Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 417
Filtrar
1.
Environ Sci Technol ; 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32609501

RESUMO

Although the bioaccumulation of organophosphate flame retardants (OPFRs) in aquatic organisms has been investigated, little information is available about their bioaccumulation in mammals following chronic inhalation exposure. To address this knowledge gap, C57BL/6 mice were exposed to 7 PM2.5-associated OPFRs via the trachea to study their bioaccumulation, tissue distribution and urinary metabolites. Low (corresponding to the real PM2.5 concentrations occurring in winter in Guangzhou), medium, and high dosages were examined. After 72 days' exposure, ∑OPFR concentrations in tissues from mice in the medium dosage group decreased in the order of intestine > heart > stomach > testis > kidney > spleen > brain > liver > lung > muscle. Of the OPFRs detected in all three exposure groups, chlorinated alkyl OPFRs were the most heavily accumulated in mice. We found a significant positive correlation between the bioaccumulation ratio and octanol-air partition coefficient (KOA) in mice tissues for low log KOW OPFR congeners (log KOW≤4, p<0.05). Three urinary metabolites (di-p-cresyl phosphate: DCrP, diphenyl phosphate: DPhP, Dibutyl phosphate: DnBP) were detected from the high dosage group. These results provide important insights into the bioaccumulation potential of OPFRs in mammals and emphasize the health risk of chlorinated alkyl OPFRs.

3.
Mass Spectrom Rev ; 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32608069

RESUMO

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are of particular concern due to their ubiquitous distribution and adverse health effects. Significant progress has been made in the characterization of OH-PBDEs by using mass spectrometry (MS). In this review, we summarize applications of MS-based techniques in detection, environmental and biota distribution, and potential health risk effects, hoping to unfold an overall picture on account of current knowledge of OH-PBDEs. The analytical methodologies are discussed from sample pretreatment to MS analysis. The methods including gas chromatography-MS (GC-MS), liquid chromatography-MS (LC-MS), and ion mobility spectrometry-MS (IMS-MS) are discussed. GC-MS is the most frequently adopted method in the analysis of OH-PBDEs due to its excellent chromatographic resolution, high sensitivity, and strong ability for unknown identification. LC-MS has been widely used for its high sensitivity and capability of direct analysis. As a newly developed technique, IMS-MS provides high specificity, which greatly facilitates the identification of isomers. OH-PBDEs pervasively existed in both abiotic and biotic samples, including humans, animals, and environmental matrices. Multiple adverse health effects have been reported, such as thyroid hormone disruption, estrogen effects, and neurotoxicity. The reported potential pathological mechanisms are also reviewed. Additionally, MS-based metabolomics, lipidomics, and proteomics have been shown as promising tools to unveil the molecular mechanisms of the toxicity of OH-PBDEs. © 2020 John Wiley & Sons Ltd. Mass Spec Rev 00, 1-25, 2020.

4.
J Hazard Mater ; 398: 122828, 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32512437

RESUMO

The presence of benzotriazoles and benzothiazoles (BTs) in maternal urine and amniotic fluid indicated the widespread fetal exposure to the contaminants. We investigated the associations of prenatal BTs exposure with fetal and birth size and explored the window of susceptibility. Participants consisted of 856 mother-infant pairs drawn from a prospective birth cohort between 2014 and 2015 in Wuhan, China. Prenatal BTs exposure were measured in multiple urine samples collected across three trimesters. We observed positive associations between prenatal exposure to specific BTs (e.g., 1-H-benzotriazole, 1-hydroxy-benzotriazole and 2-amino-benzothiazole) and femur length (FL) and birth length z-scores among girls. In boys, a 2-fold increase of averaged concentration of urinary benzothiazole (BTH) was associated with decrement in FL (ß = -0.068, p < 0.001) and birth length (ß = -0.055, p = 0.005) z-scores. Further analysis indicated that the negative associations between urinary concentrations of BTH and birth length z-score among boys were observed at exposure measurement in 25-35 gestational weeks. This study reported the associations between prenatal exposure to BTs and fetal and birth size, suggests the associations maybe in a sex-specific manner and the window of exposure may influence susceptibility. These findings require replication in future research.

5.
J Agric Food Chem ; 68(26): 6956-6966, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516537

RESUMO

Many physicochemical changes occur during food storage and processing, such as rancidity, hydrolysis, oxidation, and aging, which may alter the taste, flavor, and texture of food products and pose risks to public health. Analysis of these changes has become of great interest to many researchers. Mass spectrometry is a promising technique for the study of food and nutrition domains as a result of its excellent ability in molecular profiling, food authentication, and marker detection. In this review, we summarized recent advances in mass spectrometry techniques and their applications in food storage and processing. Furthermore, current technical challenges associated with these methodologies were discussed.

6.
Ecotoxicol Environ Saf ; 201: 110827, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32535366

RESUMO

Numerous experimental and epidemiological studies have demonstrated that exposure to PM2.5 may result in pathogenesis of several major cardiovascular diseases (CVDs), which can be attributed to the combined adverse effects induced by the complicated components of PM2.5. Organic materials, which are major components of PM2.5, contain thousands of chemicals, and most of them are environmental hazards. However, the contamination profile and contribution to overall toxicity of PM2.5-bound organic components (OCs) have not been thoroughly evaluated yet. Herein, we aim to provide an overview of the literature on PM2.5-bound hydrophobic OCs, with an emphasis on the chemical identity and reported impairments on the cardiovascular system, including the potential exposure routes and mechanisms. We first provide an update on the worldwide mass concentration and composition data of PM2.5, and then, review the contamination profile of PM2.5-bound hydrophobic OCs, including constitution, concentration, distribution, formation, source, and identification. In particular, the link between exposure to PM2.5-bound hydrophobic OCs and CVDs and its possible underlying mechanisms are discussed to evaluate the possible risks of PM2.5-bound hydrophobic OCs on the cardiovascular system and to provide suggestions for future studies.

7.
Mikrochim Acta ; 187(7): 370, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504203

RESUMO

Core-shell structured magnetic covalent organic framework (Fe3O4@COF) nanospheres were rapidly synthesized at room temperature using the monodisperse Fe3O4 nanoparticles (NPs) as magnetic core and benzene-1,3,5-tricarbaldehyde (BTA) and 3,3'-dihydroxybenzidine (DHBD) as two building blocks (denoted as Fe3O4@BTA-DHBD), respectively. They can serve as a mass spectrometry probe for rapid and high-throughput screening of bisphenols (BPs) from pharmaceuticals and personal care products (PPCPs) by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS). The Fe3O4@BTA-DHBD nanospheres showed some superior features involving average pore size distribution (2.82 nm), high magnetization values (42.5 emu g-1), high specific surface area (82.96 m2 g-1), and good chemical/thermal stability. It was used as both ideal adsorbent for enrichment of BPs and new substrate to assist ionization in SELDI-TOF-MS. The method exhibited good linearity in the range 0.05-4000 ng mL-1 with correlation coefficients (r) higher than 0.9920. Low limits of detection (LODs) (500 pg mL-1 for bisphenol A (BPA), 2 pg mL-1 for bisphenol B (BPB), 28 pg mL-1 for bisphenol C (BPC), 60 pg mL-1 for bisphenol F (BPF), 33 pg mL-1 for bisphenol AF (BPAF), 200 pg mL-1 for bisphenol BP (BPBP), 10 pg mL-1 for bisphenol S (BPS), 90 pg mL-1 for tetrabromobisphenol A (BPA(Br)4), and 380 pg mL-1 for tetrabromobisphenol S (BPS(Br)4)) and good recoveries (80.6-115%) of BPs in PPCPs were achieved. The relative standard deviations (RSDs) of spot-to-spot (n = 10) and sample-to-sample (n = 5) were in the ranges 5-11% and 5-12%, respectively. The dual-function platform was successfully applied to the quantitative determination of BPs in PPCPs. It not only expanded the scope of the application of COFs but also provided an alternative strategy for the determination of hazardous compounds in PPCPs. Graphical abstract Schematic representation of the synthesis of core-shell structured magnetic covalent organic framework nanospheres (Fe3O4@COFs) and its application in the analysis of bisphenols by using Fe3O4@BTA-DHBD nanospheres as a MS probe based on surface-enhanced laser desorption/ionization time-of-flight mass spectrometry.

8.
Anal Chem ; 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539344

RESUMO

Phosphotyrosine (pTyr) signaling complexes are important resources of biomarkers and drug targets which often need to be profiled with enough throughput. Current profiling approaches are not feasible to meet this need due to either biased profiling by antibody-based detection or low throughput by traditional affinity purification-mass spectrometry approach (AP-MS), as exemplified by our previously developed photo-pTyr-scaffold approach. To address these limitations, we developed a 96-well microplate-based sample preparation and fast data independent proteomic analysis workflow. By assembling the photo-pTyr-scaffold probe into a 96-well microplate, we achieved steric hindrance-free photoaffinity capture of pTyr signaling complexes, selective enrichment under denaturing conditions, and efficient in-well digestion in a fully integrated manner. EGFR signaling complex proteins could be efficiently captured and identified by using 300 times less cell lysate and 100 times less photo-pTyr-scaffold probe as compared with our previous approach operated in an Eppendorf tube. Furthermore, the lifetime of the photo-pTyr-scaffold probe in a 96-well microplate was significantly extended from 1 week up to 1 month. More importantly, by combining with high-flow nano LC separation and data independent acquisition on the Q Exactive HF-X mass spectrometer, LC-MS time could be significantly reduced to only 35 min per sample without increasing sample loading amount and compromising identification and quantification performance. This new high-throughput proteomic approach allowed us to rapidly and reproducibly profile dynamic pTyr signaling complexes with EGF stimulation at five time points and EGFR inhibitor treatment at five different concentrations. We are therefore optimized for its generic application in biomarkers discovery and drug screening in a high-throughput fashion.

9.
Mol Cell Proteomics ; 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424026

RESUMO

MERS is a life-threatening disease and MERS-CoV has the potential to cause the next pandemic. Protein acetylation is known to play a crucial role in host response to viral infection. Acetylation of viral proteins encoded by other RNA viruses have been reported to affect viral replication. It is therefore of interest to see whether MERS-CoV proteins are also acetylated. Viral proteins obtained from infected cells were trypsin-digested into peptides. Acetylated peptides were enriched by immunoprecipitation and subject to nano-LC-Orbitrap analysis. Bioinformatic analysis was performed to assess the conservation level of identified acetylation sites and to predict the upstream regulatory factors. A total of 12 acetylation sites were identified from 7 peptides, which all belong to the replicase polyprotein pp1ab. All identified acetylation sites were found to be highly conserved across MERS-CoV sequences in NCBI database. Upstream factors, including deacetylases of the SIRT1 and HDAC families as well as acetyltransferases of the TIP60 family, were predicted to be responsible for regulating the acetylation events identified. Western blot confirms that acetylation events indeed occur on pp1ab protein by expressing NSP4 in HEK293 cells. Acetylation events on MERS-CoV viral protein pp1ab were identified for the first time, which indicate that MERS-CoV might use the host acetylation machinery to regulate its enzyme activity and to achieve optimal replication. Upstream factors were predicted, which might facilitate further analysis of the regulatory mechanism of MERS-CoV replication.

10.
J Mater Chem B ; 8(21): 4642-4647, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32373807

RESUMO

Immobilization of enzymes onto metal-organic frameworks (MOFs) through a biomimetic mineralization approach can preserve biological functionality in harsh environments. Despite the success of this approach, the alkaline environment of the reaction system, which is caused by the organic monomers of MOFs, makes it unsuitable for some pH-sensitive enzymes, especially for trypsin. Herein, we reported a facile approach for the one-pot synthesis of trypsin-immobilized magnetic zeolite imidazolate framework-8 (iron oxide@ZIF-8@trypsin), where the growth of ZIF-8 around the citric acid-modified iron oxide and immobilization of trypsin occurred simultaneously when the pH of the reaction system was changed to some extent. With a large specific surface area and a high enzyme loading capacity, the resultant iron oxide@ZIF-8@trypsin exhibited 2.6 times higher enzymatic activity than free trypsin. Moreover, it showed a favourable magnetic response (43 emu g-1) which made the operation and recycling easy and convenient. In addition, iron oxide@ZIF-8@trypsin could be applied as an immobilized enzyme microreactor (IMER) to rapidly and efficiently digest proteins and complex human serum samples with satisfactory results, showing great promise for application in proteomic analysis.

11.
Anal Chem ; 92(11): 7413-7418, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-32374161

RESUMO

Increasing studies have utilized mass spectrometry imaging (MSI) that is a label-free tool to investigate drug penetration and drug biotransformation in multicellular tumor spheroids (MCTS). Currently, the gelatin-assisted sectioning method is widely used to prepare frozen sections of MCTS for MSI. However, owing to the limited transparency of frozen gelatin, MCTS with diameters less than 500 µm that closely mimic solid tumors are difficult to be detected when cryosectioning. In order to identify the presence of MCTS, hematoxylin and eosin staining for frozen sections and dye pretreatment for MCTS were employed in previous works, which either increased the analytical time and cost in sample preparation or caused signal suppression in sample analysis. Herein, a new sectioning method was developed to prepare MCTS frozen sections. MCTS was coated with ice to ensure good visibility for small-size MCTS. The optimal cutting temperature compound was added around the ice block to assist the formation of frozen sections. A precast frozen mold was prepared to allow the acquisition of complete MCTS frozen sections. The developed method was applied to investigate lipid distribution in MCTS by using matrix-assisted laser desorption/ionization MSI. Compared to the gelatin-assisted sectioning method, our method did not cause signal suppression and analyte delocalization. Thus, this method provides an easy, universal, and innovative strategy to prepare MCTS frozen sections for further MSI analysis. Besides, we applied our method to investigate the penetration of bisphenol A in MCTS.

12.
Sci Total Environ ; 732: 139304, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438171

RESUMO

Exposure to fine particulate matter (PM2.5) is associated with decreased cardiac function, especially in high risk populations such as obese ones. In this study, impacts of PM2.5 exposure on cardiac function were investigated by using the diet-induced obesity mice model. Mice were fed with normal diet or high-fat diet (HFD) for four weeks and then exposed to phosphate-buffered solution or Taiyuan winter PM2.5 (0.25 mg/kg body/day) through intratracheal instillation for another four weeks. Among physiological indices recorded, heart rate and blood pressure were increased after PM2.5 exposure in the heart of the obese mice. Metabolomics and lipidomics were applied to explore molecular alterations in response to the co-treatment of PM2.5 and HFD. Our results demonstrated both direct impacts on cardiac function and indirect effects resulted from the injury of other organs. Inflammation of lung and hypothalamus may be responsible for the elevation of phenylalanine metabolism in serum and its downstream products: epinephrine and norepinephrine, the catecholamines involves in regulating cardiac system. In intracardiac system, the co-treatment led to imbalance of energy metabolism, in addition to oxidative stress and inflammation. In contrast to the upregulation of glucose and fatty acids uptake and CoA synthesis, levels of ATP, acetyl-CoA and the intermediates in glycolysis pathway decreased in the heart. The results indicated that energy metabolism disorder was possibly one of the important contributing factors to the more severe adverse effects of the combined treatment of HFD and PM2.5.


Assuntos
Obesidade , Poluentes Atmosféricos , Animais , Dieta Hiperlipídica , Camundongos , Camundongos Endogâmicos C57BL , Tamanho da Partícula , Material Particulado
13.
Mar Drugs ; 18(5)2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32466241

RESUMO

Tetrodotoxin (TTX) is a potent neurotoxin isolated mainly from toxic puffer fish. To date, the TTX biosynthetic mechanism inside its hosts remains unresolved. Here, we hypothesize the TTX synthesis relies on the host gut microbiota, including the neglected non-culturable bacteria. In these studies, we collected the gut contents from 5 puffer fish species of the genus Takifugu including one suspected hybrid species for gut microbiota study by 16S rRNA amplicon metagenomics approach. Their gut samples were divided into toxic and non-toxic groups based on the TTX concentrations in the livers detected by LC-MS/MS. Bacterial diversity studies showed that gut microbiota structures were significantly different between toxic and non-toxic species. Vibrio and Cyanobacteria centered at the gut bacterial co-occurrence network, suggesting their importance in TTX biosynthesis. The results of PICRUSt2 metagenomic prediction and gene set enrichment analysis provided new support of arginine-precursor required in TTX biosynthesis. This is the first study to profile the gut microbiota in toxic and non-toxic puffer fish species by 16S rRNA amplicon metagenomic approach, defining significant microbial co-occurrence patterns in their gut environment. Our data supported the proposed biosynthesis of TTX inside the hosts by their gut bacterial symbionts using arginine as a precursor.

14.
J Agric Food Chem ; 68(24): 6776-6787, 2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32396374

RESUMO

Genetic engineering (GE) technology is widely used in plant modification. However, the results of modification may not exactly meet the expectations. Herein, we propose a new multi-omics method for GE plant evaluation based on the optimized use of the metID algorithm. Using this method, we found that flavonoid accumulation was at the expense of the great sacrifice of l-phenylalanine in GE tomatoes for the first time. Meanwhile, the ceramide series of sphingolipid is synthesized de novo from l-serine, and ceramides are the primary source of vesicles coated with flavonoids and secreted from the endoplasmic reticulum. Therefore, the accumulation of the ceramide series of sphingolipid changed the cell component of intracellular organelles. Furthermore, the improvement of the method allows us to identify more metabolites related to dysregulated pathways.

15.
Chemosphere ; 256: 127133, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32454355

RESUMO

Atmospheric fine particulate matter exposure (PM2.5) can increase the incidence and mortality of heart disease, and raise the risk of fetal congenital heart defect, which have recently drawn much attention. In this study, C57BL/6 mice were exposed to PM2.5 (approximately equivalent to 174 µg/m3) by intratracheal instillation during the gestation. After birth, 10 weeks old offspring mice were divided into four groups: male exposed group (ME), female exposed group (FE), male control group (MC), female control group (FC). The pathological injury, pro-inflammatory cytokines, histone acetylation levels, and expressions of GATA-binding protein 4 (GATA4) and downstream genes were investigated. The results showed that exposure to PM2.5 in utero increased pathological damage and TNF-α and IL-6 levels in hearts of offspring mice, and effects in ME were more serious than FE. Notably, GATA4 protein levels in hearts in ME were significantly lower than that of MC, accompanied by down-regulation of histone acetyltransferase (HAT)-p300 and up-regulation of histone deacetylase-SIRT3. As GATA4 downstream genes, ratios of ß-MHC gene expression to α-MHC significantly raised in ME relative to the MC. Results of chromatin immunoprecipitation (ChIP)-qPCR assay found that binding levels of acetylated histone 3 lysine 9 (H3K9ac) in GATA4 promoter region in the hearts of ME or FE were markedly decreased compared with their corresponding control groups. It suggested that maternal exposure to PM2.5 may cause cardiac injury in the offspring, heart damage of male mice was worse than female mice, in which process HAT-p300, H3K9ac, transcription factor GATA4 may play an important regulation role.

16.
Dalton Trans ; 49(17): 5445-5453, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32266905

RESUMO

A completely water-soluble, high quantum yield blue-fluorescent benzimidazole derivative (AQ), containing a rigid benzimidazole-thiophene structure, was synthesized. Among 21 metal ions, the fluorescence of AQ was selectively turned off by Cu2+ to form an AQ-Cu2+ ensemble. Thereafter, the fluorescence of the AQ-Cu2+ ensemble was turned on by sulfide (S2-) with high selectivity and sensitivity in pure water solution. In comparison with AQ-Ag+ and AQ-Hg2+ ensembles, AQ-Cu2+ was the only ensemble that was capable of detecting a sulfide anion. Also, the fluorescence intensity of AQ was linearly proportional to the concentration of Cu2+ and S2-. Both Cu2+ and S2- were detected within a minute in vitro. Moreover, AQ worked best in the pH range of 5-10 and had a limit of detection of 50 nM and 354 nM for Cu2+ and S2- respectively. It was employed for the detection of sulfide in human lung cancer A549 cells with low cytotoxicity.

17.
Waste Manag ; 106: 110-119, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32203898

RESUMO

Co-incinerating sewage sludge in municipal solid waste incinerators (MSWIs) is an up-to-date disposal way with great prospects to market. To verify the environmental safety of this disposal method, a field study was conducted in a MSWI which has achieved PCDD/Fs ultra-low emission. PCDD/F phase partitioning characteristics, congener profiles, and the influence of selective catalytic reduction (SCR) were also investigated. PCDD/F emission levels ranged from 0.0031 to 0.0053 ng I-TEQ/Nm3, distinctly lower than the national standard. For tests co-incinerating 5% sludge, PCDD/F emission levels were averagely 32% lower than tests mono-combusting municipal solid waste. The phase partitioning study found that PCDD/Fs enriched in condensed water took a non-negligible proportion of the total concentration in flue gas. The removal efficiency of SCR in tests co-incinerating sludge was averaged at 41.9%. However, in tests without adding sewage sludge, PCDD/F concentrations in flus gas after SCR were increased. It was found that the elevations were mainly attributed to the increase of low-chlorinated PCDF congeners in gas-phase. By inference, memory effect existing in SCR might be responsible for the increase of PCDD/F levels. PCDD to PCDF ratios in most of the sampling points were >1, suggesting that de novo synthesis is not the dominant formation pathway in the studied incinerator. This study verified that co-incinerating sewage sludge in the MSWI would not elevate the emission levels of PCDD/Fs. If all of the yielded municipal waste is incinerated with adding 5% sewage sludge, more than half of sewage sludge can be disposed safely in Shenzhen.


Assuntos
Poluentes Atmosféricos , Dibenzodioxinas Policloradas , Dibenzofuranos , Dibenzofuranos Policlorados , Incineração , Esgotos , Resíduos Sólidos
18.
Analyst ; 145(8): 3125-3130, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32163066

RESUMO

A spherical vinyl-functionalized covalent-organic framework (COF-V) was prepared at room temperature by a facile method and applied as a novel substrate for surface-enhanced laser desorption/ionization mass spectrometry (SELDI-MS). Compared with conventional organic matrices, the spherical COF-V with high crystallinity and good monodispersity exhibited high sensitivity, no matrix background interference, wide-range applicability, high salt tolerance and reproducibility in the characterization of small molecules. Considering these advantages, the applicability of the spherical COF-V-based SELDI-MS method was successfully demonstrated by determining trace amounts of glucose in diabetic urine, which would be a promising candidate for clinical diagnosis of diabetes. In addition, the morphological effect and the desorption/ionization mechanism of the COF-V were investigated in detail and the results indicated that the spherical COF-V substrate could greatly enhance the LDI process compared with the bulk COF-V. This work not only extends the application of COFs in MS, but also offers a promising alternative for small molecule identification and clinical diagnosis of diabetes.

19.
J Hazard Mater ; 392: 122475, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32208312

RESUMO

Humans are frequently exposed to the antimicrobial triclocarban (TCC) due to its widespread use in consumer and personal care products. However, there is a paucity of research on potential hepatotoxic risks of TCC exposure. In this study, nontargeted metabolomics approach was applied to simultaneously investigate TCC-induced perturbation of endogenous metabolites and generation of xenobiotic metabolites in human hepatic cells. In normal hepatocytes, TCC exposure induced cellular redox imbalance as evidenced by the decrease of glutathione metabolism and overproduction of reactive oxygen species (ROS), resulting in DNA damage and lipid peroxidation. Defective oxidative phosphorylation and increased purine metabolism were two potential sources of elevated ROS. However, in cancerous hepatocytes, TCC exposure enhanced glutathione metabolism, glycolysis, and glutaminolysis, which contributed to the cellular homeostasis of redox and energy status, as well as the progression of liver cancer. As a xenobiotic, metabolic activation of TCC through phase I hydroxylation was observed. The hepatic cytotoxicity follows the order of 6-OH-TCC > 2'-OH-TCC > 3'-OH-TCC > DHC, with EC50 values of 2.42, 3.38, 7.38, and 24.8 µM, respectively, in 48 h-treated normal cells. This study improves current understanding of TCC-triggered hepatotoxicity, and provides novel perspectives for evaluating the interaction of environmental pollutants with biological systems.

20.
Ecotoxicol Environ Saf ; 193: 110368, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32114245

RESUMO

Emerging POPs have received increasing attention due to their potential persistence and toxicity, but thus far the report regarding the occurrence and distribution of these POPs in PM2.5 is limited. In this study, an extremely sensitive and reliable method, using ultrasonic solvent extraction and silica gel purification followed by gas chromatography coupled with electron ionization triple quadrupole mass spectrometry, was developed and used for the trace analysis of hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and its analogs chlorobenzenes (CBs) in PM2.5 from Taiyuan within a whole year. The limits of detection and limits of quantitation of analytes were 1.14 × 10-4‒2.74 × 10-4 pg m-3 and 3.80 × 10-4‒9.14 × 10-4 pg m-3. HCBD and PCA were detected at the mean concentrations of 3.69 and 1.84 pg m-3 in PM2.5, which is reported for the first time. Based on the results of statistical analysis, HCBD may come from the unintentional emission of manufacture or incineration of chlorinate-contained products but not coal combustion, while O3-induced photoreaction was the potential source of PCA in PM2.5. The temporal distributions of CBs in PM2.5 were closely related to coal-driven or agricultural activities. Accordingly, our study reveals the contamination profiles of emerging POPs in PM2.5 from Taiyuan.


Assuntos
Poluentes Atmosféricos/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Material Particulado/química , Anisóis/análise , Butadienos/análise , Clorobenzenos/análise , Carvão Mineral , Incineração , Espectrometria de Massas em Tandem/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA