title: Hydrogen sulphide triggers VEGF-induced intracellular Ca²⁺ signals in human endothelial cells but not in their immature progenitors.
abstract: Hydrogen sulphide (H2S) is a newly discovered gasotransmitter that regulates multiple steps in VEGF-induced angiogenesis. An increase in intracellular Ca(2+) concentration ([Ca(2+)]i) is central to endothelial proliferation and may be triggered by both VEGF and H2S. Albeit VEGFR-2 might serve as H2S receptor, the mechanistic relationship between VEGF- and H2S-induced Ca(2+) signals in endothelial cells is unclear. The present study aimed at assessing whether and how NaHS, a widely employed H2S donor, stimulates pro-angiogenic Ca(2+) signals in Ea.hy926 cells, a suitable surrogate for mature endothelial cells, and human endothelial progenitor cells (EPCs). We found that NaHS induced a dose-dependent increase in [Ca(2+)]i in Ea.hy926 cells. NaHS-induced Ca(2+) signals in Ea.hy926 cells did not require extracellular Ca(2+) entry, while they were inhibited upon pharmacological blockade of the phospholipase C/inositol-1,4,5-trisphosphate (InsP3) signalling pathway. Moreover, the Ca(2+) response to NaHS was prevented by genistein, but not by SU5416, which selectively inhibits VEGFR-2. However, VEGF-induced Ca(2+) signals were suppressed by dl-propargylglycine (PAG), which blocks the H2S-producing enzyme, cystathionine γ-lyase. Consistent with these data, VEGF-induced proliferation and migration were inhibited by PAG in Ea.hy926 cells, albeit NaHS alone did not influence these processes. Conversely, NaHS elevated [Ca(2+)]i only in a modest fraction of circulating EPCs, whereas neither VEGF-induced Ca(2+) oscillations nor VEGF-dependent proliferation were affected by PAG. Therefore, H2S-evoked elevation in [Ca(2+)]i is essential to trigger the pro-angiogenic Ca(2+) response to VEGF in mature endothelial cells, but not in their immature progenitors.
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy.
authors.forename: Duilio Michele
authors.initials: DM
authors.lastname: Potenza
authors.affiliation: Department of Health Sciences, University of Molise, Via F. De Santis, 86100 Campobasso, Italy.
authors.forename: Germano
authors.initials: G
authors.lastname: Guerra
authors.affiliation: Department of Life Sciences and Systems Biology, Centre for Nanostructured Interfaces and Surfaces, Centre for Complex Systems in Molecular Biology and Medicine, University of Torino, 10123 Torino, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Avanzato
authors.affiliation: Center for the Study of Myelofibrosis, Research Laboratory of Biotechnology, IRCCS Policlinico San Matteo Foundation, Piazzale Golgi 19, 27100 Pavia, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Poletto
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy.
authors.forename: Sumedha
authors.initials: S
authors.lastname: Pareek
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Guido
authors.affiliation: Department of Molecular Medicine, University of Pavia, Via Taramelli 10, 27100 Pavia, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Gallanti
authors.affiliation: Center for the Study of Myelofibrosis, Research Laboratory of Biotechnology, IRCCS Policlinico San Matteo Foundation, Piazzale Golgi 19, 27100 Pavia, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rosti
authors.affiliation: Department of Life Sciences and Systems Biology, Centre for Nanostructured Interfaces and Surfaces, Centre for Complex Systems in Molecular Biology and Medicine, University of Torino, 10123 Torino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Munaron
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Tanzi
authors.affiliation: Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy. Electronic address: francesco.moccia@unipv.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Moccia
mesh_terms: D000328:Adult; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003593:Cytoplasm / Q000378:metabolism; D066026:Endothelial Progenitor Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D064368:Healthy Volunteers; D006801:Humans; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D010738:Type C Phospholipases / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects; D055815:Young Adult
chemical_list: C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases; D006862:Hydrogen Sulfide
keywords: Ca(2+) release; Endothelial progenitor cells; HUVECs; Hydrogen sulphide; Proliferation; dl-Propargylglycine