Publication Date:
2004-12-25
Description:
Hair graying is the most obvious sign of aging in humans, yet its mechanism is largely unknown. Here, we used melanocyte-tagged transgenic mice and aging human hair follicles to demonstrate that hair graying is caused by defective self-maintenance of melanocyte stem cells. This process is accelerated dramatically with Bcl2 deficiency, which causes selective apoptosis of melanocyte stem cells, but not of differentiated melanocytes, within the niche at their entry into the dormant state. Furthermore, physiologic aging of melanocyte stem cells was associated with ectopic pigmentation or differentiation within the niche, a process accelerated by mutation of the melanocyte master transcriptional regulator Mitf.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nishimura, Emi K -- Granter, Scott R -- Fisher, David E -- AR43369/AR/NIAMS NIH HHS/ -- New York, N.Y. -- Science. 2005 Feb 4;307(5710):720-4. Epub 2004 Dec 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pediatric Hematology/Oncology, Melanoma Program in Medical Oncology, Dana-Farber Cancer Institute, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. emi_k_nishimura@yahoo.co.jp〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15618488" target="_blank"〉PubMed〈/a〉
Keywords:
Adult
;
Aged
;
Aged, 80 and over
;
Aging/*physiology
;
Animals
;
Apoptosis
;
Cell Differentiation
;
Cell Shape
;
DNA-Binding Proteins/genetics/metabolism
;
*Hair Color
;
Hair Follicle/cytology/*physiology
;
Humans
;
Melanins/biosynthesis
;
Melanocytes/*physiology
;
Mice
;
Mice, Inbred C57BL
;
Mice, Transgenic
;
Microphthalmia-Associated Transcription Factor
;
Middle Aged
;
Morphogenesis
;
Proto-Oncogene Proteins/genetics/metabolism
;
Proto-Oncogene Proteins c-bcl-2
;
Stem Cells/*physiology
;
Transcription Factors/genetics/metabolism
;
Vibrissae/cytology/physiology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
