We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Human islet amyloid polypeptide accumulates at similar sites in islets of transgenic mice and humans.
- Authors
De Koning, Eelco J. P.; Höppener, Jo W. M.; Verbeek, J. Sjef; Oosterwijk, Cor; Van Hulst, Karen L.; Baker, Catherine A.; Lips, Cees J. M.; Morris, John F.; Clark, Anne; de Koning, E J; Höppener, J W; Verbeek, J S; Oosterwijk, C; van Hulst, K L; Baker, C A; Lips, C J; Morris, J F; Clark, A
- Abstract
The cellular mechanisms responsible for conversion of islet amyloid polypeptide (IAPP) into insoluble amyloid deposits in non-insulin-dependent diabetes mellitus (NIDDM) are not clear. Overexpression of IAPP and the amino acid sequence of human IAPP (hIAPP) have both been implicated. To examine factors involved in amyloid formation, transgenic mice expressing the hIAPP or rat IAPP (rIAPP) gene were generated. These mice had elevated plasma IAPP concentrations, and they were normoglycemic and normoinsulinemic. No amyloid deposits were detected by light microscopy. To examine the ultrastructure of islets, pancreatic tissue was studied from hIAPP and rIAPP transgenic mice and from age-matched control mice by immunoelectron microscopy. IAPP was immunolocalized in beta-cell secretory granules of all mice, and the COOH- and NH2-terminal flanking peptides of hIAPP were localized in beta-cell granules of hIAPP mice. Accumulations of nonfibrillar perivascular IAPP-immunoreactive material were found between capillaries and beta-cells in hIAPP transgenic mice but not in rIAPP transgenic or control mice. Similar nonfibrillar masses were identified in islets of an NIDDM patient. Secondary lysosomes in beta-cells and macrophages of hIAPP transgenic mice showed dense labeling for IAPP. We suggest that hIAPP is degraded more slowly than rIAPP or mouse IAPP by beta-cell lysosomes. Accumulations of IAPP in islet perivascular spaces may represent the early stages of islet amyloid formation.
- Publication
Diabetes, 1994, Vol 43, Issue 5, p640
- ISSN
0012-1797
- Publication type
journal article
- DOI
10.2337/diab.43.5.640