Peroxidized Linoleic Acid, 13-HPODE, Alters Gene Expression Profile in Intestinal Epithelial Cells

Abstract

Lipid peroxides (LOOHs) abound in processed food and have been implicated in the pathology of diverse diseases including gut, cardiovascular, and cancer diseases. Recently, RNA Sequencing (RNA-seq) has been widely used to profile gene expression. To characterize gene expression and pathway dysregulation upon exposure to peroxidized linoleic acid, we incubated intestinal epithelial cells (Caco-2) with 100 µM of 13-hydroperoxyoctadecadienoic acid (13-HPODE) or linoleic acid (LA) for 24 h. Total RNA was extracted for library preparation and Illumina HiSeq sequencing. We identified 3094 differentially expressed genes (DEGs) in 13-HPODE-treated cells and 2862 DEGs in LA-treated cells relative to untreated cells. We show that 13-HPODE enhanced lipid metabolic pathways, including steroid hormone biosynthesis, PPAR signaling, and bile secretion, which alter lipid uptake and transport. 13-HPODE and LA treatments promoted detoxification mechanisms including cytochrome-P450. Conversely, both treatments suppressed oxidative phosphorylation. We also show that both treatments may promote absorptive cell differentiation and reduce proliferation by suppressing pathways involved in the cell cycle, DNA synthesis/repair and ribosomes, and enhancing focal adhesion. A qRT-PCR analysis of representative DEGs validated the RNA-seq analysis. This study provides insights into mechanisms by which 13-HPODE alters cellular processes and its possible involvement in mitochondrial dysfunction-related disorders and proposes potential therapeutic strategies to treat LOOH-related pathologies.

Keywords

• lipid peroxidation
• gene expression
• metabolism