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Cigarette smoke regulates the expression of TLR4 and IL-8 production by human macrophages.

Sarir H, Mortaz E, Karimi K, Kraneveld AD, Rahman I, Caldenhoven E, Nijkamp FP, Folkerts G - J Inflamm (Lond) (2009)

Bottom Line: In this study, we evaluated the effects of cigarette smoke medium (CSM) on TLR4 expression and interleukin (IL)-8 production by human macrophages investigating the involvement of ROS.CSM stimulation increased intracellular ROS-production and decreased glutathione (GSH) levels.TLR4 may be involved in the pathogenesis of lung emphysema and oxidative stress and seems to be a crucial contributor in lung inflammation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Pharmacology and Pathophysiology, Departement of Pharmaceutical Sciences, Faculty of Sciences, Utrecht University, the Netherlands. e.mortaz@uu.nl.

ABSTRACT

Background: Toll-like receptors (TLRs) are present on monocytes and alveolar macrophages that form the first line of defense against inhaled particles. The importance of those cells in the pathophysiology of chronic obstructive pulmonary disease (COPD) has well been documented. Cigarette smoke contains high concentration of oxidants which can stimulate immune cells to produce reactive oxygen species, cytokines and chemokines.

Methods: In this study, we evaluated the effects of cigarette smoke medium (CSM) on TLR4 expression and interleukin (IL)-8 production by human macrophages investigating the involvement of ROS.

Results and discussion: TLR4 surface expression was downregulated on short term exposure (1 h) of CSM. The downregulation could be explained by internalization of the TLR4 and the upregulation by an increase in TLR4 mRNA. IL-8 mRNA and protein were also increased by CSM. CSM stimulation increased intracellular ROS-production and decreased glutathione (GSH) levels. The modulation of TLR4 mRNA and surface receptors expression, IRAK activation, IkappaB-alpha degradation, IL-8 mRNA and protein, GSH depletion and ROS production were all prevented by antioxidants such as N-acetyl-L-cysteine (NAC).

Conclusion: TLR4 may be involved in the pathogenesis of lung emphysema and oxidative stress and seems to be a crucial contributor in lung inflammation.

No MeSH data available.


Related in: MedlinePlus

Antioxidant prevents intracellular GSH depletion-induced by CSM. MDMs (5 × 106 cells) were pretreated with NAC (10 mM) and DMSO (2%) for 30 min and then stimulated with CSM (0.06 OD) at various time points (1, 2.5, 5, and 24 h). Intracellular GSH contents were measured by cellular lysate as described at "material and methods" section and expressed as mean ± SEM of medium-treated cells. * p < 0.05 versus un-stimulated control; # p < 0.05 versus.
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Figure 7: Antioxidant prevents intracellular GSH depletion-induced by CSM. MDMs (5 × 106 cells) were pretreated with NAC (10 mM) and DMSO (2%) for 30 min and then stimulated with CSM (0.06 OD) at various time points (1, 2.5, 5, and 24 h). Intracellular GSH contents were measured by cellular lysate as described at "material and methods" section and expressed as mean ± SEM of medium-treated cells. * p < 0.05 versus un-stimulated control; # p < 0.05 versus.

Mentions: We measured the levels of GSH in MDMs after CSM stimulation at various time points. CSM time-dependently decreased GSH concentrations for 5 h and after long time exposure this effects was restored (Fig. 7). Preincubation of cells with NAC (10 mM) and DMSO (2%) for 20 minutes restored/attenuated the loss of intracellular GSH levels at all time points. The period and concentration of NAC and DMSO was chosen on the basis of previous studies with these agents [18,33].


Cigarette smoke regulates the expression of TLR4 and IL-8 production by human macrophages.

Sarir H, Mortaz E, Karimi K, Kraneveld AD, Rahman I, Caldenhoven E, Nijkamp FP, Folkerts G - J Inflamm (Lond) (2009)

Antioxidant prevents intracellular GSH depletion-induced by CSM. MDMs (5 × 106 cells) were pretreated with NAC (10 mM) and DMSO (2%) for 30 min and then stimulated with CSM (0.06 OD) at various time points (1, 2.5, 5, and 24 h). Intracellular GSH contents were measured by cellular lysate as described at "material and methods" section and expressed as mean ± SEM of medium-treated cells. * p < 0.05 versus un-stimulated control; # p < 0.05 versus.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2683828&req=5

Figure 7: Antioxidant prevents intracellular GSH depletion-induced by CSM. MDMs (5 × 106 cells) were pretreated with NAC (10 mM) and DMSO (2%) for 30 min and then stimulated with CSM (0.06 OD) at various time points (1, 2.5, 5, and 24 h). Intracellular GSH contents were measured by cellular lysate as described at "material and methods" section and expressed as mean ± SEM of medium-treated cells. * p < 0.05 versus un-stimulated control; # p < 0.05 versus.
Mentions: We measured the levels of GSH in MDMs after CSM stimulation at various time points. CSM time-dependently decreased GSH concentrations for 5 h and after long time exposure this effects was restored (Fig. 7). Preincubation of cells with NAC (10 mM) and DMSO (2%) for 20 minutes restored/attenuated the loss of intracellular GSH levels at all time points. The period and concentration of NAC and DMSO was chosen on the basis of previous studies with these agents [18,33].

Bottom Line: In this study, we evaluated the effects of cigarette smoke medium (CSM) on TLR4 expression and interleukin (IL)-8 production by human macrophages investigating the involvement of ROS.CSM stimulation increased intracellular ROS-production and decreased glutathione (GSH) levels.TLR4 may be involved in the pathogenesis of lung emphysema and oxidative stress and seems to be a crucial contributor in lung inflammation.

View Article: PubMed Central - HTML - PubMed

Affiliation: Division of Pharmacology and Pathophysiology, Departement of Pharmaceutical Sciences, Faculty of Sciences, Utrecht University, the Netherlands. e.mortaz@uu.nl.

ABSTRACT

Background: Toll-like receptors (TLRs) are present on monocytes and alveolar macrophages that form the first line of defense against inhaled particles. The importance of those cells in the pathophysiology of chronic obstructive pulmonary disease (COPD) has well been documented. Cigarette smoke contains high concentration of oxidants which can stimulate immune cells to produce reactive oxygen species, cytokines and chemokines.

Methods: In this study, we evaluated the effects of cigarette smoke medium (CSM) on TLR4 expression and interleukin (IL)-8 production by human macrophages investigating the involvement of ROS.

Results and discussion: TLR4 surface expression was downregulated on short term exposure (1 h) of CSM. The downregulation could be explained by internalization of the TLR4 and the upregulation by an increase in TLR4 mRNA. IL-8 mRNA and protein were also increased by CSM. CSM stimulation increased intracellular ROS-production and decreased glutathione (GSH) levels. The modulation of TLR4 mRNA and surface receptors expression, IRAK activation, IkappaB-alpha degradation, IL-8 mRNA and protein, GSH depletion and ROS production were all prevented by antioxidants such as N-acetyl-L-cysteine (NAC).

Conclusion: TLR4 may be involved in the pathogenesis of lung emphysema and oxidative stress and seems to be a crucial contributor in lung inflammation.

No MeSH data available.


Related in: MedlinePlus