Published online Jun 26, 2015. doi: 10.4252/wjsc.v7.i5.866
Peer-review started: December 2, 2014
First decision: January 20, 2015
Revised: February 22, 2015
Accepted: April 1, 2015
Article in press: April 7, 2015
Published online: June 26, 2015
Hair follicle stem cells (HFSCs) normally give rise to keratinocytes, sebocytes, and transient amplifying progenitor cells. Along with the capacity to proliferate rapidly, HFSCs provide the basis for establishing a putative source of stem cells for cell therapy. HFSCs are multipotent stem cells originating from the bulge area. The importance of these cells arises from two important characteristics, distinguishing them from all other adult stem cells. First, they are accessible and proliferate for long periods. Second, they are multipotent, possessing the ability to differentiate into mesodermal and ectodermal cell types. In addition to a developmental capacity in vitro, HFSCs display an ability to form differentiated cells in vivo. During the last two decades, numerous studies have led to the development of an appropriate culture condition for producing various cell lineages from HFSCs. Therefore, these stem cells are considered as a novel source for cell therapy of a broad spectrum of neurodegenerative disorders. This review presents the current status of human, rat, and mouse HFSCs from both the cellular and molecular biology and cell therapy perspectives. The first section of this review highlights the importance of HFSCs and in vitro differentiation, while the final section emphasizes the significance of cell differentiation in vivo.
Core tip: Hair follicle stem cells (HFSCs) can proliferate in vitro and retain the label for a long time. Various types of stem cells, including epidermal-neural crest stem cells, nestin-positive, keratin 15-negative cells, and CD34-positive cells have been demonstrated in hair follicles. HFSCs normally give rise to keratinocytes, sebocytes, and transient amplifying cells in vivo. In addition, these cells differentiate into ectodermal lineages including oligodendrocytes, astrocytes, and neurons. Neural cells derived from HFSCs can replace lost cells in neurodegenerative diseases. Their easy accessibility along with their potential for neural differentiation makes HFSCs an ideal stem cell source for treatment of neurodegenerative disorders.