November 19, 2013
Reading Eyes May Give Clues To Health Of The Pancreas
April Flowers for redOrbit.com - Your Universe Online
An innovative way to study glucose regulation in the body has been discovered by a research team from the Karolinska Institutet in Sweden.
By transferring the vital insulin-producing cells from the pancreas to the eye, the team found that the eye can serve as a window through which health reports can be obtained from the pancreas. The results, published in Proceedings of the National Academy of Sciences (PNAS), are expected to have a significant impact on diabetes research.
Insulin, the hormone that is released into the blood at an amount that is in direct proportion to the amount of food ingested, is produced and secreted in the Islets of Langerhans, the endocrine portion of the pancreas. Large amounts of insulin are required to compensate for the high consumption of food and insensitivity to the hormone in patients with conditions such as obesity.
The Islets adapt themselves to obesity by increasing the number of insulin-producing beta-cells and/or modulating the cells individual secretion of insulin in response to the intake of sugar. This plasticity is necessary for maintaining normal blood sugar levels. The malfunctioning of this plasticity leads to diabetes, a serious disease that has reached pandemic proportions.
Studying the exact workings of the Islets of Langerhans and how they adapt to individual conditions presents challenges. The biggest challenge is their relative inaccessibility -- they lie deeply embedded in and are distributed throughout the tissue. The research team has found a new way to study the insulin-producing beta-cells by transferring them to the eye.
"What we've done is made the cells optically accessible by grafting a small number of 'reporter islets' into the eyes of mice, which allows us to monitor the activity of the pancreas just by looking into the eye," says Per-Olof Berggren, professor of experimental endocrinology at Karolinska Institutet's Department of Molecular Medicine and Surgery, and director of the Rolf Luft Research Centre for Diabetes and Endocrinology. "We're now able to really study the insulin-producing beta-cells in detail in a way that wasn't possible before."
The researchers say that the eye can be used as a sort of reporter by reproducing the activity of the pancreas and allowing readings of the status of the pancreas under different conditions in health and disease.
"The Islets of Langerhans can be visualized repeatedly over a period of several months, and our work shows that during this time, functional and morphological changes occur in them that are identical to those occurring in the pancreas," says Dr Erwin Ilegems, researcher at the Rolf Luft Centre.
The team used the new monitoring system and pharmacological treatment to reduce food consumption in obese mice models. This stopped the enormous growth in beta-cell population, meaning that the team is now able to individually tweak drug doses.
"We'll also be using the system to identify new drug substances that regulate beta-cell plasticity and function," says Professor Berggren. "In the future we may also conceive a similar use of reporter islets in humans in order to find unique, tailored treatment principles, to measure the effects of personal medication, or to diagnose problems with the pancreatic islets."