Figure 4.

PDE1C inhibition or PDE1C silencing, inhibit, rather than promote, SOCE-associated increases in HASMCs cAMP.A, representative single cell traces of normalized FRET emission ratios measured in H134-expressing HASMCs treated as in Figure 1B in the absence (black line) or the presence (red line) of C33 (1 μM). B–D, changes in normalized FRET emission ratios measured in control (n = 25) or C33-treated (n = 32) HASMCs during (B) ER(Ca²⁺) store depletions, (C) the early phase of SOCE or (D) the later phase of SOCE. E, rate of change in cAMP during the later phase of SOCE in HASMC; ∗p < 0.05, Student’s unpaired t test. F, representative single cell traces of normalized FRET emission ratios measured in control siRNA-transfected H134-expressing HASMCs (black line) or PDE1C-silenced H134-expressing HASMCs treated as in Figure 1B. G–I, changes in normalized FRET emission ratios measured in control (n = 23) or PDE1C-silenced (n = 32) HASMCs during (G) ER(Ca²⁺) store depletion, (H) the early phase of SOCE or (I) the later phase of SOCE. J, rate of change in cAMP during the later phase of SOCE in HASMCs. ∗p < 0.05, ∗∗∗p < 0.001, Student’s unpaired t test. cAMP, cyclic AMP; FRET, fluorescence resonance energy transfer; HASMC, human arterial smooth muscle cell; PDE, phosphodiesterase; PDE1C, phosphodiesterase 1C; SOCE, store-operated calcium entry.