Vision loss

Lab-made retinas offer a new approach to battling vision loss

/ Kevin McCormack / 3 Comments

Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. Now, new research using 3D organoid models of the eye has uncovered clues as to what happens in AMD, and how to stop it. 

In AMD, a person loses their central vision because the light sensitive cells in the macula, a part of the retina, are damaged or destroyed. This impacts a person’s ability to see fine details, recognize faces or read small print, and means they can no longer drive. 

AMD causes blurry and distorted vision 

No one is quite sure what causes AMD, but in a study in the journal Nature Communications, German researchers used miniature human retina organoids to get some clues.  

Building a better model for research

Organoids are 3D models made from human cells that are grown in the lab. Because they have some of the characteristics of a human organ—in this case the retina—they help researchers better understand what is happening in the AMD-affected eye. 

In this study they found that photoreceptors, the light sensitive cells at the back of the retina, were missing but there was no sign of dead cells in the organoid. This led them to suspect that something called cell extrusion was at play.  

Cell extrusion is where a cell exports or sends large particles outside the cell. In this case it appeared that something was causing these photoreceptors to be extruded, leading to the impaired visual ability.  

In a news release Mark Karl, one of the authors of the study, said, “This was the starting point for our research project: we observed that photoreceptors are lost, but we could not detect any cell death in the retina. Half of all photoreceptors disappeared from the retinal organoid within ten days, but obviously they did not die in the retina. That made us curious.” 

Using snakes to fight AMD 

Further research identified two proteins that appeared to play a key role in the process, triggering the degeneration of the retinal organoid. They also tested a potential therapy to see if they could stop the process and save the photoreceptors. The therapy they tried, a snake venom, not only stopped the photoreceptors from being ejected, but it also prevented further damage to the retinal cells. 

Karl says this is the starting point for the next step in the research. “This gives hope for the development of future preventive and therapeutic treatments for complex neurodegenerative diseases such as AMD.” 

CIRM’s fight against blindness 

The California Institute for Regenerative Medicine (CIRM) has funded six clinical trials targeting vision loss, including one for AMD. We recently interviewed Dr. Dennis Clegg, one of the team trying to develop a treatment for AMD and he talked about the encouraging results they have seen so far. You can hear that interview on our podcast “Talking ‘Bout (re)Generation.” 

Stem cells help researchers map out glaucoma in search for new treatments

/ Kevin McCormack / 2 Comments

Glaucoma is the world’s leading cause of irreversible blindness. There is no cure and current treatments are only able to slow down the progression of the disease. Now research using stem cells to create a genetic blueprint of glaucoma is giving scientist a powerful new tool to combat the disease.

Glaucoma occurs when healthy retinal ganglion cells, which relay information from the eyes to the brain, are damaged and die. However, researchers were unable to really understand what was happening because the only way to look at retinal ganglion cells was through very invasive procedures.

So, researchers in Australia took skin cells from people with glaucoma and people with healthy eyes and, using the iPSC method, turned them into retinal ganglion cells. They were then able to map the genetic expression of these cells and compare the healthy cells with the diseased ones.

In an interview with Science Daily, Professor Joseph Powell , who led the team, says they were able to identify more than 300 unique genetic features which could provide clues as to what is causing the vision loss.

“The sequencing identifies which genes are turned on in a cell, their level of activation and where they are turned on and off —— like a road network with traffic lights. This research gives us a genetic roadmap of glaucoma and identifies 312 sites in the genome where these lights are blinking. Understanding which of these traffic lights should be turned off or on will be the next step in developing new therapies to prevent glaucoma.”

Powell says by identifying underlying causes for glaucoma researchers may be able to develop new, more effective therapies.

The study is published in Cell Genomics.

Study shows sleep deprivation impairs stem cells in the cornea 

/ Esteban Cortez / 1 Comment

We spend around one third of our life sleeping—or at least we should. Not getting enough sleep can have serious consequences on many aspects of our health and has been linked to high blood pressure, heart disease and stroke. 

A study by the American Sleep Apnea Association found that some 70 percent of Americans report getting too little sleep at least one night a month, and 11 percent report not enough sleep every night. Over time that can take a big toll on your mental and physical health. Now a new study says that impact can also put you at increased risk for eye disease.  

The study published in the journal Stem Cell Reports, looked at how sleep deprivation affects corneal stem cells. These cells are essential in replacing diseased or damaged cells in the cornea, the transparent tissue layer that covers and protects the eye.  

Researchers Wei Li, Zugou Liu and colleagues from Xiamen University, China and Harvard Medical School, USA, found that, in mice short-term sleep deprivation increased the rate at which stem cells in the cornea multiplied. Having too many new cells created vision problems.  

They also found that long-term sleep deprivation had an even bigger impact on the health of the cornea. Sleep-deprived mice had fewer active stem cells and so were not as effective in replacing damaged or dying cells. That in turn led to a thinning of the cornea and a loss of transparency in the remaining cells.  

The cornea— the transparent tissue layer covering the eye—is maintained by stem cells, which divide to replace dying cells and to repair small injuries.

The findings suggest that sleep deprivation negatively affects the stem cells in the cornea, possibly leading to vision impairment in the long run. It’s not clear if these findings also apply to people, but if they do, the implications could be enormous.  

The California Institute for Regenerative Medicine (CIRM) is also heavily involved in searching for treatments for diseases or conditions that affect vision. We have invested almost $150 million in funding 31 projects on vision loss including a clinical trial with UCLA’s Dr. Sophie Deng targeting the cornea, and other clinical trials for age-related macular degeneration and retinitis pigmentosa. 

Shared with permission from International Society for Stem Cell Research. Read the source release here. 

How a tiny patch is helping restore lasting vision

/ Kevin McCormack / 4 Comments

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Researchers are working on a stem cell-based retinal implant that could be used for people with with advanced dry age-related macular degeneration. (Photo/ Britney O. Pennington)

When Anna Kuehl began losing her vision, she feared losing the ability to read and go on long walks in nature—two of her favorite pastimes. Anna had been diagnosed with age-related macular degeneration, the leading cause of vision loss in the US. She lost the central vision in her left eye, which meant she could no longer make out people’s faces clearly, drive a car, or read the time on her watch.

Anna Kuehl

But a clinical trial funded by the California Institute for Regenerative Medicine  (CIRM) helped change that. And now, new data from that trial shows the treatment appears to be long lasting.

The treatment sprang out of research done by Dr. Mark Humayun and his team at USC. In collaboration with Regenerative Patch Technologies they developed a stem cell-derived implant using cells from a healthy donor. The implant was then placed under the retina in the back of the eye. The hope was those stem cells would then repair and replace damaged cells and restore some vision.

Dr. Mark Humayun, photo courtesy USC

In the past, using donor cells meant that patients often had to be given long-term immunosuppression to stop their body’s immune system attacking and destroying the patch. But in this trial, the patients were given just two months of immunosuppression, shortly before and after the implant procedure.

In a news story on the USC website, Dr. Humayun said this was an important advantage. “There’s been some debate on whether stem cells derived from a different, unrelated person would survive in the retina without long-term immunosuppression. For instance, if you were to receive a kidney transplant, long-term immunosuppression would be required to prevent organ rejection. This study indicates the cells on the retinal implant can survive for up to two years without long-term immunosuppression.”

Cells show staying power

When one of the patients in the clinical trial died from unrelated causes two years after getting the implant, the research team were able to show that even with only limited immunosuppression, there was no evidence that the patient’s body was rejecting the donor cells.

“These findings show the implant can improve visual function in some patients who were legally-blind before treatment and that the cells on the implant survive and remain functional for at least two years despite not being matched with those of the patient,” Humayun said.

For Anna Kuehl, the results have been remarkable. She was able to read an additional 17 letters on a standard eye chart. Even more importantly, she is able to read again, and able to walk and enjoy nature again.

Dr. Humayun says the study—published in the journal Stem Cell Reports—may have implications for treating other vision-destroying diseases. “This study addresses the debate over the viability of using mismatched stem cells — this shows that a mismatched stem cell derived implant can be safe and viable over multiple years.”

Reprogramming brain cells to restore vision after a stroke

/ Katie Sharify / Leave a comment

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About one third of stroke survivors experience vision loss. It can be a devastating side effect as most patients will not fully recover their vision and there are currently no reliable treatments available. But thanks to a collaborative effort by two teams of researchers from Purdue University and Jinan University in China, there may be a way to use gene therapy to recover lost vision after a stroke.

A stroke happens when part of the brain is starved of oxygen which can result in death of brain cells or neurons. Oftentimes this is caused by a blockage in an artery in the brain. Given the location of these vital arteries, most strokes lead to loss of motor function and in some cases, permanent vision loss.

The brain is an incredible machine and capable of remapping its neural pathways enough to restore some visual function, but this isn’t always the case. The neurons that are destroyed in the process of experiencing a stroke do not regenerate and lose their ability to communicate/transmit information between different areas of the brain, and between the brain and the rest of the nervous system.

Two research teams, one led by Alexander Chubykin at Purdue University’s and the other led by Gong Chen at Jinan University, have taken a different approach to neural regeneration by reprogramming local glial cells into neurons, therefore restoring connections between the old neurons and the newly reprogrammed neurons.

In a news release, Dr. Chubykin says the results in the lab look promising. “We can watch the mice get their vision back. We don’t have to implant new cells, so there’s no immunogenic rejection. This process is easier to do than stem cell therapy, and there’s less damage.”

The collaborative research, published in the journal Frontiers in Cell and Developmental Biology, is promising not only in aiding with vision restoration after a stroke but could also lead to similar treatment for reestablishing motor function. Visual function is easier than motor skills to measure accurately and the scientists are looking into the effectiveness of this procedure in live mice using advanced optical imaging tools. If the study continues to provide positive results, it might not be long before human trials are started. 

CIRM is also funding clinical trials to help repair vision loss and to help people recovering from a stroke.

National Academy of Medicine honors CIRM Grantees

/ Kevin McCormack / 2 Comments 
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As someone who is not always as diligent as he would like to be about sending birthday cards on time, I’m used to sending belated greetings to people. So, I have no shame in sending belated greetings to four CIRM grantees who were inducted into the National Academy of Medicine in 2020.

I say four, but it’s really three and a half. I’ll explain that later.

Being elected to the National Academy of Medicine is, in the NAM’s own modest opinion, “considered one of the highest honors in the fields of health and medicine and recognizes individuals who have demonstrated outstanding professional achievement and commitment to service.”

To be fair, NAM is right. The people elected are among the best and brightest in their field and membership is by election from the other members of NAM, so they are not going to allow any old schmuck into the Academy (which could explain why I am still waiting for my membership).

The CIRM grantees elected last year are:

Dr. Antoni Ribas: Photo courtesy UCLA

Antoni Ribas, MD, PhD, professor of medicine, surgery, and molecular and medical pharmacology, U. C. Los Angeles.

Dr. Ribas is a pioneer in cancer immunology and has devoted his career to developing new treatments for malignant melanoma. When Dr. Ribas first started malignant melanoma was an almost always fatal skin cancer. Today it is one that can be cured.

In a news release Dr. Ribas said it was a privilege to be honored by the Academy: “It speaks to the impact immunotherapy has played in cancer research. When I started treating cases of melanoma that had metastasized to other organs, maybe 1 in 20 responded to treatment. Nobody in their right mind wanted to be a specialist in this field. It was the worst of the worst cancers.”

Looks like he chose his career path wisely.

Dr. Jeffrey Goldberg: Photo courtesy Stanford

Jeffrey Louis Goldberg, MD, PhD, professor and chair of ophthalmology, Stanford University, Palo Alto, Calif.

Dr. Goldberg was honored for his contribution to the understanding of vision loss and ways to reverse it. His lab has developed artificial retinas that transmit images down the optic nerve to the brain through tiny silicon chips implanted in the eye. He has also helped use imaging technology to better improve our ability to detect damage in photoreceptor cells (these are cells in the retina that are responsible for converting light into signals that are sent to the brain and that give us our color vision and night vision)

In a news release he expressed his gratitude saying: “I look forward to serving the goals of the National Academies, and to continuing my collaborative research efforts with my colleagues at the Byers Eye Institute at Stanford and around the world as we further our efforts to combat needless blindness.”

Dr. Mark Anderson; photo courtesy UCSF

Mark S. Anderson, MD, PhD, professor in Diabetes Research, Diabetes Center, U. C. San Francisco.

Dr. Anderson was honored for being a leader in the study of autoimmune diseases such as type 1 diabetes. This focus extends into the lab, where his research examines the genetic control of autoimmune diseases to better understand the mechanisms by which immune tolerance is broken.

Understanding what is happening with the immune system, figuring out why it essentially turns on the body, could one day lead to treatments that can stop that, or even reverse it by boosting immune activity.

Dr. John Dick: Photo courtesy University Health Network, Toronto

Remember at the beginning I said that three and a half CIRM grantees were elected to the Academy, well, Canadian researcher, Dr. John Dick is the half. Why? Well, because the award we funded actually went to UC San Diego’s Dennis Carson but it was part of a Collaborative Funding Partnership Program with Dr. Dick at the University of Toronto. So, we are going to claim him as one of our own.

And he’s a pretty impressive individual to partner with. Dr. Dick is best known for developing a test that led to the discovery of leukemia stem cells. These are cells that can evade surgery, chemotherapy and radiation and which can lead to patients relapsing after treatment. His work helped shape our understanding of cancer and revealed a new strategy for curing it.

Sometimes a cold stare is a good thing

/ Kevin McCormack / 6 Comments
A retina of a patient with macular degeneration. (Photo credit: Paul Parker/SPL)

Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness in the elderly in the U.S. It’s estimated that some 11 million Americans could have some form of the disease, a number that is growing every year. So if you are going to develop a treatment for this condition, you need to make sure it can reach a lot of people easily. And that’s exactly what some CIRM-supported researchers are doing.

Let’s back up a little first. AMD is a degenerative condition where the macular, the small central portion of your retina, is slowly worn away. That’s crucial because the retina is the light-sensing nerve tissue at the back of your eye. At first you notice that your vision is getting blurry and it’s hard to read fine print or drive a car. As it progresses you develop dark, blurry areas in the center of your vision.

There are two kinds of AMD, a wet form and a dry form. The dry form is the most common, affecting 90% of patients. There is no cure and no effective treatment. But researchers at the University of Southern California (USC), the University of California Santa Barbara (UCSB) and a company called Regenerative Patch Technologies are developing a method that is looking promising.

They are using stem cells to grow retinal pigment epithelium (RPE) cells, the kind attacked by the disease, and putting them on a tiny synthetic scaffold which is then placed at the back of the eye. The hope is these RPE cells will help slow down the progression of the disease or even restore vision.

Early results from a CIRM-funded clinical trial are encouraging. Of the five patients enrolled in the Phase 1/2a trial, four maintained their vision in the treated eye, two showed improvement in the stability of their vision, and one patient had a 17-letter improvement in their vision on a reading chart. In addition, there were no serious side effects or unanticipated problems.

So now the team are taking this approach one step further. In a study published in Scientific Reports, they say they have developed a way to cryopreserve or freeze this cell and scaffold structure.

In a news release, Dr. Dennis Clegg of UCSB, says the frozen implants are comparable to the non-frozen ones and this technique will extend shelf life and enable on-demand distribution to distant clinical sites, increasing the number of patients able to benefit from such treatments.

“It’s a major advance in the development of cell therapies using a sheet of cells, or a monolayer of cells, because you can freeze them as the final product and ship them all over the world.”

Cool.

/ Kevin McCormack / 1 Comment

Two voices, one message, watch out for predatory stem cell clinics

Last week two new papers came out echoing each other about the dangers of bogus “therapies” being offered by predatory stem cell clinics and the risks they pose to patients.

The first was from the Pew Charitable Trusts entitled: ‘Harms Linked to Unapproved Stem Cell Interventions Highlight Need for Greater FDA Enforcement’ with a subtitle: ‘Unproven regenerative medical products have led to infections, disabilities, and deaths.’

That pretty much says everything you need to know about the report, and in pretty stark terms; need for greater FDA enforcement and infections, disabilities and deaths.

Just two days later, as if in response to the call for greater enforcement, the Food and Drug Administration (FDA) came out with its own paper titled: ‘Important Patient and Consumer Information About Regenerative Medicine Therapies.’ Like the Pew report the FDA’s paper highlighted the dangers of unproven and unapproved “therapies” saying it “has received reports of blindness, tumor formation, infections, and more… due to the use of these unapproved products.”

The FDA runs down a list of diseases and conditions that predatory clinics claim they can cure without any evidence that what they offer is even safe, let alone effective. It says Regenerative Medicine therapies have not been approved for the treatment of:

  • Arthritis, osteoarthritis, rheumatism, hip pain, knee pain or shoulder pain.
  • Blindness or vision loss, autism, chronic pain or fatigue.
  • Neurological conditions like Alzheimer’s and Parkinson’s.
  • Heart disease, lung disease or stroke.

The FDA says it has warned clinics offering these “therapies” to stop or face the risk of legal action, and it warns consumers: “Please know that if you are being charged for these products or offered these products outside of a clinical trial, you are likely being deceived and offered a product illegally.”

It tells consumers if you are offered one of these therapies – often at great personal cost running into the thousands, even tens of thousands of dollars – you should contact the FDA at ocod@fda.hhs.gov.

The Pew report highlights just how dangerous these “therapies” are for patients. They did a deep dive into health records and found that between 2004 and September 2020 there were more than 360 reported cases of patients experiencing serious side effects from a clinic that offered unproven and unapproved stem cell procedures.

Those side effects include 20 deaths as well as serious and even lifelong disabilities such as:

  • Partial or complete blindness (9).
  • Paraplegia (1).
  • Pulmonary embolism (6).
  • Heart attack (5).
  • Tumors, lesions, or other growths (16).
  • Organ damage or failure in several cases that resulted in death.

More than one hundred of the patients identified had to be hospitalized.

The most common type of procedures these patients were given were stem cells taken from their own body and then injected into their eye, spine, hip, shoulder, or knee. The second most common was stem cells from a donor that were then injected.

The Pew report cites the case of one California-based stem cell company that sold products manufactured without proper safety measures, “including a failure to properly screen for communicable diseases such as HIV and hepatitis B and C.” Those products led to at least 13 people being hospitalized due to serious bacterial infection in Texas, Arizona, Kansas, and Florida.

Shocking as these statistics are, the report says this is probably a gross under count of actual harm caused by the bogus clinics. It says the clinics themselves rarely report adverse events and many patients don’t report them either, unless they are so serious that they require medical intervention.

The Pew report concludes by saying the FDA needs more resources so it can more effectively act against these clinics and shut them down when necessary. It says the agency needs to encourage doctors and patients to report any unexpected side effects, saying: “devising effective strategies to collect more real-world evidence of harm can help the agency in its efforts to curb the growth of this unregulated market and ensure that the regenerative medicine field develops into one that clinicians and patients can trust and safely access.”

We completely support both reports and will continue to work with the FDA and anyone else opposed to these predatory clinics. You can read more here about what we have been doing to oppose these clinics, and here is information that will help inform your decision if you are thinking about taking part in a stem cell clinical trial but are not sure if it’s a legitimate one.

The Top CIRM Blogs of 2019

/ Kevin McCormack / 3 Comments

This year the most widely read blog was actually one we wrote back in 2018. It’s the transcript of a Facebook Live: “Ask the Stem Cell Team” event about strokes and stroke recovery. Because stroke is the third leading cause of death and disability in the US it’s probably no surprise this blog has lasting power. So many people are hoping that stem cells will help them recover from a stroke.

But of the blogs that we wrote and posted this year there’s a really interesting mix of topics.

The most read 2019 blog was about a potential breakthrough in the search for a treatment for type 1 diabetes (T1D).  Two researchers at UC San Francisco, Dr. Matthias Hebrok and Dr. Gopika Nair developed a new method of replacing the insulin-producing cells in the pancreas that are destroyed by type 1 diabetes. 

Dr. Matthias Hebrok
Dr. Gopika Nair

Dr. Hebrok described it as a big advance saying: “We can now generate insulin-producing cells that look and act a lot like the pancreatic beta cells you and I have in our bodies. This is a critical step towards our goal of creating cells that could be transplanted into patients with diabetes.”

It’s not too surprising a blog about type 1 diabetes was at the top. This condition affects around 1.25 million Americans, a huge audience for any potential breakthrough. However, the blog that was the second most read is the exact opposite. It is about a rare disease called cystinosis. How rare? Well, there are only around 500 children and young adults in the US, and just 2,000 worldwide diagnosed with this condition.  

It might be rare but its impact is devastating. A genetic mutation means children with this condition lack the ability to clear an amino acid – cysteine – from their body. The buildup of cysteine leads to damage to the kidneys, eyes, liver, muscles, pancreas and brain.

Dr. Stephanie Cherqui

UC San Diego researcher Dr. Stephanie Cherqui and her team are taking the patient’s own blood stem cells and, in the lab, genetically re-engineering them to correct the mutation, then returning the cells to the patient. It’s hoped this will create a new, healthy blood system free of the disease.

Dr. Cherqui says if it works, this could help not just people with cystinosis but a wide array of other disorders: “We were thrilled that the stem cells and gene therapy worked so well to prevent tissue degeneration in the mouse model of cystinosis. This discovery opened new perspectives in regenerative medicine and in the application to other genetic disorders. Our findings may deliver a completely new paradigm for the treatment of a wide assortment of diseases including kidney and other genetic disorders.”

Sickled cells

The third most read blog was about another rare disease, but one that has been getting a lot of media attention this past year. Sickle cell disease affects around 100,000 Americans, mostly African Americans. In November the Food and Drug Administration (FDA) approved Oxbryta, a new therapy that reduces the likelihood of blood cells becoming sickle shaped and clumping together – causing blockages in blood vessels.

But our blog focused on a stem cell approach that aims to cure the disease altogether. In many ways the researchers in this story are using a very similar approach to the one Dr. Cherqui is using for cystinosis. Genetically correcting the mutation that causes the problem, creating a new, healthy blood system free of the sickle shaped blood cells.

Two other blogs deserve honorable mentions here as well. The first is the story of James O’Brien who lost the sight in his right eye when he was 18 years old and now, 25 years later, has had it restored thanks to stem cells.

The fifth most popular blog of the year was another one about type 1 diabetes. This piece focused on the news that the CIRM Board had awarded more than $11 million to Dr. Peter Stock at UC San Francisco for a clinical trial for T1D. His approach is transplanting donor pancreatic islets and parathyroid glands into patients, hoping this will restore the person’s ability to create their own insulin and control the disease.

2019 was certainly a busy year for CIRM. We are hoping that 2020 will prove equally busy and give us many new advances to write about. You will find them all here, on The Stem Cellar.

Stem Cell Agency Heads to Inland Empire for Free Patient Advocate Event

/ Kevin McCormack / 2 Comments

UCRiversidePatientAdvocateMtg_EventBrite copy

I am embarrassed to admit that I have never been to the Inland Empire in California, the area that extends from San Bernardino to Riverside counties.  That’s about to change. On Monday, April 16th CIRM is taking a road trip to UC Riverside, and we’re inviting you to join us.

We are holding a special, free, public event at UC Riverside to talk about the work that CIRM does and to highlight the progress being made in stem cell research. We have funded 45 clinical trials in a wide range of conditions from stroke and cancer, leukemia, lymphoma, vision loss, diabetes and sickle cell disease to name just a few. And will talk about how we plan on funding many more clinical trials in the years to come.

We’ll be joined by colleagues from both UC Riverside, and City of Hope, talking about the research they are doing from developing new imaging techniques to see what is happening inside the brain with diseases like Alzheimer’s, to using a patient’s own cells and immune system to attack deadly brain cancers.

It promises to be a fascinating event and of course we want to hear from you, our supporters, friends and patient advocates. We are leaving plenty of time for questions, so we can hear what’s on your mind.

So, join us at UC Riverside on Monday, April 16th from 12.30pm to 2pm. The doors open at 11am so you can enjoy a poster session (highlighting some of the research at UCR) and a light lunch before the event. Parking will be available on site.

Visit the Eventbrite page we have created for all the information you’ll need about the event, including a chance to RSVP and book your place.

The event is free so feel free to share this with anyone and everyone you think might be interested in joining us.