title: Proteomics identifies enhanced expression of stefin A in neonatal murine skin compared with adults: functional implications.
abstract: BACKGROUND
  Skin develops through a process of epidermal proliferation, maturation, and remodelling of the epidermis and dermis. This period also involves the maturation of the skin immune system, such that antigen applied though the skin of a neonatal mouse always results in immunosuppression, whereas in adults, immunity will occur.
  
  
  OBJECTIVE
  Using proteomics, to identify proteins uniquely involved in the development of the skin and skin immune system.
  
  
  METHODS
  Proteins were extracted from whole skin of mice aged 4 and 21 days, and separated using two-dimensional electrophoresis.
  
  
  RESULTS
  Of the 25 proteins that were sequenced by peptide mass fingerprinting with matrix-assisted laser desorption/ionization-time of flight-mass spectrometry, three were known markers of keratinocyte differentiation and proliferation. These were cyclophilin A, epidermal fatty acid binding protein 5 and stefin A. Of interest were the two isoforms of stefin A, an intracellular protease inhibitor, found in neonatal skin. The strong expression of stefin A in neonates was confirmed by immunohistochemical analysis, suggesting an important role in the development of the epidermis. Additionally, Western blotting identified two larger isoforms in adult skin, revealing a change in the stefin A during development.
  
  
  CONCLUSIONS
  We propose that stefin A is involved in development of the skin, that development of the skin and of immune function is linked, and that stefin A has an important function in neonatal skin and potentially the neonatal immune response.
authors: Cancer and Immunology Research Group, Menzies Research Institute, University of Tasmania, Private Bag 29, Hobart, Tasmania 7001, Australia. dkscott@postoffice.utas.edu.au
authors: D K
authors: DK
authors: Scott
authors: R
authors: R
authors: Lord
authors: H K
authors: HK
authors: Muller
authors: R C
authors: RC
authors: Malley
authors: G M
authors: GM
authors: Woods
mesh_terms: D000818:Animals; D015153:Blotting, Western / Q000379:methods* / Q000592:standards; D055312:Cystatin A; D015891:Cystatins / Q000032:analysis / Q000096:biosynthesis*; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D010449:Peptide Mapping; D040901:Proteomics / Q000379:methods*; D012867:Skin / Q000166:cytology / Q000378:metabolism*
chemical_list: D055312:Cystatin A; D015891:Cystatins