SOX11 promotes skin fibrosis by inducing fibrotic factors

In this study, we demonstrated that baseline SOX11 expression was significantly higher in dermal fibroblasts (DFs) isolated from patients with SSc than that in controls, and increased in response to TGF-b. We then showed that SOX11 is involved in the expression of periostin and some periostin-dependent fibrotic factors identified in lung fibroblasts previously. Moreover, we identified some fibrotic factors induced by SOX11 in DNA microarrays combining TGF-b induction and SOX11 knockdown. Finally, we showed that genetic deletion of SOX11 in Postn positive fibroblast cells protects from bleomycin (BLM)-induced skin fibrosis. Altogether, our data indicate that SOX11 and periostin forms a vicious circle and that TGF-b activates this circle specifically in SSc dermal fibroblasts. In order to clarify the mechanism of dermal fibrosis dependent on the SOX11/periostin pathway, we annotated the gene expression profiles of SSc dermal fibroblasts into TGF-b–dependent/independent genes and SOX11-dependent/independent genes using DNA microarray analysis