Dimethyl fumarate protects against hepatic ischemia-reperfusion injury by alleviating ferroptosis via the NRF2/SLC7A11/HO-1 axis.

CELL CYCLE 2023, VOL. 22, NO. 7, 818–828 https://doi.org/10.1080/15384101.2022.2155016 RESEARCH PAPER Dimethyl fumarate protects against hepatic ischemia-reperfusion injury by alleviating ferroptosis via the NRF2/SLC7A11/HO-1 axis Debin Qi*, Peng Chen*, Haili Bao, Lei Zhang, Keyan Sun, Shaohua Song, and Tao Li Department of General Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China ABSTRACT ARTICLE HISTORY Dimethyl fumarate (DMF), a therapeutic agent for relapsing-remitting multiple sclerosis, has cytoprotective and antioxidant effects. Ferroptosis, a pathological cell death process, is recently shown to play a vital part in ischemia-reperfusion injury (IRI). This study aimed to unveil the suppressive role of DMF on ferroptosis in liver IRI. The anti-ferroptosis effect of DMF on hepatic IRI was investigated using a liver IRI mouse model and a hypoxia-reoxygenation injury (HRI) model in alpha mouse liver (AML12) cells. Serum transaminase concentrations reflected liver function. Hematoxylin and eosin staining was used to assess liver damage. Cell viability was evaluated utilizing the CCK-8 assay. Malondialdehyde (MDA), the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and BODIPY 581/591C11 were measured to estimate the injury caused by lipid peroxidation. Western blotting and real-time polymerase chain reaction (RT-PCR) were performed to explore the underlying molecular mechanisms. We demonstrated the anti-ferroptosis effects of DMF both in vivo and in vitro. DMF treatment ameliorated hepatic IRI. KEGG enrichment analysis and transmission electron microscopy revealed a close relationship between ferroptosis and liver IRI. Furthermore, DMF protected against HRI by inhibiting ferroptosis via activating the nuclear factor E2-related factor 2 (NRF2) pathway. Interestingly, NRF2 knockdown notably decreased the expression of SLC7A11 and HO-1 and blocked the anti-ferroptosis effects of DMF. DMF inhibits ferroptosis by activating the NRF2/SLC7A11/HO-1 axis and exerts a protective effect against hepatic IRI. Received 19 September 2022 Revised 17 November 2022 Accepted 1 December 2022 1. Introduction Ischemic tissues and organs suffer aggravated tis sue damage after blood perfusion, termed ische mia-reperfusion injury (IRI). The normal functional metabolism of the liver is highly depen dent on oxygen supply, and IRI is inevitable in liver transplantation, hemorrhagic shock, and severe trauma [1]. Therefore, inhibiting liver IRI would improve clinical outcomes and expand the donor pool by utilizing marginal liver grafts [2]. Despite its clinical importance, the mechanisms underlying liver IRI remain unclear, and effective preventive and therapeutic strategies are required. IRI is closely related to an increase in free radical generation, among which OH· is the most active oxygen free radical. The increase in ferrous iron ions or copper ions accelerates the reaction rate of H2O2 to ·OH, which is called the Fenton/HaberWeiss reaction [3]. KEYWORDS Dimethyl fumarate; ischemia-reperfusion injury; ferroptosis; NRF2; SLC7A11 Ferroptosis, a distinct iron-dependent cell death paradigm, causes cell death via extensive lipid per oxidation [4]. It plays a necessary part in oxidative stress-related diseases, including tumors, nervous system diseases, and acute kidney injury [5]. Inhibition of ferroptosis has been demonstrated in recent research to be a viable therapeutic method for heart, kidney, and lung IRI, while ferroptosis inducers can be optimized as antitumor agents [6–9]. However, there is limited evidence of ferroptosis in liver IRI and a lack of a defined treatment strategy. Dimethyl fumarate (DMF), a derivative of the Krebs cycle intermediate fumarate, has been con firmed with cytoprotective and antioxidant effects that activate the nuclear factor E2-related factor 2 (NRF2) pathway [10,11]. In chronic cerebral hypo perfusion, alcoholic liver disease, acute kidney injury and acute lung injury models, DMF CONTACT Keyan Sun ; Shaohua Song ; Tao Li Department of General Surgery, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, No.197, Ruijin 2nd Road, Huangpu District, Shanghai, 200025, China *These 2 authors have equally contributed. © 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-ncnd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. CELL CYCLE inhibited ferroptosis through the NRF2 signaling pathway, showing a significant protective effect [12–15]. NRF2 is an anti-ferroptosis transcrip tional regulator that can prevent the accumulation of free iron and lipid peroxidation [16]. Multiple human malignancies have elevated levels of the cystine/glutamate antiporter SLC7A11, which imports cystine for glutathione production and antioxidant defense. According to recent research, SLC7A11 overexpression encourages tumor devel opment in part by inhibiting ferroptosis [17] and NRF2 reduces ferroptosis via modulating SLC7A11 and HO-1 [18]. This research focused on seeing how DMF affected ferroptosis in liver IRI. We found that DMF attenuated IRI-induced liver damage, inflammation, and ferroptosis in an IRI mouse model and explored the underlying molecular mechanisms in an HR cell model. And we con firmed that DMF inhibited ferroptosis by activat ing the NRF2/SLC7A11/HO-1 axis. Our research sheds new light on the mechanism of DMF in ferroptosis and identifies a previously untapped therapeutic target for liver IRI. 819 oral gavage for a week before surgery, as pre viously reported [10]. As stated in a prior study, the partial warm liver IRI model was developed [19]. Briefly, the sham group only had free hepatic portal blood vessels after laparotomy, and the blood flow was not obstructed. As for the hepatic IR group, the blood supply to the left and mid-hepatic lobes was blocked, resulting in 70% mouse liver IRI for 90 min. The mice were put on a heated blanket after surgery in order to maintain body tempera ture and monitor vital signs. Blood supply was restored for 6 h. Died mice were eliminated for testing prior to sample collection. The mice were euthanized after the sample were obtained. The same experimenter carried out all surgeries. 2.2. Assessment of liver function After reperfusion, serum aspartate transaminase (AST) and alanine transaminase (ALT) concentra tions were measured using a standard modular auto-analyzer (NX500i, FUJIFILM, Japan) accord ing to the manufacturer’s procedure. 2.3. Histopathological examination 2. Materials and methods 2.1. Animals and hepatic IR surgery Joint Ventures Sipper BK Experimental Animals (Shanghai, China) provi (...truncated)