cardiology

Tell-Tale Heart

‘Heart-In-A-Dish’ Sheds Light on Heart Disease Genetics

By Nicole Davis for The Jackson Laboratory for Genomic Medicine
Photography by Peter Morenus

Dr. Travis Hinson holds petri dishes containing beating heart tissue

Dr. J. Travis Hinson is seen holding petri dishes that contain heart cells. Hinson, a joint faculty appointment at UConn Health and The Jackson Laboratory for Genomic Medicine, has pioneered a system to study the genetics of heart failure by recreating beating heart tissue using patients’ stem cells. Photo: Peter Morenus


When a patient shows symptoms of cancer, a biopsy is taken. Scientists study the tissue, examining it under a microscope to determine exactly what’s going on.

But the same can’t be done for heart disease, the leading cause of death among Americans. Until now.

Dr. J. Travis Hinson, a physician-scientist who joined the faculties of UConn Health and The Jackson Laboratory for Genomic Medicine (JAX) in January, uses a novel system he pioneered to study heart tissue.

Hinson engineers heart-like structures with cells containing specific genetic mutations in order to study the genetics of cardiomyopathies, the diseases of the heart muscle that can lead to heart failure and, ultimately, death.

“We basically try to rebuild a little piece of a patient’s heart in a dish,” says Hinson, who developed the technique during his postdoctoral fellowship.
He combines cardiac muscle cells with support cells, such as fibroblasts, and other key factors, including extracellular matrix proteins. Although these tiny, three-dimensional structures do not pump blood, they do contract rhythmically, and their beating strength can be studied.

Making a Difference

Hinson is applauded for his ability to move seamlessly between research, clinical practice, and teaching — the three prongs of an academic medical center’s mission. He’s able to do so, perhaps, because his own career began at the intersection of multiple scientific specialties.

As a University of Pennsylvania undergraduate, Hinson interned at DuPont in New Jersey to explore interests in chemistry and engineering. But he soon realized his passion for science needed a real-word focus. “I wanted to do science that made a difference in people’s health,” he says.

The same summer, he volunteered in the emergency department of a local hospital. Impressed by a cardiologist’s calm and collected manner in a crisis, and gaining interest in the heart, Hinson changed his career trajectory from engineering to medical school.

Hinson and his colleagues can isolate skin or blood cells directly from cardiomyopathy patients and coax them to form heart muscle cells, making it possible to study the biological effects of patients’ own mutations.

Hinson joined the laboratory of Dr. Robert J. Levy, a pediatric cardiologist and researcher at The Children’s Hospital of Philadelphia, working to harness gene therapy techniques to make artificial heart valves and other cardiovascular devices more durable. Through this early foray into biomedical research, Hinson deepened his interest in biomedical science and gained an appreciation of the work of a physician-scientist.

In Dr. Christine Seidman’s lab at Harvard Medical School, Hinson chose to lead a project on Björnstad syndrome, a rare, inherited syndrome characterized by hearing loss and twisted, brittle hair. At the time, little was known about the molecular causes of the disorder, although the genetic culprits were thought to reside within a large swath of chromosome 2. Using genetic mapping techniques and DNA sequencing, Hinson homed in on the precise mutations.

In addition to casting light on disease biology, he glimpsed the power of genomic information. “I was fascinated by the potential for understanding new genes that cause human diseases, and how important that was to society,” Hinson says.

Matters of the Heart

Throughout his medical training, Hinson noticed there were some significant stumbling blocks to gathering a deep knowledge of heart disease, particularly cardiomyopathies.

Cardiac muscle has essentially two paths toward dysfunction and ultimate failure. It can either dilate — become abnormally large and distended — or it can thicken. Both routes severely impair how well the heart performs as a pump. These conditions, known as dilated cardiomyopathy (DCM) and hypertrophic cardiomyopathy (HCM), can stem from pre-existing disorders of the heart, such as a previous heart attack or long-standing hypertension, or from DNA mutations.

Fueled by advances in genomics over the last two decades, more than 40 genes have been identified that underlie cardiomyopathy. But unlike diseases such as cystic fibrosis or sickle cell anemia, where it is fairly common for affected individuals from different families to carry the exact same genetic typo, it is exceedingly rare for unrelated patients with cardiomyopathy to share the same mutation. With such a complex genetic architecture, figuring out how the different genes and gene mutations contribute to heart disease has been an enormous challenge.


Dr. Travis Hinson speaks with others in his lab

Above: Dr. J. Travis Hinson gives a tour of his laboratory. Photo: Peter Morenus


Because of this formidable hurdle, drug discovery for the cardiomyopathies has languished. “There really has not been a paradigm-shifting drug developed for heart failure in the last 20 years,” says Hinson. Moreover, the few treatments that do exist are primarily aimed at controlling patients’ symptoms, not slowing or halting their disease.

Hinson aims to improve this picture. With his “heart-in-a-dish” technique, he and his team are now unraveling the effects of genetic mutations on cardiac biology.

The system harnesses multiple recent advances in both stem cell and genome editing technologies. With these capabilities, Hinson and his colleagues can isolate skin or blood cells directly from cardiomyopathy patients and coax them to form heart muscle cells, making it possible to study the biological effects of patients’ own mutations. Moreover, he can correct those mutations, or create additional ones, to further probe how genetic differences influence heart biology.

Part of the allure of Hinson’s approach is that it can be readily applied to study other forms of heart disease. It can also be leveraged for drug discovery, providing a platform to screen and test compounds with therapeutic potential in a wide range of cardiovascular diseases.

In addition to his research lab based at JAX, Hinson continues to practice cardiology at UConn Health. He helps run a specialized clinic focused on genetic forms of heart disease, as well as arrhythmias, connective tissue disorders, and other conditions.

“We have an exciting opportunity to provide clinical services in cardiac genetics in the corridor between New York and Boston,” he says. That means state-of-the-art genetic testing, including gene panels and genome sequencing, as well as genetic counseling for both patients and family members to help inform disease diagnosis and guide treatment. Although there are only a handful of treatments now available, Hinson believes this clinic will be uniquely poised to take advantage of a new generation of personalized treatments that are precisely tailored to patients’ specific gene mutations.

“Travis really is a quintessential physician-scientist,” says Dr. Bruce Liang, dean of UConn School of Medicine and director of the Pat and Jim Calhoun Cardiology Center at UConn Health.

“He has a remarkable ability to link basic science with important clinical problems, and his work holds a great deal of promise for developing new treatments for patients with cardiomyopathy. I wish there were two or three Travis Hinsons.”


Hinson’s beating heart tissue. Provided by Dr. Travis Hinson

Close at Heart

By Kim Kreiger
Illustration by Yesenia Carrero

Radiation treatment for breast cancer can inadvertently graze the heart, leading to damage and disease years later. UConn doctors are working to change that.

closeatheart


Getting radiation treatment for breast cancer can make you feel vulnerable. Sitting in a machine with radiation pointed directly at your chest, you have to trust that the doctor knows what she’s doing, that the X-rays are aimed right, that the machine is properly calibrated … and then you just sit perfectly still.

But what if you could have some control over the process?

Dr. Robert Dowsett, chief of UConn’s Division of Radiation Oncology, and
colleagues in the Carole and Ray Neag Comprehensive Cancer Center are using a new technique to give breast cancer patients agency in their radiation treatments. And they’re taking better care of the patients’ hearts in the process.

A patient can intentionally increase the heart-chest wall distance by more than a centimeter by controlling her breathing using the Deep Inspiration Breath Hold.

Using the technique, called Deep Inspiration Breath Hold, patients can help control the accuracy and timing of their own radiation dose. The patient takes a breath of specific depth before the radiation machine turns on. Doing this correctly can increase the distance between the heart and the breast by a centimeter or two, lowering the amount of radiation hitting the heart by as much as 50 percent.

Jeryl Dickson, 62, of Manchester, Conn., was one of the first patients at UConn Health to use the technique, from late 2015 through Feb. 2. Her doctors, including Dowsett, prescribed a course of radiation therapy to make sure there were no lingering cancer cells remaining after a lumpectomy removed her breast cancer.

“I practiced deep breathing and breath holds prior to radiation treatment with the radiation oncology staff so I could feel what it would be like,” says Dickson.

Radiation treatment of breast cancer can be very effective, eradicating tumor cells hiding in the chest wall. But breast cancer survivors have a heightened risk of heart disease that shows itself years later. Ironically, the heart disease stems from the radiation that originally saved their lives. Radiation is a type of light, and like visible light, it has a tendency to reflect and scatter. Just as even the sharpest spotlight has blurred edges where it blends into shadow, even the best-aimed medical radiation beam occasionally scatters into tissue outside of the tumor it targets. Sometimes it hits the heart.

Dr. Agnes Kim, director of the Cardio-Oncology Program at UConn Health, analyzes echocardiography images as one way to monitor cancer patients’ risk of heart disease.

Dr. Agnes Kim, director of the Cardio-Oncology Program at UConn Health, analyzes echocardiography images as one way to monitor cancer patients’ risk of heart disease.
Tina Encarnacion/UConn Health Photo

“We worry about heart attacks down the road, 10 to 15 years after radiation treatment of cancer in the chest. We also worry about inflammation on the outside of the heart in the short term. We don’t exactly know how the radiation damages the tissue, but it definitely seems to accelerate damage to blood vessels. It can also cause scarring and fibrosis damage,” says Dowsett.

But the distance between the heart and the chest wall varies from person to person. And a patient can intentionally increase the heart-chest wall distance by controlling her breathing using the Deep Inspiration Breath Hold.

To make the best use of the Deep Inspiration Breath Hold technique, Dowsett and his colleagues at UConn Health combine it with an optical scanning system supplied by C-RAD. The scanning system is essentially a computer with a camera that models the surface of the skin on the patient’s chest. It tracks the patient’s breathing, and coaches her to inhale just the right amount. As the patient, you wear virtual-reality goggles in which you see a bar graph showing your inhalation, with a box at the top. Your goal is to hit the box and then hold your breath for the 20 to 30 seconds it takes to complete the radiation treatment. Some patients can hold their breath that long; others can’t. It doesn’t matter, because if you exhale, or giggle, or cough, the system sees your chest move out of the perfect range and stops the radiation. It won’t restart until you get yourself back in position and inhale to just the right spot again.

“The deep breathing technique was not difficult at all,” says Dickson, “Honestly, I was more focused on my cancer, and heart health never entered my mind. But I am glad I put my trust in my doctors, and I never had any doubts.”

UConn Health is the only hospital using this technology in Central Connecticut. It’s a powerful, precise way to make sure the radiation beam gets the cancer, and to minimize the risk to other organs.

Previously, “the area we treated inevitably ended up being bigger than the target (tumor) itself,” Dowsett says. “Now we’ve expanded this to abdominal targets such as the pancreas and adrenal lesions,” while sparing healthy surrounding organs.

Honor Roll – Winter 2015

For the second consecutive year, UConn Health has received a Gold Award from Get With The Guidelines, an American College of Cardiology and American Heart Association initiative that recognizes hospitals for providing exceptional care to heart-attack victims according to evidence-based guidelines.


UConn Health psychiatrist Dr. Kristina Zdanys was voted onto the Medical and Scientific Advisory Council for the Connecticut Alzheimers Association in June. She will join colleagues Rick Fortinsky and Dr. Lavern Wright, who also sit on the council.


Hartford Magazine’s 2015 list of Best Doctors in Connecticut includes 53 UConn Health faculty members. See the list of cited UConn docs at UConn Today.