Towards a "free radical theory of graying"

TY - JOUR

T1 - Towards a "free radical theory of graying"

T2 - melanocyte apoptosis in the aging human hair follicle is an indicator of oxidative stress induced tissue damage

AU - Arck, Petra Clara

AU - Overall, Rupert

AU - Spatz, Katharina

AU - Liezman, Christiane

AU - Handjiski, Bori

AU - Klapp, Burghard F

AU - Birch-Machin, Mark A

AU - Peters, Eva Milena Johanne

PY - 2006/7

Y1 - 2006/7

N2 - Oxidative stress is generated by a multitude of environmental and endogenous challenges such as radiation, inflammation, or psychoemotional stress. It also speeds the aging process. Graying is a prominent but little understood feature of aging. Intriguingly, the continuous melanin synthesis in the growing (anagen) hair follicle generates high oxidative stress. We therefore hypothesize that hair bulb melanocytes are especially susceptible to free radical-induced aging. To test this hypothesis, we subjected human scalp skin anagen hair follicles from graying individuals to macroscopic and immunohistomorphometric analysis and organ culture. We found evidence of melanocyte apoptosis and increased oxidative stress in the pigmentary unit of graying hair follicles. The "common" deletion, a marker mitochondrial DNA-deletion for accumulating oxidative stress damage, occurred most prominently in graying hair follicles. Cultured unpigmented hair follicles grew better than pigmented follicles of the same donors. Finally, cultured pigmented hair follicles exposed to exogenous oxidative stress (hydroquinone) showed increased melanocyte apoptosis in the hair bulb. We conclude that oxidative stress is high in hair follicle melanocytes and leads to their selective premature aging and apoptosis. The graying hair follicle, therefore, offers a unique model system to study oxidative stress and aging and to test antiaging therapeutics in their ability to slow down or even stop this process.

AB - Oxidative stress is generated by a multitude of environmental and endogenous challenges such as radiation, inflammation, or psychoemotional stress. It also speeds the aging process. Graying is a prominent but little understood feature of aging. Intriguingly, the continuous melanin synthesis in the growing (anagen) hair follicle generates high oxidative stress. We therefore hypothesize that hair bulb melanocytes are especially susceptible to free radical-induced aging. To test this hypothesis, we subjected human scalp skin anagen hair follicles from graying individuals to macroscopic and immunohistomorphometric analysis and organ culture. We found evidence of melanocyte apoptosis and increased oxidative stress in the pigmentary unit of graying hair follicles. The "common" deletion, a marker mitochondrial DNA-deletion for accumulating oxidative stress damage, occurred most prominently in graying hair follicles. Cultured unpigmented hair follicles grew better than pigmented follicles of the same donors. Finally, cultured pigmented hair follicles exposed to exogenous oxidative stress (hydroquinone) showed increased melanocyte apoptosis in the hair bulb. We conclude that oxidative stress is high in hair follicle melanocytes and leads to their selective premature aging and apoptosis. The graying hair follicle, therefore, offers a unique model system to study oxidative stress and aging and to test antiaging therapeutics in their ability to slow down or even stop this process.

KW - Aging/physiology

KW - Free Radicals

KW - Hair Color/physiology

KW - Hair Follicle/growth & development

KW - Humans

KW - Melanocytes/cytology

KW - Models, Biological

KW - Oxidative Stress/physiology

U2 - 10.1096/fj.05-4039fje

DO - 10.1096/fj.05-4039fje

M3 - SCORING: Journal article

C2 - 16723385

VL - 20

SP - 1567

EP - 1569

JO - FASEB J

JF - FASEB J

SN - 0892-6638

IS - 9

ER -