Generation and Characterization of Multipotent Stem Cells from Established Dermal Cultures

This study demonstrated that human dermal fibroblasts (DF), both normal and diseased, pre-cultured in monolayers, could form multipotent skin-derived precursor cells (m-SKPs), similar to those from dissociated dermal tissues. These m-SKPs could be passaged and cryopreserved without reducing yield, although extensive passaging did decrease yield. m-SKPs expressed various stem cell markers and could differentiate into mesenchymal or neural lineages. Neonatal foreskin cultures produced more m-SKPs than adult DF cultures, but their capacity decreased more with passaging. Higher m-SKP yield was linked to adult DF cultures with more alpha-smooth muscle actin (αSMA), which correlated with specimens from biopsies with more terminal hair follicles. However, αSMA expression was lost upon m-SKP formation. Interestingly, human hair follicle dermal papilla (DP) cells in monolayer culture did not form m-SKPs, unlike murine vibrissae follicles. These findings highlighted the potential of expanded DF cultures for SKP production and questioned the progenitor status of human hair follicle DP cells.