Androgen receptor co-activator Hic-5/ARA55 as a molecular regulator of androgen sensitivity in dermal papilla cells of human hair follicles

J Invest Dermatol. 2007 Oct;127(10):2302-6. doi: 10.1038/sj.jid.5700883. Epub 2007 May 17.


Androgen site-specifically affects human hair growth after puberty through androgen receptors in the dermal papilla, which transactivate target genes acting in conjunction with co-activators. To examine the regulation of androgen sensitivity in hair follicles, we focused on androgen receptor co-activator Hic-5/ARA55. Its interaction with transfected androgen receptor in beard dermal papilla cells was confirmed with mammalian two-hybrid assays. The semiquantitative reverse transcriptase-polymerase chain reaction showed that Hic-5/ARA55 mRNA expression was high in dermal papilla cells from the beard and bald frontal scalp but low in cells from the occipital scalp. To determine whether Hic-5/ARA55 mRNA level correlates with its endogenous activity, we studied the effect of dominant negative Hic-5/ARA55 on transfected androgen receptor transactivation induced by R1881 using mouse mammary tumor virus-luciferase assays. We found that it suppressed the transactivation by 64.5 and 71.4% in dermal papilla cells from the beard and bald frontal scalp, respectively, whereas it showed no significant effect in cells from the occipital scalp. Our findings suggest that Hic-5/ARA55 is a molecular regulator for androgen sensitivity in human hair follicles.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Androgens / physiology*
  • Cells, Cultured
  • Face
  • Hair / growth & development
  • Hair / physiology
  • Hair Follicle / cytology
  • Hair Follicle / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • LIM Domain Proteins
  • Male
  • Mammary Tumor Virus, Mouse / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Androgen / physiology*
  • Scalp / cytology
  • Scalp / metabolism
  • Transcriptional Activation
  • Transfection


  • Androgens
  • Intracellular Signaling Peptides and Proteins
  • LIM Domain Proteins
  • RNA, Messenger
  • Receptors, Androgen
  • TGFB1I1 protein, human