Project Description

Blood sugar levels are managed by micro-organs, so-called pancreatic islets, that are located in the pancreas. These micro-organs are small accumulations of different cell types named alpha, beta and delta. Each of these cell types is responsible for the production and release of different hormones called glucagon, insulin, and somatostatin, respectively. These hormones work together as a team to make sure our blood sugar levels stay stable. Simplified, glucagon can increase blood sugar if it drops too low and insulin can decrease it in case it reaches too high. Somatostatin makes sure that glucagon and insulin levels are appropriate. However, except for their action on blood sugar levels, all hormones can change the behavior of their surrounding islet cells. This is called paracrine control and is crucial for proper islet hormone release. This is exemplified by the role of somatostatin or beta-cell death in type 1 diabetes (T1D) leading to an increase in glucagon release, further contributing to increased blood sugar levels.

It has been found that islet cells are able to release other molecules in addition to their hormones. These molecules also change the behavior of the surrounding islet cells, engaging in paracrine action. One of these molecules is gamma-aminobutyric acid (GABA), which I focus on in my research.

GABA is commonly known as a substance produced by the central nervous system that regulates brain activity. There, it reduces neuron activity and affects mood and motor functions. A pathological reduction in the function of GABA in the central nervous system can cause anxiety, insomnia, or epilepsy. The only other place in the body, besides the central nervous system, that generates large amounts of GABA is the pancreatic islet. However, the role of GABA in the pancreatic islet or how GABA deficiency in the islet will affect blood sugar levels or diabetes is not yet understood. Therefore, we want to study how the pancreatic GABA system works and whether it could potentially be targeted as a treatment for type 1 or type 2 diabetes.

In line with GABA being a molecule of critical function within the central nervous system, our data indicates that altering GABA in the pancreas also affects insulin release. However, other studies have shown that GABA might also affect glucagon and somatostatin release. Changing the release of any of these hormones will influence blood sugar levels. Therefore, GABA seems to be critically altering the function of the pancreatic islet.

Click HERE to view Dr. Sandra Mara Ferreira’s video.