Ferroptosis—A Novel Mechanism With Multifaceted Actions on Stroke

SLC40A1 in iron metabolism, ferroptosis, and disease: A review

Solute carrier family 40 member 1 (SLC40A1) plays an essential role in transporting iron from intracellular to extracellular environments. When SLC40A1 expression is abnormal, cellular iron metabolism becomes dysregulated, resulting in an overload of intracellular iron, which induces cell ferroptosis. Numerous studies have confirmed that ferroptosis is closely associated with the development of many diseases. Here, we review recent findings on SLC40A1 in ferroptosis and its association with various diseases, intending to explore new directions for research on disease pathogenesis and new therapeutic targets for prevention and treatment. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics Metabolic Diseases > Molecular and Cellular Physiology.

[The secretome of mesenchymal stromal cells as a new hope in the treatment of acute brain tissue injuries]

Ischemic and hemorrhagic strokes, traumatic brain injury, bacterial and viral encephalitis, toxic and metabolic encephalopathies are very different pathologies. But, they have much more in common than it might seem at first glance. In this review, the authors propose to consider these brain pathologies from the point of view of the unity of their pathogenetic mechanisms and approaches to therapy. Particular attention is paid to promising therapeutic approaches, such as therapy using cells and their secretion products: an analysis of the accumulated experimental data, the advantages and limitations of these approaches in the treatment of brain damage was carried out. The review may be of interest both to specialists in the field of neurology, neurosurgery and neurorehabilitation, and to readers who want to learn more about the progress of regenerative biomedicine in the treatment of brain pathologies.

CircAFF2 Promotes Neuronal Cell Injury in Intracerebral Hemorrhage by Regulating the miR-488/CLSTN3 Axis

BACKGROUND

Intracerebral hemorrhage (ICH), a subtype of devastating stroke, carries high morbidity and mortality worldwide. CircRNA AFF2 (circAFF2) was significantly increased in ICH patients, but the underlying mechanism of circAFF2 is unknown.

METHODS

Hemin was employed to treat neuronal cells to mimic ICH in vitro. Mice were injected with collagenase VII-S to establish in vivo ICH models. Genes and protein expressions were detected using qRT-PCR and Western blotting. The interaction among circAFF2, miR-488, and CLSTN3 was validated by dual-luciferase reporter assay and RNA-RIP. Cell viability, MDA, iron, GSH, and lipid ROS were examined using the MTT, the commercial kits, and flow cytometry, respectively. ICH injury in mice was evaluated using neurological deficit scores and brain water measurements.

RESULTS

CircAFF2 was significantly increased in ICH in vivo and in vitro models. CircAFF2 bound to miR-488 and knockdown of circAFF2 or overexpression of miR-488 inhibited hemin-induced injury of neuronal cells as indicated by increased cell viability and reduced markers of oxidative stress and lipid peroxidation. CLSTN3 was the downstream target of miR-488. Silencing of circAFF2 or miR-488 overexpression reduced CLSTN3 expression and protected against the injury of neuronal cells. In vivo experiments finally confirmed that circAFF2 knockdown attenuated mice ICH injury via the miR-488/CLSTN3 axis.

CONCLUSION

CircAFF2 promotes the injury of neuronal cells and exacerbates ICH via increasing CLSTN3 by sponging miR-488, suggesting that circAFF2 may be a potential therapeutic target for ICH treatment.

Mesenchymal stem cell-derived exosomes: Shaping the next era of stroke treatment

Exosome-based treatments are gaining traction as a viable approach to addressing the various issues faced by an ischemic stroke. These extracellular vesicles, mainly produced by Mesenchymal Stem Cells (MSCs), exhibit many properties with substantial therapeutic potential. Exosomes are particularly appealing for stroke therapy because of their low immunogenicity, effective cargo transport, and ability to cross the blood-brain barrier. Their diverse effects include neuroprotection, angiogenesis stimulation, inflammatory response modulation, and cell death pathway attenuation, synergistically promoting neuronal survival, tissue regeneration, and functional recovery. Exosomes also show potential as diagnostic indicators for early stroke identification and customized treatment options. Despite these promising qualities, current exosome-based therapeutics have some limitations. The heterogeneity of exosome release among cell types, difficulty in standardization and isolation techniques, and complications linked to dosage and targeted administration necessitates extensive investigation. It is critical to thoroughly understand exosomal processes and their complicated interactions within the cellular milieu. To improve the practicality and efficacy of exosome-based medicines, research efforts must focus on improving production processes, developing robust evaluation criteria, and developing large-scale isolation techniques. Altogether, exosomes' multifunctional properties offer a new route for transforming stroke treatment and significantly improving patient outcomes.

Scientific Landscape of Oxidative Stress in Stroke: From a Bibliometric Analysis to an in-Depth Review

Stroke is an acute cerebrovascular disease resulting from either obstruction or rupture of a blood vessel in the brain. Oxidative stress (OS), referred to a status where cellular oxidative capacities overwhelm antioxidative defenses, is involved in the pathophysiology of stroke. The bibliometric analysis and in-depth review aim to depict the research trend of OS in stroke. Relevant scientific publications were acquired from the Web of Science Core Collection database. Scientific landscape of OS in stroke was illustrated by general quantitative trend, impactful journals, and co-authorship of various academic units (i.e., countries/regions, organizations, and authors). Furthermore, theme analysis predicting the hot research issues and frontiers was performed. 15,826 documents regarding OS in stroke were obtained over a time span of more than 20 years from 1992 to 2021. The overall tendency of publication counts was continuously on the rise. Bibliometric analysis indicated China and the United States were predominant in this study field, as reflected by their high publication counts and intensive collaboration with other countries. Current key research areas of OS in stroke may lie in the investigation of neuroinflammation, and interaction among multiple cell death mechanisms including apoptosis, autophagy, and ferroptosis to search for effective treatments. Moreover, another hot topic could be the association between air pollution and stroke, and its underlying mechanisms. As the exploration of OS in stroke is speculated to be a continuous hot spot in the future, this article may be helpful for researchers to conduct future studies with the understanding of influential academic forces and research highlights.

TMT and PRM Based Quantitative Proteomics to Explore the Protective Role and Mechanism of Iristectorin B in Stroke

Stroke is a serious disease caused by the rupture or blockage of the cerebrovascular system. Its pathogenesis is complex and involves multiple mechanisms. Iristectorin B is a natural isoflavone that has certain anti stroke effects. In this study, an in vitro stroke injury model of glyoxylate deprivation was established using PC12 cells, which was used to evaluate the anti-stroke activity of Iristectorin B in ejecta stem. The results showed that Iristectorin B, a natural isoflavone derived from Dried Shoot, significantly reduced the damage to PC12 cells caused by oxygen glucose deprivation/reoxygenation, decreased apoptosis, enhanced cell survival and reduced Ca2+, LDH and ROS levels. The results showed that Iristectorin B had a significant protective effect on Na2S2O4-injured PC12 cells, and the mechanism may be related to the protective effect of neurons in the brain. After protein extraction and various analyses were performed, a series of cutting-edge technologies were organically combined to study the quantitative proteome of each group. Differential proteins were then analyzed. According to the protein screening principle, ferroptosis-related proteins were most closely associated with stroke. The differential proteins associated with ferroptosis screened were SLC3A2, TFR1 and HMOX1, with HMOX1 being the most significantly elevated and reduced via dosing. Iristectorin B may act as a protective agent against stroke by regulating ferroptosis, and SLC3A2, TFR1 and HMOX1 may serve as potential diagnostic biomarkers for stroke, providing additional evidence to support the importance of ferroptosis in stroke.

Knockdown of A20 attenuates microglial susceptibility to OGD/R-induced ferroptosis and upregulates inflammatory responses

The A20 protein is considered to have a potent anti-inflammatory effect, but its mechanism of action in the regulation of ferroptosis and inflammation after stroke is still unknown. In this study, the A20-knockdown BV2 cell line (sh-A20 BV2) was constructed at first, and the oxygen-glucose deprivation/re-oxygenation (OGD/R) cell model was constructed. Both the BV2 and sh-A20 BV2 cells were treated with the ferroptosis inducer erastin for 48 h, the ferroptosis-related indicators were detected by western blot. The mechanism of ferroptosis was explored by western blot and immunofluorescence. Under OGD/R pressure, the oxidative stress level of sh-A20 BV2 cells was inhibited, but the secretion of the inflammatory factors TNF-α, IL-1β, and IL-6 was significantly upregulated. And sh-A20 BV2 cells had higher expression levels of GPX4 and NLRP3 proteins under OGD/R induction. Western blot further confirmed that sh-A20 BV2 cells inhibited OGD/R-induced ferroptosis. Under the effect of erastin of the ferroptosis inducer (0-1000 nM), sh-A20 BV2 cells had higher cell viability than wild-type BV2 cells and significantly inhibited the accumulation of ROS and the level of oxidative stress damage. It was confirmed that A20 could promote the activation of the IκBα/NFκB/iNOS pathway. It was confirmed by an iNOS inhibitor that iNOS inhibition could reverse the resistance effect of BV2 cells to OGD/R-induced ferroptosis after A20 knockdown. In conclusion, this study demonstrated that inhibition of A20 mediates a stronger inflammatory response while enhancing microglial resistance by knocking down A20 in BV2 cells.

The Role of Potential Oxidative Biomarkers in the Prognosis of Acute Ischemic Stroke and the Exploration of Antioxidants as Possible Preventive and Treatment Options

Ischemic strokes occur when the blood supply to a part of the brain is interrupted or reduced due to arterial blockage, and it often leads to damage to brain cells or death. According to a myriad of experimental studies, oxidative stress is an important pathophysiological mechanism of ischemic stroke. In this narrative review, we aimed to identify how the alterations of oxidative stress biomarkers could suggest a severity-reflecting diagnosis of ischemic stroke and how these interactions may provide new molecular targets for neuroprotective therapies. We performed an eligibility criteria-based search on three main scientific databases. We found that patients with acute ischemic stroke are characterized by increased oxidative stress markers levels, such as the total antioxidant capacity, F2-isoprostanes, hydroxynonenal, total and perchloric acid oxygen radical absorbance capacity (ORACTOT and ORACPCA), malondialdehyde (MDA), myeloperoxidase, and urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine. Thus, acute ischemic stroke is causing significant oxidative stress and associated molecular and cellular damage. The assessment of these molecular markers could be useful in diagnosing ischemic stroke, finding its causes, predicting its severity and outcomes, reducing its impact on the cellular structures of the brain, and guiding preventive treatment towards antioxidant-based therapy as novel therapeutic alternatives.

Salvia miltiorrhiza Alleviates Memory Deficit Induced by Ischemic Brain Injury in a Transient MCAO Mouse Model by Inhibiting Ferroptosis

Salvia miltiorrhiza (SM) has been used in oriental medicine for its neuroprotective effects against cardiovascular diseases and ischemic stroke. In this study, we investigated the therapeutic mechanism underlying the effects of SM on stroke using a transient middle cerebral artery occlusion (tMCAO) mouse model. Our results showed that SM administration significantly attenuated acute brain injury, including brain infarction and neurological deficits, 3 days after tMCAO. This was confirmed by our magnetic resonance imaging (MRI) study, which revealed a reduction in brain infarction with SM administration, as well as our magnetic resonance spectroscopy (MRS) study, which demonstrated the restoration of brain metabolites, including taurine, total creatine, and glutamate. The neuroprotective effects of SM were associated with the reduction in gliosis and upregulation of inflammatory cytokines, such as interleukin-6 (IL-6) and Tumor necrosis factor-α (TNF-α), along with the upregulation of phosphorylated STAT3 in post-ischemic brains. SM also reduced the levels of 4-Hydroxynonenal (4-HNE) and malondialdehyde (MDA), which are markers of lipid peroxidation, induced by oxidative stress upregulation in the penumbra of the tMCAO mouse brain. SM administration attenuated ischemic neuronal injury by inhibiting ferroptosis. Additionally, post-ischemic brain synaptic loss and neuronal loss were alleviated by SM administration, as demonstrated by Western blot and Nissl staining. Moreover, daily administration of SM for 28 days after tMCAO significantly reduced neurological deficits and improved survival rates in tMCAO mice. SM administration also resulted in improvement in post-stroke cognitive impairment, as measured by the novel object recognition and passive avoidance tests in tMCAO mice. Our findings suggest that SM provides neuroprotection against ischemic stroke and has potential as a therapeutic agent.

Enriched Environment Attenuates Ferroptosis after Cerebral Ischemia/Reperfusion Injury via the HIF-1α-ACSL4 Pathway

Enriched environment (EE) has been proven to be an effective intervention strategy which can improve neurofunctional recovery following cerebral ischemia/reperfusion (I/R) injury. However, it still needs further investigation for the underlying mechanisms. Recently, it has been shown that ferroptosis played an essential role in the pathophysiological development of ischemic stroke (IS). This study is aimed at investigating whether EE plays a neuroprotective role by attenuating ferroptosis after cerebral I/R injury. We used middle cerebral artery occlusion/reperfusion (MCAO/R) to build a model of cerebral I/R injury. To evaluate the effect of EE on neurological recovery, we used the modified neurological severity score (mNSS) and the Morris water maze (MWM). We used the western blot to detect the protein levels of glutathione peroxidase 4 (GPX4), hypoxia-inducible factor-1α (HIF-1α), and acyl-CoA synthetase long-chain family member 4 (ACSL4). We used the quantitative real-time PCR (qRT-PCR) to measure the mRNA levels of ACSL4 and inflammatory cytokines including tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6), and interleukin 1 beta (IL-1β). The occurrence of ferroptosis was detected by TdT-mediated dUTP nick-end labeling (TUNEL) assay, diaminobenzidine- (DAB-) enhanced Perls' staining, iron level assays, and malondialdehyde (MDA) level assays. The results verified that EE enhanced functional recovery and attenuated ferroptosis and neuroinflammation after cerebral I/R injury. EE increased the expression of HIF-1α while inhibited the expression of ACSL4. Our research indicated that EE improved functional recovery after cerebral I/R injury through attenuating ferroptosis, and this might be related to its regulation of the neuroinflammation and HIF-1α-ACSL4 pathway.

Mitochondrial permeability transition pore-dependent necrosis

Mitochondrial permeability transition pore (mPTP)-dependent cell death is a form of necrotic cell death that is driven by mitochondrial dysfunction by the opening of the mPTP and is triggered by increases in matrix levels of Ca2+ and reactive oxygen species. This form of cell death has been implicated in ischemic injuries of the heart and brain as well as numerous degenerative diseases in the brain and skeletal muscle. This review focuses on the molecular triggers and regulators of mPTP-dependent necrosis in the context of myocardial ischemia reperfusion injury. Research over the past 50 years has led to the identity of regulators and putative pore-forming components of the mPTP. Finally, downstream consequences of activation of the mPTP as well as ongoing questions and areas of research are discussed. These questions pose a particular interest as targeting the mPTP could potentially represent an efficacious therapeutic strategy to reduce infarct size following an ischemic event.

Evaluation the Therapeutic Effect of Adipose-Derived Mesenchymal Stem Cells on Chronic Mild Stress by Activating PEBP1-GPX4 Axis in Ferroptosis Using qRT-PCR, Fluorescence Microscope and Iron Determination Analysis

About 50% of depressive patients failed to respond to the treatment, mainly because of insufficient knowledge about the pathogenesis of depression. The current study’s objectives were to look into the potential role of ferroptosis in the etiology of depression in the mice model of chronic mild stress (CMS) and investigate the effects of adipose-derived mesenchymal stem cells (ADSCs) on PEBP1-GPX4 axis controlled ferroptosis in mice. We grouped the male C57BL/6 mice randomly as follows: normal control (NC), CMS, and CMS+ADSCs. The second two groups’ animals were exposed to CMS for a total of six weeks. From the fourth week of modeling to the sixth week, cell therapy was given once a week. SPT, TST, FST, and NSFT behavior assessments were used to evaluate the depression-like behavior brought on by CMS. We selected the ferroptosis-related parameters, including the expression of GPX4, FTH1, ACSL4, and COX2. The amount of iron was determined in the hippocampus of the model organism by using the iron assay kit. By measuring the PEBP1 and ERK1/2 levels, as well as evaluating the expression of GFAP and IBA1, we assessed the biological function of astrocytes and microglia in mice hippocampus. It was found that six weeks after modeling in the CMS+ADSCs group, the mice’s depression-like behavior induced by CMS had significantly improved. We found a significantly changed level of genes, including GPX4, ACSL4, FTH1, COX2, ERK1/2, GFAP, PEBP1 and IBA1. Also, we found the differentiated level of total and ferric iron in our model mice. All these findings demonstrated that ADSCs had a therapeutic effect on CMS-induced depression-like behavior, probably by activating the PEBP1-GPX4 axis in ferroptosis. This anti-depression role of ADSCs may be associated with the activation of the PEBP1-GPX4 axis in ferroptosis, implying that regulation of ferroptosis is a crucial therapeutic target for depression.

Exploring the Ferroptosis Mechanism of Zhilong Huoxue Tongyu Capsule for the Treatment of Intracerebral Hemorrhage Based on Network Pharmacology and In Vivo Validation

Objective. The purpose of this study is to explore the mechanism of the Zhilong Huoxue Tongyu (ZL) capsule in the treatment of intracerebral hemorrhage (ICH) via targeting ferroptosis based on network pharmacology. Methods. The active ingredients and related key targets of the ZL capsule were screened using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). The gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were also performed. Finally, identified targets were validated in an in-vivo model of ICH. Results. A total of 30 active ingredients and 33 intersecting targets were identified through a TCMSP database search. Ingredients-Targets-Pathways network was constructed to filter out the key targets according to the degree value. TP53 was selected as the key target. The in-vivo validation studies demonstrated that TP53 was down-regulated and GPX4 was upregulated in rats following ZL capsule treatment. Conclusions. It is concluded that the ZL capsule could alleviate ICH in a muti-target and multi-pathway manner. ZL capsule could alleviate ICH by inhibiting ferroptosis, and TP53 is identified to be the potential target. Further research is needed to clarify the detailed anti-ferroptotic mechanism of the ZL capsule.