Our lab studies cardiovascular diseases such as high blood pressure (hypertension), which affects roughly one third of American adults and puts them at a higher risk for heart disease and stroke, both of which are leading causes of death in the United States . One of our overarching questions addresses the role that the tissue surrounding our blood vessels, or “perivascular adipose tissue” (PVAT), plays in obesity-related hypertension. PVAT contains various types of cells, including adipocytes (fat cells), endothelial cells, macrophages, lymphocytes, fibroblasts, and more . We have previously shown that PVAT contains functional norepinephrine, a signaling molecule that constricts blood vessels and thus increases blood pressure . My project addresses where and how PVAT actually stores this norepinephrine using the PVAT surrounding normal rat mesenteric resistance vessels- the small arteries and veins that branch into the small intestine and are important for blood pressure regulation. We hypothesize that it is specifically the adipocytes in PVAT that store NE, and that they use the vesicular monoamine transporter (VMAT) to do so. A better understanding of this mechanism is important for the future development of treatments for obesity-related hypertension.
Realities of Research
When I first joined the Watts Lab a little over three years ago, I was a wide-eyed freshman who had never even used a micropipette before. Since then, my wonderful mentors have trained me in methods such as immunohistochemistry, brightfield and fluorescent microscopy, cell culture, handling and euthanizing rats, performing dissections, and isolating adipocytes from rat PVAT. More importantly, through these lab experiences, I have learned a scientific way of thinking and hypothesizing. This has been essential for my research project because it was incredibly challenging to develop a new protocol for the functional experiments using live adipocytes. It took over a year and endless troubleshooting for me to get to a point where I had a working procedure, and even longer to replicate the experiments to obtain a large enough sample size. One major obstacle was that freshly isolated adipocytes do not attach well to surfaces such as a microscope chamber slide. Additionally, one of the drugs I tested is only soluble in ethanol, which was toxic to the cells at most concentrations, so we had to find an alternative compound to use. Through trial and error, we have designed methods to effectively isolate, treat, and image PVAT adipocytes for this application. I am also very proud of the protocol we developed to quantify the fluorescent intensities of the cells I imaged, as it is crucial to analyze and present data in as objective and consistent a way possible. I was able to present our work in San Francisco at Council on Hypertension this past September, which was truly an incredible experience.
Conducting research in a lab has been one of the most rewarding adventures of my life. There is a certain thrill in knowing I am working to answer a question that no one else in the world is investigating in the same way. There are definitely setbacks that can be difficult to deal with, such as antibodies that do not work, cells that die for seemingly no reason, or not knowing how to begin designing an experiment you have in mind. However, this is why I love being a part of the scientific community- I have the opportunity to collaborate with the other scientists in our lab and department, or even at other institutions, to gain insight into how to better approach a research question. In addition to the hard work any researcher has to put into his or her own project, I believe it is this enthusiasm to help one another that ultimately allows all of us to be successful. Oh, and a little bit of luck never hurt anyone!
- High Blood Pressure Fact Sheet [Online]. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention: 2016. https://www.cdc.gov/dhdsp/data_statistics/fact_sheets/fs_bloodpressure.htm [14 Jul. 2017].
- Miao CY and Li ZY. The role of perivascular adipose tissue in vascular smooth muscle cell growth. British Journal of Pharmacology 165(3): 643-658, 2012.
- Ayala‐Lopez N, Martini M, Jackson WF, Darios E, Burnett R, Seitz B, Fink GD, Watts SW. Perivascular adipose tissue contains functional catecholamines [Online]. Pharmacology Research & Perspectives: 2014. http://onlinelibrary.wiley.com/doi/10.1002/prp2.41/full [14 Jul. 2017].
- CD® IGS Rat Crl:CD(SD) [Online]. CD® IGS Rat | Charles River. http://www.criver.com/products-services/basic-research/find-a-model/cd-igs-rat?loc=US [14 Jul. 2017].