Posted on by Dr. Francis Collins
The blood-brain barrier, or BBB, is a dense sheet of cells that surrounds most of the brain’s blood vessels. The BBB’s tiny gaps let vital small molecules, such as oxygen and water, diffuse from the bloodstream into the brain while helping to keep out larger, impermeable foreign substances that don’t belong there.
But in people with certain neurological disorders—such as amyotrophic lateral sclerosis (ALS) and Huntington’s disease—abnormalities in this barrier may block the entry of biomolecules essential to healthy brain activity. The BBB also makes it difficult for needed therapies to reach their target in the brain.
To help look for solutions to these and other problems, researchers can now grow human blood-brain barriers on a chip like the one pictured above. The high-magnification image reveals some of the BBB’s cellular parts. There are endothelial-like cells (magenta), which are similar to those that line the small vessels surrounding the brain. In close association are supportive brain cells known as astrocytes (green), which help to regulate blood flow.
While similar organ chips have been created before, what sets apart this new BBB chip is its use of induced pluripotent stem cell (iPSC) technology combined with advanced chip engineering. The iPSCs, derived in this case from blood samples, make it possible to produce a living model of anyone’s unique BBB on demand.
The researchers, led by Clive Svendsen, Cedars-Sinai, Los Angeles, first use a biochemical recipe to coax a person’s white blood cells to become iPSCs. At this point, the iPSCs are capable of producing any other cell type. But the Svendsen team follows two different recipes to direct those iPSCs to differentiate into endothelial and neural cells needed to model the BBB.
Also making this BBB platform unique is its use of a sophisticated microfluidic chip, produced by Boston-based Emulate, Inc. The chip mimics conditions inside the human body, allowing the blood-brain barrier to function much as it would in a person.
The channels enable researchers to flow cerebral spinal fluid (CSF) through one side and blood through the other to create the fully functional model tissue. The BBB chips also show electrical resistance and permeability just as would be expected in a person. The model BBBs are even able to block the entry of certain drugs!
As described in Cell Stem Cell, the researchers have already created BBB chips using iPSCs from a person with Huntington’s disease and another from an individual with a rare congenital disorder called Allan-Herndon-Dudley syndrome, an inherited disorder of brain development.
In the near term, his team has plans to model ALS and Parkinson’s disease on the BBB chips. Because these chips hold the promise of modeling the human BBB more precisely than animal models, they may accelerate studies of potentially promising new drugs. Svendsen suggests that individuals with neurological conditions might one day have their own BBB chips made on demand to help in selecting the best-available therapeutic options for them. Now that’s a future we’d all like to see.
 Human iPSC-Derived Blood-Brain Barrier Chips Enable Disease Modeling and Personalized Medicine Applications. Vatine GD, Barrile R, Workman MJ, Sances S, Barriga BK, Rahnama M, Barthakur S, Kasendra M, Lucchesi C, Kerns J, Wen N, Spivia WR, Chen Z, Van Eyk J, Svendsen CN. Cell Stem Cell. 2019 Jun 6;24(6):995-1005.e6.
Tissue Chip for Drug Screening (National Center for Advancing Translational Sciences/NIH)
Stem Cell Information (NIH)
Svendsen Lab (Cedars-Sinai, Los Angeles)
NIH Support: National Institute of Neurological Disorders and Stroke; National Center for Advancing Translational Sciences
Posted on by Dr. Francis Collins
A lot of young people are driven—driven to get a good education, land a great job, find true love, or see the world. But, today, I want to honor the life of a young man who was driven by something even bigger. Andrew Lee was driven to cure kidney cancer—not only for himself, but for others as well.
I knew and loved Andrew. And so did the legion of doctors, nurses, researchers, and other team members who had the privilege of fighting cancer with him over four very challenging years. Andrew was 19, just finishing his freshman year of college, when he received a devastating diagnosis: stage 4 kidney cancer, a rare type called Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC). There is no known cure for HLRCC, and doctors estimated his survival at about a year at best.
Still, Andrew and his family weren’t about to go hide somewhere and wait for the end. They began a journey that led him to take part in at least seven clinical trials, including ones at Yale University, New Haven, CT; Georgetown University, Washington, DC; and the NIH Clinical Center, Bethesda, MD. Experimental treatments slowed down the cancer, but sometimes made him terribly sick. Yet, Andrew always remained optimistic and cheerful. If a trial didn’t help him, maybe it would help someone else.
Andrew’s generosity didn’t stop there. Inspired by his father’s gift of a totally awesome 2015 Liberty Walk Nissan GT-R, he founded the Driven To Cure (DTC) nonprofit and traveled the country in his orange sports car to raise funds for kidney cancer research. According to the National Cancer Institute, nearly 63,000 Americans are diagnosed with kidney and renal pelvis cancers each year.
Andrew figured out how to put the “fun” in fundraising, drawing crowds at car shows and raising more than $500,000 in donations in just three years. His efforts were recognized by the Foundation for the NIH’s Charlie Sanders Award, which I had the privilege of presenting to him last fall.
But I think it was Andrew’s humanity that touched us the most. He always had time to share his story, to encourage another child or adult struggling with a frightening diagnosis. He’d give thrills to kids at The Children’s Inn at NIH when he rumbled into the parking lot with his 700 horsepower GT-R. At car shows, throngs of people were drawn in by the turbocharged ride and then captivated by the young man with the bright smile and compelling story. Andrew wrote: “I realized that the vehicle of my dreams was also the vehicle which gave me the opportunity to make a difference; to do something bigger than myself.”
Still, on the personal level, kidney cancer proved relentless. Options for treatment eventually ran out. As the disease progressed, Andrew and his family had to make another difficult transition—choosing to celebrate life, even in the face of its approaching end. He needed a wheelchair, so family and friends came up with one, keeping in mind one of Andrew’s last wishes. When Andrew needed 24-hour care and pain control, he was admitted to the NIH Clinical Center Hospice Unit, where comfort could be provided and his loved ones could gather around. That even included getting government permission for a visit from his dog Milo! Surrounded by friends and family, he died peacefully on April 21.
Andrew made friends with everyone—especially kids at The Children’s Inn. One special buddy was Isaac Barchus, who has a rare autoinflammatory disease called CANDLE Syndrome. When he was back home in Omaha, NE, Isaac enjoyed challenging Andrew to long-distance video games, especially FIFA Soccer.
Although Isaac can walk, it can be very painful, so he sometimes turned to an old, beat-up wheelchair to cover long distances. But not anymore. When Isaac turned 15 on June 7, Andrew’s father Bruce Lee fulfilled his son’s wish for the future of his wheelchair. He presented Isaac with Andrew’s wheelchair, which had now been painted the same orange color as Andrew’s GT-R and emblazoned with the feisty slogan on Andrew’s personalized license plate—F CANCR. What a cool birthday gift!
During his final weeks and days, Andrew and his dad often listened to the Andy Grammer song, “Don’t Give Up on Me.” Andrew’s family never gave up on him, and he never gave up on them either. In fact, Andrew never gave up caring, loving, and believing. He wouldn’t want us to either, as his favorite song reminds us: “I will fight, I will fight for you; I always do until my heart is black and blue.”
Yes, Andrew, our hearts are black and blue from losing you. But we won’t give up on all you stood for in your short but inspiring life. Race In Peace, dear Andrew.
Remembering Andrew Lee (Foundation for the National Institutes of Health)
NIH Cancer Patient Receives Humanitarian Award (The NIH Record)
Driven To Cure (Silver Spring, MD)
Video: Fighting Cancer With a 700-hp Nissan GT-R (The Drive)
Video: Andy Grammer—”Don’t Give Up On Me” [Official Lyric Video] from the film Five Feet Apart
Hereditary Leiomyomatosis and Renal Cell Cancer (National Library of Medicine/NIH)
Kidney (Renal Cell) Cancer (National Cancer Institute/NIH)
CANDLE Syndrome (Genetic and Rare Diseases Information Center/NIH)
Treating CANDLE Syndrome (National Institute of Allergy and Infectious Diseases/NIH)
Posted on by Dr. Francis Collins
With advances in induced pluripotent stem cell (iPSC) technology, it’s now possible to reprogram adult skin or blood cells to form miniature human organs in a lab dish. While these “organoids” closely mimic the structures of the liver and other vital organs, it’s been tough to get them to represent inflammation, fibrosis, fat accumulation, and many other complex features of disease.
Fatty liver diseases are an increasingly serious health problem. So, I’m pleased to report that, for the first time, researchers have found a reliable way to make organoids that display the hallmarks of those conditions. This “liver in a dish” model will enable the identification and preclinical testing of promising drug targets, helping to accelerate discovery and development of effective new treatments.
Previous methods working with stem cells have yielded liver organoids consisting primarily of epithelial cells, or hepatocytes, which comprise most of the organ. Missing were other key cell types involved in the inflammatory response to fatty liver diseases.
To create a better organoid, the team led by Takanori Takebe, Cincinnati Children’s Hospital Medical Center, focused its effort on patient-derived iPSCs. Takebe and his colleagues devised a special biochemical “recipe” that allowed them to grow liver organoids with sufficient cellular complexity.
As published in Cell Metabolism, the recipe involves a three-step process to coax human iPSCs into forming multi-cellular liver organoids in as little as three weeks. With careful analysis, including of RNA sequencing data, they confirmed that those organoids contained hepatocytes and other supportive cell types. The latter included Kupffer cells, which play a role in inflammation, and stellate cells, the major cell type involved in fibrosis. Fibrosis is the scarring of the liver in response to tissue damage.
Now with a way to make multi-cellular liver organoids, the researchers put them to the test. When exposed to free fatty acids, the organoids gradually accumulated fat in a dose-dependent manner and grew inflamed, which is similar to what happens to people with fatty liver diseases.
The organoids also showed telltale biochemical signatures of fibrosis. Using a sophisticated imaging method called atomic force microscopy (AFM), the researchers found as the fibrosis worsened, they could measure a corresponding increase in an organoid’s stiffness.
Next, as highlighted in the confocal microscope image above, Takebe’s team produced organoids from iPSCs derived from children with a deadly inherited form of fatty liver disease known as Wolman disease. Babies born with this condition lack an enzyme called lysosomal acid lipase (LAL) that breaks down fats, causing them to accumulate dangerously in the liver. Similarly, the miniature liver shown here is loaded with accumulated fat lipids (blue).
That brought researchers to the next big test. Previous studies had shown that LAL deficiency in kids with Wolman disease overactivates another signaling pathway, which could be suppressed by targeting a receptor known as FXR. So, in the new study, the team applied an FXR-targeted compound called FGF19, and it prevented fat accumulation in the liver organoids derived from people with Wolman disease. The organoids treated with FGF19 not only were protected from accumulating fat, but they also survived longer and had reduced stiffening, indicating a reduction in fibrosis.
These findings suggest that FGF19 or perhaps another compound that acts similarly might hold promise for infants with Wolman disease, who often die at a very early age. That’s encouraging news because the only treatment currently available is a costly enzyme replacement therapy. The findings also demonstrate a promising approach to accelerating the search for new treatments for a variety of liver diseases.
Takebe’s team is now investigating this approach for non-alcoholic steatohepatitis (NASH), a common cause of liver failure and the need for a liver transplant. The hope is that studies in organoids will lead to promising new treatments for this liver condition, which affects millions of people around the world.
Ultimately, Takebe suggests it might prove useful to grow liver organoids from individual patients with fatty liver diseases, in order to identify the underlying biological causes and test the response of those patient-specific organoids to available treatments. Such evidence could one day help doctors to select the best available treatment option for each individual patient, and bring greater precision to treating liver disease.
 Modeling steatohepatitis in humans with pluripotent stem cell-derived organoids. Ouchi R, Togo S, Kimura M, Shinozawa T, Koido M, Koike H, Thompson W, Karns RA, Mayhew CN, McGrath PS, McCauley HA, Zhang RR, Lewis K, Hakozaki S, Ferguson A, Saiki N, Yoneyama Y, Takeuchi I, Mabuchi Y, Akazawa C, Yoshikawa HY, Wells JM, Takebe T. Cell Metab. 2019 May 14. pii: S1550-4131(19)30247-5.
Wolman Disease (Genetic and Rare Diseases Information Center/NIH)
Nonalcoholic Fatty Liver Disease & NASH (National Institute of Diabetes and Digestive and Kidney Diseases/NIH)
Stem Cell Information (NIH)
Tissue Chip for Drug Screening (National Center for Advancing Translational Sciences/NIH)
Takebe Lab (Cincinnati Children’s Hospital Medical Center)
NIH Support: National Institute of Diabetes and Digestive and Kidney Diseases
Posted on by Dr. Francis Collins
There are nearly 7,000 rare diseases, some of which affect just a few dozen people. Yet, if one considers all these conditions together, about 30 million people in the United States have rare diseases. On this Rare Disease Day, I’d like to challenge each of you to think about how we can raise the visibility of individuals living with rare diseases, as well as the researchers working hard to help them.
I’d like to introduce you to Harper Spero, who is using her rare gift of storytelling to share the experiences of people with a wide variety of conditions that she likes to call “invisible illnesses.” Through her podcast series, called Made Visible, this 34-year-old New York City native is among the many people helping to spread the word that rare diseases are not rare.
Spero knows what it’s like to live with a rare disease. Shortly after she was born, it became clear that she was unusually prone to infections. But doctors had a hard time figuring out what exactly was wrong with this little girl. Finally, at the age of 10, Spero was diagnosed with Hyper-Immunoglobulin E Syndrome (HIES), also known as Job’s syndrome. There currently is no cure for this rare genetic disease, which impairs the immune system and affects multiple parts of the body. But Spero is determined to live a normal life despite her chronic “invisible illness.”
Spero also knows what it’s like to take part in biomedical research. Seven years ago, she came to the NIH Clinical Center here in Bethesda, MD, seeking help for a large cyst in her right lung. It marked the beginning of a positive partnership with a Job’s syndrome research team led by two of NIH’s many dedicated physician-scientists, Alexandra Freeman and Steven Holland. Not only did the NIH researchers work with Spero to figure out the best ways of managing her symptoms, they are using what they’ve learned from her and about 175 other Job’s syndrome patients to develop approaches for earlier diagnosis and interventions. Spero, who visits the Clinical Center annually and communicates with the NIH team on a weekly basis, has been so inspired by the experience that she even chose to feature Dr. Freeman in one of her recent podcasts.
Unlike Spero, I don’t have a podcast—at least not yet. But I do have a blog, and Spero was kind enough to respond to a few of my questions on rare diseases and medical research. So, I’m sharing her thoughts below—I hope you are inspired by them as much as I was!
Why do you feel it is important for people with rare diseases to take part in medical research?
Without research, we can’t make any improvements, changes or find cures. Participating in medical research allows researchers and doctors to learn about the trends (or lack of) between patients, and determine what’s working and what’s not.
What have your own experiences been with the health-care system and medical research?
When I was younger, I really didn’t want to be a specimen. I was going through so much trying to find answers and treatments for myself that it was hard to think about how it would help other patients down the road to be sharing my experiences. I didn’t want to add another doctor’s visit to my schedule. After coming to NIH in 2012, I recognized the importance of being part of the research because it could essentially help me, other patients and for early detection of rare diseases. I recognize that the medical researchers are often much more compassionate than many doctors who simply treat symptoms. Researchers are curious and genuinely care to understand you and your story.
Your podcast is fantastic. How has it affected you to hear and share the stories of so many people affected by rare diseases?
I was definitely aware how many people were living with rare diseases, but I was surprised by how many people were willing to share their stories on my show and how many people wanted to listen to these stories. I hadn’t heard stories being shared in this way around this topic and I wanted to be the one who brought them to life. Many of my guests haven’t publicly (let alone with friends or family) shared their stories so I’m honored that they’re willing to do it with me. They see how important it is to have these conversations and to educate people on what it’s like to have an invisible illness.
What would you tell someone who’s just learned he or she has a rare disease?
You don’t have to do this alone! Find a team of medical professionals you trust to support you. I spent most of my life without a team of doctors that I loved and truly understood me, and now I can’t imagine my life without my team at NIH. Also, talk to your loved ones—let them know what you’re feeling and discuss how they can support you. This is likely new for them too and there’s no right way of navigating and managing a rare disease.
What would you tell a young person who’s considering becoming a rare disease researcher?
Thank you for your interest in doing this! We need more compassionate, curious and passionate people doing this work and investing their time to learn more and help find answers for rare diseases. Please treat us with respect and care.
If you could change one thing in the medical care/research of rare disease, what would it be? And what about in society in general?
There’s a way to do your job without treating patients like guinea pigs. We’re humans too, and we’re humans who have likely been through the wringer in the medical world. Be kind to us. Treat us the way you’d like to be treated. Compassion seems to be a word I’m using a lot. I think society can be more compassionate towards one another especially around rare disease. You can never fully understand what someone is going through so ask questions, show you care and treat people with kindness.
What are your hopes for the future?
I’d love there to be more answers and solutions for navigating a rare disease. A lot of the treatments I do are based on trial-and-error. What works for one patient definitely doesn’t always work for me. So, we’re constantly trying to navigate what works best for me. I’d love to see a cure to be found for Hyper IgE/Job’s Syndrome, as well as other rare diseases.
Podcast Series: Made Visible
NIH Patient Shares Stories of ‘Invisible Illness,’ The NIH Record, February 8, 2019
Hyper-Immunoglobulin E Syndrome (HIES) (National Institute of Allergy and Infectious Diseases/NIH)
Rare Disease Day at NIH 2019 (National Center for Advancing Translational Sciences/NIH)
Video: Rare Disease Patient Profiles (NCATS)
Undiagnosed Diseases Network (Common Fund/NIH)
Video: One in a Million (Undiagnosed Diseases Network, University of Utah Health, Salt Lake City)
Posted on by Dr. Francis Collins
Thanks to CRISPR and other gene editing technologies, hopes have never been greater for treating or even curing Duchenne muscular dystrophy (DMD) and many other rare, genetic diseases that once seemed tragically out of reach. The latest encouraging news comes from a study in which a single infusion of a CRISPR editing system produced lasting benefits in a mouse model of DMD.
There currently is no way to cure DMD, an ultimately fatal disease that mainly affects boys. Caused by mutations in a gene that codes for a critical protein called dystrophin, DMD progressively weakens the skeletal and heart muscles. People with DMD are usually in wheelchairs by the age of 10, with most dying before the age of 30.
The exquisite targeting ability of CRISPR/Cas9 editing systems rely on a sequence-specific guide RNA to direct a scissor-like, bacterial enzyme (Cas9) to just the right spot in the genome, where it can be used to cut out, replace, or repair disease-causing mutations. In previous studies in mice and dogs, researchers directly infused CRISPR systems directly into the animals bodies. This “in vivo” approach to gene editing successfully restored production of functional dystrophin proteins, strengthening animals’ muscles within weeks of treatment.
But an important question remained: would CRISPR’s benefits persist over the long term? The answer in a mouse model of DMD appears to be “yes,” according to findings published recently in Nature Medicine by Charles Gersbach, Duke University, Durham, NC, and his colleagues . Specifically, the NIH-funded team found that after mice with DMD received one infusion of a specially designed CRISPR/Cas9 system, the abnormal gene was edited in a way that restored dystrophin production in skeletal and heart muscles for more than a year. What’s more, lasting improvements were seen in the structure of the animals’ muscles throughout the same time period.
As exciting as these results may be, much more research is needed to explore both the safety and the efficacy of in vivo gene editing before it can be tried in humans with DMD. For instance, the researchers found that older mice that received the editing system developed an immune response to the bacterially-derived Cas9 protein. However, this response didn’t prevent the CRISPR/Cas9 system from doing its job or appear to cause any adverse effects. Interestingly, younger animals didn’t show such a response.
It’s worth noting that the immune systems of mice and people often respond quite differently. But the findings do highlight some possible challenges of such treatments, as well as approaches to reduce possible side effects. For instance, the latest findings suggest CRISPR/Cas9 treatment might best be done early in life, before an infant’s immune system is fully developed. Also, if it’s necessary to deliver CRISPR/Cas9 to older individuals, it may be beneficial to suppress the immune system temporarily.
Another concern about CRISPR technology is the potential for damaging, “off-target” edits to other parts of the genome. In the new work, the Duke team found that its CRISPR system made very few “off-target” edits. However, the system did make a surprising number of complex edits to the targeted dystrophin gene, including integration of the viral vector used to deliver Cas9. While those editing “errors” might reduce the efficacy of treatment, researchers said they didn’t appear to affect the health of the mice studied.
It’s important to emphasize that this gene editing research aimed at curing DMD is being done in non-reproductive (somatic) cells, primarily muscle tissue. The NIH does not support the use of gene editing technologies in human embryos or human reproductive (germline) cells, which would change the genetic makeup of future offspring.
As such, the Duke researchers’ CRISPR/Cas9 system is designed to work optimally in a range of muscle and muscle-progenitor cells. Still, they were able to detect editing of the dystrophin-producing gene in the liver, kidney, brain, and other tissues. Importantly, there was no evidence of edits in the germline cells of the mice. The researchers note that their CRISPR system can be reconfigured to limit gene editing to mature muscle cells, although that may reduce the treatment’s efficacy.
It’s truly encouraging to see that CRISPR gene editing may confer lasting benefits in an animal model of DMD, but a great many questions remain before trying this new approach in kids with DMD. But that time is coming—so let’s boldly go forth and get answers to those questions on behalf of all who are affected by this heartbreaking disease.
 Long-term evaluation of AAV-CRISPR genome editing for Duchenne muscular dystrophy. Nelson CE, Wu Y, Gemberling MP, Oliver ML, Waller MA, Bohning JD, Robinson-Hamm JN, Bulaklak K, Castellanos Rivera RM, Collier JH, Asokan A, Gersbach CA. Nat Med. 2019 Feb 18.
Muscular Dystrophy Information Page (National Institute of Neurological Disorders and Stroke/NIH)
Gersbach Lab (Duke University, Durham, NC)
Somatic Cell Genome Editing (Common Fund/NIH)
NIH Support: National Institute of Arthritis and Musculoskeletal and Skin Diseases; National Institute of Biomedical Imaging and Bioengineering
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