First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Joseph A. Brazzo III is first author on ‘ Mechanosensitive expression of lamellipodin promotes intracellular stiffness, cyclin expression and cell proliferation’, published in JCS. Joseph is an MD–PhD student in the lab of Yongho Bae at the Jacobs School of Medicine and Biomedical Sciences, State University of New York University at Buffalo, NY, USA, investigating how extracellular matrix stiffness affects cell functions and behaviors, and dissecting the cellular pathways and molecular mechanisms that mediate mechanotransduction in health and disease.

Joseph A. Brazzo III

How would you explain the main findings of your paper in lay terms?

The central focus of our research is to better understand how the hardening or stiffening of a cell's environment controls its internal biology and, ultimately, how that cell behaves. Both scientists and medical doctors alike have known for quite some time that when healthy tissues – made up of billions of cells – become diseased, they also become stiffer or harder. For example, tissue hardening commonly occurs in many different types of cancers, as well as in liver and lung fibrosis, and also happens to our blood vessels as we age. We see that cells become very abnormal in hardened tissue as they grow, divide and migrate more rapidly, while their insides also become stiffer. What still puzzles scientists today is exactly how the stiffer environment is able to signal to the cell inside to change its biology and behavior. In our lab, we found that the expression of a cell protein called lamellipodin is acutely sensitive to the hardening of the cell's environment. When lamellipodin was first discovered, it was shown to be very important to a cell's ability to migrate, and thus a great deal of research since has largely focused on its role in cell migration. Interestingly, we found that in response to a stiff environment, lamellipodin also tightly controls (1) the cell's ability to grow and divide, and (2) the cell's own internal stiffness or hardness. We also have described a pathway inside the cell that allows lamellipodin to directly sense the cell's stiff environment. These are novel findings in the rapidly growing field of mechanobiology, in that we show that in response to a cell's stiff environment, lamellipodin, an essential protein in cell migration, controls cell growth, division and internal stiffness of the cell.

Were there any specific challenges associated with this project? If so, how did you overcome them?

What I found to be most challenging with this research project was western blotting for lamellipodin, our main protein of interest. Being a rather large protein of roughly 175 kilodaltons (kDa), it took almost six months to optimize its detection. When I was first immunoblotting for lamellipodin, I was separating the protein samples using an 8% SDS–PAGE gel, which at the time I believed to be scientifically reasonable, because theoretically this could give good resolution of a 175 kDa protein while also allowing separation of smaller proteins of interest, including various lower molecular weight cyclins. Although I had no problems blotting for these smaller proteins, I was unable to detect lamellipodin. Because western blotting is highly procedural and inherently qualitative, it was really hard to pinpoint which western blotting step I needed to optimize – gel electrophoresis, transfer, blocking, washing, or primary and secondary antibody incubations. I didn't know where to begin, and this really made me feel overwhelmed and inadequate. Fortunately, one day, I observed that significant amounts of the large bands of the protein ladder were getting stuck at the interface between the stacking (5% SDS–PAGE) and resolving (8% SDS–PAGE) gels. When I switched from using an 8% resolving gel to a 6% gel, this greatly improved the migration of high molecular weight protein bands from the stacking gel to the resolving gel, and I was finally able to detect lamellipodin.

When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?

When I saw for the first time how the various cell cyclins were upregulated as a direct result of lamellipodin overexpression, I became deeply fascinated with the idea of cell migration and cell proliferation being inherently coupled processes. So, while I was carrying out ‘wet’ experiments for this research project, I was also trying to conceptualize how lamellipodin, which is integral to cell migration and largely recruited to the cell's leading edge in response to mechanical stiffness, simultaneously regulates cell proliferation that occurs very far away in the cell nucleus. I found this to be really fascinating, and it occurred to me that although we are taught that cell migration and proliferation are distinct cellular processes, they actually seem to require a lot of the same nanomachinery. It took me a while to ideate this dual-purpose function of lamellipodin, which led me to think of a real-life analogy. If you can imagine, lamellipodin seems to operate similarly to a coupled car transmission and accelerator. A car transmission transfers the power of the car engine to the wheel system to push the car forward. Separately, the accelerator, or gas pedal, increases the power of the engine. The equivalence here is that lamellipodin puts the cell in gear to migrate forward at the cell periphery, while also driving cell growth and division in the cell nucleus.

“…although we are taught that cell migration and proliferation are distinct cellular processes, they actually seem to require a lot of the same nanomachinery.”

Why did you choose Journal of Cell Science for your paper?

Journal of Cell Science has been serving cell biologists for almost 170 years. Our findings are in the field of mechanobiology, which is a relatively new area of research in cell biology. We felt that by publishing in JCS, we could cast a wide net, reaching the expansive cell biology community throughout the world that regularly read JCS but may not be familiar with mechanobiology.

A proposed integrin-dependent FAK–Cas–Rac signaling module for stiffness-mediated lamellipodin (Lpd) expression.

A proposed integrin-dependent FAK–Cas–Rac signaling module for stiffness-mediated lamellipodin (Lpd) expression.

Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?

I have had three scientific mentors who have been instrumental in my journey to becoming a physician-scientist. Dr John Staropoli, who is a physician-scientist in biotechnology, has been a lifelong friend and beacon of incredible support and guidance throughout my many ups-and-downs, both personally and professionally. Dr Dario Fauza is a tremendous surgeon-scientist and a modern-day Leonardo da Vinci. He showed me the importance of patience and graciousness in science. His unparalleled scientific approach really set the foundations of the budding scientist I am today. Lastly, Dr Yongho Bae, who is also my PhD advisor, has been most influential in honing my research skills. He has given me the autonomy to explore my scientific interests and make the necessary mistakes and setbacks to learn from, all the while gently guiding me back to the figurative life raft. For them I am grateful.

What motivated you to pursue a career in science, and what have been the most interesting moments on the path that led you to where you are now?

I was a very curious child growing up. I often found myself trying to understand ‘why’ things were. Coming from humble beginnings, I didn't have early scholarly exposure. Rather, it was really my mother's commitment to public education that provided me with opportunities that fostered my interest in becoming a scientist and physician. I was fortunate to attend a college preparatory high school, Boston Latin School, which propelled me forward in my career by allowing me to realize my academic potential. All-in-all there isn't a defining moment or event in my life that led me to where I am now, but rather it is the collection of humble life experiences and the incredible individuals in my life that have brought me here.

Who are your role models in science? Why?

My role models in science are all the physician-scientists who have come before me. The tremendous sacrifices these individuals have made in their professional and personal lives to push beyond the frontiers of biomedical science are deeply inspiring. Pursuing a career that seeks to integrate science and medicine can often prove to be both challenging and humbling. It requires an uncanny ability to cognitively synergize two independent skill sets – scientific research and clinical acumen – both of which individually take years to master. I hope that one day I can help advance biology and medicine to even a fraction of the individual contributions made by the physician-scientists before me.

What's next for you?

I am currently in my sixth year of the combined MD–PhD program at the Jacobs School of Medicine and Biomedical Sciences in Buffalo, New York. I completed my first two years of medical school upon entering the program. Since then, I've been carrying out my PhD research in Dr Bae's lab over the past three years, which I plan to defend and complete next year. I will then finish my last two clinical years of medical school before heading off to medical residency. Given my unwavering commitment to biomedical research, I hope to enter a medical residency that permits considerable research time, where I would be able to continue my research and further hone my skills as a scientist. It is my long-term goal to become a physician-scientist at an academic institution. Ultimately, my chosen specialty would be one where I lead a clinical team in investigating, diagnosing and treating undifferentiated and complex illnesses, while also leading a research program in dissecting undiscovered cellular pathways and molecular mechanisms in health and disease.

Tell us something interesting about yourself that wouldn't be on your CV

I really enjoy cooking – this may explain why I also really enjoy western blotting. The chemistry of cooking is fascinating. I also think that being able to smell colors elevates my experience of taste. I find that there are striking parallels between how science experiments are technically carried out and how a dish is cooked by a chef. Even more so, just like in science, there is a lot of honed finesse that goes into both. When I am not conducting research or cooking, I am thrifting or exploring unbeaten paths in the Western New York wilderness with my girlfriend. Also, over the years, I have acquired an extensive collection of old dictionaries and medical textbooks.

Joseph A. Brazzo III's contact details: Jacobs School of Medicine and Biomedical Sciences, State University of New York University at Buffalo, 955 Main St., Buffalo, NY 14203, USA

E-mail: jbrazzo@buffalo.edu

Brazzo
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J. A.
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Biber
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J. C.
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Nimmer
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E.
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Heo
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Y.
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Ying
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L.
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Zhao
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R.
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Lee
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K.
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Krause
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Bae
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2021
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Mechanosensitive expression of lamellipodin promotes intracellular stiffness, cyclin expression and cell proliferation
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J. Cell Sci
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134
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jcs257709
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