34] In vitro and in vivo modulation of transforming growth factor β1 gene expression by antisense oligomer

Abstract

Antisense technology is emerging as an effective means of lowering the levels of specific gene products. It is based on the findings that these antisense sequences hybridize to specific ribonucleic acid (RNA) transcripts, thereby disrupting normal RNA processing, stability, and translation and preventing the expression of a targeted gene. Administration of antisense oligonucleotides, or transfer of expression constructs capable of producing intracellular antisense sequences complementary to the messenger RNA (mRNA) of interest, blocks the translation of specific genes in vitro and in vivo. Because antisense oligomer inhibits expression of specific genes, this approach provides the opportunity to examine the role of the expression of transforming growth factor beta (TGF-β1) during macrophage activation or wound healing processes. Thus, the approach introduces in vitro and in vivo modulation of TGF-β1 gene expression by antisense oligomer complementary to TGF-β1 mRNA. The materials with which the antisense approach can be applied are classified as antisense oligodeoxynucleotides (ODNs), antisense RNAs, and catalytic RNAs or ribozymes. Antisense sequences can be engineered either chemically (antisense ODNs) or genetically (antisense RNAs). This chapter discusses antisense ODNs, which offer important stability and synthetic advantages over the use of antisense RNAs, and is intended as an introduction to practical approaches in the use of antisense ODNs. Evidence of the cellular uptake of antisense TGF-β1 and its effect on TGF-β1 expression in cultured macrophages is presented and the skin absorption of antisense and scar-removing effect by the inhibition of TGF-β1 expression on the skin are described in the chapter.