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Regulation of sterol transporter expression by plant sterols in HepG2 cells
Author(s) -
Park YoungKi,
Carr Timothy P.
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.541.15
Subject(s) - sterol , cholesterol , stigmasterol , transporter , sterol regulatory element binding protein , reductase , biology , biochemistry , abca1 , reverse cholesterol transport , scavenger receptor , liver x receptor , hmg coa reductase , gene expression , receptor , cholesterol 7 alpha hydroxylase , chemistry , gene , enzyme , transcription factor , nuclear receptor , lipoprotein , genetics
Intake of plant sterols has long been shown to reduce cholesterol absorption and subsequently plasma cholesterol concentrations. However, it has not been fully elucidated whether plant sterols can alter the expression of cholesterol transporters by functioning as a signaling molecule to elicit responses at the cellular sterol level. This study tested the hypothesis that plant sterols can modulate the expression of transporters including Niemann‐Pick C1‐Like 1 (NPC1L1) and scavenger receptor class B, type I (SR‐BI) in liver. HepG2 cells, a human hepatoma cell line, were used as a model of hepatocytes. The cells were treated with 25α‐hydroxycholesterol (10 μmol/L) or 100 μmol/L of cholesterol, sitosterol and stigmasterol for 24 h to measure genes involved in cholesterol transport using quantitative realtime PCR. All sterols significantly reduced the mRNA expression levels of hydroxy‐3‐methyl glutaryl CoA reductase (HMG‐CoA reductase), NPC1L1, SR‐BI and LDL receptor. Importantly, sitosterol and stigmasterol reduced the mRNA levels of genes to a similar extent of cholesterol. Our findings indicate that plant sterols can modulate expression of cholesterol‐related genes by functioning as a signaling molecule in HepG2 cells. [Research supported by USDA‐NRI competitive grant no. 2007‐35200‐18298]