Reactive oxygen species damage various cell components including DNA, proteins, and lipids, and these impairments could be a reason for severe human diseases including atherosclerosis. Forkhead box O1 (FOXO1), an important metabolic transcription factor, upregulates antioxidant and proapoptotic genes during oxidative stress. Apolipoprotein A-I (ApoA-I) forms high density lipoprotein (HDL) particles that are responsible for cholesterol transfer from peripheral tissues to liver for removal in bile in vertebrates. The main sources for plasma ApoA-I in mammals are liver and jejunum. Hepatic apoA-I transcription depends on a multitude of metabolic transcription factors. We demonstrate that ApoA-I synthesis and secretion are decreased during H2O2-induced oxidative stress in human hepatoma cell line HepG2. Here, we first show that FOXO1 binds to site B of apoA-I hepatic enhancer and downregulates apoA-I gene activity in HepG2 cells. Moreover, FOXO1 and LXR alpha transcription factors participate in H2O2-triggered downregulation of apoA-I gene together with Src, JNK, p38, and AMPK kinase cascades. Mutations of sites B or C as well as the administration of siRNAs against FOXO1 or LXR alpha to HepG2 cells abolished the hydrogen peroxide-mediated suppression of apoA-I gene.

Original languageEnglish
Pages (from-to)123-134
Number of pages12
JournalCell Stress and Chaperones
Volume22
Issue number1
DOIs
StatePublished - Jan 2017

    Research areas

  • Apolipoprotein A-I, Oxidative stress, Hydrogen peroxide, FOXO1, LXR alpha, LIVER-X RECEPTOR, INSULIN-RESPONSE SEQUENCES, TISSUE-SPECIFIC EXPRESSION, COMPLEMENT C3 EXPRESSION, HIGH-DENSITY-LIPOPROTEIN, ORPHAN NUCLEAR RECEPTOR, PROTEIN-KINASE B, TRANSCRIPTION FACTORS, TNF-ALPHA, APOA-I

ID: 7614924