Two Early-Stage Research Programs Targeting Cartilage Damage Get Funding from Stem Cell Agency

Darryl D’Lima: Scripps Health

Every year millions of Americans suffer damage to their cartilage, either in their knee or other joints, that can eventually lead to osteoarthritis, pain and immobility. Today the governing Board of the California Institute for Regenerative Medicine (CIRM) approved two projects targeting repair of damaged cartilage.

The projects were among 17 approved by CIRM as part of the DISC2 Quest Discovery Program. The program promotes the discovery of promising new stem cell-based and gene therapy technologies that could be translated to enable broad use and ultimately, improve patient care.

Dr. Darryl D’Lima and his team at Scripps Health were awarded $1,620,645 to find a way to repair a torn meniscus. Every year around 750,000 Americans experience a tear in their meniscus, the cartilage cushion that prevents the bones in the knee grinding against each other. These injuries accelerate the early development of osteoarthritis, for which there is no effective treatment other than total joint replacement, which is a major operation. There are significant socioeconomic benefits to preventing disabling osteoarthritis. The reductions in healthcare costs are also likely to be significant.

The team will use stem cells to produce meniscal cells in the lab. Those are then seeded onto a scaffold made from collagen fibers to create tissue that resembles the knee meniscus. The goal is to show that, when placed in the knee joint, this can help regenerate and repair the damaged tissue.

This research is based on an earlier project that CIRM funded. It highlights our commitment to helping good science progress, hopefully from the bench to the bedside where it can help patients.

Dr. Kevin Stone: Photo courtesy Stone Research Foundation

Dr. Kevin Stone and his team at The Stone Research Foundation for Sports Medicine and Arthritis were awarded $1,316,215 to develop an approach to treat and repair damaged cartilage using a patient’s own stem cells.

They are using a paste combining the patient’s own articular tissue as well as Mesenchymal Stem Cells (MSC) from their bone marrow. This mixture is combined with an adhesive hydrogel to form a graft that is designed to support cartilage growth and can also stick to surfaces without the need for glue. This paste will be used to augment the use of a microfracture technique, where micro-drilling of the bone underneath the cartilage tear brings MSCs and other cells to the fracture site. The hope is this two-pronged approach will produce an effective and functional stem cell-based cartilage repair procedure.

If effective this could produce a minimally invasive, low cost, one-step solution to help people with cartilage injuries and arthritis.

The full list of DISC2 grantees is:

ApplicationTitlePrincipal Investigator and InstitutionAmount
DISC2-13212Preclinical development of an exhaustion-resistant CAR-T stem cell for cancer immunotherapy  Ansuman Satpathy – Stanford University    $ 1,420,200  
DISC2-13051Generating deeper and more durable BCMA CAR T cell responses in Multiple Myeloma through non-viral knockin/knockout multiplexed genome engineering  Julia Carnevale – UC San Francisco  $ 1,463,368  
DISC2-13020Injectable, autologous iPSC-based therapy for spinal cord injury  Sarah Heilshorn – Stanford University    $789,000
DISC2-13009New noncoding RNA chemical entity for heart failure with preserved ejection fraction.  Eduardo Marban – Cedars-Sinai Medical Center  $1,397,412  
DISC2-13232Modulation of oral epithelium stem cells by RSpo1 for the prevention and treatment of oral mucositis  Jeffrey Linhardt – Intact Therapeutics Inc.  $942,050  
DISC2-13077Transplantation of genetically corrected iPSC-microglia for the treatment of Sanfilippo Syndrome (MPSIIIA)  Mathew Blurton-Jones – UC Irvine    $1,199,922  
DISC2-13201Matrix Assisted Cell Transplantation of Promyogenic Fibroadipogenic Progenitor (FAP) Stem Cells  Brian Feeley – UC San Francisco  $1,179,478  
DISC2-13063Improving the efficacy and tolerability of clinically validated remyelination-inducing molecules using developable combinations of approved drugs  Luke Lairson – Scripps Research Inst.  $1,554,126  
DISC2-13213Extending Immune-Evasive Human Islet-Like Organoids (HILOs) Survival and Function as a Cure for T1D  Ronald Evans – The Salk Institute for Biological Studies    $1,523,285  
DISC2-13136Meniscal Repair and Regeneration  Darryl D’Lima – Scripps Health      $1,620,645  
DISC2-13072Providing a cure for sphingosine phosphate lyase insufficiency syndrome (SPLIS) through adeno-associated viral mediated SGPL1 gene therapy  Julie Saba – UC San Francisco  $1,463,400  
DISC2-13205iPSC-derived smooth muscle cell progenitor conditioned medium for treatment of pelvic organ prolapse  Bertha Chen – Stanford University  $1,420,200  
DISC2-13102RNA-directed therapy for Huntington’s disease  Gene Wei-Ming Yeo  – UC San Diego  $1,408,923  
DISC2-13131A Novel Therapy for Articular Cartilage Autologous Cellular Repair by Paste Grafting  Kevin Stone – The Stone Research Foundation for Sports Medicine and Arthritis    $1,316,215  
DISC2-13013Optimization of a gene therapy for inherited erythromelalgia in iPSC-derived neurons  Ana Moreno – Navega Therapeutics    $1,157,313  
DISC2-13221Development of a novel stem-cell based carrier for intravenous delivery of oncolytic viruses  Edward Filardo – Cytonus Therapeutics, Inc.    $899,342  
DISC2-13163iPSC Extracellular Vesicles for Diabetes Therapy  Song Li – UC Los Angeles  $1,354,928  

Researchers develop a stem cell-based implant for cartilage restoration and treating osteoarthritis

The Plurocart’s scaffold membrane seeded with stem cell-derived chondrocytes. Image courtesy of USC Photo/Denis Evseenko.

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Researchers at the Keck School of Medicine of USC have used a stem cell-based bio-implant to repair cartilage and delay joint degeneration in a large animal model. This paves the way to potentially treat humans with cartilage injuries and osteoarthritis, which occurs when the protective cartilage at the ends of the bones wears down over time. The disorder affects millions worldwide.

 The researchers are using this technology to manufacture the first 64 implants to be tested on humans with support from a $6 million grant from the California Institute for Regenerative Medicine (CIRM).

Researchers Dr. Denis Evseenko, and Dr. Frank Petrigliano led the development of the therapeutic bio-implant, called Plurocart. It’s composed of a scaffold membrane seeded with stem cell-derived chondrocytes, the cells responsible for producing and maintaining healthy articular cartilage tissue. 

In the study, the researchers implanted the Plurocart membrane into a pig model of osteoarthritis, resulting in the long-term repair of articular cartilage defects. Evseenko said the findings are significant because the implant fully integrated in the damaged articular cartilage tissue and survived for up to six months. “Previous studies have not been able to show survival of an implant for such a long time,” Evseenko added.

The researchers also found that the cartilage tissue generated was strong enough to withstand compression and elastic enough to accommodate movement without breaking.

Osteoarthritis, an often-painful disorder, can affect any joint, but most commonly affects those in our knees, hips, hands and spine. The USC researchers hope their implant will help prevent the development of arthritis and alleviate the need for invasive joint replacement surgeries.

“Many of the current options for cartilage injury are expensive, involve complex logistical planning, and often result in incomplete regeneration,” said Petrigliano. “Plurocart represents a practical, inexpensive, one-stage therapy that may be more effective in restoring damaged cartilage and improve the outcome of such procedures.”

Read the full study here and learn more about the CIRM grant here.

A hair raising tale

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For many men, losing their hair is not just something that happens with age, it’s traumatic. A survey of men from the UK, France, Germany, Italy and Spain found that more than 70% of men who reported losing their hair said it was an important feature of their image, and 62% agreed that hair loss could affect self-esteem. So, while a scientist who comes up with a way to prevent hair loss may not win a Nobel Prize, they will certainly get the undying gratitude of millions of men, and some women, around the world.

Now a team at Northwestern Medicine may just have found some clues as to why it happens, and some clues on how to stop it.

As we age our hair follicles go through a cycle of growth and death. As older hairs die there are stem cells in the hair follicles that produce new, replacement hair follicle cells. In this study, which was done in older male mice, the researchers found that as the mice age the stem cells in the hair start to lose the stickiness that helps them remain in the hair follicles. Without that stickiness they drift outside of the protective environment and can’t survive.

As Dr. Rui Yi, lead author of the study says in a news release; no hair stem cells, no hair replacements. “The result is fewer and fewer stem cells in the hair follicle to produce hair. This results in thinning hair and ultimately baldness during aging.”

Happily, the team also discovered two genes that seem to play a key role in generating the stickiness the cells need to stay in the follicle. They are now trying to reinstate those genes to see if that can reverse hair loss.

While this was done in mice the researchers say there are a lot of similarities between mice and humans in hair and stem cells.

One can only hope.

The study is published in the journal Nature Aging.

Some good news for people with dodgy knees

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Graphic contrasting a healthy knee with one that has osteoarthritis

About 10% of Americans suffer from knee osteoarthritis, a painful condition that can really impair mobility and quality of life. It’s often caused by an injury to cartilage, say when you were playing sports in high school or college, and over time it continues to degenerate and ultimately results in the  loss of both cartilage and bone in the joint.

Current treatments involve either medication to control the pain or surgery. Medication works up to a point, but as the condition worsens it loses effectiveness.  Knee replacement surgery can be effective, but is a serious, complicated procedure with a long recovery time.  That’s why the governing Board of the California Institute for Regenerative Medicine (CIRM) voted to invest almost $6 million in an innovative stem cell therapy approach to helping restore articular cartilage in the knee.

Dr. Frank Petrigliano, Chief of the Epstein Family Center for Sports Medicine at Keck Medicine of the University of Southern California (USC), is using pluripotent stem cells to create chondrocytes (the cells responsible for cartilage formation) and then seeding those onto a scaffold. The scaffold is then surgically implanted at the site of damage in the knee. Based on scientific data, the seeded scaffold has the potential to regenerate the damaged cartilage, thus decreasing the likelihood of progression to knee osteoarthritis.  In contrast to current methods, this new treatment could be an off-the-shelf approach that would be less costly, easier to administer, and might also reduce the likelihood of progression to osteoarthritis.

This is a late-stage pre-clinical program. The goals are to manufacture clinical grade product, carry out extensive studies to demonstrate safety of the approach, and then file an IND application with the FDA, requesting permission to test the product in a clinical trial in people.

“Damage to the cartilage in our knees can have a big impact on quality of life,” says Dr. Maria T. Millan, MD, President and CEO of CIRM. “It doesn’t just cause pain, it also creates problems carrying out simple, everyday activities such as walking, climbing stairs, bending, squatting and kneeling. Developing a way to repair or replace the damaged cartilage to prevent progression to knee osteoarthritis could make a major difference in the lives of millions of Americans. This program is a continuation of earlier stage work funded by CIRM at the Basic Biology and Translational stages, illustrating how CIRM supports scientific programs from early stages toward the clinic.”

Celebrating Stem Cell Awareness Day

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The second Wednesday in October is celebrated as Stem Cell Awareness Day. It’s an event that CIRM has been part of since then Governor Arnold Schwarzenegger launched it back in 2008 saying: ”The discoveries being made today in our Golden State will have a great impact on many around the world for generations to come.”

In the past we would have helped coordinate presentations by scientists in schools and participated in public events. COVID of course has changed all that. So, this year, to help mark the occasion we asked some people who have been in the forefront of making Governor Schwarzenegger’s statement come true, to share their thoughts and feelings about the day. Here’s what they had to say.

What do you think is the biggest achievement so far in stem cell research?

Dr. Jan Nolta

Jan Nolta, PhD., Director of the Stem Cell Program at UC Davis School of Medicine, and directs the new Institute for Regenerative Cures. “The work of Don Kohn and his UCLA colleagues and team members throughout the years- developing stem cell gene therapy cures for over 50 children with Bubble baby disease. I was very fortunate to work with Don for the first 15 years of my career and know that development of these cures was guided by his passion to help his patients.

Dr. Clive Svendsen

Clive Svendsen, PhD. Director, Board of Governors Regenerative Medicine Institute at Cedars-Sinai: “Without a doubt the discovery of how to make human iPSCs by Shinya Yamanaka and Jamie Thomson.”

When people ask you what kind of impact CIRM and stem cell research has had on your life what do you say?

Ronnie and his parents celebrating his 1st birthday. (Photo courtesy of Pawash Priyank)

Pawash Priyank and Upasana Thakur, parents of Ronnie, who was born with a life-threatening immune disorder but is thriving today thanks to a CIRM-funded clinical trial at UC San Francisco. “This is beyond just a few words and sentences but we will give it a shot. We are living happily today seeing Ronnie explore the world day by day, and this is only because of what CIRM does every day and what Stem cell research has done to humanity. Researchers and scientists come up with innovative ideas almost every day around the globe but unless those ideas are funded or brought to implementation in any manner, they are just in the minds of those researchers and would never be useful for humanity in any manner. CIRM has been that source to bring those ideas to the table, provide facilities and mechanisms to get those actually implemented which eventually makes babies like Ronnie survive and see the world. That’s the impact CIRM has. We have witnessed and heard several good arguments back in India in several forums which could make difference in the world in different sectors of lives but those ideas never come to light because of the lack of organizations like CIRM, lack of interest from people running the government. An organization like CIRM and the interest of the government to fund them with an interest in science and technology actually changes the lives of people when some of those ideas come to see the light of real implementation. 

What are your biggest hopes for the future at UC Davis?

Jan Nolta, PhD: “The future of stem cell and gene therapy research is very bright at UC Davis, thanks to CIRM and our outstanding leadership. We currently have 48 clinical trials ongoing in this field, with over 20 in the pipeline, and are developing a new education and technology complex, Aggie Square, next to the Institute for Regenerative Cures, where our program is housed. We are committed to our very diverse patient population throughout the Sacramento region and Northern California, and to expanding and increasing the number of novel therapies that can be brought to all patients who need them.”

What are your biggest hopes for the future at Cedars-Sinai?

Clive Svendsen, PhD: “That young investigators will get CIRM or NIH funding and be leaders in the regenerative medicine field.”

What do you hope is the future for stem cell research?

Pawash Priyank and Upasana Thakur: “We always have felt good about stem cell therapy. For us, a stem cell has transformed our lives completely. The correction of sequencing in the DNA taken out of Ronnie and injecting back in him has given him life. It has given him the immune system to fight infections. Seeing him grow without fear of doing anything, or going anywhere gives us so much happiness every hour. That’s the impact of stem cell research. With right minds continuing to research further in stem cell therapy bounded by certain good processes & laws around (so that misuse of the therapy couldn’t be done) will certainly change the way treatments are done for certain incurable diseases. I certainly see a bright future for stem cell research.”

On a personal note what is the moment that touched you the most in this journey.

Jan Nolta, PhD: “Each day a new patient or their story touches my heart. They are our inspiration for working hard to bring new options to their care through cell and gene therapy.”

Clive Svendsen, PhD: “When I realized we would get the funding to try and treat ALS with stem cells”

How important is it to raise awareness about stem cell research and to educate the next generation about it?

Pawash Priyank and Upasana Thakur: “Implementing stem cell therapy as a curriculum in the educational systems right from the beginning of middle school and higher could prevent false propaganda of it through social media. Awareness among people with accurate articles right from the beginning of their education is really important. This will also encourage the new generation to choose this as a subject in their higher studies and contribute towards more research to bring more solutions for a variety of diseases popping up every day.”

Them bones them bones them dry bones – and how to help repair them

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Broken bones

People say that with age comes wisdom, kindness and confidence. What they usually don’t say is that it also comes with aches and pains and problems we didn’t have when we were younger. For example, as we get older our bones get thinner and more likely to break and less likely to heal properly.

That’s a depressing opening paragraph isn’t it. But don’t worry, things get better from here because new research from Germany has found clues as to what causes our bones to become more brittle, and what we can do to try and stop that.

Researchers at the Max Planck Institute for Biology of Ageing and CECAD Cluster of Excellence for Ageing Research at the University of Cologne have identified changes in stem cells from our bone marrow that seem to play a key role in bones getting weaker as we age.

To explain this we’re going to have to go into the science a little, so bear with me. One of the issues the researchers focused on is the role of epigenetics, this is genetic information that doesn’t change the genes themselves but does change their activity. Think of it like a light switch. The switch doesn’t change the bulb, but it does control when it’s on and when it’s off. So this team looked at the epigenome of MSCs, the stem cells found in the bone marrow. These cells play a key role in the creation of cartilage, bone and fat cells.

In a news release, Dr. Andromachi Pouikli, one of the lead researchers in the study, says these MSCs don’t function as well as we get older.

“We wanted to know why these stem cells produce less material for the development and maintenance of bones as we age, causing more and more fat to accumulate in the bone marrow. To do this, we compared the epigenome of stem cells from young and old mice. We could see that the epigenome changes significantly with age. Genes that are important for bone production are particularly affected.”

So, they took some stem cells from the bone marrow of mice and tested them with a solution of sodium acetate. Now sodium acetate has a lot of uses, including being used in heating pads, hand warmers and as a food seasoning, but in this case the solution was able to make it easier for enzymes to get access to genes and boost their activity.

“This treatment impressively caused the epigenome to rejuvenate, improving stem cell activity and leading to higher production of bone cells,” Pouikli said.

So far so good. But does this work the same way in people? Maybe so. The team analyzed MSCs from people who had undergone hip surgery and found that they showed the same kind of age-related changes as the cells from mice.

Clearly there’s a lot more work to do before we can even think about using this finding as a solution to aging bones. But it’s an encouraging start.

The study is published in the journal Nature Aging.

Feds hit predatory stem cell clinics with a one-two punch

Federal Trade Commission

Stem cells have a number of amazing properties and tremendous potential to heal previously untreatable conditions. But they also have the potential to create a financial windfall for clinics that are more focused on lining their wallets than helping patients. Now the federal government is cracking down on some of these clinics in a couple of different ways.

The Food and Drug Administration (FDA) sent a warning letter to the Utah Cord Bank LLC and associated companies warning them that the products it sold – specifically “human umbilical cord blood, umbilical cord, and amniotic membrane derived cellular products” – were violating the law.

At the same time the Federal Trade Commission and the Georgia Office of the Attorney General began legal proceedings against Regenerative Medicine Institute of America. The lawsuit says the company claims its products can rebuild cartilage and help treat joint and arthritis pain, and is charging patients thousands of dollars for “treatments” that haven’t been shown to be either safe or effective.

Bloomberg Law reporter Jeannie Baumann recently wrote a fine, in-depth article on these latest steps against predatory stem cell clinics.

CIRM has been a fierce opponents of bogus stem cell clinics for years and has worked with California lawmakers to try and crack down on them. We’re delighted to see that the federal government is stepping up its efforts to stop them marketing their snake oil to unsuspecting patients and will support them every step along the way.

CIRM has produced a short video and other easy to digest information on questions people should ask before signing up for any clinical trial. You can find those resources here.

CIRM has also published findings in Stem Cells Translational Medicine that discuss the three R’s–regulated, reliable, and reputable–and how these can help protect patients with uniform standards for stem cell treatments .

Paving the way for a treatment for dementia

What happens in a stroke

When someone has a stroke, the blood flow to the brain is blocked. This kills some nerve cells and injures others. The damaged nerve cells are unable to communicate with other cells, which often results in people having impaired speech or movement.

While ischemic and hemorrhagic strokes affect large blood vessels and usually produce recognizable symptoms there’s another kind of stroke that is virtually silent. A ‘white’ stroke occurs in blood vessels so tiny that the impact may not be noticed. But over time that damage can accumulate and lead to a form of dementia and even speed up the progression of Alzheimer’s disease.

Now Dr. Tom Carmichael and his team at the David Geffen School of Medicine at UCLA have developed a potential treatment for this, using stem cells that may help repair the damage caused by a white stroke. This was part of a CIRM-funded study (DISC2-12169 – $250,000).

Instead of trying to directly repair the damaged neurons, the brain nerve cells affected by a stroke, they are creating support cells called astrocytes, to help stimulate the body’s own repair mechanisms.

In a news release, Dr. Irene Llorente, the study’s first author, says these astrocytes play an important role in the brain.

“These cells accomplish many tasks in repairing the brain. We wanted to replace the cells that we knew were lost, but along the way, we learned that these astrocytes also help in other ways.”

The researchers took skin tissue and, using the iPSC method (which enables researchers to turn cells into any other kind of cell in the body) turned it into astrocytes. They then boosted the ability of these astrocytes to produce chemical signals that can stimulate healing among the cells damaged by the stroke.

These astrocytes were then not only able to help repair some of the damaged neurons, enabling them to once again communicate with other neurons, but they also helped another kind of brain cell called oligodendrocyte progenitor cells or OPCs. These cells help make a protective sheath around axons, which transmit electrical signals between brain cells. The new astrocytes stimulated the OPCs into repairing the protective sheath around the axons.

Mice who had these astrocytes implanted in them showed improved memory and motor skills within four months of the treatment.  

And now the team have taken this approach one step further. They have developed a method of growing these astrocytes in large amounts, at very high quality, in a relatively short time. The importance of that is it means they can produce the number of cells needed to treat a person.

“We can produce the astrocytes in 35 days,” Llorente says. “This process allows rapid, efficient, reliable and clinically viable production of our therapeutic product.”

The next step is to chat with the Food and Drug Administration (FDA) to see what else they’ll need to do to show they are ready for a clinical trial.

The study is published in the journal Stem Cell Research.

City of Hope scientists use stem cells to develop ‘mini-brains’ to study Alzheimer’s and to test drugs in development

Alzheimer’s is a progressive disease that destroys memory and other important mental functions. According to the non-profit HFC, co-founded by CIRM Board member Lauren Miller Rogen and her husband Seth Rogen, more than 5 million Americans are living with Alzheimer’s. It is the 6th leading cause of death in the U.S and it is estimated that by 2050 as many as 16 million Americans will have the disease. Alzheimer’s is the only cause of death among the top 10 in the U.S. without a way to prevent, cure, or even slow its progression, which is it is crucial to better understand the disease and to develop and test potential treatments.

It is precisely for this reason that researchers led by Yanhong Shi, Ph.D. at City of Hope have developed a ‘mini-brain’ model using stem cells in order to study Alzheimer’s and to test drugs in development.

The team was able to model sporadic Alzheimer’s, the most common form of the disease, by using human induced pluripotent stem cells (iPSCs), a kind of stem cell that can be created from skin or blood cells of people through reprogramming and has the ability to turn into virtually any other kind of cell. The researchers used these iPSCs to create ‘mini-brains’, also known as brain organoids, which are 3D models that can be used to analyze certain features of the human brain. Although they are far from perfect replicas, they can be used to study physical structure and other characteristics. 

The scientists exposed the ‘mini-brains’ to serum that mimics age-associated blood-brain barrier (BBB) breakdown. The BBB is a protective barrier that surrounds the brain and its breakdown has been associated with Alzheimer’s and other age-related neurodegenerative diseases . After exposure, the team tested the ‘mini-brains’ for various Alzheimer’s biomarkers. These markers included elevated levels of proteins known as amyloid and tau that are associated with the disease and synaptic breaks linked to cognitive decline.

Research using brain organoids has shown that exposure to serum from blood could induce multiple Alzheimer’s symptoms. This suggests that combination therapies targeting multiple areas would be more effective than single-target therapies currently in development.

The team found that attempting a single therapy, such as inhibiting only amyloid or tau proteins, did not reduce the levels of tau or amyloid, respectively. These findings suggest that amyloid and tau likely cause disease progression independently. Furthermore, exposure to serum from blood, which mimics BBB breakdown, could cause breaks in synaptic connections that help brains remember things and function properly.

Image Description: Yanhong Shi, Ph.D.

In a press release from the Associated Press, Dr. Shi elaborated on the importance of their model for studying Alzheimer’s.

“Drug development for Alzheimer’s disease has run into challenges due to incomplete understanding of the disease’s pathological mechanisms. Preclinical research in this arena predominantly uses animal models, but there is a huge difference between humans and animals such as rodents, especially when it comes to brain architecture. We, at City of Hope, have created a miniature brain model that uses human stem cell technology to study Alzheimer’s disease and, hopefully, to help find treatments for this devastating illness.”

The full results of this study were published in Advance Science.

Dr. Shi has previously worked on several CIRM-funded research projects, such as looking at a potential link between COVID-19 and a gene for Alzheimer’s as well as the development of a therapy for Canavan disease.

Scientists use stem cell ‘mini-brains’ to better understand signs of frontotemporal dementia

Dementia is a general term that describes a set of diseases that impair the ability to remember, think, or make decisions that interfere with doing everyday activities. According to the World Health Organization (WHO), around 50 million people worldwide have dementia with nearly 10 million new cases every year. Although it primarily affects older people it is not a normal part of aging. As our population ages its critical to better understand why this occurs.

Frontotemporal dementia is a rare form of dementia where people start to show signs between the ages of 40 and 60. It affects the front and side (temporal) areas of the brain, hence the name. It leads to behavior changes and difficulty with speaking and thinking. This form of the disease is caused by a genetic mutation called tau, which is known to be associated with Alzheimer’s disease and other dementias.

A CIRM supported study using induced pluripotent stem cells (iPSCs) led by Kathryn Bowles, Ph.D. and conducted by a team of researchers at Mount Sinai were able to recreate much of the damage seen in a widely studied form of the frontotemporal dementia by growing special types of ‘mini-brains’, also known as cerebral organoids.

iPSCs are a kind of stem cell that can be created from skin or blood cells through reprogramming and have the ability to turn into virtually any other kind of cell. The team used iPSCs to create thousands of tiny, 3D ‘mini-brains’, which mimic the early growth and development of the brain.

The researchers examined the growth and development of these ‘mini-brains’ using stem cells derived from three patients, all of whom carried a mutation in tau. They then compared their results with those observed in “normal” mini-brains which were derived from patient stem cells in which the disease-causing mutation was genetically corrected.

After six months, signs of neurodegeneration were seen in the patient ‘mini-brains’. The patient-derived ‘mini-brains’ had fewer excitatory neurons compared to the “normal” ones which demonstrates that the tau mutation was sufficient to cause higher levels of cell death of this specific class of neurons. Additionally, the patient-derived ‘mini-brains’ also had higher levels of harmful versions of tau protein and elevated levels of inflammation.

In a news release from Mount Sinai, Dr. Bowles elaborated on the results of this study.

“Our results suggest that the V337M mutant tau sets off a vicious cycle in the brain that puts excitatory neurons under great stress. It hastens the production of new proteins needed for maturation but prevents disposal of the proteins that are being replaced.”

The full results of this study were published in Cell.