Hepcidin Promoted Ferroptosis through Iron Metabolism which Is Associated with DMT1 Signaling Activation in Early Brain Injury following Subarachnoid Hemorrhage.

Hongxia Zhang,Xiang Xiang,Zhaohui He,Robert Ostrowski,Dengzhi Jiang,Qing Zhao,Yidan Liang,Wang Qin,Xudong Che,Jun Zhao,Kamil Duris

doi:10.1155/2021/9800794

Abstract

Iron metabolism disturbances play an important role in early brain injury (EBI) after subarachnoid hemorrhage (SAH), and hepcidin largely influences iron metabolism. Importantly, iron metabolism may be associated with ferroptosis, recently a nonapoptotic iron-dependent form of cell death that may have a great impact on brain injury after SAH. We investigated hepcidin on iron metabolism and ferroptosis involving divalent metal transporter 1 (DMT1), and ferroportin-1 (FPN1) in a rat model of SAH. Male Sprague-Dawley rats were subjected to the endovascular perforation to induce SAH, and treated with heparin (inhibitor of hepcidin), or oncostatin M (OSM, inducer of hepcidin), or ebselen (inhibitor of DMT1) by intracerebroventricular injections. Hepcidin, DMT1, FPN1 and glutathione peroxidase 4 (GPX4), were detected by western blot and immunofluorescence. Iron metabolism was detected through Perl's iron staining and iron content assay. Ferroptosis, the ROS production, lipid peroxidation (LPO) was evaluated by monitoring methane dicarboxylic aldehyde (MDA), glutathione (GSH), glutathione peroxidase 4 (GPX4) activity, and transmission electron microscopy. Neurological deficit scores, Evans blue staining and brain water content were also determined to detect EBI 72 h after SAH. Our results showed that inhibition of DMT1 by ebselen could suppress iron accumulation and lipid peroxidation, and thereby alleviate ferroptosis and EBI in SAH rats. Heparin downregulated the expression of hepcidin and DMT1, increased FPN1, and exerted protective effects that were equivalent to those of ebselen on ferroptosis and EBI. In addition, OSM increased the expression of hepcidin and DMT1, decreased FPN1, and aggravated ferroptosis and EBI, while the effect on ferroptosis was reversed by ebselen. Therefore, the study revealed that hepcidin could regulate iron metabolism and contribute to ferroptosis via DMT1 signaling activation in rats with EBI after SAH.

Highlights

Subarachnoid hemorrhage (SAH) is a devastating condition
Double immunofluorescence staining revealed that hepcidin, divalent metal transporter 1 (DMT1), and glutathione peroxidase 4 (GPX4) were mainly present in the cytoplasm of cortical neurons after SAH (n = 6, Figure 3(a))
The Western blot results indicated that the hepcidin and DMT1 levels increased with time, and in particular hepcidin was significantly increased from 24 h to 72 h (p

Summary

Introduction

Subarachnoid hemorrhage (SAH) is a devastating condition. Increasing evidence indicates that early brain injury (EBI), a recently proposed concept referring to a direct damage to the whole brain within 72 h after SAH, is the most crucial etiological factor of poor clinical prognosis amongst SAH cases [1, 2]. Our previous research focused on the iron metabolism in EBI after SAH, it reported that iron metabolism may induce ferroptosis, a new form of cell death. Ferroptosis mainly caused by iron overload and the accumulation of lipid peroxide [3]. It has reported ferroptosis occurs after SAH, and reduction of lipid peroxidation could alleviate ferroptosis in early brain injury after SAH [4]. Whether the disorder of iron metabolism might lead to ferroptosis after SAH has not reported, and the pathway not. Studies revealed that hepcidin had a potent influence on iron metabolism [5], our group has found that the expression hepcidin increased in EBI after SAH [6]

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Conclusion