title: Arachidonic acid-evoked Ca2+signals promote nitric oxide release and proliferation in human endothelial colony forming cells.
abstract: Arachidonic acid (AA) stimulates endothelial cell (EC) proliferation through an increase in intracellular Ca2+concentration ([Ca2+]i), that, in turn, promotes nitric oxide (NO) release. AA-evoked Ca2+signals are mainly mediated by Transient Receptor Potential Vanilloid 4 (TRPV4) channels. Circulating endothelial colony forming cells (ECFCs) represent the only established precursors of ECs. In the present study, we, therefore, sought to elucidate whether AA promotes human ECFC (hECFC) proliferation through an increase in [Ca2+]iand the following activation of the endothelial NO synthase (eNOS). AA induced a dose-dependent [Ca2+]iraise that was mimicked by its non-metabolizable analogue eicosatetraynoic acid. AA-evoked Ca2+signals required both intracellular Ca2+release and external Ca2+inflow. AA-induced Ca2+release was mediated by inositol-1,4,5-trisphosphate receptors from the endoplasmic reticulum and by two pore channel 1 from the acidic stores of the endolysosomal system. AA-evoked Ca2+entry was, in turn, mediated by TRPV4, while it did not involve store-operated Ca2+entry. Moreover, AA caused an increase in NO levels which was blocked by preventing the concomitant increase in [Ca2+]iand by inhibiting eNOS activity with NG-nitro-l-arginine methyl ester (l-NAME). Finally, AA per se did not stimulate hECFC growth, but potentiated growth factors-induced hECFC proliferation in a Ca2+- and NO-dependent manner. Therefore, AA-evoked Ca2+signals emerge as an additional target to prevent cancer vascularisation, which may be sustained by ECFC recruitment.
authors.affiliation: Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy.
authors.forename: Estella
authors.initials: E
authors.lastname: Zuccolo
authors.affiliation: Department of Cell Biology, Institute of Ophthalmology, University College London, 11-43 Bath Street, EC1V 9EL London, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Dragoni
authors.affiliation: Center for the Study of Myelofibrosis, Biotechnology Research Laboratory, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Poletto
authors.affiliation: Center for the Study of Myelofibrosis, Biotechnology Research Laboratory, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Catarsi
authors.affiliation: Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Guido
authors.affiliation: Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rappa
authors.affiliation: Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Reforgiato
authors.affiliation: Laboratory of General Physiology, Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Lodola
authors.affiliation: Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", 28100 Novara, Italy.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Lim
authors.affiliation: Center for the Study of Myelofibrosis, Biotechnology Research Laboratory, Fondazione IRCCS Policlinico San Matteo, 27100 Pavia, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rosti
authors.affiliation: Department of Medicine and Health Sciences "Vincenzo Tiberio", University of Molise, 86100 Campobasso, Italy.
authors.forename: Germano
authors.initials: G
authors.lastname: Guerra
authors.affiliation: Department of Cell Biology, Institute of Ophthalmology, University College London, 11-43 Bath Street, EC1V 9EL London, United Kingdom. Electronic address: francesco.moccia@unipv.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Moccia
mesh_terms: D000328:Adult; D016718:Arachidonic Acid / Q000008:administration & dosage / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004721:Endoplasmic Reticulum / Q000378:metabolism; D066026:Endothelial Progenitor Cells / Q000378:metabolism*; D006801:Humans; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D055815:Young Adult
chemical_list: D016718:Arachidonic Acid; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester
keywords: Arachidonic acid; Ca(2+); Endothelial colony forming cells; Nitric oxide; Proliferation; TRPV4