Rutin suppresses human-amylin/hIAPP misfolding and oligomer formation in-vitro, and ameliorates diabetes and its impacts in human-amylin/hIAPP transgenic mice

Research output: Contribution to journalArticle

  • External authors:
  • Jacqueline F. Aitken
  • Kerry M. Loomes
  • Isabel Riba Garcia
  • Gordana Prijic
  • Ashley Phillips
  • Anthony R J Phillips
  • Donghai Wu
  • Sally D. Poppitt
  • Ke Ding
  • Andrew Dowsey

Abstract

Pancreatic islet β-cells secrete the hormones insulin and amylin, and defective β-cell function plays a central role in the pathogenesis of type-2 diabetes (T2D). Human amylin (hA, also termed hIAPP) misfolds and forms amyloid aggregates whereas orthologous mouse amylin does neither. Furthermore, hA elicits apoptosis in cultured β-cells and β-cell death in ex-vivo islets. In addition, hA-transgenic mice that selectively express hA in their β-cells, manifest β-cell apoptosis and progressive islet damage that leads to diabetes closely resembling that in patients with T2D. Aggregation of hA is thus linked to the causation of diabetes. We employed time-dependent thioflavin-T spectroscopy and ion-mobility mass spectrometry to screen potential suppressors of hA misfolding for anti-diabetic activity. We identified the dietary flavonol rutin as an inhibitor of hA-misfolding and measured its anti-diabetic efficacy in hA transgenic mice. In vitro, rutin bound hA, suppressed misfolding, disaggregated oligomers and reverted hA-conformation towards the physiological. In hA-transgenic mice, measurements of glucose, fluid-intake, and body-weight showed that rutin-treatment slowed diabetes-progression by lowering of rates of elevation in blood glucose (P=0.030), retarding deterioration from symptomatic diabetes to death (P=0.014) and stabilizing body-weight (P<0.0001). In conclusion, rutin treatment suppressed hA-aggregation in vitro and doubled the lifespan of diabetic mice (P=0.011) by a median of 69 days compared with vehicle-treated control-diabetic hA-transgenic mice.

Bibliographical metadata

Original languageEnglish
Pages (from-to)625-631
Number of pages7
JournalBiochemical and biophysical research communications
Volume482
Issue number4
Early online date16 Nov 2016
DOIs
StatePublished - 22 Jan 2017