Limits...
Activation of c-Src tyrosine kinase mediated the degradation of occludin in ventilator-induced lung injury.

Zhao T, Liu M, Gu C, Wang X, Wang Y - Respir. Res. (2014)

Bottom Line: HE staining and lung injury score showed more severe lung injury and alveolar edema in group H compared with group M and group C.For the in vitro study, occludin expression decreased and c-Src activation increased as indicated by the phosphorylation of c-Src over time.Mechanical ventilation can activate c-Src by phosphorylation and increase the degradation of occludin. c-Src inhibitor can ameliorate barrier function and lung injury by up-regulating occludin.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Qianfoshan Hospital, Shandong University, No. 16766 Jingshi Road, Jinan, 250014, Shandong Province, China. feishi_xin@126.com.

ABSTRACT

Background: Ventilator-induced lung injury (VILI) is characterized by increased alveolar permeability, pulmonary edema. The tyrosine kinase, c-Src, is involved in VILI but its role has not been fully elucidated. This study examined the relationship between c-Src activation and occludin levels in VILI both in vitro and in vivo.

Methods: For the in vivo study, Wistar rats were randomly divided into five groups: control (group C); normal tidal volume (group M); normal tidal volume + c-Src inhibitor (PP2) (group M + P); high tidal volume (group H); and high tidal volume + c-Src inhibitor (PP2) (group H + P). Rats in all groups but group C underwent mechanical ventilation for 4 h. For the in vitro study, MLE-12 cells pretreated with PP2 and siRNA underwent cyclic stretching at 8% or 20% for 0, 1, 2 and 4 h. The expressions of occludin, c-Src, and p-c-Src were analyzed by western blotting, hematoxylin and eosin (HE) staining, and immunofluorescence.

Results: For the in vivo study, rats in group H showed decreased occludin expression and activated c-Src compared with group C. HE staining and lung injury score showed more severe lung injury and alveolar edema in group H compared with group M and group C. Group H + P had less pulmonary edema induced by the high tidal volume ventilation. For the in vitro study, occludin expression decreased and c-Src activation increased as indicated by the phosphorylation of c-Src over time. Consistently, PP2 could restore occludin levels.

Conclusions: Mechanical ventilation can activate c-Src by phosphorylation and increase the degradation of occludin. c-Src inhibitor can ameliorate barrier function and lung injury by up-regulating occludin.

Show MeSH

Related in: MedlinePlus

Occluin expression in MLE-12 cells treated by different concentrations of occludin-siRNA. MLE-12 epithelial cell monolayers were incubated with different concentrations. Representative Western blotting of occludin protein expressions and the density of proteins in occludin-siRNA 0nM group was used as a standard to compare relative densities in the other groups. *P < 0.05, compared with the occludin-siRNA 30 nM group. Data are representative of 3 independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4262993&req=5

Fig4: Occluin expression in MLE-12 cells treated by different concentrations of occludin-siRNA. MLE-12 epithelial cell monolayers were incubated with different concentrations. Representative Western blotting of occludin protein expressions and the density of proteins in occludin-siRNA 0nM group was used as a standard to compare relative densities in the other groups. *P < 0.05, compared with the occludin-siRNA 30 nM group. Data are representative of 3 independent experiments.

Mentions: MLE-12 cells were manipulated at 10 nM, 20 nM and 30 nM concentrations of occludin-siRNA to choose proper concentration for stretching before being examined by western blotting (P < 0.05) (Figure 4). c-Src levels did not show significant differences among MLE-12 cells treating with different concentrations of occludin-siRNA (P > 0.05) (Figure 5). Compared with MLE-12 cells that had been stretched, the level of c-Src in MLE-12 cells pretreating with Occludin-siRNA did not change (P > 0.05) (Figure 5). Knock down of occludin did not appear to affect the expression of c-Src, regardless of whether cells were stretched.Figure 4


Activation of c-Src tyrosine kinase mediated the degradation of occludin in ventilator-induced lung injury.

Zhao T, Liu M, Gu C, Wang X, Wang Y - Respir. Res. (2014)

Occluin expression in MLE-12 cells treated by different concentrations of occludin-siRNA. MLE-12 epithelial cell monolayers were incubated with different concentrations. Representative Western blotting of occludin protein expressions and the density of proteins in occludin-siRNA 0nM group was used as a standard to compare relative densities in the other groups. *P < 0.05, compared with the occludin-siRNA 30 nM group. Data are representative of 3 independent experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4262993&req=5

Fig4: Occluin expression in MLE-12 cells treated by different concentrations of occludin-siRNA. MLE-12 epithelial cell monolayers were incubated with different concentrations. Representative Western blotting of occludin protein expressions and the density of proteins in occludin-siRNA 0nM group was used as a standard to compare relative densities in the other groups. *P < 0.05, compared with the occludin-siRNA 30 nM group. Data are representative of 3 independent experiments.
Mentions: MLE-12 cells were manipulated at 10 nM, 20 nM and 30 nM concentrations of occludin-siRNA to choose proper concentration for stretching before being examined by western blotting (P < 0.05) (Figure 4). c-Src levels did not show significant differences among MLE-12 cells treating with different concentrations of occludin-siRNA (P > 0.05) (Figure 5). Compared with MLE-12 cells that had been stretched, the level of c-Src in MLE-12 cells pretreating with Occludin-siRNA did not change (P > 0.05) (Figure 5). Knock down of occludin did not appear to affect the expression of c-Src, regardless of whether cells were stretched.Figure 4

Bottom Line: HE staining and lung injury score showed more severe lung injury and alveolar edema in group H compared with group M and group C.For the in vitro study, occludin expression decreased and c-Src activation increased as indicated by the phosphorylation of c-Src over time.Mechanical ventilation can activate c-Src by phosphorylation and increase the degradation of occludin. c-Src inhibitor can ameliorate barrier function and lung injury by up-regulating occludin.

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology, Qianfoshan Hospital, Shandong University, No. 16766 Jingshi Road, Jinan, 250014, Shandong Province, China. feishi_xin@126.com.

ABSTRACT

Background: Ventilator-induced lung injury (VILI) is characterized by increased alveolar permeability, pulmonary edema. The tyrosine kinase, c-Src, is involved in VILI but its role has not been fully elucidated. This study examined the relationship between c-Src activation and occludin levels in VILI both in vitro and in vivo.

Methods: For the in vivo study, Wistar rats were randomly divided into five groups: control (group C); normal tidal volume (group M); normal tidal volume + c-Src inhibitor (PP2) (group M + P); high tidal volume (group H); and high tidal volume + c-Src inhibitor (PP2) (group H + P). Rats in all groups but group C underwent mechanical ventilation for 4 h. For the in vitro study, MLE-12 cells pretreated with PP2 and siRNA underwent cyclic stretching at 8% or 20% for 0, 1, 2 and 4 h. The expressions of occludin, c-Src, and p-c-Src were analyzed by western blotting, hematoxylin and eosin (HE) staining, and immunofluorescence.

Results: For the in vivo study, rats in group H showed decreased occludin expression and activated c-Src compared with group C. HE staining and lung injury score showed more severe lung injury and alveolar edema in group H compared with group M and group C. Group H + P had less pulmonary edema induced by the high tidal volume ventilation. For the in vitro study, occludin expression decreased and c-Src activation increased as indicated by the phosphorylation of c-Src over time. Consistently, PP2 could restore occludin levels.

Conclusions: Mechanical ventilation can activate c-Src by phosphorylation and increase the degradation of occludin. c-Src inhibitor can ameliorate barrier function and lung injury by up-regulating occludin.

Show MeSH
Related in: MedlinePlus