Stem Cells Research Today is a free monthly online journal that collates and summarizes the latest research about Stem Cells, including details on research, transplants, therapy, benefits.

Requirement of Rac1 distinguishes follicular from interfollicular epithelial stem cells.

Castilho RM, Squarize CH, Patel V, Millar SE, Zheng Y, Molinolo A, Gutkind JS

Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4340, USA.

Epithelial stem cells in the bulge region within the hair follicle maintain the cyclic hair growth, but whether these stem cells also contribute to the epidermal renewal remains unclear. Here, we observed that the conditional deletion of the Rac1 gene in the mouse skin, including the potential follicular and epidermal stem cell compartments, results in alopecia owing to defective hair development. Surprisingly, mice lacking the expression of this Rho GTPase do not display major alterations in the interfollicular skin. Furthermore, Rac1 excision from primary epithelial keratinocytes results in the inability to reconstitute hair follicles and sebaceous glands when grafted onto mice, but epithelial cells lacking Rac1 can nonetheless form a healthy epidermis. Together, these findings support the emerging view that the epidermis and the hair follicles are maintained by different epithelial stem cells, and provide evidence that the requirement for Rac1 function can distinguish these distinct stem cells populations.

Published 2 August 2007 in Oncogene, 26(35): 5078-85.
Full-text of this article is available online (may require subscription).

© 2004-2008 Stem Cells Research Today. All Rights Reserved.