Abstract
Islet amyloid polypeptide (IAPP), or 'amylin', is co-stored with insulin in secretory granules of pancreatic islet beta-cells. In Type 2 diabetes, IAPP converts into a beta-sheet conformation and oligomerizes to form amyloid fibrils and islet deposits. Granule components, including insulin, inhibit spontaneous IAPP fibril formation in vitro. To determine the mechanism of this inhibition, molecular interactions of insulin with human IAPP (hIAPP), rat IAPP (rIAPP) and other peptides were examined using surface plasmon resonance (BIAcore), CD and transmission electron microscopy (EM). hIAPP and rIAPP complexed with insulin, and this reaction was concentration-dependent. rIAPP and insulin, but not pro-insulin, bound to hIAPP. Insulin with a truncated B-chain, to prevent dimerization, also bound hIAPP. In the presence of insulin, hIAPP did not spontaneously develop beta-sheet secondary structure or form fibrils. Insulin interacted with pre-formed IAPP fibrils in a regular repeating pattern, as demonstrated by immunoEM, suggesting that the binding sites for insulin remain exposed in hIAPP fibrils. Since rIAPP and hIAPP form complexes with insulin (and each other), this could explain the lack of amyloid fibrils in transgenic mice expressing hIAPP. It is likely that IAPP fibrillogenesis is inhibited in secretory granules (where the hIAPP concentration is in the millimolar range) by heteromolecular complex formation with insulin. Alterations in the proportions of insulin and IAPP in granules could disrupt the stability of the peptide. The increase in the proportion of unprocessed pro-insulin produced in Type 2 diabetes could be a major factor in destabilization of hIAPP and induction of fibril formation.
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- Badman M. K., Shennan K. I., Jermany J. L., Docherty K., Clark A. Processing of pro-islet amyloid polypeptide (proIAPP) by the prohormone convertase PC2. FEBS Lett. 1996 Jan 15;378(3):227–231. doi: 10.1016/0014-5793(95)01460-8. [DOI] [PubMed] [Google Scholar]
- Bailyes E. M., Bennett D. L., Hutton J. C. Proprotein-processing endopeptidases of the insulin secretory granule. Enzyme. 1991;45(5-6):301–313. doi: 10.1159/000468903. [DOI] [PubMed] [Google Scholar]
- Betsholtz C., Svensson V., Rorsman F., Engström U., Westermark G. T., Wilander E., Johnson K., Westermark P. Islet amyloid polypeptide (IAPP):cDNA cloning and identification of an amyloidogenic region associated with the species-specific occurrence of age-related diabetes mellitus. Exp Cell Res. 1989 Aug;183(2):484–493. doi: 10.1016/0014-4827(89)90407-2. [DOI] [PubMed] [Google Scholar]
- Butler P. C., Chou J., Carter W. B., Wang Y. N., Bu B. H., Chang D., Chang J. K., Rizza R. A. Effects of meal ingestion on plasma amylin concentration in NIDDM and nondiabetic humans. Diabetes. 1990 Jun;39(6):752–756. doi: 10.2337/diab.39.6.752. [DOI] [PubMed] [Google Scholar]
- Castillo M. J., Scheen A. J., Lefèbvre P. J. Amylin/islet amyloid polypeptide: biochemistry, physiology, patho-physiology. Diabete Metab. 1995 Feb;21(1):3–25. [PubMed] [Google Scholar]
- Clark A., Cooper G. J., Lewis C. E., Morris J. F., Willis A. C., Reid K. B., Turner R. C. Islet amyloid formed from diabetes-associated peptide may be pathogenic in type-2 diabetes. Lancet. 1987 Aug 1;2(8553):231–234. doi: 10.1016/s0140-6736(87)90825-7. [DOI] [PubMed] [Google Scholar]
- Clark A., Holman R. R., Matthews D. R., Hockaday T. D., Turner R. C. Non-uniform distribution of islet amyloid in the pancreas of 'maturity-onset' diabetic patients. Diabetologia. 1984 Nov;27(5):527–528. doi: 10.1007/BF00290389. [DOI] [PubMed] [Google Scholar]
- Couce M., Kane L. A., O'Brien T. D., Charlesworth J., Soeller W., McNeish J., Kreutter D., Roche P., Butler P. C. Treatment with growth hormone and dexamethasone in mice transgenic for human islet amyloid polypeptide causes islet amyloidosis and beta-cell dysfunction. Diabetes. 1996 Aug;45(8):1094–1101. doi: 10.2337/diab.45.8.1094. [DOI] [PubMed] [Google Scholar]
- Hekman C. M., DeMond W. S., Kelley P. J., Mauch S. F., Williams J. D. Isolation and identification of cyclic imide and deamidation products in heat stressed pramlintide injection drug product. J Pharm Biomed Anal. 1999 Sep;20(5):763–772. doi: 10.1016/s0731-7085(99)00075-8. [DOI] [PubMed] [Google Scholar]
- Higham C. E., Jaikaran E. T., Fraser P. E., Gross M., Clark A. Preparation of synthetic human islet amyloid polypeptide (IAPP) in a stable conformation to enable study of conversion to amyloid-like fibrils. FEBS Lett. 2000 Mar 17;470(1):55–60. doi: 10.1016/s0014-5793(00)01287-4. [DOI] [PubMed] [Google Scholar]
- Hutton J. C. Secretory granules. Experientia. 1984 Oct 15;40(10):1091–1098. doi: 10.1007/BF01971456. [DOI] [PubMed] [Google Scholar]
- Jaikaran E. T., Clark A. Islet amyloid and type 2 diabetes: from molecular misfolding to islet pathophysiology. Biochim Biophys Acta. 2001 Nov 29;1537(3):179–203. doi: 10.1016/s0925-4439(01)00078-3. [DOI] [PubMed] [Google Scholar]
- Jaikaran E. T., Higham C. E., Serpell L. C., Zurdo J., Gross M., Clark A., Fraser P. E. Identification of a novel human islet amyloid polypeptide beta-sheet domain and factors influencing fibrillogenesis. J Mol Biol. 2001 May 4;308(3):515–525. doi: 10.1006/jmbi.2001.4593. [DOI] [PubMed] [Google Scholar]
- Janciauskiene S., Eriksson S., Carlemalm E., Ahrén B. B cell granule peptides affect human islet amyloid polypeptide (IAPP) fibril formation in vitro. Biochem Biophys Res Commun. 1997 Jul 30;236(3):580–585. doi: 10.1006/bbrc.1997.7014. [DOI] [PubMed] [Google Scholar]
- Kahn S. E., Andrikopoulos S., Verchere C. B. Islet amyloid: a long-recognized but underappreciated pathological feature of type 2 diabetes. Diabetes. 1999 Feb;48(2):241–253. doi: 10.2337/diabetes.48.2.241. [DOI] [PubMed] [Google Scholar]
- Kahn S. E., Halban P. A. Release of incompletely processed proinsulin is the cause of the disproportionate proinsulinemia of NIDDM. Diabetes. 1997 Nov;46(11):1725–1732. doi: 10.2337/diab.46.11.1725. [DOI] [PubMed] [Google Scholar]
- Kahn S. E., Verchere C. B., Andrikopoulos S., Asberry P. J., Leonetti D. L., Wahl P. W., Boyko E. J., Schwartz R. S., Newell-Morris L., Fujimoto W. Y. Reduced amylin release is a characteristic of impaired glucose tolerance and type 2 diabetes in Japanese Americans. Diabetes. 1998 Apr;47(4):640–645. doi: 10.2337/diabetes.47.4.640. [DOI] [PubMed] [Google Scholar]
- Kautzky-Willer A., Thomaseth K., Pacini G., Clodi M., Ludvik B., Streli C., Waldhäusl W., Prager R. Role of islet amyloid polypeptide secretion in insulin-resistant humans. Diabetologia. 1994 Feb;37(2):188–194. doi: 10.1007/s001250050092. [DOI] [PubMed] [Google Scholar]
- LeVine H., 3rd Quantification of beta-sheet amyloid fibril structures with thioflavin T. Methods Enzymol. 1999;309:274–284. doi: 10.1016/s0076-6879(99)09020-5. [DOI] [PubMed] [Google Scholar]
- Lukinius A., Wilander E., Westermark G. T., Engström U., Westermark P. Co-localization of islet amyloid polypeptide and insulin in the B cell secretory granules of the human pancreatic islets. Diabetologia. 1989 Apr;32(4):240–244. doi: 10.1007/BF00285291. [DOI] [PubMed] [Google Scholar]
- Nishi M., Sanke T., Nagamatsu S., Bell G. I., Steiner D. F. Islet amyloid polypeptide. A new beta cell secretory product related to islet amyloid deposits. J Biol Chem. 1990 Mar 15;265(8):4173–4176. [PubMed] [Google Scholar]
- Sanke T., Hanabusa T., Nakano Y., Oki C., Okai K., Nishimura S., Kondo M., Nanjo K. Plasma islet amyloid polypeptide (Amylin) levels and their responses to oral glucose in type 2 (non-insulin-dependent) diabetic patients. Diabetologia. 1991 Feb;34(2):129–132. doi: 10.1007/BF00500385. [DOI] [PubMed] [Google Scholar]
- Thompson R. G., Gottlieb A., Organ K., Koda J., Kisicki J., Kolterman O. G. Pramlintide: a human amylin analogue reduced postprandial plasma glucose, insulin, and C-peptide concentrations in patients with type 2 diabetes. Diabet Med. 1997 Jul;14(7):547–555. doi: 10.1002/(SICI)1096-9136(199707)14:7<547::AID-DIA390>3.0.CO;2-U. [DOI] [PubMed] [Google Scholar]
- Tsuzuki K., Fukatsu R., Hayashi Y., Yoshida T., Sasaki N., Takamaru Y., Yamaguchi H., Tateno M., Fujii N., Takahata N. Amyloid beta protein and transthyretin, sequestrating protein colocalize in normal human kidney. Neurosci Lett. 1997 Feb 7;222(3):163–166. doi: 10.1016/s0304-3940(97)13369-9. [DOI] [PubMed] [Google Scholar]
- Tsuzuki K., Fukatsu R., Yamaguchi H., Tateno M., Imai K., Fujii N., Yamauchi T. Transthyretin binds amyloid beta peptides, Abeta1-42 and Abeta1-40 to form complex in the autopsied human kidney - possible role of transthyretin for abeta sequestration. Neurosci Lett. 2000 Mar 10;281(2-3):171–174. doi: 10.1016/s0304-3940(00)00834-x. [DOI] [PubMed] [Google Scholar]
- Verchere C. B., D'Alessio D. A., Palmiter R. D., Weir G. C., Bonner-Weir S., Baskin D. G., Kahn S. E. Islet amyloid formation associated with hyperglycemia in transgenic mice with pancreatic beta cell expression of human islet amyloid polypeptide. Proc Natl Acad Sci U S A. 1996 Apr 16;93(8):3492–3496. doi: 10.1073/pnas.93.8.3492. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang Z. L., Bennet W. M., Ghatei M. A., Byfield P. G., Smith D. M., Bloom S. R. Influence of islet amyloid polypeptide and the 8-37 fragment of islet amyloid polypeptide on insulin release from perifused rat islets. Diabetes. 1993 Feb;42(2):330–335. doi: 10.2337/diab.42.2.330. [DOI] [PubMed] [Google Scholar]
- Westermark G. T., Gebre-Medhin S., Steiner D. F., Westermark P. Islet amyloid development in a mouse strain lacking endogenous islet amyloid polypeptide (IAPP) but expressing human IAPP. Mol Med. 2000 Dec;6(12):998–1007. [PMC free article] [PubMed] [Google Scholar]
- Westermark P., Li Z. C., Westermark G. T., Leckström A., Steiner D. F. Effects of beta cell granule components on human islet amyloid polypeptide fibril formation. FEBS Lett. 1996 Feb 5;379(3):203–206. doi: 10.1016/0014-5793(95)01512-4. [DOI] [PubMed] [Google Scholar]
- Westermark P., Wernstedt C., Wilander E., Hayden D. W., O'Brien T. D., Johnson K. H. Amyloid fibrils in human insulinoma and islets of Langerhans of the diabetic cat are derived from a neuropeptide-like protein also present in normal islet cells. Proc Natl Acad Sci U S A. 1987 Jun;84(11):3881–3885. doi: 10.1073/pnas.84.11.3881. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Westermark P., Wilander E. Islet amyloid in Type 2 (non-insulin-dependent) diabetes is related to insulin. Diabetologia. 1983 May;24(5):342–346. doi: 10.1007/BF00251821. [DOI] [PubMed] [Google Scholar]