Limits...
Mite and cockroach proteases activate p44/p42 MAP kinases in human lung epithelial cells.

Kuderer NM, San-Juan-Vergara HG, Kong X, Esch R, Lockey RF, Mohapatra SS - Clin Mol Allergy (2003)

Bottom Line: RESULTS: Each of these antigens induced a significant increase in IL-8 levels compared to the medium control.PD98059, a MEK1 inhibitor, significantly decreased phosphorylation of p44/p42 MAPKs and IL-8 production.Exposure of A549 cells with antigens, which had been preincubated with different protease inhibitors, also resulted in a reduction of both MAPK phosphorylation and IL-8 production.

View Article: PubMed Central - HTML - PubMed

Affiliation: Joy McCann Culverhouse Airway Disease Center, University of South Florida and James A Haley VA Hospital, Tampa, FL, USA. smohapat@hsc.usf.edu

ABSTRACT
BACKGROUND: The mechanisms underlying epithelial cell activation by indoor inhaled antigens are poorly understood. METHODS: In this study, we investigated the role of mitogen-activated protein kinases (MAPKs) in A549 epithelial cells upon exposure to antigens of house dust mite (HDMA), German cockroach (GCA), and American cockroach (ACA). RESULTS: Each of these antigens induced a significant increase in IL-8 levels compared to the medium control. Exposure of A549 cells to these antigens induced the phosphorylation of p44/42 MAPKs within 5 minutes, which reached a peak at 25 minutes later and reached baseline levels at 1 hour after exposure. PD98059, a MEK1 inhibitor, significantly decreased phosphorylation of p44/p42 MAPKs and IL-8 production. Exposure of A549 cells with antigens, which had been preincubated with different protease inhibitors, also resulted in a reduction of both MAPK phosphorylation and IL-8 production. CONCLUSION: Thus, proteolytic antigens present in HDMA, GCA and ACA activate the p44/42 MAPKs airway epithelial cells, which lead to elevated IL-8 production and initiation of the inflammatory cascade.

No MeSH data available.


Related in: MedlinePlus

Allergenic extracts from GCA and ACA induced phosphorylation of p44/p42 MAPK. Following exposure of A549 cells to GCA (25 μg/ml) and ACA (25 μg/ml) at indicated time points, total protein extracts were evaluated by western immunoblotting with antibodies specific for phosphorylated and non-phosphorylated p44/p42 MAPK. Phospho-p44/p42 MAPK bands were quantified by densitometry and normalized to p44/p42 MAPK levels of intensity. The experiment was repeated twice. A representative experiment is shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC312598&req=5

Figure 3: Allergenic extracts from GCA and ACA induced phosphorylation of p44/p42 MAPK. Following exposure of A549 cells to GCA (25 μg/ml) and ACA (25 μg/ml) at indicated time points, total protein extracts were evaluated by western immunoblotting with antibodies specific for phosphorylated and non-phosphorylated p44/p42 MAPK. Phospho-p44/p42 MAPK bands were quantified by densitometry and normalized to p44/p42 MAPK levels of intensity. The experiment was repeated twice. A representative experiment is shown.

Mentions: Allergen-induced activation of p44/p42 and p38 MAP kinases was examined by Western immunoblot analysis using antibodies against both the phosphorylated and non-phosphorylated forms of the MAP kinases. Resting cells before exposure and medium-control exposed cells (data not shown) exhibited extremely low levels of phosphorylated p44/p42 MAP kinases (Figure 2 and 3). Exposure to HDMA resulted in a distinct increase in phosphorylated p44/p42 MAP kinase levels in A549 cells. A 5 min exposure to these mite allergens caused a rapid phosphorylation of p44/p42 MAP kinase with peak levels between 5 and 10 minutes, lasting for at least 30 minutes post-exposure (Figure 2). Figure 3 illustrates the time course of p44/p42 MAP kinase phosphorylation following exposure to German and American cockroach extract in A549 cells. As seen with the mite extract, a distinct phosphorylation of the two kinases was observed 5 minutes after exposure compared to controls. Peak levels of activation with both cockroach antigens occurred slightly later compared to the mite extract. Both p44 and p42 MAP kinases exhibited very similar patterns of activation; however, p38 MAP kinase was not activated by any of the antigens (data not shown).


Mite and cockroach proteases activate p44/p42 MAP kinases in human lung epithelial cells.

Kuderer NM, San-Juan-Vergara HG, Kong X, Esch R, Lockey RF, Mohapatra SS - Clin Mol Allergy (2003)

Allergenic extracts from GCA and ACA induced phosphorylation of p44/p42 MAPK. Following exposure of A549 cells to GCA (25 μg/ml) and ACA (25 μg/ml) at indicated time points, total protein extracts were evaluated by western immunoblotting with antibodies specific for phosphorylated and non-phosphorylated p44/p42 MAPK. Phospho-p44/p42 MAPK bands were quantified by densitometry and normalized to p44/p42 MAPK levels of intensity. The experiment was repeated twice. A representative experiment is shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC312598&req=5

Figure 3: Allergenic extracts from GCA and ACA induced phosphorylation of p44/p42 MAPK. Following exposure of A549 cells to GCA (25 μg/ml) and ACA (25 μg/ml) at indicated time points, total protein extracts were evaluated by western immunoblotting with antibodies specific for phosphorylated and non-phosphorylated p44/p42 MAPK. Phospho-p44/p42 MAPK bands were quantified by densitometry and normalized to p44/p42 MAPK levels of intensity. The experiment was repeated twice. A representative experiment is shown.
Mentions: Allergen-induced activation of p44/p42 and p38 MAP kinases was examined by Western immunoblot analysis using antibodies against both the phosphorylated and non-phosphorylated forms of the MAP kinases. Resting cells before exposure and medium-control exposed cells (data not shown) exhibited extremely low levels of phosphorylated p44/p42 MAP kinases (Figure 2 and 3). Exposure to HDMA resulted in a distinct increase in phosphorylated p44/p42 MAP kinase levels in A549 cells. A 5 min exposure to these mite allergens caused a rapid phosphorylation of p44/p42 MAP kinase with peak levels between 5 and 10 minutes, lasting for at least 30 minutes post-exposure (Figure 2). Figure 3 illustrates the time course of p44/p42 MAP kinase phosphorylation following exposure to German and American cockroach extract in A549 cells. As seen with the mite extract, a distinct phosphorylation of the two kinases was observed 5 minutes after exposure compared to controls. Peak levels of activation with both cockroach antigens occurred slightly later compared to the mite extract. Both p44 and p42 MAP kinases exhibited very similar patterns of activation; however, p38 MAP kinase was not activated by any of the antigens (data not shown).

Bottom Line: RESULTS: Each of these antigens induced a significant increase in IL-8 levels compared to the medium control.PD98059, a MEK1 inhibitor, significantly decreased phosphorylation of p44/p42 MAPKs and IL-8 production.Exposure of A549 cells with antigens, which had been preincubated with different protease inhibitors, also resulted in a reduction of both MAPK phosphorylation and IL-8 production.

View Article: PubMed Central - HTML - PubMed

Affiliation: Joy McCann Culverhouse Airway Disease Center, University of South Florida and James A Haley VA Hospital, Tampa, FL, USA. smohapat@hsc.usf.edu

ABSTRACT
BACKGROUND: The mechanisms underlying epithelial cell activation by indoor inhaled antigens are poorly understood. METHODS: In this study, we investigated the role of mitogen-activated protein kinases (MAPKs) in A549 epithelial cells upon exposure to antigens of house dust mite (HDMA), German cockroach (GCA), and American cockroach (ACA). RESULTS: Each of these antigens induced a significant increase in IL-8 levels compared to the medium control. Exposure of A549 cells to these antigens induced the phosphorylation of p44/42 MAPKs within 5 minutes, which reached a peak at 25 minutes later and reached baseline levels at 1 hour after exposure. PD98059, a MEK1 inhibitor, significantly decreased phosphorylation of p44/p42 MAPKs and IL-8 production. Exposure of A549 cells with antigens, which had been preincubated with different protease inhibitors, also resulted in a reduction of both MAPK phosphorylation and IL-8 production. CONCLUSION: Thus, proteolytic antigens present in HDMA, GCA and ACA activate the p44/42 MAPKs airway epithelial cells, which lead to elevated IL-8 production and initiation of the inflammatory cascade.

No MeSH data available.


Related in: MedlinePlus