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1.
Environ Sci Nano ; 11(1): 324-335, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38577066

RESUMO

Multi-walled carbons nanotubes (MWCNTs) are used in materials for the construction, automotive, and aerospace industries. Workers and consumers are exposed to these materials via inhalation. Existing recommended exposure limits are based on MWCNT exposures that do not take into account more realistic co-exposures. Our goal was to understand how a common allergen, house dust mites, interacts with pristine MWCNTs and lung fluid proteins. We used gel electrophoresis, western blotting, and proteomics to characterize the composition of the allergen corona formed from house dust mite extract on the surface of MWCNTs. We found that the corona is dominated by der p 2, a protein associated with human allergic responses to house dust mites. Der p 2 remains adsorbed on the surface of the MWCNTs following subsequent exposures to lung fluid proteins. The high concentration of der p 2, localized on surface of MWCNTs, has important implications for house dust mite-induced allergies and asthma. This research provides a detailed characterization of the complex house dust mite-lung fluid protein coronas for future cellular and in vivo studies. These studies will help to address the molecular and biochemical mechanisms underlying the exacerbation of allergic lung disease by nanomaterials.

2.
Part Fibre Toxicol ; 20(1): 32, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580758

RESUMO

BACKGROUND: Pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) has been reported to exert strong pro-inflammatory and pro-fibrotic adjuvant effects in mouse models of allergic lung disease. However, the molecular mechanisms through which MWCNTs exacerbate allergen-induced lung disease remain to be elucidated. We hypothesized that protease-activated receptor 2 (PAR2), a G-protein coupled receptor previously implicated in the pathogenesis of various diseases including pulmonary fibrosis and asthma, may play an important role in the exacerbation of house dust mite (HDM) allergen-induced lung disease by MWCNTs. METHODS: Wildtype (WT) male C57BL6 mice and Par2 KO mice were exposed to vehicle, MWCNTs, HDM extract, or both via oropharyngeal aspiration 6 times over a period of 3 weeks and were sacrificed 3-days after the final exposure (day 22). Bronchoalveolar lavage fluid (BALF) was harvested to measure changes in inflammatory cells, total protein, and lactate dehydrogenase (LDH). Lung protein and RNA were assayed for pro-inflammatory or profibrotic mediators, and formalin-fixed lung sections were evaluated for histopathology. RESULTS: In both WT and Par2 KO mice, co-exposure to MWCNTs synergistically increased lung inflammation assessed by histopathology, and increased BALF cellularity, primarily eosinophils, as well as BALF total protein and LDH in the presence of relatively low doses of HDM extract that alone produced little, if any, lung inflammation. In addition, both WT and par2 KO mice displayed a similar increase in lung Cc1-11 mRNA, which encodes the eosinophil chemokine CCL-11, after co-exposure to MWCNTs and HDM extract. However, Par2 KO mice displayed significantly less airway fibrosis as determined by quantitative morphometry compared to WT mice after co-exposure to MWCNTs and HDM extract. Accordingly, at both protein and mRNA levels, the pro-fibrotic mediator arginase 1 (ARG-1), was downregulated in Par2 KO mice exposed to MWCNTs and HDM. In contrast, phosphorylation of the pro-inflammatory transcription factor NF-κB and the pro-inflammatory cytokine CXCL-1 was increased in Par2 KO mice exposed to MWCNTs and HDM. CONCLUSIONS: Our study indicates that PAR2 mediates airway fibrosis but not eosinophilic lung inflammation induced by co-exposure to MWCNTs and HDM allergens.


Assuntos
Hipersensibilidade , Nanotubos de Carbono , Pneumonia , Fibrose Pulmonar , Receptor PAR-2 , Animais , Masculino , Camundongos , Alérgenos/toxicidade , Líquido da Lavagem Broncoalveolar , Modelos Animais de Doenças , Fibrose , Hipersensibilidade/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Nanotubos de Carbono/toxicidade , Pneumonia/patologia , Fibrose Pulmonar/metabolismo , Pyroglyphidae , Receptor PAR-2/genética , Receptor PAR-2/metabolismo , RNA Mensageiro/metabolismo
3.
Inhal Toxicol ; 34(9-10): 244-259, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35704474

RESUMO

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) have been associated with respiratory diseases in humans, yet the mechanisms through which PFAS cause susceptibility to inhaled agents is unknown. Herein, we investigated the effects of ammonium perfluoro(2-methyl-3-oxahexanoate) (GenX), an emerging PFAS, on the pulmonary immune response of mice to carbon black nanoparticles (CBNP). We hypothesized that pulmonary exposure to GenX would increase susceptibility to CBNP through suppression of innate immunity. METHODS: Male C57BL/6 mice were exposed to vehicle, 4 mg/kg CBNP, 10 mg/kg GenX, or CBNP and GenX by oropharyngeal aspiration. Bronchoalveolar lavage fluid (BALF) was collected at 1 and 14 days postexposure for cytokines and total protein. Lung tissue was harvested for histopathology, immunohistochemistry (Ki67 and phosphorylated (p)-STAT3), western blotting (p-STAT3 and p-NF-κB), and qRT-PCR for cytokine mRNAs. RESULTS: CBNP increased CXCL-1 and neutrophils in BALF at both time points evaluated. However, GenX/CBNP co-exposure reduced CBNP-induced CXCL-1 and neutrophils in BALF. Moreover, CXCL-1, CXCL-2 and IL-1ß mRNAs were increased by CBNP in lung tissue but reduced by GenX. Western blotting showed that CBNP induced p-NF-κB in lung tissue, while the GenX/CBNP co-exposed group displayed decreased p-NF-κB. Furthermore, mice exposed to GenX or GenX/CBNP displayed increased numbers of BALF macrophages undergoing mitosis and increased Ki67 immunostaining. This was correlated with increased p-STAT3 by western blotting and immunohistochemistry in lung tissue from mice co-exposed to GenX/CBNP. CONCLUSIONS: Pulmonary exposure to GenX suppressed CBNP-induced innate immune response in the lungs of mice yet promoted the proliferation of macrophages and lung epithelial cells.


Assuntos
Compostos de Amônio , Fluorocarbonos , Imunidade Inata , Nanopartículas , Fuligem , Compostos de Amônio/toxicidade , Animais , Líquido da Lavagem Broncoalveolar/química , Proliferação de Células , Citocinas/metabolismo , Fluorocarbonos/toxicidade , Antígeno Ki-67/metabolismo , Pulmão , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Nanopartículas/toxicidade , Fuligem/toxicidade
4.
Toxicol In Vitro ; 83: 105394, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35623502

RESUMO

We previously reported that delivery of nickel nanoparticles (NiNPs) and bacterial lipopolysaccharide (LPS) into the lungs of mice synergistically increased IL-6 production and inflammation, and male mice were more susceptible than female mice. The primary goal of this study was to utilize an in vitro human lung epithelial cell model (BEAS-2B) to investigate the intracellular signaling mechanisms that mediate IL-6 production by LPS and NiNPs. We also investigated the effect of sex hormones on NiNP and LPS-induced IL-6 production in vitro. LPS and NiNPs synergistically induced IL-6 mRNA and protein in BEAS-2B cells. TPCA-1, a dual inhibitor of IKK-2 and STAT3, blocked the synergistic increase in IL-6 caused by LPS and NiNPs, abolished STAT3 activation, and reduced C/EBPß. Conversely, SC144, an inhibitor of the gp130 component of the IL-6 receptor, enhanced IL-6 production induced by LPS and NiNPs. Treatment of BEAS-2B cells with sex hormones (17ß-estradiol, progesterone, or testosterone) or the anti-oxidant NAC, had no effect on IL-6 induction by LPS and NiNPs. These data suggest that LPS and NiNPs induce IL-6 via STAT3 and C/EBPß in BEAS-2B cells. While BEAS-2B cells are a suitable model to study mechanisms of IL-6 production, they do not appear to be suitable for studying the effect of sex hormones.


Assuntos
Lipopolissacarídeos , Nanopartículas , Animais , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Linhagem Celular , Células Epiteliais , Feminino , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Níquel , Fator de Transcrição STAT3/metabolismo
5.
Toxicol Sci ; 183(1): 170-183, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34175951

RESUMO

Ozone (O3) is a criteria air pollutant known to increase the morbidity and mortality of cardiopulmonary diseases. This occurs through a pulmonary inflammatory response characterized by increased recruitment of immune cells into the airspace, pro-inflammatory cytokines, and pro-inflammatory lipid mediators. Recent evidence has demonstrated sex-dependent differences in the O3-induced pulmonary inflammatory response. However, it is unknown if this dimorphic response is evident in pulmonary lipid mediator metabolism. We hypothesized that there are sex-dependent differences in lipid mediator production following acute O3 exposure. Male and female C57BL/6J mice were exposed to 1 part per million O3 for 3 h and were necropsied at 6 or 24 h following exposure. Lung lavage was collected for cell differential and total protein analysis, and lung tissue was collected for mRNA analysis, metabololipidomics, and immunohistochemistry. Compared with males, O3-exposed female mice had increases in airspace neutrophilia, neutrophil chemokine mRNA, pro-inflammatory eicosanoids such as prostaglandin E2, and specialized pro-resolving mediators (SPMs), such as resolvin D5 in lung tissue. Likewise, precursor fatty acids (arachidonic and docosahexaenoic acid; DHA) were increased in female lung tissue following O3 exposure compared with males. Experiments with ovariectomized females revealed that loss of ovarian hormones exacerbates pulmonary inflammation and injury. However, eicosanoid and SPM production were not altered by ovariectomy despite depleted pulmonary DHA concentrations. Taken together, these data indicate that O3 drives an increased pulmonary inflammatory and bioactive lipid mediator response in females. Furthermore, ovariectomy increases susceptibility to O3-induced pulmonary inflammation and injury, as well as decreases pulmonary DHA concentrations.


Assuntos
Ozônio , Caracteres Sexuais , Animais , Eicosanoides , Feminino , Pulmão , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ozônio/toxicidade
6.
NanoImpact ; 222021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33860111

RESUMO

There is increasing evidence that inhaled multi-walled carbon nanotubes (MWCNTs) can have harmful effects on the respiratory system. Rodent studies suggest that individuals with asthma may be susceptible to the adverse pulmonary effects of MWCNTs. Asthma is an allergic lung disease characterized by a TH2 immune response that results in chronic airway disease characterized by eosinophilic lung inflammation, airway mucous cell metaplasia, and airway fibrosis. Signal transducer and activator of transcription 6 (STAT6) is a transcription factor with multiple roles in TH2 type inflammation. Herein we sought to examine the role of STAT6 in the exacerbation of house dust mite (HDM) allergen-induced allergic airway disease by MWCNTs. Male wild type (WT) and STAT6 knockout (Stat6 KO) mice were dosed via intranasal aspiration on days 0, 2, 4, 14, 16 and 18 with either vehicle, HDM extract, MWCNTs, or a combination of HDM and MWCNTs. Necropsy was performed on day 21 to collect bronchoalveolar lavage fluid (BALF), serum and lung tissue. MWCNTs exacerbated HDM-induced allergic endpoints, including eosinophilic lung inflammation, mucous cell metaplasia, and serum IgE levels. HDM-induced eosinophilic lung inflammation, mucous cell metaplasia, and serum IgE and exacerbation of these endpoints by MWCNTs were ablated in Stat6 KO mice. In addition, airway fibrosis was significantly increased by the combination of HDM and MWCNTs in WT mice but not in Stat6 KO mice. These findings provide new mechanistic insight by demonstrating a requirement for STAT6 in MWCNT-induced exacerbation of allergic respiratory disease.


Assuntos
Nanotubos de Carbono , Pyroglyphidae , Animais , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Knockout , Nanotubos de Carbono/efeitos adversos , Pyroglyphidae/metabolismo , Fator de Transcrição STAT6/genética
7.
Toxicol In Vitro ; 73: 105126, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33652123

RESUMO

Mesothelioma is a cancer of the lung pleura primarily associated with inhalation of asbestos fibers. Multi-walled carbon nanotubes (MWCNTs) are engineered nanomaterials that pose a potential risk for mesothelioma due to properties that are similar to asbestos. Inhaled MWCNTs migrate to the pleura in rodents and some types cause mesothelioma. Like asbestos, there is a diversity of MWCNT types. We investigated the neoplastic potential of tangled (tMWCNT) versus rigid (rMWCNT) after chronic exposure using serial passages of rat mesothelial cells in vitro. Normal rat mesothelial (NRM2) cells were exposed to tMWCNTs or rMWCNTs for 45 weeks over 85 passages to determine if exposure resulted in transformation to a neoplastic phenotype. Rat mesothelioma (ME1) cells were used as a positive control. Osteopontin (OPN) mRNA was assayed as a biomarker of transformation by real time quantitative polymerase chain reaction (qPCR) and transformation was determined by a cell invasion assay. Exposure to rMWCNTs, but not tMWCNTs, resulted in transformation of NRM2 cells into an invasive phenotype that was similar to ME1 cells. Moreover, exposure of NRM2 cells to rMWCNTs increased OPN mRNA that correlated with cellular transformation. These data suggest that OPN is a potential biomarker that should be further investigated to screen the carcinogenicity of MWCNTs in vitro.


Assuntos
Transformação Celular Neoplásica/genética , Células Epiteliais/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Osteopontina/genética , Animais , Biomarcadores , Linhagem Celular , Células Epiteliais/metabolismo , Masculino , Mesotelioma/genética , Pleura/citologia , RNA Mensageiro , Ratos Endogâmicos F344
8.
Part Fibre Toxicol ; 18(1): 9, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602232

RESUMO

BACKGROUND: In vitro models are widely used in nanotoxicology. In these assays, a careful documentation of the fraction of nanomaterials that reaches the cells, i.e. the in vitro delivered dose, is a critical element for the interpretation of the data. The in vitro delivered dose can be measured by quantifying the amount of material in contact with the cells, or can be estimated by applying particokinetic models. For carbon nanotubes (CNTs), the determination of the in vitro delivered dose is not evident because their quantification in biological matrices is difficult, and particokinetic models are not adapted to high aspect ratio materials. Here, we applied a rapid and direct approach, based on femtosecond pulsed laser microscopy (FPLM), to assess the in vitro delivered dose of multi-walled CNTs (MWCNTs). METHODS AND RESULTS: We incubated mouse lung fibroblasts (MLg) and differentiated human monocytic cells (THP-1) in 96-well plates for 24 h with a set of different MWCNTs. The cytotoxic response to the MWCNTs was evaluated using the WST-1 assay in both cell lines, and the pro-inflammatory response was determined by measuring the release of IL-1ß by THP-1 cells. Contrasting cell responses were observed across the MWCNTs. The sedimentation rate of the different MWCNTs was assessed by monitoring turbidity decay with time in cell culture medium. These turbidity measurements revealed some differences among the MWCNT samples which, however, did not parallel the contrasting cell responses. FPLM measurements in cell culture wells revealed that the in vitro delivered MWCNT dose did not parallel sedimentation data, and suggested that cultured cells contributed to set up the delivered dose. The FPLM data allowed, for each MWCNT sample, an adjustment of the measured cytotoxicity and IL-1ß responses to the delivered doses. This adjusted in vitro activity led to another toxicity ranking of the MWCNT samples as compared to the unadjusted activities. In macrophages, this adjusted ranking was consistent with existing knowledge on the impact of surface MWCNT functionalization on cytotoxicity, and might better reflect the intrinsic activity of the MWCNT samples. CONCLUSION: The present study further highlights the need to estimate the in vitro delivered dose in cell culture experiments with nanomaterials. The FPLM measurement of the in vitro delivered dose of MWCNTs can enrich experimental results, and may refine our understanding of their interactions with cells.


Assuntos
Nanotubos de Carbono , Técnicas de Cultura de Células , Macrófagos , Microscopia Confocal , Monócitos
9.
Part Fibre Toxicol ; 17(1): 60, 2020 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-33243293

RESUMO

BACKGROUND: Inhalation of multi-walled carbon nanotubes (MWCNTs) poses a potential risk to human health. In order to safeguard workers and consumers, the toxic properties of MWCNTs need to be identified. Functionalization has been shown to either decrease or increase MWCNT-related pulmonary injury, depending on the type of modification. We, therefore, investigated both acute and chronic pulmonary toxicity of a library of MWCNTs derived from a common pristine parent compound (NC7000). METHODS: MWCNTs were thermally or chemically purified and subsequently surface functionalized by carboxylation or amination. To evaluate pulmonary toxicity, male C57BL6 mice were dosed via oropharyngeal aspiration with either 1.6 or 4 mg/kg of each MWCNT type. Mitsui-7 MWCNT was used as a positive control. Necropsy was performed at days 3 and 60 post-exposure to collect bronchoalveolar lavage fluid (BALF) and lungs. RESULTS: At day 3 all MWCNTs increased the number of neutrophils in BALF. Chemical purification had a greater effect on pro-inflammatory cytokines (IL-1ß, IL-6, CXCL1) in BALF, while thermal purification had a greater effect on pro-fibrotic cytokines (CCL2, OPN, TGF-ß1). At day 60, thermally purified, carboxylated MWCNTs had the strongest effect on lymphocyte numbers in BALF. Thermally purified MWCNTs caused the greatest increase in LDH and total protein in BALF. Furthermore, the thermally purified and carboxyl- or amine-functionalized MWCNTs caused the greatest number of granulomatous lesions in the lungs. The physicochemical characteristics mainly associated with increased toxicity of the thermally purified derivatives were decreased surface defects and decreased amorphous content as indicated by Raman spectroscopy. CONCLUSIONS: These data demonstrate that the purification method is an important determinant of lung toxicity induced by carboxyl- and amine-functionalized MWCNTs.


Assuntos
Poluentes Atmosféricos/toxicidade , Pulmão/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Administração por Inalação , Animais , Líquido da Lavagem Broncoalveolar/química , Citocinas/metabolismo , Exposição por Inalação , Lesão Pulmonar , Camundongos , Camundongos Endogâmicos C57BL , Fator de Crescimento Transformador beta1/metabolismo
10.
Int J Mol Sci ; 21(19)2020 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-33022979

RESUMO

Engineered nanomaterials (ENMs) are products of the emerging nanotechnology industry and many different types of ENMs have been shown to cause chronic inflammation in the lungs of rodents after inhalation exposure, suggesting a risk to human health. Due to the increasing demand and use of ENMs in a variety of products, a careful evaluation of the risks to human health is urgently needed. An assessment of the immunotoxicity of ENMs should consider susceptibility factors including sex, pre-existing diseases, deficiency of specific genes encoding proteins involved in the innate or adaptive immune response, and co-exposures to other chemicals. This review will address evidence from experimental animal models that highlights some important issues of susceptibility to chronic lung inflammation and systemic immune dysfunction after pulmonary exposure to ENMs.


Assuntos
Inflamação/patologia , Pulmão/efeitos dos fármacos , Nanoestruturas/efeitos adversos , Pneumonia/tratamento farmacológico , Animais , Humanos , Inflamação/induzido quimicamente , Inflamação/complicações , Exposição por Inalação , Pulmão/patologia , Nanoestruturas/uso terapêutico , Pneumonia/complicações , Pneumonia/patologia
11.
Nanotoxicology ; 14(8): 1058-1081, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32813574

RESUMO

Nickel nanoparticles (NiNPs) are increasingly used in nanotechnology applications, yet information on sex differences in NiNP-induced lung disease is lacking. The goal of this study was to explore mechanisms of susceptibility between male and female mice after acute or subchronic pulmonary exposure to NiNPs. For acute exposure, male and female mice received a single dose of NiNPs with or without LPS by oropharyngeal aspiration and were necropsied 24 h later. For subchronic exposure, mice received NiNPs with or without LPS six times over 3 weeks prior to necropsy. After acute exposure to NiNPs and LPS, male mice had elevated cytokines (CXCL1 and IL-6) and more neutrophils in bronchoalveolar lavage fluid (BALF), along with greater STAT3 phosphorylation in lung tissue. After subchronic exposure to NiNPs and LPS, male mice exhibited increased monocytes in BALF. Moreover, subchronic exposure of male mice to NiNP only induced higher CXCL1 and CCL2 in BALF along with increased alveolar infiltrates and CCL2 in lung tissue. STAT1 in lung tissue was induced by subchronic exposure to NiNPs in females but not males. Males had a greater induction of IL-6 mRNA in liver after acute exposure to NiNPs and LPS, and greater CCL2 mRNA in liver after subchronic NiNP exposure. These data indicate that susceptibility of males to acute lung inflammation involves enhanced neutrophilia with increased CXCL1 and IL-6/STAT3 signaling, whereas susceptibility to subchronic lung inflammation involves enhanced monocytic infiltration with increased CXCL1 and CCL2. STAT transcription factors appear to play a role in these sex differences. This study demonstrates sex differences in the lung inflammatory response of mice to NiNPs that has implications for human disease.


Assuntos
Pulmão/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Níquel/toxicidade , Pneumonia/induzido quimicamente , Caracteres Sexuais , Animais , Líquido da Lavagem Broncoalveolar/citologia , Quimiocina CXCL1/metabolismo , Feminino , Humanos , Exposição por Inalação , Interleucina-6/metabolismo , Pulmão/imunologia , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/citologia , Neutrófilos/efeitos dos fármacos , Pneumonia/patologia , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Testes de Toxicidade Aguda , Testes de Toxicidade Subcrônica
12.
Inhal Toxicol ; 31(5): 192-202, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31345048

RESUMO

Background: Increasing evidence from rodent studies indicates that inhaled multi-walled carbon nanotubes (MWCNTs) have harmful effects on the lungs. In this study, we examined the effects of inhalation exposure to MWCNTs on allergen-induced airway inflammation and fibrosis. We hypothesized that inhalation pre-exposure to MWCNTs would render mice susceptible to developing allergic lung disease induced by house dust mite (HDM) allergen. Methods: Male B6C3F1/N mice were exposed by whole-body inhalation for 6 h a day, 5 d a week, for 30 d to air control or 0.06, 0.2, and 0.6 mg/m3 of MWCNTs. The exposure atmospheres were agglomerates (1.4-1.8 µm) composed of MWCNTs (average diameter 16 nm; average length 2.4 µm; 0.52% Ni). Mice then received 25 µg of HDM extract by intranasal instillation 6 times over 3 weeks. Necropsy was performed at 3 and 30 d after the final HDM dose to collect serum, bronchoalveolar lavage fluid (BALF), and lung tissue for histopathology. Results: MWCNT exposure at the highest dose inhibited HDM-induced serum IgE levels, IL-13 protein levels in BALF, and airway mucus production. However, perivascular and peribronchiolar inflammatory lesions were observed in the lungs of mice at 3 d with MWCNT and HDM, but not MWCNT or HDM alone. Moreover, combined HDM and MWCNT exposure increased airway fibrosis in the lungs of mice. Conclusions: Inhalation pre-exposure to MWCNTs inhibited HDM-induced TH2 immune responses, yet this combined exposure resulted in vascular inflammation and airway fibrosis, indicating that MWCNT pre-exposure alters the immune response to allergens.


Assuntos
Antígenos de Dermatophagoides/imunologia , Hipersensibilidade/fisiopatologia , Exposição por Inalação/efeitos adversos , Pulmão/fisiologia , Nanotubos de Carbono/toxicidade , Animais , Líquido da Lavagem Broncoalveolar , Relação Dose-Resposta Imunológica , Fibrose , Imunoglobulina E/sangue , Interleucina-13/análise , Masculino , Camundongos , Células Th2/imunologia
13.
Nanotoxicology ; 12(9): 975-991, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30317900

RESUMO

The fiber-like shape of multi-walled carbon nanotubes (MWCNTs) is reminiscent of asbestos, suggesting they pose similar health hazards when inhaled, including pulmonary fibrosis and mesothelioma. Mice deficient in the tumor suppressor p53 are susceptible to carcinogenesis. However, the chronic pathologic effect of MWCNTs delivered to the lungs of p53 heterozygous (p53+/-) mice has not been investigated. We hypothesized that p53+/- mice would be susceptible to lung tumor development after exposure to either tangled (t-) or rod-like (r-) MWCNTs. Wild-type (p53+/+) or p53+/- mice were exposed to MWCNTs (1 mg/kg) via oropharyngeal aspiration weekly over four consecutive weeks and evaluated for cellular and pathologic outcomes 11-months post-initial exposure. No lung or pleural tumors were observed in p53+/+ or p53+/- mice exposed to either t- or rMWCNTs. In comparison to tMWCNTs, the rMWCNTs induced the formation of larger granulomas, a greater number of lymphoid aggregates and greater epithelial cell hyperplasia in terminal bronchioles in both p53+/- and p53+/+ mice. A constitutively larger area of CD45R+/CD3+ lymphoid tissue was observed in p53+/- mice compared to p53+/+ mice. Importantly, p53+/- mice had larger granulomas induced by rMWCNTs as compared to p53+/+ mice. These findings indicate that a combination of p53 deficiency and physicochemical characteristics including nanotube geometry are factors in susceptibility to MWCNT-induced lymphoid infiltration and granuloma formation.


Assuntos
Granuloma do Sistema Respiratório/induzido quimicamente , Pulmão/efeitos dos fármacos , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Estruturas Linfoides Terciárias/induzido quimicamente , Proteína Supressora de Tumor p53/fisiologia , Animais , Relação Dose-Resposta a Droga , Granuloma do Sistema Respiratório/genética , Granuloma do Sistema Respiratório/imunologia , Exposição por Inalação , Pulmão/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Propriedades de Superfície , Estruturas Linfoides Terciárias/genética , Estruturas Linfoides Terciárias/imunologia , Proteína Supressora de Tumor p53/genética
14.
Curr Environ Health Rep ; 5(1): 100-109, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29441464

RESUMO

PURPOSE OF REVIEW: The explosive growth of the nanotechnology industry has necessitated the examination of engineered nanomaterials (ENMs) for their toxicity. The unique properties that make ENMs useful also make them a health risk, and individuals with pre-existing diseases such as asthma are likely more susceptible. This review summarizes the current literature on the ability of ENMs to both exacerbate and directly cause asthma. RECENT FINDINGS: Recent studies highlight the ability of metal nanoparticles (NPs) and carbon nanotubes (CNTs) to not only exacerbate pre-existing asthma in animal models but also initiate allergic airway disease directly. CNTs alone are shown to cause airway mucus production, elevated serum IgE levels, and increased TH2 cytokine levels, all key indicators of asthma. The ability of ENMs to modulate the immune response in asthma varies depending on their physicochemical properties and exposure timing. CNTs consistently exacerbate asthma, as do Ni and TiO2 NPs, whereas some NPs like Au attenuate asthma. Evidence is strong that ENMs can contribute to allergic airway disease; however, more work is required to determine their mechanisms, and more epidemiological studies are needed to validate results from animal models.


Assuntos
Asma/induzido quimicamente , Nanoestruturas/toxicidade , Humanos , Pulmão/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Nanotubos de Carbono/toxicidade
15.
Artigo em Inglês | MEDLINE | ID: mdl-28984415

RESUMO

Carbon nanotubes (CNTs) are engineered nanomaterials (ENMs) with numerous beneficial applications. However, they could pose a risk to human health from occupational or consumer exposures. Rodent models demonstrate that exposure to CNTs via inhalation, instillation, or aspiration results in pulmonary fibrosis. The severity of the fibrogenic response is determined by various physicochemical properties of the nanomaterial such as residual metal catalyst content, rigidity, length, aggregation status, or surface charge. CNTs are also increasingly functionalized post-synthesis with organic or inorganic agents to modify or enhance surface properties. The mechanisms of CNT-induced fibrosis involve oxidative stress, innate immune responses of macrophages, cytokine and growth factor production, epithelial cell injury and death, expansion of the pulmonary myofibroblast population, and consequent extracellular matrix accumulation. A comprehensive understanding of how physicochemical properties affect the fibrogenic potential of various types of CNTs should be considered in combination with genetic variability and gain or loss of function of specific genes encoding secreted cytokines, enzymes, or intracellular cell signaling molecules. Here, we cover the current state of the literature on mechanisms of CNT-exposed pulmonary fibrosis in rodent models with a focus on physicochemical characteristics as principal drivers of the mechanisms leading to pulmonary fibrosis. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Respiratory Disease Toxicology and Regulatory Issues in Nanomedicine > Toxicology of Nanomaterials.


Assuntos
Nanotubos de Carbono , Fibrose Pulmonar/induzido quimicamente , Animais , Células Cultivadas , Fenômenos Químicos , Modelos Animais de Doenças , Exposição Ambiental , Transição Epitelial-Mesenquimal , Camundongos , Nanotubos de Carbono/química , Nanotubos de Carbono/toxicidade , Nanotubos de Carbono/ultraestrutura , Estresse Oxidativo , Ratos
16.
Part Fibre Toxicol ; 14(1): 26, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28716119

RESUMO

BACKGROUND: Pulmonary toxicity of multi-walled carbon nanotubes (MWCNTs) is influenced by physicochemical characteristics and genetic susceptibility. We hypothesized that contrasting rigidities of tangled (t) versus rod-like (r) MWCNTs would result in differing immunologic or fibrogenic responses in mice and that these responses would be exaggerated in transgenic mice lacking the signal transducer and activator of transcription-1 (STAT1), a susceptible mouse model of pulmonary fibrosis. METHODS: Male wild type (Stat1 +/+ ) and STAT1-deficient (Stat1 -/- ) mice were exposed to 4 mg/kg tMWCNTs, rMWCNTs, or vehicle alone via oropharyngeal aspiration and evaluated for inflammation at one and 21 days post-exposure via histopathology, differential cell counts, and cytokine levels in bronchoalveolar lavage fluid (BALF). Granuloma formation, mucous cell metaplasia, and airway fibrosis were evaluated by quantitative morphometry. Airway epithelial cell proliferation was assessed by bromodeoxyuridine (BrdU) incorporation. Cytokine protein levels in BALF and serum IgE levels were measured by ELISA. Lung protein Smad2/3 levels and activation were measured by Western blot. Lung mRNAs were measured by PCR. RESULTS: There was a 7-fold difference in rigidity between tMWCNTs and rMWCNTs as determined by static bending ratio. Both MWCNT types resulted in acute inflammation (neutrophils in BALF) after one-day post-exposure, yet only rMWCNTs resulted in chronic inflammation at 21 days as indicated by neutrophil influx and larger granulomas. Both MWCNTs induced BrdU uptake in airway epithelial cells, with the greatest proliferative response observed in rMWCNT-exposed mice after one-day. Only rMWCNTs induced mucous cell metaplasia, but this index was not different between genotypes. Stat1 -/- mice had higher levels of baseline serum IgE than Stat1 +/+ mice. Greater airway fibrosis was observed with rMWCNTs compared to tMWCNTs, and exaggerated airway fibrosis was seen in the Stat1 -/- mouse lungs with rMWCNTs but not tMWCNTs. Increased fibrosis correlated with elevated levels of TGF-ß1 protein levels in the BALF of Stat1 -/- mice exposed to rMWCNTs and increased lung Smad2/3 phosphorylation. CONCLUSIONS: Rigidity plays a key role in the toxicity of MWCNTs and results in increased inflammatory, immunologic, and fibrogenic effects in the lung. STAT1 is an important protective factor in the fibroproliferative response to rMWCNTs, regulating both induced TGF-ß1 production and Smad2/3 phosphorylation status. Therefore, both rigidity and genetic susceptibility should be major considerations for risk assessment of MWCNTs.


Assuntos
Células Epiteliais/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Fibrose Pulmonar/induzido quimicamente , Hipersensibilidade Respiratória/induzido quimicamente , Fator de Transcrição STAT1/metabolismo , Animais , Líquido da Lavagem Broncoalveolar/química , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Predisposição Genética para Doença , Granuloma do Sistema Respiratório/induzido quimicamente , Granuloma do Sistema Respiratório/metabolismo , Granuloma do Sistema Respiratório/patologia , Imunoglobulina E/sangue , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos Knockout , Nanotubos de Carbono/química , Fenótipo , Fosforilação , Pneumonia/induzido quimicamente , Pneumonia/metabolismo , Pneumonia/patologia , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Hipersensibilidade Respiratória/genética , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/patologia , Medição de Risco , Fator de Transcrição STAT1/deficiência , Fator de Transcrição STAT1/genética , Transdução de Sinais/efeitos dos fármacos , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Fatores de Tempo , Fator de Crescimento Transformador beta1/metabolismo
17.
Nanotoxicology ; 11(3): 313-326, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28277982

RESUMO

Carbon nanotubes (CNTs), a prototypical engineered nanomaterial, have been increasingly manufactured for a variety of novel applications over the past two decades. However, since CNTs possess fiber-like shape and cause pulmonary fibrosis in rodents, there is concern that mass production of CNTs will lead to occupational exposure and associated pulmonary diseases. The aim of this study was to use contemporary proteomics to investigate the mechanisms of cellular response in E10 mouse alveolar epithelial cells in vitro after exposure to multi-walled CNTs (MWCNTs) that were functionalized by atomic layer deposition (ALD). ALD is a method used to generate highly uniform and conformal nanoscale thin-film coatings of metals to enhance novel conductive properties of CNTs. We hypothesized that specific types of metal oxide coatings applied to the surface of MWCNTs by ALD would determine distinct proteomic profiles in mouse alveolar epithelial cells in vitro that could be used to predict oxidative stress and pulmonary inflammation. Uncoated (U)-MWCNTs were functionalized by ALD with zinc oxide (ZnO) to yield Z-MWCNTs or aluminum oxide (Al2O3) to yield A-MWCNTs. Significant differential protein expression was found in the following critical pathways: mTOR/eIF4/p70S6K signaling and Nrf-2 mediated oxidative stress response increased following exposure to Z-MWCNTs, interleukin-1 signaling increased following U-MWCNT exposure, and inhibition of angiogenesis by thrombospondin-1, oxidative phosphorylation, and mitochondrial dysfunction increased following A-MWCNT exposure. This study demonstrates that specific types of metal oxide thin film coatings applied by ALD produce distinct cellular and biochemical responses related to lung inflammation and fibrosis compared to uncoated MWCNT exposure in vitro.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Proteômica/métodos , Óxido de Alumínio/toxicidade , Células Epiteliais Alveolares/química , Animais , Células Cultivadas , Camundongos , Fibrose Pulmonar/etiologia , Óxido de Zinco/toxicidade
18.
ACS Nano ; 10(8): 7675-88, 2016 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-27459049

RESUMO

Commercialization of multiwalled carbon nanotubes (MWCNT)-based applications has been hampered by concerns regarding their lung toxicity potential. Hyaluronic acid (HA) is a ubiquitously found polysaccharide, which is anti-inflammatory in its native high molecular weight form. HA-functionalized smart MWCNTs have shown promise as tumor-targeting drug delivery agents and can enhance bone repair and regeneration. However, it is unclear whether HA functionalization could reduce the pulmonary toxicity potential of MWCNTs. Using in vivo and in vitro approaches, we investigated the effectiveness of MWCNT functionalization with HA in increasing nanotube biocompatibility and reducing lung inflammatory and fibrotic effects. We utilized three-dimensional cultures of differentiated primary human bronchial epithelia to translate findings from rodent assays to humans. We found that HA functionalization increased stability and dispersion of MWCNTs and reduced postexposure lung inflammation, fibrosis, and mucus cell metaplasia compared with nonfunctionalized MWCNTs. Cocultures of fully differentiated bronchial epithelial cells (cultivated at air-liquid interface) and human lung fibroblasts (submerged) displayed significant reduction in injury, oxidative stress, as well as pro-inflammatory gene and protein expression after exposure to HA-functionalized MWCNTs compared with MWCNTs alone. In contrast, neither type of nanotubes stimulated cytokine production in primary human alveolar macrophages. In aggregate, our results demonstrate the effectiveness of HA functionalization as a safer design approach to eliminate MWCNT-induced lung injury and suggest that HA functionalization works by reducing MWCNT-induced epithelial injury.


Assuntos
Lesão Pulmonar/prevenção & controle , Nanotubos de Carbono , Fibroblastos , Humanos , Ácido Hialurônico , Pulmão , Macrófagos Alveolares , Peso Molecular
19.
Part Fibre Toxicol ; 13(1): 29, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27278808

RESUMO

BACKGROUND: Atomic layer deposition (ALD) is a method for applying conformal nanoscale coatings on three-dimensional structures. We hypothesized that surface functionalization of multi-walled carbon nanotubes (MWCNTs) with polycrystalline ZnO by ALD would alter pro-inflammatory cytokine expression by human monocytes in vitro and modulate the lung and systemic immune response following oropharyngeal aspiration in mice. METHODS: Pristine (U-MWCNTs) were coated with alternating doses of diethyl zinc and water over increasing ALD cycles (10 to 100 ALD cycles) to yield conformal ZnO-coated MWCNTs (Z-MWCNTs). Human THP-1 monocytic cells were exposed to U-MWCNTs or Z-MWCNTs in vitro and cytokine mRNAs measured by Taqman real-time RT-PCR. Male C57BL6 mice were exposed to U- or Z-MWCNTs by oropharyngeal aspiration (OPA) and lung inflammation evaluated at one day post-exposure by histopathology, cytokine expression and differential counting of cells in bronchoalveolar lavage fluid (BALF) cells. Lung fibrosis was evaluated at 28 days. Cytokine mRNAs (IL-6, IL-1ß, CXCL10, TNF-α) in lung, heart, spleen, and liver were quantified at one and 28 days. DNA synthesis in lung tissue was measured by bromodeoxyuridine (BrdU) uptake. RESULTS: ALD resulted in a conformal coating of MWCNTs with ZnO that increased proportionally to the number of coating cycles. Z-MWCNTs released Zn(+2) ions in media and increased IL-6, IL-1ß, CXCL10, and TNF-α mRNAs in THP-1 cells in vitro. Mice exposed to Z-MWCNTs by OPA had exaggerated lung inflammation and a 3-fold increase in monocytes and neutrophils in BALF compared to U-MWCNTs. Z-MWCNTs, but not U-MWCNTs, induced IL-6 and CXCL10 mRNA and protein in the lungs of mice and increased IL-6 mRNA in heart and liver. U-MWCNTs but not Z-MWCNTs stimulated airway epithelial DNA synthesis in vivo. Lung fibrosis at 28 days was not significantly different between mice treated with U-MWCNT or Z-MWCNT. CONCLUSIONS: Pulmonary exposure to ZnO-coated MWCNTs produces a systemic acute phase response that involves the release of Zn(+2), lung epithelial growth arrest, and increased IL-6. ALD functionalization with ZnO generates MWCNTs that possess increased risk for human exposure.


Assuntos
Reação de Fase Aguda/induzido quimicamente , Poluentes Atmosféricos/toxicidade , Exposição por Inalação/efeitos adversos , Pulmão/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Óxido de Zinco/toxicidade , Reação de Fase Aguda/imunologia , Reação de Fase Aguda/metabolismo , Reação de Fase Aguda/patologia , Poluentes Atmosféricos/química , Animais , Linhagem Celular , Citocinas/agonistas , Citocinas/genética , Citocinas/metabolismo , Progressão da Doença , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão e Varredura , Monócitos/imunologia , Monócitos/metabolismo , Monócitos/patologia , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Fibrose Pulmonar/etiologia , RNA Mensageiro/metabolismo , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/imunologia , Mucosa Respiratória/patologia , Propriedades de Superfície , Óxido de Zinco/química
20.
Arch Toxicol ; 90(7): 1769-83, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27121469

RESUMO

The increasing use of multi-walled carbon nanotubes (MWCNTs) in consumer products and their potential to induce adverse lung effects following inhalation has lead to much interest in better understanding the hazard associated with these nanomaterials (NMs). While the current regulatory requirement for substances of concern, such as MWCNTs, in many jurisdictions is a 90-day rodent inhalation test, the monetary, ethical, and scientific concerns associated with this test led an international expert group to convene in Washington, DC, USA, to discuss alternative approaches to evaluate the inhalation toxicity of MWCNTs. Pulmonary fibrosis was identified as a key adverse outcome linked to MWCNT exposure, and recommendations were made on the design of an in vitro assay that is predictive of the fibrotic potential of MWCNTs. While fibrosis takes weeks or months to develop in vivo, an in vitro test system may more rapidly predict fibrogenic potential by monitoring pro-fibrotic mediators (e.g., cytokines and growth factors). Therefore, the workshop discussions focused on the necessary specifications related to the development and evaluation of such an in vitro system. Recommendations were made for designing a system using lung-relevant cells co-cultured at the air-liquid interface to assess the pro-fibrogenic potential of aerosolized MWCNTs, while considering human-relevant dosimetry and NM life cycle transformations. The workshop discussions provided the fundamental design components of an air-liquid interface in vitro test system that will be subsequently expanded to the development of an alternative testing strategy to predict pulmonary toxicity and to generate data that will enable effective risk assessment of NMs.


Assuntos
Exposição por Inalação/efeitos adversos , Pulmão/efeitos dos fármacos , Nanoestruturas/toxicidade , Fibrose Pulmonar/induzido quimicamente , Testes de Toxicidade/métodos , Aerossóis , Alternativas ao Uso de Animais , Animais , Técnicas de Cultura de Células , Células Cultivadas , Desenho de Equipamento , Humanos , Pulmão/citologia , Modelos Biológicos , Nanoestruturas/administração & dosagem , Testes de Toxicidade/instrumentação
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