Airspace Enlargement Research Articles

A Regulatory Role of Chemokine Receptor CXCR3 in the Pathogenesis of Chronic Obstructive Pulmonary Disease and Emphysema.

Chronic obstructive pulmonary disease (COPD)/pulmonary emphysema is driven by the dysregulated airway inflammation and primarily influenced by the interaction between cigarette smoking (CS) and the individual's susceptibility. The inflammation in COPD involves both innate and adaptive immunity. By binding to its specific ligands, chemokine receptor CXCR3 plays an important role in regulating tissue inflammation and damage. In acute animal model challenged with either CS or pathogens, CXCR3 knockout (KO) attenuated lung inflammation and pathology. However, the role of CXCR3 in CS-induced chronic airway inflammation and pulmonary emphysema remains unknown. In this present study, we investigated the effect of CXCR3 in CS-induced pulmonary emphysema in an animal model, and the association between CXCR3 single nucleotide polymorphisms (SNPs) and COPD susceptibility in human subjects. We found that after chronic exposure to side stream CS (SSCS) for 24 weeks, CXCR3 KO mice demonstrated significant airspace enlargement expressed by mean linear intercept (Lm) compared with the wild-type (WT) mice. Consistently, CXCR3 KO mice had significantly higher BAL fluid macrophages and neutrophils, TNFα, and lung homogenate MMP-9 and MMP-12. Through genetic analysis of CXCR3 polymorphisms in a cohort of COPD patients with Han Chinese ethnicity, one CXCR3 SNP, rs2280964, was found to be genetically related to COPD susceptibility. Furthermore, CXCR3 SNP rs2280964 was significantly associated with the levels of serum MMP-9 in COPD patients. Our data from both animal and human studies revealed a novel role of CXCR3 possibly via influencing MMP9 production in the pathogenesis and progression of CS-associated COPD/pulmonary emphysema.

Effect of low VEGF on lung development and function.

Vascular endothelial growth factor (VEGF) is important for lung development and function but ideal mouse models are limited to decipher the quantitative relationship between VEGF expression levels and its proper development and pathogenesis. Human SPC promoter has been used to faithfully express genes or cDNAs in the pulmonary epithelium in many transgenic mouse models. In the study, a mouse model of lung-specific and reversible VEGF repression (hspc-rtTRtg/+/VegftetO/tetO) was generated. Human SPC promoter was used to drive lung-specific rtTR expression, a cDNA coding for doxycycline-regulated transcription repression protein. By crossing with VegftetO/tetO mice, that has tetracycline operator sequences insertion in 5'-UTR region, it allows us to reversibly inhibit lung VEGF transcription from its endogenous level through doxycycline food, water or injection. The tissue-specific inhibition of VEGF is used to mimic abnormal expression levels of VEGF in lung. Reduced VEGF expression in lung is confirmed by quantitative real time PCR and immunoblotting. Lung development and structure was analyzed by histology analysis and found significantly affected under low VEGF. The pulmonary epithelium and alveolarization are found abnormal with swelling alveolar septum and enlargement of air space. Genome-wide gene expression analysis identified that immune activities are involved in the VEGF-regulated lung functions. The transgenic mouse model can be used to mimic human pulmonary diseases. The mouse model confirms the important regulatory roles of epithelial expressed VEGF in lung development and function. This mouse model is valuable for studying VEGF-regulated lung development, pathogenesis and drug screening under low VEGF expression.

Alveolar Airspace Size in Healthy and Diseased Infant Lungs Measured via Hyperpolarized 3He Gas Diffusion Magnetic Resonance Imaging

Background: Alveolar development and lung parenchymal simplification are not well characterized in vivo in neonatal patients with respiratory morbidities, such as bronchopulmonary dysplasia (BPD). Hyperpolarized (HP) gas diffusion magnetic resonance imaging (MRI) is a sensitive, safe, nonionizing, and noninvasive biomarker for measuring airspace size in vivo but has not yet been implemented in young infants. Objective: This work quantified alveolar airspace size via HP gas diffusion MRI in healthy and diseased explanted infant lung specimens, with comparison to histological morphometry. Methods: Lung specimens from 8 infants were obtained: 7 healthy left upper lobes (0–16 months, post-autopsy) and 1 left lung with filamin-A mutation, closely representing BPD lung disease (11 months, post-transplantation). Specimens were imaged using HP ³He diffusion MRI to generate apparent diffusion coefficients (ADCs) as biomarkers of alveolar airspace size, with comparison to mean linear intercept (L_m) via quantitative histology. Results: Mean ADC and L_m were significantly increased throughout the diseased specimen (ADC = 0.26 ± 0.06 cm²/s, L_m = 587 ± 212 µm) compared with healthy specimens (ADC = 0.14 ± 0.03 cm²/s, L_m = 133 ± 37 µm; p < 1 × 10⁻⁷); increased values reflect enlarged airspaces. Mean ADCs in healthy specimens were significantly correlated to L_m (r = 0.69, p = 0.041). Conclusions: HP gas diffusion MRI is sensitive to healthy and diseased regional alveolar airspace size in infant lungs, with good comparison to quantitative histology in ex vivo specimens. This work demonstrates the translational potential of gas MRI techniques for in vivo assessment of normal and abnormal alveolar development in neonates with pulmonary disease.

Mitotic Spindle Apparatus Abnormalities in Chronic Obstructive Pulmonary Disease Cells: A Potential Pathway to Lung Cancer.

Chronic obstructive pulmonary disease (COPD) is a long-term lung disease characterized by irreversible lung damage resulting in airflow limitation, abnormal permanent air-space enlargement, and emphysema. Cigarette smoking is the major cause of COPD with 15% to 30% of smokers developing either disease. About 50% to 80% of patients with lung cancer have preexisting COPD and smokers who have COPD are at an increased risk for developing lung cancer. Therefore, COPD is considered an independent risk for lung cancer, even after adjusting for smoking. A crucial early event in carcinogenesis is the induction of the genomic instability through alterations in the mitotic spindle apparatus. To date, the underlying mechanism by which COPD contributes to lung cancer risk is unclear. We hypothesized that tobacco smoke carcinogens induce mitotic spindle apparatus abnormalities and alter expression of crucial genes leading to increased genomic instability and ultimately tumorigenesis. To test our hypothesis, we assessed the genotoxic effects of a potent tobacco-smoke carcinogen [4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, (NNK)] on bronchial epithelial cells from patients with COPD and normal bronchial epithelial cells and identified genes associated with mitotic spindle defects and chromosome missegregation that also overlap with lung cancer. Our results indicate that exposure to NNK leads to a significantly altered spindle orientation, centrosome amplification, and chromosome misalignment in COPD cells as compared with normal epithelial cells. In addition, we identified several genes (such as AURKA, AURKB, and MAD2L2) that were upregulated and overlap with lung cancer suggesting a potential common pathway in the transition from COPD to lung cancer.

Fine particulate matter exposure promotes M2 macrophage polarization through inhibiting histone deacetylase 2 in the pathogenesis of chronic obstructive pulmonary disease.

BackgroundChronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality globally. Fine particulate matter (PM2.5) has been indicated to be a major detrimental risk factor for COPD by numerous epidemiological studies. Histone deacetylase 2 (HDAC2), a critical regulator of chromatin remodeling, plays a pivotal role in the development of COPD. However, the underlying mechanisms regarding the relationship between PM2.5 and HDAC2 in the pathogenesis of COPD have yet to be elucidated. In the present study, we aim to investigate the role and the underlying mechanism of HDAC2 in the development of PM2.5-induced COPD.MethodsThe effects of PM2.5 exposure on M2 macrophage polarization and the expression levels of HDAC2 were examined in vitro. The influence of HDAC2 deficiency on M2 macrophage polarization and the pathogenesis of COPD was investigated in a PM2.5-induced mouse model.ResultsPM2.5 exposure down-regulated the protein level of HDAC2 and enhanced M2 macrophage polarization in vitro. In the COPD murine model, myeloid-specific deficiency of HDAC2 augmented PM2.5-induced M2 polarization of alveolar macrophages (AMs) and up-regulation of tumor necrosis factor (TGF)-β, matrix metallopeptidase (MMP)-9, and MMP-12 in lung tissue, which resulted in more prominent lung function deterioration, airspace enlargement, alveolar wall destruction, and airway remodeling, indicating a key role of HDAC2 in the pathogenesis of PM2.5-induced COPD.ConclusionsPM2.5 facilitated M2 polarization by inhibiting HDAC2, leading to the development of COPD. Targeting of HDAC2 would provide a novel approach to prevent the development of PM2.5 exposure-induced COPD.

EFFECT OF GENDER ON THE TREATMENT RESPONSES TO RAPAMYCIN ON THE PROGRESSION OF EMPHYSEMA IN CIGARETTE SMOKE-EXPOSED MICE

SESSION TITLE: Obstructive Lung Disease Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Emphysema is characterized by the permanent enlargement of distal airspaces. Current therapies focus on symptom relief as little can halt disease progression. Given its role in cell aging/damage, the mTOR pathway has been studied with respect to emphysema. While inhibition of this pathway with rapamycin has been shown to delay progression of cigarette-smoke (CS) induced emphysema, effects of gender have not been examined. We aim to characterize the effects of rapamycin on the progression of CS induced lung injury in male and female mice. METHODS: A prospective study of 151 mice (C57B/6 strain) was conducted. The mice were separated into two cohorts: CS exposure vs. no CS exposure. The CS exposed group was stratified based on gender and treatment with rapamycin (CS-D) or a vehicle (CS-V) whereas the no CS exposure group was stratified by gender alone. Mice were sacrificed at 0, 3 and 5 months to obtain alveolar histologic data (chord length [Lm]) and pre-mortem physiologic data by Scireq Flexivent (total lung capacity [TLC], static compliance [Cst], dynamic compliance [Cdy], and Pressure-Volume [PV] loops). Statistical analysis was performed by Mann-Whitney t-test and Kruskall-Wallis test using PRISM GraphPad software with a p < 0.05 considered significant. RESULTS: Male CS-V mice had a higher lung compliance at 3 months compared to male CS-D mice as seen on the PV loops. Ventilator data showed male CS-V mice to have a higher average TLC (1.56mL vs 1.43mL; p= 0.002) and Cst (0.11 mL/cmH2O vs 0.09 mL/cmH2O; p = 0.002) at 3 months compared to male CS-D mice. This difference in ventilator parameters did not persist at 5 months and were not different between CS-V and CS-D mice (p > 0.05). On histology, CS-V mice had longer Lm than non-CS exposed mice over the 5 month study period with the largest difference at 5 months (75.12 um vs 66.28 um; p= 0.003). Male CS-V mice had longer Lm than CS-D mice at 3 months (69.59 um vs 65.47 um; p= 0.016), but not at 5 months. No significant differences in Lm were seen between CS-V and CS-D mice at 3 and 5 months in the female group. CONCLUSIONS: Protection against CS induced emphysema by treatment with rapamycin is highly gender dependent. Males benefit significantly with rapamycin treatment while females do not. This therapeutic effect is not durable over long/chronic CS exposure. CLINICAL IMPLICATIONS: Rapamycin may be a viable option for temporarily delaying the progression of CS-induced emphysema, though further investigation into the mechanisms by which gender influences the progression of CS-induced emphysema related to the biology of mTOR and aging are needed. DISCLOSURES: No relevant relationships by Marie Burdick, source=Web Response No relevant relationships by Kranthikiran Earasi, source=Web Response No relevant relationships by Mu He, source=Web Response No relevant relationships by Jamie MacLeod, source=Web Response No relevant relationships by Lukasz Myc, source=Web Response No relevant relationships by Zaid Obaida, source=Web Response No relevant relationships Added 05/30/2020 by Yun Shim, source=Web Response, value=Intellectual property rights Removed 06/01/2020 by Yun Shim, source=Web Response No relevant relationships Added 05/30/2020 by Yun Shim, source=Web Response, value=Salary Removed 06/01/2020 by Yun Shim, source=Web Response No relevant relationships by Chunzi Song, source=Web Response No relevant relationships by Zhimin Zhang, source=Web Response

Cigarette smoke induction of S100A9 contributes to chronic obstructive pulmonary disease

S100 calcium-binding protein A9 (S100A9) is elevated in plasma and bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD), and aging enhances S100A9 expression in several tissues. Currently, the direct impact of S100A9-mediated signaling on lung function and within the aging lung is unknown. Here, we observed that elevated S100A9 levels in human BALF correlated with age. Elevated lung levels of S100A9 were higher in older mice compared with in young animals and coincided with pulmonary function changes. Both acute and chronic exposure to cigarette smoke enhanced S100A9 levels in age-matched mice. To examine the direct role of S100A9 on the development of COPD, S100a9-/- mice or mice administered paquinimod were exposed to chronic cigarette smoke. S100A9 depletion and inhibition attenuated the loss of lung function, pressure-volume loops, airway inflammation, lung compliance, and forced expiratory volume in 0.05 s/forced vital capacity, compared with age-matched wild-type or vehicle-administered animals. Loss of S100a9 signaling reduced cigarette smoke-induced airspace enlargement, alveolar remodeling, lung destruction, ERK and c-RAF phosphorylation, matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-9 (MMP-9), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), and keratinocyte-derived chemokine (KC) release into the airways. Paquinimod administered to nonsmoked, aged animals reduced age-associated loss of lung function. Since fibroblasts play a major role in the production and maintenance of extracellular matrix in emphysema, primary lung fibroblasts were treated with the ERK inhibitor LY3214996 or the c-RAF inhibitor GW5074, resulting in less S100A9-induced MMP-3, MMP-9, MCP-1, IL-6, and IL-8. Silencing Toll-like receptor 4 (TLR4), receptor for advanced glycation endproducts (RAGE), or extracellular matrix metalloproteinase inducer (EMMPRIN) prevented S100A9-induced phosphorylation of ERK and c-RAF. Our data suggest that S100A9 signaling contributes to the progression of smoke-induced and age-related COPD.

Pyrethroid-Induced Organ Toxicity and Anti-Oxidant-Supplemented Amelioration of Toxicity and Organ Damage: The Protective Roles of Ascorbic Acid and α-Tocopherol.

The pyrethroid toxicants, fatal at high doses, are found as remnants of crop pesticides and ingredients of commercially available insecticides. The toxic effects of high-content insecticidal pyrethroid formulations are available in 0.05 g, 1.17 g, and 0.04 g pyrethroid-instilled products, namely burning coils, pyrethroid-soaked mats, and liquid formulations of pyrethroids that release pyrethroid vapor/smoke upon heating. They provided 5.46 g/kg, 21.15 g/kg, and 4.24 g/kg of toxicants to the experimental animals over a total of 3 weeks/5 h per os (p.o.) administration, producing necrosis, hyperemia, and fatty changes in the liver; fiber separation in cardiac muscles; atrophy, lymphatic infiltration, blood vessel congestion, and hyperemia in the heart tissues of the experimental animals. The glomerular tuft necrosis, cytoplasmic degeneration of renal tubular cells, necrotic tubules, congestion, and dilatation of blood vessels were observed in the kidney tissue of intoxicated animals. Air-space enlargement, interstitial inflammation, lymphocyte infiltration aggregates, connective tissue infiltration by inflammatory cells, and hyperemia were found in the lung tissues. The pyrethroid toxicants also produced nervous tissue degeneration and decreased neurons in the brain, which were observed through histopathological examinations of the brain, lungs, heart, kidneys, and liver. The protective effects of ascorbic acid (AA/vitamin C) and α-tocopherol (E307/vitamin E) at 100 mg/kg oral doses administered daily for the entire period of the toxicant exposure of three weeks to the experimental mice, aged between 3–4 months and weighing ≈30 g, ameliorated the tissue damage, as observed through the histopathological examinations. The ascorbic acid caused recovery of the liver, kidney, brain, and heart tissue damage, while α-tocopherol was effective at ameliorating the damage in the kidneys and lung tissue compared with the control groups. The high levels of tissue damage recovery suggested a prophylactic effect of the concurrent use of ascorbic acid and α-tocopherol for the subjects under the exposure of pyrethroids.

Differential lung inflammation and injury with tobacco smoke exposure in Wistar Kyoto and spontaneously hypertensive rats

Objective Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and has been associated with periods of intense lung inflammation. The objective of this study was to characterize whether similar rat strains, possessing different genetic predispositions, might play a role in exacerbating the pathophysiology of COPD-like cellular and structural changes with progressive 12-week exposure to tobacco smoke (TS). Normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SH) rats were compared. Materials and methods WKY and SH rats were exposed to filtered air or to tobacco smoke at a particulate concentration of 80 mg/m3 for 4, 8, or 12 weeks. Necropsy was performed 24 h after the last exposure to obtain cells by bronchoalveolar lavage for total cell and differential counts. Scoring of lung tissues and immunohistochemical staining for M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages were performed on paraffin-embedded lung sections. Results and discussion With progressive exposure, TS-exposed SH rats demonstrated significant airspace enlargement, mucin production, and lung inflammation compared to their FA control and TS-matched WKY rats. Moreover, SH rats also demonstrated increased expression of the M1 marker in alveolar macrophages compared to FA control, as well as the M2 marker compared to controls and TS-exposed WKY rats. Conclusion The progressive tobacco smoke exposure contributes to persistent lung injury and inflammation that can be significantly enhanced by rat strain susceptibility in the genesis of COPD.

Lung and Eye Disease Develop Concurrently in Supplemental Oxygen–Exposed Neonatal Mice

Bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP) are two debilitating disorders that develop in preterm infants exposed to supplemental oxygen to prevent respiratory failure. Both can lead to lifelong disabilities, such as chronic obstructive pulmonary disease and vision loss. Due to the lack of a standard experimental model of coincident disease, the underlying associations between BPD and ROP are not well characterized. To address this gap, we used the robust mouse model of oxygen-induced retinopathy exposing C57BL/6 mice to 75% oxygen from postnatal day 7 to 12. The cardinal features of ROP were replicated by this strategy, and the lungs of the same mice were simultaneously examined for evidence of BPD-like lung injury, investigating both the short- and long-term effects of early-life supplemental oxygen exposure. At postnatal days 12 and 18, mild lung disease was evident by histopathologic analysis together with the expected vasculopathy in the inner retina. At later time points, the lung lesion had progressed to severe airspace enlargement and alveolar simplification, with concurrent thinning in the outer layer of the retina. In addition, critical angiogenic oxidative stress and inflammatory factors reported to be dysregulated in ROP were similarly impaired in the lungs. These data shed new light on the interconnectedness of these two neonatal disorders, holding potential for the discovery of novel targets to treat BPD and ROP.

Morphological, physiological, anatomical and histochemical responses of micropropagated plants of Trichosanthes kirilowii to hydroponic and soil conditions during acclimatization

Acclimatization of tissue cultured plants to greenhouse or field conditions is the final and most crucial step of micropropagation. Hydroponic system has the potential to harden in vitro plants in an efficient and convenient way. Herein, in vitro regenerated plants of Trichosanthes kirilowii were cultured in 1/4, 1/2 and full strength Hoagland nutrient solution under a simple hydroponic system during acclimatization, respectively, and soil culture was prepared as a control. Morphological, physiological, anatomical and histochemical alterations of the plants treated by different concentrations of nutrient solution and soil conditions were analyzed after 30 days of growth. Results showed that all the three concentrations of nutrient solution significantly improved the survival rate, plant growth, pigment content, photosynthesis capacity, and stomatal density compared with those grown in soil, and there were no significant differences of the plant morphological parameters and the stomatal characteristics among the three hydroponic treatments. The plants grown in the 1/4 Hoagland solution yielded the highest net photosynthesis rate, transpiration rate and stomatal conductance, as might be attributed to their highest photosynthetic pigment content among the treatments. Anatomical and histochemical studies revealed that enlarged air spaces, multiple lignified Φ thickenings, and heavier suberin and lignin were formed in the cortex of the adventitious roots grown in 1/4 Hoagland nutrient solution as compared with those cultured in soil conditions, indicating that T. kirilowii had enough phenotypic plasticity in the root structure to grow in hydroponic conditions by formation of larger aerenchyma spaces and apoplastic barriers. This study clearly demonstrates that hydroponics is an alternative for the tissue cultured plants of T. kirilowii to adapt to great environmental changes during acclimatization. Micropropagated plants of T. kirilowii can adapt to hydroponic conditions through changes in plant morphological, physiological and stomatal characteristics, and anatomical and histochemical features of roots during acclimatization.

Cigarette smoke-initiated autoimmunity facilitates sensitisation to elastin-induced COPD-like pathologies in mice.

It is currently not understood whether cigarette smoke exposure facilitates sensitisation to self-antigens and whether ensuing auto-reactive T cells drive chronic obstructive pulmonary disease (COPD)-associated pathologies.To address this question, mice were exposed to cigarette smoke for 2 weeks. Following a 2-week period of rest, mice were challenged intratracheally with elastin for 3 days or 1 month. Rag1-/- , Mmp12-/- , and Il17a-/- mice and neutralising antibodies against active elastin fragments were used for mechanistic investigations. Human GVAPGVGVAPGV/HLA-A*02:01 tetramer was synthesised to assess the presence of elastin-specific T cells in patients with COPD.We observed that 2 weeks of cigarette smoke exposure induced an elastin-specific T cell response that led to neutrophilic airway inflammation and mucus hyperproduction following elastin recall challenge. Repeated elastin challenge for 1 month resulted in airway remodelling, lung function decline and airspace enlargement. Elastin-specific T cell recall responses were dose dependent and memory lasted for over 6 months. Adoptive T cell transfer and studies in T cells deficient Rag1-/- mice conclusively implicated T cells in these processes. Mechanistically, cigarette smoke exposure-induced elastin-specific T cell responses were matrix metalloproteinase (MMP)12-dependent, while the ensuing immune inflammatory processes were interleukin 17A-driven. Anti-elastin antibodies and T cells specific for elastin peptides were increased in patients with COPD.These data demonstrate that MMP12-generated elastin fragments serve as a self-antigen and drive the cigarette smoke-induced autoimmune processes in mice that result in a bronchitis-like phenotype and airspace enlargement. The study provides proof of concept of cigarette smoke-induced autoimmune processes and may serve as a novel mouse model of COPD.

LJ-529, a partial peroxisome proliferator-activated receptor gamma (PPARγ) agonist and adenosine A3 receptor agonist, ameliorates elastase-induced pulmonary emphysema in mice.

Chronic obstructive pulmonary disease (COPD) is the leading cause of human death worldwide. Currently available therapies for COPD mainly relieve symptoms and preserve lung function, suggesting the need to develop novel therapeutic or preventive regimens. Because chronic inflammation is a mechanism of emphysematous lesion formation and because adenosine A3 receptor signaling and peroxisome proliferator-activated receptor gamma (PPARγ) regulate inflammation, we investigated the effect of LJ-529, a selective adenosine A3 receptor agonist and partial PPARγ agonist, on inflammation in vitro and elastase-induced pulmonary emphysema in vivo. LJ-529 markedly ameliorated elastase-induced emphysematous lesion formation in the lungs in vivo, as indicated by the restoration of pulmonary function, suppression of airspace enlargement, and downregulation of elastase-induced matrix metalloproteinase activity and apoptotic cell death in the lungs. LJ-529 induced the expression of PPARγ target genes, the activity of PPARγ and several cytokines involved in inhibiting inflammation and inducing anti-inflammatory M2-like phenotypes. Moreover, LJ-529 did not exhibit significant cytotoxicity in normal cell lines derived from various organs in vitro and induced minimal changes in body weight in vivo, suggesting no overt toxicity of LJ-529 in vitro or in vivo. These results indicate the potential of LJ-529 as a novel therapeutic/preventive agent for emphysema with limited toxicity.

Comparison of anti-inflammatory efficacy between dexamethasone and a standardized herbal formula, PM014, in a cigarette smoke-induced subacute mouse model of chronic obstructive pulmonary disease

Objective: A standardized herbal formula, PM014, originated from Chungsangboha -tang, which has been used to treat various respiratory diseases, including bronchitis, asthma, and emphysema. Several previous studies have reported that the therapeutic mechanism of PM014 was mediated by an anti-inflammatory effect. Therefore, we compared anti-inflammatory efficacy between PM014 and dexamethasone (DEX) using a mouse model of cigarette smoke (CS)-induced subacute pulmonary inflammation. Materials and Methods: Female C57BL/6 mice were revealed to CS for 2 h/day, three cigarettes per day, 5 days a week for 3 weeks; the control group got no other treatment, while the DEX and PM014 groups received 1 mg/kg of DEX and 100 mg/kg of PM014, respectively (both were orally administered). The histological morphology and average alveolar size were determined by lung histology. The inflammatory cell profiles and protein expressions of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 β, IL-6, and one pro-inflammatory chemokine (monocyte chemoattractant protein 1 [MCP-1]), were measured in bronchoalveolar lavage fluid (BALF). The mRNA expressions of the pro-inflammatory cytokines and chemokine were also measured in lung tissues. Results: Both PM014 and DEX attenuated histological injury and air space enlargement in lung tissue and decreased the number of inflammatory cells in BALF. Both also decreased the mRNA expressions of TNF-α, IL-6, and IL-1 β in lung tissue and reduced the protein expressions of TNF-α, IL-1 β, IL-6, and MCP-1 in BALF. Conclusion: Our results showed that the anti-inflammatory efficacy of PM014 and DEX was equivalent in a subacute mouse model of CS-induced chronic obstructive pulmonary disease.

IL10 deficiency promotes alveolar enlargement and lymphoid dysmorphogenesis in the aged murine lung.

The connection between aging‐related immune dysfunction and the lung manifestations of aging is poorly understood. A detailed characterization of the aging IL10‐deficient murine lung, a model of accelerated aging and frailty, reconciles features of both immunosenescence and lung aging in a coherent model. Airspace enlargement developed in the middle‐aged (12 months old) and aged (20–22 months old) IL10‐deficient lung punctuated by an expansion of macrophages and alveolar cell apoptosis. Compared to wild‐type (WT) controls, the IL10‐deficient lungs from young (4‐month‐old) mice showed increased oxidative stress which was enhanced in both genotypes by aging. Active caspase 3 staining was increased in the alveolar epithelial cells of aged WT and mutant lungs but was greater in the IL10‐deficient milieu. Lung macrophages were increased in the aged IL10‐deficient lungs with exuberant expression of MMP12. IL10 treatment of naïve and M2‐polarized bone marrow‐derived WT macrophages reduced MMP12 expression. Conditioned media studies demonstrated the secretome of aged mutant macrophages harbors reduced AECII prosurvival factors, specifically keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF), promotes cell death, and reduces survival of primary alveolar epithelial cells. Compared to WT controls, aged IL10‐deficient mice have increased parenchymal lymphoid collections comprised of a reduced number of apoptotic cells and B cells. We establish that IL10 is a key modulator of airspace homeostasis and lymphoid morphogenesis in the aging lung enabling macrophage‐mediated alveolar epithelial cell survival and B‐cell survival within tertiary lymphoid structures.

Gallic acid protects against the COPD-linked lung inflammation and emphysema in mice.

Gallic acid (GA) a naturally occurring phenolic compound, known to possess antioxidant/anti-inflammatory activities. The aim of the present work was to investigate the beneficial effects of GA against COPD-linkedlung inflammation/emphysema by utilizing elastase (ET) and cigarette smoke (CS)-induced mice model. Male BALB/c mice were treated with ET (1U/mouse) or exposed to CS (9 cigarettes/day for 4days). GA administration was started 7days (daily) prior to ET/CS exposure. Broncho-alveolar lavage was analyzed for inflammatory cells and pro-inflammatory cytokines. Lung homogenate was assessed for MPO activity/GSH/MDA/protein carbonyls. Further, Lung tissue was subjected to semi-quantitative RT-PCR, immunoblotting, and histological analysis. GA suppressed the ET-induced neutrophil infiltration, elevated MPO activity and production of pro-inflammatory cytokines (IL-6/TNF-α/IL-1β) at 24h. Reduced inflammation was accompanied with normalization of redox balance as reflected by ROS/GSH/MDA/protein carbonyl levels. Further, GA suppressed phosphorylation of p65NF-κB and IκBα along with down-regulation of IL-1β/TNF-α/KC/MIP-2/GCSF genes. Furthermore, GA offered protection against ET-induced airspace enlargement and ameliorated MMP-2/MMP-9. Finally, GA suppressed the CS-induced influx of neutrophils and macrophages and blunted gene expression of TNF-α/MIP-2/KC. Overall, our data show that GA effectively modulates pulmonary inflammation and emphysema associated with COPD pathogenesis in mice.

LJ-2698, an Adenosine A3 Receptor Antagonist, Alleviates Elastase-Induced Pulmonary Emphysema in Mice.

Emphysema, a major component of chronic obstructive pulmonary disease (COPD), is a leading cause of human death worldwide. The progressive deterioration of lung function that occurs in the disease is caused by chronic inflammation of the airway and destruction of the lung parenchyma. Despite the main impact of inflammation on the pathogenesis of emphysema, current therapeutic regimens mainly offer symptomatic relief and preservation of lung function with little therapeutic impact. In the present study, we aimed to discover novel therapeutics that suppress the pathogenesis of emphysema. Here, we show that LJ-2698, a novel and highly selective antagonist of the adenosine A3 receptor, a G protein-coupled receptor involved in various inflammatory diseases, significantly reversed the elastase-induced destructive changes in murine lungs. We found that LJ-2698 significantly prevented elastase-induced airspace enlargement, resulting in restoration of pulmonary function without causing any obvious changes in body weight in mice. LJ-2698 was found to inhibit matrix metalloproteinase activity and pulmonary cell apoptosis in the murine lung. LJ-2698 treatment induced increases in anti-inflammatory cytokines in macrophages at doses that displayed no significant cytotoxicity in normal cell lines derived from various organs. Treatment with LJ-2698 significantly increased the number of anti-inflammatory M2 macrophages in the lungs. These results implicate the adenosine A3 receptor in the pathogenesis of emphysema. Our findings also demonstrate the potential of LJ-2698 as a novel therapeutic/preventive agent in suppressing disease development with limited toxicity.

Late Rescue Therapy with Cord-Derived Mesenchymal Stromal Cells for Established Lung Injury in Experimental Bronchopulmonary Dysplasia.

Bronchopulmonary dysplasia (BPD), the main complication of extreme prematurity, has lifelong consequences for lung health. Mesenchymal stromal cells (MSCs) prevent lung injury in experimental BPD in newborn rodents when given in the immediate neonatal period. Whether MSC therapy can restore normal lung growth after established lung injury in adulthood is clinically relevant, but currently unknown. Experimental BPD was achieved by exposing newborn rats to 95% O2 from postnatal days 4-14. Human umbilical cord-derived MSCs were intratracheally administered to rats (1 × 106cells/kg body weight) as a single dose at 3 or 6 months of age followed by assessment at 5 or 8 months of age, respectively. Lung alveolar structure and vessel density were histologically analyzed. O2-exposed rats exhibited persistent lung injury characterized by arrested alveolar growth with airspace enlargement and a lower vessel density at both 5 and 8 months of age compared with controls. Single-dose MSC treatment at 3 months partially attenuated O2-induced alveolar injury and restored vessel density at 5 months. Treatment with a single dose at 6 months did not attenuate alveolar injury or vessel density at 8 months. However, treatment with multiple MSC doses at 6, 6.5, 7, and 7.5 months significantly attenuated alveolar injury and improved vessel density at 8 months of age. Treatment of the adult BPD lung with MSCs has the potential to improve lung injury if administered in multiple doses or at an early stage of adulthood.

Utricularia.

Whitewoods introduces the plant genus Utricularia.

Severe but not moderate hyperoxia of newborn mice causes an emphysematous lung phenotype in adulthood without persisting oxidative stress and inflammation

BackgroundPreterm newborns typically require supplemental oxygen but hyperoxic conditions also damage the premature lung. Oxygen-induced lung damages are mainly studied in newborn mouse models using oxygen concentrations above 75% and looking at short-term effects. Therefore, we aimed at the investigation of long-term effects and their dependency on different oxygen concentrations.MethodsNewborn mice were exposed to moderate vs. severe hyperoxic air conditions (50 vs. 75% O2) for 14 days followed by a longer period of normoxic conditions. Lung-related parameters were collected at an age of 60 or 120 days.ResultsSevere hyperoxia caused lower alveolar density, enlargement of parenchymal air spaces and fragmented elastic fibers as well as higher lung compliance with peak airflow limitations and higher sensitivity to ventilation-mediated damages in later life. However, these long-term lung structural and functional changes did not restrict the voluntary physical activity. Also, they were not accompanied by ongoing inflammatory processes, increased formation of reactive oxygen species (ROS) or altered expressions of antioxidant enzymes (superoxide dismutases, catalase) and lung elasticity-relevant proteins (elastin, pro-surfactant proteins) in adulthood. In contrast to severe hyperoxia, moderate hyperoxia was less lung damaging but also not free of long-term effects (higher lung compliance without peak airflow limitations, increased ROS formation).ConclusionsSevere but not moderate neonatal hyperoxia causes emphysematous lungs without persisting oxidative stress and inflammation in adulthood. As the existing fragmentation of the elastic fibers seems to play a pivotal role, it indicates the usefulness of elastin-protecting compounds in the reduction of long-term oxygen-related lung damages.