Dissociated skin cells regenerate hair follicles in a microwound, “The Punch Assay”

Abstract

The purpose of this study was to develop a new, easily executed hair follicle regeneration system and assay, which could be further developed for clinical or cosmetic applications. Dissociated epidermal and dermal progenitor cells, isolated either from neonatal C57BL/6 mice or human foetal scalp tissues, were suspended in (10 μL) F12 medium and pipetted into a 1 or 2 mm-diameter punch biopsy wounds on the back skin of immunodeficient mice. At 3 weeks after transplantation, although pigmented mouse hairs could efficiently form at the injection sites with delivery of mouse cells, none hair formed on the host mouse skin at 3 months after delivery of human cells. Under the same conditions, human follicles could be regenerated when the human skin cells were delivered onto a 2 mm size punch created on a reconstituted human skin (hRSK), which previously generated on the back of an immunodeficient mouse, but the efficiency of hair formation was low. We demonstrated that both mouse and human regenerated follicles showed normal histology and differentiation markers; moreover, the cell chasing experiment confirmed that the regenerated hair follicles were formed from transplanted cells. Compared to other current hair reconstituted assays, the Punch Assay is relatively simple and generates normal hair follicles within a smaller wound. We suggest that the punch assay is a better in vivo assay of cell trichogenicity.

More than just bricks and mortar: Fibroblasts and ECM in skin health and disease

“…35,38,39 Compared to hairless wounds, fibroblast populations in hair-forming wounds are enriched for retinoic acid binding protein Crabp1, a marker of upper wound cells. 33 41,42 the efficacy of this phenomenon drops as a factor of developmental age and remains low in a human system. 43…”

“…A better understanding of lineage potential by diverse skin fibroblasts is required to advance the efficiency of hair follicle reconstitution from dissociated skin cells. While hair follicles readily reconstitute from newborn mouse keratinocytes and fibroblasts, 41,42 the efficacy of this phenomenon drops as a factor of developmental age and remains low in a human system 43 …”

Metformin Promotes the Hair-Inductive Activity of Three-Dimensional Aggregates of Epidermal and Dermal Cells Self-Assembled in vitro

“…For grafting cultured 3D aggregates, we used a modified mini-incision procedure described by Leng et al [20]. Briefly, epidermal cells and DCs were isolated from 1-day-old C57BL/6 mouse pups, and the two types of dissociated cells were mixed at a 1:1 ratio to prepare 3D aggregates as described above.…”

In vitro hair follicle growth model for drug testing

“…However, adult epithelial and mesenchymal cells isolated from hair follicles, especially of human origin, have shown considerably lower or almost no hair-inductive ability 20 . Thus, the feasibility of a new approach has typically been examined using a unique combination of cells, such as human adult epithelial cells and murine fetal mesenchymal cells or murine fetal epithelial cells and human adult mesenchymal cells [21][22][23] . Considering these facts, it is surprising that AA-M provided the best condition for hair peg-like sprouting among the combinations used in this study (Fig.…”