Abstract
Objectives - The purposes of this study were to characterize the direct effect of the C-terminal fragment of fibrinogen γ chain (γC) on microvascular endothelial permeability and to examine its molecular mechanism of action. Methods and Results-Intravital microscopy was performed to measure albumin extravasation in intact mesenteric microvasculature, followed by quantification of hydraulic conductivity in single perfused micro vessels. Transendothelial electric resistance was measured in microvascular endothelial cells in combination with immunoblotting and immunocytochemistry. The results show that γC induced time- and concentration-dependent increases in protein transvascular flux and water permeability and decreases in endothelial barrier function, coupled with Rho GTPase activation, myosin light chain phosphorylation, and stress fiber formation. Depletion of RhoA via siRNA knockdown or pharmacological inhibition of RhoA signaling attenuated γC-induced barrier dysfunction. Imaging analyses demonstrated binding of γC to endothelial cells; the interaction was inhibited during blockage of the αvβ3 integrin. Furthermore, in vivo experiments showed that the microvascular leak response to γC was attenuated in integrin β3 -/- animals. Conclusion-Fibrinogen-γ C terminus directly interacts with the microvascular endothelium causing fluid and protein leak. The endothelial response to γC involves an integrin receptor-mediated RhoA-dependent signaling pathway that leads to paracellular hyperpermeability.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 394-400 |
| Number of pages | 7 |
| Journal | Arteriosclerosis, Thrombosis, and Vascular Biology |
| Volume | 29 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2009 |
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Keywords
- Fibrinogen degradation products
- Microvascular permeability
- Rho-GTPase
- Signal transduction
- Thrombosis
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
Cite this
Fibrinogen-γ C-Terminal fragments induce endothelial barrier dysfunction and microvascular leak via integrin-mediated and RhoA-dependent mechanism. / Guo, Mingzhang; Daines, Dayle; Tang, Jing; Shen, Qiang; Perrin, Rachel M.; Takada, Yoshikazu; Yuan, Sarah Y.; Wu, Mack H.
In: Arteriosclerosis, Thrombosis, and Vascular Biology, Vol. 29, No. 3, 03.2009, p. 394-400.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fibrinogen-γ C-Terminal fragments induce endothelial barrier dysfunction and microvascular leak via integrin-mediated and RhoA-dependent mechanism
AU - Guo, Mingzhang
AU - Daines, Dayle
AU - Tang, Jing
AU - Shen, Qiang
AU - Perrin, Rachel M.
AU - Takada, Yoshikazu
AU - Yuan, Sarah Y.
AU - Wu, Mack H.
PY - 2009/3
Y1 - 2009/3
N2 - Objectives - The purposes of this study were to characterize the direct effect of the C-terminal fragment of fibrinogen γ chain (γC) on microvascular endothelial permeability and to examine its molecular mechanism of action. Methods and Results-Intravital microscopy was performed to measure albumin extravasation in intact mesenteric microvasculature, followed by quantification of hydraulic conductivity in single perfused micro vessels. Transendothelial electric resistance was measured in microvascular endothelial cells in combination with immunoblotting and immunocytochemistry. The results show that γC induced time- and concentration-dependent increases in protein transvascular flux and water permeability and decreases in endothelial barrier function, coupled with Rho GTPase activation, myosin light chain phosphorylation, and stress fiber formation. Depletion of RhoA via siRNA knockdown or pharmacological inhibition of RhoA signaling attenuated γC-induced barrier dysfunction. Imaging analyses demonstrated binding of γC to endothelial cells; the interaction was inhibited during blockage of the αvβ3 integrin. Furthermore, in vivo experiments showed that the microvascular leak response to γC was attenuated in integrin β3 -/- animals. Conclusion-Fibrinogen-γ C terminus directly interacts with the microvascular endothelium causing fluid and protein leak. The endothelial response to γC involves an integrin receptor-mediated RhoA-dependent signaling pathway that leads to paracellular hyperpermeability.
AB - Objectives - The purposes of this study were to characterize the direct effect of the C-terminal fragment of fibrinogen γ chain (γC) on microvascular endothelial permeability and to examine its molecular mechanism of action. Methods and Results-Intravital microscopy was performed to measure albumin extravasation in intact mesenteric microvasculature, followed by quantification of hydraulic conductivity in single perfused micro vessels. Transendothelial electric resistance was measured in microvascular endothelial cells in combination with immunoblotting and immunocytochemistry. The results show that γC induced time- and concentration-dependent increases in protein transvascular flux and water permeability and decreases in endothelial barrier function, coupled with Rho GTPase activation, myosin light chain phosphorylation, and stress fiber formation. Depletion of RhoA via siRNA knockdown or pharmacological inhibition of RhoA signaling attenuated γC-induced barrier dysfunction. Imaging analyses demonstrated binding of γC to endothelial cells; the interaction was inhibited during blockage of the αvβ3 integrin. Furthermore, in vivo experiments showed that the microvascular leak response to γC was attenuated in integrin β3 -/- animals. Conclusion-Fibrinogen-γ C terminus directly interacts with the microvascular endothelium causing fluid and protein leak. The endothelial response to γC involves an integrin receptor-mediated RhoA-dependent signaling pathway that leads to paracellular hyperpermeability.
KW - Fibrinogen degradation products
KW - Microvascular permeability
KW - Rho-GTPase
KW - Signal transduction
KW - Thrombosis
UR - http://www.scopus.com/inward/record.url?scp=61549138382&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=61549138382&partnerID=8YFLogxK
U2 - 10.1161/ATVBAHA.108.180950
DO - 10.1161/ATVBAHA.108.180950
M3 - Article
C2 - 19122172
AN - SCOPUS:61549138382
VL - 29
SP - 394
EP - 400
JO - Arteriosclerosis, Thrombosis, and Vascular Biology
JF - Arteriosclerosis, Thrombosis, and Vascular Biology
SN - 1079-5642
IS - 3
ER -