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Involvement of Protein Kinase C-δ in Vascular Permeability in Acute Lung Injury.

Ahn JJ, Jung JP, Park SE, Lee M, Kwon B, Cho HR - Immune Netw (2015)

Bottom Line: Pulmonary edema is a major cause of mortality due to acute lung injury (ALI).A neutrophil transmigration assay indicated that the PKC-δ inhibition increased neutrophil transmigration through an endothelial monolayer.This suggests that PKC-δ inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine, Ulsan University Hospital, School of Medicine, University of Ulsan, Ulsan 44033, Korea.

ABSTRACT
Pulmonary edema is a major cause of mortality due to acute lung injury (ALI). The involvement of protein kinase C-δ (PKC-δ) in ALI has been a controversial topic. Here we investigated PKC-δ function in ALI using PKC-δ knockout (KO) mice and PKC inhibitors. Our results indicated that although the ability to produce proinflammatory mediators in response to LPS injury in PKC-δ KO mice was similar to that of control mice, they showed enhanced recruitment of neutrophils to the lung and more severe pulmonary edema. PKC-δ inhibition promoted barrier dysfunction in an endothelial cell layer in vitro, and administration of a PKC-δ-specific inhibitor significantly increased steady state vascular permeability. A neutrophil transmigration assay indicated that the PKC-δ inhibition increased neutrophil transmigration through an endothelial monolayer. This suggests that PKC-δ inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.

No MeSH data available.


Related in: MedlinePlus

Inhibition of PKC-δ promotes pulmonary edema and vascular permeability. (A) Total protein levels in BAL fluid at various time points after LPS infusion. n=3-14 for each group. *p<0.05, **p<0.01, and ***p<0.001 between the two groups. (B) The lung wet/dry weight ratio at 24 h after LPS infusion. n=12-13 for each group. *p<0.05. (C and D) EBD was injected 4 h after LPS infusion and lungs were harvested 30 min later. Gross observation (left column) and concentrations of EBD in extracted lung tissue (right column). n=12-13 for each group. *p<0.05. (D)δV1-1 or ΨδRACK peptide was intratracheally injected 30 min before LPS infusion. Lungs were harvested 30 min after EBD injection. n=6-8 for each group. *p<0.05 between the indicated groups.
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Figure 2: Inhibition of PKC-δ promotes pulmonary edema and vascular permeability. (A) Total protein levels in BAL fluid at various time points after LPS infusion. n=3-14 for each group. *p<0.05, **p<0.01, and ***p<0.001 between the two groups. (B) The lung wet/dry weight ratio at 24 h after LPS infusion. n=12-13 for each group. *p<0.05. (C and D) EBD was injected 4 h after LPS infusion and lungs were harvested 30 min later. Gross observation (left column) and concentrations of EBD in extracted lung tissue (right column). n=12-13 for each group. *p<0.05. (D)δV1-1 or ΨδRACK peptide was intratracheally injected 30 min before LPS infusion. Lungs were harvested 30 min after EBD injection. n=6-8 for each group. *p<0.05 between the indicated groups.

Mentions: To test the above hypothesis, we measured the amount of total proteins in BAL fluid at various time points after LPS infusion as a parameter for protein leakage from vessels. As expected, the BAL fluid of PKC-δ KO mice contained a greater amount of total proteins at all time points investigated, relative to that of WT mice (Fig. 2A). The lung wet/dry ratio showed that the increased permeability in PKC-δ KO mice indeed resulted in severe pulmonary edema following LPS infusion (Fig. 2B). To directly show that PKC-δ KO vessels had a higher capacity for permeability, we i.v.-injected EBD 4 h after LPS infusion and measured the quantity of EBD that extravasated from vessels 30 min after EBD injection. We could easily distinguish the thicker blue lungs in PKC-δ KO mice by gross observation (Fig. 2C) and quantification of EBD extracted from lungs confirmed this result (Fig. 2C). We repeated the same EBD assay using cell-permeable PKC-δ inhibitor (10). Interestingly, in vivo injection of PKC-δ inhibitor enhanced not only steady state vascular permeability, but also LPS-initiated permeability (Fig. 2F). However, the PKC-δ activator had no effect on vascular permeability (Fig. 2F).


Involvement of Protein Kinase C-δ in Vascular Permeability in Acute Lung Injury.

Ahn JJ, Jung JP, Park SE, Lee M, Kwon B, Cho HR - Immune Netw (2015)

Inhibition of PKC-δ promotes pulmonary edema and vascular permeability. (A) Total protein levels in BAL fluid at various time points after LPS infusion. n=3-14 for each group. *p<0.05, **p<0.01, and ***p<0.001 between the two groups. (B) The lung wet/dry weight ratio at 24 h after LPS infusion. n=12-13 for each group. *p<0.05. (C and D) EBD was injected 4 h after LPS infusion and lungs were harvested 30 min later. Gross observation (left column) and concentrations of EBD in extracted lung tissue (right column). n=12-13 for each group. *p<0.05. (D)δV1-1 or ΨδRACK peptide was intratracheally injected 30 min before LPS infusion. Lungs were harvested 30 min after EBD injection. n=6-8 for each group. *p<0.05 between the indicated groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553259&req=5

Figure 2: Inhibition of PKC-δ promotes pulmonary edema and vascular permeability. (A) Total protein levels in BAL fluid at various time points after LPS infusion. n=3-14 for each group. *p<0.05, **p<0.01, and ***p<0.001 between the two groups. (B) The lung wet/dry weight ratio at 24 h after LPS infusion. n=12-13 for each group. *p<0.05. (C and D) EBD was injected 4 h after LPS infusion and lungs were harvested 30 min later. Gross observation (left column) and concentrations of EBD in extracted lung tissue (right column). n=12-13 for each group. *p<0.05. (D)δV1-1 or ΨδRACK peptide was intratracheally injected 30 min before LPS infusion. Lungs were harvested 30 min after EBD injection. n=6-8 for each group. *p<0.05 between the indicated groups.
Mentions: To test the above hypothesis, we measured the amount of total proteins in BAL fluid at various time points after LPS infusion as a parameter for protein leakage from vessels. As expected, the BAL fluid of PKC-δ KO mice contained a greater amount of total proteins at all time points investigated, relative to that of WT mice (Fig. 2A). The lung wet/dry ratio showed that the increased permeability in PKC-δ KO mice indeed resulted in severe pulmonary edema following LPS infusion (Fig. 2B). To directly show that PKC-δ KO vessels had a higher capacity for permeability, we i.v.-injected EBD 4 h after LPS infusion and measured the quantity of EBD that extravasated from vessels 30 min after EBD injection. We could easily distinguish the thicker blue lungs in PKC-δ KO mice by gross observation (Fig. 2C) and quantification of EBD extracted from lungs confirmed this result (Fig. 2C). We repeated the same EBD assay using cell-permeable PKC-δ inhibitor (10). Interestingly, in vivo injection of PKC-δ inhibitor enhanced not only steady state vascular permeability, but also LPS-initiated permeability (Fig. 2F). However, the PKC-δ activator had no effect on vascular permeability (Fig. 2F).

Bottom Line: Pulmonary edema is a major cause of mortality due to acute lung injury (ALI).A neutrophil transmigration assay indicated that the PKC-δ inhibition increased neutrophil transmigration through an endothelial monolayer.This suggests that PKC-δ inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.

View Article: PubMed Central - PubMed

Affiliation: Department of Internal Medicine, Ulsan University Hospital, School of Medicine, University of Ulsan, Ulsan 44033, Korea.

ABSTRACT
Pulmonary edema is a major cause of mortality due to acute lung injury (ALI). The involvement of protein kinase C-δ (PKC-δ) in ALI has been a controversial topic. Here we investigated PKC-δ function in ALI using PKC-δ knockout (KO) mice and PKC inhibitors. Our results indicated that although the ability to produce proinflammatory mediators in response to LPS injury in PKC-δ KO mice was similar to that of control mice, they showed enhanced recruitment of neutrophils to the lung and more severe pulmonary edema. PKC-δ inhibition promoted barrier dysfunction in an endothelial cell layer in vitro, and administration of a PKC-δ-specific inhibitor significantly increased steady state vascular permeability. A neutrophil transmigration assay indicated that the PKC-δ inhibition increased neutrophil transmigration through an endothelial monolayer. This suggests that PKC-δ inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.

No MeSH data available.


Related in: MedlinePlus