Peribronchiolar Inflammation Research Articles

Pharmacological inhibition of SIRT-2 by AK-7 modulates redox status and apoptosis via regulating Nrf2 in an experimental model of chronic obstructive pulmonary disease: an invivo and insilico study

Chronic obstructive pulmonary disease (COPD) is defined by inflammation and emphysema. Sirtuins (SIRT) are NAD+-dependent histone deacetylases that regulate oxidative stress and inflammation. The present work investigates the modulatory role of SIRT-2 in experimental COPD model. Insilico comparative assessment of SIRT-2 inhibitors (AK-7 and AGK-2) by ADMET and molecular docking revealed AK-7 as suitable candidate for invivo application. COPD in mice was established by cigarette smoke (CS) exposure for 2 months. AK-7 (100 µg/kg and 200 µg/kg body weight) was administered intranasally one hour before CS exposure. The present investigation demonstrates that CS exposure increases total cell count, and free radical production (total reactive oxygen species, total oxidant status, myeloperoxidase, and nitric oxide), which were decreased by AK-7. It also altered antioxidant enzymatic activity (total antioxidant status, catalase, superoxide dismutase, glutathione peroxidase, glutathione-s-transferase, glutathione reductase, and reduced glutathione), hence preserving the redox balance. AK-7 significantly decreases apoptosis, protein carbonylation, lipid peroxidation, TNF-α and IFN-ﻻ levels represent COPD generation in mice and were dramatically decreased by AK-7. Histopathological studies shows that CS exposure damages alveoli and produces peribronchiolar inflammation; both of these events were reduced by AK-7. The antioxidative potency of AK-7 was confirmed by observing Nrf2 and Keap1 proteins. Keap-dependent Nrf2 regulation was observed, with cytosolic Nrf2 and Keap1 expression elevated in COPD and reduced in the AK-7 group while nuclear Nrf2 was reduced in COPD and increased in the AK-7 group. The present study concludes that inhibition of SIRT-2 minimizes COPD severity and mediates therapeutic effects in the lungs.

Molecular Features and Stages of Pulmonary Fibrosis Driven by Type 2 Inflammation.

Systemic sclerosis (SSc) is a progressive, multiorgan disease with limited treatment options. Although a recent proof-of-concept study using romilkimab or SAR156597, a bispecific IL-4/IL-13 antibody, suggests a direct role of these cytokines in the pathophysiology of SSc, their contributions to the balance between inflammation and fibrosis are unclear. Here, we determine the roles of type 2 inflammation in fibrogenesis using FRA2-Tg (Fos-related antigen 2-overexpressing transgenic) mice, which develop spontaneous, age-dependent progressive lung fibrosis. We defined the molecular signatures of inflammation and fibrosis at three key stages in disease progression, corresponding to preonset, inflammatory dominant, and fibrosis dominant biology, and revealed an early increase in cytokine-cytokine receptor interactions and antigen-processing and presentation pathways followed by enhanced Th2- and M2 macrophage-driven type 2 responses. This type 2 inflammation progressed to extensive fibrotic pathology by 14-18 weeks of age, with these gene signatures overlapping significantly with those seen in the lungs of patients with SSc with interstitial lung disease (ILD). These changes were also evident in the histopathology, which showed perivascular and peribronchiolar inflammation with prominent eosinophilia and accumulation of profibrotic M2-like macrophages followed by rapid progression to fibrosis with thickened alveolar walls with multifocal fibrotic bands and signs of interstitial pneumonia. Critically, treatment with a bispecific antibody targeting IL-4 and IL-13 during the inflammatory phase abrogated the Th2 and M2 responses and led to near-complete abrogation of lung fibrosis. These data recapitulate important features of fibrotic progression in the lungs of patients with SSc-ILD and enhance our understanding of the progressive pathobiology of SSc. This study also further establishes FRA2-Tg mice as a valuable tool for testing future therapeutic agents in SSc-ILD.

A Comparative Histological Study of Effects of Cigarette and Shisha Smoke on Lungs of Mice

Background: The most popular way to take in tobacco is as cigarettes, which are now frequently accessible as vaporizers. When inhaled for an extended period of time, the smoke's respiratory tract irritants cause fibrosis, inflammation, and precancerous diseases. Nicotine is the main alkaloid found in both commercial and home-made tobacco products, making up 0.6-3.0% of the dry weight of the tobacco plant. Aim: To compare the histological effects of cigarettes and shisha on the lungs of experimental animals. Study design: Randomized control trial. Methodology: A randomised control trial was used. In partnership with the National Institute of Health (NIH), Islamabad, the Department of Anatomy at the Islamic International Medical College in Rawalpindi developed and carried out this six-month study. 40 mature male BALB/c mice were allocated into three groups at random. Mice from the Control group C were housed in a fresh air- and smoke-exposed environment. Third Group CS was exposed to cigarette smoke, while Experimental Group SS was subjected to shisha smoke. Two exposures per day, five days per week, were administered. After a total of eight months of exposure, the subjects were dissected, the lung tissue was evaluated under a microscope, and the outcomes were compared across experimental groups. The quantity of carbon-loaded alveolar macrophages per unit was measured in the lung tissues. SPSS 20.0 was utilized to analyze the data. For quantitative histology data, mean and standard deviation were provided, while frequencies and percentages were provided for qualitative factors. The Pearson Chi Square test was used to determine the p value when comparing two groups and one way analysis of variance (ANOVA) was used to evaluate the mean differences between the control and experimental groups. Statistical significance was defined as a p-value of 0.05. Results: In comparison to group CS, group SS showed significantly more fibrosis, peribronchiolar inflammation, and bronchiolar constriction. Additionally, there were more carbon-loaded alveolar macrophages in group SS than in group CS, and this difference was statistically significant. Practical implication: As sheesha and vaping are now popular trends, this study will aid researchers in determining the risk linked with sheesha smoking. Conclusions: Shisha use is not a risk-free substitute for cigarette use. Compared to cigarette smoke, it has a larger concentration of toxicants that alter tissue at a far higher rate. Keywords: Shisha Smoke, Cigarette Smoke, Lungs Tissue, Mice and Histology.

Sublingual prophylactic administration of OVA-loaded MSC-derived exosomes to prevent allergic sensitization

AimThis study evaluated the immunomodulatory and delivery potential of adipose tissue-isolated MSC-derived exosomes as a prophylactic regimen through a sublingual route in the ovalbumin (OVA)-induced allergic asthma murine model. Material and methodsBalb/c mice received 10 μg/dose of OVA-enriched MSC-derived exosomes as a prophylactic regimen in six doses during three weeks, and then OVA sensitization was conducted through intraperitoneal and aerosol administration of allergen. The total cells and eosinophils counted in nasal lavage fluid (NALF) and lung tissues were assessed for histopathological analysis. In addition, the secretion of IFN-γ, IL-4, and TGF-β by spleen cells and serum OVA-specific IgE levels were measured via ELISA. ResultsSignificant reduction in the IgE levels and IL-4 production, along with elevated TGF-β levels, were observed. Also, limited cellular infiltrations and perivascular and peribronchiolar inflammation in the lung tissues and normal total numbers of cells and eosinophils in the NALF were reported. ConclusionProphylactic regimen using OVA-enriched MSC-derived exosomes modulated immune responses and inhibited allergic OVA sensitization.

Recombinant human DNase-I improves acute respiratory distress syndrome via neutrophil extracellular trap degradation

BackgroundRespiratory failure is the primary cause of death in patients with COVID-19, whereas coagulopathy is associated with excessive inflammation and multiorgan failure. Neutrophil extracellular traps (NETs) may exacerbate inflammation and provide a scaffold for thrombus formation. ObjectivesThe goal of this study was to determine whether degradation of NETs by recombinant human DNase-I (rhDNase), a safe, Food and Drug Administration–approved drug, reduces excessive inflammation, reverses aberrant coagulation, and improves pulmonary perfusion after experimental acute respiratory distress syndrome (ARDS). MethodsIntranasal poly(I:C), a synthetic double-stranded RNA, was administered to adult mice for 3 consecutive days to simulate a viral infection, and these subjects were randomized to treatment arms, which received either an intravenous placebo or rhDNase. The effects of rhDNase on immune activation, platelet aggregation, and coagulation were assessed in mice and donor human blood. ResultsNETs were observed in bronchoalveolar lavage fluid and within regions of hypoxic lung tissue after experimental ARDS. The administration of rhDNase mitigated peribronchiolar, perivascular, and interstitial inflammation induced by poly(I:C). In parallel, rhDNase degraded NETs, attenuated platelet-NET aggregates, reduced platelet activation, and normalized the clotting time to improve regional perfusion, as observed using gross morphology, histology, and microcomputed tomographic imaging in mice. Similarly, rhDNase reduced NETs and attenuated platelet activation in human blood. ConclusionNETs exacerbate inflammation and promote aberrant coagulation by providing a scaffold for aggregated platelets after experimental ARDS. Intravenous administration of rhDNase degrades NETs and attenuates coagulopathy in ARDS, providing a promising translational approach to improve pulmonary structure and function after ARDS.

Extracorporeal Photopheresis Suppresses Transplant Fibrosis by Inducing Decorin Expression in Alveolar Macrophages.

Extracorporeal Photopheresis Suppresses Transplant Fibrosis by Inducing Decorin Expression in Alveolar Macrophages.

MR imaging of the airways.

The need for airway imaging is defined by the limited sensitivity of common clinical tests like spirometry, lung diffusion (DLCO) and blood gas analysis to early changes of peripheral airways and to inhomogeneous regional distribution of lung function deficits. Therefore, X-ray and computed tomography (CT) are frequently used to complement the standard tests.As an alternative, magnetic resonance imaging (MRI) offers radiation-free lung imaging, but at lower spatial resolution. Non-contrast enhanced MRI shows healthy airways down to the first subsegmental level/4th order (CT: eighth). Bronchiectasis can be identified by wall thickening and fluid accumulation. Smaller airways become visible, when altered by peribronchiolar inflammation or mucus retention (tree-in-bud sign).The strength of MRI is functional imaging. Dynamic, time-resolved MRI directly visualizes expiratory airway collapse down to the lobar level (CT: segmental level). Obstruction of even smaller airways becomes visible as air trapping on the expiratory scans. MRI with hyperpolarized noble gases (3He, 129Xe) directly shows the large airways and peripheral lung ventilation. Dynamic contrast-enhanced MRI (DCE MRI) indirectly shows airway dysfunction as perfusion deficits resulting from hypoxic vasoconstriction of the dependent lung volumes. Further promising scientific approaches such as non-contrast enhanced, ventilation-/perfusion-weighted MRI from periodic signal changes of respiration and blood flow are in development.In summary, MRI of the lungs and airways excels with its unique combination of morphologic and functional imaging capacities for research (e.g., in chronic obstructive lung disease or asthma) as well as for clinical imaging (e.g., in cystic fibrosis).

Effect of transduced mesenchymal stem cells with IL-10 gene on control of allergic asthma.

Asthma is an important pulmonary disease associated with T helper lymphocyte (Th)2 dominant immune response, which can initiate allergic and inflammatory reactions. Interleukin (IL)-10 is the main immune suppressor cytokine, and mesenchymal stem cells (MSCs) have an immune-modulatory potential that can be transduced with the expression of the IL-10 gene to control pathophysiology of allergic asthma. Bone marrow's MSCs were isolated and transduced with the expression vector that contains the expressible IL-10 gene. Then, allergic asthma mouse model was produced and treated with manipulated MSCs. Methacholine challenge test; measurement of IL-4, IL-5, IL-8, IL-13, IL-25, and IL-33; and total and ovalbumin (OVA)-specific immunoglobulin (Ig)E levels were done. Hyperplasia of the goblet cell, secretion of mucus, and peribronchiolar and perivascular eosinophilic inflammation were evaluated in lung pathological sections. IL-25, IL-33, and total IgE levels; AHR; eosinophilic inflammation; hyperplasia of the goblet cell; and secretion of mucus could be controlled in M, MV, and MV-10 groups, and the control in the MV-10 group was strong compared to M and MV groups. MSCs have immune-modulatory capacity that can control allergic asthma pathophysiology, and this effect can be strengthened and reinforced by the expression of IL-10 gene.

Immune response modulation by allergen loaded into mesenchymal stem cell-derived exosomes as an effective carrier through sublingual immunotherapy

BackgroundAllergen-specific sublingual immunotherapy (SLIT) was considered an interesting needle-free alternative for subcutaneous immunotherapy (SCIT). Mesenchymal stem cell (MSC)-derived exosomes were introduced as potent nanoscale delivery systems with immunomodulatory potentials. The current study investigated the therapeutic efficacy of SLIT using ovalbumin (OVA)-enriched MSC-derived exosomes formulation in a murine model of allergic asthma. Material and methodsMSCs were harvested from mice adipose tissues. Then, exosomes were isolated, and OVA-loaded exosomes were prepared. Following sensitization, Balb/c mice received therapeutic formulation (10 μg/dose OVA-containing MSC-derived exosomes) twice a week for two months. Serum OVA-specific IgE levels as well as IFN-γ, IL-4, and TGF-β secretions by cultured splenocytes were measured by ELISA. Also, lung tissue underwent histopathologic analysis, and the numbers of inflammatory cells and eosinophils in nasopharyngeal lavage fluid (NALF) were examined. ResultsSLIT using OVA-enriched exosomes significantly reduced IgE levels and IL-4 production, while the secretion of IFN-γ and TGF-β were significantly elevated. Also, a decrease was observed in the numbers of total cells and eosinophils in the NALF, and lower levels of perivascular and peribronchiolar inflammation and cellular infiltrations were observed in the lung tissue. ConclusionSLIT using OVA-loaded exosomes improved immunomodulatory responses and efficiently alleviated allergic inflammation.

Histopathological Study to Evaluate the Effect of Aqueous Extract of Portunuspelagicus and Mebendazole on Hydatid Cysts in Mice.

Hydatid disease is a parasitic infestation by a tapeworm of the genus Echinococcus sp., which has a global distribution. The current study was conducted to evaluate the effectiveness of the crustacean aqueous extract of Portunuspelagicus for 2 weeks of treatment compared to mebendazole on hydatid cyst in laboratory mice male Balb / C strain. Mice were infected intraperitoneally with 2000 protoscolices. After 12 weeks of infection, each mouse was treated with mebendazole (50mg/kg) and the hot aqueous extract of p. pelagicus (8, 16 g/kg). Samples of infected organs (liver, spleen, and lungs) were examined under a microscope to evaluate the morphological and histopathological changes of hydatid cysts and tissues. The study confirmed macroscopically that there were a number of hydatid cysts of different sizes in the liver, spleen, and lungs, splenomegaly, and congestion of the lungs of the positive control group. The histological changes in the organs of the group treated with the crustacean extract were represented by the vacuolation of hepatocytes in the centrilobular area of the liver. At the same time, the lungs show intensive peri-bronchiolar inflammation, pulmonary vascular congestion, and in the spleen, the deposition of amyloid-like material in the white pulp, extramedullary hematopoiesis, While the histopathological changes in the organs of mice treated with mebendazole, were represented by the presence in the mild liver vacuolation of the centrilobular area. In contrast, the lungs show mild pulmonary vascular congestion and emphysema, and the spleen shows normal white pulp, the normal red pulp of mice. The aqueous extract Portunuspelagicus and mebendazole are effective in controlling the contamination in the intermediate hosts.

Refined polysaccharide from Dendrobium devonianum resists H1N1 influenza viral infection in mice by activating immunity through the TLR4/MyD88/NF-κB pathway.

Dendrobium polysaccharide exhibits multiple biological activities, such as immune regulation, antioxidation, and antitumor. However, its resistance to viral infection by stimulating immunity is rarely reported. In this study, we explored the effect and mechanism of DVP-1, a novel polysaccharide from Dendrobium devonianum, in the activation of immunity. After being activated by DVP-1, the ability of mice to prevent H1N1 influenza virus infection was investigated. Results of immune regulation showed that DVP-1 significantly improved the immune organ index, lymphocyte proliferation, and mRNA expression level of cytokines, such as IL-1β, IL-4, IL-6, and TNF-α in the spleen. Immunohistochemical results showed that DVP-1 obviously promoted the mucosal immunity in the jejunum tissue. In addition, the expression levels of TLR4, MyD88, and TRAF6 and the phosphorylation levels of TAK1, Erk, JNK, and NF-κB in the spleen were upregulated by DVP-1. The virus infection results showed that the weight loss of mice slowed down, the survival rate increased, the organ index of the lung reduced, and the virus content in the lung decreased after DVP-1 activated immunity. By activating immunity with DVP-1, the production of inflammatory cells and inflammatory factors in BALF, and alveolar as well as peribronchiolar inflammation could be prevented. The results manifested that DVP-1 could resist H1N1 influenza virus infection by activating immunity through the TLR4/MyD88/NF-κB pathway.

Constrictive bronchiolitis obliterans with a presumptive etiology of preceding feline herpesvirus infection in a cat

BackgroundBronchiolar disorders are rarely recognized in cats. Constrictive bronchiolitis obliterans is characterized by concentric peribronchiolar fibrosis and inflammation of the bronchioles, but the underlying causes remain poorly understood in current small animal medicine.Case presentationA 9-year-old cat presented with paroxysmal tachypnea, infrequent cough and persistent labor breathing. Thoracic radiography showed lung hyperinflation and bronchointerstitial pattern, and pulmonary function assessment revealed flow limitation in the late-expiratory phase and poor response to short-acting bronchodilator. Dorsally distributed subpleural ground glass opacities with distinct margin and tree-in-bud opacities were observed on lung high-resolution computed tomography. The cat underwent bronchoalveolar lavage (BAL) and showed severe neutrophilic inflammation. Feline herpesvirus was the only pathogen detected in the BAL fluid. Multiple therapeutic attempts were unsuccessful and the cat died 8 weeks after the initial presentation. Necropsy revealed the infiltration of inflammatory cells, obstruction of the bronchiolar lumen, and submucosal concentric fibrosis suggesting constrictive bronchiolitis obliterans. Combining the pre- and post-mortem findings, as well as the time from symptom onset or BAL to necropsy, constrictive bronchiolitis obliterans was possibly triggered by a preceding feline herpesvirus infection in this case.ConclusionsThe history of nonvaccinated status, lower airway neutrophilic inflammation, and presence of feline herpesvirus in the BAL fluid without coexistence of other pathogens led to the presumption that constrictive bronchiolitis obliterans was induced by a preceding feline herpesvirus infection in this cat. The pathological changes of bronchiolitis obliterans induced by a preceding feline herpesvirus infection could be different from that of cats with acute herpesvirus pneumonia, such as intranuclear inclusions would disappear over time and were no longer found 7–10 days after inoculation. The presence of patchy distribution of subpleural ground glass opacities on lung high-resolution computed tomography should raise the suspicion of peribronchiolar fibrosis. Clinical awareness of bronchiolar disorders as a differential diagnosis is important in cats with lung hyperinflation and labored breathing who show poor reversibility to bronchodilator.

Exposure to Vishniacozyma victoriae elicits airway inflammation and a CD4+ T cell-driven lymphocytic response.

Abstract Like the pathogenic yeast Cryptococcus neoformans, Vishniacozyma victoriae (syn. Cryptococcus victoriae), a non-pathogenic yeast, has been associated with allergic airway disease. Although V. victoriae is frequently detected in indoor environments, the impact of repeated exposure is currently unknown. In this study, mice were exposed via oropharyngeal aspiration to V. victoriae or C. neoformans every other day for a total of six exposures, and responses were analyzed 1 day and 21 days post final exposure. As expected, repeated exposure to C. neoformans resulted in an increase of myeloid and lymphoid cells in the bronchoalveolar lavage fluid (BALF), granuloma formation with intralesional yeast, and peribronchiolar and perivascular inflammation 1 day post exposure. This response was exacerbated 21 days post exposure as the yeast cells replicated. Repeated exposure to V. victoriae resulted in an increase in eosinophils, Ly6Chi/int monocytes, and CD103+ dendritic cells in the BALF, and mild perivascular and peribronchiolar inflammation 1 day post exposure. Surprisingly, V. victoriae cells were present in the lungs of exposed mice 21 days post exposure, and the response shifted toward a nodular lymphocytic response with an increase of CD4+ T cells in the BALF. Lastly, C. neoformans exposure was predicted to activate antigen presentation, B cell development and Th2 proteomic pathways, whereas V. victoriae was predicted to activate VDR/RXR activation, Granzyme A signaling, and IGF-1 signaling pathways 21 days post exposure. The results of this study suggest that exposure to environmentally ubiquitous V. victoriae may exacerbate allergic airway disease, although not to the extent of exposure to pathogenic C. neoformans. Interagency Agreement between NIEHS & NIOSH: AES 12007001-1-0-6

Final results from a 90-day quantitative inhalation toxicology study evaluating the dose-response and fate in the lung and pleura of chrysotile-containing brake dust compared to TiO2, chrysotile, crocidolite or amosite asbestos: Histopathological examination, confocal microscopy and collagen quantification of the lung and pleural cavity

The final results from this multi-dose, 90-day inhalation toxicology study in the rat with life-time post-exposure observation have shown a significant fundamental difference in pathological response and tumorgenicity between brake dust generated from brake pads manufactured with chrysotile or from chrysotile alone in comparison to the amphiboles, crocidolite and amosite asbestos.The groups exposed to brake dust showed no significant pathological or tumorigenic response in the respiratory track compared to the air control group at exposure concentrations and deposited doses well above those at which humans have been exposed. Slight alveolar/interstitial macrophage accumulation of particles was noted. Wagner grades were 1–2 (1 = control group), similar to the TiO2 particle control group.Chrysotile was not biopersistent, exhibiting in the lung a deterioration of its matrix which results in breakage into particles and short fibers which can be cleared by alveolar macrophages and which can continue to dissolve. Particle-laden macrophage accumulation was observed, leading to a very-slight interstitial inflammatory response (Wagner grade 1–3). There was no peribronchiolar inflammation, occasional very-slight interstitial fibrosis (Wagner grade 4), and no exposure-related tumorigenic response.The pathological response of crocidolite and amosite compared to the brake dust and chrysotile was clearly differentiated by the histopathology and the confocal analysis. Crocidolite and amosite induced persistent inflammation, microgranulomas, persistent fibrosis (Wagner grades 4), and a dose-related lung tumor response. Confocal microscopy quantified extensive inflammatory response and collagen development in the lung, visceral and parietal pleura as well as pleural adhesions.These results provide a clear foundation for differentiating the innocuous effects of brake dust exposure from the adverse effects following amphibole asbestos exposure.

Sex differences in the induction of angiotensin converting enzyme 2 (ACE-2) in mouse lungs after e-cigarette vapor exposure and its relevance to COVID-19

The COVID-19 pandemic has affected over 114 million people and has resulted in >2.5 million deaths so far. Some people have greater susceptibility which influences both SARS-CoV-2 infectivity and COVID-19...

Long-Term Sequelae of Smoking and Cessation in Spontaneously Hypertensive Rats.

Smoking is a major risk factor for heart attack, stroke, and lung cancer. Tobacco smoke (TS) causes bronchitis, emphysema, persistent cough, and dyspnea. Smoking cessation minimizes risks of TS-related disease. To determine whether smoking cessation could reverse TS-induced pulmonary changes, 10-week-old male spontaneously hypertensive rats were exposed to TS or filtered air (FA) for 39 weeks and allowed to live out their normal lifespan. Significantly (P ≤ .05) decreased survival was noted by 21 months in TS versus FA rats. In TS rats, persistent peribronchiolar, perivascular, alveolar, and subpleural inflammation were observed with pervasive infiltration of pigmented foamy macrophages and plausible intra-alveolar fibrosis and osseous metaplasia. Alveolar airspace was significantly (P ≤ .05) increased in TS versus FA rats as was the volume of stored epithelial mucosubstances in the left central axial airway. Increased mucin contributes to airflow obstruction and increased lung infection risks. Findings suggest TS-induced changes do not attenuate with smoking cessation but result in irreversible damage similar to chronic obstructive pulmonary disease. The observed persistent pulmonary changes mirror common TS effects such as chest congestion, sputum production, and shortness of breath long after smoking cessation and represent important targets for treatment of former smokers.

Evaluation of the dose-response and fate in the lung and pleura of chrysotile-containing brake dust compared to TiO2, chrysotile, crocidolite or amosite asbestos in a 90-day quantitative inhalation toxicology study – Interim results Part 2: Histopathological examination, Confocal microscopy and collagen quantification of the lung and pleural cavity

The interim results from this 90-day multi-dose, inhalation toxicology study with life-time post-exposure observation has shown an important fundamental difference in persistence and pathological response in the lung between brake dust derived from brake-pads manufactured with chrysotile, TiO2 or chrysotile alone in comparison to the amphiboles, crocidolite and amosite asbestos.In the brake dust exposure groups no significant pathological response was observed at any time. Slight macrophage accumulation of particles was noted. Wagner-scores, were from 1 to 2 (1 = air-control group) and were similar to the TiO2 group.Chrysotile being biodegradable, shows a weakening of its matrix and breaking into short fibers & particles that can be cleared by alveolar macrophages and continued dissolution. In the chrysotile exposure groups, particle laden macrophage accumulation was noted leading to a slight interstitial inflammatory response (Wagner-score 1–3). There was no peribronchiolar inflammation and occasional very slight interstitial fibrosis.The histopathology and the confocal analyses clearly differentiate the pathological response from amphibole asbestos, crocidolite and amosite, compared to that from the brake dust and chrysotile. Both crocidolite and amosite induced persistent inflammation, microgranulomas, and fibrosis (Wagner-scores 4), which persisted through the post exposure period. The confocal microscopy of the lung and snap-frozen chestwalls quantified the extensive inflammatory response and collagen development in the lung and on the visceral and parietal surfaces.The interim results reported here, provide a clear basis for differentiating the effects from brake dust exposure from those following amphibole asbestos exposure. The subsequent results through life-time post-exposure will follow.

Immunomodulatory effect of pigeon serum in an acute and chronic murine model of bird fanciers lung

IntroductionSince the immunopathological mechanisms of bird fancier’s lung (BFL) are not well known, we created two models of the disease (acute and chronic BFL) to study and compare the pathways involved in its immunopathogenesis. Materials and methodsC57BL/6 mice were used. Two intraperitoneal injections of 100 μL of commercial pigeon serum (PS) or saline (SAL) were administered with an interval of 48 h in between. Subsequently, intranasal instillations of 40 μL of PS or SAL were performed three days a week, for three weeks in the acute model (AC/PS) and for twelve weeks in the chronic model (CR/PS). Total lung capacity (TLC) was assessed. Pulmonary inflammation was evaluated in bronchoalveolar lavage (BAL), and total serum immunoglobulin (Ig) G was measured in serum samples 24 h, 7 days and 14 days after the last exposure. Histological studies of lungs were assessed. ResultsA drop in TLC was observed in treated mice. This decrease was more marked in the CR/PS group (p < 0.001). Neutrophil and lymphocyte counts increased in both AC/PS and CR/PS groups (p < 0.01). The extent of airway inflammation was also examined in the histological analysis of the lungs, which showed predominant perivascular and peribronchiolar inflammation, with centrilobular oedema and subpleural inflammation in the AC/PS group. In the CR/PS group, the changes were greater, with increased levels of IL-5, IL-17F, IL-13 and IL-10 and decreased levels of IL-2. ConclusionsBronchial inflammation is present in acute and chronic models of HP following exposure to PS. Our results support the role of neutrophils and IL-17 in the development of the disease and an evolution towards a Th-2 immune response in chronic HP. These models may serve as a tool for future studies of the pathogenesis of HP.

Chronic exposure to non-eruptive volcanic activity as cause of bronchiolar histomorphological alteration and inflammation in mice

It is estimated that 10% of the worldwide population lives in the vicinity of an active volcano. However, volcanogenic air pollution studies are still outnumbered when compared with anthropogenic air pollution studies, representing an unknown risk to human populations inhabiting volcanic areas worldwide. This study was carried out in the Azorean archipelago of Portugal, in areas with active non-eruptive volcanism. The hydrothermal emissions within the volcanic complex of Furnas (São Miguel Island) are responsible for the emission of nearly 1000 tons of CO2 per day, along with H2S, the radioactive gas – radon, among others. Besides the gaseous emissions, metals (e.g., Hg, Cd, Al, Ni) and particulate matter are also released into the environment. We test the hypothesis that chronic exposure to volcanogenic air pollution alters the histomorphology of the bronchioles and terminal bronchioles, using the house mouse, Mus musculus, as bioindicator species. Mus musculus were live-captured at three different locations: two villages with active volcanism and a village without any type of volcanic activity (reference site). The histomorphology of the bronchioles (diameter, epithelium thickness, smooth muscle layer thickness, submucosa thickness and the histological evaluation of the peribronchiolar inflammation) and of the terminal bronchioles (epithelium thickness and classification) were evaluated. Mice chronically exposed to volcanogenic air pollution presented bronchioles with increased epithelial thickness, increased smooth muscle layer, increased submucosa thickness and increased peribronchiolar inflammation. Similarly, terminal bronchioles presented structural alterations consistent with bronchodysplasia. For the first time we demonstrate that chronic exposure to non-eruptive volcanically active environments causes inflammation and histomorphological alterations in mice lower airways consistent with asthma and chronic bronchitis. These results reveal that chronic exposure to non-eruptive volcanic activity represents a risk factor that can affect the health of the respiratory system of humans inhabiting hydrothermal areas.

Indoor PM2.5 from coal combustion aggravates ovalbumin-induced asthma-like airway inflammation in BALB/c mice.

We hypothesized that indoor PM2.5 exposure from coal combustion exaggerates airway inflammation in the lung tissue of asthmatic mice induced with ovalbumin (OVA). Forty BALB/c mice, randomly divided into four groups (n = 10 per group), were intratracheally instilled with normal saline alone, PM2.5 (2.5 mg/ml PM2.5 alone), OVA (15 μg/ml OVA alone), and PM2.5+OVA (2.5 mg/ml PM2.5 and 15 μg/ml OVA), respectively, four times at 2-wk intervals. Daily mean concentration of PM2.5 from indoor coal combustion was 156.95 μg/m3. The highest metal composition in PM2.5 was Zn (34.81 ± 1.8 μg/m3). Exposure to PM2.5+OVA significantly elevated IL-4 and decreased IFN-γ production in mice compared with the control (P < 0.05). Exposure to PM2.5+OVA showed a significant increase in the protein levels of granulocyte-macrophage colony-stimulating factor and IL-8 and a decrease in the protein level of transforming growth factor-β1 in bronchoalveolar lavage fluid of mice compared with the control (P < 0.05). The expression of IL-4 mRNA was significantly increased, whereas the expression of IFN-γ mRNA was decreased in lung tissue of the PM2.5+OVA group (P < 0.05). The expression level of Foxp3 mRNA in the PM2.5+OVA group was significantly lower than that in the control group in lung tissue (P < 0.05). Treatment with PM2.5+OVA promoted a prominent neutrophil sequestration into the lung parenchyma, goblet cell proliferation, and severe inflammatory cell infiltration in the airways. Exposure to PM2.5 from indoor coal combustion might induce airway inflammatory immune responses and exacerbate peribronchiolar inflammation due to infiltration of inflammatory cells into the airway submucosa and airway structural pathological changes.