Ferroptosis in Neurological Disease

Research Progress on the Correlation Between Atmospheric Particulate Matter and Autism

Autism spectrum disorder (ASD) is a neurodevelopmental disorder caused by the interaction of genetic and complex environmental factors. The prevalence of autism has dramatically increased in countries and regions undergoing rapid industrialization and urbanization. Recent studies have shown that particulate matter (PM) in air pollution affects the development of neurons and disrupts the function of the nervous system, leading to behavioral and cognitive problems and increasing the risk of ASD. However, research on the mechanism of environmental factors and ASD is still in its infancy. On this basis, we conducted a literature search and analysis to review epidemiological studies on the correlation between fine particulate matter (PM2.5) and inhalable particulate matter (PM10) and ASD. The signaling pathways and pathogenic mechanisms of PM in synaptic injury and neuroinflammation are presented, and the mechanism of the ASD candidate gene SHANK3 was reviewed. Additionally, the different sites of action of different particles in animal models and humans were highlighted, and the differences of their effects on the pathogenesis of ASD were explained. We summarized the aetiology and mechanisms of PM-induced autism and look forward to future research breakthroughs in improved assessment methods, multidisciplinary alliances and high-tech innovations.

Tetramethylpyrazine attenuates cerebral ischemia-reperfusion injury by inhibiting ferroptosis via the AMPK / Nrf2 pathways

OBJECTIVES

Ferroptosis is involved in the development and exacerbation of cerebral ischemia-reperfusion injury (CIRI), and its inhibition can alleviate CIRI. Tetramethylpyrazine (TMP) is used for the treatment of ischemic stroke. However, the mechanism by which TMP regulates ferroptosis in CIRI is yet to be explored. This study demonstrated the effects of TMP on ferroptosis and CIRI, including the roles of the adenosine 5'-monophosphate-activated protein kinase (AMPK)/nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway.

MATERIALS AND METHODS

A Sprague-Dawley rat middle cerebral artery occlusion/reperfusion (MCAO/R) model was generated. The extent of neuronal injury was measured using 2,3,5-triphenyl tetrazolium chloride staining and Garcia neurological scoring and behavior was evaluated using open-field tests. Ferroptosis-related indexes were examined and ferroptosis-related proteins were detected using western blotting. The binding modes of TMP and AMPK were evaluated using molecular docking and molecular dynamics simulations.

RESULTS

MCAO/R rats showed a reduced cerebral infarct area and improved neurological function after TMP intervention. TMP reduced levels of Fe2+, 4-hydroxynonenal, malonaldehyde, and acyl-coenzyme synthetase long-chain family member 4 and increased levels of glutathione and glutathione peroxidase 4. Increased AMPK phosphorylation and Nrf2 expression were also detected. TMP bound tightly to the AMPKα subunit in silico, and the LEU157, VAL41, LEU33, VAL107, and TYR106 residues were important for binding.

CONCLUSIONS

Our results indicate that TMP can alleviate CIRI by inhibiting ferroptosis via the activation of the AMPK/Nrf2 pathway, providing a theoretical basis for the clinical use of TMP in treating CIRI.

Advancements in Single-Cell RNA Sequencing Research for Neurological Diseases

Neurological diseases are a major cause of the global burden of disease. Although the mechanisms of the occurrence and development of neurological diseases are not fully clear, most of them are associated with cells mediating neuroinflammation. Yet medications and other therapeutic options to improve treatment are still very limited. Single-cell RNA sequencing (scRNA-seq), as a delightfully potent breakthrough technology, not only identifies various cell types and response states but also uncovers cell-specific gene expression changes, gene regulatory networks, intercellular communication, and cellular movement trajectories, among others, in different cell types. In this review, we describe the technology of scRNA-seq in detail and discuss and summarize the application of scRNA-seq in exploring neurological diseases, elaborating the corresponding specific mechanisms of the diseases as well as providing a reliable basis for new therapeutic approaches. Finally, we affirm that scRNA-seq promotes the development of the neuroscience field and enables us to have a deeper cellular understanding of neurological diseases in the future, which provides strong support for the treatment of neurological diseases and the improvement of patients' prognosis.

Targeting ferroptosis promotes diabetic wound healing via Nrf2 activation

Wound healing impairment is a frequent diabetes problem leading to amputation. Hyperglycemia induces the overproduction of reactive oxygen species (ROS), iron overload and sustained inflammation, resulting in the persistence of chronic wounds. However, the intrinsic mechanisms of impaired diabetic wound healing remain enigmatic. A new non-apoptotic regulatory cellular death called Ferroptosis, is distinguished by iron-driven lipid peroxidation products accumulation along with insufficient antioxidant enzymes. A decline in antioxidant capacity, excess accumulation of peroxidation of iron and lipid have been identified in wound sites of streptozotocin-induced diabetes mellitus (DM) rats and elevated glucose (EG)-cultured macrophages. Additionally, sustained inflammation and increased inflammatory cytokines were observed in DM rats and HG-cultured macrophages. Importantly, ferrostatin-1 (Fer-1) is a ferroptosis suppressor treatment significantly ameliorated diabetes-related ferroptosis and inflammation. This treatment also enhanced cell proliferation and neovascularization, ultimately thereby accelerating diabetic wound healing. Meanwhile, our study demonstrated that an anti-ferroptotic and anti-inflammatory effects of Fer-1 were mediated through stimulation of nuclear erythroid-associated factor 2 (Nrf2). The current study may provide a new rationale for diabetic wound healing.

The Role of Ferroptosis in Amyotrophic Lateral Sclerosis Treatment

Amyotrophic lateral sclerosis (ALS) is a rare neurodegenerative disease with a challenging treatment landscape, due to its complex pathogenesis and limited availability of clinical drugs. Ferroptosis, an iron-dependent form of programmed cell death (PCD), stands distinct from apoptosis, necrosis, autophagy, and other cell death mechanisms. Recent studies have increasingly highlighted the role of iron deposition, reactive oxygen species (ROS) accumulation, oxidative stress, as well as systemic Xc- and glutamate accumulation in the antioxidant system in the pathogenesis of amyotrophic lateral sclerosis. Therefore, targeting ferroptosis emerges as a promising strategy for amyotrophic lateral sclerosis treatment. This review introduces the regulatory mechanism of ferroptosis, the relationship between amyotrophic lateral sclerosis and ferroptosis, and the drugs used in the clinic, then discusses the current status of amyotrophic lateral sclerosis treatment, hoping to provide new directions and targets for its treatment.

Phytochemicals targeting ferroptosis in cardiovascular diseases: Recent advances and therapeutic perspectives

Ferroptosis is a form of iron-dependent regulatory cell death that is related to the pathogenesis and progression of various cardiovascular diseases, such as arrhythmia, diabetic cardiomyopathy, myocardial infarction, myocardial ischemia/reperfusion injury, and heart failure. This makes it a promising therapeutic target for cardiovascular diseases. It is interesting that a significant number of cardiovascular disease treatment drugs derived from phytochemicals have been shown to target ferroptosis, thus producing cardioprotective effects. This study offers a concise overview of the initiation and control mechanisms of ferroptosis. It discusses the core regulatory factors of ferroptosis as potential new therapeutic targets for various cardiovascular diseases, elucidating how ferroptosis influences the progression of cardiovascular diseases. In addition, this review systematically summarizes the regulatory effects of phytochemicals on ferroptosis, emphasizing their potential mechanisms and clinical applications in treating cardiovascular diseases. This study provides a reference for further elucidating the molecular mechanisms of phytochemicals in treating cardiovascular diseases. This may accelerate their application in the treatment of cardiovascular diseases and is worth further research in this field.

Ferroptosis inhibitor improves outcome after early and delayed treatment in mild spinal cord injury

We show that redox active iron can induce a regulated form of non-apoptotic cell death and tissue damage called ferroptosis that can contribute to secondary damage and functional loss in the acute and chronic periods after spinal cord injury (SCI) in young, adult, female mice. Phagocytosis of red blood cells at sites of hemorrhage is the main source of iron derived from hemoglobin after SCI. Expression of hemeoxygenase-1 that induces release of iron from heme, is increased in spinal cord macrophages 7 days after injury. While iron is stored safely in ferritin in the injured spinal cord, it can, however, be released by NCOA4-mediated shuttling of ferritin to autophagosomes for degradation (ferritinophagy). This leads to the release of redox active iron that can cause free radical damage. Expression of NCOA4 is increased after SCI, mainly in macrophages. Increase in the ratio of redox active ferrous (Fe2+) to ferric iron (Fe3+) is also detected after SCI by capillary electrophoresis inductively coupled mass spectrometry. These changes are accompanied by other hallmarks of ferroptosis, i.e., deficiency in various elements of the antioxidant glutathione (GSH) pathway. We also detect increases in enzymes that repair membrane lipids (ACSL4 and LPCAT3) and thus promote on-going ferroptosis. These changes are associated with increased levels of 4-hydroxynonenal (4-HNE), a toxic lipid peroxidation product. Mice with mild SCI (30 kdyne force) treated with the ferroptosis inhibitor (UAMC-3203-HCL) either early or delayed times after injury showed improvement in locomotor recovery and secondary damage. Cerebrospinal fluid and serum samples from human SCI cases show evidence of increased iron storage (ferritin), and other iron related molecules, and reduction in GSH. Collectively, these data suggest that ferroptosis contributes to secondary damage after SCI and highlights the possible use of ferroptosis inhibitors to treat SCI.

Hispolon inhibits neuronal ferroptosis by promoting the expression of Nrf-2

Research has shown that neuronal ferroptosis is associated with various central nervous system diseases, including Parkinson's disease, acute brain injury, and spinal cord injury. Inhibiting neuronal ferroptosis can greatly alleviate the progression of these diseases. However, there is currently a lack of effective drugs to inhibit neuronal ferroptosis. In this study, we pretreated neuronal cells with Hispolon and subsequently induced a neuronal ferroptosis model using Erastin. We further assessed the changes in the protein expression levels of SLC7A11, GPX4, ACSL4, Nrf-2, and HO-1 using Western blot and immunofluorescence techniques. Additionally, we measured the intracellular levels of Fe2+, GSH, and MDA using relevant assay kits. The research findings revealed that after Hispolon treatment, the expression of the pro-ferroptosis protein ACSL4 decreased, while the expression of the ferroptosis-regulating proteins GPX4 and SLC7A11 increased. Moreover, the use of an Nrf-2-specific inhibitor was able to reverse the effects of Hispolon as mentioned above. In this study, we discovered that Hispolon can promote the expression of Nrf-2 and inhibit the occurrence of neuronal ferroptosis induced by Erastin.

Iron Stress Affects the Growth and Differentiation of Toxoplasma gondii

Iron is an indispensable nutrient for the survival of Toxoplasma gondii; however, excessive amounts can lead to toxicity. The parasite must overcome the host's "nutritional immunity" barrier and compete with the host for iron. Since T. gondii can infect most nucleated cells, it encounters increased iron stress during parasitism. This study assessed the impact of iron stress, encompassing both iron depletion and iron accumulation, on the growth of T. gondii. Iron accumulation disrupted the redox balance of T. gondii while enhancing the parasite's ability to adhere in high-iron environments. Conversely, iron depletion promoted the differentiation of tachyzoites into bradyzoites. Proteomic analysis further revealed proteins affected by iron depletion and identified the involvement of phosphotyrosyl phosphatase activator proteins in bradyzoite formation.

Iron in multiple sclerosis - Neuropathology, immunology, and real-world considerations

Iron is an essential element involved in a multitude of bodily processes. It is tightly regulated, as elevated deposition in tissues is associated with diseases such as multiple sclerosis (MS). Iron accumulation in the central nervous system (CNS) of MS patients is linked to neurotoxicity through mechanisms including oxidative stress, glutamate excitotoxicity, misfolding of proteins, and ferroptosis. In the past decade, the combination of MRI and histopathology has enhanced our understanding of iron deposition in MS pathophysiology, including in the pro-inflammatory and neurotoxicity of iron-laden rims of chronic active lesions. In this regard, iron accumulation may not only have an impact on different CNS-resident cells but may also promote the innate and adaptive immune dysfunctions in MS. Although there are discordant results, most studies indicate lower levels of iron but higher amounts of the iron storage molecule ferritin in the circulation of people with MS. Considering the importance of iron, there is a need for evidence-guided recommendation for dietary intake in people living with MS. Potential novel therapeutic approaches include the regulation of iron levels using next generation iron chelators, as well as therapies to interfere with toxic consequences of iron overload including antioxidants in MS.

Novel Mechanisms of Perioperative Neurocognitive Disorders: Ferroptosis and Pyroptosis

Perioperative neurocognitive disorders (PNDs) are some of the most common postoperative complications among the elderly and susceptible individuals, which significantly worsens the clinical outcome of patients. However, the prevention and treatment strategies of PNDs are difficult to determine and implement since the pathogenesis of PNDs is not well understood. The development of living organisms is associated with active and organized cell death, which is essential for maintaining the homeostasis of life. Ferroptosis is a programmed cell death (different from apoptosis and necrosis) mainly caused by an imbalance in the generation and degradation of intracellular lipid peroxides due to iron overload. Pyroptosis is an inflammatory cell death characterized by the creation of membrane holes mediated by the gasdermin (GSDM) family, followed by cell lysis and the release of pro-inflammatory cytokines. Ferroptosis and pyroptosis are involved in the pathogenesis of various central nervous system (CNS) diseases. Furthermore, ferroptosis and pyroptosis are closely associated with the occurrence and development of PNDs. This review summarizes the main regulatory mechanisms of ferroptosis and pyroptosis and the latest related to PNDs. Based on the available evidence, potential intervention strategies that can alleviate PNDs by inhibiting ferroptosis and pyroptosis have also been provided.

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.

Ferroptosis induces detrimental effects in chronic EAE and its implications for progressive MS

Ferroptosis is a form of lipid peroxidation-mediated cell death and damage triggered by excess iron and insufficiency in the glutathione antioxidant pathway. Oxidative stress is thought to play a crucial role in progressive forms of multiple sclerosis (MS) in which iron deposition occurs. In this study we assessed if ferroptosis plays a role in a chronic form of experimental autoimmune encephalomyelitis (CH-EAE), a mouse model used to study MS. Changes were detected in the mRNA levels of several ferroptosis genes in CH-EAE but not in relapsing-remitting EAE. At the protein level, expression of iron importers is increased in the earlier stages of CH-EAE (onset and peak). While expression of hemoxygenase-1, which mobilizes iron from heme, likely from phagocytosed material, is increased in macrophages at the peak and progressive stages. Excess iron in cells is stored safely in ferritin, which increases with disease progression. Harmful, redox active iron is released from ferritin when shuttled to autophagosomes by 'nuclear receptor coactivator 4' (NCOA4). NCOA4 expression increases at the peak and progressive stages of CH-EAE and accompanied by increase in redox active ferrous iron. These changes occur in parallel with reduction in the antioxidant pathway (system xCT, glutathione peroxidase 4 and glutathione), and accompanied by increased lipid peroxidation. Mice treated with a ferroptosis inhibitor for 2 weeks starting at the peak of CH-EAE paralysis, show significant improvements in function and pathology. Autopsy samples of tissue sections of secondary progressive MS (SPMS) showed NCOA4 expression in macrophages and oligodendrocytes along the rim of mixed active/inactive lesions, where ferritin+ and iron containing cells are located. Cells expressing NCOA4 express less ferritin, suggesting ferritin degradation and release of redox active iron, as indicated by increased lipid peroxidation. These data suggest that ferroptosis is likely to contribute to pathogenesis in CH-EAE and SPMS.