Nonviral In Situ Green Fluorescent Protein Labeling and Culture of Primary, Adult Human Hair Follicle Epithelial Progenitor Cells

The study demonstrated a method for labeling and culturing primary, adult human hair follicle epithelial progenitor cells using a nonviral approach. By cloning the human K15 promoter before a GFP/geneticin-resistance cassette and transfecting it into microdissected, organ-cultured adult human scalp hair follicles, researchers achieved specific GFP expression in the stem cell-rich bulge region. The K15-GFP+ cells were identified by their green fluorescence and selected based on their adhesion to collagen type IV and fibronectin, as well as geneticin resistance. These cells expressed epithelial progenitor markers, exhibited the gene expression profile typical of human bulge epithelium, and formed holoclones. This technique facilitated the study and manipulation of human epithelial stem cells and was suggested to be applicable to other complex human tissues.