title: Increased factor XIIIa transglutaminase expression in dermal dendrocytes after treatment with alpha-hydroxy acids: potential physiologic significance.
abstract: BACKGROUND
  Topical alpha-hydroxy acids (AHAs) have been shown to improve photoaging in human skin.
  
  
  OBJECTIVE
  We studied factor XIIIa transglutaminase expression in dermal dendrocytes (DDs) and mast cell degranulation after treatment of the skin with AHAs.
  
  
  METHODS
  Skin biopsy specimens obtained from patients after 4 to 8 months of treatment with lotions containing 25% AHAs were evaluated for factor XIIIa transglutaminase expression with immunoperoxidase and electron microscopy. Immunoperoxidase-stained sections were studied by means of semiquantitative methods and image analysis. Mast cell degranulation was studied by image analysis.
  
  
  RESULTS
  Increased factor XIIIa transglutaminase expression was seen after treatment with AHAs. All treated sites had increased scores compared with control sites by semiquantitative methods. Seventy-five percent of treated sites showed an increased mean area over control sites of factor XIIIa transglutaminase positivity with image analysis. These results correlated with an increased level of mast cell degranulation in treated sites and with activation of DDs as seen by electron microscopy.
  
  
  CONCLUSIONS
  Treatment of the skin with AHAs leads to mast cell degranulation and increased expression of factor XIIIa transglutaminase by activated DDs. Mast cell degranulation may lead to activation of DDs and increased factor XIIIa transglutaminase expression, via the action of tumor necrosis factor-alpha. We speculate that clinical and histologic improvement in photoaged skin after treatment with AHAs may be somehow related to this process.
authors.affiliation: Department of Dermatology, Graduate Hospital, Philadelphia, Pennsylvania, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Griffin
authors.forename: G F
authors.initials: GF
authors.lastname: Murphy
authors.forename: H
authors.initials: H
authors.lastname: Sueki
authors.forename: B
authors.initials: B
authors.lastname: Telegan
authors.forename: W C
authors.initials: WC
authors.lastname: Johnson
authors.forename: C M
authors.initials: CM
authors.lastname: Ditre
authors.forename: R J
authors.initials: RJ
authors.lastname: Yu
authors.forename: E J
authors.initials: EJ
authors.lastname: Van Scott
mesh_terms: D000279:Administration, Cutaneous; D015550:Cell Degranulation / Q000187:drug effects; D003029:Coagulants / Q000032:analysis*; D003713:Dendritic Cells / Q000187:drug effects* / Q000201:enzymology / Q000648:ultrastructure; D018870:Endoplasmic Reticulum, Rough / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D006880:Hydroxy Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D007091:Image Processing, Computer-Assisted; D007124:Immunoenzyme Techniques; D008407:Mast Cells / Q000187:drug effects / Q000648:ultrastructure; D008854:Microscopy, Electron; D012867:Skin / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D015595:Skin Aging / Q000187:drug effects; D011503:Transglutaminases / Q000032:analysis / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
chemical_list: D003029:Coagulants; D006880:Hydroxy Acids; D014409:Tumor Necrosis Factor-alpha; D011503:Transglutaminases