A sense phosphorothioate oligodeoxynucleotide containing the transforming growth factor beta regulatory element acts as a novel local nonsteroidal antifibrotic drug

Fibrosis is a potential response to tissue injury. At present, glucocortico ids with their numerous toxic side effects are the only effective treatment for fibrotic diseases. Granulomas induced by sponge implantation were trea ted with single-stranded phosphorothioate oligodeoxynucleotides containing the wild type or mutated transforming growth factor-beta response element d esigned to inhibit the rat pro alpha1(l) promoter activity. Single-stranded phosphorothioate oligonucleotides resulted in antifibrotic activity based on their ability to reduce granuloma tissue formation and selectively inhib it collagen synthesis. The mutated single-standed phosphorothioate oligonuc leotides or dexamethasone given at an equivalent dose to single-standed pho sphorothioate oligonucleotides failed to do so. These data suggest that the phosphorothioate oligodeoxynucleotide containing the transforming growth f actor-beta regulatory element has an antifibrotic effect and may be used to inhibit the development of fibrosis.