Low anticoagulant heparin blocks thrombin-induced endothelial permeability in a PAR-dependent manner.
Acute lung injury and acute respiratory distress syndrome are accompanied by thrombin activation and fibrin deposition that enhance lung inflammation, activate endothelial cells and disrupt lung paracellular permeability. Heparin possesses anti-inflammatory properties but its clinical use is limited by hemorrhage and heparin induced thrombocytopenia. We studied the effects of heparin and low anticoagulant 2-O, 3-O desulfated heparin (ODSH) on thrombin-induced increases in paracellular permeability of cultured human pulmonary endothelial cells (ECs). Pretreatment with heparin or ODSH blocked thrombin-induced decrease in the EC transendothelial electrical resistance (TER), attenuated thrombin-stimulated paracellular gap formation and actin cytoskeletal rearrangement. Our data demonstrated that heparin and ODSH had inhibitory effects on thrombin-induced RhoA activation and intracellular calcium elevation. Thrombin-stimulated phosphorylation of the cytoskeletal regulatory proteins, myosin light chain and ezrin/radixin/moesin was also reduced. In these effects, low anticoagulant ODSH was more potent than heparin. Heparin or ODSH alone produced decreases in the EC TER that were abolished by siRNA-mediated depletion of the thrombin receptor, PAR-1. We also demonstrated that, in contrast to heparin, ODSH did not possess thrombin-binding activity. Results suggest that heparin and low anticoagulant ODSH can interfere with thrombin-activated signaling.
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA; Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: jgonzales@gru.edu.
Joyce N
JN
Gonzales
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: i60p68@hotmail.com.
Kyung-mi
KM
Kim
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: mzemskova@gru.edu.
Marina A
MA
Zemskova
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: rrafikov@gru.edu.
Ruslan
R
Rafikov
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: bheeke@gru.edu.
Brenten
B
Heeke
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: mvarn@gru.edu.
Matthew N
MN
Varn
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: sblack@gru.edu.
Stephen
S
Black
Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: tkennedy@gru.edu.
Thomas P
TP
Kennedy
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: averin@gru.edu.
Alexander D
AD
Verin
Vascular Biology Center, Georgia Regents University, Augusta, GA 30912, USA. Electronic address: ezemskov@gru.edu.
Evgeny A
EA
Zemskov
D000199:Actins / Q000378:metabolism; D000925:Anticoagulants / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D006493:Heparin / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D018994:Myosin Light Chains / Q000378:metabolism; D010539:Permeability / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D018179:Receptors, Thrombin / Q000378:metabolism*; D013917:Thrombin / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism; D000099149:Ezrin
D000199:Actins; D000925:Anticoagulants; D002118:Calcium; D003598:Cytoskeletal Proteins; D006493:Heparin; D008565:Membrane Proteins; D008840:Microfilament Proteins; D018994:Myosin Light Chains; D018179:Receptors, Thrombin; D013917:Thrombin; D020742:rhoA GTP-Binding Protein; D000099149:Ezrin; C410523:heparin, O-desulfated; C071058:moesin; C071776:radixin
Endothelium; Heparin; ODSH; PAR; Thrombin