Research Models to Study Ferroptosis's Impact in Neurodegenerative Diseases

Betulinic acid protects against lipopolysaccharide and ferrous sulfate-induced oxidative stress, ferroptosis, apoptosis, and neuroinflammation signaling relevant to Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the selective degeneration of dopaminergic neurons in the substantia nigra, leading to profound motor dysfunction and non-motor symptoms.

OBJECTIVES

Despite significant advancements in understanding PD pathophysiology, effective disease-modifying therapies remain elusive. Current research efforts are increasingly focused on developing and refining advanced in-vivo models to unravel PD mechanisms and explore novel therapeutic interventions. In this study, we investigated the neuroprotective potential of Betulinic acid (BA), a natural triterpenoid, in an experimental model of PD.

MATERIAL AND METHODS

We evaluated the amelioration of motor impairments and associated pathological alterations in Wistar rats. The experimental model involved the administration of lipopolysaccharide (LPS) and ferrous sulfate (FeSO4). BA was administered orally to evaluate its potential neuroprotective effects.

RESULTS

Our findings demonstrated that BA administration significantly reversed behavioral deficits and mitigated molecular, immunohistopathological, and biochemical abnormalities in LPS + FeSO4-induced PD model. Notably, BA treatment restored levels of tyrosine hydroxylase (TH) and reduced alpha-synuclein (α-syn) accumulation, both of which were significantly altered in this model. These neuroprotective effects were accompanied by a reduction in oxidative stress, ferroptosis, and apoptosis biomarkers implicated in neurodegeneration.

SUMMARY

These results collectively suggested that α-syn aggregation, ferroptosis, and apoptotic cell death are the critical contributors to PD pathology and highlighted Betulinic acid as a promising therapeutic candidate for combating neurodegeneration in PD. These findings may open new avenues for developing pharmacological agents targeting the complex mechanisms of PD.

The landscape of research on ferroptosis under hypoxic conditions: a bibliometric analysis

Background

Ferroptosis is a newly identified type of iron-dependent cell death that characterized by an increase in intracellular iron ions, which disrupt the balance of the cellular lipid peroxidation system, causing lipid peroxidation and ultimately resulting in cell death. Interestingly, ferroptosis is modulated by hypoxia and plays a role in hypoxia-related diseases. Therefore, we performed a bibliometric review of the Web of Science Core Collection (WoSCC) database to investigate the link between ferroptosis and hypoxia from January 2013 to December 2023.

Method

The core collection within the Web of Science bibliographic index was consulted to extract relevant articles and reviews. Data on publications, countries, institutions, authors, journals, citations, and keywords in the included studies were systematically analyzed using Microsoft Excel 2019 and CiteSpace 6.3.R1 software.

Result

A comprehensive analysis and visualization of 472 research papers on ferroptosis under hypoxic conditions published between 2013 and 2023 revealed emerging research hotspots and trends. Initially, a scarcity of studies existed in this field. However, this was succeeded by a significant increase in research interest in subsequent years, culminating in a peak of 204 publications in 2023. Research in this field focused primarily on the Asian region. Notably, research hotspots include diseases related to hypoxia, treatment therapy and pathogenesis. Among the researchers in this field, Supuran emerged as the most prolific author. Wuhan University was the leading institution in terms of research output, and China was the most prolific country in this area of study. Among the top ten journals ranked by the number of publications, nine were classified as Q1, indicating the high level of credibility of these studies. The research conducted by Stockwell et al., featured in the journal "Cell," currently has the most citations. Present scholarly pursuits are primarily focused on comprehending the mechanisms through which interventions affect hypoxia-related diseases through the ferroptosis pathway, as well as on probing and pinpointing prospective treatment targets.

Conclusion

This study highlights key areas of interest and emerging trends in ferroptosis research in the presence of hypoxic conditions, thus providing valuable insights for future directions of exploration for the diagnosis and treatment of hypoxia-related diseases.

Ferroptosis role in complexity of cell death: unrevealing mechanisms in Parkinson's disease and therapeutic approaches

Parkinson's disease (PD), a common neurodegenerative disorder, is characterized by progressive loss of dopaminergic neurons, and accumulation of α-synuclein in the substantial nigra. Emerging evidence identifies ferroptosis as a regulated iron-dependent cell death mechanism marked by excessive lipid peroxidation (LPO) as a key contributor to PD pathogenesis. Ferroptosis is intertwined with critical disease processes such as aggregation of α-synuclein protein, oxidative stress generation, mitochondrial alteration, iron homeostasis dysregulation, and neuroinflammation. This mechanism disrupts cellular homeostasis by impairing iron metabolism and antioxidant pathways like the xc-/glutathione/GPX4 axis and the CoQ10 pathway. This review consolidates current advancements in understanding ferroptosis in these mechanisms, increasing interest in contribution to PD pathology. In addition, it explores the latest developments in ferroptosis-targeting pharmacological agents, including their application in the preclinical and clinical study, and highlights their potential to revolutionize PD management. Unraveling the interplay between ferroptosis and PD offers a transformative perspective, paving the way for innovative therapies to combat this debilitating disease condition.

Retinoic Acid Promotes Neuronal Differentiation While Increasing Proteins and Organelles Related to Autophagy

Retinoic acid (RA) is commonly used to differentiate SH-SY5Y neuroblastoma cells. This effect is sustained by a specific modulation of gene transcription, leading to marked changes in cellular proteins. In this scenario, autophagy may be pivotal in balancing protein synthesis and degradation. The present study analyzes whether some autophagy-related proteins and organelles are modified during RA-induced differentiation of SH-SY5Y cells. RA-induced effects were compared to those induced by starvation. SH-SY5Y cells were treated with a single dose of 10 µM RA or grown in starvation, for 3 days or 7 days. After treatments, cells were analyzed at light microscopy and transmission electron microscopy to assess cell morphology and immunostaining for specific markers (nestin, βIII-tubulin, NeuN) and some autophagy-related proteins (Beclin 1, LC3). We found that both RA and starvation differentiate SH-SY5Y cells. Specifically, cell differentiation was concomitant with an increase in autophagy proteins and autophagy-related organelles. However, the effects of a single dose of 10 μM RA persist for at least 7 days, while prolonged starvation produces cell degeneration and cell loss. Remarkably, the effects of RA are modulated in the presence of autophagy inhibitors or stimulators. The present data indicate that RA-induced differentiation is concomitant with an increased autophagy.

Copper exposure induces neurotoxicity through ferroptosis in C. elegans

Copper, as a vital trace element and ubiquitous environmental pollutant, exhibits a positive correlation with the neurodegenerative diseases. Recent studies have highlighted ferroptosis's significance in heavy metal-induced neurodegenerative diseases, yet its role in copper-related neurotoxicity remains unclear. This study aimed to investigate the role of ferroptosis in copper-induced neurotoxicity. Previously, we established that copper induced motor behaviors inhibition and neuronal degeneration through oxidative stress in Caenorhabditis elegans (C. elegans). This study revealed that the behavior inhibition (head thrash, body bends, pumping frequency and defecation interval) and neuronal degeneration (GABAergic neurons and dopaminergic neurons) in copper-treated nematodes were reversed by the ferroptosis inhibitor Fer-1. Additionally, copper treatment increased the Fe2+ level and MDA content, and decreased GSH content, suggesting copper activated the ferroptosis in C. elegans. Furthermore, studies found that copper exposure altered the expression of ferroptosis-related genes gpx-1, ftn-1, and acs-17 in C. elegans. The results showed RNAi of gpx-1 and RNAi of ftn-1 significantly promoted Cu-induced neurotoxicity, while the RNAi of acs-17 appeared to rescue the Cu-induced ferroptosis and neurotoxicity. In conclusion, Cu might induce behavior inhibition and neuronal degeneration through ferroptosis in C. elegans. The findings of this study provided new insights in the mechanisms underlying Cu-induced neurotoxicity.

Progressive iron overload in middle-aged mice impairs olfactory function, triggers lipid oxidation and induces apoptosis

Introduction

This study aims to investigate the progressive impact of chronic iron overload on the olfactory bulb, a region significantly affected in early neurodegenerative diseases like Parkinson's and Alzheimer's. The focus is on understanding how iron accumulation leads to oxidative stress, mitochondrial dysfunction, and neuronal damage over time in middle-aged mice.

Method

The mice were continuously administered FC for a duration of 16 weeks, and the olfactory behavior of the mice was observed at intervals of 4 weeks. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to detect alterations in iron content within the olfactory bulb of the mice, while levels of lipid peroxidation and antioxidant indexes were assessed using biochemical kits. Additionally, western blotting and qPCR techniques were utilized to analyze transcriptional and expression changes in proteins and genes related to iron metabolism. Furthermore, microstructural modifications as well as mitochondrial observations were conducted through paraffin sectioning and transmission electron microscopy (TEM).

Result

A significant and progressive increase in iron accumulation in the olfactory bulb, starting from week 8 and peaking at week 16. This accumulation coincided with a decline in olfactory function observed at week 12. Key markers of oxidative stress, such as 4-HNE and MDA, were elevated in specific layers, and antioxidant defenses were reduced. Mitochondrial damage became evident from week 8, with caspase-3 activation indicating increased apoptosis, particularly in the granular layer. This study is to demonstrate the link between chronic iron overload and progressive olfactory dysfunction in the context of neurodegenerative diseases. It provides evidence that iron-induced oxidative stress and mitochondrial damage in the olfactory bulb contribute to early sensory deficits, suggesting that the olfactory bulb's selective vulnerability can serve as an early biomarker for neurodegenerative conditions.

Conclusion

Chronic iron overload leads to progressive oxidative damage, mitochondrial dysfunction, and apoptosis in the olfactory bulb, causing sensory deficits. Targeting iron accumulation and oxidative damage may offer new strategies for early intervention in neurodegenerative diseases, highlighting the importance of addressing iron dysregulation.

Ginsenoside compound K alleviates brain aging by inhibiting ferroptosis through modulation of the ASK1-MKK7-JNK signaling pathway

BACKGROUND

Aging of the brain is a major contributor to the onset and progression of neurodegenerative diseases. Conventional treatments for these diseases are often limited by significant side effects and a lack of efficacy in halting disease progression. Ginsenoside compound K (CK), a bioactive secondary metabolite derived from ginseng, has shown promise because of its potent antioxidant properties.

PURPOSE

This study aimed to elucidate the molecular mechanisms underlying the impact of CK on brain senescence, with a particular focus on its role in modulating oxidative stress and related signaling pathways.

METHODS

We employed a d-galactose (D-gal)-induced PC-12 senescent cell model and a mouse brain aging model to explore the antioxidant properties of CK in the context of brain aging. The effects of CK on mitochondrial dysfunction associated with brain aging were assessed using immunofluorescence and western blotting techniques. The potential molecular mechanisms by CK influences brain aging were investigated using transcriptomic analysis and western blotting. Additionally, CK's regulatory effect on apoptosis signal-regulating kinase 1 (ASK1) was validated by molecular docking, microscale thermophoresis, and small interfering RNA transfection.

RESULTS

Our findings demonstrate that CK effectively alleviates cognitive decline associated with brain aging. CK reduces the number of senescent cells, alleviates neuronal damage, and enhances the activity of key antioxidant enzymes, including catalase, superoxide dismutase, and glutathione peroxidase. Additionally, CK restores mitochondrial function and upregulated the expression of solute carrier family 7 member 11 and glutathione peroxidase 4, thereby inhibiting ferroptosis. Furthermore, CK targets ASK1 and suppresses the hyperphosphorylation of MAPK kinase 7 (MKK7) and c-Jun N-terminal kinase (JNK). This suppression promotes the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2), effectively reducing ferroptosis and oxidative damage linked to brain aging.

CONCLUSION

In summary, our research demonstrates that CK effectively delays brain aging by inhibiting the ASK1-MKK7-JNK signaling pathway, enhancing nuclear Nrf2 expression, and suppressing the ferroptosis response. These findings highlight CK as a promising therapeutic agent for slowing brain aging and alleviating neurodegenerative diseases.

Ironing out the Links: Ferroptosis in epilepsy and SUDEP

Iron is a crucial element for almost all organisms because it plays a vital role in oxygen transport, enzymatic processes, and energy generation due to its electron transfer capabilities. However, its dysregulation can lead to a form of programmed cell death known as ferroptosis, which is characterized by cellular iron accumulation, reactive oxygen species (ROS) production, and unrestricted lipid peroxidation. Both iron and ferroptosis have been identified as key players in the pathogenesis of various neurodegenerative diseases. While in epilepsy this phenomenon remains relatively understudied, seizures can be considered hypoxic-ischemic episodes resulting in increased ROS production, lipid peroxidation, membrane disorganization, and cell death. All of this is accompanied by elevated intracellular free Fe2+ concentration and hemosiderin precipitation, as existing reports suggest a significant accumulation of iron in the brain and heart associated with epilepsy. Generalized tonic-clonic seizures (GTCS), a primary risk factor for Sudden Unexpected Death in Epilepsy (SUDEP), not only have an impact on the brain but also lead to cardiogenic dysfunctions associated with "Iron Overload and Cardiomyopathy" (IOC) and "Epileptic heart" characterized by electrical and mechanical dysfunction and a high risk of malignant bradycardia. In line with this phenomenon, studies conducted by our research group have demonstrated that recurrent seizures induce hypoxia in cardiomyocytes, resulting in P-glycoprotein (P-gp) overexpression, prolonged Q-T interval, severe bradycardia, and hemosiderin precipitation, correlating with an elevated spontaneous death ratio. In this article, we explore the intricate connections among ferroptosis, epilepsy, and SUDEP. By synthesizing current knowledge and drawing insights from recent publications, this study provides a comprehensive understanding of the molecular underpinnings. Furthermore, this review offers insights into potential therapeutic avenues and outlines future research directions.

Modeling ferroptosis in human dopaminergic neurons: Pitfalls and opportunities for neurodegeneration research

The activation of ferroptosis is being pursued in cancer research as a strategy to target apoptosis-resistant cells. By contrast, in various diseases that affect the cardiovascular system, kidneys, liver, and central and peripheral nervous systems, attention is directed toward interventions that prevent ferroptotic cell death. Mechanistic insights into both research areas stem largely from studies using cellular in vitro models. However, intervention strategies that show promise in cellular test systems often fail in clinical trials, which raises concerns regarding the predictive validity of the utilized in vitro models. In this study, the human LUHMES cell line, which serves as a model for human dopaminergic neurons, was used to characterize factors influencing the activation of ferroptosis. Erastin and RSL-3 induced cell death that was distinct from apoptosis. Parameters such as the differentiation state of LUHMES cells, cell density, and the number and timing of medium changes were identified as determinants of sensitivity to ferroptosis activation. In differentiated LUHMES cells, interventions at mechanistically divergent sites (iron chelation, coenzyme Q10, peroxidase mimics, or inhibition of 12/15-lipoxygenase) provide almost complete protection from ferroptosis. LUHMES cells allowed the experimental modulation of intracellular iron concentrations and demonstrated a correlation between intracellular iron levels, the rate of lipid peroxidation, as well as the sensitivity of the cells to ferroptotic cell death. These findings underscore the importance of understanding the various factors that influence ferroptosis activation and highlight the need for well-characterized in vitro models to enhance the reliability and predictive value of observations in ferroptosis research, particularly when translating findings into in vivo contexts.

Uncovering the ferroptosis related mechanism of laduviglusib in the cell-type-specific targets of the striatum in Huntington's disease

Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder featured by abnormal movements, arising from the extensive neuronal loss and glial dysfunction in the striatum. Although the causes and pathogenetic mechanisms of HD are well established, the development of disease-modifying pharmacological therapies for HD remains a formidable challenge. Laduviglusib has demonstrated neuroprotective effects through the enhancement of mitochondrial function in the striatum of HD animal models. Ferroptosis is a nonapoptotic form of cell death that occurs as a consequence of lethal iron-dependent lipid peroxidation and mitochondrial dysfunction. However, the ferroptosis-related mechanisms underlying the neuroprotective effects of laduviglusib in the striatum of HD patients remain largely uncharted. In this study, we leveraged single-nucleus RNA sequencing data obtained from the striatum of HD patients in stages 2-4 to identify differentially expressed genes within distinct cell-type. We subsequently integrated these differentially expressed genes of HD, laduviglusib target genes and ferroptosis-related genes to predict the ferroptosis-related mechanisms underpinning the neuroprotective effects of laduviglusib in HD patients. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses unveiled that the effects of laduviglusib on direct pathway striatal projection neurons (dSPNs) is mainly associated with Th17 cell differentiation pathways. Conversely, its impact on indirect pathway striatal projection neurons (iSPNs) extends to the Neurotrophin signaling pathway, FoxO signaling pathway, and reactive oxygen species pathway. In microglia, laduviglusib appears to contribute to HD pathology via mechanisms related to Th17 cell differentiation and the FoxO signaling pathway. Further, molecular docking results indicated favorable binding of laduviglusib with PARP1 (associated with dSPNs and iSPNs), SCD (associated with astrocytes), ALOX5 (associated with microglia), and HIF1A (associated with dSPNs, iSPNs, and microglia). In addition, the KEGG results suggest that laduviglusib may enhance mitochondrial function and protect against neuronal loss by targeting ferroptosis-related signaling pathways, particularly mediated by ALOX5 in microglia. These findings provide valuable insights into the potential mechanisms through which laduviglusib exerts its effects on distinct cell-types within the HD striatum.

Exposure to 6-PPD quinone causes ferroptosis activation associated with induction of reproductive toxicity in Caenorhabditis elegans

Exposure to N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6-PPDQ) caused toxicity on Caenorhabditis elegans, including reproductive toxicity. However, the underlying mechanisms for this induced reproductive toxicity by 6-PPDQ remain largely unclear. We examined possible association of ferroptosis activation with reproductive toxicity of 6-PPDQ. In 1-100 μg/L 6-PPDQ exposed nematodes, Fe2+ content was increased, which was accompanied with enhanced lipid peroxidation, increased malonydialdehyde (MDA) content, and decreased L-glutathione (GSH) content. Exposure to 1-100 μg/L 6-PPDQ decreased expressions of ftn-1 encoding ferritin, ads-1 encoding AGPS, and gpx-6 encoding GPX4 and increased expression of bli-3 encoding dual oxidase. After 6-PPDQ exposure, RNAi of ftn-1 decreased ads-1 and gpx-6 expressions and increased bli-3 expression. RNAi of ftn-1, ads-1, and gpx-6 strengthened alterations in ferroptosis related indicators, and RNAi of bli-3 suppressed changes of ferroptosis related indicators in 6-PPDQ exposed nematodes. Meanwhile, RNAi of ftn-1, ads-1, and gpx-6 induced susceptibility, and RNAi of bli-3 caused resistance to 6-PPDQ reproductive toxicity. Moreover, expressions of DNA damage checkpoint genes (clk-2, mrt-2, and hus-1) could be increased by RNAi of ftn-1, ads-1, and gpx-6 in 6-PPDQ exposed nematodes. Therefore, our results demonstrated activation of ferroptosis in nematodes exposed to 6-PPDQ at environmentally relevant concentrations, and this ferroptosis activation was related to reproductive toxicity of 6-PPDQ.

Neuroprotective effect of emodin on Aβ25-35-induced cytotoxicity in PC12 cells involves Nrf2/GPX4 and TLR4/p-NF-κB/NLRP3 pathways

The present study aims to investigate the neuroprotective effects of emodin in Alzheimer's disease (AD). PC12 cells were used to explore the underlying mechanism and were incubated with Aβ25-35 for 24 h as the model group, incubated with emodin at different concentrations (2.5, 5, 10 μM) as the drug administration groups. The content of MDA and the enzymic activities of CAT, GSH-Px were detected by the corresponding commercial kits. The ROS level in Aβ25-35 induced cells was decreased by emodin dose-dependently, but the MMP in these cells were elevated. The expressions of AChE, TLR4, p-NF-κB, NLRP3, IL-1β, and TNF-α in PC12 cells were increased by Aβ25-35 treatment, the expressions of Nrf2, HO-1, GPX4, xCT were decreased, all the levels of expressions were reversed by emodin. Besides, ultraviolet spectrophotometry and infrared spectrophotometry were ultilized to ascertain the production of emodin-Fe (Ⅱ) complex. The FerroOrange results showed that emodin reduced free Fe2+ in cells. The immunofluorescent intensities of Nrf2, GPX4, and p-NF-κB offered direct visible evidence for emodin's multi-targets in AD treatment. Collectively, emodin could inhibit the activity of AChE and exert neuroprotective effects against AD through antioxidant, anti-ferroptotic, anti-inflammatory properties via Nrf2/GPX4 and TLR4/p-NF-κB/NLRP3 pathways.

Iron toxicity, ferroptosis and microbiota in Parkinson's disease: Implications for novel targets

Parkinson's Disease (PD) is a progressive neurodegenerative disease characterized by loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). Iron (Fe)-dependent programmed cell death known as ferroptosis, plays a crucial role in the etiology and progression of PD. Since SNpc is particularly vulnerable to Fe toxicity, a central role for ferroptosis in the etiology and progression of PD is envisioned. Ferroptosis, characterized by reactive oxygen species (ROS)-dependent accumulation of lipid peroxides, is tightly regulated by a variety of intracellular metabolic processes. Moreover, the recently characterized bi-directional interactions between ferroptosis and the gut microbiota, not only provides another window into the mechanistic underpinnings of PD but could also suggest novel interventions in this devastating disease. Here, following a brief discussion of PD, we focus on how our expanding knowledge of Fe-induced ferroptosis and its interaction with the gut microbiota may contribute to the pathophysiology of PD and how this knowledge may be exploited to provide novel interventions in PD.

IP3R-Mediated Calcium Release Promotes Ferroptotic Death in SH-SY5Y Neuroblastoma Cells

Ferroptosis is an iron-dependent cell death pathway that involves the depletion of intracellular glutathione (GSH) levels and iron-mediated lipid peroxidation. Ferroptosis is experimentally caused by the inhibition of the cystine/glutamate antiporter xCT, which depletes cells of GSH, or by inhibition of glutathione peroxidase 4 (GPx4), a key regulator of lipid peroxidation. The events that occur between GPx4 inhibition and the execution of ferroptotic cell death are currently a matter of active research. Previous work has shown that calcium release from the endoplasmic reticulum (ER) mediated by ryanodine receptor (RyR) channels contributes to ferroptosis-induced cell death in primary hippocampal neurons. Here, we used SH-SY5Y neuroblastoma cells, which do not express RyR channels, to test if calcium release mediated by the inositol 1,4,5-trisphosphate receptor (IP3R) channel plays a role in this process. We show that treatment with RAS Selective Lethal Compound 3 (RSL3), a GPx4 inhibitor, enhanced reactive oxygen species (ROS) generation, increased cytoplasmic and mitochondrial calcium levels, increased lipid peroxidation, and caused cell death. The RSL3-induced calcium signals were inhibited by Xestospongin B, a specific inhibitor of the ER-resident IP3R calcium channel, by decreasing IP3R levels with carbachol and by IP3R1 knockdown, which also prevented the changes in cell morphology toward roundness induced by RSL3. Intracellular calcium chelation by incubation with BAPTA-AM inhibited RSL3-induced calcium signals, which were not affected by extracellular calcium depletion. We propose that GPx4 inhibition activates IP3R-mediated calcium release in SH-SY5Y cells, leading to increased cytoplasmic and mitochondrial calcium levels, which, in turn, stimulate ROS production and induce lipid peroxidation and cell death in a noxious positive feedback cycle.

Interplay of Vitamin D, Unfolded Protein Response, and Iron Metabolism in Neuroblastoma Cells: A Therapeutic Approach in Neurodegenerative Conditions

Vitamin D3 (VD) is crucial for various cell functions, including gene regulation, antioxidant defense, and neural health. Neurodegenerative conditions are closely linked to the unfolded protein response (UPR), a mechanism reacting to endoplasmic reticulum (ER) stress. Iron metabolism is intricately associated with UPR and neurodegeneration. This study used SH-SY5Y neuroblastoma cells to investigate the relationship between UPR, iron metabolism, and VD. Different sequences of treatments (pre- and post-treatments) were applied using VD and thapsigargin (Tg), and various methods were used for evaluation, including real-time qPCR, Western blotting, ELISA, and iron content analysis. The findings indicate that VD affects UPR pathways, cytokine release, and iron-related genes, potentially offering anti-inflammatory benefits. It also influences iron transporters and storage proteins, helping to maintain cellular iron balance. Furthermore, pro-inflammatory cytokines like interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα) were impacting UPR activation in cells. VD also influenced fractalkine (CX3CL1) gene expression and secretion, suggesting its potential as a therapeutic agent for addressing neuroinflammation and iron dysregulation. This research provides insights into the intricate connections among VD, UPR, and iron metabolism in SH-SY5Y neuroblastoma cells, with implications for future investigations and potential therapeutic approaches in neurodegenerative diseases characterized by UPR dysregulation and iron accumulation.

The antidepressant effect of short- and long-term zinc exposition is partly mediated by P2X7 receptors in male mice

Background: As a member of the purinergic receptor family, divalent cation-regulated ionotropic P2X7 (P2rx7) plays a role in the pathophysiology of psychiatric disorders. This study aimed to investigate whether the effects of acute zinc administration and long-term zinc deprivation on depression-like behaviors in mice are mediated by P2X7 receptors. Methods: The antidepressant-like effect of elevated zinc level was studied using a single acute intraperitoneal injection in C57BL6/J wild-type and P2rx7 gene-deficient (P2rx7 -/-) young adult and elderly animals in the tail suspension test (TST) and the forced swim test (FST). In the long-term experiments, depression-like behavior caused by zinc deficiency was investigated with the continuous administration of zinc-reduced and control diets for 8 weeks, followed by the same behavioral tests. The actual change in zinc levels owing to the treatments was examined by assaying serum zinc levels. Changes in monoamine and brain-derived neurotrophic factor (BDNF) levels were measured from the hippocampus and prefrontal cortex brain areas by enzyme-linked immunosorbent assay and high-performance liquid chromatography, respectively. Results: A single acute zinc treatment increased the serum zinc level evoked antidepressant-like effect in both genotypes and age groups, except TST in elderly P2rx7 -/- animals, where no significant effect was detected. Likewise, the pro-depressant effect of zinc deprivation was observed in young adult mice in the FST and TST, which was alleviated in the case of the TST in the absence of functional P2X7 receptors. Among elderly mice, no pro-depressant effect was observed in P2rx7 -/- mice in either tests. Treatment and genotype changes in monoamine and BDNF levels were also detected in the hippocampi. Conclusion: Changes in zinc intake were associated with age-related changes in behavior in the TST and FST. The antidepressant-like effect of zinc is partially mediated by the P2X7 receptor.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.