Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 231
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Gene ; 740: 144570, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32165298

RESUMO

Recent studies have found multiple single nucleotide variants (SNVs) associated with DNA damage. However, previous association analysis may ignore the potential interaction effects between SNVs. Therefore, we used an improved random forest (RF) analysis to identify the SNVs related to personal DNA damage in exon-focused genome-wide association study (GWAS). A total of 301 subjects from three independent centers (Zhuhai, Wuhan, and Tianjin) were retained for analysis. An improved RF procedure was used to systematically screen key SNVs associated with DNA damage. Furthermore, we used genetic risk score (GRS) and mediation analysis to investigate the integrative effect and potential mechanism of these genetic variants on DNA damage. Besides, gene set enrichment analysis was conducted to identify the pathways enriched by key SNVs using the Data-driven Expression Prioritized Integration for Complex Traits (DEPICT). Finally, a set of 24 SNVs with the lowest mean square errors (MSE) were identified by improved RF analysis. Both weighted and unweighted GRSs were associated with increased DNA damage levels (Pweight < 0.001 and Punweight < 0.001). Gene set enrichment analysis indicated that these loci were significantly enriched in several biological features associated with DNA damage. These findings suggested the role of SNVs in modifying DNA damage levels. It may be convincing that this improved RF analysis can effectively identify SNVs associated with DNA damage levels.


Assuntos
Dano ao DNA , Material Particulado/toxicidade , China , Dano ao DNA/genética , Dano ao DNA/fisiologia , Interpretação Estatística de Dados , Humanos , Material Particulado/sangue , Material Particulado/metabolismo , Polimorfismo de Nucleotídeo Único
2.
Environ Pollut ; 256: 113342, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31676093

RESUMO

PM2.5 exposure aggravates type 2 diabetes, in which inflammatory factors play an important role. In this study, we aimed to explore the mechanisms responsible for aggravating diabetes after PM2.5 exposure, and study the roles of inflammatory factors in insulin-resistant type 2 diabetes. Our study indicated that short-time PM2.5 exposure enhances insulin resistance in type 2 diabetic rats and significantly raises inflammatory factors, including IL-6, TNF-α, and MCP-1, in lungs. However, we found that of these inflammatory factors only IL-6 levels are elevated in blood, liver, adipose tissue, and macrophages, but not in skeletal muscle. IL-6 induced activation of the STAT3/SOCS3 pathway in liver, but not other downstream pathways including STAT1, ERK1/2, and PI3K. Both STAT3 inhibition and IL-6 neutralization effectively alleviated the disorders of glucose metabolism after PM2.5 exposure. Taken together, this suggests that the systemic increase in IL-6 may play an important role in the deterioration of the type 2 diabetes via IL-6/STAT3/SOCS3 pathway in liver after short-time exposure to PM2.5. Besides, we unexpectedly found a stronger resistance to the PM2.5 exposure-induced increase in IL-6 in skeleton muscle than those of many other tissues.


Assuntos
Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Tipo 2/imunologia , Interleucina-6/sangue , Material Particulado/toxicidade , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Animais , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/metabolismo , Resistência à Insulina , Fígado/efeitos dos fármacos , Fígado/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/imunologia , Material Particulado/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais
3.
Chemosphere ; 239: 124734, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31494317

RESUMO

Dam construction and fish culture can change the biogeochemical processes in river, yet their impact on the spectral properties of particulate organic matter (POM) remains to be studied. This was investigated in a reservoir-type river (Minjiang river, SE China) using absorption spectroscopy and fluorescence excitation-emission matrices-parallel factor analysis (EEMs-PARAFAC). Five fluorescent components were identified from POM with PARAFAC. Four components C1-C4 were affected by the seasonal variations of rainfall and runoff, indicating the influences of hydrological condition and terrestrial inputs. The Chlorophyll a concentration (Chl a) correlated significantly with the humic-like C3 (p < 0.05) and the protein-like C4 (p < 0.01), indicating phytoplankton was an important source of C3 and C4. The Chl a and fluorescence intensities of C3-C4 were higher in the fish culture zones than in other areas, and the absorption coefficient a300 and C1-C4 were lower downstream the dam. These results indicated that fish farming in the reservoir probably promoted the production of POM. The a300 and C1 per unit mass of suspended particulate matter (a300/TSM and C1/TSM) correlated significantly with the median particle size (p < 0.01), which might be related to the contribution of micro-phytoplankton. The absorption spectra of POM showed a shoulder peak at ∼280 nm, and its intensity correlated significantly and positively with Chl a (p < 0.01). These results indicated that the peak was probably derived from phytoplankton production. Our results have implications for better understanding the influences of human activities on the dynamics of river POM.


Assuntos
Pesqueiros , Material Particulado/metabolismo , Rios/química , Espectrometria de Fluorescência/métodos , China , Clorofila A/metabolismo , Monitorização de Parâmetros Ecológicos , Monitoramento Ambiental/métodos , Análise Fatorial , Fluorescência , Tamanho da Partícula , Material Particulado/análise , Fitoplâncton , Chuva , Estações do Ano
4.
Environ Pollut ; 255(Pt 1): 113366, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31668954

RESUMO

Air pollution is one of the leading preventable threats to public health. Emerging evidence indicates that exposure to environmental stressors is associated with abnormal foetal development. However, how prenatal exposure to diesel exhaust PM2.5 (DEP) predisposes adult offspring to the development of non-alcoholic fatty liver disease (NAFLD) remains unclear. To examine this, C57BL/6J mice were exposed to DEP or a vehicle before conception and during pregnancy and fed normal chow or a high-fat diet. Then, the hepatic fatty accumulation in the adult male offspring and possible molecular mechanisms were assessed. Our data showed that prenatal exposure to DEP on normal chow led to hepatic steatosis in adult male offspring with normal liver function. However, prenatal DEP exposure relieved the hepatic steatosis and liver function in offspring of mice fed a high-fat diet. Furthermore, prenatal exposure to DEP on normal chow increased lipogenesis and worsened fatty acid oxidation. The counteractive effect of prenatal DEP exposure on high-fat-diet-induced hepatic steatosis was produced through upregulated adenosine 5'-monophosphate-activated protein kinase, and this improved lipogenesis and fatty acid oxidation. Collectively, prenatal exposure to DEP programmed the development of NAFLD differently in the adult male offspring of mice fed normal chow and a high-fat diet, showing the pleotrophic effects of exposure to adverse environmental factors in early life.


Assuntos
Dieta Hiperlipídica , Hepatopatia Gordurosa não Alcoólica , Material Particulado/toxicidade , Emissões de Veículos/toxicidade , Crianças Adultas , Poluição do Ar , Animais , Feminino , Desenvolvimento Fetal , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Material Particulado/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo
5.
Environ Pollut ; 255(Pt 3): 113331, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31614245

RESUMO

We previously found that folic acid (FA) attenuated cardiac defects in zebrafish embryos exposed to extractable organic matter (EOM) from PM2.5, but the underlining mechanisms remain to be elucidated. Since DNA methylation is crucial to cardiac development, we hypothesized that EOM-induced aberrant DNA methylation changes could be diminished by FA supplementation. In this study, zebrafish embryos were exposed to EOM in the absence or presence of FA. Genomic-wide DNA methylation analysis identified both DNA hypo- and hyper-methylation changes in CCGG sites in zebrafish embryos exposed to EOM, which were attenuated by FA supplementation. We identified a total of 316 genes with extensive DNA methylation changes in EOM samples but little or no DNA methylation changes in EOM plus FA samples. The genes were involved in critical cellular processes and signaling pathways important for embryo development. In addition, the EOM-decreased SAM/SAH ratio was counteracted by FA supplementation. Furthermore, FA attenuated the EOM-induced changes in the expression of genes involved in the regulation of DNA methylation and in folate biosynthesis. In conclusion, our data suggest that FA supplementation protected zebrafish embryos from the cardiac developmental toxicity of PM2.5 by alleviating EOM-induced DNA methylation changes.


Assuntos
Ácido Fólico/metabolismo , Material Particulado/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Metilação de DNA/efeitos dos fármacos , Desenvolvimento Embrionário/efeitos dos fármacos , Coração/efeitos dos fármacos , Material Particulado/metabolismo , Transdução de Sinais/efeitos dos fármacos , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo
6.
Environ Sci Pollut Res Int ; 26(31): 32476-32487, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31617135

RESUMO

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 (PM2.5) 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 PM2.5 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 PM2.5 sampled in areas with different pollution indexes can change the redox status and cause damage to different tissues.


Assuntos
Antioxidantes/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Animais , Glutamato-Cisteína Ligase , Glutationa Transferase/metabolismo , Metais/química , Material Particulado/química , Ratos , Substâncias Reativas com Ácido Tiobarbitúrico/química
7.
J Toxicol Sci ; 44(9): 633-641, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474744

RESUMO

Asian Sand Dust-Particulate Matter (ASD-PM) aerosol brings large amounts of wind-eroded soil particles containing high concentrations of metallic components caused by industrialization and vehicles. Proinflammatory and cytotoxic cytokines trigger local inflammatory responses and cause a systematically high incidence of cardiovascular and other diseases. Tenascin C (Tn-C) is known to be expressed in damaged tissue or in a developmental stage of tissue. In this study, we examined the expression of Tn-C and Fibronectin in human cancer-cell lines and in liver tissue of mice treated with ASD-PM to investigate the inflammatory and cell-damage effects of ASD-PM. In our in vivo study, mice were intratracheally instilled with saline suspensions of ASD-PM particles. Instillation of these particles was repeated twice a week for 12 weeks and the liver tissues were stained with hematoxylin, eosin, and Masson's trichrome, and we carried out an IF. Tn-C expression in liver tissues was detected by RT-PCR and western blot analysis. In the results, the expression of Tn-C increased in a dose-dependent manner in both RNA and Immunofluorescence assay (IF). In our in vitro study, A549 and Hep3B cell lines were incubated in culture media with Transforming Growth Factor-Beta1(TGF-ß1) and ASD-PM. Immunofluorescence microscopy images showed a two times stronger expression of fluorescence in the ASD-treated group than in that treated with TGF-ß1. They also showed a stronger expression of Tn-C in proportion to the concentration of ASD-PM. We confirmed that ASD-PM when inhaled formally migrated to other organs and induced Tn-C expression. ASD-PM containing metals causes expression of Tn-C in liver tissue in proportion to the concentration of ASD-PM.


Assuntos
Carcinoma Hepatocelular/metabolismo , Poeira , Exposição Ambiental/efeitos adversos , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Material Particulado/toxicidade , 24975 , Tenascina/metabolismo , Aerossóis , Animais , Linhagem Celular Tumoral , China , Fibronectinas/genética , Fibronectinas/metabolismo , Expressão Gênica , Humanos , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mongólia , Material Particulado/metabolismo , Tenascina/genética
8.
Environ Pollut ; 254(Pt A): 112933, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31382213

RESUMO

Exposure to fine atmospheric Particulate Matter (PM) is one of the major environmental causes involved in the development of inflammatory lung diseases, such as chronic obstructive pulmonary disease (COPD) or asthma. When PM is penetrating in the pulmonary system, alveolar macrophages represent the first line of defense, in particular by triggering a pro-inflammatory response, and also by their ability to recruit infiltrating macrophages from the bone marrow. The aim of this in vitro study was to evaluate the gene expression and cytokine production involved in the toxicological and inflammatory responses of infiltrating macrophages, as well as the Extracellular Vesicles (EVs) production, after their exposure to PM. The ability of these EVs to convey information related to PM exposure from exposed macrophages to pulmonary epithelial cells was also evaluated. Infiltrating macrophages respond to fine particles exposure in a conventional manner, as their exposure to PM induced the expression of Xenobiotic Metabolizing Enzymes (XMEs) such as CYP1A1 and CYP1B1, the enzymes involved in oxidative stress SOD2, NQO1 and HMOX as well as pro-inflammatory cytokines in a dose-dependent manner. Exposure to PM also induced a greater release of EVs in a dose-dependent manner. In addition, the produced EVs were able to induce a pro-inflammatory phenotype on pulmonary epithelial cells, with the induction of the release of IL6 and TNFα proinflammatory cytokines. These results suggest that infiltrating macrophages participate in the pro-inflammatory response induced by PM exposure and that EVs could be involved in this mechanism.


Assuntos
Poluentes Atmosféricos/toxicidade , Células Epiteliais/metabolismo , Vesículas Extracelulares/metabolismo , Macrófagos Alveolares/metabolismo , Material Particulado/toxicidade , Poluentes Atmosféricos/metabolismo , Linhagem Celular , Citocinas/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Pulmão/metabolismo , Pneumopatias/induzido quimicamente , Estresse Oxidativo , Tamanho da Partícula , Material Particulado/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Chemosphere ; 235: 794-804, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31280048

RESUMO

Particulate matter (PM) is a risk factor for lung cancer development and chromosomal missegregation and cell cycle disruptions are key cellular events that trigger tumorigenesis. We aimed to study the effect of PM10 (PM with an aerodynamic diameter ≤10 µm) on mitotic arrest and chromosomal segregation, evaluating the spindle assembly checkpoint (SAC) protein dynamics in the human lung A549 adenocarcinoma cell line. For this purpose, synchronized cells were exposed to PM10 for 24 h to obtain the frequency of micronucleated (MN) and trinucleated (TN) cells. Then, the efficiency of the mitotic arrest after PM10 exposure was analyzed. To elucidate the effect of PM10 in chromosomal segregation, the levels and subcellular localization of essential SAC proteins were evaluated. Results indicated that A549 cells exposed to PM10 exhibited an increase in MN and TN cells and a decrease in mitotic indexes and G2/M phase. A549 cells treated with PM10 showed reduced protein levels of MDC1 and NEK2 (38% and 35% respectively), which is required for MAD2 recruitment to kinetochores, MAD2 and BUBR1, effectors of the SAC (25% and 18% respectively), and CYCLIN B1, required during G2/M phase (35%). Besides, PM10 exposure increase the levels of AURORA B and SURVIVIN, required for SAC activation through chromosome-microtubule attachment errors (85% and 74% respectively). We suggest that PM10 causes mitotic slippage due to alterations in MAD2 localization. Thus, PM10 causes inadequate chromosomal segregation and deficient mitotic arrest by altering SAC protein levels, predisposing A549 cells to chromosomal instability, a common feature observed in cancer.


Assuntos
Material Particulado/toxicidade , Testes de Toxicidade , Aurora Quinase B , Carcinogênese , Pontos de Checagem do Ciclo Celular , Segregação de Cromossomos , Humanos , Cinetocoros , Pontos de Checagem da Fase M do Ciclo Celular , Proteínas Mad2 , Microtúbulos , Mitose , Quinases Relacionadas a NIMA , Neoplasias , Material Particulado/metabolismo , Fuso Acromático
10.
PLoS One ; 14(7): e0218752, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31276538

RESUMO

Nitrate can be reduced to other N inorganic species via denitrification and incorporated into organic matter by immobilization; however, the effect of biotic/abiotic and redox condition on immobilization and denitrification processes from a single system are not well documented. We hypothesize nitrate (NO3-) transformation pathways leading to the formation of dissolved- and solid-phase organic N are predominantly controlled by abiotic reactions, but the formation of soluble inorganic N species is controlled by redox condition. In this study, organic matter in the form of leaf compost (LC) was spiked with 15NO3- and incubated under oxic/anoxic and biotic/abiotic conditions at pH 6.5. We seek to understand how variations in environmental conditions impact NO3- transformation pathways through laboratory incubations. We find production of NH4+ is predominantly controlled by redox whereas NO3- conversion to dissolved organic nitrogen (DON) and immobilization in solid-phase N are predominantly controlled by abiotic processes. Twenty % of added 15N-NO3- was incorporated into DON under oxic conditions, with abiotic processes accounting for 85% of the overall incorporation. Nitrogen immobilization processes resulted in N concentrations of 4.1-6.6 µg N (g leaf compost)-1, with abiotic processes accounting for 100% and 66% of the overall (biotic+abiotic) N immobilization under anoxic and oxic conditions, respectively. 15N-NMR spectroscopy suggests 15NO3- was immobilized into amide/aminoquinones and nitro/oxime under anoxic conditions. A fraction of the NH4+ was produced abiotically under anoxic conditions (~10% of the total NH4+ production) although biotic organic N mineralization contributed to most of NH4+ production. Our results also indicate Fe(II) did not act as an electron source in biotic-oxic incubations; however, Fe(II) provided electrons for NO3- reduction in biotic-anoxic incubations although it was not the sole electron source. It is clear that, under the experimental conditions of this investigation, abiotic and redox processes play important roles in NO3- transformations. As climatic conditions change (e.g., frequency/intensity of rainfall), abiotic reactions that shift transformation pathways and N species concentrations from those controlled by biota might become more prevalent.


Assuntos
Ferro/metabolismo , Nitratos/metabolismo , Compostos Orgânicos/metabolismo , Material Particulado/metabolismo , Acer/metabolismo , Anaerobiose , Biotransformação , Desnitrificação , Concentração de Íons de Hidrogênio , Nitritos/metabolismo , Compostos de Nitrogênio/metabolismo , Isótopos de Nitrogênio/metabolismo , Óxidos de Nitrogênio/metabolismo , Oxirredução , Folhas de Planta/metabolismo
11.
Environ Sci Pollut Res Int ; 26(19): 19749-19762, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31089995

RESUMO

In the present study, the distribution and chemical fractionation of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in PM2.5 collected at Sikandarpur in Agra from September 2015 to February 2016 were carried out to evaluate their mobility potential, environmental, and human health risk through inhalation. Sequential extraction procedure was applied to partition the heavy metals into four fractions (soluble and exchangeable fraction (F1); carbonates, oxides, and reducible fraction (F2); bound to organic matter, oxidizable, and sulphidic fraction (F3); and residual fraction (F4)) in PM2.5 samples. The metals in each fraction were analyzed by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Daily PM2.5 concentration ranged between 13 and 238 µg m-3 during the study period. For more than 92% of the days, the mass concentrations were greater than the National Ambient Air Quality Standard (NAAQS) set at 60 µg m-3. The total mass concentration of the eight metals was 3.3 µg m-3 that accounted for 2.5% of the PM2.5 mass concentration and followed the order Fe > Zn > Cu > Mn > Pb > Ni > Cd > Cr in dominance. The carcinogenic metals (Cd, Cr, Ni, and Pb) comprised 10% of the total metal determined. Almost all the metals had the highest proportion in the residual fraction (F4) except Ni, which had the highest proportion in the reducible fraction (F2). Chemical fractionation and contamination factor (CF) showed that Pb and Ni are readily mobilized and more bioavailable. Risk assessment code (RAC) showed that Cd, Cu, Mn, Ni, Pb, and Zn had medium environmental risk, while Cr and Fe had low risk. When the bioavailable (F1 + F2) concentrations were applied to calculate non-carcinogenic and carcinogenic risk, the results showed that the value of hazard index (HI) for toxic metals was 1.7 for both children and adults through inhalation. The integrated carcinogenic risk was 1.8 × 10-6 for children and 7.3 × 10-6 for adults, with both values being higher than the precautionary criterion (1 × 10-6). Enrichment factor (EF) calculations showed that Cd, Pb, Zn, and Ni were enriched being contributed by anthropogenic activities carried out in the industrial sectors of the city.


Assuntos
Monitoramento Ambiental/métodos , Exposição por Inalação/análise , Metais Pesados/análise , Material Particulado/análise , Adulto , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Disponibilidade Biológica , Fracionamento Químico , Criança , Cidades , Feminino , Humanos , Índia , Exposição por Inalação/efeitos adversos , Metais Pesados/metabolismo , Material Particulado/metabolismo , Medição de Risco
12.
Artigo em Inglês | MEDLINE | ID: mdl-30708968

RESUMO

The potential of urban greening plants to capture particulate matter (PM) from the ambient atmosphere is contingent on interactions between the level of pollution and leaf surfaces. For this study, thirteen plant species were investigated to quantify their capacity of PM accumulation under three atmospheric environments, that is, industrial, traffic and university campus (control), in Kunming City (Southwest China). The sampled sites represented different pollution levels (that is, high pollution, slight pollution and clean air, respectively). The plant species differed in their accumulation of PM by six- to eight-fold across the three sites. Magnolia grandiflora was the most efficient evergreen tree species, whereas Platanus acerifolia had the highest capture of PM among deciduous trees. The accumulation capacity of the same species varied with the degree of pollution. For example, Osmanthus fragrans, Loropetalum chinense and Cinnamomum japonicum were highly efficient for the capture of PM in the traffic and university campus areas; however, they exhibited medium accumulation in the industrial area. Prunus majestica demonstrated an intermediate accumulation capacity in the industrial area, but was low in the traffic and university campus areas. The capturing capacity of the same genus was also different among the different levels of pollution. For example, C. japonicum had a 2.9⁻4.2-times higher PM accumulation than did C. camphora across the three sites. There were significant differences in leaf surface area, stomata density/length, guard cell area, and trichome density/length among these species. The species-specific efficacy of PM capture was primarily contributed to by leaf size and surface roughness, stomata density, and trichome length. In particular, hairy-leaf leaves with medium stomatal density exhibited higher PM capture. Therefore, leaf micromorphology, leaf size and longevity appeared to be significant predictive factors for the accumulation of PM, which may aid in the selection of greening plant species for the remediation of pollutants in urban areas.


Assuntos
Poluentes Atmosféricos/metabolismo , Recuperação e Remediação Ambiental/estatística & dados numéricos , Material Particulado/metabolismo , Folhas de Planta/metabolismo , Plantas/metabolismo , China , Cidades , Recuperação e Remediação Ambiental/métodos , Folhas de Planta/anatomia & histologia , Plantas/anatomia & histologia , Plantas/classificação , Especificidade da Espécie
13.
Environ Pollut ; 248: 269-278, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30798028

RESUMO

Exposure to ambient particular matters (PM) has been associated with the development of non-alcoholic fatty liver disease (NAFLD), but the underlying mechanism remains unclear. Given that microRNA (miRNA) is recognized as a key regulator of lipid metabolism and a potential mediator of environmental cues, this study aimed to explore the role of miRNA-mRNA regulation underlying abnormal lipid metabolism triggered by PM2.5liposoluble extracts. We confirmed that 72-h exposure to liposoluble extracts of PM2.5 from Nanjing at 25 µg/cm2 induced lipid accumulation in HepG2 cells by promoting uptake of free fatty acids (FFAs). Notably, lipid accumulation induced by PM2.5 liposoluble extracts was associated with decreased expression of miR-26a and consequent upregulation of fatty acid translocase (FAT, also known as CD36). Using gain- and loss-of-function assays, we demonstrated that miR-26a negatively regulated CD36 to mediate lipid accumulation in HepG2 cells. We further confirmed that miR-26a directly acted on the 3' untranslated region (3'UTR) of CD36. Furthermore, overexpression of miR-26a abolished steatosis in HepG2 cells treated with PM2.5 liposoluble extracts by suppressing CD36. In addition, we demonstrated that PM2.5 liposoluble extracts caused inflammation in HepG2 cells by raising p65 phosphorylation, thereby fuelling the transition from simple non-alcoholic fatty liver to non-alcoholic steatohepatitis. In conclusion, this study demonstrated a novel mechanism by which miR-26a-CD36 pathway mediated lipid accumulation induced by PM2.5 liposoluble extracts in hepatocytes. Lipid accumulation and inflammation induced by PM2.5 liposoluble extracts implied the potential role of PM2.5 in developing NAFLD.


Assuntos
Poluentes Atmosféricos/toxicidade , Material Particulado/toxicidade , Testes de Toxicidade , Animais , Transporte Biológico , Células Hep G2 , Hepatócitos , Humanos , Metabolismo dos Lipídeos , Lipídeos , Fígado/metabolismo , MicroRNAs/metabolismo , Hepatopatia Gordurosa não Alcoólica , Material Particulado/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Transdução de Sinais , Regulação para Cima
14.
Free Radic Biol Med ; 130: 206-214, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30420332

RESUMO

Exposure to fine particulate matter (PM2.5) can induce oxidative stress and proinflammatory cytokine production, which are central for the induction of PM2.5-mediated adverse effects on public health. Nuclear factor kappa B (NF-κB) signaling is essential for inflammation. The subcellular distribution of thioredoxin (Trx) is related to the activation of NF-κB, but the mechanism involved is unclear. In the current study, we focused on the relationship between the antioxidant Trx and NF-κB in human bronchial epithelial cells (BEAS-2B) after PM2.5 exposure. We inhibited the nuclear translocation of Trx by cHCEU (4-cyclohexyl-[3-(2-chloroethyl)ureido]benzene) and subsequently increased the transcriptional activity of Nrf2 to upregulate the expression of Trx by t-BHQ. Our data suggest that PM2.5 exposure induces the activation of NF-κB and the expression of the downstream proinflammatory cytokines IL-1, IL-6, IL-8 and TNF-α in BEAS-2B cells. CHCEU alleviates inflammatory cytokines by blocking Trx nuclear translocation and inhibits the DNA binding activity of NF-κB. T-BHQ could promote the transcriptional activity of Nrf2 but failed to alleviate the production of inflammatory cytokines. Furthermore, the synergistic effect of t-BHQ and cHCEU on alleviating PM2.5-induced inflammation is more effective than the use of cHCEU alone. Our findings characterize the underlying molecular mechanisms of proinflammatory responses induced by PM2.5 and show that the nuclear translocation and accumulation of Trx in nuclei play important roles in PM2.5-induced NF-κB activation and proinflammatory responses.


Assuntos
Brônquios/patologia , Núcleo Celular/metabolismo , Células Epiteliais/metabolismo , Inflamação/metabolismo , Material Particulado/metabolismo , Tiorredoxinas/metabolismo , Transporte Ativo do Núcleo Celular , Poluentes Atmosféricos , Linhagem Celular , Citocinas/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica , Humanos , Mediadores da Inflamação/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Agregação Patológica de Proteínas , Ativação Transcricional
15.
Environ Pollut ; 244: 549-559, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30384061

RESUMO

Aquatic systems are important sinks of antibiotics; however, their final destination has not been completely elucidated. Therefore, we investigated the adsorption behaviors of suspended particulate matter (SPM) in lakes to support the analysis of the migration and transformation of antibiotics in lacustrine environments. SPM was collected from Meiliang Bay (ML) and Gonghu Bay (GH) in Lake Taihu, China, which was sieved into four particle sizes of >300, 150-300, 63-150, and <63 µm for subsequent antibiotic adsorption experiments. All particles exhibited rapid and substantial adsorption of tetracycline and norfloxacin. Most size fractions fit a Langmuir model, indicative of monomolecular adsorption, except the <63-µm fraction, which fit a Freundlich model. Particle size had a substantial influence on antibiotic adsorption; the 63-150-µm fraction had the greatest adsorption capacity, while the >300-µm fraction had the lowest capacity. The influence of particle size on adsorption was mainly related to SPM physicochemical properties, such as cation exchange capacity, surface area, and organic matter content, rather than types of functional groups. Considering the mass ratios, the <63-µm fraction had the greatest contribution to adsorption. Antibiotics adsorbed onto the SPM from ML and GH exhibited different behaviors. The ML SPM settled more readily into sediment, and larger, denser particles were more resistant to resuspension. Conversely, the GH SPM was more likely to be found in the water column, and larger, less-dense particles remained in the water column. These results help improve our understanding of the interactions between SPM and antibiotics in aquatic systems.


Assuntos
Antibacterianos/metabolismo , Sedimentos Geológicos/química , Norfloxacino/metabolismo , Material Particulado/metabolismo , Tetraciclina/metabolismo , Poluentes Químicos da Água/análise , Adsorção/fisiologia , Antibacterianos/análise , China , Lagos/química , Norfloxacino/análise , Tamanho da Partícula , Material Particulado/análise , Tetraciclina/análise , Água/análise
16.
Ecotoxicol Environ Saf ; 168: 9-16, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30384172

RESUMO

Cold exposure aggravates respiratory diseases, which are also influenced by the exposures to particulate matter and endotoxin in the air. The aim of this study was to investigate the potential interactions among cold stress, fine particulate matter (PM2.5, particles with aerodynamic diameter of 2.5 µm or less) and lipopolysaccharide (LPS, pure chemical form of endotoxin) on rat lung and to explore the related possible mechanisms of the interactions. Wistar rats were randomly grouped to be exposed to, 1) normal saline (0.9% NaCl), 2) PM2.5, 3) LPS, and 4) PM2.5 and LPS (PM2.5 + LPS) through intratracheal instillation under cold stress (0 °C) and normal temperature (20 °C). Lung function, lung tissue histology, inflammatory response and oxidative stress levels were measured to examine the lung injury and to investigate the potential mechanisms. Exposure to PM2.5 or LPS substantially changed pulmonary function [indicated by peak inspiratory flow (PIF) and peak expiratory flow (PEF)], inflammatory cytokine levels [indicated by interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] and lung histology, compared to the non-exposed groups. Exposure to PM2.5 + LPS under cold stress induced the most significant changes, including the increases of IL-6, TNF-α and thiobarbituric acid-reactive substances (TBARS), the decreases of PIF and PEF and more severe lung injury, among all exposure scenarios. Glutathione peroxidase activity and, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were found to be suppressed under cold stress, whereas Nrf2 and HO-1 levels were observed to be upregulated by exposure to PM2.5 or LPS under normal temperature. In conclusion, cold stress may aggravate the lung injury in rats induced by simultaneous exposure to PM2.5 and LPS. The progress may involve the suppressing of Nrf2/HO-1 signal pathway.


Assuntos
Resposta ao Choque Frio/fisiologia , Lipopolissacarídeos/toxicidade , Lesão Pulmonar/etiologia , Material Particulado/toxicidade , Animais , Citocinas/metabolismo , Pulmão/patologia , Lesão Pulmonar/patologia , Masculino , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/fisiologia , Material Particulado/metabolismo , Distribuição Aleatória , Ratos Wistar , Transdução de Sinais/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
17.
Chemosphere ; 216: 396-403, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30384309

RESUMO

Epidemiological studies and experimental research have illustrated that PM2.5 has an association with cardiovascular adverse events. However, the underlying mechanisms are still unknown. Long non-coding RNAs (lncRNAs) have been proposed to take part in diverse diseases. To comprehensively gain insight into the molecular toxicity of PM2.5, expression patterns are analyzed in EA.hy926 cell line through RNAs microarray. A total of 356 lncRNA transcripts are dysregulated in 2.5 µg/cm2 group, and there are 1283 lncRNAs differentially expressed in 10 µg/cm2 group. From functional analysis, several lncRNAs may be implicated in the bio-pathways of phagosome, TNF signaling pathway, chemokine signaling pathway and gap junction. Moreover, certain lncRNAs participate in the toxicity of PM2.5 through cis- and/or trans-regulation of their co-expressed genes. Therefore, lncRNAs may be used as new candidate biomarkers and potentially preventive targets in cardiotoxicity of PM2.5. Our study indicates that not limited to transcriptional regulation, post-transcriptional regulation plays a pivotal role in PM2.5-caused toxicity.


Assuntos
Células Endoteliais/metabolismo , Regulação da Expressão Gênica/genética , Material Particulado/metabolismo , RNA Longo não Codificante/genética , Linhagem Celular , Humanos
18.
Sci Total Environ ; 650(Pt 1): 56-64, 2019 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-30195131

RESUMO

In this study, 46 PM2.5 samples collected from Nanjing, China were analyzed for total PAH concentration, with 14 samples assessed for PAH inhalation bioaccessibility and dioxin toxicity. The concentration of 19 PAH compounds in PM2.5 ranged from 4.03 to 102 ng m-3. When PAH inhalation bioaccessibility was assessed using simulated epithelial lung fluid, mean bioaccessibility values ranged from 3.21% (Benzo(c)fluorene) to 44.2% (Acenaphthylene). Benzo(a)pyrene concentration in 50% of the PM2.5 samples exceeded the Chinese air quality standard of 2.5 ng m-3, however, when bioaccessibility was considered, all samples were below the criterion. Similarly, the cancer risk probability for all PM2.5 samples was >10-4 incidences on the basis of total PAH concentration, while only 37% of samples posed a risk >10-4 after incorporation of bioaccessibility. Dioxin toxicity of PM2.5-bound PAHs was also investigated by characterizing mRNA expression of cytochrome P450 superfamily members in human lung cells (A549 cell). Compared to total PAH concentration, the use of bioaccessible concentration was better at predicting dioxin toxicity of PM2.5-associated PAHs (correlation coefficient R2 = 0.40-0.83 with p < 0.05). This study indicates that PAH inhalation bioaccessibility is an important consideration when assessing and predicting the risk posed by PM2.5 particles, which is particularly important for countries with deteriorating air quality.


Assuntos
Poluentes Atmosféricos/metabolismo , Exposição por Inalação/análise , Material Particulado/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Atmosféricos/toxicidade , Disponibilidade Biológica , China , Dioxinas/toxicidade , Humanos , Material Particulado/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Medição de Risco , Estações do Ano
19.
Toxicol Appl Pharmacol ; 361: 81-88, 2018 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-30563646

RESUMO

Human autopsied lung sections from a resident in the Quebec asbestos region were examined. The study utilized high resolution transmission electron microscopy, scanning transmission electron microscopy (HRTEM/STEM) with the analytical capabilities of electron energy loss spectroscopy (EELS) and energy dispersive spectroscopy (EDS) detectors. We report the first analytical ultrastructural characteristics of EMPs, detailing chemical concentration gradients inside the iron-protein coatings and lateral elemental gradients in the local tissue regions. It is shown that the EMPs are subjected to bioprocessing which involves physicochemical transformations and also an elemental transport mechanism that alters the inhaled EMP as well as the surrounding cellular matrix. At high resolution imaging the iron-rich coating around the EMP was observed to have a distinct channel-like nanostructure with some parallel aligned nanofibrils that are reminiscent of tooth enamel which consists of biomineralized nanocomposites with alternating organic/inorganic matrices.


Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Exposição por Inalação/efeitos adversos , Pulmão/metabolismo , Minerais/toxicidade , Material Particulado/toxicidade , Poluentes Ocupacionais do Ar/metabolismo , Autopsia , Humanos , Pulmão/patologia , Pulmão/ultraestrutura , Microscopia Eletrônica de Transmissão , Minerais/metabolismo , Nanopartículas/metabolismo , Nanopartículas/toxicidade , Material Particulado/metabolismo , Pleura/metabolismo , Fibrose Pulmonar/patologia , Espectrometria por Raios X
20.
Chem Res Toxicol ; 31(12): 1398-1404, 2018 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30479130

RESUMO

The deposition and transport of toxicants on pulmonary surfactant are important processes in human health and medical care. We have introduced classical density functional theory (CDFT) to provide insight into this process. Nine typical toxicants in PM2.5 were considered, and their free energy and structural information have been examined. The free energy profile indicates that PbO, As2O3, and CdO are the three toxicants most easily deposited in the pulmonary alveolus, which is consistent with survey data. CuO appears to be the easiest toxicant to transport through the surfactant. Structural analysis indicates that the toxicants tend to pass through the surfactant with rotation. The configuration of the pulmonary surfactant was examined by extending our previous work to polymer systems, and it appears that both the configurational entropy and the direct interaction between the surfactant and the toxicant dominate the configuration of the pulmonary surfactant.


Assuntos
Modelos Teóricos , Material Particulado/metabolismo , Alvéolos Pulmonares/metabolismo , Animais , Trióxido de Arsênio/química , Trióxido de Arsênio/metabolismo , Trióxido de Arsênio/toxicidade , Compostos de Cádmio/química , Compostos de Cádmio/metabolismo , Compostos de Cádmio/toxicidade , Humanos , Chumbo/química , Chumbo/metabolismo , Chumbo/toxicidade , Óxidos/química , Óxidos/metabolismo , Óxidos/toxicidade , Material Particulado/química , Material Particulado/toxicidade , Alvéolos Pulmonares/química , Tensoativos/química , Termodinâmica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA