1. Hydrogen sulphide triggers VEGF-induced intracellular Ca2+ signals in human endothelial cells but not in their immature progenitors
- Author
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Vittorio Rosti, Francesco Moccia, Germano Guerra, Duilio Michele Potenza, Daniele Avanzato, Franco Tanzi, Daniele Guido, Sumedha Pareek, Valentina Poletto, Luca Munaron, and Angelo Gallanti
- Subjects
Phospholipase C ,Physiology ,Angiogenesis ,Medicine (all) ,Dl-Propargylglycine ,Proliferation ,Genistein ,Cell Biology ,Biology ,Cystathionine beta synthase ,Cell biology ,Ca2+ release ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Endothelial progenitor cells ,HUVECs ,Hydrogen sulphide ,Molecular Biology ,biology.protein ,Extracellular ,Progenitor cell ,Receptor ,Intracellular - Abstract
Hydrogen sulphide (H 2 S) 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 H 2 S. Albeit VEGFR-2 might serve as H 2 S receptor, the mechanistic relationship between VEGF- and H 2 S-induced Ca 2+ signals in endothelial cells is unclear. The present study aimed at assessing whether and how NaHS, a widely employed H 2 S 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 (InsP 3 ) 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 H 2 S-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, H 2 S-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.
- Published
- 2014