Redox homeostasis maintained by GPX4 facilitates STING activation

Blue light induced ferroptosis in retinal damage via iron overload-associated oxidative stress

The issue of light pollution has garnered increased attention recently, largely due to the widespread use of electronic devices. Blue light (BL) holds the highest energy level among visible light and has been extensively researched for its potential to cause damage to the retina. Ferroptosis, a recently identified form of programmed cell death form, has been linked to retinal diseases. However, the connection between BL-induced retinal damage and ferroptosis remains elusive. This study aims to investigate the involvement of ferroptosis in retinal damage under BL exposure and its underlying mechanism. In this study, a mouse retinal damage model and cultured ARPE-19 cells exposed to BL were employed. Various techniques including Haematoxylin-eosin staining, fundus photography, immunostaining, and transmission electron microscopy were employed to examine retinal structure and morphology changes resulting from BL exposure. To identify ferroptosis levels in vitro, we employed DCFH-DA, C11-BODIPY 581/591, and FeRhoNox™-1 probes. Additionally, real-time PCR and western blotting techniques were used to uncover potential targets in BL-induced ferroptosis. Our study showed that BL exposure can result in iron overload, oxidative stress, evidenced by increased markers TFR1, ACSL4, HO-1 and decreased expression level of SOD2, CAT and ferroptosis-associated gene of GPX4. Interestingly, we found that Deferoxamine mesylate, a compound capable of chelating excess Fe2+ caused by BL, effectively mitigated lipid peroxidation, and alleviated retinal damage both in vivo and in vitro. The discoveries will advance our knowledge of BL-induced retinal damage.

MINT3 promotes STING activation and facilitates antiviral immune responses

Stimulator-of-interferon genes (STING) translocation is the rate-limiting step in the cGAS-STING signaling which detects cytosolic DNA and produces type I interferons. However, the mechanism by which this process is modulated remains to be further clarified. In the present study, we identified munc18-1-interacting protein 3 (MINT3) as a positive regulator of STING signaling. MINT3 promotes type I interferons production induced by herpes simplex virus-1 (HSV-1) infection and ISD or cGAMP stimulation in mouse peritoneal macrophages. Deficiency of Mint3 greatly inhibited STING and IRF3 activation in macrophages. Mint3 knockdown also attenuated STING and IRF3 activation in macrophages, human THP-1 cells, and RAW264.7 cells. Mechanistically, MINT3 interacted with STING, selectively enhanced its K63-linked polyubiquitination and facilitated STING translocation to the Golgi, resulting in the enhancement of the STING and TBK1 interaction. Furthermore, MINT3 also facilitated HSV-1-induced innate antiviral immune responses and impaired HSV-1 replication in vitro and in vivo. Interestingly, we showed that the expression of MINT3 was dramatically elevated during HSV-1 infection, and ISD stimulation in macrophages. Thus, we have revealed a feedback mechanism for the regulation of the cGAS-STING pathway, providing a promising therapeutic target for the treatment of disorders triggered by aberrant STING activity.

STING and metabolism-related diseases: Roles, mechanisms, and applications

The stimulator of interferon genes (STING) pathway plays a critical role in innate immunity, acting as a central mediator that links cytosolic DNA sensing to inflammatory signaling. STING not only responds to cellular metabolic states but also actively regulates key metabolic processes, including glycolysis, lipid metabolism, and redox balance. This bidirectional interaction underscores the existence of a dynamic feedback mechanism between STING signaling and metabolic pathways, which is essential for maintaining cellular homeostasis. This review provides a comprehensive analysis, beginning with an in-depth overview of the classical STING signaling pathway, followed by a detailed examination of its reciprocal regulation of various metabolic pathways. Additionally, it explores the role and mechanisms of STING signaling in metabolic disorders, including obesity, diabetes, and atherosclerosis. By integrating these insights into the mutual regulation between STING and its metabolism, novel therapeutic strategies targeting this pathway in metabolic diseases have been proposed.

Inhibition of the cGAS-STING pathway: contributing to the treatment of cerebral ischemia-reperfusion injury

The cGAS-STING pathway plays an important role in ischemia-reperfusion injury in the heart, liver, brain, and kidney, but its role and mechanisms in cerebral ischemia-reperfusion injury have not been systematically reviewed. Here, we outline the components of the cGAS-STING pathway and then analyze its role in autophagy, ferroptosis, cellular pyroptosis, disequilibrium of calcium homeostasis, inflammatory responses, disruption of the blood-brain barrier, microglia transformation, and complement system activation following cerebral ischemia-reperfusion injury. We further analyze the value of cGAS-STING pathway inhibitors in the treatment of cerebral ischemia-reperfusion injury and conclude that the pathway can regulate cerebral ischemia-reperfusion injury through multiple mechanisms. Inhibition of the cGAS-STING pathway may be helpful in the treatment of cerebral ischemia-reperfusion injury.

Epigenetic regulation of ferroptosis in gastrointestinal cancers (Review)

Ferroptosis is a type of iron‑dependent cell death characterized by excessive lipid peroxidation and may serve as a potential therapeutic target in cancer treatment. While the mechanisms governing ferroptosis continue to be explored and elucidated, an increasing body of research highlights the significant impact of epigenetic modifications on the sensitivity of cancer cells to ferroptosis. Epigenetic processes, such as DNA methylation, histone modifications and non‑coding RNAs, have been identified as key regulators that modulate the expression of ferroptosis‑related genes. These alterations can either enhance or inhibit the sensitivity of gastrointestinal cancer (GIC) cells to ferroptosis, thereby affecting the fate of GICs. Drugs that target epigenetic markers for advanced‑stage cancer have shown promising results in enhancing ferroptosis and inhibiting tumor growth. This review explores the intricate relationship between epigenetic regulation and ferroptosis in GICs. Additionally, the potential of leveraging epigenetic modifications to trigger ferroptosis in GICs is investigated. This review highlights the importance of further research to elucidate the specific mechanisms underlying epigenetic control of ferroptosis and to advance the development of novel therapeutic approaches.

The cGAS-STING-mediated ROS and ferroptosis are involved in manganese neurotoxicity

Manganese (Mn) has been characterized as an environmental pollutant. Excessive releases of Mn due to human activities have increased Mn levels in the environment over the years, posing a threat to human health and the environment. Long-term exposure to high concentrations of Mn can induce neurotoxicity. Therefore, toxicological studies on Mn are of paramount importance. Mn induces oxidative stress through affecting the level of reactive oxygen species (ROS), and the overabundance of ROS further triggers ferroptosis. Additionally, Mn2+ was found to be a novel activator of the cyclic guanosine-adenosine synthase (cGAS)-stimulator of interferon genes (STING) pathway in the innate immune system. Thus, we speculate that Mn exposure may promote ROS production by activating the cGAS-STING pathway, which further induces oxidative stress and ferroptosis, and ultimately triggers Mn neurotoxicity. This review discusses the mechanism between Mn-induced oxidative stress and ferroptosis via activation of the cGAS-STING pathway, which may offer a prospective direction for future in-depth studies on the mechanism of Mn neurotoxicity.

Rebalancing redox homeostasis: A pivotal regulator of the cGAS-STING pathway in autoimmune diseases

Autoimmune diseases (ADs) arise from the breakdown of immune tolerance to self-antigens, leading to pathological tissue damage. Proinflammatory cytokine overproduction disrupts redox homeostasis across diverse cell populations, generating oxidative stress that induces DNA damage through multiple mechanisms. Oxidative stress-induced alterations in membrane permeability and DNA damage can lead to the recognition of double-stranded DNA (dsDNA), mitochondrial DNA (mtDNA) and micronuclei-DNA (MN-DNA) by DNA sensors, thereby initiating activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. While previous reviews have characterized cGAS-STING activation in autoimmunity, the reciprocal regulation between redox homeostasis and cGAS-STING activation remains insufficiently defined. This narrative review examines oxidative stress-mediated DNA damage as a critical driver of pathological cGAS-STING signaling and delineates molecular mechanisms linking redox homeostasis to autoimmune pathogenesis. Furthermore, we propose therapeutic strategies that combine redox restoration with the attenuation of aberrant cGAS-STING activation, thereby establishing a mechanistic foundation for precision interventions in autoimmune disorders. METHODS: The manuscript is formatted as a narrative review. We conducted a comprehensive search strategy using electronic databases such as PubMed, Google Scholar and Web of Science. Various keywords were used, such as "cGAS-STING," "Redox homeostasis," "Oxidative stress," "pentose phosphate pathway," "Ferroptosis," "mtDNA," "dsDNA," "DNA damage," "Micronuclei," "Reactive oxygen species," "Reactive nitrogen species," "Nanomaterial," "Autoimmune disease," "Systemic lupus erythematosus," "Type 1 diabetes," "Rheumatoid arthritis," "Multiple sclerosis," "Experimental autoimmune encephalomyelitis," "Psoriasis," etc. The titles and abstracts were reviewed for inclusion into this review. After removing duplicates and irrelevant studies, 174 articles met inclusion criteria (original research, English language).

Cryptotanshinone alleviates cerebral ischemia reperfusion injury by regulating ferroptosis through the PI3K/AKT/Nrf2 and SLC7A11/GPX4 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

The Cryptotanshinone (CT) is a kind of Chinese medicine extracted from salvia miltiorrhiza, which has various pharmacological activities and is widely used in the treatment of diseases.

AIM OF THE STUDY

The objective is to delve into the mechanism by which cryptotanshinone (CT) exerts its effects on rats with the middle cerebral artery occlusion/reperfusion (MCAO/R) model. Additionally, it aims to further assess the interplay between inflammation and oxidative stress, along with the underlying mechanism of CT's anti-ferroptosis function.

MATERIALS AND METHODS

We constructed the middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats. The effects of cryptotanshinone (CT) were evaluated using 2,3,5 - triphenyltetrazolium chloride (TTC) staining, behavioral assays, immunofluorescence, hematoxylin - eosin (HE) staining, and Nissl staining. Additionally, in vitro, cell viability was assessed by the Cell Counting Kit - 8 (CCK - 8) assay following experimental dosing. Oxygen - glucose deprivation/oxidation (OGD/R) models were established in PC12 and BV2 cells. Flow cytometry was employed to detect cellular reactive oxygen species (ROS) expression. The activities of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-px), and Mitochondrial Membrane Potential Assay Kit with JC-1(JC-1) were measured using biochemical methods. Inflammatory factor levels were determined using enzyme-linked immunosorbent assay (ELISA) kits. Immunoblotting was used to detect the levels of rat phosphatidylinositol 3 - kinase (PI3K), phosphorylated-PI3K (P-PI3K), protein kinase B (AKT), phosphorylated - AKT (P-AKT), nuclear factor erythroid 2 - related factor 2 (Nrf2), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4).

RESULTS

In rats with the MCAO/R model, CT demonstrated the ability to decrease ROS levels, enhance the activity of glutathione (GSH), mitigate inflammation, augment the activity of glutathione peroxidase 4 (GPX4), inhibit ferroptosis, safeguard neurons, and facilitate the restoration of nerve function. Results from network pharmacology indicated that the action of CT might be mediated via the PI3K/Akt signaling pathway. Simultaneously, in-vivo investigations revealed that CT curbs ferroptosis through the PI3K/AKT/Nrf2 and SLC7A11/GPX4 signaling pathways.

CONCLUSION

CT can inhibit ferroptosis by inhibiting the vicious cycle between oxidative stress and inflammation, protect neurons and promote motor function recovery.

Targeting mitochondria with natural polyphenols for treating Neurodegenerative Diseases: a comprehensive scoping review from oxidative stress perspective

Neurodegenerative diseases are a class of conditions with widespread detrimental impacts, currently lacking effective therapeutic drugs. Recent studies have identified mitochondrial dysfunction and the resultant oxidative stress as crucial contributors to the pathogenesis of neurodegenerative diseases. Polyphenols, naturally occurring compounds with inherent antioxidant properties, have demonstrated the potential to target mitochondria and mitigate oxidative stress. This therapeutic potential has garnered significant attention in recent years. Investigating the mitochondrial targeting capacity of polyphenols, their role in functional regulation, and their ability to modulate oxidative stress, along with exploring novel technologies and strategies for modifying polyphenol compounds and their formulations, holds promise for providing new avenues for the treatment of neurodegenerative diseases.

ATF4 participates in perfluorooctane sulfonate-induced neurotoxicity by regulating ferroptosis

Evidence from animal and human research suggests that perfluorooctane sulfonate (PFOS), a prevalent persistent organic pollutant (POP), exerts neurotoxic effects, but the precise mechanisms remain unclear. Additionally, the function of activating transcription factor 4 (ATF4), a crucial modulator of cellular metabolism, redox balance, and survival, in PFOS-induced neurotoxicity has not been fully elucidated. In vitro metabolomics studies revealed that PFOS elevated the intracellular concentration of reactive oxygen species (ROS) and lowered the levels of reduced L-glutathione (GSH). Significant alterations in the mRNA and protein expression levels of ferroptosis-related biomarkers, including ferroptosis-related genes [NRF2, nuclear receptor coactivator 4 (NCOA4), KEAP1, xCT/SLC7A11, GPX4, and FTH1], cellular iron, and lipid peroxidation were observed. Moreover, erastin (Ers) exacerbated lipid peroxidation, which was alleviated by ferrostatin-1 (Fer-1) and N-acetyl-L-cysteine (NAC). In mice, PFOS exposure damaged the structure and function of the hippocampus, including decreasing the number of neurons and impairing spatial learning and memory capacity. Importantly, ferroptosis was also observed in vivo, concomitant with the inhibition of ATF4, which was also observed in vitro. ATF4 silencing further increased ROS levels, lipid peroxidation, and ferroptosis induced by PFOS, whereas NAC and Fer-1 abrogated the effects of ATF4 silencing. Treatment with E235, an ATF4 activator, alleviated PFOS-induced ferroptosis. In conclusion, this study revealed that ATF4-mediated ferroptosis is involved in PFOS-induced neurotoxicity, offering novel mechanistic insights into the neurotoxic effects of PFOS and potentially paving the way for new therapeutic strategies.

Hetero-Trimetallic Atom Catalysts Enable Targeted ROS Generation and Redox Signaling for Intensive Apoptosis and Ferroptosis

Reactive oxygen species (ROS) play crucial roles in cellular metabolic processes by acting as primary intracellular chemical substrates and secondary messengers for cellular signal modulation. However, the artificial engineering of nanozymes to generate ROS is restricted by their low catalytic efficiency, high toxicity, and off-target consumption. Herein, hetero-trimetallic atom catalysts (TACs) anchored on a stable symmetrical pyramid structure are designed in the presence of N and P surface ligands from cross-linked polyphosphazene interlayer-coated MIL-101(Fe). The 3D network TACs with a uniform dispersion of Cu, Co, and Fe hetero-single atoms effectively tailor the active sites to avoid metal sintering, thereby providing sufficient catalytic activity for ROS blooms. Nanovesicle membranes facilitate the stable accumulation of nanozymes with homologous targeting, recognition, and endocytosis, effectively addressing the potentially high toxicity and off-target defects. Therefore, the outcome of the in situ ROS-bloom acts as a redox signal for directly regulating oxidative stress in the tumor microenvironment. Meanwhile, ROS intervene in the glutathione peroxidase 4, long-chain acyl-CoA synthetase 4, and cysteinyl aspartate specific proteinase-3 pathways as second messengers, fostering the proclivity toward apoptosis and lipid peroxidation-regulated ferroptosis pathway concurrently, thereby highlighting the application prospects of TACs in the biomedical field.

Glabridin protects against paraquat-induced acute lung injury by targeting ME1 to mitigate oxidative stress, mitochondrial dysfunction, and cGAS-STING activation

BACKGROUND

Acute lung injury (ALI) resulting from paraquat (PQ) poisoning constitutes a significant mortality risk, predominantly due to oxidative stress and mitochondrial dysfunction. Despite this, effective treatment options are currently limited.

PURPOSE

This study examines the protective effects of Glabridin (Glab), a flavonoid with noted antioxidant properties, against PQ-induced ALI, with a focus on its mitochondrial function and modulation of oxidative stress.

METHODS

The research utilized human normal lung epithelial line BEAS-2B cells (B2B) and PQ-exposed C57BL/6J mice to evaluate the role of Glab. Assessments included lung inflammation, oxidative stress markers, and mitochondrial dysfunction, as well as the involvement of the cGAS-STING and caspase-3 pathways. Molecular docking and western blot analyses were used to investigate the interaction between Glab and malic enzyme 1 (ME1).

RESULTS

The findings indicate that Glab significantly enhances survival rates, reduces inflammation, and mitigates oxidative stress in PQ-exposed mice. In vitro experiments demonstrated that Glab inhibited the cGAS-STING and caspase-3 pathways, release of mitochondrial contents (cytochrome C and mtDNA), decreased mitochondrial ROS production, and stabilized ME1, resulting in increased NADPH levels.

CONCLUSION

Glab confers protection against PQ-induced ALI by modulating oxidative stress, preserving mitochondrial function, and inhibiting both inflammatory and apoptotic pathways. Notably, the stabilization of malic enzyme 1 (ME1) and the consequent increase in NADPH levels play a critical role in this protective mechanism. These results underscore the potential of Glab as a therapeutic agent for addressing PQ poisoning, with particular emphasis on the pivotal role of ME1 in mediating its effects.

STING aggravates ferroptosis-dependent myocardial ischemia-reperfusion injury by targeting GPX4 for autophagic degradation

Despite advancements in interventional coronary reperfusion technologies following myocardial infarction, a notable portion of patients continue to experience elevated mortality rates as a result of myocardial ischemia-reperfusion (MI/R) injury. An in-depth understanding of the mechanisms underlying MI/R injury is crucial for devising strategies to minimize myocardial damage and enhance patient survival. Here, it is discovered that during MI/R, double-stranded DNA (dsDNA)-cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signal accumulates, accompanied by high rates of myocardial ferroptosis. The specific deletion of cgas or Sting in cardiomyocytes, resulting in the inhibition of oxidative stress, has been shown to mitigate ferroptosis and I/R injury. Conversely, activation of STING exacerbates ferroptosis and I/R injury. Mechanistically, STING directly targets glutathione peroxidase 4 (GPX4) to facilitate its degradation through autophagy, by promoting the fusion of autophagosomes and lysosomes. This STING-GPX4 axis contributes to cardiomyocyte ferroptosis and forms a positive feedback circuit. Blocking the STING-GPX4 interaction through mutations in T267 of STING or N146 of GPX4 stabilizes GPX4. Therapeutically, AAV-mediated GPX4 administration alleviates ferroptosis induced by STING, resulting in enhanced cardiac functional recovery from MI/R injury. Additionally, the inhibition of STING by H-151 stabilizes GPX4 to reverse GPX4-induced ferroptosis and alleviate MI/R injury. Collectively, a novel autophagy-dependent ferroptosis mechanism is identified in this study. Specifically, STING autophagy induced by anoxia or ischemia-reperfusion leads to GPX4 degradation, thereby presenting a promising therapeutic target for heart diseases associated with I/R.

Glutathion peroxidase 4 (GPX4) and Ribosomal Protein L40 (RPL40) participate in arsenic induced progression of renal cell carcinoma by regulating the NLRP3 mediated classic pyroptosis pathway

Epidemiological studies have demonstrated that long-term exposure to high‑arsenic water increases the risk of kidney cancer. Kidney dysfunction can lead to the accumulation of metabolic waste and chronic inflammation, with the latter being a significant factor in tumor development. Therefore, it is crucial to investigate how environmental arsenic exposure affects renal function and inflammation, as well as its potential influence on the progression of renal carcinoma. Additionally, pyroptosis plays an essential role in immune responses and the maintenance of cellular homeostasis. However, the role and mechanisms of pyroptosis in arsenic-induced kidney cancer progression remain unexplored. Our findings indicated that low-dose arsenic exposure reduces pyroptosis and promotes abnormal proliferation of renal tubular epithelial cells, while high-dose exposure enhances pyroptosis and damages renal tissue structure in mouse models. Mechanistically, in vitro studies confirmed that low-dose arsenic exposure promotes the progression of renal cell carcinoma by downregulating NLRP3 and inhibiting pyroptosis, whereas high-dose exposure has the opposite effect. Proteomics analysis identified GPX4 and RPL40 as key proteins mediating pyroptosis induced by low and high doses of arsenic, respectively. Furthermore, GPX4 and RPL40 were shown to regulate the malignant progression of renal cell carcinoma through their effects on NLRP3-mediated pyroptosis. This study reveals that arsenic exposure induces pyroptosis via NLRP3, leading to renal injury and influencing the malignant progression of renal cancer. Notably, GPX4 and RPL40 regulate this progression under low and high-dose arsenic exposure, respectively.

Effects of exercise on different antioxidant enzymes and related indicators: a systematic review and meta-analysis of randomized controlled trials

Numerous studies on the effects of exercise on antioxidant enzymes have generally concluded that regular exercise positively impacts antioxidant enzyme activity. However, some studies suggest that regular exercise may have no effect on antioxidant enzymes or could even negatively impact them. This suggests that other potential factors may influence antioxidant enzyme activity. Therefore, this study synthesizes existing literature on the effects of exercise interventions on antioxidant enzymes and employs subgroup analysis to identify factors that may influence exercise outcomes, offering insights for individuals aiming to enhance antioxidant capacity through exercise. A systematic review and meta-analysis were performed on exercise intervention studies measuring changes in blood antioxidant enzymes. This study was registered in PROSPERO (identifier: CRD 42023477230). (1) Exercise did not significantly increase superoxide dismutase (SOD) activity in women. (2) In individuals over 45 years of age, exercise did not significantly improve SOD activity or total antioxidant capacity (T-AOC) levels. (3) Regardless of exercise type, trends in SOD and catalase (CAT) activity were similar; however, only resistance exercise increased glutathione peroxidase (GPX) activity and reduced thiobarbituric Acid Reactive Substances (TBARS) levels. (4) High-intensity exercise significantly reduced CAT levels but did not significantly increase GPX levels. (5) Exercise interventions lasting more than 16 weeks showed no significant impact on the activity of SOD, CAT, or GPX. 6. Regular exercise at least three times per week significantly increased SOD and GPX activity and had a notable impact on T-AOC and TBARS levels. This study found that exercise significantly enhanced the activity of most antioxidant enzymes and overall antioxidant capacity. Moderate-to-low intensity exercise, performed at least three times per week for more than 16 weeks, demonstrated the greatest efficacy in enhancing antioxidant enzyme activity. Notably, we also found that women may need to exert more effort than men to achieve increases in antioxidant enzyme activity.

Unveiling the crossroads of STING signaling pathway and metabolic reprogramming: the multifaceted role of the STING in the TME and new prospects in cancer therapies

The cGAS-STING signaling pathway serves as a critical link between DNA sensing and innate immunity, and has tremendous potential to improve anti-tumor immunity by generating type I interferons. However, STING agonists have shown decreasing biotherapeutic efficacy in clinical trials. Tumor metabolism, characterized by aberrant nutrient utilization and energy production, is a fundamental hallmark of tumorigenesis. And modulating metabolic pathways in tumor cells has been discovered as a therapeutic strategy for tumors. As research concerning STING progressed, emerging evidence highlights its role in metabolic reprogramming, independent its immune function, indicating metabolic targets as a strategy for STING activation in cancers. In this review, we delve into the interplay between STING and multiple metabolic pathways. We also synthesize current knowledge on the antitumor functions of STING, and the metabolic targets within the tumor microenvironment (TME) that could be exploited for STING activation. This review highlights the necessity for future research to dissect the complex metabolic interactions with STING in various cancer types, emphasizing the potential for personalized therapeutic strategies based on metabolic profiling.

Resveratrol reduces RVLM neuron activity via activating the AMPK/Sirt3 pathway in stress-induced hypertension

Neuronal hyperexcitability in the rostral ventrolateral medulla (RVLM), driven by oxidative stress, plays a crucial role in stress-induced hypertension (SIH). While resveratrol (RSV) is known for its antioxidant properties, its effects on RVLM neurons in SIH remain unclear. We investigated this using an SIH rat model exposed to electric foot shocks and noise stimulation for 15 days. Analysis of RVLM tissue revealed increased mitochondrial damage, oxidative stress, apoptosis, and dysregulated ferroptosis in SIH rats. RSV microinjection into the RVLM reduced blood pressure, sympathetic vascular tone, and neuronal excitability. Both in vivo and in vitro studies showed that RSV treatment alleviated mitochondrial oxidative stress, apoptosis, and ferroptosis through AMPK activation and subsequent Sirt3 upregulation. These therapeutic effects were blocked by either AMPK inhibition or Sirt3 knockdown. Our findings demonstrate that RSV attenuates SIH by activating the AMPK/Sirt3 pathway, thereby reducing RVLM oxidative stress and cell death.

Viral Infections and the Glutathione Peroxidase Family: Mechanisms of Disease Development

Significance: The glutathione peroxidase (GPx) family is recognized for its essential function in maintaining cellular redox balance and countering the overproduction of reactive oxygen species (ROS), a process intricately linked to the progression of various diseases including those spurred by viral infections. The modulation of GPx activity by viruses presents a critical juncture in disease pathogenesis, influencing cellular responses and the trajectory of infection-induced diseases. Recent Advances: Cutting-edge research has unveiled the GPx family's dynamic role in modulating viral pathogenesis. Notably, GPX4's pivotal function in regulating ferroptosis presents a novel avenue for the antiviral therapy. The discovery that selenium, an essential micronutrient for GPx activity, possesses antiviral properties has propelled us toward rethinking traditional treatment modalities. Critical Issues: Deciphering the intricate relationship between viral infections and GPx family members is paramount. Viral invasion can precipitate significant alterations in GPx function, influencing disease outcomes. The multifaceted nature of GPx activity during viral infections suggests that a deeper understanding of these interactions could yield novel insights into disease mechanisms, diagnostics, prognostics, and even chemotherapeutic resistance. Future Directions: This review aims to synthesize current knowledge on the impact of viral infections on GPx activity and expression and identify key advances. By elucidating the mechanisms through which GPx family members intersect with viral pathogenesis, we propose to uncover innovative therapeutic strategies that leverage the antioxidant properties of GPx to combat viral infections. The exploration of GPx as a therapeutic target and biomarker holds promise for the development of next-generation antiviral therapies. Antioxid. Redox Signal. 42, 623-639.

SARS-CoV-2 Membrane Protein Induces MARCHF1/GPX4-Mediated Ferroptosis by Promoting Lipid Accumulation

The membrane protein (M), a key structural protein of SARS-CoV-2 that regulates virus assembly and morphogenesis, is involved in the pathological processes of multiple organ damage and metabolic disorders. This study aims to elucidate the mechanisms of M-mediated host ferroptosis and lipid accumulation during SARS-CoV-2 infection. Here, we detected that M protein enhances cellular sensitivity to ferroptosis. Additionally, we uncovered the pivotal role of perilipin-2 and sterol regulatory element-binding protein 1 in M-induced lipid accumulation. Xanthohumol, a cost-effective and orally available diacylglycerol acyltransferase inhibitor, alleviated triglyceride and total cholesterol accumulation, thereby counteracting the M-induced ferroptosis. Furthermore, we identified that the mitochondrial import inner membrane translocase subunit TIM23 and the mitochondrial import receptor subunit TOM20 homolog contribute to M-induced mitochondrial dysfunction. Notably, inhibiting lipid synthesis effectively reduced mitochondrial reactive oxygen species and transmembrane potential, indicating a cross-talk between lipid and ferro metabolic pathways. Mechanistically, glutathione peroxidase 4 (GPX4) interacts with SARS-CoV-2 M, leading to its subsequent degradation by the Membrane Associated Ring-CH-Type Finger 1 (MARCHF1) ubiquitin ligase. M-GPX4 interaction occurs at the R72 residue, which may represent a potential therapeutic target against SARS-CoV-2 infection. M modulates lipid accumulation and further impairs mitochondrial functions, ultimately resulting in ferroptosis through MARCHF1-GPX4 axis. Disrupting host-virus interactions along this pathway may provide a therapeutic strategy for SARS-CoV-2 infection.

Identification of aberrant interferon-stimulated gene associated host responses potentially linked to poor prognosis in COVID-19 during the Omicron wave

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron has demonstrated decreased pathogenicity, yet a few individuals suffer severe pneumonia from coronavirus disease 2019 (COVID-19) infection; the underlying mechanisms are unknown.

METHODS

The present work investigated the role of Interferon-stimulated genes (ISGs) in the occurrence and progression of severe Omicron infection. The expression and dynamic changes of ISGs were assessed using quantitative real-time polymerase chain reaction (qRT-PCR), and the anti-ISG15 autoantibody in infected patients was detected by ELISA. Moreover, we evaluated the correlation of ISGs with disease severity and outcomes by comparing expression of ISGs among each group.

RESULTS

Decreased expression of several ISGs such as IFI6 are potentially linked to increased severity or poor outcomes of Omicron infection. Longitudinal data also demonstrates that the dynamic variation of IFI6 in the Omicron infection phase may be linked to the prognosis of the disease. The increase of anti-ISG15 autoantibody potentially links to the disease progression and poor outcome of patients with high level of ISG15 expression.

CONCLUSIONS

These findings define aberrant Interferon-stimulated gene associated host responses and reveal potential mechanisms and therapeutic targets for Omicron or other viral infection.

ROS Regulate Rotenone-induced SH-SY5Y Dopamine Neuron Death Through Ferroptosis-mediated Autophagy and Apoptosis

Rotenone, a plant-derived natural insecticide, is widely used to induce Parkinson's disease (PD) models. However, the mechanisms of rotenone-induced cell death remain unclear. Here, we found that rotenone (0.01, 0.1, or 1 μmol/L) suppressed SH-SY5Y dopamine neuron viability and led to PD-like pathological changes, such as reduced tyrosine hydroxylase (TH) but increased α-synuclein. Rotenone increased the levels of intracellular reactive oxygen species (ROS) and mitochondrial ROS, as well as the levels of the antioxidants nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), ultimately resulting in oxidative stress. Moreover, rotenone significantly downregulated the expression of GPX4 and xCT but upregulated the expression of COX2 and NCOA4, which are markers of ferroptosis. Furthermore, rotenone decreased phosphorylated mTOR level but increased Beclin-1, ATG5, LC3 and p62 expression, suggesting that rotenone enhances autophagy and reduces autophagy flux. Additionally, rotenone reduced Bcl-2 levels and the mitochondrial membrane potential (MMP) while promoting BAX and Caspase-3 expression, thus initiating cell apoptosis. N-acetylcysteine (NAC), a ROS scavenger, and ferrostatin-1 (Fer-1) and deferoxamine (DFO), two ferroptosis inhibitors, significantly eliminated rotenone-induced autophagy and apoptosis. Moreover, ML385, a specific inhibitor of Nrf2, suppressed rotenone-induced ferroptosis. Our results demonstrated that ROS might mediate rotenone-induced PD-like pathological changes by regulating iron death, autophagy, and apoptosis. Inhibiting ferroptosis blocked the rotenone-induced increase in autophagy and apoptosis. Thus, the ability of ROS to regulate rotenone-induced death through autophagy and apoptosis is dependent on ferroptosis. The findings require validation in multiple neuronal cell lines and in vivo.

cGAS/STING/NLRP3 Signaling Pathway-Mediated Pyroptosis in Hypertrophic Cardiomyopathy Radiotherapy

BACKGROUND

Radiotherapy is a commonly employed treatment modality for cancer; however, its radiobiological effects in hypertrophic cardiomyopathy (HCM) remain unclear. Radiation exposure activates the cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway, which is functionally associated with the activation of NOD-like Receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasomes, known mediators of pyroptotic cell death. Nonetheless, the underlying mechanism requires further investigation. Therefore, the objective of this study is to elucidate the role of the cGAS/STING/NLRP3 pathway in the process of cardiomyocyte pyroptosis during radiotherapy for HCM.

METHODS

Transverse aortic constriction surgery was conducted to establish a mouse model of pressure overload-induced HCM, followed by the administration of 30 Gray (Gy) radiation one-week post-surgery. Cardiac morphology and function were evaluated through echocardiographic techniques. Hematoxylin & Eosin staining, along with Wheat Germ Agglutinin (WGA) staining, were utilized to quantify the cross-sectional area of cardiomyocytes and the degree of left ventricular hypertrophy. The HL-1 mouse cardiac muscle cell line was subjected to 40 Gy of radiation using an X-ray irradiator to establish an in vitro model of HCM, with or without the application of the NLRP3 inhibitor MCC950 and cGAS overexpression. Various assays, including the Cell Counting Kit-8 (CCK8), enzyme-linked immunosorbent assay (ELISA), and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimi- dazolylcarbocyanine iodide (JC-1) probe assays, were performed to assess cell viability, the concentrations of Interleukin (IL)-1β, IL-18, and cGAMP, as well as mitochondrial membrane potential. The morphology of cell membranes and mitochondria was analyzed using scanning electron microscopy (SEM) and fluorescence in situ hybridization (FISH) dual labelling techniques. The expression levels of cGAS, STING, and NLRP3 were evaluated through by western blot analysis.

RESULTS

Radiotherapy reduced cardiac hypertrophy, improved cardiac function, and decreased fibrotic changes in HCM mice when compared to control groups. The application of radiation resulted in pyroptosis in HL-1 cells and a reduction in cell viability; this effect that was alleviated by the inhibition of NLRP3, while overexpression of cGAS exacerbated the situation. Furthermore, radiation led to a decline in mitochondrial membrane potential and the leakage of mitochondrial DNA into the cytoplasm, which activated the cGAS-STING signaling pathway, thereby initiating pyroptosis. This activation was corroborated by elevated levels of pyroptosis-associated proteins, including cGAS, STING, NLRP3, caspase-1, Gasdermin D (GSDMD), cGAMP, IL-18, and IL-1β. Notably, the inhibition of NLRP3 effectively abolished the upregulation of IL-18, and IL-1β levels.

CONCLUSION

Radiation can improve cardiac function, decrease hypertrophy of myocardial cells, and induce oxidative stress. This oxidative stress results in the leakage of mitochondrial DNA (mtDNA), which subsequently activates the cGAS/STING/NLRP3 signalling pathway, culminating in pyroptosis.

Targeting GOLPH3L improves glioblastoma radiotherapy by regulating STING-NLRP3-mediated tumor immune microenvironment reprogramming

Radiotherapy (RT) has been the standard-of-care treatment for patients with glioblastoma (GBM); however, the clinical effectiveness is hindered by therapeutic resistance. Here, we demonstrated that the tumor immune microenvironment (TIME) exhibited immunosuppressive properties and high expression of Golgi phosphoprotein 3 like (GOLPH3L) in RT-resistant GBM. Our study showed that GOLPH3L interacted with stimulator of interferon genes (STING) at the aspartic acid residue 184 in Golgi after RT, leading to coat protein complex II-mediated retrograde transport of STING from Golgi to endoplasmic reticulum. This suppressed the STING-NOD-like receptor thermal protein domain associated protein 3 (NLRP3)-mediated pyroptosis, resulting in suppressive TIME, driving GBM resistance to RT. Genetic GOLPH3L ablation in RT-resistant GBM cells augmented antitumor immunity and overcame tumor resistance to RT. Moreover, we have identified a small molecular inhibitor of GOLPH3L, vitamin B5 calcium (VB5), which improved the therapeutic efficacy of RT and immune checkpoint blockade by inducing a robust antitumor immune response in mouse models. Clinically, patients with GBM treated with VB5 exhibited improved responses to RT. Thus, reprogramming the TIME by targeting GOLPH3L may offer a potential opportunity to improve RT in GBM.

The neuroimmune nexus: unraveling the role of the mtDNA-cGAS-STING signal pathway in Alzheimer's disease

The relationship between Alzheimer's disease (AD) and neuroimmunity has gradually begun to be unveiled. Emerging evidence indicates that cyclic GMP-AMP synthase (cGAS) acts as a cytosolic DNA sensor, recognizing cytosolic damage-associated molecular patterns (DAMPs), and inducing the innate immune response by activating stimulator of interferon genes (STING). Dysregulation of this pathway culminates in AD-related neuroinflammation and neurodegeneration. A substantial body of evidence indicates that mitochondria are involved in the critical pathogenic mechanisms of AD, whose damage leads to the release of mitochondrial DNA (mtDNA) into the extramitochondrial space. This leaked mtDNA serves as a DAMP, activating various pattern recognition receptors and immune defense networks in the brain, including the cGAS-STING pathway, ultimately leading to an imbalance in immune homeostasis. Therefore, modulation of the mtDNA-cGAS-STING pathway to restore neuroimmune homeostasis may offer promising prospects for improving AD treatment outcomes. In this review, we focus on the mechanisms of mtDNA release during stress and the activation of the cGAS-STING pathway. Additionally, we delve into the research progress on this pathway in AD, and further discuss the primary directions and potential hurdles in developing targeted therapeutic drugs, to gain a deeper understanding of the pathogenesis of AD and provide new approaches for its therapy.

Endogenous metabolite N-chlorotaurine attenuates antiviral responses by facilitating IRF3 oxidation

Cellular microenvironments critically control the activation of innate immune responses. N-chlorotaurine (Tau-Cl) is an endogenous metabolite that is markedly produced and secreted during pathogenic invasion. However, its effect on the antiviral innate immune responses remains unclear. Here, we demonstrate that viral infection upregulates cellular Tau-Cl level. Tau-Cl attenuates viral infection-induced expression of type I IFNs and facilitates viral replication both in vitro and in vivo. Mechanistically, Tau-Cl facilitates the oxidation of IRF3 at Cys222 and Cys371, a key transcription factor that governs the transcription of type I IFNs. Tau-Cl inhibits phosphorylation and nuclear translocation of IRF3, and blocks IRF3 binding to the IFN-β promoter region. Therefore, we identify Tau-Cl as an endogenous suppressor of IRF3-driven antiviral innate responses and uncover an immune escape mechanism of viruses by affecting host microenvironments.

Examining the prognostic and clinicopathological significance of GPX4 in human cancers: a meta-analysis

Elevated levels of the enzyme GPX4 have been detected in tumor tissues, which may play a role in cancer progression. We did a meta-analysis of eight studies encompassing 1180 individuals to evaluate the importance of GPX4 in cancer, particularly in terms of prognosis and clinicopathological characteristics. Research results indicate that higher levels of GPX4 were linked to worse overall survival (OS) (HR = 1.47 [95%CI = 1.18-1.76], p < .001). Elevated levels of GPX4 were linked to lymph node invasion (OR.69 [95% CI.44-1.10], p =.12), metastasis (OR 1.58 [95% CI.97-2.55], p =.06, p <.0001), and advanced clinical stage III-IV (OR.82 [95% CI.70-.96], p =.001). A sensitivity study revealed that the general findings were constant across all levels of impact intensity. The findings of this meta-analysis suggest that increased GPX4 levels are not only correlated with reduced overall survival rates for patients with tumors but it also offers valuable insights regarding the clinical traits of tumor malignancy and metastasis. Based on these connections, GPX4 has the potential to serve as a biomarker for tumor detection, prognosis, and targeted therapy.

AKR1C1 protects against intracerebral hemorrhage by suppressing neuronal cell death via the P53/SLC7A11/GPX4 axis

Intracerebral hemorrhage (ICH) is associated with the highest rates of mortality and residual disability. To date, effective treatments to delay or prevent ICH are still lacking. Multiple forms of neuronal cell death have been discovered following ICH, including apoptosis, necrosis, autophagy, and ferroptosis. Aldo-keto reductase family 1 member C1 (AKR1C1) has been identified to act as a protective factor in ferroptosis. However, whether AKR1C1 was involved in the development of ICH was unknown. In this study, the left cerebral striatum of the Sprague-Dawley rat was injected with collagenase type IV to induce an in vivo model. Primary rat cortical neurons treated with oxygen hemoglobin (OxyHb) were applied to as an in vitro model. AKR1C1 was found to be downregulated and immunoreactivity colocalized with NeuN-positive neurons in the perihematomal region. Rats injected with lentiviral particles overexpressing AKR1C1 showed the reduction of cerebral hematoma and the remission of blood-brain barrier disruption. Moreover, AKR1C1 upregulation repressed cell apoptosis and ferroptosis induced by ICH through downregulating the expression of pro-apoptotic factors, inhibiting iron accumulation and lipid peroxidation, along with increasing the expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4). The results of in vitro assays were consistent with results from the in vivo. Mechanistically, P53 overexpression augmented the cellular damage in OxyHb-stimulated neurons when AKR1C1 was overexpressed. Taken together, AKR1C1 improves ICH injury by inhibiting neuronal cell death via negatively regulating P53 expression and affecting the SLC7A11/GPX4 pathway.

TREM2 alleviates sepsis-induced acute lung injury by attenuating ferroptosis via the SHP1/STAT3 pathway

Sepsis-induced acute lung injury (ALI) is a complex and life-threatening condition characterized by excessive inflammatory responses, ferroptosis, and oxidative stress. A comprehensive investigation and effective therapeutic strategies are crucial for managing this condition. In this study, we established in vivo sepsis models using lipopolysaccharide (LPS) in wild-type (WT) mice and triggering receptor expressed on myeloid cells 2 (TREM2) knockout (TREM2-KO) mice to assess lung morphology, oxidative stress, and ferroptosis. In vitro, RAW264.7 cells with TREM2 overexpression (TREM2-OE) or knockdown (TREM2-SiRNA) were utilized to assess oxidative stress and ferroptosis. RNA sequencing of LPS-stimulated cells transfected with either vector or TREM2-OE revealed significant differences in inflammation- and ferroptosis-related pathways. LPS-induced lung injury and ferroptosis were exacerbated in TREM2-KO mice and TREM2-SiRNA cells but alleviated by the ferroptosis inhibitor ferrostatin-1 (Fer-1). Mechanistically, TREM2-KO led to SHP1 downregulation and STAT3-P upregulation, which were reversed by the SHP1 agonist SC-43. These findings highlight the role of TREM2 in the SHP1/STAT3 signaling pathway and its regulatory effects on ferroptosis. Our study demonstrates that TREM2, via the SHP1/STAT3 pathway, suppresses oxidative stress and ferroptosis, thereby significantly mitigating sepsis-induced ALI. These results underscore the pivotal role of TREM2 in modulating inflammatory responses and immunity, providing a theoretical foundation for developing therapeutic strategies.

Crosstalk between ferroptosis and innate immune in diabetic kidney disease: mechanisms and therapeutic implications

Diabetic kidney disease (DKD) is a prevalent complication of diabetes mellitus (DM), and its incidence is increasing alongside the number of diabetes cases. Effective treatment and long-term management of DKD present significant challenges; thus, a deeper understanding of its pathogenesis is essential to address this issue. Chronic inflammation and abnormal cell death in the kidney closely associate with DKD development. Recently, there has been considerable attention focused on immune cell infiltration into renal tissues and its inflammatory response's role in disease progression. Concurrently, ferroptosis-a novel form of cell death-has emerged as a critical factor in DKD pathogenesis, leading to increased glomerular filtration permeability, proteinuria, tubular injury, interstitial fibrosis, and other pathological processes. The cardiorenal benefits of SGLT2 inhibitors (SGLT2-i) in DKD patients have been demonstrated through numerous large clinical trials. Moreover, further exploratory experiments indicate these drugs may ameliorate serum and urinary markers of inflammation, such as TNF-α, and inhibit ferroptosis in DKD models. Consequently, investigating the interplay between ferroptosis and innate immune and inflammatory responses in DKD is essential for guiding future drug development. This review presents an overview of ferroptosis within the context of DKD, beginning with its core mechanisms and delving into its potential roles in DKD progression. We will also analyze how aberrant innate immune cells, molecules, and signaling pathways contribute to disease progression. Finally, we discuss the interactions between ferroptosis and immune responses, as well as targeted therapeutic agents, based on current evidence. By analyzing the interplay between ferroptosis and innate immunity alongside its inflammatory responses in DKD, we aim to provide insights for clinical management and drug development in this area.

Fabrication of a Redox-Reversible Near-Infrared Fluorogenic Probe for Ferroptosis Process Monitoring and the Early Diagnosis of Diabetes

Ferroptosis is a type of cell death triggered by the iron-dependent accumulation of lipid peroxides in cells. Diabetes, a chronic metabolic disorder characterized by hyperglycemia, can lead to various health complications. The process of ferroptosis and the progression of diabetes are closely linked to redox homeostasis, which is regulated by the levels of reactive oxygen and sulfur species. Currently, there are no fluorescent probes available to monitor changes in redox homeostasis during ferroptosis and diabetes. Here, we report the first endeavor to create a reversible near-infrared fluorogenic (NIRF) probe for monitoring the process of ferroptosis reversal and precise diabetes diagnosis. In vitro data demonstrated that NIR-CSTe could cyclically and reversibly detect ONOO- and GSH up to four times with minimal loss in fluorescence intensity. With the help of NIR-CSTe, we observed that HT-1080 cells, induced to undergo ferroptosis by erastin after being washed with PBS for 24 h and then treated with ferrostatin-1, showed a recovery in intracellular GSH levels. In contrast, treatment with deferoxamine did not yield similar results. Lastly, NIR-CSTe was also utilized for the early diagnosis and efficacy assessment of diabetes in relation to ONOO-/GSH redox balance, with results illustrating that the combined administration of metformin and empagliflozin was more effective than using either drug alone. Thus, this smart probe holds significant potential as an essential tool for clinical diagnosis and treatment of diseases associated with redox homeostasis.

Lamp2 Deficiency Enhances Susceptibility to Oxidative Stress-Induced RPE Degeneration

Purpose

Autophagy and lysosomal degradation are vital processes that protect cells from oxidative stress. This study investigated the role of lysosome-associated membrane protein 2 (Lamp2), a lysosomal protein essential for autophagosome maturation and lysosome biogenesis, in maintaining retinal health under oxidative stress.

Methods

To induce oxidative stress, young Lamp2 knockout (KO) and wild-type mice received an intravenous injection of a low dose (10 mg/kg) of sodium iodate (NaIO3). We examined retinal histopathology and morphological changes in the RPE. The involvement of resident microglia or infiltrating macrophages was assessed using immunostaining, flow cytometry, and real-time PCR for chemokines and cytokines.

Results

After administering a low-dose NaIO3, Lamp2 KO mice showed significant RPE degeneration, whereas wild-type mice had minimal damage. Histological analysis and electron microscopy revealed significant thinning of the outer nuclear layer and loss of RPE epithelial polarity in Lamp2 KO mice. Additionally, there was a significant increase in ionized calcium-binding adaptor molecule 1-positive microglia and macrophages in the outer retina. Early proliferation of CD45lowMHC-IIlow resident microglia was followed by the infiltration of CD45highLy6Chigh monocytes and the engraftment of CD11b+CD45high monocyte-derived macrophages. Transcript levels of monocyte chemoattractant protein 1, macrophage inflammatory protein 1β, Il- 1β, and Il-6 also increased in the retinas of Lamp2 KO mice. Furthermore, pretreatment with the macrophage-depleting agent clodronate prevented NaIO3-induced RPE degeneration and macrophage infiltration in Lamp2 KO mice.

Conclusions

Lamp2 deficiency, when combined with oxidative stress, leads to RPE degeneration in vivo. Lysosomal dysfunction also promotes macrophage engraftment and triggers neurotoxic inflammation.

Ginger protects against vein graft remodeling by precisely modulating ferroptotic stress in vascular smooth muscle cell dedifferentiation

Vein graft (VG) failure (VGF) is associated with VG intimal hyperplasia, which is characterized by abnormal accumulation of vascular smooth muscle cells (VSMCs). Most neointimal VSMCs are derived from pre-existing VSMCs via a process of VSMC phenotypic transition, also known as dedifferentiation. There is increasing evidence to suggest that ginger or its bioactive ingredients may block VSMC dedifferentiation, exerting vasoprotective functions; however, the precise mechanisms have not been fully characterized. Therefore, we investigated the effect of ginger on VSMC phenotypic transition in VG remodeling after transplantation. Ginger significantly inhibited neointimal hyperplasia and promoted lumen (L) opening in a 3-month VG, which was primarily achieved by reducing ferroptotic stress. Ferroptotic stress is a pro-ferroptotic state. Contractile VSMCs did not die but instead gained a proliferative capacity and switched to the secretory type, forming neointima (NI) after vein transplantation. Ginger and its two main vasoprotective ingredients (6-gingerol and 6-shogaol) inhibit VSMC dedifferentiation by reducing ferroptotic stress. Network pharmacology analysis revealed that 6-gingerol inhibits ferroptotic stress by targeting P53, while 6-shogaol inhibits ferroptotic stress by targeting 5-lipoxygenase (Alox5), both promoting ferroptosis. Furthermore, both ingredients co-target peroxisome proliferator-activated receptor gamma (PPARγ), decreasing PPARγ-mediated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (Nox1) expression. Nox1 promotes intracellular reactive oxygen species (ROS) production and directly induces VSMC dedifferentiation. In addition, Nox1 is a ferroptosis-promoting gene that encourages ferroptotic stress production, indirectly leading to VSMC dedifferentiation. Ginger, a natural multi-targeted ferroptotic stress inhibitor, finely and effectively prevents VSMC phenotypic transition and protects against venous injury remodeling.

The STING signaling pathways and bacterial infection

As antibiotic-resistant bacteria continue to emerge frequently, bacterial infections have become a significant and pressing challenge to global public health. Innate immunity triggers the activation of host responses by sensing "non-self" components through various pattern recognition receptors (PRRs), serving as the first line of antibacterial defense. Stimulator of interferon genes (STING) is a PRR that binds with cyclic dinucleotides (CDN) to exert effects against bacteria, viruses, and cancer by inducing the production of type I interferon and inflammatory cytokines, and facilitating regulated cell death. Currently, drugs targeting the STING signaling pathway are predominantly applied in the fields of modulating host immune defense against cancer and viral infections, with relatively limited application in treating bacterial infections. Given the significant immunomodulatory functions of STING in the interaction between bacteria and hosts, this review summarizes the research progress on STING signaling pathways and their roles in bacterial infection, as well as the novel functions of STING modulators, aiming to offer insights for the development of antibacterial drugs.

Ferroptosis and pyroptosis are connected through autophagy: a new perspective of overcoming drug resistance

Drug resistance is a common challenge in clinical tumor treatment. A reduction in drug sensitivity of tumor cells is often accompanied by an increase in autophagy levels, leading to autophagy-related resistance. The effectiveness of combining chemotherapy drugs with autophagy inducers/inhibitors has been widely confirmed, but the mechanisms are still unclear. Ferroptosis and pyroptosis can be affected by various types of autophagy. Therefore, ferroptosis and pyroptosis have crosstalk via autophagy, potentially leading to a switch in cell death types under certain conditions. As two forms of inflammatory programmed cell death, ferroptosis and pyroptosis have different effects on inflammation, and the cGAS-STING signaling pathway is also involved. Therefore, it also plays an important role in the progression of some chronic inflammatory diseases. This review discusses the relationship between autophagy, ferroptosis and pyroptosis, and attempts to uncover the reasons behind the evasion of tumor cell death and the nature of drug resistance.

Regulation of enzymatic lipid peroxidation in osteoblasts protects against postmenopausal osteoporosis

Oxidative stress plays a critical role in postmenopausal osteoporosis, yet its impact on osteoblasts remains underexplored, limiting therapeutic advances. Our study identifies phospholipid peroxidation in osteoblasts as a key feature of postmenopausal osteoporosis. Estrogen regulates the transcription of glutathione peroxidase 4 (GPX4), an enzyme crucial for reducing phospholipid peroxides in osteoblasts. The deficiency of estrogen reduces GPX4 expression and increases phospholipid peroxidation in osteoblasts. Inhibition or knockout of GPX4 impairs osteoblastogenesis, while the elimination of phospholipid peroxides rescues bone formation and mitigates osteoporosis. Mechanistically, 4-hydroxynonenal, an end-product of phospholipid peroxidation, binds to integrin-linked kinase and triggers its protein degradation, disrupting RUNX2 signaling and inhibiting osteoblastogenesis. Importantly, we identified two natural allosteric activators of GPX4, 6- and 8-Gingerols, which promote osteoblastogenesis and demonstrate anti-osteoporotic effects. Our findings highlight the detrimental role of phospholipid peroxidation in osteoblastogenesis and underscore GPX4 as a promising therapeutic target for osteoporosis treatment.

The therapeutic potential of Osmundacetone for rheumatoid arthritis: Effects and mechanisms on osteoclastogenesis

The present study aimed to investigate the therapeutic potential of Osmundacetone (Osu), a natural plant product, for the treatment of rheumatoid arthritis (RA). The study revealed that Osu effectively reduced arthritis-induced swelling and bone destruction, as well as alleviating inflammation-related factors and oxidative stress in animal models. We focused the mechanism exploration on its regulatory mechanism on osteoclastogenesis in the next investigation. In vitro experiments demonstrated a dose-dependent inhibition of osteoclastic differentiation by Osu, as evidenced by tartrate resistant acid phosphatase (TRAP) staining and a reduction in osteoclastic differentiation markers observed through Western blotting analysis. And three different approaches Osu inhibiting osteoclastogenesis were found in our researches: (1) The binding of Receptor Activator of Nuclear Factor Kappa B (RANK) and Osu was revealed by the in-silico analysis. (2) According to 2,7-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining, Osu attenuated the level of reactive oxygen species (ROS), and western blotting studies revealed this effect was modulated by the regulation of Kelch-like ECH-associated protein 1/Nuclear Factor erythroid 2-Related Factor 2 (Keap1/Nrf2) pathway. (3) Interestingly, we found that Osu increased the lipid peroxidation via downregulating the expression of glutathione peroxidase 4 (GPX4) at the same time as reducing the ROS, leading to the reduction of the fluidity of the membrane and the fusion of osteoclasts which could be reversed by using the ferroptosis inhibitor- Ferrostatin-1 (Fer-1). Overall, a natural compound to the existing therapeutics for rheumatoid arthritis was confirmed and a new strategy for inhibiting osteoclastogenesis was added.

Regulation of cGAS-STING signalling and its diversity of cellular outcomes

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signalling pathway, which recognizes both pathogen DNA and host-derived DNA, has emerged as a crucial component of the innate immune system, having important roles in antimicrobial defence, inflammatory disease, ageing, autoimmunity and cancer. Recent work suggests that the regulation of cGAS-STING signalling is complex and sophisticated. In this Review, we describe recent insights from structural studies that have helped to elucidate the molecular mechanisms of the cGAS-STING signalling cascade and we discuss how the cGAS-STING pathway is regulated by both activating and inhibitory factors. Furthermore, we summarize the newly emerging understanding of crosstalk between cGAS-STING signalling and other signalling pathways and provide examples to highlight the wide variety of cellular processes in which cGAS-STING signalling is involved, including autophagy, metabolism, ageing, inflammation and tumorigenesis.

ASFV infection induces lipid metabolic disturbances and promotes viral replication

Introduction

African swine fever is a highly transmissible and lethal infectious disease caused by the African swine fever virus (ASFV), which has considerably impacted the global swine industry. Lipid metabolism plays a vital role in sustaining lipid and energy homeostasis within cells and influences the viral life cycle.

Methods and results

In this study, we found that ASFV infection disrupts lipid metabolism in the host. Transcriptomic analysis of cells infected with ASFV revealed that the levels of lipid metabolism significantly changed as the duration of the infection progressed. The intracellular cholesterol levels of the host exhibited a pattern similar to the viral growth curve during the course of infection. Notably, increased cholesterol levels promoted ASFV replication in host cells, whereas inhibition of the cholesterol biosynthesis pathway markedly reduced intracellular ASFV replication.

Discussion

The findings of this study showed that ASFV led to lipid metabolism disturbances to facilitate its replication, which is useful for revealing the mechanism underlying ASFV infection.

Persistent Ferroptosis Modulates Cardiac Remodeling and M2 Macrophage Polarization, Which Can be Mitigated by Astaxanthin During Myocardial Infarction Recovery

The role of ferroptosis, an iron-dependent lipid peroxidation regulated cell death pathway, remains obscure during myocardial infarction (MI) recovery. Our study aims to clarify ferroptosis' function in post-MI cardiac recovery, explore the consequences of iron overload and ferroptosis for myocardial remodeling, and assess the effects of Liproxstatin-1 (Lipro-1) treatment on macrophage functionality. Moreover, we examine the potential of Astaxanthin (ASTX), recognized for its antioxidative properties, to mitigate ferroptosis during MI recovery and its subsequent ramifications for myocardial remodeling. Our results demonstrate persistent ferroptosis during MI recovery, marked by decreased Glutathione Peroxidase 4 and increased Acyl-CoA Synthetase Long-Chain Family Member 4 (ACSL4) and Ferroportin 1 alongside elevated lipid peroxidation and iron levels up to D21. We identified a significant correlation between ferroptosis and macrophage activity, noted by the increase in macrophage populations co-expressing GPX4 and ACSL4 markers in the peri-infarct area by D21. Liproxstatin-1 treatment reduced macrophage (CD68 +) counts, promoted M2 polarization decreased inflammation, and improved cardiac function. Myocardial remodeling was improved in Lipro-1-treated rats, as shown by decreased fibrosis and reduced levels of α-SMA, Collagen I, and Collagen III proteins. ASTX treatment also exhibited an inhibiting effect on ferroptosis indicators, and encouraged M2 macrophage polarization, reduced inflammation, and enhanced both cardiac function and myocardial remodeling, mirroring the beneficial effects observed with Lipro-1. In summary, the interactions between ferroptosis, macrophage polarization, and myocardial remodeling are crucial for cardiac function improvement post-MI. Lipro-1 and ASTX emerge as promising therapeutic agents by modulating post-MI ferroptosis and related immune responses.

Recent Progress of Glutathione Peroxidase 4 Inhibitors in Cancer Therapy

Ferroptosis is a novel type of programmed cell death that relies on the build-up of intracellular iron and leads to an increase in toxic lipid peroxides. Glutathione Peroxidase 4 (GPX4) is a crucial regulator of ferroptosis that uses glutathione as a cofactor to detoxify cellular lipid peroxidation. Targeting GPX4 in cancer could be a promising strategy to induce ferroptosis and kill drugresistant cancers effectively. Currently, research on GPX4 inhibitors is of increasing interest in the field of anti-tumor agents. Many reviews have summarized the regulation and ferroptosis induction of GPX4 in human cancer and disease. However, insufficient attention has been paid to GPX4 inhibitors. This article outlines the molecular structures and development prospects of GPX4 inhibitors as novel anticancer agents.

Ruscogenin attenuates osteoarthritis by modulating oxidative stress-mediated macrophage reprogramming via directly targeting Sirt3

BACKGROUND

Synovial inflammation, Cartilage erosion, and subchondral osteosclerosis, which are collectively referred to as the triad of pathogenesis, contribute to osteoarthritis (OA) progression. Specifically, the M1 macrophage in the synovium worsens the development of the illness and is a significant factor in the deterioration and functioning of cartilage.

OBJECTIVE

To investigate whether Ruscogenin attenuates progressive degeneration of articular cartilage in rats with anterior cruciate ligament transection (ACLT)-induced osteoarthritis (OA) by modulating macrophage reprogramming and to explore its specific mechanism of action.

METHODS

In vitro, SW1353 cells and RAW264.7 cells were applied to elucidate the mechanisms by which Ruscogenin protects articular cartilage. Specifically, the expression levels of molecules related to cartilage ECM synthesis and degradation enzymes and macrophages were analysed. In vivo, a rat osteoarthritis model was established using ACLT. The protective effect of Ruscogenin on articular cartilage was observed.

RESULTS

Ruscogenin significantly reversed LPS-induced macrophage inflammatory response and promoted cartilage regeneration-related factors. In addition, Ruscogenin had a significant protective effect on the knee joint of ACLT rats, effectively preventing cartilage degeneration. These positive therapeutic effects were achieved on the one hand by Ruscogenin regulating macrophage reprogramming by targeting Sirt3, and on the other hand Ruscogenin could attenuate the ROS level of chondrocytes thereby inhibiting chondrocyte ferroptosis.

CONCLUSIONS

Ruscogenin exerts chondroprotective effects by regulating macrophage reprogramming and inhibiting chondrocyte ferroptosis.

The role of cGAS-STING signaling pathway in ferroptosis

The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has been identified as a crucial mechanism in antiviral defense and innate immunity pathway. Ferroptosis, characterized by iron dependence and lipid peroxidation, represents a specialized form of cell death. A burgeoning collection of studies has demonstrated that the cGAS-STING signaling pathway participates in the homeostatic regulation of the organism by modulating ferroptosis-associated enzyme activity or gene expression. Consequently, elucidating the specific roles of the STING signaling pathway and ferroptosis in vivo is vital for targeted disease intervention. This review systematically examines the interactions between the cGAS-STING signaling pathway and ferroptosis, highlighting their influence on disease progression in the contexts of inflammation, injury, and cancerous cell dynamics. Understanding these interactions may provide novel therapeutic strategies. The STING pathway has been implicated in the regulation of various cell death mechanisms, including apoptosis, pyroptosis, necroptosis, autophagy, and ferroptosis. Our focus primarily addresses the role and mechanism of the cGAS-STING signaling pathway and ferroptosis in diseases, limiting discussion of other cell death modalities and precluding a comprehensive overview of the pathway's additional functions.

Decoding ferroptosis: transforming orthopedic disease management

As a mechanism of cell death, ferroptosis has gained popularity since 2012. The process is distinguished by iron toxicity and phospholipid accumulation, in contrast to autophagy, apoptosis, and other cell death mechanisms. It is implicated in the advancement of multiple diseases across the body. Researchers currently know that osteosarcoma, osteoporosis, and other orthopedic disorders are caused by NRF2, GPX4, and other ferroptosis star proteins. The effective relief of osteoarthritis symptoms from deterioration has been confirmed by clinical treatment with multiple ferroptosis inhibitors. At the same time, it should be reminded that the mechanisms involved in ferroptosis that regulate orthopedic diseases are not currently understood. In this manuscript, we present the discovery process of ferroptosis, the mechanisms involved in ferroptosis, and the role of ferroptosis in a variety of orthopedic diseases. We expect that this manuscript can provide a new perspective on clinical diagnosis and treatment of related diseases.

RNF39 facilitates antiviral immune responses by promoting K63-linked ubiquitination of STING

The cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS)-dependent pathway is a key DNA-sensing pathway that recognizes cytosolic DNA and plays a crucial role in initiating innate immune responses against pathogenic microbes and cancer. Various molecules have been identified as regulators of the cGAS-dependent pathway that controls innate immune responses. However, despite the important roles of Stimulator-of-interferon genes (STING) in the cGAS-dependent pathway, the regulation of its activation has not been elucidated. Here, we show that the E3 ubiquitin ligase, RING finger protein 39 (RNF39), interacts with STING in macrophages and HERK293T cells. Moreover, RNF39 accelerates DNA-sensing pathways by promoting lysine (K)63-linked ubiquitination of STING, and then facilitating the formation of STING-TBK1 complex. Concordantly, Rnf39 deficiency inhibits innate immune responses triggered by DNA viral infection and accelerates viral replication. Furthermore, herpes simplex virus-1 (HSV-1) infection induces RNF39 expression in an IFN-I-dependent manner. Thus, we outline a novel mechanism for controlling STING activation and a feedback mechanism for controlling antiviral immune responses. RNF39 could be a priming intervention target for the prevention and treatment of viral diseases, especially DNA viral infections.

Hyperglycemia-triggered lipid peroxidation destabilizes STAT4 and impairs anti-viral Th1 responses in type 2 diabetes

Patients with type 2 diabetes (T2D) are more susceptible to severe respiratory viral infections, but the underlying mechanisms remain elusive. Here, we show that patients with T2D and coronavirus disease 2019 (COVID-19) infections, and influenza-infected T2D mice, exhibit defective T helper 1 (Th1) responses, which are an essential component of anti-viral immunity. This defect stems from intrinsic metabolic perturbations in CD4+ T cells driven by hyperglycemia. Mechanistically, hyperglycemia triggers mitochondrial dysfunction and excessive fatty acid synthesis, leading to elevated oxidative stress and aberrant lipid accumulation within CD4+ T cells. These abnormalities promote lipid peroxidation (LPO), which drives carbonylation of signal transducer and activator of transcription 4 (STAT4), a crucial Th1-lineage-determining factor. Carbonylated STAT4 undergoes rapid degradation, causing reduced T-bet induction and diminished Th1 differentiation. LPO scavenger ameliorates Th1 defects in patients with T2D who have poor glycemic control and restores viral control in T2D mice. Thus, this hyperglycemia-LPO-STAT4 axis underpins reduced Th1 activity in T2D hosts, with important implications for managing T2D-related viral complications.

Multiple myeloma exosomal miRNAs suppress cGAS-STING antiviral immunity

DNA virus infection is a significant cause of morbidity and mortality in patients with multiple myeloma (MM). Monocyte dysfunction in MM patients plays a central role in infectious complications, but the precise molecular mechanism underlying the reduced resistance of monocytes to viruses in MM patients remains to be elucidated. Here, we found that MM cells were able to transfer microRNAs (miRNAs) to host monocytes/macrophages via MM cell-derived exosomes, resulting in the inhibition of innate antiviral immune responses. The screening of miRNAs enriched in exosomes derived from the bone marrow (BM) of MM patients revealed five miRNAs that negatively regulate the cGAS-STING antiviral immune response. Notably, silencing these miRNAs with antagomiRs in MM-bearing C57BL/KaLwRijHsd mice markedly reduced viral replication. These findings identify a novel mechanism whereby MM cells possess the capacity to inhibit the innate immune response of the host, thereby rendering patients susceptible to viral infection. Consequently, targeting the aberrant expression patterns of characteristic miRNAs in MM patients is a promising avenue for therapeutic intervention. Considering the miRNA score and relevant clinical factors, we formulated a practical and efficient model for the optimal assessment of susceptibility to DNA viral infection in patients with MM.

Ferroptosis crosstalk in anti-tumor immunotherapy: molecular mechanisms, tumor microenvironment, application prospects

Immunotherapies for cancer, specifically immune checkpoint inhibition (ICI), have shown potential in reactivating the body's immune response against tumors. However, there are challenges to overcome in addressing drug resistance and improving the effectiveness of these treatments. Recent research has highlighted the relationship between ferroptosis and the immune system within immune cells and the tumor microenvironment (TME), suggesting that combining targeted ferroptosis with immunotherapy could enhance anti-tumor effects. This review explores the potential of using immunotherapy to target ferroptosis either alone or in conjunction with other therapies like immune checkpoint blockade (ICB) therapy, radiotherapy, and nanomedicine synergistic treatments. It also delves into the roles of different immune cell types in promoting anti-tumor immune responses through ferroptosis. Together, these findings provide a comprehensive understanding of synergistic immunotherapy focused on ferroptosis and offer innovative strategies for cancer treatment.

The Hippo Coactivator TAZ Exacerbates Cisplatin-Induced Acute Renal Injury

Introduction

Transcriptional coactivator with PDZ-binding motif (TAZ), a Hippo signaling pathway effector, maintains the balance of cell proliferation, differentiation, and death. However, the role of TAZ in tubular cell survival and acute kidney injury (AKI) remains largely unknown.

Methods

We used the RNA-seq database, Western blot, and immunohistochemistry to examine TAZ expression in kidneys from cisplatin-induced AKI. We generated tubular-specific TAZ knockout mice to assess the role of TAZ in cisplatin-induced renal toxicity. Immunoprecipitation-mass spectrometry followed standard procedures.

Results

TAZ was activated in tubular cells in kidneys injected with cisplatin. Conditional deletion of TAZ in tubular cells confers ferroptosis resistance and protects kidneys from cisplatin-induced AKI, whereas overexpression of TAZ(S89A) exacerbates cisplatin-induced ferroptosis. Inhibition of ferroptosis with ferrostatin-1 potently preserves renal function and alleviates morphological injury and tubular cell ferroptosis induced by cisplatin. Mechanistically, in a PPARδ-dependent manner, but not TEAD, TAZ reduces the expression of glutathione peroxidase 4 (GPX4), thus exacerbating cisplatin-induced ferroptosis.

Conclusions

Our findings show that cisplatin-induced AKI and tubular cell ferroptosis are mediated by TAZ-PPARδ interaction through regulation of GPX4, highlighting TAZ as a potential therapeutic candidate for AKI.

Molecular mechanisms of ferroptosis in cardiovascular disease

Ferroptosis is a newly recognized type of regulated cell death that is characterized by the accumulation of iron and lipid peroxides in cells. Studies have shown that ferroptosis plays a significant role in the pathogenesis of various diseases, including cardiovascular diseases. In cardiovascular disease, ferroptosis is associated with ischemia-reperfusion injury, myocardial infarction, heart failure, and atherosclerosis. The molecular mechanisms underlying ferroptosis include the iron-dependent accumulation of lipid peroxidation products, glutathione depletion, and dysregulation of lipid metabolism, among others. This review aims to summarize the current knowledge of the molecular mechanisms of ferroptosis in cardiovascular disease and discuss the potential therapeutic strategies targeting ferroptosis as a treatment for cardiovascular disease.

Pathological insights into cell death pathways in diabetic wound healing

Diabetic foot ulcers (DFUs) are a microvascular complication that affects almost 21 % of the diabetic population. DFUs are characterized by lower limb abnormalities, chronic inflammation, and a heightened hypoxic environment. The challenge of healing these chronic wounds arises from impaired blood flow, neuropathy, and dysregulated cell death processes. The pathogenesis of DFUs involves intricate mechanisms of programmed cell death (PCD) in different cell types, which include keratinocytes, fibroblasts, and endothelial cells. The modes of cell death comprise apoptosis, autophagy, ferroptosis, pyroptosis, and NETosis, each defined by distinct biochemical hallmarks. These diverse mechanisms contribute to tissue injury by inducing neutrophil extracellular traps and generating cellular stressors like endoplasmic reticulum stress, oxidative stress, and inflammation. Through a comprehensive review of experimental studies identified from literature databases, this review synthesizes current knowledge on the critical signaling cascades implicated in programmed cell death within the context of diabetic foot ulcer pathology.