June 2021
Pancreatic beta cells are only cells that can make insulin in humans. In type 2 diabetes, pancreatic beta cells are damaged and cannot make sufficient insulin to keep blood glucose levels normal. As overnutrition and obesity is a well-known risk factor for type 2 diabetes, it is important to find a way to protect beta cells from over nutrition.
In a recently published study in the scientific journal JCI Insight, led by Dr. Yumi Imai, Associate Professor of Internal Medicine and member of the FOEDRC, her laboratory has discovered that a protein known as Perilipin 2 plays an important role in protecting beta cells under nutritional challenge. Perilipin 2, regulates an organelle called lipid droplets that prevent toxic lipids from being released from these lipid droplets. When these lipids or fats are released into the cell, they will damage beta cells and reduce their ability to produce insulin. Diabetes increases the number of lipid droplets that accumulate in beta cells in the pancreas. Therefore, it is very important under these circumstances that more perilipin is available to prevent these lipid droplets from releasing toxic lipids. Their study showed that lowering the levels of perilipin 2 led to increased injury of beta cells and reduced insulin secretion. The study was performed through collaboration with other members of FOEDRC including, Drs. James Ankrum, Brian O’Neill, Samuel Stephens, William Sivitz, and Stefan Strack. Each of these researchers brought specific expertise to the project. For example, they visualized a previously unrecognized connection between perilipin 2 and another organelle the mitochondria (that makes energy for insulin release), using sophisticated techniques and in human islet cells. This study increases our understanding of why beta cells fail during states of overnutrition and identified a new target Perilipin, whose levels if increased can protect beta cells and reduce the risk of developing type 2 diabetes.