title: Adrenomedullin enhances invasion of human extravillous cytotrophoblast-derived cell lines by regulation of urokinase plasminogen activator expression and s-nitrosylation.
abstract: Extravillous cytotrophoblast (EVCT) is responsible for trophoblast invasion, which is an important process during placentation. Dysregulation of the process is associated with a wide range of pregnancy complications. Adrenomedullin (ADM) is a polypeptide expressed most abundantly in first-trimester placentas. We hypothesized that ADM modulated the invasion of human EVCT. Our results showed that ADM enhanced invasion and migration but not proliferation in two EVCT cell lines, JEG-3 and TEV-1. Similar observation can also be obtained in primary EVCTs. JEG-3 and TEV-1 cells expressed ADM receptor components as demonstrated by immunostaining, Western blotting, and RT-PCR. The ADM antagonist ADM(22-52) (ADM C-terminal 22-52 amino acid fragment) suppressed ADM-induced invasion and migration, confirming that ADM exerted its biological effects through its classical receptors. The stimulatory effect of ADM on EVCT invasiveness was associated with induction (P < 0.05) of urokinase plasminogen activator (uPA) and nitric oxide synthase (NOS) expression and activity. Silencing of uPA by siRNA transfection abolished the stimulatory effect of ADM, suggesting that uPA is the key mediator for ADM-induced invasion. The involvement of NO in enhancing the invasion and biosynthesis of uPA in EVCT cell lines was confirmed by using pharmacological inhibitors of NOS and NO donors. ADM-mediated NO production also increased protein S-nitrosylation of JEG-3 cells. S-nitrosylation activated uPA in vitro and induced a higher proteinase activity. These findings provide indications that ADM and its downstream NO signaling may play an important role in modulating human EVCT functions.
authors.affiliation: Department of Obstetrics and Gynaecology, The University of Hong Kong, Queen Mary Hospital, Hong Kong, Hong Kong SAR.
authors.forename: Ben S T
authors.initials: BS
authors.lastname: Wong
authors.forename: Kevin K W
authors.initials: KK
authors.lastname: Lam
authors.forename: Cheuk-Lun
authors.initials: CL
authors.lastname: Lee
authors.forename: Vera H H
authors.initials: VH
authors.lastname: Wong
authors.forename: Maggie P Y
authors.initials: MP
authors.lastname: Lam
authors.forename: Ivan K
authors.initials: IK
authors.lastname: Chu
authors.forename: William S B
authors.initials: WS
authors.lastname: Yeung
authors.forename: Philip C N
authors.initials: PC
authors.lastname: Chiu
mesh_terms: D053607:Adrenomedullin / Q000494:pharmacology*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010920:Placenta; D010929:Placentation / Q000502:physiology; D011247:Pregnancy; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D014327:Trophoblasts / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D034741:RNA, Small Interfering; D053607:Adrenomedullin; D019001:Nitric Oxide Synthase; D014568:Urokinase-Type Plasminogen Activator