Inhibition of collagen synthesis by IWR-1 in normal and keloid-derived skin fibroblasts

Keloid is a benign tumor that is characterized by the hyperproliferation of dermal fibroblasts and excessive deposition of extracellular matrix (ECM) especially the collagen. Aberrant activation of Wnt/β-catenin signaling is implicated in the pathogenesis of keloid. In this study, we investigated the effects of IWR-1, a small molecule inhibitor for Wnt/β-catenin signaling via the inhibition of tankyrase, on production of collagen and matrix metalloproteinase (MMP) in dermal fibroblasts.We cultured human normal skin- and keloid-derived fibroblasts, then treated with IWR-1. The effects of IWR-1 on collagen and MMP production were determined by Western blot, ELISA and zymography.IWR-1 significantly suppressed the proliferation and migration of both the normal and keloid fibroblasts. IWR-1 also inhibited the production and secretion of type I collagen from the fibroblasts. In addition, IWR-1 significantly increased the expression of MMPs, such as MMP-1, MMP-3 and MMP-13, along with the increase of gelatinase activity. These results suggest that inhibitory effect of IWR-1 on collagen production may be related with the increased MMP activity.This study provides the possible action mechanism of IWR-1 on regulation of collagen expression, on which to base further investigation for preventing skin fibrotic diseases such as keloid.