Human Follicular Stem Cells: Their Presence in Plucked Hair and Follicular Cell Culture

This study investigated the presence of stem cells in plucked hair follicles by examining their cytokeratin (CK) profiles and apoptosis-related proteins. Researchers found that cells expressing CK19 and the apoptosis-suppressing protein Bcl-2, but not the apoptosis-promoting protein Bax, were present in specific areas of the hair follicle and in cultured follicular cells. These findings suggested that CK19/Bcl-2-positive and Bax-negative cells, potentially representing follicular stem cells, could be derived from plucked hair and maintained in culture. The study supported the hypothesis that stem cells are located in the bulge area of the hair follicle, rather than near the dermal papilla.