OBJECTIVETo investigate the inhibitory effects of AP-1 decoy oligodeoxynucleotides (ODNs) on angiotensin II (AngII)-induced proliferation and collagen synthesis in neonatal rat cardiac fibroblasts (CFs).

METHODSThe CFs of neonatal SD rats were cultured in serum-free medium for 24 h and stimulated with 10(-7) mol/L AngII in the presence of AP-1 decoy ODNs or mutational AP-1 decoy ODNs at varied concentrations. MTT assay was employed for quantitative evaluation of the CF proliferation. Collagen synthesis in the CFs was assessed with hydroxyproline, and the cell cycle distribution determined with flow cytometry (FCM).

RESULTSWith the increase of the concentration of AP-1 decoy ODNs, the absorbance at 490 nm (OD490) of the CFs decreased gradually as shown by MTT assay. Treatment with 100 or 200 nmol/L AP-1 decoy ODNs resulted in significantly lowered OD490 of the CFs as compared with that of AngII group. The concentration of hydroxyproline increased significantly after treatment with 10(-7) mol/L AngII in comparison with the control group (P<0.05). Hydroxyproline concentration in cells treated with 100 or 200 nmol/L AP-1 decoy ODNs was significantly lower than that in the 10(-7) mol/L AngII-treated cells. AP-1 decoy ODNs decreased the cell percentage in S phase and increased hydroxyproline concentration, but increased the percentage of cells in G0/G1 phase. AP-1 decoy ODNs at 100 and 200 nmol/L did not obviously affect AngII-induced CF proliferation and collagen synthesis (P<0.01).

CONCLUSIONAP-1 decoy can inhibit AngII-induced rat CF proliferation and collagen synthesis possibly by affecting the cell cycle distribution.