High migratory activity of dermal sheath cup cells associated with the clinical efficacy of autologous cell-based therapy for pattern hair loss.

BACKGROUND: Autologous cell-based therapy using dermal sheath cup (DSC) cells was reported as a new treatment for male and female pattern hair loss. However, the mechanisms underlying its action remain unclear. OBJECTIVE: We investigated the mechanisms underlying the efficacy of DSC cells in cell-based therapy. METHODS: We conducted multivariate analysis to categorize individuals based on treatment response as responders and non-responders. The differentially expressed genes in DSC cells from the two groups were evaluated using bulk transcriptome, quantitative polymerase chain reaction, and single-cell transcriptome analyses. We performed live cell imaging combined with immunostaining to characterize the DSC subpopulation associated with responders. RESULTS: We identified nine and three genes as high efficacy (HE) and low efficacy (LE) marker genes, respectively. The HE subpopulations were enriched for cell migration-related genes in single-cell analysis. In contrast, the LE subpopulation was enriched for basement membrane and vasculature-related genes. Moreover, DSC cells in culture were immunocytochemically and morphologically heterogeneous, expressing characteristic factors. Furthermore, live cell imaging showed that DSC cells expressing integrin subunit alpha 6 (ITGA6), an HE subpopulation gene, had markedly higher mobility than those expressing the LE subpopulation genes collagen type IV or CD36. CONCLUSIONS: ITGA6-positive DSC cells, with superior migratory activity, may contribute to cell-based therapy by promoting cell migration into nearby hair follicles.

Hair follicle regeneration using grafted rodent and human cells.

Hair follicle regeneration involves epithelial-mesenchymal interactions (EMIs) of follicular epithelial and dermal papilla (DP) cells. Co-grafting of those cellular components from mice allows complete hair reconstitution. However, regeneration of human hair in a similar manner has not been reported. Here, we investigated the possibility of cell-based hair generation from human cells. We found that DP-enriched cells (DPE) are more critical than epidermal cells in murine hair reconstitution on a cell number basis, and that murine DPE are also competent for hair regeneration with rat epidermal cells. Co-grafting of human keratinocytes derived from neonatal foreskins with murine DPE produced hair follicle-like structures consisting of multiple epidermal cell layers with a well-keratinized innermost region. Those structures expressed hair follicle-specific markers including hair keratin, and markers expressed during developmental stages. However, the lack of regular hair structures indicates abnormal folliculogenesis. Similar hair follicle-like structures were also generated with cultured human keratinocytes after the first passage, or with keratinocytes derived from adult foreskins, demonstrating that epidermal cells even at a mature stage can differentiate in response to inductive signals from DP cells. This study emphasizes the importance of EMI in follicular generation and the differentiation potential of epidermal keratinocytes.