Iron toxicity, lipid peroxidation and ferroptosis after intracerebral haemorrhage

Bone morphogenetic protein 4 derived from the cerebrospinal fluid in patients with postherpetic neuralgia induces allodynia via the crosstalk between microglia and astrocyte

INTRODUCTION

During postherpetic neuralgia (PHN), the cerebral spinal fluid (CSF) possesses the capability to trigger glial activation and inflammation, yet the specific changes in its composition remain unclear. Recent findings from our research indicate elevations of central bone morphogenetic protein 4 (BMP4) during neuropathic pain (NP), serving as an independent modulator of glial cells. Herein, the aim of the present study is to test the CSF-BMP4 expressions and its role in the glial modulation in the process of PHN.

METHODS

CSF samples were collected from both PHN patients and non-painful individuals (Control) to assess BMP4 and its antagonist Noggin levels. Besides, intrathecal administration of both CSF types was conducted in normal rats to evaluate the impact on pain behavior, glial activity, and inflammation.; Additionally, both Noggin and STAT3 antagonist-Stattic were employed to treat the PHN-CSF or exogenous BMP4 challenged cultured astrocytes to explore downstream signals. Finally, microglial depletion was performed prior to the PHN-CSF intervention so as to elucidate the microglia-astrocyte crosstalk.

RESULTS

BMP4 levels were significantly higher in PHN-CSF compared to Control-CSF (P < 0.001), with a positive correlation with pain duration (P < 0.05, r = 0.502). Comparing with the Control-CSF producing moderate paw withdrawal threshold (PWT) decline and microglial activation, PHN-CSF further exacerbated allodynia and triggered both microglial and astrocytic activation (P < 0.05). Moreover, PHN-CSF rather than Control-CSF evoked microglial proliferation and pro-inflammatory transformation, reinforced iron storage, and activated astrocytes possibly through both SMAD159 and STAT3 signaling, which were all mitigated by the Noggin application (P < 0.05). Next, both Noggin and Stattic effectively attenuated BMP4-induced GFAP and IL-6 upregulation, as well as SMAD159 and STAT3 phosphorylation in the cultured astrocytes (P < 0.05). Finally, microglial depletion diminished PHN-CSF induced astrogliosis, inflammation and endogenous BMP4 expression (P < 0.05).

CONCLUSION

Our study highlights the role of CSF-BMP4 elevation in glial activation and allodynia during PHN, suggesting a potential therapeutic avenue for future exploration.

The neuroprotective effects of normobaric oxygen therapy after stroke

BACKGROUND

Stroke, including ischemic and hemorrhagic stroke, is a severe and prevalent acute cerebrovascular disease. The development of hypoxia following stroke can trigger a cascade of pathological events, including mitochondrial dysfunction, energy deficiency, oxidative stress, neuroinflammation, and excitotoxicity, all of which are often associated with unfavorable prognosis. Nonetheless, a noninvasive intervention, referred to as normobaric hyperoxia (NBO), is known to have neuroprotective effects against stroke.

RESULTS

NBO can exert neuroprotective effects through various mechanisms, such as the rescue of hypoxic tissues, preservation of the blood-brain barrier, reduction of brain edema, alleviation of neuroinflammation, improvement of mitochondrial function, mitigation of oxidative stress, reduction of excitotoxicity, and inhibition of apoptosis. These mechanisms may help improve the prognosis of stroke patients.

CONCLUSIONS

This review summarizes the mechanism by which hypoxia causes brain injury and how NBO can act as a neuroprotective therapy to treat stroke. We conclude that NBO has significant potential for treating stroke and may represent a novel therapeutic strategy.

Recent advances in potential therapeutic targets of ferroptosis‑associated pathways for the treatment of stroke (Review)

Stroke is a severe neurological disease that is associated with high rates of morbidity and mortality, and the underlying pathological processes are complex. Ferroptosis fulfills a significant role in the progression and treatment of stroke. It is well established that ferroptosis is a type of programmed cell death that is distinct from other forms or types of cell death. The process of ferroptosis involves multiple signaling pathways and regulatory mechanisms that interact with mechanisms inherent to stroke development. Inducers and inhibitors of ferroptosis have been shown to exert a role in the onset of this cell death process. Furthermore, it has been shown that interfering with ferroptosis affects the occurrence of stroke, indicating that targeting ferroptosis may offer a promising therapeutic approach for treating patients of stroke. Hence, the present review aimed to summarize the latest progress that has been made in terms of using therapeutic interventions for ferroptosis as treatment targets in cases of stroke. It provides an overview of the relevant pathways and molecular mechanisms that have been investigated in recent years, highlighting the roles of inducers and inhibitors of ferroptosis in stroke. Additionally, the intervention potential of various types of Traditional Chinese Medicine is also summarized. In conclusion, the present review provides a comprehensive overview of the potential therapeutic targets afforded by ferroptosis‑associated pathways in stroke, offering new insights into how ferroptosis may be exploited in the treatment of stroke.

Egr1 promotes Nlrc4-dependent neuronal pyroptosis through phlda1 in an in-vitro model of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a fatal brain injury, but the current treatments for it are inadequate to reduce the severity of secondary brain injury. Our study aims to explore the molecular mechanism of Egr1 and Phlda1 in regulating hemin-induced neuronal pyroptosis, and hope to provide novel therapeutic targets for ICH treatment. Mouse hippocampal neuron cells treated with hemin were used to simulate an in-vitro ICH model. Using qRT-PCR and western blot to evaluate mRNA and protein concentrations. MTT assay was utilized to assess cell viability. LDH levels were determined by lactate Dehydrogenase Activity Assay Kit. IL-1β and IL-18 levels were examined by ELISA. The interaction of Egr1 and Phlda1 promoter was evaluated using chromatin immunoprecipitation and dual-luciferase reporter assays. Egr1 and Phlda1 were both upregulated in HT22 cells following hemin treatment. Hemin treatment caused a significant reduction in HT22 cell viability, an increase in Nlrc4 and HT22 cell pyroptosis, and heightened inflammation. However, knocking down Egr1 neutralized hemin-induced effects on HT22 cells. Egr1 bound to the promoter of Phlda1 and transcriptionally activated Phlda1. Silencing Phlda1 significantly reduced Nlrc4-dependent neuronal pyroptosis. Conversely, overexpressing Phlda1 mitigated the inhibitory effects of Egr1 knockdown on Nlrc4 and neuronal pyroptosis during ICH. Egr1 enhanced neuronal pyroptosis mediated by Nlrc4 under ICH via transcriptionally activating Phlda1.

The Role of Oxidative Stress in the Progression of Secondary Brain Injury Following Germinal Matrix Hemorrhage

Germinal matrix hemorrhage (GMH) can be a fatal condition responsible for the death of 1.7% of all neonates in the USA. The majority of GMH survivors develop long-term sequalae with debilitating comorbidities. Higher grade GMH is associated with higher mortality rates and higher prevalence of comorbidities. The pathophysiology of GMH can be broken down into two main titles: faulty hemodynamic autoregulation and structural weakness at the level of tissues and cells. Prematurity is the most significant risk factor for GMH, and it predisposes to both major pathophysiological mechanisms of the condition. Secondary brain injury is an important determinant of survival and comorbidities following GMH. Mechanisms of brain injury secondary to GMH include apoptosis, necrosis, neuroinflammation, and oxidative stress. This review will have a special focus on the mechanisms of oxidative stress following GMH, including but not limited to inflammation, mitochondrial reactive oxygen species, glutamate toxicity, and hemoglobin metabolic products. In addition, this review will explore treatment options of GMH, especially targeted therapy.

Botulinum toxin A attenuates osteoarthritis development via inhibiting chondrocyte ferroptosis through SLC7Al1/GPX4 axis

Osteoarthritis (OA) is a prevalent joint degenerative disease, resulting in a significant societal burden. However, there is currently a lack of effective treatment option available. Previous studies have suggested that Botulinum toxin A (BONT/A), a macromolecular protein extracted from Clostridium Botulinum, may improve the pain and joint function in OA patients, but the mechanism remains elusive. This study was to investigate the impact and potential mechanism of BONT/A on OA in vivo and in vitro experiment. LPS increased the levels of ROS, Fe2+and Fe3+, as well as decreased GSH levels, the ratio of GSH / GSSH and mitochondrial membrane potential. It also enhanced the degeneration of extracellular matrix (ECM) and altered the ferroptosis-related protein expression in chondrocytes. BONT/A rescued LPS-induced decrease in collagen type II (Collagen II) expression and increase in matrix metalloproteinase 13 (MMP13), mitigated LPS-induced cytotoxicity in chondrocytes, abolished the accumulation of ROS and iron, upregulated GSH and the ratio of GSH/ GSSH, improved mitochondrial function, and promoted SLC7A11/GPX4 anti-ferroptosis system activation. Additionally, intra-articular injection of BONT/A inhibited the degradation of cartilage in OA model rats. This chondroprotective effect of BONT/A was reversed by erastin (a classical ferroptosis agonist) and enhanced by liproxstatin-1 (a classic ferroptosis inhibitor). Our research confirms that BONT/A alleviates the OA development by inhibiting the ferroptosis of chondrocytes, which revealed to be a potential therapeutic mechanism for BONT/A treating the OA.

Salvianolic acid A inhibits ferroptosis and protects against intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a common cerebral vascular disease with high incidence, disability, and mortality. Ferroptosis is a regulated type of iron-dependent, non-apoptotic programmed cell death. There is increasing evidence that ferroptosis may lead to neuronal damage mediated by hemorrhagic stroke mediated neuronal damage. Salvianolic acid A (SAA) is a natural bioactive polyphenol compound extracted from salvia miltiorrhiza, which has anti-inflammatory, antioxidant, and antifibrosis activities. SAA is reported to be an iron chelator that inhibits lipid peroxidation and provides neuroprotective effects. However, whether SAA improves neuronal ferroptosis mediated by hemorrhagic stroke remains unclear. The study aims to evaluate the therapeutic effect of SAA on Ferroptosis mediated by Intracerebral hemorrhage and explore its potential mechanisms. We constructed in vivo and in vitro models of intracerebral hemorrhage in rats. Multiple methods were used to analyze the inhibitory effect of SAA on ferroptosis in both in vivo and in vitro models of intracerebral hemorrhage in rats. Then, network pharmacology is used to identify potential targets and mechanisms for SAA treatment of ICH. The SAA target ICH network combines SAA and ICH targets with protein-protein interactions (PPIs). Find the specific mechanism of SAA acting on ferroptosis through molecular docking and functional enrichment analysis. In rats, SAA (10 mg/kg in vivo and 50 μM in vitro, p < 0.05) alleviated dyskinesia and brain injury in the ICH model by inhibiting ferroptosis (p < 0.05). The molecular docking results and functional enrichment analyses suggested that AKT (V-akt murine thymoma viral oncogene homolog) could mediate the effect of SAA. NRF2 (Nuclear factor erythroid 2-related factor 2) was a potential target of SAA. Our further experiments showed that salvianolic acid A enhanced the Akt /GSK-3β/Nrf2 signaling pathway activation in vivo and in vitro. At the same time, SAA significantly expanded the expression of GPX4, XCT proteins, and the nuclear expression of Nrf2, while the AKT inhibitor SH-6 and the Nrf2 inhibitor ML385 could reduce them to some extent. Therefore, SAA effectively ameliorated ICH-mediated neuronal ferroptosis. Meanwhile, one of the critical mechanisms of SAA inhibiting ferroptosis was activating the Akt/GSK-3β/Nrf2 signaling pathway.

Ferroptosis: a potential therapeutic target for stroke

Ferroptosis is a form of regulated cell death characterized by massive iron accumulation and iron-dependent lipid peroxidation, differing from apoptosis, necroptosis, and autophagy in several aspects. Ferroptosis is regarded as a critical mechanism of a series of pathophysiological reactions after stroke because of iron overload caused by hemoglobin degradation and iron metabolism imbalance. In this review, we discuss ferroptosis-related metabolisms, important molecules directly or indirectly targeting iron metabolism and lipid peroxidation, and transcriptional regulation of ferroptosis, revealing the role of ferroptosis in the progression of stroke. We present updated progress in the intervention of ferroptosis as therapeutic strategies for stroke in vivo and in vitro and summarize the effects of ferroptosis inhibitors on stroke. Our review facilitates further understanding of ferroptosis pathogenesis in stroke, proposes new targets for the treatment of stroke, and suggests that more efforts should be made to investigate the mechanism of ferroptosis in stroke.

Iron/ROS/Itga3 mediated accelerated depletion of hippocampal neural stem cell pool contributes to cognitive impairment after hemorrhagic stroke

Hemorrhagic stroke, specifically intracerebral hemorrhage (ICH), has been implicated in the development of persistent cognitive impairment, significantly compromising the quality of life for affected individuals. Nevertheless, the precise underlying mechanism remains elusive. Here, we report for the first time that the accumulation of iron within the hippocampus, distal to the site of ICH in the striatum, is causally linked to the observed cognitive impairment with both clinical patient data and animal model. Both susceptibility-weighted imaging (SWI) and quantitative susceptibility mapping (QSM) demonstrated significant iron accumulation in the hippocampus of ICH patients, which is far from the actual hematoma. Logistical regression analysis and multiple linear regression analysis identified iron level as an independent risk factor with a negative correlation with post-ICH cognitive impairment. Using a mouse model of ICH, we demonstrated that iron accumulation triggers an excessive activation of neural stem cells (NSCs). This overactivation subsequently leads to the depletion of the NSC pool, diminished neurogenesis, and the onset of progressive cognitive dysfunction. Mechanistically, iron accumulation elevated the levels of reactive oxygen species (ROS), which downregulated the expression of Itga3. Notably, pharmacological chelation of iron accumulation or scavenger of aberrant ROS levels, as well as conditionally overexpressed Itga3 in NSCs, remarkably attenuated the exhaustion of NSC pool, abnormal neurogenesis and cognitive decline in the mouse model of ICH. Together, these results provide molecular insights into ICH-induced cognitive impairment, shedding light on the value of maintaining NSC pool in preventing cognitive dysfunction in patients with hemorrhagic stroke or related conditions.

Circ_005077 accelerates myocardial lipotoxicity induced by high-fat diet via CyPA/p47PHOX mediated ferroptosis

The long-term high-fat diet (HFD) can cause myocardial lipotoxicity, which is characterized pathologically by myocardial hypertrophy, fibrosis, and remodeling and clinically by cardiac dysfunction and heart failure in patients with obesity and diabetes. Circular RNAs (circRNAs), a novel class of noncoding RNA characterized by a ring formation through covalent bonds, play a critical role in various cardiovascular diseases. However, few studies have been conducted to investigate the role and mechanism of circRNA in myocardial lipotoxicity. Here, we found that circ_005077, formed by exon 2-4 of Crmp1, was significantly upregulated in the myocardium of an HFD-fed rat. Furthermore, we identified circ_005077 as a novel ferroptosis-related regulator that plays a role in palmitic acid (PA) and HFD-induced myocardial lipotoxicity in vitro and in vivo. Mechanically, circ_005077 interacted with Cyclophilin A (CyPA) and inhibited its degradation via the ubiquitination proteasome system (UBS), thus promoting the interaction between CyPA and p47phox to enhance the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase responsible for ROS generation, subsequently inducing ferroptosis. Therefore, our results provide new insights into the mechanisms of myocardial lipotoxicity, potentially leading to the identification of a novel therapeutic target for the treatment of myocardial lipotoxicity in the future.

DMT1 ubiquitination by Nedd4 protects against ferroptosis after intracerebral hemorrhage

OBJECTIVE

Neuronal precursor cells expressed developmentally down-regulated 4 (Nedd4) are believed to play a critical role in promoting the degradation of substrate proteins and are involved in numerous biological processes. However, the role of Nedd4 in intracerebral hemorrhage (ICH) remains unknown. This study aims to investigate the regulatory role of Nedd4 in the ICH model.

METHODS

Male C57BL/6J mice were induced with ICH. Subsequently, the levels of glutathione peroxidase 4 (GPX4), malondialdehyde (MDA) concentration, iron content, mitochondrial morphology, as well as the expression of divalent metal transporter 1 (DMT1) and Nedd4 were assessed after ICH. Furthermore, the impact of Nedd4 overexpression was evaluated through analyses of hematoma area, ferroptosis, and neurobehavioral function. The mechanism underlying Nedd4-mediated degradation of DMT1 was elecidated using immunoprecipitation (IP) after ICH.

RESULTS

Upon ICH, the level of DMT1 in the brain increased, but decreased when Nedd4 was overexpressed using Lentivirus, suggesting a negative correlation between Nedd4 and DMT1. Additionally, the degradation of DMT1 was inhibited after ICH. Furthermore, it was found that Nedd4 can interact with and ubiquitinate DMT1 at lysine residues 6, 69, and 277, facilitating the degradation of DMT1. Functional analysis indicated that overexpression of Nedd4 can alleviate ferroptosis and promote recovery following ICH.

CONCLUSION

The results demonstrated that ferroptosis occurs via the Nedd4/DMT1 pathway during ICH, suggesting it potential as a valuable target to inhibit ferroptosis for the treatment of ICH.

Targeting cell death pathways in intestinal ischemia-reperfusion injury: a comprehensive review

Intestinal ischemia-reperfusion (I/R) is a multifaceted pathological process, and there is a lack of clear treatment for intestinal I/R injury. During intestinal I/R, oxidative stress and inflammation triggered by cells can trigger a variety of cell death mechanisms, including apoptosis, autophagy, pyroptosis, ferroptosis, and necrosis. These cell death processes can send a danger signal for the body to be damaged and prevent intestinal I/R injury. Therefore, identifying key regulatory molecules or markers of these cell death mechanisms when intestinal I/R injury occurs may provide valuable information for the treatment of intestinal I/R injury. This paper reviews the regulatory molecules and potential markers that may be involved in regulating cell death during intestinal I/R and elaborates on the cell death mechanism of intestinal I/R injury at the molecular level to provide a theoretical basis for discovering new molecules or markers regulating cell death during intestinal I/R injury and provides ideas for drug development for the treatment of intestinal I/R injury.

Role of dendritic cells in spinal cord injury

BACKGROUND

Inflammation can worsen spinal cord injury (SCI), with dendritic cells (DCs) playing a crucial role in the inflammatory response. They mediate T lymphocyte differentiation, activate microglia, and release cytokines like NT-3. Moreover, DCs can promote neural stem cell survival and guide them toward neuron differentiation, positively impacting SCI outcomes.

OBJECTIVE

This review aims to summarize the role of DCs in SCI-related inflammation and identify potential therapeutic targets for treating SCI.

METHODS

Literature in PubMed and Web of Science was reviewed using critical terms related to DCs and SCI.

RESULTS

The study indicates that DCs can activate microglia and astrocytes, promote T-cell differentiation, increase neurotrophin release at the injury site, and subsequently reduce secondary brain injury and enhance functional recovery in the spinal cord.

CONCLUSIONS

This review highlights the repair mechanisms of DCs and their potential therapeutic potential for SCI.

Soluble epoxide hydrolase inhibitor (TPPU) alleviates ferroptosis by regulating CCL5 after intracerebral hemorrhage in mice

Soluble epoxide hydrolase (sEH) inhibition has been shown multiple beneficial effects against brain injuries of Intracerebral hemorrhage (ICH). However, the underlying mechanism of its neuroprotective effects after ICH has not been explained fully. Ferroptosis, a new form of iron-dependent programmed cell death, has been shown to be implicated in the secondary injuries after ICH. In this study, We examined whether sEH inhibition can alleviate brain injuries of ICH through inhibiting ferroptosis. Expression of several markers for ferroptosis was observed in the peri-hematomal brain tissues in mice after ICH. lip-1, a ferroptosis inhibitor, alleviated iron accumulation, lipid peroxidation and the secondary damages post-ICH in mice model. Intraperitoneal injection of 1-Trifluoromethoxyphenyl-3- (1-propionylpiperidin-4-yl)urea (TPPU), a highly selective sEH inhibitor, could inhibit ferroptosis and alleviate brain damages in ICH mice. Furthermore, RNA-sequencing was applied to explore the potential regulatory mechanism underlying the effects of TPPU in ferroptosis after ICH. C-C chemokine ligand 5 (CCL5) may be the key factor by which TPPU regulated ferroptosis after ICH since CCL5 antagonist could mimic the effects of TPPU and CCL5 reversed the inhibitive effect of TPPU on ferroptosis and the neuroprotective effects of TPPU on secondary damage after ICH. Taken together, these data indicate that ferroptosis is a key pathological feature of ICH and Soluble epoxide hydrolase inhibitor can exert neuroprotective effect by preventing ferroptosis after ICH.

Spotlight on iron overload and ferroptosis: Research progress in female infertility

Iron is an essential trace element for organisms. However, iron overload, which is common in haematological disorders (e.g. haemochromatosis, myelodysplastic syndromes, aplastic anaemia, and thalassaemia, blood transfusion-dependent or not), can promote reactive oxygen species generation and induce ferroptosis, a novel form of programmed cell death characterised by excess iron and lipid peroxidation, thus causing cell and tissue damage. Infertility is a global health concern. Recent evidence has indicated the emerging role of iron overload and ferroptosis in female infertility by inducing hypogonadism, causing ovary dysfunction, impairing preimplantation embryos, attenuating endometrial receptivity, and crosstalk between subfertility-related disorders, such as polycystic ovary syndrome and endometriosis. In addition, gut microbiota and their metabolites are involved in iron metabolism, ferroptosis, and female infertility. In this review, we systematically elaborate on the current research progress in female infertility with a novel focus on iron overload and ferroptosis and summarise promising therapies targeting iron overload and ferroptosis to recover fertility in women. In summary, our study provides new insights into female infertility and offers literature references for the clinical management of female infertility associated with iron overload and ferroptosis, which may be beneficial for females with haematopoietic disorders suffering from both iron overload and infertility.

ERBB1 alleviates secondary brain injury induced by experimental intracerebral hemorrhage in rats by modulating neuronal death via PLC-γ/PKC pathway

AIMS

Intracerebral hemorrhage (ICH) is a disease with high rates of disability and mortality. The role of epidermal growth factor receptor 1 (ERBB1) in ICH was elucidated in this study.

METHODS

ICH model was constructed by injecting autologous arterial blood into the right basal ganglia. The protein level of ERBB1 was detected by western blot analysis. To up- and downregulation of ERBB1 in rats, intraventricular injection of a lentivirus overexpression vector of ERBB1 and AG1478 (a specific inhibitor of ERBB1) was used. The cell apoptosis, neuronal loss, and pro-inflammatory cytokines were assessed by TUNEL, Nissl staining, and ELISA. Meanwhile, behavioral cognitive impairment of ICH rats was evaluated after ERBB1-targeted interventions.

RESULTS

ERBB1 increased significantly in brain tissue of ICH rats. Overexpression of ERBB1 remarkably reduced cell apoptosis and neuronal loss induced by ICH, as well as pro-inflammatory cytokines and oxidative stress. Meanwhile, the behavioral and cognitive impairment of ICH rats were alleviated after upregulation of ERBB1; however, the secondary brain injury (SBI) was aggravated by AG1478 treatment. Furthermore, the upregulation of PLC-γ and PKC in ICH rats was reversed by AG1478 treatment.

CONCLUSIONS

ERBB1 can improve SBI and has a neuroprotective effect in experimental ICH rats via PLC-γ/PKC pathway.

MiRNAs as potential therapeutic targets and biomarkers for non-traumatic intracerebral hemorrhage

Non-traumatic intracerebral hemorrhage (ICH) is the most common type of hemorrhagic stroke, most often occurring between the ages of 45 and 60. Hypertension is most often the cause of ICH. Less often, atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication, vitamin deficiencies, and other reasons cause hemorrhages. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. This very dangerous disease is difficult to treat, requires surgery and can lead to disability or death. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that are involved in a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., through gene repression. A growing number of studies have demonstrated miRNAs deregulation in various cardiovascular diseases, including ICH. In addition, given that computed tomography (CT) and/or magnetic resonance imaging (MRI) are either not available or do not show clear signs of possible vessel rupture, accurate and reliable analysis of circulating miRNAs in biological fluids can help in early diagnosis for prevention of ICH and prognosis patient outcome after hemorrhage. In this review, we highlight the up-to-date findings on the deregulated miRNAs in ICH, and the potential use of miRNAs in clinical settings, such as therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

The interplay of miRNAs and ferroptosis in diseases related to iron overload

Ferroptosis has been conceptualized as a novel cell death modality distinct from apoptosis, necroptosis, pyroptosis and autophagic cell death. The sensitivity of cellular ferroptosis is regulated at multiple layers, including polyunsaturated fatty acid metabolism, glutathione-GPX4 axis, iron homeostasis, mitochondria and other parallel pathways. In addition, microRNAs (miRNAs) have been implicated in modulating ferroptosis susceptibility through targeting different players involved in the execution or avoidance of ferroptosis. A growing body of evidence pinpoints the deregulation of miRNA-regulated ferroptosis as a critical factor in the development and progression of various pathophysiological conditions related to iron overload. The revelation of mechanisms of miRNA-dependent ferroptosis provides novel insights into the etiology of diseases and offers opportunities for therapeutic intervention. In this review, we discuss the interplay of emerging miRNA regulators and ferroptosis players under different pathological conditions, such as cancers, ischemia/reperfusion, neurodegenerative diseases, acute kidney injury and cardiomyopathy. We emphasize on the relevance of miRNA-regulated ferroptosis to disease progression and the targetability for therapeutic interventions.

Inhibition of ferroptosis underlies EGCG mediated protection against Parkinson's disease in a Drosophila model

Ferroptosis, a new type of cell death accompanied by iron accumulation and lipid peroxidation, is implicated in the pathology of Parkinson's disease (PD), which is a prevalent neurodegenerative disorder that primarily occurred in the elderly population. Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea with known neuroprotective effects in PD patients. But whether EGCG-mediated neuroprotection against PD involves regulation of ferroptosis has not been elucidated. In this study, we established a PD model using PINK1 mutant Drosophila. Iron accumulation, lipid peroxidation and decreased activity of GPX, were detected in the brains of PD flies. Additionally, phenotypes of PD, including behavioral defects and dopaminergic neurons loss, were ameliorated by ferroptosis inhibitor ferrostatin-1 (Fer-1). Notably, the increased iron level, lipid peroxidation and decreased GPX activity in the brains of PD flies were relieved by EGCG. We found that EGCG exerted neuroprotection mainly by restoring iron homeostasis in the PD flies. EGCG inhibited iron influx by suppressing Malvolio (Mvl) expression and simultaneously promoted the upregulation of ferritin, the intracellular iron storage protein, leading to a reduction in free iron ions. Additionally, EGCG downregulated the expression of Duox and Nox, two NADPH oxidases that produce reactive oxygen species (ROS) and increased SOD enzyme activity. Finally, modulation of intracellular iron levels or regulation of oxidative stress by genetic means exerted great influence on PD phenotypes. As such, the results demonstrated that ferroptosis has a role in the established PD model. Altogether, EGCG has therapeutic potentials for treating PD by targeting the ferroptosis pathway, providing new strategies for the prevention and treatment of PD and other neurodegenerative diseases.

Ferroptosis: Mechanisms and role in diabetes mellitus and its complications

Diabetes mellitus (DM) and its complications are major diseases that affect human health and pose a serious threat to global public health. Although the prevention and treatment of DM and its complications are constantly being revised, optimal treatment strategies remain unavailable. Further exploration of new anti-diabetic strategies is an arduous task. Revealing the pathological changes and molecular mechanisms of DM and its complications is the cornerstone for exploring new therapeutic strategies. Ferroptosis is a type of newly discovered iron-dependent regulated cell death. Notably, the role of ferroptosis in the occurrence, development, and pathogenesis of DM and its complications has gradually been revealed. Numerous studies have shown that ferroptosis plays an important role in the pathophysiology and pathogenesis of DM and its associated complications. The aim of this review is to discuss the known underlying mechanisms of ferroptosis, the relationship between ferroptosis and DM, and the relationship between ferroptosis as a mode of cell death and diabetic kidney disease, diabetic retinopathy, diabetic cardiomyopathy, diabetic osteoporosis, diabetes-associated cognitive dysfunction, DM-induced erectile dysfunction, and diabetic atherosclerosis.

Febuxostat attenuates secondary brain injury caused by cerebral hemorrhage through inhibiting inflammatory pathways

Objectives

Neuroinflammation is considered an important step in the progression of secondary brain injury (SBI) induced by cerebral hemorrhage (ICH). The nucleotide-binding and oligomerization structural domain-like receptor family of pyridine structural domain-containing 3 (NLRP3) inflammasomes play an important role in the immune pathophysiology of SBI. Febuxostat (Feb) is a xanthine oxidase inhibitor that is approved for the treatment of gout and has been found to have potent anti-inflammatory effects. However, it has been less studied after ICH and we aimed to explore its protective role in ICH.

Materials and Methods

We established an autologous blood-brain hemorrhage model in C57BL/6 mice. Functions of co-expressed genes were analyzed by trend analysis and bioinformatics analysis. Enzyme-linked immunosorbent assay were used to assess the inflammatory factor levels. Fluoro-Jade B histochemistry and TUNEL staining were used to detect neuronal apoptosis. Immunofluorescence staining and western blotting were used to detect the expression of NLRP3 inflammasomes.

Results

Pretreatment with Feb reduced neuronal cell death and degeneration and alleviated neurobehavioral disorders in vivo. Feb was found to modulate inflammation-related pathways by trend analysis and bioinformatics analysis. In addition, Feb inhibited microglia activation and elevated cytokine levels after ICH. Furthermore, double immunofluorescence staining showed that co-localization of NLRP3 with Iba1 positive cells was reduced after treatment with Feb. Finally, we found that Feb inhibited the activation of the NLRP3/ASC/caspase-1 pathway after ICH.

Conclusion

By inhibiting the NLRP3 inflammasome, preconditioning Feb attenuates inflammatory injury after ICH. Our findings may provide new insights into the role of Feb in neuroprotection.

Environmental Enrichment for Stroke and Traumatic Brain Injury: Mechanisms and Translational Implications

Acquired brain injuries, such as ischemic stroke, intracerebral hemorrhage (ICH), and traumatic brain injury (TBI), can cause severe neurologic damage and even death. Unfortunately, currently, there are no effective and safe treatments to reduce the high disability and mortality rates associated with these brain injuries. However, environmental enrichment (EE) is an emerging approach to treating and rehabilitating acquired brain injuries by promoting motor, sensory, and social stimulation. Multiple preclinical studies have shown that EE benefits functional recovery, including improved motor and cognitive function and psychological benefits mediated by complex protective signaling pathways. This article provides an overview of the enriched environment protocols used in animal models of ischemic stroke, ICH, and TBI, as well as relevant clinical studies, with a particular focus on ischemic stroke. Additionally, we explored studies of animals with stroke and TBI exposed to EE alone or in combination with multiple drugs and other rehabilitation modalities. Finally, we discuss the potential clinical applications of EE in future brain rehabilitation therapy and the molecular and cellular changes caused by EE in rodents with stroke or TBI. This article aims to advance preclinical and clinical research on EE rehabilitation therapy for acquired brain injury. © 2024 American Physiological Society. Compr Physiol 14:5291-5323, 2024.

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.

Targeting epigenetic and posttranslational modifications regulating ferroptosis for the treatment of diseases

Ferroptosis, a unique modality of cell death with mechanistic and morphological differences from other cell death modes, plays a pivotal role in regulating tumorigenesis and offers a new opportunity for modulating anticancer drug resistance. Aberrant epigenetic modifications and posttranslational modifications (PTMs) promote anticancer drug resistance, cancer progression, and metastasis. Accumulating studies indicate that epigenetic modifications can transcriptionally and translationally determine cancer cell vulnerability to ferroptosis and that ferroptosis functions as a driver in nervous system diseases (NSDs), cardiovascular diseases (CVDs), liver diseases, lung diseases, and kidney diseases. In this review, we first summarize the core molecular mechanisms of ferroptosis. Then, the roles of epigenetic processes, including histone PTMs, DNA methylation, and noncoding RNA regulation and PTMs, such as phosphorylation, ubiquitination, SUMOylation, acetylation, methylation, and ADP-ribosylation, are concisely discussed. The roles of epigenetic modifications and PTMs in ferroptosis regulation in the genesis of diseases, including cancers, NSD, CVDs, liver diseases, lung diseases, and kidney diseases, as well as the application of epigenetic and PTM modulators in the therapy of these diseases, are then discussed in detail. Elucidating the mechanisms of ferroptosis regulation mediated by epigenetic modifications and PTMs in cancer and other diseases will facilitate the development of promising combination therapeutic regimens containing epigenetic or PTM-targeting agents and ferroptosis inducers that can be used to overcome chemotherapeutic resistance in cancer and could be used to prevent other diseases. In addition, these mechanisms highlight potential therapeutic approaches to overcome chemoresistance in cancer or halt the genesis of other diseases.

Multifunctional Carbon Quantum Dots: Iron Clearance and Antioxidation for Neuroprotection in Intracerebral Hemorrhage Mice

Iron overload and oxidative stress are pivotal in the pathogenesis of brain injury secondary to intracerebral hemorrhage (ICH). There is a compelling need for agents that can chelate iron and scavenge free radicals, particularly those that demonstrate substantial brain penetration, to mitigate ICH-related damage. In this study, we have engineered an amine-functionalized aspirin-derived carbon quantum dot (NACQD) with a nominal diameter of 6-13 nm. The NACQD possesses robust iron-binding and antioxidative capacities. Through intrathecal administration, NACQD therapy substantially reduced iron deposition and oxidative stress in brain tissue, alleviated meningeal inflammatory responses, and improved the recovery of neurological function in a murine ICH model. As a proof of concept, the intrathecal injection of NACQD is a promising therapeutic strategy to ameliorate the ICH injury.

Emerging roles and therapeutic potentials of ferroptosis: from the perspective of 11 human body organ systems

Since ferroptosis was first described as an iron-dependent cell death pattern in 2012, there has been increasing interest in ferroptosis research. In view of the immense potential of ferroptosis in treatment efficacy and its rapid development in recent years, it is essential to track and summarize the latest research in this field. However, few writers have been able to draw on any systematic investigation into this field based on human body organ systems. Hence, in this review, we provide a comprehensive description of the latest progress in unveiling the roles and functions, as well as the therapeutic potential of ferroptosis, in treating diseases from the aspects of 11 human body organ systems (including the nervous system, respiratory system, digestive system, urinary system, reproductive system, integumentary system, skeletal system, immune system, cardiovascular system, muscular system, and endocrine system) in the hope of providing references for further understanding the pathogenesis of related diseases and bringing an innovative train of thought for reformative clinical treatment.

To re-examine the intersection of microglial activation and neuroinflammation in neurodegenerative diseases from the perspective of pyroptosis

Neurodegenerative diseases (NDs), such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and motor neuron disease, are diseases characterized by neuronal damage and dysfunction. NDs are considered to be a multifactorial disease with diverse etiologies (immune, inflammatory, aging, genetic, etc.) and complex pathophysiological processes. Previous studies have found that neuroinflammation and typical microglial activation are important mechanisms of NDs, leading to neurological dysfunction and disease progression. Pyroptosis is a new mode involved in this process. As a form of programmed cell death, pyroptosis is characterized by the expansion of cells until the cell membrane bursts, resulting in the release of cell contents that activates a strong inflammatory response that promotes NDs by accelerating neuronal dysfunction and abnormal microglial activation. In this case, abnormally activated microglia release various pro-inflammatory factors, leading to the occurrence of neuroinflammation and exacerbating both microglial and neuronal pyroptosis, thus forming a vicious cycle. The recognition of the association between pyroptosis and microglia activation, as well as neuroinflammation, is of significant importance in understanding the pathogenesis of NDs and providing new targets and strategies for their prevention and treatment.

Prominent elevation of extracellular matrix molecules in intracerebral hemorrhage

Background

Intracerebral hemorrhage (ICH) is the predominant type of hemorrhagic stroke with high mortality and disability. In other neurological conditions, the deposition of extracellular matrix (ECM) molecules is a prominent obstacle for regenerative processes and an enhancer of neuroinflammation. Whether ECM molecules alter in composition after ICH, and which ECM members may inhibit repair, remain largely unknown in hemorrhagic stroke.

Methods

The collagenase-induced ICH mouse model and an autopsied human ICH specimen were investigated for expression of ECM members by immunofluorescence microscopy. Confocal image z-stacks were analyzed with Imaris 3D to assess the association of immune cells and ECM molecules. Sections from a mouse model of multiple sclerosis were used as disease and staining controls. Tissue culture was employed to examine the roles of ECM members on oligodendrocyte precursor cells (OPCs).

Results

Among the lectican chondroitin sulfate proteoglycan (CSPG) members, neurocan but not aggrecan, versican-V1 and versican-V2 was prominently expressed in perihematomal tissue and lesion core compared to the contralateral area in murine ICH. Fibrinogen, fibronectin and heparan sulfate proteoglycan (HSPG) were also elevated after murine ICH while thrombospondin and tenascin-C was not. Confocal microscopy with Imaris 3D rendering co-localized neurocan, fibrinogen, fibronectin and HSPG molecules to Iba1+ microglia/macrophages or GFAP+ astrocytes. Marked differentiation from the multiple sclerosis model was observed, the latter with high versican-V1 and negligible neurocan. In culture, purified neurocan inhibited adhesion and process outgrowth of OPCs, which are early steps in myelination in vivo. The prominent expression of neurocan in murine ICH was corroborated in human ICH sections.

Conclusion

ICH caused distinct alterations in ECM molecules. Among CSPG members, neurocan was selectively upregulated in both murine and human ICH. In tissue culture, neurocan impeded the properties of oligodendrocyte lineage cells. Alterations to the ECM in ICH may adversely affect reparative outcomes after stroke.

Molecular Mechanisms of Ferroptosis and Their Involvement in Acute Kidney Injury

Ferroptosis is a novel way of regulating cell death, which occurs in a process that is closely linked to intracellular iron metabolism, lipid metabolism, amino acid metabolism, and multiple signaling pathways. The latest research shows that ferroptosis plays a key role in the pathogenesis of acute kidney injury (AKI). Ferroptosis may be an important target for treating AKI caused by various reasons, such as ischemia-reperfusion injury, rhabdomyolysis syndrome, sepsis, and nephrotoxic drugs. This paper provides a review on the regulatory mechanisms of ferroptosis and its role in AKI, which may help to provide new research ideas for the treatment of AKI and future research.

Involvement of histone methylation in the regulation of neuronal death

Neuronal death occurs in various physiological and pathological processes, and apoptosis, necrosis, and ferroptosis are three major forms of neuronal death. Neuronal apoptosis, necrosis, and ferroptosis are widely identified to involve the progress of stroke, Parkinson's disease, and Alzheimer's disease. A growing body of evidence has pointed out that neuronal death is tightly associated with expression of related genes and alteration of signaling molecules. In addition, recently, epigenetics has been increasingly focused on as a vital regulatory mechanism for neuronal apoptosis, necrosis, and ferroptosis, providing a new direction for treating nervous system diseases. Moreover, growing researches suggest that histone methylation or demethylation is involved in the processes of neuronal apoptosis, necrosis, and ferroptosis. These researches may imply that studying the potential roles of histone methylation is essential for treating the nervous system diseases. Here, we review potential roles of histone methylation and demethylation in neuronal death, which may give us a new direction in treating the nervous system diseases.

Common Mutation in the HFE Gene Modifies Recovery After Intracerebral Hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) is characterized by bleeding into the brain parenchyma. During an ICH, iron released from the breakdown of hemoglobin creates a cytotoxic environment in the brain through increased oxidative stress. Interestingly, the loss of iron homeostasis is associated with the pathological process of other neurological diseases. However, we have previously shown that the H63D mutation in the homeostatic iron regulatory (HFE) gene, prevalent in 28% of the White population in the United States, acts as a disease modifier by limiting oxidative stress. The following study aims to examine the effects of the murine homolog, H67D HFE, on ICH.

METHODS

An autologous blood infusion model was utilized to create an ICH in the right striatum of H67D and wild-type mice. The motor recovery of each animal was assessed by rotarod. Neurodegeneration was measured using fluorojade-B and mitochondrial damage was assessed by immunofluorescent numbers of CytC+ (cytochrome C) neurons and CytC+ astrocytes. Finally, the molecular antioxidant response to ICH was quantified by measuring Nrf2 (nuclear factor-erythroid 2 related factor), GPX4 (glutathione peroxidase 4), and FTH1 (H-ferritin) levels in the ICH-affected and nonaffected hemispheres via immunoblotting.

RESULTS

At 3 days post-ICH, H67D mice demonstrated enhanced performance on rotarod compared with wild-type animals despite no differences in lesion size. Additionally, H67D mice displayed higher levels of Nrf2, GPX4, and FTH1 in the ICH-affected hemisphere; however, these levels were not different in the contralateral, non-ICH-affected hemisphere. Furthermore, H67D mice showed decreased degenerated neurons, CytC+ Neurons, and CytC+ astrocytes in the perihematomal area.

CONCLUSIONS

Our data suggest that the H67D mutation induces a robust antioxidant response 3 days following ICH through Nrf2, GPX4, and FTH1 activation. This activation could explain the decrease in degenerated neurons, CytC+ neurons, and CytC+ astrocytes in the perihematomal region, leading to the improved motor recovery. Based on this study, further investigation into the mechanisms of this neuroprotective response and the effects of the H63D HFE mutation in a population of patients with ICH is warranted.

Targeting the ferroptosis crosstalk: novel alternative strategies for the treatment of major depressive disorder

Depression is a major contributor to poor global health and disability, with a recently increasing incidence. Although drug therapy is commonly used to treat depression, conventional antidepressant drugs have several disadvantages, including slow onset, low response rates and severe adverse effects. Therefore, developing effective therapies for depression remains challenging. Although various aetiological theories of depression exist, the underlying mechanisms of depression are complex, and further research is crucial. Moreover, oxidative stress (OS)-induced lipid peroxidation has been demonstrated to trigger ferroptosis. Both OS and ferroptosis are pivotal mechanisms implicated in the pathogenesis of neurological disorders, and investigation of the mediators involved in these processes has emerged as a prominent and active research direction. One previous study revealed that regulatory proteins involved in ferroptosis are implicated in the pathogenesis of depression, and antidepressant drugs could reverse depressive symptoms by inhibiting ferroptosis in vivo, suggesting an important role of ferroptosis in the pathogenesis of depression. Hence, our current comprehensive review offers an up-to-date perspective on the intricate mechanisms involved, specifically concerning ferroptosis and OS in the context of depression, along with promising prospects for using molecular mediators to target ferroptosis. We delineate the key targets of molecular mediators involved in OS and ferroptosis implicated in depression, most notably reactive oxygen species and iron overload. Considering the pivotal role of OS-induced ferroptosis in the pathogenesis of neurological disorders, delving deeper into the underlying subsequent mechanisms will contribute significantly to the identification of novel therapeutic targets for depression.

Role of mass effect on neuronal iron deposition after intracerebral hemorrhage

Mass effect after intracerebral hemorrhage (ICH) not only mechanically induces the brain damage, but also influences the progress of secondary brain damage. However, the influence of mass effect on the iron overload after ICH is still unclear. Here, a fixed volume of ferrous chloride solution and different volumes of poly(N-isopropylacrylamide) (PNIPAM) hydrogel were co-injected into the right basal ganglia of rats to establish the ICH model with certain degree of iron deposition but different degrees of mass effect. We found that mass effect significantly increased the iron deposition on neuronal cells at 6 h after ICH in a volume-dependent manner. Furthermore, the upregulation of Piezo-2, divalent metal transporter 1 (DMT1), transferrin receptor (TfR), and ferroptosis expressions were noted as the increase of mass effect. In addition, the pERK1/2 inhibitor PD98059 treated ICH rats reversed the upregulation of iron uptake protein and ferroptosis. Our findings revealed the relationship between mass effect and the iron uptake and ferroptosis, which are benefit to understand the brain damage process after ICH.

Multiple sevoflurane exposures during mid-trimester induce neurotoxicity in the developing brain initiated by 15LO2-Mediated ferroptosis

AIMS

Mid-gestational sevoflurane exposure may induce notable long-term neurocognitive impairment in offspring. This study was designed to investigate the role and potential mechanism of ferroptosis in developmental neurotoxicity induced by sevoflurane in the second trimester.

METHODS

Pregnant rats on day 13 of gestation (G13) were treated with or without 3.0% sevoflurane, Ferrostatin-1 (Fer-1), PD146176, or Ku55933 on three consecutive days. Mitochondrial morphology, ferroptosis-relative proteins, malondialdehyde (MDA) levels, total iron content, and glutathione peroxidase 4 (GPX4) activities were measured. Hippocampal neuronal development in offspring was also examined. Subsequently, 15-lipoxygenase 2 (15LO2)-phosphatidylethanolamine binding protein 1 (PEBP1) interaction and expression of Ataxia telangiectasia mutated (ATM) and its downstream proteins were also detected. Furthermore, Morris water maze (MWM) and Nissl's staining were applied to estimate the long-term neurotoxic effects of sevoflurane.

RESULTS

Ferroptosis mitochondria were observed after maternal sevoflurane exposures. Sevoflurane elevated MDA and iron levels while inhibiting GPX4 activity, and resultant long-term learning and memory dysfunction, which were alleviated by Fer-1, PD146176, and Ku55933. Sevoflurane could enhance 15LO2-PEBP1 interaction and activate ATM and its downstream P53/SAT1 pathway, which might be attributed to excessive p-ATM nuclear translocation.

CONCLUSION

This study proposes that 15LO2-mediated ferroptosis might contribute to neurotoxicity induced by maternal sevoflurane anesthesia during the mid-trimester in the offspring and its mechanism may be ascribed to hyperactivation of ATM and enhancement of 15LO2-PEBP1 interaction, indicating a potential therapeutic target for ameliorating sevoflurane-induced neurotoxicity.

Anti-oxidant effects of cannabidiol relevant to intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a subtype of stroke with a high mortality rate. Oxidative stress cascades play an important role in brain injury after ICH. Cannabidiol, a major non-psychotropic phytocannabinoids, has drawn increasing interest in recent years as a potential therapeutic intervention for various neuropsychiatric disorders. Here we provide a comprehensive review of the potential therapeutic effects of cannabidiol in countering oxidative stress resulting from ICH. The review elaborates on the various sources of oxidative stress post-ICH, including mitochondrial dysfunction, excitotoxicity, iron toxicity, inflammation, and also highlights cannabidiol's ability to inhibit ROS/RNS generation from these sources. The article also delves into cannabidiol's role in promoting ROS/RNS scavenging through the Nrf2/ARE pathway, detailing both extranuclear and intranuclear regulatory mechanisms. Overall, the review underscores cannabidiol's promising antioxidant effects in the context of ICH and suggests its potential as a therapeutic option.

Advances of nanotechnology for intracerebral hemorrhage therapy

Intracerebral hemorrhage (ICH), the most devastating subtype of stoke, is of high mortality at 5 years and even those survivors usually would suffer permanent disabilities. Fortunately, various preclinical active drugs have been approached in ICH, meanwhile, the therapeutic effects of these pharmaceutical ingredients could be fully boosted with the assistance of nanotechnology. In this review, besides the pathology of ICH, some ICH therapeutically available active drugs and their employed nanotechnologies, material functions, and therapeutic principles were comprehensively discussed hoping to provide novel and efficient strategies for ICH therapy in the future.

Exosomes from young healthy human plasma promote functional recovery from intracerebral hemorrhage via counteracting ferroptotic injury

Intracerebral hemorrhage (ICH), as a type of life-threatening and highly disabled disease, has limited therapeutic approaches. Here, we show that exosomes derived from young healthy human plasma exhibiting typical exosomes features could facilitate functional recovery of ICH mice. When these exosomes are intraventricularly delivered into the brain after ICH, they mainly distribute around the hematoma and could be internalized by neuronal cells. Strikingly, exosomes administration markedly enhanced the behavioral recovery of ICH mice through reducing brain injury and cell ferroptosis. MiRNA sequencing revealed that microRNA-25-3p (miR-25-3p) was differentially expressed miRNA in the exosomes from young healthy human plasma, compared with exosomes from the old control. Importantly, miR-25-3p mimicked the treatment effect of exosomes on behavioral improvement, and mediated the neuroprotective effect of exosomes against ferroptosis in ICH. Furthermore, luciferase assay and western blotting data illustrated that P53 as assumed the role of a downstream effector of miR-25-3p, thereby regulating SLC7A11/GPX4 pathway to counteract ferroptosis. Taken together, these findings firstly reveal that exosomes from young healthy human plasma improve functional recovery through counteracting ferroptotic injury by regulating P53/SLC7A11/GPX4 axis after ICH. Given the easy availability of plasma exosomes, our study provides a potent therapeutic strategy for ICH patients with quick clinical translation in the near future.

Serum β2-microglobulin is closely associated with 3-month outcome of acute intracerebral hemorrhage: a retrospective cohort study

BACKGROUND

Intracerebral hemorrhage (ICH) is a frequent type of hemorrhagic stroke. Numerous studies have suggested that inflammation plays an important role in the injury and recovery of ICH. β2-microglobulin (β2M) is an inflammatory indicator with an unclear association with ICH development. This study aimed to explore the role of β2M in the outcome of patients with ICH after 3 months of ICH onset.

METHODS

The β2M and other baseline information of 231 patients with ICH were assessed (83 females and 148 males). We followed up with all patients 3 months after ICH onset, and severe disability or a worse outcome was our main focus. We collected the serum β2M levels, National Institutes of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores, and other relevant baseline information of each patient. We used multiple regression analysis to explore the association between β2M levels and follow-up outcomes.

RESULTS

Our results indicated that the β2M level of the good outcome (2.35 ± 0.84 mg/l) group was significantly lower than that of the poor outcome group (3.06 ± 1.71 mg/l) (P < 0.001). Further multiple regression analysis showed that β2M was regarded as a risk factor that was closely associated with the poor outcome 3 months after ICH onset (odds ratio = 2.26, 95% confidence interval = 1.22-4.19, P = 0.009). Further correlation analysis revealed that β2M was significantly correlated with NIHSS scores (r = 0.187, P = 0.004) and follow-up mRS scores (r = 0.25, P < 0.001).

CONCLUSION

β2M was a risk factor for early outcome after ICH onset, and high β2M level was associated with short-time poor prognosis of ICH patients.

Overexpression of FSP1 Ameliorates ferroptosis via PI3K/ AKT /GSK3β pathway in PC12 cells with Oxygen-Glucose Deprivation/Reoxygenation

After ischemia and reperfusion (I/R), nerve cell damage is a pathogenic process that involves numerous molecular processes. In the last ten years, one new classification of programmed cell death is ferroptosis. More recent research has demonstrated that ferroptosis has a role in a variety of neurological disorders, including stroke, cancer, and neurodegenerative illnesses. Ferroptosis suppressor protein 1 (FSP1) plays a significant role in inhibiting ferroptosis. The purpose of this work is to determine how overexpression of FSP1 affects the ferroptosis of PC12 cells under the condition of oxygen-glucose deprivation/reoxygenation (OGD/R). The expression of FSP1 was regulated by lentivirus transfection technology. Western blot and immunofluorescence were used to measure protein levels related to ferroptosis and the PI3K/AKT/GSK3β signal pathway. Determine cell viability using the appropriate kit. Mitochondrial structural morphology was checked by transmission electron microscopy in PC12 cells. Reactive oxygen species (ROS) and Malondialdehyde (MDA) were quantified using the relevant kits. OGD/R induced ferroptosis in PC12 cells, however, FSP1 overexpression reverses ferroptosis and promotes cell viability, lowering ROS and MDA content. The expression of FSP1 decreased in OGD/R0h and OGD/R6h and rebounded in OGD/R24h and OGD/R48h. During the processes of OGD/R-induced ferroptosis, FSP1 overexpression significantly stimulated PI3K/AKT/GSK3β pathway, but LY294002 weakens the protective effect of FSP1 overexpression. Our outcomes demonstrate that overexpression of FSP1 markedly enhances the ability to resist ferroptosis via the PI3K/AKT/GSK3β pathway. The above results may provide a new preliminary lead for the treatment of the cerebral ischemia-reperfusion injury.

Pharmacological Inhibition of Ferroptosis as a Therapeutic Target for Neurodegenerative Diseases and Strokes

Emerging evidence suggests that ferroptosis, a unique regulated cell death modality that is morphologically and mechanistically different from other forms of cell death, plays a vital role in the pathophysiological process of neurodegenerative diseases, and strokes. Accumulating evidence supports ferroptosis as a critical factor of neurodegenerative diseases and strokes, and pharmacological inhibition of ferroptosis as a therapeutic target for these diseases. In this review article, the core mechanisms of ferroptosis are overviewed and the roles of ferroptosis in neurodegenerative diseases and strokes are described. Finally, the emerging findings in treating neurodegenerative diseases and strokes through pharmacological inhibition of ferroptosis are described. This review demonstrates that pharmacological inhibition of ferroptosis by bioactive small-molecule compounds (ferroptosis inhibitors) could be effective for treatments of these diseases, and highlights a potential promising therapeutic avenue that could be used to prevent neurodegenerative diseases and strokes. This review article will shed light on developing novel therapeutic regimens by pharmacological inhibition of ferroptosis to slow down the progression of these diseases in the future.

Autophagy mediates an amplification loop during ferroptosis

Ferroptosis, a programmed cell death, has been identified and associated with cancer and various other diseases. Ferroptosis is defined as a reactive oxygen species (ROS)-dependent cell death related to iron accumulation and lipid peroxidation, which is different from apoptosis, necrosis, autophagy, and other forms of cell death. However, accumulating evidence has revealed a link between autophagy and ferroptosis at the molecular level and has suggested that autophagy is involved in regulating the accumulation of iron-dependent lipid peroxidation and ROS during ferroptosis. Understanding the roles and pathophysiological processes of autophagy during ferroptosis may provide effective strategies for the treatment of ferroptosis-related diseases. In this review, we summarize the current knowledge regarding the regulatory mechanisms underlying ferroptosis, including iron and lipid metabolism, and its association with the autophagy pathway. In addition, we discuss the contribution of autophagy to ferroptosis and elucidate the role of autophagy as a ferroptosis enhancer during ROS-dependent ferroptosis.

Berberine ameliorates iron levels and ferroptosis in the brain of 3 × Tg-AD mice

BACKGROUND

Berberine (BBR) is a natural alkaloid extracted from the herb Coptis chinensis. This compound has the ability to penetrate the blood-brain barrier (BBB) and exhibit neuroprotective value in the treatment of Alzheimer's disease (AD). AD is a neurodegenerative disease characterized by β-amyloid (Aβ) deposition, hyperphosphorylated tau and other characters. Iron accumulation and ferroptosis were also detected in AD brain, which can result in neuronal damage. However, it is still unclear whether BBR can suppress ferroptosis in AD and alleviate its underlying pathology.

PURPOSE

This study investigated whether BBR may affect ferroptosis and related signaling pathways in triple transgenic AD (3 × Tg-AD) mice.

METHODS

Four-month-old 3 × Tg-AD mice received oral administration of BBR at a dose of 50 mg/kg for 7.5 months. Cognitive function and anxiety levels in mice were assessed using the morris water maze test, open field test, and novel object recognition test. Western blot, immunohistochemistry, and ICP-MS were employed to assess the pathology of AD, brain iron metabolism, and ferroptosis signaling pathways. Transmission electron microscopy was used to detect mitochondrial changes. The synergistic effects of BBR combined with Nrf2 were investigated using molecular docking programs and surface plasmon resonance technology. Co-inmunoprecipitation assay was used to examine the effect of BBR on the binding ability of Nrf2 and Keap1.

RESULTS

The results indicated that chronic treatment of BBR mitigated cognitive disorders in 3 × Tg-AD model mice. Reductions in Aβ plaque, hyperphosphorylated tau protein, neuronal loss, and ferroptosis in the brains of 3 × Tg-AD mice suggested that BBR could alleviate brain injury. In addition, BBR treatment attenuated ferroptosis, as evidenced by decreased levels of iron, MDA, and ROS, while enhancing SOD, GSH, GPX4, and SLC7A11. Consistent with the in vivo assay, BBR inhibited RSL3-induced ferroptosis in N2a-sw cells. BBR increased the expression levels of GPX4, FPN1 and SLC7A11 by regulating Nrf2 transcription levels, thereby inhibiting ferroptosis. Molecular docking programs and surface plasmon resonance technology demonstrated the direct combination of BBR with Nrf2. Co-inmunoprecipitation analysis showed that BBR inhibited the interaction between Keap1 and Nrf2.

CONCLUSION

For the first time, these results showed that BBR could inhibit iron levels and ferroptosis in the brains of 3 × Tg-AD model mice and partially protect against RSL3-induced ferroptosis via the activation of Nrf2 signaling.

Ferroptosis: a new strategy for Chinese herbal medicine treatment of diabetic nephropathy

Diabetic nephropathy (DN) is a serious microvascular complication of diabetes. It has become a leading cause of death in patients with diabetes and end-stage renal disease. Ferroptosis is a newly discovered pattern of programmed cell death. Its main manifestation is the excessive accumulation of intracellular iron ion-dependent lipid peroxides. Recent studies have shown that ferroptosis is an important driving factor in the onset and development of DN. Ferroptosis is closely associated with renal intrinsic cell (including renal tubular epithelial cells, podocytes, and mesangial cells) damage in diabetes. Chinese herbal medicine is widely used in the treatment of DN, with a long history and definite curative effect. Accumulating evidence suggests that Chinese herbal medicine can modulate ferroptosis in renal intrinsic cells and show great potential for improving DN. In this review, we outline the key regulators and pathways of ferroptosis in DN and summarize the herbs, mainly monomers and extracts, that target the inhibition of ferroptosis.

The Secretome of Mesenchymal Stromal Cells in Treating Intracerebral Hemorrhage: The First Step to Bedside

Intracerebral hemorrhage is an unmet medical need that often leads to the disability and death of a patient. The lack of effective treatments for intracerebral hemorrhage makes it necessary to look for them. Previously, in our proof-of-concept study (Karagyaur M et al. Pharmaceutics, 2021), we have shown that the secretome of multipotent mesenchymal stromal cells (MSC) provides neuroprotection of the brain in a model of intracerebral hemorrhage in rats. Here, we have conducted a systematic study of the therapeutic potential of the MSC secretome in the model of hemorrhagic stroke and provided answers to the questions that need to be addressed in order to translate the secretome-based drug into clinical practice: routes and multiplicity of administration, optimal dose and door-to-treatment time. We have found that MSC secretome reveals prominent neuroprotective activity when administered intranasally or intravenously within 1-3 h after hemorrhage modeling, even in aged rats, and its multiple injections (even within 48 h) are able to reduce the delayed negative effects of hemorrhagic stroke. To our knowledge, this study provides the first systematic investigation of the therapeutic activity of a biomedical MSC-based cell-free drug in intracerebral hemorrhage and is an integral part of its preclinical studies.

An enriched environment improves long-term functional outcomes in mice after intracerebral hemorrhage by mechanisms that involve the Nrf2/BDNF/glutaminase pathway

Post-stroke depression exacerbates neurologic deficits and quality of life. Depression after ischemic stroke is known to some extent. However, depression after intracerebral hemorrhage (ICH) is relatively unknown. Increasing evidence shows that exposure to an enriched environment (EE) after cerebral ischemia/reperfusion injury has neuroprotective effects in animal models, but its impact after ICH is unknown. In this study, we investigated the effect of EE on long-term functional outcomes in mice subjected to collagenase-induced striatal ICH. Mice were subjected to ICH with the standard environment (SE) or ICH with EE for 6 h/day (8:00 am-2:00 pm). Depressive, anxiety-like behaviors and cognitive tests were evaluated on day 28 with the sucrose preference test, tail suspension test, forced swim test, light-dark transition experiment, morris water maze, and novel object recognition test. Exposure to EE improved neurologic function, attenuated depressive and anxiety-like behaviors, and promoted spatial learning and memory. These changes were associated with increased expression of transcription factor Nrf2 and brain-derived neurotrophic factor (BDNF) and inhibited glutaminase activity in the perihematomal tissue. However, EE did not change the above behavioral outcomes in Nrf2-/- mice on day 28. Furthermore, exposure to EE did not increase BDNF expression compared to exposure to SE in Nrf2-/- mice on day 28 after ICH. These findings indicate that EE improves long-term outcomes in sensorimotor, emotional, and cognitive behavior after ICH and that the underlying mechanism involves the Nrf2/BDNF/glutaminase pathway.

Sodium hydrosulfide inhibits hemin-induced ferroptosis and lipid peroxidation in BV2 cells via the CBS/H2S system

Ferroptosis is a form of iron-dependent programmed cell death discovered in recent years that has been shown to be involved in diverse neurological disorders. Hydrogen sulfide (H₂S) is an important signaling molecule with neuroprotective effects, including antioxidation. However, whether the protective mechanism of H₂S is related to ferroptosis remains unknown. Therefore, in this study, we focused on the protective mechanisms of sodium hydrosulfide (NaHS, a donor of H₂S) against ferroptosis caused by intracerebral hemorrhage (ICH) using a hemin-induced BV2 cell injury model in vitro. Our results indicated that NaHS enhanced cell viability and reduced hemin-induced lactate dehydrogenase (LDH) release. NaHS suppressed ferroptosis after hemin treatment, which was confirmed by attenuated reactive oxygen species (ROS) and lipid peroxidation, maintained iron homeostasis, recovery of the expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7-member 11 (SLC7A11), and increased glutathione (GSH) production. Moreover, we demonstrated that inhibiting ferroptosis improved cell survival and prevented hemin-induced oxidative stress. In addition, NaHS was also able to block ferroptosis inducer RSL3-induced ferroptotic cell death. We also found that NaHS increased cystathionine-β-synthase (CBS) expression and H₂S levels after hemin treatment. Furthermore, NaHS-induced ferroptosis reduction was inhibited by the CBS inhibitor aminooxyacetic acid (AOAA) as well as by CBS small interference RNA (siCBS). In summary, these findings demonstrated that NaHS protects against hemin-induced ferroptosis by reducing lipid peroxidation, inhibiting iron overload, increasing GSH production, and improving GPX4 and SLC7A11 via the CBS/H₂S system. The CBS/H₂S system may be a promising target for preventing ferroptosis after ICH.

Nox4-and Tf/TfR-mediated peroxidation and iron overload exacerbate neuronal ferroptosis after intracerebral hemorrhage: Involvement of EAAT3 dysfunction

Intracerebral hemorrhage (ICH) induces high mortality and disability. Neuronal death is the principal factor to unfavourable prognosis in ICH. However, the mechanisms underlying this association remain unclear. In this study, we investigated the molecular mechanisms by which neuronal ferroptosis occurs after ICH and whether the use of corresponding modulators can inhibit neuronal death and improve early outcomes in a rat ICH model. Our findings indicated that Nox4 and TF/TfR were upregulated in the perihematomal tissues of ICH rats. Oxidative stress and iron overload induced by Nox4 and TF/TfR promoted neuronal ferroptosis post-ICH. In contrast, application of Nox4-siRNA and the deferoxamine (DFO) attenuated peroxidation and iron deposition in the hemorrhagic brain, alleviated neuronal ferroptosis, and improved sensorimotor function in ICH rats. Additionally, our findings indicated that the post-ICH neuronal reduced glutathione (GSH) depletion were not related to dysfunctional glutamine delivery in astrocytes but rather to downregulation of EAAT3 due to lipid peroxidation-induced dysfunction in the neuronal membrane. These findings indicate that ferroptosis is involved in neuronal death in model rats with collagenase-induced ICH. Oxidative stress and iron overload induced by Nox4 and TF/TfR exacerbate ferroptosis after ICH, while Nox4 downregulation and iron chelation exert neuroprotective effects. The present results highlight the cysteine importer EAAT3 as a potential biomarker of ferroptosis and provide insight into the neuronal death process that occurs following ICH, which may aid in the development of translational treatment strategies for ICH.

Mitochondrial Inhibitor Rotenone Triggers and Enhances Neuronal Ferroptosis Following Intracerebral Hemorrhage

Ferroptosis, a form of regulatory non-apoptotic cell death driven by iron-dependent lipid peroxidation, accounts for more than 80% of the total types of neuronal death in the acute phase of intracerebral hemorrhage (ICH). Mitochondria have essential roles in energy production, macromolecule synthesis, cellular metabolism, and cell death regulation. However, its role in ferroptosis remains unclear and somewhat controversial, especially in ICH. This study aimed to investigate whether damaged mitochondria could trigger and enhance neuronal ferroptosis in ICH. The isobaric tag for relative and absolute quantitation proteomics on human ICH samples suggested that ICH caused significant damage to the mitochondria, which presented ferroptosis-like morphology under electron microscopy. Subsequently, use of the mitochondrial special inhibitor Rotenone (Rot) to induce mitochondrial damage showed that it has significant dose-dependent toxicity on primary neurons. Single Rot administration markedly inhibited neuronal viability, promoted iron accumulation, increased malondialdehyde (MDA) contents, decreased total superoxide dismutase (SOD) activity, and downregulated ferroptosis-related proteins RPL8, COX-2, xCT, ASCL4, and GPX4 in primary neurons. Moreover, Rot enhanced these changes via hemin and autologous blood administration in primary neurons and mice, mimicking the in vitro and in vivo ICH models, respectively. Furthermore, Rot exacerbated the ICH-induced hemorrhagic volumes, brain edema, and neurological deficits in mice. Together, our data revealed that ICH induced significant mitochondrial dysfunction and that mitochondrial inhibitor Rot can trigger and enhance neuronal ferroptosis.

Dihydromyricetin attenuates intracerebral hemorrhage by reversing the effect of LCN2 via the system Xc- pathway

BACKGROUND

The limited understanding of the pathological mechanisms of intracerebral hemorrhage (ICH) and the absence of successful therapies lead to poor prognoses for patients with ICH. Dihydromyricetin (DMY) has many physiological functions, such as regulating lipid and glucose metabolism and modulating tumorigenesis. Moreover, DMY has been proven to be an effective treatment of neuroprotection. However, no reports to date have been made regarding the impact of DMY on ICH.

PURPOSE

This investigation aimed to identify the role of DMY on ICH in mice and the underlying mechanisms.

METHODS/RESULTS

This study demonstrated that DMY treatment effectively reduced hematoma size and cell apoptosis of brain tissue, and improved neurobehavioral outcomes in mice with ICH. Transcriptional and network pharmacological analyses revealed that lipocalin-2 (LCN2) was a potential target of DMY in ICH. After ICH, LCN2 mRNA and protein expression in brain tissue increased and DMY could inhibit the expression of LCN2. The rescue experiment with the implementation of LCN2 overexpression verified these observations. Furthermore, after DMY treatment, there was a significant decrease in cyclooxygenase 2 (COX2), phospho-extracellular regulated protein kinase (P-ERK), iron deposition, and the number of abnormal mitochondria, which were reversed by the overexpression of LCN2. Proteomics analysis suggests that SLC3A2 may be the downstream target of LCN2, promoting ferroptosis. Finally, LCN2 was shown to bind to SLC3A2 and regulate the downstream glutathione (GSH) synthesis and Glutathione Peroxidase 4 (GPX4) expression and glutathione (GSH) synthesis, as determined by molecular docking and co-immunoprecipitation analysis.

CONCLUSION

Our study confirmed for the first time that DMY might offer a favorable treatment for ICH through its action on LCN2. The possible mechanism for this could be that DMY reverses the inhibitory effect of LCN2 on the system Xc-, lessening ferroptosis in brain tissue. The findings of this study offer a greater understanding of how DMY affects ICH at a molecular level and could be conducive to developing therapeutic targets for ICH.

Network Pharmacology Prediction and Experimental Verification for Anti-Ferroptosis of Edaravone After Experimental Intracerebral Hemorrhage

Neuronal ferroptosis plays an important role in secondary brain injuries after intracerebral hemorrhage (ICH). Edaravone (Eda) is a promising free radical scavenger that inhibits ferroptosis in neurological diseases. However, its protective effects and underlying mechanisms in ameliorating post-ICH ferroptosis remain unclear. We employed a network pharmacology approach to determine the core targets of Eda against ICH. Forty-two rats were subjected to successful striatal autologous whole blood injection (n=28) or sham operation (n=14). The 28 blood-injected rats were randomly assigned to either the Eda or vehicle group (n=14) for immediate administration and then for 3 consecutive days. Hemin-induced HT22 cells were used for in vitro studies. The effects of Eda in ICH on ferroptosis and the MEK/ERK pathway were investigated in vivo and in vitro. Network pharmacology-based analysis revealed that candidate targets of Eda-treated ICH might be related to ferroptosis; among which prostaglandin G/H synthase 2 (PTGS2) was a ferroptosis marker. In vivo experiments showed that Eda alleviated sensorimotor deficits and decreased PTGS2 expression (all p<0.05) after ICH. Eda rescued neuron pathological changes after ICH (increased NeuN⁺ cells and decreased FJC⁺ cells, all p<0.01). In vitro experiments showed that Eda reduced intracellular reactive oxygen species and reversed mitochondria damage. Eda repressed ferroptosis by decreasing malondialdehyde and iron deposition and by influencing ferroptosis-related protein expression (all p<0.05) in ICH rats and hemin-induced HT22 cells. Mechanically, Eda significantly suppressed phosphorylated-MEK and phosphorylated-ERK1/2 expression. These results indicate that Eda has protective effects on ICH injury through ferroptosis and MEK/ERK pathway suppression.