Adenovirus-mediated transfer of the atrial natriuretic peptide gene in rat pulmonary vascular smooth muscle cells leads to apoptosis

Atrial natriuretic peptide (ANP) exhibits relaxant and growth-inhibiting effects on vascular smooth muscle cells (VSMCs). To obtain ANP gene expression in VSMCs, we built a recombinant adenovirus containing the ANP cDNA controlled by the adenovirus major late promotor (AdMLP-ANP). After pulmonary VSMC treatment with AdMLP-ANP at a multiplicity of infection ranging from 5 to 100 TCID50/cell, immunoreactive ANP was detectable in the cell culture medium at a level that reached 101 ± 27 pmol/well after 2 days. The newly expressed ANP was biologically active, as evidenced by its ability to induce cyclic guanosine monophosphate accumulation in target cells and to mimic the effect of exogenous ANP (10–8 to 10–7 mol/L). Cell growth and survival of AdMLP-ANP–infected cells were decreased and were associated with the promotion of VSMC apoptosis. These effects, which occurred at a multiplicity of infection of 10 to 100 TCID50/cell, were observed neither in cells infected with the control adenoviral constructs (AdMLP-βGAL and AdMLP-gD) nor in cells treated with exogenous ANP (10–7 to 10–6 mol/L). These results showing VSMC apoptosis in response to ANP gene expression may have important implications for the prevention of vascular remodeling by gene therapy. (J Lab Clin Med 2001;137:155-64)