Relative expression of cholesterol transport-related proteins and inflammation markers through the induction of 7-ketosterol-mediated stress in Caco-2 cells

• Published in: Food and chemical toxicology 2013-06, Vol.56, p.247-253
• Main Authors: Alemany, L., Laparra, J.M., Barberá, R., Alegría, A.
• Format: Article
• Language: English
• Subjects: 7-Ketocholesterol; 7-Ketostigmasterol; absorption; Acetyl-CoA C-Acetyltransferase - genetics; Acetyl-CoA C-Acetyltransferase - metabolism; Acyl Coenzyme A - genetics; Acyl Coenzyme A - metabolism; Anticholesteremic Agents - pharmacology; ATP Binding Cassette Transporter, Sub-Family G, Member 5; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Biological and medical sciences; Biological Transport - drug effects; biomarkers; Biomarkers - metabolism; bradykinin; Bradykinin - pharmacology; Caco-2 Cells; calcium; cholesterol; Cholesterol metabolism; cytotoxicity; diet; Down-Regulation; enzymes; excretion; gene expression; gene expression regulation; human cell lines; Humans; Inflammation; Inflammation - pathology; interleukin-10; Interleukin-10 - genetics; Interleukin-10 - metabolism; interleukin-1beta; Interleukin-1beta - genetics; Interleukin-1beta - metabolism; interleukin-8; Interleukin-8 - genetics; Interleukin-8 - metabolism; Ketocholesterols - pharmacokinetics; Lipoproteins - genetics; Lipoproteins - metabolism; Medical sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; messenger RNA; metabolism; oxidation; oxides; Oxysterols; RNA, Messenger - genetics; RNA, Messenger - metabolism; signal transduction; stigmasterol; Stigmasterol - pharmacokinetics; Toxicology; transporters; tumor necrosis factor-alpha; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - metabolism; Up-Regulation
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2013.02.040

► 7-Ketostigmasterol have a greater proinflammatory potential than 7-ketocholesterol. ► 7-Ketostigmasterol-mediated alterations in cholesterol metabolism are mediated by changes in intracellular calcium levels. ► 7-Ketosterol-induced changes in gene expression of enzymes related to cholesterol metabolism. Human diets contain sterol oxidation products that can induce cytotoxic effects, mainly caused by cholesterol oxides. However, phytosterol oxides effects have been less extensively investigated. This study evaluates the production of inflammatory biomarkers (IL-1β, IL-8, IL-10, TNFα) and the influence of gene expression transporters and enzymes related to cholesterol absorption and metabolism (NPC1L1, ABCG5/8, HMGCoA, ACAT) produced by 7-ketosterols (stigmasterol/cholesterol) in Caco-2 cells. These effects were linked to intracellular signaling pathways by using several inhibitors. Results showed 7-ketostigmasterol to have a greater proinflammatory potential than 7-ketocholesterol. In non-pre-treated cells, only efflux transporters were down-regulated by 7-ketosterols, showing a greater influence upon ABCG5 expression. Cell-pre-incubation with bradykinin induced changes in ABCG expression levels after 7-ketostigmasterol-incubation; however, the energetic metabolism inhibition reduced NPC1L1 expression only in 7-ketocholesterol-incubated cells. In non-pre-treated cells, HMG-CoA was up-regulated by both 7-ketosterols. However, exposure to inhibitors down-regulated the expression levels, mainly in 7-ketocholesterol-incubated cells. While ACAT expression values in non-pre-treated cells were unchanged, exposure to inhibitors caused down-regulation of mRNA levels. These results suggest that internalization and excretion of 7-ketostigmasterol is probably influenced by [Ca]i, which also could mediate HMGCoA activity in POPs metabolism. However, energetic metabolism and reducing equivalents exert different influences upon the 7-ketosterol internalization.