Environmental allergens house dust mite-induced asthma is associated with ferroptosis in the lungs

Ferroptosis in Pulmonary Disease and Lung Cancer: Molecular Mechanisms, Crosstalk Regulation, and Therapeutic Strategies

Ferroptosis is a distinct form of iron-dependent programmed cell death characterized primarily by intracellular iron accumulation and lipid peroxidation. Multiple cellular processes, including amino acid metabolism, iron metabolism, lipid metabolism, various signaling pathways, and autophagy, have been demonstrated to influence the induction and progression of ferroptosis. Recent investigations have elucidated that ferroptosis plays a crucial role in the pathogenesis of various pulmonary disorders, including lung injury, chronic obstructive pulmonary disease, pulmonary fibrosis, and asthma. Ferroptosis is increasingly recognized as a promising novel strategy for cancer treatment. Various immune cells within the tumor microenvironment, including CD8+ T cells, macrophages, regulatory T cells, natural killer cells, and dendritic cells, have been shown to induce ferroptosis in tumor cells and modulate the process through the regulation of iron and lipid metabolism pathways. Conversely, ferroptosis can reciprocally alter the metabolic environment, leading to the activation or inhibition of immune cell functions, thereby modulating immune responses. This paper reviews the molecular mechanism of ferroptosis and describes the tumor immune microenvironment, discusses the connection between ferroptosis and the tumor microenvironment in lung cancer and pulmonary diseases, and discusses the development prospect of their interaction in the treatment of lung cancer and pulmonary diseases.

Cell death crosstalk in respiratory diseases: unveiling the relationship between pyroptosis and ferroptosis in asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous obstructive diseases characterized by airflow limitations and are recognized as significant contributors to fatality all over the globe. Asthma accounts for about 4, 55,000 deaths, and COPD is the 3rd leading contributor of mortality worldwide. The pathogenesis of these two obstructive disorders is complex and involves numerous mechanistic pathways, including inflammation-mediated and non-inflammation-mediated pathways. Among all the pathological categorizations, programmed cell deaths (PCDs) play a dominating role in the progression of these obstructive diseases. The two major PCDs that are involved in structural and functional remodeling in the progression of asthma and COPD are Pyroptosis and Ferroptosis. Pyroptosis is a PCD mechanism mediated by the activation of the Nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome, leading to the maturation and release of Interleukin-1β and Interleukin-18, whereas ferroptosis is a lipid peroxidation-associated cell death. In this review, the major molecular pathways contributing to these multifaceted cell deaths have been discussed, and crosstalk among them regarding the pathogenesis of asthma and COPD has been highlighted. Further, the possible therapeutic approaches that can be utilized to mitigate both cell deaths at once have also been illustrated.

Airway Epithelium-derived CXCL14 Promotes Eosinophil Accumulation in Allergic Airway Inflammation

CXCL14 (C-X-C motif chemokine ligand 14) is expressed in the airway epithelial cells of patients with asthma. However, the mechanisms of CXCL14 secretion and its effects on asthma pathogenesis remain unclear. Here, we investigated the role of CXCL14 in allergic airway inflammation and its effects on eosinophil infiltration. Our findings showed that Alternaria alternata, a major environmental allergen, stimulated CXCL14 secretion from airway epithelial cells via reactive oxygen species generated in mitochondrial oxidative phosphorylation complexes, especially in oxidative phosphorylation complex II. In vivo, in a mouse model of allergic airway inflammation, intranasal administration of anti-CXCL14 antibody suppressed eosinophil and dendritic cell infiltration into the airways and goblet cell hyperplasia. In vitro, in human eosinophil-like cells, CXCL14 promoted cell migration through CXCR4 binding. Eosinophil CXCR4 expression was upregulated by Alternaria stimulation via reactive oxygen species production. These findings suggest that the cross-talk between Alternaria-stimulated airway epithelial CXCL14 secretion and eosinophil CXCR4 upregulation plays an important role in eosinophil infiltration into the lungs during allergic airway inflammation. In summary, this study demonstrates that CXCL14 could be a therapeutic target for allergic airway inflammation.

The molecular and metabolic landscape of ferroptosis in respiratory diseases: Pharmacological aspects

Ferroptosis is a form of cell death that occurs when there is an excess of reactive oxygen species (ROS), lipid peroxidation, and iron accumulation. The precise regulation of metabolic pathways, including iron, lipid, and amino acid metabolism, is crucial for cell survival. This type of cell death, which is associated with oxidative stress, is controlled by a complex network of signaling molecules and pathways. It is also implicated in various respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), acute lung injury (ALI), lung cancer, pulmonary fibrosis (PF), and the coronavirus disease 2019 (COVID-19). To combat drug resistance, it is important to identify appropriate biological markers and treatment targets, as well as intervene in respiratory disorders to either induce or prevent ferroptosis. The focus is on the role of ferroptosis in the development of respiratory diseases and the potential of targeting ferroptosis for prevention and treatment. The review also explores the interaction between immune cell ferroptosis and inflammatory mediators in respiratory diseases, aiming to provide more effective strategies for managing cellular ferroptosis and respiratory disorders.

NLRP3 regulates ferroptosis via the JAK2/STAT3 pathway in asthma inflammation: Insights from in vivo and in vitro studies

BACKGROUND

Ferroptosis, an iron-dependent form of cell death, plays a pivotal role in the pathologic progression of asthma. Electroacupuncture (EA) has demonstrated considerable efficacy in mitigating asthma airway inflammation, although its underlying mechanisms remain partially elucidated.

METHODS

We investigated the regulatory effect of NLRP3 on ferroptosis using a lipopolysaccharide (LPS)-induced inflammation model in BEAS-2B cells, where NLRP3 expression was modulated with si-RNA and overexpression plasmids. The levels of inflammatory cytokines TNF-α, IL-1β, and IL-6 were quantified. We also assessed NLRP3 and JAK2/STAT3 pathway-related proteins, and evaluated lipid peroxidation, mitochondrial membrane potential (ΔΨm), and antioxidant system functionality. In vivo, we examined the impact of EA on ferroptosis and airway inflammation by modulating NLRP3 activation. Asthma inflammation severity was evaluated using H&E, Masson, and PAS staining, alongside ELISA. NLRP3 and JAK2/STAT3 pathway-related proteins, as well as ferroptosis indicators, were also analyzed. The mechanism by which NLRP3 activates ferroptosis was investigated through in vitro assays.

RESULTS

LPS exposure resulted in increased intracellular inflammatory cytokines, and activation of the NLRP3 and JAK2/STAT3 pathways, leading to enhanced lipid peroxidation, decreased ΔΨm, and disruption of antioxidant system balance, ultimately inducing ferroptosis. Si-NLRP3 countered the effects of LPS, whereas oe-NLRP3 exacerbated symptoms. In vivo studies revealed that EA reduced airway inflammation, inhibited NLRP3 activation, and decreased phosphorylation of JAK2/STAT3, effectively lowering ferroptosis-related indicators. Utilizing JAK2/STAT3 activators and inhibitors, we confirmed that NLRP3 mediates ferroptosis via the JAK2/STAT3 pathway.

CONCLUSIONS

EA alleviates HDM-induced asthma, primarily through the inhibition of NLRP3 activation, which modulates the JAK2/STAT3 pathway and mediates ferroptosis.

Evaluation of the safety, tolerability, pharmacokinetics and pharmacodynamics of SM17 in healthy volunteers: results from pre-clinical models and a first-in-human, randomized, double blinded clinical trial

Background

Alarmins mediate type 2 T helper cell (Th2) inflammation and serve as upstream signaling elements in allergic inflammation and autoimmune responses. The alarmin interleukin (IL)-25 binds to a multi-domain receptor consisting of IL-17RA and IL-17RB subunits, resulting in the release of Th2 cytokines IL-4, IL-5, IL-9 and IL-13 to drive an inflammatory response. Therefore, the blockage of IL-17RB via SM17, a novel humanized monoclonal antibody, offers an attractive therapeutic target for Th2-mediated diseases, such as asthma.

Methods

Wild-type mice were stimulated with house dust mite (HDM) extracts for evaluation of SM17's pre-clinical efficacy in allergic asthma. The safety, pharmacokinectics (PK), pharmacodynamics (PD), and immunogenicity of intravenous (IV) doses of SM17 were assessed in a 2-part clinical study in healthy adult subjects. In Part A, 53 healthy participants were enrolled to receive a single IV dose of SM17 (2, 20, 70, 200, 400, 600, 1200 mg) or placebo. In Part B, 24 healthy subjects were enrolled to receive a single IV dose of SM17 every two weeks (Q2W; 200, 400, 600 mg) or placebo for a total of 3 doses.

Results

Animal studies demonstrated that SM17 significantly suppressed Th2 inflammation in the bronchoalveolar lavage fluid and infiltration of immune cells into the lungs. In the Phase I clinical study, no drug-related serious adverse events were observed. Total SM17 exposure increased by approximately 60- to 188-fold with a 60-fold increase in dose from 20 to 1200 mg SM17. Upon administration of the third dose, mean accumulation ratios over 200-600 mg was 1.5 to 2.1, which confirms moderate accumulation of SM17. After Q2W dosing of SM17 over 4 weeks, total exposure increased in a dose-proportional manner from 200 mg to 600 mg SM17.

Conclusion

In the pre-clinical studies, we demonstrated that SM17 is a potential therapeutic agent to treat allergic asthma. In the Phase 1 clinical trial, a single IV dose of SM17 up to 1200 mg and three Q2W doses up to 600 mg were well tolerated in healthy participants and demonstrated a favorable safety profile. The pre-clinical efficacy and clinical PK and immunogenicity results of SM17 support further clinical development.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT05332834.

Transcriptomic analysis and validation study of key genes and the HIF‑1α/HO‑1 pathway associated with ferroptosis in neutrophilic asthma

Ferroptosis, as a unique form of cell death caused by iron overload and lipid peroxidation, is involved in the pathogenesis of various inflammatory diseases of the airways. Inhibition of ferroptosis has become a novel strategy for reducing airway epithelial cell death and improving airway inflammation. The aim of the present study was to analyze and validate the key genes and signaling pathways associated with ferroptosis by bioinformatic methods combined with experimental analyzes in vitro and in vivo to aid the diagnosis and treatment of neutrophilic asthma. A total of 1,639 differentially expressed genes (DEGs) were identified in the transcriptome dataset. After overlapping with ferroptosis-related genes, 11 differentially expressed ferroptosis-related genes (DE-FRGs) were obtained. A new diagnostic model was constructed by these DE-FRGs from the transcriptome dataset with those from the GSE108417 dataset. The receiver operating characteristic curve analysis indicated that the area under the curve had good diagnostic performance (>0.8). As a result, four key DE-FRGs (CXCL2, HMOX1, IL-6 and SLC7A5) and biological pathway [hypoxia-inducible factor 1 (HIF-1) signaling pathway] associated with ferroptosis in neutrophilic asthma were identified by the bioinformatics analysis combined with experimental validation. The upstream regulatory network of key DE-FRGs and target drugs were predicted and the molecular docking results from screened 37 potential therapeutic drugs revealed that the 13 small-molecule drugs exhibited a higher stable binding to the primary proteins of key DE-FRGs. The results suggested that four key DE-FRGs and the HIF-1α/heme oxygenase 1 pathway associated with ferroptosis have potential as novel markers or targets for the diagnosis or treatment of neutrophilic asthma.

Coke oven emissions exacerbate allergic asthma by promoting ferroptosis in airway epithelial cells

Epidemiological studies have shown that coke oven emissions (COEs) affect the deterioration of asthma, but has not been proven by experimental results. In this study, we found for the first time that COEs exacerbate allergen house dust mite (HDM)-induced allergic asthma in the mouse model. The findings reveal that airway inflammation, airway remodeling and allergic reaction were aggravated in the COE + HDM combined exposure group compared with the individual exposure group. Mechanism studies indicated higher levels of iron and MDA in the COE + HDM combined exposure group, along with increased expression of Ptgs2 and reduced GPX4 expression. Iron chelator deferoxamine (DFO) effectively inhibited ferroptosis induced by COE synergistically with HDM in vitro. Further studies highlighted the role of ferritinophagy in the COE + HDM-induced ferroptosis. 3-methyladenine (3-MA) could inhibit ferroptosis in the COE + HDM exposure group. Interestingly, we injected DFO intraperitoneally into mice in the combined exposure group and found DFO could significantly inhibit the COE-exacerbated ferroptosis and allergic asthma. Our findings link ferroptosis with COE-exacerbated allergic asthma, implying that ferroptosis may have important therapeutic potential for asthma in patients with occupational exposure of COE.

Photobiomodulation Mitigates PM2.5-Exacerbated Pathologies in a Mouse Model of Allergic Asthma

Exposure to particulate matter (PM), especially PM2.5, is known to exacerbate asthma, posing a significant public health risk. This study investigated the asthma-reducing effects of photobiomodulation (PBM) in a mice model mimicking allergic airway inflammation exacerbated by PM2.5 exposure. The mice received sensitization with ovalbumin (OVA) and were subsequently treated with PM2.5 at a dose of 0.1 mg/kg every 3 days, for 9 times over 3 weeks during the challenge. PBM, using a 610 nm wavelength LED, was applied at 1.7 mW/cm2 to the respiratory tract via direct skin contact for 20 min daily for 19 days. Results showed that PBM significantly reduced airway hyperresponsiveness, plasma immunoglobulin E (IgE) and OVA-specific IgE, airway inflammation, T-helper type 2 cytokine, histamine and tryptase in bronchoalveolar lavage fluid (BALF), and goblet cell hyperplasia in PM2.5-exposed asthmatic mice. Moreover, PBM alleviated subepithelial fibrosis by reducing collagen deposition, airway smooth muscle mass, and expression of fibrosis-related genes. It mitigated reactive oxygen species generation, oxidative stress, endoplasmic reticulum stress, apoptotic cell death, ferroptosis, and modulated autophagic signals in the asthmatic mice exposed to PM2.5. These findings suggest that PBM could be a promising intervention for PM2.5-induced respiratory complications in patients with allergic asthma.

Revealing the regulation of allergic asthma airway epithelial cell inflammation by STEAP4 targeting MIF through machine learning algorithms and single-cell sequencing analysis

Asthma comprises one of the most common chronic inflammatory conditions, yet still lacks effective diagnostic markers and treatment targets. To gain deeper insights, we comprehensively analyzed microarray datasets of airway epithelial samples from asthmatic patients and healthy subjects in the Gene Expression Omnibus database using three machine learning algorithms. Our investigation identified a pivotal gene, STEAP4. The expression of STEAP4 in patients with allergic asthma was found to be reduced. Furthermore, it was found to negatively correlate with the severity of the disease and was subsequently validated in asthmatic mice in this study. A ROC analysis of STEAP4 showed the AUC value was greater than 0.75. Functional enrichment analysis of STEAP4 indicated a strong correlation with IL-17, steroid hormone biosynthesis, and ferroptosis signaling pathways. Subsequently, intercellular communication analysis was performed using single-cell RNA sequencing data obtained from airway epithelial cells. The results revealed that samples exhibiting low levels of STEAP4 expression had a richer MIF signaling pathway in comparison to samples with high STEAP4 expression. Through both in vitro and in vivo experiments, we further confirmed the overexpression of STEAP4 in airway epithelial cells resulted in decreased expression of MIF, which in turn caused a decrease in the levels of the cytokines IL-33, IL-25, and IL-4; In contrast, when the STEAP4 was suppressed in airway epithelial cells, there was an upregulation of MIF expression, resulting in elevated levels of the cytokines IL-33, IL-25, and IL-4. These findings suggest that STEAP4 in the airway epithelium reduces allergic asthma Th2-type inflammatory reactions by inhibiting the MIF signaling pathway.

Adjuvant-independent airway sensitization and infection mouse models leading to allergic asthma

Asthma is a chronic respiratory disease of global importance. Mouse models of allergic asthma have been instrumental in advancing research and novel therapeutic strategies for patients. The application of relevant allergens and physiological routes of exposure in such models has led to valuable insights into the complexities of asthma onset and development as well as key disease mechanisms. Furthermore, environmental microbial exposures and infections have been shown to play a fundamental part in asthma pathogenesis and alter disease outcome. In this review, we delve into physiological mouse models of allergic asthma and explore literature reports on most significant interplays between microbial infections and asthma development with relevance to human disease.

The disrupted molecular circadian clock of monocytes and macrophages in allergic inflammation

Introduction

Macrophage dysfunction is a common feature of inflammatory disorders such as asthma, which is characterized by a strong circadian rhythm.

Methods and results

We monitored the protein expression pattern of the molecular circadian clock in human peripheral blood monocytes from healthy, allergic, and asthmatic donors during a whole day. Monocytes cultured of these donors allowed us to examine circadian protein expression in human monocyte-derived macrophages, M1- and M2- polarized macrophages. In monocytes, particularly from allergic asthmatics, the oscillating expression of circadian proteins CLOCK, BMAL, REV ERBs, and RORs was significantly altered. Similar changes in BMAL1 were observed in polarized macrophages from allergic donors and in tissue-resident macrophages from activated precision cut lung slices. We confirmed clock modulating, anti-inflammatory, and lung-protective properties of the inverse ROR agonist SR1001 by reduced secretion of macrophage inflammatory protein and increase in phagocytosis. Using a house dust mite model, we verified the therapeutic effect of SR1001 in vivo.

Discussion

Overall, our data suggest an interaction between the molecular circadian clock and monocytes/macrophages effector function in inflammatory lung diseases. The use of SR1001 leads to inflammatory resolution in vitro and in vivo and represents a promising clock-based therapeutic approach for chronic pulmonary diseases such as asthma.

Bronchom assuages airway hyperresponsiveness in house dust mite-induced mouse model of allergic asthma and moderates goblet cell metaplasia, sub-epithelial fibrosis along with changes in Th2 cytokines and chemokines

Background

Asthma is a common obstructive airway disease with an inflammatory etiology. The main unmet need in the management of asthma is inadequate adherence to pharmacotherapy, leading to a poorly-controlled disease state, necessitating the development of novel therapies. Bronchom is a calcio-herbal formulation, which is purported to treat chronic asthma. The objective of the current study was to examine the in-vivo efficacy of Bronchom in mouse model of allergic asthma.

Methods

Ultra high performance liquid chromatography was utilized to analyze the phytocompounds in Bronchom. Further, the in-vivo efficacy of Bronchom was evaluated in House dust mite (HDM)-induced allergic asthma in mice. Mice were challenged with aerosolized methacholine to assess airway hyperresponsiveness. Subsequently, inflammatory cell influx was evaluated in bronchoalveolar lavage fluid (BALF) followed by lung histology, wherein airway remodeling features were studied. Simultaneously, the levels of Th2 cytokines and chemokines in the BALF was also evaluated. Additionally, the mRNA expression of pro-inflammatory and Th2 cytokines was also assessed in the lung along with the oxidative stress markers.

Results

Phytocompounds present in Bronchom included, gallic acid, protocatechuic acid, methyl gallate, rosmarinic acid, glycyrrhizin, eugenol, 6-gingerol and piperine. Bronchom effectively suppressed HDM-induced airway hyperresponsiveness along with the influx of leukocytes in the BALF. Additionally, Bronchom reduced the infiltration of inflammatory cells in the lung and it also ameliorated goblet cell metaplasia, sub-epithelial fibrosis and increase in α-smooth muscle actin. Bronchom decreased Th2 cytokines (IL-4 and IL-5) and chemokines (Eotaxin and IP-10) in the BALF. Likewise, it could also suppress the mRNA expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-6 and IL-33), and IL-13. Moreover, Bronchom restored the HDM-induced diminution of endogenous anti-oxidants (GSH and SOD) and the increase in pro-oxidants (GSSG and MDA). Furthermore, Bronchom could also decrease the nitrosative stress by lowering the observed increase in nitrite levels.

Conclusion

Taken together, the results of the present study data convincingly demonstrate that Bronchom exhibits pharmacological effects in an animal model of allergic asthma. Bronchom mitigated airway hyperresponsiveness, inflammation and airway remodeling evoked by a clinically relevant allergen and accordingly it possesses therapeutic potential for the treatment of asthma.

Rhizoma Dioscoreae Nipponicae Relieves Asthma by Inducing the Ferroptosis of Eosinophils and Inhibiting the p38 MAPK Signaling Pathway

Rhizoma Dioscoreae Nipponicae (RDN) is a traditional Chinese medicine that widely applied in the treatment of human diseases. This study aims to explore the therapeutic potential of RDN in asthma and the underlying mechanisms. A mouse model of asthma was established by the stimulation of ovalbumin (OVA). HE staining was performed to detect the pathological injuries of tracheal tissues. The protein expression of collagen I, FN1, α-SMA (airway remodeling markers), and p-p38 (a marker of the p38 MAPK pathway) were detected by Western blot. Eosinophils were then isolated from the model mice. Cell viability and ROS level were measured by CCK-8 and Flow cytometry, respectively. The mRNA expression of GPX4 and ACSL4 (ferroptosis markers) in eosinophils were measured by qRT-PCR. RDN significantly reduced the numbers of total cells and eosnophils in bronchoalveolar lavage fluid (BALF), inhibited inflammatory cell infiltration, and down-regulated remodeling markers (Collagen I, FN1, and α-SMA) in OVA-induced mice. The p38 MAPK pathway was blocked by the intervention of RDN in the model mice, and its blocking weakens the poor manifestations of OVA-induced asthma. In addition, RDN induced the ferroptosis of eosnophils both in vitro and in vivo. Blocking of the p38 MAPK pathway also enhanced the ferroptosis of eosnophils in vitro, evidenced by the decreased cell viability and GPX4 expression, and increased ROS level and ACSL4 expression. RDN induced the ferroptosis of eosinophils through inhibiting the p38 MAPK pathway, contributing to the remission of asthma.

Ferritinophagy Mediated by Oxidative Stress-Driven Mitochondrial Damage Is Involved in the Polystyrene Nanoparticles-Induced Ferroptosis of Lung Injury

Nanoplastics are a common type of contaminant in the air. However, no investigations have focused on the toxic mechanism of lung injury induced by nanoplastic exposure. In the present study, polystyrene nanoplastics (PS-NPs) caused ferroptosis in lung epithelial cells, which could be alleviated by ferrostatin-1, deferoxamine, and N-acetylcysteine. Further investigation found that PS-NPs disturbed mitochondrial structure and function and triggered autophagy. Mechanistically, oxidative stress-derived mitochondrial damage contributed to ferroptosis, and autophagy-dependent ferritinophagy was a pivotal intermediate link, resulting in ferritin degradation and iron ion release. Furthermore, inhibition of ferroptosis using ferrostatin-1 alleviated pulmonary and systemic toxicity to reverse the mouse lung injury induced by PS-NPs inhalation. Most importantly, the lung-on-a-chip was further used to clarify the role of ferroptosis in the PS-NPs-induced lung injury by visualizing the ferroptosis, oxidative stress, and alveolar-capillary barrier dysfunction at the organ level. In summary, our study indicated that ferroptosis was an important mechanism for nanoplastics-induced lung injury through different lung cells, mouse inhalation models, and three-dimensional-based lung-on-a-chip, providing an insightful reference for pulmonary toxicity assessment of nanoplastics.

Tollip deficiency exaggerates airway type 2 inflammation in mice exposed to allergen and influenza A virus: role of the ATP/IL-33 signaling axis

Toll-interacting protein (Tollip) is a negative regulator of the pro-inflammatory response to viruses, including influenza A virus (IAV). Genetic variation of Tollip has been associated with reduced airway epithelial Tollip expression and poor lung function in patients with asthma. Whether Tollip deficiency exaggerates type 2 inflammation (e.g., eosinophils) and viral infection in asthma remains unclear. We sought to address this critical, but unanswered question by using a Tollip deficient mouse asthma model with IAV infection. Further, we determined the underlying mechanisms by focusing on the role of the ATP/IL-33 signaling axis. Wild-type and Tollip KO mice were intranasally exposed to house dust mite (HDM) and IAV with or without inhibitors for IL-33 (i.e., soluble ST2, an IL-33 decoy receptor) and ATP signaling (i.e., an antagonist of the ATP receptor P2Y13). Tollip deficiency amplified airway type 2 inflammation (eosinophils, IL-5, IL-13 and mucins), and the release of ATP and IL-33. Blocking ATP receptor P2Y13 decreased IL-33 release during IAV infection in HDM-challenged Tollip KO mice. Furthermore, soluble ST2 attenuated airway eosinophilic inflammation in Tollip KO mice treated with HDM and IAV. HDM challenges decreased lung viral load in wild-type mice, but Tollip deficiency reduced the protective effects of HDM challenges on viral load. Our data suggests that during IAV infection, Tollip deficiency amplified type 2 inflammation and delayed viral clearance, in part by promoting ATP signaling and subsequent IL-33 release. Our findings may provide several therapeutic targets, including ATP and IL-33 signaling inhibition for attenuating excessive airway type 2 inflammation in human subjects with Tollip deficiency and IAV infection.

Integrated analysis of ATAC-seq and RNA-seq unveils the role of ferroptosis in PM2.5-induced asthma exacerbation

BACKGROUND

PM2.5 exposure increases asthma exacerbation risk and worsens airway inflammation and mucus secretion, but the underlying mechanisms, especially the epigenetic modification changes, are not fully understood.

METHODS

ATAC-seq was conducted in Beas-2B cells to explore the differential chromatin accessibilities before and after exposure to PM2.5. RNA-seq was applied to screen the differentially expressed genes (DEGs) as well. The integrated analysis of ATAC-seq and RNA-seq was performed. The key up-regulated genes in the ferroptosis signaling pathway were identified by combined analysis with the FerrDb database and then verified. Meanwhile, to access the role of PM2.5-induced ferroptosis in asthma mice, house dust mites (HDM) were employed to conduct an allergic asthma mice model, and the ferroptosis-specific inhibitor (Ferrostatin-1, Fer-1) was used. The H&E staining, PAS staining, airway hyperresponsiveness, and bronchoalveolar lavage fluid (BALF) cell counting were used to investigate the impact of PM2.5-induced ferroptosis in asthma mice.

RESULTS

A total of 4,921 regions with differential accessibility were identified, encompassing 4,031 unique genes. Among these, 250 regions exhibited increased accessibility while 4,671 regions displayed reduced accessibility. Through the integrated analysis of ATAC-seq and RNA-seq, ferroptosis was determined as the key enriched pathway based on up-regulated DEGs and increased chromatin accessibilities. Furthermore, the decreased cell viability, accelerated lipid peroxide and morphological changes in mitochondria observed upon PM2.5 exposure were rescued by Fer-1, which are indicative of ferroptosis. By overlapping with ferroptosis-related genes from the FerrDb database, FTH1 and FTL were identified as the prominent up-regulated genes with increased chromatin accessibility in ferroptosis pathway. In addition, ChIP-qPCR analysis indicated that histone modification like H3K4me3 and H3K27ac positively regulated FTH1 and FTL expression. Subsequently, in PM2.5-exposed asthmatic mice, inhibition of ferroptosis effectively attenuated airway inflammation and mucus secretion.

CONCLUSION

These findings shed light on the molecular mechanisms underlying PM2.5-induced asthma exacerbation, with epigenetic modifications playing a pivotal role. Furthermore, it suggests the therapeutic potential of targeting ferroptosis as an intervention strategy.

Exploration and Validation of Potential Biomarkers and Therapeutic Targets in Ferroptosis of Asthma

Purpose

Asthma is a chronic inflammatory airway disease involving multiple mechanisms, of which ferroptosis is a form of programmed cell death. Recent studies have shown that ferroptosis may play a crucial role in the pathogenesis of asthma, but no specific ferroptosis gene has been found in asthma, and the exact mechanism is still unclear. The present study aimed to screen ferroptosis genes associated with asthma and find therapeutic targets, in order to contribute a new clue for the diagnosis and therapy of asthma.

Methods

Ferroptosis-related differentially expressed genes (FR-DEGs) in asthma were selected by the GSE41861, GSE43696 and ferroptosis datasets. Next, the FR-DEGs were subjected by GO and KEGG enrichment, and the mRNA-miRNA network was constructed. Then, GSEA and GSVA enrichment analysis and Immune infiltration analysis were performed, followed by targeted drug prediction. Finally, the expression of FR-DEGs was confirmed using GSE63142 dataset and RT-PCR assay.

Results

We found 13 FR-DEGs by the GSE41861, GSE43696 and ferroptosis database. Functional enrichment analysis revealed that the 13 FR-DEGs were enriched in oxidative stress, immune response, ferroptosis, lysosome, necrosis, apoptosis etc. Moreover, our results revealed the mRNA-miRNA network of the FR-DEGs and identified candidate drugs. Also, immune infiltration revealed that ELAVL1, CREB5, CBR1 and NR1D2 are associated with the immune cells and may be potential targets in asthma. Finally, 10 FR-DEGs were validated by the GSE63142 database. It was verified that 7 FR-DEGs were differentially expressed by collecting asthma patients and healthy controls.

Conclusion

This study ultimately identified 7 FR-DEGs for the diagnosis and therapy of asthma. These 7 FR-DEGs contribute to oxidative stress and immune responses. This study provides potential therapeutic targets and biomarkers for asthma patients, shedding further light on the pathogenesis of asthma as well as providing new insights into the treatment of asthma.

Programmed Cell Death in Asthma: Apoptosis, Autophagy, Pyroptosis, Ferroptosis, and Necroptosis

Bronchial asthma is a complex heterogeneous airway disease, which has emerged as a global health issue. A comprehensive understanding of the different molecular mechanisms of bronchial asthma may be an efficient means to improve its clinical efficacy in the future. Increasing research evidence indicates that some types of programmed cell death (PCD), including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis, contributed to asthma pathogenesis, and may become new targets for future asthma treatment. This review briefly discusses the molecular mechanism and signaling pathway of these forms of PCD focuses on summarizing their roles in the pathogenesis and treatment strategies of asthma and offers some efficient means to improve clinical efficacy of therapeutics for asthma in the near future.

Constructing ferroptosis-related competing endogenous RNA networks and exploring potential biomarkers correlated with immune infiltration cells in asthma using combinative bioinformatics strategy

BACKGROUND

Asthma is a common chronic respiratory disease worldwide. Recent studies have revealed the critical effects of the ceRNA network and ferroptosis on patients with asthma. Thus, this study aimed to explore the potential ferroptosis-related ceRNA network, investigate the immune cell infiltration level in asthma through integrated analysis of public asthma microarray datasets, and find suitable diagnostic biomarkers for asthma.

METHODS

First, three asthma-related datasets which were downloaded from the Gene Expression Omnibus (GEO) database were integrated into one pooled dataset after correcting for batch effects. Next, we screened differentially expressed lncRNAs (DElncRNAs) between patients and healthy subjects, constructed a ceRNA network using the StarBase database and screened ferroptosis-related genes from the predicted target mRNAs for Disease Ontology (DO), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. We also performed Gene Set Enrichment Analysis (GSEA) and Gene Set Variation Analysis (GSVA) on the batch effect-corrected mRNA expression profile. Then, Least Absolute Shrinkage and Selection Operator (LASSO) regression was used to screen potential diagnostic biomarkers, and the diagnostic efficacy was assessed using a receiver operating characteristic (ROC) curve. Finally, we determined the proportion of 22 immune cells in patients with asthma using CIBERSORT and investigated the correlation between key RNAs and immune cells.

RESULTS

We obtained 19 DElncRNAs, of which only LUCAT1 and MIR222HG had corresponding target miRNAs. The differentially expressed ferroptosis-related genes were involved in multiple programmed cell death-related pathways. We also found that the mRNA expression profile was primarily enriched in innate immune system responses. We screened seven candidate diagnostic biomarkers for asthma using LASSO regression (namely, BCL10, CD300E, IER2, MMP13, OAF, TBC1D3, and TMEM151A), among which the area under the curve (AUC) value for CD300E and IER2 were 0.722 and 0.856, respectively. Finally, we revealed the infiltration ratio of different immune cells in asthma and found a correlation between LUCAT1, MIR222HG, CD300E, and IER2 with some immune cells.

CONCLUSION

This study explored a potential lncRNA-miRNA-mRNA regulatory network and its underlying diagnostic biomarkers (CD300E and IER2) in asthma and identified the immune cells most associated with them, providing possible diagnostic markers and immunotherapeutic targets for asthma.

Ferroptosis participates in dibutyl phthalate-aggravated allergic asthma in ovalbumin-sensitized mice

Dibutyl phthalate (DBP), used as a plasticizer, is of wide concern as an environmental pollutant since it has certain immunotoxicity. Although there is growing evidence supporting a link between DBP exposure and allergic airway inflammation, there is less information concerned with whether the ferroptosis pathway is involved in DBP-aggravated allergic asthma in ovalbumin (OVA)-sensitized mice. This study aimed to investigate the role and underlying mechanisms of ferroptosis in DBP-exposed allergic asthmatic mice. Balb/c mice were orally exposed to 40 mg/kg^-1 DBP for 28 days, followed by sensitization with OVA and seven consecutive challenges with nebulized OVA. We analyzed airway hyperresponsiveness (AHR), immunoglobulins, inflammation and pulmonary histopathology, to investigate whether DBP exacerbates allergic asthma in OVA-induced mice. We also measured the biomarkers of ferroptosis (Fe²⁺, GPX4, PTGS2), proteins related to the ferroptosis pathway (VEGF, IL-33, HMGB1, SLC7A11, ALOX15, PEBP1), and indices of lipid peroxidation (ROS, Lipid ROS, GSH, MDA, 4-HNE), to explore the role of ferroptosis in DBP+OVA mice. Finally, we used ferrostatin-1 (Fer-1) as an antagonist against the harmful effects of DBP. The results showed that, DBP+OVA mice had a significant increase in AHR, airway wall remodeling and airway inflammation. Further, we showed that DBP aggravated allergic asthma via ferroptosis and lipid peroxidation, and that Fer-1 inhibited ferroptosis and alleviated the pulmonary toxicity of DBP. These results suggest that ferroptosis participates in the exacerbation of allergic asthma resulting from oral exposure to DBP, highlighting a novel pathway for the connection between DBP and allergic asthma.

The role of ferroptosis-related genes in airway epithelial cells of asthmatic patients based on bioinformatics

It has been reported that airway epithelial cells and ferroptosis have certain effect on asthma. However, the action mechanism of ferroptosis-related genes in airway epithelial cells of asthmatic patients is still unclear. Firstly, the study downloaded the GSE43696 training set, GSE63142 validation set and GSE164119 (miRNA) dataset from the gene expression omnibus database. 342 ferroptosis-related genes were downloaded from the ferroptosis database. Moreover, differentially expressed genes (DEGs) between asthma and control samples in the GSE43696 dataset were screened by differential analysis. Consensus clustering analysis was performed on asthma patients to classify clusters, and differential analysis was performed on clusters to obtain inter-cluster DEGs. Asthma-related module was screened by weighted gene co-expression network analysis. Then, DEGs between asthma and control samples, inter-cluster DEGs and asthma-related module were subjected to venn analysis for obtaining candidate genes. The last absolute shrinkage and selection operator and support vector machines were respectively applied to the candidate genes to screen for feature genes, and functional enrichment analysis was performed. Finally, a competition endogenetic RNA network was constructed and drug sensitivity analysis was conducted. There were 438 DEGs (183 up-regulated and 255 down-regulated) between asthma and control samples. 359 inter-cluster DEGs (158 up-regulated and 201 down-regulated) were obtained by screening. Then, the black module was significantly and strongly correlated with asthma. The venn analysis yielded 88 candidate genes. 9 feature genes (NAV3, ITGA10, SYT4, NOX1, SNTG2, RNF182, UPK1B, POSTN, SHISA2) were screened and they were involved in proteasome, dopaminergic synapse etc. Besides, 4 mRNAs, 5 miRNAs, and 2 lncRNAs collectively formed competition endogenetic RNA regulatory network, which included RNF182-hsa-miR-455-3p-LINC00319 and so on. The predicted therapeutic drug network map contained NAV3-bisphenol A and other relationship pairs. The study investigated the potential molecular mechanisms of NAV3, ITGA10, SYT4, NOX1, SNTG2, RNF182, UPK1B, POSTN, SHISA2 in airway epithelial cells of asthmatic patients through bioinformatics analysis, providing a reference for the research of asthma and ferroptosis.

Evaluation of genetic variants in ferroptosis-related genes and house dust mite-induced allergic rhinitis risk

BACKGROUND

Ferroptosis-related genes disrupt iron homeostasis and enhance lipid peroxidation to initiate respiratory system diseases. However, the association between genetic variants in the ferroptosis-related genes with house dust mite (HDM)-induced allergic rhinitis (AR) susceptibility remains unclear.

METHODS

A case-control study, involving 222 cases and 237 healthy controls from a Chinese population, was conducted to evaluate the relationship between single nucleotide polymorphisms (SNPs) in ferroptosis-related genes and HDM-induced AR risk. A gene-based analysis was performed by multi-marker analysis of genomic annotation (MAGMA) to identify candidate associated ferroptosis-related genes. A logistic regression model and joint analysis were used to assess the effect of SNPs on HDM-induced AR susceptibility.

RESULTS

Two independent SNPs (rs2305128 in ENPP2 and rs1868088 in EPAS1) were significantly associated with HDM-induced AR risk (OR = 1.82, 95% CI = 1.19-2.79, P = 5.98 × 10-3, PFDR = 4.88 × 10-2; OR = 2.14, 95% CI = 1.23-3.72, P = 6.95 × 10-3, PFDR = 4.87 × 10-2, respectively). Moreover, combined analysis of these two SNPs revealed that an increased risk of HDM-induced AR was positively associated with an increasing number of risk genotypes (Ptrend = 8.48 × 10-5). The stratification analysis showed that the cumulative effect of two SNPs on HDM-induced AR risk was more pronounced among patients presenting more serious symptoms and harboring one or two risk genotypes.

CONCLUSIONS

These findings suggest that the genetic variants in ferroptosis-related genes ENPP2 and EPAS1 may increase HDM-induced AR risk and serve as potential predictors of HDM-induced AR susceptibility.

Regulation of ferroptosis and ACSL4-15LO1 pathway contributed to the anti-asthma effect of acupuncture

Acupuncture has been frequently used in China for the treatment asthma for thousands of years. Ferroptosis was recently revealed to be involved in several pathological conditions including asthma. However, the detailed links between ferroptosis and airway inflammation in asthma, as well as the detailed regulation of acupuncture on these disorders remains unclear. Our results demonstrated that the non-haem Fe²⁺ level increased markedly in the lung tissue of mouse asthma model, and positively correlated with R_L and IL-4 level in BALF. Furthermore, lipid peroxidation markers MDA and GSSG increased remarkably in OVA-induced experimental asthma mice. Up-regulation of lipid peroxidation associated proteins ACSL4 and15-LO1 was also observed in OVA-induced experimental asthma mice. To demonstrate the role of ferroptosis in asthma and the effect of acupuncture on these disorders, ferroptosis-induction agent erastin and ferroptosis-inhibition agent fer-1 were used, and our data demonstrated that erastin could augment lung inflammation and lipid peroxidation in OVA induced asthma model. Fer-1 was able to relieve AHR, lung inflammation, non-haem Fe²⁺ level, lipid peroxidation and ferroptosis related pathway ACSL4-15LO1 in OVA-induced experimental asthma mice. Acupuncture treatment alleviated R_L, lung inflammation as well as type 2 cytokines IL-4 and IL-13 levels induced by OVA inhalation. What's more, acupuncture significantly reduced the MDA and GSSG levels, the non-haem Fe²⁺ level and ACSL4-15-LO1 proteins expression. Acupuncture also relieved erastin-induced exacerbation in lung inflammation and lipid peroxidation in ferroptosis. Acupuncture treatment could relieve ferroptosis related exacerbation in airway inflammation. Our study provided insights into the underlying mechanisms for the protective effects of acupuncture and highlighted a therapeutic potential of acupuncture treatment in the attenuation of lipid peroxidation and ferroptosis in asthma.

Ferroptosis triggers airway inflammation in asthma

Ferroptosis is a regulatory cell death characterized by intracellular iron accumulation and lipid peroxidation that leads to oxidative stress. Many signaling pathways such as iron metabolism, lipid metabolism, and amino acid metabolism precisely regulate the process of ferroptosis. Ferroptosis is involved in a variety of lung diseases, such as acute lung injury, chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis. Increasing studies suggest that ferroptosis is involved in the development of asthma. Ferroptosis plays an important role in asthma. Iron metabolism disorders, lipid peroxidation, amino acid metabolism disorders lead to the occurrence of ferroptosis in airway epithelial cells, and then aggravate clinical symptoms in asthmatic patients. Moreover, several regulators of ferroptosis are involved in the pathogenesis of asthma, such as Nrf2, heme oxygenase-1, mevalonate pathway, and ferroptosis inhibitor protein 1. Importantly, ferroptosis inhibitors improve asthma. Thus, the pathogenesis of ferroptosis and its contribution to the pathogenesis of asthma help us better understand the occurrence and development of asthma, and provide new directions in asthma treatment. This article aimed to review the role and mechanism of ferroptosis in asthma, describing the relationship between ferroptosis and asthma based on signaling pathways and related regulatory factors. At the same time, we summarized current observations of ferroptosis in eosinophils, airway epithelial cells, and airway smooth muscle cells in asthmatic patients.

The role of ferroptosis in chronic intermittent hypoxia-induced lung injury

PURPOSE

Chronic intermittent hypoxia (CIH) causes lung injury but the mechanism is unclear. Ferroptosis is a novel form of programmed cell death. In this research, we attempted to explore the role of ferroptosis in CIH-induced lung injury both in vitro and in vivo.

METHODS

Sprague-Dawley rats were randomly separated into control group, CIH group and CIH + ferrostatin-1 group (CIH + Fer-1). Rats in the CIH group and CIH + Fer-1 group were exposed to intermittent hypoxia for 12 weeks. Human bronchial epithelial cell line (BEAS-2B) was cultivated for 24 h in either conventional culture medium or under CIH conditions. Fer-1 was applied to observe its treatment effects. Histological changes were evaluated by Hematoxylin-eosin (HE) staining and masson staining. The expression levels of Acyl-CoA synthetase long-chain family member 4 (ACSL4), glutathione peroxidase 4 (GPX4), interleukin-6 (IL-6) and tumour necrosis factor α (TNFα) were detected via qRT-PCR or Western blot. Cell counting kit-8 (CCK-8) was used to assess cell viability. The apoptotic rate and reactive oxygen species (ROS) was calculated by flow cytometry.

RESULTS

Histology showed that CIH treatment induced lung injury and pulmonary fibrosis in lung tissue. After Fer-1 treatment, the pathological changes caused by CIH alleviated. The mRNA and protein levels of GPX4 decreased significantly in lung tissues of CIH-treated rats and BEAS-2B, (p < 0.05). The mRNA and protein levels of ACSL4 increased significantly in lung tissues of CIH-treated rats and BEAS-2B, (p < 0.05). The mRNA levels of IL-6 and TNFα in BEAS-2B increased after CIH treatment, (p < 0.05). Cell viability decreased, apoptosis rate and ROS increased in CIH-treated BEAS-2B, (p < 0.05). Cotreatment with Fer-1 reversed CIH-induced apoptosis, cell viability, ROS accumulation, mRNA and protein levels of GPX4, ACSL4, IL-6 and TNFα both in vitro and in vivo (p < 0.05).

CONCLUSIONS

Ferroptosis occurred in CIH-induced lung injury, both in vitro and in vivo. The ferroptosis inhibitor Fer-1 alleviated cell injury and ferroptosis in CIH-treated BEAS-2B and lung tissues of rats.

IL13 Promoter (-1055) Polymorphism Associated with Leukocyte Mitochondria DNA Copy Number in Chronic Obstructive Pulmonary Disease

IL13 polymorphism is associated with chronic obstructive pulmonary disease (COPD). Patients with COPD have smaller numbers of mitochondria deoxyribonucleic acid copies (mtDNA-CN) than people without COPD do. However, whether IL13 polymorphism affects the mutation and recombination of mitochondria remains unclear. Data for patients with COPD and non-COPD were collected from Kaohsiung Chang Gung Memorial Hospital to enable a comparison of their leukocyte mtDNA-CN and the association of this information with IL-13 promoter (−1055) polymorphism. This study included 99 patients with COPD and 117 individuals without COPD. The non-COPD individuals included 77 healthy individuals that never smoked and 40 healthy smokers. The patients with COPD exhibited significantly lower mtDNA-CN than non-COPD did (250.34 vs. 440.03; p < 0.001); mtDNA-CN was particularly pronounced in individuals with the IL13 CC and CT genotypes compared with individuals with the TT genotype. When only individuals without COPD were considered and when all participants were considered, the differences in the mtDNA-CNs in individuals with the CC and CT genotypes were more significant than those in individuals with the TT genotype (448.4 and 533.6 vs. 282.8; p < 0.05 in non-COPD group); (368.8 and 362.6 vs. 249.6, p < 0.05 in all participants). The increase mtDNA-CN in the CC and CT genotypes was also more than that in the TT genotype in COPD patients, but showed no significance (260.1 and 230.5 vs. 149.9; p = 0.343). The finding shows that COPD is a mitochondria regulatory disorder and IL-13 promoter (−1055) polymorphism is associated with leukocyte mtDNA-CN. Developing COPD control methods based on mitochondrial regulation will be possible.

PM2.5 inhibits system Xc- activity to induce ferroptosis by activating the AMPK-Beclin1 pathway in acute lung injury

Urban airborne fine particulate matter (PM2.5) is a global pollution source that has been strongly related to multiple respiratory diseases involving various types of regulated cell death (RCD). However, the role of ferroptosis, a novel form of RCD, in PM2.5-induced acute lung injury (ALI), has not been elucidated. Herein, we define the role and mechanism of ferroptosis in a PM2.5-induced ALI model. First, we demonstrated that lipid peroxidation and iron accumulation were significantly enhanced in ALI models and were accompanied by activation of the AMP-activated protein kinase (AMPK)-Beclin1 signaling pathway and inhibition of the key subunit SLC7A11 of System Xc-. However, these abnormalities were partially reversed by ferroptosis inhibitors. We further revealed that Beclin1 knockdown or overexpression ameliorated or exacerbated PM2.5-induced ferroptosis, respectively. Mechanistically, we verified that Beclin1 blocks System Xc- activity to trigger ferroptosis by directly binding to SLC7A11. Finally, knockdown of Beclin1 by AAV-shRNA or inhibition of AMPK, an upstream activator of Beclin1, ameliorated PM2.5-induced ferroptosis and ALI. Taken together, our results revealed that ferroptosis plays a novel role in PM2.5-induced ALI and elucidated the specific mechanism involving the AMPK-Beclin1 pathway and System Xc-, which may provide new insight into the toxicological effects of PM2.5 on respiratory problems.

Multifaceted Roles of Ferroptosis in Lung Diseases

Ferroptosis is a distinct type of programmed cell death (PCD) that depends on iron and is characterized by the accumulation of intracellular iron, exhaustion of glutathione, deactivation of glutathione peroxidase, and promotion of lipid peroxidation. Recently, accumulated investigations have demonstrated that ferroptosis is strongly correlated with the initiation and development of many lung diseases. In this review, we summarized the contribution of ferroptosis to the pathologic process of lung diseases, namely, obstructive lung diseases (chronic obstructive pulmonary disease, asthma, and cystic fibrosis), interstitial lung diseases (pulmonary fibrosis of different causes), pulmonary diseases of vascular origin (ischemia-reperfusion injury and pulmonary hypertension), pulmonary infections (bacteria, viruses, and fungi), acute lung injury, acute respiratory distress syndrome, obstructive sleep apnea, pulmonary alveolar proteinosis, and lung cancer. We also discussed the therapeutic potential of targeting ferroptosis for these lung diseases.

HDM induce airway epithelial cell ferroptosis and promote inflammation by activating ferritinophagy in asthma

Asthma is a disease characterized by airway epithelial barrier destruction, chronic airway inflammation, and airway remodeling. Repeated damage to airway epithelial cells by allergens in the environment plays an important role in the pathophysiology of asthma. Ferroptosis is a novel form of regulated cell death mediated by lipid peroxidation in association with free iron-mediated Fenton reactions. In this study, we explored the contribution of ferroptosis to house dust mite (HDM)-induced asthma models. Our in vivo and in vitro models showed labile iron accumulation and enhanced lipid peroxidation with concomitant nonapoptotic cell death upon HDM exposure. Treatment with ferroptosis inhibitors deferoxamine (DFO) and ferrostatin-1 (Fer-1) illuminated the role of ferroptosis and related damage-associated molecular patterns in HDM-treated airway epithelial cells. Furthermore, DFO and Fer-1 reduced HDM-induced airway inflammation in model mice. Mechanistically, NCOA4-mediated ferritin-selective autophagy (ferritinophagy) was initiated during ferritin degradation in response to HDM exposure. Together, these data suggest that ferroptosis plays an important role in HDM-induced asthma and that ferroptosis may be a potential treatment target for HDM-induced asthma.

Ferrostatin-1 and 3-Methyladenine Ameliorate Ferroptosis in OVA-Induced Asthma Model and in IL-13-Challenged BEAS-2B Cells

Ferroptosis was reported to be involved in the occurrence and development of asthma. However, the potential mechanism underlying the role of ferroptosis in asthma remains unclear. In this study, we established the mouse asthma model following the ovalbumin (OVA) method in C57BL/6 mice and the cell model with IL-13 induction in bronchial epithelial cells (BEAS-2B cells). Treatment of ferrostatin-1 (Ferr-1) and 3-methyladenine (3-MA) decreased iron deposition in IL-13-induced BEAS-2B cells and lung tissues of asthma mice, opposite to that in bronchoalveolar lavage fluid (BALF). Meanwhile, excessive lipid peroxidation asthma model in vivo and in vitro was alleviated by Ferr-1 or 3-MA treatment. In addition, Ferr-1 and 3-MA inhibited the expression of LC-3 in these cells and lung tissues of mice. Moreover, Ferr-1 and 3-MA also suppressed the production of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and oxidative stress factors (ROS and MDA), while promoting the level of SOD, in vivo and in vitro. Furthermore, application of Ferr-1 exhibited a greater inhibitory effect on iron release and lipid peroxidation in IL-13-induced BEAS-2B cells and asthma mice than 3-MA, accompanied with a weaker effect on ferritinophagy than 3-MA. Collectively, Ferr-1 and 3-MA ameliorated asthma in vivo and in vitro through inhibiting ferroptosis, providing a new strategy for the clinical treatment of asthma.

Ferroptosis in Non-Small Cell Lung Cancer: Progression and Therapeutic Potential on It

As a main subtype of lung cancer, the current situation of non-small cell lung cancer (NSCLC) remains severe worldwide with a 19% survival rate at 5 years. As the conventional therapy approaches, such as chemotherapy, radiotherapy, targeted therapy, and immunotherapy, gradually develop into therapy resistance, searching for a novel therapeutic strategy for NSCLC is urgent. Ferroptosis, an iron-dependent programmed necrosis, has now been widely considered as a key factor affecting the tumorigenesis and progression in various cancers. Focusing on its effect in NSCLC, in different situations, ferroptosis can be triggered or restrained. When ferroptosis was induced in NSCLC, it was available to inhibit the tumor progression both in vitro and in vivo. The dominating mechanism was due to a regulation of the classic ferroptosis-repressed GSH-dependent GPX4 signaling pathway instead of other fractional regulating signal axes that regulated ferroptosis via impacting on the ROS, cellular iron levels, etc. In terms of the prevention of ferroptosis in NSCLC, an GSH-independent mechanism was also discovered, interestingly exhibiting the same upstream as the GPX4 signaling. In addition, this review summarizes the progression of ferroptosis in NSCLC and elaborates their association and specific mechanisms through bioinformatics analysis with multiple experimental evidence from different cascades. Finally, this review also points out the possibility of ferroptosis working as a novel strategy for therapy resistance in NSCLC, emphasizing its therapeutic potential.