title: Cyclic AMP potentiates vascular endothelial cadherin-mediated cell-cell contact to enhance endothelial barrier function through an Epac-Rap1 signaling pathway.
abstract: Cyclic AMP (cAMP) is a well-known intracellular signaling molecule improving barrier function in vascular endothelial cells. Here, we delineate a novel cAMP-triggered signal that regulates the barrier function. We found that cAMP-elevating reagents, prostacyclin and forskolin, decreased cell permeability and enhanced vascular endothelial (VE) cadherin-dependent cell adhesion. Although the decreased permeability and the increased VE-cadherin-mediated adhesion by prostacyclin and forskolin were insensitive to a specific inhibitor for cAMP-dependent protein kinase, these effects were mimicked by 8-(4-chlorophenylthio)-2'-O-methyladenosine-3', 5'-cyclic monophosphate, a specific activator for Epac, which is a novel cAMP-dependent guanine nucleotide exchange factor for Rap1. Thus, we investigated the effect of Rap1 on permeability and the VE-cadherin-mediated cell adhesion by expressing either constitutive active Rap1 or Rap1GAPII. Activation of Rap1 resulted in a decrease in permeability and enhancement of VE-cadherin-dependent cell adhesion, whereas inactivation of Rap1 had the counter effect. Furthermore, prostacyclin and forskolin induced cortical actin rearrangement in a Rap1-dependent manner. In conclusion, cAMP-Epac-Rap1 signaling promotes decreased cell permeability by enhancing VE-cadherin-mediated adhesion lined by the rearranged cortical actin.
authors.affiliation: Department of Structural Analysis, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan.
authors.forename: Shigetomo
authors.initials: S
authors.lastname: Fukuhara
authors.forename: Atsuko
authors.initials: A
authors.lastname: Sakurai
authors.forename: Hideto
authors.initials: H
authors.lastname: Sano
authors.forename: Akiko
authors.initials: A
authors.lastname: Yamagishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Somekawa
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takakura
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Saito
authors.forename: Kenji
authors.initials: K
authors.lastname: Kangawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Mochizuki
mesh_terms: D000199:Actins / Q000378:metabolism; D000256:Adenoviridae / Q000235:genetics; D015703:Antigens, CD; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion; D002450:Cell Communication; D002460:Cell Line; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D011464:Epoprostenol / Q000494:pharmacology; D020690:GTPase-Activating Proteins; D005982:Glutathione Transferase / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D010539:Permeability; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011994:Recombinant Proteins / Q000737:chemistry; D015398:Signal Transduction; D013997:Time Factors; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D000199:Actins; D015703:Antigens, CD; D015820:Cadherins; D005576:Colforsin; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D011464:Epoprostenol; D020690:GTPase-Activating Proteins; D005982:Glutathione Transferase; D020662:Guanine Nucleotide Exchange Factors; D006160:Guanosine Triphosphate; D011994:Recombinant Proteins; D020827:rap1 GTP-Binding Proteins; D000099152:Cadherin 5; C473217:8-(4-chloro-phenylthio)-2'-O-methyladenosine-3'-5'-cyclic monophosphate; C484658:RAP1GAP protein, human; C116122:RAPGEF3 protein, human