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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 extravasation of proteins and neutrophils through an endothelial monolayer. (A) A confluent monolayer of HUVEC cells was treated with rottlerin 30 min before the addition of LPS. Four hour later, HRP was added to HUVEC cells and extravasation was allowed to proceed for 30 min. n=3 for each group. *p<0.05 and ***p<0.001 between the indicated groups. (B) PKC-δ inhibitors and LPS were treated as described in A and neutrophil transmigration was allowed for 15 h. n=3 for each group. **p<0.01 and ***p<0.001 between the indicated groups.
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Figure 3: Inhibition of PKC-δ promotes extravasation of proteins and neutrophils through an endothelial monolayer. (A) A confluent monolayer of HUVEC cells was treated with rottlerin 30 min before the addition of LPS. Four hour later, HRP was added to HUVEC cells and extravasation was allowed to proceed for 30 min. n=3 for each group. *p<0.05 and ***p<0.001 between the indicated groups. (B) PKC-δ inhibitors and LPS were treated as described in A and neutrophil transmigration was allowed for 15 h. n=3 for each group. **p<0.01 and ***p<0.001 between the indicated groups.

Mentions: Finally, we explored the direct involvement of PKC-δ in permeability of an endothelial monolayer. For this, we cultured HUVEC cells in transwell plates until they reached confluence, and then performed a permeability assay. As seen in Fig. 3A, rottlerin, a purported PKC-δ inhibitor, increased permeability to a similar degree, regardless of whether or not HUVEC cells were pre-activated by LPS, indicating again that PKC-δ regulated steady state vascular permeability. Using this system, we further examined whether transendothelial migration of neutrophils could be regulated by PKC-δ. In this case, we showed that PKC-δ inhibitors (rottlerin and ΨδRACK peptide) enhanced KC- and MIP-2-induced transendothelial migration of neutrophils through the HUVEC cell monolayer only when HUVEC cells were pre-activated by LPS (Fig. 3B). These results indicated that LPS-induced upregulation of cell adhesion molecules might be required for interactions with neutrophils before their endothelial transmigration. As HEVEC cells remained healthy until the end of our experiments, it was unlikely that there was a physical lesion in the HEVEC cell monolayer.


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 extravasation of proteins and neutrophils through an endothelial monolayer. (A) A confluent monolayer of HUVEC cells was treated with rottlerin 30 min before the addition of LPS. Four hour later, HRP was added to HUVEC cells and extravasation was allowed to proceed for 30 min. n=3 for each group. *p<0.05 and ***p<0.001 between the indicated groups. (B) PKC-δ inhibitors and LPS were treated as described in A and neutrophil transmigration was allowed for 15 h. n=3 for each group. **p<0.01 and ***p<0.001 between the indicated groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Figure 3: Inhibition of PKC-δ promotes extravasation of proteins and neutrophils through an endothelial monolayer. (A) A confluent monolayer of HUVEC cells was treated with rottlerin 30 min before the addition of LPS. Four hour later, HRP was added to HUVEC cells and extravasation was allowed to proceed for 30 min. n=3 for each group. *p<0.05 and ***p<0.001 between the indicated groups. (B) PKC-δ inhibitors and LPS were treated as described in A and neutrophil transmigration was allowed for 15 h. n=3 for each group. **p<0.01 and ***p<0.001 between the indicated groups.
Mentions: Finally, we explored the direct involvement of PKC-δ in permeability of an endothelial monolayer. For this, we cultured HUVEC cells in transwell plates until they reached confluence, and then performed a permeability assay. As seen in Fig. 3A, rottlerin, a purported PKC-δ inhibitor, increased permeability to a similar degree, regardless of whether or not HUVEC cells were pre-activated by LPS, indicating again that PKC-δ regulated steady state vascular permeability. Using this system, we further examined whether transendothelial migration of neutrophils could be regulated by PKC-δ. In this case, we showed that PKC-δ inhibitors (rottlerin and ΨδRACK peptide) enhanced KC- and MIP-2-induced transendothelial migration of neutrophils through the HUVEC cell monolayer only when HUVEC cells were pre-activated by LPS (Fig. 3B). These results indicated that LPS-induced upregulation of cell adhesion molecules might be required for interactions with neutrophils before their endothelial transmigration. As HEVEC cells remained healthy until the end of our experiments, it was unlikely that there was a physical lesion in the HEVEC cell monolayer.

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