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Microbiota-mediated metabolic perturbations in the gut and brain of mice after microplastic exposure. CHEMOSPHERE 2024; 350:141026. [PMID: 38145850 DOI: 10.1016/j.chemosphere.2023.141026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 12/27/2023]
Abstract
Microplastics (MPs), emerging environmental toxicants, have drawn attention because of their wide distribution in the environment. Exposure to MPs induces gut microbiota dysbiosis, intestinal barrier dysfunction, metabolic perturbations, and neurotoxicity in different rodents. However, the relationship between MPs, gut microbiota, and the metabolome of the gut and brain in mice remains unclear. In this study, female C57BL/6 mice were orally gavaged with vehicle, 200 nm MP, and 800 nm MP three times per week for four weeks. Cecal contents were collected for gut microbiota analysis using 16S rRNA gene sequencing. Intestinal and brain tissues from mice were used to determine metabolic profiles using liquid chromatography-mass spectrometry (LC-MS). The results showed that MP altered microbiota composition, accompanied by metabolic perturbations in the mouse gut and brain. Specifically, Firmicutes and Bacteroidetes were suggested to be important phyla for MP exposure, partially dominating further metabolite alterations. Simultaneously, MP-induced metabolic profiles were associated with energy homeostasis and bile acid, nucleotide, and carnitine metabolic pathways. The results of the mediation analysis further revealed an MP-microbiota-metabolite relationship. Our results indicate that MPs can induce gut dysbiosis and disturb metabolic dysfunction in the mouse brain and/or intestine. Integrative omics approaches have the potential to monitor MP-induced molecular responses in various organs and systematically elucidate the complex mechanisms of human health effects.
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Distribution and toxicity of submicron plastic particles in mice. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 97:104038. [PMID: 36528214 DOI: 10.1016/j.etap.2022.104038] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/06/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Although microplastics (MPs) have become a global issue, the biodistribution and toxicities of MPs were still unclear. In this study, c57BL/6 mice were treated with submicron-sized MPs labeled with Nile red fluorescence by oral gavage three times a week for four consecutive weeks. Flow cytometry and microscopy technique were used to examine the concentration and distribution of MPs in various tissues and biofluids. The oxidative stress and inflammation were assessed via liquid chromatography-mass spectrometry and enzyme-linked immunosorbent assay, respectively. Submicron-sized MP signals were found in the intestines, liver, spleen, kidney, lungs, blood, and urine of mice after MP exposure. Increased oxidative stress in mouse urine and elevated inflammatory cytokines in mouse kidney were also recorded. In conclusion, flow cytometry is a useful tool for examining the number concentrations of MPs. Increased oxidative stress and inflammation after MP treatment indicates that the toxicity of MP warrants further investigation.
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Distinct brain lipid signatures in response to low-level PM 2.5 exposure in a 3xTg-Alzheimer's disease mouse inhalation model. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156456. [PMID: 35660587 DOI: 10.1016/j.scitotenv.2022.156456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/11/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Fine particulate matter (PM2.5) poses a significant risk to human health. The molecular mechanisms underlying low-level PM2.5-induced neurotoxicity in the central nervous system remain unclear. In addition, changes in lipids in response to PM2.5 exposure have not yet been fully elucidated. In this study, 3xTg-Alzheimer's disease (AD) mice experienced continuous whole-body exposure to non-concentrated PM2.5 for three consecutive months, while control mice inhaled particulate matter-filtered air over the same time span. A liquid chromatography-mass spectrometry-based lipidomic platform was used to determine the distinct lipid profiles of various brain regions. The average PM2.5 concentration during the exposure was 11.38 μg/m3, which was close to the regulation limits of USA and Taiwan. The partial least squares discriminant analysis model showed distinct lipid profiles in the cortex, hippocampus, and olfactory bulb, but not the cerebellum, of mice in the exposure group. Increased levels of fatty acyls, glycerolipids, and sterol lipids, as well as the decreased levels of glycerophospholipids and sphingolipids in PM2.5-exposed mouse brains may be responsible for the increased energy demand, membrane conformation, neuronal loss, antioxidation, myelin function, and cellular signaling pathways associated with AD development. Our research suggests that subchronic exposure to low levels of PM2.5 may cause neurotoxicity by changing the lipid profiles in a susceptible model. Lipidomics is a powerful tool to study the early effects of PM2.5-induced AD toxicity.
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White matter pathology in alzheimer's transgenic mice with chronic exposure to low-level ambient fine particulate matter. Part Fibre Toxicol 2022; 19:44. [PMID: 35768852 PMCID: PMC9245233 DOI: 10.1186/s12989-022-00485-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 04/29/2022] [Indexed: 03/13/2023] Open
Abstract
Background Air pollution, especially fine particulate matter (PM), can cause brain damage, cognitive decline, and an increased risk of neurodegenerative disease, especially alzheimer’s disease (AD). Typical pathological findings of amyloid and tau protein accumulation have been detected in the brain after exposure in animal studies. However, these observations were based on high levels of PM exposure, which were far from the WHO guidelines and those present in our environment. In addition, white matter involvement by air pollution has been less reported. Thus, this experiment was designed to simulate the true human world and to discuss the possible white matter pathology caused by air pollution. Results 6 month-old female 3xTg-AD mice were divided into exposure and control groups and housed in the Taipei Air Pollutant Exposure System (TAPES) for 5 months. The mice were subjected to the Morris water maze test after exposure and were then sacrificed with brain dissection for further analyses. The mean mass concentration of PM2.5 during the exposure period was 13.85 μg/m3. After exposure, there was no difference in spatial learning function between the two groups, but there was significant decay of memory in the exposure group. Significantly decreased total brain volume and more neuronal death in the cerebral and entorhinal cortex and demyelination of the corpus callosum were noted by histopathological staining after exposure. However, there was no difference in the accumulation of amyloid or tau on immunohistochemistry staining. For the protein analysis, amyloid was detected at significantly higher levels in the cerebral cortex, with lower expression of myelin basic protein in the white matter. A diffuse tensor image study also revealed insults in multiple white matter tracts, including the optic tract. Conclusions In conclusion, this pilot study showed that even chronic exposure to low PM2.5 concentrations still caused brain damage, such as gross brain atrophy, cortical neuron damage, and multiple white matter tract damage. Typical amyloid cascade pathology did not appear prominently in the vulnerable brain region after exposure. These findings imply that multiple pathogenic pathways induce brain injury by air pollution, and the optic nerve may be another direct invasion route in addition to olfactory nerve. Supplementary Information The online version contains supplementary material available at 10.1186/s12989-022-00485-8.
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Lipid changes in extrapulmonary organs and serum of rats after chronic exposure to ambient fine particulate matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 784:147018. [PMID: 34088028 DOI: 10.1016/j.scitotenv.2021.147018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/12/2021] [Accepted: 04/04/2021] [Indexed: 06/12/2023]
Abstract
Fine particulate matter (PM2.5) is able to pass through the respiratory barrier to enter the circulatory system and can consequently spread to the whole body to cause toxicity. Although our previous studies have revealed significantly altered levels of phosphorylcholine-containing lipids in the lungs of rats after chronic inhalation exposure to PM2.5, the effects of PM2.5 on phosphorylcholine-containing lipids in the extrapulmonary organs have not yet been elucidated. In this study, we examined the lipid effects of chronic PM2.5 exposure on various organs and serum by using a rat inhalation model followed by a mass spectrometry-based lipidomic approach. Male Sprague-Dawley rats were continuously exposed at the whole body level to nonfiltered and nonconcentrated ambient air from the outside environment of Taipei city for 8 months, while the control rats inhaled filtered air simultaneously. After exposure, serum samples and various organs, including the testis, pancreas, heart, liver, kidney, spleen, and epididymis, were collected for lipid extraction and analysis to examine the changes in phosphorylcholine-containing lipids after exposure. The results from the partial least squares discriminant analysis models demonstrated that the lipid profiles in the PM2.5 exposure group were different from those in the control group in the rat testis, pancreas, heart, liver, kidney and serum. The greatest PM2.5-induced lipid effects were observed in the testes. Decreased lyso-phosphatidylcholines (PCs) as well as increased unsaturated diacyl-PCs and sphingomyelins in the testes may be related to maintaining the membrane integrity of spermatozoa, antioxidation, and cell signaling. Additionally, our results showed that decreased PC(16:0/18:1) was observed in both the serum and testes. In conclusion, exposure to chronic environmental concentrations of PM2.5 caused lipid perturbation, especially in the testes of rats. This study highlighted the susceptibility of the testes and suggested possible molecular events for future study.
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Effect of particle morphology on performance of an electrostatic air-liquid interface cell exposure system for nanotoxicology studies. Nanotoxicology 2020; 15:433-445. [PMID: 33378224 DOI: 10.1080/17435390.2020.1863499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Particle morphology can affect the performance of an electrostatic precipitator air-liquid interface (ESP-ALI) cell exposure system and the resulting cell toxicity. In this study, three types of monodisperse aerosols - spherical sucrose particles, nonspherical align soot aggregates, and nanosilver aggregates/agglomerates - were selected to evaluate the collection efficiency at flow rates ranging from 0.3 to 1.5 lpm. To quantify the particle morphology, the fractal dimensions (Df) of the tested aerosols were characterized. The penetration of fine particles (dp = 100-250 nm) under different operating conditions was correlated with a characteristic exponential curve using the dimensionless drift velocity (Vc/Vavg,r) as the scaling parameter. For nanoparticles (NPs, dp <100 nm) with different particle morphologies, the particle penetrations in the ESP-ALI were similar, but their diffusion losses were not negligible. In contrast, for fine particles, the collection efficiency of soot nanoaggregates (Df = 2.29) was higher than that of spherical sucrose particles. This difference might be due to the simultaneous influences of the electric field-induced and flow field-induced alignment. Furthermore, based on Zhibin and Guoquan's Deutsch model, a quadratic equation was applied to fit the experimental data and to predict the performance of the ESP-ALI.
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Neuropathology changed by 3- and 6-months low-level PM 2.5 inhalation exposure in spontaneously hypertensive rats. Part Fibre Toxicol 2020; 17:59. [PMID: 33243264 PMCID: PMC7691081 DOI: 10.1186/s12989-020-00388-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
Background Epidemiological evidence has linked fine particulate matter (PM2.5) to neurodegenerative diseases; however, the toxicological evidence remains unclear. The objective of this study was to investigate the effects of PM2.5 on neuropathophysiology in a hypertensive animal model. We examined behavioral alterations (Morris water maze), lipid peroxidation (malondialdehyde (MDA)), tau and autophagy expressions, neuron death, and caspase-3 levels after 3 and 6 months of whole-body exposure to urban PM2.5 in spontaneously hypertensive (SH) rats. Results SH rats were exposed to S-, K-, Si-, and Fe-dominated PM2.5 at 8.6 ± 2.5 and 10.8 ± 3.8 μg/m3 for 3 and 6 months, respectively. We observed no significant alterations in the escape latency, distance moved, mean area crossing, mean time spent, or mean swimming velocity after PM2.5 exposure. Notably, levels of MDA had significantly increased in the olfactory bulb, hippocampus, and cortex after 6 months of PM2.5 exposure (p < 0.05). We observed that 3 months of exposure to PM2.5 caused significantly higher expressions of t-tau and p-tau in the olfactory bulb (p < 0.05) but not in other brain regions. Beclin 1 was overexpressed in the hippocampus with 3 months of PM2.5 exposure, but significantly decreased in the cortex with 6 months exposure to PM2.5. Neuron numbers had decreased with caspase-3 activation in the cerebellum, hippocampus, and cortex after 6 months of PM2.5 exposure. Conclusions Chronic exposure to low-level PM2.5 could accelerate the development of neurodegenerative pathologies in subjects with hypertension. Supplementary Information The online version contains supplementary material available at 10.1186/s12989-020-00388-6.
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Secure Health Care Workers' Health and Safety Methodically During COVID-19 Epidemic in Taiwan. Asia Pac J Public Health 2020; 32:485-488. [PMID: 33063525 DOI: 10.1177/1010539520963629] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
Reducing nosocomial transmission within health care facilities is important, but the number of negative-pressure airborne infection isolation rooms for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is limited. It is a daunting challenge to cope with a surge of suspected infectious patients in hospitals. We installed air exhaust fans on the windows to change the pressure direction within the wards rapidly. The best location for the fans was 90 cm from the floor and 90 cm from the edge of bed whether the indoor air conditioners were on or off. The noise level should be <60 dB(A) as per government regulations. General wards can be transformed into makeshift negative-pressure rooms easily and effectively within 24 hours, which is really the simple, fast, and effective way for the transformation being applied.
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Brain lipid profiles in the spontaneously hypertensive rat after subchronic real-world exposure to ambient fine particulate matter. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 707:135603. [PMID: 31784156 DOI: 10.1016/j.scitotenv.2019.135603] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 11/15/2019] [Accepted: 11/16/2019] [Indexed: 06/10/2023]
Abstract
Recent studies have illustrated an association between ambient fine particulate matter (PM2.5) exposure and neuronal toxicity in epidemiological studies and animal models. However, the possible molecular effects on brains under real-world exposure to PM2.5 remain unclear. In this pilot study, male spontaneously hypertensive rats were whole-bodily exposed to ambient air from the outdoor environment of Taipei City for 3 months, while the control rats inhaled HEPA-filtered air. The PM2.5-induced phosphatidylcholine and sphingomyelin profiles in the hippocampus, cortex, medulla, cerebellum, and olfactory bulb were assessed by mass spectrometry (MS)-based lipidomics. Partial least squares discriminant analysis (PLS-DA) and the Wilcoxon rank sum test were used to examine the lipid changes between the exposed and control groups. The PLS-DA models showed that phosphatidylcholine and sphingomyelin profiles of the PM2.5 exposure group were different from those of the control group in each brain region except the cortex. More lipid changes were found in the hippocampus, while fewer lipid changes were observed in the olfactory bulb. The lipid alteration in the hippocampus may strengthen membrane integrity, modulate signaling pathways, and avoid accumulation of lipofuscin to counter the PM2.5-induced stress. The lipid changes in the cortex and medulla may respond to PM2.5-induced injury and inflammation; while the lipid changes in the cerebellum were associated with neuron protection. This study suggests that the MS-based lipidomics is a powerful approach to discriminate the brain lipid profiles even at the environmental level of ambient PM2.5 and has the potential to suggest possible adverse health effects in long-term PM2.5 exposure studies.
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The effect of the inhalation of and topical exposure to zinc oxide nanoparticles on airway inflammation in mice. Toxicol Appl Pharmacol 2019; 384:114787. [PMID: 31669718 DOI: 10.1016/j.taap.2019.114787] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/19/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023]
Abstract
Zinc oxide nanoparticles (ZnONPs) are widely used in the manufacturing of many commercial products. Workers exposed to ZnO particles may develop metal fume fever. Our previous study suggested that the oropharyngeal aspiration of ZnONPs could cause eosinophilic airway inflammation and increase T helper 2 (Th2) cytokine expression in the absence of allergens in mice. ZnO has been used topically as a sunscreen and a therapeutic agent for dermatological conditions. To understand whether inhalation and topically applied ZnONPs might cause or exert an adjuvant effect on the development of allergic airway inflammation in mice, C57BL/6 J mice were exposed to filtered air or 2.5 mg/m3 ZnONPs via whole-body inhalation for 5 h a day over 5 days, and BALB/c mice were topically exposed to ZnONPs using modified mouse models of atopic dermatitis (AD) and asthma. Ovalbumin (OVA) solution was used as an allergen in the topical exposure experiments. A significantly increased eosinophil count and mixed Th1/Th2 cytokine expression were detected in the bronchoalveolar lavage fluid (BALF) after ZnONP inhalation. However, only mild eosinophilia and low Th2 cytokine expression were detected in the BALF after oropharyngeal OVA aspiration in the high-dose ZnONP topical treatment group. These results suggest that ZnONP inhalation might play a role in the development of allergic airway inflammation in mice. However, topically applied ZnONPs only play a limited role in the development of allergic airway inflammation in mice.
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Correction to: Particle toxicology and health - where are we? Part Fibre Toxicol 2019; 16:26. [PMID: 31248442 PMCID: PMC6595670 DOI: 10.1186/s12989-019-0308-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 05/22/2019] [Indexed: 12/16/2022] Open
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Abstract
Background Particles and fibres affect human health as a function of their properties such as chemical composition, size and shape but also depending on complex interactions in an organism that occur at various levels between particle uptake and target organ responses. While particulate pollution is one of the leading contributors to the global burden of disease, particles are also increasingly used for medical purposes. Over the past decades we have gained considerable experience in how particle properties and particle-bio interactions are linked to human health. This insight is useful for improved risk management in the case of unwanted health effects but also for developing novel medical therapies. The concepts that help us better understand particles’ and fibres’ risks include the fate of particles in the body; exposure, dosimetry and dose-metrics and the 5 Bs: bioavailability, biopersistence, bioprocessing, biomodification and bioclearance of (nano)particles. This includes the role of the biomolecule corona, immunity and systemic responses, non-specific effects in the lungs and other body parts, particle effects and the developing body, and the link from the natural environment to human health. The importance of these different concepts for the human health risk depends not only on the properties of the particles and fibres, but is also strongly influenced by production, use and disposal scenarios. Conclusions Lessons learned from the past can prove helpful for the future of the field, notably for understanding novel particles and fibres and for defining appropriate risk management and governance approaches.
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Abstract
BACKGROUND Effects of air pollution on neurotoxicity and behavioral alterations have been reported. The objective of this study was to investigate the pathophysiology caused by particulate matter (PM) in the brain. We examined the effects of traffic-related particulate matter with an aerodynamic diameter of < 1 μm (PM1), high-efficiency particulate air (HEPA)-filtered air, and clean air on the brain structure, behavioral changes, brainwaves, and bioreactivity of the brain (cortex, cerebellum, and hippocampus), olfactory bulb, and serum after 3 and 6 months of whole-body exposure in 6-month-old Sprague Dawley rats. RESULTS The rats were exposed to 16.3 ± 8.2 (4.7~ 68.8) μg/m3 of PM1 during the study period. An MRI analysis showed that whole-brain and hippocampal volumes increased with 3 and 6 months of PM1 exposure. A short-term memory deficiency occurred with 3 months of exposure to PM1 as determined by a novel object recognition (NOR) task, but there were no significant changes in motor functions. There were no changes in frequency bands or multiscale entropy of brainwaves. Exposure to 3 months of PM1 increased 8-isoporstance in the cortex, cerebellum, and hippocampus as well as hippocampal inflammation (interleukin (IL)-6), but not in the olfactory bulb. Systemic CCL11 (at 3 and 6 months) and IL-4 (at 6 months) increased after PM1 exposure. Light chain 3 (LC3) expression increased in the hippocampus after 6 months of exposure. Spongiosis and neuronal shrinkage were observed in the cortex, cerebellum, and hippocampus (neuronal shrinkage) after exposure to air pollution. Additionally, microabscesses were observed in the cortex after 6 months of PM1 exposure. CONCLUSIONS Our study first observed cerebral edema and brain impairment in adult rats after chronic exposure to traffic-related air pollution.
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Chronic pulmonary exposure to traffic-related fine particulate matter causes brain impairment in adult rats. Part Fibre Toxicol 2018; 15:44. [PMID: 30413208 PMCID: PMC6234801 DOI: 10.1186/s12989-018-0281-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 10/24/2018] [Indexed: 11/30/2022] Open
Abstract
Background Effects of air pollution on neurotoxicity and behavioral alterations have been reported. The objective of this study was to investigate the pathophysiology caused by particulate matter (PM) in the brain. We examined the effects of traffic-related particulate matter with an aerodynamic diameter of < 1 μm (PM1), high-efficiency particulate air (HEPA)-filtered air, and clean air on the brain structure, behavioral changes, brainwaves, and bioreactivity of the brain (cortex, cerebellum, and hippocampus), olfactory bulb, and serum after 3 and 6 months of whole-body exposure in 6-month-old Sprague Dawley rats. Results The rats were exposed to 16.3 ± 8.2 (4.7~ 68.8) μg/m3 of PM1 during the study period. An MRI analysis showed that whole-brain and hippocampal volumes increased with 3 and 6 months of PM1 exposure. A short-term memory deficiency occurred with 3 months of exposure to PM1 as determined by a novel object recognition (NOR) task, but there were no significant changes in motor functions. There were no changes in frequency bands or multiscale entropy of brainwaves. Exposure to 3 months of PM1 increased 8-isoporstance in the cortex, cerebellum, and hippocampus as well as hippocampal inflammation (interleukin (IL)-6), but not in the olfactory bulb. Systemic CCL11 (at 3 and 6 months) and IL-4 (at 6 months) increased after PM1 exposure. Light chain 3 (LC3) expression increased in the hippocampus after 6 months of exposure. Spongiosis and neuronal shrinkage were observed in the cortex, cerebellum, and hippocampus (neuronal shrinkage) after exposure to air pollution. Additionally, microabscesses were observed in the cortex after 6 months of PM1 exposure. Conclusions Our study first observed cerebral edema and brain impairment in adult rats after chronic exposure to traffic-related air pollution. Electronic supplementary material The online version of this article (10.1186/s12989-018-0281-1) contains supplementary material, which is available to authorized users.
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Association of ultrafine particles with cardiopulmonary health among adult subjects in the urban areas of northern Taiwan. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 627:211-215. [PMID: 29426143 DOI: 10.1016/j.scitotenv.2018.01.218] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 01/14/2018] [Accepted: 01/22/2018] [Indexed: 05/07/2023]
Abstract
The association between short-term exposure to particulate air pollution, especially fine particles, and cardiopulmonary health has been well-established in previous studies. However, previous findings regarding the effect of ultrafine particles (UFPs) on cardiopulmonary health are inconsistent. We repeatedly measured the mass concentrations of UFPs using a Micro-Orifice Uniform Deposit Impactor (MOUDI) in the apartments of 100 adult participants and collected the participants' health data from the pulmonary outpatient unit of Shuang-Ho Hospital to investigate the association between short-term exposure to UFPs and cardiopulmonary health using mixed-effects models from January 1, 2014 to August 31, 2017. We also collected ambient air pollution monitoring data from the Taiwan Environmental Protection Administration for data analysis. We observed that an interquartile range increase in the 24-hour mean UFPs (0.97 μg/m3) was associated with a 6.3% [95% confidence interval (CI) = 2.9, 9.7], 5.6% (95% CI = 4.1, 7.1) and 8.5% (95% CI = 3.9, 13.1) increase in systolic blood pressure, diastolic blood pressure and high sensitivity-C-reactive protein, respectively. We also observed the association of particulate matter less than or equal to 2.5 μm in diameter and nitrogen dioxide with increased blood pressure and ozone with decreased lung function. A negative trend between UFPs and forced expiratory volume in the first second was observed. We concluded that short-term exposure to UFPs was associated with cardiovascular health in adult subjects in the urban areas of northern Taiwan.
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LC-MS-based lipidomics to examine acute rat pulmonary responses after nano- and fine-sized ZnO particle inhalation exposure. Nanotoxicology 2018; 12:439-452. [DOI: 10.1080/17435390.2018.1458918] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Effects of physical characteristics of carbon black on metabolic regulation in mice. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 232:494-504. [PMID: 28993026 DOI: 10.1016/j.envpol.2017.09.077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/22/2017] [Accepted: 09/25/2017] [Indexed: 06/07/2023]
Abstract
Potential adverse effects of human exposure to carbon black (CB) have been reported, but limited knowledge regarding CB-regulated metabolism is currently available. To evaluate how physical parameters of CB influence metabolism, we investigated CB and diesel exhaust particles (DEPs) and attempted to relate various physical parameters, including the hydrodynamic diameter, zeta potential, and particle number concentrations, to lung energy metabolism in female BALB/c mice. A body weight increase was arrested by 3 months of exposure to CB of smaller-size fractions, which was negatively correlated with pyruvate in plasma. There were no significant differences in cytotoxic lactate dehydrogenase (LDH) or total protein in bronchoalveolar lavage fluid (BALF) after 3 months of CB exposure. However, we observed alterations in acetyl CoA and the NADP/NADPH ratio in lung tissues with CB exposure. Additionally, the NADP/NADPH ratio was associated with the zeta potential of CB. Mild peribronchiovascular and interstitial inflammation and multinucleated giant cells (macrophages) with a transparent and rhomboid appearance and containing foreign bodies were observed in lung sections. We suggest that physical characteristics of CB, such as the zeta potential, may disrupt metabolism after pulmonary exposure. These results, therefore, provide the first evidence of a link between pulmonary exposure to CB and metabolism.
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Characterization of titanium dioxide nanoparticle removal in simulated drinking water treatment processes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 601-602:886-894. [PMID: 28582734 DOI: 10.1016/j.scitotenv.2017.05.228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 05/24/2017] [Accepted: 05/24/2017] [Indexed: 06/07/2023]
Abstract
This study characterized the fate of nano-TiO2 in both powder (TiO2(P)) and suspension (TiO2(S)) forms in simulated drinking water treatments. Nano-TiO2 solutions of 0.1, 1.0, and 10mg/L were prepared with deionized water and raw waters from the Changxing and Fengshan Water Treatment Plants in Taiwan to assess the effects of water matrices on nano-TiO2 behavior during water treatment. After the laboratory simulated water treatment, including pre-chlorination, coagulation, sedimentation, filtration and post-chlorination, the residual Ti concentration ranged from 2.7 to 47.4% in different treatment units and overall removal efficiency was between 52.6% and 97.3% in all cases except for nano-TiO2 at concentration of 0.1mg/L. Overall removal efficiency for the TiO2 at 10mg/L concentration ranged from 9.3 to 53.5%. Sedimentation (after coagulation) and filtration were the most important processes for removing nano-TiO2 due in part to particle agglomeration, which was confirmed by size distribution and zeta potential measurements. The size of nano-TiO2 increased from 21-36nm to 4490nm in the supernatant after sedimentation, and subsequent filtration treatment further removed all agglomerates at size >1μm. Zeta potential revealed interactions between nano-TiO2 particles and anionic functional groups or negatively-charged natural organic matters, leading to a decrease in surface charge. After sedimentation and filtration, the zeta potential of supernatants and filtrates were close to zero, meaning the absence of nanoparticles. The highest Ti removal after sedimentation occurred in Fengshan raw water due to higher ionic strength and coagulant dosage applied. On the other hand, the surfactant additives in TiO2(S) promoted dispersion of nano-TiO2 particles, which in turn led to lower particle removal. SEM images of nanoparticles after chlorination or coagulation revealed the coverage of nano-TiO2 particles by viscous substances and formation of colloidal structures.
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Alterations in cardiovascular function by particulate matter in rats using a crossover design. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 231:812-820. [PMID: 28866422 DOI: 10.1016/j.envpol.2017.08.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 08/21/2017] [Accepted: 08/21/2017] [Indexed: 06/07/2023]
Abstract
The objective of this study was to investigate associations between cardiovascular effects and urban ambient particle constituents using an in vivo crossover experimental design. Ambient particles were introduced to an exposure chamber for whole-body exposure of WKY rats, where the particulate matter with an aerodynamic diameter of <2.5 μm (PM2.5) mass concentration, particle number concentration, and black carbon (BC) were monitored. Organic carbon (OC), elemental carbon (EC), and soluble ions of PM2.5 were determined. In a crossover design, rats were exposed to ambient particles or high-efficiency particle arrestance (HEPA)-filtered control air for 7 days following a 7-day washout interval. The crossover exposure between particles and HEPA-filtered air was repeated 4 times. Radiotelemetric data on blood pressure (BP) [systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), and mean arterial pressure (MAP)], heart rate (HR), and heart rate viability (HRV) were subsequently obtained during the entire study. Exposure to the PM2.5 mass concentration was associated with decreases in the SBP, DBP, MAP, and HR (p < 0.05), whereas no significant changes in the BP or HR occurred with the particle number or black carbon. For HRV, the ln 5-min standard deviation of the normal-to-normal (NN) interval (LnSDNN) and the ln root mean square of successive differences in adjacent NN intervals (LnRMSSD) were positively associated with the PM2.5 mass concentration (p < 0.05). There were no significant effects of the particle number concentration or BC on HRV. Alterations in the HR were associated with OC, EC, Na+, Cl-, and NO3-. Cl- was associated with the DBP, MAP, HR, SDNN, and RMSSD. NO3- was correlated with the SBP, MAP, HR, SDNN, and RMSSD. In conclusion, we observed cardiovascular responses to ambient particles in vivo using a crossover design which can reduce animal use in future environmental studies.
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Sustained renal inflammation following 2 weeks of inhalation of occupationally relevant levels of zinc oxide nanoparticles in Sprague Dawley rats. J Toxicol Pathol 2017; 30:307-314. [PMID: 29097840 PMCID: PMC5660952 DOI: 10.1293/tox.2017-0025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/30/2017] [Indexed: 11/19/2022] Open
Abstract
Exposure to zinc oxide (ZnO) has been linked to adverse health effects, but the renal effects of ZnO nanoparticles (ZnONPs) remain unclear. The objective of this study was to determine the renal toxicity of inhaled ZnONPs. Sprague Dawley (SD) rats were exposed to occupationally relevant levels of 1.1 (low dose) and 4.9 mg/m3 (high dose) ZnONPs or high-efficiency particulate arresting-filtered air (HEPA-FA) via inhalation for 2 weeks. Histopathological examinations of rat kidneys were performed at 24 hours, 7 days, and 1 month after exposure. A significant increase in microscopic inflammatory foci with pronounced periglomerular inflammation and interstitial lymphocytic infiltration was found in rats exposed to low and high doses of ZnONPs compared with rats exposed to HEPA-FA at the three time points following 2 weeks of exposure. Tubulitis featuring lymphocytic infiltrate within the tubular epithelium was found after 24 hours but had disappeared at 7 and 30 days in both the low- and high-dose exposure groups. Our findings demonstrate that inhaled ZnONPs cause sustained renal periglomerular and interstitial inflammation through lymphocytic infiltration. These findings provide histopathological evidence regarding sustained renal inflammation of nanoparticle exposure in rats and may provide some insight into the occupational health effects of ZnONPs on exposed workers.
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Pulmonary pathobiology induced by zinc oxide nanoparticles in mice: A 24-hour and 28-day follow-up study. Toxicol Appl Pharmacol 2017; 327:13-22. [DOI: 10.1016/j.taap.2017.04.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 03/20/2017] [Accepted: 04/18/2017] [Indexed: 12/12/2022]
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Comparative Proteomic Analysis of Rat Bronchoalveolar Lavage Fluid after Exposure to Zinc Oxide Nanoparticles. Mass Spectrom (Tokyo) 2017; 6:S0066. [PMID: 28573081 DOI: 10.5702/massspectrometry.s0066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/19/2017] [Indexed: 11/23/2022] Open
Abstract
Zinc oxide nanoparticles (ZnO NPs) are one of the most widely used nanomaterials in consumer products and industrial applications. As a result of all these uses, this has raised concerns regarding their potential toxicity. We previously found that candidate markers of idiopathic pulmonary fibrosis and lung cancer were significantly up-regulated in rat bronchoalveolar lavage fluid (BALF) following exposure to ZnO NPs by using a liquid chromatography (LC)-based proteomic approach. To achieve comprehensive protein identification analysis, we conducted the two-dimensional gel electrophosis (2-DE)-based proteomic workflow to analyze the differences in BALF proteins from rats that had been exposed to a high dose of 35 nm ZnO NPs. A total of 31 differentially expressed protein spots were excised from the gels and analyzed by nanoLC-tandem mass spectrometry (MS/MS). Gene ontology (GO) annotation of these proteins showed that most of the differentially expressed proteins were involved in response to stimulus and inflammatory response processes. Moreover, pulmonary surfactant-associated protein D and gelsolin, biomarkers of idiopathic pulmonary fibrosis, were significantly up-regulated in rat BALF after ZnO NPs exposure (2.42- and 2.84-fold, respectively). The results obtained from this present study could provide a complementary consequence with our previous study and contribute to a better understanding of the molecular mechanisms involved in ZnO NP-induced lung disorders.
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Development and collection efficiency of an electrostatic precipitator for in-vitro toxicity studies of nano- and submicron-sized aerosols. J Taiwan Inst Chem Eng 2017. [DOI: 10.1016/j.jtice.2017.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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The effect of size-segregated ambient particulate matter on Th1/Th2-like immune responses in mice. PLoS One 2017; 12:e0173158. [PMID: 28245275 PMCID: PMC5330505 DOI: 10.1371/journal.pone.0173158] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 02/15/2017] [Indexed: 12/12/2022] Open
Abstract
Background Particulate matter (PM) has been associated with increased pulmonary and cardiovascular mortality and morbidity. Additionally, PM is known to exacerbate asthma. However, whether ambient PM exposure contributes to the onset of asthma, especially in non-atopic children and adults, is less conclusive. The current study aimed to evaluate the effects of size-fractioned PM on lung immune responses in healthy BALB/c mice. Methods and principal findings We collected PM10, PM2.5, PM1 and PM0.1 samples from October 2012 to August 2013 in the Taipei Basin. These PM samples were representative of urban traffic pollution. The samples were extracted and sonicated in phosphate-buffered saline (PBS). Female BALB/c mice were exposed to the samples via intratracheal instillation at three different doses: 1.75 mg/kg (35 μg/per mouse), 5 mg/kg (100 μg/per mouse), and 12.5 mg/kg (250 μg/per mouse). The mice were exposed on days 0 and 7, and PBS alone was used as a control. Following the exposures, the expression profiles of inflammatory cells and cytokines in bronchoalveolar lavage fluid (BALF) were assessed. Exposure to PM10 resulted in inflammatory responses, including the recruitment of neutrophils and the induction of T helper 1 (Th1) cell-related cytokine release, such as TNF-α and IFN-γ. Furthermore, an allergic immune response, including the recruitment of eosinophils and the up-regulation of T helper 2 (Th2) cell-related cytokine release, such as IL-5 and IL-13, was also observed in the BALF of mice exposed to PM10. Conclusions Our study showed that exposure to PM alone caused mixed Th1/Th2 inflammatory responses in healthy mice. These findings support the hypothesis that PM may contribute to the onset of asthma.
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Association of temporal distribution of fine particulate matter with glucose homeostasis during pregnancy in women of Chiayi City, Taiwan. ENVIRONMENTAL RESEARCH 2017; 152:81-87. [PMID: 27743970 DOI: 10.1016/j.envres.2016.09.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 09/21/2016] [Accepted: 09/26/2016] [Indexed: 05/22/2023]
Abstract
BACKGROUND To investigate the effects of fine particulate matter (PM2.5) on the indicators of glucose homeostasis during pregnancy. METHODS A total of 3589 non-diabetic pregnant women who underwent a 3-h 100-g oral glucose tolerance test (OGTT) were enrolled from a tertiary teaching hospital in Chiayi City, Taiwan between 2006 and 2014. Fasting, 1-h, 2-h, and 3-h glucose levels after an OGTT were used as indicators of glucose homeostasis. PM2.5 and other air pollution data were obtained from one fixed-site monitoring station (Chiayi City station) operated by Taiwan Environmental Protection Administration (EPA). We used mixed models for indicators of glucose homeostasis to estimate the effects of PM2.5. The models were adjusted for individual-specific effects (nulliparous status, age, body mass index, season, and year) and the moving averages of temperature and relative humidity in the corresponding study period. RESULTS There were significant relationships between PM2.5 and the glucose homeostasis indicators, including fasting, 1-h, 2-h, and 3-h glucose levels in the single-pollutant covariate-adjusted model. The pre-screening 1-month to 1-year moving averages of IQR increases in PM2.5 were significantly associated with elevated fasting OGTT glucose levels (1.32-5.87mg/dL). The two-pollutant covariate-adjusted models had similar results. CONCLUSIONS We found positive associations between PM2.5 and OGTT glucose levels during pregnancy. The association was especially pronounced for the fasting and 1-h glucose levels. PM2.5 exposure in the second trimester may enhance this effect. Exposure to PM2.5 was associated with glucose homeostasis during pregnancy.
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Concurrent quantification of multiple biomarkers indicative of oxidative stress status using liquid chromatography-tandem mass spectrometry. Anal Biochem 2016; 512:26-35. [DOI: 10.1016/j.ab.2016.07.030] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 07/27/2016] [Accepted: 07/29/2016] [Indexed: 12/31/2022]
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NMR-based metabolomics to determine acute inhalation effects of nano- and fine-sized ZnO particles in the rat lung. Nanotoxicology 2016; 10:924-34. [DOI: 10.3109/17435390.2016.1144825] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Zinc oxide nanoparticles induce eosinophilic airway inflammation in mice. JOURNAL OF HAZARDOUS MATERIALS 2015; 297:304-312. [PMID: 26010476 DOI: 10.1016/j.jhazmat.2015.05.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 05/12/2015] [Accepted: 05/14/2015] [Indexed: 06/04/2023]
Abstract
Zinc oxide nanoparticles (ZnO NPs) have been widely used in industry. The metal composition of PM2.5 might contribute to the higher prevalence of asthma. To investigate the effects of ZnO NPs on allergic airway inflammation, mice were first exposed to different concentrations of ZnO NPs (0.1 mg/kg, 0.5 mg/kg) or to a combination of ZnO NPs and chicken egg ovalbumin (OVA) by oropharyngeal aspiration on day 0 and day 7 and then were sacrificed 5 days later. The subsequent time course of airway inflammation in the mice after ZnO NPs exposure was evaluated on days 1, 7, and 14. To further determine the role of zinc ions, ZnCl2 was also administered. The inflammatory cell count, cytokine levels in the bronchoalveolar lavage fluid (BALF), and lung histopathology were examined. We found significant neutrophilia after exposure to high-dose ZnO NPs on day 1 and significant eosinophilia in the BALF at 7 days. However, the expression levels of the T helper 2 (Th2) cytokines IL-4, IL-5, and IL-13 increased significantly after 24h of exposure to only ZnO NPs and then decreased gradually. These results suggested that ZnO NPs could cause eosinophilic airway inflammation in the absence of allergens.
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Chronic exposure to particulate matter and risk of cardiovascular mortality: cohort study from Taiwan. BMC Public Health 2015; 15:936. [PMID: 26392179 PMCID: PMC4578246 DOI: 10.1186/s12889-015-2272-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2015] [Accepted: 09/14/2015] [Indexed: 11/23/2022] Open
Abstract
Background Evidence on the association between long-term exposure to air pollution and cardiovascular mortality is limited in Asian populations. Methods We conducted a cohort study on the association between fine particulate matter (PM2.5) and cardiovascular mortality using 43,227 individuals in a civil servants health service in Taiwan. Each participant was assigned an exposure level of particulate matter based on their district of residence using air pollution data collected by the Taiwan Environmental Protection Agency and with modeling using geographic information systems. The participants were followed up from 1989 to 2008 and the vital status was ascertained from death records. Cox regression models were used to adjust for confounding factors. Results The district-level average of PM2.5 ranged from 22.8 to 32.9 μg/m3 in the study area. After a median follow-up of 18 years, 1992 deaths from all causes including 230 cardiovascular deaths occurred. After adjustment for potential confounders, PM2.5 levels were not significantly associated with mortality from cardiovascular disease [Hazard Ratio (HR) 0.80; 95 % Confidence Interval (CI), 0.43 to 1.50 per 10 μg/m3 increase in PM2.5] or all causes (HR 0.92; 95 % CI, 0.72 to 1.17 per 10 μg/m3 increase in PM2.5). The results were similar when the analysis was restricted to the urban areas and when the PM2.5 measurement was changed from the period average (2000–2008) to annual average. Discussion Our findings are different from those in prior cohort studies conducted in Asia where ambient air pollutionwas associated with an increased risk of cardiovascular mortality. The high background level of air pollutionin our study area and the small number of event cases limited the power of this study. Conclusions In this population-based cohort study in Taiwan, we found no evidence of increased risk for all-cause or cardiovascular mortality with long-term exposure to PM2.5. Electronic supplementary material The online version of this article (doi:10.1186/s12889-015-2272-6) contains supplementary material, which is available to authorized users.
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Effects of non-protein-type amino acids of fine particulate matter on E-cadherin and inflammatory responses in mice. Toxicol Lett 2015; 237:174-80. [DOI: 10.1016/j.toxlet.2015.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 05/25/2015] [Accepted: 06/13/2015] [Indexed: 12/09/2022]
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Alterations in rat pulmonary phosphatidylcholines after chronic exposure to ambient fine particulate matter. MOLECULAR BIOSYSTEMS 2015; 10:3163-9. [PMID: 25236678 DOI: 10.1039/c4mb00435c] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
This study elucidated the underlying pathophysiological changes that occur after chronic ambient fine particulate matter (PM2.5) exposure via a lipidomic approach. Five male Sprague-Dawley rats were continually whole-body exposed to ambient air containing PM2.5 at 16.7 ± 10.1 μg m(-3) from the outside of the building for 8 months, whereas a control group (n = 5) inhaled filtered air. Phosphorylcholine-containing lipids were extracted from lung tissue and profiled using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The phosphatidylcholine (PC) signal features of the two groups were compared using partial least squares discriminant analysis (PLS-DA) and Wilcoxon rank sum tests. The PC profile of the exposure group differed from that of the control group; the R(2)Y and Q(2) were 0.953 and 0.677, respectively, in the PLS-DA model. In the exposure group, a significant 0.66- to 0.80-fold reduction in lyso-PC levels, which may have resulted from repeated inflammation, was observed. Decreased surfactant PCs by 16% at most may indicate injuries to alveolar type II cells. Cell function and cell signalling are likely to be altered because the decrease in unsaturated PCs may reduce membrane fluidity. Accompanied by the decline in plasmenylcholines, decreased unsaturated PCs may indicate the attack of reactive oxygen species generated by PM2.5 exposure. The physiological findings conformed to the histopathological changes in the exposed animals. PC profiling using UPLC-MS/MS-based lipidomics is sensitive for reflecting pathophysiological perturbations in the lung after long-term and low concentration PM2.5 exposure.
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Increased night duty loading of physicians caused elevated blood pressure and sympathetic tones in a dose-dependent manner. Int Arch Occup Environ Health 2015; 89:413-23. [DOI: 10.1007/s00420-015-1080-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 07/19/2015] [Indexed: 12/12/2022]
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Effects of particulate air pollution and ozone on lung function in non-asthmatic children. ENVIRONMENTAL RESEARCH 2015; 137:40-8. [PMID: 25486544 DOI: 10.1016/j.envres.2014.11.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 11/06/2014] [Accepted: 11/27/2014] [Indexed: 05/07/2023]
Abstract
INTRODUCTION Information on the long-term effects of different air pollutant levels on lung function is relatively lacking in Asia and still inconclusive in the world. Age differential effects of air pollution are not known. OBJECTIVES To assess the acute and subchronic effects of ambient air pollution on lung function and compared among children of different ages. METHODS From April to May 2011, a nationwide study was conducted on schoolchildren aged 6-15 years in 44 schools of 24 districts in Taiwan. Spirograms were obtained from 1494 non-asthmatic children. Air pollution data were retrieved from air monitoring stations within one kilometre of the schools. Using three-level hierarchical linear models, individual lung function was fitted to air pollution, with adjustments for demographics, indoor exposures, outdoor activity, and districts. RESULTS Lung function changes per inter-quartile increase of the past two-months average levels of particulate matter <2.5 μm (PM2.5) and ozone (12 μg/m(3), 32-44 and 6.7 ppb, 32-38, respectively) were -103 and -142 ml on FVC, -86 and -131 on FEV1, and -102 and -188 ml/s on MMEF, respectively. Lag-1-day ozone exposure was associated with decreased MMEF. In children aged 6-10, PM2.5 was associated with decreased FEV1/FVC and MMEF/FVC ratios. CONCLUSIONS In children aged 6-15 years, sub-chronic exposure to ambient PM2.5 and ozone leads to reduced lung capacity, whereas acute exposure to ozone decreases mid-expiratory flow. In children aged 6-10 years, additional airway obstructive patterns in lung function may be associated with PM2.5 exposure.
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Allergen exposure induces adipose tissue inflammation and insulin resistance. Int Immunopharmacol 2014; 23:104-12. [DOI: 10.1016/j.intimp.2014.07.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2014] [Revised: 07/29/2014] [Accepted: 07/30/2014] [Indexed: 12/17/2022]
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Subchronic effects of inhaled ambient particulate matter on glucose homeostasis and target organ damage in a type 1 diabetic rat model. Toxicol Appl Pharmacol 2014; 281:211-20. [PMID: 25454026 DOI: 10.1016/j.taap.2014.10.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/08/2014] [Accepted: 10/11/2014] [Indexed: 01/07/2023]
Abstract
Epidemiological studies have reported associations between particulate matter (PM) and cardiovascular effects, and diabetes mellitus (DM) patients might be susceptible to these effects. The chief chronic injuries resulting from DM are small vascular injuries (micro-vascular complications) or large blood vessel injuries (macro-vascular complications). However, toxicological data regarding the effects of PM on DM-related cardiovascular complications is limited. Our objective was to investigate whether subchronic PM exposure alters glucose homeostasis and causes cardiovascular complications in a type 1 DM rat model. We constructed a real world PM2.5 exposure system, the Taipei Air Pollution Exposure System for Health Effects (TAPES), to continuously deliver non-concentrated PM for subchronic exposure. A type 1 DM rat model was induced using streptozotocin. Between December 22, 2009 and April 9, 2010, DM rats were exposed to PM or to filtered air (FA) using TAPES in Taipei, Taiwan, 24h/day, 7days/week, for a total of 16weeks. The average concentrations (mean [SD]) of PM2.5 in the exposure and control chambers of the TAPES were 13.30 [8.65] and 0.13 [0.05]μg/m(3), respectively. Glycated hemoglobin A1c (HbA1c) was significantly elevated after exposure to PM compared with exposure to FA (mean [SD], 7.7% [3.1%] vs. 4.7% [1.0%], P<0.05). Interleukin 6 and fibrinogen levels were significantly increased after PM exposure. PM caused focal myocarditis, aortic medial thickness, advanced glomerulosclerosis, and accentuation of tubular damage of the kidney (tubular damage index: 1.76 [0.77] vs. 1.15 [0.36], P<0.001). PM exposure might induce the macro- and micro-vascular complications in DM through chronic hyperglycemia and systemic inflammation.
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Physicochemical and biological characterization of single-walled and double-walled carbon nanotubes in biological media. JOURNAL OF HAZARDOUS MATERIALS 2014; 280:216-225. [PMID: 25164386 DOI: 10.1016/j.jhazmat.2014.07.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 07/14/2014] [Accepted: 07/23/2014] [Indexed: 06/03/2023]
Abstract
To study the toxicity of nanoparticles under relevant conditions, it is important to reproducibly disperse nanoparticles in biological media in in vitro and in vivo studies. Here, single-walled nanotubes (SWNTs) and double-walled nanotubes (DWNTs) were physicochemically and biologically characterized when dispersed in phosphate-buffered saline (PBS) and bovine serum albumin (BSA). BSA-SWNT/DWNT interaction resulted in a reduction of aggregation and an increase in particle stabilization. Based on the protein sequence coverage and protein binding results, DWNTs exhibited higher protein binding than SWNTs. SWNT and DWNT suspensions in the presence of BSA increased interleukin-6 (IL-6) levels and reduced tumor necrosis factor-alpha (TNF-α) levels in A549 cells as compared to corresponding samples in the absence of BSA. We next determined the effects of SWNTs and DWNTs on pulmonary protein modification using bronchoalveolar lavage fluid (BALF) as a surrogate collected form BALB/c mice. The BALF proteins bound to SWNTs (13 proteins) and DWNTs (11 proteins), suggesting that these proteins were associated with blood coagulation pathways. Lastly, we demonstrated the importance of physicochemical and biological alterations of SWNTs and DWNTs when dispersed in biological media, since protein binding may result in the misinterpretation of in vitro results and the activation of protein-regulated biological responses.
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Changes in protein expression in rat bronchoalveolar lavage fluid after exposure to zinc oxide nanoparticles: an iTRAQ proteomic approach. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:974-980. [PMID: 24623703 DOI: 10.1002/rcm.6866] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 02/02/2014] [Accepted: 02/03/2014] [Indexed: 06/03/2023]
Abstract
RATIONALE Zinc oxide nanoparticles (ZnO NPs) are widely used in consumer products and various biomedical fields. As a result, humans are frequently exposed to these NPs. However, there is a lack of information about the proteins that are expressed in the airway in response to exposure to ZnO NPs. METHODS Bronchoalveolar lavage fluid (BALF) from Sprague-Dawley (SD) rats that had been exposed to high-dose 35 nm ZnO NPs (N = 6) and filtered air (N = 4) was collected and then labeled with isobaric tags for relative and absolute quantitation (iTRAQ). The differentially expressed proteins were identified by two-dimensional liquid chromatography/tandem mass spectrometry (2D-LC/MS/MS) and further classified by Gene Ontology (GO) annotation. RESULTS A total of 46 proteins displayed significant changes after exposure. GO annotation of these differentially expressed proteins indicated that exposure to ZnO NPs mainly affected immune and inflammatory processes. Furthermore, S100A8 and S100A9, candidate markers of idiopathic pulmonary fibrosis and lung cancer, were significantly up-regulated (2.78- and 2.87-fold, respectively) following exposure. CONCLUSIONS Our data are consistent with recent study results that exposure to ZnO NPs induces lung inflammation. These data contribute to a better understanding of how exposure to ZnO NPs leads to lung damage through the functional classification of these proteins.
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Characterization of the interactions between protein and carbon black. JOURNAL OF HAZARDOUS MATERIALS 2014; 264:127-135. [PMID: 24291665 DOI: 10.1016/j.jhazmat.2013.10.055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/23/2013] [Accepted: 10/25/2013] [Indexed: 06/02/2023]
Abstract
A considerable amount of studies have been conducted to investigate the interactions of biological fluids with nanoparticle surfaces, which exhibit a high affinity for proteins and particles. However, the mechanisms underlying these interactions have not been elucidated, particularly as they relate to human health. Using bovine serum albumin (BSA) and mice bronchoalveolar lavage fluid (BALF) as models for protein-particle conjugates, we characterized the physicochemical modifications of carbon blacks (CB) with 23nm or 65nm in diameter after protein treatment. Adsorbed BALF-containing proteins were quantified and identified by pathways, biological analyses and protein classification. Significant modifications of the physicochemistry of CB were induced by the addition of BSA. Enzyme modulators and hydrolase predominately interacted with CB, with protein-to-CB interactions that were associated with the coagulation pathways. Additionally, our results revealed that an acute-phase response could be activated by these proteins. With regard to human health, the present study revealed that the CB can react with proteins (∼55kDa and 70kDa) after inhalation and may modify the functional structures of lung proteins, leading to the activation of acute-inflammatory responses in the lungs.
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Allergenicity and toxicology of inhaled silver nanoparticles in allergen-provocation mice models. Int J Nanomedicine 2013; 8:4495-506. [PMID: 24285922 PMCID: PMC3841295 DOI: 10.2147/ijn.s52239] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Silver nanoparticles (AgNP) have been associated with the exacerbation of airway hyperresponsiveness. However, the allergenicity and toxicology of AgNP in healthy and allergic individuals are unclear. We investigated the pathophysiological responses to AgNP inhalation in a murine model of asthma. Continuous and stable levels of 33 nm AgNP were maintained at 3.3 mg/m3 during the experimental period. AgNP exposure concomitant with ovalbumin challenge increased the enhanced pause (Penh) in the control and allergic groups. AgNP evoked neutrophil, lymphocyte and eosinophil infiltration into the airways and elevated the levels of allergic markers (immunoglobulin E [IgE] and leukotriene E4 [LTE4]), the type 2 T helper (Th2) cytokine interleukin-13 (IL-13), and oxidative stress (8-hydroxy-2′-deoxyguanosine [8-OHdG]) in healthy and allergic mice. Bronchocentric interstitial inflammation was observed after AgNP inhalation. After inhalation, the AgNP accumulated predominantly in the lungs, and trivial amounts of AgNP were excreted in the urine and feces. Furthermore, the AgNP induced inflammatory responses in the peritoneum. The inhalation of AgNP may present safety concerns in healthy and susceptible individuals.
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Risks perception of electromagnetic fields in Taiwan: the influence of psychopathology and the degree of sensitivity to electromagnetic fields. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2013; 33:2002-2012. [PMID: 23551091 DOI: 10.1111/risa.12041] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Little is known about the perceived health risks of electromagnetic fields (EMFs) and factors associated with risk perception in non-Western countries. Psychological conditions and risk perception have been postulated as factors that facilitate the attribution of health complaints to environmental factors. This study investigated people's perceived risks of EMFs and other environmental sources, as well as the relationships between risk perception, psychopathology, and the degree of self-reported sensitivity to EMFs. A total of 1,251 adults selected from a nationwide telephone interviewing system database responded to a telephone survey about the relationships between environmental sources and human health. The interview included questions assessing participants' psychiatric conditions and the presence and degree of sensitivity to EMFs. One hundred and seventy participants were self-identified as having sensitivity to EMFs, and 141 met the criteria for psychiatric conditions without EMF sensitivity. More than half of the survey respondents considered power lines and mobile phone base stations to affect people's health to a big extent. Higher sensitivity to EMFs, psychopathology, being female, being married, more years of education, and having a catastrophic illness had positive associations with perceived risks of EMF-related environmental sources as well as for all environmental sources combined. We observed no moderating effect of psychopathology on the association between degree of sensitivity to EMF and risk perception. Thus, psychopathology had influence on general people's risk perception without having influence on the relationship between people's degree of sensitivity to EMF and risk perception. The plausible explanations are discussed in the text.
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Comparative proteomics of inhaled silver nanoparticles in healthy and allergen provoked mice. Int J Nanomedicine 2013; 8:2783-99. [PMID: 23946650 PMCID: PMC3742529 DOI: 10.2147/ijn.s46997] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background Silver nanoparticles (AgNPs) have been associated with the exacerbation of asthma; however, the immunological basis for the adjuvant effects of AgNPs is not well understood. Objective The aim of the study reported here was to investigate the allergic effects of AgNP inhalation using proteomic approaches. Methods Allergen provoked mice were exposed to 33 nm AgNPs at 3.3 mg/m3. Following this, bronchoalveolar lavage fluid (BALF) and plasma were collected to determine protein profiles. Results In total, 106 and 79 AgNP-unique proteins were identified in the BALF of control and allergic mice, respectively. Additionally, 40 and 26 AgNP-unique proteins were found in the plasma of control and allergic mice, respectively. The BALF and plasma protein profiles suggested that metabolic, cellular, and immune system processes were associated with pulmonary exposure to AgNPs. In addition, we observed 18 proteins associated with systemic lupus erythematosus that were commonly expressed in both control and allergic mice after AgNP exposure. Significant allergy responses were observed after AgNP exposure in control and allergic mice, as determined by ovalbumin-specific immunoglobulin E. Conclusion Inhaled AgNPs may regulate immune responses in the lungs of both control and allergic mice. Our results suggest that immunology is a vital response to AgNPs.
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Cardiopulmonary toxicity of pulmonary exposure to occupationally relevant zinc oxide nanoparticles. Nanotoxicology 2013; 8:593-604. [PMID: 23738974 DOI: 10.3109/17435390.2013.809809] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Exposure to zinc oxide (ZnO) metal fumes is linked to adverse human health effects; however, the hazards of ZnO nanoparticles (ZnONPs) remain unclear. To determine pulmonary exposure to occupationally relevant ZnONPs cause cardiopulmonary injury, Sprague-Dawley rats were exposed to ZnONPs via intratracheal (IT) instillation and inhalation. The relationship between intrapulmonary zinc levels and pulmonary oxidative-inflammatory responses 72 h after ZnONP instillation was determined in bronchoalveolar lavage fluid (BALF). Instilled ZnONPs altered zinc balance and increased the levels of total cells, neutrophils, lactate dehydrogenase (LDH) and total protein in BALF and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in blood after 72 h. The ZnONPs accumulated predominantly in the lungs over 24 h, and trivial amounts of zinc were determined in the heart, liver, kidneys and blood. Furthermore, the inflammatory-oxidative responses induced by occupationally relevant levels of 1.1 and 4.9 mg/m(3) of ZnONP inhalation for 2 weeks were determined in BALF and blood at 1, 7 and 30 days post-exposure. Histopathological examinations of the rat lungs and hearts were performed. Inhalation of ZnONP caused an inflammatory cytological profile. The total cell, neutrophil, LDH and total protein levels were acutely increased in the BALF, and there was an inflammatory pathology in the lungs. There were subchronic levels of white blood cells, granulocytes and 8-OHdG in the blood. Cardiac inflammation and the development of fibrosis were detected 7 days after exposure. Degeneration and necrosis of the myocardium were detected 30 days after exposure. The results demonstrate that ZnONPs cause cardiopulmonary impairments. These findings highlight the occupational health effects for ZnONP-exposed workers.
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Nickel-regulated heart rate variability: The roles of oxidative stress and inflammation. Toxicol Appl Pharmacol 2013; 266:298-306. [DOI: 10.1016/j.taap.2012.11.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 11/07/2012] [Accepted: 11/08/2012] [Indexed: 11/16/2022]
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Protective effects of pulmonary epithelial lining fluid on oxidative stress and DNA single-strand breaks caused by ultrafine carbon black, ferrous sulphate and organic extract of diesel exhaust particles. Toxicol Appl Pharmacol 2012; 266:329-34. [PMID: 23261976 DOI: 10.1016/j.taap.2012.12.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2012] [Revised: 12/03/2012] [Accepted: 12/06/2012] [Indexed: 11/30/2022]
Abstract
Pulmonary epithelial lining fluid (ELF) is the first substance to make contact with inhaled particulate matter (PM) and interacts chemically with PM components. The objective of this study was to determine the role of ELF in oxidative stress, DNA damage and the production of proinflammatory cytokines following physicochemical exposure to PM. Ultrafine carbon black (ufCB, 15 nm; a model carbonaceous core), ferrous sulphate (FeSO(4); a model transition metal) and a diesel exhaust particle (DEP) extract (a model organic compound) were used to examine the acellular oxidative potential of synthetic ELF and non-ELF systems. We compared the effects of exposure to ufCB, FeSO(4) and DEP extract on human alveolar epithelial Type II (A549) cells to determine the levels of oxidative stress, DNA single-strand breaks and interleukin-8 (IL-8) production in ELF and non-ELF systems. The effects of ufCB and FeSO(4) on the acellular oxidative potential, cellular oxidative stress and DNA single-strand breakage were mitigated significantly by the addition of ELF, whereas there was no decrease following treatment with the DEP extract. There was no significant effect on IL-8 production following exposure to samples that were suspended in ELF/non-ELF systems. The results of the present study indicate that ELF plays an important role in the initial defence against PM in the pulmonary environment. Experimental components, such as ufCB and FeSO(4), induced the production of oxidative stress and led to DNA single-strand breaks, which were moderately prevented by the addition of ELF. These findings suggest that ELF plays a protective role against PM-driven oxidative stress and DNA damage.
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The association of ambient air pollution with airway inflammation in schoolchildren. Am J Epidemiol 2012; 175:764-74. [PMID: 22408045 DOI: 10.1093/aje/kwr380] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The biologic mechanisms involved in airway inflammatory response to air pollution are not clearly understood. The authors conducted a longitudinal study to investigate whether exposure to ambient air pollutants affected inflammatory cells and mediators from nasal lavage in schoolchildren. Study participants were 100 elementary and middle-school students in New Taipei City, Taiwan. A structured respiratory health questionnaire was administered in September 2007, followed by monthly measurement of nasal inflammation from October 2007 to November 2009. During the study period, daily concentrations of air pollutants were obtained from the Environmental Protection Administration monitoring station and the Aerosol Supersite. Mixed-effects models were applied to examine the association between air pollution and nasal inflammatory cells and mediators, including percentages of neutrophils, eosinophils, and monocytes in lavaged cells and interleukin-8. A total of 824 measurements were obtained from 100 participants over a period of 10 months. The level of particulate matter with an aerodynamic diameter of 2.5 μm or less (PM(2.5)) was found to be associated with percentage of neutrophils (β = 3.45%, 95% confidence interval: 0.89, 6.01) and interleukin-8 level (β = 29.98 pg/mL, 95% confidence interval: 3.26, 56.69) in the nasal lavage on the day of exposure. In this longitudinal cohort study of schoolchildren, results indicated that exposure to PM(2.5) might induce nasal inflammation.
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Demonstration of an olfactory bulb-brain translocation pathway for ZnO nanoparticles in rodent cells in vitro and in vivo. J Mol Neurosci 2012; 48:464-71. [PMID: 22528453 DOI: 10.1007/s12031-012-9756-y] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Accepted: 03/16/2012] [Indexed: 01/08/2023]
Abstract
ZnO nanoparticles (ZnO-NPs) are widely used in the engineering and cosmetic industries, and inhaled airborne particles pose a known hazard to human health; their translocation into humans is a recognized public health concern. The pulmonary-blood pathway for ZnO-NP toxicity is well documented, but whether translocation of these particles can also occur via an olfactory bulb-brain route remains unclear. The potential toxicity of ZnO-NPs for the human central nervous system (CNS) is predicated on the possibility of their translocation. Our study investigated translocation of ZnO-NPs both in vitro using the neuronal cell line PC12 and in vivo in a Sprague-Dawley rat model. Our findings indicate that the zinc-binding dye, Newport-Green DCF, binds ZnO stoichiometrically and that ZnO-NP concentration can therefore be measured by the fluorescence intensity of the bound dye in confocal fluorescence microscopy. Confocal data obtained using Newport-Green DCF-2 K(+)-conjugated ZnO-NPs along with the membrane probe FM1-43 demonstrated endocytosis of ZnO-NPs by PC12 cells. In addition, Fluozin-3 measurement showed elevation of cytosolic Zn(2+) concentration in these cells. Following in vivo nasal exposure of rats to airborne ZnO-NPs, olfactory bulbs and brains that were examined by Newport-Green fluorescence and TEM particle measurement clearly showed the presence of ZnO-NPs in brain. We conclude that an olfactory bulb-brain translocation pathway for airborne ZnO-NPs exists in rats, and that endocytosis is required for interneuron translocation of these particles.
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Pulmonary toxicity of inhaled nanoscale and fine zinc oxide particles: mass and surface area as an exposure metric. Inhal Toxicol 2012; 23:947-56. [PMID: 22122307 DOI: 10.3109/08958378.2011.629235] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The total surface area is known to be an effective exposure metric for predicting the lung toxicity of low solubility nanoparticles (NPs). However, if NPs are dissolved quickly enough in the lungs, the mass may be correlated with the toxicity. Recent studies have found that the toxicity of zinc oxide (ZnO) NPs was caused by the release of zinc ions. Thus, we hypothesized that mass could be used as an exposure metric for the toxicity of ZnO NPs. Healthy Sprague-Dawley rats were exposed to a low, moderate, or high dose of 35 and 250 nm ZnO particles or filtered air. Bronchoalveolar lavage fluid was collected to determine lung inflammation, injury and oxidative stress. The lung inflammation induced by ZnO particles according to different concentration metrics, including number, mass and surface area, was compared. The mass concentration was significantly correlated with the percentage of neutrophils (R(2) = 0.84), number of neutrophils (R(2) = 0.84) and total cells (R(2) = 0.73). Similarly, surface area concentration was significantly correlated with the percentage of neutrophils (R(2) = 0.94), number of neutrophils (R(2) = 0.81) and total cells (R(2) = 0.76). There was no correlation between the number and lung inflammation. We found that both mass and surface area were effective as metrics for the toxicity of ZnO NPs, although only surface area was previously indicated to be an effective metric. Our results are also consistent with recent study results that ZnO NPs and released zinc ions may play a role mediating the toxicity of NPs.
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Zinc oxide nanoparticles interfere with zinc ion homeostasis to cause cytotoxicity. Toxicol Sci 2011; 125:462-72. [PMID: 22112499 DOI: 10.1093/toxsci/kfr319] [Citation(s) in RCA: 192] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The toxicological effects of zinc oxide nanoparticles (ZnO-NPs) are attracting increasing concern as the field of nanotechnology progresses. Although the literature suggests that toxicity of ZnO-NPs may be related to their dissolution, the mechanism for ZnO-NP perturbation of cytosolic zinc concentration ([Zn(2+)](c)) homeostasis remains obscure. Using FluoZin-3 and RhodZin-3, this study investigated changes in both [Zn(2+)](c) and mitochondrial free Zn(2+) concentration ([Zn(2+)](m)) under conditions of ZnO-NP treatment in vivo and in vitro. In human leukemia Jurkat cells and human lung carcinoma H1355 cells, ZnO-NP treatment resulted in an elevation of both [Zn(2+)](c) and [Zn(2+)](m). In H1355 cells, ZnO-NP treatment induced depolarization of mitochondrial membrane potential, as well as caspase-3 activation and lactic dehydrogenase (LDH) release. In our in vivo experiments, when rats were exposed to ZnO-NPs, higher [Zn(2+)](c) and [Zn(2+)](m) were recorded in both broncho-alveolar lavage (BAL) cells and white blood cells isolated from ZnO-NP-exposed rats, compared with high efficiency particulate air-filter-protected controls LDH levels were also elevated in the BAL of ZnO-NP-exposed rats compared with controls. A mechanical toxicological pathway for ZnO-NP toxicity is suggested by these results: an elevation in [Zn(2+)](c) resulting from ZnO-NP dissolution in the intracellular endosome; cytosolic Zn(2+) sequestration by mitochondria; and elevated [Zn(2+)](m) leading to mitochondrial dysfunction, caspase activation, and cell apoptosis. We conclude that exposure to ZnO-NPs interferes with the homeostasis of [Zn(2+)](c,) and that elevated [Zn(2+)](c) results in cell apoptosis.
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Enhanced insulin resistance in diet-induced obese rats exposed to fine particles by instillation. Inhal Toxicol 2011; 23:507-19. [PMID: 21736501 DOI: 10.3109/08958378.2011.587472] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Epidemiological studies indicate that diabetes is a sub-population at risk for particulate matter (PM)-associated cardiovascular disease (CVD). Recent animal studies suggested PM might impair glucose tolerance, which may lead to CVD. However, the mechanism remains unclear. OBJECTIVE To investigate further the PM effect on insulin resistance (IR) in obese and healthy rats. MATERIALS AND METHODS Male Sprague-Dawley rats were fed with either a high fat diet (HFD) or normal chow diet (NCD) for 6 weeks. Both groups were then further assigned to receive PM(10), PM(2.5) or normal saline (n = 6 per group) by intratracheal instillation (IT) once per week for 3 weeks. Fasting glucose and insulin were measured and homeostasis model assessment-insulin resistance (HOMA-IR) was used to assess IR. Biochemistry tests and lipids profile were examined at sacrifice. The markers of fibrinogen and [nitrate+nitrite], an indicator of nitric oxide (NO) production, C-reactive protein (CRP) and white blood counts (WBCs) in peripheral blood were also determined. RESULTS Body weight, insulin and HOMA-IR of HFD rats were significantly increased compared with a NCD after 6 weeks. In HFD rats, PM(2.5) increased HOMA-IR after first IT and further increased HOMA-IR at the end of exposure. However, this increase was not observed in NCD rats and after PM(10) exposure. Increased fibrinogen was also noted after chronic PM(2.5) exposure in both HFD and NCD rats. DISCUSSION AND CONCLUSION Exposure to PM(2.5) enhanced IR in HFD rats but not in NCD rats. Obese subjects with IR may be a susceptible population to particulate air pollution.
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