Phosphorothioate-modified antisense TGF-β1 oligodeoxynucleotide inhibits neointimal hyperplasia after vascular balloon injury in rats

AIM: To evaluate the effects of antisense TGF-β1 oligodeoxynucleotide (AS TGF-β1) on the expression of TGF-β1, deposition of extracellular matrix (ECM) and the neointima formation in the arteries after balloon injury. METHODS: The unmodified and phosphorothioate-modified AS TGF-β1 which containing 15 bases and surrounding the initiation codon region (ATG) of rat TGF-β1 complementary DNA (cDNA) were designed. At the same time, sense TGF-β1 oligodeoxynucleotide (S TGF-β1) with the base sequence complement to AS TGF-β1 was synthesized as a control. The oligodeoxynucleotides were introduced into in vivo and in vitro experiments, respectively. RESULTS: The AS TGF-β1 significantly inhibited the protein expression of TGF-β1 in a concentration-dependent manner, and S TGF-β1 did not have the same effect. Furthermore, no effect of the AS TGF-β1 on the mRNA expression of TGF-β1 in injured VSMCs was observed. Moreover, for the injured VSMCs, AS TGF-β1 significantly and concentration-dependently inhibited the basal DNA synthesis. Both AS TGF-β1 and S TGF-β1 did not exhibit dose-dependent effects on DNA synthesis in uninjured VSMCs. Fibronectin (FN) mRNA expression in injured VSMCs was significantly decreased by AS TGF-β1 in a concentration (001~1 μmol/L)-dependent manner. AS TGF-β1 significantly increased the mRNA expression of contractile marker SM22α, and decreased the mRNA expression of synthetic markers osteopontin and matrix Gla, especially at the concentration of 001 μmol/L and 01 μmol/L. After treatment with AS TGF-β1 (90 μg·kg-1·d-1) for 28 d, the neointima formation was significantly inhibited, and the area ratio of intima/media was markedly decreased by 68% compared with untreated group, but S TGF-β1 had no effect on neointimal formation. CONCLUSION：The AS TGF-β1 specifically inhibits the protein expression of TGF-β1 in the VSMCs derived from injured arteries. Moreover, it significantly inhibits DNA synthesis and cell proliferation, and decreases the expression of FN. Therefore, AS TGF-β1 dramatically attenuates neointima formation after balloon njury. The effects of AS TGF-β1 on the injured VSMCs may be associated with its reverse effects on the alteration of VSMC phenotype after balloon injury.