title: Keratinocytes can differentiate into eccrine sweat ducts in vitro: involvement of epidermal growth factor and fetal bovine serum.
abstract: BACKGROUND
  in addition to formation of an epidermal sheet and dermal substitution, reconstruction of skin that possesses functionality is an important goal for dermatologists.
  
  
  OBJECTIVE
  we attempted to regenerate eccrine sweat glands in vitro.
  
  
  METHODS
  we constructed skin equivalent models with various combination of normal human keratinocytes and fibroblasts and also examined the effect of various growth factors.
  
  
  RESULTS
  we found that keratinocytes invaded the collagen gels and formed eccrine duct-like structures, only when (i) the culture media contained at least 15 ng/ml of epidermal growth factor (EGF) and fetal bovine serum (FBS), (ii) the keratinocytes were derived from young donors, and (iii) fibroblasts were present in the gel. Interestingly, when cultured under the same conditions eccrine gland duct cells were unable to invade the gel. Immunohistochemical analyses revealed induction of carcinoembryonic antigen by EGF at the inner part of the eccrine duct-like structures. Proliferating cell nuclear antigen was expressed mainly in basal layers of the epithelia but was not observed in the deeply invaded part. Cytokeratin profiles of the reconstructed epithelia were consistent with those of the regenerating epidermis and partly with the eccrine sweat duct.
  
  
  CONCLUSIONS
  although not perfect model, these results indicate that 'young' keratinocytes could differentiate into/toward eccrine sweat ducts in vitro in the presence of EGF and FBS in cooperation with dermal fibroblasts.
authors.affiliation: Department of Dermatology, School of Medicine, The University of Tokushima, 3-18 Kuramoto-cho, Tokushima, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Shikiji
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Minami
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Inoue
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirose
authors.forename: Hajimu
authors.initials: H
authors.lastname: Oura
authors.forename: Seiji
authors.initials: S
authors.lastname: Arase
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D004439:Eccrine Glands / Q000254:growth & development*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007223:Infant; D007231:Infant, Newborn; D015603:Keratinocytes / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D017768:Skin, Artificial
chemical_list: D012710:Serum Albumin, Bovine; D004815:Epidermal Growth Factor