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Biological responses to diesel exhaust particles (DEPs) depend on the physicochemical properties of the DEPs.

Park EJ, Roh J, Kang MS, Kim SN, Kim Y, Choi S - PLoS ONE (2011)

Bottom Line: Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response.Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs.Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Science and Technology, Ajou University, Suwon, Korea.

ABSTRACT
Diesel exhaust particles (DEPs) are the main components of ambient particulate materials, including polyaromatic hydrocarbons (PAHs), n-PAHs, heavy metals, and gaseous materials. Many epidemiological, clinical, and toxicological studies have shown that ambient particles, including DEPs, are associated with respiratory disorders, such as asthma, allergic rhinitis, and lung cancer. However, the relationship between the biological response to DEPs and their chemical composition remains unclear. In this study, we investigated the physicochemical properties of DEPs before toxicological studies, and then administered a single intratracheal instillation of DEPs to mice. The mice were then killed 1, 7, 14 and 28 days after DEP exposure to observe the biological responses induced by DEPs over time. Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response. Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs. Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles.

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Related in: MedlinePlus

Changes in the cell distribution in BAL fluid after instillation of DEPs (n = 4).Mice were administered a single intratracheal instillation of DEPs at a dose of 10 mg/kg and then killed on the designated day (1, 7, 14, or 28 days after exposure). The cells in the BAL fluid were quantified by hemocytometric counting (A), and the distributions of alveolar macrophages, neutrophils, and lymphocytes were assessed on the basis of their characteristic cell shapes (B). The cell number in each group was expressed as mean ± SD. *; P<0.05, **; P<0.01.
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pone-0026749-g003: Changes in the cell distribution in BAL fluid after instillation of DEPs (n = 4).Mice were administered a single intratracheal instillation of DEPs at a dose of 10 mg/kg and then killed on the designated day (1, 7, 14, or 28 days after exposure). The cells in the BAL fluid were quantified by hemocytometric counting (A), and the distributions of alveolar macrophages, neutrophils, and lymphocytes were assessed on the basis of their characteristic cell shapes (B). The cell number in each group was expressed as mean ± SD. *; P<0.05, **; P<0.01.

Mentions: The total number of cells in the BAL fluid was significantly greater in the DEP-treated mice than in the controls: the value in the control group was (0.05±0.00)×105 cells, while that in the DEP-treated mice examined on days 1, 7, 14, and 28 after treatment were (0.68±0.08), (0.37±0.07), (0.14±0.03), and (0.08±0.01)×105 cells, respectively (Fig. 3A). The percentage of macrophages in the BAL fluid decreased rapidly on day 1 (81.7±2.1%), and continued to decrease over time (Fig. 3B). At all the defined time points, the percentage of neutrophils in the BAL fluid samples of DEP-treated mice was significantly greater than that in the controls: in controls, it was 0.1±0.1% and in DEP-treated mice examined on days 1, 7, 14, and 28 after treatment, it was 18.3±2.1%, 8.3±1.2%, 5.4±2.4%, and 2.4±1.0%, respectively. On day 7, the percentage of lymphocytes was significantly greater in the DEP-treated mice (7.13±0.51%) than in the controls.


Biological responses to diesel exhaust particles (DEPs) depend on the physicochemical properties of the DEPs.

Park EJ, Roh J, Kang MS, Kim SN, Kim Y, Choi S - PLoS ONE (2011)

Changes in the cell distribution in BAL fluid after instillation of DEPs (n = 4).Mice were administered a single intratracheal instillation of DEPs at a dose of 10 mg/kg and then killed on the designated day (1, 7, 14, or 28 days after exposure). The cells in the BAL fluid were quantified by hemocytometric counting (A), and the distributions of alveolar macrophages, neutrophils, and lymphocytes were assessed on the basis of their characteristic cell shapes (B). The cell number in each group was expressed as mean ± SD. *; P<0.05, **; P<0.01.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198839&req=5

pone-0026749-g003: Changes in the cell distribution in BAL fluid after instillation of DEPs (n = 4).Mice were administered a single intratracheal instillation of DEPs at a dose of 10 mg/kg and then killed on the designated day (1, 7, 14, or 28 days after exposure). The cells in the BAL fluid were quantified by hemocytometric counting (A), and the distributions of alveolar macrophages, neutrophils, and lymphocytes were assessed on the basis of their characteristic cell shapes (B). The cell number in each group was expressed as mean ± SD. *; P<0.05, **; P<0.01.
Mentions: The total number of cells in the BAL fluid was significantly greater in the DEP-treated mice than in the controls: the value in the control group was (0.05±0.00)×105 cells, while that in the DEP-treated mice examined on days 1, 7, 14, and 28 after treatment were (0.68±0.08), (0.37±0.07), (0.14±0.03), and (0.08±0.01)×105 cells, respectively (Fig. 3A). The percentage of macrophages in the BAL fluid decreased rapidly on day 1 (81.7±2.1%), and continued to decrease over time (Fig. 3B). At all the defined time points, the percentage of neutrophils in the BAL fluid samples of DEP-treated mice was significantly greater than that in the controls: in controls, it was 0.1±0.1% and in DEP-treated mice examined on days 1, 7, 14, and 28 after treatment, it was 18.3±2.1%, 8.3±1.2%, 5.4±2.4%, and 2.4±1.0%, respectively. On day 7, the percentage of lymphocytes was significantly greater in the DEP-treated mice (7.13±0.51%) than in the controls.

Bottom Line: Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response.Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs.Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Science and Technology, Ajou University, Suwon, Korea.

ABSTRACT
Diesel exhaust particles (DEPs) are the main components of ambient particulate materials, including polyaromatic hydrocarbons (PAHs), n-PAHs, heavy metals, and gaseous materials. Many epidemiological, clinical, and toxicological studies have shown that ambient particles, including DEPs, are associated with respiratory disorders, such as asthma, allergic rhinitis, and lung cancer. However, the relationship between the biological response to DEPs and their chemical composition remains unclear. In this study, we investigated the physicochemical properties of DEPs before toxicological studies, and then administered a single intratracheal instillation of DEPs to mice. The mice were then killed 1, 7, 14 and 28 days after DEP exposure to observe the biological responses induced by DEPs over time. Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response. Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs. Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles.

Show MeSH
Related in: MedlinePlus