A Survey of Attachment and Proliferative Characteristics of Different Population of Hair Follicle Epithelial Cells in Culture

“The bulge activation hypothesis” has recently provided significant interest in the hair follicle cycle. One facet of this hypothesis suggests that the epithelial cells located at the base of the follicle are ‘transient amplifying, that limit the duration of the follicle’s growth phase. In this study, we investigate the pattern of cell division and proliferation of these cells and compared with those from upper part of follicle. To fulfill this task, epidermal cells from lower and upper vibrissa follicles were cultured after isolation and growth characteristics of these two cell types were measured and recorded over a period of weeks. Data provided here demonstrated that epidermal cells from lower region of follicle normally attached to the substrate and started dividing more slowly than their counterparts from the upper part of the follicle. In addition, although the majority of the basal cells failed to grow for extended periods and underwent terminal differentiation, a small subset of these cells grew as large single colonies for more than 10 weeks and they were able to be passaged several times. Contrary to the current dogma, we here showed that, at least in culture medium, some of basal hair follicle cells have a proliferative capacity which is much further than duration of the growth phase of follicle. Therefore, the termination of growth phase can not be related to the replicative potential of these cells.