LncRNA-XIST promotes dermal papilla induced hair follicle regeneration by targeting miR-424 to activate hedgehog signaling

Abstract

Background: Alopecia is a highly prevalent disease characterizing by the loss of hair. Dermal papilla (DP) cells are the inducer of hair follicle regeneration, and in vitro three-dimensional (3D) culturing DP cells have been proven to induce hair follicle regeneration. However, the molecular mechanisms behind the regulation of 3D culturing DP cells remain unclear.

Methods: 3D-cultivated DP cells were used as in vitro cell model. DP sphere xenograft to nude mice was performed for in vivo study of hair follicle regeneration. qRT-PCR, Western blotting, and immunofluorescence were used for detecting the level of XIST, miR-424 and Hedgehog pathway-related proteins, respectively. H&E staining was used to examine hair neogenesis. Cell viability, proliferation and ALP activity were measured by MTT, CCK-8 and ELISA assays, respectively. Luciferase assays were used for studying molecular regulation between XIST, miR-424 and Shh 3'UTR.

Results: XIST and Shh were up-regulated, and miR-424 was down-regulated in 3D DP cells. Molecular regulation studies suggested that XIST sponged miR-424 to promote Shh expression. Knockdown of XIST suppressed DP cell activity, cell proliferation, ALP activity and the expression of other DP markers by sponging miR-424. Knockdown of XIST suppressed Shh mediated hedgehog signaling by targeting miR-424. Moreover, the knockdown of XIST inhibited DP sphere induced in vivo hair follicle regeneration and hair development.

Conclusion: XIST sponges miR-424 to promote Shh expression, thereby activating hedgehog signaling and facilitating DP mediated hair follicle regeneration.

Keywords: Dermal papilla; Hair follicle regeneration; Hedgehog signaling pathway; lncRNA-XIST; miR-424.