Diabetes, enzymes and fatty livers: Type II diabetes research

Confidence building through science: A glimpse into SRAP research life
The Student Research Apprenticeship Program (SRAP) is a paid summer research program at the University of Wyoming for high school students in tenth through twelfth grade. It is sponsored by Wyoming EPSCoR and funded by the National Science Foundation. This is the fifth of eleven stories about the laboratories where this year’s SRAP students are working.

Kaycee Perez works with Cathepsin K in Dr. Nair's lab.

Diabetes affects almost 26 million people in the United States today. The number of adults with diagnosed diabetes continues to increase, especially as obesity rates increase. While the relationship between diabetes and obesity is well documented, the mechanisms behind the relationship are still being investigated. This summer, Kaycee Perez and Alexzandria Steiner, with their mentors Yinan Hua and Evgeniy Panzhinskiy, graduate students in the lab of Dr. Sreejayan Nair, are working on understanding the role of two enzymes in the relationship between obesity and type II diabetes.

Alexzandria’s work is focused on an enzyme called protein-tryosine phosphatase 1B (PTP1B) while Kaycee’s research is centered on another enzyme called Cathepsin K.

PTP1B is an enzyme that prevents the actions of insulin in the body. It is part of the development of insulin resistance and obesity. Insulin resistance is when the body does not react to the effects of a normal amount of insulin, so it creates more insulin in order to have the same effect. Cathepsin K is an important part of fat formation in the body. Both projects are looking at how the enzymes impact fatty liver formation in a high-fat diet. Fatty liver is the accumulation of fat in the liver, most often due to insulin resistance.

Alexzandria Steiner works with PTP1B in Dr. Nair's lab.

In order to understand the role these two enzymes play, Kaycee and Alexzandria are using mice treated with a high-fat diet. These mice have been genetically engineered so that they are missing PTP1B in Alexzandria’s project and Cathepsin K in Kaycee’s project.

In the short amount of time Alexzandria and Kaycee have been working in Dr. Nair’s lab, they have come to two conclusions about the enzymes. Alexzandria found that mice without PTP1B do not develop fatty liver formation, despite being on a high-fat diet. Kaycee, on the other hand, found out that even without Cathepsin K, the mice developed fatty-liver formation. Her findings however, indicate that while fatty-liver was formed, the absence of Cathepsin K increased insulin signaling, meaning that insulin resistance decreased.

Dr. Nair is pleased by Kaycee and Alexzandria’s work and their experience in his lab. “The SRAP students get an overview of the process of scientific research and hands-on training on a variety of techniques,” he says.

Kaycee Perez and Alexzandria Steiner in Dr. Nair's lab.

He adds that they bring a valuable experience to his lab. “Oftentimes the SRAP students are trained by graduate students in my lab which provides a good opportunity for the graduate students to assume the role of mentor.”

Alexzandria and Kaycee’s findings are important contributions to studies about diabetes and obesity. They may help identify future treatments and controls for diabetes, as well as raise more questions about the molecular mechanics behind diabetes development.






By Kali S. McCrackin

Photos by Beth Cable