3.7 | WISP-1 activates Hedgehog-Gli1 signaling in LF fibroblasts
In order to elucidate the underlying mechanism by which elevated WISP-1 promoted LF fibrosis, we analyzed the effect of WISP-1 over-expression and knockdown on the expression of Hedgehog signaling-related proteins, including Gli1 and Shh, in LF cells from the LSCS patients. As a result, we found that over-expression of WISP-1 increased the levels of Gli1 and Shh in LF fibroblast, and knockdown of WISP-1 inhibited the expression of Gli1 and Shh (Fig. 7 A and B). Consistent with these results, recombinant human WISP-1 promoted Gli1 protein expression in a dose-dependent manner in WISP-1-treated LF cells (Fig. 7C).
Furthermore, we used immunofluorescence staining to investigate Gli1 expression and nucleus translocation upon the effect of WISP-1. The results revealed that Gli1 was preferentially distributed in the cytoplasm rather than in the nucleus in the control group. However, under the stimulation of WISP-1 over-expression, most Gli1 translocated to the nucleus. Moreover, Gli1 translocation was inhibited in the WISP-1 knockdown LF cells (Fig. 7D), indicating that WISP-1 could activate the Hedgehog-Gli1 pathway in LF fibroblasts.