Glutathione peroxidase 4 deficit-mediated fer⁃roptosis contributes to dopaminergic neuron degeneration under synucleinopathy

OBJECTIVE Intracellular aggre⁃gation ofα-synuclein(SNCA)is one of the core pathological features of neurodegenerative disor⁃ders including Parkinson disease,whilst the detailed mechanism for consequently neuron loss has not been fully illustrated.Since the altered phospholipid homeostasis has been suggested to play a role in synucleinopathy,this study aims to depict the fully-featured status of phospholip⁃ids and the targets reposingα-synuclein-related neurotoxicity.METHODS SNCAA53T transgenic mice were utilized as the model of Parkinson disease.Behavioral tests including pole test,rotarod test and gait analysis were conducted to assess the motor features of Parkinsonism.Tyro⁃sine hydroxylase were determined by immunohis⁃tochemistry.Glutathione,dopamine,3,4-dihy⁃droxyphenylacetic acid and homovanillic acid were determined by HPLC-ECD analysis.Assess⁃ment of lipid peroxidation included MDA assay and Liperfluo staining.Phospholipid-omics was analyzed based on LC-MS/MS.Investigation on mechanism was relied on Western blotting and qPCR assay.The injection of AAV into midbrain was achieved by ultra-micro injection pump to obtain the target genotype.RESULTS SNCAA53T transgenic mice displayed progres⁃sively deteriorated motor coordination functions and the mechanisms were related with lipid per⁃oxidation and ferroptosis,which might help to explain the parkinsonism.These hydroperoxides were observed on plasm membrane and were further characterized by LC-MS/MS-based phos⁃pholipid-omics analysis.α-synucleinA53T trans⁃genic mice displayed distinct patterns of phos⁃pholipid peroxidation in midbrain regions com⁃pared to wild type littermates.Among different subtypes of oxidized phospholipids,oxidative phosphatidylcholine(PC-ox)was more promi⁃nently elevated.Phospholipid peroxidation is believed as a biomarker of ferroptosis,which is largely a specialized death program caused by insufficiency of glutathione peroxidase-4(GPX4),the only known enzyme that can reduce lipid hydroperoxides within biological membranes.The deficiency of Gpx4 was demonstrated to be responsible forα-synuclein-induced lipid peroxi⁃dation,and the cell lines and mouse models underwent genetic Gpx4 downregulation showed exacerbated dopaminergic neuron loss and par⁃kinsonism.On the other hand,the potentiation of Gpx4 expression remarkably inhibited dopami⁃nergic ferroptotic death and behavioral deficits in a mouse model with synucleinopathy.CONCLU⁃SION A cellular pathway that Gpx4 deficit-medi⁃ated phospholipid peroxidation and behavioral consequence participated in synucleinopathy,suggesting a potential strategy targeting Gpx4 to alleviate PD symptoms.

有氧运动对高脂膳食小鼠心肌损伤中Nrf2/GPX4/Ferroptosis通路的作用

目的:探讨核因子E2相关因子2(Nrf 2)激活谷胱甘肽过氧化物酶4(GPX4)抑制铁死亡(Ferroptosis)的通路在有氧运动预防高脂膳食小鼠心肌损伤中的保护作用。方法:40只5周龄SPF级C57BL/6雄性小鼠随机分为安静对照组(NC)、运动组(NE)、高脂组(HC)和高脂+运动组(HE,高脂与跑台运动同时开始),每组10只。高脂膳食采用60%Kcal SPF级高脂模型饲料喂养,自由进食。有氧运动采用递增负荷跑台运动,每周5 d, 60 min/d,速度从13 m/min开始,每两周速度递增1 m/min。14周后取心肌和血液。HE染色观察心肌组织结构变化。Western blot检测心肌Nrf2/GPX4/Ferroptosis相关蛋白表达。分光光度法测定心肌过氧化物浓度和抗氧化酶活性。ELISA法检测心肌线粒体8-OHdG和血清胰岛素水平。结果:与对照组相比,高脂组的心肌纤维间隙脂质集聚增加,FBG和FINS显著增加,而ISI显著下降(P<0.01);与高脂组相比,高脂运动组的心肌纤维间隙脂质集聚减少,T-AOC、T-SOD、GSH活性显著增强,心肌线粒体8-OHdG和心肌铁含量降低(P<0.01),FPN1、FTH1、GPX4、GLUT1和细胞核内Nrf2显著升高(P<0.01)。结论:有氧运动可促进小鼠心肌Nrf2转位入核增强GPX4表达,抑制心肌Ferroptosis发生,同时促进心肌抗氧化酶活性,抑制心肌线粒体过氧化损伤。

Ancient dormant virus remnant ERVW-1 drives ferroptosis via degradation of GPX4 and SLC3A2 in schizophrenia

Human endogenous retroviruses(HERVs)are remnants of retroviral infections in human germline cells from millions of years ago.Among these,ERVW-1(also known as HERV-W-ENV,ERVWE1,or ENVW)encodes the envelope protein of the HERV-W family,which contributes to the pathophysiology of schizophrenia.Additionally,neuropathological studies have revealed cell death and disruption of iron homeostasis in the brains of individuals with schizophrenia.Here,our bioinformatics analysis showed that differentially expressed genes in the human prefrontal cortex RNA microarray dataset(GSE53987)were mainly related to ferroptosis and its associated pathways.Clinical data demonstrated significantly lower expression levels of ferroptosis-related genes,particularly Glutathione peroxidase 4(GPX4)and solute carrier family 3 member 2(SLC3A2),in schizophrenia patients compared to normal controls.Further in-depth analyses revealed a significant negative correlation between ERVW-1 expression and the levels of GPX4/SLC3A2 in schizophrenia.Studies indicated that ERVW-1 increased iron levels,malondialdehyde(MDA),and transferrin receptor protein 1(TFR1)expression while decreasing glutathione(GSH)levels and triggering the loss of mitochondrial membrane potential,suggesting that ERVW-1 can induce ferroptosis.Ongoing research has shown that ERVW-1 reduced the expression of GPX4 and SLC3A2 by inhibiting their promoter activities.Moreover,Ferrostatin-1(Fer-1),the ferroptosis inhibitor,reversed the iron accumulation and mitochondrial membrane potential loss,as well as restored the expressions of ferroptosis markers GSH,MDA,and TFR1 induced by ERVW-1.In conclusion,ERVW-1 could promote ferroptosis by downregulating the expression of GPX4 and SLC3A2,revealing a novel mechanism by which ERVW-1 contributes to neuronal cell death in schizophrenia.

The ferroptosis activity is associated with neurological recovery following chronic compressive spinal cord injury

Chronic compressive spinal cord injury in compressive cervical myelopathy conditions can lead to rapid neurological deterioration in the early phase,followed by partial self-recovery,and ultimately an equilibrium state of neurological dysfunction.Ferroptosis is a crucial pathological process in many neurodegenerative diseases;however,its role in chro nic compressive spinal cord injury remains unclear.In this study,we established a chronic compressive spinal cord injury rat model,which displayed its most severe behavioral and electrophysiological dysfunction at 4 wee ks and partial recovery at 8 weeks after compression.Bulk RNA sequencing data identified enriched functional pathways,including ferroptosis,presynapse,and postsynaptic membrane activity at both 4 and 8 wee ks following chro nic compressive spinal co rd injury.Tra nsmission electron microscopy and malondialdehyde quantification assay confirmed that ferroptosis activity peaked at 4 weeks and was attenuated at 8 weeks after chronic compression.Ferro ptosis activity was negatively correlated with behavioral score.Immunofluorescence,quantitative polymerase chain reaction,and western blotting showed that expression of the anti-ferroptosis molecules,glutathione peroxidase 4(GPX4) and MAF BZIP transcription factor G(MafG),in neuro ns was suppressed at 4 weeks and upregulated at 8 weeks following spinal co rd compression.There was a positive correlation between the expression of these two molecules,suggesting that they may work together to contribute to functional recovery following chronic compressive spinal cord injury.In conclusion,our study determined the genome-wide expression profile and fe rroptosis activity of a consistently compressed spinal cord at different time points.The results showed that anti-fe rroptosis genes,specifically GPX4 and MafG,may be involved in spontaneous neurological recovery at 8 weeks of chronic compressive spinal cord injury.These findings contribute to a better understanding of the mechanisms underlying chronic compressive spinal cord injury and may help identify new therapeutic targets for compressive cervical myelopathy.

Novel perspective in transplantation therapy of mesenchymal stem cells:targeting the ferroptosis pathway

Ex vivo culture-amplified mesenchymal stem cells(MSCs)have been studied because of their capacity for healing tissue injury.MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells,but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period.Hence,strategies to increase the efficacy of MSC treatment are urgently needed.Iron overload,reactive oxygen species deposition,and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs,thereby hastening cell death.Notably,oxidative stress(OS)and deficient antioxidant defense induced by iron overload can result in ferroptosis.Ferroptosis may inhibit cell survival after MSC transplantation,thereby reducing clinical efficacy.In this review,we explore the role of ferroptosis in MSC performance.Given that little research has focused on ferroptosis in transplanted MSCs,further study is urgently needed to enhance the in vivo implantation,function,and duration of MSCs.

A novel anticancer property of Lycium barbarum polysaccharide in triggering ferroptosis of breast cancer cells

Breast cancer is one of the most malignant tumors and is associated with high mortality rates among women.Lycium barbarum polysaccharide(LBP)is an extract from the fruits of the traditional Chinese herb,L.barbarum.LBP is a promising anticancer drug,due to its high activity and low toxicity.Although it has anticancer properties,its mechanisms of action have not been fully established.Ferroptosis,which is a novel anticancer strategy,is a cell death mechanism that relies on iron-dependent lipid reactive oxygen species(ROS)accumulation.In this study,human breast cancer cells(Michigan Cancer Foundation-7(MCF-7)and MD Anderson-Metastatic Breast-231(MDA-MB-231))were treated with LBP.LBP inhibited their viability and proliferation in association with high levels of ferroptosis.Therefore,we aimed to ascertain whether LBP reduced cell viability through ferroptosis.We found that the structure and function of mitochondria,lipid peroxidation,and expression of solute carrier family 7 member 11(SLC7 A11,also known as x CT,the light-chain subunit of cystine/glutamate antiporter system X_(c)^(-))and glutathione peroxidase 4(GPX4)were altered by LBP.Moreover,the ferroptosis inhibitor,Ferrostatin-1(Fer-1),rescued LBP-induced ferroptosis-associated events including reduced cell viability and glutathione(GSH)production,accumulation of intracellular free divalent iron ions and malondialdehyde(MDA),and down-regulation of the expression of x CT and GPX4.Erastin(x CT inhibitor)and RSL3(GPX4 inhibitor)inhibited the expression of x CT and GPX4,respectively,which was lower after the co-treatment of LBP with Erastin and RSL3.These results suggest that LBP effectively prevents breast cancer cell proliferation and promotes ferroptosis via the x CT/GPX4 pathway.Therefore,LBP exhibits novel anticancer properties by triggering ferroptosis,and may be a potential therapeutic option for breast cancer.

Protective effect of dihydropteridine reductase against oxidative stress is abolished with A278C mutation

Objective: To evaluate the antioxidation of dihydrobiopterin reductase and to explore the effect of A278C mutation of the quinoid dihydropteridine reductase(QDPR) gene on its antioxidant activity. Methods: First, plasmids with different genes(wild and mutant QDPR) were constructed. After gene sequencing, they were transfected into human kidney cells(HEK293T). Then, the intracellular production of reactive oxygen species(ROS) and tetrahydrobiopterin(BH4) was detected after cells were harvested. Activations of nicotinamide adenine dinucleotide phosphate oxidase 4(NOX4), glutathione peroxidase 3(GPX3), and superoxide dismutase 1(SOD1) were analyzed to observe the oxidative stress after transfection. The expression of the neuronal nitric oxide synthase(n NOS) gene was analyzed by semiquantitative reverse-transcription polymerase chain reaction(RT-PCR). We also detected the activation of transforming growth factor β1(TGF-β1) by enzyme-linked immunosorbent assay(ELISA) to observe the connection of TGF-β1 and oxidative stress. Results: The exogenous wild-type QDPR significantly decreased the expression of n NOS, NOX4, and TGF-β1 and induced the expression of SOD1 and GPX3, but the mutated QDPR lost this function and resulted in excessive ROS production. Our data also suggested that the influence on the level of BH4 had no significant difference between mutated and the wild-type QDPR transfection. Conclusions: Wild-type QDPR played an important role in protecting against oxidative stress, but mutant QDPR failed to have these beneficial effects.