Particle pollution in Rio de Janeiro, Brazil: increase and decrease of pro-inflammatory cytokines IL-6 and IL-8 in human lung cells

PM2.5 Extracts Induce INFγ-Independent Activation of CIITA, MHCII, and Increases Inflammation in Human Bronchial Epithelium

The capacity of particulate matter (PM) to enhance and stimulate the expression of pro-inflammatory mediators has been previously demonstrated in non-antigen-presenting cells (human bronchial epithelia). Nonetheless, many proposed mechanisms for this are extrapolated from known canonical molecular pathways. This work evaluates a possible mechanism for inflammatory exacerbation after exposure to PM2.5 (from Puerto Rico) and CuSO4, using human bronchial epithelial cells (BEAS-2B) as a model. The induction of CIITA, MHCII genes, and various pro-inflammatory mediators was investigated. Among these, the phosphorylation of STAT1 Y701 was significantly induced after 4 h of PM2.5 exposure, concurrent with a slight increase in CIITA and HLA-DRα mRNA levels. INFγ mRNA levels remained low amidst exposure time, while IL-6 levels significantly increased at earlier times. IL-8 remained low, as expected from attenuation by IL-6 in the known INFγ-independent inflammation pathway. The effects of CuSO4 showed an increase in HLA-DRα expression after 8 h, an increase in STAT1 at 1 h, and RF1 at 8 h We hypothesize and show evidence that an inflammatory response due to PM2.5 extract exposure in human bronchial epithelia can be induced early via an alternate non-canonical pathway in the absence of INFγ.

Antitumor Effects of Carrier-Free Functionalized Lignin Materials on Human Hepatocellular Carcinoma (HepG2) Cells

Lignin, as an abundant aromatic biopolymer in plants, has great potential for medical applications due to its active sites, antioxidant activity, low biotoxicity, and good biocompatibility. In this work, a simple and ecofriendly approach for lignin fractionation and modification was developed to improve the antitumor activity of lignin. The lignin fraction KL-3 obtained by the lignin gradient acid precipitation at pH = 9-13 showed good cytotoxicity. Furthermore, the cell-feeding lignin after additional structural modifications such as demethylation (DKL-3), sulfonation (SL-3), and demethylsulfonation (DSKL-3) could exhibit higher glutathione responsiveness in the tumor microenvironment, resulting in reactive oxygen species accumulation and mitochondrial damage and eventually leading to apoptosis in HepG2 cells with minimal damage to normal cells. The IC50 values for KL-3, SL-3, and DSKL-3 were 0.71, 0.57, and 0.41 mg/mL, respectively, which were superior to those of other biomass extractives or unmodified lignin. Importantly, in vivo experiments conducted in nude mouse models demonstrated good biosafety and effective tumor destruction. This work provides a promising example of constructing carrier-free functionalized lignin antitumor materials with different structures for inhibiting the growth of human hepatocellular carcinoma (HepG2) cells, which is expected to improve cancer therapy outcomes.

A study on specific factors related to inflammation and autophagy in BEAS-2B cells induced by urban particulate matter (PM, 1648a) and histological evaluation of PM-induced bronchial asthma model in mice

As particulate matter (PM) poses an increasing risk, research on its correlation with diseases is active. However, researchers often use their own PM, making it difficult to determine its components. To address this, we investigated the effects of PM with known constituents on BEAS-2B cells, examining cytokine levels, reactive oxygen species ROS production, DNA damage, and MAPK phosphorylation. Additionally, we evaluated the effects of PM on normal and OVA-induced asthmatic mice by measuring organ weight, cytokine levels, and inflammatory cells in bronchoalveolar lavage fluid, and examining histological changes. PM markedly increased levels of IL-6, GM-CSF, TNF-α, ROS, nitric oxide, and DNA damage, while surprisingly reducing IL-8 and MCP-1. Moreover, PM increased MAPK phosphorylation and inhibited mTOR and AKT phosphorylation. In vivo, lung and spleen weights, IgE, OVA-specific IgE, IL-4, IL-13, total cells, macrophages, lymphocytes, mucus generation, and LC3II were higher in the asthma group. PM treatment in asthmatic mice increased lung weight and macrophage infiltration, but decreased IL-4 and IL-13 in BALF. Meanwhile, PM treatment in the Nor group increased total cells, macrophages, lymphocytes, and mucus generation. Our study suggests that PM may induce and exacerbate lung disease by causing immune imbalance via the MAPK and autophagy pathways, resulting in decreased lung function due to increased smooth muscle thickness and mucus generation.

Causal relationship between particulate matter 2.5 (PM2.5), PM2.5 absorbance, and COVID-19 risk: A two-sample Mendelian randomisation study

Background

Several observational studies reported on the association between particulate matter ≤2.5μm (PM_2.5) and its absorbance with coronavirus (COVID-19), but none use Mendelian randomisation (MR). To strengthen the knowledge on causality, we examined the association of PM_2.5 and its absorbance with COVID-19 risk using MR.

Methods

We selected genome-wide association study (GWAS) integration data from the UK Biobank and IEU Open GWAS Project for two-sample MR analysis. We used inverse variance weighted (IVW) and its multiple random effects and fixed effects alternatives to generally predict the association of PM_2.5 and its absorbance with COVID-19, and six methods (MR Egger, weighted median, simple mode, weighted mode, maximum-likelihood and MR-PRESSO) as complementary analyses.

Results

MR results suggested that PM_2.5 absorbance was associated with COVID-19 infection (odds ratio (OR) = 2.64; 95% confidence interval (CI) = 1.32-5.27, P = 0.006), hospitalisation (OR = 3.52; 95% CI = 1.05-11.75, P = 0.041) and severe respiratory symptoms (OR = 28.74; 95% CI = 4.00-206.32, P = 0.001) in IVW methods. We observed no association between PM_2.5 and COVID-19.

Conclusions

We found a potential causal association of PM_2.5 absorbance with COVID-19 infection, hospitalisation, and severe respiratory symptoms using MR analysis. Prevention and control of air pollution could help delay and halt the negative progression of COVID-19.

Porcine Epidemic Diarrhea Virus and Its nsp14 Suppress ER Stress Induced GRP78

Porcine epidemic diarrhea virus (PEDV), a member of the α-coronavirus genus, can cause vomiting, diarrhea, and dehydration in piglets. Neonatal piglets infected with PEDV have a mortality rate as high as 100%. PEDV has caused substantial economic losses to the pork industry. Endoplasmic reticulum (ER) stress, which can alleviate the accumulation of unfolded or misfolded proteins in ER, involves in coronavirus infection. Previous studies have indicated that ER stress could inhibit the replication of human coronaviruses, and some human coronaviruses in turn could suppress ER stress-related factors. In this study, we demonstrated that PEDV could interact with ER stress. We determined that ER stress could potently inhibit the replication of GⅠ, GⅡ-a, and GⅡ-b PEDV strains. Moreover, we found that these PEDV strains can dampen the expression of the 78 kDa glucose-regulated protein (GRP78), an ER stress marker, while GRP78 overexpression showed antiviral activity against PEDV. Among different PEDV proteins, PEDV non-structural protein 14 (nsp14) was revealed to play an essential role in the inhibition of GRP78 by PEDV, and its guanine-N7-methyltransferase domain is necessary for this role. Further studies show that both PEDV and its nsp14 negatively regulated host translation, which could account for their inhibitory effects against GRP78. In addition, we found that PEDV nsp14 could inhibit the activity of GRP78 promotor, helping suppress GRP78 transcription. Our results reveal that PEDV possesses the potential to antagonize ER stress, and suggest that ER stress and PEDV nsp14 could be the targets for developing anti-PEDV drugs.

Toxicological evaluation of polycrystalline wools in human lung cells

Aim: Polycrystalline wools (PCW) are included with Refractory ceramic fibers (RCF) in the alumino-silicates family of High Temperature Insulation Wools (HTIW). IARC includes PCW in the ceramic fibers group and considers them as possible human carcinogens (GROUP 2B). Since PCW toxicity is not yet clear, our aim was to evaluate their toxic and inflammatory effects and to compare them with the known RCF effects.Method: We exposed human bronchial (BEAS-2B) and alveolar (A549) cells to 2-100 µg/mL (2.4 × 10³-1.2 × 10⁵ fibers/mL; 2.51 × 10³-1.26 × 10⁵ fibers/cm² of PCW and 7.4 × 10³-3.7 × 10⁵ fibers/mL; 7.75 × 10³-3.87 × 10⁵ fibers/cm² of RCF) of the tested fibers to evaluate potential viability reduction, apoptosis, membrane damage, direct/oxidative DNA-damage, cytokine release.Results: In A549, PCW did not induce cytotoxicity and apoptosis but they induced significant dose-dependent DNA-damage, although lower than RCF; only RCF induced oxidative effects. PCW also induced an increase in IL-6 release at 100 µg/mL (1.2 × 10⁵ fibers/mL; 1.26 × 10⁵ fibers/cm²). In BEAS-2B, PCW did not induce cell-viability reduction RCF induced a dose-dependent cell-viability decrease. Both fibers show a dose-dependent increase of apoptosis. In BEAS-2B, PCW also induced dose-dependent DNA-damage, although lower than RCF, and slight oxidative effects similar to RCF. PCW also induced an increase of IL-6 release; RCF induced a decrease of IL-8. Summarizing, PCW induce direct-oxidative DNA-damage although to a lower extent than RCF observed by both mass-based and fiber number-based analysis.Conclusion: For the first time, the study shows the potential toxicity of PCW, usually considered safe, and suggests to perform further in vitro studies, also on other cell types, to confirm these findings.

The Effects and Pathogenesis of PM2.5 and Its Components on Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD), a heterogeneous disease, is the leading cause of death worldwide. In recent years, air pollution, especially particulate matter (PM), has been widely studied as a contributing factor to COPD. As an essential component of PM, PM2.5 is associated with COPD prevalence, morbidity, and acute exacerbations. However, the specific pathogenic mechanisms were still unclear and deserve further research. The diversity and complexity of PM2.5 components make it challenging to get its accurate effects and mechanisms for COPD. It has been determined that the most toxic PM2.5 components are metals, polycyclic aromatic hydrocarbons (PAHs), carbonaceous particles (CPs), and other organic compounds. PM2.5-induced cytokine release and oxidative stress are the main mechanisms reported leading to COPD. Nonnegligibly, the microorganism in PM 2.5 may directly cause mononuclear inflammation or break the microorganism balance contributing to the development and exacerbation of COPD. This review focuses on the pathophysiology and consequences of PM2.5 and its components on COPD.

Increased allergic and asthmatic risks in children residing in industrial areas by surveying the pre-inflammatory (IgE, IL-4 and IL-13) biomarkers

Toxic metal(loid)s can lead to high damages on human. This work was conducted to investigate the levels of metal(loid)s in PM2.5 and a total of 123 male children's (aged 6-9 years) blood chosen from different areas in Ahvaz and their association with the pre-inflammatory (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13) responses in serum cells. Six metal(loid)s (arsenic, cadmium, chromium, mercury, nickel and lead) in three regions including industrial (Padad), vehicle traffic (Golestan) and reference (Kianpars) areas were studied. Results showed the concentrations of As, Cr, Cd, Ni and Hg in the ambient air of industrial area (Padad) (P < 0.001), and Pb in vehicle traffic area (Golestan) were higher (p < 0.001). Moreover, the mean levels of IgE (mean = 146.44 pg/200landa, P < 0.003), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 53.21 pg/200landa, P < 0.001) in Padad were higher than Golestan and Kianpars. Our results suggest that living in industrial areas leads to accelerated synthesis of IgE, IL-4 and IL-13 in blood. The spatial distribution of children's serum IgE, IL-4 and IL-13 concentrations showed an abnormal increase of 240 to 400 pg/200landa for IgE, 950 to 1400 pg/200landa for IL-4 and 90 to 128 pg/200landa for IL-13. Our results indicate children in the industrial area are prone to asthma, allergy, miRNA mutation, and other chronic diseases.

A novel particulate matter sampling and cell exposure strategy based on agar membrane for cytotoxicity study

Laboratories use different strategies to sample and extract atmospheric particulate matter (PM), some of which can be very complicated. Due to the absence of a standard protocol, it is difficult to compare the results of PM toxicity assessment across different laboratories. Here, we proposed a novel PM sampling and cell exposure strategy based on agar membrane. The agar membrane, prepared by a simple freeze-drying method, has a relatively flat surface and porous interior. We demonstrated that the agar membrane was a reliable substitute material for PM sampling. Then the PM on the agar membranes was directly extracted with the culture medium by vortex method, and the PM on the polytetrafluoroethylene (PTFE) filters was extracted with water by the traditional ultrasonic method for comparison. The extraction efficiency was evaluated and in vitro cytotoxicity assays were carried out to investigate the toxic effects of PM extracted with two strategies on macrophage cells. The results showed that the PM extracted from agar membranes induced higher cytotoxicity and more differentially expressed proteins. Overall, the novel PM sampling-cell exposure strategy based on the agar membrane is easy to operate, biocompatible and comparable, and has low disturbance, could be an alternative sampling and extraction method for PM toxicity assessment.

Biomarkers for the adverse effects on respiratory system health associated with atmospheric particulate matter exposure

Large amounts of epidemiological evidence have confirmed the atmospheric particulate matter (PM_2.5) exposure was positively correlated with the morbidity and mortality of respiratory diseases. Nevertheless, its pathogenesis remains incompletely understood, probably resulting from the activation of oxidative stress, inflammation, altered genetic and epigenetic modifications in the lung upon PM_2.5 exposure. Currently, biomarker investigations have been widely used in epidemiological and toxicological studies, which may help in understanding the biologic mechanisms underlying PM_2.5-elicited adverse health outcomes. Here, the emerging biomarkers to indicate PM_2.5-respiratory system interactions were summarized, primarily related to oxidative stress (ROS, MDA, GSH, etc.), inflammation (Interleukins, FE_NO, CC16, etc.), DNA damage (8-OHdG, γH2AX, OGG1) and also epigenetic modulation (DNA methylation, histone modification, microRNAs). The identified biomarkers shed light on PM_2.5-elicited inflammation, fibrogenesis and carcinogenesis, thus may favor more precise interventions in public health. It is worth noting that some inconsistent findings may possibly relate to the inter-study differentials in the airborne PM_2.5 sample, exposure mode and targeted subjects, as well as methodological issues. Further research, particularly by -omics technique to identify novel, specific biomarkers, is warranted to illuminate the causal relationship between PM_2.5 pollution and deleterious lung outcomes.

Effect of ambient air PM2.5-bound heavy metals on blood metal(loid)s and children's asthma and allergy pro-inflammatory (IgE, IL-4 and IL-13) biomarkers

BACKGROUND

We investigated the concentrations of metals in fine particulate matter PM_2.5 in the outdoor air around the home sites of 123 male children from Ahvaz, average age 7.56, along with their blood samples to measure pro-inflammatory responses (Immunoglobulin E and cytokines: IgE, IL-4 and IL-13).

METHODS

We measured 6 metals (As, Cd, Cr, Hg, Ni and Pb) in three Ahvaz's regions including industrial (Padad), vehicle traffic (Golestan) and control (Kianpars).

RESULTS

The higher concentrations of metals in the Padad as the industrial ambient air i.e., arsenic, cadmium, chromium, mercury and nickel coincided with the higher concentrations of those metals in exposed children (P < 0.05) versus the controls. Children in Golestan, the high traffic air pollution area had the highest lead concentrations (p < 0.05). Also a significant association was shown in Padad between blood arsenic and IgE (β = 26.59, P < 0.001), IL-4 (β = 172.1, P < 0.001) and IL-13 (β = 14.84, P < 0.001), blood chromium and IgE (β = 10.38, P < 0.001), IL-4 (β = 75.27, P < 0.001) and IL-13 (β = 5.27, P < 0.001) and blood mercury and IgE (β = 13.11, P < 0.001), IL-4 (β = 108.09, P < 0.001) and IL-13 (β = 7.96, P < 0.001) and blood lead and IgE(β = 0.92, P = 0.025), IL-4(β = 7.16, P < 0.001) and IL-13(β = 0.58, P = 0.003). However, no significant relation was found for Cadmium, Nickel in blood with IgE, IL-4 and IL-13 levels. Moreover, children from industrial areas showed significantly higher concentrations of IgE (mean = 146.44 pg/200landa, P < 0.001), IL-4 (mean = 548.23 pg/200landa, P < 0.001) and IL-13 (mean = 52.93 pg/200landa, P < 0.001) versus Golestan and Kianpars.

CONCLUSION

Children residing in an industrial area with high concentrations of metals in PM_2.5 had high metals in blood and high production of IgE, IL-4 and IL-13, reflecting an immune dysregulation and brisk inflammatory responses.

Airborne fine particulate matter in Japan induces lipid synthesis and inhibits autophagy in HepG2 cells

Inhalation of particulate matter with a diameter less than 2.5 µm has been reported to exacerbates fatty liver disease. However, the components and mechanisms of particulate matter involved in hepatic lipid metabolism and autophagy have not been fully elucidated. We found that atmospheric particulate matter in Japan stimulated lipogenesis in hepatocytes even when its lipid component was removed. Furthermore, we demonstrated that particulate matter did not promote autophagosome formation but inhibited autophagic degradation in hepatocytes. In previous toxicity experiments, particulate matter collected from atmosphere often contained contaminants originating from filters. In this study, we exposed the powdery particulate matter with less contaminants collected using a cyclone and impactor system to HepG2 cells, human hepatocyte. This particulate matter induced lipogenesis and endoplasmic reticulum stress in HepG2 cells as well as previous reports of particulate matter in the USA and China. On the other hand, when autophagic flux were examined in detail, the particulate matter did not promote autophagosome formation, but inhibited autophagic degradation. Since these effects were similar to those of palmitate, a fatty acid, we prepared particulate matter in which lipid component was removed by acetone and compared the effects on HepG2 cells with those of untreated one. The particulate matter without lipid component induced lipid droplets as well as did the untreated one although it induced less endoplasmic reticulum stress. These results suggest that hepatic lipid synthesis is stimulated not only by the uptake of lipid but also by other components in the particulate matter.

[Environmental surveillance of the steel industry by the people: the experiences of Piquiá de Baixo (MA) and Santa Cruz (RJ)]

Environmental surveillance by the people fosters the protagonism of individuals in a situation of environmental vulnerability to generate and evaluate data regarding the pollution to which they are exposed. The scope of this work was to analyze such experiences in two areas impacted by the steel industry: Santa Cruz/RJ and Piquiá de Baixo/MA. At these sites, community environmental monitoring (CEM) activities were conducted to measure 2.5 micrometer particulate matter (PM2.5) levels in the atmosphere, between November/2016 and July/2017. Such activities were conducted using a low-cost and easy-to-operate air quality monitor. Monthly averages of PM2.5 levels in Piquiá and Santa Cruz were high, depending on the period assessed, since they surpassed the annual average recommended by the World Health Organization (WHO) of 10 µg/m3, and, on several occasions, the recommended daily average of 25 µg/m3. The main idea of this monitoring proposal was to establish a process capable of presenting a counterpoint to official information on local atmospheric pollution scenarios, with the involvement of affected communities. The pollution data produced enable these communities to participate in public debates and decision-making processes in a more informed way.

Cytotoxicity and toxicoproteomic analyses of human lung epithelial cells exposed to extracts of atmospheric particulate matters on PTFE filters using acetone and water

Differences of cytotoxicity associated with exposure to different extracts of atmospheric particulate matters (PMs) are still not well characterized by in vitro toxicoproteomics. In this study, in vitro cytotoxicity assays and toxicoproteomic analyses were carried out to investigate toxic effects of PM collected using polytetrafluoroethylene (PTFE) filters extracted with acetone for PM_2.1 and water for PM_2.1 and PM₁₀ on A549 human lung epithelial cells. The cytotoxicity assays based on cell viability, cell apoptosis and reactive oxygen species generation indicated that PM_2.1 extracted with acetone had the highest toxicity. iTRAQ labeling and LC-MS/MS analyses indicated that the number of differentially expressed proteins in A549 cells affected by PM_2.1 extracted with acetone was noticeably higher than that of the other two groups. Hierarchical cluster analyses showed that the influences of the extracts of PM_2.1 and PM₁₀ using water on the proteome of A549 cells were similar, whereas significantly different from the effect of PM_2.1 extracted with acetone. Pathways analyses indicated that PM_2.1 extracted with acetone influenced the expression of proteins involved in 14 pathways including glycolysis/gluconeogenesis, pentose phosphate pathway, proteasome, etc. PM_2.1 extracted with water affected the expression of proteins involved in 3 pathways including non-homologous end-joining, ribosome and endocytosis. However, PM₁₀ extracted with water affected the expression of proteins involved in only spliceosome pathway. The extracts of PM using different extractants to detach PM from PTFE filters influenced the cytotoxic effects of PM and the proteome of A549 cells. Therefore, extractants should be assessed carefully before the investigations on cytotoxicity to improve the compatibility of experimental results among research teams.

Nrf2 positively regulates autophagy antioxidant response in human bronchial epithelial cells exposed to diesel exhaust particles

Diesel exhaust particles (DEP) are known to generate reactive oxygen species in the respiratory system, triggering cells to activate antioxidant defence mechanisms, such as Keap1-Nrf2 signalling and autophagy. The aim of this study was to investigate the relationship between the Keap1-Nrf2 signalling and autophagy pathways after DEP exposure. BEAS-2B cells were transfected with silencing RNA (siRNA) specific to Nrf2 and exposed to DEP. The relative levels of mRNA for Nrf2, NQO1, HO-1, LC3B, p62 and Atg5 were determined using RT-PCR, while the levels of LCB3, Nrf2, and p62 protein were determined using Western blotting. The autophagy inhibitor bafilomycin caused a significant decrease in the production of Nrf2, HO-1 and NQO1 compared to DEPs treatment, whereas the Nrf2 activator sulforaphane increased the LC3B (p = 0.020) levels. BEAS-2B cells exposed to DEP at a concentration of 50 μg/mL for 2 h showed a significant increase in the expression of LC3B (p = 0.001), p62 (p = 0.008), Nrf2 (p = 0.003), HO-1 (p = 0.001) and NQO1 (p = 0.015) genes compared to control. In siRNA-transfected cells, the LC3B (p < 0.001), p62 (p = 0.001) and Atg5 (p = 0.024) mRNA levels and the p62 and LC3II protein levels were decreased, indicating that Nrf2 modulated the expression of autophagy markers (R < 1). These results imply that, in bronchial cells exposed to DEP, the Nrf2 system positively regulates autophagy to maintain cellular homeostasis.

The impact of polar fraction of the fine particulate matter on redox responses in different rat tissues

Particulate matter (PM) contains different chemical substances that have been associated with health effects and an increased risk of mortality due to their toxicity. In this study, fine particulate matter (PM_2.5) samples were collected in a region with rural characteristics (Seropédica (Se)) and another with some industries (Duque de Caxias (DC)) (Brazil, RJ). Rats were exposed to PM_2.5 extracts daily for 25 days at different dilutions: 10×, 5×, and a concentrated solution (CS). Biochemical analyses were investigated for total antioxidant capacity (ACAP), lipid peroxidation (LPO) levels, reduced glutathione (GSH) concentration, activity of glutamate cysteine ligase (GCL), and activity of glutathione S-transferase (GST). The liver showed a significant increase in GCL (DC-5×, DC-CS and Se-CS) and GST activities (DC-CS and Se-CS) in both regions when compared to the control group. In the renal cortex, GCL activity decreased in most of the tested groups while GST activity increased only in the 5× groups of both regions (DC and Se). In the renal medulla, GCL activity decreased for Se-10× and DC-CS but increased for Se-5×, and GST activity increased in the Se-10×, DC-5×, and DC-CS groups. Lung GCL increased in all groups for both regions. Moreover, this organ also showed an increase in GST activity when higher metal concentrations were present (5× and CS). TBARS levels were increased for all tissues in most tested concentrations. These data indicate that soluble compounds (e.g., metals) from PM_2.5 sampled in areas with different pollution indexes can change the redox status and cause damage to different tissues.

Proinflammatory effects of dust storm and thermal inversion particulate matter (PM10) on human peripheral blood mononuclear cells (PBMCs) in vitro: a comparative approach and analysis

Particulate matter (PM) as the carcinogenic air pollutants can lead to aggravated health outcomes. Epidemiological studies demonstrated that PM can be engaged in different diseases such as cardiovascular, respiratory and cancer. The in vitro secretion of proinflammatory cytokines by human peripheral blood mononuclear cells (PBMCs) has been used to assess the effects of PM with an aerodynamic diameter < 10 μm (PM10). This study compared the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 1-beta (IL1-β) secretions of PBMCs exposed to PM10 of dust storm and inversion. We collected PM10 samples during the spring and autumn seasons in two locations. Isolated PBMCs were exposed separately to 50, 150, and 300 μg/ml of different type of PM10 for 4 and 24 h. The mean concentrations of TNF-α for the PM of dust storm and inversion were 6305.61 ± 2421 and 6651.74 ± 2820, respectively. Also the mean concentrations of IL1-β for the PM of dust storm and inversion were 556.86 ± 162 and 656.35 ± 196, respectively. Furthermore, these values for the production of IL-6 were 12,655 ± 5661 and 16,685 ± 8069, respectively. Although no significant difference was observed between the PM of dust storm and that of inversion with regard to PBMCs, the results showed a significant increase in the proinflammatory cytokine secretion of both PMs compared with the controls. Moreover, TNF-α, IL1-β, and IL-6 secreted in cells exposed to PM10 of dust storm were about 10 times more than the controls, these values for cells exposed to PM10 of inversion were around 10, 12, and 14 times more than the controls, respectively. It can be concluded that the PM10 of both dust storm and inversion can play a significant role in proinflammatory cytokine secretion due to its harmful effect on human health. Graphical abstractThis picture shows the Proinflammatory cytokine producing potential of PM10 with two sources (dust storm and urban air pollution) in exposure with human PBMCs in vitro.

Monitoring of air quality before the Olympic Games Rio 2016

For the accomplishment of Olympic and Paralympic Games in Rio de Janeiro city (Rio 2016), the government of the Rio de Janeiro state has undertaken to monitor air quality before and during the events. In Beijing, China, and Athens, Greece, the air quality was monitored in Olympic venues in order to evaluate the athletes' performance in relation to the environment in which they were exposed. This study has the same proposal to Rio de Janeiro, Brazil. The air quality scenario of the three previous years (2013, 2014, 2015) of Rio 2016 was considered. Coarse (PM10) and fine (PM2.5) particles and O3 were monitored continuously on the stations located near to competition venues, as required by International Olympic Committee (IOC). The levels registered ranged from 6 to 96 μg m-3 for PM10, 1 to 44 μg m-3 for PM2.5 and 121 to 269 μg m-3 for O3. These concentrations exceeded the national and international air quality standards. These high concentrations are associated with uncountable civil works to build Olympic arenas and the urban mobility´s improvement. However, the concentrations for all the pollutants monitored in Rio de Janeiro city were in lower concentrations than in Beijing Olympic Games 2008.

Chitosan oligosaccharides alleviate PM2.5-induced lung inflammation in rats

Air pollution of particulate matter (PM), especially PM_2.5, has become a major public health problem in China. Exploration of therapeutic and preventive measures against PM_2.5 toxicity is of practical significance. The aim of this study was to examine the inhibitory effects of chitosan oligosaccharides (COS) on PM_2.5-induced lung inflammation in rats. Forty SPF (specific pathogen-free) male Wistar rats weighing 200-220 g were randomly divided into four groups: control group, COS group, PM_2.5 group, and PM_2.5+COS group. COS was pre-administered to rats by gavage at a single dose of 500 mg/kg 2 h before intratracheal instillation of PM_2.5 at a single dose of 1.2 mg/kg daily for 3 consecutive days. Normal saline (NS) was used as negative control. Twenty-four hours after the last instillation of PM_2.5, rats were sacrificed and subjected to bronchoalveolar lavage (BAL). The BAL fluids (BALF) were collected for measurement of levels of total proteins, lactate dehydrogenase (LDH), interleukin-1 (IL-1β), IL-8, and tumor necrosis factor-ɑ (TNF-ɑ) using colorimetric or ELISA kits. Levels of total proteins, LDH activities, and pro-inflammatory mediators including IL-1β, IL-8, and TNF-ɑ in BALF of rats in PM_2.5 group significantly increased in comparison with those of the control group. Pre-treatment of rats with COS markedly blocked PM_2.5-induced increase in LDH, IL-8, and TNF-ɑ levels in BALF. In conclusion, PM_2.5 exposure induces rat lung inflammation, which could be ameliorated by the pre-treatment of COS.

PM2.5 stimulated the release of cytokines from BEAS-2B cells through activation of IKK/NF-κB pathway

Previous studies indicated that exposure to fine particulate matter (PM_2.5) was related to pulmonary inflammatory diseases through activation of nuclear factor kappa B (NF-κB) signaling pathway to trigger cytokine secretions in human lung carcinoma cells. To investigate the potential mechanisms underlying expression of cytokines via activated NF-κB by PM_2.5, human bronchial epithelial cells (BEAS-2B cells) were treated with PM_2.5 extracts at different concentrations (6, 13, 25, 50, 100, 200, and 400 µg mL^-1) for 6 and 24 h. We found that 100 µg mL^-1 PM_2.5 increased interleukin 6 (IL-6) and IL-8 expression at 24 h (p < 0.05 or p < 0.01). Moreover, 100 µg mL^-1 PM_2.5 upregulated phosphorylated IκB kinase (IKK), p65, and IκBα at 6 h, which could be reversed by the IKK inhibitor Bay11-7082 (p < 0.05 or p < 0.01). The p65 subunit of NF-κB was translocated into the nucleus of the cells treated with 100 µg mL^-1 PM_2.5 at 6 and 24 h. Bay11-7082 partly inhibited PM_2.5-induced increases of IL-6 and IL-8 secretion. The results indicated that PM_2.5 extract increased IL-6 and IL-8 levels in BEAS-2B cells through activation of IKK/NF-κB pathway. Our study will contribute to better understanding of the mechanism of PM_2.5-induced pulmonary inflammatory diseases.

Milan winter fine particulate matter (wPM2.5) induces IL-6 and IL-8 synthesis in human bronchial BEAS-2B cells, but specifically impairs IL-8 release

Inflammatory responses have an important role in the onset of many lung diseases associated with urban airborne particulate matter (PM). Here we investigate effects and mechanisms linked to PM-induced expression and release of two main interleukins, IL-6 and IL-8, in human bronchial epithelial BEAS-2B cells. The cells were exposed to well characterized Milan city PM, winter PM2.5 (wPM2.5) and summer PM10 (sPM10), representing combustion and non-combustion sources, respectively. Both wPM2.5 and sPM10 increased mRNA-synthesis and intracellular protein levels of IL-6 and IL-8. Exposure to sPM10 also resulted in continuous and time-dependent increases in release of IL-6 and IL-8 for up to 48 h. By comparison, in wPM2.5-exposed cells IL-8 release was not significantly augmented, while extracellular IL-6 levels were increased but remained constant beyond 24 h exposure. Moreover, wPM2.5 also reduced the lipopolysaccharide (LPS)-increased release of IL-8. No cytotoxicity or significant adsorption of cytokines to wPM2.5 were observed. Immunofluorescence microscopy revealed an accumulation of IL-8 in intracellular vesicles and alterations in actin filament organization in wPM2.5 exposed cells, suggesting that the trafficking of vesicles carrying interleukins to the plasma membrane might be inhibited. Thus, wPM2.5 appeared to impair cytokine release in BEAS-2B cells, in particular of IL-8, possibly by damaging cytoskeletal function involved in protein secretion.

Aqueous and organic extract of PM2.5 collected in different seasons and cities of Japan differently affect respiratory and immune systems

Particulate matter with diameters <2.5 μm (i.e., PM_2.5) has multiple natural and anthropological sources. The association between PM_2.5 and the exacerbation of respiratory allergy and asthma has been well studied, but the components of PM_2.5 that are responsible for allergies have not yet been determined. Here, we elucidated the effects of aqueous and organic extract of PM_2.5 collected during four seasons in November 2014-December 2015 in two cities (Kawasaki, an industrial area and Fukuoka, an urban area affected by transboundary pollution matter) of Japan on respiratory health. Ambient PM_2.5 was collected by high-volume air samplers and extracted into water soluble and lipid soluble components. Human airway epithelial cells, murine bone marrow-derived antigen-presenting cells (APC) and splenocytes were exposed to PM_2.5 extracts. We measured the cell viability and release of interleukin (IL)-6 and IL-8 from airway epithelial cells, the DEC205 and CD86 expressions on APCs and cell proliferation, and TCR and CD19 expression on splenocytes. The water-soluble or aqueous extracts, especially those from Kawasaki in fall, had a greater cytotoxic effect than the lipid-soluble or organic extracts in airway epithelial cells, but they caused almost no pro-inflammatory response. Extract of fall, especially the aqueous extract from Fukuoka, increased the DEC205 and CD86 expressions on APC. Moreover, aqueous extracts of fall, summer, and spring from Fukuoka significantly increased proliferation of splenocytes. Organic extract of spring and summer from Kawasaki significantly elevated the TCR expression, and organic extract of summer from Kawasaki decreased the CD19 expression. These results suggest that PM_2.5 extract samples are responsible for cytotoxicity in airway epithelial cells and for activating APCs and T-cells, which can contribute to the exacerbation of respiratory diseases such as asthma. These effects can differ by PM_2.5 components, collection areas and seasons.

REDUCTION OF PM2.5 TOXICITY ON HUMAN ALVEOLAR EPITHELIAL CELLS A549 BY TEA POLYPHENOLS

Tea-derived polyphenols have anticancer and antioxidant properties, and they can regulate oxidative stress. This study was designed to quantify both the toxic effects of fine particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) and determine whether tea polyphenols could provide a protective effect against PM2.5 toxicity on human alveolar epithelial A549 cells in vitro. Cytotoxic effects of the PM2.5 on A549 cells were measured by means of cell viability, the expression of caspase-3, bax/bcl-2 and C/EBP-homologous protein (CHOP), and the generation of intracellular reactive oxygen species, malondialdehyde and superoxide dismutase. The results showed that tea polyphenols ameliorated some of the adverse effects of PM2.5 on A549 cell viability and superoxide dismutase levels. In addition, tea polyphenols decreased the production of reactive oxygen species, malondialdehyde generation, and apoptosis in response to PM2.5 exposure. Therefore, our results support a role for tea polyphenols in reducing the toxicity of PM2.5, particularly with regard to targeting oxidative stress and apoptosis.

Crucial role of pro-inflammatory cytokines from respiratory tract upon PM2.5 exposure in causing the BMSCs differentiation in cells and animals

Fine particulate matter exposure may cause health risk, including cardiovascular diseases and cancer. Bone marrow mesenchymal stem cell (BMSC), a typical model for evaluating pollutant toxicity, has been closely linked to these diseases, due to its characteristics of differentiation. We therefore studied the BMSCs differentiation and its roles in inflammatory activation in the respiratory tract upon PM2.5 exposure using both in vitro and in vivo models. BMSCs differentiation into endothelial-like cells (ELCs) and cancer-associated fibroblasts cells (CAFs) was enhanced in response to conditioned medium from PM2.5-treated 16HBE cells. PM2.5 elevated inflammatory cytokines' expression and secretion in 16HBE cells. However, induction of differentiation markers was reduced when IL-1β, IL-6 and COX-2 neutralizing antibodies were added to the conditioned medium. Furthermore, PM2.5 induced ROS formation and NADPH oxidase (NOX) expression in 16HBE cells. DPI (inhibitor of ROS from NOX) or NAC (inhibitor of ROS) supplement reduced PM2.5-induced inflammatory activation and BMSCs differentiation. Likewise, a concomitant disorder of mitochondrial morphology and respiratory chain was observed. In addition, Rot or AA (inhibitor of mitochondrial complex I or III) supplement restored PM2.5-induced toxic effects. Moreover, the results coincided with the in vitro data obtained from SD rats post-exposed to different doses of PM2.5 for 30 days. PM2.5 enhanced the BMSCs differentiation and inflammatory cytokines' expression in respiratory organs of SD rats, including lung and trachea tissue. This study uncovers that PM2.5 promotes the BMSCs differentiation via inflammatory activation mediated by ROS induction from NOX and mitochondria in the respiratory tract.

MiR-26a functions as a tumor suppressor in ambient particulate matter-bound metal-triggered lung cancer cell metastasis by targeting LIN28B-IL6-STAT3 axis

Exposure to ambient particulate matter (PM) has been linked to the increasing incidence and mortality of lung cancer, but the principal toxic components and molecular mechanism remain to be further elucidated. In this study, human lung adenocarcinoma A549 cells were treated with serial concentrations of water-extracted PM₁₀ (WE-PM₁₀) collected from Beijing, China. Our results showed that exposure to 25 and 50 μg/ml of WE-PM₁₀ for 48 h significantly suppressed miR-26a to upregulate lin-28 homolog B (LIN28B), and in turn activated interleukin 6 (IL6) and signal transducer and activator of transcription 3 (STAT3) in A549 cells, subsequently contributing to enhanced epithelial-mesenchymal transition and accelerated migration and invasion. In vivo pulmonary colonization assay further indicated that WE-PM₁₀ enhanced the metastatic ability of A549 cells. In addition, luciferase reporter assay demonstrated that 3' untranslated region of LIN28B was a direct target of miR-26a. Last but not the least, the key toxic contribution of metals in WE-PM₁₀ was confirmed by the finding that removal of metals through chelation significantly rescued WE-PM₁₀-mediated inflammatory, carcinogenic and metastatic responses. Taken together, miR-26a could act as the tumor suppressor in PM₁₀-related lung cancer, and PM₁₀-bound metals promoted lung cancer cell metastasis through downregulation of miR-26a that directly mediated LIN28B expression.

Synergistic effect of carbon nuclei and polyaromatic hydrocarbons on respiratory and immune responses

Particulate matter with aerodynamic diameter ≤2.5 μm (PM_2.5 ) is generally composed of carbon nuclei associated with various organic carbons, metals, ions and biological materials. Among these components, polyaromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BaP) and quinones have detrimental effects on airway epithelial cells and immunodisrupting effects, which leads to the exacerbation of respiratory allergies. The effects of PAHs and the carbon nuclei, separately as well as in combination, remain to be established. We investigated the effects of BaP, 9,10-phenanthroquinone (9,10-PQ), and 1,2-napthoquinone (1,2-NQ) and their combined effects with heated diesel exhaust particle (H-DEP) as carbon nuclei of typical PM_2.5 . We exposed human airway epithelial cells (BEAS-2B), murine bone marrow-derived antigen-presenting cells (APCs), and murine splenocytes to BaP, 9,10-PQ, or 1,2-NQ in the presence and absence of H-DEP. Several important inflammatory cytokines and cell surface molecules were measured. PAHs alone did not have apparent cytotoxic effects on BEAS-2B, whereas combined exposure with H-DEP induced noticeable detrimental effects which mainly reflected the action of H-DEP itself. BaP increased CD86 expression as an APC surface molecule regardless of the presence or absence of H-DEP. None of the BaP, 9,10-PQ, or 1,2-NQ exposure alone or their combined exposure with H-DEP resulted in any significant activation of splenocytes. These results suggest that PAHs and carbon nuclei show additive effects, and that BaP with the carbon nuclei may contribute to exacerbations of allergic respiratory diseases including asthma by PM_2.5 , especially via antigen-presenting cell activation.

Selective ATP-Binding Cassette Subfamily C Gene Expression and Proinflammatory Mediators Released by BEAS-2B after PM2.5, Budesonide, and Cotreated Exposures

ATP-binding cassette subfamily C (ABCC) genes code for phase III metabolism proteins that translocate xenobiotic (e.g., particulate matter 2.5 (PM_2.5)) and drug metabolites outside the cells. IL-6 secretion is related with the activation of the ABCC transporters. This study assesses ABCC1–4 gene expression changes and proinflammatory cytokine (IL-6, IL-8) release in human bronchial epithelial cells (BEAS-2B) exposed to PM_2.5 organic extract, budesonide (BUD, used to control inflammation in asthmatic patients), and a cotreatment (Co-T: PM_2.5 and BUD). A real-time PCR assay shows that ABCC1 was upregulated in BEAS-2B exposed after 6 and 7 hr to PM_2.5 extract or BUD but downregulated after 6 hr of the Co-T. ABCC3 was downregulated after 6 hr of BUD and upregulated after 6 hr of the Co-T exposures. ABCC4 was upregulated after 5 hr of PM_2.5 extract, BUD, and the Co-T exposures. The cytokine assay revealed an increase in IL-6 release by BEAS-2B exposed after 5 hr to PM_2.5 extract, BUD, and the Co-T. At 7 hr, the Co-T decreases IL-6 release and IL-8 at 6 hr. In conclusion, the cotreatment showed an opposite effect on exposed BEAS-2B as compared with BUD. The results suggest an interference of the BUD therapeutic potential by PM_2.5.

Human health impact assessment of exposure to particulate matter: an AirQ software modeling

The aim of this study was to assess the health impacts related to particulate matter less than 10 μm (PM₁₀) exposure in the city of Yazd, Iran. For this aim, AirQ 2.2.3 software was used to model relationship between short-term exposure to PM₁₀ and disease cases proposed by the World Health Organization (WHO). The annual mean concentration of PM₁₀ was 97 μg/m³. The maximum concentration value of PM₁₀ was measured during the summer (731 μg/m³). 4.988% (95%CI: 3.381-6.542%) of the total mortality, 7.3% (95%CI; 4.19-10.21%) of cardiovascular mortality, and 10.21% (95%CI; 4.19-14.89%) of respiratory mortality were related to the PM₁₀ concentrations. Consequently, the AirQ software can provide valuable information about the importance of air pollution and the substantial impacts of PM₁₀ on the society for policymakers.

Serum cytokine levels related to exposure to volatile organic compounds and PM2.5 in dwellings and workplaces in French farmers - a mechanism to explain nonsmoking COPD

Although French farmers smoke less on average than individuals from the general population, they suffer more from COPD. Exposure to biological and chemical air pollutants in the farm may be the cause of these higher COPD rates. This study investigates the role of bio-contaminants, including the relationship of exposure to volatile organic compounds (VOCs) and fine particulate matter (of diameter of 2.5 µm [PM_2.5]) objectively measured in the farm settings (dwellings and workplaces) to serum cytokines involved in COPD, in a sample of 72 farmers from 50 farms in the Auvergne region, France. Mean concentrations of VOCs were highest inside the home, while levels of PM_2.5 were highest in workplaces (stables and granaries). After adjusting for confounders, high exposure to PM_2.5 was significantly associated with a decreased level of serum cytokines (among others, IL13: β: −0.94, CI: −1.5 to −0.2, P-value =0.004; IL8: β: −0.82, CI: −1.4 to −0.2, P-value =0.005) and high exposure to VOCs according to a VOC global score with a decreased IL13 level (β: −0.5, CI: −0.9 to −0.1, P-value =0.01). Moreover, respiratory symptoms and diseases, including COPD, were associated with a decreased level of serum cytokines significantly in the case of IL5. An alteration of immune response balance in terms of cytokine levels in relation to indoor chemical air pollution exposure may contribute to respiratory health impairment in farmers.

Diesel exhaust particles (DEP) pre-exposure contributes to the anti-oxidant response impairment in hCMEC/D3 during post-oxygen and glucose deprivation damage

Recently, air pollution has been identified as a significant modifiable risk factor to the increasing stroke burden. Diesel exhaust particles, characterized by high polycyclic aromatic hydrocarbons content, constitute an important component of outdoor air pollution and is known to cause oxidative stress, and could therefore contribute to and exacerbate the effects of ROS in post-ischemic injury. hCMEC/D3 cells have been submitted to 48h treatment with diesel exhaust particles (25μg/ml and 50μg/ml, DEP50) or alternatively to 3h of oxygen and glucose deprivation, followed by 1h of oxygen and glucose restoration. The combined treatment consisted in 48h of diesel exhaust particles (25μg/ml and 50μg/ml, DEP50) followed by 3h of oxygen and glucose deprivation and 1h of restoration. A panel of markers related to oxidative stress and inflammatory responses, such as transcription factors (Nrf2 and HIF-1α), anti-oxidant proteins (HO-1, SOD-1, Hsp70) and proteins potentially inducing further oxidative-stress or inflammation (Cyp1b1, iNOS, COX-2, TNF-α, IL-1α, IL-1β, IL-8, VEGF), have been examined. Data obtained showed that diesel exhaust particles and oxygen and glucose deprivation treatments alone elicited the antioxidants response, each by means of a different transcription factor, while the combined treatment led to a dysregulation of the antioxidant response during ischemic injury reperfusion.

Air quality in the Olona Valley and in vitro human health effects

Air quality is a major point in current health policies in force globally to protect human health and ecosystems. Cardiovascular and lung diseases are the pathologies most commonly associated with air pollution and it has been estimated that exposure to particulate matters and ground-level ozone and nitric oxides caused >500.000 premature deaths in Europe. Although air quality was generally improved in the recent years, further efforts are required to reduce the impact of air pollution on humans. The present study applied a multidisciplinary approach to estimate the adverse effects on the health of the inhabitants of the Olona Valley in the north of Italy. Chemical analyses quantified the air levels of metals, dioxins, PCBs, PAHs and some macropollutants, including total, fine and coarse airborne particles. These results were used as input for the health risk assessment and in vitro bioassays were used to evaluate possible adverse effects on the respiratory tract due to the organic pollutants adsorbed on the airborne particulate matter. Critical alerts were identified from the air characterization and from the chemical-based risk assessment in view of the levels of arsenic, nickel, benzene, fine and coarse particulate matters found in the investigated zone, which can induce severe adverse effects on human health. These findings were confirmed by bioassays with A549 and BEAS-2B cells. We also used the cell transformation assay with BALB/c 3T3 cells to assess the carcinogenicity of the organic extracts of collected particles as an innovative tool to establish the possible chronic effects of inhaled pollutants. No significant changes in morphological transformation were found suggesting that, although the extracts contain compounds with proven carcinogenic potential, in our experimental conditions the levels of these pollutants were too low to induce carcinogenesis as resulted also by the chemical-based risk assessment.

Effects of Components of PM2.5 Collected in Japan on the Respiratory and Immune Systems

Epidemiologic studies have reported that particulate matter with aerodynamic diameters ≤2.5 μm (PM_2.5) affect respiratory diseases, including asthma. The components and/or factors of PM_2.5 that contribute to the exacerbation of asthma have not been identified. We investigated the effects of extracts of PM_2.5 collected in Japan on the respiratory and immune systems. PM_2.5 was collected from an industrial area and an urban area in December 2013. Airway epithelial cells and immune cells were exposed to aqueous or organic extracts of PM_2.5. Exposure to extracts from both areas, especially to organic extracts rather than aqueous extracts, caused a pro-inflammatory response via interleukin (IL) 6 production from airway epithelial cells, and it induced the maturation/activation of bone marrow-derived antigen-presenting cells via dendritic and epithelial cell (DEC) 205 and cluster of differentiation (CD) 86 expression and proportional changes in the constitution of the splenocytes. The extracts collected from the industrial area tended to show greater effects than those from the urban area. These results suggest that organic components of PM_2.5 affect the respiratory and immune systems. These effects can differ by the collection areas. In addition, IL-6, DEC205, and CD86 can be predictive biomarkers for the respiratory and immune effects of ambient PM_2.5.

Toxicological effects of particulate matter (PM2.5) on rats: Bioaccumulation, antioxidant alterations, lipid damage, and ABC transporter activity

Previous studies have demonstrated the harmful effects of atmospheric pollutants on cardiac systems because of the presence of particulate matter (PM), a complex mixture of numerous substances including trace metals. In this study, the toxicity of PM2.5 from two regions, rural (PM2.5 level of 8.5 ± 4.0 μg m(-3)) and industrial (PM2.5 level of 14.4 ± 4.1 μg m(-3)) in Brazil, was investigated through in vivo experiments in rats. Metal accumulation and biochemical responses were evaluated after rats were exposed to three different concentrations of PM2.5 in saline extract (10× dilution, 5× dilution, and concentrated). The experimental data showed the bioaccumulation of diverse trace metals in the hearts of groups exposed to PM2.5 from both regions. Furthermore, mobilization of the antioxidant defenses and an increase in lipid peroxidation of the cardiac tissue was observed in response to the industrial and rural area PM2.5. Glutathione-S-transferase activity was increased in groups exposed to the 5× and concentrated rural PM2.5. Additionally, ATP-binding cassette (ABC) transporter activity in the cardiac tissue exposed to PM2.5 was reduced in response to the 5× dilution of the rural and industrial region PM2.5. Histological analysis showed a decrease in the percentage of cardiac cells in the heart at all tested concentrations. The results indicate that exposure to different concentrations of PM2.5 from both sources causes biochemical and histological changes in the heart with consequent damage to biological structures; these factors can favor the development of cardiac diseases.

Biodiesel from soybean promotes cell proliferation in vitro

Toxicological responses of exhaust emissions of biodiesel are different due to variation in methods of generation and the tested biological models. A chemical profile was generated using ICP-MS and GC-MS for the biodiesel samples obtained in Brazil. A cytotoxicity assay and cytokine secretion experiments were evaluated in human bronchial epithelial cells (BEAS-2B). Cells were exposed to polar (acetone) and nonpolar (hexane) extracts from particles obtained from fuel exhaust: fossil diesel (B5), pure soybean biodiesel (B100), soybean biodiesel with additive (B100A) and ethanol additive (EtOH). Biodiesel and its additives exhibited higher organic and inorganic constituents on particles when compared to B5. The biodiesel extracts did not exert any toxic effect at concentrations 10, 25, 50, 75, and 100μgmL(-1). In fact quite the opposite, a cell proliferation effect induced by the B100 and B100A extracts is reported. A small increase in concentrations of inflammatory mediators (Interleukin-6, IL-6; and Interleukin-8, IL-8) in the medium of biodiesel-treated cells was observed, however, no statistical difference was found. An interesting finding indicates that the presence of metals in the nonpolar (hexane) fraction of biodiesel fuel (B100) represses cytokine release in lung cells. This was revealed by the use of the metal chelator. Results suggest that metals associated with biodiesel's organic constituents might play a significant role in molecular mechanisms associated to cellular proliferation and immune responses.

Human bronchial epithelial cells exposed in vitro to diesel exhaust particles exhibit alterations in cell rheology and cytotoxicity associated with decrease in antioxidant defenses and imbalance in pro- and anti-apoptotic gene expression

Diesel exhaust particles (DEPs) from diesel engines produce adverse alterations in cells of the airways by activating intracellular signaling pathways and apoptotic gene overexpression, and also by influencing metabolism and cytoskeleton changes. This study used human bronchial epithelium cells (BEAS-2B) in culture and evaluates their exposure to DEPs (15ug/mL for 1 and 2 h) in order to determine changes to cell rheology (viscoelasticity) and gene expression of the enzymes involved in oxidative stress, apoptosis, and cytotoxicity. BEAS-2B cells exposed to DEPs were found to have a significant loss in stiffness, membrane stability, and mitochondrial activity. The genes involved in apoptosis [B cell lymphoma 2 (BCL-2 and caspase-3)] presented inversely proportional expressions (p = 0.05, p = 0.01, respectively), low expression of the genes involved in antioxidant responses [SOD1 (superoxide dismutase 1); SOD2 (superoxide dismutase 2), and GPx (glutathione peroxidase) (p = 0.01)], along with an increase in cytochrome P450, family 1, subfamily A, polypeptide 1 (CYP1A1) (p = 0.01). These results suggest that alterations in cell rheology and cytotoxicity could be associated with oxidative stress and imbalance between pro- and anti-apoptotic genes.

Progression and inflammation of human myeloid leukemia induced by ambient PM2.5 exposure

PM2.5 (aerodynamic diameter ≤2.5 μm) has been a dominating and ubiquitous air pollutant and has become a global concern. Emerging evidences suggest a positive correlation between PM2.5 and leukemia, but the underlying molecular mechanisms remain unclear and need to be elucidated. Here, we assessed the impacts of PM2.5 on the progression and inflammation of human myeloid leukemia at lower environmental doses and explored the possible pathway. We showed that PM2.5 exposure significantly induced the leukemia cell growth and enhanced the release of inflammatory mediators in both in vitro and in vivo models. Additionally, NF-κB p65 and p-STAT3 were activated in PM2.5-treated leukemia cells, with a concomitant increase in both ROS formation and NADPH oxidase expressions. Strikingly, the supplement of inhibitors, including NAC (ROS), PDTC (NF-κB), or WP1066 (STAT3), contributed to a decline in leukemia cell growth. Furthermore, enhanced expressions of inflammatory cytokines were attenuated by the addition of NAC or PDTC, but not affected by WP1066. This study demonstrates that PM2.5 promotes leukemia progression, identifies a potential intervention target, and provides further understanding of the detrimental effect of PM2.5 exposure on human health.