Islet amyloid polypeptide (IAPP) is a beta-cell peptide hormone that forms toxic and pro-inflammatory aggregates in pathological states, including T2D and islet transplants. Recent evidence suggests the presence of fibrillar aggregates of IAPP (islet amyloid) in some T1D pancreatic islets. In T2D and mouse
models of islet amyloid formation, aggregates of human IAPP recruit and induce a pro-inflammatory phenotype in macrophages in pancreatic islets. Since islet macrophages may play a key role in triggering autoimmunity in T1D, it follows that IAPP aggregation in stressed islets could be a key initiating event in T1D, via induction of inflammation and islet macrophage activation. Here we will study nPOD pancreas sections for the presence of pre-fibrillar (oligomeric) IAPP aggregates and fibrillar amyloid, the association of IAPP aggregates/amyloid with islet macrophages, and the presence of markers of pro-inflammatory macrophage phenotype. The goal is to determine if induction of islet inflammation induced by IAPP aggregates may be an early event in T1D.
