title: Age-dependent damage of hair cuticle: contribution of S100A3 protein and its citrullination.
abstract: BACKGROUND
  There are two types of damage pattern of human hair cuticle: type L, where the cell membrane complex is split and the cuticle lifts up, and type E, where the fragile substructure of the cuticle cell (endocuticle) is broken. In our previous paper, it was reported that the dominant damage pattern shifts from type L to E with the subjects' age around the 40s. Loss of the cuticle due to daily grooming stresses increases with the subjects' age and is related to the level of type E damage. It is supposed that deterioration of endocuticle advances the loss of cuticle. S100A3 protein, located at the endocuticle, was found to be citrullinated and transformed into tetramer to improve its Ca(2+) -binding ability. It is postulated that this biochemical property affects the maturation of cuticle and contributes to its reinforcement.
  
  
  OBJECTIVE
  This study aims to elucidate the role that S100A3 plays in age-dependent cuticle damage.
  
  
  METHODS
  Hair fibers collected from Japanese females were evaluated for the content and citrullination rate of S100A3, incidence of type E damage, and resistance of cuticle.
  
  
  RESULTS
  In the aged hair, the content of S100A3 was positively correlated with the level of type E damage and low resistance to stress. Hair fibers in which S100A3 is highly citrullinated, however, showed low levels of type E damage and high resistance of cuticle, even in the aged hair as well as at younger ages.
  
  
  CONCLUSIONS
  S100A3 and its citrullination process are related to rigidity of endocuticle of aged hair.
authors.affiliation: R&D - Development Research - Hair Care Products Research, Kao Corporation, Tokyo, Japan.
authors.forename: Toshie
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: R&D - Development Research - Hair Care Products Research, Kao Corporation, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Mamada
authors.affiliation: R&D - Core Technology - Biological Science Research, Kao Corporation, Kanagawa, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kizawa
authors.affiliation: R&D - Development Research - Hair Care Products Research, Kao Corporation, Tokyo, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Suzuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001120:Arginine / Q000378:metabolism; D002956:Citrulline / Q000378:metabolism*; D005260:Female; D006197:Hair / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D006920:Hygiene; D008875:Middle Aged; D009418:S100 Proteins / Q000378:metabolism*; D015595:Skin Aging / Q000473:pathology / Q000502:physiology*; D013314:Stress, Mechanical; D055815:Young Adult
chemical_list: D009418:S100 Proteins; C082356:S100A3 protein, human; D002956:Citrulline; D001120:Arginine
keywords: S100A3; age; citrulline; cuticle; damage; hair