Functional expression of PDE3 in HAECs.

(A) Top, Representative immunoblot showing PDE3A and PDE3B expression in human adipose, artery, and HAECs. Bottom, Fluorescence microscopy analysis of PDE3A and PDE3B expression in HAECs (green, VE-Cadherin; red, PDE3A or 3B). (B) Top, Effect of PDE3-targeting siRNAs (iPDE3A and 3B) or non-targeting siRNAs (iCt) on protein levels in HAEC. Bottom, Down-regulation of PDE3A and PDE3B expression increases intracellular cAMP levels in HAECs. HAECs were transfected with a iCT, iPDE3A, or iPDE3B. Post-transfection HAECs were treated with vehicle (Veh) or 30 μM cilostazol (C30), and then the intracellular cAMP concentration was determined. (C) Down-regulation of PDE3A and PDE3B expression increases PGI₂ production in HAECs. HAECs were transfected with a iCT, iPDE3A, or iPDE3B. Post-transfection HAECs were treated with vehicle (Veh) or 30 μM cilostazol (C30), and then the PGI₂ concentration in medium was determined (n = 4; †† p < 0.01 vs. iCT, t-test; ** p < 0.01 vs. Veh, t-test).