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.

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Snapshots of Life: A Van Gogh Moment for Pancreatic Cancer

Pancreatic Cancer

Credit: Nathan Krah, University of Utah,
Salt Lake City

Last year, Nathan Krah sat down at his microscope to view a thin section of pre-cancerous pancreatic tissue from mice. Krah, an MD/PhD student in the NIH-supported lab of Charles Murtaugh at the University of Utah, Salt Lake City, had stained the tissue with three dyes, each labelling a different target of interest. As Krah leaned forward to look through the viewfinder, he fully expected to see the usual scattershot of color. Instead, he saw enchanting swirls reminiscent of the famous van Gogh painting, The Starry Night.

In this eye-catching image featured in the University of Utah’s 2016 Research as Art exhibition, red indicates a keratin protein found in the cytoskeleton of precancerous cells; green, a cell adhesion protein called E-cadherin; and yellow, areas where both proteins are present. Finally, blue marks the cell nuclei of the abundant immune cells and fibroblasts that have expanded and infiltrated the organ as a tumor is forming. Together, they paint a fascinating new portrait of pancreatic ductal adenocarcinoma (PDAC), the most common form of pancreatic cancer.

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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.

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Snapshots of Life: Bring on the Confetti!

Renal Pericytes

Credit: Heinz Baumann, Sean T. Glenn, Mary Kay Ellsworth, and Kenneth W. Gross, Roswell Park Cancer Institute, Buffalo, NY

If this explosion of color reminds you of confetti, you’re not alone—scientists think it does too. In fact, they’ve even given the name “Confetti mouse” to a strain of mice genetically engineered so that their cells glow in various combinations of red, blue, yellow, or green markers, depending on what particular proteins those cells are producing. This color coding, demonstrated here in mouse kidney cells, can be especially useful in cancer research, shedding light on subtle molecular differences among tumors and providing clues to what may be driving the spread, or metastasis, of cancer cells beyond the original tumor site.

Not only is the Confetti mouse a valuable scientific tool, this image recently earned Heinz Baumann and colleagues at the Roswell Park Cancer Institute, Buffalo, NY, a place of honor in the Federation of American Societies for Experimental Biology’s 2015 Bioart competition. Working in the NIH-funded lab of Kenneth Gross, Baumann’s team created a Confetti mouse system that enables them to manipulate and explore in exquisite detail the expression of proteins in renal pericytes, a type of cell associated with the blood filtration system in the kidney.

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Cystic Fibrosis: Keeping the Momentum Going

Cystic Fibrosis: 1989 and 2015

Caption: Lower left, me, Lap-Chee Tsui, and John Riordan celebrating our discovery of the cystic fibrosis gene. Right, Robert J. Beall, me, and Doris Tulcin at a November Cystic Fibrosis Foundation event honoring Dr. Beall.

It’s been more than a quarter-century since my colleagues and I were able to identify the gene responsible for cystic fibrosis (CF), a life-shortening inherited disease that mainly affects the lungs and pancreas [1]. And, at a recent event in New York, I had an opportunity to celebrate how far we’ve come since then in treating CF, as well as to honor a major force behind that progress, Dr. Bob Beall, who has just retired as president and chief executive officer of the Cystic Fibrosis Foundation.

Thanks to the tireless efforts of Bob and many others in the public and private sectors to support basic, translational, and clinical research, we today have two therapies from Vertex Pharmaceuticals that are targeted specifically at CF’s underlying molecular cause: ivacaftor (Kalydeco™), approved by the Food and Drug Administration (FDA) in 2012 for people with an uncommon mutation in the CF gene; and the combination ivacaftor-lumacaftor (Orkambi™), approved by the FDA in July for the roughly 50 percent of CF patients with two copies of the most common mutation. Yet more remains to be done before we can truly declare victory. Not only are new therapies needed for people with other CF mutations, but also for those with the common mutation who don’t respond well to Orkambi™. So, the work needs to go on, and I’m encouraged by new findings that suggest a different strategy for helping folks with the most common CF mutation.

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