Funding sources This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (2009-0086846).
Hair greying is associated with active hair growth
Article first published online: 24 NOV 2011
© 2011 The Authors. BJD © 2011 British Association of Dermatologists
British Journal of Dermatology
Volume 165, Issue 6, pages 1183–1189, December 2011
How to Cite
Choi, H.I., Choi, G.I., Kim, E.K., Choi, Y.J., Sohn, K.C., Lee, Y., Kim, C.D., Yoon, T.J., Sohn, H.J., Han, S.H., Kim, S., Lee, J.H. and Lee, Y.H. (2011), Hair greying is associated with active hair growth. British Journal of Dermatology, 165: 1183–1189. doi: 10.1111/j.1365-2133.2011.10625.x
Conflicts of interest None declared.
- Issue published online: 24 NOV 2011
- Article first published online: 24 NOV 2011
- Accepted manuscript online: 14 SEP 2011 06:29PM EST
- Accepted for publication 6 September 2011
Background Hair greying is an obvious sign of ageing in humans. White (nonpigmented) hair is thicker than black (pigmented) hair. The growth rate of white hair is also significantly higher than that of black hair. However, the mechanism underlying this is largely unknown.
Objectives To examine the association between hair greying and hair growth patterns by evaluating expression of the genes or proteins related to hair growth in white and black hairs.
Methods Morphological characteristics were observed in eyebrow and scalp hairs. The differential expression of genes was analysed in black and white hairs from human scalp by a microarray analysis. Reverse transcription–polymerase chain reaction (RT-PCR) and immunohistochemistry for genes and proteins related to hair growth were performed in black and white hairs.
Results Keratin and keratin-associated protein (KRTAP) genes in white hair were upregulated at least two-fold in comparison with black hair in a microarray analysis. Upregulation of selected keratin genes and KRTAP4 isoform genes in white hair was validated by RT-PCR. Immunoreactivity for KRT6, KRT14/16 and KRT25 was increased in the hair follicle of white hair compared with black hair. Gene expression of fibroblast growth factor 5 (FGF5) was downregulated in white hair compared with black hair. However, gene expression of FGF7 was upregulated in white hair compared with black hair.
Conclusions Expression of genes and proteins associated with active hair growth is upregulated in white (nonpigmented) hair compared with black (pigmented) hair. These results suggest that hair greying is associated with active hair growth.