Multi-layered environmental regulation on the homeostasis of stem cells: The saga of hair growth and alopecia

Chih Chiang Chen*, Cheng Ming Chuong

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

50 Scopus citations


Stem cells are fascinating because of their potential in regenerative medicine. Stem cell homeostasis has been thought to be mainly regulated by signals from their adjacent micro-environment named the "stem cell niche" However, recent studies reveal that there can be multiple layers of environmental controls. Here we review these environmental controls using the paradigm of hair stem cells, because to observe and analyze the growth of hair is easier due to their characteristic cyclic regeneration pattern. The length of hair fibers is regulated by the duration of the growth period. In the hair follicles, hair stem cells located in the follicle bulge interact with signals from the dermal papilla. Outside of the follicle, activation of hair stem cells has been shown to be modulated by molecules released from the intra-dermal adipose tissue as well as body hormone status, immune function, neural activities, and aging. The general physiological status of an individual is further influenced by circadian rhythms and changing seasons. The interactive networks of these environmental factors provide new understanding on how stem cell homeostasis is regulated, inspiring new insights for regenerative medicine. Therapies do not necessarily have to be achieved by using stem cells themselves which may constitute a higher risk but by modulating stem cell activity through targeting one or multiple layers of their micro- and macro-environments.

Original languageEnglish
Pages (from-to)3-11
Number of pages9
JournalJournal of Dermatological Science
Issue number1
StatePublished - Apr 2012


  • Adipose cell
  • Alopecia
  • Bmp
  • Dkk
  • Hair
  • Macro-environment
  • Niche
  • Regeneration
  • Sfrp
  • Stem cell


Dive into the research topics of 'Multi-layered environmental regulation on the homeostasis of stem cells: The saga of hair growth and alopecia'. Together they form a unique fingerprint.

Cite this