Aconitate decarboxylase 1 mediates the acute airway inflammatory response to environmental exposures.

Background: Environmental lipopolysaccharide (LPS) and microbial component-enriched organic dusts cause significant lung disease. These environmental exposures induce the recruitment and activation of distinct lung monocyte/macrophage subpopulations involved in disease pathogenesis. Aconitate decarboxylase 1 (Acod1) was one of the most upregulated genes following LPS (vs. saline) exposure of murine whole lungs with transcriptomic profiling of sorted lung monocyte/macrophage subpopulations also highlighting its significance. Given monocyte/macrophage activation can be tightly linked to metabolism, the objective of these studies was to determine the role of the immunometabolic regulator ACOD1 in environmental exposure-induced lung inflammation. Methods: Wild-type (WT) mice were intratracheally (i.t.) instilled with 10 µg of LPS or saline. Whole lungs were profiled using bulk RNA sequencing or sorted to isolate monocyte/macrophage subpopulations. Sorted subpopulations were then characterized transcriptomically using a NanoString innate immunity multiplex array 48 h post-exposure. Next, WT and Acod1-/- mice were instilled with LPS, 25% organic dust extract (ODE), or saline, whereupon serum, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. BALF metabolites of the tricarboxylic acid (TCA) cycle were quantified by mass spectrometry. Cytokines/chemokines and tissue remodeling mediators were quantitated by ELISA. Lung immune cells were characterized by flow cytometry. Invasive lung function testing was performed 3 h post-LPS with WT and Acod1-/- mice. Results: Acod1-/- mice treated with LPS demonstrated decreased BALF levels of itaconate, TCA cycle reprogramming, decreased BALF neutrophils, increased lung CD4+ T cells, decreased BALF and lung levels of TNF-α, and decreased BALF CXCL1 compared to WT animals. In comparison, Acod1-/- mice treated with ODE demonstrated decreased serum pentraxin-2, BALF levels of itaconate, lung total cell, neutrophil, monocyte, and B-cell infiltrates with decreased BALF levels of TNF-α and IL-6 and decreased lung CXCL1 vs. WT animals. Mediators of tissue remodeling (TIMP1, MMP-8, MMP-9) were also decreased in the LPS-exposed Acod1-/- mice, with MMP-9 also reduced in ODE-exposed Acod1-/- mice. Lung function assessments demonstrated a blunted response to LPS-induced airway hyperresponsiveness in Acod1-/- animals. Conclusion: Acod1 is robustly upregulated in the lungs following LPS exposure and encodes a key immunometabolic regulator. ACOD1 mediates the proinflammatory response to acute inhaled environmental LPS and organic dust exposure-induced lung inflammation.

Zafirlukast ameliorates lipopolysaccharide and bleomycin-induced lung inflammation in mice.

Acute lung injury (ALI) is the result of damage to the capillary endothelia and the alveolar epithelial cell caused by various direct and indirect factors, leading to significant pulmonary interstitial and alveolar edema and acute hypoxic respiratory insufficiency. A subset of ALI cases progresses to irreversible pulmonary fibrosis, a condition with fatal implications. Zafirlukast is a leukotriene receptor antagonist licensed for asthma prevention and long-term treatment. This study demonstrated a significant improvement in lung tissue pathology and a reduction in inflammatory cell infiltration in models of lipopolysaccharide (LPS)-induced ALI and bleomycin (BLM)-induced lung inflammation following zafirlukast administration, both in vivo and in vitro. Moreover, zafirlukast was found to suppress the inflammatory response of alveolar epithelial cells in vitro and lung inflammation in vivo by reducing the activation of the TLR4/NF-κB/NLRP3 inflammasome pathway. In conclusion, zafirlukast relieved lung injury and the infiltration of inflammatory cells in the lung by regulating the TLR4/NF-κB/NLRP3 pathway.

High Burden of Ileus and Pneumonia in Clozapine-Treated Individuals With Schizophrenia: A Finnish 25-Year Follow-Up Register Study.

OBJECTIVE: The authors used longitudinal biobank data with up to 25 years of follow-up on over 2,600 clozapine users to derive reliable estimates of the real-world burden of clozapine adverse drug events (ADEs). METHODS: A total of 2,659 participants in the FinnGen biobank project had a schizophrenia diagnosis and clozapine purchases with longitudinal electronic health record follow-up for up to 25 years after clozapine initiation. Diseases and health-related events enriched during clozapine use were identified, adjusting for disease severity. The incidence and recurrence of ADEs over years of clozapine use, their effect on clozapine discontinuation and deaths, and their pharmacogenetics were studied. RESULTS: Median follow-up time after clozapine initiation was 12.7 years. Across 2,157 diseases and health-related events, 27 were enriched during clozapine use, falling into five disease categories: gastrointestinal hypomotility, seizures, pneumonia, other acute respiratory tract infections, and tachycardia, along with a heterogeneous group including neutropenia and type 2 diabetes, among others. Cumulative incidence estimates for ileus (severe gastrointestinal hypomotility) and pneumonia were 5.3% and 29.5%, respectively, 20 years after clozapine initiation. Both events were significantly associated with increased mortality among clozapine users (ileus: odds ratio=4.5; pneumonia: odds ratio=2.8). Decreased genotype-predicted CYP2C19 and CYP1A2 activities were associated with higher pneumonia risk. CONCLUSIONS: Clozapine-induced ileus and pneumonia were notably more frequent than has previously been reported and were associated with increased mortality. Two CYP genes influenced pneumonia risk. Pneumonia and ileus call for improved utilization of available preventive measures.

Anti-Inflammatory Effect of Fucoidan from Costaria costata Inhibited Lipopolysaccharide-Induced Inflammation in Mice.

Seaweed extracts, especially fucoidan, are well known for their immune-modulating abilities. In this current study, we extracted fucoidan from Costaria costata, a seaweed commonly found in coastal Asia, and examined its anti-inflammatory effect. Fucoidan was extracted from dried C. costata (FCC) using an alcohol extraction method at an extraction rate of 4.5 ± 0.21%. The extracted FCC comprised the highest proportion of carbohydrates, along with sulfate and uronic acid. The immune regulatory effect of FCC was examined using bone marrow-derived dendritic cells (BMDCs). Pretreatment with FCC dose-dependently decreased the lipopolysaccharide (LPS)-induced upregulation of co-stimulatory molecules and major histocompatibility complex. In addition, FCC prevented morphological changes in LPS-induced BMDCs. Moreover, treatment of LPS-induced BMDCs with FCC suppressed the secretion of pro-inflammatory cytokines. In C57BL/6 mice, oral administration of FCC suppressed LPS-induced lung inflammation, reducing the secretion of pro-inflammatory cytokines in the bronchoalveolar lavage fluid. Finally, the administration of FCC suppressed LPS-induced sepsis. Therefore, FCC could be developed as a health supplement based on the observed anti-inflammatory effects.

Bronchoalveolar lavage fluid analysis in patients with checkpoint inhibitor pneumonitis.

BACKGROUND: Checkpoint inhibitor pneumonitis (CIP) is a relatively uncommon but potentially life-threatening immune-related adverse event (irAE). Lung biopsies have not been commonly performed for CIP patients. Bronchoalveolar lavage fluid (BALF) analysis is a useful diagnostic approach for interstitial lung disease. However, BALF features were inconsistent across different studies. METHODS: We retrospectively reviewed the medical records of 154 patients with pathologically confirmed malignancies and suffering from CIPs between July 2018 and December 2022. Patients who had bronchoalveolar lavage (BAL) data available were enrolled in our study. Patient clinical, laboratory, radiological and follow-up data were reviewed and analyzed. RESULTS: The BALF differential cell count and lymphocyte subset analysis were performed for 42 CIP patients. There were 32 males (76.2%). The mean age at diagnosis of CIP was 62.0 ± 10.4 (range: 31-78) years. The median time to onset of CIP was 98.5 days after the start of immunotherapy. There were 18 patients (42.9%) with low-grade CIPs and 24 patients (57.1%) with high-grade CIPs. The mean lymphocyte percentage was 36.7 ± 22.5%. There were 34 (81%) CIP patients with a lymphocytic cellular pattern. The median ratio of CD3+CD4+/CD3+CD8+ lymphocytes was 0.5 (0.3, 1.0). The ratio was less than 1.0 for 31 CIP patients (73.8%). However, there was no significant difference in the BALF features between patients with low-grade CIPs and those with high-grade CIPs. CONCLUSIONS: The CD3+CD8+ lymphocytosis pattern was the main inflammatory profile in the BALF of CIP patients in this cohort. Targeting CD3+CD8+ lymphocytes might be a treatment option for CIPs.

Effects of Bryophyllum pinnatum on Dysfunctional Autophagy in Rats Lungs Exposed to Zinc Oxide Nanoparticles.

Lung inflammation as a result of exposure to toxicants is a major pathological problem. Autophagy (AP) is a process of cell self-digestion and can be disrupted by environmental toxicants, leading to oxidative stress, inflammation and cellular damage. Bryophyllum pinnatum (Lam.) Oken has been used in folklore medicine to manage pathological abnormalities, including inflammation, but mechanisms remain unclear. This work investigated the effects of Bryophyllum pinnatum ethanol leaf extract (BP) on dysfunctional AP in the lungs of Wistar rats exposed to zinc oxide nanoparticles (ZONPs). The experimental rats were orally administered ZONPs for seven days (10 mg/kg). Some exposed rats were post-treated with BP (62.5 and 125 mg/kg) through oral gavage. Oxidative stress, inflammation, and apoptotic and autophagic parameters were assessed using biochemical assay and gene expression methods. Several indices of pulmonary damage were also evaluated. PCR analysis suggested that ZONP downregulated the expression of pro-autophagy-related genes (Beclin 2, ATG5, DAPK, and FOXP3) and upregulated the expression of the TNF-alpha, NF-Kb, LC3 and Bcl2 genes. In contrast, BP significantly (p < 0.0001) reversed ZONP-induced pulmonary toxicity and oxidative stress. It reduced MDA levels and increased SOD, CAT, GSH and GPxD activities. BP significantly (p < 0.0001) downregulated the expressions of proinflammatory genes (IL-6 and JNK) and upregulated the expressions of IL-10, CAT and SOD genes in ZONP-exposed rats. BP restored the lung's histoarchitectural structure after ZNOP-induced distortion. The results suggested that BP has antioxidant and anti-inflammatory properties, and could effectively restore ZNOP-induced dysfunctional AP in the lungs of Wistar rats.

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.

Investigation of pulmonary inflammatory responses following intratracheal instillation of and inhalation exposure to polypropylene microplastics.

BACKGROUND: Microplastics have been detected in the atmosphere as well as in the ocean, and there is concern about their biological effects in the lungs. We conducted a short-term inhalation exposure and intratracheal instillation using rats to evaluate lung disorders related to microplastics. We conducted an inhalation exposure of polypropylene fine powder at a low concentration of 2 mg/m3 and a high concentration of 10 mg/m3 on 8-week-old male Fischer 344 rats for 6 h a day, 5 days a week for 4 weeks. We also conducted an intratracheal instillation of polypropylene at a low dose of 0.2 mg/rat and a high dose of 1.0 mg/rat on 12-week-old male Fischer 344 rats. Rats were dissected from 3 days to 6 months after both exposures, and bronchoalveolar lavage fluid (BALF) and lung tissue were collected to analyze lung inflammation and lung injury. RESULTS: Both exposures to polypropylene induced a persistent influx of inflammatory cells and expression of CINC-1, CINC-2, and MPO in BALF from 1 month after exposure. Genetic analysis showed a significant increase in inflammation-related factors for up to 6 months. The low concentration in the inhalation exposure of polypropylene also induced mild lung inflammation. CONCLUSION: These findings suggest that inhaled polypropylene, which is a microplastic, induces persistent lung inflammation and has the potential for lung disorder. Exposure to 2 mg/m3 induced inflammatory changes and was thought to be the Lowest Observed Adverse Effect Level (LOAEL) for acute effects of polypropylene. However, considering the concentration of microplastics in a real general environment, the risk of environmental hazards to humans may be low.

The potential role of lung microbiota and lauroylcarnitine in T-cell activation associated with checkpoint inhibitor pneumonitis.

BACKGROUND: Checkpoint inhibitor pneumonitis (CIP) is a potentially fatal adverse event characterized by new pulmonary infiltrates in cancer patients receiving immune checkpoint inhibitor therapy. This study aims to explore the interplay between lung microbiota, dysregulated metabolites, and host immunity in CIP. METHODS: We recruited thirteen hospitalized CIP patients, eleven idiopathic pulmonary fibrosis (IPF) patients, and ten new-onset non-small cell lung cancer patients. Bronchoalveolar lavage fluid samples were collected for 16S rRNA gene sequencing. The percentages of immune cells were determined using manual counting and flow cytometry. Interactions among microbiota, metabolites, and lymphocytes were analyzed using cultured mouse splenocytes and human T cells. FINDINGS: Proteobacteria emerged as the dominant phylum, notably abundant in both the CIP and IPF groups. Vibrio, Halomonas, Mangrovibacter, and Salinivibrio were the predominant microbiota because of their discriminative abundance patterns. Vibrio (r = 0.72, P-adj = 0.007) and Halomonas (r = 0.65, P-adj = 0.023) demonstrated strong correlations with lymphocytes. Vibrio metschnikovii and Mangrovibacter plantisponsors were more abundant in the CIP group than in the IPF group. Lauroylcarnitine, a key intermediary metabolite co-occurring with the predominant microbiota, exhibited a potent effect on cytokine secretion by mouse and human T cells, notably enhancing IFN-γ and TNF-α production from CD4 and CD8 cells in vitro. INTERPRETATION: Lauroylcarnitine, co-occurring with the predominant lung microbiota in CIP, could activate T cells in vitro. These findings suggest potential involvement of lung microbiota and acylcarnitine metabolism dysregulation in the pathogenesis of CIP. FUNDING: This work was supported by Peking University People's Hospital Scientific Research Development Funds (RDJ2022-15) and Provincial Key Clinical Specialty Capacity Building Project 2020 (Department of the Respiratory Medicine).

MMP-3 mediates copper oxide nanoparticle-induced pulmonary inflammation and fibrosis.

BACKGROUND: The increasing production and usage of copper oxide nanoparticles (Nano-CuO) raise human health concerns. Previous studies have demonstrated that exposure to Nano-CuO could induce lung inflammation, injury, and fibrosis. However, the potential underlying mechanisms are still unclear. Here, we proposed that matrix metalloproteinase-3 (MMP-3) might play an important role in Nano-CuO-induced lung inflammation, injury, and fibrosis. RESULTS: Exposure of mice to Nano-CuO caused acute lung inflammation and injury in a dose-dependent manner, which was reflected by increased total cell number, neutrophil count, macrophage count, lactate dehydrogenase (LDH) activity, and CXCL1/KC level in bronchoalveolar lavage fluid (BALF) obtained on day 3 post-exposure. The time-response study showed that Nano-CuO-induced acute lung inflammation and injury appeared as early as day 1 after exposure, peaked on day 3, and ameliorated over time. However, even on day 42 post-exposure, the LDH activity and macrophage count were still higher than those in the control group, suggesting that Nano-CuO caused chronic lung inflammation. The Nano-CuO-induced pulmonary inflammation was further confirmed by H&E staining of lung sections. Trichrome staining showed that Nano-CuO exposure caused pulmonary fibrosis from day 14 to day 42 post-exposure with an increasing tendency over time. Increased hydroxyproline content and expression levels of fibrosis-associated proteins in mouse lungs were also observed. In addition, Nano-CuO exposure induced MMP-3 overexpression and increased MMP-3 secretion in mouse lungs. Knocking down MMP-3 in mouse lungs significantly attenuated Nano-CuO-induced acute and chronic lung inflammation and fibrosis. Moreover, Nano-CuO exposure caused sustained production of cleaved osteopontin (OPN) in mouse lungs, which was also significantly decreased by knocking down MMP-3. CONCLUSIONS: Our results demonstrated that short-term Nano-CuO exposure caused acute lung inflammation and injury, while long-term exposure induced chronic pulmonary inflammation and fibrosis. Knocking down MMP-3 significantly ameliorated Nano-CuO-induced pulmonary inflammation, injury, and fibrosis, and also attenuated Nano-CuO-induced cleaved OPN level. Our study suggests that MMP-3 may play important roles in Nano-CuO-induced pulmonary inflammation and fibrosis via cleavage of OPN and may provide a further understanding of the mechanisms underlying Nano-CuO-induced pulmonary toxicity.

The beneficial effects of lupeol on particulate matter-mediated pulmonary inflammation.

Particulate matter (PM) poses significant health risks, especially fine particles (PM2.5) that can cause severe lung injuries. Lupeol, a phytosterol from medicinal plants, has potential anti-cancer properties. This study investigated lupeol's protective effects against PM2.5-induced lung damage. Mice received lupeol following intratracheal PM2.5 exposure. Results showed lupeol reduced lung damage, lowered wet/dry (W/D) weight ratio, and suppressed increased permeability caused by PM2.5. Additionally, lupeol decreased plasma inflammatory cytokines, total protein concentration in bronchoalveolar lavage fluid (BALF), and PM2.5-induced lymphocyte proliferation. Lupeol also reduced expression of toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and autophagy-related proteins microtubule-associated protein 1 A/1 B-light chain 3 (LC3) II and Beclin 1, while increasing phosphorylated mammalian target of rapamycin (mTOR) phosphorylation. These findings suggest lupeol's potential as a therapeutic agent for PM2.5-induced lung damage via modulation of the TLR4-MyD88 and mTOR-autophagy pathways.

CCDC59 alleviates bleomycin-induced inflammation and pulmonary fibrosis by increasing SP-B and SP-C expression in mice.

BACKGROUND: Pulmonary fibrosis is a progressive disease with high incidence and poor prognosis. It is urgent to explore new therapeutic methods for pulmonary fibrosis. As a new treatment method, gene therapy has attracted more and more attention. CCDC59 is a transcriptional coactivator of SP-B and SP-C. Our study mainly aims to explore the effect of overexpression of CCDC59 gene in pulmonary fibrosis of mice. METHODS: CCDC59 overexpressing lentivirus was constructed and then concentrated. RT-qPCR, Western blotting, and immunofluorescence assays were used to detect the expression of CCDC59, SP-B and SP-C protein in cell line and lung tissues after infected with lentivirus. Immunohistochemical staining and hematoxylin-eosin staining assays were used to assess the degree of fibrosis and ELISA assay was used to detect the concentrations of inflammatory factors, SP-B, and SP-C in bronchoalveolar lavage fluid of mice. Dynamic changes of mice lung function at various time points were assessed by lung function test assay. HIPPO pathway and proliferation capacity of alveolar type II epithelial cells were evaluated by immunofluorescence staining and Western blotting. RESULTS: Results showed that endotracheal instillation of CCDC59 overexpressed lentivirus significantly alleviated bleomycin-induced inflammation and pulmonary fibrosis in mice. Overexpression of CCDC59 protein in type II alveolar epithelial cells can enhance the expression of SP-B and SP-C. Overexpression of CCDC59 protein significantly protected against pulmonary inflammatory response and improved lung function of mice. Overexpression of CCDC59 protein significantly alleviated the hyperactivation of HIPPO pathway and increased the proliferative capacity of type II alveolar epithelial cells in lung. CONCLUSION: CCDC59 can alleviate inflammation and pulmonary fibrosis in mice by upregulating the expression of SP-B and SP-C in type II alveolar epithelial cells and alleviating the hyperactivation of HIPPO pathway. Our study offers a new potential treatment for pulmonary fibrosis.

The oxidative stress-dependent pulmonary inflammation of inhalable multi-walled carbon nanotube-containing nano-concrete dust and its comparison with conventional concrete dust and DQ12.

Nano-concrete, which is an admixture of nanomaterials in concrete recipes, has been investigated to overcome the limitations of existing concrete, such as its stability and strength. However, there is no information on the human health effects of broken-down dust released during the construction and demolition efforts. In this study, we prepared an inhalable fraction of multi-walled carbon nanotube-containing nano-concrete dust and performed comparative toxicity studies with conventional concrete dust and DQ12 using a rat intratracheal instillation model. Although the recipes for concrete and nano-concrete are entirely different, the pulverized dust samples showed similar physicochemical properties, such as 0.46-0.48 µm diameter and chemical composition. Both concrete and nano-concrete dust exhibited similar patterns and magnitudes, representing acute neutrophilic inflammation and chronic active inflammation with lymphocyte infiltration. The toxicity endpoints of the tested particles at both time points showed an excellent correlation with the reactive oxygen species levels released from the alveolar macrophages, highlighting that alveolar macrophages are the primary target cells and that the oxidative stress paradigm is the main toxicity mechanism of the tested particles. In addition, the toxicity potentials of both concrete and nano-concrete dust were more than 10 times lower than that of DQ12.

Developmental PFOS exposure alters lung inflammation and barrier integrity in juvenile mice.

Emerging epidemiological evidence indicates perfluorooctane sulfonic acid (PFOS) is increasingly associated with asthma and respiratory viral infections. Animal studies suggest PFOS disrupts lung development and immuno-inflammatory responses, but little is known about the potential consequences on respiratory health and disease risk. Importantly, PFOS exposure during the critical stages of lung development may increase disease risk later in life. Thus, we hypothesized that developmental PFOS exposure will affect lung inflammation and alveolar/airway development in a sex-dependent manner. To address this knowledge gap, timed pregnant Balb/cJ dams were orally dosed with a PFOS (1.0 or 2.0 mg/kg/d) injected mealworm or a vehicle control daily from gestational day (GD) 0.5 to postnatal day (PND) 21, and offspring were sacrificed at PND 22-23. PFOS-exposed male offspring displayed increased alveolar septa thickness. Occludin was also downregulated in the lungs after PFOS exposure in mice, indicative of barrier dysfunction. BALF macrophages were significantly elevated at 2.0 mg/kg/d PFOS in both sexes compared with vehicles, whereas BALF cytokines (TNF-α, IL-6, KC, MIP-1α, MIP-1ß, and MCP-1) were suppressed in PFOS-exposed male offspring compared with vehicle controls. Multiplex nucleic acid hybridization assay showed male-specific downregulation of cytokine gene expression in PFOS-exposed mice compared with vehicle mice. Overall, these results demonstrate PFOS exposure exhibits male-specific adverse effects on lung development and inflammation in juvenile offspring, possibly predisposing them to later-in-life respiratory disease. Further research is required to elucidate the mechanisms underlying the sex-differentiated pulmonary toxicity of PFOS.

Investigating in VigiBase over 6000 cases of pneumonia in clozapine-treated patients in the context of the literature: focus on high lethality and the association with aspiration pneumonia.

BACKGROUND: The literature associates clozapine with pneumonia/aspiration pneumonia. RESEARCH DESIGN AND METHODS: The international pharmacovigilance database (VigiBase™) uses the information component (IC) as statistical signal. VigiBase clozapine reports were analyzed for pneumonia/aspiration pneumonia from introduction to 10 May 2023. RESULTS: There were 6392 cases of all types of pneumonia (5572 cases of pneumonia, 775 of aspiration pneumonia, and 45 combined). The IC was 3.52 for aspiration pneumonia, introduced as a VigiBase label in 2003, and 1.91 for pneumonia. Patients were reclassified as 3628 with no signs of aspiration and 1533 with signs. Signs of aspiration were strongly associated with some co-medications: olanzapine, odds ratio (OR) = 23.8, 95% confidence interval (CI), 14.9-38.0; risperidone OR = 18.6, CI, 11.4-30.4; valproic acid, OR = 5.5, CI, 4.5-6.6; and benzodiazepines OR = 5.5, CI, 4.5-6.6. In 2415 cases with completed data, fatal outcomes made up 45% (signs of aspiration made no difference), but there was wide variability from 0% (females <45 years of age; duration ≤30 days) to 76% (males >64 years of age; duration >1 year). During the first week, pneumonia was associated with 1) very high titration doses, 2) very small doses in Parkinson's disease, and 3) Japan vs other countries. CONCLUSIONS: In clozapine-treated patients: 1) at least 30% of pneumonia cases may be aspiration pneumonia, 2) stopping some co-medications may decrease the risk of aspiration pneumonia, 3) average lethality in pneumonia was 45% but may be around 75% in geriatric patients with long-term treatment, and 4) safer titrations may sometimes require 5-mg tablets.

Lactobacillus murinus alleviated lung inflammation induced by PAHs in mice.

OBJECTIVE: This study aimed to investigate the mechanism that Lactobacillus murinus (L. murinus) alleviated lung inflammation induced by polycyclic aromatic hydrocarbons (PAHs) exposure based on metabolomics. METHODS: Female mice were administrated with PAHs mix, L. murinus and indoleacrylic acid (IA) or indolealdehyde (IAId). Microbial diversity in feces was detected by 16 S rRNA gene sequencing. Non-targeted metabolomics analysis in urine samples and targeted analysis of tryptophan metabolites in serum by UPLC-Orbitrap-MS and short-chain fatty acids (SCFA) in feces by GC-MS were performed, respectively. Flow cytometry was used to determine T helper immune cell differentiation in gut and lung tissues. The levels of IgE, IL-4 and IL-17A in the bronchoalveolar lavage fluid (BALF) or serum were detected by ELISA. The expressions of aryl hydrocarbon receptor (Ahr), cytochrome P450 1A1 (Cyp1a1) and forkheadbox protein 3 (Foxp3) genes and the histone deacetylation activity were detected by qPCR and by ELISA in lung tissues, respectively. RESULTS: PAHs exposure induced lung inflammation and microbial composition shifts and tryptophan metabolism disturbance in mice. L. murinus alleviated PAHs-induced lung inflammation and inhibited T helper cell 17 (Th17) cell differentiation and promoted regulatory T cells (Treg) cell differentiation. L. murinus increased the levels of IA and IAId in the serum and regulated Th17/Treg imbalance by activating AhR. Additionally, L. murinus restored PAHs-induced decrease of butyric acid and valeric acid which can reduce the histone deacetylase (HDAC) level in the lung tissues, enhancing the expression of the Foxp3 gene and promoting Treg cell differentiation. CONCLUSION: our study illustrated that L. murinus alleviated PAHs-induced lung inflammation and regulated Th17/Treg cell differentiation by regulating host tryptophan metabolism and SCFA levels. The study provided new insights into the reciprocal influence between gut microbiota, host metabolism and the immune system, suggesting that L. murinus might have the potential as a novel therapeutic strategy for lung diseases caused by environmental pollution in the future.

Risk factors for severe immune-related pneumonitis after nivolumab plus ipilimumab therapy for non-small cell lung cancer.

BACKGROUND: The efficacy of anti-CTLA-4 antibody (ipilimumab) plus anti-programmed cell death 1 antibody (nivolumab) in treating advanced non-small cell lung cancer (NSCLC) is impeded by an elevated risk of severe immune-related adverse events. However, our understanding of associations among pre-existing fibrosis, emphysematous changes, and objective indicators as predictive factors is limited for severe pneumonitis in NSCLC patients receiving this combination therapy. Thus, we retrospectively investigated these associations, including overall tumor burden, before treatment initiation in the Japanese population. METHODS: We focused on patients (n = 76) with pre-existing interstitial lung disease (ILD) to identify predictors of severe pneumonitis. Variables included age, sex, smoking status, programmed cell death ligand 1 expression, overall tumor burden, chest computed tomography-confirmed fibrosis, serum markers, and respiratory function test results. RESULTS: Severe pneumonitis was more frequent in patients with squamous cell carcinoma, fibrosis, low diffusing capacity for carbon monoxide (%DLCO), and high surfactant protein D (SP-D) level. Notably, squamous cell carcinoma, baseline %DLCO, and SP-D level were significant risk factors. Our findings revealed the nonsignificance of tumor burden (≥85 mm) in predicting severe pneumonitis, emphasizing the importance of pre-existing ILD. Conversely, in cases without pre-existing fibrosis, severe pneumonitis was not associated with %DLCO or SP-D level (93.2% vs. 91.9%, and 63.3 vs. 40.9 ng/mL, respectively) and was more common in patients with a large overall tumor burden (97.5 vs. 70.0 mm). CONCLUSION: Vigilant monitoring and early intervention are crucial for patients with squamous cell carcinoma, high SP-D level, or low %DLCO undergoing ipilimumab plus nivolumab therapy.

A phytomedicine extract exerts an anti-inflammatory response in the lungs by reducing STING-mediated type I interferon release.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is an acute respiratory disease characterized by bilateral chest radiolucency and severe hypoxemia. Quzhou Fructus Aurantii ethyl acetate extract (QFAEE), which is prepared from the traditional Chinese respiratory anti-inflammatory natural herb Quzhou Fructus Arantii, has the potential to alleviate ARDS. In this work, we aimed to investigate the potential and mechanism underlying the action of QFAEE on ARDS and how QFAEE modulates the STING pathway to reduce type I interferon release to alleviate the inflammatory response. METHODS: Lipopolysaccharide (LPS), a potential proinflammatory stimulant capable of causing pulmonary inflammation with edema after nasal drops, was employed to model ARDS in vitro and in vivo. Under QFAEE intervention, the mechanism of action of QFAEE to alleviate ARDS was explored in this study. TREX1-/- mice were sued as a research model for the activation of the congenital STING signaling pathway. The effect of QFAEE on TREX1-/- mice could explain the STING-targeted effect of QFAEE on alleviating the inflammatory response. Our explorations covered several techniques, Western blot, histological assays, immunofluorescence staining, transcriptomic assays and qRT-PCR to determine the potential mechanism of action of QFAEE in antagonizing the inflammatory response in the lungs, as well as the mechanism of action of QFAEE in targeting the STING signaling pathway to regulate the release of type I interferon. RESULTS: QFAEE effectively alleviates ARDS symptoms in LPS-induced ARDS. We revealed that the mechanism underlying LPS-induced ARDS is the STING-TBK1 signaling pathway and further elucidated the molecular mechanism of QFAEE in the prevention and treatment of ARDS. QFAEE reduced the release of type I interferons by inhibiting the STING-TBK1-IRF3 axis, thus alleviating LPS-induced pneumonia and lung cell death in mice. Another key finding is that activation of the STING pathway by activators or targeted knockdown of the TREX1 gene can also induce ARDS. As expected, QFAEE was found to be an effective protective agent in alleviating ARDS and the antagonistic effect of QFAEE on ARDS was achieved by inhibiting the STING signaling pathway. CONCLUSIONS: The main anti-inflammatory effect of QFAEE was achieved by inhibiting the STING signaling pathway and reducing the release of type I interferons. According to this mechanism of effect, QFAEE can effectively alleviate ARDS and can be considered a potential therapeutic agent. In addition, the STING pathway plays an essential role in the development and progression of ARDS, and it is a potential target for ARDS therapy.

Deregulated immune cell recruitment orchestrated by c-MET impairs pulmonary inflammation and fibrosis.

BACKGROUND: Pulmonary fibrosis (PF) represents the pathologic end stage of several interstitial lung diseases (ILDs) associated with high morbidity and mortality rates. However, current treatments can only delay disease progression rather than provide a cure. The role of inflammation in PF progression is well-established, but new insights into immune regulation are fundamental for developing more efficient therapies. c-MET signaling has been implicated in the migratory capacity and effector functions of immune cells. Nevertheless, the role of this signaling pathway in the context of PF-associated lung diseases remains unexplored. METHODS: To determine the influence of c-MET in immune cells in the progression of pulmonary fibrosis, we used a conditional deletion of c-Met in immune cells. To induce pulmonary fibrosis mice were administered with bleomycin (BLM) intratracheally. Over the course of 21 days, mice were assessed for weight change, and after euthanasia at different timepoints, bronchoalveolar lavage fluid cells and lung tissue were assessed for inflammation and fibrosis. Furthermore, c-MET expression was assessed in cryobiopsy sections, bronchoalveolar lavage fluid cells samples and single cell RNA-sequencing dataset from human patients with distinct interstitial lung diseases. RESULTS: c-MET expression was induced in lung immune cells, specifically in T cells, interstitial macrophages, and neutrophils, during the inflammatory phase of BLM-induced PF mouse model. Deletion of c-Met in immune cells correlated with earlier weight recovery and improved survival of BLM-treated mice. Moreover, the deletion of c-Met in immune cells was associated with early recruitment of the immune cell populations, normally found to express c-MET, leading to a subsequent attenuation of the cytotoxic and proinflammatory environment. Consequently, the less extensive inflammatory response, possibly coupled with tissue repair, culminated in less exacerbated fibrotic lesions. Furthermore, c-MET expression was up-regulated in lung T cells from patients with fibrosing ILD, suggesting a potential involvement of c-MET in the development of fibrosing disease. CONCLUSIONS: These results highlight the critical contribution of c-MET signaling in immune cells to their enhanced uncontrolled recruitment and activation toward a proinflammatory and profibrotic phenotype, leading to the exacerbation of lung injury and consequent development of fibrosis.