[Amylin under examination. Fibrillation - cytotoxic pancreatic polypeptide aggregation]

In patients or animals affected by type 2 diabetes mellitus (DM2, non-insulin dependent diabetes mellitus [NIDDM]), some pathological deposits, called amyloid, are observed among cells of islets of Langerhans. Among other constituents, the deposits consist of an insoluble, fibrillar form of polypeptide neurohormone called amylin, produced by pancreatic beta cells. It is thought that formation of fibrillar deposits of misfolded and aggregated polypeptide is highly toxic to beta cells and leads to cell dysfunction, cell loss, pancreas destruction and progress of the disease. Due to the extreme insolubility of this polypeptide and its instant fibrillation, amylin constitutes a methodological problem, and there is a need for a special methodology in experiments. Some mechanisms and factors that govern amylin fibrillization are rather poorly understood. This article presents amylin as a fibrillating molecule and some methods and methodological aspects and problems that emerge at successive steps during the fibrillation process, including hypothesized cytotoxicity mechanisms of this polypeptide.