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Adverse effect of nano-silicon dioxide on lung function of rats with or without ovalbumin immunization.

Han B, Guo J, Abrahaley T, Qin L, Wang L, Zheng Y, Li B, Liu D, Yao H, Yang J, Li C, Xi Z, Yang X - PLoS ONE (2011)

Bottom Line: Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn).The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Environmental Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Huazhong Normal University, Wuhan, China.

ABSTRACT

Background: The great advances of nanomaterials have brought out broad important applications, but their possible nanotoxicity and risks have not been fully understood. It is confirmed that exposure of environmental particulate matter (PM), especially ultrafine PM, are responsible for many lung function impairment and exacerbation of pre-existing lung diseases. However, the adverse effect of nanoparticles on allergic asthma is seldom investigated and the mechanism remains undefined. For the first time, this work investigates the relationship between allergic asthma and nanosized silicon dioxide (nano-SiO₂).

Methodology/principal findings: Ovalbumin (OVA)-treated and saline-treated control rats were daily intratracheally administered 0.1 ml of 0, 40 and 80 µg/ml nano-SiO₂ solutions, respectively for 30 days. Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn). Lung histological observation reveals obvious airway remodeling in 80 µg/ml nano-SiO₂-introduced saline and OVA groups, but the latter is worse. Additionally, increased nano-SiO₂ exposure also leads to more severe inflammation. With increasing nano-SiO₂ exposure, IL-4 in lung homogenate increases and IFN-γ shows a reverse but insignificant change. Moreover, at a same nano-SiO₂ exposure concentration, OVA-treated rats exhibit higher (significant) IL-4 and lower (not significant) IFN-γ compared with the saline-treated rats. The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.

Conclusions/significance: This was a preliminary study which for the first time involved the effect of nano-SiO₂ to OVA induced rat asthma model. The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization. This occurrence may be due to the Th1/Th2 cytokine imbalance accelerated by the nano-SiO₂ through increasing the tissue IL-4 production.

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Study protocol.(A) Saline treatment plus 0 µg/ml nano-SiO2 exposure. (B) Saline treatment plus 40 µg/ml nano-SiO2 exposure. (C) Saline treatment plus 80 µg/ml nano-SiO2 exposure. (D) OVA treatment plus 0 µg/ml nano-SiO2 exposure. (E) OVA treatment plus 40 µg/ml nano-SiO2 exposure. (F) OVA treatment plus 80 µg/ml nano-SiO2 exposure. All rats were sacrificed on day 38.
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pone-0017236-g002: Study protocol.(A) Saline treatment plus 0 µg/ml nano-SiO2 exposure. (B) Saline treatment plus 40 µg/ml nano-SiO2 exposure. (C) Saline treatment plus 80 µg/ml nano-SiO2 exposure. (D) OVA treatment plus 0 µg/ml nano-SiO2 exposure. (E) OVA treatment plus 40 µg/ml nano-SiO2 exposure. (F) OVA treatment plus 80 µg/ml nano-SiO2 exposure. All rats were sacrificed on day 38.

Mentions: Male Wistar rats (6–7 weeks old) were purchased from the Hubei experimental animal center (Wuhan, China), fed a commercial diet, and gave water ad libitum. The rats were housed in pathogen-free cages at 20–25°C and 50–70% relative humidity. The protocol of this study is shown in Figure 2. Rats were randomly divided into 6 experimental groups with 9 rats per group. The OVA-treated groups (group D, E and F) had OVA sensitization through subcutaneous injection of 1 ml of 200 µg/mL OVA solution containing 6.5 mg gelatinous Al(OH)3 (Sigma, USA) as an adjuvant at day 4, 18, and 25, followed by an aerosol challenge with 1% OVA for 30 min using an ultrasonic nebulizer (Yuyue, version 402AI, China) from days 31 to 37. Similar procedure was performed on the saline-treated groups (group A, B and C) in which OVA was replaced by saline. The exposure period lasted 30 d (from day 1 to 30), in which rats were instilled daily intratracheally with 0.1 ml of 1 of the 2 exposure solutions discussed above or saline. Finally, the rats were sacrificed at day 38 for further biochemical and histological analysis. This protocol was approved by the Office of Scientific Research Management of Huazhong Normal University with Certification on Application for the Use of Animals dated May 20th, 2007. All procedures strictly adhered to the guidelines from the National Committee of Animal Care and Use in the experiments.


Adverse effect of nano-silicon dioxide on lung function of rats with or without ovalbumin immunization.

Han B, Guo J, Abrahaley T, Qin L, Wang L, Zheng Y, Li B, Liu D, Yao H, Yang J, Li C, Xi Z, Yang X - PLoS ONE (2011)

Study protocol.(A) Saline treatment plus 0 µg/ml nano-SiO2 exposure. (B) Saline treatment plus 40 µg/ml nano-SiO2 exposure. (C) Saline treatment plus 80 µg/ml nano-SiO2 exposure. (D) OVA treatment plus 0 µg/ml nano-SiO2 exposure. (E) OVA treatment plus 40 µg/ml nano-SiO2 exposure. (F) OVA treatment plus 80 µg/ml nano-SiO2 exposure. All rats were sacrificed on day 38.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040772&req=5

pone-0017236-g002: Study protocol.(A) Saline treatment plus 0 µg/ml nano-SiO2 exposure. (B) Saline treatment plus 40 µg/ml nano-SiO2 exposure. (C) Saline treatment plus 80 µg/ml nano-SiO2 exposure. (D) OVA treatment plus 0 µg/ml nano-SiO2 exposure. (E) OVA treatment plus 40 µg/ml nano-SiO2 exposure. (F) OVA treatment plus 80 µg/ml nano-SiO2 exposure. All rats were sacrificed on day 38.
Mentions: Male Wistar rats (6–7 weeks old) were purchased from the Hubei experimental animal center (Wuhan, China), fed a commercial diet, and gave water ad libitum. The rats were housed in pathogen-free cages at 20–25°C and 50–70% relative humidity. The protocol of this study is shown in Figure 2. Rats were randomly divided into 6 experimental groups with 9 rats per group. The OVA-treated groups (group D, E and F) had OVA sensitization through subcutaneous injection of 1 ml of 200 µg/mL OVA solution containing 6.5 mg gelatinous Al(OH)3 (Sigma, USA) as an adjuvant at day 4, 18, and 25, followed by an aerosol challenge with 1% OVA for 30 min using an ultrasonic nebulizer (Yuyue, version 402AI, China) from days 31 to 37. Similar procedure was performed on the saline-treated groups (group A, B and C) in which OVA was replaced by saline. The exposure period lasted 30 d (from day 1 to 30), in which rats were instilled daily intratracheally with 0.1 ml of 1 of the 2 exposure solutions discussed above or saline. Finally, the rats were sacrificed at day 38 for further biochemical and histological analysis. This protocol was approved by the Office of Scientific Research Management of Huazhong Normal University with Certification on Application for the Use of Animals dated May 20th, 2007. All procedures strictly adhered to the guidelines from the National Committee of Animal Care and Use in the experiments.

Bottom Line: Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn).The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Environmental Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Huazhong Normal University, Wuhan, China.

ABSTRACT

Background: The great advances of nanomaterials have brought out broad important applications, but their possible nanotoxicity and risks have not been fully understood. It is confirmed that exposure of environmental particulate matter (PM), especially ultrafine PM, are responsible for many lung function impairment and exacerbation of pre-existing lung diseases. However, the adverse effect of nanoparticles on allergic asthma is seldom investigated and the mechanism remains undefined. For the first time, this work investigates the relationship between allergic asthma and nanosized silicon dioxide (nano-SiO₂).

Methodology/principal findings: Ovalbumin (OVA)-treated and saline-treated control rats were daily intratracheally administered 0.1 ml of 0, 40 and 80 µg/ml nano-SiO₂ solutions, respectively for 30 days. Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn). Lung histological observation reveals obvious airway remodeling in 80 µg/ml nano-SiO₂-introduced saline and OVA groups, but the latter is worse. Additionally, increased nano-SiO₂ exposure also leads to more severe inflammation. With increasing nano-SiO₂ exposure, IL-4 in lung homogenate increases and IFN-γ shows a reverse but insignificant change. Moreover, at a same nano-SiO₂ exposure concentration, OVA-treated rats exhibit higher (significant) IL-4 and lower (not significant) IFN-γ compared with the saline-treated rats. The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.

Conclusions/significance: This was a preliminary study which for the first time involved the effect of nano-SiO₂ to OVA induced rat asthma model. The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization. This occurrence may be due to the Th1/Th2 cytokine imbalance accelerated by the nano-SiO₂ through increasing the tissue IL-4 production.

Show MeSH
Related in: MedlinePlus