7keto-stigmasterol and 7keto-cholesterol induce differential proteome changes to intestinal epitelial (Caco-2) cells

• Published in: Food and chemical toxicology Vol. 84; pp. 29 - 36
• Main Authors: Laparra, J.M., Alfonso-García, A., Alegría, A., Barberá, R., Cilla, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-10-2015
• Subjects: 7keto-cholesterol; 7keto-stigmasterol; Caco-2 Cells; Enterocytes - drug effects; Enterocytes - enzymology; Enterocytes - metabolism; Gene Expression Profiling; Gene Expression Regulation - drug effects; Humans; Ketocholesterols - toxicity; Oxidants - toxicity; Oxysterols; Peptide Mapping; Principal Component Analysis; Proteome; Proteome - drug effects; Proteome - metabolism; RNA, Messenger - metabolism; Stigmasterol - analogs & derivatives; Stigmasterol - toxicity; Proteome; 7keto-cholesterol; 7keto-stigmasterol; Caco-2 cells; Oxysterols
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2015.06.021

Recent studies have expanded the appreciation of the roles of oxysterols triggering inflammatory, immune cytotoxic and apoptotic processes, but have not been considered for proteome analysis. A comparative proteomic study in intestinal epithelial cell cultures incubated (60 μM/24 h) with 7keto-cholesterol or 7keto-stigmasterol was performed. The influence of both compounds was studied following the nLC-TripleTOF analysis. Findings were compared to results for control cultures. In the principal component analysis (PCA) of proteome patterns, two components were extracted accounting for 99.8% of the variance in the protein expression. PCA analysis clearly discriminated between the perturbations in the proteome of cell cultures incubated with 7keto-cholesterol and 7keto-stigmasterol. These proteins participate in mitochondrial function, lipid homeostasis, inflammation and immunity and cell proliferation. Remarkable differences between proteome patterns in cell cultures exposed to 7keto-cholesterol and 7keto-stigmasterol affect macrophage migration inhibitory factor, apolipoprotein E, Bcl-2-associated transcription factor and cellular retinoic acid-binding protein. Besides, exposure to 7keto-stigmasterol increased the concentration of ubiquitin-conjugating enzyme E2 and the mitochondrial superoxide dismutase protein. Such findings raise new questions about safety studies and the regulatory potential of oxysterols in the differentiation and function of intestinal and associated immune cells, their response to environmental stimuli and impairment of absorption processes.
•7keto-stigmasterol altered proteins that participate in the immune response(s) and fat partitioning.•7keto-stigmasterol altered Bcl-2 and Cdk1 in a contrasting proteome pattern to that induced by 7keto-cholesterol.•7keto-stigmasterol seems to impair the interaction of the LXRs with their ligands.