Stem Cell Roundup: Lab-grown meat, stem cell vaccines for cancer and a free kidney atlas for all

Here are the stem cell stories that caught our eye this week.

Cool Stem Cell Photo: Kidneys in the spotlight

At an early stage, a nephron forming in the human kidney generates an S-shaped structure. Green cells will generate the kidneys’ filtering device, and blue and red cells are responsible for distinct nephron activities. (Image/Stacy Moroz and Tracy Tran, Andrew McMahon Lab, USC Stem Cell)

I had to take a second look at this picture when I first saw it. I honestly thought it was someone’s scientific interpretation of Vincent van Gogh’s Starry Night. What this picture actually represents is a nephron. Your kidney has over a million nephrons packed inside it. These tiny structures filter our blood and remove waste products by producing urine.

Scientists at USC Stem Cell are studying kidney development in animals and humans in hopes of gaining new insights that could lead to improved stem cell-based technologies that more accurately model human kidneys (by coincidence, we blogged about another human kidney study on Tuesday). Yesterday, these scientists published a series of articles in the Journal of American Society of Nephrology that outlines a new, open-source kidney atlas they created. The atlas contains a catalog of high resolution images of different structures representing the developing human kidney.

CIRM-funded researcher Andrew McMahon summed it up nicely in a USC news release:

“Our research bridges a critical gap between animal models and human applications. The data we collected and analyzed creates a knowledge-base that will accelerate stem cell-based technologies to produce mini-kidneys that accurately represent human kidneys for biomedical screening and replacement therapies.”

And here’s a cool video of a developing kidney kindly provided by the authors of this study.

Video Caption: Kidney development begins with a population of “progenitor cells” (green), which are similar to stem cells. Some progenitor cells (red) stream out and aggregate into a ball, the renal vesicle (gold). As each renal vesicle grows, it radically morphs into a series of shapes — can you spot the two S-shaped bodies (green-orange-pink structures)? – and finally forms a nephron. Each human kidney contains one million mature nephrons, which form an expansive tubular network (white) that filters the blood, ensuring a constant environment for all of our body’s functions. (Video courtesy of Nils Lindstorm, Andy McMahon, Seth Ruffins and the Microscopy Core Facility at the Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at the Keck School of Medicine of USC)


Lab-grown hamburgers coming to a McDonald’s near you…

“Lab-grown meat is coming, whether you like it or not” sure makes a splashy headline! This week, Wired magazine featured two Bay Area startup companies, Just For All and Finless Foods, dedicated to making meat-in-a-dish in hopes of one day reducing our dependence on livestock. The methods behind their products aren’t exactly known. Just For All is engineering “clean meat” from cells. On the menu currently are cultured chorizo, nuggets, and foie gras. I bet you already guessed what Finless Foods specialty is. The company is isolating stem-like muscle progenitor cells from fish meat in hopes of identifying a cell that will robustly create the cell types found in fish meat.

Just’s tacos made with lab-grown chorizo. (Wired)

I find the Wired article particularly interesting because of the questions and issues Wired author Matt Simon raises. Are clean meat companies really more environmentally sustainable than raising livestock? Currently, there isn’t enough data to prove this is the case, he argues. And what about the feasibility of convincing populations that depend on raising livestock for a living to go “clean”? And what about flavor and texture? Will people be willing to eat a hamburger that doesn’t taste and ooze in just the right way?

As clean meat technologies continue to advance and become more affordable, I’ll be interested to see what impact they will have on our eating habits in the future.


Induced pluripotent stem cells could be the next cancer vaccine

Our last story is about a new Cell Stem Cell study that suggests induced pluripotent stem cells (iPSCs) could be developed into a vaccine against cancer. CIRM-funded scientist Joseph Wu and his team at Stanford University School of Medicine found that injecting iPSCs into mice that were transplanted with breast cancer cells reduced the formation of tumors.

The team dug deeper and discovered that iPSCs shared similarities with cancer cells with respect to the panel of genes they express and the types of proteins they carry on their cell surface. This wasn’t surprising to them as both cells represent an immature development stage. Because of these similarities, injecting iPSCs primed the mouse’s immune system to recognize and reject similar cells like cancer cells.

The team will next test their approach on human cancer cells in the lab. Joseph Wu commented on the potential future of iPSC-based vaccines for cancer in a Stanford news release:

“Although much research remains to be done, the concept itself is pretty simple. We would take your blood, make iPS cells and then inject the cells to prevent future cancers. I’m very excited about the future possibilities.”

 

Seeing is believing. Proof a CIRM-funded therapy is making a difference

ThelmaScreenShotFB

Thelma, participant in the CAMELLIA clinical trial

You have almost certainly never heard of Thelma, or met her, or know anything about her. She’s a lady living in England who, if it wasn’t for a CIRM-funded therapy, might not be living at all. She’s proof that what we do, is helping people.

Thelma is featured in a video about a treatment for acute myeloid leukemia, one of the most severe forms of blood cancer. Thelma took part in a clinical trial, called CAMELLIA, at Oxford Cancer Centre in Oxford, UK. The clinical trial uses a therapy that blocks a protein called CD47 that is found on the surface of cancer cells, including cancer stem cells which can evade traditional therapies. The video was shot to thank the charity Bloodwise for raising the funds to pay for the trial.

Prof. Paresh Vyas of Oxford University, who was part of the clinical trial team that treated Thelma, says patients with this condition face long odds.

“Patients with acute myeloid leukemia have the most aggressive blood cancer. We really haven’t had good treatments for this condition for the last 40 years.”

While this video was shot in England, featuring English nurses and doctors and patients, the therapy itself was developed here in California, first at Stanford University under the guidance of Irv Weissman and, more recently, at Forty Seven Inc. That company is now about to test their approach in a CIRM-funded clinical trial here in the US.

This is an example of how CIRM doesn’t just fund research, we invest in it. We help support it at every stage, from the earliest research through to clinical trials. Without our early support this work may not have made it this far.

The Forty Seven Inc. therapy uses the patient’s own immune system to help fight back against cancer stem cells. It’s looking very promising. But you don’t have to take our word for it. Take Thelma’s.

Creating a platform to help transplanted stem cells survive after a heart attack

heart

Developing new tools to repair damaged hearts

Repairing, even reversing, the damage caused by a heart attack is the Holy Grail of stem cell researchers. For years the Grail seemed out of reach because the cells that researchers transplanted into heart attack patients didn’t stick around long enough to do much good. Now researchers at Stanford may have found a way around that problem.

In a heart attack, a blockage cuts off the oxygen supply to muscle cells. Like any part of our body starved off oxygen the muscle cells start to die, and as they do the body responds by creating a layer of scars, effectively walling off the dead tissue from the surviving healthy tissue.  But that scar tissue makes it harder for the heart to effectively and efficiently pump blood around the body. That reduced blood flow has a big impact on a person’s ability to return to a normal life.

In the past, efforts to transplant stem cells into the heart had limited success. Researchers tried pairing the cells with factors called peptides to help boost their odds of surviving. That worked a little better but most of the peptides were also short-lived and weren’t able to make a big difference in the ability of transplanted cells to stick around long enough to help the heart heal.

Slow and steady approach

Now, in a CIRM-funded study published in the journal Nature Biomedical Engineering, a team at Stanford – led by Dr. Joseph Wu – believe they have managed to create a new way of delivering these cells, one that combines them with a slow-release delivery mechanism to increase their chances of success.

The team began by working with a subset of bone marrow cells that had been shown in previous studies to have what are called “pro-survival factors.” Then, working in mice, they identified three peptides that lived longer than other peptides. That was step one.

Step two involved creating a matrix, a kind of supporting scaffold, that would enable the researchers to link the three peptides and combine them with a delivery system they hoped would produce a slow release of pro-survival factors.

Step three was seeing if it worked. Using fluorescent markers, they were able to show, in laboratory tests, that unlinked peptides were rapidly released over two or three days. However, the linked peptides had a much slower release, lasting more than 15 days.

Out of the lab and into animals

While these petri dish experiments looked promising the big question was could this approach work in an animal model and, ultimately, in people. So, the team focused on cardiac progenitor cells (CPCs) which have shown potential to help repair damaged hearts, but which also have a low survival rate when transplanted into hearts that have experienced a heart attack.

The team delivered CPCs to the hearts of mice and found the cells without the pro-survival matrix didn’t last long – 80 percent of the cells were gone four days after they were injected, 90 percent were gone by day ten. In contrast the cells on the peptide-infused matrix were found in large numbers up to eight weeks after injection. And the cells didn’t just survive, they also engrafted and activated the heart’s own survival pathways.

Impact on heart

The team then tested to see if the treatment was helping improve heart function. They did echocardiograms and magnetic resonance imaging up to 8 weeks after the transplant surgery and found that the mice treated with the matrix combination had a statistically improved left ventricular function compared to the other mice.

Jayakumar Rajadas, one of the authors on the paper told CIRM that, because the matrix was partly made out of collagen, a substance the FDA has already approved for use in people, this could help in applying for approval to test it in people in the future:

“This paper is the first comprehensive report to demonstrate an FDA-compliant biomaterial to improve stem cell engraftment in the ischemic heart. Importantly, the biomaterial is collagen-based and can be readily tested in humans once regulatory approval is obtained.”

 

Modeling the Human Brain in 3D

(Image from Pasca Lab, Stanford University)

Can you guess what the tiny white balls are in this photo? I’ll give you a hint, they represent the organ that you’re using right now to answer my question.

These are 3D brain organoids generated from human pluripotent stem cells growing in a culture dish. You can think of them as miniature models of the human brain, containing many of the brain’s various cell types, structures, and regions.

Scientists are using brain organoids to study the development of the human nervous system and also to model neurological diseases and psychiatric disorders. These structures allow scientists to dissect the inner workings of the brain – something they can’t do with living patients.

Brain-in-a-Dish

Dr. Sergiu Pasca is a professor at Stanford University who is using 3D cultures to understand human brain development. Pasca and his lab have previously published methods to make different types of brain organoids from induced pluripotent stem cells (iPSCs) that recapitulate human brain developmental events in a dish.

Sergiu Pasca, Stanford University (Image credit: Steve Fisch)

My colleague, Todd Dubnicoff, blogged about Pasca’s research last year:

“Using brain tissue grown from patient-derived iPSCs, Dr. Sergiu Pasca and his team recreated the types of nerve cell circuits that form during the late stages of pregnancy in the fetal cerebral cortex, the outer layer of the brain that is responsible for functions including memory, language and emotion. With this system, they observed irregularities in the assembly of brain circuitry that provide new insights into the cellular and molecular causes of neuropsychiatric disorders like autism.”

Pasca generated brain organoids from the iPSCs of patients with a genetic disease called Timothy Syndrome – a condition that causes heart problems and some symptoms of autism spectrum disorder in children. By comparing the nerve cell circuits in patient versus healthy brain organoids, he observed a disruption in the migration of nerve cells in the organoids derived from Timothy Syndrome iPSCs.

“We’ve never been able to recapitulate these human-brain developmental events in a dish before,” said Pasca in a press release, “the process happens in the second half of pregnancy, so viewing it live is challenging. Our method lets us see the entire movie, not just snapshots.”

The Rise of 3D Brain Cultures

Pasca’s lab is just one of many that are working with 3D brain culture technologies to study human development and disease. These technologies are rising in popularity amongst scientists because they make it possible to study human brain tissue in normal and abnormal conditions. Brain organoids have also appeared in the mainstream news as novel tools to study how epidemics like the Zika virus outbreak affect the developing fetal brain (more here and here).

While these advances are exciting and promising, the field is still in its early stages and the 3D organoid models are far from perfect at representing the complex biology of the human brain.

Pasca addresses the progress and the hurdles of 3D brain cultures in a review article titled “The rise of three-dimensional brain cultures” published this week in the journal Nature. The article, describes in detail how pluripotent stem cells can assemble into structures that represent different regions of the human brain allowing scientists to observe how cells interact within neural circuits and how these circuits are disrupted by disease.

The review goes on to compare different approaches for creating 3D brain cultures (see figure below) and their different applications. For instance, scientists are culturing organoids on microchips (brains-on-a-chip) to model the blood-brain barrier – the membrane structure that protects the brain from circulating pathogens in the blood but also makes drug delivery to brain very challenging. Brain organoids are also being used to screen for new drugs and to model complex diseases like Alzheimer’s.

Human pluripotent stem cells, adult stem cells or cancer cells  can be used to derive microfluidics-based organs-on-a-chip (top), undirected organoids (middle), and region-specific brain organoids or organ spheroids (bottom). These 3D cultures can be manipulated with CRISPR-Cas9 genome-editing technologies, transplanted into animals or used for drug screening. (Pasca, Nature)

Pasca ends the review by identifying the major hurdles facing 3D brain culture technologies. He argues that “3D cultures only approximate the appearance and architecture of neural tissue” and that the cells and structures within these organoids are not always predictable. These issues can be address over time by enforcing quality control in how these 3D cultures are made and by using new biomaterials that enable the expansion and maturation of these cultures.

Nonetheless, Pasca believes that 3D brain cultures combined with advancing technologies to study them have “the potential to give rise to novel features for studying human brain development and disease.”

He concludes the review with a cautiously optimistic outlook:

“This is an exciting new field and as with many technologies, it may follow a ‘hype’ cycle in which we overestimate its effects in the short run and underestimate its effects in the long run. A better understanding of the complexity of this platform, and bringing interdisciplinary approaches will accelerate our progress up a ‘slope of enlightenment’ and into the ‘plateau of productivity’.”

3D brain culture from the Pasca Lab, Stanford University


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Stem Cell Stories That Caught our Eye: Stem Cell Therapies for Stroke and Duchenne Muscular Dystrophy Patients

With the Thanksgiving holiday behind us, we’re back to the grind at CIRM. Here are two exciting CIRM-funded stem cell stories that happened while you were away.

Stanford Scientists Are Treating Stroke Patients with Stem Cells

Smithsonian Magazine featured the work of a CIRM-funded scientist in their December Magazine issue. The article, “A Neurosurgeon’s Remarkable Plan to Treat Stroke Victims with Stem Cells”, features Dr. Gary Steinberg, who is the Chair of Neurosurgery at Stanford Medical Center and the founder of the Stanford Stroke Center.

Gary Steinberg (Photo by Jonathan Sprague)

The brain and its 100 billion cells need blood, which carries oxygen and nutrients, to function. When that blood supply is cut off, brain cells start to die and patients experience a stroke. Stroke can happen in one of two ways: either by blood clots that block the arteries and blood vessels that send blood to the brain or by blood vessels that burst within the brain itself. Symptoms experienced by stroke victims vary based on the severity of the stroke, but often patients report experiencing numbness or paralysis in their limbs or face, difficulty walking, talking and understanding.

Steinberg and his team at Stanford are developing a stem cell treatment to help stroke patients. Steinberg believes that not all brain cells die during a stroke, but rather some brain cells become “dormant” and stop functioning instead. By transplanting stem cells derived from donated bone marrow into the brains of stroke patients, Steinberg thinks he can wake up these dormant cells much like how the prince wakens Sleeping Beauty from her century of enchanted sleep.

Basically, the transplanted cells act like a defibrillator for the dormant cells in the stroke-damaged area of the brain. Steinberg thinks that the transplanted cells secrete proteins that signal dormant brain cells to wake up and start functioning normally again, and that they also trigger a “helpful immune response” that prompts the brain to repair itself.

Sonia has seen first hand how a stroke can rob you of even your most basic abilities.

Steinberg tested this stem cell treatment in a small clinical trial back in 2013. 18 patients were treated and many of them showed improvements in their symptoms. The Smithsonian piece mentions a particular patient who had a remarkable response to the treatment. Sonia Olea Coontz, at age 32, suffered a stroke that robbed her of most of her speech and her ability to use her right arm and leg. After receiving Steinberg’s stem cell treatment, Sonia rapidly improved and was able to raise her arm above her head and gained most of her speech back. You can read more about her experience in our Stories of Hope.

In collaboration with a company called SanBio, Steinberg’s team is now testing this stem cell therapy in 156 stroke patients in a CIRM-funded phase 2 clinical trial. The trial will help answer the question of whether this treatment is safe and also effective in a larger group of patients.

The Smithsonian article, which I highly recommend reading, shared Steinberg’s future aspirations to pursue stem cell therapies for traumatic brain and spinal cord injuries as well as neurodegenerative diseases like Alzheimer’s, Parkinson’s and ALS.

 

Capricor Approved to Launch New Clinical Trial for Duchenne Muscular Dystrophy

On Wednesday, Capricor Therapeutics achieved an exciting milestone for its leading candidate CAP-1002 – a stem cell-based therapy developed to treat boys and young men with a muscle-wasting disease called Duchenne muscular dystrophy (DMD).

The Los Angeles-based company announced that it received approval from the US Food and Drug Administration (FDA) for their investigational new drug (IND) application to launch a new clinical trial called HOPE II that’s testing repeated doses of CAP-1002 cells in DMD patients. The cells are derived from donated heart tissue and are believed to release regenerative factors that strengthen heart and other muscle function in DMD patients.

Capricor is currently conducting a Phase 2 trial, called HOPE-1, that’s testing a single dose of CAP-1002 cells in 24 DMD patients. CIRM is funding this trial and you can learn more about it on our clinical dashboard website and watch a video interview we did with a young man who participated in the trial.

Earlier this year, the company shared encouraging, positive results from the HOPE-1 trial suggesting that the therapy was improving some heart function and upper limb movement six months after treatment and was well-tolerated in patients. The goal of the new trial will be to determine whether giving patients repeated doses of the cell therapy over time will extend the benefits in upper limb movement in DMD patients.

In a news release, Capricor President and CEO Dr. Linda Marbán shared her company’s excitement for the launch of their new trial and what this treatment could mean for DMD patients,

Linda Marban, CEO of Capricor Therapeutics

“The FDA’s clearance of this IND upon its initial submission is a significant step forward in our development of CAP-1002. While there are many clinical initiatives in Duchenne muscular dystrophy, this is one of the very few to focus on non-ambulant patients. These boys and young men are looking to maintain what function they have in their arms and hands and, based on our previous study, we think CAP-1002 may be able to do exactly that.”

Progress to a Cure for Bubble Baby Disease

Welcome back to our “Throwback Thursday” series on the Stem Cellar. Over the years, we’ve accumulated an arsenal of exciting stem cell stories about advances towards stem cell-based cures for serious diseases. Today we’re featuring stories about the progress of CIRM-funded clinical trials for the treatment of a devastating, usually fatal, primary immune disease that strikes newborn babies.

evangelina in a bubble

Evie, a former “bubble baby” enjoying life by playing inside a giant plastic bubble

‘Bubble baby disease’ will one day be a thing of the past. That’s a bold statement, but I say it with confidence because of the recent advancements in stem cell gene therapies that are curing infants of this life-threatening immune disease.

The scientific name for ‘bubble baby disease’ is severe combined immunodeficiency (SCID). It prevents the proper development of important immune cells called B and T cells, leaving newborns without a functioning immune system. Because of this, SCID babies are highly susceptible to deadly infections, and without treatment, most of these babies do not live past their first year. Even a simple cold virus can be fatal.

Scientists are working hard to develop stem cell-based gene therapies that will cure SCID babies in their first months of life before they succumb to infections. The technology involves taking blood stem cells from a patient’s bone marrow and genetically correcting the SCID mutation in the DNA of these cells. The corrected stem cells are then transplanted back into the patient where they can grow and regenerate a healthy immune system. Early-stage clinical trials testing these stem cell gene therapies are showing very encouraging results. We’ll share a few of these stories with you below.

CIRM-funded trials for SCID

CIRM is funding three clinical trials, one from UCLA, one at Stanford and one from UCSF & St. Jude Children’s Research Hospital, that are treating different forms of SCID using stem cell gene therapies.

Adenosine Deaminase-Deficient SCID

The first trial is targeting a form of the disease called adenosine deaminase-deficient SCID or ADA-SCID. Patients with ADA-SCID are unable to make an enzyme that is essential for the function of infection-fighting immune cells called lymphocytes. Without working lymphocytes, infants eventually are diagnosed with SCID at 6 months. ADA-SCID occurs in approximately 1 in 200,000 newborns and makes up 15% of SCID cases.

CIRM is funding a Phase 2 trial for ADA-SCID that is testing a stem cell gene therapy called OTL-101 developed by Dr. Don Kohn and his team at UCLA and a company called Orchard Therapeutics. 10 patients were treated in the trial, and amazingly, nine of these patients were cured of their disease. The 10th patient was a teenager who received the treatment knowing that it might not work as it does in infants. You can read more about this trial in our blog from earlier this year.

In a recent news release, Orchard Therapeutics announced that the US Food and Drug Administration (FDA) has awarded Rare Pediatric Disease Designation to OTL-101, meaning that the company will qualify for priority review for drug approval by the FDA. You can read more about what this designation means in this blog.

X-linked SCID

The second SCID trial CIRM is funding is treating patients with X-linked SCID. These patients have a genetic mutation on a gene located on the X-chromosome that causes the disease. Because of this, the disease usually affects boys who have inherited the mutation from their mothers. X-linked SCID is the most common form of SCID and appears in 1 in 60,000 infants.

UCSF and St. Jude Children’s Research Hospital are conducting a Phase 1/2 trial for X-linked SCID. The trial, led by Dr. Brian Sorrentino, is transplanting a patient’s own genetically modified blood stem cells back into their body to give them a healthy new immune system. Patients do receive chemotherapy to remove their diseased bone marrow, but doctors at UCSF are optimizing low doses of chemotherapy for each patient to minimize any long-term effects. According to a UCSF news release, the trial is planning to treat 15 children over the next five years. Some of these patients have already been treated and we will likely get updates on their progress next year.

CIRM is also funding a third clinical trial out of Stanford University that is hoping to make bone marrow transplants safer for X-linked SCID patients. The team, led by Dr. Judy Shizuru, is developing a therapy that will remove unhealthy blood stem cells from SCID patients to improve the survival and engraftment of healthy bone marrow transplants. You can read more about this trial on our clinical trials page.

SCID Patients Cured by Stem Cells

These clinical trial results are definitely exciting, but what is more exciting are the patient stories that we have to share. We’ve spoken with a few of the families whose children participated in the UCLA and UCSF/St. Jude trials, and we asked them to share their stories so that other families can know that there is hope. They are truly inspiring stories of heartbreak and joyful celebration.

Evie is a now six-year-old girl who was diagnosed with ADA-SCID when she was just a few months old. She is now cured thanks to Don Kohn and the UCLA trial. Her mom gave a very moving presentation about Evie’s journey at the CIRM Bridges Trainee Annual Meeting this past July.  You can watch the 20-minute talk below:

Ronnie’s story

Ronnie SCID kid

Ronnie: Photo courtesy Pawash Priyank

Ronnie, who is still less than a year old, was diagnosed with X-linked SCID just days after he was born. Luckily doctors told his parents about the UCSF/St. Jude trial and Ronnie was given the life-saving stem cell gene therapy before he was six months old. Now Ronnie is building a healthy immune system and is doing well back at home with his family. Ronnie’s dad Pawash shared his families moving story at our September Board meeting and you can watch it here.

Our mission at CIRM is to accelerate stem cell treatments to patients with unmet medical needs. We hope that by funding promising clinical trials like the ones mentioned in this blog, that one day soon there will be approved stem cell therapies for patients with SCID and other life-threatening diseases.

Stanford scientists are growing brain stem cells in bulk using 3D hydrogels

This blog is the final installment in our #MonthofCIRM series. Be sure to check out our other blogs highlighting important advances in CIRM-funded research and initiatives.

Neural stem cells from the brain have promising potential as cell-based therapies for treating neurological disorders such as Alzheimer’s disease, Parkinson’s, and spinal cord injury. A limiting factor preventing these brain stem cells from reaching the clinic is quantity. Scientists have a difficult time growing large populations of brain stem cells in an efficient, cost-effective manner while also maintaining the cells in a stem cell state (a condition referred to as “stemness”).

CIRM-funded scientists from Stanford University are working on a solution to this problem. Dr. Sarah Heilshorn, an associate professor of Materials Science and Engineering at Stanford, and her team are engineering 3D hydrogel technologies to make it easier and cheaper to expand high-quality neural stem cells (NSCs) for clinical applications. Their research was published yesterday in the journal Nature Materials.

Stem Cells in 3D

Similar to how moviegoers prefer to watch the latest Star Wars installment in 3D, compared to the regular screen, scientists are turning to 3D materials called hydrogels to grow large numbers of stem cells. Such an environment offers more space for the stem cells to proliferate and expand their numbers while keeping them happy in their stem cell state.

To find the ideal conditions to grow NSCs in 3D, Heilshorn’s team tested two important properties of hydrogels: stiffness and degradability (or how easy it is to remodel the structure of the hydrogel material). They designed a range of hydrogels, made from proteins with elastic qualities, that varied in these two properties. Interestingly, they found that the stiffness of the material did not have a profound effect on the “stemness” of NSCs. This result contrasts with other types of adult stem cells like muscle stem cells, which quickly differentiate into mature muscle cells when exposed to stiffer materials.

On the other hand, the researchers found that it was crucial for the NSCs to be able to remodel their 3D environment. NSCs maintained their stemness by secreting enzymes that broke down and rearranged the molecules in the hydrogels. If this enzymatic activity was blocked, or if the cells were grown in hydrogels that couldn’t be remodeled easily, NSCs lost their stemness and stopped proliferating. The team tested two other hydrogel materials and found the same results. As long as the NSCs were in a 3D environment they could remodel, they were able to maintain their stemness.

NSCs maintain their stemness in hydrogels that can be remodeled easily. Nestin (green) and Sox2 (red) are markers that indicate “high-quality” NSCs. (Image courtesy of Chris Madl, Stanford)

Caption: NSCs maintain their stemness in hydrogels that can be remodeled easily. Nestin (green) and Sox2 (red) are markers that indicate “high-quality” NSCs. (Images courtesy of Chris Madl)

Christopher Madl, a PhD student in the Heilshorn lab and the first author on the study, explained how remodeling their 3D environment allows NSCs to grow robustly in an interview with the Stem Cellar:

Chris Madl

“In this study, we identified that the ability of the neural stem cells to dynamically remodel the material was critical to maintaining the correct stem cell state. Being able to remodel (or rearrange) the material permitted the cells to contact each other.  This cell-cell contact is responsible for maintaining signals that allow the stem cells to stay in a stem-like state. Our findings allow expansion of neural stem cells from relatively low-density cultures (aiding scale-up) without the use of expensive chemicals that would otherwise be required to maintain the correct stem cell behavior (potentially decreasing cost).”

To 3D and Beyond

When asked what’s next on the research horizon, Heilshorn said two things:

Sarah Heilshorn

“First, we want to see if other stem cell types – for example, pluripotent stem cells – are also sensitive to the “remodel-ability” of materials. Second, we plan to use our discovery to create a low-cost, reproducible material for efficient expansion of stem cells for clinical applications. In particular, we’d like to explore the use of a single material platform that is injectable, so that the same material could be used to expand the stem cells and then transplant them.”

Heilshorn is planning to apply the latter idea to advance another study that her team is currently working on. The research, which is funded by a CIRM Tools and Technologies grant, aims to develop injectable hydrogels containing NSCs derived from human induced pluripotent stem cells to treat mice, and hopefully one day humans, with spinal cord injury. Heilshorn explained,

“In our CIRM-funded studies, we learned a lot about how neural stem cells interact with materials. This lead us to realize that there’s another critical bottleneck that occurs even before the stage of transplantation: being able to generate a large enough number of high-quality stem cells for transplantation. We are developing materials to improve the transplantation of stem cell-derived therapies to patients with spinal cord injuries. Unfortunately, during the transplantation process, a lot of cells can get damaged. We are now creating injectable materials that prevent this cell damage during transplantation and improve the survival and engraftment of NSCs.”

An injectable material that promotes the expansion of large populations of clinical grade stem cells that can also differentiate into mature cells is highly desired by scientists pursuing the development of cell replacement therapies. Heilshorn and her team at Stanford have made significant progress on this front and are hoping that in time, this technology will prove effective enough to reach the clinic.

CIRM Board Appoints Dr. Maria Millan as President and CEO

Dr. Maria Millan, President and CEO of CIRM, at the September Board meeting. (Todd Dubnicoff, CIRM)

Yesterday was a big day for CIRM. Our governing Board convened for its September ICOC meeting and appointed Dr. Maria Millan as our new President and CEO. Dr. Millan has been serving as the Interim President/CEO since July, replacing former President Dr. Randal Mills.

Dr. Millan has been at CIRM since 2012 and was instrumental in the development of CIRM’s infrastructure programs including the Alpha Stem Cell Clinics Network and the agency’s Strategic Plan, a five-year plan that lays out our agency’s goals through 2020. Previously, Dr. Millan was the Vice President of Therapeutics at CIRM, helping the agency fund 23 new clinical trials since the beginning of 2016.

The Board vote to appoint Dr. Millan as President and CEO was unanimous and enthusiastic. Chairman of the Board, Jonathan Thomas, shared the Board’s sentiments when he said,

“Dr. Millan is absolutely the right person for this position. Having seen Dr. Millan as the Interim CEO of CIRM for three months and how she has operated in that position, I am even more enthusiastic than I was before. I am grateful that we have someone of Maria’s caliber to lead our Agency.”

Dr. Millan has pursued a career devoted to helping patients. Before working at CIRM, she was an organ transplant surgeon and researcher and served as an Associate Professor of Surgery and Director of the Pediatric Organ Transplant Program at Stanford University. Dr. Millan was also the Vice President and Chief Medical Officer at StemCells, Inc.

In her permanent role as President, Dr. Millan is determined to keep CIRM on track to achieve the goals outlined in our strategic plan and to achieve its mission to accelerate treatments to patients with unmet needs. She commented in a CIRM press release,

“I joined the CIRM team because I wanted to make a difference in the lives of patients. They are the reason why CIRM exists and why we fund stem cell research. I am humbled and very honored to be CIRM’s President and look forward to further implementing our agency’s Strategic Plan in the coming years.”

The Board also voted to fund two new Alpha Stem Cell Clinics at UC Davis and UC San Francisco and five new clinical trials. Three of the clinical awards went to projects targeting cancer.

The City of Hope received $12.8 million to fund a Phase 1 trial targeting malignant gliomas (an aggressive brain cancer) using CAR-T cell therapy. Forty Seven Inc. received $5 million for a Phase 1b clinical trial treating acute myeloid leukemia. And Nohla Therapeutics received $6.9 million for a Phase 2 trial testing a hematopoietic stem cell and progenitor cell therapy to help patients suffering from neutropenia, a condition that leaves people susceptible to deadly infections, after receiving chemotherapy for acute myeloid leukemia.

The other two trials target diabetes and end stage kidney failure. ViaCyte, Inc. was awarded $20 million to fund a Phase 1/2 clinical trial to test its PEC-Direct islet cell replacement therapy for high-risk type 1 diabetes. Humacyte Inc. received $14.1 million to fund a Phase 3 trial that is comparing the performance of its acellular bioengineered vessel with the current standard of dialysis treatment for kidney disease patients.

The Board also awarded $5.2 million to Stanford Medicine for a late stage preclinical project that will use CRISPR gene editing technology to correct the sickle cell disease mutation in blood-forming stem cells to treat patients with sickle cell disease. This award was particularly well timed as September is Sickle Cell Awareness month.

The Stanford team, led by Dr. Matthew Porteus, hopes to complete the final experiments required for them to file an Investigational New Drug (IND) application with the FDA so they can be approved to start a clinical trial hopefully sometime in 2018. You can read more about Dr. Porteus’ work here and you can read our past blogs featuring Sickle Cell Awareness here and here.

With the Board’s vote yesterday, CIRM’s clinical trial count rises to 40 funded trials since its inception. 23 of these trials were funded after the launch of our Strategic Plan bringing us close to the half way point of funding 50 new clinical trials by 2020. With more “shots-on-goal” CIRM hopes to increase the chances that one of these trials will lead to an FDA-approved therapy for patients.


Related Links:

CIRM weekly stem cell roundup: stomach bacteria & cancer; vitamin C may block leukemia; stem cells bring down a 6’2″ 246lb football player

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This is what your stomach glands looks like from the inside:  Credit: MPI for Infection Biology”

Stomach bacteria crank up stem cell renewal, may be link to gastric cancer (Todd Dubnicoff)

The Centers for Disease Control and Prevention estimate that two-thirds of the world’s population is infected with H. pylori, a type of bacteria that thrives in the harsh acidic conditions of the stomach. Data accumulated over the past few decades shows strong evidence that H. pylori infection increases the risk of stomach cancers. The underlying mechanisms of this link have remained unclear. But research published this week in Nature suggests that the bacteria cause stem cells located in the stomach lining to divide more frequently leading to an increased potential for cancerous growth.

Tumors need to make an initial foothold in a tissue in order to grow and spread. But the cells of our stomach lining are replaced every four days. So, how would H. pylori bacterial infection have time to induce a cancer? The research team – a collaboration between scientists at the Max Planck Institute in Berlin and Stanford University – asked that question and found that the bacteria are also able to penetrate down into the stomach glands and infect stem cells whose job it is to continually replenish the stomach lining.

Further analysis in mice revealed that two groups of stem cells exist in the stomach glands – one slowly dividing and one rapidly dividing population. Both stem cell populations respond similarly to an important signaling protein, called Wnt, that sustains stem cell renewal. But the team also discovered a second key stem cell signaling protein called R-spondin that is released by connective tissue underneath the stomach glands. H. pylori infection of these cells causes an increase in R-spondin which shuts down the slowly dividing stem cell population but cranks up the cell division of the rapidly dividing stem cells. First author, Dr. Michal Sigal, summed up in a press release how these results may point to stem cells as the link between bacterial infection and increased risk of stomach cancer:

“Since H. pylori causes life-long infections, the constant increase in stem cell divisions may be enough to explain the increased risk of carcinogenesis observed.”

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Vitamin C may have anti-blood cancer properties

Vitamin C is known to have a number of health benefits, from preventing scurvy to limiting the buildup of fatty plaque in your arteries. Now a new study says we might soon be able to add another benefit: it may be able to block the progression of leukemia and other blood cancers.

Researchers at the NYU School of Medicine focused their work on an enzyme called TET2. This is found in hematopoietic stem cells (HSCs), the kind of stem cell typically found in bone marrow. The absence of TET2 is known to keep these HSCs in a pre-leukemic state; in effect priming the body to develop leukemia. The researchers showed that high doses of vitamin C can prevent, or even reverse that, by increasing the activity level of TET2.

In the study, in the journal Cell, they showed how they developed mice that could have their levels of TET2 increased or decreased. They then transplanted bone marrow with low levels of TET2 from those mice into healthy, normal mice. The healthy mice started to develop leukemia-like symptoms. However, when the researchers used high doses of vitamin C to restore the activity levels of TET2, they were able to halt the progression of the leukemia.

Now this doesn’t mean you should run out and get as much vitamin C as you can to help protect you against leukemia. In an article in The Scientist, Benjamin Neel, senior author of the study, says while vitamin C does have health benefits,  consuming large doses won’t do you much good:

“They’re unlikely to be a general anti-cancer therapy, and they really should be understood based on the molecular understanding of the many actions vitamin C has in cells.”

However, Neel says these findings do give scientists a new tool to help them target cells before they become leukemic.

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Bad toe forces Jordan Reed to take a knee: Photo courtesy FanRag Sports

Toeing the line: how unapproved stem cell treatment made matters worse for an NFL player  

American football players are tough. They have to be to withstand pounding tackles by 300lb men wearing pads and a helmet. But it wasn’t a crunching hit that took Washington Redskins player Jordan Reed out of the game; all it took to put the 6’2” 246 lb player on the PUP (Physically Unable to Perform) list was a little stem cell injection.

Reed has had a lingering injury problem with the big toe on his left foot. So, during the off-season, he thought he would take care of the issue, and got a stem cell injection in the toe. It didn’t quite work the way he hoped.

In an interview with the Richmond Times Dispatch he said:

“That kind of flared it up a bit on me. Now I’m just letting it calm down before I get out there. I’ve just gotta take my time, let it heal and strengthen up, then get back out there.”

It’s not clear what kind of stem cells Reed got, if they were his own or from a donor. What is clear is that he is just the latest in a long line of athletes who have turned to stem cells to help repair or speed up recovery from an injury. These are treatments that have not been approved by the Food and Drug Administration (FDA) and that have not been tested in a clinical trial to make sure they are both safe and effective.

In Reed’s case the problem seems to be a relatively minor one; his toe is expected to heal and he should be back in action before too long.

Stem cell researcher and avid blogger Dr. Paul Knoepfler wrote he is lucky, others who take a similar approach may not be:

“Fortunately, it sounds like Reed will be fine, but some people have much worse reactions to unproven stem cells than a sore toe, including blindness and tumors. Be careful out there!”

Stories that caught our eye: smelling weight gain, colon cancer & diet and diabetes & broken bones

How smelling your food could cause weight gain (Karen Ring).
Here’s the headline that caught my eye this week: “Smelling your food first can make you fat…”

It’s a bizarre statement, but the claim is backed by scientific research coming from a new study in Cell Metabolism by researchers at the University of California Berkeley. The team found that obese mice who smelled their food before eating it were more likely to gain weight compared to obese mice that couldn’t smell their food.

Their experiments revealed a connection between the olfactory system, which is responsible for our sense of smell, and how the mice metabolize food into energy. Obese mice that lost their ability to smell actually lost weight on a high-fat diet, burned more fat, and became more sensitive to the hormone insulin. Insulin regulates how much glucose, or sugar, is in the blood by facilitating the absorption of glucose by fat, liver and muscle cells. In obese individuals, insulin resistance can occur where their cells are no longer sensitive to the hormone and therefore can’t regulate how much glucose is in the blood.

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Both mice in this picture were fed the same high-fat diet. The only difference: the lower mouse’s sense of smell was temporarily blocked. Image: UC Berkeley

For obese mice that could smell their food, the same high fat diet given to the “no-smellers” resulted in massive weight gain in the “smellers” because their metabolism was impaired. Even more interesting is the fact that other types of smells unrelated to food, such as the scent of other mice, influenced weight gain in the “smellers”.

The authors concluded that the centers in our brain that are responsible for smell (the olfactory system) and metabolism (the hypothalamus) are connected and that manipulating smell could be a future strategy to influence how the brain controls the balance of energy during food consumption.

In an interview with Tech Times, senior author on the study, Dr. Andrew Dillin, explained how their research could potentially lead to a new strategy to promote weight loss,

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Andrew Dillin. Image: HHMI

“Sensory systems play a role in metabolism. Weight gain isn’t purely a measure of the calories taken in; it’s also related to how those calories are perceived. If we can validate this in humans, perhaps we can actually make a drug that doesn’t interfere with smell but still blocks that metabolic circuitry. That would be amazing.”

A link between colorectal cancer and a Western diet identified
Weight gain isn’t the only concern of a eating a high-fat diet. It’s thought that 80% of colorectal cases are associated with a high-fat, Western diet. The basis for this connection hasn’t been well understood. But this week, researchers at the Cleveland Clinic report in Stem Cell Reports that they’ve pinpointed a protein signaling network within cancer stem cells as a possible source of the link.

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Cancer stem cells have properties that resemble embryonic stem cells and are thought to be the source of a cancer’s unlimited growth and spread. A cancer stem cell maintains its properties by exploiting various cell signaling processes that when functioning abnormally can lead to inappropriate cell division and tumor growth. In this study, the team focused on one cell signaling process carried out by a protein called STAT3, known to promote tumor growth in a mouse model of colon cancer. When the team blocked STAT3 activity, high fat diet-induced cancer stem cell growth subsided.

In a press release, Dr. Matthew Kalady, a colorectal surgeon at the Cleveland Clinic and an author on this study, explained how this new insight can open new therapeutic avenues:

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Matthew Kalady. Image: Cleveland Clinic

“We have known the influence of diet on colorectal cancer. However, these new findings are the first to show the connection between high-fat intake and colon cancer via a specific molecular pathway. We can now build upon this knowledge to develop new treatments aimed at blocking this pathway and reducing the negative impact of a high-fat diet on colon cancer risk.”

 

 

Scientists connect dots between diabetes and broken bones.
Type 2 diabetes carries a whole host of long-term complications including heart disease, nerve damage, kidney dysfunction and even an increased risk for bone fractures. The connection between diabetes and fragile bones has not been well understood. But this week, researchers at New York University of Dentistry, Stanford University and China’s Dalian Medical University published a report, funded in part by CIRM, in this week’s Nature Communications showing a biochemical basis for this connection. The new insight may lead to treatment options to prevent fractures.

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Chemical structure of succinate.
Image: Wikimedia Commons.

Fundamentally, diabetes is a disease that causes hyperglycemia, or abnormally high levels of blood sugar. The team ran a systematic analysis of hyperglycemia’s effects on bone metabolism using bone marrow samples from diabetic and healthy mice. They found that the levels of succinate, a key molecule involved in energy production, are over 20 times higher in the diabetic mice. In turns out that succinate also acts as a stimulator of bone breakdown. Now, bone is continually in a process of turnover and, in a healthy state, the breakdown of old bone is balanced with the formation of new bone. So, it appears that the huge increase of succinate is tipping the balance of bone turnover. In fact, the team found that the porous, yet strong inner region of bone, called trabecular bone, was significantly reduced in the diabetic mice, making them more susceptible to fractures.

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The density of spongy bone, or trabecular bone, is reduced in type 2 diabetes.
Image: Wikimedia commons

Dr. Xin Li, the study’s lead scientist, explained the importance of these new insights for people living with type 2 diabetes in a press release:

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Xin Li.
Image: NYU Dentistry

“The results are important because diabetics have a significantly higher fracture risk and their healing process is always delayed. In our study, the hyperglycemic mice had increased bone resorption [the breakdown and absorption of old bone], which outpaced the formation of new bone. This has implications for bone protection, as well as for the treatment of diabetes-associated collateral bone damage.”