Premature graying as a consequence of compromised antioxidant activity in hair bulb melanocytes and their precursors.
Intricate coordinated mechanisms that govern the synchrony of hair growth and melanin synthesis remain largely unclear. These two events can be uncoupled in prematurely gray hair, probably due to oxidative insults that lead to the death of oxidative stress-sensitive melanocytes. In this study, we examined the gene expression profiles of middle (bulge) and lower (hair bulb) segments that had been micro-dissected from unpigmented and from normally pigmented hair follicles from the same donors using quantitative real-time RT-PCR (qPCR) arrays. We found a significant down-regulation of melanogenesis-related genes (TYR, TYRP1, MITF, PAX3, POMC) in unpigmented hair bulbs and of marker genes typical for melanocyte precursor cells (PAX3, SOX10, DCT) in unpigmented mid-segments compared with their pigmented analogues. qPCR, western blotting and spin trapping assays revealed that catalase protein expression and hydroxyl radical scavenging activities are strongly repressed in unpigmented hair follicles. These data provide the first clear evidence that compromised antioxidant activity in gray hair follicles simultaneously affects mature hair bulb melanocytes and their immature precursor cells in the bulge region.
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Ying
Y
Shi
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Long-Fei
LF
Luo
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Xiao-Ming
XM
Liu
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Qiong
Q
Zhou
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Shi-Zheng
SZ
Xu
Department of Dermatology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, China.
Tie-Chi
TC
Lei
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western; D017931:DNA Primers; D005260:Female; D020869:Gene Expression Profiling; D006197:Hair / Q000378:metabolism*; D006200:Hair Color; D006801:Humans; D008297:Male; D008544:Melanocytes / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013113:Spin Labels; D055815:Young Adult
D000975:Antioxidants; D017931:DNA Primers; D013113:Spin Labels