Research carried out at Washington University School of Medicine in St. Louis shows that the body’s fat cells help the pancreas secrete insulin, a finding which could lead to new methods in improving glucose metabolism in type 2 diabetics or insulin-resistant people.
In the November 7, 2007 issue of Cell Metabolism, scientists at the School of Medicine describe a study using laboratory mice where fat cells release a protein that aids insulin secretion from pancreatic beta cells, the sole source of insulin. The protein is an enzyme that the pancreatic cells produce in minimal amounts; the enzyme enhances glucosde-stimulated insulin secretion from pancreatic beta cells.
The enzyme secreted by fat cells is called Nampt (NMN) and is an important component of the insulin-secretion pathway. "We think this secretion process allows fat cells to communicate with the pancreas and aid its function," says senior author Shin-ichiro Imai, M.D., Ph.D., assistant professor of medicine and of molecular biology and pharmacology. "I suspect this process could be critical for compensating pancreatic beta cell function in the face of increasing insulin resistance." "Our work marks a conceptual breakthrough," continued Imai. "Nampt synthesizes a compound in the bloodstream, and when that compound reaches the pancreas it stimulates insulin secretion. This is a surprising mechanism by which a circulating metabolite modulates pancreatic function."
Imai believes that the compound produced by Nampt could be used to raise insulin secretion from pancreatic cells, and so improve the way the body handles sugar. NMN was measured in the bloodstreams of laboratory mice at a concentration sufficient to enhance insulin secretion from pancreatic cells; previously it not known that NMN circulated in the bloodstream.
In conjunction with the Office of Technology Management at the University, Imai has patented the use of Nampt and NMN for the prevention and treatment of metabolic complications, such as type 2 diabetes.
Source: Cell Metabolism, November 7, 2007.