TY - JOUR
T1 - Exchange protein directly activated by cAMP plays a critical role in regulation of vascular fibrinolysis
AU - He, Xi
AU - Drelich, Aleksandra
AU - Chang, Qing
AU - Gong, Dejun
AU - Zhou, Yixuan
AU - Qu, Yue
AU - Yu, Shangyi
AU - Yuan, Yang
AU - Qian, Jiao
AU - Qiu, Yuan
AU - Tang, Shao Jun
AU - Gaitas, Angelo
AU - Ksiazek, Thomas
AU - Xu, Zhiyun
AU - Wakamiya, Maki
AU - Lu, Fanglin
AU - Gong, Bin
N1 - Publisher Copyright:
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Rationale To maintain vascular patency, endothelial cells (ECs) actively regulate hemostasis. Among the myriad of pathways by which they control both fibrin formation and fibrinolysis is EC expression of annexin A2 (ANXA2) in a heterotetrameric complex with S100A10 [(ANXA2-S100A10)2]. This complex is a well-recognized endothelial surface platform for the activation of plasminogen by tissue plasminogen activator. A noteworthy advance in this field came about when it was shown that the cAMP pathway is linked to the regulation of (ANXA2-S100A10)2 in ECs. Objective These findings prompted us to determine whether a druggable target, namely the exchange protein directly activated by cAMP (EPAC) pathway, plays a role in vascular luminal fibrinolysis. Methods and Results Taking advantage of our Epac1-null mouse model, we found that depletion of Epac1 results in fibrin deposition, fibrinolytic dysfunction, and decreased endothelial surface ANXA2 in mice, which are similar to phenomena discovered in ANXA2-null and S100A10-null mice. We observed upregulation of EPAC1 and downregulation of fibrin in endocardial tissues beneath atrial mural thrombi in humans. Of note, our thrombosis model revealed that dysfunction of fibrinolysis in EPAC1-null mice can be ameliorated by recombinant ANXA2. Furthermore, we demonstrated that suppression of EPAC1 using a small-molecule inhibitor (ESI09) reduces the expression of ANXA2 in lipid rafts and impedes ANXA2 association with S100A10. Endothelial apical surface expression of both ANXA2 and S100A10 were markedly decreased in ESI09-treated ECs, which was corroborated by results from a nanoforce spectroscopy study. Moreover, inactivation of EPAC1 decreases tyrosine 23 phosphorylation of ANXA2 in the cell membrane compartment. Conclusions Our data reveal a novel role for EPAC1 in vascular fibrinolysis, by showing that EPAC1 is responsible for the translocation of ANXA2 to the EC surface. This process promotes conversion of plasminogen to plasmin, thereby enhancing local fibrinolytic activity.
AB - Rationale To maintain vascular patency, endothelial cells (ECs) actively regulate hemostasis. Among the myriad of pathways by which they control both fibrin formation and fibrinolysis is EC expression of annexin A2 (ANXA2) in a heterotetrameric complex with S100A10 [(ANXA2-S100A10)2]. This complex is a well-recognized endothelial surface platform for the activation of plasminogen by tissue plasminogen activator. A noteworthy advance in this field came about when it was shown that the cAMP pathway is linked to the regulation of (ANXA2-S100A10)2 in ECs. Objective These findings prompted us to determine whether a druggable target, namely the exchange protein directly activated by cAMP (EPAC) pathway, plays a role in vascular luminal fibrinolysis. Methods and Results Taking advantage of our Epac1-null mouse model, we found that depletion of Epac1 results in fibrin deposition, fibrinolytic dysfunction, and decreased endothelial surface ANXA2 in mice, which are similar to phenomena discovered in ANXA2-null and S100A10-null mice. We observed upregulation of EPAC1 and downregulation of fibrin in endocardial tissues beneath atrial mural thrombi in humans. Of note, our thrombosis model revealed that dysfunction of fibrinolysis in EPAC1-null mice can be ameliorated by recombinant ANXA2. Furthermore, we demonstrated that suppression of EPAC1 using a small-molecule inhibitor (ESI09) reduces the expression of ANXA2 in lipid rafts and impedes ANXA2 association with S100A10. Endothelial apical surface expression of both ANXA2 and S100A10 were markedly decreased in ESI09-treated ECs, which was corroborated by results from a nanoforce spectroscopy study. Moreover, inactivation of EPAC1 decreases tyrosine 23 phosphorylation of ANXA2 in the cell membrane compartment. Conclusions Our data reveal a novel role for EPAC1 in vascular fibrinolysis, by showing that EPAC1 is responsible for the translocation of ANXA2 to the EC surface. This process promotes conversion of plasminogen to plasmin, thereby enhancing local fibrinolytic activity.
KW - annexin A2
KW - atomic force microscopy
KW - EPAC1
KW - thrombosis
KW - vascular endothelial fibrinolysis
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U2 - 10.1101/196899
DO - 10.1101/196899
M3 - Article
AN - SCOPUS:85095547234
JO - Molecular Oncology
JF - Molecular Oncology
SN - 1574-7891
ER -