title: Investigation by imaging mass spectrometry of biomarker candidates for aging in the hair cortex.
abstract: BACKGROUND
  Human hair is one of the essential components that define appearance and is a useful source of samples for non-invasive biomonitoring. We describe a novel application of imaging mass spectrometry (IMS) of hair biomolecules for advanced molecular characterization and a better understanding of hair aging. As a cosmetic and biomedical application, molecules whose levels in hair altered with aging were comprehensively investigated.
  
  
  METHODS
  Human hair was collected from 15 young (20±5 years old) and 15 older (50±5 years old) volunteers. Matrix-free laser desorption/ionization IMS was used to visualize molecular distribution in the hair sections. Hair-specific ions displaying a significant difference in the intensities between the 2 age groups were extracted as candidate markers for aging. Tissue localization of the molecules and alterations in their levels in the cortex and medulla in the young and old groups were determined.
  
  
  RESULTS
  Among the 31 molecules detected specifically in hair sections, 2--one at m/z 153.00, tentatively assigned to be dihydrouracil, and the other at m/z 207.04, identified to be 3,4-dihydroxymandelic acid (DHMA)--exhibited a higher signal intensity in the young group than in the old, and 1 molecule at m/z 164.00, presumed to be O-phosphoethanolamine, displayed a higher intensity in the old group. Among the 3, putative O-phosphoethanolamine showed a cortex-specific distribution. The 3 molecules in cortex presented the same pattern of alteration in signal intensity with aging, whereas those in medulla did not exhibit significant alteration.
  
  
  CONCLUSIONS
  Three molecules whose levels in hair altered with age were extracted. While they are all possible markers for aging, putative dihydrouracil and DHMA, are also suspected to play a role in maintaining hair properties and could be targets for cosmetic supplementation. Mapping of ion localization in hair by IMS is a powerful method to extract biomolecules in specified regions and determine their tissue distribution.
authors: Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan.
authors: Michihiko Luca
authors: ML
authors: Waki
authors: Kenji
authors: K
authors: Onoue
authors: Tsukasa
authors: T
authors: Takahashi
authors: Kensuke
authors: K
authors: Goto
authors: Yusuke
authors: Y
authors: Saito
authors: Katsuaki
authors: K
authors: Inami
authors: Ippei
authors: I
authors: Makita
authors: Yurika
authors: Y
authors: Angata
authors: Tomomi
authors: T
authors: Suzuki
authors: Mihi
authors: M
authors: Yamashita
authors: Narumi
authors: N
authors: Sato
authors: Saki
authors: S
authors: Nakamura
authors: Dai
authors: D
authors: Yuki
authors: Yuki
authors: Y
authors: Sugiura
authors: Nobuhiro
authors: N
authors: Zaima
authors: Naoko
authors: N
authors: Goto-Inoue
authors: Takahiro
authors: T
authors: Hayasaka
authors: Yutaka
authors: Y
authors: Shimomura
authors: Mitsutoshi
authors: M
authors: Setou
mesh_terms: D000328:Adult; D000375:Aging / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism*; D003430:Cross-Sectional Studies; D006197:Hair / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D015415:Biomarkers