Academic Spotlight: Leila Mohammadi, MD, PhD
Combining the Best of All Worlds
All her life, Leila Mohammadi, MD, PhD, has moved skillfully between different worlds, bringing the best of each to her work. Fluent in Farsi, Russian and English, she trained as a cardiologist and also earned a doctorate in cardiovascular sciences. Since 2015 she has worked in the lab of Matthew Springer, PhD, professor in the UCSF Division of Cardiology, investigating how tobacco and cannabis affect cardiovascular health. Soon, Dr. Mohammadi hopes to make the transition from assistant professional researcher to leading her own lab.
Dr. Mohammadi was born in Iran, and from a young age wanted to become a doctor so she could help people. She also had an insatiable curiosity. One year during the two-week Persian New Year break, when her classmates were eating and playing with their friends, she decided to research the history of oil discovery and the first refinery in Iran. “I talked with lots of people, asked them questions, then made a poster which I put up in the corridor outside our classroom when we went back to school,” she said. “All my friends said, ‘Seriously? That’s what you did during break?’ It was so nerdy, and was the moment I realized I like research.”
Navigating a New Language and Culture
Dr. Mohammadi’s father earned his MBA at Harvard and worked as a chemical engineer in Iran. He wanted to return to the U.S. for his PhD, but the Iranian Revolution and high tensions between Iran and the U.S. put that dream out of reach. So when he got a job offer in Russia and was then accepted to a PhD program in Moscow, he decided to move there with his family. It was a challenging transition for Dr. Mohammadi, who was 13 at the time. “I’d been a really good student in Iran,” she said. “When I was thrown into the Russian system, it was hard for me to blend in with people because I didn’t look like them and I couldn’t speak the language. It was hard to adjust.”
She had a steep learning curve, but Dr. Mohammadi eventually mastered Russian. In Russia, like many countries outside the U.S., aspiring doctors begin medical school immediately after high school. When she was 17, she was accepted at the prestigious I.M. Sechenov First Moscow State University, where she earned her medical degree and PhD in cardiovascular science, and also completed internal medicine residency and the equivalent of a general cardiology fellowship.
Medical school was challenging yet rewarding. “I was studying with international students, and the courses were in both English and Russian,” said Dr. Mohammadi. She had studied English back in Iran, but hadn’t used it much until starting medical school. “By that time I had learned Russian, but in addition to speaking English I needed to learn Latin for all the medical terms,” she said.
She also continued to feel like an outsider. “While they respect other cultures, some Russians may find it challenging to fully embrace and integrate immigrants into their community, and it’s hard to become part of their society because of language barriers and cultural aspects,” said Dr. Mohammadi. “That being said, when they become your friend, they are your true friend. I had a lot of great times and good friends who helped me to grow.”
She was lucky to find some excellent mentors, including a pathology professor, Evgenia Alexanderovna Kogan, MD, PhD, who encouraged her to pursue research. Dr. Mohammadi had an interest in OB/GYN, so Dr. Kogan suggested she study tissue from a fetus with tuberous sclerosis, a rare genetic disorder that causes noncancerous tumors to develop in many parts of the body. Dr. Mohammadi delved into the fascinating case for her graduation thesis, focusing on the cardiac aspects of this systemic disease.
She presented her findings at a meeting of the European Association of Medical Students in Belgium. “That was my very first international presentation, and professors came up to me and asked questions,” said Dr. Mohammadi. “People saw me and valued my work, and that made me more interested in cardiology.” The experience also fueled her passion for research. “I wanted to learn more about cellular and functional changes,” she said. “If I see a disease, I don’t want to just prescribe medication, I want to find out why it happens.”
Studying Endothelial Dysfunction
She also loved medical education, inspired by her respect for her own teachers as well as her enjoyment of explaining how things work. To teach at a medical school she needed a PhD, so she pursued a combined internal medicine residency and PhD track. She worked with another mentor, cardiac electrophysiologist Aida Ilgizovna Tarzimanova, MD, PhD, who taught Dr. Mohammadi about endothelial dysfunction.
“The endothelium is the innermost layer of the blood vessels, which plays a very important role in regulating the vessels’ function and tone,” said Dr. Mohammadi. Using ultrasound, she learned how to measure flow-mediated dilation (FMD). It is one way to assess health of the endothelium, particularly its ability to dilate to accommodate increased blood flow, such as during exercise. She also learned how to measure pulse wave velocity, which measures vascular stiffness and helps predict atherosclerosis in the blood vessels.
Their hospital specialized in treating patients with hypertension and cardiac arrhythmias, or abnormal heart rhythms. Dr. Mohammadi was particularly interested in the relationship between impaired endothelial function and atrial fibrillation, a cardiac arrhythmia that causes the upper chambers of the heart to quiver rather than contracting in a smooth, coordinated manner. Atrial fibrillation is the most common cardiac arrhythmia, and a risk factor for heart failure and stroke. She found that the more endothelial dysfunction a patient had, the more frequently they experienced episodes of atrial fibrillation, and the longer those episodes lasted.
Conducting research in Russia gave her clinical insights that might have been more difficult to achieve in the U.S. “Health care is free in Russia, so patients came to see us frequently because they weren’t worried about paying for visits,” said Dr. Mohammadi. “We had access to all their medical histories, and could talk with patients, look at outcomes, and follow up with them.”
Also, tobacco smoking is an integral part of Russian culture. “Most of our study participants were heavy smokers,” said Dr. Mohammadi. “They tended to be relatively young and didn’t have other pathologies such as diabetes, but had smoked since they were teenagers.” Conducting research on endothelial dysfunction and caring for these patients in clinic made her wonder about the effect of smoking on her patients’ cardiovascular health. “It made me think about tobacco as one of the biggest risks for cardiovascular disease,” she said.
The habit of smoking was deeply ingrained. One of her colleagues’ patients was hospitalized for severe chronic obstructive pulmonary disease (COPD), and was prescribed a very strict diet and lifestyle modifications. He used an oxygen mask to help him breathe; although smoking was prohibited, one night he decided to smoke in his private hospital room while wearing his oxygen mask. “He set one of the hospital wings on fire, and they had to renovate the whole floor,” said Dr. Mohammadi.
With Dr. Tarzimanova, Dr. Mohammadi studied the efficacy of four different medications for improving cardiac function, and found that successfully treating patients’ atrial fibrillation also improved pathological remodeling of their heart – the problematic structural changes that developed in response to atrial fibrillation, heart failure and hypertension. This work formed the basis for her doctoral dissertation, and also reinforced her desire to pursue a research career. “Seeing the [positive] changes in my own patients made me want to learn more about what was going on and how to improve treatment, or prevent these problems the first place,” she said. “In Farsi we have a saying: ‘Prevention is better than treatment.’ That philosophy has shaped me.”
A Turning Point
Dr. Tarzimanova encouraged Dr. Mohammadi to disseminate her work. Despite Dr. Mohammadi’s challenges with writing her first abstract in academic English, in 2012 the American Heart Association (AHA) accepted it for an upcoming meeting. However, as an Iranian citizen studying in Russia on a visa, Dr. Mohammadi was unable to obtain a U.S. visa in time for the conference. She did present abstracts the following year at the European Society of Cardiology.
In 2013, Dr. Mohammadi was visiting family in Iran when the U.S. Embassy informed her that her visa application from a year and a half before had finally been approved. “I’d forgotten all about it!” she recalled. She found out that the AHA was holding a scientific session in Dallas, and was able to stay with her uncle in Plano, Tex. Each day her uncle drove her to and from the conference. “I’m so thankful, because I had never been to the U.S. and didn’t even know what Uber was,” she said. “I didn’t know anyone at the conference, and everyone was speaking English that was too fast for me. But as I sat in meetings, I learned about the AHA and postdoc positions.”
It was a watershed moment. Back in Russia, she faced many obstacles to career advancement. “I couldn’t be first author of my own papers because of the seniority system,” said Dr. Mohammadi. “Investigators wanted to have their own team members working on most of the clinical trials. Many patients would rather see a Russian doctor, and I literally ran after them to recruit them for studies. I wasn’t giving up, but I saw it would be difficult to grow. In the U.S., they don’t care where you come from. It can be hard, but if you’re in the right place, you can grow and progress. I remember sitting in that AHA meeting and thinking, ‘What am I doing with my life? This is what I want!’”
That intuition was reinforced by the wonderful physician-scientists she met, such as Noel Bairey Merz, MD, an international expert in women’s heart health based at Cedars-Sinai. Others encouraged her to apply for postdoctoral positions. “I was in a room with amazing, knowledgeable and friendly people who saw me, talked with me, and asked about my plans,” said Dr. Mohammadi. Attendees who filled out a questionnaire were entered into a raffle to win prizes. “I won my very first iPad!” said Dr. Mohammadi.
When her uncle picked her up that night, he took her to Best Buy and bought her a pink case for her iPad. “I said, ‘I think I want to apply for a postdoc in the U.S., but I don’t know what I’m doing,’ and he told me, ‘Let’s make this happen!’” recalled Dr. Mohammadi. He connected her with a Texas cardiologist originally from Iran, who introduced her to other international researchers in the U.S. They encouraged her, but cautioned about the difficulties of obtaining a postdoc in the U.S. as an international scholar.
Comparing Vaping with Smoking
Ever the researcher, Dr. Mohammadi investigated all the possibilities, making a spreadsheet of ideal universities where she could pursue her dream of becoming a physician-scientist focused on endothelial dysfunction. “Unlike people who apply to 200 programs to get into one, I applied for only five because I knew what I wanted,” she said.
One of those was Dr. Springer, who responded to her initial email with interest. Although he didn’t currently have postdoc funding for her and focused on laboratory rather than clinical studies, he connected her with one of his collaborators, Suzaynn Schick, PhD, a tobacco researcher based at Zuckerberg San Francisco General Hospital who was starting a study focused on e-cigarettes.
Dr. Mohammadi joined Dr. Springer’s lab in October 2015 in an unpaid position, with the understanding that they would both pursue funding to support her work. She learned how to conduct cell studies, and within a year, Dr. Springer obtained funding for a paid postdoc position. In 2019, she was awarded an AHA postdoctoral fellowship to study the effect of tobacco and e-cigarettes on endothelial function, and in 2021 became an assistant professional researcher in the Springer Lab.
“The public may assume that vaping is safer because paper and tobacco aren’t burned like with cigarettes, and they can’t smell it,” said Dr. Mohammadi. “But we found that chemicals in the e-cigarette liquid can be as harmful as cigarette smoking to endothelial health, which is a predictor of cardiovascular disease. We also found specific pathways affected by e-cigarette use which are different from those affected by cigarette use. In addition, dual use – in which people use both e-cigarettes and cigarettes – is becoming more popular. However, we found this can actually be more harmful, because you harm your body through two different pathways, which can come together and make it even more dangerous.”
Dr. Mohammadi is proud of her contribution to this novel research, which received considerable press and is informing public discussion and policy decisions about e-cigarettes and other newer nicotine delivery devices. “I’m happy that I joined Matt’s lab to be one of the first to study effects of e-cigarettes on human health at the clinical and cellular levels,” she said.
Launching the CANDIDE Study
She is now applying that experience to a new question: how do the cardiovascular effects of cannabis smoke compare with those of tobacco smoke? The Springer Lab recently launched the CANDIDE (CANnabis: Does it Damage Endothelium?) Study, with Dr. Mohammadi as its clinical lead.
“As a PhD scientist trained in basic and translational research, I had dabbled in human subjects research before by collaborating with clinical colleagues in the Division, but there was a limit to my ability to design and lead a clinical study,” said Dr. Springer. “Leila coming to my lab several years ago was a huge stroke of good fortune. She brought her clinical cardiology and vascular medicine experience to the lab, learned cell and biochemical techniques, and combined all her experiences to do a really nice study of health effects in people who vape e-cigarettes, resulting in an influential paper that’s gotten a lot of recognition.
“Since my lab has years of rodent research indicating harmful cardiovascular effects of marijuana smoke, including secondhand smoke, I asked if she would like to design and lead a clinical study to see if our rodent results truly reflected cardiovascular risk of cannabis in humans,” said Dr. Springer. “She dove into it, and the CANDIDE Study was born. I could not be more delighted with how it’s gone. We discuss the research frequently, but she’s in the driver’s seat. The study design and implementation are almost entirely hers, with support from a great team that she is leading.”
Dr. Springer and Dr. Mohammadi spent many hours discussing their ideas for the study and were preparing to launch a pilot to gather preliminary data so they could apply for grant funding. Then COVID hit. “We had this great idea, but what were we going to do?” said Dr. Mohammadi. As she has done many times before, she figured out workarounds.
In August 2020, no one was in the lab because of COVID, so she turned Dr. Springer’s office into a makeshift exam room and purchased a massage bed to use as an exam table. She posted fliers and reached out to friends, asking them to send their friends to participate. “This was before vaccines, and some people showed up without masks,” said Dr. Mohammadi. “I told them, ‘If you don’t wear a mask, you’re not coming in.’ Many people stood me up. There was so much going on.”
She met with about 25 participants individually, including tobacco smokers, cannabis smokers, and non-smokers. In addition to obtaining informed consent, demographic information and data about their use of tobacco or cannabis, she measured their FMD. “In the preliminary data we collected from that small group, we found that vascular endothelial function of cannabis smokers was as bad as that of tobacco smokers, and was lower in both those groups compared with non-smokers,” said Dr. Mohammadi.
With that preliminary data, she and Dr. Springer were awarded a grant from the Department of Cannabis Control, and in 2023 successfully obtained grant funding from the National Institute on Drug Abuse to continue the CANDIDE Study. Now that clinical and research environments have returned to normal, they are grateful to have access to a clinical research room at the Center for Prevention of Heart and Vascular Disease at Mission Bay. This allows them to study FMD, conduct pulse wave analysis, and collect blood and urine samples. They also give study participants a home blood pressure monitoring device, and study cellular changes in the lab. Because cannabis can be used in so many different ways, Dr. Mohammadi is excited to study many subgroups, including joint smokers, THC edible users, people who use both tobacco and cannabis, and non-users.
“Leila has moved mountains to make the study productive and rigorous, including navigating the effects of the pandemic shutdowns as we were trying to get our initial results,” said Dr. Springer. “She’s already presented intriguing results at last year’s AHA conference, and is writing a paper that I feel will be the first in a string of highly cited publications from her work.”
Contributing to Science and the Community
In addition to her passion for research, Dr. Mohammadi advocates to improve the experience of other international faculty, staff and trainees, particularly postdocs. This is inspired by her own challenges. Shortly after Donald Trump took office, he instituted a travel ban on people from several countries, including Iran. “That made my life hell,” she said. “I wasn’t able to see my family for many years. I didn’t know what would happen with our visas. I was in the same vulnerable position that I was in when I was in Moscow as an international student.”
She and some of her colleagues developed a questionnaire for international postdocs, receiving inspiration from Michelle Albert, MD, Walter A. Haas-Lucie Stern Endowed Chair in Cardiology. Dr. Albert is an international expert on the biology of adversity who studies the cardiovascular effects of cumulative toxic stress. Dr. Mohammadi’s research helped shed light on the need for emotional support, mentorship and other resources, as well particular challenges that this group faces. She presented this data at the National Postdoctoral Association Symposium in 2019. Inspired by her research findings as well as own experiences, she recently founded a mentoring group called the Medical Mentoring Hub. Its mission is to assist international medical graduates and scientists in finding their paths in the U.S.
She is particularly grateful for the help she received from Dr. Springer and her lab colleagues. “I’m so lucky to have ended up here, surrounded by really nice people who support my career and value my input,” said Dr. Mohammadi. “Matt is a brilliant scientist and human, and I love learning from him. I respect him from my heart. When my dad was unable to obtain a visa to attend my wedding, I asked Matt to deliver a speech on the night of my wedding.”
Dr. Mohammadi is married to Peter Neumann, PhD, a neuroscientist who works for a biomedical company. “He is the love of my life, my biggest cheerleader and greatest support,” she said. “I am grateful to have such an amazing husband by my side.”
Dr. Mohammadi looks forward to pursuing a career in research, and hopes to launch her own independent lab in the near future. “Wherever I land, I want to be successful, useful, and hopefully able to contribute to science and medicine,” she said.
Outside the lab, Dr. Mohammadi enjoys learning Spanish, planning parties, and cooking for friends.
- Elizabeth Chur