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

Solasodine binds to glucocorticoid receptor to ameliorate airway remodeling and excessive autophagy in bronchial smooth muscle cells for allergic asthma

This study was designed to analyze the potential mechanism of action of solasodine by which solasodine suppresses airway remodeling and autophagy in allergic asthma. Human bronchial smooth muscle cells (HBSMCs) were induced by 10 ng/mL of transforming growth factor (TGF)-β1 for 24 h and treated with a series of solasodine (10, 20, 40 μM) for another 24 h. In the TGF-β1-induced HBSMCs, solasodine treatment downregulated the α- smooth muscle actin (α-SMA) level but upregulated the glucocorticoid receptor (GR) level compared with the vehicle treatment (P < 0.05). The binding of solasodine to GR was analyzed using molecular docking and MST measurement. As a result, a direct interaction between solasodine and GR was found. RU486, a GR antagonist, was used to verify that solasodine attenuates TGF-β1-induced fibrosis and autophagy by regulating GR. The RU486 treatment suppressed the effects of solasodine on the TGF-β1-induced FOXO3A, fibrosis and autophagy in the HBSMCs. Subsequently, C57BL/6 J mice were induced with ovalbumin (OVA) and treated with 10 mg/kg/d of solasodine or 2.5 mg/kg/d of dexamethasone (Dex). In the OVA-induced mice, solasodine or Dex treatment attenuated airway inflammation, airway remodeling, and abnormal autophagy compared with the vehicle treatment (P < 0.05). Moreover, the solasodine or Dex treatment increased the expression of GR and FOXO3A in the OVA-induced mice compared with the vehicle treatment (P < 0.01). This study showed that solasodine ameliorated airway remodeling and abnormal autophagy by binding to GR in the allergic model, presenting a possible therapeutic agent for the allergic asthma.

Wuwei Shaji powder alleviates OVA-induced allergic asthma by protecting bronchial epithelial cells from ferroptosis via the S-sulfhydration of Keap1

ETHNOPHARMACOLOGICAL RELEVANCE

Asthma is a chronic inflammatory airway disease. Current treatments have limited efficacy and often cause severe side effects. Wuwei Shaji Powder (WSP), a traditional Mongolian remedy, is used for treating chronic pulmonary diseases, but its efficacy against asthma and underlying mechanisms are still unclear.

AIM OF THE STUDY

To investigate the therapeutic effect of WSP on asthma and elucidate its molecular mechanisms.

MATERIALS AND METHODS

An ovalbumin (OVA)-induced allergic asthma model was established in rats. Ferroptosis or apoptosis was induced in BEAS-2B cells using Erastin or CdCl2. Various techniques including histopathological staining, ELISA, Western blot, flow cytometry, and transmission electron microscopy were employed to assess WSP's effects and mechanisms.

RESULTS

WSP alleviated OVA-induced allergic asthma in rats without the immunosuppressive side effects observed with dexamethasone. WSP suppressed ferroptosis in bronchial epithelial cells both in vivo and in vitro. It reduced thiol- and sulfonic-based oxidative stress through Keap1 S-sulfhydration, disrupted the Keap1-Nrf2 interaction, and promoted Nrf2 nuclear translocation. Notably, we discovered that CdCl2 can induce ferroptosis in BEAS-2B cells, and WSP prevented both ferroptosis and apoptosis in these cells.

CONCLUSION

WSP alleviates OVA-induced allergic asthma by protecting bronchial epithelial cells from ferroptosis via S-sulfhydration of Keap1, providing new insights for its clinical application.

Non-coding RNA as a key regulator and novel target of apoptosis in diabetic cardiomyopathy: Current status and future prospects

The occurrence of diabetic cardiomyopathy (DCM) can be independent of several risk factors such as hypertension and myocardial ischemia, which can lead to heart failure, thus seriously threatening human health and life. Sustained hyperglycemic stimulation can induce cardiomyocyte apoptosis, which is recognized as the pathological basis of DCM. It has been demonstrated that dysregulation induced by apoptosis is closely associated to progression of DCM, but mechanisms behind it requires further clarification. Currently, increasing evidence has shown that non-coding RNA (ncRNA), especially microRNA, long-chain non-coding RNA (lncRNA), and circular RNA (circRNA), play a regulative role in apoptosis, thus affecting the progression of DCM. Notably, some ncRNAs have also exhibit potential significance as biomarkers and/or therapeutic targets for patients with DCM. In this review, recent findings regarding the potential mechanisms of ncRNA in regulating apoptosis and their role in the progression of DCM were systematically summarized in this research. The conclusion reveals that ncRNA abnormalities exert a crucial role in pathological changes of DCM, which offers potential therapeutic targets for the prevention of DCM.

KLF12 inhibits lipopolysaccharide-induced inflammatory responses, oxidative stress, pyroptosis, and endoplasmic reticulum stress in human airway epithelial cells through inhibition of the NF-κB pathway

Asthma is a common and frequent chronic disease in pediatrics with obvious pathological features, particularly inflammation, oxidative stress, pyroptosis, and endoplasmic reticulum (ER) stress. Some Krüppel-like factors (KLFs), such as KLF2, KLF4, KLF5, and KLF10, have been reported to be associated with several respiratory diseases, including asthma. However, the role of KLF12 in asthma pathogenesis is unknown. Based on the GEO analysis, KLF12 mRNA expression was reduced in asthma patients. We further assessed the role of KLF12 in protecting airway epithelial cells (BEAS-2B cells) against stimuli using an in vitro model of asthma. The results showed that lipopolysaccharide (LPS) stimulation caused a decrease in KLF12 expression. LPS-induced increase in the mRNA levels of inflammatory cytokines TNF-α, IL-6, and IL-8 were attenuated by KLF12 overexpression. LPS induced the production ROS and MDA and reduced the activities of enzymatic antioxidants SOD, CAT, and GSH-Px, which were prevented by KLF12 overexpression. KLF12 overexpression also blocked LPS-induced pyroptosis, as shown by decreased levels of IL-1β, IL-18, and LDH, as well as downregulated expression levels of pyroptosis-related proteins including NLRP3, ASC, cleaved caspase-1, and GSDMD-N. LPS-induced expression levels of ER stress markers GRP78, CHOP, p-eIF2α, and ATF-4 were inhibited by KLF12 overexpression. In addition, the protective effects of KLF12 on LPS-stimulated cells were enhanced by PDTC, an inhibitor of NF-κB. KLF12 knockdown showed an opposite effect to KLF12 overexpression. These results indicated that KLF12 suppressed LPS-induced inflammatory response, oxidative stress, pyroptosis, and ER stress, which were mediated by the inactivation of the NF-κB pathway.

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.

Distinct single-cell transcriptional profile in CD4+ T-lymphocytes among obese children with asthma

Obesity is a risk factor for asthma morbidity, associated with less responsiveness to inhaled corticosteroids. CD4+ T cells are central to the immunology of asthma and may contribute to the unique obese asthma phenotype. We sought to characterize the single-cell CD4+ transcriptional profile differences in obese children with asthma compared with normal-weight children with asthma. Eight normal-weight and obese participants with asthma were clinically phenotyped and matched based on asthma control. Peripheral blood (PB) CD4+ T cells were sorted, and single-cell RNA sequencing was conducted. Cell clusters were identified by canonical gene expression and differential gene expression and reactome pathway analysis was applied. The obese PB bulk transcriptomic signature from the U-BIOPRED pediatric cohort was assessed in our cohort as well. Obese children with asthma have a distinct CD4+ transcriptional profile with differential gene expression. There were more activated protein tyrosine phosphate receptor type C (PTPRC)high cells and less PTPRClow in children with obesity. Children with obesity had higher enrichment of the neutrophil degranulation, interleukin-7 (IL-7) receptor, and IL-7-related janus kinase-signal transducer and activator of transcription signaling pathways. Genes previously associated with more severe asthma, IL-32, FKBP5 gene expression, IL-6, and Rho transcriptional signaling, were also enriched in obese children with asthma. Our findings shed insight into the molecular mechanisms underpinning more severe and steroid-resistant asthma among children with obesity. Further investigation is needed to identify potential new therapeutic targets for this group.NEW & NOTEWORTHY This study identified unique contributors to asthma in children with obesity and found novel pathways. Increased expression of IL-7R, IL-32, PARP-1, FKBP5 gene, IL-6, and Rho transcriptional signaling were observed in obese individuals with asthma.

Research review and transcriptomic insights into Benzalkonium chloride inhalation and disease association

The widespread use of disinfectants, particularly during the coronavirus disease (COVID-19) pandemic, has significantly increased human exposure to biocides, raising concerns about their potential health risks, especially when inhaled. Benzalkonium chloride (BKC), a quaternary ammonium compound commonly used as a disinfectant and preservative, is a notable example because it is frequently used in household products and medical settings. Despite its broad usage, limited research has been conducted on the respiratory and systemic toxicities of BKC. Here, we conducted a research review of the literature on the respiratory toxicity of BKC. This research review suggests that, while current studies imply that BKC may induce respiratory diseases, the evidence remains insufficient. We employed an aerosol exposure model using primary bronchial epithelial cells to simulate inhalation exposure to BKC in humans. Transcriptomic analysis was performed to identify differentially expressed genes (DEGs) associated with toxicological pathways, including endoplasmic reticulum (ER) stress, apoptosis, mitochondrial dysfunction, and epithelial-mesenchymal transition (EMT). The results were integrated with gene-disease association databases to explore the links between BKC exposure and respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis. Our study also examined the systemic effects of BKC by analysing the secreted proteins, suggesting possible cardiovascular implications. These findings highlight the need for further research on the health impacts of BKC, particularly its long-term effects, and underscore the importance of regulating its use to minimise the potential health risks associated with exposure via inhalation.

ASIC1a regulates airway epithelial cell pyroptosis in acute lung injury by NLRP3-Caspase1-GSDMD pathway

BACKGROUND

Acidosis is the most common complication that seriously affects the prognosis of acute respiratory distress syndrome (ARDS). Acid-sensitive ion channel 1a (ASIC1a) is activated in acidic environments to regulate inflammatory process. However, the role of ASIC1a in ARDS is unclear.

METHODS

In this study, we examined the expression of ASIC1a in airway epithelial cells in an acidic environment. We then investigated whether blocking ASIC1a could inhibit pyroptosis of airway epithelial cells and the molecular mechanism. In the mouse acute lung injury (ALI) model, we observed the changes of lung histopathology, arterial blood gas and pyroptosis related indexes after ASIC1a inhibition. Bronchoalveolar lavage fluid (BALF) from patients with ARDS were collected to explore the expression level of ASIC1a in ARDS patients.

RESULTS

Inhibiting ASIC1a can reduce the airway epithelial cell pyroptosis induced by an extracellular acidic environment. ASIC1a can bind to PRKACA, and silencing ASIC1a and PRKACA can inhibit the occurrence of pyroptosis in airway epithelial cells. Compared with control group, arterial blood pH and PaO2 in ALI group were significantly reduced. The inflammation in the lungs is more intense, and the mRNA and protein of NLRP3, Caspase1 and GSDMD were increased, while ASIC1a specific blocker psalmotoxin-1 alleviated this phenomenon. The expression of ASIC1a in BALF of ARDS patients was significantly increased, especially in non-survival group.

CONCLUSION

Acidic micro-environment can induce the increased expression of ASIC1a, and inhibition of ASIC1a can alleviate the inflammation and airway epithelial cell pyroptosis in ARDS. ASIC1a may be a new target for the treatment of ARDS.

Nicotinamide mononucleotide mitigates neuroinflammation by enhancing GPX4-mediated ferroptosis defense in microglia

BACKGROUND

Numerous neurological diseases involving neuroinflammation, particularly microglia, contribute to neuronal death. Ferroptosis is implicated in various diseases characterized by neuronal injury. Studies showed that nicotinamide mononucleotide (NMN) inhibits both neuroinflammation and ferroptosis. However, the mechanisms of NMN in both ferroptosis and neuroinflammation remain unclear. We aimed to explore the effects of NMN on neuroinflammation and the susceptibility of microglia to ferroptosis.

METHODS

Ferroptosis markers in macroglia exposed to lipopolysaccharides (LPS) were analyzed using CCK8, flow cytometry, ELISA, and quantitative RT-PCR. The effects of NMN on LPS-induced ferroptosis in microglia were evaluated through flow cytometry, western blot, and immunofluorescence staining. RT-PCR analysis assessed the inflammatory cytokine production of microglia subjected to Ferrostatin-1-regulated ferroptosis. RNA sequencing elucidated the underlying mechanism of NMN-involved microglia ferroptosis under LPS induction. In BV2 microglia, an inhibitor of GPX4, RSL3, was employed to suppress GPX4 expression. Intracerebroventricular injection of LPS was performed to evaluate neuroinflammation and microglia activation in vivo.

RESULTS

NMN effectively rescued LPS-induced ferroptosis and improved cell viability in microglia. Co-administration of NMN and ferrostatin-1 significantly reduced proinflammatory cytokine production in microglia following the introduction of LPS stimuli. Mechanistically, NMN facilitated glutathione (GSH) production, and enhanced resistance to lipid peroxidation occurred in a manner dependent on GPX4, repressing cytokine transcription and protecting cells from ferroptosis. RNA sequencing elucidated the underlying mechanism of NMN-associated microglia ferroptosis under LPS induction. Furthermore, simultaneous injection of NMN ameliorated LPS-induced ferroptosis and neuroinflammation in mouse brains. The data from the present study indicated that NMN enhances GPX4-mediated ferroptosis defense against LPS-induced ferroptosis in microglia by recruiting GSH, thereby inhibiting neuroinflammation.

CONCLUSION

Therapeutic approaches to effectively target ferroptosis in diseases using NMN, consideration should be given to both its anti-ferroptosis and anti-inflammatory effects to attain optimal outcomes, presenting promising strategies for treating neuroinflammation-related diseases or disorders.

Silencing SMAD4 inhibits inflammation and ferroptosis in asthma by blocking the IL-17A signaling pathway

BACKGROUND

The TGF-β/SMAD signaling pathway is crucial in the pathogenesis of asthma. However, SMAD family member 4 (SMAD4), a key mediator of TGF-β, its roles and underlying mechanisms in asthma remain unclear.

METHODS

The in vivo and in vitro roles of SMAD4 in asthma were investigated through an ovalbumin (OVA)-induced mouse model and an interleukin-13 (IL-13)-induced cell model. The molecular mechanism of SMAD4 influenced asthma was examined using transcriptome sequencing, followed by feedback experiments involving recombinant human interleukin 17 A (rhIL-17 A), an IL-17 A signaling pathway activator.

RESULTS

SMAD4 was highly expressed in the asthma models. SMAD4 silencing alleviated damage to lung tissue and decreased inflammatory infiltration. Expression levels of Caspase-3, IgG, and inflammatory factors were reduced after silencing SMAD4. Silencing SMAD4 suppressed ferroptosis. Silencing SMAD4 also enhanced IL-13-induced BEAS-2B cell proliferation and suppressed apoptosis. Furthermore. IL-17 A signaling pathway was promoted in the asthma models, as evidenced by elevated IL-17RA, IL-17 A, and Act1 protein levels. SMAD4 silencing inhibited the expression levels of these IL-17 A pathway-associated proteins. Moreover, rhIL-17 A treatment notably reversed the impacts of SMAD4 silencing on asthma in the IL-13-induced cell model and OVA-induced mouse model, indicating that silencing SMAD4 inhibited inflammation and ferroptosis in asthma by blocking the IL-17 A signaling pathway.

CONCLUSION

Silencing SMAD4 prevents inflammation and ferroptosis in asthma by inhibiting the IL-17 pathway, which provides a novel potential approach for asthma therapy.

Screening, identification and targeted intervention of necroptotic biomarkers of asthma

BACKGROUND

As a pivotal pathway of programmed cell death, necroptosis significantly contributes to the pathogenesis of respiratory disorders. However, its role in asthma is not yet fully elucidated. Therefore, this study aimed to identify markers associated with necroptosis, evaluate their functions in asthma, and explore potential therapeutic agents targeting necroptosis for the management of asthma.

METHODS

Firstly, machine learning algorithms, including Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest, and Support Vector Machine-Recursive Feature Elimination (SVM-RFE), were utilized to identify necroptosis-related differentially expressed genes (NRDEGs) in asthma patients compared to healthy controls. Concurrently, the expression of NRDEGs was validated using external datasets, Western blot, and quantitative real-time polymerase chain reaction (qPCR). Secondly, the clinical relevance of NRDEGs was assessed through Receiver Operating Characteristic (ROC) curve analysis and correlation with clinical indicators. Thirdly, the relationship between NRDEGs and pulmonary immune cell infiltration, as well as the signaling interactions between different cells types, were analyzed through immune infiltration and single-cell analysis. Fourthly, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA), were conducted to elucidate the functional roles of NRDEGs. Finally, compounds targeting NRDEGs were screened, and their binding affinities were evaluated using molecular docking studies.

RESULTS

In asthma, necroptosis is activated, leading to the identification of four NRDEGs: NLRP3, PYCARD, ALOX15, and VDAC3. Among these, NLRP3, PYCARD, and ALOX15 are upregulated, whereas VDAC3 is downregulated in asthma. Comprehensive clinical evaluations indicated that NRDEGs hold diagnostic value for asthma. Specifically, NLRP3 was inversely correlated with forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), while VDAC3 showed an inverse correlation with sputum neutrophils. Conversely, ALOX15 expression was positively correlated with fractional exhaled nitric oxide (FeNO) levels, as well as sputum eosinophils, blood eosinophils, and blood IgE levels. Subsequent immune infiltration analysis revealed associations between NRDEGs and activated dendritic cells, mast cells, and eosinophils. Single-cell RNA sequencing (scRNA-seq) further confirmed the communication signals between myeloid dendritic cells, fibroblasts, neutrophils, and helper T cells, predominantly related to fibrosis and immune-inflammatory responses. Pathway enrichment analysis demonstrated that NRDEGs are involved in ribosomal function, oxidative phosphorylation, and fatty acid metabolism. Finally, resveratrol and triptonide were identified as potential therapeutic agents targeting the proteins encoded by NRDEGs for asthma treatment.

CONCLUSIONS

The necroptosis pathway is activated in asthma, with NRDEGs-namely PYCARD, NLRP3, ALOX15, and VDAC3-correlated with declines in lung function and airway inflammation. These genes serve as reliable predictors of asthma risk and are involved in the regulation of the immune-inflammatory microenvironment. Resveratrol and triptolide have been identified as promising therapeutic candidates due to their potential to target the proteins encoded by these genes.

Pyroptosis in asthma: inflammatory phenotypes, immune and non-immune cells, and novel treatment approaches

Pyroptosis is a form of inflammatory programmed cell death, and is activated by pathogen infections or endogenous danger signals. The canonical pyroptosis process is characterized by the inflammasome (typically NLRP3)-mediated activation of caspase-1, which in turn cleaves and activates IL-1β and IL-18, as well as gasdermin D, which is a pore-forming executor protein, leading to cell membrane rupture, and the release of proinflammatory cytokines and damage-associated molecular pattern molecules. Pyroptosis is considered a part of the innate immune response. A certain level of pyroptosis can help eliminate pathogenic microorganisms, but excessive pyroptosis can lead to persistent inflammatory responses, and cause tissue damage. In recent years, pyroptosis has emerged as a crucial contributor to the development of chronic inflammatory respiratory diseases, such as asthma. The present study reviews the involvement of pyroptosis in the development of asthma, in terms of its role in different inflammatory phenotypes of the disease, and its influence on various immune and non-immune cells in the airway. In addition, the potential therapeutic value of targeting pyroptosis for the treatment of specific phenotypes of asthma is discussed.

TRIM11 Prevents Ferroptosis in model of asthma by UBE2N-TAX1BP1 signaling

Asthma is a complex chronic respiratory inflammatory disease affected by both genetic and environmental factors. Therefore, our study explored the influence of TRIM11 on asthma and its underlying mechanisms. Our research involved patients diagnosed with asthma and healthy volunteers recruited from our hospital. We observed a reduction in serum TRIM11 expression in asthma patients, which positively correlated with the levels of anti-IgE or IgE. Additionally, both TRIM11 mRNA and protein expression in lung tissue were diminished. The introduction of the TRIM11 gene resulted in a reduction in inflammation in an in vitro asthma model and prevented the development of asthma in a mouse model. Moreover, the TRIM11 gene exhibited a suppressive effect on Ferroptosis and mitigated ROS-induced mitochondrial damage in the asthma model. TRIM11 was found to stimulate UBE2N-TAX1BP1 signaling in the asthma model, with UBE2N being identified as the specific target for TRIM11's effects on Ferroptosis. Furthermore, TRIM11 protein interacted with UBE2N protein and facilitated the dissociation of UBE2N-UBE2N in the asthma model. In conclusion, TRIM11 plays a vital role in preventing Ferroptosis in the asthma model through UBE2N-TAX1BP1 signaling. This indicates that targeting the TRIM11 mechanism could serve as a promising strategy for anti-Ferroptosis immunotherapy in asthma treatment.

Characterization of PANoptosis-related genes with immunoregulatory features in osteoarthritis

This study aimed to characterize PANoptosis-related genes with immunoregulatory features in osteoarthritis (OA) and investigate their potential diagnostic and therapeutic implications. Gene expression data from OA patients and healthy controls were obtained from the Gene Expression Omnibus (GEO) database. Differential expression analysis and functional enrichment analysis were conducted to identify PANoptosis-related genes (PRGs) associated with OA pathogenesis. A diagnostic model was developed using LASSO regression, and the diagnostic value of key PRGs was evaluated using Receiver Operating Characteristic Curve (ROC) analysis. The infiltration of immune cells and potential small molecule agents were also examined. A total of 39 differentially expressed PANoptosis-related genes (DE-PRGs) were identified, with functional enrichment analysis revealing their involvement in inflammatory response regulation and immune modulation pathways. Seven key PRGs, including CDKN1A, EZH2, MEG3, NR4A1, PIK3R2, S100A8, and SYVN1, were selected for diagnostic model construction, demonstrating high predictive performance in both training and validation datasets. The correlation between key PRGs and immune cell infiltration was explored. Additionally, molecular docking analysis identified APHA-compound-8 as a potential therapeutic agent targeting key PRGs. This study identified and analyzed PRGs in OA, uncovering their roles in immune regulation. Seven key PRGs were used to construct a diagnostic model with high predictive performance. The identified PRGs' correlation with immune cell infiltration was elucidated, and APHA-compound-8 was highlighted as a potential therapeutic agent. These findings offer novel diagnostic markers and therapeutic targets for OA, warranting further in vivo validation and exploration of clinical applications.

Increased Pneumonia Risk Associated with Concomitant Use of Inhaled Corticosteroids and Benzodiazepines: A Pharmacovigilance Analysis

BACKGROUND

Inhaled corticosteroids (ICS) are effective in managing asthma and chronic obstructive pulmonary disease (COPD) but increase the risk of pneumonia. Benzodiazepines (BZD), commonly prescribed for comorbid psychiatric disorders in asthma or COPD patients, are also associated with pneumonia. This study investigates the risk of pneumonia associated with the concomitant use of ICS and BZD.

METHODS

Data from the FDA Adverse Event Reporting System from Q4 2013 to Q3 2023 were extracted. Reports involving asthma or COPD patients were included. Disproportionality analysis and logistic regression analysis were performed to assess the risk of pneumonia associated with the combined use of ICS and BZD. Additive and multiplicative models were used to further confirm the results. Additionally, subgroup analyses were conducted based on gender, age, and disease type.

RESULTS

A total of 238,411 reports were included. The combined use of ICS and BZD was associated with a higher reporting of pneumonia (ROR: 2.41, 95% CI 2.25-2.58). Using additive and multiplicative methods, the results remained significant. The strongest risk signals were observed in specific drug combinations, such as mometasone with clonazepam, budesonide with temazepam, and mometasone with zopiclone. Subgroup analyses showed higher pneumonia risks in females, patients over 60 years old, and those with asthma.

CONCLUSION

Our findings identified a significantly elevated pneumonia risk with the combined use of ICS and BZD. These results highlighted the necessity for cautious co-prescription of ICS and BZD and suggested the need for more comprehensive clinical studies to assess this interaction.

The NLRP3 inflammasome in allergic diseases: mechanisms and therapeutic implications

In recent years, there has been a global increase in the prevalence of allergic diseases, including allergic rhinitis, chronic rhinosinusitis, allergic asthma, atopic dermatitis, allergic conjunctivitis, and food allergies. Since the pathogenic mechanisms of these allergic diseases are not yet fully understood, targeted and effective therapies are lacking. The NLRP3 inflammasome, a multiprotein complex implicated in various inflammatory diseases, can be activated by diverse stimuli. It assembles into NLRP3 inflammasome complexes through conformational changes, initiating the proteolytic cleavage of dormant procaspase-1 into active caspase-1 and promoting the maturation of inflammatory cytokines, including IL-1β and IL-18. Dysfunction of the NLRP3 inflammasome may serve as a key driver of inflammatory diseases, leading to pyroptosis and amplifying the local inflammatory response. As preliminarily demonstrated, specific NLRP3 inflammatory vesicle inhibitors play refectory roles in animal models of allergic diseases, and it is believed that specific NLRP3 inflammasome inhibitors may be potential therapeutic agents for allergic diseases. This review highlights the progress of research on the NLRP3 inflammasome in allergic diseases, explores its contribution to different types of allergic diseases, and identifies promising clinical targets for intervention.

FUNDC1 mediated mitochondria-dependent ferroptosis of epithelial cells in model of asthma by FBXL2/ar/GPX4 signaling pathway of SUMO1 at K136

This study aimed to explore the critical role of FUNDC1 on epithelial cells in model of asthma. Patients with asthma and normal healthy volunteers were obtained from our hospital. The serum of FUNDC1 mRNA expression was down-regulated in patients with asthma. Meanwhile, the serum of FUNDC1 mRNA expression was positive correlation with IgE and anti-HDM IgE protein. FUNDC1 expression in lung tissue of mice model was decreased in mice model of asthma. Sh-FUNDC1 enhanced asthma in mice model of asthma. FUNDC1 up-regulation reduced IL-4, IL-5, IL-10 and IL-13 activity levels in vitro model of asthma.FUNDC1 down-regulation promoted IL-4, IL-5, IL-10 and IL-13 activity levels in vitro model of asthma. FUNDC1 reduced ferroptosis of epithelial cells in model of asthma through the inhibition of mitochondrial damage. FUNDC1 induced FBXL2 and AR protein expression in model of asthma. FUNDC1 interlinked with FBXL2 is modified by SUMO1 at K136. FBXL2, ASN-205, GLN-204, ARG-235, and GLN-237 form hydrogen bonds with FUNDC1's ASP-15, ASP-16, GLU-25, and ARG-29, with lengths of 2.3, 3.1, 2.9, 2.3, and 2.9 Å, respectively. The induction of FBXL2 reduced the effects of Sh-FUNDC1 on asthma in mice model of asthma. The inhibition of AR reduced the effects of Sh-FUNDC1 on asthma in mice model of asthma Overall, FUNDC1 prevents ferroptosis of airway epithelial cells of asthma through FBXL2/AR/GPX4 signaling pathway of SUMO1 at K136. FUNDC1 might benefit the treatment of asthma or other pulmonary disease.

Beyond CAR-T: The rise of CAR-NK cell therapy in asthma immunotherapy

Asthma poses a major public health burden. While existing asthma drugs manage symptoms for many, some patients remain resistant. The lack of a cure, especially for severe asthma, compels exploration of novel therapies. Cancer immunotherapy successes with CAR-T cells suggest its potential for asthma treatment. Researchers are exploring various approaches for allergic diseases including membrane-bound IgE, IL-5, PD-L2, and CTLA-4 for asthma, and Dectin-1 for fungal asthma. NK cells offer several advantages over T cells for CAR-based immunotherapy. They offer key benefits: (1) HLA compatibility, meaning they can be used in a wider range of patients without the need for matching tissue types. (2) Minimal side effects (CRS and GVHD) due to their limited persistence and cytokine profile. (3) Scalability for "off-the-shelf" production from various sources. Several strategies have been introduced that highlight the superiority and challenges of CAR-NK cell therapy for asthma treatment including IL-10, IFN-γ, ADCC, perforin-granzyme, FASL, KIR, NCRs (NKP46), DAP, DNAM-1, TGF-β, TNF-α, CCL, NKG2A, TF, and EGFR. Furthermore, we advocate for incorporating AI for CAR design optimization and CRISPR-Cas9 gene editing technology for precise gene manipulation to generate highly effective CAR constructs. This review will delve into the evolution and production of CAR designs, explore pre-clinical and clinical studies of CAR-based therapies in asthma, analyze strategies to optimize CAR-NK cell function, conduct a comparative analysis of CAR-T and CAR-NK cell therapy with their respective challenges, and finally present established novel CAR designs with promising potential for asthma treatment.

ChRIPK1 caused necroptosis signaling pathway deficiency in Crassostrea hongkongensis

RIPK1/TAK1 are important for programmed cell death, including liver death, necroptosis and apoptosis. However, there have been few published reports on the functions of RIPK1/TAK1 in invertebrates. In this study, full-length ChRIPK1 and ChTAK1 were cloned from C. hongkongensis through the rapid amplification of cDNA ends (RACE) technology. ChRIPK1 has almost no homology with human RIPK1 and lacks a kinase domain at the N-terminus but has a DD and RHIM domain. ChTAK1 is conserved throughout evolution. qRT‒PCR was used to analyze the mRNA expression patterns of ChRIPK1 in different tissues, developmental stages, and V. coralliilyticus-infected individuals, and both were highly expressed in the mantle and gills, while ChRIPK1 was upregulated in hemocytes and gills after V. coralliilyticus or S. aureus infection, which indicates that ChRIPK1 is involved in immune regulation. Fluorescence assays revealed that ChRIPK1 localized to the cytoplasm of HEK293T cells in a punctiform manner, but the colocalization of ChRIPK1 with ChTAK1 abolished the punctiform morphology. In the dual-luciferase reporter assay, both ChRIPK1 and ChRIPK1-RIHM activated the NF-κB signaling pathway in HEK293T cells, and ChTAK1 activated ChRIPK1 in the NF-κB signaling pathway. The apoptosis rate of the hemocytes was not affected by the necroptosis inhibitor Nec-1 but was significantly decreased, and ChRIPK1 expression was knocked down in the hemocytes of C. hongkongensis. These findings indicated that ChRIPK1 induces apoptosis but not necroptosis in oysters. This study provides a theoretical basis for further research on the molecular mechanism by which invertebrates regulate the programmed cell death of hemocytes in oysters.

Necroptosis plays a role in TL1A-induced airway inflammation and barrier damage in asthma

BACKGROUND

Airway epithelial cell (AEC) necroptosis contributes to airway allergic inflammation and asthma exacerbation. Targeting the tumor necrosis factor-like ligand 1 A (TL1A)/death receptor 3 (DR3) axis has a therapeutic effect on asthmatic airway inflammation. The role of TL1A in mediating necroptosis of AECs challenged with ovalbumin (OVA) and its contribution to airway inflammation remains unclear.

METHODS

We evaluated the expression of the receptor-interacting serine/threonine-protein kinase 3(RIPK3) and the mixed lineage kinase domain-like protein (MLKL) in human serum and lung, and histologically verified the level of MLKL phosphorylation in lung tissue from asthmatics and OVA-induced mice. Next, using MLKL knockout mice and the RIPK3 inhibitor GSK872, we investigated the effects of TL1A on airway inflammation and airway barrier function through the activation of necroptosis in experimental asthma.

RESULTS

High expression of necroptosis marker proteins was observed in the serum of asthmatics, and necroptosis was activated in the airway epithelium of both asthmatics and OVA-induced mice. Blocking necroptosis through MLKL knockout or RIPK3 inhibition effectively attenuated parabronchial inflammation, mucus hypersecretion, and airway collagen fiber accumulation, while also suppressing type 2 inflammatory factors secretion. In addition, TL1A/ DR3 was shown to act as a death trigger for necroptosis in the absence of caspases by silencing or overexpressing TL1A in HBE cells. Furthermore, the recombinant TL1A protein was found to induce necroptosis in vivo, and knockout of MLKL partially reversed the pathological changes induced by TL1A. The necroptosis induced by TL1A disrupted the airway barrier function by decreasing the expression of tight junction proteins zonula occludens-1 (ZO-1) and occludin, possibly through the activation of the NF-κB signaling pathway.

CONCLUSIONS

TL1A-induced airway epithelial necroptosis plays a significant role in promoting airway inflammation and barrier dysfunction in asthma. Inhibition of the TL1A-induced necroptosis pathway could be a promising therapeutic strategy.

Obstructive sleep apnea hypopnea syndrome and vascular lesions: An update on what we currently know

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is the most prevalent sleep and respiratory disorder. This syndrome can induce severe cardiovascular and cerebrovascular complications, and intermittent hypoxia is a pivotal contributor to this damage. Vascular pathology is closely associated with the impairment of target organs, marking a focal point in current research. Vascular lesions are the fundamental pathophysiological basis of multiorgan ailments and indicate a shared pathogenic mechanism among common cardiovascular and cerebrovascular conditions, suggesting their importance as a public health concern. Increasing evidence shows a strong correlation between OSAHS and vascular lesions. Previous studies predominantly focused on the pathophysiological alterations in OSAHS itself, such as intermittent hypoxia and fragmented sleep, leading to vascular disruptions. This review aims to delve deeper into the vascular lesions affected by OSAHS by examining the microscopic pathophysiological mechanisms involved. Emphasis has been placed on examining how OSAHS induces vascular lesions through disruptions in the endothelial barrier, metabolic dysregulation, cellular phenotype alterations, neuroendocrine irregularities, programmed cell death, vascular inflammation, oxidative stress and epigenetic modifications. This review examines the epidemiology and associated risk factors for OSAHS and vascular diseases and subsequently describes the existing evidence on vascular lesions induced by OSAHS in the cardiovascular, cerebrovascular, retinal, renal and reproductive systems. A detailed account of the current research on the pathophysiological mechanisms mediating vascular lesions caused by OSAHS is provided, culminating in a discussion of research advancements in therapeutic modalities to mitigate OSAHS-related vascular lesions and the implications of these treatment strategies.

Identifying ALOX15-initiated lipid peroxidation increases susceptibility to ferroptosis in asthma epithelial cells

Ferroptosis is a programmed form of cell death regulated by iron and has been linked to the development of asthma. However, the precise mechanisms driving ferroptosis in asthma remain elusive. To gain deeper insights, we conducted an analysis of nasal epithelial and sputum samples from the GEO database using three machine learning methods. Our investigation identified a pivotal gene, Arachidonate 15-lipoxygenase (ALOX15), associated with ferroptosis in asthma. Through both in vitro and in vivo experiments, we further confirmed the significant role of ALOX15 in ferroptosis in asthma. Our results demonstrate that ferroptosis manifests in an HDM/LPS-induced allergic airway inflammation (AAI) mouse model, mimicking human asthma, and in HDM/LPS-stimulated 16HBE cells. Moreover, we observed an up-regulation of ALOX15 expression in HDM/LPS-induced mice and cells. Notably, silencing ALOX15 markedly decreased HDM/LPS-induced ferroptosis in 16HBE cells. These findings indicate that ferroptosis may be implicated in the onset and progression of asthma, with ALOX15-induced lipid peroxidation raising the susceptibility to ferroptosis in asthmatic epithelial cells.

CAR-NKT Cells in Asthma: Use of NKT as a Promising Cell for CAR Therapy

NKT cells, unique lymphocytes bridging innate and adaptive immunity, offer significant potential for managing inflammatory disorders like asthma. Activating iNKT induces increasing IFN-γ, TGF-β, IL-2, and IL-10 potentially suppressing allergic asthma. However, their immunomodulatory effects, including granzyme-perforin-mediated cytotoxicity, and expression of TIM-3 and TRAIL warrant careful consideration and targeted approaches. Although CAR-T cell therapy has achieved remarkable success in treating certain cancers, its limitations necessitate exploring alternative approaches. In this context, CAR-NKT cells emerge as a promising approach for overcoming these challenges, potentially achieving safer and more effective immunotherapies. Strategies involve targeting distinct IgE-receptors and their interactions with CAR-NKT cells, potentially disrupting allergen-mast cell/basophil interactions and preventing inflammatory cytokine release. Additionally, targeting immune checkpoints like PDL-2, inducible ICOS, FASL, CTLA-4, and CD137 or dectin-1 for fungal asthma could further modulate immune responses. Furthermore, artificial intelligence and machine learning hold immense promise for revolutionizing NKT cell-based asthma therapy. AI can optimize CAR-NKT cell functionalities, design personalized treatment strategies, and unlock a future of precise and effective care. This review discusses various approaches to enhancing CAR-NKT cell efficacy and longevity, along with the challenges and opportunities they present in the treatment of allergic asthma.

KLF5-mediated pyroptosis of airway epithelial cells leads to airway inflammation in asthmatic mice through the miR-182-5p/TLR4 axis

Asthma is viewed as an airway disease and an inflammatory condition. This study aims to reveal the role of Kruppel-like factor 5 (KLF5)-mediated pyroptosis of airway epithelial cells in airway inflammation in asthma. The asthmatic mouse model was established. The mice were infected with the lentivirus containing sh-KLF5, antagomiR-182-5p, and pc-Toll-like receptor 4 (TLR4). Airway hyperresponsiveness was measured, and the cells in bronchoalveolar lavage fluid (BALF) were sorted and counted. The expression levels of interleukin (IL)-4/IL-13/IL-6/IL-18/IL-1β/NOD-like receptor family pyrin domain containing 3 (NLRP3)/N-gasdermin D (GSDMD-N)/cleaved caspase-1 were detected. The pathological changes in lung tissue were observed. The enrichment of KLF5 in the miR-182-5p promoter region was measured. The binding relationship among KLF5, miR-182-5p, and TLR4 were analyzed. KLF5 was highly expressed in asthmatic mice. Silencing KLF5 improved airway resistance and lung dynamic compliance, reduced the cells in BALF and the expression of IL-4/IL-13/IL-6/NLRP3/GSDMD-N/cleaved caspase-1/IL-18/IL-1β, and alleviated the pathological changes. Mechanistically, KLF5 bonded to the miR-182-5p promoter to inhibit miR-182-5p expression, and miR-182-5p inhibited TLR4. Silencing miR-182-5p or TLR4 overexpression reversed the improvement of silencing KLF5 on airway inflammation and pyroptosis in asthmatic mice. In conclusion, KLF5 inhibited miR-182-5p to promote TLR4 expression, thus aggravating pyroptosis and airway inflammation in asthmatic mice.

Iron-induced kidney cell damage: insights into molecular mechanisms and potential diagnostic significance of urinary FTL

Background: Iron overload can lead to organ and cell injuries. Although the mechanisms of iron-induced cell damage have been extensively studied using various cells, little is known about these processes in kidney cells. Methods: In this study, we first examined the correlation between serum iron levels and kidney function. Subsequently, we investigated the molecular impact of excess iron on kidney cell lines, HEK293T and HK-2. The presence of the upregulated protein was further validated in urine. Results: The results revealed that excess iron caused significant cell death accompanied by morphological changes. Transcriptomic analysis revealed an up-regulation of the ferroptosis pathway during iron treatment. This was confirmed by up-regulation of ferroptosis markers, ferritin light chain (FTL), and prostaglandin-endoperoxide synthase 2 (PTGS2), and down-regulation of acyl-CoA synthetase long-chain family member 4 (ACSL4) and glutathione peroxidase 4 (GPX4) using real-time PCR and Western blotting. In addition, excess iron treatment enhanced protein and lipid oxidation. Supportively, an inverse correlation between urinary FTL protein level and kidney function was observed. Conclusion: These findings suggest that excess iron disrupts cellular homeostasis and affects key proteins involved in kidney cell death. Our study demonstrated that high iron levels caused kidney cell damage. Additionally, urinary FTL might be a useful biomarker to detect kidney damage caused by iron toxicity. Our study also provided insights into the molecular mechanisms of iron-induced kidney injury, discussing several potential targets for future interventions.

Research trends on airway remodeling: A bibliometrics analysis

Background

Airway remodeling is an essential pathological basis of respiratory diseases such as asthma and COPD, which is significantly related to pulmonary function and clinical symptoms. And pulmonary disease can be improved by regulating airway remodeling. This study aimed to establish a knowledge map of airway remodeling to clarify current research hotspots and future research trends.

Methods

A comprehensive search was performed to analyze all relevant articles on airway remodeling using the Web of Science Core Collection Database from January 01, 2004 to June 03, 2023.2 reviewers screened the retrieved literature. Besides, the CiteSpace (6.2. R3) and VOSviewer (1.6.19) were utilized to visualize the research focus and trend regarding the effect of airway remodeling.

Results

A total of 4077 articles about airway remodeling were retrieved. The United States is the country with the most published literature, underscoring the country's role in airway remodeling. In recent years, China has been the country with the fastest growth in the number of published literature, suggesting that China will play a more critical role in airway remodeling in the future. From the perspective of co-operation among countries, European co-operation was closer than Asian co-operation. The co-citation analysis showed that 98,313 citations were recorded in 3594 articles, and 25 clusters could be realized. In recent years, Burst detection shows that oxidative stress and epithelial-mesenchymal transition are hot words.

Conclusions

Based on the bibliometric analysis of airway remodeling studies in the past 20 years, a multi-level knowledge structure map was drawn, it mainly includes countries, institutions, research fields, authors, journals, keywords and so on. The research directions represented by obstructive airway disease, PDGF-BB treatment of airway smooth muscle, allergen-induced airway remodeling, extracellular matrix, and non-coding RNA are the research hotspots in the field of airway remodeling. While the risk factors for airway remodeling, the application of new noninvasively assessing tools, biomarkers as well as The molecular mechanism represented by EMT and autophagy had been frontiers in recent years.

Respiratory Toxicology of Graphene-Based Nanomaterials: A Review

Graphene-based nanomaterials (GBNs) consist of a single or few layers of graphene sheets or modified graphene including pristine graphene, graphene nanosheets (GNS), graphene oxide (GO), reduced graphene oxide (rGO), as well as graphene modified with various functional groups or chemicals (e.g., hydroxyl, carboxyl, and polyethylene glycol), which are frequently used in industrial and biomedical applications owing to their exceptional physicochemical properties. Given the widespread production and extensive application of GBNs, they can be disseminated in a wide range of environmental mediums, such as air, water, food, and soil. GBNs can enter the human body through various routes such as inhalation, ingestion, dermal penetration, injection, and implantation in biomedical applications, and the majority of GBNs tend to accumulate in the respiratory system. GBNs inhaled and substantially deposited in the human respiratory tract may impair lung defenses and clearance, resulting in the formation of granulomas and pulmonary fibrosis. However, the specific toxicity of the respiratory system caused by different GBNs, their influencing factors, and the underlying mechanisms remain relatively scarce. This review summarizes recent advances in the exposure, metabolism, toxicity and potential mechanisms, current limitations, and future perspectives of various GBNs in the respiratory system.

The research progress of crosstalk mechanism of autophagy and apoptosis in diabetic vascular endothelial injury

In recent years, the widespread prevalence of diabetes has become a major killer that threatens the health of people worldwide. Of particular concern is hyperglycemia-induced vascular endothelial injury, which is one of the factors that aggravate diabetic vascular disease. During the process of diabetic vascular endothelial injury, apoptosis is an important pathological manifestation and autophagy is a key regulatory mechanism. Autophagy and apoptosis interact with each other. Hence, the crosstalk mechanism between the two processes is an important means of regulating diabetic vascular endothelial injury. This article reviews the research progress in apoptosis in the context of diabetic vascular endothelial injury and discusses the crosstalk mechanism of autophagy and apoptosis and its role in this injury. The purpose is to guide the prevention and treatment of diabetic vascular endothelial injury in the future.

Pramipexole has a neuroprotective effect in spinal cord injury and upregulates D2 receptor expression in the injured spinal cord tissue in rats

Spinal cord injury (SCI) has emerged as a prevalent condition with limited effective treatment options. The neuroprotective role of pramipexole (PPX) in inhibiting nerve cell apoptosis in central nervous system injuries is well established. Therefore, we investigated the effects of PPX in SCI. Adult Sprague-Dawley rats were divided into four groups (sham, SCI, PPX-0.25, and PPX-2.0 groups) according to the PPX therapy (n = 24). Then, SCI was induced using the modified Allen method, and PPX was intravenously administered into the tail at dosages of 0.25 or 2.0 mg/kg following the injury. Motor function was evaluated using the Rivlin-modified inclined plate apparatus and the Basso Beattie Bresnahan (BBB) workout scale. Western blotting assay was used to measure protein expression levels of DRD2, NeuN, Bax/Bcl-2, and caspase-3. Furthermore, immunohistochemistry assessed the effect of PPX on the quantity of NeuN-positive cells in the spinal cord tissue after SCI. Our findings revealed that the BBB and slanting board test scores of the PPX-treated model groups were considerably higher for the SCI group and significantly lower for the sham operation group (P < 0.001). Moreover, the PPX-2.0 group exhibited significantly higher NeuN expression levels than the SCI group (P < 0.01). Our findings indicate that PPX exerts a neuroprotective effect in secondary neuronal injury following SCI, facilitating the recovery of hind limb function by downregulating Bax/Bcl-2, caspase-3, and IL-1β.

The role of pyroptosis-related lncRNA risk signature in ovarian cancer prognosis and immune system

Ovarian cancer is a leading cause of death in females with gynecologic cancers. Pyroptosis is a relatively new discovered programmed cell death that is believed to be associated with inflammation. However, studies on pyroptosis-related lncRNAs in ovarian cancer are limited. In this study, we identified 29 pyroptosis-related genes and screened out 72 pyroptosis-related lncRNAs. Furthermore, the 72 lncRNAs were eliminated to 2 survival-related lncRNAs using Cox regression and Lasso regression to build an ovarian cancer prognostic prediction signature and were further validated on the test set. We adopted a riskscore from the two-gene signature, and the survival in low-risk group was higher than the high-risk group. Functional enrichment analysis indicated that the differentially expressed genes (DEGs) between two risk groups were associated with tumor immunity. This study implies that pyroptosis-related genes are closely related to tumor immunity and could be potential therapeutic factors for ovarian cancer treatment.

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.