title: The effect of mechanical strain on protease production by keratinocytes.
abstract: BACKGROUND
  Intact skin is under constant tension, transmitted from the underlying dermis, but when tension is lost (i.e. upon wounding) protease activity is upregulated.
  
  
  OBJECTIVE
  To investigate the effect of mechanical strain on protease production by both normal and transformed keratinocytes in vitro.
  
  
  METHODS
  Keratinocytes were seeded on to membranes precoated with either type I or type IV collagen. After 48 h medium was replaced with serum-free medium and mechanical strain was applied.
  
  
  RESULTS
  Mechanical strain resulted in decreased urokinase-type plasminogen activator (uPA) production by normal human keratinocytes (P<0.05) but increased production by transformed keratinocytes (P<0.05) cultured on type I and type IV collagen.
  
  
  CONCLUSIONS
  Differential production of uPA by normal and transformed keratinocytes is relevant in the context of normal function, wound healing and tumorigenesis.
authors: UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK.
authors: N
authors: N
authors: Bhadal
authors: I B
authors: IB
authors: Wall
authors: S R
authors: SR
authors: Porter
authors: S
authors: S
authors: Broad
authors: G E
authors: GE
authors: Lindahl
authors: S
authors: S
authors: Whawell
authors: M P
authors: MP
authors: Lewis
mesh_terms: D002478:Cells, Cultured / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism*; D012867:Skin / Q000378:metabolism*; D013314:Stress, Mechanical; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism*; D014945:Wound Healing / Q000502:physiology
chemical_list: D014568:Urokinase-Type Plasminogen Activator