Despite scientific evidence and government actions aimed at reducing air pollution, it remains a major public health issue in large urban centers, compromising human health, particularly among the most vulnerable populations, including the elderly. Polyphenolic compounds are believed to have antiaging effects, reducing DNA damage and exhibiting anti-inflammatory and antioxidant properties. The polyphenol resveratrol (Resv) has demonstrated protective effects in the lungs against harmful stimuli in adult mice; however, few studies have extended these investigations to elderly animals, which have reduced antioxidant responses. This study aimed to evaluate the effects of Resv on the lungs of 15-month-old mice exposed to diesel exhaust (DE). Animals were exposed to 1200 & micro;g/m3 of PM2.5 over 30 consecutive days. Resv (1200 & micro;g/m3) was administered for 40 days, beginning 10 days before DE exposure. We evaluated the inflammatory profile in bronchoalveolar lavage fluid (BALF) and serum; quantified macrophages; and assessed antioxidant enzymes (glutathione peroxidase [GPx], glutathione reductase [GR], glutathione-S-transferase [GST], and copper/zinc superoxide dismutase [Cu/Zn SOD]), 8-OHdG, 8-iso-prostaglandin F2 alpha (8-isoprostane), collagen and elastic fiber content, and sirtuin protein levels (Sirt1, Sirt2, and Sirt6) in the lung parenchyma. Resv administration increased GR and Sirt1 levels and decreased Sirt2 levels. DE caused inflammatory changes in BALF and lung tissue, increased 8-OHdG and 8-isoprostane levels, and modulated antioxidant enzymes, sirtuins, and lung collagen. Resv administration after DE exposure did not significantly alter 8-OHdG, antioxidant enzymes, sirtuins, or collagen levels in the lungs, but it reduced BALF cellularity and IL-1 beta and 8-isoprostane levels. Our data suggest moderate protective effects of Resv in aged lungs exposed to DE.

Background 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. Methods 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. Results 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 2 /FiO 2 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. Conclusions 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.

Fine particulate matter (PM2.5) is a complex mixture of components with diverse chemical and physical characteristics associated with increased respiratory and cardiovascular diseases mortality. Our study aimed to investigate the effects of exposure to concentrated PM2.5 on LPS-induced lung injury onset. BALB/c male mice were exposed to either filtered air or ambient fine PM2.5 in an ambient particle concentrator for 5 weeks. Then, an acute lung injury was induced with nebulized LPS. The animals were euthanized 24 h after the nebulization to either LPS or saline. Inflammatory cells and cytokines (IL-1β, IL-4, IL-5, IL-6, IL-10, IL-17, TNF) were assessed in the blood, bronchoalveolar lavage fluid (BALF), and lung tissue. In addition, lung morphology was assessed by stereological methods. Our results showed that the PM+LPS group showed histological evidence of injury, leukocytosis with increased neutrophils and macrophages, and a mixed inflammatory response profile, with increased KC, IL-6, IL-1β, IL-4, and IL-17. Our analysis shows that there is an interaction between the LPS nebulization and PM2.5 exposure, differently modulating the inflammatory response, with a distinct response pattern as compared to LPS or PM2.5 exposure alone. Further studies are required to explain the mechanism of immune modulation caused by PM2.5 exposure.

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 PM2.5 (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 PM2.5 could be influenced by low systemic and local lymphocyte counts, which lead to impaired lung injury recovery and tissue remodeling.

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.

Background: The sirtuins family plays an important role in aging. These proteins are modulated by environmental factors and life style. It is believed that air pollution impacts adversely lung aging. Aims and objective: This study investigates if diesel exhaust (DE) exposure modulates gene expression of Sirt1, Sirt2 and Sirt6 in old mice. Methods: Two and 15 month-old C57/BL6 mice (n=10/group) were exposed to DE (1200ug/m3 1hour/day) or filtered air in an exposure chamber during 30 days. After the exposure period, lung samples were collected for Sirt1, Sirt2 and Sirt6 RT-PCR and anti-oxidative enzymes analyses. Results: Sirt1 mRNA expression was decreased in aged animals, without effect of the exposure. Sirt6 mRNA expression was decreased due to diesel exposure in both groups, no difference was observed in Sirt2 expression. SOD1 levels were increased in exposed animals. GPx, GR and GST were differentially expressed in older mice, without effects of exposure. See table. Conclusion: Aging affects Sirt1 gene expression. DE exposure decreases Sirt6. The decreased levels of Sirt1 and 6 associated with altered antioxidant system in older mice could adversely impact lung aging.

Background and objectiveAcute 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.MethodsMice 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.ResultsThe 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.ConclusionWe 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.

Epidemiological evidence from different parts of the world show that gestational exposure to air pollution are associated with reduced birth weight. However, results are divergent regarding which pollutant and which trimester of pregnancy presents the highest risks. The present study aimed to investigate experimentally the association between gestational (GS) exposure to the ambient levels of urban air pollution and the risk of low birth weight in mice exposed to real world concentration of PM2.5 and further explore if maternal pre-gestational (MPG) exposures are relevant for this outcome. Experiments were carried out in Sao Paulo city where the source of air pollution is predominantly automotive. Mice were raised and maintained in two inhalation chambers, one receiving ambient air (P) and the other filtered air (C) 24hs/day. Females (n=100) were mated with non-exposed males and divided in 10 groups submitted to differential exposure protocols (Pre-gestational and three gestational periods in order to mimic the trimesters of human gestation). Gestations resulted in 508 live born pups that were weighted after birth. We used a logistic regression to estimate the association between reduced birth weight and MPG and G exposure to PM2.5 which was assessed by daily mean concentration inside chambers. Daily mean PM2.5 concentration during the studies period were 6.4 µm³ in C and 32.8 µm³ in P (p= 0.002). Results show that the maternal exposure increases the risk of low birth weight in 11.17% and the critical gestational stage exposure was GS1, which corresponds to the 1st trimester in humans, increasing the risk in 5.4 %. Our findings agree with results obtained from epidemiological study in humans suggesting that the early gestational exposure to air pollution are critical to increased risk for low birth weight and has shown for the first time that maternal pre-gestational exposure to PM2.5 are more critical for this outcome.

Estudos epidemiologicos e experimentais tem mostrado consistentemente que tanto as exposicoes agudas e cronicas a poluicao do ar estao associadas com uma variedade de doencas cardiovasculares. A poluicao atmosferica e composta por uma mistura de substâncias nocivas incluindo particulas e gases. Os efeitos adversos cardiovasculares sao mais comumente atribuidos as particulas e experimentos toxicologicos tem demonstrado diferentes mecanismos pelos quais a exposicao as particulas pode provocar estes efeitos. Neste estudo nos investigamos os efeitos do tempo (7, 15 e 21 dias) de exposicao as particulas ambientais (dose = 600 g/m³) nos parâmetros funcionais e morfologicos do coracao de ratos normais e ratos com hipertrofia ventricular esquerda (HVE) induzida pelo isoproterenol (agonista nao seletivo -adrenergico de acao direta) (1,2 mg/kg). A utilizacao de ratos com HVE foi motivado pelo fato de que a existencia de uma doenca cardiovascular previa representa um fator de risco elevado para estes individuos. Nossos dados mostraram que o tempo de exposicao ao material particulado concentrado e um fator importante para a magnitude dos efeitos sobre a funcao e morfologia do coracao, como mostrado pelo aumento da variabilidade da frequencia cardiaca, diminuicao da frequencia cardiaca e aumento no volume de tecido conjuntivo no miocardio do ventriculo esquerdo. Os ratos com HVE mostraram efeitos similares, porem mais graves sobre o coracao, que incluiram diminuicao da pressao arterial e aumento da hipertrofia dos cardiomiocitos em comparacao com ratos com HVE nao expostos. Concluindo, nossos resultados corroboram com achados anteriores que mostram que a poluicao atmosferica particulada induz alteracoes no controle autonomico do coracao e que individuos com doencas cardiovasculares preexistentes sao mais afetados que individuos normais. Mostramos ainda que o material particulado concentrado e capaz de induzir alteracoes na microestrutura do miocardio, dependendo da dose acumulada de exposicao%%%%Epidemiological and experimental studies have consistently shown that both short- and long-term exposures to air pollution are associated with a variety of cardiovascular diseases. Air pollution is composed by a mixture of noxious substance including particles and gases. The cardiovascular adverse effects are more commonly attributed to particles and toxicological experiments have demonstrated several mechanisms by which particle exposure may trigger these effects. In this study we investigated the effects of time (7, 15 and 21 days) of exposure to concentrated ambient particles (dose = 600 g/m³) on morphofunctional parameters of the heart in normal and rats with left ventricular hypertrophy (LVH) induced by isoproterenol (nonselective -adrenergic agonist with direct action) (1.2 mg/kg). The use of LVH rats was motivated by the fact that individuals with cardiovascular diseases are considered at higher risk for effect of ambient PM. Our data have shown that time is an important factor on the magnitude of the effects of concentrated…

Analysis of fuel emissions is crucial for understanding the pathogenesis of mortality because of air pollution. The objective of this study is to assess cardiovascular and inflammatory toxicity of diesel and biodiesel particles. Mice were exposed to fuels for 1 h. Heart rate (HR), heart rate variability, and blood pressure were obtained before exposure, as well as 30 and 60 min after exposure. After 24 h, bronchoalveolar lavage, blood, and bone marrow were collected to evaluate inflammation. B100 decreased the following emission parameters: mass, black carbon, metals, CO, polycyclic aromatic hydrocarbons, and volatile organic compounds compared with B50 and diesel; root mean square of successive differences in the heart beat interval increased with diesel (p < 0.05) compared with control; low frequency increased with diesel (p < 0.01) and B100 (p < 0.05) compared with control; HR increased with B100 (p < 0.05) compared with control; mean corpuscular volume increased with B100 compared with diesel (p < 0.01), B50, and control (p < 0.001); mean corpuscular hemoglobin concentration decreased with B100 compared with B50 (p < 0.001) and control (p < 0.05); leucocytes increased with B50 compared with diesel (p < 0.05); platelets increased with B100 compared with diesel and control (p < 0.05); reticulocytes increased with B50 compared with diesel, control (p < 0.01), and B100 (p < 0.05); metamyelocytes increased with B50 and B100 compared with diesel (p < 0.05); neutrophils increased with diesel and B50 compared with control (p < 0.05); and macrophages increased with diesel (p < 0.01), B50, and B100 (p < 0.05) compared with control. Biodiesel was more toxic than diesel because it promoted cardiovascular alterations as well as pulmonary and systemic inflammation.