Subcellular expression of CYP2E1 in HepG2 cells impacts response to free oleic and palmitic acid.

Aims: Cytochrome P450 2E1 (CYP2E1) is a mammalian monooxygenase expressed at high levels in the liver that metabolizes low molecular weight pollutants and drugs, as well as endogenous fatty acids and ketones. Although CYP2E1 has been mainly studied in the endoplasmic reticulum (ER, microsomal fraction), it also localizes in significant amounts to the mitochondria, where it has been far less studied. We investigated the effects of CYP2E1 expression in mitochondria, endoplasmic reticulum, or both organelles in transgenic HepG2 cells exposed to free oleic and palmitic acid, including effects on cytotoxicity, lipid storage, respiration, and gene expression.

Transgenic expression of human cytochrome P450 2E1 in C. elegans and rat PC-12 cells sensitizes to ethanol-induced locomotor and mitochondrial effects.

Chronic alcohol (ethanol) use is increasing in the United States and has been linked to numerous health issues in multiple organ systems including neurological dysfunction and diseases. Ethanol toxicity is mainly driven by the metabolite acetaldehyde, which is generated through three pathways: alcohol dehydrogenase (ADH2), catalase (CAT), and cytochrome P450 2E1 (CYP2E1). ADH2, while the main ethanol clearance pathway in the liver, is not expressed in the mammalian brain, resulting in CAT and CYP2E1 driving local metabolism of ethanol in the central nervous system.