tested a synthetic version of 25HC in animal and primate models, they found that it protected against infection. They also tested the compound on human brain organoids, or mini brains in a dish made from pluripotent stem cells. Brain organoids are typically susceptible to Zika infection, which causes substantial cell damage, but this was prevented by treatment with 25HC.

Left to right: (1) Zika virus (green) infects and destroys the formation of neurons (pink) in human stem cell-derived brain organoids.  (2) 25HC blocks Zika infection and preserves neuron formation in the organoids. (3) Reduced brain size and structure in a Zika-infected mouse brain. (4) 25HC preserves mouse brain size and structure. Image courtesy of UCLA Stem Cell.

A UCLA news release summarized the impact that this research could have on the prevention of Zika infection,

“The new research highlights the potential use of 25HC to combat Zika virus infection and prevent its devastating outcomes, such as microcephaly. The research team will further study whether 25HC can be modified to be even more effective against Zika and other mosquito-borne viruses.”

Harnessing a naturally made weapon already found in the human body to fight Zika could be an alternative strategy to preventing Zika infection.

Gene therapy in stem cells gives hope to bubble-babies.

Last week, an inspiring and touching story was reported by Erin Allday in the San Francisco Chronicle. She featured Ja’Ceon Golden, a young baby not even 6 months old, who was born into a life of isolation because he lacked a properly functioning immune system. Ja’Ceon had a rare disease called severe combined immunodeficiency (SCID), also known as bubble-baby disease.

 

Ja’Ceon Golden is treated by patient care assistant Grace Deng (center) and pediatric oncology nurse Kat Wienskowski. Photo: Santiago Mejia, The Chronicle.

Babies with SCID lack the body’s immune defenses against infectious diseases and are forced to live in a sterile environment. Without early treatment, SCID babies often die within one year due to recurring infections. Bone marrow transplantation is the most common treatment for SCID, but it’s only effective if the patient has a donor that is a perfect genetic match, which is only possible for about one out of five babies with this disease.

Advances in gene therapy are giving SCID babies like Ja’Ceon hope for safer, more effective cures. The SF Chronicle piece highlights two CIRM-funded clinical trials for SCID run by UCLA in collaboration with UCSF and St. Jude Children’s Research Hospital. In these trials, scientists isolate the bone marrow stem cells from SCID babies, correct the genetic mutation causing SCID in their stem cells, and then transplant them back into the patient to give them a healthy new immune system.

The initial results from these clinical trials are promising and support other findings that gene therapy could be an effective treatment for certain genetic diseases. CIRM’s Senior Science Officer, Sohel Talib, was quoted in the Chronicle piece saying,

“Gene therapy has been shown to work, the efficacy has been shown. And it’s safe. The confidence has come. Now we have to follow it up.”

Ja’Ceon was the first baby treated at the UCSF Benioff Children’s Hospital and so far, he is responding well to the treatment. His great aunt Dannie Hawkins said that it was initially hard for her to enroll Ja’Ceon in this trial because she was a partial genetic match and had the option of donating her own bone-marrow to help save his life. In the end, she decided that his involvement in the trial would “open the door for other kids” to receive this treatment if it worked.

Ja’Ceon Golden plays with patient care assistant Grace Deng in a sterile play area at UCSF Benioff Children’s Hospital.Photo: Santiago Mejia, The Chronicle

It’s brave patients and family members like Ja’Ceon and Dannie that make it possible for research to advance from clinical trials into effective treatments for future patients. We at CIRM are eternally grateful for their strength and the sacrifices they make to participate in these trials.

Stem cell stories that caught our eye: building an embryo and reviving old blood stem cells

Building an embryo in the lab from stem cells
The human body has been studied for centuries yet little is known about the first 14 days of human development when the fertilized embryo implants into the mother’s uterus and begins to divide and grow. Being able to precisely examine this critical time window may help researchers better understand why 75% of conceptions never implant and why 30% of pregnancies end in miscarriage.

This lack of knowledge is due in part to a lack of embryos to study. Researchers rely on embryos donated by couples who’ve gone through in vitro fertilization to get pregnant and have left over embryos that are otherwise discarded. Using mouse stem cells, a research team from Cambridge University reports today in Nature that they’ve generated a cellular structure that has the hallmarks of a fertilized embryo.

embryo

Stem cell-modeled mouse embryo (left) Mouse embryo (right); The red part is embryonic and the blue extra-embryonic.
Credit: Sarah Harrison and Gaelle Recher, Zernicka-Goetz Lab, University of Cambridge

This technique has been tried before without success. The breakthrough here was in the types of cells used. Rather that only relying on embryonic stems cells (ESCs), this study also included extra-embryonic trophoblast stem cells (TSCs), the cell type that goes on to form the placenta.

When grown on a 3D scaffold made from biological materials, the two cell types self-organized themselves into a pattern that closely resembles the early development of a true embryo. In a press release that was picked up by many media outlets, senior author Zernicka-Goetz spoke about the importance of including both TSCs and ESCs:

“We knew that interactions between the different types of stem cell are important for development, but the striking thing that our new work illustrates is that this is a real partnership – these cells truly guide each other. Without this partnership, the correct development of shape and form and the timely activity of key biological mechanisms doesn’t take place properly.”

The researchers think that lab-made embryos from mouse or human stem cells have little chance of developing into a fetus because other cell types critical for continued growth are not included. And there’s much to be learned by focusing on these very early events:

“We are very optimistic that this will allow us to study key events of this critical stage of human development without actually having to work on embryos.  Knowing how development normally occurs will allow us to understand why it so often goes wrong,” says Zernicka-Goetz.

Reviving old blood stem cells, part 1: repair the garbage collectors
One of the reasons that our bodies begin to deteriorate in old age is a weakening, dysfunctional immune system that increases the risk for serious infection, blood cancers and chronic inflammatory diseases like atherosclerosis (hardening of the arteries). Reporting this week in Nature, a UCSF research team presents evidence that a breakdown in our cell’s natural garbage collecting system may be partially to blame.

The team focused on a process called autophagy (literally meaning self “auto”-eating “phagy”) that keeps cells functioning properly by degrading faulty proteins and cellular structures. In particular, they examined autophagy in blood-forming stem cells, which give rise to all the cell types of the immune system. They found that autophagy was not working in 70 percent of blood stem cells from old mice. And these cells had all the hallmarks of an old cell. And the other 30 percent? In those cells, autophagy was fully functional and they looked like blood stem cells found in young mice.

The team went on to show that in blood stem cells, autophagy had an additional role that until now had not been observed: it helped slow the activity of the stem cells back to its default state by gobbling up excess mitochondria, the structures that produces a cell’s energy needs. Without this quieting of the stem cell, the over-active mitochondria led to chemical modification of the cell’s DNA that disrupted the blood stem cells’ ability to give rise to a proper balance of immune cells. In fact, young mice with genetic modifications that block autophagy generated blood stem cells with these old age-related characteristics.

But the researchers were also able to restore autophagy in blood stem cells collected from old mice by adding various drugs. Team lead Emmanuelle Passegué is optimistic this result could be translated into a therapeutic approach:

“This discovery might provide an interesting therapeutic angle to use in re-activating autophagy in all of the old HSCs, to slow the aging of the blood system and to improve engraftment during bone marrow or HSC transplantation,” Passegué said in a university press release.

Reviving old blood stem cells, part 2: fix the aging neighborhood
Another study this week focused on age-related disruptions in the function of blood stem cells but in this case an aging neighborhood is to blame. Blood stem cells form and hang out in areas of the bone marrow called niches. Researchers at the Cincinnati Children’s Hospital Medical Center and the University of Ulm in Germany reported this week in EMBO that the age of the niche affects blood stem cell function.

bonemarrow

Microscopy of bone marrow. Red staining indicates osteopotin, blue staining indicates cell nuclei. Credit: University of Ulm

 

When blood stem cells from two-year old mice were transplanted into the bone marrow of eight-week old mice, the older stem cells took on characteristics of young stem cells including an enhance ability to form all the different cell types of the immune system. In trying to understand what was going on, the researchers focused on a bone marrow cell called an osteoblast which gives rise to bone. Osteoblasts produce osteopontin, a protein that plays an important role in the structure of the bone marrow. The team showed that as the bone marrow ages, osteopontin levels go down. And this reduction had effects on the health of blood stem cells. But, as team lead Hartmut Geiger mentions in a press release, this impact could be reversed which points to a potential new therapeutic strategy for age-related disease:

“We show that the place where HSCs form in the bone marrow loses osteopontin upon aging, but if you give back the missing protein to the blood-forming cells they suddenly rejuvenate and act younger. Our study points to exciting novel ways to have a better immune system and possibly less blood cancer upon aging by therapeutically targeting the place where blood stem cells form.”

Partnering with the best to help find cures for rare diseases

As a state agency we focus most of our efforts and nearly all our money on California. That’s what we were set up to do. But that doesn’t mean we don’t also look outside the borders of California to try and find the best research, and the most promising therapies, to help people in need.

Today’s meeting of the CIRM Board was the first time we have had a chance to partner with one of the leading research facilities in the country focusing on children and rare diseases; St. Jude Children’s Researech Hospital in Memphis, Tennessee.

a4da990e3de7a2112ee875fc784deeafSt. Jude is getting $11.9 million to run a Phase I/II clinical trial for x-linked severe combined immunodeficiency disorder (SCID), a catastrophic condition where children are born without a functioning immune system. Because they are unable to fight off infections, many children born with SCID die in the first few years of life.

St. Jude is teaming up with researchers at the University of California, San Francisco (UCSF) to genetically modify the patient’s own blood stem cells, hopefully creating a new blood system and repairing the damaged immune system. St. Jude came up with the method of doing this, UCSF will treat the patients. Having that California component to the clinical trial is what makes it possible for us to fund this work.

This is the first time CIRM has funded work with St. Jude and reflects our commitment to moving the most promising research into clinical trials in people, regardless of whether that work originates inside or outside California.

The Board also voted to fund researchers at Cedars-Sinai to run a clinical trial on ALS or Lou Gehrig’s disease. Like SCID, ALS is a rare disease. As Randy Mills, our President and CEO, said in a news release:

CIRM CEO and President, Randy Mills.

CIRM CEO and President, Randy Mills.

“While making a funding decision at CIRM we don’t just look at how many people are affected by a disease, we also look at the severity of the disease on the individual and the potential for impacting other diseases. While the number of patients afflicted by these two diseases may be small, their need is great. Additionally, the potential to use these approaches in treating other disease is very real. The underlying technology used in treating SCID, for example, has potential application in other areas such as sickle cell disease and HIV/AIDS.”

We have written several blogs about the research that cured children with SCID.

The Board also approved funding for a clinical trial to develop a treatment for type 1 diabetes (T1D). This is an autoimmune disease that affects around 1.25 million Americans, and millions more around the globe.

T1D is where the body’s own immune system attacks the cells that produce insulin, which is needed to control blood sugar levels. If left untreated it can result in serious, even life-threatening, complications such as vision loss, kidney damage and heart attacks.

Researchers at Caladrius Biosciences will take cells, called regulatory T cells (Tregs), from the patient’s own immune system, expand the number of those cells in the lab and enhance them to make them more effective at preventing the autoimmune attack on the insulin-producing cells.

The focus is on newly-diagnosed adolescents because studies show that at the time of diagnosis T1D patients usually have around 20 percent of their insulin-producing cells still intact. It’s hoped by intervening early the therapy can protect those cells and reduce the need for patients to rely on insulin injections.

David J. Mazzo, Ph.D., CEO of Caladrius Biosciences, says this is hopeful news for people with type 1 diabetes:

David Mazzo

David Mazzo

“We firmly believe that this therapy has the potential to improve the lives of people with T1D and this grant helps us advance our Phase 2 clinical study with the goal of determining the potential for CLBS03 to be an effective therapy in this important indication.”

 


Related Links:

Stem Cell Stories that caught our eye: a womb with a view, reversing aging and stabilizing stem cells

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

Today we bring you a trifecta of stem cell stories that were partially funded by grants from CIRM.

A womb with a view: using 3D imaging to observe embryo implantation. Scientists have a good understanding of how the beginning stages of pregnancy happen. An egg cell from a woman is fertilized by a sperm cell from a man and the result is a single cell called a zygote. Over the next week, the zygote divides into multiple cells that form the developing embryo. At the end of that period, the embryo hatches out of its protective membrane and begins implanting itself into the lining of the mother’s uterus.

It’s possible to visualize the early stages of embryo development in culture dishes, which has helped scientists understand the biological steps required for an embryo to survive and develop into a healthy fetus. However, something that is not easy to observe is the implantation stage of the embryo in the uterus. This process is complex and involves a restructuring of the uterine wall to accommodate the developing embryo. As you can imagine, replicating these events would be extremely complicated and difficult to do in a culture dish, and current imaging techniques aren’t adequate either.

That’s where new CIRM-funded research from a team at UCSF comes to the rescue. They developed a 3D imaging technology and combined it with a previously developed “tissue clearing” method, which uses chemicals to turn tissues translucent, to provide clear images of the uterine wall during embryo implantation in mice. Their work was published this week in the journal Development.

According to a UCSF news release,

“Using their new approach, the team observed that the uterine lining becomes extensively folded as it approaches its window of receptivity for an embryo to implant. The geometry of the folds in which the incoming embryos dwell is important, the team found, as genetic mutants with defects in implantation have improper patterns of folding.”

Ultimately, the team aims to use their new imaging technology to get an inside scoop on how to prevent or treat pregnancy disorders and also how to improve the outcome of pregnancies by in vitro fertilization.

Senior author on the study, UCSF professor Diana Laird concluded:

“This new view of early pregnancy lets us ask fundamentally new questions about how the embryo finds its home within the uterus and what factors are needed for it to implant successfully. Once we can understand how these processes happen normally, we can also ask why certain genetic mutations cause pregnancies to fail, to study the potential dangers of environmental toxins such as the chemicals in common household products, and even why metabolic disease and obesity appears to compromise implantation.”

If you want to see this womb with a view, check out the video below.

Watch these two videos for more information:

Salk scientists reverse signs of aging in mice. For our next scintillating stem cell story, we’re turning back the clock – the aging clock that is. Scientists from the Salk Institute in La Jolla, reported an interesting method in the journal Cell  that reverses some signs of aging in mice. They found that periodic expression of embryonic stem cell genes in skin cells and mice could reverse some signs of aging.

The Salk team made use of cellular reprogramming tools developed by the Nobel Prize winning scientist Shinya Yamanaka. He found that four genes normally expressed in embryonic stem cells could revert adult cells back to a pluripotent stem cell state – a process called cellular reprogramming. Instead of turning adult cells back into stem cells, the Salk scientists asked whether the Yamanaka factors could instead turn back the clock on older, aging cells – making them healthier without turning them back into stem cells or cancer-forming cells.

The team found that they could rejuvenate skin cells from mice without turning them back into stem cells if they turned on the Yamanaka genes on for a short period of time. These skin cells were taken from mice that had progeria – a disease that causes them to age rapidly. Not only did their skin cells look and act younger after the treatment, but when the scientists used a similar technique to turn on the Yamanaka genes in progeria mice, they saw rejuvenating effects in the mice including a more rapid healing and regeneration of muscle and pancreas tissue.

(Left) impaired muscle repair in aged mice; (right) improved muscle regeneration in aged mice subjected to reprogramming. (Salk Institute)

(Left) impaired muscle repair in aged mice; (right) improved muscle regeneration in aged mice subjected to reprogramming. (Salk Institute)

The senior author on the study, Salk Professor Juan Carlos Izpisua Belmonte, acknowledged in a Salk news release that this is early stage work that focuses on animal models, not humans:

“Obviously, mice are not humans and we know it will be much more complex to rejuvenate a person. But this study shows that aging is a very dynamic and plastic process, and therefore will be more amenable to therapeutic interventions than what we previously thought.”

This story was very popular, which is not surprising as aging research is particularly fascinating to people who want to live longer lives. It was covered by many news outlets including STATnews, Scientific American and Science Magazine. I also recommend reading Paul Knoepfler’s journal club-style blog on the study for an objective take on the findings and implications of the study. Lastly, you can learn more about the science of this work by watching the movie below by the Salk.

Movie:

Stabilizing unstable stem cells. Our final stem cell story is brought to you by scientists from the UCLA Broad Stem Cell Research Center. They found that embryonic stem cells can harbor genetic instabilities that can be passed on to their offspring and cause complications, or even disease, later in life. Their work was published in two separate studies in Cell Stem Cell and Cell Reports.

The science behind the genetic instabilities is too complicated to explain in this blog, so I’ll refer you to the UCLA news release for more details. In brief, the UCLA team found a way to reverse the genetic instability in the stem cells such that the mature cells that they developed into turned out healthy.

As for the future impact of this research, “The research team, led by Kathrin Plath, found a way to correct the instability by resetting the stem cells from a later stage of development to an earlier stage of development. This fundamental discovery could have great impact on the creation of healthy tissues to cure disease.”

Stem cell stories that caught our eye: Blood stem cells on a diet, Bladder control after spinal cord injuries, new ALS insights

Putting blood stem cells on a diet. (Karen Ring)

valine

Valine. Image: BMRB

Scientists from Stanford and the University of Tokyo have figured out a new way to potentially make bone marrow transplants more safe. Published yesterday in the journal Science, the teams discovered that removing an essential amino acid, called valine, from the diets of mice depleted their blood stem cells and made it easier for them to receive bone marrow transplants from other mice without the need for radiation or chemotherapy. Removing valine from human blood stem cells yielded similar results suggesting that this therapeutic approach could potentially change and improve the way that certain cancer patients are treated.

In an interview with Science Magazine, senior author Satoshi Yamazaki explained how current bone marrow transplants are toxic to patients and that an alternative, safer form of treatment is needed.

“Bone marrow transplantation is a toxic therapy. We have to do it to treat diseases that would otherwise be fatal, but the quality of life afterward is often not good. Relative to chemotherapy or radiation, the toxicity of a diet deficient in valine seems to be much, much lower. Mice that have been irradiated look terrible. They can’t have babies and live for less than a year. But mice given a diet deficient in valine can have babies and will live a normal life span after transplantation.”

The scientists found that the effects of a valine-deficient diet were mostly specific to blood stem cells in the mice, but also did affect hair stem cells and some T cells. The effects on these other populations of cells were not as dramatic however as the effects on blood stem cells.

Going forward, the teams are interested to find out whether valine deficiency will be a useful treatment for leukemia stem cells, which are stem cells that give rise to a type of blood cancer. As mentioned before, this alternative form of treatment would be very valuable for certain cancer patients in comparison to the current regimen of radiation treatment before bone marrow transplantation.

Easing pain and improving bladder control in spinal cord injury (Kevin McCormack)
When most people think of spinal cord injuries (SCI) they focus on the inability to walk. But for people with those injuries there are many other complications such as intense nerve or neuropathic pain, and inability to control their bladder. A CIRM-funded study from researchers at UCSF may help point at a new way of addressing those problems.

The study, published in the journal Cell Stem Cell, zeroed in on the loss in people with SCI of a particular amino acid called GABA, which acts as a neurotransmitter in the central nervous system and inhibits nerve transmission in the brain, calming nervous activity.

Here’s where we move into alphabet soup, but stick with me. Previous studies showed that using cells called inhibitory interneuron precursors from the medial ganglionic eminence (MGE) helped boost GABA signaling in the brain and spinal cord. So the researchers turned some human embryonic stem cells (hESCs) into MGEs and transplanted those into the spinal cords of mice with SCI.

Six months after transplantation those cells had integrated into the mice’s spinal cord, and the mice not only showed improved bladder function but they also seemed to have less pain.

Now, it’s a long way from mice to men, and there’s a lot of work that has to be done to ensure that this is safe to try in people, but the researchers conclude: “Our findings, therefore, may have implications for the treatment of chronically spinal cord-injured patients.”

CIRM-funded study reveals potential new ALS drug target (Todd Dubnicoff)
Of the many diseases CIRM-funded researchers are tackling, Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s Disease, has got to be one of the worst.

yeo_healthy_ipsc_derived_mo

Motor neurons derived from skin cells of a healthy donor
Image: UC San Diego

This neurodegenerative disorder attacks and kills motor neurons, the nerve cells that control voluntary muscle movement. People diagnosed with ALS, gradually lose the ability to move their limbs, to swallow and even to breathe. The disease is always fatal and people usually die within 3 to 5 years after initial diagnosis. There’s no cure for ALS mainly because scientists are still struggling to fully understand what causes it.

Stem cell-derived “disease in a dish” experiments have recently provided many insights into the underlying biology of ALS. In these studies, skin cells from ALS patients are reprogrammed into an embryonic stem cell-like state called induced pluripotent stem cells (iPSCS). These iPS cells are grown in petri dishes and then specialized into motor neurons, allowing researchers to carefully look for any defects in the cells.

This week, a UC San Diego research team using this disease in a dish strategy reported they had uncovered a cellular process that goes haywire in ALS cells. The researchers generated motor neurons from iPS cells that had been derived from the skin samples of ALS patients with hereditary forms of the disease as well as samples from healthy donors. The team then compared the activity of thousands of genes between the ALS and healthy motor neurons. They found that a particular hereditary mutation doesn’t just impair a protein called hnRNP A2/B1, it actually gives the protein new toxic activities that kill off the motor neurons.

Fernando Martinez, the first author on this study in Neuron, told the UC San Diego Health newsroom that these news results reveal an important context for their on-going development of therapeutics that target proteins like hnRNP:

“These … therapies [targeting hnRNP] can eliminate toxic proteins and treat disease. But this strategy is only viable if the proteins have gained new toxic functions through mutation, as we found here for hnRNP A2/B1 in these ALS cases.”

Stem cell stories that caught our eye: healing diabetic ulcers, new spinal cord injury insights & an expanding CRISPR toolbox

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

Stem cells heal diabetic foot ulcers in pilot study
Foot ulcers are one of the many long-term complications that diabetics face. About 15 percent of patients develop these open sores which typically appear at the bottom of the foot. In a quarter of these cases, the ulcers lead to serious infection requiring amputation.

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Diabetic foot ulcers are open sores that don’t heal and in many cases leads to amputation. Image source: Izunpharma

But help may be on the horizon in the form of stem cells. Researchers at Mansoura University in Egypt recently presented results of a small study in which 10 patients with diabetic foot ulcers received standard care and another 10 patients received standard care plus injections of mesenchymal stem cells that had been collected from each patient’s own bone marrow. After just six weeks, the stem cell treated group showed a 50% reduction in the foot ulcers while the group with only standard care had a mere 7% reduction.

These superior results with the stem cells were observed even though the group receiving the stem cells had larger foot ulcers to begin with compared to the untreated patients. There are many examples of mesenchymal stem cells’ healing power which make them an extremely popular cell source for hundreds of on-going clinical trials. Mesenchymal stem cells are known to reduce inflammation and increase blood vessel formation, two properties that may be at work to give diabetic foot ulcers the chance to get better.

Medscape Medical News reported on these results which were presented at the 2016 annual meeting of the European Association for the Study of Diabetes (EASD) 2016 Annual Meeting

Suppressing nerve signals to help spinal cord injury victims
Losing the use of one’s limbs is a profound life-altering change for spinal cord injury victims. But their quality of life also suffers tremendously from the loss of bladder control and chronic pain sensations. So much so, victims often say that just improving these secondary symptoms would make a huge improvement in their lives.

While current stem cell-based clinical trials, like the CIRM-funded Asterias study, aim to reverse paralysis by restoring loss nerve signals, recent CIRM-funded animal data published in Cell Stem Cell from UC San Francisco suggest that nerve cells that naturally suppress nerve signals may be helpful for these other symptoms of spinal cord injury.

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Mature inhibitory neuron derived from human embryonic stem cells is shown after successfully migrated and integrated into the injured mouse spinal cord.
Photo by Jiadong Chen, UCSF

It turns out that the bladder control loss and chronic pain may be due to overactive nerve signals. So the lab of Arnold Kriegstein transplanted inhibitory nerve cells – derived from human embryonic stem cells – into mice with spinal cord injuries. The scientists observed that these human inhibitory nerve cells, or interneurons, successfully made working connections in the damaged mouse spinal cords. The rewiring introduced by these interneurons also led to reduced pain behaviors in the mice as well as improvements in bladder control.

 

 

In a Yahoo Finance interview, Kreigstein told reporters he’s eager to push forward with these intriguing results:

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Arnold Kriegstein, UCSF

“As a clinician, I’m very aware of the urgency that’s felt among patients who are often very desperate for treatment. As a result, we’re very interested in accelerating this work toward clinical trials as soon as possible, but there are many steps along the way. We have to demonstrate that this is safe, as well as replicating it in other animals. This involves scaling up the production of these human interneurons in a way that would be compatible with a clinical product.”

 

Expanding the CRISPR toolbox
If science had a fashion week, the relatively new gene editing technology called CRISPR/Cas9 would be sure to dominate the runway. You can think of CRISPR/Cas9 as a protein and RNA complex that acts as a molecular scissor which directly targets and cuts specific sequences of DNA in the human genome. Scientists are using CRISPR/Cas9 to develop innovative biomedical techniques such as removing disease-causing mutations in stem cells in hopes of developing potential treatments for patients suffering from diseases that have no cures.

What’s particularly interesting about the CRISPR/Cas9 system is that the Cas9 protein responsible for cutting DNA is part of a family of CRISPR associated proteins (Cas) that have similar but slightly different functions. Scientists are currently expanding the CRISPR toolbox by exploring the functions of other CRISPR associated proteins for gene editing applications.

A CIRM-funded team at UC Berkeley is particularly interested in a CRISPR protein called C2c2, which is different from Cas9 in that it targets and cuts RNA rather than DNA. Led by Berkeley professor Jennifer Doudna, the team discovered that the CRISPR/C2c2 complex has not just one, but two, distinct ways that it cuts RNA. Their findings were published this week in the journal Nature.

The first way involves creation: C2c2 helps make the guide RNAs that are used to find the RNA molecules that it wants to cut. The second way involves destruction: after the CRISPR/C2c2 complex finds it’s RNAs of choice, C2c2 can then cut and destroy the RNAs.

Doudna commented on the potential applications for this newly added CRISPR tool in a Berkeley News release:

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Jennifer Doudna: Photo courtesy of iPSCell.com

“This study expands our molecular understanding of C2c2 to guide RNA processing and provides the first application of this novel RNase. C2c2 is essentially a self-arming sentinel that attacks all RNAs upon detecting its target. This activity can be harnessed as an auto-amplifying detector that may be useful as a low-cost diagnostic.”

 

Beige isn’t bland when it comes to solving the obesity epidemic

Americans spend over $60 billion a year to lose weight and yet two-thirds (that’s more than 200 million) are considered overweight or obese. Losing weight should be easy: just eat less and exercise more, right? But our body’s metabolism is a very complex thing and appears to fight against our best efforts to shed pounds. A recent analysis of clinical trial data and mathematical modeling suggests that over the long haul, none of the various diet strategies lead to meaningful weight loss. Even the contribution of exercise to weight loss has been called into question.

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Lose weight by simply eating less calories than you burn. Easier said than done! (Image credit)

All is not lost. In fact, the fat we carry in our bodies may hold the key to overcoming our obesity woes. A recent CIRM-funded UC Francisco study published in Cell Metabolism finds that harnessing a calorie burning form of fat cells may help guard against the development of obesity.

The Many Hues of Fat
Humans, like other mammals, have two very different types of fat tissue. The more abundant white fat acts to store fat and provides a form of energy to help our body function. An excess of white fat tissue is associated with metabolic diseases including diabetes and obesity. Brown fat tissue, on the other hand, generates heat and is associated with slimness. It was thought that only babies have brown fat which protects them against cold temperatures – they lack the muscle strength for the shivering response – but research in 2009 identified this fat tissue in adults as well.

The UCSF team, led by professor Shingo Kajimura, showed last year that adults actually have so-called beige fat cells that are able to switch from white to brown fat in the presence of colder temperatures and vice versa. This discovery presents the tantalizing potential of promoting weight loss in people by pushing white fat cells toward energy burning brown fat. In that earlier work, the team identified a protein that when inhibited with drugs caused the white fat cells to burn energy like the beige and brown fat. But this effect was short lived and these cells reverted back to the typical features of white fat cells. Kajimura reflected on these previous studies in a university press release:

“Our focus has been on learning to convert white fat into beige fat. Now we’re realizing we also have to think about how to keep it there for longer time.”

In the new study, the team focused on the fact that as beige cells revert back to white cells, their mitochondria – a cell’s energy producing factories – begin to disappear. First author Svetlana Altshuler-Keylin wanted to understand why:

“We knew that the color of brown and beige fat comes from the amount of pigmented mitochondria they contain, so we wondered whether something was going on with the mitochondria when beige fat turns white.”

Stopping cells from eating up too much mitochondria
Examining gene activity as cells went from beige to white implicated a process called autophagy was at play. This house cleaning function of a cell involves the breakdown of its own internal structures that are not functioning properly or aren’t needed. So perhaps stopping the autophagy process from occurring would prevent the energy burning beige cells from eating up their own mitochondria and reverting them back to the energy hoarding white cells.

To test this idea, the team relied on mice lacking genes that play important roles in autophagy. They beefed up their beige fat by subjecting the mice to cold temperatures. But when returned to a normal environment, the mice kept their beige fat and it didn’t convert back to white cells. This change impacted the mice overall health: when place on a fatty diet for two months these mice with the defective autophagy gained less weight. These mice were also able to better regulate blood sugar levels, an indication they there were protected from type 2 diabetes symptoms.

While these results represent very early stage research, Kajimura and his team now have a solid path to travel toward trying to help obese individual burn more calories, especially as they age:

“With age you tend to naturally lose your beige fat, which we think is one of the main drivers of age-related obesity. Your calorie intake stays the same, but you’re not burning as much. Maybe by understanding this process we can help people keep more beige fat, and therefore stay healthier.”

Young Minds Shine Bright at the CIRM SPARK Conference

SPARK students take a group photo with CIRM SPARK director Karen Ring.

SPARK students take a group photo with CIRM SPARK director Karen Ring.

Yesterday was one of the most exciting and inspiring days I’ve had at CIRM since I joined the agency one year ago. We hosted the CIRM SPARK conference which brought together fifty-five high school students from across California to present their stem cell research from their summer internships.

The day was a celebration of their accomplishments. But it was also a chance for the students to hear from scientists, patient advocates, and clinicians about the big picture of stem cell research: to develop stem cell treatments and cures for patients with unmet medical needs.

Since taking on the role of the CIRM SPARK director, I’ve been blown away by the passion, dedication, and intelligence that our SPARK interns have shown during their short time in the lab. They’ve mastered techniques and concepts that I only became familiar with during my PhD and postdoctoral research. And even more impressive, they eloquently communicated their research through poster presentations and talks at the level of professional scientists.

During their internships, SPARK students were tasked with documenting their research experiences through blogs and social media. They embraced this challenge with gusto, and we held an awards ceremony to recognize the students who went above and beyond with these challenges.

I’d like to share the winning blogs with our readers. I hope you find them as inspiring and motivating as I do. These students are our future, and I look forward to the day when one of them develops a stem cell treatment that changes the lives of patients. 

Andrew Choi

Andrew Choi

Andrew Choi, Cedars-Sinai SPARK student

Am I crying or is my face uncontrollably sweating right now? I think I am doing both as I write about my unforgettable experiences over the course of the past 6 weeks and finalize my poster.

As I think back, I am very grateful for the takeaways of the research field, acquiring them through scientific journals, lab experiments with my mentor, and both formal and informal discourses. It seems impossible to describe all the episodes and occurrences during the program in this one blog post, but all I can say is that they were all unique and phenomenal in their own respective ways.

Gaining new perspectives and insights and being acquainted with many of the techniques, such as stereology, immunocytochemistry and immunohistochemistry my peers have utilized throughout their careers, proved to me the great impact this program can make on many individuals of the younger generation.

CIRM SPARK not only taught me the goings on behind the bench-to-bedside translational research process, but also morals, work ethics, and effective collaboration with my peers and mentors. My mentor, Gen, reiterated the importance of general ethics. In the process of making my own poster for the program, her words resonate even greater in me. Research, education, and other career paths are driven by proper ethics and will never continue to progress if not made the basic standard.

I am thankful for such amazing institutions: California Institute of Regenerative Medicine (CIRM) and Cedars-Sinai Medical Center for enabling me to venture out into the research career field and network. Working alongside with my fellow seven very brilliant friends, motivated me and made this journey very enjoyable. I am especially thankful my mentor, Gen, for taking the time to provide me with the best possible resources, even with her busy ongoing projects. She encouraged me to be the best that I am.

I believe, actually, I should say, I KNOW Cedars-Sinai’s CIRM SPARK program does a SUPERB and astounding job of cultivating life-long learners and setting exceptional models for the younger generation. I am hoping that many others will partake in this remarkable educational program.

I am overall very blessed to be part of a successful summer program. The end of this program does not mark the end of my passions, but sparks them to even greater heights.

Jamey Guzman

Jamey Guzman

Jamey Guzman, UC Davis SPARK student

When I found out about this opportunity, all I knew was that I had a fiery passion for learning, for that simple rush that comes when the lightbulb sputters on after an unending moment of confusion. I did not know if this passion would translate into the work setting; I sometimes wondered if passion alone would be enough to allow me to understand the advanced concepts at play here. I started at the lab nervous, tentative – was this the place for someone so unsure exactly what she wanted to be ‘when she grew up,’ a date now all too close on the horizon? Was I going to fit in at this lab, with these people who were so smart, so busy, people fighting for their careers and who had no reason to let a 16-year-old anywhere near experiments worth thousands of dollars in cost and time spent?

I could talk for hours about the experiments that I worked to master; about the rush of success upon realizing that the tasks now completed with confidence were ones that I had once thought only to belong to the lofty position of Scientist. I could fill pages and pages with the knowledge I gained, a deep and personal connection to stem cells and cell biology that I will always remember, even if the roads of Fate pull me elsewhere on my journey to a career.

The interns called the experience #CIRMSparkLab in our social media posts, and I find this hashtag so fitting to describe these last few months. While there was, of course, the lab, where we donned our coats and sleeves and gloves and went to work with pipets and flasks…There was also the Lab. #CIRMSparkLab is so much more than an internship; #CIRMSparkLab is an invitation into the worldwide community of learned people, a community that I found to be caring and vibrant, creative and funny – one which for the first time I can fully imagine myself joining “when I grow up.”

#CIRMSparkLab is having mentors who taught me cell culture with unerring patience and kindness. It is our team’s lighthearted banter across the biosafety cabinet; it is the stories shared of career paths, of goals for the present and the future. It is having mentors in the best sense of the word, trusting me, striving to teach and not just explain, giving up hours and hours of time to draw up diagrams that ensured that the concepts made so much sense to me.

#CIRMSparkLab is the sweetest ‘good-morning’ from scientists not even on your team, but who care enough about you to say hi, to ask about your projects, to share a smile. It is the spontaneity and freedom with which knowledge is dispensed: learning random tidbits about the living patterns of beta fish from our lab manager, getting an impromptu lecture about Time and the Planck Constant from our beloved professor as he passes us at lunch. It is getting into a passionate, fully evidence-backed argument about the merits of pouring milk before cereal that pitted our Stem Cell team against our Exosome team: #CIRMSparkLab is finding a community of people with whom my “nerdy” passion for learning does not leave me an oddball, but instead causes me to connect instantly and deeply with people at all ages and walks of life. And it is a community that, following the lead of our magnificent lab director, welcomed ten interns into their lab with open arms at the beginning of this summer, fully cognizant of the fact that we will break beakers, overfill pipet guns, drop gels, bubble up protein concentration assays, and all the while never stop asking, “Why? Why? Why? Is this right? Like this? WHY?”

I cannot make some sweeping statement that I now know at age 16 exactly what I want to do when I grow up. Conversely, to say I learned so much – or I am so grateful – or you have changed my life is simply not enough; words cannot do justice to those sentiments which I hope that all of you know already. But I can say this: I will never forget how I felt when I was at the lab, in the community of scientists. I will take everything I learned here with me as I explore the world of knowledge yet to be obtained, and I will hold in my heart everyone who has helped me this summer. I am truly a better person for having known all of you.

Thank you, #CIRMSparkLab. 

Adriana Millan

Adriana Millan

Adriana Millan, CalTech SPARK student

As children, we all grew up with the companionship of our favorite television shows. We enjoyed sitcoms and other animations throughout our childhood and even as adults, there’s no shame. The goofy and spontaneous skits we enjoyed a laugh over, yet we did not pay much attention to the lessons they attempted to teach us. As a child, these shows play crucial roles in our educational endeavors. We are immediately hooked and tune in for every episode. They spark curiosity, as they allow our imaginations to run wild. For me, that is exactly where my curiosity stemmed and grew for science over the years. A delusional young girl, who had no idea what the reality of science was like.

You expect to enter a lab and run a full day of experimentations. Accidentally mix the wrong chemicals and discover the cure for cancer. Okay, maybe not mix the incorrect chemicals together, I learned that in my safety training class. The reality is that working in a lab was far from what I expected — eye opening. Working alongside my mentor Sarah Frail was one of the best ways I have spent a summer. It was not my ideal summer of sleeping in until noon, but it was worthwhile.

My experience is something that is a part of me now. I talk about it every chance I get, “Mom, can you believe I passaged cells today!” It changed the way I viewed the principles of science. Science is one of the most valuable concepts on this planet, it’s responsible for everything and that’s what I have taken and construed from my mentor. She shared her passion for science with me and that completed my experience. Before when I looked at cells, I did not know exactly what I was supposed to observe. What am I looking at? What is that pink stuff you are adding to the plate?

However, now I feel accomplished. It was a bit of a roller coaster ride, with complications along the way, but I can say that I’m leaving this experience with a new passion. I am not just saying this to please the audience, but to express my gratitude. I would have never even looked into Huntington’s Disease. When I first arrived I was discombobulated. Huntington’s Disease? Now I can proudly say I have a grasp on the complexity of the disease and not embarrass my mentor my calling human cells bacteria – quite embarrassing in fact.  I’m a professional pipette handler, I work well in the hood, I can operate a microscope – not so impressive, I have made possibly hundreds of gels, I have run PCRs, and my cells love me, what else can I ask for.

If you are questioning what career path you are to take and even if it is the slightest chance it may be a course in science, I suggest volunteering in a lab. You will leave with your questioned answered. Is science for me? This is what I am leaving my experience with. Science is for me.

Other SPARK 2016 Awards

Student Speakers: Jingyi (Shelly) Deng (CHORI), Thomas Thach (Stanford)

Poster Presentations: Jerusalem Nerayo (Stanford), Jared Pollard (City of Hope), Alina Shahin (City of Hope), Shuling Zhang (UCSF)

Instagram Photos: Roxanne Ohayon (Stanford), Anna Victoria Serbin (CHORI), Diana Ly (UC Davis)

If you want to see more photos from the CIRM SPARK conference, check out our Instagram page @CIRM_Stemcells or follow the hashtag #CIRMSPARKLab on Instagram and Twitter.

California high schoolers SPARK interest in stem cell research through social media

I have a job for you today and it’s a fun one. Open your Instagram app on your phone. If you’re not an Instagrammer, don’t worry, you can access the website on your computer.

Do you have it open? OK now type in the hashtag #CIRMSparkLab and click on it.

What you’ll find is around 200 posts of the most inspiring and motivating pictures of stem cell research that I’ve seen. These pictures are from high school students currently participating in the CIRM summer SPARK program, one of our educational programs, which has the goal to train the next generation of stem cell scientists.

The SPARK program offers California high school students an invaluable opportunity to gain hands-on training in regenerative medicine at some of the finest stem cell research institutes in the state. And while they gain valuable research skills, we are challenging them to share their experiences with the general public through blogging and social media.

Communicating science to the public is an important mission of CIRM, and the SPARK students are excelling at this task by posting descriptive photos on Instagram that document their internships. Some of them are fun lab photos, while others are impressive images of data with detailed explanations about their research projects.

Below are a few of my favorite posts so far this summer. I’ve been so inspired by the creativity of these posts that we are now featuring some of them on the @CIRM_Stemcells account. (Yes this is a shameless plug for you to follow us on Instagram!).

City of Hope SPARK program.

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I encourage you all to follow our talented SPARK students this summer as they continue to document their exciting journeys on Instagram. These students are our future and supporting their training and education in stem cell research is an honor for CIRM and a vital step towards achieving our mission of accelerating stem cell treatments to patients with unmet medical needs.

Stay tuned for more blog coverage about SPARK and our other educational program, the Bridges to Stem Cell Research program for undergraduate and master-level students. The annual Bridges conference that brings all the students together to present their research will be held next week, and the SPARK conference is on August 8th both in Berkeley.