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.

Dietary lipid peroxides (LOOHs) have been linked to gut pathologies including inflammatory bowel disease and cancer. As poorly differentiated (PDiff) intestinal epithelial (Caco-2) cells represent tumor cells and could model intestinal crypt cells, we investigated the cellular response of PDiff Caco-2 cells to the most common dietary LOOH, 13-hydroperoxyoctadecadienoic acid (13-HPODE), using RNA sequencing (RNA-seq). Further, we compared the results with the transcriptomic profiles of PDiff cells exposed to linoleic acid (LA) or hydrogen peroxide (H2O2). The results showed that 13-HPODE treatment induces expression of genes related to detoxification and several metabolic pathways including glycogen and amino acid metabolism, which may create a tumorigenic environment despite the downregulation of some proliferation-related genes. 13-HPODE also enhanced peroxisome proliferator-activated receptor signaling involved in lipid metabolism, homeostasis, and inflammation. Additionally, results indicated that 13-HPODE impacts ribosome biogenesis, phagosome, and mitochondrial function through disrupted electron transport chain, which may contribute to disease development or progression. RNA-seq results were validated using qRT-PCR. This study provides an understanding of PDiff Caco-2 cell response to 13-HPODE and the mechanisms by which 13-HPODE modulates cellular processes that may contribute to disease development or progression.