Can Artificial Cells Take Over for Lost Insulin-Secreting Cells?

artificial beta cells

Caption: Artificial beta cell, made of a lipid bubble (purple) carrying smaller, insulin-filled vesicles (green). Imaged with cryo-scanning electron microscope (cryo-SEM) and colorized.
Credit: Zhen Gu Lab

People with diabetes have benefited tremendously from advances in monitoring and controlling blood sugar, but they’re still waiting and hoping for a cure. Some of the most exciting possibilities aim to replace the function of the insulin-secreting pancreatic beta cells that is deficient in diabetes. The latest strategy of this kind is called AβCs, short for artificial beta cells.

As you see in the cryo-SEM image above, AβCs are specially designed lipid bubbles, each of which contains hundreds of smaller, ball-like vesicles filled with insulin. The AβCs are engineered to “sense” a rise in blood glucose, triggering biochemical changes in the vesicle and the automatic release of some of its insulin load until blood glucose levels return to normal.

In recent studies of mice with type 1 diabetes, researchers partially supported by NIH found that a single injection of AβCs under the skin could control blood glucose levels for up to five days. With additional optimization and testing, the hope is that people with diabetes may someday be able to receive AβCs through patches that painlessly stick on their skin.

Continue reading

Cool Videos: Insulin from Bacteria to You

If you have a smartphone, you’ve probably used it to record a video or two. But could you use it to produce a video that explains a complex scientific topic in 2 minutes or less? That was the challenge posed by the RCSB Protein Data Bank last spring to high school students across the nation. And the winning result is the video that you see above!

This year’s contest, which asked students to provide a molecular view of diabetes treatment and management, attracted 53 submissions from schools from coast to coast. The winning team—Andrew Ma, George Song, and Anirudh Srikanth—created their video as their final project for their advanced placement (AP) biology class at West Windsor-Plainsboro High School South, Princeton Junction, NJ.

Continue reading

Creative Minds: Potential Diabetes Lessons from Binge-Eating Snakes

Secor with a snake

Stephen Secor/Credit: Secor Lab

Many people would do just about anything to avoid an encounter with a snake. Not Stephen Secor. Growing up in central New York State, Secor was drawn to them. He’d spend hours frolicking through forest and field, flipping rocks and hoping to find one. His animal-loving mother encouraged him to keep looking, and she even let him keep a terrarium full of garter snakes in his bedroom. Their agreement: He must take good care of them—and please make sure they don’t get loose.

As a teen, Secor considered a career as a large-animal veterinarian. But a college zoology course led him right back to his fascination with snakes. Now a professor at the University of Alabama, Tuscaloosa, he’s spent 25 years trying to understand how some snakes, such as the Burmese python shown above, can fast for weeks or even months, and then go on a sudden food binge. Secor’s interest in the feast-or-famine digestive abilities of these snakes has now taken an unexpected turn that he never saw coming: a potential treatment to help people with diabetes.

Continue reading

Progress Toward Stem Cell Treatment for Diabetes

patient-derived pancreatic beta cells

Caption: Insulin-containing pancreatic beta cells (green) derived from human stem cells. The red cells are producing another metabolic hormone, glucagon, that regulates blood glucose levels. Blue indicates cell nuclei.
Credit: The Salk Institute for Biological Studies, La Jolla, CA

In people with type 1 diabetes, the immune system kills off insulin-producing beta cells of the pancreas needed to control the amount of glucose in their bloodstream. As a result, they must monitor their blood glucose often and take replacement doses of insulin to keep it under control. Transplantation of donated pancreatic islets—tissue that contains beta cells—holds some promise as a therapy or even a cure for type 1 diabetes. However, such donor islets are in notoriously short supply [1]. Recent advances in stem cell research have raised hopes of one day generating an essentially unlimited supply of replacement beta cells perfectly matched to the patient to avoid transplant rejection.

A couple of years ago, researchers took a major step toward this goal by coaxing induced pluripotent stem cells (iPSCs), which are made from mature human cells, to differentiate into cells that closely resembled beta cells. But a few things were troublesome. The process was long and difficult, and the iPSC-derived cells were not quite as good at sensing glucose and secreting insulin as cells in a healthy person. They also looked and, in some ways, acted like beta cells, but were unable to mature fully in the lab. Now, an NIH-funded team has succeeded in finding an additional switch that enables iPSC-derived beta cells to mature and produce insulin in a dish—a significant step toward moving this work closer to the clinical applications that many diabetics have wanted.

Continue reading

Blood Sugar Control for Diabetes: Asking the Heart Questions

Glucose testing

Credit: Thinkstock

When most people think about risk factors for cardiovascular disease, they likely think of blood pressure readings or cholesterol levels. But here’s something else that should be high on that list: diabetes. That’s because people with diabetes are roughly twice as likely to die of heart disease than other folks [1]. Yet the issue of how best to help such people lower their cardiovascular risks remains a matter of intense debate. Some studies have suggested that part of the answer may lie in tightly controlling blood sugar (glucose) levels with a strict regimen of medications and monitoring [2]. Other research has shown that the intense effort needed to keep blood glucose levels under tight control might not be worth it and may even make things worse for certain individuals [3].

Now, a follow up of a large, clinical trial involving nearly 1,800 U.S. military veterans with type 2 diabetes—the most common form of diabetes—provides further evidence that tight blood glucose control may indeed protect the cardiovascular system. Reporting in The New England Journal of Medicine [4], researchers found a significant reduction in a composite measure of heart attacks, strokes, heart failure, and circulation-related amputations among the vets who maintained tight glucose control for about five and a half years on average. What’s particularly encouraging is most of the cardiovascular-protective benefit appears to be achievable through relatively modest, rather than super strict, reductions in blood glucose levels.

Continue reading