Pepsin Digest of Gliadin Forms Spontaneously Amyloid‐Like Nanostructures Influencing the Expression of Selected Pro‐Inflammatory, Chemoattractant, and Apoptotic Genes in Caco‐2 Cells: Implications for Gluten‐Related Disorders

Maria Georgina Herrera, Francesco Nicoletti, Marion Gras, Philipp W. Dörfler, Nicolo Tonali, Yvonne Hannappel, Inga Ennen, Andreas Hütten, Thomas Hellweg, Karen M. Lammers, Veronica I. Dodero
2021 Molecular Nutrition & Food Research  
Proteolysis-resistant gliadin peptides are intensely investigated in biomedical research related to Celiac Disease and gluten-related disorders. Herein, the first integrated supramolecular investigation of pepsin-digested gliadin peptides, p-gliadin, is presented in combination with its functional behavior in Caco-2 cell line. First, we investigated gliadin degradation by pepsin at pH 3, and the physicochemical properties of p-gliadin were compared with gliadin. An integrated approach using
more » ... rfacial, spectroscopic, and microscopic techniques revealed that the p-gliadin forms spontaneously soluble large supramolecular structures, mainly oligomers and fibrils capable of binding amyloid-sensitive dyes. The self-assembly of p-gliadin starts at a concentration of 0.40 μg/ml. Second, we stimulated CaCo-2 cells with the p-gliadin supramolecular system and screened the mRNA expression levels of a panel of genes involved in cellular inflammation, apoptosis, permeability, and chemoattraction of immune cells. Our findings suggest that p-gliadin composed of supramolecular structures triggers significant mRNA up-regulation (p < 0.05) of pro-apoptotic biomarkers (ratio Bcl2/Bak-1), chemokines (CCL2, CCL3, CCL4, CCL5, CXCL8) and the chemokine receptor CXCR3. This work demonstrates that p-gliadin is interfacial active, forming spontaneously amyloid-type structures that trigger genes in the Caco-2 cell line involved in the recruitment of specialized immune cells. This article is protected by copyright. All rights reserved.
doi:10.1002/mnfr.202100200 pmid:34110092 fatcat:43ygot2ddvbndbrzyb3ykdg374