As Dr. Erica Herzog journeyed down the path of her medical education, several key factors breathed life into her decision to focus on pulmonary disease research.
In addition to an overriding interest in the workings of the lungs, she hoped to develop additional therapies for the many conditions that afflict patients. And she felt a commitment to helping those patients live their best possible lives with their disease.
“With the cards they were dealt medically, I thought that a contribution I could make to medicine would transcend the day-to-day care for patients — the best part of my job and something I love,” she explained. “It would also be to move the field forward to try and understand pulmonary fibrosis.”
Today, Dr. Herzog has done precisely that as director of Yale University’s Interstitial Lung Disease Center of Excellence, associate dean of medical student research and an endowed professor of pulmonary medicine. The distinguished physician scientist will share her wealth of experience and insights as keynote speaker at USF Health Research Day on Feb. 28.
Dr. Herzog’s laboratory at Yale, where she has worked for close to 25 years, has made a sustained impact on better understanding pulmonary fibrosis — a chronic lung disease marked by scarring and thickening of lung tissue, impinging on the exchange of oxygen and carbon dioxide, which results in shortness of breath, among other symptoms.
Dr. Erica Herzog
She is credited with several influential discoveries verified in other labs worldwide. Her early work helped generate interest in the mechanisms through which innate immunity is linked to pulmonary fibrosis and her lab recently reported that a previously unrecognized nerve-lung connection is tied to lung disease. In addition to being published in myriad medical journals, Dr. Herzog has been honored by peers with the Jo Rae Wright Award from the American Thoracic Society and induction into the American Society of Clinical Investigation.
“So you might ask, ‘Why pulmonary fibrosis?’” she said. “This is a condition of impaired wound healing in the lungs, where there has been some type of injury. The lungs’ response to it is to develop a progressive form of scar tissue. And my idea was that the processes that are taking place in this impaired wound healing and fibrosis might reflect more global paradigms that the lung can help us understand. That would allow us to expand upon not just pulmonary fibrosis but other forms of lung disease as well — and potentially even diseases outside the lungs.”
Dr. Herzog, a New Jersey native, earned her bachelor’s degree and medical degree at the University of North Carolina at Chapel Hill and did her residency at Mount Sinai Medical Center in New York, followed by her PhD and fellowship at Yale School of Medicine. It was during her fellowship that she ultimately settled on her career direction.
“I was fortunate to have some really wonderful mentors and role models,” she said. “What made the difference was interacting with those individuals and seeing their approaches to pulmonary fibrosis research — and how they were working every day to understand the diseases of the patients they were treating. Working with those individuals was how I knew that focusing on pulmonary fibrosis was for me.”
Pursuing that focus as a physician scientist — both seeing patients at New Haven Hospital’s medical intensive care unit and conducting research in her lab — has been particularly rewarding.
“You can make a clinical observation with patients that then can inspire a research question, which you evaluate in the lab,” she said. “As a scientist, any question you ask and answer is important, because it’s just as necessary to find out what does work as what doesn’t. In the end, what you learn was wrong could lead you toward something that will help.”
One of Dr. Herzog’s early research discoveries occurred in the mid-to-late 2000s, at a time when it was believed that pulmonary fibrosis was a disease specifically confined to the lungs, in which the immune system had no part.
“We noticed, through some observations I made in my patients, that perhaps there was an immune perturbation that could be orchestrating the disease. The immune system doesn’t have to be the reason a patient develops the disease, but maybe it is supposed to suppress the disease and forgets to do so. Or maybe the immune system gets confused and becomes overactive in a way that’s detrimental when you have a fibrotic condition in the lungs.”
Dr. Herzog feels lucky to have had a motivated group of patients to participate in and help her conduct her studies, propelling her research forward.
“It took a long time to get our findings published because they were contrary to the prevailing thought at the time,” she explained. “We actually put forth a new way of looking at fibrosis: that it was not caused by the immune system but by whatever injured the lung — and the lungs’ attempt to make repairs. The immune system is trying to regulate this repair, either dampening the scar formation, or in some situations, worsening it.”
This knowledge resulted in the creation of several drugs that are now in various stages of clinical development.
“Whether they work or not, we don’t know yet, but we’ve been able to contribute to the pulmonary fibrosis drug pipeline by providing information about immunity that can be used to help patients,” she said. “In addition, when we make a discovery in a disease in one organ, it can have an impact for other diseases and other organs. In fact, our work in the lung has been used as a model that has informed some discoveries in other organ systems such as the kidney and liver.”
More recently, Dr. Herzog’s lab discovered that sympathetic nerves, which drive the fight-or-flight response, contribute to fibrotic disease in the lungs.
“It was a happy accident,” she said. “As we were studying immune findings, we noticed that one population of cells called macrophages was adopting characteristics of macrophages that are normally found in the brain. We wondered, ‘Is it possible these cells in the lung are adopting brain-type functions?’ We took some time to study how nerves in the lung work — nobody had done this before. And we were able to find that, yes, during pulmonary fibrosis, nerves in the lung become very abnormal and activate an enhanced fight-or-flight response that appears to contribute to the progression of the disease.”
The good news: a number of drugs on the market suppress the fight-or-flight response and offer a possible new treatment method for patients. “We’re not studying what it’s doing to your emotions or your heart rate,” she said. “We’re studying what it’s doing to the lung, and it seems to really be doing a number on the lungs’ ability to repair itself. It appears to make cells rev up and act inappropriately.”
As associate dean of Medical Student Research, Dr. Herzog also is deeply involved in the development and success of Yale School of Medicine students’ research. And she’s looking forward to being part of Research Day, the largest celebration of health sciences research collaboration across all four USF Health colleges. During a visit to USF last year, she spoke to medical school fellows, visited the pulmonary department and was impressed by all she saw. Her message to students is simple:
“Always put the patient first, no matter what the situation is,” she said. “But also don’t be afraid to think creatively, because you never know where that new idea will bring you and how it might allow you to help patients one day.”
— Video by Allison Long, USF Health News