December 2017 | Issue 33


New insights open avenue for potential ways to preserve insulin-producing cell function

Editor mug shot.jpgBy Nicole Lim, Senior Assistant Director, Communications & External Relations

To keep our blood sugar levels within the narrow range that is healthy for us, the human body is equipped with around one million 'mini factories'. In a recent breakthrough, scientists from LKCMedicine and the Karolinska Institutet have shown that these factories operate their own internal 'shifts', possibly conserving the function of insulin-producing cells by preventing fatigue.

Known as Islets of Langerhans, each factory or islet consists of about 3,000 to 4,000 cells, including thousands of hormone-producing cells. Among them are alpha cells, which produce the hormone glucagon that releases sugar when levels in the blood are too low; and beta cells, which release insulin when sugar levels are too high. Beta cells in particular can be quite fragile and exposure to long-term workload stress may destroy them, impairing the body’s insulin-producing capability.

In a study published earlier this year in Cell Reports, LKCMedicine Visiting Professor Per-Olof Berggren and the islet imaging team at LKCMedicine observed that primate islets channel blood flow very specifically.
Professor Berggren said, "This observation suggests a mechanism whereby primate islets respond to a higher metabolic demand of active endocrine [hormone-producing] cell clusters by precisely diverting blood flow to these areas without increasing it in the whole islet." The researchers speculate that this could be a way for islets to preserve function longer.

Islet image adapted from Cell Reports (Custom).jpg
Blood flow is channelled very specifically in primate islets, whereas in rodents, blood flow remains continuous
 (Adapted from: 
Cell Reports)

This breakthrough has been possible thanks to a novel primate model where islets are transplanted into the anterior chamber of the eye. Using the body’s only natural window, the scientists were able to track the inner workings of the islets in real-time at single-cell resolution over periods of time.

"Taking the advantage of our novel in vivo human-like model system we demonstrate that islet vasculature is an active and dynamic factor in the regulation of primate islet function, which is in marked contrast to what is found in a mouse model," said LKCMedicine Assistant Professor of Metabolic Disease Yusuf Ali, one of the co-authors of the study.

While more work is needed to fully understand the impact of this gated blood flow on islet function, i t could offer new approaches to help preserve the function of islets in people with type 2 diabetes.