An antisense of protein kinase C-zeta inhibits proliferation of human airway smooth muscle cells

We hypothesized that an atypical isoform of protein kinase (PK) C, PKC-zeta , is essential for proliferation of human airway smooth muscle (HASM) cells in primary culture. Recombinant replication-deficient El-deleted adenoviru ses (100 plaque-forming units [pfu]/cell) expressing the antisense of PKC-z eta and the wild-type PKC-zeta (Ad-CMV-PKC-zeta) were added to actively gro wing cells that were subsequently incubated for 48 h in platelet-derived gr owth factor (PDGF) 40 ng/mL or 10% fetal bovine serum (FBS). Expression of the antisense at a virus concentration of 100 pfu/cell produced a significa nt (n = 3, P < 0.05) decrease in the mean manual cell count in the presence of PDGF to 37 +/- 5% relative to that in cells with no virus (100%), where as in cells infected with virus containing no construct, this figure was 10 2 +/- 13%. The increase in cell number in response to FBS, however, was not affected by the presence of the antisense. Corresponding values for cells in 10% FBS were 100 +/- 22%, 85 +/- 22%, and 122 +/- 18%. Western blotting revealed decreased levels of PKC-zeta protein, but not PKC-alpha or PKC-eps ilon protein, in cells infected with the antisense when compared with level s in control cells. Thus, in HASM cells, PKC-zeta is involved in proliferat ion in response to PDGF, but not in response to FBS, for which alternate si gnal transduction pathways independent of PKC-zeta must exist.