Organogenesis From Dissociated Cells: Generation of Mature Cycling Hair Follicles From Skin-Derived Cells

In 2005, researchers developed a method to generate hair follicles from dissociated skin cells of newborn mice, which were then injected into adult mouse skin. The process involved the formation of clusters from epithelial cells, which then underwent apoptosis to create "infundibular cysts". These cysts led to the formation of hair germs, follicular buds, and pegs that differentiated into mature pilosebaceous structures. The study, conducted over a thousand assays, found that the newly formed hair follicles cycled in aggregate and that the internal clock of follicle cycling was inherent in the trichogenic cells, not dependent on the host skin hair cycle. The researchers also discovered that the number of hair follicles formed was significantly reduced when the total number of cells was decreased, but remained comparable when the number of epidermal cells varied while keeping the dermal cells constant. The study concluded that this system could serve as an assay for trichogenic cells and as a model for studying new organ formation from dissociated cells.