SPUR 2019: Autophagy and arterial function


Autophagy (i.e., self-eating) is a cellular process whereby garbage (e.g., damaged proteins) is collected (by the autophagosome), transported to the recycling depot (lysosome), and recycled for future use (e.g., ATP production). Autophagy is critical for maintaining quality control of the cell. Relatively recent evidence indicates that aging compromises the process of autophagy in a number of cell types, damaged proteins accumulate, and cellular dysfunction occurs. While aging too is associated with a progressive decline in arterial function, the mechanisms are unclear, and a direct link with vascular autophagy has not been tested. What is meant by arterial dysfunction?

Arterial dysfunction is, in part, a limitation of the ability of endothelial cells to synthesize and release nitric oxide (NO), but the mechanisms are unclear. We plan to determine whether limited endothelial cell autophagy contributes to repressed endothelial cell NO production, and subsequent vascular dysfunction, during the process of aging. How can the specific contribution from EC autophagy be tested?

The process of autophagy requires autophagy-related genes (Atg’s). One of these genes is Atg3. After determining that indices of endothelial cell autophagy (e.g., Atg3) decline in old vs. adult mice, we showed that repressed endothelial cell autophagy per se contributes to impaired endothelial cell NO generation using endothelial cell specific “knockout” mice, and we elucidated the mechanisms responsible. The 2019 SPUR student will help to determine whether the aging-associated decline in arterial autophagy contributes directly to the aging associated decline in arterial function..

Student Role

The student will be involved with setting up for and assisting with experiments designed to determine vascular function using isobaric and isometric procedures. Second, the student will assist with making buffer solutions and vasoactive drugs, used to assess vascular function. Third, the student will assist with and eventually be responsible for completing vascular function experiments, reducing and interpreting the data, entering into excel spreadsheets, performing statistical analyses, and making tables and figures as appropriate. Finally, the student will be responsible for putting together oral and / or poster presentations for conferences such as UCUR, URS, NCUR, and Experimental Biology.

Student Learning Outcomes & Benefits

We have various "loss of function" models e.g, endothelial cell specific "knockout" of Atg3, p62, Atg16L1, to determine the role of endothelial cell autophagy in contributing to arterial dysfunction. The student will learn how to answer a question using the scientific method i.e., what is the background / rationale for completing the project, what is the hypothesis, what are the methods that will be used to test the hypothesis, what are the results, how can the results we synthesized with what is known to move the field forward in a manner that is non incremental, what are the next steps? The student will learn how to assess vascular function and complete an experiment from start to finish. This is an important component to an undergraduate education. When the student attends professional school interviews, and the interviewer asks "I see you completed some research, can you tell me about what you did? It is m hope the student can answer the above questions in a confident manner, and be able to provide a "hard copy" of the product e.g., published abstract or mauscript.

J David Symons

Nutrition & Integrative Physiology
College of Health
Molecular Biology Program

The more the student is in the lab, the more they will learn. Depending upon the student level of effort, many new laboratory skills can be learned. Mentoring activities include:

  1. one on one interaction in the lab (I perform many laboratory experiments alongside of the students);
  2. presentations at lab meetings;
  3. presentation at UCUR, NCUR, URS, EB.

I interact with students on a daily basis. I am personally involved in every vessel harvest and vascular function experiment. Every Monday morning we have joint laboratory meetings with 3 other PI’s and their laboratory staff. We hold our own laboratory meeting on Wednesday mornings. The SPUR student will make presentations of data and provide progress reports to me during informal daily / weekly meetings, and will make at least two formal presentations at the joint laboratory meeting. I will help the student prepare for all presentations. Every Thursday afternoon we attend the “Seminars in Metabolism” Group Meeting. Additional interaction with the student will be in one-on-one sessions talking about recent and/or topical journal articles and recently obtained data. Finally, each student must go through mandatory IACUC, IRB, HIPPA, FERPA, and EHS training in order to be placed on my IRB and IACUC protocols. A research ethics course is offered during the summer and is encouraged. All data are obtained using encrypted software and each student must go through Institutional Training.