mouse | APS Undergraduate Researcher

This summer I worked in a lab that studies the Ts65Dn mouse, which is an animal model for Down syndrome. Previous studies have shown that people with Down syndrome suffer from sleep apnea during the night, which exacerbates some of the cardiovascular and neurological deficits that are already associated with the disease. My role this summer was to collect breathing and metabolic data from an older cohort of this strain as they were exposed to various gases that stressed their respiratory system. Other members of the lab collected data on the muscular and neurological functions of these mice. The overall goal of our work is to identify the causes of the deficits found within this strain of mouse. In the long run we are hopeful that the work we are doing could eventually lead to therapies for people with Down syndrome who suffer from sleep apnea.

Before my summer research started I had already been working in my current lab for about two semesters. I did not really have to adjust to much about the lab besides the fact that I was going in all day, every day. I was conducting my experiments using a barometric plethysmography technique. This technique involves placing mice in a chamber that records several respiratory outputs as air is pumped into and out of the chamber. Even though I was familiar with the technique that I used to collect breathing data, there were a few calibration issues that required some troubleshooting when I first began collection. Once those issues were fixed data collection went smoothly. In addition to conducting plethysmography experiments, I was working with the rest of my lab to harvest and freeze organs that were dissected from our mice in order to look at the specific proteins related to muscle function. We are currently working through analyzing and interpreting our data, but so far have found interesting results that lead us to believe that there is a neurological component that is modulating the deficits found in the Ts65Dn mouse.

Over the course of my summer, I realized that the life of a scientist varies every day. I was on a strict schedule during plethymosgraphy data collection because the mice needed to be tested during specific hours and within days of each other in order to attain accurate results. On the days that I was helping with harvesting and freezing organs, the work moved quickly because organs needed to be removed in a timely fashion in order for them to be viable for further testing. Once all of our mice were euthanized the work calmed down a bit and I was able to take my time analyzing my data, running stats and working through interpretation of statistical outputs. I really enjoyed watching the older members of our lab work through their experiments. I have learned a lot from them and it is helpful to be able to see what my life could look like if I continue down this path. I did struggle a bit at first with learning new techniques and how to run some statistical tests, but having to work through issues and figure those things out for myself has already made me a better scientist. I think that learning how to troubleshoot and work through experimental/statistical/interpretational issues on my own has been the most valuable part of my summer research experience.

Brianna Eassa is a senior Biology major at Le Moyne College in Syracuse, NY. She is a 2018 Undergraduate Summer Research Fellow (UGSRF) working in Dr. Lara DeRuisseau’s lab at Le Moyne College. The UGSRF award is funded by the APS. In the future, Brianna hopes to continue to work in a lab setting in order to get more experience to learn what direction she wants to go towards when entering graduate school.

While the prevalence of obesity increases each year and continues to underlie many serious health conditions in children and adults alike, the genetic aspects and pathophysiology associated with the disease are not fully understood. Consequently, the obscurity of the mechanisms underlying obesity makes treating affected patients difficult. Now more than ever, as we face an intercontinental obesity pandemic, our knowledge about the disease must grow faster than the climbing obesity rates.

Sources: NCHS, National Health Examination Survey and National Health and Nutrition Examination Surveys.

The Src homology 2 B adaptor protein 1 (SH2B1) has recently been identified as a gene associated with obesity, and SH2B1 mutations have been identified in a large cohort of patients with severe early-onset obesity. Three of the human mutations identified in the obese patients are located in the pleckstrin homology (PH) domain of SH2B1. The Carter-Su Lab is currently studying one of these point mutations (P322S) using a CRISP-Cas9 generated mouse model. Along with the P322S mouse model, the Carter-Su Lab has also generated a mouse model with a six base-pair deletion that causes a 2 amino acid deletion (ΔP317, R318) in the PH domain of SH2B1. This mouse model is important because it explores the function of the PH domain, which seems to be important for the function of SH2B1, yet has not been fully investigated. For my summer research project, I have been working on determining the metabolic phenotype of the ΔP317, R318 mice. I have been measuring the food intake and body weight of a cohort of 48 animals, as well as performing glucose tolerance tests and insulin tolerance tests to investigate whether the six base-pair deletion affects glucose metabolism. I am also performing blood draws to examine levels of insulin and leptin, the latter of which is referred to as the “satiety hormone.” My project using the ΔP317, R318 mouse model will help investigate the function of SH2B1 in regulating energy homeostasis as well as provide insight into the function of the PH domain of SH2B1, which is conserved across species. This is all extremely important since understanding how SH2B1 works will provide insight that may enable identification of new therapeutic targets for obesity.

Wild-type mouse (left) pictured next to a SH2B1β ΔP317,R318/ΔP317,R318 mouse (right).

Doing research in a lab is an incredibly rewarding experience. I have made plenty of mistakes along the way (my lab can verify this), but each day I am getting better. What surprised me the most about working in a research lab this summer was how much other people were truly willing to teach me — not because I asked them to or because they had to, but because they knew I wanted to learn. In research there is no “one size fits all” policy, and that is okay. It is all about finding what works for you. The reality is that the process of doing research is not perfect; things will go wrong, and that is a fact. The honest truth is that many experiments will have to be done…and redone, but in my case, all of the experiments I have performed in my 7 weeks so far have been successful in the end. My preliminary results are mostly what my research host and I expected, some of the phenotypes being even more extreme that originally hypothesized (cue obese mouse below!)

SH2B1β ΔP317,R318/ΔP317,R318 female on a scale weighing more than three times the amount of a wild-type female of comparable age.

There are days when I feel extremely frustrated, days when I think I’ll be stuck in lab all night, and days when I feel like the luckiest person in the world just to be where I am, doing what I’m doing. The day-to-day life of a scientist is different every day, and that is what draws many of us to science in the first place. Science allows us to be innovative and creative and to spend each day with other people who share similar interests, working on different pieces of our own puzzle. Working as part of a lab team has provided me with an amazing support system, and I could not be more thankful for that. As a member of a team, you are responsible for pulling your own weight, which is both a blessing and a curse. When something goes right, that is on you, but if something goes wrong, you must take responsibility for that too. The biggest struggle that comes with this is managing your time effectively, especially when faced with so many time sensitive issues. Your animals will not stop aging; your cells will not live forever if they are not split. The life of a scientist is a roller coaster, but it is one that I would choose to ride each day.

References

Overweight & Obesity Statistics | NIDDK. [online] National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/health-statistics/overweight-obesity [13 Jul. 2017].

Lauren DeSantis is a junior double majoring in Neuroscience and Spanish at the University of Michigan in Ann Arbor, MI. She is a 2017 Undergraduate Summer Research Fellow (UGSRF) doing research in Dr. Carter-Su’s lab in the Molecular and Integrative Physiology Department at the University of Michigan Medical School in Ann Arbor, MI. Lauren’s fellowship is funded by the APS. After graduation, she plans on pursuing her MD-PhD to become a neurosurgeon-neuroscientist.