Pancreatic cells activated by blue light produce insulin on demand, study says

Diabetes is one of the major health problems in the world today and requires careful management of the patient’s insulin levels. New research from Tufts University may make the process easier. In mice tests, the team implanted beta cells that were activated by blue light to produce more insulin on demand.


At the heart of both types of diabetes are insulin, a hormone that regulates blood sugar levels and allows cells in the body to use it appropriately as energy. In type 1 diabetes, beta cells in the pancreas do not produce enough insulin, sometimes because the immune system destroys these important beta cells. In type 2 diabetes, the patient’s cells stop responding to insulin, or the pancreas does not meet demand, which means blood sugar levels can soar to dangerously high levels.

Controlling the condition requires constant monitoring of blood sugar levels and increasing insulin levels as needed, either directly with hormones or by drugs that produce hormones through increased beta cells.

For the new study, researchers at Tufts University designed islet beta cells that produce insulin on demand – in this case, the “demand” is the blue light pulse. Beta cells have been engineered to produce an enzyme called photoactivated adenosine cyclase (PAC) – essentially, when these enzymes are activated by blue light, they produce a molecule called cyclophosphate adenosine (cAMP).

This molecule, in turn, instructs beta cells to produce more insulin, but interestingly, it does so only when glucose levels are already high. This helps prevent common complications in diabetes treatment, where the production of too much insulin can cause the body to consume available glucose too quickly, leading to hypoglycemia.

To test the new technique, the Tufts University team implanted its engineered islet beta cells under the skin of diabetic mice. The researchers found that when blue light and high glucose levels triggered, these cells produced two to three times more insulin.

“In this way, we can help people with diabetes better control and maintain appropriate glucose levels in their environments without the need for drug intervention,” said Emmanuel Tzanakakis, a co-author of the study. These cells naturally produce insulin, and the regulatory circuits in it play the same role; we only temporarily increase the amount of cAMP in beta cells so that they produce more insulin only when needed. “

Much remains to be done before the treatment is available in human trials, but researchers say the use of light is a step in the right direction.

“There are many advantages to using light to control treatment,” said Zhang Fan, lead author of the study. Obviously, there is an immediate response, and although our research shows that despite increased insulin secretion, there has been no significant change in the amount of oxygen consumed by cells. Hypoxia is a common problem in studies involving transplanted pancreatic cells. “

Eventually, tiny light sources can be embedded next to cells, allowing doctors to trigger them remotely when needed. Or they can be activated automatically by a glucose sensor.

The study was published in the journal ACS Synthetic Biology.

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