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.”
Our 2021-22 Annual Report is now online. It’s filled with information about the work we have done over the last year (we are on a fiscal calendar year from July 1 – June 30), the people who have helped us do that work, and some of the people who have benefited from that work. One of those is Dr. Alysson Muotri, a professor in the Departments of Pediatrics and Cellular & Molecular Medicine at the University of California, San Diego.
Dr. Alysson Muotri, in his lab at UCSD
For Dr. Alysson Muotri, trying to unlock the secrets of the brain isn’t just a matter of scientific curiosity, it’s personal. He has a son with autism and Dr. Muotri is looking for ways to help him, and millions of others like him around the world.
He created the Tooth Fairy project where parents donated more than 3,000 baby teeth from children with autism and children who are developing normally. Dr. Muotri then turned cells from those teeth into neurons, the kind of brain cell affected by autism. He is using those cells to try and identify how the brain of a child with autism differs from a child who is developing normally.
“We’ve been using cells from this population to see what are the alterations (in the gene) and if we can revert them back to a normal state. If you know the gene that is affected, and autism has a strong genetic component, by genome sequencing you can actually find what are the genes that are affected and in some cases there are good candidates for gene therapy. So, you just put the gene back. And we can see that in the lab where we are correcting the gene that is mutated, the networks start to function in a way that is more neurotypical or normal. We see that as highly promising, there’s a huge potential here to help those individuals.”
He is also creating brain organoids, three-dimensional structures created from stem cells that mimic some of the actions and activities of the brain. Because these are made from human cells, not mice or other animals, they may be better at indicating if new therapies have any potential risks for people.
“We can test drugs in the brain organoids of the person and see if it works, see if there’s any toxicity before you actually give the drug to a person, and it will save us time and money and will increase our knowledge about the human brain.”
He says he still gets excited seeing how these cells work. “It’s amazing, it’s a miracle. Every time I see it, it’s like seeing dolphins in the sea because it’s so beautiful.”
Dr. Muotri is also a big proponent of diversity, equity and inclusion in scientific research. He says in the past it was very much a top-down model with scientists deciding what was important. He says we need to change that and give patients and communities a bigger role in shaping the direction of research.
“I think this is something we scientists have to learn, how to incorporate patients in our research. These communities are the ones we are studying, and we need to know what they want and not assume that what we want is what they want. They should be consulted on our grants, and they should participate in the design of our experiments. That is the future.”
Dr. Jill Helms, and associate! Photo courtesy Stanford University
Jill Helms is not your average Stanford University faculty member. Yes, she is a professor in the Department of Surgery. Yes, she has published lots of scientific studies. Yes, she is a stem cell scientist (funded by CIRM). And yes, she is playing a leading role in Ankasa Regenerative Therapeutics, a company focused on tissue repair and regeneration. But she is so much more than all that.
She is a brilliant public speaker, a fashionista, and has ridden her horse to work (well, Stanford is referred to as The Farm, so why not!) and she lives on a farm of her own called “Follow Your Bliss.” The name comes from philosopher Joseph Campbell who wrote, “If you follow your bliss, you put yourself on a kind of path that has been there all the while, waiting for you. And the life you ought to be living is the one you are living.”
Dr. Helms says that pretty much sums up her life. She says she feels enormously blessed.
Well, we felt enormously blessed when she agreed to sit down with us and chat about her work, her life and her love of fashion for the California Institute for Regenerative Medicine podcast, Talking ‘Bout (re)Generation.
Every day I field phone calls and emails from people looking for a stem cell therapy to help them cope with everything from arthritis to cancer. Often, they will mention that they saw an ad for a clinic online or in a local newspaper claiming they had stem cell therapies that could help fix anything and asking me if they are legitimate.
Even after I try to explain that the therapies these clinics are offering haven’t been tested in a clinical trial and that there’s scant evidence to show they are even safe let alone effective, I know that a good chunk of the callers are going to try them anyway.
Now a survey by the Mayo Clinic takes a deeper dive into why people are willing to put science aside and open up their wallets to go to predatory stem cell clinics for so-called “therapies”.
Dr. Zubin Master. Photo courtesy Mayo Clinic
In a news release Dr. Zubin Master, a co-author of the study, says many patients are lured in by hype and hope.
“We learned that many patients interested in stem cells had beliefs that are not supported by current medical evidence. For example, many thought stem cells were better than surgery or the standard of care.”
The survey asked 533 people, who had approached the Mayo Clinic’s Regenerative Medicine Therapeutic Suites for a consultation about arthritis or musculoskeletal problems, three questions.
Why are you interested in stem cell treatment for your condition?
How did you find out about stem cell treatment for your condition?
Have you contacted a stem cell clinic?
A whopping 46 percent of those who responded said they thought stem cell therapy would help them avoid or at least delay having to get a hip or knee replacement, or that it was a better option than surgery. Another 26 percent said they thought it would ease the pain of an arthritic joint.
The fact that there is little or no evidence to support any of these beliefs didn’t seem to matter. Most people say they got their information about these “therapies” online or by talking to friends and family.
These “therapies” aren’t cheap either. They can cost thousands, sometimes tens of thousands of dollars, and that comes out of the patient’s pocket because none of this is covered by insurance. Yet every year people turn to these bogus clinics because they don’t like the alternatives, mainly surgery.
There is a lot of promising stem cell research taking place around the US trying to find real scientific solutions to arthritic joints and other problems. The California Institute for Regenerative Medicine (CIRM) has invested almost $24 million in this research. But until those approaches have proven themselves effective and, hopefully, been approved for wider use by the Food and Drug Administration, CIRM and other agencies will have to keep repeating a message many people just don’t want to hear, that these therapies are not yet ready for prime time.
While stem cell and gene therapy research has advanced dramatically in recent years, there are still many unknowns and many questions remaining about how best to use these approaches in developing therapies. That’s why the governing Board of the California Institute for Regenerative Medicine (CIRM) today approved investing almost $25 million in 19 projects in early stage or Discovery research.
The awards are from CIRM’s DISC2 Quest program, which supports 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.
“Every therapy that helps save lives or change lives begins with a researcher asking a simple question, “What if?”, says Dr. Maria T. Millan, the President and CEO of CIRM. “Our Quest awards reflect the need to keep supporting early stage research, to gain a deeper understanding of stem cells work and how we can best tap into that potential to advance the field.”
Dr. Judy Shizuru at Stanford University was awarded $1.34 million to develop a safer, less-toxic form of bone marrow or hematopoietic stem cell transplant (HCT). HCT is the only proven cure for many forms of blood disorders that affect people of all ages, sexes, and races worldwide. However, current methods involve the use of chemotherapy or radiation to destroy the patient’s own unhealthy blood stem cells and make room for the new, healthy ones. This approach is toxic and complex and can only be performed by specialized teams in major medical centers, making access particularly difficult for poor and underserved communities.
Dr. Shizuru proposes developing an antibody that can direct the patient’s own immune cells to kill diseased blood stem cells. This would make stem cell transplant safer and more effective for the treatment of many life-threatening blood disorders, and more accessible for people in rural or remote parts of the country.
Lili Yang UCLA Broad Stem Cell Research Center: Photo courtesy Reed Hutchinson PhotoGraphics
Dr. Lili Yang at UCLA was awarded $1.4 million to develop an off-the-shelf cell therapy for ovarian cancer, which causes more deaths than any other cancer of the female reproductive system.
Dr. Yang is using immune system cells, called invariant natural killer T cells (iNKT) to attack cancer cells. However, these iNKT cells are only found in small numbers in the blood so current approaches involve taking those cells from the patient and, in the lab, modifying them to increase their numbers and strength before transplanting them back into the patient. This is both time consuming and expensive, and the patient’s own iNKT cells may have been damaged by the cancer, reducing the likelihood of success.
In this new study Dr. Yang will use healthy donor cord blood cells and, through genetic engineering, turn them into the specific form of iNKT cell therapy targeting ovarian cancer. This DISC2 award will support the development of these cells and do the necessary testing and studies to advance it to the translational stage.
Timothy Hoey and Tenaya Therapeutics Inc. have been awarded $1.2 million to test a gene therapy approach to replace heart cells damaged by a heart attack.
Heart disease is the leading cause of death in the U.S. with the highest incidence among African Americans. It’s caused by damage or death of functional heart muscle cells, usually due to heart attack. Because these heart muscle cells are unable to regenerate the damage is permanent. Dr. Hoey’s team is developing a gene therapy that can be injected into patients and turn their cardiac fibroblasts, cells that can contribute to scar tissue, into functioning heart muscle cells, replacing those damaged by the heart attack.
One of my favorite phrases is “standing room only”. I got a chance to use it last week when we held a panel discussion on whether regenerative medicine could turn back the clock on aging. The event was at the annual conference of the International Society for Stem Cell Research (ISSCR) and more than 150 people packed into a conference room to hear the debate (so far more than 800 also watched a live stream of the event.)
It’s not surprising the place was jammed. The speakers included:
Dr. Deepak Srivastava, the President of the Gladstone Institutes, an expert on heart disease and the former President of ISSCR.
Dr. Stanley “Tom” Carmichael, Chair of the Department of Neurology at UCLA and an expert on strokes and other forms of brain injury.
Adrienne Shapiro, the mother of a daughter with sickle cell disease, a tireless patient advocate and supporter of regenerative medicine research, and the co-founder of Axis Advocacy, a family support organization for people with sickle cell.
And the topic is a timely one. It is estimated that as many as 90 percent of the people who die every day, die from diseases of aging such as heart disease, stroke, and cancer. So, what can be done to change that, to not just slow down or stop these diseases, but to turn back the clock, to repair the damage already done and replace cells and tissues already destroyed.
The conversation was enlightening, hopeful and encouraging, but also cautionary.
You can watch the whole event on our Youtube channel.
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.
It is estimated that as many as 90 percent of people in industrialized countries who die every day, die from diseases of aging such as heart disease, stroke, and cancer. Of those still alive the numbers aren’t much more reassuring. More than 80 percent of people over the age of 65 have a chronic medical condition, while 68 percent have two or more.
Current medications can help keep some of those conditions, such as high blood pressure, under control but regenerative medicine wants to do a lot more than that. We want to turn back the clock and restore function to damaged organs and tissues and limbs. That research is already underway and we are inviting you to a public event to hear all about that work and the promise it holds.
On June 16th from 3p – 4.30p PST we are holding a panel discussion exploring the impact of regenerative medicine on aging. We’ll hear from experts on heart disease and stroke; we will look at other ground breaking research into aging; and we’ll discuss the vital role patients and patient advocates play in helping advance this work.
The discussion is taking place in San Francisco at the annual conference of the International Society for Stem Cell Research. But you can watch it from the comfort of your own home. That’s because we are going to live stream the event.
Smoking medical marijuana: Photo courtesy Elsa Olofsson
Millions of Americans use marijuana for medical reasons, such as reducing anxiety or helping ease the side effects of cancer therapy. Millions more turn to it for recreational reasons, saying it helps them relax. Now a new study says those who smoke marijuana regularly might be putting themselves at increased risk of heart disease and heart attack.
There has long been debate about the benefits versus the risks for using cannabis, with evidence on both sides to support each position. For example some studies have shown taking oral cannabinoids can help people cope with the nausea brought on by chemotherapy. Other studies have shown that regular use of marijuana can cause problems such as marijuana use disorder, a condition where the user is showing physical or psychological problems but has difficulty controlling or reducing their use of cannabis.
Now this latest study, from researchers at Stanford Medicine, shows that THC, the psychoactive part of the drug, can cause inflammation in endothelial cells. These are the cells that line the interior of blood vessels. When these cells become inflamed it can cause a constriction of the vessels and reduce blood flow. Over time this can create conditions that increase the risk of heart disease and heart attack.
The researchers, led by Dr. Joe Wu, began by analyzing data from the UK Biobank. This included information about some 35,000 people who reported smoking marijuana. Of these around 11,000 smoked more than once a month. The researchers found that regular marijuana smokers:
Were significantly more likely than others to have a heart attack.
Were also more likely to have their first heart attack before the age of 50, increasing their risk of subsequent attacks.
The team then used the iPSC method to create human endothelial cells and, in the lab, found that THC appeared to promote inflammation in the cells. They also found signs it created early indications of atherosclerosis, where there is a buildup of fat and plaque in the arteries.
They then tested mice which had been bred to have high levels of cholesterol and who were given a high fat diet. Some of the mice were then injected with THC, at a level comparable to smoking one marijuana cigarette a day. Those mice had far larger amounts of atherosclerosis plaque in their arteries compared to the mice who didn’t get the THC.
In a news release, Dr.Wu, the lead author of the study, said: “There’s a growing public perception that marijuana is harmless or even beneficial. Marijuana clearly has important medicinal uses, but recreational users should think carefully about excessive use.”
On the bright side, the team also reported that the damage caused by THC can be stopped by genistein, a naturally occurring compound found in soy and fava beans. The study, in the journal Cell, also found that genistein blocked the bad impact of THC without impeding the good impacts.
“As more states legalize the recreational use of marijuana, users need to be aware that it could have cardiovascular side effects,” said Dr. Wu. “But genistein works quite well to mitigate marijuana-induced damage of the endothelial vessels without blocking the effects marijuana has on the central nervous system, and it could be a way for medical marijuana users to protect themselves from a cardiovascular standpoint.”
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 Stem Cellar 