Persistent Lung Inflammation Research Articles

Eclipta prostrata improves alveolar development of bronchopulmonary dysplasia via suppressing the NLRP3 inflammasome in a DLD-dependent manner.

Bronchopulmonary dysplasia (BPD), the most common late morbidity in preterm infants, is characterized by impaired alveolar development caused by persistent lung inflammation. Studies have shown that NOD-, LRR- and pyrin domain-containing 3 (NLRP3) inflammasome-mediated inflammation is critically involved in the development of BPD. As a traditional Chinese medicinal herb, Eclipta prostrata (EAP) exhibits potent anti-inflammatory properties. Our study aims to investigate whether EAP could improve the lung development of BPD by suppressing the lung inflammatory response. The BPD rat model was established by intra-amniotic injection of lipopolysaccharide (LPS) and postnatal exposure to hyperoxia. Changes in the NLRP3 inflammasome and pyroptosis were assessed by treatment with EAP. The effect of EAP on the NLRP3 inflammasome was tested in vitro using the THP-1 cell line and primary alveolar macrophages. Proteomics analysis was used to elucidate the mechanism of action of EAP. Histopathological and immunofluorescence results of lung tissues revealed that LPS and hyperoxia induced lung injury and triggered NLRP3 inflammasome activation and pyroptosis in alveolar macrophages. EAP ameliorated BPD lung injury, inhibited NLRP3 inflammasome activation and reduced gasdermin D (GSDMD) expression in alveolar macrophages. EAP downregulated the expression of NLRP3 inflammasome pathway molecules (NLRP3, caspase-1, and IL-1β) and GSDMD in LPS-stimulated THP-1 macrophages and primary alveolar macrophages. In addition, proteomics analysis identified that dihydrolipoamide dehydrogenase (DLD) interacted with EAP. Inhibition of DLD activity abolished the protective effects of EAP. Our study suggested that EAP could attenuate arrest of alveolar development via inhibiting NLRP3 inflammasome in a DLD-dependent way, and could be a potential therapeutic method for BPD.

Understanding the molecular basis of anti-fibrotic potential of intranasal curcumin and its association with mitochondrial homeostasis in silica-exposed mice

Silicosis is an occupational disease of the lungs brought in by repeated silica dust exposures. Inhalation of crystalline silica leads to persistent lung inflammation characterized by lung lesions due to granuloma formation. The specific molecular mechanism has not yet been identified, though. The Present study investigated the impact of silica-exposed lung fibrosis and probable molecular mechanisms. Here, Curcumin, derived from Curcuma longa shown to be an effective anti-inflammatory and anti-fibrotic molecule has been taken to investigate its therapeutic efficacy in silica-induced lung fibrosis. An experimental model of silicosis was established in mice where curcumin was administered an hour before intranasal silica exposure every alternate day for 35 days. Intranasal Curcumin treatment reduced silica-induced oxidative stress, inflammation marked by inflammatory cell recruitment, and prominent granuloma nodules along with aberrant collagen repair. Its protective benefits were confirmed by reduced MMP9 activities along with EMT markers (Vimentin and α-SMA). It has restored autophagy and suppressed the deposition of damaged mitochondria after silica exposure. Intranasal Curcumin also inhibited oxidative stress by boosting antioxidant enzyme activities and enhanced Nrf2-Keap1 expressions. Higher levels of PINK1, PARKIN, Cyt-c, P62/SQSTM, and damaged mitochondria in the silicosis group were significantly lowered after curcumin and dexamethasone treatments. Curcumin-induced autophagy resulted in reduced silica-induced mitochondria-dependent apoptosis. We report that intranasal curcumin treatment showed protective properties on pathological features prompted by silica particles, suggesting that the compound may constitute a promising strategy for the treatment of silicosis in the near future.

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

BackgroundMicroplastics 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.ResultsBoth 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.ConclusionThese 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.

Current incidence, risk factor and outcome of acute respiratory distress syndrome in Nasser Institute ICU, Cairo, Egypt

Abstract Background Acute respiratory distress syndrome (ARDS) represents the severe end of a spectrum of acute lung injury due to many different insults. It manifests as acute and persistent lung inflammation with increased lung permeability. Aim of the study To assess the current incidence, risk factors and outcome of acute respiratory distress syndrome at Nasser Institute ICU during the period from January 2019 till the end of July 2019. Methodology The study enrolled 50 patients who were admitted to Nasser Institute ICU and met the Berlin criteria for ARDS during the study period. Results The incidence of ARDS was (3.12%), 54% of which were severe, 26% were moderate, and 20% were mild. Mortality rate was 52%, 88.46% of which were severe cases. Severity index was positively correlated with mortality rate (P- value <0.001). Pneumonia with sepsis was the most common risk factor (74%) and had statistically significant positive correlation with mortality (P = 0.017). Conclusion Incidence of ARDS was relatively small at our institute (3.12%), yet, it has a serious and a potentially fatal outcome with high mortality rate (52%). Key words: Acute Respiratory Distress Syndrome, ARDS, ICU, incidence, risk factor, outcome, mortality, Nasser Institute. Abbreviations: ARDS: Acute Respiratory Distress Syndrome. PaO2: Partial pressure of oxygen. FiO2: Fraction of inspired oxygen. PEEP : Positive end expiratory pressure.TV: Tidal volume. ABG: Arterial blood gases. PH: potential hydrogen. PaCO2: partial pressure of carbon dioxide. HCO3: Bicarbonate. SO2: blood oxygen saturation. ICU: intensive care unit.

Sex-based differences in persistent lung inflammation following influenza infection of juvenile outbred mice.

Children are susceptible to influenza infections and can experience severe disease presentation due to a lack of or limited pre-existing immunity. Despite the disproportionate impact influenza has on this population, there is a lack of focus on pediatric influenza research, particularly when it comes to identifying the pathogenesis of long-term outcomes that persist beyond the point of viral clearance. In this study, juvenile outbred male and female mice were infected with influenza and analyzed following viral clearance to determine how sex impacts the persistent inflammatory responses to influenza. It was found that females maintained a broader cytokine response in the lung following clearance of influenza, with innate, type I and type II cytokine signatures in almost all mice. Males, on the other hand, had higher levels of IL-6 and other macrophage-related cytokines, but no evidence of a type I or type II response. The immune landscape was similar in the lungs between males and females postinfection, but males had a higher regulatory T cell to TH1 ratio compared with female mice. Cytokine production positively correlated with the frequency of TH1 cells and exudate macrophages, as well as the number of cells in the bronchoalveolar lavage fluid. Furthermore, female lungs were enriched for metabolites involved in the glycolytic pathway, suggesting glycolysis is higher in female lungs compared with males after viral clearance. These data suggest juvenile female mice have persistent and excessive lung inflammation beyond the point of viral clearance, whereas juvenile males had a more immunosuppressive phenotype.NEW & NOTEWORTHY This study identifies sex-based differences in persistent lung inflammation following influenza infection in an outbred, juvenile animal model of pediatric infection. These findings indicate the importance of considering sex and age as variable in infectious disease research.

FOXF1 reverses lung fibroblasts transdifferentiation via inhibiting TGF-β/SMAD2/3 pathway in silica-induced pulmonary fibrosis

Silicosis is one of the most common and severe types of pneumoconiosis and is characterized by lung dysfunction, persistent lung inflammation, pulmonary nodule formation, and irreversible pulmonary fibrosis. The transdifferentiation of fibroblasts into myofibroblasts is one of the main reasons for the exacerbation of silicosis. However, the underlying mechanism of transcription factors regulating silicosis fibrosis has not been clarified. The aim of this study was to investigate the potential mechanism of transcription factor FOXF1 in fibroblast transdifferentiation in silica-induced pulmonary fibrosis. Therefore, a silicosis mouse model was established, and we found that FOXF1 expression level was significantly down-regulated in the silicosis group, and after overexpression of FOXF1 by adeno-associated virus (AAV), FOXF1 expression level was up-regulated, and silicosis fibrosis was alleviated. In order to further explore the specific regulatory mechanism of FOXF1 in silicosis, we established a fibroblasts transdifferentiation model induced by TGF-β in vitro. In the model, the expression levels of SMAD2/3 and P-SMAD2/3 were up-regulated, but the expression levels of SMAD2/3 and P-SMAD2/3 were down-regulated, inhibiting transdifferentiation and accumulation of extracellular matrix after the overexpressed FOXF1 plasmid was constructed. However, after silencing FOXF1, the expression levels of SMAD2/3 and P-SMAD2/3 were further up-regulated, aggravating transdifferentiation and accumulation of extracellular matrix. These results indicate that the activation of FOXF1 in fibroblasts can slow down the progression of silicosis fibrosis by inhibiting TGF-β/SMAD2/3 classical pathway, which provides a new idea for further exploration of silicosis treatment.

In vitro inflammation and toxicity assessment of pre- and post-incinerated organomodified nanoclays to macrophages using high-throughput screening approaches

BackgroundOrganomodified nanoclays (ONC), two-dimensional montmorillonite with organic coatings, are increasingly used to improve nanocomposite properties. However, little is known about pulmonary health risks along the nanoclay life cycle even with increased evidence of airborne particulate exposures in occupational environments. Recently, oropharyngeal aspiration exposure to pre- and post-incinerated ONC in mice caused low grade, persistent lung inflammation with a pro-fibrotic signaling response with unknown mode(s) of action. We hypothesized that the organic coating presence and incineration status of nanoclays determine the inflammatory cytokine secretary profile and cytotoxic response of macrophages. To test this hypothesis differentiated human macrophages (THP-1) were acutely exposed (0–20 µg/cm2) to pristine, uncoated nanoclay (CloisNa), an ONC (Clois30B), their incinerated byproducts (I-CloisNa and I-Clois30B), and crystalline silica (CS) followed by cytotoxicity and inflammatory endpoints. Macrophages were co-exposed to lipopolysaccharide (LPS) or LPS-free medium to assess the role of priming the NF-κB pathway in macrophage response to nanoclay treatment. Data were compared to inflammatory responses in male C57Bl/6J mice following 30 and 300 µg/mouse aspiration exposure to the same particles.ResultsIn LPS-free media, CloisNa exposure caused mitochondrial depolarization while Clois30B exposure caused reduced macrophage viability, greater cytotoxicity, and significant damage-associated molecular patterns (IL-1α and ATP) release compared to CloisNa and unexposed controls. LPS priming with low CloisNa doses caused elevated cathepsin B/Caspage-1/IL-1β release while higher doses resulted in apoptosis. Clois30B exposure caused dose-dependent THP-1 cell pyroptosis evidenced by Cathepsin B and IL-1β release and Gasdermin D cleavage. Incineration ablated the cytotoxic and inflammatory effects of Clois30B while I-CloisNa still retained some mild inflammatory potential. Comparative analyses suggested that in vitro macrophage cell viability, inflammasome endpoints, and pro-inflammatory cytokine profiles significantly correlated to mouse bronchioalveolar lavage inflammation metrics including inflammatory cell recruitment.ConclusionsPresence of organic coating and incineration status influenced inflammatory and cytotoxic responses following exposure to human macrophages. Clois30B, with a quaternary ammonium tallow coating, induced a robust cell membrane damage and pyroptosis effect which was eliminated after incineration. Conversely, incinerated nanoclay exposure primarily caused elevated inflammatory cytokine release from THP-1 cells. Collectively, pre-incinerated nanoclay displayed interaction with macrophage membrane components (molecular initiating event), increased pro-inflammatory mediators, and increased inflammatory cell recruitment (two key events) in the lung fibrosis adverse outcome pathway.

Effect of biofuel vulnerability on lungs in Chronic Obstructive Pulmonary disease patients

Background : Incurable COPD is preventable and treatable. Airflow restriction, persistent lung inflammation, and respiratory tract symptoms lead to bronchiolitis and emphysema. It's caused by constant chemical and gas exposure. Comorbidities and exacerbations aggravate COPD, which is caused by complex biological processes. Globally, COPD will be the third greatest cause of death by 2030. Since 16th century, COPD, its diseases, and clinical presentation have been understood. Smoking, tobacco, industrial pollutants, interior pollution, outdoor air pollution, gender, and genetic inheritance affect worldwide incidence, morbidity, and mortality. Chemical exposure and population ageing will exacerbate COPD in the coming years. COVID-19 accelerates COPD and slows recovery. Keywords: COPD, airflow restriction, inflammation, comorbidities

Mammalian Target of Rapamycin Complex 1 Activation in Macrophages Contributes to Persistent Lung Inflammation following Respiratory Tract Viral Infection

Respiratory virus infections cause millions of hospitalizations worldwide each year. Severe infections lead to lung damage that coincides with persistent inflammation and a lengthy repair period. Vaccination and anti-viral therapy help to mitigate severe infections prior to or during the acute stage of disease, but there are currently limited specific treatment options available to individuals suffering from the long-term sequelae of respiratory viral infection. C57BL/6 mice were infected with influenza A/PR/8/34 as a model for severe viral lung infection and allowed to recover for 21 days. Mice were treated with rapamycin, a well characterized mTORC1 inhibitor on days 12 to 20 post infection; a time period after viral clearance. Persistent inflammation following severe influenza infection in mice was primarily driven by macrophages and T cells. UMAP analysis of flow cytometry data revealed that lung macrophages had high activation of mTORC1, an energy sensing kinase involved in inflammatory immune cell effector functions. Rapamycin treatment reduced lung inflammation and the frequency of exudate macrophages, T cells, and B cells in the lung, while not impacting epithelial progenitor cells or adaptive immune memory. These data highlight mTORC1’s role in sustaining persistent inflammation following clearance of a viral respiratory pathogen and suggest a possible intervention for post-viral chronic lung inflammation.

Targeting STING-mediated pro-inflammatory and pro-fibrotic effects of alveolar macrophages and fibroblasts blunts silicosis caused by silica particles

Silica is utilized extensively in industrial and commercial applications as a chemical raw material, increasing its exposure and hazardous potential to populations, with silicosis serving as an important representative. Silicosis is characterized by persistent lung inflammation and fibrosis, for which the underlying pathogenesis of silicosis is unclear. Studies have shown that the stimulating interferon gene (STING) participates in various inflammatory and fibrotic lesions. Therefore, we speculated that STING might also play a key role in silicosis. Here we found that silica particles drove the double-stranded DNA (dsDNA) release to activate the STING signal pathway, contributing to alveolar macrophages (AMs) polarization by secreting diverse cytokines. Then, multiple cytokines could generate a micro-environment to exacerbate inflammation and promote the activation of lung fibroblasts, hastening fibrosis. Intriguingly, STING was also crucial for the fibrotic effects induced by lung fibroblasts. Loss of STING could effectively inhibit silica particles-induced pro-inflammatory and pro-fibrotic effects by regulating macrophages polarization and lung fibroblasts activation to alleviate silicosis. Collectively, our results have revealed a novel pathogenesis of silica particles-caused silicosis mediated by the STING signal pathway, indicating that STING may be regarded as a promising therapeutic target in the treatment of silicosis.

Effects of concomitant chronic obstructive pulmonary disease on immune microenvironment in non-small cell lung cancer patients.

e20522 Background: Chronic obstructive pulmonary disease (COPD) as a progressive deterioration of lung function, has caused significant morbidity and mortality, especially in developing countries. Persistent lung inflammation and potential lung stroma remodeling in COPD may be important causes of lung cancer. Previous studies have shown that non-small cell lung cancer (NSCLC) patients with COPD have a worse prognosis than those without, but the reasons have not been determined. Due to the increasing application of ICIs in the NSCLC, the characteristics of the immune microenvironment in the NSCLC patients concomitant COPD are worth exploring. Methods: Immune microenvironment and the next generation sequencing (NGS) data of twenty NSCLC patients from Sun Yat-sen Memorial Hospital were analyzed. Formalin-fixed paraffin-embedded biopsy tissue before first-line treatment to prepare tumor tissue slides. Samples were stained using an Opal automation mIF Detection Kit (Akoya) for immune cells. The immune cell infiltration were reported as percentages and density from each individual cell subpopulation in the tumor or stromal area. The landscape of gene mutantions was obtained by NGS detection of 733-gene panel, sequencing depth was 35000x. Results: There were 8 (40%) patients concomitant COPD, and the median age was 65.5-year-old. Analysis the immune cell infiltration in all patients, including T cells, B cells, macrophages and NK cells through 13 markers, showed no difference between COPD and non-COPD groups. However, comparing the differences between tumor and stromal immune microenvironment, it was found that there was a significant difference in the percentages of M1 macrophages between tumor and stromal in COPD group (P = 0.031), but no difference in non-COPD group (P = 0.47). Further analysis of the difference in cell density between tumor and stroma showed that the stromal M1 macrophages in the COPD group was significantly higher than that in the non-COPD group (P = 0.017), as well as PD-1+CD8+ T cells (P = 0.05). Additionally, a preliminary analysis of the gene mutation characteristics had done. In COPD patients with somatic mutations, the most frequently mutated gene was EGFR (60%), followed by TP53 (50%) and GLI2 (50%), which were similar as non-COPD patients. The most common variant of COPD patients are the missense mutation of EGFR L858R, but it was EGFR 19del in non-COPD. Conclusions: The results showed that the COPD was correlated with the infiltration status of M1 macrophages and PD-1+CD8+ T cell, and poor immune cell infiltration in tumor of COPD patients may be the potential influencing factors for the worse prognosis. The characteristics of immune microenvironment suggest that promoting the entry of immune cells from stroma into tumor may be a potential mechanism for the benefit of immunotherapy in NSCLC patients with COPD.

93 Linking the Molecular Mechanisms of Alveolar Macrophage Cell Death Induced by Inhaled Nanoparticles with the Subsequent Pathological Outcome

Abstract Background Carbon Nanomaterials (CNM) get released into the environment as combustion by-products and engineered materials. Our previous work has shown that inhalation of CNMs differing in shape, such as spherical carbon nanoparticles (CNPs) or fiber-shaped nanotubes (CNTs) triggers different response pattern ranging from acute and resolving to persistent and chronic lung inflammation. Furthermore, our cell and mouse data showed that, particularly rigid, multi-walled nanotubes (MWCNTs) can cell-specifically and persistently kill alveolar macrophages (AM). Here we hypothesize that the AM death pathway determines the fate of lung inflammation, as acute or chronic. Results Exposure of the murine AM cell line MH-S to MWCNT led to significant decrease of cell viability in a dose-dependent manner (IC50: 10±5 μg/ml). In comparison, CNPs showed relatively low toxicity (IC50: >200 ug/ml) to MH-S cells. Also in contrast to hardly detectable apoptosis (cleaved-Caspase3), immunoblot and -fluorescence analysis demonstrated significant induction of LC3II, a central protein in the autophagy pathway, 12h after MWCNT treatment. The MWCNT triggered cell death response from BMDM-derived AM-like cells however, did not differ between LC3B-/- and wt mice, indicating the autophagy pathway as dispensable. In contrast, inhibition of lysosomal Cathepsins via K777, rescued MWCNT induced cell death of either MH-S or AM-like cells suggesting lysosomal Cathepsins as key player in AM cell death. Conclusion Lysosomal damage with subsequent Cathepsin activity seem a central key event in MWCNT triggered AM cell death. Current studies investigate the relevance of Cathepsins for the inflammatory consequences of CNT triggered AM cell death.

1539. A Nine-Gene Blood-Based Signature Meets the World Health Organization Target Product Profiles for Diagnosis of Active Tuberculosis and Predicting Progression from Latent to Active Disease

Abstract Background As part of its End TB strategy, the WHO has identified the need for non-sputum-based diagnostics that meet target product profiles (TPP) of 90% sensitivity and 70% specificity for diagnosis of Active TB (ATB) and 75% sensitivity and specificity for predicting progression from Latent TB (LTB) to ATB. The successful translation of a 3-gene blood-based signature, identified using diverse datasets, into a prototype point-of-care diagnostic, that meets the WHO TPPs, has demonstrated the power of integrating large amounts of heterogeneous data to identify generalizable disease signatures. We hypothesized that integration of more diverse datasets, comprising patients with ATB or other inflammatory lung diseases, would identify novel, robust signatures, for diagnosing ATB and predicting progression from LTB to ATB, that meet the WHO TPPs. Methods Using multi-cohort analyses, we integrated and analyzed data from 3,615 peripheral blood samples, in 49 publicly available transcriptomic datasets (discovery cohorts), from healthy controls and patients with LTB, ATB, and other diseases (COPD, viral infections, sarcoidosis, etc.). We used data from (1) 3,836 blood samples in 28 retrospective datasets and (2) 360 prospectively collected blood samples, from a household contact study in Moldova, as validation cohorts. Results Using the discovery cohorts we identified a 9-gene signature for diagnosing ATB patients from healthy controls, or individuals with LTB or other diseases. The signature achieved 90% sensitivity and 82% specificity in retrospective validation (Figure 1A) and 90% sensitivity and 69% specificity in the prospective cohort from Moldova (Figure 1B). In a longitudinal cohort of adolescents, the 9-gene signature predicted progression from LTB to ATB up to 1 year prior to sputum conversion with 76% sensitivity and 83% specificity (Figure 1C). Finally, the signature predicted prolonged lung inflammation post-treatment in the Catalysis Treatment Response Cohort (Figure 1D). 9-gene TB signature validates in independent retrospective and prospective cohorts. (A) ROC curves for comparing ATB vs. all other samples (All), or individually comparing ATB vs. Healthy, LTBI or Other Disease (OD) samples in independent retrospective validation and (B) a prospective Moldova cohort. (C) ROC curves comparing progressor and non-progressor samples collected at different time points in the Adolescent Cohort Study (ACS), for the 9-gene signature in solid lines and a previous 3-gene signature in dashed lines, (D) Distribution of the 9-gene score at different time points post-treatment in the Catalysis Treatment Response Cohort Study, for individuals with persistent lung inflammation at 24 weeks compared with those who had clear lungs at 24 weeks. Conclusion Overall, the 9-gene signature meets the WHO TPPs required for the End TB strategy. Disclosures Purvesh Khatri, PhD, Cepheid, Inc.: Advisor/Consultant|Inflammatix, Inc.: Advisor/Consultant|Inflammatix, Inc.: Inflammatix is in negotiations to license the 9-gene signature discussed here.|Inflammatix, Inc.: Stocks/Bonds.

Recruited monocytes/macrophages drive pulmonary neutrophilic inflammation and irreversible lung tissue remodeling in cystic fibrosis

Persistent neutrophil-dominated lung inflammation contributes to lung damage in cystic fibrosis (CF). However, the mechanisms that drive persistent lung neutrophilia and tissue deterioration in CF are not well characterized. Starting from the observation that, in patients with CF, c-c motif chemokine receptor 2 (CCR2)+ monocytes/macrophages are abundant in the lungs, we investigate the interplay between monocytes/macrophages and neutrophils in perpetuating lung tissue damage in CF. Here we show that CCR2+ monocytes in murine CF lungs drive pathogenic transforming growth factor β (TGF-β) signaling and sustain a pro-inflammatory environment by facilitating neutrophil recruitment. Targeting CCR2 to lower the numbers of monocytes in CF lungs ameliorates neutrophil inflammation and pathogenic TGF-β signaling and prevents lung tissue damage. This study identifies CCR2+ monocytes as a neglected contributor to the pathogenesis of CF lung disease and as a therapeutic target for patients with CF, for whom lung hyperinflammation and tissue damage remain an issue despite recent advances in CF transmembrane conductance regulator (CFTR)-specific therapeutic agents.

Interleukin-11 receptor subunit α-1 is required for maximal airway responsiveness to methacholine after acute exposure to ozone.

Interleukin (IL)-11, a multifunctional cytokine, contributes to numerous biological processes, including adipogenesis, hematopoiesis, and inflammation. Asthma, a respiratory disease, is notably characterized by reversible airway obstruction, persistent lung inflammation, and airway hyperresponsiveness (AHR). Nasal insufflation of IL-11 causes AHR in wild-type mice while lung inflammation induced by antigen sensitization and challenge, which mimics features of atopic asthma in humans, is attenuated in mice genetically deficient in IL-11 receptor subunit α-1 (IL-11Rα1-deficient mice), a transmembrane receptor that is required conjointly with glycoprotein 130 to transduce IL-11 signaling. Nevertheless, the contribution of IL-11Rα1 to characteristics of nonatopic asthma is unknown. Thus, based on the aforementioned observations, we hypothesized that genetic deficiency of IL-11Rα1 attenuates lung inflammation and increases airway responsiveness after acute inhalation exposure to ozone (O3), a criteria pollutant and nonatopic asthma stimulus. Accordingly, 4 and/or 24 h after cessation of exposure to filtered room air or O3, we assessed lung inflammation and airway responsiveness in wild-type and IL-11Rα1-deficient mice. With the exception of bronchoalveolar lavage macrophages and adiponectin, which were significantly increased and decreased, respectively, in O3-exposed IL-11Rα1-deficient as compared with O3-exposed wild-type mice, no other genotype-related differences in lung inflammation indices that we quantified were observed in O3-exposed mice. However, airway responsiveness to acetyl-β-methylcholine chloride (methacholine) was significantly diminished in IL-11Rα1-deficient as compared with wild-type mice after O3 exposure. In conclusion, these results demonstrate that IL-11Rα1 minimally contributes to lung inflammation but is required for maximal airway responsiveness to methacholine in a mouse model of nonatopic asthma.

The Levels of the Human-β-Defensin-2 and LL-37 in the Sputum of Children with Cystic Fibrosis: A Case–control Study and Literature Review

BACKGROUND: Cystic fibrosis (CF) is a genetic disorder with an autosomal-recessive type of inheritance. Based on their host-defending and pro-inflammatory functions, antimicrobial peptides (AMPs) likely have one of the central roles in the pathogenesis of lung disease in CF. AIM: The purpose of the study was to measure the concentration of AMPs in the sputum of children with CF and evaluate any correlation with a bacterial profile of the lungs. METHODS: Lung colonization was evaluated using a culture-dependent method, sputum was utilized. A sandwich-ELISA was used to measure hBD-2 and hCAP-18/LL-37 in the sputum. RESULTS: There were 27 children enrolled in the study group, median age of inclusion was 11.4 (8.5; 14.8) years old. The control group consisted of 14 children, 11.6 (8.6; 12.6) years old. The concentration of AMPs was not correlating with participants` age (rs = −0.286, p = 0.148 – defensin hDB-2; rs = −0.084, p = 0.676 – cathelicidin hCAP-18/LL-37). The concentration of hBD-2 was from 64.01 to 813.61 pg/mL. The concentration of hCAP-18/LL-37 was from 3.24 to 35.98 ng/mL. There were significant differences in the content of AMPs on respiratory samples between study and control group (U = 976.5, p = 0.001 – for hBD-2; U = 1080.5, p < 0.001). The correlation between current infection Pseudomonas aeruginosa and concentration of hBD-2 (rs = 0.167; p = 0.406) was not found. However, the presence of P. aeruginosa correlated with density of neutrophilic infiltration (rs = 0.622; p = 0.001). The concentration of hBD-2 showed direct medium correlation with total cells count (rs = 0.881, p < 0.001). Correlation between current infection P. aeruginosa and concentration of hCAP-18/LL-37 (rs = 0.788; p < 0.001) was observed. With increases in total cell count and relative neutrophils count, the concentration of hCAP-18/LL-37 was increased and the power of the association was medium (rs = 0.453; p = 0,018; rs = 0,592; p = 0,001). The correlation between concentrations of hBD-2 and hCAP-18/LL-37 (rs = 0.316, p > 0.1) was not found. CONCLUSIONS: Measured AMPs correlated with cellular inflammatory markers and, probably, their overexpression is dedicated to stimulating a cellular component of innate immune response; there was no correlation between bacterial colonization of lungs and levels of hBD-2, so our findings sustain that P. aeruginosa is a leading but non-single contributor to persistent local inflammation in polymicrobial lungs.

Comparing cardiac MRI and lung PET/CT after completion of tuberculosis treatment – preliminary findings of participants co-enrolled into the StatinTB trial and Cardiac Imaging After TB (CIA-TB) study

Abstract Introduction Mortality rates after successful tuberculosis (TB) treatment remain elevated and healthy survival is impaired by chronic pulmonary disease and persistent inflammation. Inflammation leads to a complex cascade of events and has been associated with cardiovascular disease (CVD). Recent epidemiological work described an increased risk of CVD in persons with history of TB. Aims and objectives In our ongoing StatinTB trial (NCT04147286), we evaluate safety and efficacy of 40 mg atorvastatin to reduce persistent lung inflammation (PLI) after TB treatment in HIV−/HIV+ adults measured by 18F-FDG-PET/CT. Participants are co-enrolled into the Cardiac Imaging After Tuberculosis (CIA-TB) study. Here we report preliminary findings of participants enrolled into the StatinTB trial and CIA-TB study with the aim to correlate PLI with cardiac magnetic resonance imaging (CMR) parameters. Methods Participants with clinical response to TB treatment and a negative sputum culture at 16 weeks were screened at the end of a 24-week course of treatment for drug-sensitive TB. PET/CT was performed on a Philips Gemini TF scanner and analysed using MIM®Software. PLI was defined as total lung glycolysis (TLG) ≥50 SUV·mL (Figure 1). CMR was performed using a 3T Siemens Magnetom Skyra scanner and parameters were derived from the following acquisitions: SSFP cine imaging of the short and long axes, T1 mapping (MOLLI, 5 (3) 3), T2 mapping and late gadolinium enhancement (LGE) imaging. StatinTB trial is conducted according to ICH-GCP. Results 26 participants (mean age 37.8±13.8 years, 38.5% women) underwent PET/CT and CMR. 23.1% were infected with HIV, 34.6% smokers, and 26.9% had a previous history of TB. Median BMI was 21.3 (IQR 19.7; 24.3). One participant reported hypertension. Common symptoms at enrollment were cough (26.9%), shortness of breath (11.5%), and chest pain (3.9%). On CT scan, 73.1% had pulmonary nodules, 57.7% scarring, 50.0% cavities, 42.3% bronchiectasis, 19.2% centrilobular disease, 19.2% distorted lung architecture, and 11.5% consolidations. On PET/CT, PLI was detected among 11 (42.3%) participants with a mean TLG of 216.0 (IQR 78.2; 384.0). In a multivariable regression analysis, left ventricular end systolic volume (LVESV) (−1.46; 95% CI: −2.89, −0.23; p=0.047) and distorted lung architecture (2.84; 95% CI: 1.17, 4.52; p=0.003) were significantly associated with TLG. Native T1 relaxation time showed a strong, but not significant association with TLG (15.01; 95% CI: −8.08, 38.10; p=184). Conclusion We present data of a young cohort at the end of TB treatment without significant cardiac risk factors. Structural lung disease is affecting at least half of participants, and many remain symptomatic. PLI is present in more than one-third of participants and our preliminary findings suggest an association with cardiac impairment. Further enrolment and ongoing laboratory studies will shed more light into post-TB cardio-pulmonary sequelae. Funding Acknowledgement Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EDCTP

Atherosclerotic Coronary Plaque features in patients with Acute Coronary Syndrome and Chronic Obstructive Pulmonary Disease

Abstract Background Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder characterized by airflow limitation, persistent respiratory symptoms and chronic lung inflammation. Previous studies reported a robust relationship between COPD and coronary artery disease (CAD). Local and systemic inflammation, known to play a role in atherosclerosis development, has been reported in patients with COPD, and has been proposed as one of the possible pathogenetic factors linking COPD and CAD. However, data on atherosclerotic coronary pattern and coronary inflammation in COPD patients are lacking. Purpose To study the characteristics of atherosclerotic coronary plaques and local inflammation by using optical coherence tomography (OCT) in COPD patients presenting with acute coronary syndromes (ACS). Methods ACS patients undergoing intracoronary OCT imaging of the culprit vessel were retrospectively identified. Coronary plaque characteristics and OCT-defined macrophage infiltration (MØI) were assessed by OCT. ACS patients were divided into 2 groups according to the presence or the absence of an established diagnosis of COPD, and coronary plaque features and MØI both at the culprit plaque site and along the culprit vessel were compared between the two groups. Results Among 146 ACS patients (mean age, 66,1±12,7 years, 109 males), 47 (32,2%) had COPD. Patients with COPD were older, were more frequently on therapy with an angiotensin receptor blocker, had lower hemoglobin, total cholesterol and triglycerides levels, and had higher serum creatinine levels. The prevalence of different mechanisms of ACS were similar between COPD and noCOPD patients (plaque rupture: 57,4% vs. 45,4%, plaque erosion: 23,4% vs. 32,3%, calcified plaque: 19,1% vs. 22,2%, respectively, overall p=0,381). OCT analysis of plaque microstructures showed that COPD patients had significantly higher prevalence of MØI (78,7% vs. 54,4%, p=0,005), thin cap fibroatheroma (TCFA) (48,9% vs. 22,2%, p=0,001), spotty calcium (68,1% vs. 26,3%, p<0,001) and calcifications (83,0% vs. 66,7%, p=0,040) at the culprit site than noCOPD patients. In the multivariate logistic regression analysis performed to adjust for clinical features, COPD was independently associated with MØI both at the culprit site (OR: 4,726, CI: 1,599; 13,971, p=0,005) and along the culprit vessel (OR: 2,193, CI: 1,110; 4,332, p=0,024). Similarly, COPD was independently associated with the presence of TCFA both at the culprit site (OR: 5,737, CI: 1,877; 17,540, p=0,002) and along the culprit vessel (OR: 2,796, CI: 1,408; 5,553, p=0,003). Conclusions In ACS patients undergoing OCT imaging of the culprit vessel, COPD was an independent predictor of local plaque inflammation and plaque vulnerability both at the culprit site and along the culprit vessel. Our results may suggest that a higher inflammatory milieu in COPD patients might enhance local coronary inflammation, promoting CAD development and plaque vulnerability. Funding Acknowledgement Type of funding sources: None.

Lung recovery from DNA damage induced by graphene oxide is dependent on size, dose and inflammation profile

BackgroundA key aspect of any new material safety assessment is the evaluation of their in vivo genotoxicity. Graphene oxide (GO) has been studied for many promising applications, but there are remaining concerns about its safety profile, especially after inhalation. Herein we tested whether GO lateral dimension, comparing micrometric (LGO) and nanometric (USGO) GO sheets, has a role in the formation of DNA double strand breaks in mouse lungs. We used spatial resolution and differential cell type analysis to measure DNA damages in both epithelial and immune cells, after either single or repeated exposure.ResultsGO induced DNA damages were size and dose dependent, in both exposure scenario. After single exposure to a high dose, both USGO and LGO induced significant DNA damage in the lung parenchyma, but only during the acute phase response (p < 0.05 for USGO; p < 0.01 for LGO). This was followed by a fast lung recovery at day 7 and 28 for both GOs. When evaluating the chronic impact of GO after repeated exposure, only a high dose of LGO induced long-term DNA damages in lung alveolar epithelia (at 84 days, p < 0.05). Regardless of size, low dose GO did not induce any significant DNA damage after repeated exposure. A multiparametric correlation analysis of our repeated exposure data revealed that transient or persistent inflammation and oxidative stress were associated to either recovery or persistent DNA damages. For USGO, recovery from DNA damage was correlated to efficient recovery from acute inflammation (i.e., significant secretion of SAA3, p < 0.001; infiltration of neutrophils, p < 0.01). In contrast, the persistence of LGO in lungs was associated to a long-lasting presence of multinucleated macrophages (up to 84 days, p < 0.05), an underlying inflammation (IL-1α secretion up to 28 days, p < 0.05) and the presence of persistent DNA damages at 84 days.ConclusionsOverall these results highlight the importance of the exposure scenario used. We showed that LGO was more genotoxic after repeated exposure than single exposure due to persistent lung inflammation. These findings are important in the context of human health risk assessment and toward establishing recommendations for a safe use of graphene based materials in the workplace.

Smoking Cessation in Mice Does Not Switch off Persistent Lung Inflammation and Does Not Restore the Expression of HDAC2 and SIRT1.

Once COPD is established, pulmonary lesions can only progress and smoking cessation by itself is not sufficient to switch off persistent lung inflammation. Similarly, in former-smoker mice, neutrophil inflammation persists and lung lesions undergo progressive deterioration. The molecular mechanisms underlying disease progression and the inefficiency of smoking cessation in quenching neutrophilic inflammation were studied in male C57 Bl/6 mice after 6 months of rest from smoking cessation. As compared with the mice that continued to smoke, the former-smoker mice showed reduced expression of histone deacetylases HDAC2 and SIRT1 and marked expression of p-p38 MAPK and p-Ser10. All these factors are involved in corticosteroid insensitivity and in perpetuating inflammation. Former-smoker mice do show persistent lung neutrophilic influx and a high number of macrophages which account for the intense staining in the alveolar structures of neutrophil elastase and MMP-9 (capable of destroying lung scaffolding) and 8-OHdG (marker of oxidative stress). “Alarmins” released from necrotic cells together with these factors can sustain and perpetuate inflammation after smoking cessation. Several factors and mechanisms all together are involved in sustaining and perpetuating inflammation in former-smoker mice. This study suggests that a better control of COPD in humans may be achieved by precise targeting of the various molecular mechanisms associated with different phenotypes of disease by using a cocktail of drug active toward specific molecules.