Inhibition of Ferroptosis Alleviates Early Brain Injury After Subarachnoid Hemorrhage In Vitro and In Vivo via Reduction of Lipid Peroxidation

Author(s):  
Yuchen Li ◽  
Yao Liu ◽  
Pei Wu ◽  
Yang Tian ◽  
Binbing Liu ◽  
...  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yan Zhou ◽  
Tao Tao ◽  
Guangjie Liu ◽  
Xuan Gao ◽  
Yongyue Gao ◽  
...  

AbstractNeuronal apoptosis has an important role in early brain injury (EBI) following subarachnoid hemorrhage (SAH). TRAF3 was reported as a promising therapeutic target for stroke management, which covered several neuronal apoptosis signaling cascades. Hence, the present study is aimed to determine whether downregulation of TRAF3 could be neuroprotective in SAH-induced EBI. An in vivo SAH model in mice was established by endovascular perforation. Meanwhile, primary cultured cortical neurons of mice treated with oxygen hemoglobin were applied to mimic SAH in vitro. Our results demonstrated that TRAF3 protein expression increased and expressed in neurons both in vivo and in vitro SAH models. TRAF3 siRNA reversed neuronal loss and improved neurological deficits in SAH mice, and reduced cell death in SAH primary neurons. Mechanistically, we found that TRAF3 directly binds to TAK1 and potentiates phosphorylation and activation of TAK1, which further enhances the activation of NF-κB and MAPKs pathways to induce neuronal apoptosis. Importantly, TRAF3 expression was elevated following SAH in human brain tissue and was mainly expressed in neurons. Taken together, our study demonstrates that TRAF3 is an upstream regulator of MAPKs and NF-κB pathways in SAH-induced EBI via its interaction with and activation of TAK1. Furthermore, the TRAF3 may serve as a novel therapeutic target in SAH-induced EBI.


2019 ◽  
Vol 28 (8) ◽  
pp. 985-1001 ◽  
Author(s):  
Huangcheng Song ◽  
Shuai Yuan ◽  
Zhuwei Zhang ◽  
Juyi Zhang ◽  
Peng Zhang ◽  
...  

Sodium/hydrogen exchanger 1 (NHE1) plays an essential role in maintaining intracellular pH (pHi) homeostasis in the central nervous system (CNS) under physiological conditions, and it is also associated with neuronal death and intracellular Na+ and Ca2+ overload induced by cerebral ischemia. However, its roles and underlying mechanisms in early brain injury (EBI) induced by subarachnoid hemorrhage (SAH) have not been fully explored. In this research, a SAH model in adult male rat was established through injecting autologous arterial blood into prechiasmatic cistern. Meanwhile, primary cultured cortical neurons of rat treated with 5 μM oxygen hemoglobin (OxyHb) for 24 h were applied to mimic SAH in vitro. We find that the protein levels of NHE1 are significantly increased in brain tissues of rats after SAH. Downregulation of NHE1 by HOE642 (a specific chemical inhibitor of NHE1) and genetic-knockdown can effectively alleviate behavioral and cognitive dysfunction, brain edema, blood-brain barrier (BBB) injury, inflammatory reactions, oxidative stress, neurondegeneration, and neuronal apoptosis, all of which are involved in EBI following SAH. However, upregulation of NHE1 by genetic-overexpression can produce opposite effects. Additionally, inhibiting NHE1 significantly attenuates OxyHb-induced neuronal apoptosis in vitro and reduces interaction of NHE1 and CHP1 both in vivo and in vitro. Collectively, we can conclude that NHE1 participates in EBI induced by SAH through mediating inflammation, oxidative stress, behavioral and cognitive dysfunction, BBB injury, brain edema, and promoting neuronal degeneration and apoptosis.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hongxia Zhang ◽  
Robert Ostrowski ◽  
Dengzhi Jiang ◽  
Qing Zhao ◽  
Yidan Liang ◽  
...  

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.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhongyuan Bao ◽  
Yinlong Liu ◽  
Binglin Chen ◽  
Zong Miao ◽  
Yiming Tu ◽  
...  

AbstractProkineticin-2 (Prok2) is an important secreted protein likely involved in the pathogenesis of several acute and chronic neurological diseases through currently unidentified regulatory mechanisms. The initial mechanical injury of neurons by traumatic brain injury triggers multiple secondary responses including various cell death programs. One of these is ferroptosis, which is associated with dysregulation of iron and thiols and culminates in fatal lipid peroxidation. Here, we explore the regulatory role of Prok2 in neuronal ferroptosis in vitro and in vivo. We show that Prok2 prevents neuronal cell death by suppressing the biosynthesis of lipid peroxidation substrates, arachidonic acid-phospholipids, via accelerated F-box only protein 10 (Fbxo10)-driven ubiquitination, degradation of long-chain-fatty-acid-CoA ligase 4 (Acsl4), and inhibition of lipid peroxidation. Mice injected with adeno-associated virus-Prok2 before controlled cortical impact injury show reduced neuronal degeneration and improved motor and cognitive functions, which could be inhibited by Fbxo10 knockdown. Our study shows that Prok2 mediates neuronal cell deaths in traumatic brain injury via ferroptosis.


2021 ◽  
Author(s):  
xuan gao ◽  
lingyun wu ◽  
yongyue gao ◽  
zheng peng ◽  
xunzhi liu ◽  
...  

Abstract Pyruvate dehydrogenase (PDH), a key enzyme on the mitochondrial outer membrane, has been found to decrease activity notably in early brain injury (EBI) after subarachnoid hemorrhage (SAH). It has been demonstrated that PDH is associated with the production of reactive oxygen species (ROS) and apoptosis. Hence, in this study, we aimed to determine the cause of the decreased PDH activity and explore the potential role of PDH in EBI. We investigated the expression changes of PDH and pyruvate dehydrogenase kinase (PDK) in vivo and in vitro. Then, we explored the possible effects of PDH and ROS after SAH. The results showed that early overexpression of PDK4 promoted the phosphorylation of PDH, inhibited PDH activity and may play a protective role after SAH in vivo and in vitro. Finally, we investigated the levels of PDK4 and pyruvate, which accumulated due to decreased PDH activity, in the cerebrospinal fluid (CSF) of 34 patients with SAH. Statistical analysis revealed that PDK4 and pyruvate expression was elevated in the CSF of SAH patients compared with that of controls, and this high expression correlated with the degree of neurological impairment and long-term outcome. Taken together, the results show that PDK4 has the potential to serve as a new therapeutic target and biomarker for assisting in the diagnosis of SAH severity and prediction of recovery.


2015 ◽  
Vol 123 (4) ◽  
pp. 915-923 ◽  
Author(s):  
Yizhi Liu ◽  
Jiaoxue Qiu ◽  
Zhong Wang ◽  
Wanchun You ◽  
Lingyun Wu ◽  
...  

OBJECT Oxidative stress and the inflammatory response are thought to promote brain damage in the setting of subarachnoid hemorrhage (SAH). Previous reports have shown that dimethylfumarate (DMF) can activate the Kelch-like ECH-associated protein 1–nuclear factor erythroid 2-related factor 2–antioxidant-responsive element (Keap1-Nrf2-ARE) system in vivo and in vitro, which leads to the downregulation of oxidative stress and inflammation. The aim of this study was to evaluate the potential neuroprotective effect of DMF on SAH-induced brain injury in rats. METHODS Rats were subjected to SAH by the injection of 300 μl of autologous blood into the chiasmatic cistern. Rats in a DMF-treated group were given 15 mg/kg DMF twice daily by oral gavage for 2 days after the onset of SAH. Cortical apoptosis, neural necrosis, brain edema, blood-brain barrier impairment, learning deficits, and changes in the Keap1-Nrf2-ARE pathway were assessed. RESULTS Administration of DMF significantly ameliorated the early brain injury and learning deficits induced by SAH in this animal model. Treatment with DMF markedly upregulated the expressions of agents related to Keap1-Nrf2-ARE signaling after SAH. The inflammatory response and oxidative stress were downregulated by DMF therapy. CONCLUSIONS DMF administration resulted in abatement of the development of early brain injury and cognitive dysfunction in this prechiasmatic cistern SAH model. This result was probably mediated by the effect of DMF on the Keap1-Nrf2-ARE system.


2021 ◽  
Author(s):  
Wenhao Qu ◽  
Ying Cheng ◽  
Wei Peng ◽  
Tongyu Rui ◽  
Chengliang Luo ◽  
...  

Abstract Early inflammation is a significant factor in acute pathophysiological events of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Although there have been numerous studies of neuroinflammation and SAH, the effect of M1 microglia on the progressions of neuroinflammation in SAH remains non-elucidated. CXCR4 is thought to be the critical regulator of the migration and recruitment of microglia, and early studies found that iNOS/NO• does represent an effective ferroptosis regulator and leads to the M1 microglia more resistant to the initiator of ferroptosis. Thus, we investigated the effect of AMD3100 (a highly selective antagonist of CXCR4) and L-NIL (an inhibitor of iNOS) on neuroinflammation in a rat SAH model. We found AMD3100 could suppress the migration of M1 microglia through the CXCL12/CXCR4 pathway. Treatment of AMD3100 could decrease the level of related inflammation factors and improved the prognosis within 24 h after SAH. Moreover, L-NIL could inhibit the expression of (i)NOS and promote the expression of ferroptosis-related proteins and the degree of lipid peroxidation. Importantly, the combination of AMD3100 and L-NIL could reduce the quantity of M1 microglia in the injured brain area and reduce the secretion of related inflammatory factors to improve the prognosis. To sum up, these data indicate that inhibiting CXCR4 and iNOS following SAH produces cerebral protection, and its anti-inflammation provides a potential therapeutic target for treating SAH.


2020 ◽  
Author(s):  
Min Qi ◽  
Sheng-qing Gao ◽  
Jia-qiang Liu ◽  
Yan-ling Han ◽  
Bin Yuan ◽  
...  

AbstractSecondary brain injury following subarachnoid hemorrhage (SAH) is the critical contributor to the mortality of SAH patients. The underlying mechanisms are poorly understood. In this study, we utilized a mice model of SAH to investigate whether FoxO4 is related to the brain injury after SAH and identified its upstream regulator Akt. Experimental SAH was induced in adult male mice by prechiasmatic cistern injection. Brain FoxO4 protein levels in cytoplasm and nucleaus were examined in the sham-operated controls, and in mice 1h, 6h, 12h, 24h, 3d, and 5d after SAH induction. The Akt inhibitor LY294002 was administered by intracerebroventricular infusion to determine its effects on FoxO4. Moreover, the expression of FoxO4 was also investigated in neurons incubated with hemoglobin in vitro, which was also dertermined after inhibition of Akt. FoxO4 protein expression in the nuclei increased remarkably after SAH. The Akt inhibitor LY294002 induced more FoxO4 nuclear localization after SAH in vivo and in vitro. Our results suggest the activation of FoxO4 after SAH and which was inhibited by the increased phosphorylated Akt (p-Akt).


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Pengfei Xu ◽  
Chunrong Tao ◽  
Yuyou Zhu ◽  
Guoping Wang ◽  
Lingqi Kong ◽  
...  

Abstract Background Innate immunity can facilitate early brain injury (EBI) following subarachnoid hemorrhage (SAH). Numerous studies suggest that pyroptosis could exacerbate extracellular immune responses by promoting secretion of inflammatory cytokines. Transforming growth factor-β-activated kinase 1 (TAK1) is a quintessential kinase that positively regulates inflammation through NF-κB and MAPK signaling cascades. However, the effects of TAK1 on neuroinflammation in EBI following SAH are largely unknown. Methods Two hundred and forty-six male C57BL/6J mice were subjected to the endovascular perforation model of SAH. A selective TAK1 inhibitor, 5Z-7-oxozeaenol (OZ) was administered by intracerebroventricular (i.c.v) injection at 30 min after SAH induction. To genetic knockdown of TAK1, small interfering RNA (siRNA) was i.c.v injected at 48 h before SAH induction. SAH grade, brain water content, BBB permeability, neurological score, western blot, real-time PCR, ELISA, transmission electron microscope, and immunofluorescence staining were performed. Long-term behavioral sequelae were evaluated by the rotarod and Morris water maze tests. Furthermore, OZ was added to the culture medium with oxyhemoglobin (OxyHb) to mimic SAH in vitro. The reactive oxygen species level was detected by DCFH-DA staining. Lysosomal integrity was assessed by Lyso-Tracker Red staining and Acridine Orange staining. Results The neuronal phosphorylated TAK1 expression was upregulated following SAH. Pharmacologic inhibition of TAK1 with OZ could alleviate neurological deficits, brain edema, and brain-blood barrier (BBB) disruption at 24 h after SAH. In addition, OZ administration restored long-term neurobehavioral function. Furthermore, blockade of TAK1 dampened neuronal pyroptosis by downregulating the N-terminal fragment of GSDMD (GSDMD-N) expression and IL-1β/IL-18 production. Mechanistically, both in vivo and in vitro, we demonstrated that TAK1 can induce neuronal pyroptosis through promoting nuclear translocation of NF-κB p65 and activating nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 3 (NLRP3) inflammasome. TAK1 siRNA treatment mitigated SAH-induced neurobehavioral deficits and restrained phosphorylated NF-κB p65 expression and NLRP3 inflammasome activation. TAK1 blockade also ameliorated reactive oxygen species (ROS) production and prevented lysosomal cathepsin B releasing into the cytoplasm. Conclusions Our findings demonstrate that TAK1 modulates NLRP3-mediated neuronal pyroptosis in EBI following SAH. Inhibition of TAK1 may serve as a potential candidate to relieve neuroinflammatory responses triggered by SAH.


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