Duke University | Howard Hughes Undergraduate Program

 The reprogramming of Clara cells to behave more like pulmonary epithelial stem cells and monitoring their proliferation through injury models. That’s what I’ll be doing with my summer at Duke University, and a few days ago that phrase would have made absolutely no sense to me.

Thanks to the Howard Hughes Research Fellows Program, an eight-week fellowship that throws rising Duke sophomores into the seemingly daunting research community, I’ll be learning as much science as I can possible house in my tiny, undergraduate brain. This program allows Duke students to get a feel for the scientific research process by pairing each sophomore with a mentor, whose interests can range from housefly mating habits to gene regulation in plants.

Before I get carried away with describing what I’ll be researching in the lab, let me tell you a little bit about myself. As far as where my academic interests lie, I’m somewhat of an enigma. I’m lucky enough to know what I’m passionate about though – science and foreign languages. There is just something intriguing about the idea of uncovering and creating knowledge, and then being able to break down barriers and share that understanding with a foreign language. I have recently declared a double major – the first being a BS in Biology with a concentration in Genetics, the second French and Italian Studies. That will certainly keep my busy over my next three years at Duke! In my time away from the labs and lecture halls, I enjoy playing tennis, ping-pong, and board games, running, riding rollercoasters, watching James Bond movies, reading, and trying foods from around the world.

Hailing from the Jersey Shore, I have spent most of my summers relaxing on the beach in between workings as a tutor of inorganic chemistry and mathematics for high school students in the area. After only a few days in Durham, I can tell that this summer is going be quite different!

Before starting this program, I knew that stem cells were something I wanted to explore. After a preliminary interview with Dr. Barry Stripp, an expert in pulmonary stem cell research, I was glued. His awesome lab group, of which I am now a part, boasts about ten members, each with a different and impressive scientific background. Each of us is working on some aspect of lung stem cell localization, proliferation (or rapid growth), and secretion, with the goal of being able to use each other’s data to gain a better understanding of the structure and function of pulmonary epithelial cells.

Over the past several decades stem cells have been found in various organs and tissues throughout the body, often in small populations. Some of the parts of the body in which stem cells have been found include: brain, bone marrow, teeth, heart, intestine, liver, and skin. Stem cells must fulfill certain criteria: relatively undifferentiated phenotype (meaning that they are not already specialized for a specific function; some cells in the lung are responsible for gas exchange, metabolism of pollutants, etc. but lung stem cells have no specific "job"), pluripotent differentiation potential (stem cells can self-replicate to give rise to specialized cells and tissues of all three human germ layers), low rate of steady-state proliferation (if there's no need for new, specialized cells, stem cells should remain quiet), and localization to a stem cell niche (stem cells tend to inhabit specific areas in the body known as niches).

Stem cells in the lung are crucial to cell regeneration. The air that you breathe isn't always as clean as you might suspect. Even in the smallest amounts, gaseous pollutants find a way into the lungs. In some rare cases, a person may be subjected to highly polluted environments. These chemicals can kill the cells that line the lungs and metabolize dangerous pollutants, leaving the tissue very vulnerable and breathing difficult. If the damage is severe enough, the stem cell populations of the lung (which are often immune to the damage of the pollutants) will kick into high-gear and begin to regenerate those cells that were ablated (destroyed). In the lab, we subject mice to different pollutants and at different strengths and then monitor the activity of the lung tissue. We can get an idea of which types of cells were destroyed and where, what cells are seemingly immune to the pollution, and what cells are helping to regenerate the cells that were destroyed.

Unlike many other stem cells, such as intestinal or blood stem cells, those that appear in the lung do not proliferate very much. A large part of the research that we are conducting is actually proving that these seemingly lazy (we like to refer to them as “quiescent”) pulmonary cells are actually stem cells. We do this by injuring the lungs of mice with pollutants such as naphthalene and ozone, then we use immunofluorescence staining (really cool markers that glow under very expensive microscopes) to detect which cells are proliferating, which cells have been ablated (destroyed by the pollutant), and where in the airways the cells are found. We can use lineage tracing to detect progeny cells and the parent cell so that we can determine which cell is a stem cell candidate. By figuring out where, how, and to what stimuli these stem cells proliferate, we hope to one day be able to develop pharmaceuticals that will encourage lung repair in humans with damaged lung tissue.

After only one week in the lab, I have learned more about pulmonary cellular biology than I could possibly have imagined. Every lab member I meet is eager to tell me more about what they are working on, suggest journal articles to read, and teach me the techniques that they rely on. In an effort to avoid boring you, I won’t go into the details, but trust me, I’ve learned a lot!

For the past few days, besides reading and listening to the science behind our research, I’ve been sectioning and plating lung tissue embedded in wax into slices that are 5 microns thick (that’s about two 10,000ths of an inch!), staining lung tissue from mice with antibodies that are bound to molecules that glow under certain wavelengths of light, and analyzing those images with awesomely powerful microscopes.

I’d write more, but I have to get back to staining my latest batch of lung tissue!

- Tyler

 My very first set of micropippetors! Kodak moment.

Post-doc Josh explaining his next experiment setup. He has been an invaluable resource this past week, teaching me how to use our microscope and how to stain and section our tissue samples.

Huaiyong, a post-doc in Dr. Stripp's lab, pipets...umm...stains...umm...okay, I'm not really sure what he's doing.

 Fellow Dukie Linda and technician Jeff trying to figure out how to program the robot (or what I refer to as the "undergraduate replacement machine").

 Me using one of our most sophisticated pieces of high-tech equipment for antigen retrieval - yes, that's a microwave.

My work station - a notepad to chronicle my days in the lab, my MacBook (which seems to be getting a lot of negative attention from the PC users), and I just really like Diet Coke.

The microtome. This week I spent four straight hours using this machine to section my samples. I was told that this room is secluded due to the screams of frustration and occasional episodes of delusions that some researchers face when plating their tissues. Luckily, I escaped unscathed. 

 My lab bay in Dr. Stripp's lab! 

The cell culture room! I have yet to spend much time in here.

This microscope has a powerful mercury lamp that emits different wavelengths of light to excite the electrons and emit immunofluorescence in the antibodies that are bound to the lung cells we are interested in studying. 

I just thought the mouse in the microscopy room was pretty cool.

 Yeah, Danger's my middle name.