TGF-β Pathway in Salivary Gland Fibrosis

Fibrosis is presented in various physiologic and pathologic conditions of the salivary gland. Transforming growth factor beta (TGF-β) pathway has a pivotal role in the pathogenesis of fibrosis in several organs, including the salivary glands. Among the TGF-β superfamily members, TGF-β1 and 2 are pro-fibrotic ligands, whereas TGF-β3 and some bone morphogenetic proteins (BMPs) are anti-fibrotic ligands. TGF-β1 is thought to be associated with the pro-fibrotic pathogenesis of sialadenitis, post-radiation salivary gland dysfunction, and Sjögren's syndrome. Potential therapeutic strategies that target multiple levels in the TGF-β pathway are under preclinical and clinical research for fibrosis. Despite the anti-fibrotic effect of BMPs, their in vivo delivery poses a challenge in terms of adequate clinical efficacy. In this article, we will review the relevance of TGF-β signaling in salivary gland fibrosis and advances of potential therapeutic options in the field.