Oxidative stress associated melanocyte-loss and hair growth capacity in the aging hair follicle: A model for tissue-specific aging

Abstract

Melanocytes are continuously lost from the aging hair follicle resulting in the obvious graying (canities) that visibly marks our steady decline. Many roads appear to lead to this Rome either involved in the regular aging process, or causing premature Canities. Among them, oxidative stress and an altered peri- and intrafollicular neuroendocrine milleu appear to be key mechanisms enabling or forcing melanocytes to respond to stressors ranging from exogenous oxidative stress via inflammatory stress to psychoemotional stress in a highly selective and sensitive fashion. However, growth of aging hair follicles - at least in the beginning of the process - is not affected by graying. The hair follicle melanocyte therefore appears to be a kind of sentinel indicating ongoing aging, and the presence of stressors leads to a premature decline of the hair follicle pigmentary system on the one hand, but protection from oncogenic DNA damage on the other hand. © 2010 Springer-Verlag Berlin Heidelberg.