Foodborne cereulide causes beta cell dysfunction and apoptosis

  • Roman Vangoitsenhoven
  • Dieter Rondas
  • Inne Crèvecoeur
  • Wannes D'Hertog
  • Matilde Masini
  • Mirjana Andjelkovic
  • Joris Van Loco
  • Christophe Matthys
  • Chantal Mathieu
  • Lut Overbergh
  • Bart Van der Schueren
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Keywords

Beta Cell MIN6 Cell Beta Cell Dysfunction Beta Cell Line Starchy Food 

Background

Environmental factors play a major role in the rising prevalence of type 1 and type 2 diabetes mellitus. Cereulide is a lipophilic peptide that is often found at low concentrations in starchy food. It is a culprit to consider in this era of prepackaged meals.

Materials and methods

Mouse and rat insulin producing beta cell lines, MIN6 and INS-1E respectively, as well as whole mouse islets, isolated from 2 week old C57Bl/6J mice, were exposed to cereulide concentrations ranging from 0.05ng/ml to 5ng/ml for 24 and 72h. Cell death was evaluated by a Hoechst/Propidium Iodide assay, and compared to cell death in human hepatocellular HepG2 and monkey fibroblast-like COS-1 cells. Subsequently, MIN6 cells were exposed to low concentrations of cereulide (0.15 - 0.5 ng/ml) for 24h and glucose-stimulated insulin secretion was evaluated as well as mechanisms of toxicity by mRNA profiling, electron microscopy and caspase activation and cytochrome c release assay.

Results

Cereulide exposure caused cell death in MIN6, INS-1E and pancreatic islets, but not in HepG2 or COS-1E cells (Table 1). Caspase 3/7 activation confirmed the apoptotic cell death process. Glucose-stimulated insulin secretion decreased from 10.48 ± 3.33 fold to 2.01 ± 0.51 (P < 0.05) in MIN6 cells after 24h exposure with 0.25 ng/ml cereulide. Exposure to 0.25ng/ml cereulide induced markers of mitochondrial stress, including PUMA (p53 upregulated modulator of apoptosis; 271 ± 77 % of control; P < 0.05) but also markers of ER stress, such as CHOP (CCAAT/-enhancer-binding protein homologous protein; 641 ± 190 % of control; P < 0.01). EM revealed swelling and loss of mitochondria, and cytoplasmic cytochrome c release confirmed mitochondrial cell death signalling (360 ± 83 % of control after exposure to 0.5 ng/ml for 24h (P < 0.05).
Table 1

Apoptosis induced after 24h exposure to cereulide (mean percentage ± SEM).

 

MIN6 (n=5)

INS-1E (n=4)

HepG2 (n=3)

COS (n=3)

Islets (n=3)

Medium

7.3 ± 1.3

2.5 ± 0.3

5.8 ± 0.6

1.2 ± 0.6

3.1 ± 1.2

0.05 ng/ml cereulide

5.9 ± 1.0

3.2 ± 0.5

6.6 ± 2.1

1.6 ± 0.4

3.9 ± 1.5

0.25 ng/ml cereulide

31.6 ± 5.8 *

58.1 ± 11.4 *

6.9 ± 1.5

2.9 ± 0.7

8.6 ± 2.4

0.5 ng/ml cereulide

43.6 ± 6.1 *

100.0 ± 0.0 *

11.9 ± 2.5

2.6 ± 0.6

49.2 ± 9.0

5 ng/ml cereulide

100.0 ± 0.0 *

100.0 ± 0.0 *

7.7 ± 2.3

4.3 ± 0.9

96.4 ± 3.5*

* p ≤ 0.05 vs control

Conclusion

Cereulide, a toxin frequently found in prepackaged or prepared starchy meals, increases levels of mitochondrial and ER stress markers in beta cells of rats and mice, even at low doses. In a dose dependent way, it also leads to impaired beta cell function and apoptosis. Cereulide might thus be involved in the current diabetes.

Copyright information

© Vangoitsenhoven et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

Authors and Affiliations

  • Roman Vangoitsenhoven
    • 1
  • Dieter Rondas
    • 1
  • Inne Crèvecoeur
    • 1
  • Wannes D'Hertog
    • 1
  • Matilde Masini
    • 2
  • Mirjana Andjelkovic
    • 3
  • Joris Van Loco
    • 3
  • Christophe Matthys
    • 1
  • Chantal Mathieu
    • 1
  • Lut Overbergh
    • 1
  • Bart Van der Schueren
    • 1
  1. 1.Clinical and Experimental Medicine and EndocrinologyKU LeuvenBelgium
  2. 2.Department of Translational Research and of New Surgical and Medical TechnologiesUniversity of PisaItaly
  3. 3.Food, Medicines, and Consumer Safety, Scientific Institute of Public HealthBrusselsBelgium

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