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Reduced pulmonary function and increased pro-inflammatory cytokines in nanoscale carbon black-exposed workers.

Zhang R, Dai Y, Zhang X, Niu Y, Meng T, Li Y, Duan H, Bin P, Ye M, Jia X, Shen M, Yu S, Yang X, Gao W, Zheng Y - Part Fibre Toxicol (2014)

Bottom Line: The reduction of lung function parameters including FEV1%, FEV/FVC, MMF%, and PEF% in CB workers was observed, and the IL-1β, IL-6, IL-8, MIP-1beta, and TNF- alpha had 2.86-, 6.85-, 1.49-, 3.35-, and 4.87-folds increase in serum of CB workers, respectively.The data strongly suggests that nanoscale CB particles could be responsible for the lung function reduction and pro-inflammatory cytokines secretion in CB workers.These results, therefore, provide the first evidence of a link between human exposure to CB and long-term pulmonary effects.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, 29 Nanwei Road, Beijing, 100050, China. zhangr-wh@126.com.

ABSTRACT

Background: Although major concerns exist regarding the potential consequences of human exposures to nanoscale carbon black (CB) particles, limited human toxicological data is currently available. The purpose of this study was to evaluate if nanoscale CB particles could be responsible, at least partially, for the altered lung function and inflammation observed in CB workers exposed to nanoscale CB particles.

Methods: Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Brunauer-Emmett-Teller were used to characterize CB. Eighty-one CB-exposed male workers and 104 non-exposed male workers were recruited. The pulmonary function test was performed and pro-inflammatory cytokines were evaluated. To further assess the deposition and pulmonary damage induced by CB nanoparticles, male BALB/c mice were exposed to CB for 6 hours per day for 7 or 14 days. The deposition of CB and the pathological changes of the lung tissue in mice were evaluated by paraffin sections and TEM. The cytokines levels in serum and lung tissue of mice were evaluated by ELISA and immunohistochemical staining (IHC).

Results: SEM and TEM images showed that the CB particles were 30 to 50 nm in size. In the CB workplace, the concentration of CB was 14.90 mg/m³. Among these CB particles, 50.77% were less than 0.523 micrometer, and 99.55% were less than 2.5 micrometer in aerodynamic diameter. The reduction of lung function parameters including FEV1%, FEV/FVC, MMF%, and PEF% in CB workers was observed, and the IL-1β, IL-6, IL-8, MIP-1beta, and TNF- alpha had 2.86-, 6.85-, 1.49-, 3.35-, and 4.87-folds increase in serum of CB workers, respectively. In mice exposed to the aerosol CB, particles were deposited in the lung. The alveolar wall thickened and a large amount of inflammatory cells were observed in lung tissues after CB exposure. IL-6 and IL-8 levels were increased in both serum and lung homogenate.

Conclusions: The data strongly suggests that nanoscale CB particles could be responsible for the lung function reduction and pro-inflammatory cytokines secretion in CB workers. These results, therefore, provide the first evidence of a link between human exposure to CB and long-term pulmonary effects.

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Related in: MedlinePlus

Images of the lung tissue in mice and the IL-8 and IL-6 expression in the lung tissue of mice by immunohistochemical staining. A: Images of the lung tissue in mice after CB inhalation for 14 d. The mice were deeply anesthetized with chloral hydrate and perfused by injection from the left ventricle with 20 mL of 37°C saline solution and then the lung tissues were separated. B1-E1: Histopathology of the lung tissue in mice after exposure to CB particles for different time by HE staining (200×). The arrows in C2, D2, and E2 indicate the CB particles in pulmonary alveoli or bronchioli. The arrows in D1 and E1 indicated inflammatory cells. B2-E2: The IL-8 expression in lung cells after CB exposure for different time points by immunohistochemical staining (200×). The IL-8 positive cells displayed brownish yellow granules. In lung cells, IL-8 was located mainly in the cytoplasm and karyon. B3-E3: The IL-6 expression in lung tissue after CB exposure for different time points by immunohistochemical staining (200×). In lung cells, IL-6 was a granular brown substance located mainly in the cytoplasm and karyon. B1-B3: Control group; C1-C3: 7 d CB exposure group; D1-D3: 14 d CB exposure group; and E1-E3: recovery for 14 d after 14 d CB exposure. Inset: a higher magnification of the lung tissue (400×). F: TEM images of lung cells in mice after CB inhalation for 14 d. F1: Alveolar type II epithelial cells in control (5000×); F2: The disintegration of the macrophages in the lung of mice after CB exposure for 14 d (15000×) (Staining by uranyl acetate and lead citrate); and F3: The CB particles in a lung macrophage (25000×) (No uranyl acetate and lead citrate staining). The arrows indicate the CB particles in a lung macrophage.
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Fig3: Images of the lung tissue in mice and the IL-8 and IL-6 expression in the lung tissue of mice by immunohistochemical staining. A: Images of the lung tissue in mice after CB inhalation for 14 d. The mice were deeply anesthetized with chloral hydrate and perfused by injection from the left ventricle with 20 mL of 37°C saline solution and then the lung tissues were separated. B1-E1: Histopathology of the lung tissue in mice after exposure to CB particles for different time by HE staining (200×). The arrows in C2, D2, and E2 indicate the CB particles in pulmonary alveoli or bronchioli. The arrows in D1 and E1 indicated inflammatory cells. B2-E2: The IL-8 expression in lung cells after CB exposure for different time points by immunohistochemical staining (200×). The IL-8 positive cells displayed brownish yellow granules. In lung cells, IL-8 was located mainly in the cytoplasm and karyon. B3-E3: The IL-6 expression in lung tissue after CB exposure for different time points by immunohistochemical staining (200×). In lung cells, IL-6 was a granular brown substance located mainly in the cytoplasm and karyon. B1-B3: Control group; C1-C3: 7 d CB exposure group; D1-D3: 14 d CB exposure group; and E1-E3: recovery for 14 d after 14 d CB exposure. Inset: a higher magnification of the lung tissue (400×). F: TEM images of lung cells in mice after CB inhalation for 14 d. F1: Alveolar type II epithelial cells in control (5000×); F2: The disintegration of the macrophages in the lung of mice after CB exposure for 14 d (15000×) (Staining by uranyl acetate and lead citrate); and F3: The CB particles in a lung macrophage (25000×) (No uranyl acetate and lead citrate staining). The arrows indicate the CB particles in a lung macrophage.

Mentions: The changes of pro-inflammatory cytokines levels in serum and lung homogenate or lung tissue of mice were detected by ELISA or immunohistochemical staining (IHC), respectively. As shown in Figure 2, the levels of IL-6 and IL-8 significantly increased in the 7 and 14 d CB exposure groups compared with the control groups (P < 0.05). However, no significant changes were observed for the levels of the IL-1β, MIP-1β, and TNF-α in CB exposure groups compared with the control groups (data not show). In the recovery group, the level of IL-6 in lung homogenate increased compared with the 14 d CB exposure group and the control group (P < 0.05). In addition, the level of IL-8 in serum and lung homogenate increased compared with the control group (P < 0.05), but decreased compared with the 14 d CB exposure group (P < 0.05). From the images of IHC of lung tissues shown in Figure 3, the positive staining cells for IL-8 and IL-6 in the control group tended to be localized to the basal lamina of epithelial cells and in close proximity to the musculature of the vessels or airways, while there was little staining in the alveolar epithelial cells. In mice treated with CB for 7 and 14 d, there was a clear increase in the positive staining for IL-8 and IL-6 around airways and bronchium (Figure 3C2, C3, D2, and D3). In the recovery group, the IL-8 and IL-6 positive cells were similar to the CB exposure groups, but with less positive alveolar epithelial cells.Figure 2


Reduced pulmonary function and increased pro-inflammatory cytokines in nanoscale carbon black-exposed workers.

Zhang R, Dai Y, Zhang X, Niu Y, Meng T, Li Y, Duan H, Bin P, Ye M, Jia X, Shen M, Yu S, Yang X, Gao W, Zheng Y - Part Fibre Toxicol (2014)

Images of the lung tissue in mice and the IL-8 and IL-6 expression in the lung tissue of mice by immunohistochemical staining. A: Images of the lung tissue in mice after CB inhalation for 14 d. The mice were deeply anesthetized with chloral hydrate and perfused by injection from the left ventricle with 20 mL of 37°C saline solution and then the lung tissues were separated. B1-E1: Histopathology of the lung tissue in mice after exposure to CB particles for different time by HE staining (200×). The arrows in C2, D2, and E2 indicate the CB particles in pulmonary alveoli or bronchioli. The arrows in D1 and E1 indicated inflammatory cells. B2-E2: The IL-8 expression in lung cells after CB exposure for different time points by immunohistochemical staining (200×). The IL-8 positive cells displayed brownish yellow granules. In lung cells, IL-8 was located mainly in the cytoplasm and karyon. B3-E3: The IL-6 expression in lung tissue after CB exposure for different time points by immunohistochemical staining (200×). In lung cells, IL-6 was a granular brown substance located mainly in the cytoplasm and karyon. B1-B3: Control group; C1-C3: 7 d CB exposure group; D1-D3: 14 d CB exposure group; and E1-E3: recovery for 14 d after 14 d CB exposure. Inset: a higher magnification of the lung tissue (400×). F: TEM images of lung cells in mice after CB inhalation for 14 d. F1: Alveolar type II epithelial cells in control (5000×); F2: The disintegration of the macrophages in the lung of mice after CB exposure for 14 d (15000×) (Staining by uranyl acetate and lead citrate); and F3: The CB particles in a lung macrophage (25000×) (No uranyl acetate and lead citrate staining). The arrows indicate the CB particles in a lung macrophage.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4318129&req=5

Fig3: Images of the lung tissue in mice and the IL-8 and IL-6 expression in the lung tissue of mice by immunohistochemical staining. A: Images of the lung tissue in mice after CB inhalation for 14 d. The mice were deeply anesthetized with chloral hydrate and perfused by injection from the left ventricle with 20 mL of 37°C saline solution and then the lung tissues were separated. B1-E1: Histopathology of the lung tissue in mice after exposure to CB particles for different time by HE staining (200×). The arrows in C2, D2, and E2 indicate the CB particles in pulmonary alveoli or bronchioli. The arrows in D1 and E1 indicated inflammatory cells. B2-E2: The IL-8 expression in lung cells after CB exposure for different time points by immunohistochemical staining (200×). The IL-8 positive cells displayed brownish yellow granules. In lung cells, IL-8 was located mainly in the cytoplasm and karyon. B3-E3: The IL-6 expression in lung tissue after CB exposure for different time points by immunohistochemical staining (200×). In lung cells, IL-6 was a granular brown substance located mainly in the cytoplasm and karyon. B1-B3: Control group; C1-C3: 7 d CB exposure group; D1-D3: 14 d CB exposure group; and E1-E3: recovery for 14 d after 14 d CB exposure. Inset: a higher magnification of the lung tissue (400×). F: TEM images of lung cells in mice after CB inhalation for 14 d. F1: Alveolar type II epithelial cells in control (5000×); F2: The disintegration of the macrophages in the lung of mice after CB exposure for 14 d (15000×) (Staining by uranyl acetate and lead citrate); and F3: The CB particles in a lung macrophage (25000×) (No uranyl acetate and lead citrate staining). The arrows indicate the CB particles in a lung macrophage.
Mentions: The changes of pro-inflammatory cytokines levels in serum and lung homogenate or lung tissue of mice were detected by ELISA or immunohistochemical staining (IHC), respectively. As shown in Figure 2, the levels of IL-6 and IL-8 significantly increased in the 7 and 14 d CB exposure groups compared with the control groups (P < 0.05). However, no significant changes were observed for the levels of the IL-1β, MIP-1β, and TNF-α in CB exposure groups compared with the control groups (data not show). In the recovery group, the level of IL-6 in lung homogenate increased compared with the 14 d CB exposure group and the control group (P < 0.05). In addition, the level of IL-8 in serum and lung homogenate increased compared with the control group (P < 0.05), but decreased compared with the 14 d CB exposure group (P < 0.05). From the images of IHC of lung tissues shown in Figure 3, the positive staining cells for IL-8 and IL-6 in the control group tended to be localized to the basal lamina of epithelial cells and in close proximity to the musculature of the vessels or airways, while there was little staining in the alveolar epithelial cells. In mice treated with CB for 7 and 14 d, there was a clear increase in the positive staining for IL-8 and IL-6 around airways and bronchium (Figure 3C2, C3, D2, and D3). In the recovery group, the IL-8 and IL-6 positive cells were similar to the CB exposure groups, but with less positive alveolar epithelial cells.Figure 2

Bottom Line: The reduction of lung function parameters including FEV1%, FEV/FVC, MMF%, and PEF% in CB workers was observed, and the IL-1β, IL-6, IL-8, MIP-1beta, and TNF- alpha had 2.86-, 6.85-, 1.49-, 3.35-, and 4.87-folds increase in serum of CB workers, respectively.The data strongly suggests that nanoscale CB particles could be responsible for the lung function reduction and pro-inflammatory cytokines secretion in CB workers.These results, therefore, provide the first evidence of a link between human exposure to CB and long-term pulmonary effects.

View Article: PubMed Central - PubMed

Affiliation: National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, 29 Nanwei Road, Beijing, 100050, China. zhangr-wh@126.com.

ABSTRACT

Background: Although major concerns exist regarding the potential consequences of human exposures to nanoscale carbon black (CB) particles, limited human toxicological data is currently available. The purpose of this study was to evaluate if nanoscale CB particles could be responsible, at least partially, for the altered lung function and inflammation observed in CB workers exposed to nanoscale CB particles.

Methods: Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Brunauer-Emmett-Teller were used to characterize CB. Eighty-one CB-exposed male workers and 104 non-exposed male workers were recruited. The pulmonary function test was performed and pro-inflammatory cytokines were evaluated. To further assess the deposition and pulmonary damage induced by CB nanoparticles, male BALB/c mice were exposed to CB for 6 hours per day for 7 or 14 days. The deposition of CB and the pathological changes of the lung tissue in mice were evaluated by paraffin sections and TEM. The cytokines levels in serum and lung tissue of mice were evaluated by ELISA and immunohistochemical staining (IHC).

Results: SEM and TEM images showed that the CB particles were 30 to 50 nm in size. In the CB workplace, the concentration of CB was 14.90 mg/m³. Among these CB particles, 50.77% were less than 0.523 micrometer, and 99.55% were less than 2.5 micrometer in aerodynamic diameter. The reduction of lung function parameters including FEV1%, FEV/FVC, MMF%, and PEF% in CB workers was observed, and the IL-1β, IL-6, IL-8, MIP-1beta, and TNF- alpha had 2.86-, 6.85-, 1.49-, 3.35-, and 4.87-folds increase in serum of CB workers, respectively. In mice exposed to the aerosol CB, particles were deposited in the lung. The alveolar wall thickened and a large amount of inflammatory cells were observed in lung tissues after CB exposure. IL-6 and IL-8 levels were increased in both serum and lung homogenate.

Conclusions: The data strongly suggests that nanoscale CB particles could be responsible for the lung function reduction and pro-inflammatory cytokines secretion in CB workers. These results, therefore, provide the first evidence of a link between human exposure to CB and long-term pulmonary effects.

Show MeSH
Related in: MedlinePlus