Sonic hedgehog signalling regulates the self-renewal and proliferation of skin-derived precursor cells in mice.

The sonic hedgehog (Shh) signalling pathway has an important role in the maintenance of various stem cells and organogenesis during development. However, the effect of Shh in skin-derived precursors (SKPs), which have the capacity for multipotency and self-renewal, is not yet clear. The present study investigated the effects of the Shh signalling pathway on the proliferation and self-renewal of murine SKPs (mSKPs). The Shh signalling pathway was activated by treatment with purmorphamine (Shh agonist) or recombinant Shh in mSKPs. Cyclopamine (Shh antagonist) or GANT-61 (Gli inhibitor) was used to inhibit the pathway. Western blot, qPCR, and immunofluorescence were used to analyse the expression of genes related to self-renewal, stemness, epithelial-mesenchymal transition (EMT) and the Shh signalling pathway. In addition, cell proliferation and apoptosis were examined. Inhibiting the Shh signalling pathway reduced mSKP proliferation and sphere formation, but increased apoptosis. Activating this signalling pathway produced opposite results. The Shh signalling pathway also controlled the EMT phenotype in mSKPs. Moreover, purmorphamine recovered the self-renewal and proliferation of aged mSKPs. Our results suggest that the Shh signalling pathway has an important role in the proliferation, self-renewal and apoptosis of mSKPs. These findings also provide a better understanding of the cellular mechanisms underlying SKP self-renewal and apoptosis that allow more efficient expansion of SKPs.