Calcimycin Suppresses S100A4 Expression and Inhibits the Stimulatory Effect of Transforming Growth Factor β1 on Keloid Fibroblasts

Recent researches have indicated that S100A4 participates in tissue fibrosis, whereas calcimycin inhibits this process as a novel S100A4 transcription inhibitor. However, the relationship and mechanisms between calcimycin and S100A4 in keloid fibroblasts (KFs) remain unknown. The present research was aimed to evaluate the effect of calcimycin on S100A4 expression and pathogenesis in KFs. Keloid fibroblasts were cultured and exposed to different concentrations of calcimycin in the absence or presence of transforming growth factor β1 (TGF-β1). The results showed that the expression of S100A4 was significantly increased in keloid derived fibroblasts compared with normal skin fibroblasts. Calcimycin depressed S100A4 in a concentration- and time-dependent manner. Moreover, calcimycin suppressed TGF-β1–induced collagen type I, fibronectin, and α-smooth muscle actin expression and cell viability in cultured KFs. Furthermore, calcimycin modulated expression of TGF-β/Smad target genes Smad7 and phosphorylation of TGF-β1–induced Smad2/3. This research for the first time confirmed the presence of S100A4 in KFs. Calcimycin inhibits the expression of S100A4, as well as KF proliferation and migration and extracellular matrix (ECM) synthesis. Taken together, these results indicate that calcimycin might be a therapeutic candidate to keloid or other related fibrotic disorders.