Hitting our Goals: Accelerating to the finish line

Way, way back in 2015 – seems like a lifetime ago doesn’t it – the team at CIRM sat down and planned out our Big 6 goals for the next five years. The end result was a Strategic Plan that was bold, ambitious and set us on course to do great things or kill ourselves trying. Well, looking back we can take some pride in saying we did a really fine job, hitting almost every goal and exceeding them in some cases. So, as we plan our next five-year Strategic Plan we thought it worthwhile to look back at where we started and what we achieved. Goal #6 was Accelerate.

Ever wonder how long it takes for a drug or therapy to go from basic research to approval by the US Food and Drug Administration (FDA)? Around 12 years on average is the answer. That’s a long time. And it can take even longer for stem cell therapies to go that same distance.

There are a lot of reasons why it takes so long (safety being a hugely important element) but when we were sitting down in 2015 to put together our Strategic Plan we wanted to find a way to speed up that process, to go faster, without in any way reducing the focus on safety.

So, we set a goal of reducing the time it takes from identifying a stem cell therapy candidate to getting an Investigational New Drug (IND) approval from the FDA, which means it can be tested in a clinical trial. At the time it was taking us around eight years, so we decided to go big and try to reduce that time in half, to four years.

Then the question was how were we going to do that? Well, before we set the goal we did a tour of the major biomedical research institutions in California – you know, University of California Los Angeles (UCLA) UC San Francisco, Stanford etc. – and asked the researchers what would help them most. Almost without exception said “a clearing house”, a way to pair early stage investigators with later stage partners who possess the appropriate expertise and interest to advance the project to the next stage of development, e.g., helping a successful basic science investigator find a qualified partner for the project’s translational research phase.

So we set out to do that. But we didn’t stop there. We also created what we called Clinical Advisory Panels or CAPs. These consisted of a CIRM Science Officer with expertise on a particular area of research, an expert on the kind of research being done, and a Patient Representative. The idea was that CAPs would help guide and advise the research team, helping them overcome specific obstacles and get ready for a clinical trial. The Patient Representative could help the researchers understand what the needs of the patient community was, so that a trial could take those into account and be more likely to succeed. For us it wasn’t enough just to fund promising research, we were determined to do all we could to support the team behind the project to advance their work.

How did we do. Pretty good I would have to say. For our Translational stage projects, the average amount of time it took for them to move to the CLIN1 stage, the last stage before a clinical trial, was 4.18 years. For our CLIN1 programs, 73 percent of those achieved their IND within 2 years, meaning they were then ready to actually start an FDA-sanctioned clinical trial.

Of course moving fast doesn’t guarantee that the therapy will ultimately prove effective. But for an agency whose mission is “to accelerate stem cell therapies to patients with unmet medical needs”, going slow is not an option.

Hitting our goals: Making good progress

Way, way back in 2015 – seems like a lifetime ago doesn’t it – the team at CIRM sat down and planned out our Big 6 goals for the next five years. The end result was a Strategic Plan that was bold, ambitious and set us on course to do great things or kill ourselves trying. Well, looking back we can take some pride in saying we did a really fine job, hitting almost every goal and exceeding them in some cases. So, as we plan our next five-year Strategic Plan we thought it worthwhile to look back at where we started and what we achieved. Goal #5 was Advance.

A dictionary definition of progression is “The act of moving forward or proceeding in a course.” That’s precisely what we set out to do when we set one of the goals in our 2015 Strategic Plan. We wanted to do all that we could to make sure the work we were funding could advance to the next stage. The goal we set was:

Advance: Increase projects advancing to the next stage of development by 50%.

The first question we faced was what did we mean by progression and how were we going to measure it? The answer basically boiled down to this: when a CIRM award completes one stage of research and gets CIRM funding to move on to the next stage or to develop a second generation of the same device or therapy.

In the pre-2016 days we’d had some success, on average getting around nine progression events every year. But if we were going to increase that by 50 percent we knew we had to step up our game and offer some incentives so that the team behind a successful project had a reason, other than just scientific curiosity, to try and move their research to the next level.

So, we created a series of linkages between the different stages of research, so the product of each successful investment was the prerequisite for the next stage of development for the research or technology.

We changed the way we funded projects, going from offering awards on an irregular basis to having them happen according to a pre-defined schedule with each program type offered multiple times a year. This meant potential applicants knew when the next opportunity to apply would come, enabling them to prepare and file at the time that was best for them and not just because we said so. We also timed these schedules so that programs could progress from one stage to the next without interruption.

But that’s not all. We recognized that some people may be great scientists at one level but didn’t have the experience or expertise to carry their project forward. So, we created both an Accelerating Center and Translating Center to help them do that. The Translating Center helped projects do the work necessary to get ready to apply to the US Food and Drug Administration (FDA) for permission to start a clinical trial. The Accelerating Center helped the team prepare that application for the trial and then plan how that trial would be carried out.

Creating these two centers had an additional benefit; it meant the work that did progress did so faster and was of a higher quality than it might otherwise have been.

Putting all those new building blocks in place meant a lot of work for the CIRM team, on top of their normal duties. But, as always, the team rose to the challenge. By the end of December 2020, a total of 74 projects had advanced or progressed to the next level, an increase of 100 percent on our pre-2016 days.

When we were laying out the goals we said that “The full implementation of these programs will create the chassis of a machine that provides a continuous, predictable, and timely pathway for the discovery and development of promising stem cell treatments.” Thanks to the voter approved Proposition 14 we now have the fund to help those treatments realize that promise.

CIRM funding helps identify potential COVID-19 treatment

The steps of the virus growth cycle that can be targeted with therapies: The virus enters a host cell (1), the virus’s genetic instructions are released, taking over cellular machinery (2), the virus is replicated within the cell (3) and copies of the virus exit the cell in search of new host cells to infect (4). Drugs like berzosertib might disrupt steps 2 and 3.  Image credit: Marc Roseboro/California NanoSytems Institute at UCLA

During the global pandemic, many researchers have responded to the needs of patients severely afflicted with COVID-19 by repurposing existing therapies being developed to treat patients.  CIRM responded immediately to the pandemic and to researchers wanting to help by providing $5 million in emergency funding for COVID-19 related projects. 

One of these grants ($349,999), awarded to Dr. Vaithilingaraja Arumugaswami at UCLA, has aided a study that has singled out a compound that shows promise for treating SARS-CoV-2, the virus that causes COVID-19.

In the spirit of banding together to help patients severely affected by COVID-19, the project was a collaboration among scientists from UCLA and other universities in California, Delaware and Germany, as well as a German pharmaceutical company.

The compound is named berzosertib and is licensed by the company Merck KGaA in Darmstadt, Germany.  Prior to the pandemic, it was developed for potential use, in combination with chemotherapy, as a possible treatment for small-cell lung cancer, ovarian cancer, and other types of solid tumors.

The team screened 430 drugs from among the approximately 200,000 compounds in CNSI’s Molecular Screening Shared Resource libraries before zeroing in on berzosertib as the most promising candidate.  They limited their search to compounds that either had been approved, or are already in the process of being evaluated, for safety in humans.

In a press release from UCLA, Dr. Arumugawami explains the rationale behind screening a potential drug candidate.

“That way, the compounds have cleared the first regulatory hurdle and could be deployed for further clinical trials on COVID-19 faster than drugs that have not been tested in humans.”

The researchers, led by Dr. Arumugaswami and Dr. Robert Damoiseaux from UCLA, conducted a series of experiments using different cell types in lab dishes to look at how effective the compound was at blocking SARS-CoV-2 from replicating.  Unlike other approaches which attack the virus directly, targeting replication could help better address the ability of the virus to mutate. 

For this study, the team used cells from the kidney, heart and lungs, all of which are organs that the virus is known to attack. The researchers pretreated cells with berzosertib, exposed the cells to SARS-CoV-2, allowed 48 hours for infection to set in, and then evaluated the results.

The team found that the compound consistently stalled SARS-CoV-2 replication without damaging the cells. The scientists also tested the drug against SARS and MERS, both of which are other types of coronaviruses that triggered deadly outbreaks earlier in the 2000s. They found that it was effective in stopping the replication of those viruses as well.

In the same press release from UCLA, Dr. Damoiseaux expressed optimism for what these findings could mean as a potential treatment.

“This is a chance to actually find a drug that might be broader in spectrum, which could also help fight coronaviruses that are yet to come.”

The next steps for this research would be to explore the mechanism through which the compound blocks coronavirus replication.  Understanding this and conducting preclinical studies are both necessary before the compound could be tested in clinical trials for COVID-19.

The full results of this study were published in Cell Reports.

The study’s co-corresponding author is Ulrich Betz of Merck KGaA, Darmstadt, Germany; the company also provided partial funding and clinical-grade berzosertib for the research. Other co-authors are from UCLA, Cedars-Sinai Medical Center, UC Irvine, University of Delaware, the Leibniz Institute for Experimental Virology in Germany, Heidelberg University in Germany and Scripps Research Institute.

In addition to CIRM, the study was also funded by CNSI, the Broad Stem Cell Research Center, the David Geffen School of Medicine at UCLA, the National Eye Institute, and the Bill and Melinda Gates Foundation.

A Match Made in Heaven, if heaven were in Oakland!

The Matchmaker – by Gerrit van Honthorst

Throughout history, matchmakers have played an important role in bringing together couples for arranged marriages. Fast forward to today and CIRM is now playing a similar role. We’re not looking to get anyone hitched, what we are trying to do is create partnerships between people we are funding and companies looking for the next hot thing.

So far, I’d say we are doing a pretty decent job. Over the years we have leveraged our funding to bring in some $13 billion in additional investments in stem cell research. But there’s still a lot of untapped potential out there. That’s why tomorrow, March 9th, we’re joining with BIOCOM to host a Partner Day.

The idea is to highlight some of the most promising programs we are funding and see if we can find partners for them, partners who want to help advance the research and ultimately – we hope – bring those therapies to patients.

The webinar and panel discussion will feature a presentation from the CIRM Business Development team about our portfolio. That’s a pretty extensive list because it covers all stages of research from Discovery or basic, through Translational and all the way to Clinical. We’ll show how our early investment in these programs has helped de-risk them and given them the chance to get the data needed to demonstrate their promise and potential.

So, who are we interested in having join us? Pretty nearly everyone involved in the field:

  • Academic institutions
  • Research organizations
  • Entrepreneurs
  • Venture capital firms
  • Companies

And the areas of interest are equally broad:

  • Stem or progenitor cell-based therapy
  • Cell Therapy
  • Gene therapy
  • Biologic
  • Small molecule
  • Medical Device
  • Diagnostic
  • Tools/Tech
  • Other

And for those who are really interested and don’t want to waste any time, there’s an opportunity to set up one-on-one meetings right away. After all, if you have found the perfect match, why wait!

But here’s the catch. Space is limited so you need to register ahead. Here’s where you go to find out all the details and sign up for the event.

A word from our Chair, several in fact

In 2005, the New Oxford American Dictionary named “podcast” its word of the year. At the time a podcast was something many had heard of but not that many actually tuned in to. My how times have changed. Now there are some two million podcasts to chose from, at least according to the New York Times, and who am I to question them.

Yesterday, in the same New York Times, TV writer Margaret Lyons, wrote about how the pandemic helped turn her from TV to podcasts: “Much in the way I grew to prefer an old-fashioned phone call to a video chat, podcasts, not television, became my go-to medium in quarantine. With their shorter lead times and intimate production values, they felt more immediate and more relevant than ever before.”

I mention this because an old colleague of ours at CIRM, Neil Littman, has just launched his own podcast and the first guest on it was Jonathan Thomas, Chair of the CIRM Board. Their conversation ranged from CIRM’s past to the future of the regenerative field as a whole, with a few interesting diversions along the way. It’s fun listening. And as Margaret Lyons said it might be more immediate and more relevant than ever before.

Charting a course for the future

A new home for stem cell research?

Have you ever been at a party where someone says “hey, I’ve got a good idea” and then before you know it everyone in the room is adding to it with ideas and suggestions of their own and suddenly you find yourself with 27 pages of notes, all of them really great ideas. No, me neither. At least, not until yesterday when we held the first meeting of our Scientific Strategy Advisory Panel.

This is a group that was set up as part of Proposition 14, the ballot initiative that refunded CIRM last November (thanks again everyone who voted for that). The idea was to create a panel of world class scientists and regulatory experts to help guide and advise our Board on how to advance our mission. It’s a pretty impressive group too. You can see who is on the SSAP here.  

The meeting involved some CIRM grantees talking a little about their work but mostly highlighting problems or obstacles they considered key issues for the future of the field as a whole. And that’s where the ideas and suggestions really started flowing hard and fast.

It started out innocently enough with Dr. Amander Clark of UCLA talking about some of the needs for Discovery or basic research. She advocated for a consortium approach (this quickly became a theme for many other experts) with researchers collaborating and sharing data and findings to help move the field along.

She also called for greater diversity in research, including collecting diverse cell samples at the basic research level, so that if a program advanced to later stages the findings would be relevant to a wide cross section of society rather than just a narrow group.

Dr. Clark also said that as well as supporting research into neurodegenerative diseases, such as Alzheimer’s and Parkinson’s, there needed to be a greater emphasis on neurological conditions such as autism, bipolar disorder and other mental health problems.

(CIRM is already committed to both increasing diversity at all levels of research and expanding mental health research so this was welcome confirmation we are on the right track).

Dr. Mike McCun called for CIRM to take a leadership role in funding fetal tissue research, things the federal government can’t or won’t support, saying this could really help in developing an understanding of prenatal diseases.

Dr. Christine Mummery, President of ISSCR, advocated for support for early embryo research to deepen our understanding of early human development and also help with issues of infertility.

Then the ideas started coming really fast:

  • There’s a need for knowledge networks to share information in real-time not months later after results are published.
  • We need standardization across the field to make it easier to compare study results.
  • We need automation to reduce inconsistency in things like feeding and growing cells, manufacturing cells etc.
  • Equitable access to CRISPR gene-editing treatments, particularly for underserved communities and for rare diseases where big pharmaceutical companies are less likely to invest the money needed to develop a treatment.
  • Do a better job of developing combination therapies – involving stem cells and more traditional medications.

One idea that seemed to generate a lot of enthusiasm – perhaps as much due to the name that Patrik Brundin of the Van Andel Institute gave it – was the creation of a CIRM Hotel California, a place where researchers could go to learn new techniques, to share ideas, to collaborate and maybe take a nice cold drink by the pool (OK, I just made that last bit up to see if you were paying attention).

The meeting was remarkable not just for the flood of ideas, but also for its sense of collegiality.  Peter Marks, the director of the Food and Drug Administration’s Center for Biologics Evaluation and Research (FDA-CBER) captured that sense perfectly when he said the point of everyone working together, collaborating, sharing information and data, is to get these projects over the finish line. The more we work together, the more we will succeed.

Month of CIRM: Reviewing Review

Dr. Gil Sambrano, Vice President Portfolio & Review

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. Today we take a look at our Review team.

Many people who have to drive every day don’t really think about what’s going on under the hood of their car. As long as the engine works and gets them from A to B, they’re happy. I think the same is true about CIRM’s Review team. Many people don’t really think about all the moving parts that go into reviewing a promising new stem cell therapy.

But that’s a shame, because they are really missing out on watching a truly impressive engine at work.

Just consider the simple fact that since CIRM started about 4,000 companies, groups and individuals have applied to us for funding. Just take a moment to consider that number. Four thousand. Then consider that at no time have there been more than 5 people working in the review team. That’s right. Just 5 people. And more recently there have been substantially fewer. That’s a lot of projects and not a lot of people to review them. So how do they do it? Easy. They’re brilliant.

First, as applications come in they are scrutinized to make sure they meet specific eligibility requirements; do they involve stem cells, is the application complete, is it the right stage of research, is the budget they are proposing appropriate for the work they want to do etc. If they pass that initial appraisal, they then move on to the second round, the Grants Working Group or GWG.

The GWG consists of independent scientific experts from all over the US, all over the world in fact. However, none are from California because we want to ensure there are no possible conflicts of interest. When I say experts, I do mean experts. These are among the top in their field and are highly sought after to do reviews with the National Institutes of Health etc.

Mark Noble, PhD, the Director of the Stem Cell and Regenerative Medicine Institute at the University of Rochester, is a long-time member of the GWG. He says it’s a unique group of people:

“It’s a wonderful scientific education because you come to these meetings and someone is putting in a grant on diabetes and someone’s putting in a  grant on repairing the damage to the heart or spinal cord injury or they have a device that will allow you to transplant cells better and there are people  in the room that are able to talk knowledgeably about each of these areas and understand how this plays into medicine and how it might work in terms of actual financial development and how it might work in the corporate sphere and how it fits in to unmet medical needs . I don’t know of any comparable review panels like this that have such a broad remit and bring together such a breadth of expertise which means that every review panel you come to you are getting a scientific education on all these different areas, which is great.”

The GWG reviews the projects for scientific merit: does the proposal seem plausible, does the team proposing it have the experience and expertise to do the work etc. The reviewers put in a lot of work ahead of time, not just reviewing the application, but looking at previous studies to see if the new application has evidence to support what this team hope to do, to compare it to other efforts in the same field. There are disagreements, but also a huge amount of respect for each other.

Once the GWG makes its recommendations on which projects to fund and which ones not to, the applications move to the CIRM Board, which has the final say on all funding decisions. The Board is given detailed summaries of each project, along with the recommendations of the GWG and our own CIRM Review team. But the Board is not told the identity of any of the applicants, those are kept secret to avoid even the appearance of any conflict of interest.

The Board is not required to follow the recommendations of the GWG, though they usually do. But the Board is also able to fund projects that the GWG didn’t place in the top tier of applications. They have done this on several occasions, often when the application targeted a disease or disorder that wasn’t currently part of the agency’s portfolio.

So that’s how Review works. The team, led by Dr. Gil Sambrano, does extraordinary work with little fanfare or fuss. But without them CIRM would be a far less effective agency.

The passage of Proposition 14 means we now have a chance to resume full funding of research, which means our Review team is going to be busier than ever. They have already started making changes to the application requirements. To help let researchers know what those changes are we are holding a Zoom webinar tomorrow, Thursday, at noon PST. If you would like to watch you can find it on our YouTube channel. And if you have questions you would like to ask send them to info@cirm.ca.gov

A Month of CIRM: Where we’ve been, where we’re going

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. We kick off this event with a letter from our the Chair of our Board, Jonathan Thomas.

When voters approved Proposition 14 last November, they gave the Stem Cell Agency a new lease on life and a chance to finish the work we began with the approval of Proposition 71 in 2004. It’s a great honor and privilege. It’s also a great responsibility. But I think looking back at what we have achieved over the last 16 years shows we are well positioned to seize the moment and take CIRM and regenerative medicine to the next level and beyond.

When we started, we were told that if we managed to get one project into a clinical trial by the time our money ran out we would have done a good job. As of this moment we have 68 clinical trials that we have funded plus another 31 projects in clinical trials where we helped fund crucial early stage research. That inexorable march to therapies and cures will resume when we take up our first round of Clinical applications under Prop 14 in March.

But while clinical stage projects are the end game, where we see if therapies really work and are safe in people, there’s so much more that we have achieved since we were created. We have invested $900 million in  basic research, creating a pipeline of the most promising stem cell research programs, as well as investing heavily on so-called “translational” projects, which move projects from basic science to where they’re ready to apply to the Food and Drug Administration (FDA) to begin clinical trials.

We have funded more than 1,000 projects, with each one giving us valuable information to help advance the science. Our funding has helped attract some of the best stem cell scientists in the world to California and, because we only fund research in California, it has persuaded many companies to either move here or open offices here to be eligible for our support. We have helped create the Alpha Stem Cell Clinics, a network of leading medical centers around the state that have the experience and expertise to deliver stem cell therapies to patients. All of those have made California a global center in the field.

That result is producing big benefits for the state. An independent Economic Impact Analysis reported that by the end of 2018 we had already helped generate an extra $10.7 billion in new sales revenue and taxes for California, hundreds of millions more in federal taxes and created more than 56,000 new jobs.

As if that wasn’t enough, we have also:

  • Helped develop the largest iPSC research bank in the world.
  • Created the CIRM Center of Excellence in Stem Cell Genomics to accelerate fundamental understanding of human biology and disease mechanisms.
  • Helped fund the construction of 12 world class stem cell institutes throughout the state.
  • Reached a unique partnership with the National Heart, Lung and Blood Institutes to find a cure for sickle cell disease.
  • Used our support for stem cell research to leverage an additional $12 billion in private funding for the field.
  • Enrolled more than 2700 patients in CIRM funded clinical trials

In many ways our work is just beginning. We have laid the groundwork, helped enable an extraordinary community of researchers and dramatically accelerated the field. Now we want to get those therapies (and many more) over the finish line and get them approved by the FDA so they can become available to many more people around the state, the country and the world.

We also know that we have to make these therapies available to all people, regardless of their background and ability to pay. We have to ensure that underserved communities, who were often left out of research in the past, are an integral part of this work and are included in every aspect of that research, particularly clinical trials. That’s why we now require anyone applying to us for funding to commit to engaging with underserved communities and to have a written plan to show how they are going to do that.

Over the coming month, you will hear more about some of the remarkable things we have managed to achieve so far and get a better sense of what we hope to do in the future. We know there will be challenges ahead and that not everything we do or support will work. But we also know that with the team we have built at CIRM, the brilliant research community in California and the passion and drive of the patient advocate community we will live up to the responsibility the people of California placed in us when they approved Proposition 14.

“Mini-brains” model an autism spectrum disorder and help test treatments

Alysson Muotri, PhD, professor and director of the Stem Cell Program at UC San Diego School of Medicine
and member of the Sanford Consortium for Regenerative Medicine.
Image credit: UC San Diego Health

Rett syndrome is a rare form of autism spectrum disorder that impairs brain development and causes problems with movement, speech, and even breathing. It is caused by mutations in a gene called MECP2 and primarily affects females. Although there are therapies to alleviate symptoms, there is currently no cure for this genetic disorder.

With CIRM funding ($1.37M and $1.65M awards), Alysson Muotri, PhD and a team of researchers at the University of California San Diego School of Medicine and Sanford Consortium for Regenerative Medicine have used brain organoids that mimic Rett syndrome to identify two drug candidates that returned the “mini-brains” to near-normal. The drugs restored calcium levels, neurotransmitter production, and electrical impulse activity.

Brain organoids, also referred to as “mini-brains”, are 3D models made of cells 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 changes in physical structure or gene expression over time.

Dr. Muotri and his team created induced pluripotent stem cells (iPSCs), a type of stem cell that can become virtually any type of cell. For the purposes of this study, they were created from the skin cells of Rett syndrome patients. The newly created iPSCs were then turned into brain cells and used to create “mini-brains”, thereby preserving each Rett syndrome patient’s genetic background. In addition to this, the team also created “mini-brains” that artificially lack the MECP2 gene, mimicking the issues with the same gene observed in Rett syndrome.

Lack of the MECP2 gene changed many things about the “mini-brains” such as shape, neuron subtypes present, gene expression patterns, neurotransmitter production, and decreases in calcium activity and electrical impulses. These changes led to major defects in the emergence of brainwaves.

To correct the changes caused by the lack of the MECP2 gene, the team treated the brain organoids with 14 different drug candidates known to affect various brain cell functions. Of all the drugs tested, two stood out: nefiracetam and PHA 543613. The two drugs resolved nearly all molecular and cellular symptoms observed in the Rett syndrome “mini-brains”, with the number active neurons doubling post treatment.

The two drugs were previously tested in clinical trials for the treatment of other conditions, meaning they have been shown to be safe for human consumption.

In a news release from UC San Diego Health, Dr. Muotri stresses that although the results for the two drugs are promising, the end treatment for Rett syndrome may require a multi-drug cocktail of sorts.

“There’s a tendency in the neuroscience field to look for highly specific drugs that hit exact targets, and to use a single drug for a complex disease. But we don’t do that for many other complex disorders, where multi-pronged treatments are used. Likewise, here no one target fixed all the problems. We need to start thinking in terms of drug cocktails, as have been successful in treating HIV and cancers.”

The full results of this study were published in EMBO Molecular Medicine.

UCLA scientists discover how SARS-CoV-2 causes multiple organ failure in mice

Heart muscle cells in an uninfected mouse (left) and a mouse infected with SARS-CoV-2 (right) with mitochondria seen in pink. The disorganization of the cells and mitochondria in the image at right is associated with irregular heartbeat and death.
Image credit: UCLA Broad Stem Cell Center

As the worldwide coronavirus pandemic rages on, scientists are trying to better understand SARS-CoV-2, the virus that causes COVID-19, and the effects that it may have beyond those most commonly observed in the lungs. A CIRM-funded project at UCLA, co-led by Vaithilingaraja Arumugaswami, Ph.D. and Arjun Deb, M.D. discovered that SARS-CoV-2 can cause organ failure in the heart, kidney, spleen, and other vital organs of mice.

Mouse models are used to better understand the effects that a disease can have on humans. SARS-CoV-2 relies on a protein named ACE2 to infect humans. However, the virus doesn’t recognize the mouse version of the ACE2 protein, so healthy mice exposed to the SARS-CoV-2 virus don’t get sick.

To address this, past experiments by other research teams have genetically engineered mice to have the human version of the ACE2 protein in their lungs. These teams then infected the mice, through the nose, with the SARS-CoV-2 virus. Although this process led to viral infection in the mice and caused pneumonia, they don’t get as broad a range of other symptoms as humans do.

Previous research in humans has suggested that SARS-CoV-2 can circulate through the bloodstream to reach multiple organs. To evaluate this further, the UCLA researchers genetically engineered mice to have the human version of the ACE2 protein in the heart and other vital organs. They then infected half of the mice by injecting SARS-CoV-2 into their bloodstreams and compared them to mice that were not infected. The UCLA team tracked overall health and analyzed how levels of certain genes and proteins in the mice changed.

Within seven days, all of the mice infected with the virus had stopped eating, were completely inactive, and had lost an average of about 20% of their body weight. The genetically engineered mice that had not been infected with the virus did not lose a significant amount of weight. Furthermore, the infected mice had altered levels of immune cells, swelling of the heart tissue, and deterioration of the spleen. All of these are symptoms that have been observed in people who are critically ill with COVID-19.

What’s even more surprising is that the UCLA team also found that genes that help cells generate energy were shut off in the heart, kidney, spleen and lungs of the infected mice. The study also revealed that some changes were long-lasting throughout the organs in mice with SARS-CoV-2. Not only were genes turned off in some cells, the virus made epigenetic changes, which are chemical alterations to the structure of DNA that can cause more lasting effects. This might help explain why some people that have contracted COVID-19 have symptoms for weeks or months after they no longer have traces of the virus in their body.

In a UCLA press release, Dr. Deb discusses the importance and significance of their findings.

“This mouse model is a really powerful tool for studying SARS-CoV-2 in a living system. Understanding how this virus can hijack our cells might eventually lead to new ways to prevent or treat the organ failure that can accompany COVID-19 in humans.”

The full results of this study were published in JCI Insight.