HDL induces NO-dependent vasorelaxation via the lysophospholipid receptor S1P₃
J. Clin. Invest. Jerzy-Roch Nofer, et al. 113:569 doi:10.1172/JCI18004 [Go to this article.]

Figure 5
Lysophospholipid signaling mediates HDL-, SPC-, S1P-, and LSF-induced Akt and eNOS phosphorylation as well as [Ca²⁺]i increase. (a) HUVECs were stimulated with HDL (0.5 mg/ml) or with 10 μmol/l each (left) or 0.5–5 μmol/l each (right) SPC, S1P, and LSF, with or without preincubation with 100 ng/ml PTX for 16 hours. “PTX control” indicates PTX treatment alone. Cell lysates were analyzed for phospho–Ser⁴⁷³-Akt (p-Ser⁴⁷³-Akt) and phospho–Ser¹¹⁷⁷-eNOS by Western blotting. Loading controls for total eNOS and total Akt content are shown. All results are representative of one experiment of three. (b) HUVECs loaded with DAF-2DA were stimulated with SPC, S1P, and LSF (10 μmol/l each) and observed under a fluorescence microscope. Shown are representative results for one experiment of three. (c) Fura2-AM–loaded HUVECs were stimulated with SPC, S1P, and LSF (10 μmol/l each), and [Ca²⁺]i was measured by fluorescence spectroscopy. Original tracings from representative experiments were superimposed for comparison. (d) Concentration dependence of [Ca²⁺]i increase in HUVECs stimulated with SPC, S1P, and LSF measured as described in c.