Chronic Inflammatory Lung Diseases Research Articles

Knockdown of Gene Expression in Macrophages by microRNA Mimic-Containing Poly (Lactic-co-glycolic Acid) Microparticles.

Background: microRNA (miRNA) regulate target gene expression through translational repression and/or mRNA degradation and are involved in the regulation of inflammation. Macrophages are key inflammatory cells that are important in chronic inflammatory lung diseases such as cystic fibrosis (CF). Macrophage-expressed miRNA represent therapeutic drug targets, yet delivery of nucleic acids to macrophages has proved challenging. Methods: miRNAs were encapsulated in poly (lactic-co-glycolic acid) (PLGA)-based microparticles using double emulsion solvent evaporation and characterised for physicochemical features. Phorbol myristic acetate (PMA)-differentiated U937 macrophages were transfected with empty PLGA microparticles or those encapsulating a premiR-19b-3p or scrambled control miRNA mimic. miRNA internalisation and knockdown of a miR-19b-3p target gene, secretory leucoprotease inhibitor (SLPI), were determined by qRT-PCR. Results: Microparticle formulations were consistently found to be 2–3μm and all had a negative ζ potential (−5 mV to −14 mV). Encapsulation efficiency of premiR-19b-3p was 37.6 ± 13.4%. Levels of mature miR-19b-3p were higher in macrophages after delivery of premiR-19b-3p microparticles compared to empty or scrambled control miRNA-containing microparticles. Significant SLPI knockdown was achieved 72 hours post-delivery of premiR-19b-3p microparticles compared to controls. Conclusions: miRNA-encapsulating PLGA microparticles offer a new treatment paradigm for delivery to macrophages that could potentially be administered to CF lungs via inhalation.

232 - SOCS1 S-Nitrosation in the nucleus is a switch of macrophage polarization and function

Macrophages play a critical role in inflammation initiation, progression and resolution due to their capacity to assume both pro- and anti-inflammatory phenotypes. The molecular mechanisms that regulate these transitions are of great clinical interest but remain poorly understood. We discovered that suppressor of cytokine signaling-1, an enzyme that targets and degrades RelA, is susceptible to S-nitrosation on cisteines 147 and 179 specifically in the nucleus. Nitrosation in the nucleus is effected by nitric oxide synthase-1 (NOS1) in macrophages. Nitrosation of SOCS1 prevents its interaction with RelA, and the formation of the pro-inflammatory p65-p50 NFkB heterodimer. In NOS1 knockout macrophages, SOCS1 is not nitrosated upon activation of the inflammatory response leading to rapid degradation of RelA/p65 with the accumulation of p50. Accumulation of p50 promotes homodimerization (p50-p50) leading to anti-inflammatory gene transcription. Interestingly, transplantation of NOS1 knockout bone marrow-derived macrophages (BMDM) into the inflammation prone lungs of SOCS1fl/fl.LysMCre mice is protective against LPS-induced tissue injury. In addition, levels of pro-inflammatory cytokine production in these lungs are markedly reduced after LPS challenge suggesting NOS1KO BMDM have the capacity to suppress pro-inflammatory immune polarization and associated tissue injury in a model of chronic inflammatory lung disease. Overall our results indicate that SOCS1 acts as a switch between pro- and anti-inflammatory macrophage polarization regulated by NOS1-mediated nitrosation.

Increased serum Th2 chemokine levels are associated with bronchopulmonary dysplasia in premature infants.

Bronchopulmonary dysplasia (BPD) is one of the most common chronic inflammatory lung disease of premature infants, with serious short- and long-term consequences. Early identification of premature infants at risk of BPD is critical to preventing the pathogenesis of disease. Thus, in the present study, we recruited 126 premature infants, collected peripheral blood samples at different time points during early life, and measured the concentration of Th1 (MCP-1, IP-10, and MIG) and Th2 (eotaxin-1, eotaxin-2, and MCP-4) chemokines in serum. We found serum eotaxin-2 levels were significantly higher in the BPD group than in the non-BPD group on day 1 [1662pg/ml vs. 1221pg/ml, P< 0.05], day 7 [1533pg/ml vs. 1089pg/ml, P< 0.05], and day 14 [1246pg/ml vs. 704pg/ml, P< 0.05] after birth, and serum MCP-4 levels were also significantly higher in the BPD group than in the non-BPD group on day 1 [186pg/ml vs. 128pg/ml, P< 0.05], day 7 [199pg/ml vs. 101pg/ml, P< 0.05], and day 14 [238pg/ml vs. 106pg/ml, P< 0.05] of life.Conclusions: Increased levels of Th2 chemokines, eotaxin-2, and MCP-4, are associated with BPD in premature infants. What is Known: • The pathogenesis of BPD is multifactorial and it is difficult to predict and prevent. • Previous studies have demonstrated that inflammation plays a major role in the pathogenesis of BPD. What is New: • Increased Th2 chemokines, eotaxin-2 and MCP-4, were associated with BPD in premature infants. • Abnormal Th1/Th2 response in early life maybe associated with the subsequent development of BPD, which provide a new insight to understand the pathogenesis of the disease.

Multi-omics analysis: Repeated exposure of a 3D bronchial tissue culture to whole-cigarette smoke

Cigarette smoke (CS) is a major risk factor in the development of chronic inflammatory lung diseases such as chronic obstructive pulmonary disease. A comprehensive investigation of the biological impacts of chronic CS exposure on lung tissue is therefore important for understanding the pathogenesis of lung disease. We used three-dimensional (3D) organotypic human bronchial tissue cultures and metabolomics, transcriptomics, and proteomics to investigate changes in biological processes affected by repeated whole-CS exposure. We found that CS perturbed central carbon metabolism in relation with oxidative stress responses. Epidermal growth factor receptor, which is involved in the early-stage pathogenesis of airway diseases, was identified as a key regulator of the perturbed processes. Proteomic analysis of proteins in the apical surface liquid of the 3D bronchial tissue cultures indicated that repeated whole-CS exposure induced alterations in the secretion of several known biomarkers of airway diseases, including mucins and matrix metalloproteinases. These findings are consistent with observations from lung disease patients. Overall, our results suggest that 3D bronchial tissue cultures can provide valuable information on tissue-specific alterations in biological processes induced by chronic exposure to CS.

TARGETING THE TRANS-IL-6 SIGNALING PATHWAY TO REDUCE AGRICULTURE ORGANIC DUST EXPOSURE-INDUCED AIRWAY INFLAMMATION IN MICE

SESSION TITLE: Occupational and Environmental Lung Diseases SESSION TYPE: Original Investigation Posters PRESENTED ON: 10/10/2018 01:00 PM - 02:00 PM PURPOSE: Agricultural workers experience high rates of chronic inflammatory lung disease from inhalation of organic dusts. Interleukin (IL)-6 is an important cytokine linked to chronic lung disease and organic dust extract (ODE) exposure. IL-6 can activate either an anti-inflammatory (classic) or pro-inflammatory (trans) IL-6 signaling pathway. Blocking the trans-IL-6 pathway with a soluble gp130Fc protein may decrease inflammation and offer a future targeted therapy for agricultural workers. METHODS: C57BL/6 mice were pretreated with intraperitoneal injection of recombinant gp130Fc (2μg) or a vehicle control followed by intranasal inhalation of swine confinement facility ODE or a saline control daily for 9 days. Bronchoalveolar lavage fluid (BALF), lung tissue homogenates, and serum were collected for inflammatory, cellular, and cytokine analysis. Lungs were processed for histopathology and independently scored for inflammatory changes. Serum soluble-IL-6 receptor levels and serum IL-6 levels were used to determine whether gp130Fc treated animals obtained adequate therapy. Data collected from a minimum of 3 independent experiments with total of 8-12 mice per treatment group. RESULTS: ODE-induced neutrophil influx was not reduced by gp130Fc pre-treatments (p=0.61), but inflammatory mediators were decreased. Pretreatment with gp130Fc significantly reduced ODE-induced BALF levels of CXCL1 by 83% (p=0.021), CXCL2 by 102% (p=0.003), IL-6 by 86% (p=0.004), and TNF-α by 125% (p=0.009). In lung tissue, there was a significant increase in IL-12 by 72% (p=0.020), a non-significant decrease in IL-17 by 35% (p=0.400), and a non-significant increase in IL-13 by 38% (p=0.124). There were also non-significant reductions in ODE-induced lung histopathological inflammatory scoring marked by less alveolar inflammation (p=0.083), bronchial inflammation (p=0.083), and lymphoid aggregate development (p=0.100) in animals pretreated with gp130Fc. There were no differences in any outcome between vehicle injection+saline inhalation and gp130Fc injection+saline inhalation treatment groups. CONCLUSIONS: Targeting the trans-IL-6 signaling pathway by intraperitoneal administration of recombinant gp130Fc in mice prior to organic dust extract exposures attenuates the airway inflammatory response. The inhibitory effect of gp130Fc was predominately evident by reductions in ODE-induced inflammatory cytokines/chemokines and to a lesser degree in ODE-associated lung histopathology. CLINICAL IMPLICATIONS: In 2015 an estimated 2.05 million documented US citizens worked in agriculture. Of those who work with swine, up to 93% report development of respiratory symptoms. Chronic inflammatory lung disease has been well established in this sub-population. Identifying a targeted therapy, such as recombinant gp130Fc, that can prevent lung inflammation in these individuals could potentially offer an important clinical benefit. DISCLOSURES: No relevant relationships by Joseph Carrington, source=Web Response No relevant relationships by Amy Nelson, source=Web Response No relevant relationships by Jill Poole, source=Web Response No relevant relationships by Debra Romberger, source=Web Response No relevant relationships by Benjamin Swanson, source=Web Response

The Association Between Health Insurance Coverage and In-Hospital Mortality in Patients Hospitalized with a Myocardial Infarction in the State of Florida

Lung cancer is a multifactorial malignancy for which some risk factors, such as chronic lung diseases, their interactions with smoking, and how they differ by race and sex, are not fully understood. We investigated the associations between chronic inflammatory lung disease and non–small cell lung carcinoma (NSCLC) and how sex and race may affect such associations.Using logistic regression, we analyzed 1660 lung cancer cases and 1959 population controls and estimated adjusted odds ratios (AORs) and 95% confidence intervals (CIs).Chronic lung disease was significantly associated with higher odds of having NSCLC in never (AOR = 1.99; 95% CI = 1.19–3.34), former (AOR = 1.68; 95% CI = 1.29–2.20), and current smokers (AOR = 2.40; 95% CI = 1.62–3.57), after adjustment for relevant covariates. For each 5-year increment in chronic lung disease duration, the risk of lung cancer increased only among females (AOR = 1.07; 95% CI = 1.02–1.13). Females, but not males, with asthma were at risk for NSCLC (AOR = 2.08; 95% CI = 1.40–3.10).This study provides support for chronic lung inflammation as a potential contributing factor to lung cancer risk and possible sex difference in the inflammatory events underlying disease mechanisms.

Systematic analysis of transcriptomic profiles of COPD airway epithelium using next-generation sequencing and bioinformatics.

IntroductionCOPD is a chronic inflammatory disease of lung. The inflammatory response in COPD is associated with neutrophils, macrophages, T lymphocytes, and bronchial epithelial cells, and occurs mainly in the small airway, leading to irreversible airflow limitation.MethodsIn order to investigate the microRNA–mRNA interaction in the microenvironment of the COPD airway, we used next-generation sequencing and bioinformatics in this study.ResultsWe identified four genes with microRNA–mRNA interactions involved in COPD small-airway bronchial epithelial cells: NT5E, SDK1, TNS1, and PCDH7. Furthermore, miR6511a-5p–NT5E interaction was found to be involved in small-airway bronchial epithelial cells, large-airway bronchial epithelial cells, and alveolar macrophages.ConclusionOur results showed that miR6511a-5p–NT5E interaction plays an important role in COPD, which might be associated with cell–cell contact, activation of leukocytes, activation of T lymphocytes, and cellular homeostasis. These findings provide new information for further investigations of the COPD microenvironment, and may help to develop new diagnostic or therapeutic strategies targeting the bronchial epithelium for COPD.

Lung mesenchymal stem cells-derived extracellular vesicles attenuate the inflammatory profile of Cystic Fibrosis epithelial cells

BackgroundMesenchymal stromal/stem cells (MSCs) are multi-potent non-hematopoietic stem cells, residing in most tissues including the lung. MSCs have been used in therapy of chronic inflammatory lung diseases such as Cystic Fibrosis (CF), asthma, and chronic obstructive pulmonary disease (COPD) but the main beneficial effects reside in the anti-inflammatory potential of the released extracellular vesicles (EVs). Recent reports demonstrate that EVs are effective in animal model of asthma, E.coli pneumonia, lung ischemia-reperfusion, and virus airway infection among others. Despite this growing literature, the EVs effects on CF are largely unexplored. MethodsWe treated IB3-1 cells, an in vitro human model of CF, with EVs derived from human lung MSCs under basal and inflammatory conditions (TNFα stimulation). ResultsWe demonstrated here that treatment of IB3-1 CF cell line with EVs, down-regulates transcription and protein expression of pro-inflammatory cytokines such as IL-1β, IL-8, IL-6 under TNFα - stimulated conditions. EVs treatment upregulates the mRNA expression of PPARγ, a transcription factor controlling anti-inflammatory and antioxidant mechanisms via NF-kB and HO-1. Accordingly, NF-kB nuclear translocation is reduced resulting in impairment of the downstream inflammation cascade. In addition, the mRNA of HO-1 is enhanced together with the antioxidant defensive response of the cells. ConclusionsWe conclude that the anti-inflammatory and anti-oxidant efficacy of EVs derived from lung MSCs could be mediated by up-regulation of the PPARγ axis, whose down-stream effectors (NF-kB and HO-1) are well-known modulators of these pathways. General significanceEVs could be a novel strategy to control the hyper-inflamed condition in Cystic Fibrosis.

Contribution of Host Defence Proteins and Peptides to Host-Microbiota Interactions in Chronic Inflammatory Lung Diseases.

The respiratory tract harbours a variety of microorganisms, collectively called the respiratory microbiota. Over the past few years, alterations in respiratory and gut microbiota composition have been associated with chronic inflammatory diseases of the lungs. How these changes influence disease development and progression is an active field of investigation. Identifying and understanding host-microbiota interactions and factors contributing to these interactions could promote the development of novel therapeutic strategies aimed at restoring host-microbiota homeostasis. In this review, we discuss recent literature on host-microbiota interactions in the respiratory tract, with a specific focus on the influence of endogenous host defence peptides and proteins (HDPs) on the composition of microbiota populations in vivo and explore possible HDPs-related therapeutic approaches targeting microbiota dysbiosis in chronic inflammatory lung diseases.

Stem cell-based Lung-on-Chips: The best of both worlds?

Pathologies of the respiratory system such as lung infections, chronic inflammatory lung diseases, and lung cancer are among the leading causes of morbidity and mortality, killing one in six people worldwide. Development of more effective treatments is hindered by the lack of preclinical models of the human lung that can capture the disease complexity, highly heterogeneous disease phenotypes, and pharmacokinetics and pharmacodynamics observed in patients. The merger of two novel technologies, Organs-on-Chips and human stem cell engineering, has the potential to deliver such urgently needed models. Organs-on-Chips, which are microengineered bioinspired tissue systems, recapitulate the mechanochemical environment and physiological functions of human organs while concurrent advances in generating and differentiating human stem cells promise a renewable supply of patient-specific cells for personalized and precision medicine. Here, we discuss the challenges of modeling human lung pathophysiology in vitro, evaluate past and current models including Organs-on-Chips, review the current status of lung tissue modeling using human pluripotent stem cells, explore in depth how stem-cell based Lung-on-Chips may advance disease modeling and drug testing, and summarize practical consideration for the design of Lung-on-Chips for academic and industry applications.

Assessment of dynamic thiol/disulfide homeostasis in patients with asthma

AbstractBackground:Asthma is a chronic inflammatory lung disease and oxidative stress is an important component in airway inflammation. This study aims to investigate dynamic thiol/disulfide homeostasis in patients with asthma.Methods:A total of 103 subjects, including 56 patients with asthma and 47 healthy controls, of similar age and gender were included in the study. The native thiol, total thiol and disulfide levels and the disulfide-native thiol, disulfide-total thiol and native thiol-total thiol ratios were analyzed and compared between the asthma and control groups using a novel automatized spectrophotometric assay.Results:The levels of native thiol (p&lt;0.001), total thiol (p&lt;0.001) and disulfide (p&lt;0.001) were significantly lower and the C-reactive protein (CRP) levels (p&lt;0.001) were significantly higher in patients with asthma when compared with those in the control group. A negative correlation was detected between CRP levels and native thiol, total thiol and disulfide levels (p&lt;0.05). A significant positive correlation was detected between forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) levels and native thiol and total thiol levels (p&lt;0.01).Conclusions:The thiol/disulfide homeostasis parameters may be used as novel oxidative stress markers in asthma but further studies are needed to investigate the role of thiol/disulfide homeostasis in asthma.

Repurposing of statins via inhalation to treat lung inflammatory conditions.

Despite many therapeutic advancements over the past decade, the continued rise in chronic inflammatory lung diseases incidence has driven the need to identify and develop new therapeutic strategies, with superior efficacy to treat these diseases. Statins are one class of drug that could potentially be repurposed as an alternative treatment for chronic lung diseases. They are currently used to treat hypercholesterolemia by inhibiting the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, that catalyses the rate limiting step in the mevalonate biosynthesis pathway, a key intermediate in cholesterol metabolism. Recent research has identified statins to have other protective pleiotropic properties including anti-inflammatory, anti-oxidant, muco-inhibitory effects that may be beneficial for the treatment of chronic inflammatory lung diseases. However, clinical studies have yielded conflicting results. This review will summarise some of the current evidences for statins pleiotropic effects that could be applied for the treatment of chronic inflammatory lung diseases, their mechanisms of actions, and the potential to repurpose statins as an inhaled therapy, including a detailed discussion on their different physical-chemical properties and how these characteristics could ultimately affect treatment efficacies. The repurposing of statins from conventional anti-cholesterol oral therapy to inhaled anti-inflammatory formulation is promising, as it provides direct delivery to the airways, reduced risk of side effects, increased bioavailability and tailored physical-chemical properties for enhanced efficacy.

The Rationale and Evidence for Use of Inhaled Antibiotics to Control Pseudomonas aeruginosa Infection in Non-cystic Fibrosis Bronchiectasis.

Non-cystic fibrosis bronchiectasis (NCFBE) is a chronic inflammatory lung disease characterized by irreversible dilation of the bronchi, symptoms of persistent cough and expectoration, and recurrent infective exacerbations. The prevalence of NCFBE is on the increase in the United States and Europe, but no licensed therapies are currently available for its treatment. Although there are many similarities between NCFBE and cystic fibrosis (CF) in terms of respiratory symptoms, airway microbiology, and disease progression, there are key differences, for example, in response to treatment, suggesting differences in pathogenesis. This review discusses possible reasons underlying differences in response to inhaled antibiotics in people with CF and NCFBE. Pseudomonas aeruginosa infections are associated with the most severe forms of bronchiectasis. Suboptimal levels of antibiotics in the lung increase the mutation frequency of P. aeruginosa and lead to the development of mucoid strains characterized by formation of a protective polysaccharide biofilm. Mucoid strains of P. aeruginosa are associated with a chronic infection stage, requiring long-term antibiotic therapy. Inhaled antibiotics provide targeted delivery to the lung with minimal systemic toxicity and adverse events compared with oral/intravenous routes of administration, and they could be alternative treatment options to help address some of the treatment challenges in the management of severe cases of NCFBE. This review provides an overview of completed and ongoing trials that evaluated inhaled antibiotic therapy for NCFBE. Recently, several investigators conducted phase 3 randomized controlled trials with inhaled aztreonam and ciprofloxacin in patients with NCFBE. While the aztreonam trial results were not associated with significant clinical benefit in NCFBE, initial results reported from the inhaled ciprofloxacin (dry powder for inhalation and liposome-encapsulated/dual-release formulations) trials hold promise. A more targeted approach could identify specific populations of NCFBE patients who benefit from inhaled antibiotics.

Associations between history of chronic lung disease and non–small cell lung carcinoma in Maryland: variations by sex and race

PurposeLung cancer is a multifactorial malignancy for which some risk factors, such as chronic lung diseases, their interactions with smoking, and how they differ by race and sex, are not fully understood. We investigated the associations between chronic inflammatory lung disease and non–small cell lung carcinoma (NSCLC) and how sex and race may affect such associations. MethodsUsing logistic regression, we analyzed 1660 lung cancer cases and 1959 population controls and estimated adjusted odds ratios (AORs) and 95% confidence intervals (CIs). ResultsChronic lung disease was significantly associated with higher odds of having NSCLC in never (AOR = 1.99; 95% CI = 1.19–3.34), former (AOR = 1.68; 95% CI = 1.29–2.20), and current smokers (AOR = 2.40; 95% CI = 1.62–3.57), after adjustment for relevant covariates. For each 5-year increment in chronic lung disease duration, the risk of lung cancer increased only among females (AOR = 1.07; 95% CI = 1.02–1.13). Females, but not males, with asthma were at risk for NSCLC (AOR = 2.08; 95% CI = 1.40–3.10). ConclusionsThis study provides support for chronic lung inflammation as a potential contributing factor to lung cancer risk and possible sex difference in the inflammatory events underlying disease mechanisms.

Innovations in asthma therapy: is there a role for inhaled statins?

ABSTRACTIntroduction: Asthma manifests as chronic airflow obstruction with persistent inflammation and airway hyperresponsiveness. The immunomodulatory and anti-inflammatory properties of the HMG-CoA reductase (HMGCR) inhibitors (a.k.a. statins), suggest a therapeutic role in chronic inflammatory lung diseases. However, despite positive laboratory investigations and promising epidemiological data, clinical trials using statins for the treatment of asthma have yielded conflicting results. Inadequate statin levels in the airway compartment could explain these findings.Areas covered: HMGCR is in the mevalonate (MA) pathway and MA signaling is fundamental to lung biology and asthma. This article will discuss clinical trials of oral statins in asthma, review lab investigations relevant to the systemic versus inhaled administration of statins, address the advantages and disadvantages of inhaled statins, and answer the question: is there a role for inhaled statins in the treatment of asthma?Expert commentary: If ongoing investigations show that oral administration of statins has no clear clinical benefits, then repurposing statins for delivery via inhalation is a logical next step. Inhalation of statins bypasses first-pass metabolism by the liver, and therefore, allows for delivery of significantly lower doses to the airways at greater potency. Statins could become the next major class of novel inhalers for the treatment of asthma.

Early, in situ re-activation of lung memory T cells drives chronic lung inflammation

Abstract Acute immune responses within the respiratory tract generate memory T lymphocyte populations that are retained within the lung tissue and contribute to chronic inflammatory responses upon subsequent re-exposures to antigen. The generation and maintenance of antigen-specific memory T cell populations within the lung are therefore processes which, if inhibited, could ameliorate the symptoms of chronic inflammatory lung diseases. We sought to develop a model system that consistently generates lung inflammation and antigen-specific memory T cells within the lung. We show that prolonged respiratory exposure to lipopolysaccharide and a protein antigen generates a long-lived memory T cell population in the lung. These cells are retained in this compartment even after a week-long period of induced lymphopenia. Furthermore, lung memory T cells are re-activated in an antigen-specific manner upon intranasal challenge with antigen. The early in situ reactivation of memory T cells in the lung induced the recruitment of innate immune cells into the lung parenchyma and into the airways. Thus, elucidating the pathways involved in the tissue retention of the lung-retained memory T cell population may lead to therapies that can reduce harmful T cell populations within the lung.

Reduced expression of growth differentiation factor 11 promoted the progression of chronic obstructive pulmonary disease by activating the AKT signaling pathway

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease, which is associated with significant mortality and costs. The molecular mechanisms underlying the roles of cigarette smoke (an accepted risk factor for COPD) and growth differentiation factor 11 (GDF11), which is reduced in patients with COPD, in the occurrence of COPD are unclear. The aim of the present study was to explore the function of GDF11 in the progression of COPD. Western blotting analysis was used to determine the expression levels of GDF11 in serum and primary lung mesenchymal cells from patients with COPD and the healthy people, and the effect of cigarette smoke extract (CSE) on the expression of AKT, p-AKT (Ser473), p-AKT (Thr308) and GDF11 was examined. The correlations between the expression level of GDF11 and the ratio of forced expiratory volume in one second (FEV1) and forced vital capacity (FVC), as well as GDF11 and p-AKT (Ser473 and Thr308) in vivo and in vitro were examined. GDF11 expression was decreased in COPD patients’ serum and cells when compared with that from the healthy people, and it was positively correlated with the FEV1/FVC ratio. Exposure to CSE reduced the expression of GDF11 but increased the expression of p-AKT (Ser473 and Thr308). Together, the results suggested that CSE promoted the progression of COPD by downregulating the expression of GDF11, which then activated the AKT signaling pathway. This study suggests that GDF11 may be a novel target for the diagnosis and treatment of COPD.

Morphological and molecular characterization of Paragonimus caliensis Little, 1968 (Trematoda: Paragonimidae) from Medellin and Pichinde, Colombia

Paragonimiasis is a subacute to chronic inflammatory granulomatous lung disease caused by the genus Paragonimus. In Latin America Paragonimus mexicanus Miyazaki & Ishii, 1968 is the only confirmed species to cause human infections. Paragonimus caliensis Little, 1968 is an uncommon species often regarded as a synonym of P. mexicanus. Recently, the study of two types of Paragonimus metacercariae from Costa Rica has provided new molecular and morphological evidence that P. caliensis is a separate species from P. mexicanus. In the present study, molecular, morphological and phylogenetic tools have been used to characterize two populations of Paragonimus located at west of Medellin, Antioquia and at Pichinde, Valle del Cauca (type locality of P. caliensis), Colombia. Adults and metacercariae obtained from Medellin, and metacercariae from Pichinde were analyzed. For morphological observations we used light microscopy and scanning electron microscopy (SEM). Morphology of metacercariae and adults matched with the holotype of P. caliensis. The number and arrangement of sensory papillae in the acetabulum region differs from the morphotypes reported for P. caliensis in Costa Rica. Two morphotypes in branching patterns of ovary and two morphotypes in branching patterns of testes were identified. The main morphological differences between P. caliensis and P. mexicanus corresponded to the size of gonads and their relative positions in the body, and the occasional presence of a cyst wall in P. caliensis metacercariae. The molecular and phylogenetic analyses (using nuclear ribosomal ITS2 and partial cytochrome c oxidase subunit 1 CO1 sequences) confirmed that P. caliensis from the type locality is the same species from Medellin and Costa Rica. Furthermore, these analyses also suggest genetic as well as geographical separation of P. caliensis populations between Colombia and Costa Rica. Currently, P. mexicanus and P. caliensis are sympatric in the Colombian Pacific bioregion, and specific diagnosis based on their egg size is not possible. Therefore, it is necessary to determine the biogeographic distribution ranges of both species and to implement molecular techniques to establish the role of P. caliensis in human paragonimiasis in Colombia.

Mycobacterium abscessus Smooth and Rough Morphotypes Form Antimicrobial-Tolerant Biofilm Phenotypes but Are Killed by Acetic Acid.

ABSTRACTMycobacterium abscessus has emerged as an important pathogen in people with chronic inflammatory lung diseases such as cystic fibrosis, and recent reports suggest that it may be transmissible by fomites. M. abscessus exhibits two major colony morphology variants: a smooth morphotype (MaSm) and a rough morphotype (MaRg). Biofilm formation, prolonged intracellular survival, and colony variant diversity can each contribute to the persistence of M. abscessus and other bacterial pathogens in chronic pulmonary diseases. A prevailing paradigm of chronic M. abscessus infection is that MaSm is a noninvasive, biofilm-forming, persistent phenotype and MaRg an invasive phenotype that is unable to form biofilms. We show that MaRg is hyperaggregative and forms biofilm-like aggregates, which, like MaSm biofilm aggregates, are significantly more tolerant than planktonic variants to acidic pHs, hydrogen peroxide (H2O2), and treatment with amikacin or azithromycin. We further show that both variants are recalcitrant to antibiotic treatment inside human macrophage-like cells and that MaRg is more refractory than MaSm to azithromycin. Our results indicate that biofilm-like aggregation and protracted intracellular survival may each contribute to the persistence of this problematic pathogen in the face of antimicrobial agents regardless of morphotype. Biofilms of each M. abscessus variant are rapidly killed, however, by acetic acid, which may help to prevent local fomite transmission.

The Effect of Inhalant Organic Dust on Bone Health.

Agriculture remains a major economic sector globally, and workers experience high rates of chronic inflammatory lung and musculoskeletal diseases. Whereas obstructive pulmonary diseases are known risk factors for bone loss, the underlying relationship between lung inflammation and bone health is not well known. An agriculture organic dust extract inhalation animal model has recently linked lung injury-induced inflammation to systemic bone loss. This process is dependent upon lipopolysaccharide and the toll-like receptor 4 (TLR4) signaling pathway. Downstream systemic interleukin-6 is a key mediator that subsequently activates osteoclastogenesis. Age is a host factor that impacted bone disease with younger mice demonstrating increased susceptibility to bone loss following inhalant exposures as compared to older mice. Supplemental dietary vitamin D was shown to prevent organic dust-induced bone loss, but not lung disease, in animals. Recent animal studies provide new mechanistic insight into the lung-bone inflammatory axis. Host factors, diet, and lipopolysaccharide/TLR4 signaling pathways play a significant role in explaining how inhalant organic dust exposures impact bone health. These investigations might lead to specific targeted therapeutic approaches.