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Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes.

Tseng CY, Chang JF, Wang JS, Chang YJ, Gordon MK, Chao MW - PLoS ONE (2015)

Bottom Line: Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane.Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability.Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Zhongli district, Taoyuan city, Taiwan; Center of Nanotechnology, Chung Yuan Christian University, Zhongli district, Taoyuan city, Taiwan.

ABSTRACT
Exposure to diesel exhaust particles (DEP) is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

No MeSH data available.


Related in: MedlinePlus

DEPs and the induced cytokines caused in vitro capillary permeability independently of HO-1 activation.FITC-dextran was added to endothelial tubes for 4 h after a 24-h exposure to different treatments. The RFU was determined for each sample after washing of the endothelial tubes.
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pone.0131911.g005: DEPs and the induced cytokines caused in vitro capillary permeability independently of HO-1 activation.FITC-dextran was added to endothelial tubes for 4 h after a 24-h exposure to different treatments. The RFU was determined for each sample after washing of the endothelial tubes.

Mentions: Since TNF-α and IL-6 stimulated VPF/VEGF-A, further investigations were required to demonstrate a link with vasculature permeability. Although HO-1 has been shown to associate with VEGF-A-induced permeability, whether TNF-α and IL-6 are involved in the permeability mechanism of HO-1 activation remains unclear. To assess this issue, we evaluated the amount of dextran-FITC taken up by endothelial tubes exposed to TNF-α, IL-6, TNF-α plus IL-6 (with or without SnPP), and DEPs (10 or 100 μg/mL, with or without SnPP or NAC). Samples left untreated or treated with VEGF-A (100 ng/mL) were used as negative and positive controls, respectively. As shown in Fig 5, cytokine treatment induced changes in dextran uptake from 5237 ± 145 (RFU) (negative control) to 5747 ± 40 (TNF-α), 5723 ± 39 (IL-6), 5797 ± 95 (TNF-α plus IL-6), and 5781 ± 60 (TNF-α plus IL-6 and SnPP). Tube cell permeability induced by DEPs (10 μg/mL) was restored after the addition of SnPP or NAC. Moreover, 100 μg/mL DEPs and 100 μg/mL DEPs plus NAC reduced the amount of dextran-FITC taken up by the cells, while cotreatment with SnPP elevated dextran-FITC uptake. Although these values were not significantly different, there was a correlative trend between exposure of endothelial tubes to both cytokines and the amount of fluorescence taken up by the tubes, indicating changes in permeability.


Protective Effects of N-Acetyl Cysteine against Diesel Exhaust Particles-Induced Intracellular ROS Generates Pro-Inflammatory Cytokines to Mediate the Vascular Permeability of Capillary-Like Endothelial Tubes.

Tseng CY, Chang JF, Wang JS, Chang YJ, Gordon MK, Chao MW - PLoS ONE (2015)

DEPs and the induced cytokines caused in vitro capillary permeability independently of HO-1 activation.FITC-dextran was added to endothelial tubes for 4 h after a 24-h exposure to different treatments. The RFU was determined for each sample after washing of the endothelial tubes.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492618&req=5

pone.0131911.g005: DEPs and the induced cytokines caused in vitro capillary permeability independently of HO-1 activation.FITC-dextran was added to endothelial tubes for 4 h after a 24-h exposure to different treatments. The RFU was determined for each sample after washing of the endothelial tubes.
Mentions: Since TNF-α and IL-6 stimulated VPF/VEGF-A, further investigations were required to demonstrate a link with vasculature permeability. Although HO-1 has been shown to associate with VEGF-A-induced permeability, whether TNF-α and IL-6 are involved in the permeability mechanism of HO-1 activation remains unclear. To assess this issue, we evaluated the amount of dextran-FITC taken up by endothelial tubes exposed to TNF-α, IL-6, TNF-α plus IL-6 (with or without SnPP), and DEPs (10 or 100 μg/mL, with or without SnPP or NAC). Samples left untreated or treated with VEGF-A (100 ng/mL) were used as negative and positive controls, respectively. As shown in Fig 5, cytokine treatment induced changes in dextran uptake from 5237 ± 145 (RFU) (negative control) to 5747 ± 40 (TNF-α), 5723 ± 39 (IL-6), 5797 ± 95 (TNF-α plus IL-6), and 5781 ± 60 (TNF-α plus IL-6 and SnPP). Tube cell permeability induced by DEPs (10 μg/mL) was restored after the addition of SnPP or NAC. Moreover, 100 μg/mL DEPs and 100 μg/mL DEPs plus NAC reduced the amount of dextran-FITC taken up by the cells, while cotreatment with SnPP elevated dextran-FITC uptake. Although these values were not significantly different, there was a correlative trend between exposure of endothelial tubes to both cytokines and the amount of fluorescence taken up by the tubes, indicating changes in permeability.

Bottom Line: Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane.Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability.Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Engineering, College of Engineering, Chung Yuan Christian University, Zhongli district, Taoyuan city, Taiwan; Center of Nanotechnology, Chung Yuan Christian University, Zhongli district, Taoyuan city, Taiwan.

ABSTRACT
Exposure to diesel exhaust particles (DEP) is associated with pulmonary and cardiovascular diseases. Previous studies using in vitro endothelial tubes as a simplified model of capillaries have found that DEP-induced ROS increase vascular permeability with rearrangement or internalization of adherens junctional VE-cadherin away from the plasma membrane. This allows DEPs to penetrate into the cell and capillary lumen. In addition, pro-inflammatory cytokines are up-regulated and mediate vascular permeability in response to DEP. However, the mechanisms through which these DEP-induced pro-inflammatory cytokines increase vascular permeability remain unknown. Hence, we examined the ability of DEP to induce permeability of human umbilical vein endothelial cell tube cells to investigate these mechanisms. Furthermore, supplementation with NAC reduces ROS production following exposure to DEP. HUVEC tube cells contributed to a pro-inflammatory response to DEP-induced intracellular ROS generation. Endothelial oxidative stress induced the release of TNF-α and IL-6 from tube cells, subsequently stimulating the secretion of VEGF-A independent of HO-1. Our data suggests that DEP-induced intracellular ROS and release of the pro-inflammatory cytokines TNF- α and IL-6, which would contribute to VEGF-A secretion and disrupt cell-cell borders and increase vasculature permeability. Addition of NAC suppresses DEP-induced ROS efficiently and reduces subsequent damages by increasing endogenous glutathione.

No MeSH data available.


Related in: MedlinePlus