title: Activation of G protein-coupled estrogen receptor 1 induces coronary artery relaxation via Epac/Rap1-mediated inhibition of RhoA/Rho kinase pathway in parallel with PKA.
abstract: Previously, we reported that cAMP/PKA signaling is involved in GPER-mediated coronary relaxation by activating MLCP via inhibition of RhoA pathway. In the current study, we tested the hypothesis that activation of GPER induces coronary artery relaxation via inhibition of RhoA/Rho kinase pathway by cAMP downstream targets, exchange proteins directly activated by cAMP (Epac) as well as PKA. Our results show that Epac inhibitors, brefeldin A (BFA, 50 μM), or ESI-09 (20 μM), or CE3F4 (100 μM), all partially inhibited porcine coronary artery relaxation response to the selective GPER agonist, G-1 (0.3-3 μM); while concurrent administration of BFA and PKI (5 μM), a PKA inhibitor, almost completely blocked the relaxation effect of G-1. The Epac specific agonist, 8-CPT-2Me-cAMP (007, 1-100 μM), induced a concentration-dependent relaxation response. Furthermore, the activity of Ras-related protein 1 (Rap1) was up regulated by G-1 (1 μM) treatment of porcine coronary artery smooth muscle cells (CASMCs). Phosphorylation of vasodilator-stimulated phosphoprotein (p-VASP) was elevated by G-1 (1 μM) treatment, but not by 007 (50 μM); and the effect of G-1 on p-VASP was blocked by PKI, but not by ESI-09, an Epac antagonist. RhoA activity was similarly down regulated by G-1 and 007, whereas ESI-09 restored most of the reduced RhoA activity by G-1 treatment. Furthermore, G-1 decreased PGF2α-induced p-MYPT1, which was partially reversed with either ESI-09 or PKI; whereas, concurrent administration of ESI-09 and PKI totally prevented the inhibitory effect of G-1. The inhibitory effects of G-1 on p- MLC levels in CASMCs were mostly restored by either ESI-09 or PKI. These results demonstrate that activation of GPER induces coronary artery relaxation via concurrent inhibition of RhoA/Rho kinase by Epac/Rap1 and PKA. GPER could be a potential drug target for preventing and treating cardiovascular diseases.
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.
authors.forename: Xuan
authors.initials: X
authors.lastname: Yu
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.|Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.|Department of Cardiovascular Medicine, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Schwarz
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.|Women's Health Division, Michael E. DeBakey Institute, Texas A&M University, College Station, TX, United States of America.
authors.forename: John N
authors.initials: JN
authors.lastname: Stallone
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.
authors.forename: Cristine L
authors.initials: CL
authors.lastname: Heaps
authors.affiliation: Department of Physiology and Pharmacology, Texas A&M University, College Station, TX, United States of America.|Women's Health Division, Michael E. DeBakey Institute, Texas A&M University, College Station, TX, United States of America.
authors.forename: Guichun
authors.initials: G
authors.lastname: Han
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000502:physiology*; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003517:Cyclopentanes / Q000494:pharmacology; D020662:Guanine Nucleotide Exchange Factors / Q000037:antagonists & inhibitors / Q000378:metabolism; D006835:Hydrazones / Q000494:pharmacology; D007555:Isoxazoles / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011804:Quinolines / Q000494:pharmacology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D013873:Thionucleotides / Q000494:pharmacology; D020827:rap1 GTP-Binding Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: C517943:1-(4-(6-bromobenzo(1,3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta(c)quinolin-8-yl)ethanone; C579558:3-(5-tert-butylisoxazol-3-yl)-2-((3-chlorophenyl)hydrazono)-3-oxopropionitrile; D003517:Cyclopentanes; D020662:Guanine Nucleotide Exchange Factors; D006835:Hydrazones; D007555:Isoxazoles; D011804:Quinolines; D034741:RNA, Small Interfering; D011960:Receptors, Estrogen; D013873:Thionucleotides; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP; D054460:rho-Associated Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D043263:Myosin-Light-Chain Phosphatase; D020827:rap1 GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein