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Inhibition of Pyk2 blocks lung inflammation and injury in a mouse model of acute lung injury.

Duan Y, Learoyd J, Meliton AY, Leff AR, Zhu X - Respir. Res. (2012)

Bottom Line: In each paradigm, treatment with control protein TAT-GFP had no blocking effect.By contrast, production of neutrophil chemokines MIP-2 and keratinocyte-derived chemokine in the bronchoalveolar lavage was not reduced by TAT-Pyk2-CT.These results suggest that Pyk2 plays an important role in the development of acute lung injury in mice and that pharmacological inhibition of Pyk2 might provide a potential therapeutic strategy in the pretreatment for patients at imminent risk of developing acute lung injury.

View Article: PubMed Central - HTML - PubMed

Affiliation: Section of Pulmonary and Critical Care Medicine, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA.

ABSTRACT

Background: Proline-rich tyrosine kinase 2 (Pyk2) is essential in neutrophil degranulation and chemotaxis in vitro. However, its effect on the process of lung inflammation and edema formation during LPS induced acute lung injury (ALI) remains unknown. The goal of the present study was to determine the effect of inhibiting Pyk2 on LPS-induced acute lung inflammation and injury in vivo.

Methods: C57BL6 mice were given either 10 mg/kg LPS or saline intratracheally. Inhibition of Pyk2 was effected by intraperitoneal administration TAT-Pyk2-CT 1 h before challenge. Bronchoalveolar lavage analysis of cell counts, lung histology and protein concentration in BAL were analyzed at 18 h after LPS treatment. KC and MIP-2 concentrations in BAL were measured by a mouse cytokine multiplex kit. The static lung compliance was determined by pressure-volume curve using a computer-controlled small animal ventilator. The extravasated Evans blue concentration in lung homogenate was determined spectrophotometrically.

Results: Intratracheal instillation of LPS induced significant neutrophil infiltration into the lung interstitium and alveolar space, which was attenuated by pre-treatment with TAT-Pyk2-CT. TAT-Pyk2-CT pretreatment also attenuated 1) myeloperoxidase content in lung tissues, 2) vascular leakage as measured by Evans blue dye extravasation in the lungs and the increase in protein concentration in bronchoalveolar lavage, and 3) the decrease in lung compliance. In each paradigm, treatment with control protein TAT-GFP had no blocking effect. By contrast, production of neutrophil chemokines MIP-2 and keratinocyte-derived chemokine in the bronchoalveolar lavage was not reduced by TAT-Pyk2-CT. Western blot analysis confirmed that tyrosine phosphorylation of Pyk2 in LPS-challenged lungs was reduced to control levels by TAT-Pyk2-CT pretreatment.

Conclusions: These results suggest that Pyk2 plays an important role in the development of acute lung injury in mice and that pharmacological inhibition of Pyk2 might provide a potential therapeutic strategy in the pretreatment for patients at imminent risk of developing acute lung injury.

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Effects of TAT-Pyk2-CT on reduced transthoracic static compliance caused by intratracheal administration of LPS. Mice were pretreated with 10 mg/kg TAT-Pyk2-CT or TAT-GFP 1 h before saline or 10 mg/kg LPS challenge, and (A) pressure-volume (P-V) curves were generated at 18 h after challenge. B. Decrease in transthoracic static compliance caused by LPS treatment. Measurements were means ± SEM at 10 cm H2O for each group (n = 6). #P < 0.05 vs. saline control group; *P < 0.05 vs. LPS alone group.
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Figure 6: Effects of TAT-Pyk2-CT on reduced transthoracic static compliance caused by intratracheal administration of LPS. Mice were pretreated with 10 mg/kg TAT-Pyk2-CT or TAT-GFP 1 h before saline or 10 mg/kg LPS challenge, and (A) pressure-volume (P-V) curves were generated at 18 h after challenge. B. Decrease in transthoracic static compliance caused by LPS treatment. Measurements were means ± SEM at 10 cm H2O for each group (n = 6). #P < 0.05 vs. saline control group; *P < 0.05 vs. LPS alone group.

Mentions: Pretreatment with TAT-Pyk2-CT blocked substantially the decrease in lung compliance caused by LPS. Administration of intratracheal LPS into mice 18 h before measurement caused a right shift of pressure-volume (P-V) curves (Figure 6A) compared with baseline P-V curves generated from saline-challenged mice. Pretreatment with TAT-Pyk2-CT, but not TAT-GFP, significantly blocked the downward shift in Pressure-Volume curve caused by LPS.


Inhibition of Pyk2 blocks lung inflammation and injury in a mouse model of acute lung injury.

Duan Y, Learoyd J, Meliton AY, Leff AR, Zhu X - Respir. Res. (2012)

Effects of TAT-Pyk2-CT on reduced transthoracic static compliance caused by intratracheal administration of LPS. Mice were pretreated with 10 mg/kg TAT-Pyk2-CT or TAT-GFP 1 h before saline or 10 mg/kg LPS challenge, and (A) pressure-volume (P-V) curves were generated at 18 h after challenge. B. Decrease in transthoracic static compliance caused by LPS treatment. Measurements were means ± SEM at 10 cm H2O for each group (n = 6). #P < 0.05 vs. saline control group; *P < 0.05 vs. LPS alone group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3275485&req=5

Figure 6: Effects of TAT-Pyk2-CT on reduced transthoracic static compliance caused by intratracheal administration of LPS. Mice were pretreated with 10 mg/kg TAT-Pyk2-CT or TAT-GFP 1 h before saline or 10 mg/kg LPS challenge, and (A) pressure-volume (P-V) curves were generated at 18 h after challenge. B. Decrease in transthoracic static compliance caused by LPS treatment. Measurements were means ± SEM at 10 cm H2O for each group (n = 6). #P < 0.05 vs. saline control group; *P < 0.05 vs. LPS alone group.
Mentions: Pretreatment with TAT-Pyk2-CT blocked substantially the decrease in lung compliance caused by LPS. Administration of intratracheal LPS into mice 18 h before measurement caused a right shift of pressure-volume (P-V) curves (Figure 6A) compared with baseline P-V curves generated from saline-challenged mice. Pretreatment with TAT-Pyk2-CT, but not TAT-GFP, significantly blocked the downward shift in Pressure-Volume curve caused by LPS.

Bottom Line: In each paradigm, treatment with control protein TAT-GFP had no blocking effect.By contrast, production of neutrophil chemokines MIP-2 and keratinocyte-derived chemokine in the bronchoalveolar lavage was not reduced by TAT-Pyk2-CT.These results suggest that Pyk2 plays an important role in the development of acute lung injury in mice and that pharmacological inhibition of Pyk2 might provide a potential therapeutic strategy in the pretreatment for patients at imminent risk of developing acute lung injury.

View Article: PubMed Central - HTML - PubMed

Affiliation: Section of Pulmonary and Critical Care Medicine, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA.

ABSTRACT

Background: Proline-rich tyrosine kinase 2 (Pyk2) is essential in neutrophil degranulation and chemotaxis in vitro. However, its effect on the process of lung inflammation and edema formation during LPS induced acute lung injury (ALI) remains unknown. The goal of the present study was to determine the effect of inhibiting Pyk2 on LPS-induced acute lung inflammation and injury in vivo.

Methods: C57BL6 mice were given either 10 mg/kg LPS or saline intratracheally. Inhibition of Pyk2 was effected by intraperitoneal administration TAT-Pyk2-CT 1 h before challenge. Bronchoalveolar lavage analysis of cell counts, lung histology and protein concentration in BAL were analyzed at 18 h after LPS treatment. KC and MIP-2 concentrations in BAL were measured by a mouse cytokine multiplex kit. The static lung compliance was determined by pressure-volume curve using a computer-controlled small animal ventilator. The extravasated Evans blue concentration in lung homogenate was determined spectrophotometrically.

Results: Intratracheal instillation of LPS induced significant neutrophil infiltration into the lung interstitium and alveolar space, which was attenuated by pre-treatment with TAT-Pyk2-CT. TAT-Pyk2-CT pretreatment also attenuated 1) myeloperoxidase content in lung tissues, 2) vascular leakage as measured by Evans blue dye extravasation in the lungs and the increase in protein concentration in bronchoalveolar lavage, and 3) the decrease in lung compliance. In each paradigm, treatment with control protein TAT-GFP had no blocking effect. By contrast, production of neutrophil chemokines MIP-2 and keratinocyte-derived chemokine in the bronchoalveolar lavage was not reduced by TAT-Pyk2-CT. Western blot analysis confirmed that tyrosine phosphorylation of Pyk2 in LPS-challenged lungs was reduced to control levels by TAT-Pyk2-CT pretreatment.

Conclusions: These results suggest that Pyk2 plays an important role in the development of acute lung injury in mice and that pharmacological inhibition of Pyk2 might provide a potential therapeutic strategy in the pretreatment for patients at imminent risk of developing acute lung injury.

Show MeSH
Related in: MedlinePlus