Coming up with a stem cell FIX for a life-threatening blood disorder

Hemophilia

A promising new treatment option for hemophiliacs is in the works at the Salk Institute for Biological Sciences. Patients with Hemophilia B experience uncontrolled, and sometimes life threatening, bleeding due to loss or improper function of Factor IX (FIX), a protein involved in blood clotting. There is no cure for the disease and patients rely on routine infusions of FIX to prevent excessive blood loss. As you can imagine, this treatment regimen is both time consuming and expensive, while also becoming less effective over time.

Salk researchers, partially funded by CIRM, aimed to develop a more long-term solution for this devastating disease by using the body’s own cells to fix the problem.

In the study, published in the journal Cell Reports, They harvested blood cells from hemophiliacs and turned them into iPSCs (induced pluripotent stem cells), which are able to turn into any cell type. Using gene editing, they repaired the iPSCs so they could produce FIX and then turned the iPSCs into liver cells, the cell type that naturally produces FIX in healthy individuals.

One step therapy

To test whether these FIX-producing liver cells were able to reduce excess blood loss, the scientists injected the repaired human cells into a hemophiliac mouse. The results were very encouraging; they saw a greater than two-fold increase in clotting efficiency in the mice, reaching about a quarter of normal activity. This is particularly promising because other studies showed that increasing FIX activity to this level in hemophiliac humans significantly reduces bleeding rates. On top of that they also observed that these cells were able to survive and produce FIX for up to a year in the mice.

In a news release Suvasini Ramaswamy, the first author of the paper, said this method could eliminate the need for multiple treatments, as well as avoiding the immunosuppressive therapy that would be required for a whole liver transplant.

“The appeal of a cell-based approach is that you minimize the number of treatments that a patient needs. Rather than constant injections, you can do this in one shot.”

While these results provide an exciting new avenue in hemophilia treatment, there is still much more work that needs to be done before this type of treatment can be used in humans. This approach, however, is particularly exciting because it provides an important proof of principle that combining stem cell reprogramming with genetic engineering can lead to life-changing breakthroughs for treating genetic diseases that are not currently curable.

 

 

Stem Cell Roundup: The brain & obesity; iPSCs & sex chromosomes; modeling mental illness

Stem Cell Image of the Week:
Obesity-in-a-dish reveals mutations and abnormal function in nerve cells

cedars-sinai dayglo

Image shows two types of hypothalamic neurons (in magenta and cyan) that were derived from human induced pluripotent stem cells.
Credit: Cedars-Sinai Board of Governors Regenerative Medicine Institute

Our stem cell image of the week looks like the work of a pre-historic cave dweller who got their hands on some DayGlo paint. But, in fact, it’s a fluorescence microscopy image of stem cell-derived brain cells from the lab of Dhruv Sareen, PhD, at Cedars-Sinai Medical Center. Sareen’s team is investigating the role of the brain in obesity. Since the brain is a not readily accessible organ, the team reprogrammed skin and blood cell samples from severely obese and normal weight individuals into induced pluripotent stem cells (iPSCs). These iPSCs were then matured into nerve cells found in the hypothalamus, an area of the brain that regulates hunger and other functions.

A comparative analysis showed that the nerve cells derived from the obese individuals had several genetic mutations and had an abnormal response to hormones that play a role in telling our brains that we are hungry or full. The Cedars-Sinai team is excited to use this obesity-in-a-dish system to further explore the underlying cellular changes that lead to excessive weight gain. Ultimately, these studies may reveal ways to combat the ever-growing obesity epidemic, as Dr. Sareen states in a press release:

“We are paving the way for personalized medicine, in which drugs could be customized for obese patients with different genetic backgrounds and disease statuses.”

The study was published in Cell Stem Cell

Differences found in stem cells derived from male vs female.

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Microscope picture of a colony of iPS cells. Credit: Vincent Pasque

Scientists at UCLA and KU Leuven University in Belgium carried out a study to better understand the molecular mechanisms that control the process of reprogramming adult cells back into the embryonic stem cell-like state of induced pluripotent stem cells (iPSCs). Previous studies have shown that female vs male embryonic stem cells have different patterns of gene regulation. So, in the current study, male and female cells were analyzed side-by-side during the reprogramming process.  First author Victor Pasquale explained in a press release that the underlying differences stemmed from the sex chromosomes:

In a normal situation, one of the two X chromosomes in female cells is inactive. But when these cells are reprogrammed into iPS cells, the inactive X becomes active. So, the female iPS cells now have two active X chromosomes, while males have only one. Our results show that studying male and female cells separately is key to a better understanding of how iPS cells are made. And we really need to understand the process if we want to create better disease models and to help the millions of patients waiting for more effective treatments.”

The CIRM-funded study was published in Stem Cell Reports.

Using mini-brains and CRISPR to study genetic linkage of schizophrenia, depression and bipolar disorder.

If you haven’t already picked up on a common thread in this week’s stories, this last entry should make it apparent: iPSC cells are the go-to method to gain insight in the underlying mechanisms of a wide range of biology topics. In this case, researchers at Brigham and Women’s Hospital at Harvard Medical School were interested in understanding how mutations in a gene called DISC1 were linked to several mental illnesses including schizophrenia, bipolar disorder and severe depression. While much has been gleaned from animal models, there’s limited knowledge of how DISC1 affects the development of the human brain.

The team used human iPSCs to grow cerebral organoids, also called mini-brains, which are three-dimensional balls of cells that mimic particular parts of the brain’s anatomy. Using CRISPR-Cas9 gene-editing technology – another very popular research tool – the team introduced DISC1 mutations found in families suffering from these mental disorders.

Compared to cells with normal copies of the DISC1 gene, the mutant organoids showed abnormal structure and excessive cell signaling. When an inhibitor of that cell signaling was added to the growing mutant organoids, the irregular structures did not develop.

These studies using human cells provide an important system for gaining a better understanding of, and potentially treating, mental illnesses that victimize generations of families.

The study was published in Translation Psychiatry and picked up by Eureka Alert.

Building a better brain organoid

One of the reasons why it’s so hard to develop treatments for problems in the brain – things like Alzheimer’s, autism and schizophrenia – is that you can’t do an autopsy of a living brain to see what’s going wrong. People tend to object. To get around that, scientists have used stem cells to create models of what’s happening inside the brain. They’re good, but they have their limitations. Now a team at the Salk Institute for Biological Studies has found a way to create a better brain model, and hopefully a faster route to developing new treatments.

For a few years now, scientists have been able to take skin cells from patients with neurodegenerative disorders and turn them into neurons, the kind of brain cell affected by these different diseases. They grow these cells in the lab and turn them into clusters of cells, so-called brain “organoids”, to help us better understand what’s happening inside the brain and even allow us to test medications on them to see if those treatments can help ease some symptoms.

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Human organoid tissue (green) grafted into mouse tissue. Neurons are labeled with red. Credit: Salk Institute

But those models don’t really capture the complexity of our brains – how could they – and so only offer a glimpse into what’s happening inside our skulls.

Now the team at Salk have developed a way of transplanting these organoids into mouse brains, giving them access to oxygen and nutrients that can help them not only survive longer but also display more of the characteristics found in the human brain.

In a news release, CIRM Grantee and professor at Salk’s Laboratory of Genetics, Rusty Gage said this new approach gives researchers a powerful new tool:

“This work brings us one step closer to a more faithful, functional representation of the human brain and could help us design better therapies for neurological and psychiatric diseases.”

The transplanted human brain organoids showed plenty of signs that they were becoming engrafted in the mouse brain:

  • They had blood vessels form in them and blood flowing through them
  • They formed neurons
  • They formed other brain support cells called astrocytes

They also used a series of imaging techniques to confirm that the neurons in the organoid were not just connecting but also sending signals, in essence, communicating with each other.

Abed AlFattah Mansour, a Salk research associate and the paper’s first author, says this is a big accomplishment.

“We saw infiltration of blood vessels into the organoid and supplying it with blood, which was exciting because it’s perhaps the ticket for organoids’ long-term survival. This indicates that the increased blood supply not only helped the organoid to stay healthy longer, but also enabled it to achieve a level of neurological complexity that will help us better understand brain disease.”

A better understanding of what’s going wrong is a key step in being able to develop new treatments to fix the problem.

The study is published in the journal Nature Biotechnology.

CIRM has a double reason to celebrate this work. Not only is the team leader, Rusty Gage, a CIRM grantee but one of the Salk team, Sarah Fernandes, is a former intern in the CIRM Bridges to Stem Cell Research program.

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From left: Sarah Fernandes, Daphne Quang, Stephen Johnston, Sarah Parylak, Rusty Gage, Abed AlFattah Mansour, Hao Li Credit: Salk Institute

Celebrating Exciting CIRM-Funded Discovery Research on World Parkinson’s Day

April 11th is World Parkinson’s Disease Awareness Day. To mark the occasion, we’re featuring the work of CIRM-funded researchers who are pursuing new, promising ideas to treat patients with this debilitating neurodegenerative disease.


Birgitt Schuele, Parkinson’s Institute

CIRM Grant: Quest Award – Discovery Stage Research

Research: Birgitt and her team at the Parkinson’s Institute in Sunnyvale, California, are using CRISPR gene editing technology to reduce the levels of a toxic protein called alpha synuclein, which builds up in the dopaminergic brain cells affected by Parkinson’s disease.

Birgitt Schuele

“My hope is that I can contribute to stopping disease progression in Parkinson’s. If we can develop a drug that can get rid of accumulated protein in someone’s brain that should stop the cells from dying. If someone has early onset PD and a slight tremor and minor walking problems, stopping the disease and having a low dose of dopamine therapy to control symptoms is almost a cure.”

Parkinson’s disease in a dish. Dopaminergic neurons made from Parkinson’s patient induced pluripotent stem cells. (Image credit: Birgitt Schuele)


Jeanne Loring, Scripps Research Institute

CIRM Grant: Quest Award – Discovery Stage Research

Research: Jeanne Loring and her team at the Scripps Research Institute in La Jolla, California, are deriving dopaminergic neurons from the iPSCs of Parkinson’s patients. Their goal is to develop a personalized, stem cell-based therapy for PD.

Jeanne Loring

“We are working toward a patient-specific neuron replacement therapy for Parkinson’s disease.  By the time PD is diagnosed, people have lost more than half of their dopamine neurons in a specific part of the brain, and loss continues over time.  No drug can stop the loss or restore the neurons’ function, so the best possible option for long term relief of symptoms is to replace the dopamine neurons that have died.  We do this by making induced pluripotent stem cells from individual PD patients and turning them into the exact type of dopamine neuron that has been lost.  By transplanting a patient’s own cells, we will not need to use potentially dangerous immunosuppressive drugs.  We plan to begin treating patients in a year to two years, after we are granted FDA approval for the clinical therapy.”

Skin cells from a Parkinson’s patient (left) were reprogrammed into induced pluripotent stem cells (center) that were matured into dopaminergic neurons (right) to model Parkinson’s disease. (Image credit: Jeanne Loring)


Justin Cooper-White, Scaled BioLabs Inc.

CIRM Grant: Quest Award – Discovery Stage Research

Research: Justin Cooper-White and his team at Scaled Biolabs in San Francisco are developing a tool that will make clinical-grade dopaminergic neurons from the iPSCs of PD patients in a rapid and cost-effective manner.

Justin Cooper-White

“Treating Parkinson’s disease with iPSC-derived dopaminergic neuron transplantation has a strong scientific and clinical rationale. Even the best protocols are long and complex and generally have highly variable quality and yield of dopaminergic neurons. Scaled Biolabs has developed a technology platform based on high throughput microfluidics, automation, and deep data which can optimize and simplify the road from iPSC to dopaminergic neuron, making it more efficient and allowing a rapid transition to GMP-grade derivation of these cells.  In our first 6 months of CIRM-funded work, we believe we have already accelerated and simplified the production of a key intermediate progenitor population, increasing the purity from the currently reported 40-60% to more than 90%. The ultimate goal of this work is to get dopaminergic neurons to the clinic in a robust and economical manner and accelerate treatment for Parkinson’s patients.”

High throughput differentiation of dopaminergic neuron progenitors in  microbioreactor chambers in Scaled Biolabs’ cell optimization platform. Different chambers receive different differentiation factors, so that optimal treatments for conversion to dual-positive cells can be determined (blue: nuclei, red: FOXA2, green: LMX1A).


Xinnan Wang, Stanford University

CIRM Grant: Basic Biology V

Research: Xinnan Wang and her team at Stanford University are studying the role of mitochondrial dysfunction in the brain cells affected in Parkinson’s disease.

Xinnan Wang

“Mitochondria are a cell’s power plants that provide almost all the energy a cell needs. When these cellular power plants are damaged by stressful factors present in aging neurons, they release toxins (reactive oxygen species) to the rest of the neuron that can cause neuronal cell death (neurodegeneration).  We hypothesized that in Parkinson’s mutant neurons, mitochondrial quality control is impaired thereby leading to neurodegeneration. We aimed to test this hypothesis using neurons directly derived from Parkinson’s patients (induced pluripotent stem cell-derived neurons).”

Dopaminergic neurons derived from human iPSCs shown in green, yellow and red. (Image credit: Atossa Shaltouki, Stanford)


Related Blogs:

Gladstone researchers tame toxic protein that carries increased Alzheimer’s risk

With a clinical trial failure rate of 99% over the past 15 years or so, the path to a cure for Alzheimer’s disease is riddled with disappointment. In many cases, candidate therapies looked very promising in pre-clinical animal studies, only to flop when tested in people. Now, a CIRM-funded Nature Medicine study by researchers at the Gladstone Institutes sheds some light on a source of this discrepancy. And more importantly, the study points to a potential treatment strategy that can remove the hallmarks of Alzheimer’s in human brain cells.

Alzheimers_plaguestangles

Build up of tau protein (blue) and amyloid-beta (yellow) in and around neurons are hallmarks of the damage caused by Alzheimer’s disease. 
Image courtesy of the National Institute on Aging/National Institutes of Health.

For several decades, researchers have known the ApoE gene can influence the risk for an Alzheimer’s diagnosis in individuals 65 years and older. The gene comes in a few flavors with ApoE3 and ApoE4 differing in only one spot in their DNA sequences. Though nearly identical, the resulting ApoE3 and E4 proteins have very different shapes with differing function. In fact, people who inherit two copies of the ApoE4 gene have a twelve times higher risk for Alzheimer’s compared to those with the more common ApoE3.

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Yadong Huang

To better understand what’s happening at the cellular level, Yadong Huang, PhD and his team at the Gladstone Institutes obtained skin samples from Alzheimer’s donors carrying two copies of the ApoE4 gene and healthy donors with two copies of ApoE3. The skin cells were reprogrammed into induced pluripotent stem cells (iPSCs) and then matured into nerve cells, or neurons.

Compared to ApoE3 cells, the researchers observed that the ApoE4 neurons accumulated higher levels of proteins called p-tau and amyloid beta, which are hallmarks of Alzheimer’s disease. Repeating this same experiment in iPSC-derived mouse neurons showed no difference in the production of amyloid beta levels between the ApoE3 and E4 neurons. This result points to the importance of studying human disease in human cells, as first author Chengzhong Wang, PhD, points out in a press release:

“There’s an important species difference in the effect of apoE4 on amyloid beta. Increased amyloid beta production is not seen in mouse neurons and could potentially explain some of the discrepancies between mice and humans regarding drug efficacy. This will be very important information for future drug development.”

Further experiments aimed to answer a long sought-after question: is it the absence of ApoE3 or the presence of ApoE4 that causes the damaging effects on neurons? Using gene-editing techniques, the team removed both ApoE forms from the donor-derived neurons. The resulting cells appeared healthy but when ApoE4 was added back in, Alzheimer’s-associated problems emerged. This finding points to the toxicity of ApoE4 to neurons.

With this new insight in hand, the team examined what would happen if they converted the ApoE4 form into the ApoE3 form. The team had previously designed molecules, they dubbed “structure correctors”, that physically interact with the ApoE4 protein and cause it to take on the shape of the ApoE3 form found in healthy individuals. When these correctors were added to the ApoE4 neurons, it brought back normal function to the cells.

Given that the structure corrector is a chemical compound that works in human brain cells, it’s tantalizing to think about its possible use as a novel Alzheimer’s drug. And you can bet Dr. Huang and his group are eagerly embarking on that new path.

Stem Cell Roundup: watching brain cells in real time, building better heart cells, and the plot thickens on the adult neurogenesis debate

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

Watching brain cells in real time

This illustration depicts a new method that enables scientists to see an astrocyte (green) physically interacting with a neuronal synapse (red) in real time, and producing an optical signal (yellow). (Khakh Lab, UCLA Health)

Our stem cell photo of the week is brought to you by the Khakh lab at UCLA Health. The lab developed a new method that allows scientists to watch brain cells interact in real time. Using a technique called fluorescence resonance energy-transfer (FRET) microscopy, the team can visualize how astrocytes (key support cells in our central nervous system) and brain cells called neurons form connections in the mouse brain and how these connections are affected by diseases like Alzheimer’s and ALS.

Baljit Khakh, the study’s first author, explained the importance of their findings in a news release:

“This new tool makes possible experiments that we have been wanting to perform for many years. For example, we can now observe how brain damage alters the way that astrocytes interact with neurons and develop strategies to address these changes.”

The study was published this week in the journal Neuron.


Turn up the power: How to build a better heart cell (Todd Dubnicoff)

For years now, researchers have had the know-how to reprogram a donor’s skin cells into induced pluripotent stem cells (iPSCs) and then specialize them into heart muscle cells called cardiomyocytes. The intervening years have focused on optimizing this method to accurately model the biology of the adult human heart as a means to test drug toxicity and ultimately develop therapies for heart disease. Reporting this week in Nature, scientists at Columbia University report an important step toward those goals.

The muscle contractions of a beating heart occur through natural electrical impulses generated by pacemaker cells. In the case of lab-grown cardiomyocytes, introducing mechanical and electrical stimulation is required to reliably generate these cells. In the current study, the research team showed that the timing and amount of stimulation is a critical aspect to the procedure.

The iPS-derived cardiomyocytes have formed heart tissue that closely mimics human heart functionality at over four weeks of maturation. Credit: Gordana Vunjak-Novakovic/Columbia University.

The team tested three scenarios on iPSC-derived cardiomyocytes (iPSC-CMs): no electrical stimulation for 3 weeks, constant stimulation for 3 weeks, and finally, two weeks of increasingly higher stimulation followed by a week of constant stimulation. This third setup mimics the changes that occur in a baby’s heart just before and just after birth.

These scenarios were tested in 12 day-old and 28 day-old iPSC-CMs. The results show that only the 12 day-old cells subjected to the increasing amounts of stimulation gave rise to fully mature heart muscle cells. On top of that, it only took four weeks to make those cells. Seila Selimovic, Ph.D., an expert at the National Institutes of Health who was not involved in the study, explained the importance of these findings in a press release:

“The resulting engineered tissue is truly unprecedented in its similarity to functioning human tissue. The ability to develop mature cardiac tissue in such a short time is an important step in moving us closer to having reliable human tissue models for drug testing.”

Read more at: https://phys.org/news/2018-04-early-bioengineered-human-heart-cells.html#jCp


Yes we do, no we don’t. More confusion over growing new brain cells as we grow older (Kevin McCormack)

First we didn’t, then we did, then we didn’t again, now we do again. Or maybe we do again.

The debate over whether we are able to continue making new neurons as we get older took another twist this week. Scientists at Columbia University said their research shows we do make new neurons in our brain, even as we age.

This image shows what scientists say is a new neuron in the brain of an older human. A new study suggests that humans continue to make new neurons throughout their lives. (Columbia University Irving Medical Center)

In the study, published in the journal Cell Stem Cell, the researchers examined the brains of 28 deceased donors aged 14 to 79. They found similar numbers of precursor and immature neurons in all the brains, suggesting we continue to develop new brain cells as we age.

This contrasts with a UCSF study published just last month which came to the opposite conclusion, that there was no evidence we make new brain cells as we age.

In an interview in the LA Times, Dr. Maura Boldrini, the lead author on the new study, says they looked at a whole section of the brain rather than the thin tissues slices the UCSF team used:

“In science, the absence of evidence is not evidence of absence. If you can’t find something it doesn’t mean that it is not there 100%.”

Well, that resolves that debate. At least until the next study.

UC Davis researchers make stem cell-derived mini-brains that contain blood vessels

Growing neurons on a flat petri dish is a great way to study the inner workings of nerve signals in the brain. But I think it’s safe to argue that a two-dimensional lawn of cells doesn’t capture all the complexity of our intricate, cauliflower-shaped brains. Then again, cracking open the skulls of living patients is also not a viable path for fully understanding the molecular basis of brain disorders.

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Brain organoids (two white balls) growing in petri dish.
Image: Pasca Lab, Stanford University.

The recent emergence of stem cell-derived mini-brains, or brain organoids, as a research tool is bridging this impasse. With induced pluripotent stem cells (iPSCs) derived from a readily-accessible skin sample from patients, it’s possible to generate three-dimensional balls of cells that mimic particular parts of the brain’s anatomy. These mini-brains have the expected type of neurons, as well as other cells that support neuron function. We’ve written many blogs, most recently in January, on the applications of this cutting-edge tool.

With any new technology, there is always room for improvement. One thing that most mini-brains lack is their own system of blood vessels, or vasculature. That’s where Dr. Ben Waldau, a vascular neurosurgeon at UC Davis Medical Center, and his lab come into the picture. Last week, their published work in NeuroReport showed that incorporating blood vessels into a brain organoid is possible.

UCDavisorganoid

A stained cross-section of a brain organoid showing that blood vessels (in red) have penetrated both the outer, more organized layers and the inner core. Image: UC Davis Institute for Regenerative Cures

Using iPSCs from one patient, the Waldau team separately generated brain organoids and blood vessels cells, also called endothelial cells. After growing each for about a month, the organoids were embedded in a gelatin containing the endothelial cells. In an excellent Wired article, writer Megan Molteni explains what happened next:

“After incubating for three weeks, they took a single organoid and transplanted it into a tiny cavity carefully carved into a mouse’s brain. Two weeks later the organoid was alive, well—and, critically, had grown capillaries that penetrated all the way to its inner layers.”

Every tissue relies on nutrients and oxygen from the blood. As Molteni suggests, being able to incorporate blood vessels and brain organoids from the same patient’s cells may make it possible to grow and study even more complex brain structures without the need of a mouse using fluidic pumps.

As Waldau explains in the Wired article, this vascularized brain organoid system also adds promise to the ultimate goal of repairing damaged brain tissue:

waldau

Ben Waldau

“The whole idea with these organoids is to one day be able to develop a brain structure the patient has lost made with the patient’s own cells. We see the injuries still there on the CT scans, but there’s nothing we can do. So many of them are left behind with permanent neural deficits—paralysis, numbness, weakness—even after surgery and physical therapy.”

 

 

East Coast Company to Sell Research Products Derived from CIRM’s Stem Cell Bank

With patient-derived induced pluripotent stem cells (iPSCs) in hand, any lab scientist can follow recipes that convert these embryonic-like stem cells into specific cell types for studying human disease in a petri dish. iPSCs derived from a small skin sample from a Alzheimer’s patient, for instance, can be specialized into neurons – the kind of cell affected by the disease – to examine what goes wrong in an Alzheimer’s patient’s brain or screen drugs that may alleviate the problems.

exilirneurons

Neurons created from Alzheimer’s disease patient-derived iPSCs.
Image courtesy Elixirgen Scientific

But not every researcher has easy access to a bank of patient-derived iPSCs and it’s not trivial to coax iPSCs to become a particular cell type. The process is also a time sink and many scientists would rather spend that time doing what they’re good at: uncovering new insights into their disease of interest.

Since the discovery of iPSC technology over a decade ago, countless labs have worked out increasingly efficient variations on the original method. In fact, companies that deliver iPSC-derived products have emerged as an attractive option for the time-strapped stem cell researcher.

One of those companies is Elixirgen Scientific of Baltimore, Maryland. Pardon the pun but Elixirgen has turned the process of making various cell types from iPSCs into a science. Here’s how CEO Bumpei Noda described the company’s value to me:

Bumpei-Noda-200

Bumpei Noda

“Our technology directly changes stem cells into the cells that make up most of your body, such as muscle cells or neural cells, in about one week. Considering that existing technology takes multiple weeks or even months to do the same thing, imagine how much more research can get done than before.”

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With Elixirgen’s technology, different “cocktails” of ingredients can quickly and efficiently turn iPSCs into many different human cell types. Image courtesy Elixirgen Scientific

Their technology is set to become an even greater resource for researchers based on their announcement yesterday that they’ve signed a licensing agreement to sell human disease cells that were generated from CIRM’s iPSC Repository.

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Stephen Lin

“The CIRM Repository holds the largest publicly accessible collection of human iPSCs in the world and is the result of years of coordinated efforts of many groups to create a leading resource for disease modeling and drug discovery using stem cells,” said Stephen Lin, a CIRM Senior Science Officer who oversees the cell bank.

 

The repository currently contains a collection of 1,600 cell lines derived from patients with diseases that are a source of active research, including autism, epilepsy, cerebral palsy, Alzheimer’s disease, heart disease, lung disease, hepatitis C, fatty liver disease, and more (visit our iPSC Repository web page for the complete list).

While this wide variety of patient cells lines certainly played a major role in Elixirgen’s efforts to sign the agreement, Noda also noted that the CIRM Repository “has rich clinical and demographic data and age-matched control cell lines” which is key information to have when interpreting the results of experiments and drug screening.

Lin also points out another advantage to the CIRM cells:

“It’s one of the few collections with a streamlined route to commercialization (i.e. pre-negotiated licenses) that make activities like Elixirgen’s possible. iPSC technology is still under patent and technically cannot be used for drug discovery without those legal safeguards. That’s important because if you do discover a drug using iPSCs without taking care of these licensing agreements, your discovery could be owned by that original intellectual property holder.”

At CIRM, we’re laser-focused on accelerating stem cell treatments to patients with unmet medical needs. That’s why we’re excited that Elixirgen Scientific has licensed access to the our iPSC repository. We’re confident their service will help researchers work more efficiently and, in turn, accelerate the pace of new discoveries.

Tiny blood vessels in the brain can spur the growth of spinal motor neurons

Last week, researchers from Cedars-Sinai Medical Center added a new piece to the complex puzzle of what causes neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). The team discovered that the tiny blood vessels in our brains do more than provide nutrients to and remove waste products from our brain tissue. It turns out that these blood vessels can stimulate the growth of new nerve cells called spinal motor neurons, which directly connect to the muscles in our body and control how they move. The study, which was funded in part by a CIRM Discovery research-stage Inception award, was published in the journal Stem Cell Reports.

The Cedars team used a combination of human induced pluripotent stem cells (iPSCs) and organ-on-a-chip technology to model the cellular microenvironment of the spinal cord. They matured the iPSCs into both spinal motor progenitor cells and brain endothelial cells (which line the insides of blood vessels). These cells were transferred to an organ-chip where they were able to make direct contact and interact with each other.

Layers of spinal motor neuron cells (top, in blue) and capillary cells (bottom, in red) converge inside an Organ-Chip. Neurons and capillary cells interact together along the length of the chip. (Cedars-Sinai Board of Governors Regenerative Medicine Institute).

The researchers discovered that exposing the spinal motor progenitor cells to the blood vessel endothelial cells in these organ-chips activated the expression of genes that directed these progenitor cells to mature into spinal cord motor neurons.

Hundreds of spinal motor neurons spontaneously communicate through electrical signals inside an Organ-Chip. Neurons fire individually (flashing dots) and in synchronized bursts (bright waves). (Cedars-Sinai)

First author on the study, Samuel Sances, explained their findings in a news release:

“Until now, people thought these blood vessels just delivered nutrients and oxygen, removed waste and adjusted blood flow. We showed that beyond plumbing, they are genetically communicating with the neurons.”

The team also showed the power of stem cell-based organ-chip platforms for modeling diseases like ALS and answering key questions about why these diseases occur.

“What may go wrong in the spinal neurons that causes the motor neurons to die?” Sances asked. “If we can model an individual ALS patient’s tissues, we may be able to answer that question and one day rescue ALS patients’ neurons through new therapies.”

Clive Svendsen, a CIRM grantee and the senior author on the study, said that his team will conduct additional studies using organ-chip technology to study the interactions between iPSC-derived neurons and blood vessels of healthy individuals and ALS patients. Differences in these cellular interactions in diseased patient cells could offer new targets for developing ALS therapies.

The current study is a collaboration between Cedars and a Boston company called Emulate, Inc. Emulate developed the organ-chip technology and is collaborating with Svendsen at Cedars to not only model neurodegenerative diseases, but also model other organ systems. Be sure to check out our recent blog about their efforts to create a stem cell-based gut-on-a-chip, which they hope will pave the way for personalized treatments for patients with gastrointestinal diseases like Chrohn’s and inflammatory bowel disease.

Stem Cell Roundup: hESCs turn 20, tracking cancer stem cells, new ALS gene ID’d

Stem Cell Image of the Week

Picture1This week’s stunning stem cell image is brought to you by researchers in the Brivanlou Lab at Rockefeller University. What looks like the center of a sunflower is actual a ball of neural rosettes derived from human embryonic stem cells (ESCs). Neural rosettes are structures that contain neural stem and progenitor cells that can further specialize into mature brain cells like the stringy, blue-colored neurons in this photo.

This photo was part of a Nature News Feature highlighting how 20 years ago, human ESCs sparked a revolution in research that’s led to the development of ESC-based therapies that are now entering the clinic. It’s a great read, especially for those of you who aren’t familiar with the history of ESC research.

Increase in cancer stem cells tracked during one patient’s treatment
Cancer stem cells are nasty little things. They have the ability to evade surgery, chemotherapy and radiation and cause a cancer to return and spread through the body. Now a new study says they are also clever little things, learning how to mutate and evolve to be even better at evading treatment.

Researchers at the Colorado Cancer Center did three biopsies of tumors taken from a patient who underwent three surgeries for salivary gland cancer. They found that the number of cancer stem cells increased with each surgery. For example, in the first surgery the tumor contained 0.2 percent cancer stem cells. By the third surgery the number of cancer stem cells had risen to 4.5 percent.

Even scarier, the tumor in the third surgery had 50 percent more cancer-driving mutations meaning it was better able to resist attempts to kill it.

In a news release, Dr. Daniel Bowles, the lead investigator, said the tumor seemed to learn and become ever more aggressive:

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Daniel Bowles

“People talk about molecular evolution of cancer and we were able to show it in this patient. With these three samples, we could see across time how the tumor developed resistance to treatment.”

 

The study is published in the journal Clinical Cancer Research.

New gene associated with ALS identified.
This week, researchers at UMass Medical School and the National Institute on Aging reported the identification of a new gene implicated in the development of amyotrophic lateral sclerosis (ALS). Also known as Lou Gehrig’s disease, ALS is a horrific neurodegenerative disorder that degrades the connection between nerve signals and the muscles. Sufferers are robbed of their ability to move and, ultimately, even to breathe. Life expectancy is just 3 to 5 years after diagnosis.

To identify the gene, called KIF5A, the team carried out the largest genetics effort in ALS research with support from the ALS Association, creators of the Ice Bucket Challenge that raised a $115 million for research. The study compared the genomes between a group of nearly 22,000 people with ALS versus a group of over 80,000 healthy controls. Two independent genetic analyses identified differences in the expression of the KIF5A gene between the two groups.

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Cartoon representing the role that KIF5A plays in neurons. (Image: UMass Medical School)

KIF5A is active in neurons where it plays a key role in transporting cell components across the cell’s axon, the long, narrow portion of the cell that allows neurons to send long-range signals to other cells. It carries out this transport by tethering cell components on the axon’s cytoskeleton, a structural protein matrix within the cells. Several mutations in KIF5A were found in the ALS group which corroborates previous studies showing that mutations in other cytoskeleton genes are associated with ALS.

One next step for the researchers is to further examine the KIF5A mutations using patient-derived induced pluripotent stem cells.

The study was published in Neuron and picked up by Eureka Alert!