Micro-Injury Induces Hair Regeneration and Vitiligo Repigmentation Through Wnt/β-Catenin Pathway.

Xiaofeng Han,Julia Li Zhong,Qingchun Diao,Wei Xu,Yuyi Wang,Zhijin Qiu,Mao Lin,Li Chang,Deming Liu

doi:10.1089/scd.2021.0276

Abstract

Extrinsic injury can evoke intrinsic stimulation and subsequently initiate the physiological repair process. This study aims to investigate whether clinically acceptable micro-injury could be used to create local stimuli to induce hair regeneration and vitiligo repigmentation. A novel device was designed and manufactured to precisely control the micro-injury parameters. Then the most appropriate extent of micro-injury without over-damaging the skin was evaluated. Finally, the effects of micro-injury on hair regeneration and vitiligo repigmentation were examined by macroscopic observation, histological staining, gene and protein expression analysis. We discover that proper micro-injury effectively induces hair regeneration by activating the hair follicle stem cell proliferation and migration downwards to the hair matrix, finally shifting the hair follicle stage from telogen into anagen. On vitiligo model mice, micro-injury also induces the hair follicle melanocyte stem cells to migrate upwards to the interfollicular epidermis, activating and giving rise to melanocytes to repopulate the vitiligo lesion. Mechanistic analysis indicates that the canonical Wnt/β-catenin pathway plays a key role in the micro-injury-induced repair process. This study demonstrates that micro-injury has great potential in inducing hair regeneration and vitiligo repigmentation, laid a foundation to develop a micro-injury-based treatment method in alopecia and vitiligo.

Highlights

Extrinsic injury can evoke intrinsic stimulation subquently initiate physiological repair process
By a fine customer-made instrument we discover that proper injury stimulation effect both on hair regeneration and vitiligo repigmentation through injury induced Wingless-type mouse mammary tumor virus integration site (Wnt)/β-catenin pathway
Histology results show that hair follicles entered anagen in 30 micro-injuries/cm2 group while the hair follicles with sham-injury remain in telogen, histological analysis indicates the over-damage of skin in 60 micro-injuries/cm2 group, which could explain the delay of hair growth (Fig. 1B)

Summary

Introduction

Extrinsic injury can evoke intrinsic stimulation subquently initiate physiological repair process. Hair follicle harbors heterogenous stem cell populations contributing to hair cycle, hair color, epithelial renewal and skin color under physiological condition and/or stress condition. Extrinsic environmental stimuli, such as hair plucking[1] and mechanical stretch[2] can induce hair growth. Large full thickness skin excision can induce hair negeosis in the central area of wound, a phenomenon called wound-induced HF neogenesis (WIHN) in mice[3] These elegant studies inspire us that proper physical method could be employed to promote hair growth. Recent study using lineage tracing mice exactly shows that hair follicle melanocyte stem cell (HF-McSCs) give rise to epidermal melanocyte after injury or UVB treatment[9]. All these studies suggest that hair follicle serve as a cell reservoir for fuctional interfollicular epidermal melanocytes upon injuries

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Discussion

Conclusion