Researchers have discovered a new hormone, called betatrophin, that promotes pancreatic beta (β) cell proliferation and improves glucose control in mice. Scientists hope the inding may lead to new ways to prevent or slow the progression of
diabetes in humans. β cells, which produce the hormone insulin, are destroyed by the immune system in people with type 1 diabetes and may not function normally in people with type 2 diabetes. Identifying ways to replace lost β cells and restore the body’s insulin‑producing capacity would beneit people with type 1 or type 2 diabetes and is a major research goal. Previous research found that blocking insulin signaling in tissues such as the liver resulted in β cell proliferation and
increased insulin secretion. To determine what causes this effect, and to provide clues to what cellular factors may regulate β cell proliferation, researchers treated mice with a molecule that blocked insulin signaling and then studied what genes were turned on as β cells proliferated. They identiied a gene that was turned on in the liver and fat of treated mice. The gene was found to encode a protein, which they named betatrophin. The researchers discovered that the protein is secreted by the liver and fat, and travels through the bloodstream. Increasing the amount of betatrophin produced in mice
tripled the mass of their pancreatic β cells in just eight days, doubled insulin production, and led to a lower fasting glucose level and improved glucose tolerance compared to control mice. Humans have a very similar gene, though whether or not human betatrophin plays a similar role as mouse betatrophin is currently under investigation. Research to understand what proteins betatrophin interacts with, how betatrophin stimulates β cell proliferation, and what betatrophin’s other functions might be is still ongoing and could possibly lead to new therapies.
Yi P, Park JS, and Melton DA. Betatrophin: a hormone that
controls pancreatic β cell proliferation. Cell 153: 747‑758,