Australian scientists have found a potential new angle for diabetes treatment in the unlikeliest of places: the venom of the platypus and the echidna. These animals produce a stable version of the hormone glucagon-like peptide-1, which could lead to a longer-lasting version of the hormone for people with Type 2 diabetes.
Like humans, monotremes—platypus and echidnas—produce GLP-1 in their gut. The hormone triggers insulin secretion, which lowers blood glucose levels, but in people, it breaks down in less than two minutes, making it of little use for controlling blood sugar in patients with Type 2 diabetes.
The researchers, from the University of Adelaide and Flinders University, found that monotremes have evolved to produce a form of GLP-1 that's more stable than the version released in humans. This evolutionary quirk most likely came about because the GLP-1 in the venom is used to repel other males during mating season, said co-lead author Briony Forbes, of Flinders University’s School of Medicine. The findings are published in Scientific Reports.
"Our research team has discovered that monotremes … have evolved changes in the hormone GLP-1 that make it resistant to the rapid degradation normally seen in humans," said co-lead author Frank Grutzner, of the University of Adelaide's School of Biological Sciences and the Robinson Research Institute.
Because GLP-1 degrades so quickly, it is not used directly in the treatment of diabetes. Instead, several companies market GLP-1 agonists that are designed to behave like the hormone, but that last longer. These include Novo Nordisk’s Victoza (liraglutide), Sanofi’s Adlyxin (lixisenatide) and AstraZeneca’s Byetta (exenatide), which is derived from the saliva of the gila monster.
Other novel approaches to treating Type 2 diabetes include the genetic or pharmacologic removal of the protein galectin-3, which UC San Diego researchers found reverses insulin resistance and glucose intolerance in mice. Meanwhile, a team led by the Benaroya Research Institute is examining the role of T cell fatigue in patients’ responses to the diabetes drug teplizumab.
Just how the platypus and echidna will contribute to future innovations in diabetes treatment remains to be seen. "These findings have the potential to inform diabetes treatment, one of our greatest health challenges," Grutzner said, "although exactly how we can convert this finding into a treatment will need to be the subject of future research."