Induction of ferroptosis in response to graphene quantum dots through mitochondrial oxidative stress in microglia

The dual role of microglia in intracerebral hemorrhage

Intracerebral hemorrhage has the characteristics of high morbidity, disability and mortality, which has caused a heavy burden to families and society. Microglia are resident immune cells in the central nervous system, and their activation plays a dual role in tissue damage after intracerebral hemorrhage. The damage in cerebral hemorrhage is embodied in the following aspects: releasing inflammatory factors and inflammatory mediators, triggering programmed cell death, producing glutamate induced excitotoxicity, and destroying blood-brain barrier; The protective effect is reflected in the phagocytosis and clearance of harmful substances by microglia, and the secretion of anti-inflammatory and neurotrophic factors. This article summarizes the function of microglia and its dual regulatory mechanism in intracerebral hemorrhage. In the future, drugs, acupuncture and other clinical treatments can be used to intervene in the activation state of microglia, so as to reduce the harm of microglia.

Putative Adverse Outcome Pathway for Parkinson's Disease-like Symptoms Induced by Silicon Quantum Dots based on In Vivo/Vitro Approaches

Given the commercial proliferation of silicon quantum dots (SiQDs) and their inevitable environmental dispersal, this study critically examines their biological and public health implications, specifically regarding Parkinson's disease. The study investigated the toxicological impact of SiQDs on the onset and development of PD-like symptoms through the induction of ferroptosis, utilizing both in vivo [Caenorhabditis elegans (C. elegans)] and in vitro (SH-SY5Y neuroblastoma cell line) models. Our findings demonstrated that SiQDs, characterized by their stable and water-soluble physicochemical properties, tended to accumulate in neuronal tissues. This accumulation precipitated dopaminergic neurodegeneration, manifested as diminished dopamine-dependent behaviors, and escalated the expression of PD-specific genes in C. elegans. Importantly, the results revealed that SiQDs induced ferritinophagy, a selective autophagy pathway that triggered ferroptosis and resulted in PD-like symptoms, even exacerbating disease progression in biological models. These insights were incorporated into a putatively qualitative and quantitative adverse outcome pathway framework, highlighting the serious neurodegenerative risks posed by SiQDs through ferroptosis pathways. This study provides a multidisciplinary analysis critical for informing policy on the regulation of SiQDs exposure to safeguard susceptible populations and guiding the responsible development of nanotechnologies impacting environmental and public health.

Ferroptosis promotes valproate-induced liver steatosis in vitro and in vivo

Valproic acid (VPA), a common antiepileptic drug, can cause liver steatosis after long-term therapy. However, an impact of ferroptosis on VPA-induced liver steatosis has not been investigated. In the study, treatment with VPA promoted ferroptosis in the livers of mice by elevating ferrous iron (Fe2+) levels derived from the increased absorption by transferrin receptor 1 (TFR1) and the decreased storage by ferritin (FTH1 and FTL), disrupting the redox balance via reduced levels of solute carrier family 7 member 11 (SLC7A11), glutathione (GSH), and glutathione peroxidase 4 (GPX4), and augmenting acyl-CoA synthetase long-chain family member 4 (ACSL4) -mediated lipid peroxide generation, accompanied by enhanced liver steatosis. All the changes were significantly reversed by co-treatment with an iron-chelating agent, deferoxamine mesylate (DFO) and a ferroptosis inhibitor, ferrostatin-1 (Fer-1). Similarly, the increases in Fe2+, TFR1, and ACSL4 levels, as well as the decreases in GSH, GPX4, and ferroportin (FPN) levels, were detected in VPA-treated HepG2 cells. These changes were also attenuated after co-treatment with Fer-1. It demonstrates that ferroptosis promotes VPA-induced liver steatosis through iron overload, inhibition of the GSH-GPX4 axis, and upregulation of ACSL4. It offers a potential therapy targeting ferroptosis for patients with liver steatosis following VPA treatment.

Application of quantum dots in brain diseases and their neurotoxic mechanism

The early-stage diagnosis and therapy of brain diseases pose a persistent challenge in the field of biomedicine. Quantum dots (QDs), nano-luminescent materials known for their small size and fluorescence imaging capabilities, present promising capabilities for diagnosing, monitoring, and treating brain diseases. Although some investigations about QDs have been conducted in clinical trials, the concerns about the toxicity of QDs have continued. In addition, the lack of effective toxicity evaluation methods and systems and the difference between in vivo and in vitro toxicity evaluation hinder QDs application. The primary objective of this paper is to introduce the neurotoxic effects and mechanisms attributable to QDs. First, we elucidate the utilization of QDs in brain disorders. Second, we sketch out three pathways through which QDs traverse into brain tissue. Ultimately, expound upon the adverse consequences of QDs on the brain and the mechanism of neurotoxicity in depth. Finally, we provide a comprehensive summary and outlook on the potential development of quantum dots in neurotoxicity and the difficulties to be overcome.

Advances in research on immunocyte iron metabolism, ferroptosis, and their regulatory roles in autoimmune and autoinflammatory diseases

Autoimmune diseases commonly affect various systems, but their etiology and pathogenesis remain unclear. Currently, increasing research has highlighted the role of ferroptosis in immune regulation, with immune cells being a crucial component of the body's immune system. This review provides an overview and discusses the relationship between ferroptosis, programmed cell death in immune cells, and autoimmune diseases. Additionally, it summarizes the role of various key targets of ferroptosis, such as GPX4 and TFR, in immune cell immune responses. Furthermore, the release of multiple molecules, including damage-associated molecular patterns (DAMPs), following cell death by ferroptosis, is examined, as these molecules further influence the differentiation and function of immune cells, thereby affecting the occurrence and progression of autoimmune diseases. Moreover, immune cells secrete immune factors or their metabolites, which also impact the occurrence of ferroptosis in target organs and tissues involved in autoimmune diseases. Iron chelators, chloroquine and its derivatives, antioxidants, chloroquine derivatives, and calreticulin have been demonstrated to be effective in animal studies for certain autoimmune diseases, exerting anti-inflammatory and immunomodulatory effects. Finally, a brief summary and future perspectives on the research of autoimmune diseases are provided, aiming to guide disease treatment strategies.

Targeting ferroptosis in neuroimmune and neurodegenerative disorders for the development of novel therapeutics

Neuroimmune and neurodegenerative ailments impose a substantial societal burden. Neuroimmune disorders involve the intricate regulatory interactions between the immune system and the central nervous system. Prominent examples of neuroimmune disorders encompass multiple sclerosis and neuromyelitis optica. Neurodegenerative diseases result from neuronal degeneration or demyelination in the brain or spinal cord, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. The precise underlying pathogenesis of these conditions remains incompletely understood. Ferroptosis, a programmed form of cell death characterised by lipid peroxidation and iron overload, plays a pivotal role in neuroimmune and neurodegenerative diseases. In this review, we provide a detailed overview of ferroptosis, its mechanisms, pathways, and regulation during the progression of neuroimmune and neurodegenerative diseases. Furthermore, we summarise the impact of ferroptosis on neuroimmune-related cells (T cells, B cells, neutrophils, and macrophages) and neural cells (glial cells and neurons). Finally, we explore the potential therapeutic implications of ferroptosis inhibitors in diverse neuroimmune and neurodegenerative diseases.

PM2.5-induced ferroptosis by Nrf2/Hmox1 signaling pathway led to inflammation in microglia

Particulate matter (PM) has been a dominant contributor to air contamination, which will enter the central nervous system (CNS), causing neurotoxicity. However, the biological mechanism is poorly identified. In this study, C57BL/6J mice were applied to evaluate the neurotoxicity of collected fine particulate matter (PM2.5), via oropharyngeal aspiration at two ambient equivalent concentrations. The Y-maze results showed that PM2.5 exposure in mice would lead to the damage in hippocampal-dependent working memory. In addition, cell neuroinflammation, microglial activation were detected in hippocampus of PM2.5-exposure mice. To confirm the underlying mechanism, the microarray assay was conducted to screen the differentially expressed genes (DEGs) in microglia after PM2.5 exposure, and the results indicated the enrichment of DEGs in ferroptosis pathways. Furthermore, Heme oxygenase-1 (Hmox1) was found to be one of the most remarkably upregulated genes after PM2.5 exposure for 24 h. And PM2.5 exposure induced ferroptosis with iron accumulation through heme degradation by Nrf2-mediated Hmox1 upregulation, which could be eliminated by Nrf2-inhibition. Meanwhile, Hmox1 antagonist zinc protoporphyrin IX (ZnPP) could protect BV2 cells from ferroptosis. The results taken together indicated that PM2.5 resulted in the ferroptosis by causing iron overload through Nrf2/Hmox1 signaling pathway, which could account for the inflammation in microglia.

Exposure of quantum dots in the nervous system: Central nervous system risks and the blood-brain barrier interface

Quantum dots currently possess significant importance in the field of biomedical science. Upon introduction into the body, quantum dots exhibit a tendency to accumulate in diverse tissues including the central nervous system (CNS). Consequently, it becomes imperative to devote specific attention to their potential toxic effects. Moreover, the preservation of optimal CNS function relies heavily on blood-brain barrier (BBB) integrity, thereby necessitating its prioritization in neurotoxicological investigations. A more comprehensive understanding of the BBB and CNS characteristics, along with the underlying mechanisms that may contribute to neurotoxicity, will greatly aid researchers in the development of effective design strategies. This article offers an in-depth look at the methods used to reduce the harmful effects of quantum dots on the nervous system, alongside the progression of effective treatments for brain-related conditions. The focal point of this discussion is the BBB and its intricate association with the CNS and neurotoxicology. The discourse commences by recent advancements in the medical application of quantum dots are examined. Subsequently, elucidating the mechanisms through which quantum dots infiltrate the human body and traverse into the brain. Additionally, the discourse delves into the factors that facilitate the passage of quantum dots across the BBB, primarily encompassing the physicochemical properties of quantum dots and the BBB's inherent capacity for self-permeability alteration. Furthermore, a concluding summary is presented, emphasizing existing research deficiencies and identifying promising avenues for further investigation within this field.

Graphene-Based Photodynamic Therapy and Overcoming Cancer Resistance Mechanisms: A Comprehensive Review

Photodynamic therapy (PDT) is a non-invasive therapy that has made significant progress in treating different diseases, including cancer, by utilizing new nanotechnology products such as graphene and its derivatives. Graphene-based materials have large surface area and photothermal effects thereby making them suitable candidates for PDT or photo-active drug carriers. The remarkable photophysical properties of graphene derivates facilitate the efficient generation of reactive oxygen species (ROS) upon light irradiation, which destroys cancer cells. Surface functionalization of graphene and its materials can also enhance their biocompatibility and anticancer activity. The paper delves into the distinct roles played by graphene-based materials in PDT such as photosensitizers (PS) and drug carriers while at the same time considers how these materials could be used to circumvent cancer resistance. This will provide readers with an extensive discussion of various pathways contributing to PDT inefficiency. Consequently, this comprehensive review underscores the vital roles that graphene and its derivatives may play in emerging PDT strategies for cancer treatment and other medical purposes. With a better comprehension of the current state of research and the existing challenges, the integration of graphene-based materials in PDT holds great promise for developing targeted, effective, and personalized cancer treatments.

Ferroptosis in ulcerative colitis: Potential mechanisms and promising therapeutic targets

Ulcerative colitis (UC) is a complex immune-mediated chronic inflammatory bowel disease. It is mainly characterized by diffuse inflammation of the colonic and rectal mucosa with barrier function impairment. Identifying new biomarkers for the development of more effective UC therapies remains a pressing task for current research. Ferroptosis is a newly identified form of regulated cell death characterized by iron-dependent lipid peroxidation. As research deepens, ferroptosis has been demonstrated to be involved in the pathological processes of numerous diseases. A growing body of evidence suggests that the pathogenesis of UC is associated with ferroptosis, and the regulation of ferroptosis provides new opportunities for UC treatment. However, the specific mechanisms by which ferroptosis participates in the development of UC remain to be more fully and thoroughly investigated. Therefore, in this review, we focus on the research advances in the mechanism of ferroptosis in recent years and describe the potential role of ferroptosis in the pathogenesis of UC. In addition, we explore the underlying role of the crosslinked pathway between ferroptosis and other mechanisms such as macrophages, neutrophils, autophagy, endoplasmic reticulum stress, and gut microbiota in UC. Finally, we also summarize the potential compounds that may act as ferroptosis inhibitors in UC in the future.

SLC7A11 as a therapeutic target to attenuate phthalates-driven testosterone level decline in mice

INTRODUCTION

Phthalates exposure is a major public health concern due to the accumulation in the environment and associated with levels of testosterone reduction, leading to adverse pregnancy outcomes. However, the relationship between phthalate-induced testosterone level decline and ferroptosis remains poorly defined.

OBJECTIVES

Herein, we aimed to explore the mechanisms of phthalates-induced testosterone synthesis disorder and its relationship to ferroptosis.

METHODS

We conducted validated experiments in vivo male mice model and in vitro mouse Leydig TM3 cell line, followed by RNA sequencing and metabolomic analysis. We evaluated the levels of testosterone synthesis-associated enzymes and ferroptosis-related indicators by using qRT-PCR and Western blotting. Then, we analyzed the lipid peroxidation, ROS, Fe2+ levels and glutathione system to confirm the occurrence of ferroptosis.

RESULTS

In the present study, we used di (2-ethylhexyl) phthalate (DEHP) to identify ferroptosis as the critical contributor to phthalate-induced testosterone level decline. It was demonstrated that DEHP caused glutathione metabolism and steroid synthesis disorders in Leydig cells. As the primary metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP) triggered testosterone synthesis disorder accompanied by a decrease in the expression of solute carri1er family 7 member 11 (SLC7A11) protein. Furthermore, MEHP synergistically induced ferroptosis with Erastin through the increase of intracellular and mitochondrial ROS, and lipid peroxidation production. Mechanistically, overexpression of SLC7A11 counteracts the synergistic effect of co-exposure to MEHP-Erastin.

CONCLUSION

Our research results suggest that MEHP does not induce ferroptosis but synergizes Erastin-induced ferroptosis. These findings provide evidence for the role of ferroptosis in phthalates-induced testosterone synthesis disorder and point to SLC7A11 as a potential target for male reproductive diseases. This study established a correlation between ferroptosis and phthalates cytotoxicity, providing a novel view point for mitigating the issue of male reproductive disease and "The Global Plastic Toxicity Debt".

Nanomaterials-induced programmed cell death: Focus on mitochondria

Nanomaterials are widely utilized in several domains, such as everyday life, societal manufacturing, and biomedical applications, which expand the potential for nanomaterials to penetrate biological barriers and interact with cells. Multiple studies have concentrated on the particular or improper utilization of nanomaterials, resulting in cellular death. The primary mode of cell death caused by nanotoxicity is programmable cell death, which includes apoptosis, ferroptosis, necroptosis, and pyroptosis. Based on our prior publications and latest research, mitochondria have a vital function in facilitating programmed cell death caused by nanomaterials, as well as initiating or transmitting death signal pathways associated with it. Therefore, this review takes mitochondria as the focal point to investigate the internal molecular mechanism of nanomaterial-induced programmed cell death, with the aim of identifying potential targets for prevention and treatment in related studies.

Oxidative stress-induced neurotoxicity of quantum dots and influencing factors

Quantum dots (QDs) have significant potential for treating and diagnosing CNS diseases. Meanwhile, the neurotoxicity of QDs has garnered attention. In this review, we focus on elucidating the mechanisms and consequences of CNS oxidative stress induced by QDs. First, we discussed the pathway of QDs transit into the brain. We then elucidate the relationship between QDs and oxidative stress from in vivo and in vitro studies. Furthermore, the main reasons and adverse outcomes of QDs leading to oxidative stress are discussed. In addition, the primary factors that may affect the neurotoxicity of QDs are analyzed. Finally, we propose potential strategies for mitigating QDs neurotoxicity and outline future perspectives for their development.

TXNIP/NLRP3 aggravates global cerebral ischemia-reperfusion injury-induced cognitive decline in mice

Global cerebral ischemia/reperfusion (GCI/R) injury poses a risk for cognitive decline, with neuroinflammation considered pivotal in this process. This study aimed to unravel the molecular mechanisms underlying GCI/R injury and propose a potential therapeutic strategy for associated cognitive deficits. Utilizing bioinformatics analysis of a public microarray profile (GSE30655 and GSE80681) in cerebral ischemic mice, it was observed that neuroinflammation emerged as a significant gene ontology item, with an increase in the expression of thioredoxin-interacting protein (TXNIP) and NLRP3 genes. Experimental models involving bilateral occlusion of the common carotid arteries in mice revealed that GCI/R induced cognitive impairment, along with a time-dependent increase in TXNIP and NLRP3 levels. Notably, TXNIP knockdown alleviated cognitive dysfunction in mice. Furthermore, the introduction of adeno-associated virus injection with TXNIP knockdown reduced the number of activated microglia, apoptosis neurons, and levels of oxidative stress and inflammatory cytokines in the hippocampus. Collectively, these findings underscore the significance of TXNIP/NLRP3 in the hippocampus in exacerbating cognitive decline due to GCI/R injury, suggesting that TXNIP knockdown holds promise as a therapeutic strategy.

Angong Niuhuang Wan inhibit ferroptosis on ischemic and hemorrhagic stroke by activating PPARγ/AKT/GPX4 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Angong Niuhuang Wan (AGNHW) is a prescription from traditional Chinese medicine (TCM) that has been used for centuries to treat ischemic stroke (IS) and hemorrhagic stroke (HS). According to a recent study, targeting ferroptosis might be effective in the management of IS and HS. However, the ferroptosis-related effects and mechanisms of AGNHW have not yet been reported.

AIM OF THE STUDY

This research examines the anti-ferroptosis mechanisms of AGNHW in the treatment of IS and HS.

MATERIALS AND METHODS

A system pharmacological approach including in vivo experiment, UHPLC-Q-Orbitrap HRMS, network pharmacology, molecular docking, microscale thermophoresis, and in vitro experiment was utilized to study the anti-ferroptosis mechanisms of AGNHW against IS and HS.

RESULTS

In vivo experiments indicated that AGNHW enhanced nerve function, decreased cerebral infarct volume, ameliorated histological brain injuries, improved the structural integrity of the blood-brain barrier, ameliorated the mitochondrial dysfunction and morphology disruption, and inhibits ROS, LPO and Fe2+ accumulations in IS and HS rats. Using UHPLC-Q-Orbitrap HRMS, the key ingredients of AGNHW-containing serum were identified as bilirubin, berberine, baicalin, and wogonoside. According to the network pharmacology analyses, AGNHW could inhibit ferroptosis by modulating the PPAR and PI3K/AKT signaling pathways. The core targets are PPARγ, AKT, and GPX4. Molecular docking and microscale thermophoresis experiments further revealed that the key ingredients have strong interactions with ferroptosis-regulating core proteins. Moreover, in vitro experiment results showed that AGNHW alleviated ferroptosis injury induced by erastin in PC12 cells, increased cell viability, reduced the LPO and Fe2+ levels, and up-regulated mRNA expressions of PPARγ, AKT, and GPX4. AGNHW also up-regulated protein expressions of PPARγ, p-AKT/AKT, and GPX4 in IS and HS rats.

CONCLUSIONS

AGNHW attenuated ferroptosis in treating IS and HS by targeting the PPARγ/AKT/GPX4 pathway. This work reveals AGNHW's anti-ferroptosis mechanism against IS and HS, but it also develops an integrated approach to demonstrate the common characteristics of drugs in treating different diseases.

Nanoparticles and neurodegeneration: Insights on multiple pathways of programmed cell death regulated by nanoparticles

Currently, nanoparticles (NPs) are extensively applied in the diagnosis and treatment of neurodegenerative diseases (NDs). With the rapid development and increasing exposure to the public, the potential neurotoxicity associated with NDs caused by NPs has attracted the researchers' attentions but their biosafety assessments are still far behind relevant application studies. Based on recent research, this review aims to conduct a comprehensive and systematic analysis of neurotoxicity induced by NPs. The 191 studies selected according to inclusion and exclusion criteria were imported into the software, and the co-citations and keywords of the included literatures were analyzed to find the breakthrough point of previous studies. According to the available studies, the routes of NPs entering into the normal and injured brain were various, and then to be distributed and accumulated in living bodies. When analyzing the adverse effects induced by NPs, we focused on multiple programmed cell deaths (PCDs), especially ferroptosis triggered by NPs and their tight connection and crosstalk that have been found playing critical roles in the pathogenesis of NDs and their underlying toxic mechanisms. The activation of multiple PCD pathways by NPs provides a scientific basis for the occurrence and development of NDs. Furthermore, the adoption of new methodologies for evaluating the biosafety of NPs would benefit the next generation risk assessment (NGRA) of NPs and their toxic interventions. This would help ensure their safe application and sustainable development in the field of medical neurobiology.

Toxicity mechanism of engineered nanomaterials: Focus on mitochondria

With the rapid development of nanotechnology, engineered nanomaterials (ENMs) are widely used in various fields. This has exacerbated the environmental pollution and human exposure of ENMs. The study of toxicity of ENMs and its mechanism has become a hot research topic in recent years. Mitochondrial damage plays an important role in the toxicity of ENMs. This paper reviews the structural damage, dysfunction, and molecular level perturbations caused by different ENMs to mitochondria, including ZnO NPs, Ag NPs, TiO2 NPs, iron oxide NPs, cadmium-based quantum dots, CuO NPs, silica NPs, carbon-based nanomaterials. Among them, mitochondrial quality control plays an important role in mitochondrial damage. We further summarize the cellular level outcomes caused by mitochondrial damage, mainly including, apoptosis, ferroptosis, pyroptosis and inflammation response. In addition, we concluded that reducing mitochondrial damage at source as well as accelerating recovery from mitochondrial damage through ENMs modification and pharmacological intervention are two feasible strategies. This review further provides new insights into the mitochondrial toxicity mechanisms of ENMs and provides a new foothold for predicting human health and environmental risks of ENMs.

Echinacoside ameliorates doxorubicin‑induced cardiac injury by regulating GPX4 inhibition‑induced ferroptosis

Echinacoside (ECH) is a compound derived from the natural herbs Cistanche and Echinacea, which has considerable protective effects on heart failure (HF). HF is characterized by myocardial damage and abnormal ferroptosis. Glutathione peroxidase 4 (GPX4) is an important regulator of ferroptosis, which plays a role in ferroptosis-related diseases. Despite this, the therapeutic mechanisms of ECH against HF remain unknown. Therefore, the aim of the present study was to investigate the cardioprotective effect and underlying mechanisms of ECH in the treatment of doxorubicin (DOX)-induced chronic HF (CHF). Cell proliferation was assessed using a CCK-8 assay. Furthermore, cardiac cell injury and oxidative stress were determined by measuring the lactate dehydrogenase (LDH), malondialdehyde (MDA), and glutathione (GSH) levels. The levels of Fe2+ and lipid reactive oxygen species (ROS), and expression of the biomarkers of ferroptosis, including GPX4 and prostaglandin-endoperoxide synthase 2 (PTGS2), were measured to examine cardiomyocyte ferroptosis. Additionally, RNA interference was used to silence Gpx4. In vitro and in vivo, ECH considerably reduced the MDA and LDH levels and increased the GSH level, thereby attenuating DOX-induced cardiac injury and oxidative stress. Meanwhile, ECH treatment decreased the lipid ROS levels and PTGS2 expression while increasing GPX4 expression, thereby alleviating DOX-induced cardiomyocyte ferroptosis. Moreover, knockdown of Gpx4 inhibited the protective effects of ECH on DOX-induced accumulation of lipid ROS in cardiomyocytes. These findings indicate that ECH can reduce DOX-induced cardiac injury by inhibiting ferroptosis via GPX4, highlighting its value as a potentially valuable therapeutic target in the management of CHF.

Better biocompatibility of nitrogen-doped graphene compared with graphene oxide by reducing cell autophagic flux blockage and cell apoptosis

Nitrogen-doped graphene (C2 N), a novel graphene-based materials, has been proposed as a potential alternative to graphene oxide (GO) in biomedical applications. However, due to the challenges in synthesizing C2 N, reports in the biomedical field are currently rare. Here, we have modified the reported procedure and successfully synthesized C2 N nanoparticles at 120°C, which we refer to as C2 N-120. The toxicity and biocompatibility of GO and C2 N-120 were evaluated using a mouse model injected with GO/C2 N-120 via the tail vein, as well as cell models treated with GO/C2 N-120. In vivo studies revealed that GO/C2 N-120 showed similar distribution patterns after tail vein injection. The liver, spleen, and lung are the major nanoparticle uptake organs of GO and C2 N-120. However, GO deposition in the major nanoparticle uptake organs was more significant than that of C2 N-120. In addition, GO deposition caused structural abnormalities, increased apoptotic cells, and enhanced macrophage infiltration whereas C2 N-120 exhibited fewer adverse effects. In vitro experiments were conducted using different cell lines treated with GO/C2 N-120. Unlike GO which induced mitochondrial damage, oxidative stress, inflammatory response, autophagic flux blockage and cell apoptosis, C2 N-120 showed lower cytotoxicity in cell models. Our data demonstrated that C2 N-120 exhibits higher biocompatibility than GO, both in vivo and in vitro, suggesting its potential for biomedical application in the future.

Polyphenolic Carbon Quantum Dots with Intrinsic Reactive Oxygen Species Amplification for Two-Photon Bioimaging and In Vivo Tumor Therapy

Recent studies indicate that mitochondrial dysfunctions and DNA damage have a critical influence on cell survival, which is considered one of the therapeutic targets for cancer therapy. In this study, we demonstrated a comparative study of the effect of polyphenolic carbon quantum dots (CQDs) on in vitro and in vivo antitumor efficacy. Dual emissive (green and yellow) shape specific polyphenolic CQDs (G-CQDs and Y-CQDs) were synthesized from easily available nontoxic precursors (phloroglucinol), and the antitumor property of the as-synthesized probe was investigated as compared to round-shaped blue emissive CQDs (B-CQDs) derived from well-reported precursor citric acid and urea. The B-CQDs had a nuclei-targeting property, and G-CQDs and Y-CQDs had mitochondria-targeting properties. We have found that the polyphenol containing CQDs (at a dose of 100 μg mL-1) specifically attack mitochondria by excess accumulation, altering the metabolism, inhibiting branching pattern, imbalanced Bax/Bcl-2 homeostasis, and ultimately generating oxidative stress levels, leading to oxidative stress-induced cell death in cancer cells in vitro. We show that G-CQDs are the main cause of oxidative stress in cancer cells because of their ability to produce sufficient •OH- and 1O2 radicals, evidenced by electron paramagnetic resonance spectroscopy and a terephthalic acid test. Moreover, the near-infrared absorption properties of the CQDs were exhibited in two-photon (TP) emission, which was utilized for TP cellular imaging of cancer cells without photobleaching. The in vivo antitumor test further discloses that intratumoral injection of G-CQDs can significantly augment the treatment efficacy of subcutaneous tumors without any adverse effects on BalB/c nude mice. We believe that shape-specific polyphenolic CQD-based nanotheranostic agents have a potential role in tumor therapy, thus proving an insight on treatment of malignant cancers.

Ferroptosis-Regulated Cell Death as a Therapeutic Strategy for Neurodegenerative Diseases: Current Status and Future Prospects

Ferroptosis is increasingly being recognized as a key element in the pathogenesis of diverse diseases. Recent studies have highlighted the intricate links between iron metabolism and neurodegenerative disorders. Emerging evidence suggests that iron homeostasis, oxidative stress, and neuroinflammation all contribute to the regulation of both ferroptosis and neuronal health. However, the precise molecular mechanisms underlying the involvement of ferroptosis in the pathological processes of neurodegeneration and its impact on neuronal dysfunction remain incompletely understood. In our Review, we provide a comprehensive analysis and summary of the potential molecular mechanisms underlying ferroptosis in neurodegenerative diseases, aiming to elucidate the disease progression of neurodegeneration. Additionally, we discuss potential therapeutic agents that modulate ferroptosis with the goal of identifying novel drug molecules for the treatment of neurodegenerative disorders.

Ferrodifferentiation regulates neurodevelopment via ROS generation

Iron is important for life, and iron deficiency impairs development, but whether the iron level regulates neural differentiation remains elusive. In this study, with iron-regulatory proteins (IRPs) knockout embryonic stem cells (ESCs) that showed severe iron deficiency, we found that the Pax6- and Sox2-positive neuronal precursor cells and Tuj1 fibers in IRP1-/-IRP2-/- ESCs were significantly decreased after inducing neural differentiation. Consistently, in vivo study showed that the knockdown of IRP1 in IRP2-/- fetal mice remarkably affected the differentiation of neuronal precursors and the migration of neurons. These findings suggest that low intracellular iron status significantly inhibits neurodifferentiation. When supplementing IRP1-/-IRP2-/- ESCs with iron, these ESCs could differentiate normally. Further investigations revealed that the underlying mechanism was associated with an increase in reactive oxygen species (ROS) production caused by the substantially low level of iron and the down-regulation of iron-sulfur cluster protein ISCU, which, in turn, affected the proliferation and differentiation of stem cells. Thus, the appropriate amount of iron is crucial for maintaining normal neural differentiation that is termed ferrodifferentiation.

Ru360 Alleviates Postoperative Cognitive Dysfunction in Aged Mice by Inhibiting MCU-Mediated Mitochondrial Dysfunction

Purpose

Ru360, a selective inhibitor of mitochondrial calcium uptake, maintains mitochondrial calcium homeostasis. To evaluate whether mitochondrial calcium uniporter (MCU)-mediated mitochondrial function is associated with the pathological process of Postoperative cognitive dysfunction (POCD), elucidate its relationship with neuroinflammation, and observe whether the relevant pathological process can be improved with Ru360.

Methods

Aged mice underwent experimental open abdominal surgery after anesthesia. Open field tests, Novel object recognition tests and Y Maze Tests were used to conduct behavioral experiments. The reactive oxygen species (ROS) content, the levels of inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), intra-mitochondrial calcium, mitochondrial membrane potential (MMP) and the activity of antioxidant superoxide dismutase (SOD) in the hippocampus of mice were detected using kits. The expression of proteins was detected using Western blot.

Results

After treatment with Ru360, MCU-mediated mitochondrial dysfunction was inhibited, neuroinflammation was reduced, and the learning ability of the mice was improved after surgery.

Conclusion

Our study demonstrated that mitochondrial function plays a crucial role in the pathology of POCD, and using Ru360 to improve mitochondrial function may be a new and necessary direction for the treatment of POCD.

Opioids Alleviate Oxidative Stress via the Nrf2/HO-1 Pathway in LPS-Stimulated Microglia

Opioids are known to have antioxidant effects and to modulate microglial function under certain conditions. It has been previously shown that opioid ligands can effectively inhibit the release of proinflammatory cytokines when stimulated with lipopolysaccharide (LPS) and convert microglia to an anti-inflammatory polarization state. Here, we used C8-B4 cells, the mouse microglial cell line activated by LPS as a model to investigate the anti-inflammatory/antioxidant potential of selected opioid receptor agonists (DAMGO, DADLE, and U-50488). We found that all of these ligands could exert cytoprotective effects through the mechanism affecting LPS-induced ROS production, NADPH synthesis, and glucose uptake. Interestingly, opioids elevated the level of reduced glutathione, increased ATP content, and enhanced mitochondrial respiration in microglial cells exposed to LPS. These beneficial effects were associated with the upregulation of the Nrf2/HO-1 pathway. The present results indicate that activation of opioid signaling supports the preservation of mitochondrial function with concomitant elimination of ROS in microglia and suggest that an Nrf2/HO-1 signaling pathway-dependent mechanism is involved in the antioxidant efficacy of opioids. Opioid receptor agonists may therefore be considered as agents to suppress oxidative stress and inflammatory responses of microglia.

Advances in Structural Modifications and Properties of Graphene Quantum Dots for Biomedical Applications

Graphene quantum dots (GQDs) are carbon-based, zero-dimensional nanomaterials and unique due to their astonishing optical, electronic, chemical, and biological properties. Chemical, photochemical, and biochemical properties of GQDs are intensely being explored for bioimaging, biosensing, and drug delivery. The synthesis of GQDs by top-down and bottom-up approaches, their chemical functionalization, bandgap engineering, and biomedical applications are reviewed here. Current challenges and future perspectives of GQDs are also presented.

Silibinin alleviates ferroptosis of rat islet β cell INS-1 induced by the treatment with palmitic acid and high glucose through enhancing PINK1/parkin-mediated mitophagy

Type 2 diabetes (T2DM) is induced by the abundance of glucose and lipids, which causes glucolipotoxicity to the pancreatic β-cells. Silibinin is a natural flavonoid possessing the regulatory activity on insulin production and therapeutic activity in diabetic mice; however, its effect on glucolipotoxicity is not fully explained. This in vitro study investigates the effects of silibinin on palmitic acid (PA) and high glucose (HG)-induced cell loss and ferroptosis of rat insulinoma INS-1 cells. In the cells treated with PA and HG, expressions of glucose transporter 4 (Glut4) and carnitine acyltransferase I (CPT1) for β-oxidation of fatty acids are reduced. Mitochondria are the metabolic organelles for glucose and fatty acids. The mitochondrial membrane potential (MMP) and ATP production were decreased, while the ROS level was elevated in the cells treated with PA and HG, indicating an induction of mitochondrial disorder. Cell loss was partially rescued by ferroptosis inhibition, suggesting an involvement of ferroptosis in the cells treated with PA and HG. More importantly, the increases in total iron, lipid ROS, MDA and COX-2, and the decrease in ferroptosis inhibitory molecules GSH, GPX4 and FSP1 appeared in the cells treated with PA and HG, confirming the occurrence of ferroptosis. Moreover, PINK1/parkin-mediated mitophagy, a vital process for selective elimination of damaged mitochondria, was blocked. Interestingly, silibinin rescued the mitochondria, restricted the ferroptosis and restored the mitophagy. By using the pharmacological stimulator and inhibitor of mitophagy, and si-RNA transfection to silence PINK1 expression, silibinin's protective effect against ferroptosis caused by PA and HG treatment was found to depend on mitophagy. Collectively, our current study reveals the new mechanisms for the protection of silibinin against the injury of INS-1 cells treated with PA and HG, elucidates the participation of ferroptosis in glucolipotoxicity, highlighting the involvement of mitophagy in defense against ferroptotic cell death.

Implications of ferroptosis in silver nanoparticle-induced cytotoxicity of macrophages

Metal nanoparticles (NPs) are widely used in daily life and commercial activities owing to their unique physicochemical properties. Consequently, there is an increasing risk of daily and occupational exposure to metal NPs, which raises concerns regarding their health hazards. Programmed cell deaths (PCDs) have been clarified to be involved in metal NP-induced cytotoxicity, including apoptosis, autophagy, and pyroptosis. However, whether and how ferroptosis, a newly recognized PCD, contributes to metal NP-induced cell death remain unclear. In this study, we investigated the ferroptotic effects of two representative metal NPs, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs), on macrophages in vitro. Our results revealed that AgNPs, rather than AuNPs, induced non-apoptotic PCD, accompanied by lipid peroxidation and iron homeostasis disorders, which are two hallmarks of ferroptosis, in macrophages. Treatment with a ferroptosis inhibitor (ferrostatin-1) and iron chelator (deferoxamine) reversed AgNP-induced PCD, corroborating the induction of ferroptosis upon exposure to AgNPs. Moreover, our results revealed that smaller AgNPs elicited greater ferroptotic effects on macrophages than larger ones. Importantly, ferroptosis in AgNP-treated macrophages was mainly triggered by AgNPs per se rather than by Ag ions. Overall, our study highlights the ferroptotic effects elicited by AgNPs in macrophages, which will promote the understanding of their cytotoxic effects and facilitate the safer design of metal nanoproducts.

Research Models to Study Ferroptosis's Impact in Neurodegenerative Diseases

Ferroptosis is a type of regulated cell death promoted by the appearance of oxidative perturbations in the intracellular microenvironment constitutively controlled by glutathione peroxidase 4 (GPX4). It is characterized by increased production of reactive oxygen species, intracellular iron accumulation, lipid peroxidation, inhibition of system Xc-, glutathione depletion, and decreased GPX4 activity. Several pieces of evidence support the involvement of ferroptosis in distinct neurodegenerative diseases. In vitro and in vivo models allow a reliable transition to clinical studies. Several in vitro models, including differentiated SH-SY5Y and PC12 cells, among others, have been used to investigate the pathophysiological mechanisms of distinct neurodegenerative diseases, including ferroptosis. In addition, they can be useful in the development of potential ferroptosis inhibitors that can be used as disease-modifying drugs for the treatment of such diseases. On the other hand, in vivo models based on the manipulation of rodents and invertebrate animals, such as Drosophila melanogaster, Caenorhabditis elegans, and zebrafish, have been increasingly used for research in neurodegeneration. This work provides an up-to-date review of the main in vitro and in vivo models that can be used to evaluate ferroptosis in the most prevalent neurodegenerative diseases, and to explore potential new drug targets and novel drug candidates for effective disease-modifying therapies.

Assessing regulated cell death modalities as an efficient tool for in vitro nanotoxicity screening: a review

Nanomedicine is a fast-growing field of nanotechnology. One of the major obstacles for a wider use of nanomaterials for medical application is the lack of standardized toxicity screening protocols for assessing the safety of newly synthesized nanomaterials. In this review, we focus on less frequently studied nanomaterials-induced regulated cell death (RCD) modalities, including eryptosis, necroptosis, pyroptosis, and ferroptosis, as a tool for in vitro nanomaterials safety evaluation. We summarize the latest insights into the mechanisms that mediate these RCDs in response to nanomaterials exposure. Comprehensive data from reviewed studies suggest that ROS (reactive oxygen species) overproduction and ROS-mediated pathways play a central role in nanomaterials-induced RCDs activation. On the other hand, studies also suggest that individual properties of nanomaterials, including size, shape, or surface charge, could determine specific toxicity pathways with consequent RCD induction as well. We anticipate that the evaluation of RCDs can become one of the mechanism-based screening methods in nanotoxicology. In addition to the toxicity assessment, evaluation of necroptosis-, pyroptosis-, and ferroptosis-promoting capacity of nanomaterials could simultaneously provide useful information for specific medical applications as could be their anti-tumor potential. Moreover, a detailed understanding of molecular mechanisms driving nanomaterials-mediated induction of immunogenic RCDs will substantially aid novel anti-tumor nanodrugs development.

Multifunctional carbon dots for glutathione detection and Golgi imaging

Glutathione (GSH) is present in almost every cell in the body and plays various integral roles in many biological processes. The Golgi apparatus is a eukaryotic organelle for the biosynthesis, intracellular distribution, and secretion of various macromolecules; however, the mechanism of GSH in the Golgi apparatus has not been fully elucidated. Here, specific and sensitive sulfur-nitrogen co-doped carbon dots (SNCDs) with orange-red fluorescence was synthesized for the detection of GSH in the Golgi apparatus. The SNCDs have a Stokes shift of 147 nm and excellent fluorescence stability, and they exhibited excellent selectivity and high sensitivity to GSH. The linear response of the SNCDs to GSH was in the range of 10-460 μM (LOD = 0.25 μΜ). More importantly, we used SNCDs with excellent optical properties and low cytotoxicity as probes, and successfully realized golgi imaging in HeLa cells and GSH detection at the same time.

Recent Advances in Nanomedicine Development for Traumatic Brain Injury

Traumatic brain injury (TBI) is one of the major causes of morbidity and mortality worldwide, and it is also a risk factor for neurodegeneration. However, there has not been perceptible progress in treating acute TBI over the last few years, mainly due to the inability of therapeutic drugs to cross the blood-brain barrier (BBB), failing to exert significant pharmacological effects on the brain parenchyma. Recently, nanomedicines are emerging as a powerful tool for the treatment of TBI where nanoscale materials (also called nanomaterials) are employed to deliver therapeutic agents. The advantages of using nanomaterials as a drug carrier include their high solubility and stability, high carrier capacity, site-specific, improved pharmacokinetics, and biodistribution. Keeping these points in consideration, this article reviews the pathophysiology, current treatment options, and emerging nanomedicine strategies for the treatment of TBI. The review will help readers to gain insight into the state-of-the-art of nanomedicine as a new tool for the treatment of TBI.

Graphene quantum dots (GQDs) induce thigmotactic effect in zebrafish larvae via modulating key genes and metabolites related to synaptic plasticity

Graphene quantum dots (GQDs) recently gain much attention for its medicinal values in treating diseases such as neurodegeneration and inflammations. However, owing to the high permeability of GQDs across the blood-brain barrier, whether its retention in the central nervous system (CNS) perturbs neurobehaviors remains less reported. In the study, the locomotion of zebrafish larvae (Danio rerio) was fully evaluated when administrated by two GQDs in a concentration gradient, respectively as reduced-GQDs (R-GQDs): 150, 300, 600, 1200, and 2400 g/L, and graphene oxide QDs (GOQDs): 60, 120, 240, 480, and 960 g/L. After exposure, the larvae were kept for locomotion analysis within one week's depuration. Substantial data showed that the basal locomotor activity of zebrafish larvae was not significantly changed by both two GQDs at low concentrations while weakened greatly with the increase of concentrations, and the total ATP levels of zebrafish larvae were also found to decrease significantly when exposed to the highest concentrations of GQDs. Next, the thigmotactic effect was observed to be remarkably induced in larvae by both two GQDs at any concentrations during exposure, and remained strong in larvae treated by high concentrations of R-GQDs after 7 days' depuration. To be noted, we found that GQDs affected the synaptic plasticity via downregulating the mRNA levels of NMDA and AMPA receptor family members as well as the total glutamine levels in zebrafish larvae. Together, our study presented robust data underlying the locomotor abnormalities aroused by GQDs in zebrafish larvae and indicated the potential adverse effects of GQDs on synaptic plasticity.

Ferroptosis is critical for phthalates driving the blood-testis barrier dysfunction via targeting transferrin receptor

The global rate of human male infertility is rising at an alarming rate owing to environmental and lifestyle changes. Phthalates are the most hazardous chemical additives in plastics and have an apparently negative impact on the function of male reproductive system. Ferroptosis is a recently described form of iron-dependent cell death and has been linked to several diseases. Transferrin receptor (TfRC), a specific ferroptosis marker, is a universal iron importer for all cells using extracellular transferrin. We aim to investigate the potential involvement of ferroptosis during male reproductive toxicity, and provide means for drawing conclusions on the effect of ferroptosis in phthalates-induced male reproductive disease. In this study, we found that di (2-ethylhexyl) phthalate (DEHP) triggered blood-testis barrier (BTB) dysfunction in the mouse testicular tissues. DEHP also induced mitochondrial morphological changes and lipid peroxidation, which are manifestations of ferroptosis. As the primary metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP) induced ferroptosis by inhibiting glutathione defense network and increasing lipid peroxidation. TfRC knockdown blocked MEHP-induced ferroptosis by decreasing mitochondrial and intracellular levels of Fe²⁺. Our findings indicate that TfRC can regulate Sertoli cell ferroptosis and therefore is a novel therapeutic molecule for reproductive disorders in male patients with infertility.

Proteomics and Metabolomics Analysis Reveals the Toxicity of ZnO Quantum Dots on Human SMMC-7721 Cells

Purpose

ZnO quantum dots (QDs) are composed of less toxic metals than other QDs but have the same interesting photochemical properties. Thus, they have received considerable attention recently. Nevertheless, their toxicity cannot be ignored.

Methods

In this study, we incubated ZnO QDs with human SMMC-7721 cells for 24 h to assess their nanotoxicity through proteomics (Fold change >1.5 and p-value <0.05) and metabolomics (Fold change ≥ 1.5; VIP ≥ 1; p-value < 0.05) analyses.

Results

Both of 174 and 219 significantly changed metabolites were identified in human SMMC-7721 cells treated with 20 and 50 µg/mL ZnO QDs, respectively. ZnO QDs significantly modified metabolic pathways, including purine metabolism, ferroptosis, morphine addiction, alcoholism, cGMP-PKG signaling, and Cushing syndrome. Moreover, we identified 105 and 8 differentially expressed proteins in cells treated with 20 and 50 µg/mL ZnO QDs, and the pathways of alcoholism and Cushing syndrome were enriched.

Conclusion

ZnO QDs did not affect cell viability in a CCK8 assay, but disturbed the level of intracellular metabolites and proteins at 20 µg/mL. The KEGG analyses of the metabolomics and proteomics data both enriched the alcoholism and Cushing syndrome pathways. These results provide an experimental basis for future research on the safe use of nanomaterials.

Elucidating the progress and impact of ferroptosis in hemorrhagic stroke

Hemorrhagic stroke is a devastating cerebrovascular disease with high morbidity and mortality, for which effective therapies are currently unavailable. Based on different bleeding sites, hemorrhagic stroke can be generally divided into intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), whose pathogenesis share some similarity. Ferroptosis is a recently defined programmed cell deaths (PCDs), which is a critical supplement to the hypothesis on the mechanism of nervous system injury after hemorrhagic stroke. Ferroptosis is characterized by distinctive morphological changes of mitochondria and iron-dependent accumulation of lipid peroxides. Moreover, scientists have successfully demonstrated the involvement of ferroptosis in animal models of ICH and SAH, indicating that ferroptosis is a promising target for hemorrhagic stroke therapy. However, the studies on ferroptosis still faces a serious of technical and theoretical challenges. This review systematically elaborates the role of ferroptosis in the pathogenesis of hemorrhagic stroke and puts forward some opinions on the dilemma of ferroptosis research.

The Role of Mitochondria-Targeting miRNAs in 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. Arterial hypertension (AH) is most often the cause of ICH, followed by atherosclerosis, blood diseases, inflammatory changes in cerebral vessels, intoxication and vitamin deficiencies. Cerebral hemorrhage can occur by diapedesis or as a result of a ruptured vessel. AH is difficult to treat, requires surgery and can lead to disability or death. One of the important directions in the study of the pathogenesis of ICH is mitochondrial dysfunction and its regulation. The key role of mitochondrial dysfunction in AH and atherosclerosis, as well as in the development of brain damage after hemorrhage, has been acknowledged. MicroRNAs (miRNAs) are a class of non-coding RNAs (about 18-22 nucleotides) that regulate a variety of biological processes including cell differentiation, proliferation, apoptosis, etc., primarily through gene repression. There is growing evidence to support dysregulated miRNAs in various cardiovascular diseases, including ICH. Further, the realization of miRNAs within mitochondrial compartment has challenged the traditional knowledge of signaling pathways involved in the regulatory network of cardiovascular diseases. However, the role of miRNAs in mitochondrial dysfunction for ICH is still under-appreciated, with comparatively much lesser studies and investigations reported, than those in other cardiovascular diseases. In this review, we summarize the up-to-date findings on the published role miRNAs in mitochondrial function for ICH, and the potential use of miRNAs in clinical settings, such as potential therapeutic targets and non-invasive diagnostic/prognostic biomarker tools.

Metabolic alteration of Tetrahymena thermophila exposed to CdSe/ZnS quantum dots to respond to oxidative stress and lipid damage

CdSe/ZnS Quantum dots (QDs) are possibly released to surface water due to their extensive application. Based on their high reactivity, even small amounts of toxicant QDs will disturb water microbes and pose a risk to aquatic ecology. Here, we evaluated CdSe/ZnS QDs toxicity to Tetrahymena thermophila (T. thermophila), a model organism of the aquatic environment, and performed metabolomics experiments. Before the omics experiment was conducted, QDs were found to induce inhibition of cell proliferation, and reactive oxygen species (ROS) production along with Propidium iodide labeled cell membrane damage indicated oxidative stress stimulation. In addition, mitochondrial ultrastructure alteration of T. thermophila was also confirmed by Transmission Electron Microscope results after 48 h of exposure to QDs. Further results of metabolomics detection showed that 0.1 μg/mL QDs could disturb cell physiological and metabolic metabolism characterized by 18 significant metabolite changes, of which twelve metabolites improved and three decreased significantly compared to the control. Kyoto Encyclopedia of Genes and Genomes analysis showed that these metabolites were involved in the ATP-binding cassette transporter and purine metabolism pathways, both of which respond to ROS-induced cell membrane damage. In addition, purine metabolism weakness might also reflect mitochondrial dysfunction associated with energy metabolism and transport abnormalities. This research provides deep insight into the potential risks of quantum dots in aquatic ecosystems.

The impact of oxidative stress-induced mitochondrial dysfunction on diabetic microvascular complications

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycaemia, with absolute insulin deficiency or insulin resistance as the main cause, and causes damage to various target organs including the heart, kidney and neurovascular. In terms of the pathological and physiological mechanisms of DM, oxidative stress is one of the main mechanisms leading to DM and is an important link between DM and its complications. Oxidative stress is a pathological phenomenon resulting from an imbalance between the production of free radicals and the scavenging of antioxidant systems. The main site of reactive oxygen species (ROS) production is the mitochondria, which are also the main organelles damaged. In a chronic high glucose environment, impaired electron transport chain within the mitochondria leads to the production of ROS, prompts increased proton leakage and altered mitochondrial membrane potential (MMP), which in turn releases cytochrome c (cyt-c), leading to apoptosis. This subsequently leads to a vicious cycle of impaired clearance by the body's antioxidant system, impaired transcription and protein synthesis of mitochondrial DNA (mtDNA), which is responsible for encoding mitochondrial proteins, and impaired DNA repair systems, contributing to mitochondrial dysfunction. This paper reviews the dysfunction of mitochondria in the environment of high glucose induced oxidative stress in the DM model, and looks forward to providing a new treatment plan for oxidative stress based on mitochondrial dysfunction.

Copper-cysteamine nanoparticle-mediated microwave dynamic therapy improves cancer treatment with induction of ferroptosis

Photodynamic Therapy (PDT) holds a great promise for cancer patients, however, due to the hypoxic characteristics of most solid tumors and the limited penetration depth of light in tissues, the extensive clinical application of PDT is limited. Herein, we report microwave induced copper-cysteamine (Cu-Cy) nanoparticles-based PDT as a promising cancer treatment to overcome cancer resistance in combination with ferroptosis. The treatment efficiency of Cu-Cy-mediated microwave dynamic therapy (MWDT) tested on HCT15 colorectal cancer (CRC) cells via cell titer-blue cell viability assay and live/dead assay reveal that Cu-Cy upon MW irradiation can effectively destroy HCT15 CRC cells with average IC-50 values of 20 μg/mL. The cytotoxicity of Cu-Cy to tumor cells after MW stimulation can be alleviated by ferroptosis inhibitor. Furthermore, Cu-Cy mediated MWDT could deplete glutathione peroxide 4 (GPX4) and enhance lipid peroxides (LPO) and malondialdehyde (MDA). Our findings demonstrate that MW-activated Cu-Cy killed CRC cells by inducing ferroptosis. The superior in vivo antitumor efficacy of the Cu-Cy was corroborated by a HCT15 tumor-bearing mice model. Immunohistochemical experiments showed that the GPX4 expression level in Cu-Cy + MW group was significantly lower than that in other groups. Overall, these findings demonstrate that Cu-Cy nanoparticles have a safe and promising clinical application prospect in MWDT for deep-seated tumors and effectively inhibit tumor cell proliferation by inducing ferroptosis, which provides a potential solution for cancer resistance.

The emerging roles of ferroptosis in cells of the central nervous system

Ferroptosis is morphologically characterized by shrunken mitochondria and biochemically characterized by iron overload, lipid peroxidation and lipid reactive oxygen species (ROS) accumulation; these phenomena are suppressed by iron chelation, genetic inhibition of cellular iron uptake, and intervention on other pathways such as lipid metabolism. The induction of ferroptosis may be related to pathological cellular conditions in the central nervous system (CNS); thus, ferroptosis may cause disability via CNS damage. Here, we review the role of ferroptosis in the main cells of the CNS, including glial cells, neurons, and pericytes; in various diseases of the CNS; and in the interaction of glia and neurons in CNS diseases. Some small molecules and traditional Chinese drugs which inhibit ferroptosis in cells of the CNS are shown as potential therapeutic strategies for neurological diseases.

The Neurotoxic Mechanisms of Graphene Family Nanomaterials at the Cellular Level: A Solution-based Approach Review

The graphene family nanomaterials (GFNs) have been recognized to have potential applications in biomedicine, especially in the rag nostic, drug delivery and neuroimaging. Multiple studies have examined the neurotoxicity of GFNs to assay their toxic effects on organisms and ecosystems. In this article, we reviewed the different neurotoxicity effects of GFNs at intracellular levels, including nucleus-related effects and cytosolic mechanisms, as well as extracellular levels, including effects on enzyme activity, oxidative stress, behavior, neurotransmitters, and central nervous system (CNS). Furthermore, for the sake of the solution, we discussed the reducing ways of graphene toxicity. A schematic description is shown in Fig. (1).

Silica Nanoparticles Cause Activation of NLRP3 Inflammasome in-vitro Model-Using Microglia

INTRODUCTION

Silica nanoparticles (SiNPs) have been widely used in food, cosmetics, medicine and other fields; however, there have been growing concerns regarding their potential adverse effects on health. A large number of studies have confirmed that SiNPs with small particle diameters can pass through the blood brain barrier, causing irreversible damage to the nervous system. This study aims to further explore the molecular mechanism of neurotoxicity of SiNPs and provide a toxicological basis for the medical application of SiNPs.

METHODS

We conducted an in vitro study using neuroimmune cells (mouse microglial cells, BV2) of the central nervous system to study inflammation and ferroptosis after exposure to SiNPs. We detected cell viability, morphology and ultrastructure, antioxidant function, inflammation, and ferroptosis-related proteins to explore the role of pyroptosis and ferroptosis in the damage of BV2 cells induced by SiNPs. We further explored the relationship between the inflammatory response and ferroptosis induced by SiNPs by silencing the NOD-like receptor thermal protein domain associated protein 3 (NLRP3) gene and inhibiting ferroptosis.

RESULTS

The results showed that SiNPs could invade the cytoplasm, change the ultrastructure, activate NLRP3 inflammasomes, release a large number of inflammatory factors, and trigger inflammatory reaction. We also found that SiNPs could disrupt cellular antioxidant function, increase intracellular ferrous ion level and induce ferroptosis. In addition, both inflammation and ferroptosis are alleviated in NLRP3 gene-silenced cells.

CONCLUSION

SiNPs could induce BV2 cytotoxicity through inflammatory response and ferroptosis, which may be mediated by the activation of the NLRP3 inflammasomes.

Therapeutic targeting of microglia mediated oxidative stress after neurotrauma

Inflammation is a primary component of the central nervous system injury response. Traumatic brain and spinal cord injury are characterized by a pronounced microglial response to damage, including alterations in microglial morphology and increased production of reactive oxygen species (ROS). The acute activity of microglia may be beneficial to recovery, but continued inflammation and ROS production is deleterious to the health and function of other cells. Microglial nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), mitochondria, and changes in iron levels are three of the most common sources of ROS. All three play a significant role in post-traumatic brain and spinal cord injury ROS production and the resultant oxidative stress. This review will evaluate the current state of therapeutics used to target these avenues of microglia-mediated oxidative stress after injury and suggest avenues for future research.

New Target for Prevention and Treatment of Neuroinflammation: Microglia Iron Accumulation and Ferroptosis

Microglia play an important role in maintaining central nervous system homeostasis and are the major immune cells in the brain. In response to internal or external inflammatory stimuli, microglia are activated and release numerous inflammatory factors, thus leading to neuroinflammation. Inflammation and microglia iron accumulation promote each other and jointly promote the progression of neuroinflammation. Inhibiting microglia iron accumulation prevents neuroinflammation. Ferroptosis is an iron-dependent phospholipid peroxidation-driven type of cell death regulation. Cell iron accumulation causes the peroxidation of cell membrane phospholipids and damages the cell membrane. Ultimately, this process leads to cell ferroptosis. Iron accumulation or phospholipid peroxidation in microglia releases a large number of inflammatory factors. Thus, inhibiting microglia ferroptosis may be a new target for the prevention and treatment of neuroinflammation.

FTH1- and SAT1-Induced Astrocytic Ferroptosis Is Involved in Alzheimer’s Disease: Evidence from Single-Cell Transcriptomic Analysis

Objectives: Despite significant advances in neuroscience, the mechanisms of AD are not fully understood. Single-cell RNA sequencing (scRNA-seq) techniques provide potential solutions to analyze cellular composition of complex brain tissue and explore cellular and molecular biological mechanisms of AD. Methods: We investigated cellular heterogeneity in AD via utilization of bioinformatic analysis of scRNA-seq in AD patients and healthy controls from the Gene Expression Omnibus (GEO) database. The “GOplot” package was applied to explore possible biological processes in oligodendrocytes, astrocytes, and oligodendrocyte progenitor cells (OPCs). Expression patterns and biological functions of differentially expressed genes (DEGs) from scRNA-seq data were validated in RNA sequencing data. DEGs in astrocytes interacted with ferroptosis-related genes in FerrDb. CCK-8 and EdU assays were performed to measure cell proliferation ability. ROS, Fe²⁺ level, mitochondrial membrane potentials, iron concentrations, and total iron binding capacity (TIBC) in serum were evaluated. Y-maze and elevated maze were used to measure anxiety-like behavior. Autonomous and exploration behaviors or learning and memory ability in mice were analyzed using open field test and novel object recognition test. Results: Multiple clusters were identified, including oligodendrocytes, astrocytes, OPCs, neurons, microglia, doublets, and endothelial cells. Astrocytes were significantly decreased in AD, while oligodendrocytes and OPCs increased. Cell-to-cell ligand–receptor interaction analysis revealed that astrocytes, neurons, and OPCs mainly established contacts with other cells via the NRG3–ERBB4 ligand–receptor pair. GO and KEGG analyses found that astrocytes were enriched in the ferroptosis pathway. FTH1 and SAT1 in astrocytes were identified as hub mRNAs associated with ferroptosis. Serum iron concentration of 5xFAD mice was higher than that of WT, and emotional and cognitive function were significantly impaired as compared to WT. Serum iron concentration was negatively correlated with number of astrocytes and percentage of time spent entering the novelty arm in the Y-maze test, while it was positively correlated with percentage of time spent in the central area. Meanwhile, number of astrocytes was negatively correlated with percentage of time spent in the central area, while it was positively correlated with percentage of time spent entering the novelty arm. Conclusions: Through scRNA-seq analysis, we found that ferroptosis was activated in astrocytes and may contribute to the pathophysiological process in the entorhinal cortex. FTH1 and SAT1 were identified to impact astrocyte ferroptosis. Emotional and cognitive impairment in AD was associated with astrocyte ferroptosis. Our findings provide clues to reveal the pathophysiological processes following AD at the cellular level and highlight potential drug targets for the treatment of AD.

The role of ferroptosis mediated by NRF2/ERK-regulated ferritinophagy in CdTe QDs-induced inflammation in macrophage

Cadmium telluride quantum dots (CdTe QDs) exist in the environment due to the abandonment of products. There is a potential risk to organisms and toxic mechanism is worth exploring. In this study, 12.5 μmol/Kg body weight CdTe QDs triggered systemic and local inflammatory response in mice and activated macrophages, then the mechanism of activating macrophages to overexpress IL-1β and IL-6 was explored. RAW264.7 macrophages were used, and after macrophages exposing to 1 μM CdTe QDs for 24 h, oxidative stress occurred. Further investigation found that CdTe QDs triggered ferroptosis in RAW264.7 cells. And deferoxamine mesylate alleviated the excessive lipid hydroperoxide caused by QDs. Mechanistically, CdTe QDs-provoked decrease of nuclear factor erythroid 2-related factor 2 (NRF2) elicited phosphorylation of extracellular regulated protein kinases1/2 (ERK1/2) and then activated ferritinophagy, which made ferritin heavy chain 1 (FTH1) degraded in lysosome and proteasome to release free iron ions to initiate ferroptosis in macrophages. This paper updates the mechanism of macrophage activation by CdTe QDs with regard to ferritinophagy, and more importantly, identifies the key role of NRF2 and ERK1/2. Our research extends the role of ferroptosis in inflammatory responses triggered by nanoparticles (NPs) in macrophages and provides insightful reference for toxicity assessment of NPs.

An adverse outcome pathway-based approach to assess aurantio-obtusin-induced hepatotoxicity

Cassiae semen (CS), a traditional Chinese medicine, has various bioactivities in preclinical and clinical practice. Aurantio-obtusin (AO) is a major anthraquinone (AQ) ingredient derived from CS, and has drawn public concerns over its potential hepatotoxicity. We previously found that AO induces hepatic necroinflammation by activating NOD-like receptor protein 3 inflammasome signaling. However, the mechanisms contributing to AO-motivated hepatotoxicity remain unclear. Herein, we evaluated hepatotoxic effects of AO on three liver cell lines by molecular and biochemical analyses. We found that AO caused cell viability inhibition and biochemistry dysfunction in the liver cells. Furthermore, AO elevated reactive oxygen species (ROS), followed by mitochondrial dysfunction (decreases in mitochondrial membrane potential and adenosine triphosphate) and apoptosis (increased Caspase-3, Cleaved caspase-3, Cytochrome c and Bax expression, and decreased Bcl-2 expression). We also found that AO increased the lipid peroxidation (LPO) and enhanced ferroptosis by activating cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA)-cAMP response element-binding (CREB) pathway (increases in PKA, p-CREB, acyl-CoA synthetase long chain family member 4). Based on these results, we used an AOP framework to explore the mechanisms underlying AO's hepatotoxicity. It starts from molecular initiating event (ROS), and follows two critical toxicity pathways (i.e., mitochondrial dysfunction-mediated apoptosis and LPO-enhanced ferroptosis) over a series of key events (KEs) to the adverse outcome of hepatotoxicity. The results of an assessment confidence in the adverse outcome pathway (AOP) framework supported the evidence concordance in dose-response, temporal and incidence relationships between KEs in AO-induced hepatotoxicity. This study's findings offer a novel toxicity pathway network for AO-caused hepatotoxicity.

How UV radiation and pH alternation impact graphene oxide mediated environmental toxicant adsorption and resulting safety characteristics - A toxicology study beyond a classic carrier effect

Once released into water, the widely used graphene oxide (GO) is likely to adsorb classical environmental pollutants, exemplified by Microcystin-LR (MCLR) that is a representative double-bond rich liver-toxic endotoxin. While GO-mediated carrier effect is fairly predictable, the involvement of environmental factors like UV and pH may add additional level of sophistication as these factors may impact the adsorption capacity of GO to MCLR. Here, we firstly investigated the changes of GO structure under different UV-radiation durations and pH conditions with a view to establish the correlation in terms of MCLR adsorption onto GO. We demonstrated that GO reduction especially oxygen-containing groups reduction induced by UV- radiation caused the compromised adsorption MCLR capacity on GO. Besides, the higher pH decreased the non-biological MCLR adsorption to GO by reducing GO defect sites and increasing electrostatic repulsion. These abiotic discoveries were further investigated to compare the safety features of GO-MCLR complex. Under dark condition (pH = 7), we revealed the cytotoxicity of GO-MCLR to normal liver cells, which involved the ROS generation and cell ferroptosis caused by Fe²⁺ accumulation. Introduction of UV and pH alternation in environment impacted GO-mediated environmental toxicant adsorption and resulting safety characteristics, which reminded us environmental factors should not be ignored in the GO-mediated carrier effect.

Optical Visualization of Red-GQDs’ Organelles Distribution and Localization in Living Cells

Recently, there has been a rapidly expanding interest in a new nanomaterial, graphene quantum dots (GQDs), owing to its profound potential in various advanced applications. At present, the study of GQDs mainly focuses on the new synthesis methods and surface modification. However, revealing the intracellular distribution of GQDs is currently not available, limiting in-depth understanding of its biological regulatory mechanism. To fill up this gap, the visualization study of red fluorescent graphene quantum dots (Red-GQDs) is helpful to clarify their subcellular distribution and metabolism in living cells system. Here, in this study, two-photon laser confocal microscopy was used to deeply analyze the uptake and subcellular distribution of Red-GQDs by HeLa cells at different concentrations and times through visual observation and discussed the effect of Red-GQDs on the metabolic of HeLa cells. The results indicated that Red-GQDs could be well-absorbed by HeLa cells and further revealed the differential distribution of Red-GQDs in different organelles (lysosomes and mitochondria) in a time-dependent manner. In addition, we confirmed that Red-GQDs significantly affect cell biological functions. Low concentrations of Red-GQDs are related to the autophagy pathway of cells, and high concentrations of Red-GQDs can induce ferroptosis in cells and promote the secretion of cellular exosomes. In the present study, the distribution and metabolic pathways of Red-GQDs in the subcellular structure of cells were characterized in detail through visual analysis, which can bring positive reference for the application of Red-GQDs in the future.