Sanford Burnham Prebys Medical Discovery Institute

Life lessons learned in the CIRM summer intern program

/ Kevin McCormack / Leave a comment
SPARK poster session; Photo by Esteban Cortez

When I was in high school I spent my summers working in a shoe shop and playing soccer with my mates. It never occurred to me that I could do something really  worthwhile with that time. So, when I meet the high school students who took part in the California Institute for Regenerative Medicine’s SPARK program I realized I had wasted a lot of time.

For those not familiar with SPARK, it stands for Summer Program to Accelerate Regenerative Medicine Knowledge. It’s a summer program offering high school students a chance to work in a world-class stem cell and gene therapy research facility. The quality of the work they do is truly remarkable. By the end of the summer they are doing projects that many full-time researchers would be proud of.

As part of that program the students also must write blogs and post photos and videos to Instagram to chart their progress. The quality of that work is equally impressive. Last week we posted items about the two best blogs from the students. But there were so many other fine entries that we thought it would be worthwhile to highlight elements of those.

For instance, Ricardo Rodriguez at Charles R. Drew University had some interesting observations on life, even when it’s not always working out the way you planned:

Ricardo Rodriguez: Photo by Esteban Cortez

“Cancer is not life going wrong so much as it is life changing. If mutation is random, then so is life. That beautiful randomness that drives evolution and extinction, change and stagnation, life and death, and for you to think that that part of your body could be simple in any way, whether it be simply evil, simply inconvenient, simply structured, is simply hilarious. There is beauty in your body’s complexity, adaptability, and resilience, and these attributes are not barred from any part of your life.”

Mindy Rodriguez at Beckman City of Hope says she learned valuable lessons from working with mice, creatures she previously considered scary, dirty and vicious, but later came to like:

“The CIRM SPARK program reinforced the value of facing my fears by exploring the unknown and most importantly taught me to be comfortable with the uncomfortable. In both cases, I found that it is our response to fear that shapes who we are. We can either run away from the thing that scares us or take each moment as a learning opportunity, embracing change over comfort.”

Manvi Ketireddy at work at UC Davis

Manvi Ketireddy at UC Davis had a similar experience, learning to accept things not working out.

“A researcher must be persistent and have the ability to endure lots of failures. I think that is what I love about research: the slight possibility of discovery and answers amid constant defeat is one of the greatest challenges to exist. And boy, do I love challenges.”

Ameera Ali in the lab (fish not included)

Ameera Ali at Sanford Burnham Prebys says she had struggled for years to decide on a career direction, but the internship gave her a fresh perspective on it all.

“Growing up, I never really knew what I wanted to do for a living, and I think that’s because I wanted to do everything. In kindergarten I wanted to be a paleontologist. In 5th grade I wanted to be the CEO of The San Diego Union Tribune, and in 9th grade I wanted to be a physicist at NASA. By 10th grade I was having an existential crisis about what to do with my life, and so began the search for my purpose at the ripe old age of 15.

So now, writing this blog, I never thought I’d end up spending so much of my time in a room filled floor to ceiling with fish tanks. You might be wondering, how does one end up going from physicist to fish farmer? Well, I’m not completely sure to be honest, but it’s been a very fun and interesting experience nonetheless.”

She says by the end she says what initially felt like mundane chores were actually moments worth celebrating.

“These aquatic friends have taught me a lot of valuable life lessons, like being appreciative of the little things in life, caring for others and see things from a different perspective, and realizing that

working in a biology lab allows me to explore my passions, be creative, and be a mother to hundreds of fish children on the side.”

SPARK attracts students from all over California, and it’s that diversity that makes it so important.

Alexa Gastelum

My name is Alexa Gastelum and I am from a small border town called Calexico. It is located in the Imperial Valley around two hours away from San Diego. I found out about this Internship from my Math teacher and Mesa Coordinator. They discussed what it was about, and I immediately knew that I wanted to apply. I have always been interested in doing labs and researching so I knew that it would be the perfect opportunity for me. It is not normal to be presented with an opportunity like this from where I’m from because it is a small and low-income town. When I told my family about this internship they were very supportive. They agreed that I needed to apply for it since it was an extremely good opportunity. Even though I would need to spend my summer away from my hometown, they were okay with it because they knew that I could not miss out on the opportunity. I decided to write my personal statement on a disease that hit close to home with my family which was Alzheimer’s. It is a disease that runs in my family and my uncle passed from it. I believe that this is what sparked my interest because I wanted to understand how it worked and how it affects the brain.

At the SPARK event Alexa told me her grandmother was so proud of her for being accepted at the program that she was going around town telling everyone about it. Her grandmother, and all the other grandmothers and mothers and fathers, had every reason to be proud of these students. They are remarkable young people and we look forward to following their careers in the years to come.

A guide to healing

/ Kevin McCormack / 3 Comments
Dr. Evan Snyder

Having grown up in an era where to find your way around you had to use paper maps, a compass and a knowledge of the stars (OK, I’m not actually that old!) I’m forever grateful to whoever invented the GPS. It’s a lifesaver, and I daresay has also saved more than a few marriages!

Having a way to guide people where they need to be is amazing. Now researchers at Sanford Burnham Prebys Medical Discovery Institute have come up with a similar tool for stem cells. It’s a drug that can help guide stem cells to go where they need to go, to repair damaged tissue and improve the healing process.

In a news release Evan Snyder, MD, PhD, the senior author of the study, explained in wonderfully simply terms what they have done:

“The ability to instruct a stem cell where to go in the body or to a particular region of a given organ is the Holy Grail for regenerative medicine. Now, for the first time ever, we can direct a stem cell to a desired location and focus its therapeutic impact.”

More than a decade ago Snyder and his team discovered that when our body suffers an injury the result is often inflammation and that this then sends out signals for stem cells to come and help repair the damage. This is fine when the problem is a cut or sprain, short term issues in need of a quick fix. But what happens if it’s something more complex, such as a heart attack or stroke where the need is more long term.

In the study, funded in part by CIRM, the team took a molecule, called CXCL12, known to help guide stem cells to damaged tissue, and used it to create a drug called SDV1a. Snyder says this new drug has several key properties.

“Since inflammation can be dangerous, we modified CXCL12 by stripping away the risky bit and maximizing the good bit. Now we have a drug that draws stem cells to a region of pathology, but without creating or worsening unwanted inflammation.”

To test the drug to see how well it worked the team implanted SDV1a and some human brain stem cells into mice with Sandhoff disease, a condition that progressively destroys cells in the brain and spinal cord. They were able to demonstrate that the drug helped the stem cells migrate to where they were needed and to help in repairing the damage. The treated mice had a longer lifespan and better motor function, as well as developing symptoms later than untreated mice.

The team is now testing this drug to see if it has any impact on ALS, also known as Lou Gehrig’s disease. And Snyder says there are other areas where it could prove effective.

“We are optimistic that this drug’s mechanism of action may potentially benefit a variety of neurodegenerative disorders, as well as non-neurological conditions such as heart disease, arthritis and even brain cancer. Interestingly, because CXCL12 and its receptor are implicated in the cytokine storm that characterizes severe COVID-19, some of our insights into how to selectively inhibit inflammation without suppressing other normal processes may be useful in that arena as well.”

CIRM’s President & CEO, Dr. Maria Millan, says this kind of work highlights the important role the stem cell agency plays, in providing long-term support for promising but early stage research.

“Thanks to decades of investment in stem cell science, we are making tremendous progress in our understanding of how these cells work and how they can be harnessed to help reverse injury or disease. Dr. Snyder’s group has identified a drug that could boost the ability of neural stem cells to home to sites of injury and initiate repair. This candidate could help speed the development of stem cell treatments for conditions such as spinal cord injury and Alzheimer’s disease.”

The discovery is published in the Proceedings of the National Academy of Sciences (PNAS)

CIRM & CZI & MOU for COVID-19

/ Kevin McCormack / Leave a comment

Too many acronyms? Not to worry. It is all perfectly clear in the news release we just sent out about this.

A new collaboration between the California Institute for Regenerative Medicine (CIRM) and the Chan Zuckerberg Initiative (CZI) will advance scientific efforts to respond to the COVID-19 pandemic by collaborating on disseminating single-cell research that scientists can use to better understand the SARS-CoV-2 virus and help develop treatments and cures.

CIRM and CZI have signed a Memorandum of Understanding (MOU) that will combine CIRM’s infrastructure and data collection and analysis tools with CZI’s technology expertise. It will enable CIRM researchers studying COVID-19 to easily share their data with the broader research community via CZI’s cellxgene tool, which allows scientists to explore and visualize measurements of how the virus impacts cell function at a single-cell level. CZI recently launched a new version of cellxgene and is supporting the single-cell biology community by sharing COVID-19 data, compiled by the global Human Cell Atlas effort and other related efforts, in an interactive and scalable way.

“We are pleased to be able to enter into this partnership with CZI,” said Dr. Maria T. Millan, CIRM’s President & CEO. “This MOU will allow us to leverage our respective investments in genomics science in the fight against COVID-19. CIRM has a long-standing commitment to generation and sharing of sequencing and genomic data from a wide variety of projects. That’s why we created the CIRM genomics award and invested in the Stem Cell Hub at the University of California, Santa Cruz, which will process the large complex datasets in this collaboration.”  

“Quickly sharing scientific data about COVID-19 is vital for researchers to build on each other’s work and accelerate progress towards understanding and treating a complex disease,” said CZI Single-Cell Biology Program Officer Jonah Cool. “We’re excited to partner with CIRM to help more researchers efficiently share and analyze single-cell data through CZI’s cellxgene platform.”

In March 2020, the CIRM Board approved $5 million in emergency funding to target COVID-19. To date, CIRM has funded 17 projects, some of which are studying how the SARS-CoV-2 virus impacts cell function at the single-cell level.

Three of CIRM’s early-stage COVID-19 research projects will plan to participate in this collaborative partnership by sharing data and analysis on cellxgene.   

  • Dr. Evan Snyder and his team at Sanford Burnham Prebys Medical Discovery Institute are using induced pluripotent stem cells (iPSCs), a type of stem cell that can be created by reprogramming skin or blood cells, to create lung organoids. These lung organoids will then be infected with the novel coronavirus in order to test two drug candidates for treating the virus.
  • Dr. Brigitte Gomperts at UCLA is studying a lung organoid model made from human stem cells in order to identify drugs that can reduce the number of infected cells and prevent damage in the lungs of patients with COVID-19.
  • Dr. Justin Ichida at the University of Southern California is trying to determine if a drug called a kinase inhibitor can protect stem cells in the lungs and other organs, which the novel coronavirus selectively infects and kills.

“Cumulative data into how SARS-CoV-2 affects people is so powerful to fight the COVID-19 pandemic,” said Stephen Lin, PhD, the Senior CIRM Science Officer who helped develop the MOU. “We are grateful that the researchers are committed to sharing their genomic data with other researchers to help advance the field and improve our understanding of the virus.”

CZI also supports five distinct projects studying how COVID-19 progresses in patients at the level of individual cells and tissues. This work will generate some of the first single-cell biology datasets from donors infected by SARS-CoV-2 and provide critical insights into how the virus infects humans, which cell types are involved, and how the disease progresses. All data generated by these grants will quickly be made available to the scientific community via open access datasets and portals, including CZI’s cellxgene tool.

Using mini lungs to test potential COVID-19 therapies

/ Kevin McCormack / 1 Comment
Dr. Evan Snyder

If someone told you they were working on lungs in a dish you might be forgiven for thinking that’s the worst idea for a new recipe you have ever heard of. But in the case of Dr. Evan Snyder and his team at Sanford Burnham Prebys Medical Discovery Institute it could be a recipe for a powerful new tool against COVID-19. 

Earlier this month the CIRM Board approved almost $250,000 for Dr. Snyder and his team to use human induced pluripotent stem cells (hiPSCs), a type of stem cell that can be created by reprogramming skin or blood cells, to create any other cell in the body, including lung cells.

These cells will then be engineered to become 3D lung organoids or “mini lungs in a dish”. The importance of this is that these cells resemble human lungs in a way animal models do not. They have the same kinds of cells, structures and even blood vessels that lungs do.

These cells will then be infected with the coronavirus and then be used to test two drugs to see if those drugs are effective against the virus.

In a news release Dr. Snyder says these cells have some big advantages over animal models, the normal method for early stage testing of new therapies.

“Mini lungs will also help us answer why some people with COVID-19 fare worse than others. Because they are made from hiPSCs, which come from patients and retain most of the characteristics of those patients, we can make ‘patient-specific’ mini lungs. We can compare the drug responses of mini lungs created from Caucasian, African American, and Latino men and women, as well as patients with a reduced capacity to fight infection to make sure that therapies work effectively in all patients. If not, we can adjust the dose or drug regime to help make the treatment more effective.

“We can also use the mini lungs experimentally to evaluate the effects of environmental toxins that come from cigarette smoking or vaping to make sure the drugs are still effective; and emulate the microenvironmental conditions in the lungs of patients with co-morbidities such as diabetes, and heart or kidney disease.”

To date CIRM has funded 15 projects targeting COVID-19, including three that are in clinical trials.

New model unlocks clues to treating deadly childhood cancer

/ Kevin McCormack / 1 Comment

CIRM-funded research at Sanford Burnham Prebys Medical Discovery Institute in San Diego is identifying compounds that could be used to help children battling a deadly brain cancer.

The cancer is choroid plexus carcinoma (CPC), a rare brain tumor that occurs mainly in children. As it grows the tumor can affect nearby parts of the brain resulting in nausea, vomiting and headaches.

Treatment involves surgery to remove the tumor followed by chemotherapy and radiation. However, many of the children are too young to undergo radiation and only around 40 percent are still alive five years after being diagnosed. Even those who do survive often experience life-long consequences such as developmental disabilities.

One obstacle to developing better therapies has been the lack of a good animal model to enhance our understanding of the disease. That’s where this later research, published in the journal Cancer Research, comes in.

The team at Sanford Burnham developed a new mouse model, by knocking out p53, a gene known to suppress tumor formation, and activating a gene called Myc, which is known to cause cancer.  

Robert Wechsler-Reya

In a news release, Robert Wechsler-Reya, the senior author of the paper, says this new model mirrors the way CPC grows and develops in humans.

“This model is a valuable tool that will increase our understanding of the biology of the cancer and allow us to identify and test novel approaches to therapy. This advance brings us one step closer to a future where every child survives—and thrives—after diagnosis with CPC.”

As proof of that the team tested nearly 8,000 compounds against the mouse tumor cells, to see if they could help stop or slow the progression of the disease. They identified three that showed potential of not just stopping the cancer, but of also not harming healthy surrounding cells.

“These compounds are promising, much-needed leads in the quest for an effective CPC treatment,” says Wechsler-Reya. “Our laboratory plans to evaluate these and additional compounds that can effectively treat this cancer.”

Targeted treatment for pediatric brain tumors shows promising results

/ Yimy Villa / Leave a comment
Image of medulloblastoma

Imagine sitting in the doctor’s office and being told the heartbreaking news that your child has been diagnosed with a malignant brain tumor. As one might expect, the doctor states that the most effective treatment option is typically a combination of chemotherapy and radiation. However, the doctor reveals that there are additional risks to take into account that apply to children. Since children’s tiny bodies are still growing and developing, chemotherapy and radiation can cause long-term side effects such as intellectual disabilities. As a parent, it is painful enough to have to watch a child go through chemotherapy and radiation without adding permanent damage into the fold.

Sadly, this scenario is not unique. Medulloblastoma is the most prevalent form of a pediatric brain tumor with more than 350 children diagnosed with cancer each year. There are four distinct subtypes of medulloblastoma, with the deadliest being known as Group 3.

Researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) are trying to minimize the collateral damage by finding personalized treatments that reduce side effects while remaining effective. Scientists at SBP are working with an inhibitor known as LSD1 that specifically targets Group 3 medulloblastoma in a mouse model. The study, published in Nature Communications, showed that the drug dramatically decreased the size of tumors grown under the mouse’s skin by shrinking the cancer by more than 80 percent. This suggested that it could also be effective against patients’ tumors if it could be delivered to the brain. The LSD1 inhibitor has shown promise in clinical trials, where it has been tested for treating other types of cancer.

According to Robert Wechsler-Reya, Ph.D., senior author of the paper and director of the Tumor Initiation and Maintenance Program at SBP: “Our lab is working to understand the genetic pathways that drive medulloblastoma so we can find better ways to intervene and treat tumors. This study shows that a personalized treatment based upon a patient’s specific tumor type might be within our reach.”

Dr. Wechsler-Reya’s work on medulloblastoma was, in part, funded by the CIRM (LA1-01747) in the form of a Research Leadership Award for $5,226,049.

Deep dive into muscle repair yields new strategies to combat Duchenne muscular dystrophy

/ Todd Dubnicoff / 1 Comment

Researchers at the Sanford Burnham Prebys Medical Discovery Institute (SBP) reported new findings this week that may lead to novel therapeutic strategies for people suffering from Duchenne muscular dystrophy (DMD). DMD, a muscle-wasting disease that affects 1 in 7250 males aged 5 to 24 years in the United States, is caused by a genetic mutation leading to the lack of a protein called dystrophin. Without dystrophin, muscle cells become fragile and are easily damaged. Instead of self-repair, the muscles are replaced by scar tissue, a process called fibrosis that leads to muscle degeneration and wasting.

DMD_KhanAcademy

Dystrophin, a protein that maintains the structural integrity of muscle fibers, is missing in people with DMD. Image credit: Khan Academy

Boys with DMD first show signs of muscle weakness between ages 3-5 and often stop walking by the time they’re teenagers. Eventually the muscles critical for breathing and heart function stop working. Average life expectancy is 26 and there is no cure.

The SBP scientists are aiming to treat DMD by boosting muscle repair in affected individuals. But to do that, they sought to better understand how muscle regeneration works in the first place. In the current study, they focused their efforts on so-called fibro/adipogenic precursor (FAP) cells which, in response to acute injury, appear to play a role in stimulating muscle stem cells to divide and replace damaged muscle in healthy individuals. But FAPs are also implicated in the muscle wasting and scarring that’s seen in DMD.

By examining the gene activity of single FAP cells from mouse models of acute injury and DMD, the researchers identified a sub-population of FAP cells (sub-FAPs). Further study of these sub-FAPs showed that during early stages of muscle regeneration, these cells promote muscle stem cell activation but then at later stages, sub-FAPs – identified by a cell surface protein called Vcam1 – stimulate fibrosis. It turns out that during healthy acute muscle injury, the sub-FAPs with cell-surface Vcam1 protein are readily eaten up and removed by immune cells thereby avoiding muscle fibrosis. But in the DMD mouse model, removal of these sub-FAPs is impaired and instead collagen deposits and muscle fibrosis occur which are hallmarks of the progressive degeneration seen in DMD.

Barbora Malecova, Ph.D., a first author of the study, explained the implications of these results in a press release:

“This study elucidates the cellular and molecular pathogenesis of muscular dystrophy. These results indicate that removing or modulating the activity of Vcam1-positive sub-FAPs, which promote fibrosis, could be an effective treatment for DMD.”

The lab, led by Pier Lorenzo Puri, M.D., next will explore the possibility of finding drugs that target the Vcam1 sub-FAPs which in turn could help prevent fibrosis in DMD.

The study, funded in part by CIRM, appears in Nature Communications. CIRM is also funding a Phase 2 clinical trial testing a stem cell-based therapy that aims to improve the life-threatening heart muscle degeneration that occurs in DMD patients.

Stem Cell Roundup: Artificial Embryos to Study Miscarriage and ALS Insight – Muscle Repair Cells Go Rogue

/ Todd Dubnicoff / 2 Comments

Stem Cell Image of the Week: Artificial embryos for studying miscarriage (Adonica Shaw)

etxembryos

Mouse embryos artificially generated by combining three types of stem cells.
Image: University of Cambridge.

This week’s stem cell image of the week comes from a team of researchers from The University of Cambridge who published research in Nature Cell Biology earlier this week indicating they’d achieved a breakthrough in stem cell research that resulted in the generation of a key developmental step that’d never before been achieved when trying to generate an artificial embryo.

To create the artificial embryo, the scientists combined mouse embryonic stem cells with two other types of stem cells that are present in the very earliest stages of embryo development. The reseachers grew the three stem cell types into a dish and coaxed them into simulating a process called gastrulation – one of the very first events that happens during a creature’s development in which the early embryo begins reorganizing into more and more complex multilayer organ structures.

In an interview with The Next Web (TNW), Professor Magdalena Zernicka-Goetz, who led the research team, says:

”Our artificial embryos underwent the most important event in life in the culture dish. They are now extremely close to real embryos. To develop further, they would have to implant into the body of the mother or an artificial placenta.”

The goal of this research isn’t to create mice on demand. Its purpose is to gain insights into early life development. And that could lead to a giant leap in our understanding of what happens during the period in a woman’s pregnancy where the risk of miscarriage is highest.

According to professor Zernicka-Goetz,

magda3

Magdalena Zernicka-Goetz, PhD

“We can also now try to apply this to the equivalent human stem cell types and so study the very earliest events in human embryo development without actually having to use natural human embryos.The early stages of embryo development are when a large proportion of pregnancies are lost and yet it is a stage that we know very little about. Now we have a way of simulating embryonic development in the culture dish, so it should be possible to understand exactly what is going on during this remarkable period in an embryo’s life, and why sometimes this process fails.”

Muscle repair cells go rogue – a possible drug target for ALS?
Call it a case of a good cell gone bad. This week researchers at Sanford Burnham Prebys Medical Discovery Institute, report in Nature Cell Biology that fibro-adipogenic progenitors (FAPs) – cells that are critical in coordinating the repair of torn muscles – can turn rogue, causing muscles to wither and scar. This “Dr. Jekyl and Mr. Hype” discovery may lead to novel treatments for a number of incurable disorders like amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA) and spinal cord injury.

drjekyllmrhy

Senior author Pier Lorenzo Puri, M.D. (right) and co-first author Luca Madaro, Ph.D. Credit: Fondazione Santa Lucia IRCCS

When muscle is strained, whether due to an acute injury or even weight-lighting, a consistent order of events occurs within the muscle. FAB cells enter the muscle tissue after immune cells called macrophages come in and gobble up dead tissue but before muscle stem cells are stimulated to regenerate the lost muscle. However, to the researchers’ surprise, something entirely different happens in the case of neuromuscular disorders like ALS where nerve signal connections to the muscles degenerate.

Once nerves are no longer attached to muscle and stop sending movement signals from the brain, the macrophages don’t infiltrate the muscle and instead the FAPs pile up in the muscle and never leave. And as a result, muscle stem cells are never activated. In ALS patients, this cellular train crash leads to progressive loss of muscle control to move the limbs and ultimately even to breathe.

The promising news from these findings, which were funded in part by CIRM, is that the team identified of an out-of-whack cell signaling pathway that is responsible for the breakdown in the rogue function of the FAP cells. The researchers hope further studies of this pathway’s role in muscle degeneration may lead to novel therapies and disease-screening technologies for ALS and other motor neuron diseases.

Stem Cell Roundup: Rainbow Sherbet Fruit Fly Brains, a CRISPR/iPSC Mash-up and more

/ Todd Dubnicoff / Leave a comment

This week’s Round Up is all about the brain with some CRISPR and iPSCs sprinkled in:

Our Cool Stem Cell Image of the Week comes from Columbia University’s Zuckerman Institute:

Mann-SC-Hero-01-19-18

(Credit: Jon Enriquez/Mann Lab/Columbia’s Zuckerman Institute).

This rainbow sherbet-colored scientific art is a microscopy image of a fruit fly nervous system in which brain cells were randomly labeled with different colors. It was a figure in a Neuron study published this week showing how cells derived from the same stem cells can go down very different developmental paths but then later are “reunited” to carry out key functions, such as in this case, the nervous system control of leg movements.

A new therapeutic avenue for Parkinson’s disease – Buck Institute

Many animal models of Parkinson’s disease are created by mutating specific genes to cause symptoms that mimic this incurable, neurodegenerative disorder. But, by far, most cases of Parkinson’s are idiopathic, a fancy term for spontaneous with no known genetic cause. So, researchers at the Buck Institute took another approach: they generated a mouse model of Parkinson’s disease using the pesticide, paraquat, exposure to which is known to increase the risk of the idiopathic form of Parkinson’s.

Their CIRM-funded study in Cell Reports showed that exposure to paraquat leads to cell senescence – in which cells shut down and stop dividing – particularly in astrocytes, brain cells that support the function of nerve cells. Ridding the mice of these astrocytes relieved some of the Parkinson’s like symptoms. What makes these results so intriguing is the team’s analysis of post-mortem brains from Parkinson’s patients also showed the hallmarks of increased senescence in astrocytes. Perhaps, therapeutic approaches that can remove senescent cells may yield novel Parkinson’s treatments.

Discovery may advance neural stem cell treatments for brain disorders – Sanford-Burnham Prebys Medical Discovery Institute (via Eureka Alert)

Another CIRM-funded study published this week in Nature Neuroscience may also help pave the way to new treatment strategies for neurologic disorders like Parkinson’s disease. A team at Sanford Burnham Prebys Medical Discovery Institute (SBP) discovered a novel gene regulation system that brain stem cells use to maintain their ability to self-renew.

The study centers around messenger RNA, a molecular courier that transcribes a gene’s DNA code and carries it off to be translated into a protein. The team found that the removal of a chemical tag on mRNA inside mouse brain stem cells caused them to lose their stem cell properties. Instead, too many cells specialized into mature brain cells leading to abnormal brain development in animal studies. Team lead Jing Crystal Zhao, explained how this finding is important for future therapeutic development:

CrystalZhao_headshot

Crystal Zhao

“As NSCs are increasingly explored as a cell replacement therapy for neurological disorders, understanding the basic biology of NSCs–including how they self-renew–is essential to harnessing control of their in vivo functions in the brain.”

Researchers Create First Stem Cells Using CRISPR Genome Activation – The Gladstone Institutes

Our regular readers are most likely familiar with both CRISPR gene editing and induced pluripotent stem cell (iPSC) technologies. But, in case you missed it late last week, a Cell Stem Cell study out of Sheng Ding’s lab at the Gladstone Institutes, for the first time, combined the two by using CRISPR to make iPSCs. The study got a lot of attention including a review by Paul Knoepfler in his blog The Niche. Check it out for more details!

 

Stem Cell Stories that Caught Our Eye: GPS for Skin & Different Therapies for Aging vs. Injured Muscles?

/ Todd Dubnicoff / Leave a comment

Skin stem cells specialize into new skin by sensing neighborhood crowding
When embarking on a road trip, the GPS technology inside our smartphones helps us know where we are and how to get where we’re going. The stem cells buried in the deepest layers of our skin don’t have a GPS and yet, they do just fine determining their location, finding their correct destination and becoming the appropriate type of skin cell. And as a single organ, all the skin covering your body maintains the right density and just the right balance of skin stem cells versus mature skin cells as we grow from a newborn into adult.

crowdinginth

Skin cells growing in a petri dish (green: cytoskeleton, red: cell-cell junction protein).
Credit: MPI for Biology of Aging

This easily overlooked but amazing feat is accomplished as skin cells are continually born and die about every 30 days over your lifetime. How does this happen? It’s an important question to answer considering the skin is our first line of defense against germs, toxins and other harmful substances.

This week, researchers at the Max Planck Institute for Biology of Aging in Cologne, Germany reported a new insight into this poorly understood topic. The team showed that it all comes down to the skin cells sensing the level of crowding in their local environment. As skin stem cells divide, it puts the squeeze on neighboring stem cells. This physical change in tension on these cells “next door” triggers signals that cause them to move upward toward the skin surface and to begin maturing into skin cells.

Lead author Yekaterina Miroshnikova explained in a press release the beauty of this mechanism:

“The fact that cells sense what their neighbors are doing and do the exact opposite provides a very efficient and simple way to maintain tissue size, architecture and function.”

The research was picked up by Phys.Org on Tuesday and was published in Nature Cell Biology.

Stem cells respond differently to aging vs. injured muscle
From aging skin, we now move on to our aging and injured muscles, two topics I know oh too well as a late-to-the-game runner. Researchers at the Sanford Burnham Prebys Medical Discovery Institute (SBP) in La Jolla report a surprising discovery that muscle stem cells respond differently to aging versus injury. This important new insight could help guide future therapeutic strategies for repairing muscle injuries or disorders.

muscle stem cell

Muscle stem cell (pink with green outline) sits along a muscle fiber.
Image: Michael Rudnicki/OIRM

Muscle stem cells, also called satellite cells, make a small, dormant population of cells in muscle tissue that springs to life when muscle is in need of repair. It turns out that these stem cells are not identical clones of each other but instead are a diverse pool of cells.  To understand how the assortment of muscle stem cells might respond differently to the normal wear and tear of aging, versus damage due to injury or disease, the research team used a technology that tracks the fate of individual muscle stem cells within living mice.

The analysis showed a clear but unexpected result. In aging muscle, the muscle stem cells maintained their diversity but their ability to divide and grow declined. However, the opposite result was observed in injured muscle: the muscle stem cell diversity became limited but the capacity to divide was not affected. In a press release, team leader Alessandra Sacco explains the implications of these findings for therapy development:

sacco

Alessandra Sacco, PhD

“This study has shown clear-cut differences in the dynamics of muscle stem cell pools during the aging process compared to a sudden injury. This means that there probably isn’t a ‘one size fits all’ approach to prevent the decline of muscle stem cells. Therapeutic strategies to maintain muscle mass and strength in seniors will most likely need to differ from those for patients with degenerative diseases.”

This report was picked up yesterday by Eureka Alert and published in Cell Stem Cell.