Effects of oxidative stress caused by iron overload on arachidonic acid metabolites in MES23.5 cells

Abstract

Iron overload can induce oxidative stress, thereby inducing cell peroxidation. Arachidonic acid (ARA) is widely expressed in mammalian cells and esterified to membrane phospholipids. To explore the effect of iron overload on the metabolism of membrane phospholipids MES23.5 cells were treated with various concentrations of ferric ammonium citrate (FAC) to induce oxidative stress. Using UHPLC (I-Class LC, Waters) coupled to a QTRAP (AB Sciex 5500) technology, the contents of 13 substances of ARA and its metabolites were detected. When the cells were given two different concentrations of FAC, we found that both high and low concentrations decrease the expression of ARA (p=0.002, p=0.02) compared with the control group. ARA has three metabolic pathways: the COX pathway, LOX pathway and CYP450 pathway. Compared with the control group, the LTB4 content in the LOX pathway was decreased (p=0.10) after treatment with lowconcentration FAC, while the LTB4 content was increased in the high-concentration treatment group (p=0.06). However, the content of 12S-HETE (p=0.23, p=0.05) in the LOX metabolic pathway decreased with increase of FAC concentration. Similarly, the content of 15S-HETE also decreased with increase of FAC concentration (p=0.17, p=0.02). The other downstream metabolites of ARA, 9S-HODE (p=0.54, p=0.18) and 13S-HODE (p=0.81, p=0.13) were not significantly changed. The contents of thromboxane B2 (TXB2), leukotriene D4 (LTD4), prostaglandin E2 (PGE2), 8-iso-prostaglandin F2α (8-iso-PGF2α), prostaglandin F2α (PGF2α), 6-keto-PGF1α, and prostaglandin D2 (PGD2) were too low to be detected in MES23.5 cells. The above results indicate that oxidative stress caused by iron overload reduces the LOX metabolic pathway of ARA.