Christopher Brownlee on What Cells Can Teach Us About Disease

Christopher Brownlee's interest in cell biology grew from two sources: a desire to improve human health and a long-standing fascination with cellular complexity. In his lab in Stony Brook University's Department of Pharmacological Sciences, Brownlee studies how cells grow, divide, and respond to their environment using the Xenopus system, an African frog model.

To Brownlee, a cell is more than a microscopic building block. "When you look at them under a microscope, you're essentially looking at the machinery of life," he said. Understanding how these processes work together is central to his research.

Brownlee's training gradually moved toward understanding the intersection of basic cell biology and disease. Over time, he became increasingly interested in how cellular organization and physical principles shape biological function. That focus made Stony Brook University a natural fit for his work.

"Our department has a really strong culture of interdisciplinary research," he said. Brownlee emphasized that research is not a solo effort, noting that many of his lab's most productive ideas emerge from conversations with colleagues who approach problems from different perspectives.

For example, collaborations with engineers help refine microfluidic devices, while interactions with clinicians help ensure that basic discoveries remain grounded in human disease. Within the Department of Pharmacological Sciences, and other departments across Stony Brook University, colleagues provide a sounding board that pushes projects in new directions.

In his lab, Brownlee focuses on how the plasma membrane and cytoplasm interact to drive fundamental cellular processes. He explains this relationship using a factory analogy: the cytoplasm functions as the factory floor, where the machinery and workers operate. The plasma membrane forms the outer wall. For the factory to function properly, that wall must act as more than a barrier. It must also communicate with the inside.

"We basically study how this wall tells the machinery where to go and how big to grow," he said. When that communication breaks down, cells can behave abnormally, contributing to diseases such as cancer and developmental disorders.

To study these questions, Brownlee's lab uses the Xenopus system, an African frog model widely used in developmental and cell biology research for its large single cells. Because of their size, the cytoplasm can be extracted and manipulated in ways that are not possible in other systems.

Brownlee uses microfluidics to repackage that cytoplasm into droplets of different shapes and sizes, creating simplified artificial cells. These artificial systems allow the team to ask fundamental questions about cellular organization. They can add or remove organelles, change physical constraints and observe how the internal machinery responds. Findings from the frog system are then tested in human and mammalian cells to determine whether the same mechanisms are conserved.

In addition to these approaches, Brownlee uses optogenetics, a technique that allows specific proteins to be turned on or off using light. Combined with microfluidics, this approach allows researchers to control both the biochemical and physical environment of the cell in real time.

"Traditional methods often involve observation and recording," he said. "Optogenetics allows us to test causality dynamically." Together, these tools make it possible to simulate disease states and observe how cells compensate, react, or fail.

By studying these mechanisms at a fundamental level, his lab aims to understand how normal development is supported and how disease arises when coordination between the plasma membrane and the cell's internal machinery breaks down.

Looking ahead, Brownlee hopes to better understand how cells establish and maintain organization in changing environments. By combining quantitative experiments with controlled changes in the Xenopus system, his lab seeks to uncover general cellular principles that apply across development, regeneration, and disease.

-Minji Kang