Acute respiratory distress syndrome (ARDS) is a common cause of respiratory failure in critically ill patients, and diffuse alveolar damage (DAD) is considered its histological hallmark. Sepsis is ...one of the most common aetiology of ARDS with the highest case-fatality rate. Identifying ARDS patients and differentiate them from other causes of acute respiratory failure remains a challenge. To address this, many studies have focused on identifying biomarkers that can help assess lung epithelial injury. However, there is scarce information available regarding the tissue expression of these markers. Evaluating the expression of elafin, RAGE, and SP-D in lung tissue offers a potential bridge between serological markers and the underlying histopathological changes. Therefore, we hypothesize that the expression of epithelial injury markers varies between sepsis and ARDS as well as according to its severity.
We compared the post-mortem lung tissue expression of the epithelial injury markers RAGE, SP-D, and elafin of patients that died of sepsis, ARDS, and controls that died from non-pulmonary causes. Lung tissue was collected during routine autopsy and protein expression was assessed by immunohistochemistry. We also assessed the lung injury by a semi-quantitative analysis.
We observed that all features of DAD were milder in septic group compared to ARDS group. Elafin tissue expression was increased and SP-D was decreased in the sepsis and ARDS groups. Severe ARDS expressed higher levels of elafin and RAGE, and they were negatively correlated with PaO
/FiO
ratio, and positively correlated with bronchopneumonia percentage and hyaline membrane score. RAGE tissue expression was negatively correlated with mechanical ventilation duration in both ARDS and septic groups. In septic patients, elafin was positively correlated with ICU admission length, SP-D was positively correlated with serum lactate and RAGE was correlated with C-reactive protein.
Lung tissue expression of elafin and RAGE, but not SP-D, is associated with ARDS severity, but does not discriminate sepsis patients from ARDS patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Gestational exposure to air pollution is associated with negative outcomes in newborns and children. In a previous study, we demonstrated a synergistic negative effect of pre- and postnatal exposure ...to PM2.5 on lung development in mice. However, the means by which air pollution affects development of the lung have not yet been identified.
In this study, we exposed pregnant BALB/c mice and their offspring to concentrated urban PM2.5 (from São Paulo, Brazil; target dose 600 μg/m3 for 1 h daily). Exposure was started on embryonic day 5.5 (E5.5, time of placental implantation). Lung tissue of fetuses and offspring was submitted to stereological and transcriptomic analyses at E14.5 (pseudoglandular stage of lung development), E18.5 (saccular stage) and P40 (postnatal day 40, alveolarized lung). Additionally, lung function and cellularity of bronchoalveolar lavage (BAL) fluid were studied in offspring animals at P40.
Compared to control animals that were exposed to filtered air throughout gestation and postnatal life, PM-exposed mice exhibited higher lung elastance and a lower alveolar number at P40 whilst the total lung volume and cellularity of BAL fluid were not affected. Glandular and saccular structures of fetal lungs were not altered upon gestational exposure; transcriptomic signatures, however, showed changes related to DNA damage and its regulation, inflammation and regulation of cell proliferation. A differential expression was validated at E14.5 for the candidates Sox8, Angptl4 and Gas1.
Our data substantiate the in utero biomolecular effect of gestational exposure to air pollution and provide first-time stereological evidence that pre- and early life-postnatal exposure compromise lung development, leading to a reduced number of alveoli and an impairment of lung function in the adult mouse.
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•Pre- and early postnatal exposure to PM2.5 lead to a decreased number of alveoli.•Pre- and early postnatal exposure to PM2.5 lead to increased lung elastance.•Gestational exposure to PM2.5 causes transcriptomic alterations in fetal lungs.
This study is the first to provide comprehensive stereological and transcriptomic data in mice about the in utero effect of gestational exposure to PM2.5 on the fetal lung whilst demonstrating an impairment of alveolarization and lung function upon continued exposure to PM2.5 until an early stage of life.
Chitotriosidase (CHIT1) is an enzyme produced by macrophages that regulates their differentiation and polarization. Lung macrophages have been implicated in asthma development; therefore, we asked ...whether pharmacological inhibition of macrophage-specific CHIT1 would have beneficial effects in asthma, as it has been shown previously in other lung disorders. CHIT1 expression was evaluated in the lung tissues of deceased individuals with severe, uncontrolled, steroid-naïve asthma. OATD-01, a chitinase inhibitor, was tested in a 7-week-long house dust mite (HDM) murine model of chronic asthma characterized by accumulation of CHIT1-expressing macrophages. CHIT1 is a dominant chitinase activated in fibrotic areas of the lungs of individuals with fatal asthma. OATD-01 given in a therapeutic treatment regimen inhibited both inflammatory and airway remodeling features of asthma in the HDM model. These changes were accompanied by a significant and dose-dependent decrease in chitinolytic activity in BAL fluid and plasma, confirming in vivo target engagement. Both IL-13 expression and TGFβ1 levels in BAL fluid were decreased and a significant reduction in subepithelial airway fibrosis and airway wall thickness was observed. These results suggest that pharmacological chitinase inhibition offers protection against the development of fibrotic airway remodeling in severe asthma.
Evidence regarding the impact of air pollution on acute respiratory distress syndrome (ARDS) is limited, and most studies focus on ARDS onset. Our study aimed to evaluate whether exposure to fine ...particulate matter interferes with lung recovery and remodeling in a murine model of acute lung injury. Forty-eight mice received nebulized LPS or the vehicle (controls). Blood, BALF, lungs and spleen were collected after 5 weeks of exposure to either PM
(PM and LPS + PM group) or filtered air (control and LPS5w groups). Inflammatory cells and cytokines were assessed in the blood, BALF, lungs and spleen. Stereological analyses and remodeling assessments were performed by histology. The LPS + PM group showed increased BALF leukocytes, characterized by increased macrophages, increased IL-1β and IL-6 levels, anemia and thrombocytopenia. Moreover, we also observed septal thickening, decreased alveolar air space total volume and, septa surface density. Finally, regarding tissue remodeling, we observed elastosis of the lung parenchyma, and unlike in the LPS5w group, we did not observe fibrosis in the LPS + PM group. In conclusion, the delayed inflammation resolution due to subchronic exposure to PM
could be influenced by low systemic and local lymphocyte counts, which lead to impaired lung injury recovery and tissue remodeling.
Studies in adult severe treatment-resistant asthma (STRA) have demonstrated heterogeneous pathophysiology. Studies in the pediatric age group are still scarce, and few include bronchial tissue ...analysis.
We investigated 6-18-year-old patients diagnosed with STRA in Sao Paulo, Brazil, by characterizing the different lung compartments and their correlations with asthma control and lung function.
Inflammatory profiles of 13 patients with a confirmed diagnosis of STRA were analyzed using blood, induced sputum, bronchoalveolar lavage, viral and bacterial screens and endobronchial biopsy. Inflammatory cells, cytokines, and basement membrane thickening were tested for correlations with the asthma control test (ACT) and spirometry and plethysmography parameters.
Endobronchial biopsy specimens from 11 patients were viable for analysis. All biopsies showed eosinophilic infiltration. Submucosal (SM) eosinophils and neutrophils were correlated with worse lung function (pre-BD FEV1), and SM neutrophils were correlated with fixed obstruction (post-BD FEV1). Intraepithelial (IE) neutrophils were positively correlated with lung function (pre-BD sGaw). CD8 + T cells had the highest density in the IE and SM layers and were positively correlated with ACT and negatively correlated with the cytokines IL1β, IL2, IL5, IL7, IL10, IL12, IL17, GCSF, MCP-1, INF-δ, and TNFα in sputum supernatant. The ASM chymase + mast cell density correlated positively with quality-of-life score (pAQLQ) and ACT.
Eosinophils and SM neutrophils correlated with worse lung function, while IE neutrophils correlated with better lung function. Most importantly, CD8 + T cells were abundant in bronchial biopsies of STRA patients and showed protective associations, as did chymase + mast cells.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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Airway remodeling is a prominent feature of asthma, including increased airway smooth muscle (ASM) mass and altered extracellular matrix (ECM) composition. Bronchial thermoplasty ...(BT), a bronchoscopic treatment for severe asthma, targets this airway remodeling.
To investigate the effect of BT on ECM composition and its association with clinical outcomes.
This is a sub-study of the TASMA trial. Thirty severe asthma patients were BT treated, of which 13 patients prior to BT were treated by six months of standard therapy (control group). Demographic data, clinical data including pulmonary function and bronchial biopsies were collected. Biopsies at BT treated and non-treated locations were analyzed by histological and immune-histochemical staining. Associations between histology and clinical outcomes were explored.
Six months after treatment, reticular basement membrane (RBM) thickness was reduced from 7.28μm to 5.74μm (21% relative reduction) and the percentage area of tissue positive for collagen increased from 26.3% to 29.8% (13% relative increase). Collagen structure analysis revealed a reduction in the curvature frequency of fibers. The percentage area positive for fibulin-1 and fibronectin increased with 2.5% and 5.9% respectively (relative increase of 124% and 15%). No changes were found for elastin. The changes in collagen and fibulin-1 negatively associated with changes in FEV1-reversibility.
Next to ASM reduction, BT impacts RBM thickness and the ECM arrangement characterized by an increase in tissue area occupied by collagen with a less dense fiber organization. Both collagen and fibulin-1 are negatively associated with the change in FEV1-reversibility.
BT induces ECM reorganization and airway wall stability.
Life expectancy is increasing worldwide. Lung aging is a process marked by changes in multiple morphological, physiological and age-related biomarkers (e.g., sirtuins) and is influenced by external ...factors, such as air pollution. Hence, the elderly are considered more vulnerable to the air pollution hazards. We hypothesized that diesel exhaust (DE) exposure intensifies changes in lung inflammatory and structural parameters in aging subjects. Two- and fifteen-month-old mice were exposed to DE for 30 days. Lung function was measured using the forced oscillation method. The inflammatory profile was evaluated in the bronchoalveolar lavage fluid (BALF) and blood, and lung volumes were estimated by stereology. Antioxidant enzyme activity was evaluated by spectrophotometry, sirtuin 1 (SIRT1), sirtuin 2 (SIRT2) and sirtuin 6 (SIRT6) expression was assessed by reverse transcription polymerase chain reaction (RT-PCR), and levels of the sirtuin proteins were evaluated by immunohistochemical staining in lung tissues. Older mice presented decreased pulmonary resistance and elastance, increased macrophage infiltration and decreased tumor necrosis factor (TNF) and interleukin 10 (IL-10) levels in the BALF, reduced activities of the antioxidant enzymes glutathione peroxidase (GPx) and glutathione reductase (GR), and increased activity glutathione S-transferase (GST); increased lung volumes with decreased elastic fiber and increased airway collagen content. SIRT1 gene expression was decreased in older animals, but protein levels were increased. DE exposure increased macrophage infiltration and oxidative stress in the lungs of animals of both ages. SIRT6 gene expression was decreased by DE exposure, with increased protein levels. In older animals, DE affected lung structure and collagen content. Lung aging features, such as decreased antioxidant reserves, lower IL-10 expression, and decreased SIRT1 levels may predispose subjects to exacerbated responses after DE exposure. Our data support the hypothesis that strategies designed to reduce ambient air pollution are an important step towards healthy aging.
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•DE exposure accelerates lung aging in mice.•DE exposure decreases the mRNA expression and increases protein expression of SIRT6 in the lung regardless of the mice age.•Anti-oxidant enzymes imbalance occurred due to DE exposure in old and young mice.•Morphological/structural changes and increased collagen content occurred due to DE exposure only in the lungs of aged mice.
Acute respiratory distress syndrome (ARDS) has a high mortality rate of 35-46% depending on its severity. Animal models are crucial to better understand the pathophysiology of diseases, including ...ARDS. This study presents a feasible animal model of acute lung injury (ALI) using nebulized lipopolysaccharide (LPS) in a non-invasive approach, focusing on its short and long-term effects.
Mice received nebulized LPS or vehicle only (control group). Blood, BALF and lung tissue were collected 24 hours (LPS 24h) or 5 weeks (LPS 5w) after the nebulized LPS-induced lung injury. Inflammatory cytokines were assessed in the blood serum, BALF and lung tissue. Stereological analyses and remodeling changes were assessed by histology and immunohistochemistry at the specified time points.
The LPS 24h group showed increased pro-inflammatory cytokine levels, intense cell influx, increased total septal volume, septal thickening and decreased surface density of the alveolar septa. The LPS 5w group showed persistent lung inflammation, septal thickening, increased total lung volume, accentuated collagen deposition, especially of collagen type I, and decreased MMP-2 protein expression.
We present a feasible, reproducible and non-invasive nebulized-LPS animal model that allows the assessment of both the acute and late phases of acute lung injury. The presence of lung remodeling with collagen deposition after 5 weeks makes it useful to study the pathophysiology, complications, and possible therapeutic intervention studies that aim to understand and reduce pulmonary fibrosis in the late phases of ALI.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To compare two different wavelengths of the surgical contact diode laser (CDL) for producing a posterior laryngofissure in in-vivo pigs. Anesthetized pigs underwent a tracheostomy and an anterior ...laryngofissure through a cervicotomy. They were randomly selected for the CDL wavelength and Power, according to the peak of Power set at device (980nm wavelength: Ppeak power of 10 W, 15 W, and 20 W, or 1470 nm wavelength: Ppeak 3 W, 5 W, 7 W, 10 W). At the end of the experiment, the laryngotracheal specimen was extracted and sent for histology and morphometry measurements (incision size, depth, area, and lateral thermal damage). Hemodynamic data and arterial blood gases were recorded during the incisions. Statistical analysis of the comparisons between the parameters and groups had a level of significance of p < 0.05. Twenty-six pigs were divided into CDL 980 nm (n = 11) and 1470 nm (n = 15). There was a greater incision area at the thyroid level in the 980 nm CDL and a wider incision at the trachea level, with a larger distance between mucosa borders. There were no significant differences in the area of lateral thermal damage between the two groups and neither difference among the power levels tested. Both wavelengths tested showed similar results in the various combinations of power levels without significant differences in the lateral thermal damage. The posterior laryngofissure incision can be performed by either of the wavelengths at low and medium power levels without great difference on lateral thermal damage.
•PM2.5 inflammatory response has been studied on mice with or without XPC protein.•XPC-knockout mice show an increased oxidative stress response to PM2.5 exposure.•XPC mice induced 2-fold increase of ...γ-H2AX foci relative to wild type mice.•A high carcinogenic risk was estimated to PAHs and metals exposure in the SPMA.
Air pollution represents a considerable threat to health worldwide. The São Paulo Metropolitan area, in Brazil, has a unique composition of atmospheric pollutants with a population of nearly 20 million people and 9 million passenger cars. It is long known that exposure to particulate matter less than 2.5 µm (PM2.5) can cause various health effects such as DNA damage. One of the most versatile defense mechanisms against the accumulation of DNA damage is the nucleotide excision repair (NER), which includes XPC protein. However, the mechanisms by which NER protects against adverse health effects related to air pollution are largely unknown. We hypothesized that reduction of XPC activity may contribute to inflammation response, oxidative stress and DNA damage after PM2.5 exposure. To address these important questions, XPC knockout and wild type mice were exposed to PM2.5 using the Harvard Ambient Particle concentrator. Results from one-single exposure have shown a significant increase in the levels of anti-ICAM, IL-1β, and TNF-α in the polluted group when compared to the filtered air group. Continued chronic PM2.5 exposure increased levels of carbonylated proteins, especially in the lung of XPC mice, probably as a consequence of oxidative stress. As a response to DNA damage, XPC mice lungs exhibit increased γ-H2AX, followed by severe atypical hyperplasia. Emissions from vehicles are composed of hazardous substances, with polycyclic aromatic hydrocarbons (PAHs) and metals being most frequently cited as the major contributors to negative health impacts. This analysis showed that benzobfluoranthene, 2-nitrofluorene and 9,10-anthraquinone were the most abundant PAHs and derivatives. Taken together, these findings demonstrate the participation of XPC protein, and NER pathway, in the protection of mice against the carcinogenic potential of air pollution. This implicates that DNA is damaged directly (forming adducts) or indirectly (Reactive Oxygen Species) by the various compounds detected in urban PM2.5.
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