We were sorting through scientific images recently, cataloguing and filing in a well-intentioned year-end swirl. This caught our eye: it's an islet of Langerhans that has been isolated from a human pancreas and stained to highlight the expression of insulin and glucagon, the hormones that regulate blood sugar. Beta cells, which produce the insulin needed to help lower blood sugar, show up as red. The green cells are alpha cells that express glucagon, which raises blood sugar. (The cell culture and microscopy was done by Deepika Walpita here at the Broad.)
Bridget Wagner, a group leader in the Broad's Chemical Biology Program, has a vivid analogy at the ready to describe the islets, and the pancreas, the targets of much of her research.
“The pancreas is like a tree, where the ducts are the branches, and the islets [of Langerhans] are like bird’s nests,” she says. “They don’t communicate with the tree itself, but they have to have a tree to live.” Those bird’s nests, and the insulin-producing beta cells within them, are crucial to human health - when beta cells go awry, diabetes results. Type 1 diabetes, an autoimmune disease that begins in childhood and destroys beta cells, can mean a lifetime of insulin injections or infusions. Type 2 diabetes, which is linked to obesity and has reached epidemic proportions among adults in the United States, results when the beta cells do not produce enough insulin or when the body has become resistant to the effects of insulin.
A healthy islet is a beautiful thing, indeed.