title: Urocortin increased endothelial ICAM1 by cPLA2-dependent NF-κB and PKA pathways in HUVECs.
abstract: Urocortin (Ucn1), a member of the corticotrophin-releasing hormone (CRH) family, has been reported to participate in inflammation. The increased expression of intercellular adhesion molecule 1 (ICAM1) plays important roles in inflammation and immune responses. Our previous results demonstrated that Ucn1 significantly enhanced the expression of ICAM1. However, the underlying mechanisms are still unknown. The purpose of this study is to investigate the detailed mechanisms of Ucn1-induced upregulation of ICAM1. Here, we characterized the mechanisms of Ucn1 usage to regulate ICAM1 expression in human umbilical vein endothelial cells (HUVECs). Our data revealed that Ucn1 increased ICAM1 and cyclooxygenase 2 (COX2) expressions in a time-dependent manner via CRH receptor 2 (CRHR2). In addition, COX2 was involved in ICAM1 upregulation. Furthermore, Ucn1 could increase the expression and phosphorylation of cytosolic phospholipases A2 (cPLA2) in a time-dependent manner via CRHR2 and CRHR1. Moreover, ablation of cPLA2 by the inhibitor pyrrophenone or siRNA attenuated the ICAM1 increase induced by Ucn1. In addition, nuclear factor κB (NF-κB) was activated, indicated by the increase in nuclear p65NF-κB expression and phosphorylation of p65NF-κB, depending on cPLA2 and CRHR2 activation. Pyrrolidinedithiocarbamic acid, an inhibitor of NF-κB, abolished the elevation of ICAM1 but not COX2. Also, Ucn1 increased the production of prostaglandin E2 (PGE2) which further activated protein kinase A (PKA)-CREB pathways dependent of cPLA2 via CRHR2. Moreover, the increase in NF-κB phosphorylation was not affected by the selective COX2 inhibitor NS-398 or the PKA inhibitor H89. In conclusion, these data indicate that Ucn1 increase the ICAM1 expression via cPLA2-NF-κB and cPLA2-COX2-PGE2-PKA-CREB pathways by means of CRHR2.
authors.affiliation: Jiangsu Provincial Key Lab of Cardiovascular Diseases and Molecular Intervention, Department of Pharmacology, Nanjing Medical University, Nanjing 210029, People's Republic of China The Key Laboratory of Molecular Medicine, the Second Affiliated Hospital of Nanchang University, Nanchang 330006, People's Republic of China.
authors.forename: Rong
authors.initials: R
authors.lastname: Wan
authors.forename: Yunxin
authors.initials: Y
authors.lastname: Liu
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Chao
authors.initials: C
authors.lastname: Zhu
authors.forename: Lai
authors.initials: L
authors.lastname: Jin
authors.forename: Shengnan
authors.initials: S
authors.lastname: Li
mesh_terms: D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism*; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism*; D054510:Phospholipases A2, Cytosolic / Q000235:genetics / Q000378:metabolism*; D018019:Receptors, Corticotropin-Releasing Hormone / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D054832:Urocortins / Q000494:pharmacology*
chemical_list: C101531:CRF receptor type 2; D017362:Cyclic AMP Response Element-Binding Protein; D016328:NF-kappa B; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; D018799:Intercellular Adhesion Molecule-1; D051546:Cyclooxygenase 2; D017868:Cyclic AMP-Dependent Protein Kinases; D054510:Phospholipases A2, Cytosolic
keywords: COX2; CREB; ICAM1; NF-κB; cPLA2; urocortin